Ang, KCS, Sankaran, S & Killen, CP 2016, '‘Value for Whom, by Whom’: Investigating Value Constructs in Non-Profit Project Portfolios', Project Management Research and Practice, vol. 3, no. July-Dec, pp. 5038-5038.
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In most non-profit organisations (NPOs), there are multiple programs, projects or initiatives running simultaneously. The management of multiple projects in organisations can be coined as project portfolio management (PPM) (Archer & Ghasemzadeh 1999; Pennypacker & Dye 2002). In any project-based organisation, it is critical that selected projects align with and deliver the organisation’s strategy or mission. Decisions about project funding are strategic decisions, particularly when there are resource limitations. In PPM decision making, the allocation of resources to projects requires a clear judgement of value across multiple perspectives. Value has often been expressed in financial terms, however increasingly research indicates that non-financial considerations are equally important in evaluating value.A key task in project portfolio management is to maximise value across the portfolio. However, value can be a subjective notion, as each person may have different expectations of what is valuable. The involvement of diverse stakeholder interests could create complexities in decision making in non-profit organisations due to value being interpreted in different ways by the stakeholders. Furthermore in order to achieve its purpose, non-profits depend heavily on donors, patrons and sponsors - stakeholders who contribute to the portfolio but are often not the direct recipients of the services provided by the non-profit organisation (Kaplan 2012). Non-profit portfolios often compete with other initiatives for resources and attention from the same donors and sponsors, and may need to constantly justify the value they provide to these stakeholders.Most research about value in PPM has been conducted in the ‘for-profit’ sector. Recent value-based studies in the project portfolio field stress the importance of considering both commercial and non-commercial value in portfolio decision making (Killen, du Plessis & Young 2012; Kopman 2013; Mart...
Arutyunov, N, Bennett, N, Wight, N, Krause‐Rehberg, R, Emtsev, V, Abrosimov, N & Kozlovski, V 2016, 'Positron probing of disordered regions in neutron‐irradiated silicon', physica status solidi (b), vol. 253, no. 11, pp. 2175-2179.
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The vacancy‐rich disordered regions (DR) playing a key role in improving the thermoelectric figure‐of‐merit of silicon thermoelectric generators by reducing (by ∼90%) the thermal conductivity, have been probed with positrons. The DR were created by irradiating n‐Cz‐Si(P) material with the fast reactor neutrons. The parameter of the electron density rs′ ≈ 2.18 a.u. contacting positrons in DR has been reconstructed using the data of the angular correlation of the annihilation radiation (ACAR); the amendments to the rs′ value associated with the ion core electrons were taken into account. It is argued that the ion cores of atoms of silicon as well as the ones of the as‐grown impurities (O, C) are involved in the open vacancy volume to be probed with positrons: a relaxation of the ion cores directed inward toward the vacancy volume seems to take place. These positron traps are formed beyond the vacancy‐rich area of the disordered region. In the course of isochronal annealing, the traps are stable up to Tanneal. ≈ 520 °C when a recovery of ACAR parameters begins and then it continues up to ∼1050 °C.A vacancy center containing positrons in the open vacancy volume beyond the vacancy‐rich area of the disordered region is shown schematically. The emission of electron–positron annihilation gamma‐quanta dominates from within these positron traps. The values of both the electron–positron ion core radius (rm) and electron density (parameter rs′) suggest a relaxation directed toward inwards the open vacancy volume: the impurity atoms o...
Ball, D, Upcroft, B, Wyeth, G, Corke, P, English, A, Ross, P, Patten, T, Fitch, R, Sukkarieh, S & Bate, A 2016, 'Vision-based Obstacle Detection and Navigation for an Agricultural Robot', JOURNAL OF FIELD ROBOTICS, vol. 33, no. 8, pp. 1107-1130.
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This paper describes a vision-based obstacle detection and navigation system for use as part of a robotic solution for the sustainable intensification of broad-acre agriculture. To be cost-effective, the robotics solution must be competitive with current human-driven farm machinery. Significant costs are in high-end localization and obstacle detection sensors. Our system demonstrates a combination of an inexpensive global positioning system and inertial navigation system with vision for localization and a single stereo vision system for obstacle detection. The paper describes the design of the robot, including detailed descriptions of three key parts of the system: novelty-based obstacle detection, visually-aided guidance, and a navigation system that generates collision-free kinematically feasible paths. The robot has seen extensive testing over numerous weeks of field trials during the day and night. The results in this paper pertain to one particular 3 h nighttime experiment in which the robot performed a coverage task and avoided obstacles. Additional results during the day demonstrate that the robot is able to continue operating during 5 min GPS outages by visually following crop rows.
Bellmann, A, Schneider, S, Schallow, J, Hartung, J, Litterscheidt, J & Deuse, J 2016, 'Enhanced predictability of agile procedures', WT Werkstattstechnik, vol. 106, no. 7-8, pp. 550-554.
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In academics and industry the use of agile procedures for planning of production systems is a steady upward trend. Besides the potential efficiency improvements new challenges in the predictability of projects arise. The methodology described in this paper increases this by a synchronous collaboration model of all disciplines involved and with the establishment of standardized planning contents with standard times.
Bennett, NS, Byrne, D, Cowley, A & Neophytou, N 2016, 'Dislocation loops as a mechanism for thermoelectric power factor enhancement in silicon nano-layers', Applied Physics Letters, vol. 109, no. 17, pp. 173905-173905.
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A more than 70% enhancement in the thermoelectric power factor of single-crystal silicon is demonstrated in silicon nano-films, a consequence of the introduction of networks of dislocation loops and extended crystallographic defects. Despite these defects causing reductions in electrical conductivity, carrier concentration, and carrier mobility, large corresponding increases in the Seebeck coefficient and reductions in thermal conductivity lead to a significant net enhancement in thermoelectric performance. Crystal damage is deliberately introduced in a sub-surface nano-layer within a silicon substrate, demonstrating the possibility to tune the thermoelectric properties at the nano-scale within such wafers in a repeatable, large-scale, and cost-effective way.
Bennett, NS, Wong, CS & McNally, PJ 2016, 'Simultaneous depth-profiling of electrical and elemental properties of ion-implanted arsenic in silicon by combining secondary-ion mass spectrometry with resistivity measurements', Review of Scientific Instruments, vol. 87, no. 7, pp. 074702-074702.
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A method is proposed to extract the electrical data for surface doping profiles of semiconductors in unison with the chemical profile acquired by secondary-ion mass spectrometry (SIMS)—a method we call SIMSAR (secondary-ion mass spectrometry and resistivity). The SIMSAR approach utilizes the inherent sputtering process of SIMS, combined with sequential four-point van der Pauw resistivity measurements, to surmise the active doping profile as a function of depth. The technique is demonstrated for the case of ion-implanted arsenic doping profiles in silicon. Complications of the method are identified, explained, and corrections for these are given. While several techniques already exist for chemical dopant profiling and numerous for electrical profiling, since there is no technique which can measure both electrical and chemical profiles in parallel, SIMSAR has significant promise as an extension of the conventional dynamic SIMS technique, particularly for applications in the semiconductor industry.
Bovand, M, Rashidi, S, Esfahani, JA, Saha, SC, Gu, YT & Dehesht, M 2016, 'Control of flow around a circular cylinder wrapped with a porous layer by magnetohydrodynamic', Journal of Magnetism and Magnetic Materials, vol. 401, pp. 1078-1087.
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Cheng, S, Yu, L, Zhang, D, Huo, L & Ji, J 2016, 'Consensus of second-order multi-agent systems using partial agents' velocity measurements', NONLINEAR DYNAMICS, vol. 86, no. 3, pp. 1927-1935.
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Cheng, X, Jiang, Z, Monaghan, BJ, Wei, D, Longbottom, RJ, Zhao, J, Peng, J, Luo, M, Ma, L, Luo, S & Jiang, L 2016, 'Breakaway oxidation behaviour of ferritic stainless steels at 1150°C in humid air', Corrosion Science, vol. 108, pp. 11-22.
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Dantanarayana, L, Dissanayake, G & Ranasinghe, R 2016, 'C-LOG: A Chamfer distance based algorithm for localisation in occupancy grid-maps.', CAAI Trans. Intell. Technol., vol. 1, no. 3, pp. 272-284.
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Eager, D, Pendrill, A-M & Reistad, N 2016, 'Beyond velocity and acceleration: jerk, snap and higher derivatives', European Journal of Physics, vol. 37, no. 6, pp. 065008-065008.
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© 2016 IOP Publishing Ltd. The higher derivatives of motion are rarely discussed in the teaching of classical mechanics of rigid bodies; nevertheless, we experience the effect not only of acceleration, but also of jerk and snap. In this paper we will discuss the third and higher order derivatives of displacement with respect to time, using the trampolines and theme park roller coasters to illustrate this concept. We will also discuss the effects on the human body of different types of acceleration, jerk, snap and higher derivatives, and how they can be used in physics education to further enhance the learning and thus the understanding of classical mechanics concepts.
Fadavi Boostani, A, Tahamtan, S, Yazdani, S, Khosroshahi, RA, Wei, D, Sahamirad, H, Zhang, XM & Jiang, ZY 2016, 'Graphene tweaking Hamaker constant of SiC nanoparticles: A new horizon to solve the conflict between strengthening and toughening', Scripta Materialia, vol. 118, pp. 65-69.
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Fadavi Boostani, A, Taherzadeh Mousavian, R, Tahamtan, S, Yazdani, S, Azari Khosroshahi, R, Wei, D, Xu, J, Zhang, X & Jiang, ZY 2016, 'Solvothermal-assisted graphene encapsulation of SiC nanoparticles: A new horizon toward toughening aluminium matrix nanocomposites', Materials Science and Engineering: A, vol. 653, pp. 99-107.
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© 2015 Published by Elsevier B.V. Agglomeration of ceramic nanoparticles is a key challenge during manufacturing aluminium matrix composites in both solid and liquid methods. This study presents an innovative fabrication route to diminish the agglomeration of SiC nanoparticles using graphene encapsulating method stimulated by a solvothermal process. The produced SiC nanoparticles were then incorporated into A357 molten alloy using a liquid processing route. HRTEM investigations have shown the uniform distribution of SiC nanoparticles wrapped by onion-liked graphene shells within the matrix of composite, conferring 273% and 400% enhancement in yield strength and tensile ductility, respectively, compared to the unreinforced one. This is attributed to the manipulation of solidification mechanism of SiC nanoparticles from pushing to engulfment, ensued from imparting higher thermal conductivity to these particles by onion-liked graphene sheets. Fractographic observations have revealed the transgranular facture mode activated due to nano-void coalescence fracture mechanism in composites reinforced with graphene sheets associated with prolonged ductility. A devised analytical strengthening model has also demonstrated the profound efficacy of thermal activated dislocation mechanism in fortifying the matrix, brought about by the exceptional negative thermal expansion coefficient of graphene sheets.
GUERTLER, MR & LINDEMANN, UDO 2016, 'IDENTIFYING OPEN INNOVATION PARTNERS: A METHODOLOGY FOR STRATEGIC PARTNER SELECTION', International Journal of Innovation Management, vol. 20, no. 05, pp. 1640011-1640011.
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By opening a company’s innovation process, and allowing purposeful collaboration with external partners, Open Innovation (OI) offers several advantages, such as the use of external expertise, shorter time-to-market and reduced failure rates. However, the success of OI projects is directly linked to the selection of suitable partners, who operationally or strategically contribute to reach the goal of the OI project. Despite this relevance of OI-partner selection, methodical support has hitherto been limited — it is either too abstract to be helpful in practice, or too focused on single aspects. This paper presents a methodical approach to close this gap by combining identification and selection approaches from different fields, such as stakeholder analysis, lead-user identification and systems engineering. The methodology was evaluated in an industrial OI-project with an SME from plant manufacturing.
Guertler, MR, Michailidou, I & Lindemann, U 2016, 'How to assess a company’s open innovation situation?', Design Science, vol. 2.
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Open Innovation (OI) supports companies in systematically collaborating with external partners, offering various advantages. However, companies still face several challenges when applying OI, e.g., identifying relevant OI partners, collaboration methods, and project risks. Often, insufficient planning is the reason for subsequent deficits in OI projects. The analysis of relevant context factors (‘situation’) is important, which affect and constrain OI. To date, a general approach for analyzing (open) innovation situations or guidelines for developing one do not exist. Usually researchers develop their own situation analysis, including extensive literature reviews and experiencing similar challenges. This publication sets the basis for successfully planning OI projects. It focuses on developing an analysis approach for OI situations and supports other researchers in developing their own analysis approaches. The resultant objectives of the publication are to: (1) provide a list of potential situation analysis criteria; (2) provide a guideline for developing a situation analysis; (3) provide initial indications of relevant OI-specific situation criteria. The criteria were derived from the literature and qualitatively evaluated by three industry partners to assess their usability. Although this work is exploratory, and the results are not automatically generalizable, it is an important contribution for ensuring the success of OI, and for analyzing enablers and barriers to knowledge transfer from academia to industry.
Hao, L, Jiang, Z, Chen, Z, Wei, D, Cheng, X, Zhao, J, Luo, M, Ma, L, Luo, S & Jiang, L 2016, 'High Temperature Oxidation of Indefinite Chill Roll Material Under Dry and Humid Atmospheres', steel research international, vol. 87, no. 3, pp. 349-358.
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© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. In this paper, the isothermal oxidation of the indefinite chill (IC) roll is investigated by using a thermogravimetric analyzer (TGA) from 550 to 700 C under dry and humid atmospheres. It is found that the oxidation kinetics follow a linear trend and the oxide scale consists of two layers after the oxidation in dry air but three layers in humid air above 600 C. In dry air, the graphite is covered by the oxide scale above 650 C. The water vapor accelerates the oxidation of the matrix and the graphite. The graphite is covered by the extension of the oxide scale above 600 C in humid air. The as-treated samples are examined with SEM and XRD, while the kinetics is based on TGA results. The isothermal oxidation of the indefinite chill (IC) roll (shown in Figure 1) is investigated by using a thermogravimetric analyzer. Results show that the oxidation kinetics follow a linear trend, and the oxide scale consists of two layers after the oxidation in dry air but three layers in humid air above 600 C. The water vapor accelerated the oxidation of the matrix and the graphite.
Hao, L, Jiang, Z, Wei, D, Gong, D, Cheng, X, Zhao, J, Luo, S & Jiang, L 2016, 'Experimental and Numerical Study on the Effect of ZDDP Films on Sticking During Hot Rolling of Ferritic Stainless Steel Strip', Metallurgical and Materials Transactions A, vol. 47, no. 10, pp. 5195-5202.
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Huang, S & Dissanayake, G 2016, 'A critique of current developments in simultaneous localization and mapping', International Journal of Advanced Robotic Systems, vol. 13, no. 5, pp. 172988141666948-172988141666948.
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The number of research publications dealing with the simultaneous localization and mapping problem has grown significantly over the past 15 years. Many fundamental and practical aspects of simultaneous localization and mapping have been addressed, and some efficient algorithms and practical solutions have been demonstrated. The aim of this paper is to provide a critical review of current theoretical understanding of the fundamental properties of the SLAM problem, such as observability, convergence, achievable accuracy and consistency. Recent research outcomes associated with these topics are briefly discussed together with potential future research directions.
Huang, ZL, Jiang, C, Zhou, YS, Luo, Z & Zhang, Z 2016, 'An incremental shifting vector approach for reliability-based design optimization', Structural and Multidisciplinary Optimization, vol. 53, no. 3, pp. 523-543.
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© 2015, Springer-Verlag Berlin Heidelberg. This paper proposes a decoupling algorithm for reliability-based design optimization (RBDO) with high performance in terms of efficiency and convergence, which provides an effective tool for reliability design of many complex structures. The algorithm proceeds by performing a shifting vector calculation and then solving a deterministic design optimization in each step, and eventually converges to the optimal solution. An incremental shifting strategy is proposed to ensure stable convergence in the iteration process. In each step, the shifting vector preserves the information from the previous step, and only an adjustment is made for it through a shifting vector increment. A computation method is given for the shifting vector increment, avoiding solving an optimization problem during the reliability analysis and thus greatly reducing the computational cost of the iteration process. Six numerical examples and two engineering applications are presented to validate the effectiveness of the method proposed in this paper.
Islam, SU, Rahman, H, Abbasi, WS, Saha, SC & Shahina, T 2016, 'Numerical investigation of flow past a row of rectangular rods', Alexandria Engineering Journal, vol. 55, no. 3, pp. 2351-2365.
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Karimi, M, Croaker, P & Kessissoglou, N 2016, 'Boundary element solution for periodic acoustic problems', Journal of Sound and Vibration, vol. 360, no. 6, pp. 129-139.
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This work shows when using the boundary element method to solve 3D acoustic scattering problems from periodic structures, the coefficient matrix can be represented as a block Toeplitz matrix. By exploiting the Toeplitz structure, the computational time and storage requirements to construct the coefficient matrix are significantly reduced. To solve the linear system of equations, the original matrix is embedded into a larger and more structured matrix called the block circulant matrix. Discrete Fourier transform is then employed in an iterative algorithm to solve the block Toeplitz system. To demonstrate the effectiveness of the formulation for periodic acoustic problems, two exterior acoustic case studies are considered. The first case study examines a continuous structure to predict the noise generated by a sharp-edged flat plate under quadrupole excitation. Directivity plots obtained using the periodic boundary element method technique are compared with numerical results obtained using a conventional boundary element model. The second case study examines a discrete periodic structure to predict the acoustic performance of a sonic crystal noise barrier. Results for the barrier insertion loss are compared with both finite element results and available data in the literature.
Kehrel, U, Klischan, K & Sick, N 2016, 'Why Research Partnerships Fail in the Biotechnology Sector — An Empirical Analysis of Strategic Partnerships', International Journal of Innovation and Technology Management, vol. 13, no. 01, pp. 1650003-1650003.
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Over half of all research-oriented partnerships in the biotechnology industry fail due to problems in inter-organizational relationships. The analysis of factors that determine the success of strategic partnerships can help companies to reduce the high failure rates. Based on the resource-oriented and relationship-oriented approach, this study examines the influence of three structural factors and three dynamic factors on the success of strategic, research-oriented partnerships in the biotechnology industry. In the empirical study, data of 48 research collaborations by 28 companies were collected and analyzed. The results confirm the significant influence of the factors “complementary resources”, “operational compatibility”, “bilateral exchange of information” and “opportunistic behavior”. On the basis of these findings, companies can find approaches to influence the success of their own research collaborations. In particular, appropriate recommendations for action can be formulated in the areas of the structural design of partnerships and the dynamic exchange process.
Khosoussi, K, Huang, S & Dissanayake, G 2016, 'A Sparse Separable SLAM Back-End', IEEE Transactions on Robotics, vol. 32, no. 6, pp. 1536-1549.
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© 2004-2012 IEEE. We propose a scalable algorithm to take advantage of the separable structure of simultaneous localization and mapping (SLAM). Separability is an overlooked structure of SLAM that distinguishes it from a generic nonlinear least-squares problem. The standard relative-pose and relative-position measurement models in SLAM are affine with respect to robot and features' positions. Therefore, given an estimate for robot orientation, the conditionally optimal estimate for the rest of the state variables can be easily computed by solving a sparse linear least-squares problem. We propose an algorithm to exploit this intrinsic property of SLAM by stripping the problem down to its nonlinear core, while maintaining its natural sparsity. Our algorithm can be used in conjunction with any Newton-based solver and is applicable to 2-D/3-D pose-graph and feature-based SLAM. Our results suggest that iteratively solving the nonlinear core of SLAM leads to a fast and reliable convergence as compared to the state-of-the-art sparse back-ends.
Khushaba, RN, Al-Timemy, A, Kodagoda, S & Nazarpour, K 2016, 'Combined influence of forearm orientation and muscular contraction on EMG pattern recognition', EXPERT SYSTEMS WITH APPLICATIONS, vol. 61, pp. 154-161.
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Klenner, F, Lenze, D, Schwarzer, S, Deuse, J & Friedrich, T 2016, 'Smart Data Analytics zur Identifikation dynamischer Engpässe in Flexiblen Fertigungssystemen', at - Automatisierungstechnik, vol. 64, no. 7, pp. 540-554.
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Zusammenfassung Flexible Fertigungssysteme (FFS) bilden die konzeptionelle Grundlage einer hoch flexiblen und produktivenGroßserienproduktion. Die inhärente Komplexität dieser Systeme erschwert die Lokalisierung von Engpässenund damit den produktiven Systembetrieb. Dieser Artikel beschreibt eine Methode, welche mithilfe eines Smart-Data-Modellsdynamische Engpässe in FFS identifiziert. Die damit verbundene Beherrschung der Komplexität bildet die Grundlagefür einen produktiven Betrieb.
Kodagoda, S, Sehestedt, S & Dissanayake, G 2016, 'Socially aware path planning for mobile robots', Robotica, vol. 34, no. 3, pp. 513-526.
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SUMMARYHuman–robot interaction is an emerging area of research where a robot may need to be working in human-populated environments. Human trajectories are generally not random and can belong to gross patterns. Knowledge about these patterns can be learned through observation. In this paper, we address the problem of a robot's social awareness by learning human motion patterns and integrating them in path planning. The gross motion patterns are learned using a novel Sampled Hidden Markov Model, which allows the integration of partial observations in dynamic model building. This model is used in the modified A* path planning algorithm to achieve socially aware trajectories. Novelty of the proposed method is that it can be used on a mobile robot for simultaneous online learning and path planning. The experiments carried out in an office environment show that the paths can be planned seamlessly, avoiding personal spaces of occupants.
Krebs, M, Hartung, J, Hengstebeck, A, Kuske, P & Deuse, J 2016, 'Time data management in machine tool industry', Productivity Management, vol. 21, no. 4, pp. 25-28.
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Time data management is a significant success factor to unlock elusive potentials for productivity management in lean production systems. Nevertheless, the importance was underestimated for a long time and in many companies essential organizational structures as well as know-how were neglected. Reliable and precise times, however, can be estimated by using standard data building blocks with low effort in every phase of the product development process.
Kuruneru, STW, Sauret, E, Saha, SC & Gu, Y 2016, 'Numerical investigation of the temporal evolution of particulate fouling in metal foams for air-cooled heat exchangers', Applied Energy, vol. 184, pp. 531-547.
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Metal foams have gained popularity in the renewable energy industry due to their superior thermo-physical properties. In the present study, a coupled finite volume and discrete element numerical method is used to numerically investigate the mechanisms that govern particle-laden gas flows and particulate fouling in idealized metal foam air-cooled heat exchangers. This paper provides a systematic analysis of the foulant distribution and the pressure drop due to the metal foam structure and the presence of fouling. The idealized Weaire-Phelan metal foam geometry serves as a good approximation to a real metal foam geometry. The pressure drop and deposition fraction follows a linear relation for sandstone cases, whereas for the sawdust cases, the pressure drop is sensibly invariant with time although a noticeable increase in deposition fraction with time is realized. The foulant residence time in addition to the correlations between pressure drop, deposition fraction, and inlet velocity can be used to optimize metal foam heat exchanger designs. Optimum heat exchanger performance is achieved by keeping the same fiber thickness of 0.17 mm at a high porosity at 97.87%. An increase in fluid carrier velocity promotes particle transport by means of particle interception thereby reducing the deposition fraction irrespective of foam geometry.
Li, H, Luo, Z, Zhang, N, Gao, L & Brown, T 2016, 'Integrated design of cellular composites using a level-set topology optimization method', Computer Methods in Applied Mechanics and Engineering, vol. 309, pp. 453-475.
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© 2016 Elsevier B.V. This paper proposes a hierarchical multi-scale topology optimization method for the design of integrated materials and structures by taking advantage of both cellular composites and functionally graded materials. The topology optimization involves two scales: firstly, macrostructural design using SIMP to generate an overall multilayered layout with free material distribution involving intermediate densities; and secondly, microstructural design to produce periodic cellular composite for each layer, by integrating the numerical homogenization into a level set approach. Thus, the cellular composites will be characterized by variation in microstructures and the corresponding changes of properties over layers. The proposed method can generate new artificial composites similar to functionally graded materials but layer-based, to achieve multifunctional properties for energy absorption, anti-impact, thermal isolation, etc. Several numerical examples are used to demonstrate the effectiveness of this method.
Li, H, Öchsner, A, Ni, G, Wei, D & Jiang, Z 2016, 'Analysis of surface asperity flattening based on two different methods', Continuum Mechanics and Thermodynamics, vol. 28, no. 6, pp. 1623-1634.
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The stress state is an important parameter in metal forming processes, which significantly influences the strain state and microstructure of products, affecting their surface qualities. In order to make the metal products have a good surface quality, the surface stress state must be optimised. In this study, two classical methods, the upper bound method and the crystal plasticity finite element method, were investigated. The differences between the two methods were discussed in regard to the model, the velocity field, and the strain field. Then the related surface roughness is deduced.
Liang, J, Wu, J, Zhang, N, Luo, Z & Zhu, S 2016, 'Interval uncertain analysis of active hydraulically interconnected suspension system', Advances in Mechanical Engineering, vol. 8, no. 5, pp. 168781401664633-168781401664633.
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Uncertainty exists in many industry fields and needs to be dealt properly to avoid unexpected failure. This article proposes a new approach to deal with the uncertain problems encountered by the mathematical modeling of an active hydraulically interconnected suspension system. As the need for both riding comfort and the controllability is soaring nowadays, the traditional passive and semi-active suspension system could barely keep up with the pace, and the proposed active hydraulic system could be one of the solutions. In order to deal with the uncertain factors in the hydraulic system, an interval analysis method for the dynamic responses of nonlinear systems with uncertain-but-bounded parameters using Chebyshev polynomial series is introduced. The comparisons conducted in this article demonstrate the accuracy and computational efficiency of the proposed uncertain problem solver and reveal the influences of uncertain parameters in fluid and mechanical components on the dynamic responses of active hydraulically interconnected suspension.
Liu, J, Ji, J & Zhou, J 2016, 'Synchronization of networked multibody systems using fundamental equation of mechanics', APPLIED MATHEMATICS AND MECHANICS-ENGLISH EDITION, vol. 37, no. 5, pp. 555-572.
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© 2016, Shanghai University and Springer-Verlag Berlin Heidelberg. From the analytical dynamics point of view, this paper develops an optimal control framework to synchronize networked multibody systems using the fundamental equation of mechanics. A novel robust control law derived from the framework is then used to achieve complete synchronization of networked identical or non-identical multibody systems formulated with Lagrangian dynamics. A distinctive feature of the developed control strategy is the introduction of network structures into the control requirement. The control law consists of two components, the first describing the architecture of the network and the second denoting an active feedback control strategy. A corresponding stability analysis is performed by the algebraic graph theory. A representative network composed of ten identical or non-identical gyroscopes is used as an illustrative example. Numerical simulation of the systems with three kinds of network structures, including global coupling, nearest-neighbour, and small-world networks, is given to demonstrate effectiveness of the proposed control methodology.
Lozano, FJ, Freire, P, Guillén-Gozalbez, G, Jiménez-Gonzalez, C, Sakao, T, Dowell, NM, Ortiz, MG, Trianni, A, Carpenter, A & Viveros, T 2016, 'New perspectives for sustainable resource and energy use, management and transformation: approaches from green and sustainable chemistry and engineering', Journal of Cleaner Production, vol. 118, pp. 1-3.
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Lu, X, Zhou, M, Ammari, AC & Ji, J 2016, 'Hybrid Petri Nets for Modeling and Analysis of Microgrid Systems', IEEE-CAA JOURNAL OF AUTOMATICA SINICA, vol. 3, no. 4, pp. 349-356.
Luo, L, Jiang, Z, Wei, D, Manabe, K-I, Zhao, X, Wu, D & Furushima, T 2016, 'Effects of surface roughness on micro deep drawing of circular cups with consideration of size effects', Finite Elements in Analysis and Design, vol. 111, pp. 46-55.
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© 2015 Elsevier B.V. All rights reserved. Surface roughness, compared with tiny sizes of micro products, can be relatively large and has significant influences on micro forming processes and products' quality. In this study, a voronoi finite element model that considers size effects of material was developed. Next the surface roughness information was assigned to this voronoi model through different elemental thickness distributions. Furthermore, springback simulation was conducted for the micro deep drawn circular cups. Simulation results demonstrate that the surface roughness with consideration of size effects has significant influences on the overall springback, the drawability represented by the minimum thickness and products' quality regarding thickness evenness and shape accuracy. This study also shows that the results from the new models are close to the experimental results concerning the diameter of cup mouth and the maximum drawing force. The developed model for the micro deep drawing is accurate and beneficial for the development of micro deep drawing process.
Luo, Q & Tong, L 2016, 'An algorithm for eradicating the effects of void elements on structural topology optimization for nonlinear compliance', Structural and Multidisciplinary Optimization, vol. 53, no. 4, pp. 695-714.
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Luo, Q & Tong, L 2016, 'Elimination of the Effects of Low Density Elements in Topology Optimization of Buckling Structures', International Journal of Computational Methods, vol. 13, no. 06, pp. 1650041-1650041.
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This paper presents an algorithm for structural topology optimization involving linear buckling. In this algorithm, finite element analysis (FEA) is conducted only in a domain with solid and gray elements, eliminating the contribution of low density elements; and the response function is constructed in the full design domain accounting the contribution of removed low density elements. The errors induced by removing void elements in FEA on eigenvalue and eigenvectors are analyzed. By introducing a dynamic low bound of the first eigenvalue and a load-path coefficient, the algorithm allows converged, nondisjointed and accurate solutions for topology optimization of structures involving buckling. Numerical results are presented for plate and column-beam structures against linear buckling to illustrate the efficiency and effectiveness of the present algorithm. Buckling experiments of the plates manufactured from the obtained topologies further verify the present algorithm.
Luo, Q & Tong, L 2016, 'Solutions for Clamped Adhesively Bonded Single Lap Joint With Movement of Support End and Its Application to a Carbon Nanotube Junction in Tension', The Journal of Adhesion, vol. 92, no. 5, pp. 349-379.
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Mojumder, S, Rabbi, KM, Saha, S, Hasan, MN & Saha, SC 2016, 'Magnetic field effect on natural convection and entropy generation in a half-moon shaped cavity with semi-circular bottom heater having different ferrofluid inside', Journal of Magnetism and Magnetic Materials, vol. 407, pp. 412-424.
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In this study magneto-hydrodynamic convection in a half-moon shaped cavity filled with ferrofluid has been analyzed numerically. The cavity has two semi-circular bottom heaters and effect of the distance between these two heaters (λ = 0.1, 0.4) has been thoroughly investigated. Numerical simulation has been carried out for a wide range of Rayleigh number (Ra = 103 ∼ 107), Hartmann number (Ha = 0 ∼ 100) and inclination angle of magnetic field (γ = 0°∼ 90°) to understand the flow field, thermal field and entropy generation respectively. Cobalt-kerosene and Fe3O4 -water ferrofluids are used for the present investigation and considered as a single phase fluid. Galerkin weighted residual method of finite element analysis has been used for numerical solution. The code validation and grid independency test have been carried out to justify the numerical accuracy. It has been observed that increment of magnetic field reduces the heat transfer rate, whereas increment of heater distance augments the heat transfer rate significantly. Results are discussed on the basis of Nusselt number (Nu), Bejan number (Be) and shown by contours and 3D plots. It has also been found that λ = 0.4 always shows better heat transfer rate and entropy optimization.
Mutta, GR, Popuri, SR, Maciejczyk, M, Robertson, N, Vasundhara, M, Wilson, JIB & Bennett, NS 2016, 'V2O5as an inexpensive counter electrode for dye sensitized solar cells', Materials Research Express, vol. 3, no. 3, pp. 035501-035501.
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In pursuit of an abundant, inexpensive and stable counter electrode as an alternative to platinum for dye-sensitized solar cells (DSSCs), we report a new, low-cost substitute material. Here for the first time, we demonstrate that V2O5 can be used as a counter electrode material in DSSCs. We note that the efficiency of DSSCs with commercialV2O5 and hydrothermal treatedV2O5 are upto 1.2% and 1.6%, respectively. The results indicate that, with optimization, V2O5 can be a promising choice to replace platinum from a cost perspective. The innovation of new economical counter electrodes offers a potential way to cut down the industrial costs which is crucial for large-scale production and commercial applications of DSSCs.
Mutta, GR, Popuri, SR, Vasundhara, M, Maciejczyk, M, Racu, AV, Banica, R, Robertson, N, Wilson, JIB & Bennett, NS 2016, 'Facile hydrothermal synthesis of economically viable VO 2 (M1) counter electrode for dye sensitized solar cells', Materials Research Bulletin, vol. 83, pp. 135-140.
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In this study, we focus at reducing the fabrication cost of dye sensitized solar cells (DSSCs). Sphere-like VO2(M1) polymorph was synthesized by single step facile hydrothermal approach using citric acid as the reducing agent. Phase purity, charge state and surface morphology of the synthesized product were confirmed by X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy respectively. The electrochemical impedance and cyclic voltammograms of VO2 films indicated a good electrocatalytic activity towards redox reaction of the I-/I3- shuttle. Owing to the low cost, low-temperature processing and good catalytic activity, in this work we propose to use VO2 as a counter electrode to substitute the expensive platinum electrode in DSSCs. By means of VO2 based DSSCs we achieved a fivefold reduction in the cost to energy conversion efficiency ratio. It is expected that with further optimization, VO2 can be exploited as a good candidate for counter electrode in DSSC technology.
Mutta, GR, Popuri, SR, Wilson, JIB & Bennett, NS 2016, 'Sol-gel spin coated well adhered MoO3 thin films as an alternative counter electrode for dye sensitized solar cells', Solid State Sciences, vol. 61, pp. 84-88.
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In this work, we aim to develop a viable, inexpensive and non-toxic material for counter electrodes in dye sensitized solar cells (DSSCs). We employed an ultra-simple synthesis process to deposit MoO3 thin films at low temperature by sol-gel spin coating technique. These MoO3 films showed good transparency. It is predicted that there will be 150 times reduction of precursors cost by realizing MoO3 thin films as a counter electrode in DSSCs compared to commercial Pt. We achieved a device efficiency of about 20 times higher than that of the previous reported values. In summary we develop a simple low cost preparation of MoO3 films with an easily scaled up process along with good device efficiency. This work encourages the development of novel and relatively new materials and paves the way for massive reduction of industrial costs which is a prime step for commercialization of DSSCs.
Nguyen, LV, Kodagoda, S & Ranasinghe, R 2016, 'Spatial Sensor Selection via Gaussian Markov Random Fields', IEEE Transactions on Systems, Man, and Cybernetics: Systems, vol. 46, no. 9, pp. 1226-1239.
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Nguyen, LV, Kodagoda, S, Ranasinghe, R & Dissanayake, G 2016, 'Information-Driven Adaptive Sampling Strategy for Mobile Robotic Wireless Sensor Network', IEEE Transactions on Control Systems Technology, vol. 24, no. 1, pp. 372-379.
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This brief addresses the issue of monitoring physical spatial phenomena of interest using information collected by a resource-constrained network of mobile, wireless, and noisy sensors that can take discrete measurements as they navigate through the environment. We first propose an efficient novel optimality criterion for designing a sampling strategy to find the most informative locations in taking future observations to minimize the uncertainty at all unobserved locations of interest. This solution is proven to be within bounds. The computational complexity of this proposition is shown to be practically feasible. We then prove that under a certain condition of monotonicity property, the approximate entropy at resulting locations obtained by our proposed algorithm is within 1-(1/e) of the optimum, which is then utilized as a stopping criterion for the sampling algorithm. The criterion enables the prediction results to be within user-defined accuracies by controlling the number of mobile sensors. The effectiveness of the proposed method is illustrated using a prepublished data set.
Nobbs, M & Blamires, SJ 2016, 'Making up for lost time: Biophysical constraints on the temporal abundance of two fiddler crabs in wet-dry tropical mangroves', Austral Ecology, vol. 41, no. 7, pp. 791-796.
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Nöhring, F, Sackermann, R, Krebs, M & Deuse, J 2016, 'Moderne Zeitwirtschaft in der Einzel- und Kleinserienfertigung', Zeitschrift für wirtschaftlichen Fabrikbetrieb, vol. 111, no. 5, pp. 256-260.
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Kurzfassung Aktuelle sowie belastbare zeitwirtschaftliche Daten sind eine wichtige Grundlage für die Planung und Steuerung der Produktion in Unternehmen. Allerdings ist insbesondere in der Einzel- und Kleinserienfertigung mit geringen Stückzahlen und hoher Variantenvielfalt der Aufwand zum Aufbau und Betrieb einer Zeitwirtschaft im angemessenen Rahmen zu halten. In diesem Fachbeitrag wird ein Konzept zur Ermittlung, Aufbereitung und Verwendung von Planzeitbausteinen vorgestellt.
Nöhring, F, Wienzek, T, Wöstmann, R & Deuse, J 2016, 'Development of a sociotechnical design and implementation systematic', ZWF Zeitschrift fuer Wirtschaftlichen Fabrikbetrieb, vol. 111, no. 6, pp. 376-379.
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Implementation of Industry 4.0-technologies typically take place in pilot projects and require high effort. This paper presents the concept of a sociotechnical design and implementation systematic for Cyber-Physical Production Systems (CPPS) in companies with non-intensive research and development. The focus is on targetoriented choice of CPPS as well as integration in existing production systems. Four representative scenarios are presented.
Norouzi, M, Valls Miro, J & Dissanayake, G 2016, 'Probabilistic stable motion planning with stability uncertainty for articulated vehicles on challenging terrains', Autonomous Robots, vol. 40, no. 2, pp. 361-381.
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© 2015, Springer Science+Business Media New York. A probabilistic stable motion planning strategy applicable to reconfigurable robots is presented in this paper. The methodology derives a novel statistical stability criterion from the cumulative distribution of a tip-over metric. The measure is dynamically updated with imprecise terrain information, localization and robot kinematics to plan safety-constrained paths which simultaneously allow the widest possible visibility of the surroundings by simultaneously assuming highest feasible vantage robot configurations. The proposed probabilistic stability metric allows more conservative poses through areas with higher levels of uncertainty, while avoiding unnecessary caution in poses assumed at well-known terrain sections. The implementation with the well known grid based A* algorithm and also a sampling based RRT planner are presented. The validity of the proposed approach is evaluated with a multi-tracked robot fitted with a manipulator arm and a range camera using two challenging elevation terrains data sets: one obtained whilst operating the robot in a mock-up urban search and rescue arena, and the other from a publicly available dataset of a quasi-outdoor rover testing facility.
Oberst, S, Lai, JCS & Evans, TA 2016, 'Termites utilise clay to build structural supports and so increase foraging resources', Scientific Reports, vol. 6, no. 1.
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AbstractMany termite species use clay to build foraging galleries and mound-nests. In some cases clay is placed within excavations of their wooden food, such as living trees or timber in buildings; however the purpose for this clay is unclear. We tested the hypotheses that termites can identify load bearing wood and that they use clay to provide mechanical support of the load and thus allow them to eat the wood. In field and laboratory experiments, we show that the lower termite Coptotermes acinaciformis, the most basal species to build a mound-nest, can distinguish unloaded from loaded wood and use clay differently when eating each type. The termites target unloaded wood preferentially and use thin clay sheeting to camouflage themselves while eating the unloaded wood. The termites attack loaded wood secondarily and build thick, load-bearing clay walls when they do. The termites add clay and build thicker walls as the load-bearing wood is consumed. The use of clay to support wood under load unlocks otherwise unavailable food resources. This behaviour may represent an evolutionary step from foraging behaviour to nest building in lower termites.
Oberst, S, Zhang, Z & Lai, JCS 2016, 'The Role of Nonlinearity and Uncertainty in Assessing Disc Brake Squeal Propensity', SAE International Journal of Passenger Cars - Mechanical Systems, vol. 9, no. 3, pp. 980-986.
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Patten, T, Zillich, M, Fitch, R, Vincze, M & Sukkarieh, S 2016, 'Viewpoint Evaluation for Online 3-D Active Object Classification', IEEE Robotics and Automation Letters, vol. 1, no. 1, pp. 73-81.
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© 2015 IEEE. We present an end-to-end method for active object classification in cluttered scenes from RGB-D data. Our algorithms predict the quality of future viewpoints in the form of entropy using both class and pose. Occlusions are explicitly modeled in predicting the visible regions of objects, which modulates the corresponding discriminatory value of a given view. We implement a one-step greedy planner and demonstrate our method online using a mobile robot. We also analyze the performance of our method compared to similar strategies in simulated execution using the Willow Garage dataset. Results show that our active method usefully reduces the number of views required to accurately classify objects in clutter as compared to traditional passive perception.
Payne, T, Mitchell, S, Halkon, B & Bibb, R 2016, 'A systematic approach to the characterisation of human impact injury scenarios in sport', BMJ Open Sport & Exercise Medicine, vol. 2, no. 1, pp. e000017-e000017.
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Background
In contact sports (eg, American football or rugby), injuries resulting from impacts are widespread. There have been several attempts to identify and collate, within a conceptual framework, factors influencing the likelihood of an injury. To effectively define an injury event it is necessary to systematically consider all potential causal factors but none of the previous approaches are complete in this respect.
Aims
First, to develop a superior deterministic contextual sequential (DCS) model to promote a complete and logical description of interrelated injury event factors. Second, to demonstrate systematic use of the model to construct enhanced perspectives for impact-injury research.
Method
Previous models were examined and elements of best practice synthesised into a new DCS framework description categorising the types of causal factors influencing injury. The approach's internal robustness is demonstrated by consideration of its completeness, lack of redundancy and logical consistency.
Results
The model's external validity and worth are demonstrated through its use to generate superior descriptive injury models, experimental protocols and intervention opportunities. Comprehensive research perspectives have been developed using a common rugby impact-injury scenario as an example; this includes: a detailed description of the injury event, an experimental protocol for a human-on-surrogate reconstruction, and a series of practical interventions in the sport of rugby aimed at mitigating the risk of injury.
Conclusions
Our improved characterisation tool presents a structured approach to identify pertinent factors relating to an injury.
Payne, T, Mitchell, S, Halkon, B, Bibb, R & Waters, M 2016, 'Development of a synthetic human thigh impact surrogate for sports personal protective equipment testing', Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, vol. 230, no. 1, pp. 5-16.
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Synthetic impact surrogates are widely used in the sporting goods industry in the evaluation of personal protective equipment. Existing surrogates, exemplified by those used in safety standards, have many shortcomings, primarily relating to their mass, stiffness, geometries and levels of constraint which limit their biofidelity and subsequent usefulness in personal protective equipment evaluations. In sports, absence from competition is a primary severity measure for injuries; consequently, blunt trauma injuries, such as contusions and lacerations, become pertinent and serious concerns. It is important, therefore, that synthetic surrogates provide an adequate description of these soft tissues to effectively evaluate injury risk. A novel, multi-material human thigh surrogate has been presented with consideration to the tissue structures, geometries and simulant materials used. This study presents the detailed development stages undertaken to fabricate a multi-material synthetic soft tissue surrogate with skin, subcutaneous adipose and muscle tissue components. The resultant surrogate demonstrates the successful use of sequential moulding techniques to construct a full-scale anatomical human impact surrogate which can be used in personal protective equipment testing.
Polwaththe-Gallage, H-N, Saha, SC, Sauret, E, Flower, R & Gu, Y 2016, 'A coupled SPH-DEM approach to model the interactions between multiple red blood cells in motion in capillaries', International Journal of Mechanics and Materials in Design, vol. 12, no. 4, pp. 477-494.
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Red blood cells (RBCs) are the most common type of blood cells in the blood and 99 % of the blood cells are RBCs. During the circulation of blood in the cardiovascular network, RBCs squeeze through the tiny blood vessels (capillaries). They exhibit various types of motions and deformed shapes, when flowing through these capillaries with diameters varying between 5 and 10 µm. RBCs occupy about 45 % of the whole blood volume and the interaction between the RBCs directly influences on the motion and the deformation of the RBCs. However, most of the previous numerical studies have explored the motion and deformation of a single RBC when the interaction between RBCs has been neglected. In this study, motion and deformation of two 2D (two-dimensional) RBCs in capillaries are comprehensively explored using a coupled smoothed particle hydrodynamics (SPH) and discrete element method (DEM) model. In order to clearly model the interactions between RBCs, only two RBCs are considered in this study even though blood with RBCs is continuously flowing through the blood vessels. A spring network based on the DEM is employed to model the viscoelastic membrane of the RBC while the inside and outside fluid of RBC is modelled by SPH. The effect of the initial distance between two RBCs, membrane bending stiffness (Kb) of one RBC and undeformed diameter of one RBC on the motion and deformation of both RBCs in a uniform capillary is studied. Finally, the deformation behavior of two RBCs in a stenosed capillary is also examined. Simulation results reveal that the interaction between RBCs has significant influence on their motion and deformation.
Polwaththe-Gallage, H-N, Saha, SC, Sauret, E, Flower, R, Senadeera, W & Gu, Y 2016, 'SPH-DEM approach to numerically simulate the deformation of three-dimensional RBCs in non-uniform capillaries', BioMedical Engineering OnLine, vol. 15, no. S2.
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© 2016 The Author(s). Background: Blood continuously flows through the blood vessels in the human body. When blood flows through the smallest blood vessels, red blood cells (RBCs) in the blood exhibit various types of motion and deformed shapes. Computational modelling techniques can be used to successfully predict the behaviour of the RBCs in capillaries. In this study, we report the application of a meshfree particle approach to model and predict the motion and deformation of three-dimensional RBCs in capillaries. Methods: An elastic spring network based on the discrete element method (DEM) is employed to model the three-dimensional RBC membrane. The haemoglobin in the RBC and the plasma in the blood are modelled as smoothed particle hydrodynamics (SPH) particles. For validation purposes, the behaviour of a single RBC in a simple shear flow is examined and compared against experimental results. Then simulations are carried out to predict the behaviour of RBCs in a capillary; (i) the motion of five identical RBCs in a uniform capillary, (ii) the motion of five identical RBCs with different bending stiffness (K b ) values in a stenosed capillary, (iii) the motion of three RBCs in a narrow capillary. Finally five identical RBCs are employed to determine the critical diameter of a stenosed capillary. Results: Validation results showed a good agreement with less than 10% difference. From the above simulations, the following results are obtained; (i) RBCs exhibit different deformation behaviours due to the hydrodynamic interaction between them. (ii) Asymmetrical deformation behaviours of the RBCs are clearly observed when the bending stiffness (K b ) of the RBCs is changed. (iii) The model predicts the ability of the RBCs to squeeze through smaller blood vessels. Finally, from the simulations, the critical diameter of the stenosed section to stop the motion of blood flow is predicted. Conclusions: A three-dimensional spring network model based on DEM in com...
Popuri, SR, Pollet, M, Decourt, R, Morrison, FD, Bennett, NS & Bos, JWG 2016, 'Large thermoelectric power factors and impact of texturing on the thermal conductivity in polycrystalline SnSe', Journal of Materials Chemistry C, vol. 4, no. 8, pp. 1685-1691.
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Large thermoelectric power factors and low thermal conductivities linked to changes in texturing have been observed in consolidated polycrystalline SnSe ingots.
Rahmani, O, Hosseini, SAH & Hayati, H 2016, 'Frequency analysis of curved nano-sandwich structure based on a nonlocal model', Modern Physics Letters B, vol. 30, no. 10, pp. 1650136-1650136.
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In this paper, we study the vibration of curved nano-sandwich (CNS) with considering the influence of core shear based on the Eringen nonlocal theory. The equation of motion is derived and exact solution for the natural frequencies of CNS is presented. The proposed nonlocal model includes a material length scale parameter that can capture the size effect in CNS beam. The effects of important parameters, such as the thickness to length ratio, nonlocal parameter and mode number on the frequencies of CNS are investigated. The result of our research shows that as the opening angle increases, the amount of natural frequencies decrease. We have additionally validate, our results against previous research works which showed good agreement.
Rai, R, Saha, SC, Jain, A, Bagga, R, Kumar, P & Marwaha, N 2016, 'Anti-M Alloimmunization in Pregnancy: An Unusual Cause of Bad Obstetric History', The Journal of Obstetrics and Gynecology of India, vol. 66, no. S2, pp. 607-609.
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Roth, N & Deuse, J 2016, 'Excellent, lean production: Framework on the base of systematic variability and lead time reduction and continuous improvement cycles.', Productivity Management, vol. 21, no. 4, pp. 15-19.
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Within this paper lean production and business excellence approaches will be brought together to one holistic improvement approach. A performance management system, which relies on the principles of variability and lead time reduction is thereby the core, which helps companies to improve their result indicators. The approach has been developed and tested over a duration of more than 5 years within several industrial projects. In all cases, considerable improvements of bottom line indicators such as inventory, productivity or quality could be achieved.
Ruppert, MG & Moheimani, SOR 2016, 'Multimode <inline-formula> <tex-math notation='LaTeX'>$Q$ </tex-math> </inline-formula> Control in Tapping-Mode AFM: Enabling Imaging on Higher Flexural Eigenmodes', IEEE Transactions on Control Systems Technology, vol. 24, no. 4, pp. 1149-1159.
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Ruppert, MG, Harcombe, DM & Moheimani, SOR 2016, 'High-Bandwidth Demodulation in MF-AFM: A Kalman Filtering Approach', IEEE/ASME Transactions on Mechatronics, vol. 21, no. 6, pp. 2705-2715.
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Ruppert, MG, Karvinen, KS, Wiggins, SL & Reza Moheimani, SO 2016, 'A Kalman Filter for Amplitude Estimation in High-Speed Dynamic Mode Atomic Force Microscopy', IEEE Transactions on Control Systems Technology, vol. 24, no. 1, pp. 276-284.
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Ryu, K, Dantanarayana, L, Furukawa, T & Dissanayake, G 2016, 'Grid-based scan-to-map matching for accurate 2D map building.', Adv. Robotics, vol. 30, no. 7, pp. 431-448.
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This paper presents a grid-based scan-to-map matching technique for accurate 2D map building. At every acquisition of a new scan, the proposed technique matches the new scan to the previous scan similarly to the conventional techniques, but further corrects the error by matching the new scan to the globally defined map. In order to achieve best scan-to-map matching at each acquisition, the map is represented as a grid map with multiple normal distributions (NDs) in each cell, which is one contribution of this paper. Additionally, the new scan is also represented by NDs, developing a novel ND-to-ND matching technique. This ND-to-ND matching technique has significant potential in the enhancement of the global matching as well as the computational efficiency. Experimental results first show that the proposed technique accumulates very small errors after consecutive matchings and identifies that the scans are matched better to the map with the multi-ND representation than one ND representation. The proposed t...
Sato, H, Manabe, K-I, Wei, D, Jiang, Z & Alexandrov, S 2016, 'Tribological behavior in micro–sheet hydroforming', Tribology International, vol. 97, pp. 302-312.
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Sick, N, Nienaber, A-M, Liesenkötter, B, vom Stein, N, Schewe, G & Leker, J 2016, 'The legend about sailing ship effects – Is it true or false? The example of cleaner propulsion technologies diffusion in the automotive industry', Journal of Cleaner Production, vol. 137, pp. 405-413.
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The global automotive industry is faced with major technological change in the field of propulsion systems. Due to low carbon emission regulations and a rising societal demand for sustainability, original equipment manufacturers (OEMs) are forced to innovate either in the conventional technology or in the technological alternatives such as electric drives or fuel cells. However, OEMs are only marginally switching to electromobility so far, but rather incrementally innovating traditional technologies. This behaviour can be described as sailing ship effect which contains the reaction of an old technology to a new technology by fostering innovation in the old technology. Firstly, the present study contributes to the discussion in literature on the sailing ship effect by combining its underlying ideas and consequences with the rationales of path dependence to demonstrate that such a behaviour may be individually economical rational. Based on these considerations, we respond to the call for further empirical investigation of the sailing ship effect. We show patent-based evidence that there has been a temporary sailing ship effect in the automotive industry concerning traditional and emerging propulsion systems and discuss implications for corporate technology strategy and policy.
Siddiki, MN-A-A, Molla, MM & Saha, SC 2016, 'Natural convection flow in porous enclosure with localized heating from below with heat flux', AIP Conference Proceedings, vol. 1754.
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Siedelhofer, C, Henke, T, Konrad, B, Deuse, J & Litterscheidt, J 2016, 'Konzepte zur Effizienzsteigerung von Variantenfließlinien bei hohen Variantenanzahlen', Zeitschrift für wirtschaftlichen Fabrikbetrieb, vol. 111, no. 10, pp. 594-597.
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Kurzfassung Die Nachfrage nach individuellen Produkten erfordert von Unternehmen das Angebot eines breiten Produktspektrums. Zwar sind Variantenfließlinien gängige Praxis, jedoch stellt der Umgang mit weiter zunehmenden Taktzeitspreizungen und volatilen Kundenabrufen eine große Herausforderung dar. In dem Beitrag werden zwei Konzepte vorgestellt, die aufbauend auf Methoden des Data Mining sowie des flexiblen Mitarbeitereinsatzes die Linieneffizienz von Variantenfließlinien erhöhen.
Simon, H & Sick, N 2016, 'Technological distance measures: new perspectives on nearby and far away', Scientometrics, vol. 107, no. 3, pp. 1299-1320.
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© 2016, Akadémiai Kiadó, Budapest, Hungary. Understanding the competitive environment of one’s company is crucial for every manager. One tool to quantify the technological relationships between companies, evaluate industry landscapes and knowledge transfer potential in collaborations is the technological distance. There are different methods and many different factors that impact the results and thus the conclusions that are drawn from distance calculation. Therefore, the present study derives guidelines for calculating and evaluating technological distances for three common methods, i.e. the Euclidean distance, the cosine angle and the min-complement distance. For this purpose, we identify factors that influence the results of technological distance calculation using simulation. Subsequently, we analyze technological distances of cross-industry collaborations in the field of electric mobility. Our findings show that a high level of detail is necessary to achieve insightful results. If the topic in scope of the analysis does not represent the core business of the companies, we recommend filters to focus on the respective topic. Another key suggestion is to compare the calculated results to a peer group in order to evaluate if a distance can be evaluated as ‘near’ or ‘far’.
Sojoudi, A, Khezerloo, M, Saha, SC & Gu, Y 2016, 'Effect of rotating cylinder on heat transfer in a differentially heated rectangular enclosure filled with power law non-Newtonian fluid', International Journal of Numerical Methods for Heat & Fluid Flow, vol. 26, no. 6, pp. 1910-1931.
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Purpose – The purpose of this paper is to numerically investigate two dimensional steady state convective heat transfer in a differentially heated square cavity with constant temperatures and an inner rotating cylinder. The gap between the cylinder and the enclosure walls is filled with power law non-Newtonian fluid. Design/methodology/approach – Finite volume-based CFD software, Fluent (Ansys 15.0) is used to solve the governing equations. Attribution of the various flow parameters of fluid flow and heat transfer are investigated including Rayleigh number, Prandtl number, power law index, the cylinder radius and the angular rotational speed. Findings – Outcomes are reported in terms of isotherms, streamlines and average Nusselt number (Nu) of the heated wall for various considered here. Research limitations/implications – A detailed investigates is needed in the context of 3D flow. This will be a part of the future work. Practical implications – The effect of a rotating cylinder on heat transfer and fluid flow in a differentially heated rectangular enclosure filled with power law non-Newtonian fluid has practical importance in the process industry. Energy and Buildings, vol. 128, pp. 845-866.
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Sojoudi, A, Saha, SC, Xu, F & Gu, YT 2016, 'Transient air flow and heat transfer due to differential heating on inclined walls and heat source placed on the bottom wall in a partitioned attic shaped space', Energy and Buildings, vol. 113, pp. 39-50.
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Sui, C, Luo, Q, He, X, Tong, L, Zhang, K, Zhang, Y, Zhang, Y, Wu, J & Wang, C 2016, 'A study of mechanical peeling behavior in a junction assembled by two individual carbon nanotubes', Carbon, vol. 107, pp. 651-657.
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Sun, Y, Zhao, L, Zhou, G & Yan, L 2016, 'Absolute Orientation Based on Distance Kernel Functions', Remote Sensing, vol. 8, no. 3, pp. 213-213.
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The classical absolute orientation method is capable of transforming tie points (TPs) from a local coordinate system to a global (geodetic) coordinate system. The method is based only on a unique set of similarity transformation parameters estimated by minimizing the total difference between all ground control points (GCPs) and the fitted points. Nevertheless, it often yields a transformation with poor accuracy, especially in large-scale study cases. To address this problem, this study proposes a novel absolute orientation method based on distance kernel functions, in which various sets of similarity transformation parameters instead of only one set are calculated. When estimating the similarity transformation parameters for TPs using the iterative solution of a non-linear least squares problem, we assigned larger weighting matrices for the GCPs for which the distances from the point are short. The weighting matrices can be evaluated using the distance kernel function as a function of the distances between the GCPs and the TPs. Furthermore, we used the exponential function and the Gaussian function to describe distance kernel functions in this study. To validate and verify the proposed method, six synthetic and two real datasets were tested. The accuracy was significantly improved by the proposed method when compared to the classical method, although a higher computational complexity is experienced
Takami, K, Furukawa, T, Kumon, M, Kimoto, D & Dissanayake, G 2016, 'Estimation of a nonvisible field-of-view mobile target incorporating optical and acoustic sensors', Autonomous Robots, vol. 40, no. 2, pp. 343-359.
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To, AWK, Paul, G & Liu, D 2016, 'An approach for identifying classifiable regions of an image captured by autonomous robots in structural environments', Robotics and Computer-Integrated Manufacturing, vol. 37, pp. 90-102.
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© 2015 Elsevier Ltd. Abstract When an autonomous robot is deployed in a structural environment to visually inspect surfaces, the capture conditions of images (e.g. camera's viewing distance and angle to surfaces) may vary due to un-ideal robot poses selected to position the camera in a collision-free manner. Given that surface inspection is conducted by using a classifier trained with surface samples captured with limited changes to the viewing distance and angle, the inspection performance can be affected if the capture conditions are changed. This paper presents an approach to calculate a value that represents the likelihood of a pixel being classifiable by a classifier trained with a limited dataset. The likelihood value is calculated for each pixel in an image to form a likelihood map that can be used to identify classifiable regions of the image. The information necessary for calculating the likelihood values is obtained by collecting additional depth data that maps to each pixel in an image (collectively referred to as a RGB-D image). Experiments to test the approach are conducted in a laboratory environment using a RGB-D sensor package mounted onto the end-effector of a robot manipulator. A naive Bayes classifier trained with texture features extracted from Gray Level Co-occurrence Matrices is used to demonstrate the effect of image capture conditions on surface classification accuracy. Experimental results show that the classifiable regions identified using a likelihood map are up to 99.0% accurate, and the identified region has up to 19.9% higher classification accuracy when compared against the overall accuracy of the same image.
Tong, LY & Luo, QT 2016, 'Design of cellular structures with multi-volume fractions using topology optimization', Jisuan Lixue Xuebao/Chinese Journal of Computational Mechanics, vol. 33, no. 4, pp. 516-521.
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This study presents a method for finding optimum topology of cellular structure made from one material using an appropriate addition manufacturing process and tailored with different volume fractions in different structural domains. The topology optimization problem is firstly formulated allowing multi-volume fractions in cellular structures. An algorithm based on MIS T with multi-thresholds is presented and interfaced with commercial finite element analysis software. Numerical examples for the minimum mean compliance problem with three volume fractions are presented to illustrate the present algorithm. The present numerical results show that, for the optimum topology design with three volume fractions, there exists an optimum combination that yields an additional 10% reduction in the minimum mean compliance when compared to the design with two volume fractions.
Trianni, A, Cagno, E & Farné, S 2016, 'Barriers, drivers and decision-making process for industrial energy efficiency: A broad study among manufacturing small and medium-sized enterprises', Applied Energy, vol. 162, pp. 1537-1551.
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Energy efficiency has been recognized as a primary means to increase the competitiveness of the industrial sector, and in particular for small and medium-sized enterprises (SMEs), in which energy efficiency measures (EEMs) are scarcely implemented. For this reason, future policies should carefully address such issue. Hence, it is really crucial to have a precise and punctual knowledge of the barriers to be tackled in the decision-making process of adopting an EEM and the drivers to be promoted. This study discussed the findings from a broad investigation within 222 manufacturing SMEs located in a Northern Italy region. Beside economic issues particularly affecting SMEs, awareness and behavioural issues emerge as critical, affecting the very first steps of the decision-making process, related to the punctual identification and evaluation of plausible EEMs. The support from manufacturers, technology suppliers, installers and ESCOs supporting SMEs through vocational training drivers (e.g. technical support) is really important to tackle such issues. More generally, beside financial institutions, the supply chain of technologies is recognized as particularly useful for supporting enterprises in the adoption of EEMs. Additionally, having previously conducted energy audit and implemented EEMs are critical factors able to highlight non-economic barriers and drivers. Therefore, the promotion of EEMs will necessarily imply a further effort in pointing out the so-called non-energy benefits (NEBs) from the implementation of EEMs. Finally, our study reveals that smaller and non-energy intensive emerge as most critical and therefore deserve greater attention from policy-makers.
Tso, I, Zhang, S, Tan, W, Peng, P & Blamires, SJ 2016, 'Prey Luring Coloration of A Nocturnal Semi‐Aquatic Predator', Ethology, vol. 122, no. 8, pp. 671-681.
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AbstractBody coloration serves a variety of purposes in animals. Diurnal and nocturnal predators such as spiders may use their body coloration to lure prey. We predicted here that the white patches on the forelegs on females of the nocturnal semi‐aquatic spider Dolomedes raptor lure prey, explaining why they are primarily displayed when the spider forages along the water edge. To test our prediction, we developed a color vision model assessing whether the patches are visible to pygmy grasshoppers, the spider's primary prey. We conducted a field experiment using cardboard dummies that resemble D. raptor in size, shape, and color, but with half of them lacking leg patches, and we staged interactions between pygmy grasshoppers and D. raptor with and without leg patches in a greenhouse. We found the white patches to be visible to grasshoppers. The dummies with white patches attracted more grasshopper prey than the dummies without the patches. Moreover, grasshoppers were more attracted to spiders when their white patches were present. Our results supported the hypothesis that the white patches of D. raptor lure prey. Our findings, nevertheless, could not be explained as the spider's body coloration acting as a sensory trap but it should not be ruled out. More studies on a wider range of predators and prey will give more meaningful insights into the co‐evolution of predatory lures and prey sensory modalities.
Ul Islam, S, Rahman, H, Ying, ZC & Saha, SC 2016, 'Comparison of wake structures and force measurements behind three side-by-side cylinders', Journal of the Brazilian Society of Mechanical Sciences and Engineering, vol. 38, no. 3, pp. 843-858.
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Vakiloroaya, V, Samali, B & Eager, D 2016, 'Performance prediction of a new integrated central cooling plant for energy efficiency and comfort enhancement', Building Services Engineering Research and Technology, vol. 37, no. 4, pp. 379-394.
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The effective design of an energy efficient heating, ventilation and air conditioning system is reliant on multiple components. Among others, the air-handling unit cooling coil and its ability to perform efficiently directly influences heating, ventilation and air conditioning system performance. This paper investigates the energy and thermal performance of a water-cooled central cooling plant when combined with a direct evaporative cooling system located between the cooling tower and cooling coil of the air-handling unit. The evaporative cooler uses the water made by cooling tower to reduce the temperature of the 100% ambient air. The cooled air then passes through the cooling coil. This paper will demonstrate a series of mathematical models of the system components and validate them against experimental results. For this purpose, the central cooling plant is extensively equipped with a number of sensors and instrumentation devices for experimentation and data collection. The influence of the evaporative cooler on the energy saving potential and thermal comfort of the central cooling plant is evaluated. The advantages of this proposed hybrid system rests with the fact that the refrigeration effect of the chiller’s evaporator is decreased, which causes reduction of compressor power consumption. Results show that the hybrid system can provide average monthly energy savings between 11% and 24%, while enhancing the comfort level inside the building. Practical application: With traditional heating, ventilation and air conditioning systems contributing to 40% of a building’s overall energy consumption, the public’s increasing reliance on them as a necessity rather than a luxury is an issue in urgent need of attention. This together with a growing demand for cost-effective infrastructure and appliances has necessitated new installations and major retrofits in occupied buildings to achieve energy efficiency and environmental sustaina...
Vander Poorten, E, Tran, P, Devreker, A, Gruijthuijsen, C, Portoles-Diez, S, Smoljkic, G, Strbac, V, Famaey, N, Reynaerts, D, Vander Sloten, J, Tibebu, A, Yu, B, Rauch, C, Bernard, F, Kassahun, Y, Metzen, JH, Giannarou, S, Zhao, L, Lee, S, Yang, G, Mazomenos, E, Chang, P, Stoyanov, D, Kvasnytsia, M, Van Deun, J, Verhoelst, E, Sette, M, Di Iasio, A, Leo, G, Hertner, F, Scherly, D, Chelini, L, Häni, N, Seatovic, D, Rosa, B, De Praetere, H & Herijgers, P 2016, 'Cognitive AutonomouS CAtheters Operating in Dynamic Environments', Journal of Medical Robotics Research, vol. 01, no. 03, pp. 1640011-1640011.
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Advances in miniaturized surgical instrumentation are key to less demanding and safer medical interventions. In cardiovascular procedures interventionalists turn towards catheter-based interventions, treating patients considered unfit for more invasive approaches. A positive outcome is not guaranteed. The risk for calcium dislodgement, tissue damage or even vessel rupture cannot be eliminated when instruments are maneuvered through fragile and diseased vessels. This paper reports on the progress made in terms of catheter design, vessel reconstruction, catheter shape modeling, surgical skill analysis, decision making and control. These efforts are geared towards the development of the necessary technology to autonomously steer catheters through the vasculature, a target of the EU-funded project Cognitive AutonomouS CAtheters operating in Dynamic Environments (CASCADE). Whereas autonomous placement of an aortic valve implant forms the ultimate and concrete goal, the technology of individual building blocks to reach such ambitious goal is expected to be much sooner impacting and assisting interventionalists in their daily clinical practice.
Wang, Y, Huang, S, Xiong, R & Wu, J 2016, 'A framework for multi-session RGBD SLAM in low dynamic workspace environment', CAAI Transactions on Intelligence Technology, vol. 1, no. 1, pp. 90-103.
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Weisner, K, Knittel, M, Enderlein, H, Wischniewski, S, Jaitner, T, Kuhlang, P & Deuse, J 2016, 'Assistenzsystem zur Individualisierung der Arbeitsgestaltung', Zeitschrift für wirtschaftlichen Fabrikbetrieb, vol. 111, no. 10, pp. 598-601.
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Kurzfassung Zur Bewältigung der steigenden Produkt- und Prozessdiversifizierung ist die menschliche Arbeit für produzierende Unternehmen weiterhin von zentraler Bedeutung. Wesentliche Herausforderung sind in diesem Kontext die demografische Entwicklung und die damit verbundene hohe inter- und intraindividuelle Streuung der Fähigkeiten der Beschäftigten. Im Rahmen einer menschengerechten Arbeitsgestaltung ist daher die Entwicklung innovativer Assistenzsysteme zur zielgerichteten Unterstützung der Beschäftigten zu diskutieren bzw. zu erarbeiten.
Whyte, T, Gibson, T, Anderson, R, Eager, D & Milthorpe, B 2016, 'Mechanisms of Head and Neck Injuries Sustained by Helmeted Motorcyclists in Fatal Real-World Crashes: Analysis of 47 In-Depth Cases', Journal of Neurotrauma, vol. 33, no. 19, pp. 1802-1807.
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Copyright © 2016, Mary Ann Liebert, Inc. Despite an improved understanding of traumatic head and neck injury mechanisms, the impact tests required by major motorcycle helmet standards have remained unchanged for decades. Development of new test methods must reflect the specific impact loads causing injury in real crashes as well as test criteria appropriate for the observed injury profiles. This study analysed a collection of in-depth crash investigations of fatally injured helmeted riders in the Adelaide metropolitan region between 1983 and 1994 inclusive to review the head and neck injury patterns that resulted from specific types of impact. Inertial brain injury was sustained in 49% of examined cases, most often resulting from facial impacts but also in a large proportion of tangential, run over, and occipital impact cases. Focal brain and brainstem injury was also common (53%) and regularly associated with skull vault (11/12) and skull base fractures (22/31). Prevention of these fractures in impacts outside the area of required protection and in impacts with a straight edge would provide a significant increase in helmeted rider protection. Cervical spinal cord injury was sustained in facial, straight edge, and tangential impacts on the head. Motorcycle helmets are effective for preventing local skull fractures in impacts for which they are designed, whereas other serious injuries such as basilar skull fracture (BSF) and inertial brain injury persist despite helmet protection. Further impact test procedures should be developed for injurious impact types not currently assessed by major helmet standards, in particular facial impacts, and using test criteria based on commonly observed injuries. This study provides the necessary link, from impact load to injury, for guiding impact test development.
Whyte, T, Gibson, T, Eager, D & Milthorpe, B 2016, 'Response of a full-face motorcycle helmet FE model to the UNECE 22.05 chin bar impact test', International Journal of Crashworthiness, vol. 21, no. 6, pp. 555-565.
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© 2016 Informa UK Limited, trading as Taylor & Francis Group. This study investigates the role of full-face motorcycle helmet components in reducing the severity of chin bar impacts to a motorcyclist. A finite element helmet model was created for chin bar impacts by carrying out component tests on the chin bar padding, helmet shell and the chinstrap. Addition of two composite layers to the chin bar, stiffening the shell, reduced the peak headform centre of gravity acceleration from 168.3 g to 122.6 g in the UNECE 22.05 chin bar impact test configuration. The presence of chin bar foam was necessary to avoid excessive headform responses but optimal foam stiffness was dependent on shell stiffness. The lowest peak headform acceleration of 113.1 g was achieved by stiffening the helmet shell and softening the chin bar foam padding in comparison to the validated helmet model. The chinstrap was also critical, causing peak acceleration increases of 27.3 g and 118 g when slightly loose and absent, respectively. The significance of the shell and chinstrap in chin bar impacts is in contrast to cranial helmet impacts which are predominantly controlled by the crushable foam liner. The fact that chinstrap pre-test tightness influences the headform acceleration response is important for the helmet test technician.
Wiegand, M, Stolpe, M, Deuse, J & Morik, K 2016, 'Prädiktive Prozessüberwachung auf Basis verteilt erfasster Sensordaten', at - Automatisierungstechnik, vol. 64, no. 7, pp. 521-533.
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Zusammenfassung In diesem Beitrag wird ein Konzept zur prädiktiven Prozessüberwachung in Fließlinien vorgestellt, das durch die Auswertungverteilt erfasster Sensordaten mithilfe maschineller Lernverfahren die Prognose der finalen Produktqualität im laufendenProduktionsprozess erlaubt. Hierzu wird eine systematische Vorgehensweise zur Datenvorverarbeitung und -analysevorgeschlagen, die eine echtzeitfähige Verarbeitung der verteilt erfassten Daten ermöglicht.
Willis, A, Robinson, C, Thien, D & Askins, K 2016, 'Preface', Emotion, Space and Society, vol. 18, pp. 27-27.
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Wu, J, Gao, J, Luo, Z & Brown, T 2016, 'Robust topology optimization for structures under interval uncertainty', Advances in Engineering Software, vol. 99, pp. 36-48.
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© 2016 Elsevier Ltd. All rights reserved. This paper proposes a new non-probabilistic robust topology optimization approach for structures under interval uncertainty, as a complementarity of the probabilistic robust topology optimization methods. Firstly, to avoid the nested double-loop optimization procedure that is time consuming in computations, the interval arithmetic is introduced to estimate the bounds of the interval objective function and formulate the design problem under the worst scenario. Secondly, a type of non-intrusive method using the Chebyshev interval inclusion function is established to implement the interval arithmetic. Finally, a new sensitivity analysis method is developed to evaluate the design sensitivities for objective functions like structural mean compliance with respect to interval uncertainty. It can overcome the difficulty due to non-differentiability of intervals and enable the direct application of gradient-based optimization algorithms, e.g. the Method of Moving Asymptotes (MMA), to the interval uncertain topology optimization problems. Several examples are used to demonstrate the effectiveness of the proposed method.
Wu, J, Luo, Z, Zhang, N & Zhang, Y 2016, 'Dynamic computation of flexible multibody system with uncertain material properties', Nonlinear Dynamics, vol. 85, no. 2, pp. 1231-1254.
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© 2016, Springer Science+Business Media Dordrecht. Based on the theory of Absolute Nodal Coordinate Formulation, this paper proposes a new dynamic computation method to solve the flexible multibody system with uncertain material properties (Young’s modulus and Poisson’s ratio) that may be induced by the material asymmetric distribution. Rather than traditionally considering an uncertain factor as one single variable in the whole system, the material properties vary continuously in the space domain so that they are described by the random field, which is then discretized to countable random variables using the expansion optimization linear estimation method. The uncertain response of the system is approximated by the Polynomial Chaos expansion, numerically implemented by a collocation method. We propose and prove an important theory that the collocation method provides the same results as the Gaussian quadrature formula if the roots of the corresponding orthogonal polynomials are used as the collocation points. As a result, the proposed method is a nonintrusive technique that does not modify the original solver but only adds a preprocess and a postprocess. The uncertain displacement of system is finally illustrated by ellipse and ellipsoid, which visually shows the uncertainty extent and correlation between different coordinates. The numerical examples show that the proposed method has almost an equivalent accuracy of Monte Carlo simulation but much higher efficiency.
Wu, J, Luo, Z, Zheng, J & Jiang, C 2016, 'Incremental modeling of a new high-order polynomial surrogate model', Applied Mathematical Modelling, vol. 40, no. 7-8, pp. 4681-4699.
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© 2015. This study will develop a new high-order polynomial surrogate model (HOPSM) to overcome routines of expensive computer simulations in engineering. The proposed HOPSM is expected to keep advantages of the traditional low-order polynomial models in efficiency, transparency and simplicity, while avoid their disadvantage in accuracy. The zeros of Chebyshev polynomials having the highest allowable order will be utilized as the sampling candidates to improve stability and accuracy of the approximation. In the numerical process, a space-filling scheme is used to generate the initial set of samples, and then an incremental method based on the maximin principle is established to select more samples from all candidates. At the same time, the order of HOPSM is sequentially updated by using an order incremental scheme, to adaptively increase the polynomial order along with the increase of the sample size. After the order increment, the polynomial with the largest adjusted R-square is determined as the final HOPSM. Several typical test functions and two engineering applications are used to demonstrate the effectiveness of the proposed surrogate modeling method.
Xie, Q, Zhang, N, Zhang, B & Ji, J 2016, 'Boundary condition handling approaches for the model reduction of a vehicle frame', MECHANICAL SYSTEMS AND SIGNAL PROCESSING, vol. 75, pp. 123-137.
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© © 2016 Elsevier Ltd. All rights reserved. In order to apply model reduction technique to improve the computational efficiency for the large-scale FEM model of a vehicle, this paper presents the handling approaches for three widely-used boundary conditions, namely fixed boundary condition (FBC), prescribed motion (PSM) and coupling (COUP), respectively. It is found that iterated improved reduction system (IIRS) reduction method tends to generate better reduction approximation. Guyan method is not sensitive to the sequence of reduction and constraint under FBC, and can thus provide flexibility in handling different boundary conditions for the same system. As for PSM, 'constraint first' is recommended no matter which reduction method is used, and then separate reduction models can be coupled to form a new model with relative small dofs. By selecting appropriate master dofs for model reduction, the coupled model based on reduced models could produce same results as the original full one.
Xu, J, Gao, X, Jiang, Z & Wei, D 2016, 'A Comparison of Hot Deformation Behavior of High‐Cr White Cast Iron and High‐Cr White Cast Iron/Low Carbon Steel Laminate', steel research international, vol. 87, no. 6, pp. 780-788.
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In order to study the plastic deformation characteristics of the brittle high‐Cr white cast iron in upsetting process, and find out the mechanism for improving the formability of the cast iron within the laminated composite, the hot forging process of monolithic high‐Cr white cast iron and high‐Cr white cast iron/low carbon steel laminate is simulated by means of hot compression tests using Gleeble 3500 thermo mechanical simulator and professional plastic forming software DEFORM‐3D. The results reveal that during hot compression process, the monolithic cast iron suffered severe barreling and cracking, whereas the cast iron layer within the laminate underwent large plastic deformation with barreling‐free and crack‐free. Such a significant improvement can be attributed to the simultaneous deformation of the cast iron together with the low carbon steel claddings, which is beneficial to relieving the stress in the cast iron and changing its deformation mode. Under the triaxial compressive stress state, the brittle high‐Cr white cast iron within the laminate can flow like a ductile material at high temperatures and low strain rates.
Xu, J, Gao, X, Jiang, Z, Wei, D & Jiao, S 2016, 'Microstructure and hot deformation behaviour of high-carbon steel/low-carbon steel bimetal prepared by centrifugal composite casting', The International Journal of Advanced Manufacturing Technology, vol. 86, no. 1-4, pp. 817-827.
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Bimetal consisting of high-carbon steel and low-carbon steel was prepared by centrifugal composite casting, and thermo mechanical treatments were carried out by hot compression tests using Gleeble 3500 thermo mechanical simulator. The characteristics of microstructure and hot deformation behaviour of the bimetal were investigated. It is concluded that a sound metallurgical bond was achieved by micro mass transfer across the interface between the constituent steels. Four different microstructural regions (including low-carbon steel region, interface region, fully pearlitic region and pro-eutectoid ferritic/pearlitic region) with different mechanical properties were found, which resulted in heterogeneity of plastic deformation within the bimetal. Regardless of strain rate, the low-carbon steel layer preferentially extruded from the bimetal when deformation temperature was below 900 °C, whereas the extrusion was not observed at 900, 1000 and 1100 °C. This indicated that the high-carbon steel/low-carbon steel bimetal can be processed like monolithic material.
Yasin, MF, Cant, S & Arqam, M 2016, 'Validation of a benchmark methanol flame using Open FOAM', Journal of Advanced Research in Fluid Mechanics and Thermal Sciences, vol. 28, no. 1, pp. 7-16.
Yu, X, Jiang, Z, Zhao, J, Wei, D, Zhou, J, Zhou, C & Huang, Q 2016, 'The role of oxide-scale microtexture on tribological behaviour in the nanoparticle lubrication of hot rolling', Tribology International, vol. 93, pp. 190-201.
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Yu, XL, Jiang, ZY, Zhao, JW, Wei, DB & Zhou, J 2016, 'A Review of Microstructure and Microtexture of Tertiary Oxide Scale in a Hot Strip Mill', Key Engineering Materials, vol. 716, pp. 843-855.
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In hot rolling, metal oxides formed on steel surface can generally be classified as primary, secondary and tertiary oxide scales, corresponding to the reheating stages, the roughing stages and the finishing passes of continuous mills, respectively. The tertiary oxide scale grows into the final products on the hot-rolled steel strip during the finishing rolling and the subsequent cooling down to ambient temperature. We provide here a systematic overview of the oxidation mechanism, microstructure and microtexture development of the tertiary oxide scale. Mechanism of oxidation and Fe3O4 precipitation in tertiary oxide has been given as the fundamental theory. Three main sections has been divided in this review. The first section includes experimental investigations on microstructure evolution from the formation of oxide scale during hot rolling, then through continuous cooling, to Fe3O4 precipitation behaviour in storage cooling of hot-coiled strip. By using electron backscatter diffraction (EBSD) to characterise both the steel substrate and the oxide scale concurrently, the second section has further dealed with the texture-based analysis of oxide scale: phase identification, orientation analysis and coincident site lattice (CSL) boundaries. The third section has provided the general type of crystallographic texture and its evolutions in deformed Fe3O4 and steel substrate. Finally, the upcoming challenges have been addressed in this intriguing and promising research field.
Zhang, Z, Halkon, B, Chou, SM & Qu, X 2016, 'A novel phase-aligned analysis on motion patterns of table tennis strokes', International Journal of Performance Analysis in Sport, vol. 16, no. 1, pp. 305-316.
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© 2016, Routledge. All rights reserved. A wide range of human motion represent repetitive patterns particularly in racket sports. Quantitative analysis of the continuous variables during the different phases of the motion cycle helps to investigate more deeply the specific movement of the racket or player. Table tennis biomechanics research to date lacks the necessary detail of phase decomposition and phase-based quantitative analysis. Therefore, this study proposes a novel velocity-based piecewise alignment method to identify the different phases of a table tennis forehand stroke. A controlled experiment was conducted on a number of players of two differing ability levels (experts vs. novices) to implement this novel methodology. Detailed results are shown for the quantitative analysis on multiple strokes of the two groups of participants. Significant differences were found in both the displacement and velocity of the racket movement in the backswing, forward swing and follow-through phases. For example, it is clear that experts’ strokes show higher racket resultant velocity than novices during both the forward swing and follow-through phases by up to a factor of two. Furthermore, the phase-based approach to analysing racket motions leads to interrogation over a greater duration than the traditional time-based method which is generally only concerned with impact ±0.25s.
Zhang, Z, Oberst, S & Lai, JCS 2016, 'Instability analysis of friction oscillators with uncertainty in the friction law distribution', Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, vol. 230, no. 6, pp. 948-958.
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Despite substantial research efforts in the past two decades, the prediction of brake squeal propensity, as a significant noise, vibration and harshness (NVH) issue to automotive manufactures, is as difficult as ever. This is due to the complexity of the interacting mechanisms (e.g. stick-slip, sprag-slip, mode coupling and hammering effect) and the uncertain operating conditions (temperature, pressure). In particular, two major aspects in brake squeal have attracted significant attention recently: nonlinearity and uncertainty. The fugitiveness of brake squeal could be attributed to a number of factors including the difficulty in accurately modelling friction. In this paper, the influence of the uncertainty arising from the tribological aspect in brake squeal prediction is analysed. Three types of friction models, namely the Amonton-Coulomb model, the velocity-dependent model and the LuGre model, are randomly assigned to a group of interconnected oscillators which model the dynamics of a brake system. The complex eigenvalue analysis, as a standard stability analysis tool, and the friction work calculation are performed to investigate the probability for instability arising from the uncertainty in the friction models. The results are discussed with a view to apply this approach to the analysis of the squeal propensity for a full brake system.
Zhang, Z, Oberst, S & Lai, JCS 2016, 'On the potential of uncertainty analysis for prediction of brake squeal propensity', Journal of Sound and Vibration, vol. 377, pp. 123-132.
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Zhao, J, Zhang, N & Ji, N 2016, 'Steady-state response of fluid-structure interactions in hydraulic piping system of passive interconnected suspensions', International Journal of Vehicle Design, vol. 72, no. 4, pp. 305-305.
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Copyright © 2016 Inderscience Enterprises Ltd. Pressure changes in the liquid-filled fluid circuit of a hydraulically interconnected suspension (HIS) system can induce vibrations of the whole pipeline and the associated structure, and hence become a source of structural noise which degrades ride comfort. This paper presents a numerical and experimental investigation into the vibration of the hydraulic piping system of a passive interconnected suspension. The transfer matrix method (TMM) is used to develop a mathematical model, which consists of various pipe sections, hose sections, concentrated masses, spring supports, elbows, damper valves, and accumulators. Laboratory experiments are performed on two liquid-filled piping systems. The measured steady-state responses of the hydraulic circuits are compared with those obtained from numerical simulations of the developed model. It is found that the developed model of the hydraulic system has a reasonable accuracy in the frequency range of interest, and thus can be employed to optimise the design of the hydraulic system.
Zhao, L, Giannarou, S, Lee, S-L & Yang, G-Z 2016, 'SCEM+: Real-Time Robust Simultaneous Catheter and Environment Modeling for Endovascular Navigation', IEEE Robotics and Automation Letters, vol. 1, no. 2, pp. 961-968.
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Endovascular procedures are characterised by significant challenges mainly due to the complexity in catheter control and navigation. Real-time recovery of the 3-D structure of the vasculature is necessary to visualise the interaction between the catheter and its surrounding environment to facilitate catheter manipulations. State-of-the-art intraoperative vessel reconstruction approaches are increasingly relying on nonionising imaging techniques such as optical coherence tomography (OCT) and intravascular ultrasound (IVUS). To enable accurate recovery of vessel structures and to deal with sensing errors and abrupt catheter motions, this letter presents a robust and real-time vessel reconstruction scheme for endovascular navigation based on IVUS and electromagnetic (EM) tracking. It is formulated as a nonlinear optimisation problem, which considers the uncertainty in both the IVUS contour and the EM pose, as well as vessel morphology provided by preoperative data. Detailed phantom validation is performed and the results demonstrate the potential clinical value of the technique.
Zhao, L, Ji, J, Liu, J, Wu, Q & Zhou, J 2016, 'Tracking task-space synchronization of networked Lagrangian systems with switching topology', NONLINEAR DYNAMICS, vol. 83, no. 3, pp. 1673-1685.
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Zhao, M & Ji, J 2016, 'Dynamic Analysis of Wind Turbine Gearbox Components', ENERGIES, vol. 9, no. 2.
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Zhao, S, Cheng, E, Qiu, X, Burnett, I & Liu, JC-C 2016, 'Pressure spectra in turbulent flows in the inertial and the dissipation ranges', The Journal of the Acoustical Society of America, vol. 140, no. 6, pp. 4178-4182.
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Based on existing studies that provide the pressure spectra in turbulent flows from the asymptotic pressure structure function in the inertial range, this paper extends the pressure spectrum to the dissipation range by proposing a pressure structure function model that incorporates both the inertial and dissipation ranges. Existing experiment results were used to validate the proposed pressure structure function model first, and then the obtained pressure spectrum was compared with the simulation and measurement data in the literature and the wind-induced noise measured outdoors. All comparisons demonstrate that the pressure spectrum obtained from the proposed pressure structure function model can be used to estimate the pressure spectra in both the inertial and dissipation ranges in turbulent flows with a sufficiently large Reynolds number.
Abdo, P, Huynh, BP, Avakian, V, Nguyen, T, Gammon, J, Torpy, FR & Irga, PJ 1970, 'Measurement of air flow through a green-wall module', Proceedings of the 20th Australasian Fluid Mechanics Conference, AFMC 2016, Australasian Fluid Mechanics Conference, Australasian Fluid Mechanics Society, Perth.
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© 2006 Australasian Fluid Mechanics Society. All rights reserved. Green or living walls are active bio-filters developed to enhance air quality. Often, these walls form the base from which plants are grown; and the plant-wall system helps to remove both gaseous and particulate air pollutants. A green wall can be found indoors as well as outdoors, and could be assembled from modules in an arrangement similar to tiling. Measurement of air flow through such a module has been conducted in this work. The module is essentially a rectangular plastic box (dimensions about 500 mm x 500 mm x 130 mm) that holds a permeable bag containing a plant-growing medium (replacement for soil). The front face of the module has multiple openings for plants to protrude out from the bag inside. Plant roots are imbedded in the medium. A fan positioned at a central opening on the module‟s back face drives air through the medium-plant-roots mix and then onward through the plants‟ canopy; and these would help to remove both gaseous and particulate pollutants from the air. Drip-irrigation water is dispensed from a tube running along the open top-face of the module. The module has also a small drainage hole on its bottom face. Pressure drop across the module, air-flow distribution through it as well as flow rate have been obtained, in terms of variable parameters which include moisture content, growing-medium-plant-roots mix and plant type. The measurements help to determine the pattern of flow resistances which in turn will be used in a future CFD (Computational Fluid Dynamics) analysis for improving the design of the module, such that more appropriate flow distribution and flow rate would be achieved. All this is in addition to the better understanding of air flow through complex moist porous media.
Abeywardena, D, Shoudong Huang, Barnes, B, Dissanayake, G & Kodagoda, S 1970, 'Fast, on-board, model-aided visual-inertial odometry system for quadrotor micro aerial vehicles', 2016 IEEE International Conference on Robotics and Automation (ICRA), 2016 IEEE International Conference on Robotics and Automation (ICRA), IEEE, Stockholm, Sweden, pp. 1530-1537.
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© 2016 IEEE. The main contribution of this paper is a high frequency, low-complexity, on-board visual-inertial odometry system for quadrotor micro air vehicles. The system consists of an extended Kalman filter (EKF) based state estimation algorithm that fuses information from a low cost MEMS inertial measurement unit acquired at 200Hz and VGA resolution images from a monocular camera at 50Hz. The dynamic model describing the quadrotor motion is employed in the estimation algorithm as a third source of information. Visual information is incorporated into the EKF by enforcing the epipolar constraint on features tracked between image pairs, avoiding the need to explicitly estimate the location of the tracked environmental features. Combined use of the dynamic model and epipolar constraints makes it possible to obtain drift free velocity and attitude estimates in the presence of both accelerometer and gyroscope biases. A strategy to deal with the unobservability that arises when the quadrotor is in hover is also provided. Experimental data from a real-time implementation of the system on a 50 gram embedded computer are presented in addition to the simulations to demonstrate the efficacy of the proposed system.
Alambeigi, P, Zhao, S, Burry, J & Qiu, X 1970, 'Complex human auditory perception and simulated sound performance prediction', CAADRIA proceedings, CAADRIA 2016: Living Systems and Micro-Utopias - Towards Continuous Designing, CAADRIA, Hong Kong, China, pp. 631-640.
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© 2016, The Association for Computer-Aided Architectural Design Research in Asia (CAADRIA), Hong Kong. This paper reports an investigation into the degree of consistency between three different methods of sound performance evaluation through studying the performance of a built project as a case study. The non-controlled office environment with natural human speech as a source was selected for the subjective experiment and ODEON room acoustics modelling software was applied for digital simulation. The results indicate that although each participant may interpret and perceive sound in a particular way, the simulation can predict this complexity to some extent to help architects in designing acoustically better spaces. Also the results imply that architects can make valid comparative evaluations of their designs in an architecturally intuitive way, using architectural language. The research acknowledges that complicated engineering approaches to subjective analysis and to controlling the test environment and participants is difficult for architects to comprehend and implement.
Al-Widyan, F, Kirchner, N, Al-Ani, A & Zeibots, M 1970, 'A bottleneck investigation at escalator entry at the Brisbane central train station', ATRF 2016 - Australasian Transport Research Forum 2016, Proceedings, Australasian Transport Research Forum, ATRF, Melbourne, Australia, pp. 1-9.
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Escalators are an essential for passenger’s movements through multi-level rail station concourse environments. Despite the access benefits that escalators provide, they can make travel time longer and pose some challenges when bottlenecks appear at entry. Studying the passenger behaviour of bottlenecks at escalator entrances is essential for planning, designing and control of engineering transportation systems. In this paper we investigate passenger route choice behaviour while approaching an escalator-stair infrastructure set at Brisbane Central train station. A model of an escalator entry bottleneck is formulated. The developed model can explain the queuing characteristics of the bottlenecks and can be readily used to predict congested state occurrence at escalator entry bottleneck. Accurate prediction of bottlenecks occurring around escalators and the estimation of escalator capacity are obtained based on real field data collected from Brisbane Central train station. Results have provided significant insights and computational tools for understanding many features of escalator bottlenecks. Remarkably, escalator capacity at bottleneck points affects the duration and severity of the congested period.
Al-Zubaydi, AYT, Hong, G & Dartnall, WJ 1970, 'CFD Modelling and Analysis of Different Designs Plate Heat Exchangers', Proceedings of the 10th Australasian Heat and Mass Transfer Conference, Australasian Heat and Mass Transfer Conference, Queensland University of Technology, Brisbane, Australia, pp. 145-152.
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The indirect evaporative cooling system and heat recovery system utilize the return (secondary) air to condition the fresh (primary) air by means of air-to-air heat exchange between the two streams. The temperature difference between the primary and secondary air streams in indirect evaporative cooling system is relatively small. Therefore, efficient heat exchangers should be used since they play a major role in the overall system performance and economics. The parallel plate type heat exchangers have been widely adopted in Indirect Evaporative Cooling (IEC) systems due to their high efficiency in operating at small temperature difference. In this paper we present a theoretical analysis of different designs of counter flow aluminium plate type heat exchanger and results of CFD analysis of pressure drop, flow velocity and thermal effectiveness. For improving the heat transfer between the plates and minimizing the energy loss, the analysis proves useful in the optimization method for selecting parameters of the plate heat exchangers.
Ang, KCS & Killen, C 1970, 'Multi-stakeholder perspectives of value in project portfolios', Proceedings of EURAM 2016, 16th Annual Conference of the European Academy of Management (Euram) Conference 2016, European Research and Management Conference 2016, Paris.
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Organisations invest in projects to create value. One of the key goals of managing multiple projects from a project portfolio perspective is to maximise this value across the portfolio. The value generated by projects has long been understood to be more than just the direct financial value, and researchers are actively working on extending the understanding of value for project portfolio management (PPM) environments. However, value is a complex phenomenon – value is not a fixed entity, but rather it varies in the ways it is perceived by each stakeholder, and in how value perceptions are translated into practice. This paper explores practices forunderstanding value by different stakeholders in various contexts and identifies seven perspectives through which value is identified in project portfolio environments. A typology of value perspectives is presented that aims to guide and improve practice by extending the range of values that are perceived, anticipated and considered for PPM decision making.
Bai, F, Huang, S, Vidal-Calleja, T & Zhang, Q 1970, 'Incremental SQP method for constrained optimization formulation in SLAM', 2016 14th International Conference on Control, Automation, Robotics and Vision (ICARCV), 2016 14th International Conference on Control, Automation, Robotics and Vision (ICARCV), IEEE, Phuket, Thailand.
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© 2016 IEEE. The simultaneous localization and mapping (SLAM) problem has been a research focus for many years and have reached a mature state. However, more robust solutions to the SLAM problem are still required, especially in large noise level scenarios. Because of the strong non-linearity of the SLAM problem, it is vital to start from a good initial value to avoid being trapped in local minima. In this paper, we propose a new SLAM formulation transforming the unconstrained Least Squares formulation into a constrained optimization problem. Algorithms based on this new formulation can naturally start from good initial value. Different from other constrained optimization problem, this new formulation can be efficiently solved with Sequential Quadratic Programming (SQP) methods. Based on SQP, we propose an incremental SQP algorithm to solve SLAM, which shows great advantage over Gauss Newton (g2o implementation) when working in large noise level scenarios. Experimental results show the validity of the proposed approach.
Barthelmey, A, Lenkenhof, K, Schallow, J, Lemmerz, K, Deuse, J & Kuhlenkötter, B 1970, 'Technical Documentation as a Service – An Approach for Integrating Editorial and Engineering Processes of Machinery and Plant Engineers', Procedia CIRP, Elsevier BV, pp. 167-172.
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© 2016 The Authors. Delivery of technical documentation of manufacturing facilities is still mandatory for machinery and plant engineers as part of the compliance with legal regulations. In addition, current research and development indicate that digital technical documentation can be used as informative support for operating staff if contents are provided context-sensitive. Despite the importance and potentials of technical documentation for the engineering process, an integration of editorial staff into this process is not state of the art. In this paper the authors propose a reference implementation for technical documentation developed within the collaborative research project Cyber System Connector in order to fill this gap both technically and organizationally. The aim is to redesign technical documentation into a service for all participants in product and production development. This new approach is based on a CPS-supported process of creating technical documentation and a virtual representation which serves as a platform for knowledge management in machinery and plant engineering. The benefits of implementing the proposed documentation strategy along the supply chain of manufacturing facilities are depicted by chosen application scenarios.
Best, G & Fitch, R 1970, 'Probabilistic maximum set cover with path constraints for informative path planning', Australasian Conference on Robotics and Automation, ACRA, Australasian Conference on Robotics and Automation, ARAA, Brisbane, Australia, pp. 97-106.
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We pose a new formulation for informative path planning problems as a generalisation of the well-known maximum set cover problem. This new formulation adds path constraints and travel costs, as well as a probabilistic observation model, to the maximum set cover problem. Our motivation is informative path planning applications where the observation model can be naturally encoded as overlapping subsets of a set of discrete elements. These elements may include features, landmarks, regions, targets or more abstract quantities, that the robot aims to observe while moving through the environment with a given travel budget. This formulation allows directly modelling the dependencies of observations from different viewpoints. We show this problem is NP-hard and propose a branch and bound tree search algorithm. Simulated experiments empirically evaluate the bounding heuristics, several tree expansion policies and convergence rate towards optimal. The tree pruning allows finding optimal or bounded-approximate solutions in a reasonable amount of time, and therefore indicates our work is suitable for practical applications.
Best, G, Faigl, J & Fitch, R 1970, 'Multi-robot path planning for budgeted active perception with self-organising maps', 2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), IEEE, Daejeon, Korea, pp. 3164-3171.
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© 2016 IEEE. We propose a self-organising map (SOM) algorithm as a solution to a new multi-goal path planning problem for active perception and data collection tasks. We optimise paths for a multi-robot team that aims to maximally observe a set of nodes in the environment. The selected nodes are observed by visiting associated viewpoint regions defined by a sensor model. The key problem characteristics are that the viewpoint regions are overlapping polygonal continuous regions, each node has an observation reward, and the robots are constrained by travel budgets. The SOM algorithm jointly selects and allocates nodes to the robots and finds favourable sequences of sensing locations. The algorithm has polynomial-bounded runtime independent of the number of robots. We demonstrate feasibility for the active perception task of observing a set of 3D objects. The viewpoint regions consider sensing ranges and self-occlusions, and the rewards are measured as discriminability in the ensemble of shape functions feature space. Simulations were performed using a 3D point cloud dataset from a real robot in a large outdoor environment. Our results show the proposed methods enable multi-robot planning for budgeted active perception tasks with continuous sets of candidate viewpoints and long planning horizons.
Bhowmick, S, Xu, F & Saha, SC 1970, 'Transient natural convection in a valley shaped triangular cavity initially filled with stratified water', AIP Conference Proceedings, INTERNATIONAL CONFERENCE ON MECHANICAL ENGINEERING: Proceedings of the 11th International Conference on Mechanical Engineering (ICME 2015), Author(s), Bangladesh Univ Engn & Technol, Dhaka, BANGLADESH.
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Bykerk, L, Liu, D & Waldron, K 1970, 'A topology optimisation based design of a compliant gripper for grasping objects with irregular shapes', 2016 IEEE International Conference on Advanced Intelligent Mechatronics (AIM), 2016 IEEE International Conference on Advanced Intelligent Mechatronics (AIM), IEEE, Banff, Canada, pp. 383-388.
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© 2016 IEEE. Complex steel structures such as power transmission towers require regular inspection and maintenance during their lifetime. This work is currently completed by teams of human workers who climb the live structures. The exposure of these workers to the risks of climbing and completing work on towers provides motivation for developing a robotic substitute. There are many complex elements of climbing power transmission towers, such as the variation in beam shapes, sizes and orientations. To the best of our knowledge, there is no existing robotic grasping solution that can be directly used in this complex environment. This paper presents a topology optimisation based design of a compliant gripper for grasping objects with irregular shapes such as the beam members found in power transmission towers. The structure of the gripper is obtained through the use of a modified topology optimisation model where stiffness constraints are implemented in the optimisation to increase the strength of the gripper in desired areas. The stiffness constrained topology optimisation produces a novel gripper design which is validated through both simulations and physical testing of the manufactured gripper on a variety of physical objects.
Cagno, E, Moschetta, D & Trianni, A 1970, 'Only non-energy benefits when adopting an EEM? Cases from industry', Eceee Industrial Summer Study Proceedings, pp. 281-292.
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Considering the industry's contribution to energy and environmental issues, industrial energy efficiency is recognized as a fundamental step for increased sustainability. Energy efficiency in industry is achieved through the adoption of the so-called Energy Efficiency Measures (EEMs). Traditionally, it has been demonstrated how these interventions have both energy benefits, as the reduction of the energy consumption, and the so-called Non-Energy Benefits (NEBs) deriving from the adoption of a certain measure. In the existing literature, however, a considerable part of the scholars and of the practitioners just focus on the identification and definition of the positive benefits deriving from these measures after they have been completely adopted, thus neglecting to describe the full set of either positive and negative effects. Nevertheless, recently, the description of these effects has been accomplished exploiting different approaches. Thus, on the basis of previous literature studies and the emerging needs, that affect both the definition of the entire range of effects and the point of view adopted in their description, we have proposed a novel classification of the relevant items to be considered by an industrial decision-maker when deciding whether to adopt an EEM. Hence, by taking this perspective, we have investigated benefits and losses to ad-hoc selected industries where, through an interview, already adopted EEMs have been analysed. Finally, considerations and implications are drawn from the case studies and suggestion for further research are proposed, in order to improve the description of the EEMs in the industrial sector.
Christensen, J, Rasmussen, J, Halkon, B & Koike, S 1970, 'The Development of a Methodology to Determine the Relationship in Grip Size and Pressure to Racket Head Speed in a Tennis Forehand Stroke', Procedia Engineering, 11th Conference of the International Sports Engineering Association (ISEA), Elsevier BV, Delft, NETHERLANDS, pp. 787-792.
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© 2016 The Authors. Published by Elsevier Ltd. This study developed a methodology to examine the effects of grip size and grip firmness on the kinematic contribution of angular velocity (KCAV) to the generation of racket head speed during a topspin tennis forehand. The KCAV is subdivided into kinematic contribution of joint angular velocity and kinematic contribution of the body segments in the upper trunk translational and angular velocities. Two Babolat Pure Storm GT rackets, with grip sizes 2 and 4 respectively, were used with Tekscan 9811E pressure sensors applied to the handles to examine pressure distribution during the stroke. Upper body kinematic data taken from the racket arm and trunk were obtained by means of a Vicon motion capture system. One elite male tennis player was recruited. Fifty topspin forehand strokes per grip at two nominal grip pressures were performed in a laboratory environment with balls being tossed towards the player and struck on the bounce towards a target on a net in as consistent a way as practically achievable. Processing of the results showed that the firm grip condition led to a significant (p<0.001) increase in average racket head speed compared to a normal grip condition. The normal gripping condition resulted in a significant (p<0.001) increase in average racket head speed for grip size 2 compared to grip size 4. A trend in negative linear relationships was found between upper trunk and shoulder joint in KCAV across conditions. Using the smaller grip also led to a trend in negative linear relationship between shoulder joint and wrist joint in KCAV across grip conditions. Grip pressure for grip size 2 showed the same pattern across gripping conditions. From 50-75% of completion in forward swing, the pressure difference due to grip firmness decreased. This feasibility study managed to quantify the KCAV while performing a topspin forehand, with respect to changing of grip size and grip pressure in an elite male tenni...
Clemon, LM 1970, 'Energy and emission estimation uncertainty in fused deposition modeling for a job-shop', Solid Freeform Fabrication 2016: Proceedings of the 27th Annual International Solid Freeform Fabrication Symposium - An Additive Manufacturing Conference, SFF 2016, Solid Freeform Fabrication Symposium – An Additive Manufacturing Conference, University of Texas, Austin, Texas USA, pp. 1878-1889.
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Solid freeform fabrication has the potential to affect both financial and environmental concerns for manufacturing enterprises. However, when planning for installation of a new machine tool, accurate energy usage estimation relies heavily on the data and model selections of the estimator. This project used a variety data sources and model decision options to examine the spread of energy consumption and global warming potential estimates for a fused deposition modeling machine. In addition to primary and secondary data sources, the use of similar machines was explored as proxy estimates for the target machine. A Monte Carlo simulation was constructed to vary the model selections, machine utilization, and data sources. The results indicated data sources and model decisions had large effects on the output and that most model estimates were low.
Croaker, P, Moreau, D, Karimi, M & Kessissoglou, N 1970, 'Low Mach number flow induced noise prediction of wall mounted airfoil using a hybrid RANS-BEM technique', 2nd Australasian Acoustical Societies Conference, ACOUSTICS 2016, Acoustics 2016, Brisbane, Australia, pp. 1149-1156.
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A hybrid RANS-BEM technique for the prediction of low Mach number flow induced noise produced by a body immersed in the flow is presented. A steady-state Reynolds Averaged Navier-Stokes (RANS) simulation is used to obtain turbulence statistics and mean flow data of the flow. Statistical noise sources are then determined from the mean flow and turbulence statistics by employing a model for the turbulence cross spectrum. These noise sources are then combined with a boundary element method (BEM) model of the body to predict the aeroacoustic scattering and the far-field noise. The hybrid RANS-BEM technique is applied to predict the flow-induced noise produced by flow past a wall mounted NACA0012 airfoil, with Reynolds number based on chord of Rec=1.1×106 and a Mach number of M=0.12 at zero angle of attack. The results are in good agreement with experimental results.
Deuse, J, Grötsch, A, Stankiewicz, L & Wischniewski, S 1970, 'A Customizable Digital Human Model for Assembly System Design', Advances in Intelligent Systems and Computing, Springer International Publishing, pp. 167-178.
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© Springer International Publishing Switzerland 2016. For a wholesome and comprehensive planning and design of future hybrid work systems and adaptive workplace assistance systems, several components of these systems are to be considered in detail. To ensure a human-centered and safe prospective planning and design process, these components need to be thoroughly investigated already in early stages of the simulation and virtual environment. In his context, especially the joint workplaces of humans and robots are of increasing importance for industrial assembly systems. For the planning process, existing software in Computer-Aided-Engineering (CAE) provides the possibility to incorporate the factor human by means of digital human models (DHMs) as well as robots by implementing e.g. robot trajectories, path planning and specific factory characteristics. Both partners show the potential to be incorporated in a simulation tool that accounts for the flexibility of robotic technology as well as the variability of the human body, anthropometrically and biomechanically. For an accurate description and simulation of a hybrid work system it is necessary to align the DHM individually to the employee’s anthropometric data and physical performance parameters. These data can be recorded with motion capturing methods and systems and serve as a basis for the human-centered design and planning process of adaptive work assistance in assembly systems and technologies.
Eager, D, Hayati, H & Chapman, C 1970, 'Impulse Force as an Additional Safety Criterion for Improving the Injury Prevention Performance of Impact Attenuation Surfaces in Children’s Playgrounds', Volume 14: Emerging Technologies; Materials: Genetics to Structures; Safety Engineering and Risk Analysis, ASME 2016 International Mechanical Engineering Congress and Exposition, American Society of Mechanical Engineers.
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More than four decades has passed since introducing safety standards for Impact Attenuation Surfacing (IAS) used in children’s playgrounds. Falls in children’s playgrounds is a major source of injuries and IAS is one of the best safety interventions deployed to reduce the incidence and severity of these injuries. Currently there are two criteria that measure the injury prevention performance of IAS, namely: Head Injury Criteria (HIC); and maximum acceleration (Gmax). Based on the ASTM playground safety standard F1292 the thresholds of HIC and Gmax are 1000 and 200g respectively. If the playground IAS complies with this Standard the number and severity of fall-related injuries in playgrounds should be decreased. However after implementing these standards a high number of children continue to be hospitalized due to fall-related playground injuries In this paper we tested ten samples based on ASTM F1292 standard to propose the introduction of an additional criterion to HIC and Gmax which can filter and remove hazardous IAS that technically comply with the current 1000 HIC and 200g safety thresholds. The proposed criterion is called the impulse force criterion (If) and combines the change of the momentum and the impact duration. The Gmax, HIC and If results are presented graphically and numerically.
Eager, D, Hayati, H & Chapman, C 1970, 'Impulse force as an additional safety criterion for improving the injury prevention performance of impact attenuation surfaces in children's playgrounds', ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE), International Mechanical Engineering Congress & Exposition, AMER SOC MECHANICAL ENGINEERS, Phoenix, Arizona, US.
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More than four decades has passed since introducing safety standards for Impact Attenuation Surfacing (IAS) used in children's playgrounds. Falls in children's playgrounds is a major source of injuries and IAS is one of the best safety interventions deployed to reduce the incidence and severity of these injuries. Currently there are two criteria that measure the injury prevention performance of IAS, namely: Head Injury Criteria (HIC); and maximum acceleration (Gmax). Based on the ASTM playground safety standard F1292 the thresholds of HIC and Gmax are 1000 and 200g respectively. If the playground IAS complies with this Standard the number and severity of fallrelated injuries in playgrounds should be decreased. However after implementing these standards a high number of children continue to be hospitalized due to fall-related playground injuries In this paper we tested ten samples based on ASTM F1292 standard to propose the introduction of an additional criterion to HIC and Gmax which can filter and remove hazardous IAS that technically comply with the current 1000 HIC and 200g safety thresholds. The proposed criterion is called the impulse force criterion (If) and combines the change of the momentum and the impact duration. The Gmax, HIC and If results are presented graphically and numerically.
Faigl, J, Penicka, R & Best, G 1970, 'Self-organizing map-based solution for the Orienteering problem with neighborhoods', 2016 IEEE International Conference on Systems, Man, and Cybernetics (SMC), 2016 IEEE International Conference on Systems, Man, and Cybernetics (SMC), IEEE.
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Falque, R, Vidal-Calleja, T, Dissanayake, G & Miro, JV 1970, 'From the Skin-Depth Equation to the Inverse RFEC Sensor Model', 2016 14th International Conference on Control, Automation, Robotics and Vision, ICARCV 2016, International Conference on Control, Automation, Robotics and Vision, IEEE, Phuket, Thailand.
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In this paper, we tackle the direct and inverse problems for the Remote-FieldEddy-Current (RFEC) technology. The direct problem is the sensor model, wheregiven the geometry the measurements are obtained. Conversely, the inverseproblem is where the geometry needs to be estimated given the fieldmeasurements. These problems are particularly important in the field ofNon-Destructive Testing (NDT) because they allow assessing the quality of thestructure monitored. We solve the direct problem in a parametric fashion usingLeast Absolute Shrinkage and Selection Operation (LASSO). The proposed inversemodel uses the parameters from the direct model to recover the thickness usingleast squares producing the optimal solution given the direct model. This studyis restricted to the 2D axisymmetric scenario. Both, direct and inverse models,are validated using a Finite Element Analysis (FEA) environment with realisticpipe profiles.
Ghosh, S, Zheng, Y, Lammers, T, Chen, YY, Fitzmaurice, C, Johnston, S & Li, J 1970, 'Deriving Public Sector Workforce Insights: A Case Study Using Australian Public Sector Employment Profiles', Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), International Conference on Advanced Data Mining and Applications, Springer International Publishing, Gold Coast, Queensland, Australia, pp. 764-774.
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© Springer International Publishing AG 2016.Effective approaches for measurement of human capital in public sector and government agencies is essential for robust workforce planning against changing economic conditions. To this purpose, adopting innovative hypotheses driven workforce data analysis can help discover hidden patterns and trends about the workforce. These trends are useful for decision making and support the development of policies to reach desired employment outcomes. In this study, the data challenges and approaches to a real life workforce analytics scenario are described. Statistical results from numerous workforce data experiments are combined to derive three hypotheses that are useful to public sector organisations for human resources management and decision making.
Guertler, MR, Becerril, L & Lindemann, U 1970, 'How to identify suitable collaboration strategies for open innovation?', Proceedings of International Design Conference, DESIGN, International Design Conference (DESIGN), Design Society, Cavtat-Dubrovnik, Croatia, pp. 1005-1014.
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Open Innovation (OI) allows the utilisation of external expertise. Besides various benefits, OI also bears specific risks. These are often linked to the selection of the “right” partners (e.g. knowledge drain and Not-Invented-Here syndrome) that is often based on specific perspectives, e.g. focussing only on external stakeholders, and only on their technical skills and neglecting the strategic relevance. Thus, we developed an integrated methodology to systematically identify, select and involve partners. This paper focusses on deriving suitable operative and strategic collaboration strategies.
Guertler, MR, Stahl, S, Muenzberg, C & Lindemann, U 1970, 'Analysing the influence of planning-parameters on Open Innovation performance', The XXVII ISPIM Innovation Conference, Porto, pp. 1-11.
Halkon, B & Rothberg, S 1970, 'Correction of laser Doppler vibrometry measurements affected by steering mirror vibration', OPTICAL MEASUREMENT TECHNIQUES FOR STRUCTURES & SYSTEMS III, 6th International Conference on Optical Measurement Techniques for Structures and Systems III (OPTIMESS2015), SHAKER PUBLISHING BV, Univ Antwerp, Antwerp, BELGIUM, pp. 117-126.
Halkon, BJ & Rothberg, SJ 1970, 'A practical guide to laser Doppler vibrometry measurements directly from rotating surfaces', IMechE Vibrations in Rotating Machinery, IMechE Vibrations in Rotating Machinery, University of Manchester, UK.
Hassan, M, Liu, D & Paul, G 1970, 'Modeling and stochastic optimization of complete coverage under uncertainties in multi-robot base placements', 2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), IEEE, Daejeon, Korea, pp. 2978-2984.
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© 2016 IEEE. Uncertainties in base placements of mobile, autonomous industrial robots can cause incomplete coverage in tasks such as grit-blasting and spray painting. Sensing and localization errors can cause such uncertainties in robot base placements. This paper addresses the problem of collaborative complete coverage under uncertainties through appropriate base placements of multiple mobile and autonomous industrial robots while aiming to optimize the performance of the robot team. A mathematical model for complete coverage under uncertainties is proposed and then solved using a stochastic multi-objective optimization algorithm. The approach aims to concurrently find an optimal number and sequence of base placements for each robot such that the robot team's objectives are optimized whilst uncertainties are accounted for. Several case studies based on a real-world application using a realworld object and a complex simulated object are provided to demonstrate the effectiveness of the approach for different conditions and scenarios, e.g. various levels of uncertainties, different numbers of robots, and robots with different capabilities.
Hengstebeck, A, Weisner, K, Klöckner, M, Deuse, J, Kuhlenkötter, B & Roßmann, J 1970, 'Formal Modelling of Manual Work Processes for the Application of Industrial Service Robotics', Procedia CIRP, Elsevier BV, pp. 364-369.
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© 2016 The Authors. The gap between technical capability and practical application of service robotics increased constantly within the last years, especially regarding small and medium-sized enterprises. In order to facilitate the transfer of knowledge to the shop floor, a methodology for the formal modelling of originally manual work processes was developed. Here, specific work processes can be characterized under consideration of automation relevant parameters what serves as a basis for a subsequent determination of applicable and suitable service robotic solutions. By utilizing this approach, industrial operators will be considerably supported regarding the planning and implementation of automated and especially hybrid robot-assisted work systems.
Islam, MS, Saha, SC, Sauret, E & Gu, YT 1970, 'Numerical investigation of diesel exhaust particle transport and deposition in up to 17 generations of the lung airway', Proceedings of the 20th Australasian Fluid Mechanics Conference, AFMC 2016.
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Diesel exhaust particulates matter (DEPM) is a compound mixture of gases and fine particles that contains more than 40 toxic air pollutants including benzene, formaldehyde, and nitrogen oxides. Exposure of DEPM to human lung airway during respiratory inhalation causes severe health hazards like diverse pulmonary diseases. This paper studies the DEPM transport and deposition in upper 17-generation of digital lung airways. The Euler-Lagrange approach is used to solve the continuum and disperse phases of the calculation. Lagrangian based Discrete Phase Model (DPM) is used to investigate the DEPM nanoparticle dispersion and deposition in the current anatomical model. The effects of size specific monodispersed particles on deposition are extensively investigated during resting condition. The numerical results illustrate that Brownian diffusion is the dominant mechanism for smaller diameter particles. The present 17-generation bifurcation model also depicts different deposition hot spot for various diameter particles which could advance the understanding of the therapeutic drug delivery system to the specific position of the respiratory airways.
Khosoussi, K, Shoudong Huang & Dissanayake, G 1970, 'Tree-connectivity: Evaluating the graphical structure of SLAM', 2016 IEEE International Conference on Robotics and Automation (ICRA), 2016 IEEE International Conference on Robotics and Automation (ICRA), IEEE, Stockholm, Sweden, pp. 1316-1322.
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© 2016 IEEE. Simultaneous localization and mapping (SLAM) in robotics, and a number of related problems that arise in sensor networks are instances of estimation problems over weighted graphs. This paper studies the relation between the graphical representation of such problems and estimationtheoretic concepts such as the Cramér-Rao lower bound (CRLB) and D-optimality. We prove that the weighted number of spanning trees, as a graph connectivity metric, is closely related to the determinant of CRLB. This metric can be efficiently computed for large graphs by exploiting the sparse structure of underlying estimation problems. Our analysis is validated using experiments with publicly available pose-graph SLAM datasets.
Kuruneru, STW, Sauret, E, Saha, SC & Gu, YT 1970, 'Numerical assessment of wake dynamics and vortex shedding behind an array of equilateral triangular cylinders', Proceedings of the 20th Australasian Fluid Mechanics Conference, AFMC 2016.
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A numerical model is employed to examine the wake dynamics behind two equilateral triangular cylinders. Two different configurations are considered—two tandem triangular cylinders and two side-by-side triangular cylinders. A line integral convolution visualization technique is used to study the shed vortices. Results show that the wake topology between the gaps of triangles is dependent on the Reynolds number and centre-to-centre distance. Additionally, correlations between the Reynolds number and Strouhal number at various centre-to-centre distances are obtained.
Kuruneru, STW, Sauret, E, Saha, SC & Gu, YT 1970, 'Unresolved CFD-DEM of sandstone-laden air flow in a clear channel', Proceedings of the 20th Australasian Fluid Mechanics Conference, AFMC 2016.
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An unresolved finite-volume and discrete-element method that is able to capture the interaction between the lagrangian particles and carrier fluid in a clear channel is investigated. A hybrid SIMPLE-PISO algorithm is used to achieve pressure-velocity coupling whilst concurrently achieving stable and faster numerical convergence. Although the unresolved method is applicable if the CFD mesh cell size is larger than DEM particle size, this preliminary study shows that the unresolved method produces similar results in the event the particle diameter vastly exceeds the mesh cell size. Quantitative analysis shows near identical results among all four CFD grids tested. The gas void fraction exchange fields becomes smooth as the CFD mesh cell size exceeds the DEM particle size. Good agreement is observed between the analytical and numerical pressure drop profiles.
Kuruneru, STW, Sauret, E, Saha, SC & Gu, YT 1970, 'Unresolved CFD-DEM of sandstone-laden air flow in a clear channel', Proceedings of the 20th Australasian Fluid Mechanics Conference, AFMC 2016.
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© 2006 Australasian Fluid Mechanics Society. All rights reserved. An unresolved finite-volume and discrete-element method that is able to capture the interaction between the lagrangian particles and carrier fluid in a clear channel is investigated. A hybrid SIMPLE-PISO algorithm is used to achieve pressure-velocity coupling whilst concurrently achieving stable and faster numerical convergence. Although the unresolved method is applicable if the CFD mesh cell size is larger than DEM particle size, this preliminary study shows that the unresolved method produces similar results in the event the particle diameter vastly exceeds the mesh cell size. Quantitative analysis shows near identical results among all four CFD grids tested. The gas void fraction exchange fields becomes smooth as the CFD mesh cell size exceeds the DEM particle size. Good agreement is observed between the analytical and numerical pressure drop profiles.
Lenkenhoff, K, Barthelmey, A, Lemmerz, K, Kuhlenkötter, B & Deuse, J 1970, 'Communication Architecture for Automatic Plant Documentation Updates', Procedia CIRP, Elsevier BV, pp. 365-370.
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© 2016 The Authors. Today's exible demands and short product life cycles have lead to a modular thinking for machinery and plant engineering. A hidden challenge for this sector is the maintenance of plant documentation throughout the entire operating time of the machine components. This paper introduces an architecture for updating plant documentation. The concept is based on a exible masterslave hierarchy for IT-integrated machine components and aims at detecting physical changes in them. The standard data exchange format AutomationML functions as a decentralized and up-to-date virtual representation of each component carrying all types and contents of both construction and documentation disciplines.
Luo, L, Xie, H, Wei, D, Wang, X, Zhou, C & Jiang, Z 1970, 'A new micro scale FE model of crystalline materials in micro forming process', MATEC Web of Conferences, International Conference on Numerical Methods in Industrial Forming Processes, EDP Sciences, Troyes, France, pp. 02002-02002.
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© The Authors, published by EDP Sciences, 2016. Micro forming of metals has drawn global attention due to the increasing requirement of micro metal products. However, the size effects become significant in micro forming processes and affect the application of finite element (FE) simulation of micro forming processes. Dividing samples into small areas according to their microstructures and assigning individual properties to each small area are a possible access to micro forming simulation considering material size effects. In this study, a new model that includes both grains and their boundaries was developed based on the observed microstructures of samples. The divided subareas in the model have exact shapes and sizes with real crystals on the sample, and each grain and grain boundaries have their own properties. Moreover, two modelling methods using different information from the microstructural images were introduced in detail. The two modelling methods largely increase the availability of various microstructural images. The new model provides accurate results which present the size effects well.
Ma, H, Shi, L, Kodagoda, S & Xiong, R 1970, 'A semantic labeling strategy to reject unknown objects in large scale 3D point clouds', 2016 35th Chinese Control Conference (CCC), 2016 35th Chinese Control Conference (CCC), IEEE, Chengdu, Sichuan, China, pp. 7070-7075.
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In recent years, there has been a growing interest in the research of semantic labeling of indoor scenes represented by 3D point clouds. A fundamental problem that has largely been oversighted in the current research is the way of dealing with the unknown class which collectively includes all the objects that are of no interest to the application developer. In the training stage, these objects are either completely removed or labeled as unknown, resulting in a trained model which is not fully and fairly exposed to the actual sample space. In the test stage, the unknown objects are naturally present and provided to the classifier, causing a significant drop of the classification accuracy-usually 20%~30%. Simply improving the features or the classifier will not address the root cause problem. In this paper, we propose a labeling framework combining both Conditional Random Field (CRF) and PI-SVM to specifically solve the problem caused by the unknown class. First, we use a CRF to model the contextual relations in the 3D space, for which the parameters for both node potential and edge potential are learned from training data. Then, we make use of the rejection strategy of the PI-SVM, which estimates an unnormalized probability for each class. Finally, we reinforce the result of CRF with the belief provided by the PI-SVM, and the labeling result is based on the agreement of the two classifiers. The proposed method takes advantage of the global optimization of CRF and the advantage of unknown rejection of PI-SVM. Experimental results on publicly available data set show that this method has improved the classification accuracy by 10.7% given the accuracy drop of 19.23% caused by the unknown.
Mimani, A, Croaker, P, Karimi, M, Doolan, CJ & Kessissoglou, N 1970, 'Hybrid CFD-BEM and Time-Reversal techniques applied to localise flow-induced noise sources generated by a flat-plate', 2nd Australasian Acoustical Societies Conference, ACOUSTICS 2016, pp. 465-474.
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This paper presents a computational analysis of the flow-induced noise generated by a sharp-edged symmetric flat-plate located in low Mach number flow using the hybrid computational fluid dynamics (CFD)-boundary element method (BEM) and the Time-Reversal (TR) source localisation techniques. The CFD-BEM method is used to obtain the far-field acoustic spectrum of (1) the direct field generated by the turbulent flow over the flat-plate, (2) the acoustic field scattered by the body and (3) the total acoustic field at all four computational boundaries. The far-field acoustic spectrum for all three cases exhibits a broadband nature whereby the time-domain acoustic pressure data is obtained using the inverse Fast Fourier Transform followed by band-passing the signals in 1/3rd octave bands. The aeroacoustic TR simulations were implemented by numerically solving a set of 2-D Linearised Euler Equations and enforcing the band-passed time-reversed acoustic pressure signals as input at the boundary nodes. The TR source maps corresponding to the direct field indicates a lateral quadrupole source located downstream of the Trailing-Edge (TE) in the low-frequency range and a dominant longitudinal quadrupole located at the Leading-Edge (LE) in the high-frequency range. For both scattered and total fields, the TR source maps indicate a lift-dipole source at the TE in the low-frequency range whilst in the high-frequency range, the source maps indicate the occurrence of a weaker dipole source at the LE and a dominant dipole source at the TE.
Moheimani, SOR, Fowler, A, Maroufi, M & Ruppert, M 1970, 'On-chip atomic force microscopy: Mechatronic system design and control', 2016 American Control Conference (ACC), 2016 American Control Conference (ACC), IEEE.
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Neri, A, Cagno, E & Trianni, A 1970, 'Barriers to energy efficiency measures and the role of industrial sustainability', Eceee Industrial Summer Study Proceedings, pp. 233-242.
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Energy efficiency is largely recognized as a major contributor for industrial sustainability. In order to improve their energy efficiency and thus industrial sustainability performances firms should implement energy efficiency measures (EEMs) that are not largely diffused yet. Hitherto, EEMs have been evaluated exclusively by looking at barriers from an energy efficiency decision maker's viewpoint, thus not accounting for a broader sustainability perspective. When considering the latter, the Triple Bottom Line could be taken: within an industrial context, it can be identified with the areas of Occupational Health and Safety (OHS) and Eco-efficiency (in which energy efficiency is gaining increasing relevance). For this reason, the present work is aimed at better understanding barriers to EEMs adoption, by analyzing them through different perspectives and insights offered by several responsible of single areas of industrial sustainability within a firm. To address this research gap, we have investigated through explorative case studies some firms within Northern Italy with a specific model on barriers to industrial sustainability measures,. The results seem to show that an EEM should be analyzed under different perspectives. New with respect to previous literature, a more proper perspective for analyzing an EEM should be that of industrial sustainability, and not just that of energy-efficiency, since it may result limited. Energy and Environmental managers may have a different perspective on barriers than the OHS's one, highlighting barriers not perceived by just one area's responsible. Moreover, an EEM may be stopped by reasons not knowledgeable to energy efficiency, rather to other areas, such as, e.g. OHS. Lastly, an EEM may have positive effects (co-benefits) on other areas of industrial sustainability, that may be perceived only by such areas. The study concludes with some remarks for policy and industrial decision- makers, and advice for further research.
Nerse, C & Wang, S 1970, 'Experimental Modal Analysis of Rolled Multi Layer Cylindrical Shell', Conference Proceedings of the Society for Experimental Mechanics Series, 34th IMAC Conference and Exposition on Structural Dynamics, Springer International Publishing, Orlando, FL, pp. 249-254.
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Cylindrical shells are frequently encountered in industry, flight structures, pipeline systems and marine crafts. In these applications cylindrical shells are commonly subjected to harmonic excitations induced by pumps, turbines, compressors etc. Structures exposed to such loads can have structural failure due to sustained effect originated from the vibration by the dynamic load, and structural resonances. For suppression of noise and vibration in the system many design techniques have been employed, and the concept of laminated or multi layer shell has been utilized in several work. In such configuration layers with or without additional damping material stacked on top of each other to achieve the optimum vibration behavior. In rolled multi layer cylindrical shells this phenomenon is realized by rolling a thin plate around a cylindrical shell. Analyzing the coupled system in frequency domain, it is observed that the contact relation between adjacent layers change the system eigenvalues and eigenvectors, as well as resulting in overall reduction in noise and vibration compared to simple shell. In this research experimental modal analysis has been done, and case studies have been presented for different thickness configurations of rolled multi layer shell structure.
Nguyen, L & Kodagoda, S 1970, 'Soil organic matter estimation in precision agriculture using wireless sensor networks', 2016 14th International Conference on Control, Automation, Robotics and Vision (ICARCV), 2016 14th International Conference on Control, Automation, Robotics and Vision (ICARCV), IEEE, Thailand.
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Nöhring, F, Krebs, M, Pöschel, F & Deuse, J 1970, 'Practical teaching concept for the development of time management competence with IT systems from dmc-ortim and SAP', Multikonferenz Wirtschaftsinformatik, MKWI 2016, pp. 775-786.
Oldham, KM, Chung, PWH, Edirisinghe, EA & Halkon, BJ 1970, 'Table tennis and computer vision: a monocular event classifier', Advances in Intelligent Systems and Computing, 10th International Symposium on Computer Science in Sports (ISCSS), Springer International Publishing, Loughborough, ENGLAND, pp. 29-32.
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© Springer International Publishing Switzerland 2016. Detecting events in table tennis using monocular video sequences for match-play officiating is challenging. Here a low-cost monocular video installation generates image sequences and, using the Horn-Schunck Optical Flow algorithm, ball detection and location processing captures sudden changes in the ball’s motion. It is demonstrated that each abrupt change corresponds to a distinct event pattern described by its combined velocity, acceleration and bearing. Component motion threshold values are determined from the analysis of a range of table tennis event video sequences. The novel event classifier reviews change in motion data against these thresholds, for use in a rules based officiating decision support system. Experimental results using this method demonstrate an event classification success rate of 95.9%.
Parnell, J 1970, 'Are cumulative noise criteria relevant for the assessment of mining noise?', 2nd Australasian Acoustical Societies Conference, ACOUSTICS 2016, pp. 642-650.
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The NSW Department of Planning and Environment undertakes a significant amount of research into the noise generated by open cut coal mines in order to build the knowledge base and to assist industry and regulators better manage these impacts, both individually and cumulatively. The present paper considers a range of simplified theoretical scenarios as well as examining two empirical studies that were undertaken by the Department to investigate cumulative noise impacts of coal mining activities. Together, these works have been used to test a hypothesis as to whether absolute criteria, or relative criteria (as determined by the NSW Industrial Noise Policy) is the controlling criterion in regulating noise from these premises. Empirical data were collected under a range of meteorological conditions designed to align with 'worst case' scenarios for the propagation of noise and also allowed estimations of individual mine contributions to the overall noise catchments to be made. The conclusion of the present paper is that due to the geographical size of mines, the relative criteria will be the controlling criterion, and attempts to apply the absolute criteria are unnecessary where the relative criterion of surrounding mines is 40 dB(A) or less.
Patten, T, Fitch, R & Sukkarieh, S 1970, 'Multi-robot coverage planning with resource constraints for horticulture applications', Acta Horticulturae, International Horticultural Congress on Horticulture, International Society for Horticultural Science (ISHS), Brisbane, Australia, pp. 655-662.
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A multi-robot system is a team of autonomous robots that work together to perform a given task. Multi-robot systems have great potential for use in horticulture applications. Robots have the potential to perform crop surveillance, efficiently apply fertiliser and chemical inputs, and perform weeding and harvesting. In all of these tasks, robots must visit many trees or plants over a large area in a time-sensitive manner. Multi-robot systems are appropriate because many robots can work efficiently in parallel. However, a fundamental challenge to be addressed is how to coordinate the motion of many robots while also respecting resource constraints such as limited energy storage, liquid payload, and harvested product storage. The algorithmic problem of multi-robot coverage planning with resource constraints is similar to the NP-hard vehicle routing problem, but the computational complexity of general resource-constrained coverage remains unknown. We show that one variant of this problem, coverage with fixed replenishment stations and zero queuing time, can be solved in polynomial time using area partitioning and graph search. We present algorithms and analysis for this variant, and demonstrate the behaviour of our algorithms in simulation experiments with up to 100 robots. The robots cover a large area organised as a collection of sub-areas with defined boundaries and row orientations. Robots plan to visit one of several possible replenishment stations in order to satisfy resource constraints. Each robot may replenish itself multiple times throughout its mission. This work is practically applicable to systems where refill time is short relative to working time.
Paul, G, Liu, L & Liu, D 1970, 'A novel approach to steel rivet detection in poorly illuminated steel structural environments', 2016 14th International Conference on Control, Automation, Robotics and Vision (ICARCV), 2016 14th International Conference on Control, Automation, Robotics and Vision (ICARCV), IEEE, Phuket, Thailand.
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© 2016 IEEE. It is becoming increasingly achievable for steel bridge structures, which are normally both inaccessible and hazardous for humans, to be inspected and maintained by autonomous robots. Steel bridges have been traditionally constructed by securing plate members together with rivets. However, rivets present a challenge for robots both in terms of cleaning and surface traversal. This paper presents a novel approach to RGB-D image and point cloud analysis that enables rivets to be rapidly and robustly located using low cost, non-contact sensing devices that can be easily affixed to a robot. The approach performs classification based on: (a) high-intensity blobs in color images, (b) the non-linear perturbations in depth images, and (c) surface normal clusters in 3D point clouds. The predicted rivet locations from the three classifiers are combined using a probabilistic occupancy mapping technique. Experiments are conducted in several different lab and real-world steel bridge environments, where there is no external lighting infrastructure, and the sensors are attached to a mobile platform, i.e. a climbing inspection robot. The location of rivets within 2m of the robot can be robustly located within 10mm of their correct location. The state of voxels can be predicted with above 95% accuracy, in approximately 1 second per frame.
Quin, P, Paul, G, Alempijevic, A & Liu, D 1970, 'Exploring in 3D with a climbing robot: Selecting the next best base position on arbitrarily-oriented surfaces.', IROS, IEEE/RSJ International Conference on Intelligent Robots and Systems, IEEE, Daejeon, Korea, pp. 5770-5775.
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© 2016 IEEE. This paper presents an approach for selecting the next best base position for a climbing robot so as to observe the highest information gain about the environment. The robot is capable of adhering to and moving along and transitioning to surfaces with arbitrary orientations. This approach samples known surfaces, and takes into account the robot kinematics, to generate a graph of valid attachment points from which the robot can either move to other positions or make observations of the environment. The information value of nodes in this graph are estimated and a variant of A∗ is used to traverse the graph and discover the most worthwhile node that is reachable by the robot. This approach is demonstrated in simulation and shown to allow a 7 degree-of-freedom inchworm-inspired climbing robot to move to positions in the environment from which new information can be gathered about the environment.
Ranasinghe, R & Kodagoda, S 1970, 'Spatial prediction in mobile robotic wireless sensor networks with network constraints', 2016 14th International Conference on Control, Automation, Robotics and Vision (ICARCV), 2016 14th International Conference on Control, Automation, Robotics and Vision (ICARCV), IEEE, Phuket, Thailand.
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© 2016 IEEE. In recent years mobile robotic wireless sensor networks have been a popular choice for modelling spatial phenomena. This research is highly demanding and non-trivial due to challenges from both network and robotic aspects. In this paper, we address the spatial modelling of a physical phenomena with the network connectivity constraints while the mobile robots are striving to achieve the minimum modelling mismatch in terms of root mean square error (RMSE). We have resolved it through Gauss markov random field based approach which is a computationally efficient implementation of Gaussian processes. In this strategy, the Mobile Robotic Wireless Sensor Node (MRWSN) are centrally controlled to maintain the connectivity while minimizing the RMSE. Once the number of MRWSNs reach their maximum coverage, a new MRWSN is requested at the most informative location. The experimental results are convincing and they show the effectiveness of the algorithm.
Reeks, C, Carmichael, MG, Dikai Liu & Waldron, KJ 1970, 'Angled sensor configuration capable of measuring tri-axial forces for pHRI', 2016 IEEE International Conference on Robotics and Automation (ICRA), 2016 IEEE International Conference on Robotics and Automation (ICRA), IEEE, Stockholm, Sweden, pp. 3089-3094.
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© 2016 IEEE. This paper presents a new configuration for single axis tactile sensor arrays molded in rubber to enable tri-axial force measurement. The configuration requires the sensing axis of each sensor in the array to be rotated out of alignment with respect to external forces. This angled sensor array measures shear forces along axes in a way that is different to a planar sensor array. Three sensors using the angled configuration (22.5°, 45° and 67.5°) and a fourth sensor using the planar configuration (0°) have been fabricated for experimental comparison. Artificial neural networks were trained to interpret the external force applied along each axis (X, Y and Z) from raw pressure sensor values. The results show that the angled sensor configuration is capable of measuring tri-axial external forces with a root mean squared error of 1.79N, less error in comparison to the equivalent sensor utilizing the planar configuration (4.52N). The sensors are then implemented to control a robotic arm. Preliminary findings show angled sensor arrays to be a viable alternative to planar sensor arrays for shear force measurement; this has wide applications in physical Human Robot Interaction (pHRI).
Ruppert, MG, Harcombe, DM & Reza Moheimani, SO 1970, 'State estimation for high-speed multifrequency atomic force microscopy', 2016 American Control Conference (ACC), 2016 American Control Conference (ACC), IEEE.
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Shi, L, Miro, JV, Zhang, T, Vidal-Calleja, T, Sun, L & Dissanayake, G 1970, 'Constrained sampling of 2.5D probabilistic maps for augmented inference', 2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), IEEE, Daejeon, Korea, pp. 3131-3136.
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© 2016 IEEE. This work exploits modeling spatial correlation in 2.5D data using Gaussian Processes (GPs), and produces constrained sampling realizations on these models to improve certainty in the predictions by means of integrating additional sparse information. Data organized in 2.5D such as elevation and thickness maps has been extensively studied in the fields of robotics and geostatistics. These maps are typically represented as a probabilistic 2D grid that stores an estimated value (height or thickness) for each cell. With the increasing popularity and deployment of robotic devices for infrastructure inspection, 2.5D data becomes a common interpretation of the condition of the target being inspected. Modeling the spatial dependencies and making inferences on new grid locations is a common task that has been addressed using GPs, but inference results on locations which are weakly correlated with the training data are generally not sufficiently informative and distinctly uncertain. The predictive capability of the proposed framework, which is applicable to any 2.5D data, is demonstrated with field inspection data from pipelines. Specifically, sparse and complementary measurements from alternative sensing modalities have been incorporated into the model to predict in more detail local thickness conditions where GP training data is limited. The output of this work aims to probabilistically present variations of the target in the case that both accuracy and reasonable diversity are of significant interest.
Sick, N, Preschitschek, N & Broering, S 1970, 'Hot spots of convergence research', The XXVII ISPIM Conference “Blending Tomorrow's Innovation Vintage“, Porto, Portugal.
Sick, N, Preschitschek, N, Guertler, M & Broering, S 1970, 'Convergence research in technology and innovation management literature − A review on its current status, overall relevance and future challenges', R&D Management Conference ‘From Science to Society: Innovation and Value Creation’, Cambridge, United Kingdom.
Sick, N, Suseno, Y, Hofmann, E & Nienaber, A-M 1970, 'Distance and knowledge hiding in academic collaborations', ISPIM Innovation Summit 2016 “Moving the Innovation Horizon”, Kuala Lumpur, Malaysia.
Siddiki, MNAA, Molla, MM & Saha, SC 1970, 'Natural convection flow in porous enclosure with localized heating from below with heat flux', AIP Conference Proceedings.
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Unsteady natural convection flow in a two dimensional fluid saturated porous enclosure with localized heating from below with heat flux, symmetrical cooling from the sides and the insulated top wall has been investigated numerically. The governing equations are the Darcy's law for the porous media and the energy equation for the temperature field has been considered. The non-dimensional Darcy's law in terms of the stream function is solved by finite difference method using the successive over-relaxation (SOR) scheme and the energy equation is solved by Alternative Direction Alternative (ADI) scheme. The uniform heat flux source is located centrally at the bottom wall. The numerical results are presented in terms of the streamlines and isotherms, as well as the local and average rate of heat transfer for the wide range of the Darcy's Rayleigh number and the length of the heat flux source at the bottom wall.
Song, J, Wang, J, Zhao, L, Huang, S & Dissanayake, G 1970, '3D shape recovery of deformable soft-tissue with computed tomography and depth scan', Australasian Conference on Robotics and Automation, ACRA, Australasian Conference on Robotics and Automation, ARAA, Queensland, Australia, pp. 11-19.
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Knowing the tissue environment accurately is very important in minimal invasive surgery (MIS). While, as the soft-tissues is deformable, reconstruction of the soft-tissues environment is challenging. This paper proposes a new framework for recovering the deformation of the soft-tissues by using a single depth sensor. This framework makes use of the morphology information of the soft-tissues from Xray computed tomography, and deforms it by the embedded deformation method. Here, the key is to build a distance field function of the scan from the depth sensor, which can be used to perform accurate model-to-scan deformation together with robust non-rigid shape registration in the same go. Simulations show that soft-tissue shape in the previous step can be efficiently deformed to fit the partially observed scan in the current step by using the proposed method. And the results from the simulated sequential deformation of three different softtissues demonstrate the potential clinical value for MIS.
Stein, NV, Sick, N & Leker, J 1970, 'The relationship of calculated and perceived distance dimensions in interdisciplinary collaborations: Evidence from a battery research project', 2016 Portland International Conference on Management of Engineering and Technology (PICMET), 2016 Portland International Conference on Management of Engineering and Technology (PICMET), IEEE, Honolulu, Hawaii, USA, pp. 460-470.
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© 2016 Portland International Conference on Management of Engineering and Technology, Inc. Innovation collaborations experienced a substantial growth, so that the research interest in factors contributing to successful collaboration increased. One important factor in this context are distances like technological and geographical distance. The distinction between objectively calculated and individually perceived distances provides possible starting points to bridge high distances. Therefore, the study at hand aims to answer the following research question: How are calculated technological and geographical distances related to their perceived counterpart and how do these different distance dimensions influence each other? The data is collected from an interdisciplinary battery research project. The calculated technological distance is measured via a publication-based approach while the calculated geographical distance is defined as the distance between the respective working places. Perceived distances, in contrast, are received via an online questionnaire. The influence model confirms a positive relationship between the calculated distance dimensions, technological and geographical distance, and their perceived counterparts. However, respective measures do by far not entirely overlap, so that the perceived ones are further influenced by factors like e.g. scientific background or shortest travel time. This approach is especially promising to foster social innovation as the awareness of bridging mechanisms might provide avenues to deal with technological distance, which can be assumed to be comparably high in this context.
Stone, B, Halkon, B & Harland, A 1970, 'Headform Mounting Performance in Cricket Standard Testing', Procedia Engineering, 11th Conference of the International Sports Engineering Association (ISEA), Elsevier BV, Delft, NETHERLANDS, pp. 401-406.
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© 2016 The Authors. Published by Elsevier Ltd. The current British Standard for head protectors for cricketers specifies a projectile test to ensure that a helmet can prevent the ball penetrating the peak-grille gap and deformation of the grille onto the face. For practical reasons, it is specified that the headform is mounted onto a grounded frame. This study aims to determine whether this 'Fixed' mounting technique influences the response of the headform relative to a theoretically preferable 'Free' suspension. A pressurised air cannon was used to project a 'BOLA'TM ball at three nominal speeds (22, 25 and 28 m/s) and at three target impact locations (136 (Top), 108 (Middle) and 80 (Bottom) mm from the base). High speed video was used to identify the contact duration and accelerometer data were used to assess the peak resultant headform acceleration and velocity during this period. Generally, good agreement between the two scenarios was found in regard to peak resultant headform acceleration, particularly at the 25 and 28 m/s impact speeds. In terms of headform velocity, the two scenarios showed greater variation when the full contact duration was considered, with root mean square deviations ranging from 1.77-5.6 in all testing conditions. However, some portions of the impact were considerably more consistent than others. These initial results indicate that the result of the penetration test, as specified in BS 7928:2013, would be independent of the suspension technique particularly given the convergence of results at the specified standard velocity (28 m/s). Future work should look to identify the loading and unloading phases of an impact, and use this to compare headform response. Thus allowing a more in-depth investigation of headform mounting performance and provide more clarity on the use of the Fixed technique in cricket standard tests.
Stone, BW, Halkon, BJ & Harland, AR 1970, 'An explorative study into the mechanics of projectile impacts to the head', 2016 IRCOBI Conference Proceedings - International Research Council on the Biomechanics of Injury, pp. 369-380.
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There has been little research focused on the mechanics of high-velocity, low-mass projectile impacts to the head. The little work that has been conducted has focused solely on linear acceleration, despite the evidence linking rotational acceleration to the development of brain injury. The aim of this study was to explore the presence of rotational acceleration in projectile impacts and investigate the influence of impact location. A pressurised air cannon was used to project a BOLATM ball at 22 and 28 m.s-1 towards a BSEN 960:2006 headform positioned to elicit impacts at frontal and lateral locations. High-speed video and accelerometer measurements were used to investigate differences in contact duration, ball deformation and average linear and rotational acceleration during loading. Contact duration was found to be independent of impact location or speed. Greater ball deformation was observed in frontal impacts, despite no differences in time to maximum deformation. Average linear acceleration was observed to be greater during the loading phase in the frontal impacts then in the lateral impacts, potentially due to differences in surface geometry, resulting in differences in ball deformation. Average rotational acceleration was greater in lateral impacts potentially due to differences in the moments of inertia of the headform. Rotational acceleration was found to be higher than previously published injury thresholds for concussion and therefore a potentially important factor in projectile impacts, warranting further research.
Strudthoff, M, Sick, N & Leker, J 1970, 'Knowledge networks based on technological distances', The XXVII ISPIM Conference “Blending Tomorrow's Innovation Vintage“, Porto, Portugal.
Su, D, Vidal-Calleja, T & Miro, JV 1970, 'Split conditional independent mapping for sound source localisation with Inverse-Depth Parametrisation', 2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), IEEE, Daejeon, Korea, pp. 2000-2006.
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© 2016 IEEE. In this paper, we propose a framework to map stationary sound sources while simultaneously localise a moving robot. Conventional methods for localisation and sound source mapping rely on a microphone array and either, 1) a proprioceptive sensor only (such as wheel odometry) or 2) an additional exteroceptive sensor (such as cameras or lasers) to get accurately the robot locations. Since odometry drifts over time and sound observations are bearing-only, sparse and extremely noisy, the former can only deal with relatively short trajectories before the whole map drifts. In comparison, the latter can get more accurate trajectory estimation over long distances and a better estimation of the sound source map as a result. However, in most of the work in the literature, trajectory estimation and sound source mapping are treated as uncorrelated, which means an update on the robot trajectory does not propagate properly to the sound source map. In this paper, we proposed an efficient method to correlate robot trajectory with sound source mapping by exploiting the conditional independence property between two maps estimated by two different Simultaneous Localisation and Mapping (SLAM) algorithms running in parallel. In our approach, the first map has the flexibility that can be built with any SLAM algorithm (filtering or optimisation) to estimate robot poses with an exteroceptive sensor. The second map is built by using a filtering-based SLAM algorithm locating all stationary sound sources parametrised with Inverse Depth Parametrisation (IDP). Robot locations used during IDP initialisation are the common features shared between the two SLAM maps, which allow to propagate information accordingly. Comprehensive simulations and experimental results show the effectiveness of the proposed method.
Sun, L, Vidal-Calleja, T & Miro, JV 1970, 'Gaussian Markov Random Fields for fusion in information form', 2016 IEEE International Conference on Robotics and Automation (ICRA), 2016 IEEE International Conference on Robotics and Automation (ICRA), IEEE, Stockholm, Sweden, pp. 1840-1845.
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© 2016 IEEE. 2.5D maps are preferable for representing the environment owing to their compactness. When noisy observations from multiple diverse sensors at different resolutions are available, the problem of 2.5D mapping turns to how to compound the information in an effective and efficient manner. This paper proposes a generic probabilistic framework for fusing efficiently multiple sources of sensor data to generate amendable, high-resolution 2.5D maps. The key idea is to exploit the sparse structure of the information matrix. Gaussian Markov Random Fields are employed to learn a prior map, which uses the conditional independence property between spatial location to obtain a representation of the state with a sparse information matrix. This prior map encoded in information form can then be updated with other sources of sensor data in constant time. Later, mean state vector and variances can be also efficiently recovered using sparse matrices techniques. The proposed approach allows accurate estimation of 2.5D maps at arbitrary resolution, while incorporating sensor noise and spatial dependency in a statistically sound way. We apply the proposed framework to pipe wall thickness mapping and fuse data from two diverse sensors that have different resolutions. Experimental results are compared with three other methods, showing that, while greatly reducing computation time, the proposed framework is able to capture in large extend the spatial correlation to generate equivalent results to the computationally expensive optimal fusion method in covariance form with a Gaussian Process prior.
Takami, K, Furukawa, T, Kumon, M & Dissanayake, G 1970, 'Non-Field-of-View Acoustic Target Estimation in Complex Indoor Environment', Proceedings of the 10th Field and Service Robotics (FSR), International Conference on Field and Service Robotics, Springer International Publishing, Toronto, Canada, pp. 577-592.
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© Springer International Publishing Switzerland 2016.This paper presents a new approach which acoustically localizes a mobile target outside the Field-of-View (FOV), or the Non-Field-of-View (NFOV), of an optical sensor, and its implementation to complex indoor environments. In this approach, microphones are fixed sparsely in the indoor environment of concern. In a prior process, the Interaural Level Difference IID of observations acquired by each set of two microphones is derived for different sound target positions and stored as an acoustic cue. When a newsound is observed in the environment, a joint acoustic observation likelihood is derived by fusing likelihoods computed from the correlation of the IID of the new observation to the stored acoustic cues. The location of the NFOVtarget is finally estimated within the recursive Bayesian estimation framework. After the experimental parametric studies, the potential of the proposed approach for practical implementation has been demonstrated by the successful tracking of an elderly person needing health care service in a home environment.
Takami, K, Liu, H, Furukawa, T, Kumon, M & Dissanayake, G 1970, 'Non-field-of-view sound source localization using diffraction and reflection signals', 2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), IEEE, Daejeon, Korea, pp. 157-162.
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© 2016 IEEE. This paper describes a non-field-of-view (NFOV) localization approach for a mobile robot in an unknown environment based on an acoustic signal combined with the geometrical information from an optical sensor. The approach estimates the location of a target through the mobile robot's sensor observation frame, which consists of a combination of diffraction and reflection acoustic signals and a 3-D environment geometrical description. This fusion of audio-visual sensor observation likelihoods allows the robot to estimate the NFOV target. The diffraction and reflection observations from the microphone array generate the acoustic joint observation likelihood. The observed geometry also determines far-field or near-field acoustic conditions to improve the estimation of the sound direction of arrival. A mobile robot equipped with a microphone array and an RGB-D sensor was tested in a controlled environment, an anechoic chamber, to demonstrate the NFOV localization capabilities. This resulted in +/-18 degrees, and less than 0.75 m error in angle and distance estimation, respectively.
Takami, K, Liu, H, Makoto, K, Furukawa, T & Dissanayake, G 1970, 'Recursive Bayesian estimation of NFOV target using diffraction and reflection signals', FUSION 2016 - 19th International Conference on Information Fusion, Proceedings, International Conference on Information Fusion, IEEE, Heidelberg, Germany, pp. 1923-1930.
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This paper presents an approach to the recursive Bayesian estimation of non-field-of-view (NFOV) sound source tracking based on reflection and diffraction signals with an incorporation of optical sensors. The approach takes multi-modal sensoy fusion of a mobile robot, which combines an optical 3D environment geometrical description with a microphone array acoustic signal to estimate the target location. The robot estimates target location either in the field-of-view (FOV) or in the NFOV by fusion of sensor observation likelihoods. For the NFOV case, the microphone array provides reflection and diffraction observations to generate a joint acoustic observation likelihood. With the data fusion between the 3D description and the acoustic observation, the target estimation is performed in an unknown environment. Finally, the sensor observation combined with the motion model of the target iteratively performs tracking within a recursive Bayesian estimation framework. The proposed approach was tested with a microphone array with an RGB-D sensor in a controlled anechoic chamber to demonstrate the NFOV tracking capabilities for a moving target.
Thiyagarajan, K, Kodagoda, S & Alvarez, JK 1970, 'An instrumentation system for smart monitoring of surface temperature', 2016 14th International Conference on Control, Automation, Robotics and Vision (ICARCV), 2016 14th International Conference on Control, Automation, Robotics and Vision (ICARCV), IEEE, Phuket, Thailand.
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© 2016 IEEE. Reliable sensing is a crucial factor for assessing the structural health conditions of civil infrastructure such as sewerage networks, which are susceptible to hydrogen sulfide induced concrete corrosion. In this context, this paper reports the work on the development and characterization of an instrumentation system using an infrared radiometer for monitoring surface temperature variations of the concrete through non-contact measurements. The surface temperature measurements are gathered by positioning the sensor at different distance and angles from the surface of interest. The effects of ambient lighting conditions during measurements are investigated. Furthermore, the sensing performance of the sensor is evaluated by performing statistical error analysis, and the efficacy of a custom-made signal processing board is tested by comparing the electrical signal with reference measures.
Thiyagarajan, K, Kodagoda, S, Ulapane, N & IEEE 1970, 'Data-driven Machine Learning Approach for Predicting Volumetric Moisture Content of Concrete Using Resistance Sensor Measurements', PROCEEDINGS OF THE 2016 IEEE 11TH CONFERENCE ON INDUSTRIAL ELECTRONICS AND APPLICATIONS (ICIEA), IEEE Conference on Industrial Electronics and Applications, IEEE, Hefei, China, pp. 1288-1293.
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© 2016 IEEE. In sewerage industry, hydrogen sulphide induced corrosion of reinforced concretes is a global problem. To achieve a comprehensive knowledge of the propagation of concrete corrosion, it is vital to monitor the critical factors such as moisture. In this context, this paper investigates the use of resistance measuring and processing for estimating the concrete moisture content. The behavior of concrete moisture with resistance and surface temperature are studied and the effects of pH concentration on concrete are analyzed. Gaussian Process regression modeling is carried out to predict volumetric moisture content of concrete, where the results from experimental data are used to train the prediction model.
Thomas, C, Stankiewicz, L, Grötsch, A, Wischniewski, S, Deuse, J & Kuhlenkötter, B 1970, 'Intuitive Work Assistance by Reciprocal Human-robot Interaction in the Subject Area of Direct Human-robot Collaboration', Procedia CIRP, Elsevier BV, pp. 275-280.
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© 2016 The Authors. The paper focuses on the interaction in human-robot collaboration. On the one hand, the robot assistance system individually aligns itself to the employee and on the other hand, the employee gets an interface which enables him to influence certain robot positions. The aim is to support the employee in assembly tasks. The employee's personal anthropometric data and age-related as well as temporary restrictions in movements are considered by being recorded individually via motion capturing before the workplace is built in a virtual and real environment. Based on the data, task specific movements of the employee are simulated using digital human models for the virtual representation of the employee, combined with an ergonomic analysis within the work environment. The impact of the employee on the assistance robot system is provided by the design of intuitive user interfaces. The positioning of the components in the assembly is done user-specifically by the robot. In addition, the employee gets a graphical user interface and can additionally adjust the position or turn the components. In this paper, preliminary results of this ongoing research project are presented as well as two reference processes from the field of assembly technologies as application examples.
Trianni, A & Cagno, E 1970, 'Introduction to Panel 2 Sustainable production design and supply chain initiatives', Eceee Industrial Summer Study Proceedings, pp. 171-172.
vom Stein, N, Sick, N & Leker, J 1970, 'Interaction of calculated and perceived distance dimensions – Evidence from a battery research project', PICMET’16 'Technology Management for Social Innovation', Honolulu, Hawaii, USA.
Wantia, N, Esen, M, Hengstebeck, A, Heinze, F, Rossmann, J, Deuse, J & Kuhlenkoetter, B 1970, 'Task planning for human robot interactive processes', 2016 IEEE 21st International Conference on Emerging Technologies and Factory Automation (ETFA), 2016 IEEE 21st International Conference on Emerging Technologies and Factory Automation (ETFA), IEEE.
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© 2016 IEEE. One of the next steps in factory automation might not exclusively be an automation issue, but instead combining robot and human skills to further improve industrial work processes. For various reasons, there is still a low dissemination of hybrid work processes characterized by direct human robot interaction. For instance, it is very difficult to decide which manual work processes are eligible for a transformation to a human-robot interactive process. Thus, the research project MANUSERV delivers a tool to support this decision process. Here, the central concept is a task planning system capable of generating automated as well as hybrid human-robot solutions. Therefore, a structured description of manual work processes forms the input to the planning system. Subsequently, a simulation system verifies and evaluates the proposed solutions and generates the necessary information for a transformation of the planning results to a real application scenario.
Wijerathna, B, Falque, R, Kodagoda, S & Dissanayake, G 1970, 'Linear approximation for mapping remaining wall thickness using a magnetic flux leakage sensor', Australasian Conference on Robotics and Automation, ACRA, Australasian Conference on Robotics and Automation, ACRA, The University of Queensland, pp. 240-247.
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Use of an unconventional sensor for mapping the remaining wall thickness of a pipe is presented in this paper. This is achieved through the development of a sensor model relating the measurements from a Magnetic Flux Leakage (MFL) sensor to the environment geometry. Conventional sensors, such as laser-range finders commonly used in the robotic community are not able to infer thickness profiles of ferromagnetic structures such as water pipes when the surface is covered with corrosion products. Sensors based on electromagnetic principles or ultrasound are the methods of choice in such situations to estimate the extent of corrosion and predict eventual failure. The general relationship between readings from electromagnetic sensors and the environment geometry is governed by a set of partial differential equations (Maxwells equations). However, in the case of an MFL sensor, it is demonstrated that a linear combination of the thickness profiles can be used to adequately model the sensor signal. Parameters associated with the sensor model are obtained using a two-dimensional finite element simulations. Extensive simulation results are presented to validate the proposed method by estimating a remaining wall thickness map of a realistic pipe.
Woolfrey, J, Liu, D & Carmichael, M 1970, 'Kinematic control of an Autonomous Underwater Vehicle-Manipulator System (AUVMS) using autoregressive prediction of vehicle motion and Model Predictive Control', 2016 IEEE International Conference on Robotics and Automation (ICRA), 2016 IEEE International Conference on Robotics and Automation (ICRA), IEEE, Stockholm, Sweden, pp. 4591-4596.
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© 2016 IEEE. Autonomous Underwater Vehicle-Manipulator Systems (AUVMS) operating in shallow waters or near-surface environments may be exposed to wave disturbances which will cause undesired motion of the end effector. This paper presents a method to maneuver the manipulator joints and counteract undesired motion of the vehicle body, in order to maintain a steady end-effector position in the inertial frame. An Autoregressive (AR) model is used to predict vehicle motion, and then combined with Model Predictive Control (MPC) to optimize joint motion. Simulation was conducted using real data to verify the efficacy of this method.
Yang, C-HJ, Paul, G, Ward, P & Liu, D 1970, 'A path planning approach via task-objective pose selection with application to an inchworm-inspired climbing robot', 2016 IEEE International Conference on Advanced Intelligent Mechatronics (AIM), 2016 IEEE International Conference on Advanced Intelligent Mechatronics (AIM), IEEE, Banff, Canada, pp. 401-406.
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© 2016 IEEE. This paper presents a stepping path planning approach for a climbing robot inspired kinematically from an inchworm caterpillar's looping locomotion. This approach generates an optimised multi-step path to traverse through space and to land a specific footpad onto a selected point on a surface with a specific footpad orientation. The candidate landing joint configuration for each step is generated by a pose selection process, using an optimisation technique with task-objective functions based on the constraints of the robot. Then another technique is used to obtain a new set of poses satisfying strict constraints of the landing motion. The set of candidate landing poses is used to compute the subsequent steps. A valid motion trajectory, which avoids all obstacles, can be generated by a point-to-point planner for each of the landing poses from the current pose. This single step planning technique is then expanded to multi-step path planning by building a search tree, where a combination of steps is evaluated and optimised by a cost function, which includes objectives related to robot movement. This approach is implemented and validated on the climbing robot in real-world steel bridge environments. The planner successfully finds multi-step paths in these field trials enabling the robot to traverse through several complex structures inside the bridge steel box girders.
Yiyi Liao, Kodagoda, S, Yue Wang, Lei Shi & Yong Liu 1970, 'Understand scene categories by objects: A semantic regularized scene classifier using Convolutional Neural Networks', 2016 IEEE International Conference on Robotics and Automation (ICRA), 2016 IEEE International Conference on Robotics and Automation (ICRA), IEEE, Stockholm, Sweden, pp. 2318-2325.
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Scene classification is a fundamental perception task for environmental understanding in today's robotics. In this paper, we have attempted to exploit the use of popular machine learning technique of deep learning to enhance scene understanding, particularly in robotics applications. As scene images have larger diversity than the iconic object images, it is more challenging for deep learning methods to automatically learn features from scene images with less samples. Inspired by human scene understanding based on object knowledge, we address the problem of scene classification by encouraging deep neural networks to incorporate object-level information. This is implemented with a regularization of semantic segmentation. With only 5 thousand training images, as opposed to 2.5 million images, we show the proposed deep architecture achieves superior scene classification results to the state-of-the-art on a publicly available SUN RGB-D dataset. In addition, performance of semantic segmentation, the regularizer, also reaches a new record with refinement derived from predicted scene labels. Finally, we apply our model trained on SUN RGB-D dataset to a set of images captured in our university using a mobile robot, demonstrating the generalization ability of the proposed algorithm.
Zhang, T, Huang, S, Liu, D, Shi, L, Zhou, C & Xiong, R 1970, 'A method of state estimation for underwater vehicle navigation around a cylindrical structure', 2016 IEEE 11th Conference on Industrial Electronics and Applications (ICIEA), 2016 IEEE 11th Conference on Industrial Electronics and Applications (ICIEA), IEEE, Hefei, China, pp. 101-106.
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© 2016 IEEE. Recently, increasing efforts have been focused on the development and adoption of autonomous underwater vehicles (AUVs) for various applications. However, the GPS signals are usually unavailable, the vehicle dynamics is very uncertain, and the complicated vision based localization algorithms may not work well in the underwater environments. Hence, accurate and timely state estimation using low-cost sensors remains a challenge for the control and navigation of AUVs. This paper considers the state estimation problem for underwater vehicle navigation around a cylindrical structure. The vehicle is assumed to be equipped with only low-cost sensors: an inertia measurement unit (IMU), a pressure sensor and a monocular camera. By exploiting the prior knowledge on the size and shape of the structure, an efficient algorithm for estimating the state of the AUV is developed without using any dynamic model. Firstly, a state observer is proposed under the condition that the localization result (rotational and translational position) is available. Next, we present a method for localization based on the IMU readings, pressure sensor readings and the image of the cylindrical structure, which uses the geometry of the structure and only requires simple image processing (line extraction). Then we prove that the proposed observer is globally stable. Preliminary experimental results and simulation results are reasonable and promising, which implies the proposed method has potential to be used in the real AUV navigation applications.
Zhao, L, Giannarou, S, Lee, S-L & Yang, G-Z 1970, 'Registration-Free Simultaneous Catheter and Environment Modelling', Medical Image Computing and Computer-Assisted Intervention – MICCAI 2016 (LNCS), Medical Image Computing and Computer-Assisted Intervention, Springer International Publishing, Athens, Greece, pp. 525-533.
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Endovascular procedures are challenging to perform due to the complexity and difficulty in catheter manipulation. The simultaneous recovery of the 3D structure of the vasculature and the catheter position and orientation intra-operatively is necessary in catheter control and navigation. State-of-art Simultaneous Catheter and Environment Modelling provides robust and real-time 3D vessel reconstruction based on real-time intravascular ultrasound (IVUS) imaging and electromagnetic (EM) sensing, but still relies on accurate registration between EM and pre-operative data. In this paper, a registration-free vessel reconstruction method is proposed for endovascular navigation. In the optimisation framework, the EM-CT registration is estimated and updated intra-operatively together with the 3D vessel reconstruction from IVUS, EM and pre-operative data, and thus does not require explicit registration. The proposed algorithm can also deal with global (patient) motion and periodic deformation caused by cardiac motion. Phantom and in-vivo experiments validate the accuracy of the algorithm and the results demonstrate the potential clinical value of the technique.
Zhao, L, Giannarou, S, Lee, S-L, Merrifield, R & Yang, GZ 1970, 'Intra-operative Simultaneous Catheter and Environment Modelling for Endovascular Navigation Based on Intravascular Ultrasound, Electromagnetic Tracking and Pre-operative Data', Proceedings of The Hamlyn Symposium on Medical Robotics, The Hamlyn Symposium on Medical Robotics, Imperial College London and the Royal Geographical Society, London, UK, pp. 76-77.
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Cardiovascular diseases (CVD) form the single mostcommon cause of death. Catheter procedures are amongthe most common surgical interventions used to treatCVD. Due to their minimal access trauma, theseprocedures extend the range of patients able to receiveinterventional CVD treatment to age groups dominatedby co-morbidity and unacceptable risks for open surgery[1]. The downside associated with minimising accessincisions lies at the increased complexity and difficultmanipulation of the instruments and anatomical targets,which is mainly caused by the loss of direct access tothe anatomy and the poor visualisation of the surgicalsite. The current clinical approaches to endovascularprocedures mainly rely on 2D guidance based on X-rayfluoroscopy, which uses ionising radiation anddangerous contrast agents [2].In this paper, a Simultaneous Catheter and EnvironmentModelling (SCEM) method is presented forendovascular navigation based on intravascularultrasound (IVUS) imaging, electromagnetic (EM)sensing as well as the vessel structure informationprovided from the pre-operative CT/MR imaging (seeFig. 1). Thus, radiation dose and contrast agents areavoided. The proposed SCEM intra-operatively recoversthe 3D structure of the vasculature together with thepose of the catheter tip, which the knowledge of theinteraction between the catheter and its surroundingscan be provided. The corresponding uncertainties ofboth vessel reconstruction and catheter pose can also becomputed which is necessary for autonomous roboticcatheter navigation. Experimental results using threedifferent phantoms, with different catheter motions andcardiac motions simulated by using a periodic pumpdemonstrated the accuracy of the vessel reconstructionand the potential clinical value of the proposed SCEMmethod.
Zhao, S, Cheng, E, Qiu, X, Alambeigi, P, Burry, J & Burry, M 1970, 'A preliminary investigation on the sound field properties in the Sagrada Familia Basilica', 2nd Australasian Acoustical Societies Conference, ACOUSTICS 2016, Conference of the Australian Acoustical Society, AAS, Brisbane, Australia, pp. 797-806.
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This paper reports on a preliminary investigation of the sound field properties inside a large Roman Catholic Church in Barcelona, the Sagrada Familia Basilica, which is a World Heritage Site although its construction has not been completed. The impulse responses were measured at 5 sound source positions combined with 14 measurement locations inside the Sagrada Familia Basilica, and the Impulse response to Noise Ratios (INR) were examined to check the reliability of the measured impulse responses. The room acoustic parameters were calculated and the following 5 sound field properties in the Sagrada Familia Basilica were analysed: reverberation, spaciousness, loudness, warmth and clarity. No optimal values of room acoustic parameters for such large volume churches have been found in the literature; thus, the preferred values of the reverberation time (T20) and the Early Decay Time (EDT) for small volume churches, and the preferred values of the middle frequency strength of sound (Gmid), the low frequency strength of sound (G125), the clarity (C80) and the binaural quality index (1 - IACCe) for concert halls were compared with the measurement results to illustrate a primary impression of the listening experience in the Sagrada Familia Basilica. The reverberation time (T20) and the EDT in the Sagrada Familia Basilica are much higher than the preferred values, while the middle frequency strength of sound (Gmid), the low frequency strength of sound (G125) and the clarity (C80) are less than the preferred values. The binaural quality index (1 - IACCE) is just above the typical satisfactory value.
Zhao, S, Cheng, E, Qiu, X, Burnett, I & Liu, JCC 1970, 'Estimation of the frequency boundaries of the inertial range for wind noise spectra in anechoic wind tunnels', 2nd Australasian Acoustical Societies Conference, ACOUSTICS 2016, Conference of the Australian Acoustical Society, AAS, Brisbane, Australia, pp. 1187-1196.
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Wind noise generated by the intrinsic turbulence in the flow can affect outdoor noise measurements. Various attempts have been made to investigate the wind noise generation mechanism. Wind noise spectra in anechoic wind tunnels can be divided into three frequency regions: In the low frequency region known as the energy-containing range, the wind noise spectrum does not change significantly with frequency. In contrast, in the middle frequency region (or inertial range) the decay rate of the wind noise spectrum curve follows the -7/3 power law, but in the high frequency region (or dissipation range) the decay rate of the wind noise spectrum curve is faster than the -7/3 power law. The boundaries of the -7/3 power law frequency range depend on the Reynolds number; however, no exact value is known according to current literature. This paper proposes a method for predicting the boundary values based on the energy cascade theory. Large eddy simulations of free jet were performed to validate the proposed method and the results were found to be in reasonable agreement with existing experiment measurements obtained in an anechoic wind tunnel. Additional simulations were also conducted with different inflow entrance sizes to further verify the predictions from the proposed method.
Zheng, B, Yang, N, Yee, J, Gaiser, K, Lu, WY, Clemon, L, Zhou, Y, Lavernia, EJ & Schoenung, JM 1970, 'Review on laser powder injection additive manufacturing of novel alloys and composites', Laser 3D Manufacturing III, SPIE LASE, SPIE, San Francisco, CA.
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Zhu, H, Sick, N & Leker, J 1970, 'How to use crowdsourcing for innovation?: A comparative case study of internal and external idea sourcing in the chemical industry', 2016 Portland International Conference on Management of Engineering and Technology (PICMET), 2016 Portland International Conference on Management of Engineering and Technology (PICMET), IEEE, Honolulu, Hawaii, USA.
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