Besinger, A, Sztynda, T, Lal, S, Duthoit, C, Agbinya, J, Jap, B, Eager, D & Dissanayake, G 2010, 'Optical flow based analyses to detect emotion from human facial image data', EXPERT SYSTEMS WITH APPLICATIONS, vol. 37, no. 12, pp. 8897-8902.
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Artificial recognition of facial expression has attracted a lot of attention in the last few years and different facial expression detection methods have been developed. The current study uses a feature point tracking technique separately applied to the five facial image regions (eyebrows, eyes and mouth) to capture basic emotions. The used dataset contains a total 60 facial images from subject's different genders and nationality not wearing glasses and/or facial hair. Results show that the used point tracking algorithm separately applied to the five facial image regions can detect emotions in image sequences. © 2010 Elsevier Ltd. All rights reserved.
Blamires, SJ 2010, 'Plasticity in extended phenotypes: orb web architectural responses to variations in prey parameters', Journal of Experimental Biology, vol. 213, no. 18, pp. 3207-3212.
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SUMMARYA spider orb web is an extended phenotype; it modifies and interacts with the environment, influencing spider physiology. Orb webs are plastic, responding to variations in prey parameters. Studies attempting to understand how nutrients influence spider orb-web plasticity have been hampered by the inability to decouple prey nutrients from other, highly correlated, prey factors and the intrinsic link between prey protein and prey energy concentration. I analyzed the nutrient concentrations of cockroaches, and adult and juvenile crickets to devise experiments that controlled prey protein concentration while varying prey size, ingested mass, energy concentration and feeding frequency of the orb web spider Argiope keyserlingi. I found that A. keyserlingi alters overall architecture according to feeding frequency. Decoration length was inversely related to ingested prey mass and/or energy density in one experiment but directly related to ingested prey mass in another. These contradictory results suggest that factors not examined in this study have a confounding influence on decoration plasticity. As decorations attract prey as well as predators decreasing decoration investment may, in some instances, be attributable to benefits no longer outweighing the risks. Web area was altered according to feeding frequency, and mesh size altered according to feeding frequency and prey length. The number of radii in orb webs was unaffected by prey parameters. A finite amount of silk can be invested in the orb web, so spiders trade-off smaller mesh size with larger web capture area, explaining why feeding frequency influenced both web area and mesh size. Mesh size is additionally responsive to prey size via sensory cues, with spiders constructing webs suitable for catching the most common or most profitable prey.
Blamires, SJ, Chao, I-C & Tso, I-M 2010, 'Prey type, vibrations and handling interactively influence spider silk expression', Journal of Experimental Biology, vol. 213, no. 22, pp. 3906-3910.
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SUMMARYThe chemical and mechanical properties of spider major ampullate (MA) silks vary in response to different prey, mostly via differential expression of two genes – MaSp1 and MaSp2 – although the spinning process exerts additional influence over the mechanical properties of silk. The prey cues that initiate differential gene expression are unknown. Prey nutrients, vibratory stimuli and handling have been suggested to be influential. We performed experiments to decouple the vibratory stimuli and handling associated with high and low kinetic energy prey (crickets vs flies) from their prey nutrients to test the relative influence of each as inducers of silk protein expression in the orb web spider Nephila pilipes. We found that the MA silks from spiders feeding on live crickets had greater percentages of glutamine, serine, alanine and glycine than those from spiders feeding on live flies. Proline composition of the silks was unaffected by feeding treatment. Increases in alanine and glycine in the MA silks of the live-cricket-feeding spiders indicate a probable increase in MaSp1 gene expression. The amino acid compositions of N. pilipes feeding on crickets with fly stimuli and N. pilipes feeding on flies with cricket stimuli did not differ from each other or from pre-treatment responses, so these feeding treatments did not induce differential MaSp expression. Our results indicate that cricket vibratory stimuli and handling interact with nutrients to induce N. pilipes to adjust their gene expression to produce webs with mechanical properties appropriate for the retention of this prey. This shows that spiders can genetically alter their silk chemical compositions and, presumably, mechanical properties upon exposure to different prey types. The lack of any change in proline composition with feeding treatment in N. pilipes suggests that the MaSp model determined for Nephila clavipes is not universally applicable to all Nephila.
Blamires, SJ, Lee, Y-H, Chang, C-M, Lin, I-T, Chen, J-A, Lin, T-Y & Tso, I-M 2010, 'Multiple structures interactively influence prey capture efficiency in spider orb webs', Animal Behaviour, vol. 80, no. 6, pp. 947-953.
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Cagno, E, Trucco, P, Trianni, A & Sala, G 2010, 'Quick-E-scan: A methodology for the energy scan of SMEs', Energy, vol. 35, no. 5, pp. 1916-1926.
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Cheong, CY, Tan, KC, Liu, DK & Lin, CJ 2010, 'Multi-objective and prioritized berth allocation in container ports', Annals of Operations Research, vol. 180, no. 1, pp. 63-103.
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This paper considers a berth allocation problem (BAP) which requires the determination of exact berthing times and positions of incoming ships in a container port. The problem is solved by optimizing the berth schedule so as to minimize concurrently the three objectives of makespan, waiting time, and degree of deviation from a predetermined priority schedule. These objectives represent the interests of both port and ship operators. Unlike most existing approaches in the literature which are single-objective-based, a multi-objective evolutionary algorithm (MOEA) that incorporates the concept of Pareto optimality is proposed for solving the multi-objective BAP. The MOEA is equipped with three primary features which are specifically designed to target the optimization of the three objectives. The features include a local search heuristic, a hybrid solution decoding scheme, and an optimal berth insertion procedure. The effects that each of these features has on the quality of berth schedules are studied. © 2008 Springer Science+Business Media, LLC.
Du, H, Zhang, N, Ji, JC & Gao, W 2010, 'Robust Fuzzy Control of an Active Magnetic Bearing Subject to Voltage Saturation', IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY, vol. 18, no. 1, pp. 164-169.
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Based on a recently proposed model for the active- magnetic-bearing (AMB) switching mode of operation, this paper presents a robust Takagi-Sugeno-model- based fuzzy-control strategy to stabilize the AMB with fast response speed subject to control-voltage saturation and parameter uncertainties. The sufficient conditions for the existence of such a controller are derived in terms of linear matrix inequalities. Numerical simulations against the proposed AMB model and a high-fidelity AMB model are used to validate the effectiveness of the proposed approach. © 2009 IEEE.
Hosseini Hashemi, S, Es’haghi, M & Karimi, M 2010, 'Closed-form solution for free vibration of piezoelectric coupled annular plates using Levinson plate theory', Journal of Sound and Vibration, vol. 329, no. 9, pp. 1390-1408.
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Free vibration analysis of annular moderately thick plates integrated with piezoelectric layers is investigated in this study for different combinations of soft simply supported, hard simply supported and clamped boundary conditions at the inner and outer edges of the annular plate on the basis of the Levinson plate theory (LPT). The distribution of electric potential along the thickness direction in the piezoelectric layer is assumed as a sinusoidal function so that the Maxwell static electricity equation is approximately satisfied. The differential equations of motion are solved analytically for various boundary conditions of the plate. In this study the closed-form solution for characteristic equations, displacement components of the plate and electric potential are derived for the first time in the literature. To demonstrate the accuracy of the present solution, comparison studies is first carried out with the available data in the literature and then natural frequencies of the piezoelectric coupled annular plate are presented for different thickness-radius ratios, inner-outer radius ratios, thickness of piezoelectric, material of piezoelectric and boundary conditions. Present analytical model provides design reference for piezoelectric material application, such as sensors, actuators and ultrasonic motors. © 2009 Elsevier Ltd. All rights reserved.
Hosseini Hashemi, S, Es’haghi, M & Karimi, M 2010, 'Closed-form vibration analysis of thick annular functionally graded plates with integrated piezoelectric layers', International Journal of Mechanical Sciences, vol. 52, no. 3, pp. 410-428.
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This paper employs an analytical method to analyze vibration of piezoelectric coupled thick annular functionally graded plates (FGPs) subjected to different combinations of soft simply supported, hard simply supported and clamped boundary conditions at the inner and outer edges of the annular plate on the basis of the Reddy’s third-order shear deformation theory (TSDT). The properties of host plate are graded in the thickness direction according to a volume fraction power-law distribution. The distribution of electric potential along the thickness direction in the piezoelectric layer is assumed as a sinusoidal function so that the Maxwell static electricity equation is approximately satisfied. The differential equations of motion are solved analytically for various boundary conditions of the plate. In this study closed-form expressions for characteristic equations, displacement components of the plate and electric potential are derived for the first time in the literature. The present analysis is validated by comparing results with those in the literature and then natural frequencies of the piezoelectric coupled annular FG plate are presented in tabular and graphical forms for different thickness-radius ratios, inner-outer radius ratios, thickness of piezoelectric, material of piezoelectric, power index and boundary conditions. © 2009 Elsevier Ltd. All rights reserved.
Hosseini Hashemi, S, Karimi, M & Rokni Damavandi Taher, H 2010, 'Vibration analysis of rectangular Mindlin plates on elastic foundations and vertically in contact with stationary fluid by the Ritz method', Ocean Engineering, vol. 37, no. 2-3, pp. 174-185.
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In this study Free vibration analysis of vertical rectangular Mindlin plates resting on Pasternak elastic foundation and fully or partially in contact with fluid on their one side is investigated for different combinations of boundary conditions. The plate is assumed to be one of vertical rectangular walls of a container in contact with fluid. In order to analyze the interaction of the Mindlin plate with the elastic foundation and fluid system, three displacement components of the plate are expressed in the Ritz method by adopting a set of static Timoshenko beam functions satisfying geometric boundary conditions in a Cartesian co-ordinate system. The method of separation of variables and the method of Fourier series expansion is used to model fluid and to obtain the exact expression of the motion of fluid in the form of integral equations. The fluid domain is finite in depth and width but infinite in the length direction. To demonstrate the accuracy of the present solution, convergence study is first carried out and then a few comparison studies are carried out with the available data in the literature. Finally, natural frequencies of rectangular plates are presented in tabular and graphical forms for different fluid levels, foundation parameters, aspect ratios, thickness to width ratios and boundary conditions. © 2009 Elsevier Ltd. All rights reserved.
Hosseini-Hashemi, S, Karimi, M & Hossein Rokni, DT 2010, 'Hydroelastic vibration and buckling of rectangular Mindlin plates on Pasternak foundations under linearly varying in-plane loads', Soil Dynamics and Earthquake Engineering, vol. 30, no. 12, pp. 1487-1499.
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Hydroelastic vibration and buckling analysis of horizontal rectangular plates resting on Pasternak foundation and subjected to linearly varying in-plane loads is investigated for different boundary conditions. Fluid is assumed to be inviscid and incompressible. To analyze the interaction of the Mindlin plate with the elastic foundation and fluid system, three displacement components of the plate are expressed in the Ritz method by adopting a set of static Timoshenko beam functions satisfying geometric boundary conditions. Convergence study is first carried out to confirm the stability of the present method. Then, a few comparisons are made for limited cases between present results and the available data in the literature. Finally, parametric study is conducted to highlight the effects of loading factors, fluid levels, foundation stiffness parameters, aspect ratios, thickness to width ratios and different boundary conditions on the critical buckling loads and wet natural frequencies of rectangular plates. © 2010 Elsevier Ltd.
Ji, JC & Zhang, N 2010, 'Suppression of the primary resonance vibrations of a forced nonlinear system using a dynamic vibration absorber', JOURNAL OF SOUND AND VIBRATION, vol. 329, no. 11, pp. 2044-2056.
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In a single degree-of-freedom weakly nonlinear oscillator subjected to periodic external excitation, a small-amplitude excitation may produce a relatively large-amplitude response under primary resonance conditions. Jump and hysteresis phenomena that result from saddle-node bifurcations may occur in the steady-state response of the forced nonlinear oscillator. A simple mass-spring-damper vibration absorber is thus employed to suppress the nonlinear vibrations of the forced nonlinear oscillator for the primary resonance conditions. The values of the spring stiffness and mass of the vibration absorber are significantly lower than their counterpart of the forced nonlinear oscillator. Vibrational energy of the forced nonlinear oscillator is transferred to the attached light mass through linked spring and damper. As a result, the nonlinear vibrations of the forced oscillator are greatly reduced and the vibrations of the absorber are significant. The method of multiple scales is used to obtain the averaged equations that determine the amplitude and phases of the first-order approximate solutions to primary resonance vibrations of the forced nonlinear oscillator. Illustrative examples are given to show the effectiveness of the dynamic vibration absorber for suppressing primary resonance vibrations. The effects of the linked spring and damper and the attached mass on the reduction of nonlinear vibrations are studied with the help of frequency response curves, the attenuation ratio of response amplitude and the desensitisation ratio of the critical amplitude of excitation. © 2009 Elsevier Ltd. All rights reserved.
Jiang, ZY, Tang, J, Sun, W, Tieu, AK & Wei, D 2010, 'Analysis of tribological feature of the oxide scale in hot strip rolling', Tribology International, vol. 43, no. 8, pp. 1339-1345.
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Kodagoda, S & Zhang, Z 2010, 'Multiple Sensor-Based Weed Segmentation', Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering, vol. 224, no. 7, pp. 799-810.
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Bidens pilosa L (commonly known as cobbler's peg) is an annual broad-leaf weed in tropical and subtropical regions and reportedly needs to be identified and eliminated when farming 31 different crop varieties. This paper presents a multi-modal sensing approach for detecting Bidens leaves within wheat plants. Visual cue-based automatic discrimination of Bidens and wheat leaves is non-trivial owing to the curled-up nature of the wheat leaves. Therefore, spectral responses of Bidens and wheat leaves are first analysed to understand the discriminative spectral bands. Then a multi-modal sensory system consisting of a near infra red (NIR) and a visual camera set-up is proposed. Information retrieved from the sensory set up is then processed to generate a series of cues that are fed into a classification algorithm. Classification results are validated through experimentation. The proposed technique is able to achieve an accuracy of 88—95 per cent even when there is substantial overlapping between Bidens and wheat leaves. Further, it is also shown that the algorithm is robust enough to discriminate some other commonly available plant species.
Lin, J, Luo, Z & Tong, L 2010, 'A new multi-objective programming scheme for topology optimization of compliant mechanisms', Structural and Multidisciplinary Optimization, vol. 40, no. 1-6, pp. 241-255.
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This paper presents an alternative method in implementing multi-objective optimization of compliant mechanisms in the field of continuum-type topology optimization. The method is designated as "SIMP-PP" and it achieves multi-objective topology optimization by merging what is already a mature topology optimization method-solid isotropic material with penalization (SIMP) with a variation of the robust multi-objective optimization method-physical programming (PP). By taking advantages of both sides, the combination causes minimal variation in computation algorithm and numerical scheme, yet yields improvements in the multi-objective handling capability of topology optimization. The SIMP-PP multi-objective scheme is introduced into the systematic design of compliant mechanisms. The final optimization problem is formulated mathematically using the aggregate objective function which is derived from the original individual design objectives with PP, subjected to the specified constraints. A sequential convex programming method, the method of moving asymptotes (MMA) is then utilized to process the optimization evolvement based on the design sensitivity analysis. The main findings in this study include distinct advantages of the SIMP-PP method in various aspects such as computation efficiency, adaptability in convex and non-convex multi-criteria environment, and flexibility in problem formulation. Observations are made regarding its performance and the effect of multi-objective optimization on the final topologies. In general, the proposed SIMP-PP method is an appealing multi-objective topology optimization scheme suitable for "real world" problems, and it bridges the gap between standard topological design and multi-criteria optimization. The feasibility of the proposed topology optimization method is exhibited by benchmark examples.
Lin, J, Luo, Z & Tong, L 2010, 'Design of Adaptive Cores of Sandwich Structures Using a Compliant Unit Cell Approach and Topology Optimization', Journal of Mechanical Design, vol. 132, no. 8, pp. 1-8.
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This paper presents a new method in designing the core layer of adaptive sandwich structures. The proposed design formulation treats the core layer as a compliant unit cell network while the unit cell network is synthesized by repeatedly linked identical compliant unit cells. Each unit cell is designed to possess shape adaptive functions independently and through the accumulation of the number of cells within the network, the global adaptive functions are accumulated also. Therefore, the network is capable of achieving large scale shape adaptations of complex profile with high fidelity. Topology optimization is used to design the compliant unit cell. Depending on the problem formulation, topology optimization can perform the simultaneous design of both the host material and the actuation material in the defined environment. This research includes a numerical case study to illustrate the technical aspects of this design philosophy. This is followed by the rapid prototyping of two scaled models and experimental validation.
Luo, Q & Tong, L 2010, 'Multi-physics field models of photostrictive unimorphs and heterogeneous bimorphs subjected to light illumination and mechanical loading', International Journal of Solids and Structures, vol. 47, no. 16, pp. 2006-2016.
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Luo, Z, Gao, W & Song, C 2010, 'Design of Multi-phase Piezoelectric Actuators', Journal of Intelligent Material Systems and Structures, vol. 21, no. 8, pp. 1851-1865.
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A new multi-objective topology optimization method is proposed in this study for systematic design of multi-phase piezoelectric actuators. The actuator under consideration is composed of a compliant host structure equipped with piezoelectric elements, where the host structure serves as a compliant amplifier to enlarge the small stroke output generated by the actuation force of piezoelectric materials. In the context of optimal design of smart actuators, however, most up-to-date approaches are either to optimize only the host passive structure with pre-determined piezoelectric stacks or to optimize the piezoelectric actuator with pre-known structure, both of which restricts the overall performance of multi-material actuators. To capture the inherent multi-criteria characteristic of compliant actuators, this study proposes a new multi-objective topology optimization formulation to consider both the structural stiffness and mechanical flexibility of the actuation system via the physical programming. A SIMP-based interpolation scheme is applied to describe practical material properties of any points in the orthotropic design domain. The design problem of the actuator is thus transformed to a numerical process of distributing multiple materials iteratively in the design domain until both the host structure and piezoelectric material elements are optimized. Two typical numerical examples are applied to demonstrate the effectiveness of this method in the design of in-plane actuation devices
Luo, Z, Gao, W & Song, C 2010, 'Design of Multi-phase Piezoelectric Actuators', Journal of Intelligent Material Systems and Structures, vol. 21, no. 18, pp. 1851-1865.
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A new multi-objective topology optimization method is proposed in this study for systematic design of multi-phase piezoelectric actuators. The actuator under consideration is composed of a compliant host structure equipped with piezoelectric elements, where the host structure serves as a compliant amplifier to enlarge the small stroke output generated by the actuation force of piezoelectric materials. In the context of optimal design of smart actuators, however, most up-to-date approaches are either to optimize only the host passive structure with pre-determined piezoelectric stacks or to optimize the piezoelectric actuator with pre-known structure, both of which restricts the overall performance of multi-material actuators. To capture the inherent multi-criteria characteristic of compliant actuators, this study proposes a new multi-objective topology optimization formulation to consider both the structural stiffness and mechanical flexibility of the actuation system via the physical programming. A SIMP-based interpolation scheme is applied to describe practical material properties of any points in the orthotropic design domain. The design problem of the actuator is thus transformed to a numerical process of distributing multiple materials iteratively in the design domain until both the host structure and piezoelectric material elements are optimized. Two typical numerical examples are applied to demonstrate the effectiveness of this method in the design of in-plane actuation devices.
Meng, X, Wang, S, Qiu, J, Zhu, JG, Wang, Y, Guo, Y, Liu, D & Xu, W 2010, 'Dynamic Multilevel Optimization of Machine Design and Control Parameters Based on Correlation Analysis', IEEE Transactions on Magnetics, vol. 46, no. 8, pp. 2779-2782.
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In this paper, a multilevel optimization method is proposed for a motor drive system including a surface-mounted permanent magnet synchronous machine (SPMSM), the converter/inverter, and the control schemes. First, the multilevel optimization is described by using the problem matrix which may be used to allocate the design variables on different levels. The parameters in the problem matrix are deduced by using correlation analysis. Second, the architecture and implementation of multilevel genetic algorithm (MLGA) are carried out. As one of the advantages of MLGA, the dynamic adjustment strategy of GA operators is utilized to improve the optimal performance. The algorithm is then applied to a three-level optimization problem in which the optimization of SPMSM design and the control parameters of drive are considered in different levels. Finally, some results and discussions about the application of the proposed algorithm are presented. © 2006 IEEE.
Morik, K, Deuse, J, Faber, V & Bohnen, F 2010, 'Data Mining in Sensordaten verketteter Prozesse', Zeitschrift für wirtschaftlichen Fabrikbetrieb, vol. 105, no. 1-2, pp. 106-110.
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Kurzfassung Das Prinzip der autonomen Automation wird als Methode der Lean Production zur Kostensenkung durch Vermeidung von Ausschuss und Nacharbeit genutzt. Während in Arbeitssystemen geringer Komplexität integrierte automatische Qualitätsprüfungen bereits erfolgreich zum Einsatz kommen, ist eine Übertragung auf komplexe, verkettete Arbeitssysteme derzeit nicht vollständig umsetzbar. In diesem Beitrag wird am Beispiel eines Walzprozesses ein auf maschinellen Lernverfahren basierender Ansatz zur Realisierung der autonomen Automation in komplexen, verketteten Produktionsprozessen vorgestellt. Hierbei werden verschiedene Herausforderungen, welche durch produktionstechnische Restriktionen entstehen, aufgezeigt und die Notwendigkeit von Weiterentwicklungen bestehender Lernverfahren unter der Zielsetzung der Einbindung in die Produktion dargelegt.
Morik, K, Stolpe, M, Deuse, J, Bohnen, F & Reichel, U 2010, 'Forecast model for the determination of product characteristics: Application of data mining procedures in the rolling mill', Stahl und Eisen, vol. 130, no. 10, pp. 80-82.
Morik, K, Stolpe, M, Deuse, J, Bohnen, F & Reichel, U 2010, 'Use of data-mining techniques in the rolling work.', STAHL UND EISEN, vol. 130, no. 10, pp. 80-82.
Parnell, J, Samuels, S & Tsitsos, C 2010, 'The acoustic performance of novel noise barrier profiles measured at the roadside', Acoustics Australia, vol. 38, no. 3, pp. 123-128.
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As part of continuing investigation into noise barrier optimisation, a research and development study to conduct insitu empirical testing of several full size prototype barrier designs was funded by the NSW State Government. Of particular interest to this study was a design known as a random edge profile barrier. Literature research had found that there was a body of evidence indicating that a barrier with an edge irregularity can cause a substantial degradation of the diffracted signal. It is generally accepted that an increase in insertion loss occurs because the jagged edge causes a reduction in coherence of the diffracted signal being transmitted to the shadow zone as compared to a conventional straight edge barrier [1-3]. It has been suggested that the mechanism for this is that the jagged geometry on the top of a barrier alters the sound pressure level in the shadow zone by causing the region of the barrier nearest the receiver to admit multiple paths with variable phase [4]. The direct waves from the diffracting edges of the barrier and waves subsequently reflected from the ground plane are superimposed at the receiver causing constructive or destructive interference at the receiver. The present study followed a methodology that included construction of an 80m long by 2.4m high barrier that served as the base for an additional conventional top as well as a random profile and T-top novel cap. Empirical data collected showed that for the receiver locations investigated, a random edge barrier will out-perform a conventional barrier of the same nominal height for most frequencies associated with broadband tyre/road noise. A T-top barrier was found to perform better than a conventional barrier of similar height for most frequencies whilst a conventional barrier offered the most practical solution for attenuation of low frequency noise.
Parnell, J, Samuels, S & Tsitsos, C 2010, 'The performance of noise barriers in attenuating road traffic noise', Acoustics Bulletin, vol. 35, no. 3, pp. 23-29.
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A research and development study was conducted by the New South Wales State Government for empirical testing of several full size prototype barrier designs. The study site was located on a section of the Hume Highway in New South Wales between Marulan and Goulburn. The barriers were constructed of a 28mm timber laminate exclusively for use as a noise barrier. This laminate was provided in sheets that were 2.4 x 1.2 meters and were fixed between galvanized H-beams. Three precision microphones were set up at various locations in front of and behind each barrier configuration. Designated A, B, and C these microphones captured traffic noise data simultaneously at various combinations of the measurement points (MPs). Synchronized video footage of the roadway was also collected to allow identification and characterization where necessary of the traffic noise sources. The random edge barrier with a nominal height of 3.0m was found to approximate the performance of a 3.0m conventional barrier at microphone locations (MP2 and MP4) close to the barrier.
Petzelt, D, Busch, F, Schallow, J & Deuse, J 2010, 'Entwicklung einer Referenzplanungssystematik der digitalen Produktentstehung', Zeitschrift für wirtschaftlichen Fabrikbetrieb, vol. 105, no. 3, pp. 168-172.
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Kurzfassung Zur Reduzierung von Planungszeit und -kosten sowie zur Steigerung der Produktivität müssen alle Aufgaben der Produktentstehung optimal aufeinander abgestimmt sein. Die erforderliche enge Zusammenarbeit unterschiedlicher Fachdomänen wird jedoch auf Grund zahlreicher Schnittstellenprobleme vielfach nicht erreicht. Die Ursachen hierfür liegen sowohl in organisatorischen als auch in technischen Defiziten, die eine mit allen Partnern abgestimmte Planung verhindern. Gerade die Vernetzung von digitalen und nicht-digitalen Methoden ist bislang in den Unternehmen nur unzureichend realisiert. Um die Durchgängigkeit von Planungsprozessen und die Abstimmung von Planungsteilbereichen zu erhöhen, wird eine domänenübergreifende Referenzplanungssystematik entwickelt.
Raveendran, A, Gupta, S, Bagga, R, Saha, SC, Gainder, S, Dhaliwal, LK, Patel, F, Dey, P & Nijhawan, R 2010, 'Advanced germ cell malignancies of the ovary: Should neo-adjuvant chemotherapy be the first line of treatment?', Journal of Obstetrics and Gynaecology, vol. 30, no. 1, pp. 53-55.
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Saha, SC, Patterson, JC & Lei, C 2010, 'Natural convection and heat transfer in attics subject to periodic thermal forcing', International Journal of Thermal Sciences, vol. 49, no. 10, pp. 1899-1910.
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Saha, SC, Patterson, JC & Lei, C 2010, 'Natural convection boundary-layer adjacent to an inclined flat plate subject to sudden and ramp heating', International Journal of Thermal Sciences, vol. 49, no. 9, pp. 1600-1612.
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Saha, SC, Patterson, JC & Lei, C 2010, 'Natural convection in attics subject to instantaneous and ramp cooling boundary conditions', Energy and Buildings, vol. 42, no. 8, pp. 1192-1204.
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Saha, SC, Patterson, JC & Lei, C 2010, 'Natural convection in attic-shaped spaces subject to sudden and ramp heating boundary conditions', Heat and Mass Transfer, vol. 46, no. 6, pp. 621-638.
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Saha, SC, Patterson, JC & Lei, C 2010, 'Scaling of natural convection of an inclined flat plate: Ramp cooling condition', International Journal of Heat and Mass Transfer, vol. 53, no. 23-24, pp. 5156-5166.
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Su, SW, Huang, S, Wang, L, Celler, BG, Savkin, AV, Guo, Y & Cheng, TM 2010, 'Optimizing Heart Rate Regulation for Safe Exercise', ANNALS OF BIOMEDICAL ENGINEERING, vol. 38, no. 3, pp. 758-768.
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Safe exercise protocols are critical for effective rehabilitation programs. This paper aims to develop a novel control strategy for an automated treadmill system to reduce the danger of injury during cardiac rehabilitation. We have developed a control-oriented nonparametric Hammerstein model for the control of heart rate during exercises by using support vector regression and correlation analysis. Based on this nonparametric model, a model predictive controller has been built. In order to guarantee the safety of treadmill exercise during rehabilitation, this new automated treadmill system is capable of optimizing system performance over predefined ranges of speed and acceleration. The effectiveness of the proposed approach was demonstrated with six subjects by having their heart rate track successfully a predetermined heart rate. © 2009 Biomedical Engineering Society.
Vidal-Calleja, TA, Sanfeliu, A & Andrade-Cetto, J 2010, 'Action Selection for Single-Camera SLAM', IEEE Transactions on Systems, Man, and Cybernetics, Part B (Cybernetics), vol. 40, no. 6, pp. 1567-1581.
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A method for evaluating, at video rate, the quality of actions for a single camera while mapping unknown indoor environments is presented. The strategy maximizes mutual information between measurements and states to help the camera avoid making ill-conditioned measurements that are appropriate to lack of depth in monocular vision systems. Our system prompts a user with the appropriate motion commands during 6-DOF visual simultaneous localization and mapping with a handheld camera. Additionally, the system has been ported to a mobile robotic platform, thus closing the control-estimation loop. To show the viability of the approach, simulations and experiments are presented for the unconstrained motion of a handheld camera and for the motion of a mobile robot with nonholonomic constraints. When combined with a path planner, the technique safely drives to a marked goal while, at the same time, producing an optimal estimated map. © 2010 IEEE.
Wei, D, Huang, J, Zhang, A, Jiang, Z, Tieu, AK, Shi, X, Jiao, S & Chen, L 2010, 'Deformation of Oxide Scale and Roll-Strip Interface Characteristics in Hot Rolling of Stainless Steel 304', STEEL RESEARCH INTERNATIONAL, vol. 81, no. 9, pp. 102-105.
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The deformation of oxide scale affects roll-strip interface characteristics in hot rolling. Few studies have been carried out on the deformation behavior of oxide scale in hot rolling of stainless steels. In this paper, the thickness, morphology of the oxide scale and the surface roughness of workpiece in hot rolling of stainless steel 304 under the condition of a single pass were investigated, and the friction coefficients were calculated. The effect of humidity on the growth of oxide scale of stainless steel 304 has been identified. Outer and inner oxide layers can be found when the water vapor content is over 7 vol.%. An incomplete oxide layer which is a transition layer between the inner oxide layer and steel substrate can be distinguished in thick oxide scale when the water vapour content is over 12 vol.%. The oxide scale thickness decreases linearly with an increase of reduction. Surface roughness also decreases with an increase of reduction. After experiencing 20 and 30 % reduction, the surface roughness asperities are flattened, so the outmost surface of oxide scale after rolling is much smoother than that before rolling. Generally, friction coefficients decrease with an increase of reduction.
Yu, Y-H, Vo-Ky, C, Kodagoda, S & Ha, QP 2010, 'FPGA-Based Relative Distance Estimation for Indoor Robot Control Using Monocular Digital Camera', Journal of Advanced Computational Intelligence and Intelligent Informatics, vol. 14, no. 6, pp. 714-721.
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Distance measurement methodologies based on the digital camera usually require time-consuming calibration procedures, some are even derived from complicated image processing algorithms resulting in low picture frame rates. In a dynamic camera system, due to the unpredictability of intrinsic and extrinsic parameters, odometric results are highly dependent on the quality of extra sensors. In this paper, a simple and efficient algorithm is proposed for relative distance estimation in robotic active vision by using a monocular digital camera. Accuracy of the estimation is achieved by judging the 2D perspective projection image ratio of the robot labels obtained on a TFT-LCD (Thin Film Transistor – Liquid Crystal Display) monitor without the need of any additional sensory cost and complicated calibration effort. Further, the proposed algorithm does not contain any trigonometric functions so that it can be easily implemented on an embedded system using the Field Programmable Gate Array (FPGA) technology. Experimental results are included to demonstrate the effectiveness of the technique.
Zhang, X, Jiang, Z, Wei, D, Liu, X & Wang, G 2010, 'Analysis of Casting Roll during Twin-Roll Thin Strip Casting', STEEL RESEARCH INTERNATIONAL, vol. 81, no. 9, pp. 138-141.
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In twin-roll thin strip casting, the temperature of a casting roll affects the roll thermal stress, and influences the thermal deformation, the generation of roll surface cracks, the strip shape and the service life of the casting roll. In this paper, the features of the clad materials of the casting roll have been analysed, the effect of the clad thickness on the temperature field and thermal stress of casting roll has been simulated and discussed. The results show that the thick clad results in the increase of thermal resistance and then causes higher surface temperature of the clad layer, but lower temperature of copper roll sleeve. The heat expansion of the clad layer increases when the clad thickness decreases. The developed temperature model of the casting roll is helpful in optimising the design of the casting roll during twin-roll thin strip casting.
Zhang, Z, Kodagoda, S, Ruiz, D, Katupitiya, J & Dissanayake, G 2010, 'Classification of Bidens in wheat farms', International Journal of Computer Applications in Technology, vol. 39, no. 1-3, pp. 123-129.
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Bidens pilosa L. (commonly known as cobbler’s peg) is an annual broad leaf weed widely distributed in tropical and subtropical regions of the world and is reported to be a weed of 31 crops, including wheat. Automatic detection of Bidens in wheat farms is a non-trivial problem due to their similarity in colour and presence of occlusions. This paper proposes a methodology which could be used to discriminate Bidens from wheat to be used in operations such as autonomous weed destruction. A spectrometer is used to analyse the optical properties of Bidens and wheat leaves while achieving high classification results. However, due to the practical constraints of using spectrometers, a colour camera-based technique is proposed. It is shown that the colour-based segmentation followed by shape-based validation algorithm gives rise to high detection rates with lower false detections. We have experimentally evaluated the algorithm with Bidens detection rate of 80% and a false alarm rate of 10%. © 2010 Inderscience Enterprises Ltd.
Zhang, Z, Kodagoda, S, Ruiz, D, Katupitiya, J & Dissanayake, G 2010, 'Classification of Bidens in wheat farms', International Journal of Computer Applications in Technology, vol. 39, no. 1/2/3, pp. 123-123.
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Zhao, Y-S, Liu, Z-F, Cai, L-G, Yang, W-T, Yang, J & Luo, Z 2010, 'Study of control for the automated clutch of an automated manual transmission vehicle based on rapid control prototyping', Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, vol. 224, no. 4, pp. 475-487.
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Owing to external disturbances, parameter uncertainty, and measurement noise, it has been a challenging task to develop an appropriate controller for the automated clutch system. This paper proposes a new method for electromechanical clutch position control systems. First, a non-linear dynamic model for the screw-nut actuator associated with a clutch is derived, and then a dynamic sliding-mode controller with fuzzy adaptive tuning is developed. The fuzzy adaptive tuning arithmetic is used to improve the robustness and stability of the controller. At the same time, the chattering phenomenon is alleviated by adopting the proposed controller. Based on dSPACE and MATLAB—Simulink, the rapid control prototyping of the automated clutch is used as a method to demonstrate the efficiency and robustness of the proposed algorithm.
Ahmad, A, Huang, S & Dissanayake, G 1970, 'Accurate large-scale bearing-only SLAM by map joining', Proceedings of the 2010 Australasian Conference on Robotics and Automation, ACRA 2010, Proceedings of the Australasian Conference on Robotics and Automation, Australasian Conference on Robotics and Automation, Brisbane, Queensland, Australia, pp. 1-10.
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This paper presents a bearing-only SLAM algorithm that generates accurate and consistent maps of large environments by joining a series of small local maps. The local maps are built by least squares optimization with a proper landmark initialization technique. The local maps are then combined to build global map using Iterated Sparse Local Submap Joining Filter (I-SLSJF). The accuracy and consistency of the proposed algorithm is evaluated using simulation data sets. The algorithm is also tested using the DLR-Spatial-Cognition data set and the preprocessed Victoria Park data where the range information is ignored. The global map results are very similar to the result of full least squares optimization starting with very accurate initial values. As I-SLSJF is able to join a given set of local maps and associated uncertainties efficiently without any information loss, these results demonstrate that focusing on generating accurate local maps is a promising direction for solving large-scale bearing-only SLAM problems.
Behrens, M, Huang, S, Dissanayake, G & IEEE 1970, 'Models for pushing objects with a mobile robot using single point contact', IEEE/RSJ 2010 INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS (IROS 2010), IEEE/RSJ International Conference on Intelligent Robots and Systems, IEEE, Taipei, Taiwan, pp. 2964-2969.
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In many mobile robotic manipulation tasks it is desirable to interact with the robots surroundings without actually grasping the object being manipulated. Non-prehensile manipulation allows a robot to interact in situations which would otherwise be impossible due to size or weight. This paper presents the derivation of a mathematical model of an object pushed by a single point and sliding in the presence of friction where the dynamic effects of mass and inertia are significant. This model is validated using numerical simulation. The derived dynamic model is also compared with a kinematic approximation from literature, showing that under certain conditions, the motion of a pushed object is similar to the motion of a non-holonomic vehicle. Finally, the results of experimental investigations are discussed and promising directions for further work are proposed. ©2010 IEEE.
Cagno, E & Trianni, A 1970, 'Energy Efficiency in Industrial Operations: An Evaluation of Benefits and Cost of the Most Effective Interventions Within the Italian Industrial Sector', ASME 2010 4th International Conference on Energy Sustainability, Volume 1, ASME 2010 4th International Conference on Energy Sustainability, ASMEDC, Phoenix, AZ, pp. 85-93.
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The attention towards the topic of reducing the energy expenditures has dramatically grown in recent crisis times that have forced firms to reduce them. This reduction in energy expenditures of a firm can be pursued through a wise energy procurement (we can call it “administrative energy efficiency”), thus with a reduction in the specific cost of energy (both electricity and other energy sources). But, the highest effective saving — for the whole system — would come from a direct reduction of the consumption, thus increasing the so-called “operational energy efficiency”, the unique true energy efficiency, implying the effort of the whole firm, since it requires a lower and wiser use of energy, and new and more efficient technologies. It is quite diffused the perception that governments are now taking measures to reach a common and more efficient environmental and energetic policy, but the effort is still not sufficient. The attention has obviously been paid towards the industrial sector, that covers about 30% of the consumption, second just after transportation: since now several actions have been taken to achieve the energy performance of buildings, but very few in the operations. Furthermore, it should be clear that to be really effective in this field governments should focus their attention on Small & Medium Enterprises (SMEs), usually less efficient than Large Enterprises (LEs), since SMEs represent the vast majority of the total number of industries and cover a consistent share of the energy consumption of a whole domestic industrial sector. This paper aims at providing an overview of the most effective interventions for reducing energy consumption in industrial operations that have been successfully implemented in a large number of case studies investigated in North America and Europe. The paper provides different scenarios according to the implementation of those interventions, characterized all by being Best Available Technologies a...
Carmichael, MG, Liu, D & Waldron, KJ 1970, 'Investigation of reducing fatigue and musculoskeletal disorder with passive actuators', 2010 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2010 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2010), IEEE, Taipei, Taiwan, pp. 2481-2486.
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Robotic systems such as exoskeletons can be effectively used in the reduction of fatigue and musculoskeletal disorders (MSD) associated with physical tasks, but robots which work in physical contact with humans pose problems with user safety. A novel approach to developing intrinsically safe robots is to use passive actuators which have the advantage of being safer, ensuring stability, high force/weight ratios and lower power consumption. It is however not clear how effective an exoskeleton utilizing passive actuators would be in reducing fatigue and the risk of MSD. This paper analyzes the benefit of using such a system with results from dynamic simulations and an experiment using a specially designed mechanism used for evaluation. Results indicate that fatigue and effort could be reduced if robot impedance is minimized. Experiments also highlighted issues of implementing such a system into practice. ©2010 IEEE.
Czlonka, A, Nelson, T, Dibbs, RL & Huynh, P 1970, 'Performance of a new stator-diffuser design for an axial-flow pump unit', Proceedings of the 17th Australasian Fluid Mechanics Conference, Australasian Fluid Mechanics Conference, The University of Auckland, Auckland, New Zealand, pp. 1-4.
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In an axial-flow pump unit with conventional stator and diftllser, often considerable energy is still present in the swirl (rotation) of the liquid leaving the stator. This energy will eventually be lost from the pump system. In this experimental investigation a new design, combining the stator and diffuser together into a single component, was tested for its effectiveness in recovering this energy and thereby improving the performance of an industrysized single-stage axial-flow pump unit. Measurements of static pressure rise along the new stator-difTuser and of the swirl angle of the fluid leaving the pump unit indicate that the new design performs better than the conventional one, as a component. However, efticiency of the whole pump unit is in general slightly reduced with the new design. A number of factors were identified as contributing to this performance degradation. Most notable are the poor matching of the fluid's and vanes' angles at the component's inlet and the sudden expansion of the flow geometry at the component's outlet. It is thus expected that when these factors have been adequately addressed, the new design should improve the pump's overall performance.
Doull, A & Huynh, P 1970, 'An experimental investigation of pressure loss in canvas fire hose', Proceedings of the 17th Australasian Fluid Mechanics Conference, Australasian Fluid Mechanics Conference, The University of Auckland, Auckland, New Zealand, pp. 1-4.
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The NSW Rural Fire Service (RFS) of Australia uses canvas 'lay flaf' fire hose to deliver water at an incident. A single 'rule of thumb' figure for the estimated pressure loss over a length (approx 30m) of canvas hose is used. This figure is a general average based off figures published by the hose manufacturer. These figures in tmn were obtained from tests as per the Australian Standard AS-2792, which requires the hose to be under defined conditions. However, these conditions do not reproduce what is happening in a real-life fire-fighting situation. One example of the non-realistic conditions is the hose being laid completely straight. For, even in the most ideal situation, the hose still has to curve down from the back of the truck to the ground. In this experimental investigation, a test rig was set up to measure pressure loss over a length of canvas fire hose under a range of situations similar to how the hose will be laid in an actual scenario. The measured losses were found to be significantly greater than results published by the hose manufacturer, with the difference increasing with more severe bends and twists in the laid hose. The difference also varies with hose diameter. On the other hand, hose age was found to have a negligible effect on losses, contrary to expectation.
Elliott, RM, McKinley, SM & Eager, D 1970, 'A pilot study of sound levels in an Australian adult general intensive care unit', NOISE & HEALTH, 6th Annual Congress of the World Federation of Critical Care Nurses and 10th Congress of the World Federation of the Societies of Intensive and Critical Care Medicine, WOLTERS KLUWER MEDKNOW PUBLICATIONS, Florence, Italy, pp. 26-36.
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BACKGROUND/OBJECTIVES: High technology and activity levels in the intensive care unit (ICU) lead to high sound levels. As noise has been shown to affect the ability of patients to rest and sleep continuous sound levels are required during sleep investigations. The aim of this pilot study was to develop a robust protocol to measure continuous sound levels for a larger more substantive future study to improve sleep for the ICU patient. METHODS: A review of published studies of sound levels revealed sufficient information to develop a study protocol (twenty-three papers were used). An integrated sound level meter Class 1 was used. The microphone was placed 0.75 to 1m above the patientâs head. Sound recording was simultaneous to 24 hour sleep monitoring (polysomnography). Five broadband parameters were set: LAeq, LCpeak, LAFmax, LAFmin and LCeq along with LZ spectra recorded at a sampling and logging frequency of one sample per second. RESULTS: The study protocol resulted in 10 usable recordings out of 11 attempts to collect pilot data. The mean recording time was 17.49±4.5 hours. Sound levels exceeded recommendations made by the World Health Organization (WHO) for hospitals. The mean equivalent sound level (LAeq) was 56.22±1.65 dB and LA90 was 46.8±2.46 dB. CONCLUSION: The data reveal the requirement for a noise reduction program within this ICU. GRANT ACKNOWLEDGEMENT: Australian College of Critical Care Nurses awarded a research grant of A$15,000 in 2008.
Godfrey, E, Aubrey, T & King, R 1970, 'Who leaves and who stays? Retention and attrition in engineering education', Engineering Education 2010: Inspiring the Next Generation of Engineers, EE 2010, Engineering Education Conference, The Higher Education Academy Engineering Subject Centre, Aston University, UK, pp. 1-13.
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At a time of high demand for engineering graduates, the mean graduation completion rate of engineering undergraduates in Australia has been identified as approximately 54% (with considerable variation across institutions and sectors). This proportion of non-completions has been viewed as an excessive loss to the qualified workforce of Australia. Broad brush, government-collected statistics do not, however, provide the level of detail required to understand who leaves, when and why they leave, and where they go. This paper reports on a pilot study undertaken to precede and inform final decisions on research design and methodology for a multi institutional project seeking to understand and reduce student attrition from engineering degrees across Australia. The aim of the project is to produce guidelines on curriculum formulation and delivery strategies to reduce attrition in engineering programs while meeting outcomes. The pilot study was conducted at an institution which has a relatively diverse range of students, a high proportion of whom study part time, and engineering degree structures incorporating traditional and internship-based degrees. Results from a cohort analysis, tracking pathways to completion or non-completion of the degree for the cohorts from two specific entry years will be presented. From this analysis, groups of students who 'persisted over long periods', 'switched to another degree' or 'withdrew from the university' were identified and interviewed. Their experiences and stories, were an essential ingredient for a better understanding of the dynamics of retention/attrition and factors which required further questioning before proceeding with the multi institutional study. © 2009 Authors.
Godfrey, E, Aubrey, T & King, R 1970, 'Work in progress — Academic Pathways of People Learning Engineering — An Australian study', 2010 IEEE Frontiers in Education Conference (FIE), 2010 IEEE Frontiers in Education Conference (FIE), IEEE.
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In Australia a multi-institutional project is underway, with one of its major themes the understanding and reduction of attrition in engineering programs. The Academic Pathways for People Learning Engineering Survey (APPLES) instrument was trialled at a participating institution as a possible precursor to its application in the eight collaborating institutions. APPLES had been validated and delivered to over 4000 engineering undergraduates by the Academic Pathways Study in the US. The survey was trialled with 259 engineering students from different year levels to explore its potential to find links between students' perceptions of their motivation, skills and confidence with their goals to continue to degree completion and employment in engineering. This paper reports on the initial findings from the Australian pilot study. Matching the self reported data in the survey with statistical data has, even at this initial stage, highlighted some discrepancies and topics for further investigation. © 2010 IEEE.
Godfrey, E, Aubrey, T, Crosthwaite, C & King, R 1970, 'Who leaves and when do they go? Retention and attrition in engineering education', 2010 IEEE Frontiers in Education Conference (FIE), 2010 IEEE Frontiers in Education Conference (FIE), IEEE.
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At a time of high demand for engineering graduates, the mean graduation completion rate of engineering undergraduates in Australia has been identified as approximately 54% (with considerable variation across institutions and sectors). This paper reports on the initial results of cohort analyses undertaken at two engineering degree granting institutions as part of a multi institutional project seeking to understand and reduce student attrition from engineering degrees across Australia. Both institutions have a predominantly urban student population and location, but whilst one offers a conventional four year degree the other integrates two semesters of internship into its degree structure. A cohort analysis procedure, tracking pathways to completion or non-completion of the degree, applicable across diverse institutions, was piloted. Attributes such as gender, academic background, full or part time study, engineering major and student maturity were identified for each member of the cohort. The patterns revealed by these fine grained cohort analyses challenged some anecdotal perceptions and provided evidence of the inadequate nature of generalizations around attrition statistics, and the need for institutional context and culture to be considered. © 2010 Crown.
Hu, G, Huang, S, Dissanayake, G & IEEE 1970, 'Evaluation of Pose Only SLAM', IEEE/RSJ 2010 INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS (IROS 2010), IEEE/RSJ International Conference on Intelligent Robots and Systems, IEEE, Taipei, Taiwan, pp. 3732-3737.
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In recent SLAM (simultaneous localization and mapping) literature, Pose Only optimization methods have become increasingly popular. This is greatly supported by the fact that these algorithms are computationally more efficient, as they focus more on the robots trajectory rather than dealing with a complex map. Implementation simplicity allows these to handle both 2D and 3D environments with ease. This paper presents a detailed evaluation on the reliability and accuracy of Pose Only SLAM, and aims at providing a definitive answer to whether optimizing poses is more advantages than optimizing features. Focus is centered around TORO, a Tree based network optimization algorithm, which has gained increased recognition within the robotics community. We compare this with Least Squares, which is often considered one of the best Maximum Likelihood method available. Results are based on both simulated and real 2D environments, and presented in a way where our conclusions can be substantiated. ©2010 IEEE.
Huang, S, Lai, Y, Frese, U, Dissanayake, G & IEEE 1970, 'How far is SLAM from a linear least squares problem?', IEEE/RSJ 2010 INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS (IROS 2010), IEEE/RSJ International Conference on Intelligent Robots and Systems, IEEE, Taipei, Taiwan, pp. 3011-3016.
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Most people believe SLAM is a complex nonlinear estimation/optimization problem. However, recent research shows that some simple iterative methods based on linearization can sometimes provide surprisingly good solutions to SLAM without being trapped into a local minimum. This demonstrates that hidden structure exists in the SLAM problem that is yet to be understood. In this paper, we first analyze how far SLAM is from a convex optimization problem. Then we show that by properly choosing the state vector, SLAM problem can be formulated as a nonlinear least squares problem with many quadratic terms in the objective function, thus it is clearer how far SLAM is from a linear least squares problem. Furthermore, we explain that how the map joining approaches reduce the nonlinearity/nonconvexity of the SLAM problem. ©2010 IEEE.
Huynh, P 1970, 'Natural ventilation induced by solar chimneys', Proceedings of the 17th Australasian Fluid Mechanics Conference, Australasian Fluid Mechanics Conference, The University of Auckland, Auckland, New Zealand, pp. 1-4.
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Natural-ventilation flow through a two-dimensional but realsized square room is investigated numerically, using a commercial Computational Fluid Dynamics (CFD) software package. The flow is induced by a solar chimney positioned on the room's roof, and it is desired to have this flow passing through the lower part of the room for ventilation purpose. The chimney in turn is in the form of a parallel channel with one plate kept at a uniform temperature that is higher than that of the ambient air (by up to 40°C), while the other plate and all of the room's walls are insulated. Eftects on ventilation flow rate and flow pattern due to a range of changing factors are invcstigated. The factors include temperature of the chimney's heated plate, length and inclination of the chimney, its location and locations of the room's other openings, and the presence of a vertical partition in the room. It is found that all these factors affect either the flow rate or flow pattern, or both. Maximum flow rate is obtained when solar chimney is in a vertical position at a roofs corner, with its heated plate on the room side. On the other hand, flow rate increases with increasing solar plate's temperature and length, as expected, but the manner of the increase varies with relative positions behYcen the chimney and room inlcts.
Jiang, ZY, Du, XZ, Du, YB, Wei, DB & Hay, M 1970, 'Modeling of Strip Shape during Cold Rolling of Thin Strip', Key Engineering Materials, 9th Asia-Pacific Conference on Materials Processing, Trans Tech Publications, Ltd., Sydney, AUSTRALIA, pp. 9-14.
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Strip shape is an important factor affecting the strip quality significantly during cold rolling of thin strip. In the paper, finite element simulation models of the strip shape in cold rolling for both symmetrical and asymmetrical rolling cases were successfully developed. The strip edge drop and the effect of the rolling force on the strip shape (the thickness distribution along the strip width) have been obtained. The developed finite element model has been verified with the experimental value, which shows they are in good agreement. The obtained results are applicable to control the rolled thin strip shape during cold rolling practice.
Jiang, ZY, Du, XZ, Du, YB, Wei, DB & Hay, M 1970, 'Strip Shape Analysis of Asymmetrical Cold Rolling of Thin Strip', Advanced Materials Research, International Conference on Manufacturing Science and Engineering (ICMSE 2009), Trans Tech Publications, Ltd., Zhuhai, PEOPLES R CHINA, pp. 81-84.
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Strip shape control during cold rolling of thin strip is a challenge in rolling practice. In the paper, finite element model of strip shape during cold rolling of thin strip in asymmetrical rolling case was successfully developed, and the strip shape such as the thickness distribution along the strip width have been obtained. The developed finite element model has been verified with the experimental value, which shows they are in good agreement. The obtained results are applicable to control the rolled thin strip shape in practice.
Jiang, ZY, Du, XZ, Du, YB, Wei, DB & He, XF 1970, 'Analysis of Advanced Strip Shape during Cold Rolling of Thin Strip', Materials Science Forum, 7th Pacific Rim International Conference on Advanced Materials and Processing, Trans Tech Publications, Ltd., Cairns, AUSTRALIA, pp. 206-209.
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The demand of thin gauge strip with good quality such as the strip shape and surface finish is significantly increasing. In this study, finite element model of the strip shape during cold rolling of thin strip in asymmetrical rolling was developed, and the finite element simulation of the thin strip shape has been carried out in LS-DYNA. The effects of reduction and speed ratio on the strip shape and profile and the strip edge drop have been obtained. The developed finite element model has been verified with the experimental data. The obtained results are applicable to the control of the rolled thin strip shape in rolling practice.
Jiang, ZY, Tang, JN, Tieu, AK, Sun, WH & Wei, DB 1970, 'Analysis of Surface Roughness Transformation of Oxide Scale during Hot Steel Manufacturing', Advanced Materials Research, 13th International Symposium on Advances in Abrasive Technology/1st Cross-Strait Conference on Precision Machining, Trans Tech Publications, Ltd., Taipei, TAIWAN, pp. 987-992.
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In this paper, the effects of the surface asperity wavelength, reduction and lubrication (friction) on the surface roughness transformation of the oxide scale have been studied. The simulation results show that the oxide scale surface roughness decreases with an increase of the average asperity wavelength and reduction. The initial surface roughness affects the decrease rate of surface roughness when the reduction increases. The surface roughness of the oxide scale and steel is quite close when the rolling with lubrication and both of them are reduced with reduction, and the surface roughness of the oxide scale is reduced less comparing with that of without lubrication case. The calculated roughness is close to the measured data.
Kirchner, N, Alempijevic, A, Caraian, S, Fitch, R, Hordern, D, Hu, G, Paul, G, Richards, D, Singh, SPN & Webb, S 1970, 'RobotAssist - A platform for human robot interaction research', Proceedings of the 2010 Australasian Conference on Robotics and Automation, ACRA 2010, Proceedings of the Australasian Conference on Robotics and Automation, Australasian Conference on Robotics and Automation, Brisbane, pp. 1-10.
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This paper presents RobotAssist, a robotic platform designed for use in human robot interaction research and for entry into Robocup@Home competition. The core autonomy of the system is implemented as a component based software framework that allows for integration of operating system independent components, is designed to be expandable and integrates several layers of reasoning. The approaches taken to develop the core capabilities of the platform are described, namely: path planning in a social context, Simultaneous Localisation and Mapping (SLAM), human cue sensing and perception, manipulatable object detection and manipulation.
Kodagoda, S, Zhang, Z & Dissanayake, G 1970, 'Crop and weed classification based on a colour and NIR sensory setup', Proc. Innovative Production Machines and Systems - 5th I*PROMS Virtual International Conference, International Conference on Innovative Production Machines and Systems, Whittles Publishing, Virtual conference, pp. 212-217.
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This paper presents a multi-modal sensing approach for detecting Bidens pilosa L (commonly known as cobbler's peg) in wheat farms. Bidens is an annual broad leaf weed in tropical and sub-tropical regions and reported to be a weed that needs to be identified and eliminated when farming thirty one different crop varieties. Both Bidens and wheat leaves can have similar visual cues due to the curled up nature of the wheat leaves. This makes a straightforward visual image (RGB) based classification nontrivial. Therefore, we have integrated another informative band in the spectrum, which is the NIR band. Information retrieved is processed to generate a series of cues that are then fed into a classification algorithm. Bidens and wheat plant species are used to verify the classification algorithm. The proposed technique is able to achieve an accuracy of 88% - 95% even when there is substantial overlapping between Bidens and wheat leaves.
Li, HJ, Jiang, ZY, Wei, DB, Han, JT & Tieu, AK 1970, 'Crystal Plasticity Finite Element Modelling of the Influence of Friction on Surface Roughening during Uniaxial Planar Compression', Materials Science Forum, 7th Pacific Rim International Conference on Advanced Materials and Processing, Trans Tech Publications, Ltd., Cairns, AUSTRALIA, pp. 1606-1609.
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The friction is a key factor that influences the surface quality in metal forming. To figure out the relationship between the friction and the surface roughening, a finite element model is employed in the commercial finite element software ABAQUS to simulate the surface roughness of top side of Al plate during uniaxial planar compression. With the change of friction conditions, the surface roughening varies. The average surface roughness (Ra) shows a relationship with the friction coefficient. During the surface roughening process, the grain slip takes place in the “soft orientation”, and the “hard orientations” become the barrier of the slip.
Liu, M, Huang, S, Dissanayake, G, Kodagoda, S & IEEE 1970, 'Towards a Consistent SLAM Algorithm using B-Splines to Represent Environments', IEEE/RSJ 2010 INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS (IROS 2010), IEEE/RSJ International Conference on Intelligent Robots and Systems, IEEE, Taipei, Taiwan, pp. 2065-2070.
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This paper presents a statistically consistent SLAM algorithm where the environment is represented using a collection of B-Splines. The use of B-Splines allow environment to be represented without having to extract specific geometric features such as lines or points. Our previous work proposed a new observation model that enables raw measurements taken from a laser range finder to be transferred into relative position information between the control points of a B-Spline and the robot pose where the observation is made. One of the unresolved issues in the work was the estimation of the observation covariance, which is addressed through an analytical approach in this paper. As the uncertainty associated with the observation model is accurately defined and an optimization approach is used in the estimation process, the proposed SLAM algorithm can produce consistent estimates. Both simulation and experimental data are used for evaluation of the results. ©2010 IEEE.
Miro, JV & Dissanayake, G 1970, 'Automatic fine motor control behaviours for autonomous mobile agents operating on uneven terrains', Proceedings of the 3rd International Symposium on Practical Cognitive Agents and Robots, PCAR '10: 2010 International Symposium on Practical Cognitive Agents and Robots, ACM, Toronto, Canada, pp. 33-40.
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A novel mechanism able to produce increasingly stable paths for mobile robotic agents travelling over uneven terrain is proposed in this paper. In doing so, cognitive agents can focus on higher-level goal planning, with the increased confidence the resulting tasks will be automatically accomplished via safe and reliable paths within the lower-level skills of the platform. The strategy proposes the extension of the Fast Marching level-set method of propagating interfaces in 3D lattices with a metric to reduce robot body instability. This is particularly relevant for kinematically reconfigurable platforms which significantly modify their mass distribution through posture adaptation, such as humanoids or mobile robots equipped with manipulator arms or varying traction arrangements. Simulation results of an existing reconfigurable mobile rescue robot operating on real scenarios illustrate the validity of the proposed strategy. Copyright 2010 ACM.
Miro, JV, Dumonteil, G, Beck, C, Dissanayake, G & IEEE 1970, 'A Kyno-dynamic Metric to Plan Stable Paths Over Uneven Terrain', IEEE/RSJ 2010 INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS (IROS 2010), IEEE/RSJ International Conference on Intelligent Robots and Systems, IEEE, Taipei, Taiwan, pp. 294-299.
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A generic methodology to plan increasingly stable paths for mobile platforms travelling over uneven terrain is proposed in this paper. This is accomplished by extending the Fast Marching level-set method of propagating interfaces in 3D lattices with an analytical kyno-dynamic metric which embodies robot stability in the given terrain. This is particularly relevant for reconfigurable platforms which significantly modify their mass distribution through posture adaptation, such as robots equipped with manipulator arms or varying traction arrangements. Results obtained from applying the proposed strategy in a mobile rescue robot operating on simulated and real terrain data illustrate the validity of the proposed strategy. ©2010 IEEE.
Parnell, J, Wassermann, J & Samuels, S 1970, 'Relationships between noise indices, road traffic noise and criteria in NSW', 20th International Congress on Acoustics 2010, ICA 2010 - Incorporating Proceedings of the 2010 Annual Conference of the Australian Acoustical Society, pp. 1824-1827.
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A number of 'rules of thumb' exist which allow quick and simple comparison between different noise indices associated with road traffic noise, for example L10 (18h) = Leq(24h) + 3.5 dB (Brown, 1989). Most of these rules of thumb were established many years ago and it is an objective of the present paper to assess if these are still valid in 2010. In addition, an extensive data set has been interrogated to investigate the morning shoulder period between 6am and 7am when there is a significant increase in road traffic noise on many urban roads. The implications of including the morning period as part of an Leq(9h) night or an Leq(16h) day are discussed.
Patel, M, Khushaba, R, Miro, JV & Dissanayake, G 1970, 'Probabilistic models versus discriminate classifiers for human activity recognition with an instrumented mobility-assistance aid', Proceedings of the 2010 Australasian Conference on Robotics and Automation, ACRA 2010, Proceedings of the Australasian Conference on Robotics and Automation, Australasian Conference on Robotics and Automation, Brisbane, Queensland, Australia, pp. 1-8.
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Detection of individuals' intentions and actions from a stream of human behaviour is an open and complex problem. There is however an intrinsic need to automatically recognise the activities performed by users of mobility assistive aids to better understand their behavioural patterns, with the ultimate objective of improving the utility of these devices. While discriminative algorithms such as Support Vector Machines (SVM) are well understood, generative probabilistic approaches to machine learning such as Dynamic Bayesian Networks (DBN) have only recently started gaining increasing interest within the robotics community. In this paper, a comprehensive evaluation of these techniques is carried out for human activity recognition in the context of their applicability to assistive robotics. Results show comparable recognition rates, offering valuable insights into the advantageous characteristics of DBN in relation to their dynamic and unsupervised nature for realistic human-robot interaction modelling.
Patel, M, Miro, JV & Dissanayake, G 1970, 'Dynamic Bayesian Networks for Learning Interactions between Assistive Robotic Walker and Human Users', KI 2010: ADVANCES IN ARTIFICIAL INTELLIGENCE, Annual German Conference on Artificial Intelligence, Springer-Verlag Berlin Heidelberg, Germany, pp. 333-340.
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Detection of individuals intentions and actions from a stream of human behaviour is an open problem. Yet for robotic agents to be truly perceived as human-friendly entities they need to respond naturally to the physical interactions with the surrounding environment, most notably with the user. This paper proposes a generative probabilistic approach in the form of Dynamic Bayesian Networks (DBN) to seamlessly account for users attitudes. A model is presented which can learn to recognize a subset of possible actions by the user of a gait stability support power rollator walker, such as standing up, sitting down or assistive strolling, and adapt the behaviour of the device accordingly. The communication between the user and the device is implicit, without any explicit intention such as a keypad or voice.The end result is a decision making mechanism that best matches the users cognitive attitude towards a set of assistive tasks, effectively incorporating the evolving activity model of the user in the process. The proposed framework is evaluated in real-life condition. © 2010 Springer-Verlag Berlin Heidelberg.
Paul, G, Webb, S, Liu, D & Dissanayake, G 1970, 'A robotic system for steel bridge maintenance: Field testing', Proceedings of the 2010 Australasian Conference on Robotics and Automation, ACRA 2010, Proceedings of the Australasian Conference on Robotics and Automation, Australasian Conference on Robotics and Automation, Brisbane, Queensland, Australia, pp. 1-8.
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This paper presents the field testing results of an autonomous manipulator-based robotic system that strips the paint and rust from steel bridges [Liu et al., 2008]. The key components of this system are sensing and planning, which have been presented in other research papers. The grit-blasting field trial presented in this paper spanned 6 weeks, and included 20 hours over 4.5 days of actual grit-blasting operation. The field testing has verified the algorithms developed for exploration, mapping, surface segmentation, robot motion planning and collision avoidance. It has also proved that the robotic system is able to perform bridge maintenance operations (grit-blasting), reduce human workers' exposure to hazardous and dangerous debris (containing rust, lead-based paint particles), and relieve workers from labour-intensive tasks. The system has been shown to position a grit-blast nozzle so as to remove the paint and rust at the same rate that is expected of a worker with equivalent equipment: small grit-blasting pot and medium-sized hose nozzle. Testing in the field has also highlighted important issues that need to be addressed.
PETERS, G, PAGANO, D, LIU, DK & WALDRON, K 1970, 'A PROTOTYPE CLIMBING ROBOT FOR INSPECTION OF COMPLEX FERROUS STRUCTURES', Emerging Trends in Mobile Robotics, Proceedings of the 13th International Conference on Climbing and Walking Robots and the Support Technologies for Mobile Machines, WORLD SCIENTIFIC, Nagoya, Japan, pp. 150-156.
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© 2010 by World Scientific Publishing Co. Pte. Ltd. Currently many hazardous maintenance and inspection tasks, such as paint inspection and corrosion condition monitoring of steel structures, are being performed manually by workers, which causes serious health and safety problems. This paper presents a concept climbing robot, with the aim of exploring highly complex ferrous structures such as steel bridges, for the purpose of inspection duties. To demonstrate this concept, a quadruped prototype is developed. A modular architecture that simplifies the development process and improves reusability has been implemented. Permanent magnet compliant pads on each foot provide a simple method of adhesion on the highly complex and unsmooth surface of a bridge. A simple detachment mechanism has been employed. Experiments have been conducted to prove the concept and test the design of the prototype.
Petzelt, D, Schallow, J & Deuse, J 1970, 'Data integration in Digital Manufacturing based on application Protocols', 2010 3rd International Conference on Computer Science and Information Technology, 2010 3rd IEEE International Conference on Computer Science and Information Technology (ICCSIT 2010), IEEE, pp. 475-479.
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In order to improve and to shorten product and production development as well as to reach a higher planning and product quality, in industrial companies the use of software tools is state of the art. Particularly in the field of manufacturing process planning known as Digital Manufacturing a wide range of different and specialized software tools is used, e.g. in assembly planning, logistics planning or layout planning. In order to reduce planning effort and to increase planning quality, relevant planning data of the product and production development process must be avallable to any software tool employed. But due to the lack of open and generally accepted data standards a continuous exchange of data between software tools is hardly possible. The paper on hand introduces a methodology for enabling a standardized description of planning data. In this approach, application-specific data models are used to define data relevant for a certain domain of the product and production development process. © 2010 IEEE.
Richards, D, Paul, G, Webb, S & Kirchner, N 1970, 'Manipulator-based grasping pose selection by means of task-objective optimisation', Proceedings of the 2010 Australasian Conference on Robotics and Automation, ACRA 2010, Proceedings of the Australasian Conference on Robotics and Automation, Australasian Conference on Robotics and Automation, Brisbane, Queensland, Australia, pp. 1-9.
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This paper presents an alternative to inverse kinematics for mobile manipulator grasp pose selection which integrates obstacle avoidance and joint limit checking into the pose selection process. Given the Cartesian coordinates of an object in 3D space and its normal vector, end-effector pose objectives including collision checking and joint limit checks are used to create a series of cost functions based on sigmoid functions. These functions are optimised using Levenberg-Marquardt's algorithm to determine a valid pose for a given object. The proposed method has been shown to extend the workspace of the manipulator, eliminating the need for precomputed grasp sets and post pose selection collision checking and joint limit checks. This method has been successfully used on a 6 DOF manipulator both in simulation and in the real world environment.
Scholl, P & Deuse, J 1970, 'Approach to reduce costs in a warehouse with simultaneous increase of the system's flexibility', Proceedings of 2010 IEEE International Conference on Service Operations and Logistics, and Informatics, 2010 IEEE International Conference on Service Operations and Logistics and Informatics (SOLI), IEEE, pp. 183-188.
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In modern supply chains, effective and efficient warehousing processes are important to fulfill customer orders within a minimum of time at lowest possible costs for customers (picking costs). To reach minimum picking costs, flexibility strategies in a warehouse are needed to handle the effects of short-term quantity and volume fluctuations. This article describes a flexibility concept to identify an optimal strategy (sequence of actions) for adapting cost intensive capacities in a warehouse in according with variability in quantity and volume of customer orders. © 2010 IEEE.
Sehestedt, S, Kodagoda, S & Dissanayake, G 1970, 'Robot path planning in a social context', 2010 IEEE Conference on Robotics, Automation and Mechatronics, 2010 IEEE Conference on Robotics, Automation and Mechatronics (RAM), IEEE, Singapore, pp. 206-211.
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Human robot interaction has attracted significant attention over the last couple of years. An important aspect of such robotic systems is to share the working space with humans and carry out the tasks in a socially acceptable way. In this paper, we address the problem of fusing socially acceptable behaviours into robot path planning. By observing an environment for a while, the robot learns human motion patterns based on sampled Hidden Markov Models and utilises them in a Probabilistic Roadmap based path planning algorithm. This will minimise the social distractions, such as going through someone else's working space (due to the shortest path), by planning the path through minimal distractions, leading to human-like behaviours. The algorithm is implemented in Orca/C++ with appealing results in real world experiments. ©2010 IEEE.
Sehestedt, S, Kodagoda, S, Dissanayake, G & IEEE 1970, 'Models of Motion Patterns for Mobile Robotic Systems', IEEE/RSJ 2010 INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS (IROS 2010), IEEE/RSJ International Conference on Intelligent Robots and Systems, IEEE, Taipei, Taiwan, pp. 4127-4132.
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Human robot interaction is an emerging area of research with many challenges. Knowledge about human behaviors could lead to more effective and efficient interactions of a robot in populated environments. This paper presents a probabilistic framework for the learning and representation of human motion patterns in an office environment. It is based on the observation that most human trajectories are not random. Instead people plan trajectories based on many considerations, such as social rules and path length. Motion patterns are learned using an incrementally growing Sampled Hidden Markov Model. This model has a number of interesting properties which can be of use in many applications. For example, the learned knowledge can be used to predict motion, infer social rules, thus improve a robot's operation and its interaction with people in a populated space. The proposed learning method is extensively validated in real world experiments. ©2010 IEEE.
Sehestedt, S, Kodagoda, S, Dissanayake, G & IEEE 1970, 'Using Common Motion Patterns to Improve a Robot's Operation in Populated Environments', 11TH INTERNATIONAL CONFERENCE ON CONTROL, AUTOMATION, ROBOTICS AND VISION (ICARCV 2010), Int. Conf. Control, Automation, Robotics and Vision, IEEE, Singapore, pp. 2036-2041.
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Robotic devices are increasingly penetrating the human work spaces as stand alone units and helpers. It is believed that a robot could be easily integrated with humans, if the robot can learn how to behave in a socially acceptable manner. This involves a robot to observe, learn and comply with basic rules of human behaviors. As an example, one would expect a robot to travel in an environment without intruding human workspaces unnecessarily. Thus, identifying common motion patterns of people by observing a specific environment is an important task as people's trajectories are usually not random, however are tailored to the way the environment is structured. We propose a learning algorithm to construct a Sampled Hidden Markov Model (SHMM) that captures behavior of people through observations and then demonstrate how this model could be exploited for planning socially aware paths. Experimental results are presented to demonstrate the viability of the proposed approach. ©2010 IEEE.
Shi, L, Kodagoda, S & Dissanayake, G 1970, 'Environment Classification and Semantic Grid Map Building Based on Laser Range Finder Data', IROS 2010 Workshop on Semantic Mapping and Autonomous Knowledge Acquisition, Workshop on Semantic Mapping and Autonomous Knowledge Acquisition, online proceeding of IROS 2010 workshop, Taipei, pp. 1-6.
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Human robot interaction has become an important area of research in the robotics community. High level abstractions, which are commonly used by humans, can be learnt by robots to effectively communicate with humans. In this paper, we propose a Semantic Grid Map (SGM) to represent an environment. SGM is similar to an Occupancy Grid (OG) map, however with high level information as environment type labels. We use a robot-mounted laser range finder (LRF) data to learn and classify an environment into various area types. Then the classification results are combined probabilistically to update the semantic grid map. The classification accuracy is further improved by outlier rejection and topological correction. Finally we present a labeling strategy while a robot is exploring an unknown environment. Experimental results of a robot exploring in a university environment are presented to assess the performance of the algorithm.
Shi, L, Kodagoda, S & Dissanayake, G 1970, 'Semantic grid map building', Proceedings of the 2010 Australasian Conference on Robotics and Automation, ACRA 2010, Proceedings of the Australasian Conference on Robotics and Automation, Australasian Conference on Robotics and Automation, Brisbane, Australia, pp. 1-7.
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Conventional Occupancy Grid (OG) map which contains occupied and unoccupied cells can be enhanced by incorporating semantic labels of places to build semantic grid map. Map with semantic information is more understandable to humans and hence can be used for efficient communication, leading to effective human robot interactions. This paper proposes a new approach that enables a robot to explore an indoor environment to build an occupancy grid map and then perform semantic labeling to generate a semantic grid map. Geometrical information is obtained by classifying the places into three different semantic classes based on data collected by a 2D laser range finder. Classification is achieved by implementing logistic regression as a multi-class classifier, and the results are combined in a probabilistic framework. Labeling accuracy is further improved by topological correction on robot position map which is an intermediate product, and also by outlier removal process on semantic grid map. Simulation on data collected in a university environment shows appealing results.
Shi, L, Kodagoda, S, Dissanayake, G & IEEE 1970, 'Laser Range Data Based Semantic Labeling of Places', IEEE/RSJ 2010 INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS (IROS 2010), IEEE/RSJ International Conference on Intelligent Robots and Systems, IEEE, Taipei, Taiwan, pp. 5941-5946.
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Extending metric space representations of an environment with other high level information, such as semantic and topological representations enable a robotic device to efficiently operate in complex environments. This paper proposes a methodology for a robot to classify indoor environments into semantic categories. Classification task, using data collected from a laser range finder, is achieved by a machine learning approach based on the logistic regression algorithm. The classification is followed by a probabilistic temporal update of the semantic labels of places. The innovation here is that the new algorithm is able to classify parts of a single laser scan into different semantic labels rather than the conventional approach of gross categorization of locations based on the whole laser scan. We demonstrate the effectiveness of the algorithm using a data set available in the public domain. ©2010 IEEE.
Shi, L, Kodagoda, S, Dissanayake, G & IEEE 1970, 'Multi-class Classification for Semantic Labeling of Places', 11TH INTERNATIONAL CONFERENCE ON CONTROL, AUTOMATION, ROBOTICS AND VISION (ICARCV 2010), International Conference on Control, Automation, Robotics & Vision, IEEE, Singapore, pp. 2307-2312.
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Human robot interaction is an emerging area of research, where human understandable robotic representations can play a major role. Knowledge of semantic labels of places can be used to effectively communicate with people and to develop efficient navigation solutions in complex environments. In this paper, we propose a new approach that enables a robot to learn and classify observations in an indoor environment using a labeled semantic grid map, which is similar to an Occupancy Grid like representation. Classification of the places based on data collected by laser range finder (LRF) is achieved through a machine learning approach, which implements logistic regression as a multi-class classifier. The classifier output is probabilistically fused using independent opinion pool strategy. Appealing experimental results are presented based on a data set gathered in various indoor scenarios. ©2010 IEEE.
To, AWK, Paul, G & Liu, D 1970, 'Image segmentation for surface material-type classification using 3D geometry information', The 2010 IEEE International Conference on Information and Automation, 2010 International Conference on Information and Automation (ICIA), IEEE, Harbin, China, pp. 1717-1722.
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This paper describes a novel approach for the segmentation of complex images to determine candidates for accurate material-type classification. The proposed approach identifies classification candidates based on image quality calculated from viewing distance and angle information. The required viewing distance and angle information is extracted from 3D fused images constructed from laser range data and image data. This approach sees application in material-type classification of images captured with varying degrees of image quality attributed to geometric uncertainty of the environment typical for autonomous robotic exploration. The proposed segmentation approach is demonstrated on an autonomous bridge maintenance system and validated using gray level co-occurrence matrix (GLCM) features combined with a naive Bayes classifier. Experimental results demonstrate the effects of viewing distance and angle on classification accuracy and the benefits of segmenting images using 3D geometry information to identify candidates for accurate material-type classification. ©2010 IEEE.
Trianni, A & Trucco, P 1970, 'Competitiveness of small-medium reactors: A probabilistic analysis capital cost', International Congress on Advances in Nuclear Power Plants 2010, ICAPP 2010, pp. 2213-2221.
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The near-term deployment of nuclear reactors is strongly related to the perception of decision makers of the economical convenience of this kind of investment, characterized by being capital intensive. Nonetheless, there are some doubts regarding the cost of future installations, also considering the delays in which some Gen-III PWRs incurred. Analyzing available data on capital cost, the major plant's life-cycle-cost component, this paper firstly shows that the Three Miles Island accident really represented a bad turnaround, since after that the uncertainty related to the capital cost has dramatically grown: several plants have continued to being built quickly and with costs comparable to the past, others performed (economically) very poorly, mainly due to the high delays for their construction that even took decades. This uncertainty reflects today to the cost estimation of new nuclear units, and consequently to the capital cost of Small Medium Reactors, the Gen-lV Nuclear Power Plants of the mid-term future. The paper deals with this topic, trying to model the uncertainty currently affecting capital cost estimation of past reactors and evaluates its impact on the competitiveness assessment of new NPPs. Several scenarios involving Small Medium Reactors have been tested, in comparison with the Large Reactor option by means of the INCAS model. Reasonable values and distributions have been assumed from literature for all the needed parameters and the electricity wholesale prices. The competitiveness of Small Medium Reactors have been evaluated with a Monte Carlo method using the following economical competitiveness indexes: Net Present Value, financial exposure, project balance, leverage. Final results show that, under certain assumptions, Small Medium Reactors prove to be competitive, not only considering the smoother project balance and shorter leverage, even with an inferior Net Present Value, but especially the uncertainty reduction of these financial indicators.
Wang, Z, Dissanayake, G & IEEE 1970, 'Map-aided 6-DOF Relative Pose Estimation for Monocular SLAM using Sparse Information Filters', 11TH INTERNATIONAL CONFERENCE ON CONTROL, AUTOMATION, ROBOTICS AND VISION (ICARCV 2010), Int. Conf. Control, Automation, Robotics and Vision, IEEE, Singapore, pp. 1006-1011.
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This paper addresses the problem of mapping three dimensional environments from a sequence of images taken by a calibrated camera, and simultaneously generating the camera motion trajectory. This is the Monocular SLAM problem in robotics, and is akin to the Structure from Motion (SFM) problem in computer vision. We present a novel map-aided 6-DOF relative pose estimation method based on a new formulation of the Monocular SLAM that is able to provide better initial estimates of new camera poses than the simple triangulation traditionally used in this context. The '6-DOF' means relative to the map which itself is up to an unobservable scale. The proposed pose estimator also allows more effective outlier rejection in matching features present in the map and features extracted from two consecutive images. Our Monocular SLAM algorithm is able to deal with arbitrary camera motion, making the smooth motion assumption, which is required by the typically used constant velocity model, unnecessary. In the new Monocular SLAM formulation, the measurements of extracted features from images are partitioned into those used for the estimation of the environment and those used for estimating the camera motion. The new formulation enables the current map estimate to aid achieving the full 6-DOF relative pose estimation up to the mapping scale while maximally exploiting the geometry information in images. Experiment results are provided to verify the proposed algorithm.
Wei, D, Huang, J, Zhang, A, Jiang, Z, Tieu, AK, Shi, X & Jiao, S 1970, 'Friction, surface roughness and oxide scale deformation during hot rolling of stainless steels', Proceedings of the 10th International Conference on Steel Rolling.
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A well-defined boundary condition is vital for generating an accurate model for simulating metal forming process. Sticking occurs frequently during hot rolling of stainless steels, especially for rolling ferritic stainless steels, which causes surface defects on the rolled steel products and scoring on the roll surface. It is important to characterize the features of the oxide scale in hot rolling of stainless steel strip, but few studies have been carried out. This paper focuses on the deformation of oxide scale and rollstrip interface characteristics in hot rolling of austenitic stainless steel 301 and ferritic stainless steel 430. Short time oxidation tests in humid air with water vapor content of 7.0 vol. % were carried out using Gleeble 3500 thermo-mechanical simulator, and the oxidation characteristic of 301 and 430 steels was obtained. The deformation, surface morphology of oxide scale of the two steels, and the friction in hot rolling were studied by conducting hot rolling tests. Thick oxide scale of 301 steel shows high lubricative effect. The breaking of thin oxide scales of 430 steel makes the steel substrate to contact the roll, which countacts the lubricative effect of oxide scale, and results in increase of friction coefficients with an increase of reduction.
Wei, DB, Huang, JX, Zhang, AW, Jiang, ZY, Tieu, AK, Wu, F, Shi, X & Jiao, SH 1970, 'Experimental Study on the Deformation of Oxide Scale and Friction during Hot Rolling of Stainless Steel 304L', Advanced Materials Research, International Conference on Manufacturing Science and Engineering (ICMSE 2009), Trans Tech Publications, Ltd., Zhuhai, PEOPLES R CHINA, pp. 412-415.
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Contact friction is of crucial importance for the accurate modelling, optimum design and control of industrial rolling processes. Hot rolling tests were carried out to investigate the deformation of oxide scale and friction during hot rolling of stainless steel 304L. The morphology of oxide scale layer and the surface roughness transfer under the conditions of hot rolling were obtained. The friction condition at the roll-strip interface was determined.
Xie, HB, Jiang, ZY, Wei, DB & Tieu, AK 1970, 'Analysis of Edge Crack of Thin Strip during Cold Rolling', Materials Science Forum, 7th Pacific Rim International Conference on Advanced Materials and Processing, Trans Tech Publications, Ltd., Cairns, AUSTRALIA, pp. 222-225.
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Cracks in metal product significantly decrease quality and productivity of the rolled thin strip. In this paper the stress intensity factor (SIF) solution of edge crack defect of thin strip during cold rolling was investigated, and a globe analysis was applied to the problem of free edge of thin strip. The effective stress intensity factor range is important because it represents the major physical cause of crack growth. The present study provides insights of the mechanics of edge crack growth that has been frequently observed during thin strip rolling. The efficiency and reliability of the SIF analytical modelling has been demonstrated. The proposed method for predicting edge crack is useful for producing defect-free products in rolling, and provides insights of the mechanism of edge crack growth.
Xie, HB, Jiang, ZY, Wei, DB, Tieu, AK, Barlat, F, Moon, YH & Lee, MG 1970, 'Study on edge crack propagation during cold rolling of thin strip by FEM', AIP Conference Proceedings, NUMIFORM 2010: Proceedings of the 10th International Conference on Numerical Methods in Industrial Forming Processes Dedicated to Professor O. C. Zienkiewicz (1921–2009), AIP, Pohang, SOUTH KOREA, pp. 1320-1325.
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Edge crack is one common phenomenon in cold rolling of thin strip which affects qualities of the rolled strip. A three-dimensional elastic-plastic finite element (FE) model for cold flat product rolling has been developed to simulate the edge crack propagation during rolling. Stress field is investigated around the edge crack tip, and the effects of the friction coefficient, the initial crack size, reductions on crack propagation are analysed. The FE simulation provides a better understanding of the crack growth at the edge of thin strip, and could be helpful in developing of cold rolled strip with high performance mechanical properties. The optimum condition to eliminate defects is discussed, and the proposed prediction method of surface defect can be utilised to make defect free products in rolling processes.
Yu, Y-H, Kodagoda, S, Ha, QP & IEEE 1970, 'Slope-Based Point Pursuing Maneuvers of Nonholonomic Robots using FPGA', IEEE/RSJ 2010 INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS (IROS 2010), IEEE/RSJ International Conference on Intelligent Robots and Systems, IEEE, Taipei, taiwan, pp. 3694-3699.
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Steering maneuver is essential in robotic motion planning. Despite a lot of steering mechanisms successfully developed in past years, for miniature robots, real-time computation is still a limitation for robot path tracking. The design issues in cooperative control of battery-powered nonholonomic robots rest with the complicacy of the control strategies, the low power consumption and real-time processing capability. Conventionally, the improvement of computing speed mostly relies on the increment of the system clock and often results in some transient loss. Thus, an elaborate control algorithm developed for PC might not work on an embedded system. This paper presents a comprehensive steering algorithm which, via issuing predicaments for computation, will dramatically reduce the resource usage in hardware circuit design. The proposed algorithm is implemented on an embedded system for ubiquitous robotics using the field programmable gate array (FPGA) technology. ©2010 IEEE.
Yuan, S, Skinner, BT, Huang, S, Liu, DK, Dissanayake, G, Lau, H, Pagac, D, Pratley, T & IEEE 1970, 'Mathematical Modelling of Container Transfers for a Fleet of Autonomous Straddle Carriers', 2010 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION (ICRA), IEEE International Conference on Robotics and Automation, IEEE, Anchorage, Alaska, USA, pp. 1261-1266.
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The main contribution of this paper is a mathematical model describing performance metrics for coordinating multiple mobile robots in a seaport container terminal. The scenario described here requires dealing with many difficult practical challenges such as the presence of multiple levels of container stacking and sequencing, variable container orientations, and vehicular dynamics that require finite acceleration and deceleration times. Furthermore, in contrast to the automatically guided vehicle planning problem in a manufacturing environment, the container carriers described here are free ranging. Although, the port structure imposes a set of 'virtual' roadways along which the vehicles are allowed to travel, path planning is essential in preventing contention and collisions. A performance metric which minimises total yard-vehicle usage, while producing robust traffic plans by encouraging both early starting and finishing of jobs is presented for different vehicle fleet sizes and job allocation scenarios. ©2010 IEEE.
Yun, M & Huynh, P 1970, 'A numerical study of non-isothermal peristaltic flow of power-law fluids in a circular tube', Proceedings of the ASME 2010 International Mechanical Engineering Congress & Exposition IMECE2010, ASME International Mechanical Engineering Congress and Exposition, ASME, Vancouver, British Columbia, Canada, pp. 1-7.
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Non-isothermal peristaltic flow of power-law fluids in a circular tube is investigated numerically, using a commercial Computational Fluid Dynamics (CFD) software package that employs the Finite Volume Method. Simulation is performed over the range of Reynolds-number values from 1 to 100. Temperature effect on the flow field is via fluid viscosity, which is assumed to decrease exponentially with temperature. Also, except for viscosity, other fluid properties are assumed to be constant, and are similar to those of an oil. Over a range of the power-law index covering fluid behaviour from shearthinning, through Newtonian, to shear-thickening, it is found that allowing for temperature effects has significantly altered the flow pattern and pressure variation, even when the corresponding changes in temperature itself are small. Around the crest region, recirculation appears in non-isothermal flow at all power-law-index and Reynolds-number values considered in this work, in contrast to isothermal situations.
Zainudin, Z, Kodagoda, S & Dissanayake, G 1970, 'Torso detection and tracking using a 2D laser range finder', Proceedings of the 2010 Australasian Conference on Robotics and Automation, ACRA 2010, Proceedings of the Australasian Conference on Robotics and Automation, Australasian Conference on Robotics and Automation, Queensland University of Technology, Brisbane, QueenslandE, Australia, pp. 1-6.
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Detecting and tracking people in populated environments has various applications including, robotics, healthcare, automotive, security and defence. In this paper, we present an algorithm for people detection and tracking based on a two dimensional laser rage finder (LRF). The LRF was mounted on a mobile robotic platform to scan a torso section of a person. The tracker is designed to discard spurious targets based on the log likelihood ratio and can effectively handle short term occlusions. Long term occlusions are considered as new tracks. Performance of the algorithm is analysed based on experiments, which shows appealing results.
Zhan Wang & Dissanayake, G 1970, 'Efficient Monocular SLAM using sparse information filters', 2010 Fifth International Conference on Information and Automation for Sustainability, 2010 5th International Conference on Information and Automation for Sustainability (ICIAfS), IEEE, Colombo, Sri Lanka, pp. 311-316.
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A new method for efficiently mapping three dimensional environments from a platform carrying a single calibrated camera, and simultaneously localizing the platform within this map is presented in this paper. This is the Monocular SLAM problem in robotics, which is equivalent to the problem of extracting Structure from Motion (SFM) in computer vision. A novel formulation of Monocular SLAM which exploits recent results from multi-view geometry to partition the feature location measurements extracted from images into providing estimates of environment representation and platform motion is developed. Proposed formulation allows rich geometric information from a large set of features extracted from images to be maximally incorporated during the estimation process, without a corresponding increase in the computational cost, resulting in more accurate estimates. A sparse Extended Information Filter (EIF) which fully exploits the sparse structure of the problem is used to generate camera pose and feature location estimates. Experimental results are provided to verify the algorithm.
Zhang, XM, Jiang, ZY, Wei, DB, Liu, X & Wang, GD 1970, 'Study on Casting Roll during Twin-Roll Casting of Thin Strip', Materials Science Forum, 7th Pacific Rim International Conference on Advanced Materials and Processing, Trans Tech Publications, Ltd., Cairns, AUSTRALIA, pp. 1602-1605.
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In twin-roll thin strip casting, the temperature of casting roll affects the roll thermal stress, and influences the thermal deformation, the generation of roll surface cracks, the strip shape and the service life of casting roll. In this paper, the features of the casting roll materials have been analysed, the effects of the clad materials and thickness on temperature field of the casting roll have been simulated and discussed. The developed temperature model of casting roll is helpful in optimising processing parameters and the design of casting roll during twin-roll thin strip casting.
Zhao, L, Huang, S, Yan, L, Wang, JJ, Hu, G, Dissanayake, G & IEEE 1970, 'Large-Scale Monocular SLAM by Local Bundle Adjustment and Map Joining', 11TH INTERNATIONAL CONFERENCE ON CONTROL, AUTOMATION, ROBOTICS AND VISION (ICARCV 2010), IEEE, Singapore, pp. 431-436.
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This paper first demonstrates an interesting property of bundle adjustment (BA), 'scale drift correction'. Here 'scale drift correction' means that BA can converge to the correct solution (up to a scale) even if the initial values of the camera pose translations and point feature positions are calculated using very different scale factors. This property together with other properties of BA makes it the best approach for monocular Simultaneous Localization and Mapping (SLAM), without considering the computational complexity. This naturally leads to the idea of using local BA and map joining to solve large-scale monocular SLAM problem, which is proposed in this paper. The local maps are built through Scale-Invariant Feature Transform (SIFT) for feature detection and matching, random sample consensus (RANSAC) paradigm at different levels for robust outlier removal, and BA for optimization. To reduce the computational cost of the large-scale map building, the features in each local map are judiciously selected and then the local maps are combined using a recently developed 3D map joining algorithm. The proposed large-scale monocular SLAM algorithm is evaluated using a publicly available dataset with centimeter-level ground truth. ©2010 IEEE.
