BLAMIRES, SJ, THOMPSON, MB & HOCHULI, DF 2007, 'Habitat selection and web plasticity by the orb spider Argiope keyserlingi (Argiopidae): Do they compromise foraging success for predator avoidance?', Austral Ecology, vol. 32, no. 5, pp. 551-563.
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Abstract Orb web spiders face a dilemma: forage in open habitats and risk predation or forage in closed habitats to minimize risk but at reduced foraging profitability. We tested whether Argiope keyserlingi opts for safer habitats at the expense of foraging success by (i) determining habitat selection indices in open and closed habitats; (ii) marking and releasing individual juvenile, subadult and adults over two 4‐week periods to determine if life‐history stage influences habitat selection; and (iii) determining the biotic and abiotic environmental parameters that relate to A. keyserlingi abundance. We found that A. keyserlingi selected closed habitats. Sedge and anthropogenic structures were selected and trees were avoided. Juveniles were never found in open habitats, most likely because of high postdispersal mortality. Subadults and adults may shift from closed to open habitats while juveniles never shifted habitat. Foliage density, plant height, potential prey abundance, and mantid and bird abundance were correlated with A. keyserlingi abundance, with only bird abundance explaining habitat selection. We measured web capture area, spiral distance (distance between spiral threads) and the number of decoration arms (0, 1, 2, 3 or 4) in the field and did laboratory experiments to test the influence of (i) space and vegetation; (ii) prey abundance; and (iii) web damage, on web architecture. Argiope keyserlingi webs exhibited geometric plasticity by having larger prey capture areas and spiral distances in open habitats. Decoration design did not differ between habitats however. Variation in space availability, air temperature, prey abundance and web damage explained the variations in web architecture. Potential prey size and diversity differed between habitats but prey abundance did not. As ...
Deuse, J, Stausberg, JR & Wischniewski, S 2007, 'Leitsätze zur Gestaltung einer verschwendungsarmen Produktion', Zeitschrift für wirtschaftlichen Fabrikbetrieb, vol. 102, no. 5, pp. 291-294.
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Kurzfassung Ganzheitliche Produktionssysteme mit dem Toyota Produktionssystem als Ursprung [1] sind in den letzten Jahren zunehmend als konzeptioneller Ordnungsrahmen und Methodenbaukasten für einen schlanken Fabrikbetrieb populär geworden [2–4]. Insbesondere in den kleinen und mittelständischen Unternehmen (KMU) ist es jedoch nicht immer sinnvoll, alle verfügbaren Methoden einzusetzen und deren Anwendung detailliert zu dokumentieren. Dieser Beitrag stellt daher 15 Leitsätze zur Gestaltung einer verschwendungsarmen Produktion vor. Diese können auch von typischen KMU branchenübergreifend angewendet werden und bilden somit die Grundlage ihrer Produktionssysteme.
Ellekilde, L-P, Huang, S, Miro, JV & Dissanayake, G 2007, 'Dense 3D map construction for indoor search and rescue', JOURNAL OF FIELD ROBOTICS, vol. 24, no. 1-2, pp. 71-89.
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The main contribution of this paper is a new simultaneous localization and mapping (SLAM) algorithm for building dense three-dimensional maps using information acquired from a range imager and a conventional camera, for robotic search and rescue in unstructured indoor environments. A key challenge in this scenario is that the robot moves in 6D and no odometry information is available. An extended information filter (EIF) is used to estimate the state vector containing the sequence of camera poses and some selected 3D point features in the environment. Data association is performed using a combination of scale invariant feature transformation (SIFT) feature detection and matching, random sampling consensus (RANSAC), and least square 3D point sets fitting. Experimental results are provided to demonstrate the effectiveness of the techniques developed. © 2007 Wiley Periodicals, Inc.
Goldscheid, C, Deuse, J, Schlüter, N & Crostack, H-A 2007, 'Optimierung der Kommissionierqualität durch Simulation von Prüfstrategien', Zeitschrift für wirtschaftlichen Fabrikbetrieb, vol. 102, no. 6, pp. 351-354.
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Kurzfassung Kommissionierfehler führen nicht nur zu kostspieligen Retouren, sondern auch zu sinkender Zufriedenheit der internen und/oder externen Kunden. Dieser Beitrag zeigt, wie durch die Simulation verschiedener Strategien für die Qualitätsprüfung eine Verbesserung der Kommissionierprozesse hinsichtlich der Kommissionierfehlerraten erzielt werden kann. Die Abbildung unterschiedlicher Szenarien und der entsprechenden Kenngrößen (Qualität, Kosten, Zeit) für das jeweilige Kommissioniersystem liefert hierbei die Entscheidungsgrundlage zur Auswahl der optimalen Prüfstrategie.
Huang, S & Dissanayake, G 2007, 'Convergence and consistency analysis for extended Kalman filter based SLAM', IEEE TRANSACTIONS ON ROBOTICS, vol. 23, no. 5, pp. 1036-1049.
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This paper investigates the convergence properties and consistency of Extended Kalman Filter (EKF) based simultaneous localization and mapping (SLAM) algorithms. Proofs of convergence are provided for the nonlinear two-dimensional SLAM problem with point landmarks observed using a range-and- bearing sensor. It is shown that the robot orientation uncertainty at the instant when landmarks are first observed has a significant effect on the limit and/or the lower bound of the uncertainties of the landmark position estimates. This paper also provides some insights to the inconsistencies of EKF based SLAM that have been recently observed. The fundamental cause of EKF SLAM inconsistency for two basic scenarios are clearly stated and associated theoretical proofs are provided. © 2007 IEEE.
Kodagoda, KRS, Ge, SS, Wijesoma, WS & Balasuriya, AP 2007, 'IMMPDAF Approach for Road-Boundary Tracking', IEEE Transactions on Vehicular Technology, vol. 56, no. 2, pp. 478-486.
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Robust road-boundary extraction/tracking is one of the main problems in autonomous roadway navigation. Although the road boundary can be defined by various means including lane markings, curbs, and borders of vegetation, this paper focuses on road-boundary tracking using curbs. A vehicle-mounted (downward tilted) 2-D laser-measurement system is utilized to detect the curbs. The tracking problem is difficult because both the vehicle is moving and the target is disappearing, reappearing, and maneuvering in clutter. The interacting-multiple-model probabilistic-data-association filter (IMMPDAF) is proposed to solve the problems after detailed analysis. Track initiation, confirmation, and deletion are performed using the sequential-probability-ratio test. Extensive simulations followed by experiments in a campus environment show that the road-boundary tracking utilizing curbs is possible and robust through IMMPDAF. © 2007 IEEE.
Kwok, NM, Ha, QP, Huang, S, Dissanayake, G & Fang, G 2007, 'Mobile robot localization and mapping using a Gaussian sum filter', INTERNATIONAL JOURNAL OF CONTROL AUTOMATION AND SYSTEMS, vol. 5, no. 3, pp. 251-268.
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A Gaussian sum filter (GSF) is proposed in this paper on simultaneous localization and mapping (SLAM) for mobile robot navigation. In particular, the SLAM problem is tackled here for cases when only bearing measurements are available. Within the stochastic mapping framework using an extended Kalman filter (EKF), a Gaussian probability density function (pdf) is assumed to describe the range-and-bearing sensor noise. In the case of a bearing-only sensor, a sum of weighted Gaussians is used to represent the non-Gaussian robot-landmark range uncertainty, resulting in a bank of EKFs for estimation of the robot and landmark locations. In our approach, the Gaussian parameters are designed on the basis of minimizing the representation error. The computational complexity of the GSF is reduced by applying the sequential probability ratio test (SPRT) to remove under-performing EKFs. Extensive experimental results are included to demonstrate the effectiveness and efficiency of the proposed techniques.
Luo, Q & Tong, L 2007, 'A segment based sequential least squares algorithm with optimum energy control for tracking the dynamic shapes of smart structures', Smart Materials and Structures, vol. 16, no. 5, pp. 1517-1526.
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Luo, Q & Tong, L 2007, 'Closed Form Solutions for Nonlinear Analysis of Single-Sided Bonded Composite Patch Repairs', AIAA Journal, vol. 45, no. 12, pp. 2957-2965.
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Luo, Q & Tong, L 2007, 'Fully-coupled nonlinear analysis of single lap adhesive joints', International Journal of Solids and Structures, vol. 44, no. 7-8, pp. 2349-2370.
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Luo, Z, Tong, L, Wang, MY & Wang, S 2007, 'Shape and topology optimization of compliant mechanisms using a parameterization level set method', Journal of Computational Physics, vol. 227, no. 1, pp. 680-705.
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In this paper, a parameterization level set method is presented to simultaneously perform shape and topology optimization of compliant mechanisms. The structural shape boundary is implicitly embedded into a higher-dimensional scalar function as its zero
Merz, S, Oberst, S, Dyleiko, PG, Kessissoglou, N, Tso, YK & Marburg, S 2007, 'Document Development of coupled FE/BE models to investigate the structural and acoustic responses of a submerged vessel', Journal of Computational Acoustics, vol. 15, no. 1, pp. 23-47.
Rozyn, M, Zhang, N & Dissanayake, G 2007, 'Identification of Inertial Parameters of an On-Road Vehicle', SAE Technical Paper Series, vol. 116, no. 6, pp. 1680-1687.
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During normal use vehicles are loaded in multiple configurations that directly alter their inertial properties. A method of accurately identifying and tracking these changes would benefit the many vehicle subsystems that rely on the accuracy of these parameters. In this paper a novel method is presented to determine the inertial properties of a vehicle from the measured sprung mass vibration responses, without the need of sophisticated measuring devices or specialized test rigs. After a brief description of the theoretical basis of the method, experimental results are presented which show estimation of the inertial properties is possible. The results validate the accuracy and applicability of the method and illustrate that the vehicle inertial properties can be obtained even when certain system parameters, such as damping coefficients, are assumed unknown.
Shilva, Saha, SC, Kalra, J & Prasad, R 2007, 'Safety and efficacy of low‐dose MgSO4 in the treatment of eclampsia', International Journal of Gynecology & Obstetrics, vol. 97, no. 2, pp. 150-151.
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Upcroft, B, Makarenko, A, Moser, M, Alempijevic, A, Donikian, A, Uther, W & Fitch, R 2007, 'Empirical Evaluation of an Autonomous Vehicle in an Urban Environment', Journal of Aerospace Computing, Information, and Communication, vol. 4, no. 12, pp. 1086-1107.
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Operation in urban environments creates unique challenges for research in autonomous ground vehicles. Due to the presence of tall trees and buildings in close proximity to traversable areas, GPS outage is likely to be frequent and physical hazards pose real threats to autonomous systems. In this paper, we describe a novel autonomous platform developed by the Sydney-Berkeley Driving Team for entry into the 2007 DARPA Urban Challenge competition. We report empirical results analyzing the performance of the vehicle while navigating a 560-meter test loop multiple times in an actual urban setting with severe GPS outage. We show that our system is robust against failure of global position estimates and can reliably traverse standard two-lane road networks using vision for localization. Copyright © 2007 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
Wang, Z, Huang, S & Dissanayake, G 2007, 'D-SLAM: A decoupled solution to simultaneous localization and mapping', INTERNATIONAL JOURNAL OF ROBOTICS RESEARCH, vol. 26, no. 2, pp. 187-204.
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The main contribution of this paper is the reformulation of the simultaneous localization and mapping (SLAM) problem for mobile robots such that the mapping and localization can be treated as two concurrent yet separated processes: D-SLAM (decoupled SLAM). It is shown that SLAM with a range and bearing sensor in an environment populated with point features can be decoupled into solving a nonlinear static estimation problem for mapping and a low-dimensional dynamic estimation problem for localization. This is achieved by transforming the measurement vector into two parts: one containing information relating features in the map and another with information relating the map and robot. It is shown that the new formulation results in an exactly sparse information matrix for mapping when it is solved using an Extended Information Filter (EIF).Thus a significant saving in the computational effort can be achieved for large-scale problems by exploiting the special properties of sparse matrices. An important feature of D-SLAM is that the correlation among features in the map are still kept and it is demonstrated that the uncertainty of the feature estimates monotonically decreases. The algorithm is illustrated and evaluated through computer simulations and experiments. © 2007 SAGE Publications.
Wood, MDK, Sun, X, Tong, L, Luo, Q, Katzos, A & Rispler, A 2007, 'A New ENF Test Specimen for the Mode II Delamination Toughness Testing of Stitched Woven CFRP Laminates', Journal of Composite Materials, vol. 41, no. 14, pp. 1743-1772.
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This paper presents an experimental and numerical investigation on the effects of stitching distribution on the interlaminar fracture toughness of carbon fiber reinforced polymers (CFRPs) using an end notch flexure (ENF) specimen. To avoid premature failure in bending, reinforcing tabs were bonded to either side of the ENF specimens to create a tabbed ENF (TENF) specimen. The effect of stitch distribution on mode II delamination toughness is investigated by considering several stitch distribution patterns. The experimental results indicate that the mode II delamination toughness of stitched TENF specimens can be effectively measured and that stitch distribution does not play a significant role in improving the steady-state mode II delamination toughness of stitched CFRPs. Numerical results are also obtained using both MSC/NASTRAN and an in-house software for the tested specimens. A reasonable correlation exists between the numerical and experimental results.
Brown, TA, Kohan, L & Ben-Nissan, B 1970, 'Assessment by finite element analysis of the impact of osteoporosis and osteoarthritis on hip resurfacing', Proceedings of the 5th Australasian Congress on Applied Mechanics (ACAM 2007), Australasian Congress on Applied Mechanics, Engineers Australia, Brisbane, Queensland, Australia, pp. 271-276.
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Hip resurfacing is proposed as an alternative to total hip replacement (THR) for treatment of osteoarthritis (OA), especially for younger, heavier and more active sufferers. There is however, concern with regards to the incidence of post operative femoral neck fractures. We have investigated, with finite element models, the changes in stress and strain in the femoral neck following hip resurfacing. We have included several different bone material property values representing normal, elderly, osteoarthritic and osteoporotic bone. We have also modelled two different hip implant orientations. We have shown that hip resurfacing may increase the magnitude of stress and strain in the femoral neck, especially in osteoporotic bone. We have also shown that the superolateral offset associated with the valgus orientation, not the valgus orientation itself, may be what reduces the stress and strain in the neck and leads to lower incidence of fracture.
Cheong, CY, Lin, CJ, Tan, KC & Liu, DK 1970, 'A multi-objective evolutionary algorithm for berth allocation in a container port', 2007 IEEE Congress on Evolutionary Computation, 2007 IEEE Congress on Evolutionary Computation, IEEE, Singapore, pp. 927-934.
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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 make span, number of crossings, and waiting time. These objectives represent the interests of both port and ship operators. 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 a novel solution decoding scheme which is specifically designed to optimize the use of berth space. The MOEA is also able to function in a dynamic context which is of more relevance to a real-world situation. © 2007 IEEE.
Chotiprayanakul, P, Liu, D, Wang, D & Dissanayake, G 1970, 'Collision-Free Trajectory Planning for Manipulator Using Virtual Force based Approach', Proceedings of the International Conference on Engineering, Applied Sciences, and Technology (ICEAST 2007), International Conference on Engineering, Applied Sciences, and Technology, KMITL, Bangkok, Thailand, pp. 351-354.
Chotiprayanakul, P, Liu, DK, Wang, D & Dissanayake, G 1970, 'A 3-dimensional force field method for robot collision avoidance in complex environments', Automation and Robotics in Construction - Proceedings of the 24th International Symposium on Automation and Robotics in Construction, International Symposium on Automation and Robotics in Construction, Indian Institute of Technology Madras, Kochi, Kerala, India, pp. 139-145.
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This paper proposes a three-dimensional force field (3D-F 2) method for efficient motion planning and collision avoidance of a 6DOF manipulator in complex and dynamic environments while keeping the planned end-effector's path and speed unchanged. The 3D-F 2 is defined as ellipsoid shapes covering selected links of a manipulator. When the manipulator moves and its ellipsoid force field approaches to an obstacle in a tolerant range, a repulsive force will be generated and considered in the robot kinematic and dynamic analyses. In infrastructure maintenance, spray-painting and sand-blasting operations require that the operating spot 'moves' smoothly and continuously along planned path on a work surface at a constant speed, and allow changes in length and orientation of the spray/blasting stream. Thus, the stream is supposed to be another link and the end of stream performs as a spherical joint fixed on the target surface. Various simulations in a construction area show that the 3D-F 2 can retain the operating path and effectively avoid potential collisions.
D. Wang, N. M. Kwok, D. K. Liu, H. Lau & G. Dissanayake 1970, 'PSO-Tuned F<sup>2</sup> method for multi-robot navigation', 2007 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2007 IEEE/RSJ International Conference on Intelligent Robots and Systems, IEEE, San Diego, California, USA, pp. 3765-3770.
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The F2 (Force Field) method is a novel approach for multi-robot motion planning and collision avoidance. The setting of parameters is however vital to its performance. This paper presents an approach using Particle Swarm Optimization (PSO) to properly determine the control parameters for the F 2 method. The goal of the optimization is to minimize the resultant path lengths. The approach presented in this paper can be used as a tool to obtain optimal parameters for various tasks before their execution. Simulations are carried out in various environments to show the feasibility of this approach. ©2007 IEEE.
Douglas, CA, Fildes, BN, Gibson, TJ, Boström, O & Pintar, FA 1970, 'Factors influencing occupant-to-seat belt interaction in far-side crashes.', Annu Proc Assoc Adv Automot Med, United States, pp. 319-339.
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Seat belt interaction with a far-side occupant's shoulder and thorax is critical to governing excursion towards the struck-side of the vehicle in side impact. In this study, occupant-to-belt interaction was simulated using a modified MADYMO human model and finite element belts. Quasi-static tests with volunteers and dynamic sled tests with PMHS and WorldSID were used for model validation and comparison. Parameter studies were then undertaken to quantify the effect of impact direction, seat belt geometry and pretension on occupant-to-seat belt interaction. Results suggest that lowering the D-ring and increasing pretension reduces the likelihood of the belt slipping off the shoulder. Anthropometry was also shown to influence restraint provided by the shoulder belt. Furthermore, the belt may slip off the occupant's shoulder at impact angles greater than 40 degrees from frontal when no pretension is used. However, the addition of pretension allowed the shoulder to engage the belt in all impacts from 30 to 90 degrees.
Guo, Y, Zhu, J, Liu, D, Lu, H & Wang, S 1970, 'Application of multi-level multi-domain modeling in the design and analysis of a PM transverse flux motor with SMC core', 2007 INTERNATIONAL CONFERENCE ON POWER ELECTRONICS AND DRIVE SYSTEMS, VOLS 1-4, 7th International Conference on Power Electronics and Drive Systems (PEDS 2007), IEEE, Bangkok, THAILAND, pp. 275-+.
Guo, Y, Zhu, J, Liu, D, Lu, H & Wang, S 1970, 'Application of Multi-level Multi-domain Modeling in the Design and Analysis of a PM Transverse Flux Motor with SMC Core', 2007 7th International Conference on Power Electronics and Drive Systems, 2007 7th International Conference on Power Electronics and Drive Systems, IEEE, Bangkok, Thailand, pp. 27-31.
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This paper presents the design and analysis of a permanent magnet (PM) transverse flux motor with soft magnetic composite (SMC) core by applying multi-level multi-domain modeling. The design is conducted in two levels. The upper level is composed of a group of equations which describe the electrical and mechanical characteristics of the motor. The lower level consists of two domains: electromagnetic analysis and thermal calculation. The initial design, including structure, materials and major dimensions, is determined according to existing experience and empirical formulae. Then, optimization is carried out at the system level (the upper level) for the best motor performance by optimizing the structural dimensions. To successfully deal with such a multi-level multi-domain optimization problem, an effective modeling with both high computational accuracy and speed is required. For accurately computing the key motor parameters, such as back electromotive force, winding inductance and core loss, magnetic field finite element analysis is performed. The core loss in each element is stored for effective thermal calculation, and the winding inductance and back EMF are stored as a look-up table for effective analysis of the motor's dynamic performance. The presented approach is effective with good accuracy and reasonable computational speed. © 2007 IEEE.
Huynh, BP 1970, 'Convective Cooling of an Extrudate', Volume 1: Symposia, Parts A and B, ASME/JSME 2007 5th Joint Fluids Engineering Conference, ASMEDC, San Diego, California, USA, pp. 1713-1722.
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Convective heat transfer about an isothermal, cylindrical extrudate of constant diameter, issuing continuously from an extrusion die, is investigated numerically, using a commercial CFD software package. The hot extrudate is assumed to move vertically downward, thus giving rise to a combined regime of forced and free convection in the surrounding fluid. Prandtl number of 0.707, corresponding to air near standard conditions, is used. It is seen that when extrudate speed is very low, heat transfer decreases as speed is increased. However this trend is reversed at higher extrudate speed. Flow pattern in the ambient fluid, and effects of Rayleigh number on the extrudate’s heat transfer, will also be presented.
Huynh, BP 1970, 'Cooling by free convection at high Rayleigh number of cylinders positioned above a plane', Proceedings of the 16th Australasian Fluid Mechanics Conference, 16AFMC, Australasian Fluid Mechanics Conference, School of Engineering, The University of Queensland, Gold Coast, Australia, pp. 654-658.
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Free convection cooling of isothermal circular cylinders positioned above a horizontal plane is investigated numerically, using a commercial Computational Fluid Dynamics (CFD) software package. Computation is performed for high Rayleigh number, in the range 109 - 1011. Chien's turbulence model of low-Reynolds-number K-e is used, with Prandtl number of 0.707, corresponding to air near standard conditions. Influence of the underlying plane on heat transfer from the cylinders' surface is examined. As the gap between the plane and cylinders is narrowed, a pattern can be seen whereby heat transfer reaches a minimum that moves closer to the cylinder surface with higher Rayleigh number. The plane's thermal condition, adiabatic versus isothermal, produces no significant difference in the heat transfer for the present range of gap ratio, in contrast to laminar case.
Jiang, ZY, Xie, HB, Yang, LM, Zhu, HT, Wei, DB & Tieu, AK 1970, 'Mechanics of Asymmetric Rolling of Thin Strip with Effect of Work Roll Edge Contact', Materials Science Forum, 6th Pacific Rim International Conference on Advanced Materials and Processing, Trans Tech Publications, Ltd., Cheju Isl, SOUTH KOREA, pp. 115-118.
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Asymmetric rolling of thin strip has become important due to a significant decrease ofrolling force, which contributes to obtain the extremely thin strip, to reduce the rolling passes, andto save the energy by a decrease of anneal treatment. In asymmetric rolling of thin strip, edges ofwork rolls may contact and deform when no or small work roll bending force is applied. Work rolledge contact forms a new deformation feature. In this paper, the effects of initial thickness of stripand friction coefficient on the rolling pressure, roll edge contact length and strip crown duringasymmetric rolling of thin strip with work roll edge contact effect has been discussed, and thecalculated rolling force with work roll edge contact is compared with the measured value.
Jiang, ZY, Zhu, HT, Wei, DB & Tieu, AK 1970, 'Asymmetric Cold Rolling of Thin Strip with Roll Edge Kiss', 2007 2nd IEEE Conference on Industrial Electronics and Applications, 2007 2nd IEEE Conference on Industrial Electronics and Applications, IEEE, Harbin, PEOPLES R CHINA, pp. 2781-2786.
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Asymmetric rolling can reduce the thickness of rolled strip and rolling load significantly. In this paper, the asymmetric cold rolling of thin strip with roll edge kiss was analysed theoretically and the rolling pressure, intermediate force between the work roll and backup roll, the work roll edge kiss force, the strip profile after rolling are obtained for this special asymmetric rolling. The rolling pressure, intermediate force, roll edge kiss force and the strip profile are compared for various roll speed ratios, reduction and friction coefficients. Simulation result shows that the roll speed ratio and reduction have a significant influence on the profile of rolled strip, and the calculated rolling forces are consistent with the measured values. The effect of friction in the roll bite on mechanics of the asymmetric cold rolling of thin strip with roll edge kiss is also discussed.
Jiang, ZY, Zhu, HT, Wei, DB & Tieu, AK 1970, 'Mechanics of a Special Asymmetric Rolling of Thin Strip', Key Engineering Materials, 8th Asia-Pacific Symposium on Engineering Plasticity and Its Applications (AEPA 2006), Trans Tech Publications, Ltd., Nagoya Univ, Nagoya, JAPAN, pp. 707-712.
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Asymmetric rolling is used to produce thinner strip, which can reduce rolling forcesignificantly. When a thinner strip is rolled on a rolling mill, work roll edge may contact each other,which affects the mechanics of this special asymmetric rolling and the crown of the rolled strip. Inthis paper, the authors developed a numerical model to simulate this special rolling and obtained therolling force, intermediate force, roll edge contact force, the crown of the rolled strip and the edgecontact length. The effects of the initial thickness of strip and the friction variation at upper andlower work rolls on the rolling force and crown of the rolled strip are also discussed.
Kirchner, NG, Liu, D, Taha, T & Paul, G 1970, 'Capacitive Object Ranging and Material Type Classifying Sensor', Proceedings of the 8th International Conference on Intelligent Technologies (InTech), International Conference on Intelligent Technologies, University of Technology, Sydney, Sydney, Australia, pp. 130-135.
Kirchner, NG, Taha, T, Liu, D & Paul, G 1970, 'Simultaneous Material Type Classification And Mapping Data Acquisition Using A Laser Range Finder', Proceedings of the 8th International Conference on Intelligent Technologies (InTech), International Conference on Intelligent Technologies, University of Technology, Sydney, Sydney, Australia, pp. 124-129.
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This paper presents a method for single sensor simultaneous derivation of three-dimensional mapping data and material type data for use in an autonomous sandblasting system. A Hokuyo laser range finders firmware has been modified so that it returns intensity data. A range error and return intensity analyzing algorithm allows the material type of the sensed object to be determined from a set of known materials. Empirical results have demonstrated the systems ability to classify material type (under alignment and orientation constraints) from a set of known materials common to sandblasting environments (wood, concrete, metals with different finishes and cloth/fabric) and to successfully classify objects both when static and when fitted to an in-motion 6-DOF anthropomorphic robotic arm.
Kodagoda, S, Alempijevic, A, Sehestedt, S & Dissanayake, G 1970, 'Towards improving driver situation awareness at intersections', 2007 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2007 IEEE/RSJ International Conference on Intelligent Robots and Systems, IEEE, San Diego, California, pp. 3739-3744.
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Providing safety critical information to the driver is vital in reducing road accidents, especially at intersections. Intersections are complex to deal with due to the presence of large number of vehicle and pedestrian activities, and possible occlusions. Information available from only the sensors onboard a vehicle has limited value in this scenario. In this paper, we propose to utilize sensors on-board the vehicle of interest as well as the sensors that are mounted on nearby vehicles to enhance the driver situation awareness. The resulting major research challenge of sensor registration with moving observers is solved using a mutual information based technique. The response of the sensors to common causes are identified and exploited for computing their unknown relative locations. Experimental results, for a mock up traffic intersection in which mobile robots equipped with laser range finders are used, are presented to demonstrate the efficacy of the proposed technique. ©2007 IEEE.
Kodagoda, S, Alempijevic, A, Sehestedt, S & Dissanayake, G 1970, 'Towards improving driver situation awareness at intersections', 2007 IEEE/RSJ INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS, VOLS 1-9, IEEE/RSJ International Conference on Intelligent Robots and Systems, IEEE, San Diego, CA, pp. 3745-3750.
Kodagoda, S, Sehestedt, S, Alempijevic, A, Zhang, Z, Donikian, A & Dissanayake, G 1970, 'Towards an enhanced driver situation awareness system', 2007 International Conference on Industrial and Information Systems, 2007 International Conference on Industrial and Information Systems, IEEE, Sri Lanka, pp. 295-300.
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This paper outlines our current research agenda to achieve enhanced driver situation awareness. A novel approach that incorporates information gathered from sensors mounted on the neighboring vehicles, in the road infrastructure as well as onboard sensory information is proposed. A solution to the fundamental issue of registering data into a common reference frame when the relative locations of the sensors themselves are changing is outlined. A description of the vehicle test bed, experimental results from information gathered from various onboard sensors, and preliminary results from the sensor registration algorithm are presented. ©2007 IEEE.
Kwok, N, Carmichael, MG, Ha, QP & Tan, K 1970, 'Statistical decision based gray-level image feature matching', Proceedings of the 8th International Conference on Intelligent Technologies (InTech'07), International Conference on Intelligent Technologies, University of Technology Sydney, Sydney, Australia, pp. 269-274.
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Kwok, NM, Fang, G, Ha, QP & Liu, DK 1970, 'An enhanced particle swarm optimization algorithm for multi-modal functions', 2007 IEEE INTERNATIONAL CONFERENCE ON MECHATRONICS AND AUTOMATION, VOLS I-V, CONFERENCE PROCEEDINGS, IEEE International Conference on Mechatronics and Automation, IEEE, Harbin, Heilongjiang, China, pp. 457-462.
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The particle swarm optimization algorithm has been frequently employed to solve various optimization problems. Although the algorithm is performing satisfactorily while tackling unit-modal optimizations, enhancements in dealing with multi-modal functions are indeed desirable. Convergence of particles to the optimum solution is a primary and traditional requirement, however, this is achieved only after all the solutions space has been covered and evaluated. In this work, the focus is directed towards maintaining sufficient divergence of particles in multi-modal problems, by developing an alternative social interaction scheme among the swarm members. Particularly, a multiple-leaders strategy is employed in the new PSO algorithm to prevent pre-mature convergence. Results from benchmark problems are included to illustrate the effectiveness of the proposed method. © 2007 IEEE.
Kwok, NM, Ha, QP, Liu, DK, Fang, G, Tan, KC & IEEE 1970, 'Efficient particle swarm optimization: A termination condition based on the decision-making approach', 2007 IEEE CONGRESS ON EVOLUTIONARY COMPUTATION, VOLS 1-10, PROCEEDINGS, IEEE Congress on Evolutionary Computation, IEEE, Singapore, pp. 3353-3360.
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Evolutionary computation algorithms, such as the particle swarm optimization (PSO), have been widely applied in numerical optimizations and real-world product design, not only for their satisfactory performances but also in their relaxing the need for detailed mathematical modelling of complex systems. However, as iterative heuristic searching methods, they often suffer from difficulties in obtaining high quality solutions in an efficient manner. Since unnecessary resources used in computation iterations should be avoided, the determination of a proper termination condition for the algorithms is desirable. In this work, termination is cast as a decision-making process to end the algorithm. Specifically, the non-parametric sign-test is incorporated as a hypothetical test method such that a quantifiable termination in regard to specifiable decision-errors can be assured. Benchmark optimization problems are tackled using the PSO as an illustrative optimizer to demonstrate the effectiveness of the proposed termination condition. © 2007 IEEE.
Lau, H, Huang, S & Dissanayake, G 1970, 'Multi-agent search with interim positive information', 2007 IEEE/RSJ INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS, VOLS 1-9, IEEE/RSJ International Conference on Intelligent Robots and Systems, IEEE, San Diego, CA, pp. 3797-3802.
Lau, H, Huang, S & Dissanayake, G 1970, 'Multi-agent search with interim positive information', 2007 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2007 IEEE/RSJ International Conference on Intelligent Robots and Systems, IEEE, San Diego, USA, pp. 3791-3796.
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A problem of searching with multiple searchers and scouts is presented. Unlike most search problems that terminate as soon as the target is found, successful detection by scouts only improve on the current knowledge of the moving target's location, such that the searchers can more effectively find and service the target in the future. The team must correspondingly plan not only to maximize the probability of the searchers directly finding the target, but also give them the best chance of exploiting any new information from potential scout detections. It is shown that this need to plan for replanning can be addressed by equivalently solving a series of simpler detection search problems that always do terminate on detection. Optimal and heuristic solution methods for this Searcher/Scout problem are derived, such that the capabilities of all the sensing platforms in a search task are harnessed even when only a subset are capable of actually servicing the target. ©2007 IEEE.
Lindsay, E, Liu, D, Murray, SJ & Lowe, DB 1970, 'Remote Laboratories in Engineering Education: Trends in Students' Perceptions', Proceedings of the 18th Conference of the Australasian Association of Engineering Education, Annual Conference of Australasian Association for Engineering Education, Australasian Association for Engineering Education, University of Melbourne, Australia, pp. 1-6.
MERZ, S, OBERST, S, DYLEJKO, PG, KESSISSOGLOU, NJ, TSO, YK & MARBURG, S 1970, 'DEVELOPMENT OF COUPLED FE/BE MODELS TO INVESTIGATE THE STRUCTURAL AND ACOUSTIC RESPONSES OF A SUBMERGED VESSEL', Journal of Computational Acoustics, 7th International Conference on Theoretical and Computational Acoustics, World Scientific Pub Co Pte Lt, Hangzhou, PEOPLES R CHINA, pp. 23-47.
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An analytical model and a fully coupled finite element/boundary element model are developed for a simplified physical model of a submarine. The submerged body is modeled as a ring-stiffened cylindrical shell with finite rigid end closures, separated by bulkheads into a number of compartments and under axial excitation from the propeller-shafting system. Lumped masses are located at each end to maintain a condition of neutral buoyancy. Excitation of the hull axial modes from the propeller-shafting system causes both axial motion of the end closures and radial motion of the shell, resulting in a high level of radiated noise. In the low frequency range, only the axial modes in breathing motion are examined, which gives rise to an axisymmetric case, since these modes are efficient radiators. An expression for the structurally radiated sound pressure contributed by axial movement of the end plates and radial motion of the shell was obtained using the Helmholtz integral equation. In the computational model, the effects of the various influencing factors (ring stiffeners, bulkheads, realistic end closures, and fluid loading) on the free vibrational characteristics of the thin walled cylinder are examined. For both the analytical and computational models, the frequency responses, axial and radial responses of the cylinder, and the radiated sound pressure are compared.
Parnell, J & Dowdell, B 1970, 'Regulation of heavy vehicle engine brake noise in Australia', 14th International Congress on Sound and Vibration 2007, ICSV 2007, pp. 3871-3878.
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Engine brake noise is a long standing issue both in Australia and overseas with it being generally accepted that it is the character of this noise rather than its loudness that leads to most complaints. To date, the majority of the investigation and research into engine brake noise, and possible solutions, has been commissioned by Australian road agencies. There is now sufficient research in Australia, and agreement from all stakeholders, that action must be taken to provide a foundation for in-service regulations to control excessive engine brake noise. This paper describes the process being followed to achieve scientific acceptance of a method to identify excessively noisy engine brakes and its passage towards regulation in Australia. Steps in progressing this method have included developing a Modulated RMS algorithm that was capable of: • discriminating between annoying and less annoying engine brake noise; • discriminating between muffler effectiveness; • correlating well with the subjective response of panel members to engine brake noise; • being coded in software so that large amounts of roadside noise data can rapidly analysed.
Paul, G, Liu, DK, Kirchner, N & Webb, S 1970, 'Safe and Efficient Autonomous Exploration Technique for 3D Mapping of a Complex Bridge Maintenance Environment', Automation and Robotics in Construction ― Proceedings of the 24th International Symposium on Automation and Robotics in Construction, 24th International Symposium on Automation and Robotics in Construction, International Association for Automation and Robotics in Construction (IAARC), Kochi, Kerala, India, pp. 99-104.
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This paper describes a technique for autonomously exploring a complex steel bridge environment using a 6DOF anthropomorphic robotic arm, instrumented with a laser range scanner. Potential knowledge ained from a 3D range scan at an end-effector position and orientation (pose) is estimated, then arm configurations which avoid obstacles and unknown areas are computed using an optimisation approach. Safe pose solutions are compared in terms of potential gain of new weighted-information and minimal joint movement. Both simulations and robotic platform results show exploration of unknown areas occurs in a consistent and timely manner - taking an average of 4.5secs to calculate the next safe valid robot arm poses. Complex environments, typical in bridge maintenance, can be explored using an anthropomorphic arm equipped with this technique.
Pedraza, L, Dissanayake, G, Valls Miro, J, Rodriguez-Losada, D & Matia, F 1970, 'BS-SLAM: Shaping the World', Robotics: Science and Systems III, Robotics: Science and Systems 2007, Robotics: Science and Systems Foundation, Atlanta, GA, USA, pp. 1-8.
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This paper presents BS-SLAM, a simultaneous localization and mapping algorithm for use in unstructured environments that is effective regardless of whether features correspond to simple geometric primitives such as points and lines or not. The coordinates of the control points defining a set of B-splines are used to form a complete and compact description of the environment, thus making it feasible to use an extended Kalman filter based SLAM algorithm. The proposed method is the first known EKF-SLAM implementation capable of describing both straight and curve features in a parametric way. Appropriate observation equation that allows the exploitation of virtually all observations from a range sensor such as the ubiquitous laser range finder is developed. Efficient strategies for computing the relevant Jacobians, perform data association, initialization and expanding the map are presented. The effectiveness of the algorithms is demonstrated using experimental data.
Saha, SC, Lei, C & Patterson, JC 1970, 'On the natural convection boundary layer adjacent to an inclined flat plate subject to ramp heating', Proceedings of the 16th Australasian Fluid Mechanics Conference, 16AFMC, pp. 121-124.
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An investigation of the natural convection boundary layer adjacent to an inclined semi-infinite plate subject to a temperature boundary condition which follows a ramp function up until some specified time and then remains constant is reported. The development of the flow from start-up to a steadystate has been described based on scaling analyses and verified by numerical simulations. Attention in this study has been given to fluids having a Prandtl number Pr less than unity. The boundary layer flow depends on the comparison of the time at which the ramp heating is completed and the time at which the boundary layer completes its growth. If the ramp time is long compared with the steady state time, the layer reaches a quasi steady mode in which the growth of the layer is governed solely by the thermal balance between convection and conduction. On the other hand, if the ramp is completed before the layer becomes steady; the subsequent growth is governed by the balance between buoyancy and inertia, as for the case of instantaneous heating.
Saha, SC, Lei, C & Patterson, JC 1970, 'Scaling analysis of the thermal boundary layer adjacent to an abruptly heated inclined flat plate', Proceedings of the 16th Australasian Fluid Mechanics Conference, 16AFMC, pp. 117-120.
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The natural convection thermal boundary layer adjacent to an abruptly heated inclined flat plate is investigated through a scaling analysis and verified by numerical simulations. In general, the development of the thermal flow can be characterized by three distinct stages, i.e. a start-up stage, a transitional stage and a steady state stage. Major scales including the flow velocity, flow development time, and the thermal and viscous boundary layer thicknesses are established to quantify the flow development at different stages and over a wide range of flow parameters. Details of the scaling analysis and the numerical procedures are described in this paper.
Samuels, S & Parnell, J 1970, 'A recent investigation into the influences of some Australian asphalt pavement surfaces on road traffic noise', 14th International Congress on Sound and Vibration 2007, ICSV 2007, pp. 9-16.
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This paper deals with an investigation into the influences of some Australian asphalt pavement surfaces on the generation of road traffic noise. The investigation represents a recent component of an ongoing pavement surface noise research program in which both authors have been involved over several years. It focused on the roadside noise produced by a passenger vehicle travelling under controlled conditions on a set of asphaltic pavement surfaces that are typical of those adopted in the states of New South Wales and Queensland and, indeed, elsewhere throughout Australia. Results of the investigation, which are summarised in the paper, demonstrated that there is a considerable degree of variability in the acoustic attributes of the pavement surfaces studied. Interpretations and explanations of this variability are offered in the paper. Moreover, the outcomes of the investigation were compared with the acoustic attributes of sets of nominally similar and different pavement surfaces constructed in other countries and which had been previously reported in the open literature. Explanations for the similarities and differences between the acoustic attributes of the Australian and overseas asphalt pavement surfaces are also offered in the paper.
Sehestedt, S, Kodagoda, S, Alempijevic, A, Dissanayake, G & IEEE 1970, 'Robust lane detection in urban environments', 2007 IEEE/RSJ INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS, VOLS 1-9, IEEE/RSJ International Conference on Intelligent Robots and Systems, IEEE, USA, pp. 123-128.
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Most of the lane marking detection algorithms reported in the literature are suitable for highway scenarios. This paper presents a novel clustered particle filter based approach to lane detection, which is suitable for urban streets in normal traffic conditions. Furthermore, a quality measure for the detection is calculated as a measure of reliability. The core of this approach is the usage of weak models, i.e. the avoidance of strong assumptions about the road geometry. Experiments were carried out in Sydney urban areas with a vehicle mounted laser range scanner and a ccd camera. Through experimentations, we have shown that a clustered particle filter can be used to efficiently extract lane markings. ©2007 IEEE.
Sehestedt, SA, Kodagoda, S, Alempijevic, A & Dissanayake, G 1970, 'Efficient Lane Detection and Tracking in Urban Environments', third European Conference on Mobile Robots, European Conference on Mobile Robots, ECMR, Germany, pp. 78-83.
Skinner, BT, Nguyen, HT & Liu, DK 1970, 'Classification of EEG Signals Using a Genetic-Based Machine Learning Classifier', 2007 29th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2007 29th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, IEEE, Lyon, France, pp. 3120-3123.
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This paper investigates the efficacy of the genetic-based learning classifier system XCS, for the classification of noisy, artefact-inclusive human electroencephalogram (EEG) signals represented using large condition strings (108bits). EEG signals from three participants were recorded while they performed four mental tasks designed to elicit hemispheric responses. Autoregressive (AR) models and Fast Fourier Transform (FFT) methods were used to form feature vectors with which mental tasks can be discriminated. XCS achieved a maximum classification accuracy of 99.3% and a best average of 88.9%. The relative classification performance of XCS was then compared against four non-evolutionary classifier systems originating from different learning techniques. The experimental results will be used as part of our larger research effort investigating the feasibility of using EEG signals as an interface to allow paralysed persons to control a powered wheelchair or other devices. © 2007 IEEE.
Skinner, BT, Nguyen, HT & Liu, DK 1970, 'Distributed classifier migration in xcs for classification of electroencephalographic signals', 2007 IEEE Congress on Evolutionary Computation, 2007 IEEE Congress on Evolutionary Computation, IEEE, Singapore, pp. 2829-2836.
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This paper presents an investigation into combining migration strategies inspired by multi-deme Parallel Genetic Algorithms with the XCS Learning Classifier System to provide parallel and distributed classifier migration. Migrations occur between distributed XCS classifier sub-populations using classifiers ranked according to numerosity, fitness or randomly selected. The influence of the degree-of-connectivity introduced by Fully-Connected, Bi-directional Ring and Uni-directional Ring topologies is examined. Results indicate that classifier migration is an effective method for improving classification accuracy, improving learning speed and reducing final classifier population size, in the single-step classification of noisy, artefact-inclusive human electroencephalographic signals. The experimental results will be used as part of our larger research effort investigating the feasibility of using EEG signals as an interface to allow paralysed persons to control a powered wheelchair or other devices. © 2007 IEEE.
Skinner, BT, Nguyen, HT & Liu, DK 1970, 'Hybrid Optimisation Method Using PGA and SQP Algorithm', 2007 IEEE Symposium on Foundations of Computational Intelligence, 2007 IEEE Symposium on Foundations of Computational Intelligence, IEEE, Honolulu, Hawaii, USA, pp. 73-80.
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This paper investigates the hybridisation of two very different optimisation methods, namely the Parallel Genetic Algorithm (PGA) and Sequential Quadratic Programming (SQP) Algorithm. The different characteristics of genetic-based and traditional quadratic programming-based methods are discussed and to what extent the hybrid method can benefit the solving of optimisation problems with nonlinear complex objective and constraint functions. Experiments show the hybrid method effectively combines the robust and global search property of Parallel Genetic Algorithms with the high convergence velocity of the Sequential Quadratic Programming Algorithm, thereby reducing computation time, maintaining robustness and increasing solution quality. © 2007 IEEE.
Taha, T, Miro, JV & Dissanayake, G 1970, 'Wheelchair driver assistance and intention prediction using POMDPs', PROCEEDINGS OF THE 2007 INTERNATIONAL CONFERENCE ON INTELLIGENT SENSORS, SENSOR NETWORKS AND INFORMATION PROCESSING, International Conference on Intelligent Sensors, Sensor Networks and Information Processing, IEEE Computer Society, Melbourne, Victoria, pp. 449-454.
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Electric wheelchairs give otherwise immobile people the free-dom of movement, they significantly increase independence and dramatically increase quality of life. However the physical control systems of such wheelchair can be prohibitive for some users; for example, people with severe tremors. Several assisted wheelchair platforms have been developed in the past to assist such users. Algorithms that assist specific behaviors such as door - passing, follow - corridor, or avoid - obstacles have been successful. Recent research has seen a move towards systems that predict the users intentions, based on the users input. These predictions have been typically limited to locations immediately surrounding the wheelchair. This paper presents a new assisted wheelchair driving system with large scale intelligent intention recognition based on POMDPs (Partially Observable Markov Decision Processes). The systems acts as an intelligent agent/decision-maker, it relies on minimal user input; to predict the users intention and then autonomously drives the user to his destination. The prediction is constantly being updated as new user input is received allowing for true user/system integration. This shifts the users focus from fine motor-skilled control to coarse control intended to convey intention. © 2007 IEEE.
Tan, KC, Goh, CK, Teoh, EJ & Liu, D 1970, 'A hybrid evolutionary approach for heterogeneous multiprocessor scheduling', Proceedings of the 8th International Conference on Intelligent Technologies (InTech), International Conference on Intelligent Technologies, University of Technology, Sdyney, Sydney, Australia, pp. 261-268.
Valls Miro, J, Taha, T, Wang, D, Dissanayake, G & Liu, D 1970, 'An efficient strategy for robot navigation in cluttered environments in the presence of dynamic obstacles', Proceedings of the 8th International Conference on Intelligent Technologies (InTech), International Conference on Intelligent Technologies, University of Technology, Sydney, Sydney, Australia, pp. 74-81.
Vidal-Calleja, T, Bryson, M, Sukkarieh, S, Sanfeliu, A & Andrade-Cetto, J 1970, 'On the Observability of Bearing-only SLAM', Proceedings 2007 IEEE International Conference on Robotics and Automation, 2007 IEEE International Conference on Robotics and Automation, IEEE, Rome, ITALY, pp. 4114-4119.
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In this paper we present an observability analysis for a mobile robot performing SLAM with a single monocular camera. The aim is to get a better understanding of the well known intuitive behavior of these systems, such as the need for triangulation to fe
Wan, SH, Kodagoda, S & Sehestedt, SA 1970, 'Multiple Cue Based Vehicle Detection and Tracking for Road Safety', Proceedings of the 8th International Conference on Intelligent Technologies (InTech-07), International Conference on Intelligent Technologies, University of Technology, Sydney, Sydney, Australia, pp. 340-345.
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With the rise in accident related fatalities on roads, the researchers around the world are looking for solutions including integrating intelligence to vehicles. One cruicial aspects of it is the robust detection and tracking of other vehicles in the visinity. In this paper, we have proposed a probabilistic way of incorporation of several visual cues in vehicle detection and a particle filter based tracking strategy. Visual cues used are, lane markings, symmetry, entropy and shadows. Combination of visual cues provided us with robust results when compared with their individual counterparts. The definition of a region of interest lowers the computational requirements with improved robustness. Experimental results of the algorithm in Sydney urban areas are presented
Wang, D, Kwok, NM, Liu, DK, Lau, H, Dissanayake, G & IEEE 1970, 'PSO-Tuned F-2 method for multi-robot navigation', 2007 IEEE/RSJ INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS, VOLS 1-9, IEEE/RSJ International Conference on Intelligent Robots and Systems, IEEE, San Diego, CA, pp. 3771-3776.
Wang, Z, Huang, S & Dissanayake, G 1970, 'D-SLAM: Decoupled localization.and mapping for autonomous robots', Robotics Research, International Symposium on Robotics Research, Springer, San Francisco, USA, pp. 203-213.
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The main contribution of this paper is the reformulation of the simultaneous localization and mapping (SLAM) problem for mobile robots such that the mapping and localization can be treated as two concurrent yet separated processes: D-SLAM (decoupled SLAM). It is shown that SLAM can be decoupled into solving a non-linear static estimation problem for mapping and a low-dimensional dynamic estimation problem for localization. The mapping problem can be solved using an Extended Information Filter where the information matrix is shown to be exactly sparse. A significant saving in the computational effort can be achieved for large scale problems by exploiting the special properties of sparse matrices. An important feature of D-SLAM is that the correlation among landmarks are still kept and it is demonstrated that the uncertainty of the map landmarks monotonically decrease. The algorithm is illustrated through computer simulations and experiments.
Wang, Z, Huang, S & Dissanayake, G 1970, 'Multi-robot simultaneous localization and mapping using D-SLAM framework', PROCEEDINGS OF THE 2007 INTERNATIONAL CONFERENCE ON INTELLIGENT SENSORS, SENSOR NETWORKS AND INFORMATION PROCESSING, International Conference on Intelligent Sensors, Sensor Networks and Information Processing, ARC Research Network on Sensor Networks, Melbourne, pp. 317-322.
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This paper presents an algorithm for the multi-robot simultaneous localization and mapping (SLAM) problem with the robot initial locations completely unknown. Each robot builds its own local map using the traditional Extended Kalman Filter (EKF) SLAM algorithm. We provide a new method to fuse the local maps into a jointly maintained global map by first transforming the local map state estimate into relative location information and then conducting the fusion using the decoupled SLAM (D-SLAM) framework [1O]. An efficient algorithm to find the map overlap and corresponding beacons across the maps is developed from a point feature based medical image registration method and the joint compatibility test. By adding the robot initial pose of each local map into the global map state, the algorithm shows valuable properties. Simulation results are provided to illustrate the effectiveness of the algorithm. ©2007 IEEE.
Zhou, W, Miro, JV & Dissanayake, G 1970, 'Information efficient 3D visual SLAM in unstructured domains', PROCEEDINGS OF THE 2007 INTERNATIONAL CONFERENCE ON INTELLIGENT SENSORS, SENSOR NETWORKS AND INFORMATION PROCESSING, International Conference on Intelligent Sensors, Sensor Networks and Information Processing, IEEE, Melbourne, Victoria, pp. 323-328.
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This paper presents a strategy for increasing the efficiency of simultaneous localisation and mapping (SLAM) in unknown and unstructured environments using a vision-based sensory package. Traditional feature-based SLAM, using either the Extended Kalman Filter (EKF) or its dual, the Extended Information Filter (EIF), leads to heavy computational costs while the environment expands and the number of features increases. In this paper we propose an algorithm to reduce computational cost for real-time systems by giving robots the 'intelligence' to select, out of the steadily collected data, the maximally informative observations to be used in the estimation process. We show that, although the actual evaluation of information gain for each frame introduces an additional computational cost, the overall efficiency is significantly increased by keeping the matrix compact. The noticeable advantage of this strategy is that the continuously gathered data is not heuristically segmented prior to be input to the filter. Quite the opposite, the scheme lends itself to be statistically optimal. © 2007 IEEE.