Chowdhury, H, Xu, XD, Huynh, P & Cortie, MB 2005, 'Radiative heat transfer across glass coated with gold nano-particles', JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME, vol. 127, no. 1, pp. 70-75.
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Solar glazing based on reflective or absorptive coatings of noble metals or dielectric compounds respectively is well-known. However the use of gold nano-particles in an absorptive role has hardly been considered. The performance of such coatings was ass
Eager, DM 2005, 'Springing into action', Landscape Australia: Journal of the Australian Institute of Landscape Architects, vol. 26, no. 1, pp. 1-6.
Fitch, R 2005, 'Immigrants, Unions, and the New U.S. Labor Market', NEW POLITICAL SCIENCE, vol. 27, no. 4, pp. 548-549.
Ha, QP, Tran, TH & Dissanayake, G 2005, 'A wavelet- and neural network-based voice interface system for wheelchair control', International Journal of Intelligent Systems Technologies and Applications, vol. 1, no. 1/2, pp. 49-49.
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Voice control has long been considered as a natural mechanism to assist powered wheelchair users. However, one implementation difficulty is that a voice input system may fail to recognise a user’s voice. Indeed, speech activated interface between human and autonomous/semi-autonomous systems requires accurate detection and recognition. In this area pitch and end-point detection is of vital importance. This paper presents a new method for pitch detection based on the continuous wavelet transform phase. The proposed technique can serve as an accurate pitch detector, and also can offer an efficient solution to the end-point detection problem. The extracted features from a user’s speech are then used to train a neural network for speech recognition. Experimental results are provided for the detection of pitch periods and end points and the recognition of a number of commands of male and female users. Laboratory tests are reported for the proposed voice control wheelchair system. © 2005 Inderscience Enterprises Ltd.
Hossain, MA, Saha, SC & Gorla, RSR 2005, 'Viscous Dissipation Effects on Natural Convection from a Vertical Plate with Uniform Surface Heat Flux Placed in a Thermally Stratified Media', International Journal of Fluid Mechanics Research, vol. 32, no. 3, pp. 269-280.
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In the present study we investigate the effect of viscous dissipation on natural convection from a vertical plate placed in a thermally stratified environment. The reduced equations are integrated by employing the implicit finite difference scheme of Keller box method and obtained the effect of heat due to viscous dissipation on the local skin friction and local Nusselt number at various stratification levels, for fluids having Prandtl numbers of 10, 50, and 100. Solutions are also obtained using the perturbation technique for small values of viscous dissipation parameters and compared to the finite difference solutions for 0 1. Effect of viscous dissipation and temperature stratification are also shown on the velocity and temperature distributions in the boundary layer region. © 2005 Begell House, Inc.
Huang, S, James, MR, Nešić, D & Dower, PM 2005, 'Analysis of input-to-state stability for discrete time nonlinear systems via dynamic programming', Automatica, vol. 41, no. 12, pp. 2055-2065.
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The input-to-state stability (ISS) property for systems with disturbances has received considerable attention over the past decade or so, with many applications and characterizations reported in the literature. The main purpose of this paper is to present analysis results for ISS that utilize dynamic programming techniques to characterize minimal ISS gains and transient bounds. These characterizations naturally lead to computable necessary and sufficient conditions for ISS. Our results make a connection between ISS and optimization problems in nonlinear dissipative systems theory (including L2-gain analysis and nonlinear H∞ theory). As such, the results presented address an obvious gap in the literature. © 2005 Elsevier Ltd. All rights reserved.
Huynh, BP 2005, 'Numerical Study of Slider Bearings With Limited Corrugation', Journal of Tribology, vol. 127, no. 3, pp. 582-595.
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Influence of corrugation of limited extent on the performance of fixed-incline slider bearings of infinite width is investigated numerically. Effects of the corrugated section’s parameters like its location, length, and corrugation amplitude, on pressure distribution in the bearing’s fluid film, its load supporting capacity W and flow rate, are considered. When this section is near the entrance to the bearing gap, pressure and W are reduced in comparison with the smooth wall case. As this section is located further downstream, peak pressure and W increase, whereas flow rate decreases. These effects are reinforced by longer corrugated section and larger corrugation amplitude. The results thus point to a simple way to substantially enhance a bearing’s load-supporting capacity.
Ji, JC & Hansen, CH 2005, 'Forced phase-locked response of a nonlinear system with time delay after Hopf bifurcation', CHAOS SOLITONS & FRACTALS, vol. 25, no. 2, pp. 461-473.
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The trivial equilibrium of a nonlinear autonomous system with time delay may become unstable via a Hopf bifurcation of multiplicity two, as the time delay reaches a critical value. This loss of stability of the equilibrium is associated with two coincident pairs of complex conjugate eigenvalues crossing the imaginary axis. The resultant dynamic behaviour of the corresponding nonlinear non-autonomous system in the neighbourhood of the Hopf bifurcation is investigated based on the reduction of the infinite-dimensional problem to a four-dimensional centre manifold. As a result of the interaction between the Hopf bifurcating periodic solutions and the external periodic excitation, a primary resonance can occur in the forced response of the system when the forcing frequency is close to the Hopf bifurcating periodic frequency. The method of multiple scales is used to obtain four first-order ordinary differential equations that determine the amplitudes and phases of the phase-locked periodic solutions. The first-order approximations of the periodic solutions are found to be in excellent agreement with those obtained by direct numerical integration of the delay-differential equation. It is also found that the steady state solutions of the nonlinear non-autonomous system may lose their stability via either a pitchfork or Hopf bifurcation. It is shown that the primary resonance response may exhibit symmetric and asymmetric phase-locked periodic motions, quasi-periodic motions, chaotic motions, and coexistence of two stable motions. © 2005 Elsevier Ltd. All rights reserved.
Ji, JC & Hansen, CH 2005, 'Hopf bifurcation of a magnetic bearing system with time delay', JOURNAL OF VIBRATION AND ACOUSTICS-TRANSACTIONS OF THE ASME, vol. 127, no. 4, pp. 362-369.
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This paper is concerned with a study of the influence of a time delay occurring in a PD feedback control on the dynamic stability of a rotor suspended by magnetic bearings. In the presence of geometric coordinate coupling and time delay, the equations of motion governing the response of the rotor are a set of two-degree-of-freedom nonlinear differential equations with time delay coupling in nonlinear terms. It is found that as the time delay increases beyond a critical value, the equilibrium position of the rotor motion becomes unstable and may bifurcate into two qualitatively different kinds of periodic motion. The resultant Hopf bifurcation is associated with two coincident pairs of complex conjugate eigenvalues crossing the imaginary axis. Based on the reduction of the infinite dimensional problem to the flow on a four-dimensional center manifold, the bifurcating periodic solutions are investigated using a perturbation method. Copyright © 2005 by ASME.
Ji, JC & Hansen, CH 2005, 'On the approximate solution of a piecewise nonlinear oscillator under super-harmonic resonance', JOURNAL OF SOUND AND VIBRATION, vol. 283, no. 1-2, pp. 467-474.
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An approximate solution for the super-harmonic resonance response of a periodically excited nonlinear oscillator with a piecewise nonlinear-linear characteristic is constructed using both a matching method and a modified averaging method. The validity of the developed analysis is confirmed by comparing the approximate solutions with the results of direct numerical integration of the original equation. © 2004 Elsevier Ltd. All rights reserved.
Ji, JC, Hansen, CH & Li, XY 2005, 'Effect of external excitations on a nonlinear system with time delay', NONLINEAR DYNAMICS, vol. 41, no. 4, pp. 385-402.
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The trivial equilibrium of a two-degree-of-freedom autonomous system may become unstable via a Hopf bifurcation of multiplicity two and give rise to oscillatory bifurcating solutions, due to presence of a time delay in the linear and nonlinear terms. The effect of external excitations on the dynamic behaviour of the corresponding non-autonomous system, after the Hopf bifurcation, is investigated based on the behaviour of solutions to the four-dimensional system of ordinary differential equations. The interaction between the Hopf bifurcating solutions and the high level excitations may induce a non-resonant or secondary resonance response, depending on the ratio of the frequency of bifurcating periodic motion to the frequency of external excitation. The first-order approximate periodic solutions for the non-resonant and super-harmonic resonance response are found to be in good agreement with those obtained by direct numerical integration of the delay differential equation. It is found that the non-resonant response may be either periodic or quasi-periodic. It is shown that the super-harmonic resonance response may exhibit periodic and quasi-periodic motions as well as a co-existence of two or three stable motions. © Springer 2005.
Jiang, Z, Sun, W, Tang, J, Wei, D & Tieu, KA 2005, 'Analysis of oxidation and surface characteristics in hot strip rolling', Journal of Materials Science and Technology, vol. 21, no. SUPPL. 1, pp. 91-94.
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Deformation characteristics of the oxide scale in hot strip mill have not been quantified before and the principle of the effect of oxide scale deformation in the roll bite on strip surface roughness has not yet been revealed. In this paper, analysis of the thin secondary oxide scale formed in hot metal rolling and its surface roughness micro deformation is carried out by experiments and finite element analysis. Simulation results are compared with the measured values, which show that they are in close agreement. Surface roughness transfer during hot metal rolling is also discussed.
Luo, Z, Chen, L & Zhong, Y 2005, 'Computer-aided topology optimization using convex programming method', Jisuanji Fuzhu Sheji Yu Tuxingxue Xuebao/Journal of Computer-Aided Design and Computer Graphics, vol. 17, no. 4, pp. 774-781.
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A mathematic model for topology optimization of continuum structures is developed using SIMP interpolation scheme and the method of moving asymptotes(MMA) in the paper. The intermediate density in optimized structure is investigated, and a rational range for exponent of SIMP model is obtained. The numerical instability problems such as checkerboards and mesh dependencies are also discussed, and these numerical problems are settled through a kind of sensitive filter method. The flowchart for topology optimization is figured out, and a simple software for two dimensional linear elastic structures is developed. The optimal results of several examples show the efficiency of these methods proposed in the paper.
Luo, Z, Chen, L, Yang, J, Zhang, Y & Abdel-Malek, K 2005, 'Compliant mechanism design using multi-objective topology optimization scheme of continuum structures', Structural and Multidisciplinary Optimization, vol. 30, no. 2, pp. 142-154.
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Topology optimization problems for compliant mechanisms using a density interpolation scheme, the rational approximation of material properties (RAMP) method, and a globally convergent version of the method of moving asymptotes (GCMMA) are primarily discussed. First, a new multi-objective formulation is proposed for topology optimization of compliant mechanisms, in which the maximization of mutual energy (flexibility) and the minimization of mean compliance (stiffness) are considered simultaneously. The formulation of one-node connected hinges, as well as checkerboards and mesh-dependency, is typically encountered in the design of compliant mechanisms. A new hybrid-filtering scheme is proposed to solve numerical instabilities, which can not only eliminate checkerboards and mesh-dependency efficiently, but also prevent one-node connected hinges from occurring in the resulting mechanisms to some extent. Several numerical applications are performed to demonstrate the validity of the methods presented in this paper
Luo, Z, Chen, LP, Huang, YY & Zhang, YQ 2005, 'Topological optimization using RAMP interpolation scheme', Jisuan Lixue Xuebao/Chinese Journal of Computational Mechanics, vol. 22, no. 5, pp. 585-591.
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A modified mathematical model as well as a modified iterative pattern for topology optimization of linear elastic continuum is proposed based on RAMP (Rational Approximation of Material properties) interpolation scheme and the Optimality Criteria Method, where minimization compliance is regarded as the objective. Numerical instabilities, such as checkerboards and mesh dependencies, are also surveyed and investigated. Considering the undesirable numerical side effects when the sensitivity filtering method is applied, a new hybrid filtering method is presented, which can improve side effects and eliminate numerical problems effectively. The methodologies for topological optimization presented in this paper are programmed using FORTRAN. To substantiate the efficiency of these methods adopted in this paper, illustrated examples are presented both for verification and application.
Luo, Z, Guo, WD, Meng, YL & Chen, LP 2005, 'Fully compliant micro-mechanism using topological optimization approach', Hangkong Xuebao/Acta Aeronautica et Astronautica Sinica, vol. 26, no. 5, pp. 617-625.
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This work presents a methodology for fully compliant micro-mechanism design using continuum topological optimization method. The multi-objective optimization model is established by using compromise programming scheme, in which a kinernatical function and a structural function are both applied to indicate the demands of mechanism flexibility and structure stiffness, and the sensitivities for compliant mechanism optimization design are performed by adopting the adjoint sensitivity analysis method. A globally convergent method of moving asymptotes (GCMMA) is worked out based on the method of moving asymptotes (MMA) belonging to convex programming methods. Numerical instabilities occurring in resulting mechanism are also investigated and a modified SIMP density-stiffness interpolation scheme is suggested not only to eliminate checkerboards and mesh-dependency, but also to improve the one-node connected hinges. The typical application, a micro inverter mechanism, is employed to demonstrate the validation of the algorithms presented in this work. A procedure has been suggested to convert the topological optimization results to a CAD model, and the prototype has also been fabricated as the proof of concept design by laser manufacturing technology.
Shoudong Huang, James, MR, Nesic, D & Dower, PM 2005, 'A unified approach to controller design for achieving ISS and related properties', IEEE Transactions on Automatic Control, vol. 50, no. 11, pp. 1681-1697.
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A unified approach to the design of controllers achieving various specified input-to-state stability (ISS) like properties is presented. Both full state and measurement feedback cases are considered. Synthesis procedures based on dynamic programming are given using the recently developed results on controller synthesis to achieve uniform l∞ bound. Our results provide a link between the ISS literature and the nonlinear H∞ design literature. © 2005 IEEE.
Smith, DB & Aubrey, T 2005, 'Differential unitary space-time superset modulation', European Transactions on Telecommunications, vol. 16, no. 4, pp. 303-307.
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A simple framework is presented for transmission of constellation supersets, starting from a consideration of differential diagonal unitary space-time modulation (DUSTM), called DUST superset modulation (DUSTSM). The need for extension of previously stated design criteria for DUSTM is demonstrated by DUSTSM achieving full spectral efficiency with good bit error rate (BER) performance in a Rayleigh flat fading channel despite an effective multicylic group construction. Two cases for two different data rates and number of transmit antennas are illustrated in which the performance of DUSTSM exceeds that of DUSTM. Copyright © 2005 AEIT.
Smith, DB & Aubrey, TA 2005, 'Differential Unity space-time Superset Modulation', European Transactions On Telecommunications, vol. 16, no. 4, pp. 303-307.
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A simple framework is presented for transmission of constellation supersets, starting from a consideration of differential diagonal unitary space-time modulation (DUSTM), called DUST superset modulation (DUSTSM). The need for extension of previously stated design criteria for DUSTM is demonstrated by DUSTSM achieving full spectral efficiency with good bit error rate (BER) performance in a Rayleigh flat fading channel despite an effective multicylic group construction. Two cases for two different data rates and number of transmit antennas are illustrated in which the performance of DUSTSM exceeds that of DUSTM.
TAKEZAWA, S, GULREZ, T, HERATH, DC & DISSANAYAKE, G 2005, 'Environmental Recognition for Autonomous Robot using Simultaneous Localization and Map Building (SLAM) (Real Time Path Planning with Dynamical Localized Voronoi Division)', TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C, vol. 71, no. 703, pp. 904-911.
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The Goal of this work is to provide a more in depth understanding of the navigation in the autonomous robot using stable visual points derived from the repeated experimentation by the stereo vision in a natural featured environment. In order to identify the position of the robot as well as to establish the 3 D obstacle map under the unknown environment, we discuss the simultaneous stereo type localization and map building (SLAM) problem. The design of the planning algorithm for a vision guided mobile robot depends upon the two main characteristics of visual environmental recognition i.e. Uncertainty and Efficiency. The uncertainty is reduced by the Extended Kalman Filter algorithm based on the process and observation model of the mobile robot. Regarding the efficiency, the optimal path planning algorithm which uses the dynamical localized Voronoi division is a new concept in our proposal. This method has the ability to make the path for mobile robot with only suitable number of natural features.
Tan, KC, Chen, YJ, Wang, LF & Liu, DK 2005, 'INTELLIGENT SENSOR FUSION AND LEARNING FOR AUTONOMOUS ROBOT NAVIGATION', Applied Artificial Intelligence, vol. 19, no. 5, pp. 433-456.
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This paper presents the design and implementation of an autonomous robot navigation system for intelligent target collection in dynamic environments. A feature-based multi-stage fuzzy logic (MSFL) sensor fusion system is developed for target recognition, which is capable of mapping noisy sensor inputs into reliable decisions. The robot exploration and path planning are based on a grid map oriented reinforcement path learning system (GMRPL), which allows for long-term predictions and path adaptation via dynamic interactions with physical environments. In our implementation, the MSFL and GMRPL are integrated into subsumption architecture for intelligent target-collecting applications. The subsumption architecture is a layered reactive agent structure that enables the robot to implement higher-layer functions including path learning and target recognition regardless of lower-layer functions such as obstacle detection and avoidance. The real-world application using a Khepera robot shows the robustness and flexibility of the developed system in dealing with robotic behaviors such as target collecting in the ever-changing physical environment. Copyright © 2005 Taylor & Francis Inc.
Tan, YG, Liu, DK, Liu, F & Zhou, ZD 2005, 'Digital robust preview control of path tracking', Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering, vol. 219, no. 1, pp. 111-116.
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A robust optimal preview control method is presented in this paper for path tracking control problems to improve robustness and tracking precision of path tracking control systems. The known path information is used as reference input signals. Simulation results show that this method is valid not only for improving the performance of highly accurate trajectory control but also for improving system stabilization.
Zhang, N, Kirpitchenko, I & Liu, DK 2005, 'Dynamic model of the grinding process', Journal of Sound and Vibration, vol. 280, no. 1-2, pp. 425-432.
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Grinding is one of the most versatile methods of removing material from machine parts to provide precise geometry. Dynamic analysis of the grinding process is necessary to reduce the surface waviness and roughness induced by vibrations, and to offer a machining accuracy in the order of nanometers. This research is to investigate the dynamic function of the grinding process. A new approach to determination of cutting factors in dynamic grinding is proposed. Attention is paid to the mechanisms of dynamic grinding from the kinematics viewpoint. A non-linear dynamic model is developed to investigate the dynamic characteristics of the grinding process. The model demonstrates that different vibration frequencies result in qualitatively different behavior of the grinding machine. The relationship between grinding force variations and vibration frequency is revealed. The formulas to calculate cutting force variations are given. A comparison of the theoretical transfer function of dynamic grinding and experimental one shows good matching. As a result, the paper significantly expands the opportunities of vibration control of grinding machines. © 2004 Elsevier Ltd. All rights reserved.
Zhang, YX & Kim, KS 2005, 'A simple displacement-based 3-node triangular element for linear and geometrically nonlinear analysis of laminated composite plates', Computer Methods in Applied Mechanics and Engineering, vol. 194, no. 45-47, pp. 4607-4632.
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Zhang, YX & Kim, KS 2005, 'Linear and Geometrically nonlinear analysis of plates and shells by a new refined non-conforming triangular plate/shell element', Computational Mechanics, vol. 36, no. 5, pp. 331-342.
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Andrade-Cetto, J, Vidal-Calleja, T & Sanfeliu, A 1970, 'Unscented Transformation of Vehicle States in SLAM', Proceedings of the 2005 IEEE International Conference on Robotics and Automation, 2005 IEEE International Conference on Robotics and Automation, IEEE, Barcelona, SPAIN, pp. 323-328.
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In this article we propose an algorithm to reduce the effects caused by linearization in the typical EKF approach to SLAM. The technique consists in computing the vehicle prior using an Unscented Transformation. The UT allows a better nonlinear mean and
Bennett, NS, Smith, AJ, Colombeau, B, Gwilliam, R, Cowern, NEB & Sealy, BJ 1970, 'Differential Hall profiling of ultra-shallow junctions in Si and SOI', Materials Science and Engineering: B, Symposium on Materials Science and Device Issues for Future Si-Based Technologies held at the 2005 EMRS Meeting, Elsevier BV, Strasbourg, FRANCE, pp. 305-309.
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Eager, DM 1970, 'An overview of the new Australian Standard for Inflatables', AALARA Annual Conference, Gold Coast, Australia.
Eager, DM 1970, 'An overview of the new Australian Standard for Playgrounds', 2005 AALARA Annual Conference, Australian Amusement, Leisure and Recreation Assoication, Gold Coast, Australia, pp. 1-23.
Eager, DM 1970, 'Humpty dumpty had a great fall', Park and Leisure Australia 2005 Annual Conference, Park and Leisure Australia, Hobart, Australia.
Eager, DM 1970, 'New playground Standard', IPWEA 2005 Annual Conference, IPWEA 2005 Annual Conference, Institute of Public Works Engineers, Sydney, Australia, pp. 1-10.
Eager, DM & Dodd, C 1970, 'The Benefits of an Accredited Playground Inspectors Course', IPNANZ, Injury Prevention Network Aotearoa New Zealand, Wellington, New Zealand, pp. 1-6.
Fang, G, Dissanayake, G, Kwok, NM, Huang, SD & IEEE 1970, 'Near minimum time path planning for bearing-only localisation and mapping', 2005 IEEE/RSJ INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS, VOLS 1-4, IEEE/RSJ International Conference on Intelligent Robots and Systems, The Institute of Electrical and Electronic Engineers Inc, Edmonton, Canada, pp. 2763-2768.
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The main contribution of this paper is an algorithm for integrating motion planning and simultaneous localisation and mapping (SLAM). Accuracy of the maps and the robot locations computed using SLAM is strongly dependent on the characteristics of the environment, for example feature density, as well as the speed and direction of motion of the robot. Appropriate control of the robot motion is particularly important in bearing-only SLAM, where the information from a moving sensor is essential. In this paper a near minimum time path planning algorithm with a finite planning horizon is proposed for bearing-only SLAM. The objective of the algorithm is to achieve a predefined mapping precision while maintaining acceptable vehicle location uncertainty in the minimum time. Simulation results have shown the effectiveness of the proposed method. © 2005 IEEE.
Fitch, R, Butler, Z, Rus, D & IEEE 1970, 'Reconfiguration planning among obstacles for heterogeneous self-reconfiguring robots', 2005 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION (ICRA), VOLS 1-4, IEEE International Conference on Robotics and Automation (ICRA), IEEE, Barcelona, SPAIN, pp. 117-124.
Gibson, T, Bostrom, O, Kullgren, A & Milthorpe, B 1970, 'The mechanisms of early onset C5/C6 soft-tissue neck injury in rear impacts', International Research Council on the Biomechanics of Impact - 2005 International IRCOBI Conference on the Biomechanics of Impact, Proceedings, pp. 215-228.
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An anatomically based, multi-body model of the C5/C6 motion segment was developed to study soft-tissue neck injury mechanisms in rear impacts. This was integrated into the MADYMO-based van der Horst head and neck model. Responses were compared with volunteer test data up to head restraint impact. Soft-tissue loading was predicted for a series of rear-end vehicle crashes with crash recorders (n=78) and known long-term pain outcomes. Facet capsule shear and impingement injury mechanisms at C5/C6 were demonstrated. Facet capsule loading correlated well with NIC max and was able to predict the risk of AIS1 neck injuries with persisting pain.
Ha, QP, Tran, TH, Scheding, S, Dissanayake, G & Durrant-Whyte, HF 1970, 'Control Issues of an Autonomous Vehicle', Proceedings of the International Symposium on Automation and Robotics in Construction (IAARC), 22nd International Symposium on Automation and Robotics in Construction, International Association for Automation and Robotics in Construction (IAARC).
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This paper addresses some control issues of a robotic amphibious vehicle that can serve as a general framework for automation of tractors used in construction. These include the vehicle's low-level dynamic equations, the development of its braking control system, kinematics in interactions with ground and the slip problem. Simulation and real-time results to date are presented.
Ha, QP, Tran, TH, Scheding, S, Dissanayake, G & Durrant-Whyte, HF 1970, 'Control issues of an autonomous vehicle', 22nd International Symposium on Automation and Robotics in Construction, ISARC 2005, International Symposium of Automation and Robotics in Construction, Faculty of Architecture and Engineering, University of Ferrara, Farrara, Italy, pp. 1-7.
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This paper addresses some control issues of a robotic amphibious vehicle that can serve as a general framework for automation of tractors used in construction. These include the vehicle's low-level dynamic equations, the development of its braking control system, kinematics in interactions with ground and the slip problem. Simulation and real-time results to date are presented.
Ha, QP, Trinh, HM & Dissanayake, G 1970, 'A Distributed Approach to Global Feedback Control of Multi-Agent Systems', Proceedings of the 6th International Symposium on Intelligent Technologies, International Symposium on Intelligent Technologies in Tech '05, Faculty of Science and Technology, Assumption University, Phuket, Thailand, pp. 67-72.
Huang, S, Kwok, N, Dissanayake, G, Ha, QP & Fang, G 1970, 'Multi-Step Look-Ahead Trajectory Planning in SLAM: Possibility and Necessity', Proceedings of 2005 IEEE International Conference on Robotics and Automation, IEEE International Conference on Robots and Automation, The Institute of Electrical and Electronic Engineers Inc, Barcelona, Spain, pp. 1103-1108.
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In this paper, the possibility and necessity of multistep trajectory planning in Extended Kalman Filter (EKF) based SLAM is investigated. The objective of the trajectory planning here is to minimize the estimation error of the robot and landmark locations subject to a given time horizon. We show that the problem can be regarded as an optimization problem for a gradually identified model. A numerical method is proposed for trajectory planning using a variant of the nonlinear Model Predictive Control (MPC). The proposed method is optimal in the sense that the control action is computed using all the information available at the time of decision making. Simulation results are included to compare the results from the one-step look-ahead trajectory planning and the proposed multi-step lookahead technique
Jiang, ZY, Sun, WH, Tang, JN, Wei, DB & Tieu, AK 1970, 'Micromechanics of thin oxide scale and surface roughness in metal forming', 4th Australasian Congress on Applied Mechanics, ACAM 2005, pp. 447-452.
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In this paper, a thin secondary oxide scale formed in hot metal rolling is analysed using finite element method. The surface asperity micro-deformation of the secondary oxide scale and strip is focused. The micromechanics of the surface asperities and thin oxide scale are obtained from the finite element (FE) simulation and experimental measurements. Simulation results are compared with the measured values, which shows that they are in close agreement. The forming features of surface roughness during hot metal rolling with lubrication are also discussed. © Institute of Materials Engineering Australasia Ltd 2005.
Kirchner, NG & Furukawa, T 1970, 'Infrared Localisation for Indoor UAVs', ICST05: International Conference on Sensing Technology.
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This paper describes an Infrared Local Positioning System (IR-LPS) designed for indoor UAV use. Directional receivers scan the local environment for active tags that emit a unique (to each tag) IR signal. The system is constructed from inexpensive off the shelf components and requires no room calibration when introduced to a new environment. The IR-LPS is capable of three-dimensional dynamic tracking of a UAV with minimal PC processing power required. This allows for multiple systems to be run from a single PC or for the system to be battery powered and run on an embedded PC. The IR-LPS was implemented and evaluated in a large open space laboratory and provided localisation with less than 1cm error at 2m and with a range of 30m.
Kodagoda, S, Wang, C & Dissanayake, G 1970, 'Laser Based Sensing on Roads', Proceedings of the Intelligent Vehicles and Road Infrastructure Conference, Intelligent Vehicles & Road Infrastructure Conference, Society of Automotive Engineers, Australia, Melbourne, Australia, pp. 1-8.
Kwok, N, Dissanayake, G & Ha, QP 1970, 'Bearing-only SLAM using a SPRT Based Gaussian Sum Filter', Proceedings of 2005 IEEE International Conference on Robotics and Automation, IEEE International Conference on Robotics and Automation, The IEEE, Barcelona Spain, pp. 1121-1126.
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Use of a Gaussian Sum filter (GSF) to efficiently solve the initialisation problem in bearing-only simultaneous localisation and mapping (SLAM) is the main contribution of this paper. When information about the range is not available, the initial probability density function (pdf) of a landmark in the environment can not be represented using a Gaussian. The GSF is an attractive candidate for estimation in this scenario as it can deal with arbitrary pdfs represented as sets of Gaussians. However, the implementation of the GSF requires maintaining a bank of extended Kalman filters. The resulting computational complexity needs to be reduced by employing a minimum number of filters. In this work, the performance of each extended Kalman filter (EKF) in the GSF is evaluated using the sequential probability ratio test (SPRT). As such the number of members in the Gaussian sum can be reduced rapidly and the efficiency of the GSF can be significantly increased, providing a solution to the important problem of bearing-only SLAM. The effectiveness of the proposed approach is demonstrated by simulation and experiment conducted using a Pioneer mobile robot.
Kwok, NM, Dissanayake, G & Ha, QP 1970, 'Bearing-only SLAM Using a SPRT Based Gaussian Sum Filter', Proceedings of the 2005 IEEE International Conference on Robotics and Automation, 2005 IEEE International Conference on Robotics and Automation, IEEE, Barcelona, SPAIN, pp. 1109-1114.
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Lasky, V, Liu, D, Murray, SJ & Choy, KK 1970, 'A Remote PLC System for e-Learning', Proc of the 4th ASEE/AAEE Global Colloquium on Engineering Education, ASEE Global Colloquium of Engineering Education, AAEE, Sydney, Australia, pp. 1-10.
Lau, HY, Huang, SD, Dissanayake, G & IEEE 1970, 'Optimal search for multiple targets in a built environment', 2005 IEEE/RSJ International Conference on Intelligent Robots and Systems, Vols 1-4, IEEE/RSJ International Conference on Intelligent Robots and Systems, IEEE Press, Edmonton, Canada, pp. 228-233.
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The main contribution of this paper is an algorithm for autonomous search that minimizes the expected time for detecting multiple targets present in a known built environment. The proposed technique makes use of the probability distribution of the target(s) in the environment, thereby making it feasible to incorporate any additional information, known a-priori or acquired while the search is taking place, into the search strategy. The environment is divided into a set of distinct regions and an adjacency matrix is used to describe the connections between them. The costs of searching any of the regions as well as the cost of travel between them can be arbitrarily specified. The search strategy is derived using a dynamic programming algorithm. The effectiveness of the algorithm is illustrated using an example based on the search of an office environment. An analysis of the computational complexity is also presented. © 2005 IEEE.
Leung, C, Huang, SD, Dissanayake, G, Furukawa, T & IEEE 1970, 'Trajectory planning for multiple robots in bearing-only target localisation', 2005 IEEE/RSJ International Conference on Intelligent Robots and Systems, Vols 1-4, IEEE/RSJ International Conference on Intelligent Robots and Systems, IEEE, Edmonton, Canada, pp. 2312-2317.
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This paper provides a solution to the optimal trajectory planning problem in target localisation for multiple heterogeneous robots with bearing-only sensors. The objective here is to find robot trajectories that maximise the accuracy of the locations of the targets at a prescribed terminal time. The trajectory planning is formulated as an optimal control problem for a nonlinear system with a gradually identified model and then solved using nonlinear Model Predictive Control (MPC). The solution to the MPC optimisation problem is computed through Exhaustive Expansion Tree Search (EETS) plus Sequential Quadratic Programming (SQP). Simulations were conducted using the proposed methods. Results show that EETS alone performs considerably faster than EETS+SQP with only minor differences in information gain, and that a centralised approach outperforms a decentralised one in terms of information gain. We show that a centralised EETS provides a near optimal solution. We also demonstrate the significance of using a matrix to represent the information gathered. © 2005 IEEE.
McLachlan, S, Arblaster, J, Liu, DK, Miro, JV & Chenoweth, L 1970, 'A Multi-Stage Shared Control Method for an Intelligent Mobility Assistant', 9th International Conference on Rehabilitation Robotics, 2005. ICORR 2005., 9th International Conference on Rehabilitation Robotics, 2005. ICORR 2005., IEEE, Chicago, USA, pp. 426-429.
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This paper presents a multi-stage shared control method (MSSC) which can be used to control the movement of a robotic mobility assistant designed to facilitate safe mobilization for people with unstable gait. The multi-stage control module consists of user intent, obstacle avoidance and fuzzy logic components. The user intent represents the person's commands. The obstacle avoidance component reads data representing any obstacles in the vicinity of the assistant and uses the Vector Field Histogram (VFH) algorithm to select a suitable path to avoid any obstacles in the path of travel. The fuzzy logic component is responsible for merging the user intent and obstacle avoidance information such that the user's request is satisfied to the highest extent possible. When an unsafe situation presents itself the user's request(s) will be partially or wholly overridden so the assistant can return to a safe state. The system has been designed to be dynamically configurable so as to suit different users in terms of gait stability and strength, preferred speed of travel and level of control over the system. It has been tested both in a simulated environment and real-world operating conditions and has been shown to effectively avoid obstacles with minimal disruption to the user and their intent. ©2005 IEEE.
Miro, JV, Dissanayake, G, Zhou, WZ & IEEE 1970, 'Vision-based SLAM using natural features in indoor environments', Proceedings of the 2005 Intelligent Sensors, Sensor Networks & Information Processing Conference, International Conference on Intelligent Sensors, Sensor Networks and Information Processing, IEEE Publications, Melbourne, Australia, pp. 151-156.
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This paper presents a practical approach to solve the simultaneous localization and mapping (SLAM) problem for autonomous mobile platforms by using natural visual landmarks obtained from an stereoscopic camera. It is an attempt to depart from traditional sensors such as laser rangefinders in order to gain the many benefits of nature-inspired information-rich 3D vision sensors. Whilst this makes the system fully observable in that the sensor provide enough information (range and bearing) to compute the full 2D estate of the observed landmarks from a single position, it is also true that depth information is difficult to rely on, particularly on measurements beyond a few meters (in fact the full 3D estate is observable, but here robot motion is constrained to 2D and only the 2D problem is considered). The work presented here is an attempt to overcome such a drawback by tackling the problem from a partially measurable SLAM perspective in that only landmark bearing from one of the cameras is employed in the fusion estimation. Range information estimates from the stereo pair is only used during map building in the landmark initialization phase in order to provide a reasonably accurate initial estimate. An additional benefit of the approach presented here lies in the data association aspect of SLAM. The availability of powerful feature extraction algorithms from the vision community, such as SIFT, permits a more flexible SLAM implementation separated from feature representation, extraction and matching, essentially carrying out matching with minimal recourse to geometry. Simulation results on real data illustrate the validity of the approach. © 2005 IEEE.
Parnell, J & Samuels, S 1970, 'Development and evaluation of roadside barriers to attenuate road traffic noise', Annual Conference of the Australian Acoustical Society 2005 Acoustics 2005 Acoustics in A Changing Environment, pp. 218-222.
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As part of a continuing program of investigations into roadside traffic noise barrier optimisation, the NSW Roads and Traffic Authority (RTA) funded a research and development study to develop and evaluate several full size prototype barrier designs. Of particular interest to this study was a design known as a Random Edge Profile Barrier since there was a body of published evidence which indicated that a barrier of this type can cause a substantial degradation of the noise diffracted over the barrier edge. As a consequence, it has been suggested that such barriers are capable of providing improved traffic noise attenuation compared to conventional barriers. The present study involved an empirical evaluation of a prototype Random Edge Profile Barrier and the comparison of its performance with that of conventional barriers and also with that which is known as a T-Top barrier. In total four barriers types were constructed alongside a major rural freeway in NSW and were 80m long by either 2.4m or 3.0m high. A substantial body of empirical data were collected at various receiver locations in front of, behind and adjacent to each barrier. Analyses of these data showed that for the receiver locations investigated, the random edge barrier out-performed the conventional barrier of the same nominal height for most frequencies associated with broadband tyre/road noise. The T-Top barrier was found to perform the best for frequencies greater than 3.15 kHz whilst the conventional barrier offered the most practical solution for attenuation of low frequency noise.
Saha, SC, Hanke, U & Sæther, T 1970, 'Modeling, design and simulation of tunable band pass filter using RF MEMS capacitance and transmission line', SPIE Proceedings, Microelectronics, MEMS, and Nanotechnology, SPIE, pp. 60350C-60350C.
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Saha, SC, Hanke, U, Jensen, GU, Boifot, AM, Fjeldly, TA & Saether, T 1970, 'Modeling and simulation of high capacitance ratio RF MEMS shunt switch', Proceedings of the Third IASTED International Conference on Circuits, Signals, and Systems, 3rd IASTED International Conference on Circuits, Signals, and Systems, ACTA PRESS, Marina del Rey, CA, pp. 186-193.
Saha, SC, Singh, T & Saether, T 1970, 'Design and simulation of RF MEMS cantilever and bridge switches for high switching speed and low voltage operation and their comparison.', ISSCS 2005: International Symposium on Signals, Circuits and Systems, Vols 1 and 2, Proceedings, 7th International Symposium on Signals, Circuits and Systems (ISSCS 2005), IEEE, Iasi, ROMANIA, pp. 131-134.
Saha, SC, Singh, T & Saether, T 1970, 'Design and simulation of RF MEMS switches for high switching speed and moderate voltage operation', 2005 PhD Research in Microelectronics and Electronics, Vols 1 and 2, Proceedings, International Conference on PhD Research in Microelectronics and Electronics (PRIME 2005), IEEE, Lausanne, SWITZERLAND, pp. 207-210.
Shoudong Huang, Kwok, NM, Dissanayake, G, Ha, QP & Gu Fang 1970, 'Multi-Step Look-Ahead Trajectory Planning in SLAM: Possibility and Necessity', Proceedings of the 2005 IEEE International Conference on Robotics and Automation, 2005 IEEE International Conference on Robotics and Automation, IEEE, Barcelona, SPAIN, pp. 1091-1096.
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Smith, AJ, Colombeau, B, Bennett, N, Gwilliam, R, Cowern, N & Sealy, B 1970, 'Low Temperature B Activation in SOI Using Optimised Vacancy Engineering Implants', MRS Proceedings, Symposium on Semiconductor Defect Engineering-Materials, Synthetic Structures and Devices held at the 2005 MRS Spring Meeting, Springer Science and Business Media LLC, San Francisco, CA, pp. 321-325.
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AbstractIn this study 300keV and 1MeV Si vacancy engineering implants have been used to optimise the activation of a 2keV 1×1015cm-2 B implant into SOI. Although the two implants generate a similar areal density of excess vacancies in the SOI top layer, Hall Effect measurements show that low temperature activation is possible to a greater level with the 300keV Si co-implant than with the 1MeV implant. Hall and SIMS data are consistent with a high level of activation of the B at 700°C, with no significant diffusion at the metallurgical junction depth.
Takezawa, S & Dissanayake, G 1970, 'Simultaneous localisation and mapping problems in indoor environments with stereovision', 31st Annual Conference of IEEE Industrial Electronics Society, 2005. IECON 2005., 31st Annual Conference of IEEE Industrial Electronics Society, 2005. IECON 2005., IEEE, Raleigh, NC, pp. 6 pp.-6 pp..
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Wang, D, Liu, D, Wu, X & Tan, K 1970, 'A Force Field Method for Robot Navigation', Proceedings of the 3rd International Conference on Computational Intelligence, Robotics and Autonomous Systems, International Conference on Computational Intelligence, Robotics and Autonomous Systems, CIRAS & FIRA Organising Committee 2005, Singapore, pp. 1-6.
Wang, Z, Huang, SD, Dissanayake, G & IEEE 1970, 'Decoupling localization and mapping in SLAM using compact relative maps', 2005 IEEE/RSJ INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS, VOLS 1-4, IEEE/RSJ International Conference on Intelligent Robots and Systems, IEEE, Edmonton, Canada, pp. 1041-1046.
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In this paper, we propose a new algorithm for SLAM that makes use of a state vector consisting of quantities that describes the relative locations among features. In contrast to previous relative map strategies, the new state vector is compact and always consists of 2n - 3 elements (in a 2-D environment) where n is the number of features in the map. It is also shown that the information from observations can be transformed and grouped into two parts: first one containing the information about the map and the second one containing the information about the robot location relative to the features in the map. Therefore the SLAM can be decoupled into two processes where mapping uses the first part of the transformed observation vector and localization becomes a 3-dimensional estimation problem. It is also shown that the information matrix of the map is exactly sparse, resulting in potential computational savings when an information filter is used for mapping. The new decoupled SLAM algorithm is called D-SLAM and is illustrated using simulation. © 2005 IEEE.
Zhang, Y, Bradford, MA & Gilbert, RI 1970, 'Finite element analysis of reinforced concrete slabs under service loading using a new triangular layered plate element', Computational Plasticity Fundamentals and Applications Proceedings of the 8th International Conference on Computational Plasticity Complas Viii, pp. 201-204.
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This paper develops a 3-node, 18-dof triangular layered plate element for the geometric and material nonlinear analysis of RC slabs at service loads. It combines a 9-dof triangular membrane element with drilling degrees of freedom and a refined, non-conforming 9-dof triangular plate bending element to account for membrane and flexural coupling. Two numerical examples illustrais the efficacy of this robust element.
Zhang, YX, Bradford, MA & Gilbert, RI 1970, 'A triangular layered plate element for nonlinear structural analysis', Proceedings of the 10th International Conference on Civil Structural and Environmental Engineering Computing Civil Comp 2005.
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This paper develops a 3-node, 18-DOF triangular layered plate element for the geometric and material nonlinear analysis of reinforced concrete slabs at service loads. It combines a 3-node, 9-DOF triangular membrane element with drilling freedoms and a refined non-conforming 3-node, 9-DOF triangular plate bending element to account for the coupling between membrane and bending actions. The interelement conditions of continuity are satisfied in an average sense and the element performance is improved because of the inclusion of the refined nonconforming element RT9. The element is modelled as a layered system of concrete and equivalent smeared steel reinforcement layers, including crack interface effects and dowel action by using an average shear modulus. The maximum normal stress criterion is employed to detect cracking of the concrete, with a smeared fixed crack model being assumed. © 2005 Civil-Comp Press.
