311 research outputs found
Supplemental Material - The Playing Motivations of Male and Female Gamers and the Effects of Stereotypes on Their Motivations in Honor of Kings
No full textSupplemental Material for The Playing Motivations of Male and Female Gamers and the Effects of Stereotypes on Their Motivations in Honor of Kings by Chunqi Li, Luke K. Fryer, and Alex Shum in Simulation & Gaming</p
A computational analysis of the optimal power flow problem
No full text1 online resource (PDF, 20 pages, includes illustrations)Alzalg, Baha; Anghel, Catalina; Gan, Wenying; Huang, Qing; Rahman, Mustazee; Shum, Alex. (2012). A computational analysis of the optimal power flow problem. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/181205
Development of neuropsychological measures: Personal experience and lessons learnt
No full textThis paper briefly reviews the history and purposes of neuropsychological assessment, as well as advancements in this area, and discusses the development of neuropsychological tests, using examples developed by the author and his colleagues to measure different aspects of human memory. These include the Shum Visual Learning Test, the Australian Retrograde Memory Test, the Comprehensive Assessment of Prospective Memory and the Virtual Reality Prospective Memory Task. The intended uses and psychometric properties of these tests, as well as examples of their use in research and clinical settings, will also be discussed. The paper will conclude with recommendations and advice on the development of neuropsychological tests based on the author's own experience.Griffith Health, School of Applied PsychologyNo Full Tex
Fast Transformations with Walsh-Hadamard Functions
No full textTitle: Fast Transformations with Walsh-Hadamard Functions, Author: Frank Y.Y. Shum, Location: ThodeIn this thesis, various techniques to generate Walsh-Hadamard functions are discussed. Efficient algorithms to compute the discrete Walsh-Hadamard transform have been derived and implemented. The design of a simple, but very fast, digital circuit that can perform the transform or its inverse is presented. These algorithms have been applied to the processing of speech for the investigation of bit rate reduction. Intelligible speech has been reconstructed from 8 or 4 dominant Walsh-Hadamard coefficients out of a field of 64, with a constant update time of 8 milliseconds, on a CDC-1700 computer.ThesisMaster of Engineering (ME
Design and development of smart data dissemination system
No full textThis project cannot be completed without the great mentorship of the author’s supervisor, Prof Perry Shum Ping. Hence, the author would like to appreciate his expertise, understanding and generous guidance throughout the process. Especially during Prof Shum’s busy schedule, he still made time to meet the author weekly for project update and give his suggestion on the progress. He not only directed and supervised the author, but also provided pragamtic solution on applying theoretical knowledge onto the real practice.
Moreover, the author would like to express her sincere graditude to her co- supervisor, Dr. Shao Xuguang, for inspiring the student by regular catch up and building the student community to boost the interactive communication within fellow FYP participants.
The appreciation also goes to Du Hao, a current staff in School of Electrical and Electronics, for his constant support and guidance on the technical aspects of the project, as well as the sharing of his previous experience.
Last but not least, the author would like to indicate her deepest gratitude toward School of Electrical and Electronics and Nanyang Technological University, for providing the wonderful academic ambience and the most significant education to the author and trained her to be such a professional in software engineering industry.Bachelor of Engineerin
PID Control of Systems with Hysteresis
No full textHysteresis is exhibited by many physical systems. Smart materials such as piezoelectrics, magnetostrictives and shape memory alloys possess useful properties, especially in the field of micropositioning, but the control of these systems is difficult due to the presence of hysteresis. An accurate model is required to predict the behaviour of these systems so that they can be controlled.
Several hysteresis models including the backlash, elastic-plastic and Preisach operators are discussed in detail. Several other models are mentioned. Other control methods for this problem are discussed in the form of a literature review.
The focus of this thesis is on the PID control of hysteretic systems. In particular, two systems experiencing hysteresis in their controllers are examined. The hysteresis in each system is described by different sets of assumptions. These assumptions are compared and found to be very similar. In the first system, a PI controller is used to track a reference signal. In the second, a PID controller is used to control a second-order system. The stability and tracking of both systems are discussed. An extension is made to the first system to include the dynamics of a first-order system. The results of the second system are verified to hold for a general first-order system.
Simulations were performed with the extension to a first-order system using different hysteresis models
Optimal Direction-Dependent Path Planning for Autonomous Vehicles
No full textThe focus of this thesis is optimal path planning. The path planning problem is posed as an optimal control problem, for which the viscosity solution to the static Hamilton-Jacobi-Bellman (HJB) equation is used to determine the optimal path. The Ordered Upwind Method (OUM) has been previously used to numerically approximate the viscosity solution of the static HJB equation for direction-dependent weights.
The contributions of this thesis include an analytical bound on the convergence rate of the OUM for the boundary value problem to the viscosity solution of the HJB equation. The convergence result provided in this thesis is to our knowledge the tightest existing bound on the convergence order of OUM solutions to the viscosity solution of the static HJB equation. Only convergence without any guarantee of rate has been previously shown.
Navigation functions are often used to provide controls to robots. These functions can suffer from local minima that are not also global minima, which correspond to the inability to find a path at those minima. Provided the weight function is positive, the viscosity solution to the static HJB equation cannot have local minima. Though this has been discussed in literature, a proof has not yet appeared. The solution of the HJB equation is shown in this work to have no local minima that is not also global. A path can be found using this method.
Though finding the shortest path is often considered in optimal path planning, safe and energy efficient paths are required for rover path planning. Reducing instability risk based on tip-over axes and maximizing solar exposure are important to consider in achieving these goals. In addition to obstacle avoidance, soil risk and path length on terrain are considered. In particular, the tip-over instability risk is a direction-dependent criteria, for which accurate approximate solutions to the static HJB equation cannot be found using the simpler Fast Marching Method.
An extension of the OUM to include a bi-directional search for the source-point path planning problem is also presented. The solution is found on a smaller region of the environment, containing the optimal path. Savings in computational time are observed.
A comparison is made in the path planning problem in both timing and performance between a genetic algorithm rover path planner and OUM. A comparison in timing and number of updates required is made between OUM and several other algorithms that approximate the same static HJB equation. Finally, the OUM algorithm solving the boundary value problem is shown to converge numerically with the rate of the proven theoretical bound
Multi-layer Lattice Model for Real-Time Dynamic Character Deformation
No full textDue to the recent advancement of computer graphics hardware and software algorithms, deformable characters have become more and more popular in real-time applications such as computer games. While there are mature techniques to generate primary deformation from skeletal movement, simulating realistic and stable secondary deformation such as jiggling of fats remains challenging. On one hand, traditional volumetric approaches such as the finite element method require higher computational cost and are infeasible for limited hardware such as game consoles. On the other hand, while shape matching based simulations can produce plausible deformation in real-time, they suffer from a stiffness problem in which particles either show unrealistic deformation due to high gains, or cannot catch up with the body movement. In this paper, we propose a unified multi-layer lattice model to simulate the primary and secondary deformation of skeleton-driven characters. The core idea is to voxelize the input character mesh into multiple anatomical layers including the bone, muscle, fat and skin. Primary deformation is applied on the bone voxels with lattice-based skinning. The movement of these voxels is propagated to other voxel layers using lattice shape matching simulation, creating a natural secondary deformation. Our multi-layer lattice framework can produce simulation quality comparable to those from other volumetric approaches with a significantly smaller computational cost. It is best to be applied in real-time applications such as console games or interactive animation creation
Prospective memory in patients with closed head injury: A review
No full textThis paper aimed to review the limited, but growing literature on prospective memory (PM) following closed head injury (CHI). Search of two commonly used databases yielded studies that could be classified as: self- or other-report of PM deficits; behavioral PM measures in adults with CHI, behavioral PM measures in children and adolescents with CHI, and treatment of PM in adults with CHI. The methodology and findings of these studies were critically reviewed and discussed. Because of the small number of studies, meta-analysis was only conducted for studies that used behavioral PM measures in adults to integrate findings. PM deficits were found to be commonly reported by patients with CHI and their significant others and they could be identified using behavioral measures in adults, children and adolescents with CHI. However, more work is needed to clarify the nature and mechanisms of these deficits. Although some promising results have been reported by studies that evaluated PM treatment, most studies lack tight experimental control and used only a small number of participants. The paper concluded with some suggestions for future research. (C) 2011 Elsevier Ltd. All rights reserved
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