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Department Publication Year Content Type Data Sources


1.Anode boundary layer of an atmospheric free burning argon arc

Author:Liau, V.K. ; Fang, M.T.C. ; Yan, J.D.

Source:GD 2008 - 17th International Conference on Gas Discharges and Their Applications,2008,Vol.

Abstract:The anode boundary layer of an argon free burning arc is investigated using a two-temperature model, which includes convection and charge particle diffusion. The detailed structure of the boundary layer in terms of charge density, electron and ion temperature, and electrical potential distribution is given for two discharge currents, 100A and 200A. The energy flux received by the anode is also given.

2.Real-time modeling of 3-D soccer ball trajectories from multiple fixed cameras

Author:Ren, J;Orwell, J;Jones, GA;Xu, M


Abstract:In this paper, model-based approaches for real-time 3-D soccer ball tracking are proposed, using image sequences from multiple fixed cameras as input. The main challenges include filtering false alarms, tracking through missing observations, and estimating 3-D positions from single or multiple cameras. The key innovations are: 1) incorporating motion cues and temporal hysteresis thresholding in ball detection; 2) modeling each ball trajectory as curve segments in successive virtual vertical planes so that the 3-D position of the ball can be determined from a single camera view; and 4) introducing four motion phases (rolling, flying, in possession, and out of play) and employing phase-specific models to estimate ball trajectories which enables high-level semantics applied in low-level tracking. In addition, unreliable or missing ball observations are recovered using spatio-temporal constraints and temporal filtering. The system accuracy and robustness are evaluated by comparing the estimated ball positions and phases with manual ground-truth data of real soccer sequences.

3.Application of support vector machine for equipment reliability forecasting

Author:Ding F.;He Z.;Zi Y.;Chen X.;Tan J.;Cao H.;Chen H.;Ding F.

Source:IEEE International Conference on Industrial Informatics (INDIN),2008,Vol.

Abstract:In information age, reliability of digital manufacturing equipment has a large impact on throughput, productivity and executing predictive maintenance. Accurate reliability forecasts can provide a good assessment of machine performance in order to execute predictive maintenance effectively. This paper investigates a methodology of applying support vector machines(SVMs) to predict reliability in computerized numerical control(CNC) machine tool of digital manufacturing system. SVM is capable to solve nonlinear regression and times series problems lie on conducting the structural risk minimization principle seeking to minimize an upper bound of the generalization error rather than minimize the training error. A real reliability data (for 42 suits) of CNC machine tool were employed as the data set. SVM can be trained to learn the relationship between past historical reliability indices and the corresponding targets, and then future reliability or failures can be predicted. The experimental results demonstrate that the SVM prediction model is a valid potential for predicting system reliability and failures. © 2008 IEEE.

4.Population Diversity of Particle Swarms

Author:Shi, YH;Eberhart, RC


Abstract:In the field of evolutionary computation, an important attribute of a population is diversity. This paper proposes a method for measuring the diversity of a particle swarm optimization population. It involves the measurement of position and velocity attributes of the particles that comprise the population. The proposed method is computationally straightforward and is adaptable to other evolutionary algorithms.

5.Available transfer capability assessment considering economic constraint

Author:Zhang, Chang-Hua ; Cheng, Yu-Hua ; Chen, Yong ; Huang, Qi ; Song, Yong-Hua

Source:3rd International Conference on Deregulation and Restructuring and Power Technologies, DRPT 2008,2008,Vol.

Abstract:In this paper, a new mathematic model for calculating available transfer capability (ATC) of power system in power market is presented. This model considers the bidding of generators, bus locational marginal price (LMP) and system security constraints. The objective function is to maximize the total active power consumption for load in sink area. The constraint is the system operation in a security and economy way. A bi-level leader-follower decision-making measure is taken to solve the problem. Relative to the former ATC models which only consider system security constraints, this model is more in accord with the market reality and its solution can guide all parties in market to make decision more efficiently. The numerical simulation results in IEEE30 bus system demonstrate the validity of this model. © 2008 DRPT.

6.MidSens'09 - International Workshop on Middleware Tools, Services and Run-Time Support for Sensor Networks, Co-located with the 10th ACM/IFIP/USENIX International Middleware Conference Preface

Author:Michiels, Sam ; Hughes, Danny

Source:MidSens'09 - International Workshop on Middleware Tools, Services and Run-Time Support for Sensor Networks, Co-located with the 10th ACM/IFIP/USENIX International Middleware Conference,2009,Vol.

7.Artificial neural networks for optimization of gold-bearing slime smelting

Author:Liu, D;Yuan, YD;Liao, SF


Abstract:Pyrometallurgy is often used in the industrial process for treating gold-bearing slime. Slag compositions have remarkable influences on the recovery of gold and the gold content in slag. A method for determining optimum flux compounding with neural networks is studied in this paper, and the neural network model for estimating the gold contents with different slag compositions is presented. On the basis of the neural network model, an algorithm for searching the optimum flux compounding in the gold-slime smelting process is proposed, and the optimum flux compositions are obtained accordingly. (C) 2009 Elsevier Ltd. All rights reserved.

8.Gait classification in children with cerebral palsy by Bayesian approach

Author:Zhang, Bai-ling ; Zhang, Yanchun ; Begg, Rezaul K.

Source:Pattern Recognition,2009,Vol.42

Abstract:Cerebral palsy (CP) is a non-progressive neuro-developmental condition that occurs in early childhood and is associated with a motor impairment, usually affecting mobility and posture. Automatic accurate identification of CP gait has many potential applications, for example, assistance in diagnosis, clinical decision-making and communication among the clinical professionals. In previous studies, support vector machine (SVM) and neural networks have been applied to classify CP gait patterns. However, one of the disadvantages of SVM and many neural network models is that given a gait sample, it only predicts a gait pattern class label without providing any estimate of the underlying probability, which is particularly important in computer aided diagnostics applications. The objective of this study is to first investigate different pattern classification paradigms in the automatic gait analysis and address the significance of Bayesian classifier model, and then give a comprehensive performances comparison. Bayesian classification is based on Bayes' decision theory, which compute the probability of a given data point belonging to a class. Then among all classes, we choose the one that has the largest probability, and classify the data point as being of that class. Using a publicly available CP gait data set (68 normal healthy and 88 with spastic diplegia form of CP), different features including the two basic temporal-spatial gait parameters (stride length and cadence) have been experimented. Various hold-out and cross-validation testing show that the Bayesian model offers excellent classification performances compared with some popular classifiers such as random forest and multiple layer perceptron. With many advantages considered, Bayesian classifier model is very significant in establishing a clinical decision system for gait analysis. © 2008 Elsevier Ltd. All rights reserved.

9.A technique for blood detection in wireless capsule endoscopy images

Author:Penna, Barbara ; Tillo, Tammam ; Grangetto, Marco ; Magli, Enrico ; Olmo, Gabriella

Source:European Signal Processing Conference,2009,Vol.

Abstract:Wireless capsule endoscopy is an innovative technology for visualizing anomalies in the gastrointestinal tract, useful to replace traditional endoscopic diagnosis. Its advantages are related to the capability to reach the duodenum and small intestine, while eliminating the discomfort of patients. The time spent by a physician analyzing the results of wireless capsule endoscopy video can vary between 45 and 180 minutes, limiting its widespread diffusion. Therefore, methods able to perform an automatic pre-screening of images of interest are necessary. This paper presents an innovative technique to detect bleeding regions in wireless capsule en-doscopy video. Experimental results show that the proposed algorithm exhibits a low false alarm rate, and is effective at reducing the time needed to analyze video sequences. © EURASIP, 2009.

10.Case Studies with Process Analysis Toolkit (PAT)

Author:Man, KL;Krilavicius, T;Leung, HL


Abstract:Ad-hoc approach for the development of electronic systems does not satisfy current needs of industry. Therefore, new approaches and techniques are required. Formal Methods are well-known in Software Engineering for a long time, as a potential tool for a faultless development of safety critical systems. Moreover, Process Algebras are one of the most successful techniques that allow formally specifying and analyzing diverse systems. We exemplify application of formal methods by applying Process Analysis Toolkit (PAT), a toolset based on a CPS-style process algebra, to model and analyze a pipeline process and a TLM buffer. In addition, we present the analysis results of several benchmark systems using PAT, namely asynchronous arbiter, hazardous circuit and four-tap FIR filter.

11.DARMA Adaptable service and resource management for wireless sensor networks

Author:Del Cid, Pedro Javier ; Hughes, Danny ; Ueyama, Jó ; Michiels, Sam ; Joosen, Wouter

Source:MidSens'09 - International Workshop on Middleware Tools, Services and Run-Time Support for Sensor Networks, Co-located with the 10th ACM/IFIP/USENIX International Middleware Conference,2009,Vol.

Abstract:This paper argues that service oriented architectures provide a good mechanism for managing outside interaction with software resources on wireless sensor networks. Specifically, this paper introduces a lightweight service platform designed to meet the specific characteristics of wireless sensor networks. The proposed architecture provides lightweight, yet flexible service-level agreements, together with adaptive management of sensor network resources. Critically for resource constrained sensor networks, our framework ensures that services are shared in an optimal manner between multiple client applications, while providing autonomic mechanisms to reason about fault tolerance and optimization. Furthermore, our approach actively promotes point of action processing which provides significant benefits in both embedded and enterprise deployments. We illustrate the appropriateness of the proposed architecture through a prototype implementation and evaluation using the LooCI component model and the SunSPOT platform. Copyright 2009 ACM.

12.Single development project

Author:Stankovic, N


Abstract:An often-cited problem in undergraduate software engineering courses states that some topics are difficult to teach in a university setting and, although laboratory work is a useful supplement to the lectures, it is difficult to make projects realistic and relevant. In recognition of this problem, and based on our past experience, we started preparing a new course by examining the pedagogies and curricular aspects of software engineering that are important for the Net Generation of software engineers. The course project described in this paper concentrates on those aspects that can be dealt with effectively within the environment, i.e., the software lifecycle, system interdependences, teamwork, and realistic yet manageable project dynamics, all supported by various means of communication. The workload per students must be balanced with their lack of knowledge and skills. so that their unpreparedness to deal with complex issues does not abate their motivation. The approach was tested on six large projects over the period of one semester. We believe that the results reflect the students' strong interest and commitment, and demonstrate their ability to stay focused and work at a level that is well above the obvious. (C) 2009 Elsevier Inc. All rights reserved.

13.Tracking the soccer ball using multiple fixed cameras

Author:Ren, JC;Orwell, J;Jones, GA;Xu, M


Abstract:This paper demonstrates innovative techniques for estimating the trajectory of a soccer ball from multiple fixed cameras. Since the ball is nearly always moving and frequently occluded, its size and shape appearance varies over time and between cameras. Knowledge about the soccer domain is utilized and expressed in terms of field, object and motion models to distinguish the ball from other movements in the tracking and matching processes. Using ground plane velocity, longevity, normalized size and color features, each of the tracks obtained from a Kalman filter is assigned with a likelihood measure that represents the ball. This measure is further refined by reasoning through occlusions and back-tracking in the track history. This can be demonstrated to improve the accuracy and continuity of the results. Finally, a simple 3D trajectory model is presented, and the estimated 3D ball positions are fed back to constrain the 2D processing for more efficient and robust detection and tracking. Experimental results with quantitative evaluations from several long sequences are reported. (C) 2008 Elsevier Inc. All rights reserved.

14.Computer-supported collaboration in language learning

Author:Zou, Bin

Source:Monitoring and Assessment in Online Collaborative Environments Emergent Computational Technologies for E-Learning Support,2009,Vol.

Abstract:Studies suggest that the computer can support collaborative learning between learners. This chapter discusses collaboration between language learners while using computer-based tasks. The researcher aims to look at in what ways students collaborate when completing tasks using computers during language learning, particularly in developing their listening and speaking skills. This chapter also explores the possibilities of monitoring and assessment for this collaborative language learning. The analysis is based on interview, observation and questionnaire data from both teachers and students at two UK university language centers. The findings indicate that collaboration in computer-based environments organized by teachers is useful for students to develop their language skills. Computer-supported collaboration increases students' confidence and encourages them to maintain active learning, thus reduces the passive reliance on teachers' feedback. © 2010, IGI Global.

15.Structural signature and contact force distributions in the simulated three-dimensional sphere packs subjected to uniaxial compression

Author:Liu, LF;Zhang, L;Liao, SF


Abstract:Packing of spherical particles in a three-dimensional cylindrical container is simulated by using Discrete Element Method. The packed bed of spheres is also subjected to vertical compression which results in a dense compact. Microstructures of the packing during compaction are examined in detail in terms of the contact number, deviator fabric, and radial distribution function. Furthermore, contact force distributions are measured at different locations in the pack, i.e. the centre, the side wall, and the base (or bottom wall) of the container. The simulations show that random close packing (RCP) tends to exist in the centre of the pack, while ordered packing structures exist near the container's walls. The uniaxial compression doesn't seem to alter the packing structure in the pack centre remarkably, but to reduce the structural anisotropy of the packing close to the container's base. The simulated results have also helped to establish the correlations between packing structures and contact force distributions. Further, it is shown that small contact force distributions are sensitive to local packing structures. The simulated results are shown to be consistent with the recent experimental and simulation findings.

16.Multi-camera video surveillance for real-time analysis and reconstruction of soccer games

Author:Ren, JC;Xu, M;Orwell, J;Jones, GA


Abstract:Soccer analysis and reconstruction is one of the most interesting challenges for wide-area video surveillance applications. Techniques and system implementation for tracking the ball and players with multiple stationary cameras are discussed. With video data captured from a football stadium, the real-world, real-time positions of the ball and players can be generated. The whole system contains a two-stage workflow, i.e., single view and multi-view processing. The first stage includes categorizing of players and filtering of the ball after changing detection against an adaptive background and image-plane tracking. Occlusion reasoning and tracking-back is applied for robust ball filtering. In the multi-view stage, multiple observations from overlapped single views are fused to refine players' positions and to estimate 3-D ball positions using geometric constraints. Experimental results on real data from long sequences are demonstrated.

17.Building wireless sensor network applications with LooCI

Author:Hughes, Daniel ; Thoelen, Klaas ; Horré, Wouter ; Matthys, Nelson ; Del Cid, Javier ; Michiels, Sam ; Huygens, Christophe ; Joosen, Wouter ; Ueyama, Jó

Source:International Journal of Mobile Computing and Multimedia Communications,2010,Vol.2

Abstract:Considerable research has been performed in applying run-time reconfigurable component models to the domain of wireless sensor networks. The ability to dynamically deploy and reconfigure software components has clear advantages in sensor networks, which are typically large in scale and expected to operate for long periods in the face of node mobility, dynamic environmental conditions, and changing application requirements. LooCI is a component and binding model that is optimized for use in resource-constrained environments such as Wireless Sensor Networks. LooCI components use a novel event-based binding model that allows developers to model rich component interactions, while providing support for run-time reconfiguration, reflection, and policy-based management. This paper reports on the design of LooCI and describes a prototype implementation for the Sun SPOT. This platform is then evaluated in context of a real-world river monitoring and warning scenario in the city of Sa˜o Carlos, Brazil. Copyright © 2010, IGI Global.

18.Decentralized fault detection and management for Wireless Sensor Networks

Author:Man, Ka Lok ; Chen, Chen ; Hughes, Danny

Source:2010 5th International Conference on Future Information Technology, FutureTech 2010 - Proceedings,2010,Vol.

Abstract:Wireless Sensor Networks are increasingly being deployed in long-lived challenging application scenarios which demand a high level of availability and reliability. To achieve these characteristics in inherently unreliable and resource constrained sensor network environments fault tolerance is required. This paper presents a generic and efficient fault tolerance algorithm for Wireless Sensor Networks. In contrast to existing approaches the algorithm presented in this paper is entirely decentralized and can thus be used to support fully autonomic fault tolerance in sensor network environments. © 2010 IEEE.

19.Working towards efficient parallel computing of integral images on multi-core processors

Author:Zhang, Nan

Source:ICCET 2010 - 2010 International Conference on Computer Engineering and Technology, Proceedings,2010,Vol.2

Abstract:This paper presents a novel multi-threaded parallel algorithm for computing integral images on multi-core processors. At each stage of the design, we evaluated several approaches, well-established as well as newly proposed. According to the results of the evaluations and our analysis the best suitable solutions have been identified, from which the parallel algorithm was synthesised. Tests were made and showed that on systems with fast FSB, e.g., 1333MHz, when running with two threads bound on distinctive processors sharing the same L2 cache the implementation of the algorithm could run at a speed twice as fast as that of the best known sequential reference. Tests also revealed that L2 cache size, system bus speed, micro-architecture and topology of the processor all had their share in determining the performance of the implementation relative to the sequential reference. © 2010 IEEE.

20.Middleware for resource sharing in multi-purpose wireless sensor networks

Author:Del Cid, Pedro Javier ; Michiels, Sam ; Joosen, Wouter ; Hughes, Danny

Source:2010 IEEE International Conference on Networked Embedded Systems for Enterprise Applications, NESEA 2010,2010,Vol.

Abstract:In order to improve application reaction times and decrease overall transmission overhead, Wireless Sensor Network (WSN) applications are being developed to push intelligence into the network. In multi-purpose enterprise deployments of WSNs the infrastructure is considered a light-weight service platform that can provide services for multiple concurrent distributed applications. In this context our middleware focuses on efficiently managing shared resources while considering Quality of Data (QoD) and context aware operation. In this paper we address the issue of how concurrent use of WSN services may lead to consequential contention over a sensor node's resources. We contribute by introducing share-able components that minimize the consequential resources needed and a resource planner that effectively reserves these resources. A prototype implementation and evaluation are provided. ©2010 IEEE.
Total 1,780 results found
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