XJTLU Research Repository

1. 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.

2. Classified Vector Quantisation and population decoding for pattern recognition

Author:Bailing Zhang;Sheng-Uei Guan

Source:International journal of artificial intelligence and soft computing: IJAISC,2009,Vol.

Abstract:Learning Vector Quantisation (LVQ) is a method of applying the Vector Quantisation (VQ) to generate references for Nearest Neighbour (NN) classification. Though successful in many occasions, LVQ suffers from several shortcomings, especially the reference vectors are prone to diverge. In this paper, we propose a Classified Vector Quantisation (CVQ) to establish VQ for classification. By CVQ, each data category is represented by its own codebook, which can be implemented by some learning algorithms. In classification process, each codebook offers a generalised NN. The examples of handwritten digit recognition and offline signature verification are used to demonstrate the efficiency of the proposed scheme.

3. An integrated crystal plasticity fe system for microforming simulation

Author:Cao,J.;Zhuang,W.;Wang,S.;Ho,K. C.;Zhang,N.;Lin,J.;Dean,T. A.

Source:Journal of Multiscale Modeling,2009,Vol.1

Abstract:Based on Voronoi tessellation and the probability theory, a VGRAIN system is created for the generation of grains and grain boundaries for micromaterials. This system requires physical parameters obtained from microstructures of materials, such as the average, minimum and maximum grain sizes. Numerical procedures have been established to link the physical parameters of a material to the control variable in a gamma distribution equation and a method has been developed to solve the probability equation. These are the basis for the development of the VGRAIN system, which can be used to generate different grain structures and shapes that follow a certain pattern according to the probability theory. Statistical analyses have been carried out to investigate the distribution of generated virtual grains. The generated virtual microstructure is then implemented in the commercial FE code, ABAQUS, for mesh generation and micromechanics analysis using crystal plasticity (CP) equations for face-centered cubic (FCC) materials, which are implemented in the commercial FE solver, ABAQUS, through the user-defined subroutines, VUMAT/UMAT. FE analyses have been carried out to demonstrate the effectiveness of the integrated system for the investigation of localized straining and necking, encountered in microforming processes, such as extrusion of micropins, deformation of microfilms and hydroforming of microtubes. © 2009 Imperial College Press.

4. Learning kernel subspace classifier for robust face recognition

Author:Zhang,Bailing;Guan,Sheng Uei;Ko,Hanseok

Source:International Journal of Soft Computing,2009,Vol.4

Abstract:Subspace classifiers are very important in pattern recognition in which pattern classes are described in terms of linear subspaces spanned by their respective basis vectors. To overcome the limitations of linear methods, kernel based subspace models have been proposed in the past by applying the Kernel Principal Component Analysis (KPCA). However, the projection variance in the kernel space as applied in the previously proposed kernel subspace methods, is not a good criteria for the data representation and they simply fail in many recognition problems. We address this issue by proposing a learning kernel subspace classifier which attempts to reconstruct data in the input space through the kernel subspace projection. Comparing with the pre-image methods, we emphasize the problem of how to use a kernel subspace as a model to describe input space rather than finding an approximate pre-image for each input by minimization of the reconstruction error in the kernel space. Experimental results on occluded face recognition demonstrated the efficiency of the proposed method. © Medwell Journals, 2009.

5. 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.

6. Automatic Differentiation Applied to Economics

Author:Tadjouddine, EM

Source:IMECS 2009: INTERNATIONAL MULTI-CONFERENCE OF ENGINEERS AND COMPUTER SCIENTISTS, VOLS I AND II,2009,Vol.

Abstract:This paper discusses the use of the Automatic Differentiation approach in evaluating derivatives of functions represented by computer programs. We then considered a Cournot oligopoly modeled by a system of stochastic differential equations. The setting is that of a set of self-interested firms striving to adjust their productions in the direction of higher profits subject to mistakes or random shocks. The stochastic differential equations are solved by a numerical method and the profits are calculated using a Monte Carlo simulation. Then, Automatic Differentiation is used to propagate sensitivities along each path in an automated fashion. Numerical results have confirmed the intuition one may have that noisy environments can lead to important profit differences between firms as well as higher sensitivities as opposed to less noisy ones.

7. High-k dielectrics' radiation response to X-ray and gamma-ray exposure

Author:Zhao,C. Z.;Wemer,M.;Taylor,S.;Chalker,P. R.;Potter,R. J.;Gaskell,J.

Source:Proceedings of the International Symposium on the Physical and Failure Analysis of Integrated Circuits, IPFA,2009,Vol.

Abstract:Radiation-induced degradation of HfO 2, ZrO 2' LaAIO 3, and NdAIO 3 thin films was studied and compared based on a Fe 55 X-ray source and Cs 137137 γ-ray source . After the X-ray exposure of a total dose of lOOkrad, negative VFB shifts were observed in these thin films, whereas after the γ-ray exposures of the same dose, positive VFB shifts was observed. ©2009 IEEE.

8. 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.

9. Randomness quality of permuted pseudorandom binary sequences

Author:Tan, SK;Guan, SU

Source:MATHEMATICS AND COMPUTERS IN SIMULATION,2009,Vol.79

Abstract:This paper uses the DIEHARD statistical test suite to test the randomness quality of "permuted" versions of maximum length sequences generated by linear finite state machines (LFSM) such as cellular automata and linear feedback shift registers. Analysis shows that permuted sequences can be equivalently generated by using time-varying transformations derived from the original LFSM. Based on the above, we suggest the permuted transformation sequence scheme. Experimental results show that DIEHARD results are improved with respect to the original non-permuted sequences-up to seven more tests can be passed (total of 19 tests). Furthermore, a permutation vector is used to generate cyclically distinct permuted sequences and each sequence has a desirable maximum length period of 2(n) - 1. (C) 2008 IMACS. Published by Elsevier B.V. All rights reserved.

10. Hybrid Wyner-Ziv Video Coding Structure for Removing Feedback Channel

Author:Lee, H;Tillo, T;Jeon, B

Source:2009 IEEE PACIFIC RIM CONFERENCE ON COMMUNICATIONS, COMPUTERS AND SIGNAL PROCESSING, VOLS 1 AND 2,2009,Vol.

Abstract:This paper proposes a hybrid Wyner-Ziv video coding scheme without requiring the feedback channel which is a limiting factor for many practical applications. In order to remove the feedback channel, we develop a hybrid structure combining the conventional predictive video coding and the Wyner-Ziv video coding schemes. From the information of the neighboring predictive-coded macro blocks, the proposed hybrid scheme estimates the required channel code rate of the Wyner-Ziv coded macro blocks in order to eliminate the requirement of feedback channel. Experiment results indicate that it achieves good coding performance on sequences having linear and slow motion.

11. Case Studies with Process Analysis Toolkit (PAT)

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

Source:2009 INTERNATIONAL SOC DESIGN CONFERENCE (ISOCC 2009),2009,Vol.

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.

12. High-k materials and their response to gamma ray radiation

Author:Zhao, CZ;Taylor, S;Werner, M;Chalker, PR;Potter, RJ;Gaskell, JM;Jones, AC

Source:JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B,2009,Vol.27

Abstract:The radiation response of four different high-k materials has been investigated by irradiating them using a 979 MBq Cs(137) gamma-ray source and a dose absorption rate of 0.71 rad(Si)/s. Acceptorlike electron traps and donorlike traps were observed in HfO(2) and ZrO(2) metal-oxide-semiconductor capacitors originating from radiation-induced defects. A lower density of donor-like traps were created in LaAlO(3) and NdAlO(3) capacitors, but both electron and hole trapping play a role in shifting the flat band voltage. The radiation hardness of the LaAlO(3) and NdAlO(3) thin films is similar to thermal SiO(2) but better than the HfO(2) and ZrO(2). (C) 2009 American Vacuum Society. [DOI: 10.1116/1.3071848]

13. Dielectric relaxation of lanthanum doped zirconium oxide

Author:Zhao, CZ;Taylor, S;Werner, M;Chalker, PR;Murray, RT;Gaskell, JM;Jones, AC

Source:JOURNAL OF APPLIED PHYSICS,2009,Vol.105

Abstract:Lanthanum doped zirconium oxide (La-x-Zr1-xO2-delta) films, with La contents, up to x=0.35, were studied. Films were annealed at 900 degrees C to crystallize them into phases with higher kappa-values. Increasing the La content suppressed the monoclinic phase and stabilized the tetragonal or cubic phase. The highest dielectric constant was obtained for a lightly doped film with a La content of x=0.09, for which a kappa-value of 40 was obtained. This was accompanied by a significant dielectric relaxation, following a single Curie-von Schweidler power-law dependency with frequency, changing to a mixed Curie-von Schweidler and Kohlrausch-Williams-Watts relationships after annealing. The dielectric relaxation was most severe for lightly doped films, which had the highest kappa-values. The dielectric relaxation appears to be related to the size of crystal grains formed during annealing, which was dependent on the doping level.

14. Layered RDF: An object-oriented approach to web information representation

Author:Vølstad,Torunn;Liu,Fei;Guan,Sheng Uei

Source:Web Intelligence and Agent Systems,2009,Vol.7

Abstract:Based on XML, RDF(S) has been recommended as the basic layer of the Semantic Web, providing a foundation for the higher layers of ontology, logic and trust. Although RDF(S) enables specification and identification of data and relationships between data, it has some limitations as a foundational language of the Semantic Web. Firstly, the unconstrained framework of the RDF Schema makes it hard to share information from different sources. Furthermore, RDF(S) has limited expres-siveness as a vocabulary description language, which is partly due to insufficient object-oriented features. Finally, the unclear semantics of RDF(S), caused by language constructs with dual roles, impede any approach to provide reasoning support for the language. To overcome some of the limitations, this paper presents Layered RDF, a web information representation language based on RDF(S). Layered RDF distinguishes schema information from instance information by having separated layers. Furthermore, Layered RDF provides more powerful schema mechanisms than does RDF Schema, by incorporating object-oriented features such as inheritance and polymorphism. © 2009 IOS Press and the authors. All rights reserved.

15. On the activation and passivation of precursors for process-induced positive charges in Hf-dielectric stacks

Author:Chang,M. H.;Zhao,C. Z.;Ji,Z.;Zhang,J. F.;Groeseneken,G.;Pantisano,L.;De Gendt,S.;Heyns,M. M.

Source:Journal of Applied Physics,2009,Vol.105

Abstract:Hf-based dielectric stack is replacing SiON as gate dielectric even though our understanding of it is incomplete. It has been reported that a thermal exposure above 450 °C can lead to positive charging in both unoptimized Si O2 layer and Hf-based dielectric stack. At present, there is little information on how this process-induced positive charging (PIPC) occurs in the Hf-based stack and how to suppress it. The objective of the current work is to improve our understanding by addressing three key issues. First, the activation of PIPC precursors after device fabrication is investigated and it will be shown that the loss of certain species from the gate edge through lateral diffusion is responsible for it. Second, the passivation of the precursor is studied and the relevant species are explored. It is found that both water- and chlorine-related species play a role. Finally, the reactivation of the passivated precursor is examined and the results show that it is not thermally accelerated. © 2009 American Institute of Physics.

16. A Context-Aware Trust Model for Service-Oriented Multi-Agent Systems

Author:Wan, K;Alagar, V

Source:SERVICE-ORIENTED COMPUTING - ICSOC 2008 WORKSHOPS,2009,Vol.5472

Abstract:Service-oriented systems offer the potential for minimizing the development time of business applications within an enterprise while promoting collaborative joint ventures among enterprisers distributed geographically. Service-oriented applications assembled from services obtained from different vendors, sometimes anonymous, should be trustworthy. In this paper we investigate context-aware multi-agent systems (MAS) which can dynamically form coalitions of trusted partners as an effective mechanism to act on behalf of service requestors, find services requested by them, determine trusted services, and provide services to the requestors without violating the privacy of the partners involved in such transactions. The MAS is open with respect to external agents requesting and receiving services, but closed with respect to other activities initiated by external agents. The agents in MAS may have different trust models. We explain how trust models of different agents should be composed into a web of trust for trusted transactions in MAS.

17. Computing Parallel Speeded-Up Robust Features (P-SURF) via POSIX Threads

Author:Zhang, N

Source:EMERGING INTELLIGENT COMPUTING TECHNOLOGY AND APPLICATIONS, PROCEEDINGS,2009,Vol.5754

Abstract:Speeded-Up Robust Features (SURF); an image local feature extracting and describing method, finds and describes point correspondences between images with different viewing conditions. Despite the fact that it has recently been developed; SURF leas already successfully found its applications in the area of computer vision, and was reported to be more appealing than the earlier Scale-Invariant Feature Transform (SIFT) in terms of robustness and performance. This paper presents a multi-threaded algorithm and its implementation that computes the same SURF. The algorithm parallelises several stages of computations in the original, sequential design. The main benefit brought; about; is the acceleration in computing the descriptor. Tests have been performed to show that the parallel SURF (P-SURF) generally shortened the computation time by a factor of 2 to 6 than the original; sequential method when running on multi-core processors.

18. 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.

19. Single development project

Author:Stankovic, N

Source:JOURNAL OF SYSTEMS AND SOFTWARE,2009,Vol.82

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.

20. Frequency dispersion and dielectric relaxation of La2Hf2O7

Author:Zhao, CZ;Taylor, S;Werner, M;Chalker, PR;Gaskell, JM;Jones, AC

Source:JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B,2009,Vol.27

Abstract:Thin films of La2Hf2O7 have been deposited by liquid injection atomic layer deposition and post-deposition annealed at 900 degrees C. The dielectric frequency dispersion was more serious for thinner films which is attributed to the effect of a lossy interfacial layer between the La2Hf2O7 dielectric and silicon substrate. The effect of the interfacial layer was modeled based on a dual-frequency measurement technique. The dielectric relaxation of the La2Hf2O7 thin films was modelled using both the Curie-von Schweidler and Havriliak-Negami relationships. Post deposition annealing in nitrogen at 900 degrees C for 15 min improved dielectric relaxation and reduced the dielectric loss. (C) 2009 American Vacuum Society. [DOI: 10.1116/1.3043535]

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