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A Training Algorithm For Sparse Ls-Svm Using Compressive Sampling, Jie Yang, Son Lam Phung, Abdesselam Bouzerdoum 2010 University of Wollongong

A Training Algorithm For Sparse Ls-Svm Using Compressive Sampling, Jie Yang, Son Lam Phung, Abdesselam Bouzerdoum

Faculty of Informatics - Papers (Archive)

Least Squares Support Vector Machine (LS-SVM) has become a fundamental tool in pattern recognition and machine learning. However, the main disadvantage is lack of sparseness of solutions. In this article Compressive Sampling (CS), which addresses the sparse signal representation, is employed to find the support vectors of LS-SVM. The main difference between our work and the existing techniques is that the proposed method can locate the sparse topology while training. In contrast, most of the traditional methods need to train the model before finding the sparse support vectors. An experimental comparison with the standard LS-SVM and existing algorithms is given ...


On The Analysis Of Background Subtraction Techniques Using Gaussian Mixture Models, Abdesselam Bouzerdoum, Azeddine Beghdadi, Son Lam Phung, Philippe L. Bouttefroy 2010 University of Wollongong

On The Analysis Of Background Subtraction Techniques Using Gaussian Mixture Models, Abdesselam Bouzerdoum, Azeddine Beghdadi, Son Lam Phung, Philippe L. Bouttefroy

Faculty of Informatics - Papers (Archive)

In this paper, we conduct an investigation into background subtraction techniques using Gaussian Mixture Models (GMM) in the presence of large illumination changes and background variations. We show that the techniques used to date suffer from the trade-off imposed by the use of a common learning rate to update both the mean and variance of the component densities, which leads to a degeneracy of the variance and creates “saturated pixels”. To address this problem, we propose a simple yet effective technique that differentiates between the two learning rates, and imposes a constraint on the variance so as to avoid the ...


Automatic Parameter Selection For Feature-Enhanced Radar Image Restoration, Moeness G Amin, Cher Hau Seng, Son Lam Phung, Abdesselam Bouzerdoum 2010 Villanova University

Automatic Parameter Selection For Feature-Enhanced Radar Image Restoration, Moeness G Amin, Cher Hau Seng, Son Lam Phung, Abdesselam Bouzerdoum

Faculty of Informatics - Papers (Archive)

In this paper, we propose a new technique for optimum parameter selection in non-quadratic radar image restoration. Although both the regularization hyper-parameter and the norm value are influential factors in the characteristics of the formed restoration, most existing optimization methods either require memory intensive computation or prior knowledge of the noise. Here, we present a contrast measure-based method for automated hyper-parameter selection. The proposed method is then extended to optimize the norm value used in non-quadratic image formation and restoration. The proposed method is evaluated on the MSTAR public target database and compared to the GCV method. Experimental results show ...


Feature Selection For Facial Expression Recognition, Abdesselam Bouzerdoum, Son Lam Phung, Fok Hing Chi Tivive, Peiyao Li 2010 University of Wollongong

Feature Selection For Facial Expression Recognition, Abdesselam Bouzerdoum, Son Lam Phung, Fok Hing Chi Tivive, Peiyao Li

Faculty of Informatics - Papers (Archive)

In daily interactions, humans convey their emotions through facial expression and other means. There are several facial expressions that reflect distinctive psychological activities such as happiness, surprise or anger. Accurate recognition of these activities via facial image analysis will play a vital role in natural human-computer interfaces, robotics and mimetic games. This paper focuses on the extraction and selection of salient features for facial expression recognition. We introduce a cascade of fixed filters and trainable non-linear 2-D filters, which are based on the biological mechanism of shunting inhibition. The fixed filters are used to extract primitive features, whereas the adaptive ...


Fast Digital Optical Flow Estimation Based On Emd, Mickael Quelin, Abdesselam Bouzerdoum, Son Lam Phung 2010 University of Wollongong

Fast Digital Optical Flow Estimation Based On Emd, Mickael Quelin, Abdesselam Bouzerdoum, Son Lam Phung

Faculty of Informatics - Papers (Archive)

This paper presents an optical flow estimation technique based on the so called Elementary Motion Detector (EMD). The aim is to provide a fast but not necessarily very accurate system to be used for specific post processing purposes. This model uses a low complexity algorithm for detecting motion in four directions by identifying specific motion templates. By extending the motion templates to different scales of the input video, an Elementary Velocity Detector (EVD) is created. This one can save computation time by estimating different speeds in parallel. Information from the EVD outputs is then used to generate an estimate of ...


Adaptive Hierarchical Architecture For Visual Recognition, Fok Hing Chi Tivive, Abdesselam Bouzerdoum, Son Lam Phung, Khan M. Iftekharuddin 2010 University of Wollongong

Adaptive Hierarchical Architecture For Visual Recognition, Fok Hing Chi Tivive, Abdesselam Bouzerdoum, Son Lam Phung, Khan M. Iftekharuddin

Faculty of Informatics - Papers (Archive)

We propose a new hierarchical architecture for visual pattern classification. The new architecture consists of a set of fixed, directional filters and a set of adaptive filters arranged in a cascade structure. The fixed filters are used to extract primitive features such as orientations and edges that are present in a wide range of objects, whereas the adaptive filters can be trained to find complex features that are specific to a given object. Both types of filters are based on the biological mechanism of shunting inhibition. The proposed architecture is applied to two problems: pedestrian detection and car detection. Evaluation ...


A Direct Approach To Co-Universal Algebras Associated To Directed Graphs, Aidan Sims, S B. Webster 2010 University of Wollongong

A Direct Approach To Co-Universal Algebras Associated To Directed Graphs, Aidan Sims, S B. Webster

Faculty of Informatics - Papers (Archive)

We prove directly that if $E$ is a directed graph in which every cycle has an entrance, then there exists a $C^*$-algebra which is co-universal for Toeplitz-Cuntz-Krieger $E$-families. In particular, our proof does not invoke ideal-structure theory for graph algebras, nor does it involve use of the gauge action or its fixed point algebra.


Aperiodicity And Cofinality For Finitely Aligned Higher-Rank Graphs, Peter Lewin, Aidan Sims 2010 University of Wollongong

Aperiodicity And Cofinality For Finitely Aligned Higher-Rank Graphs, Peter Lewin, Aidan Sims

Faculty of Informatics - Papers (Archive)

We introduce new formulations of aperiodicity and cofinality for finitely aligned higher-rank graphs $\Lambda$, and prove that $C^*(\Lambda)$ is simple if and only if $\Lambda$ is aperiodic and cofinal. The main advantage of our versions of aperiodicity and cofinality over existing ones is that ours are stated in terms of finite paths. To prove our main result, we first characterise each of aperiodicity and cofinality of $\Lambda$ in terms of the ideal structure of $C^*(\Lambda)$. In an appendix we show how our new cofinality condition simplifies in a number of special cases which have been treated previously in ...


Motion Estimation With Adaptive Regularization And Neighborhood Dependent Constraint, Muhammad Wasim Nawaz, Abdesselam Bouzerdoum, Son Lam Phung 2010 University of Wollongong

Motion Estimation With Adaptive Regularization And Neighborhood Dependent Constraint, Muhammad Wasim Nawaz, Abdesselam Bouzerdoum, Son Lam Phung

Faculty of Informatics - Papers (Archive)

Modern variational motion estimation techniques use total variation regularization along with the L1 norm in constant brightness data term. An algorithm based on such homogeneous regularization is unable to preserve sharp edges and leads to increased estimation errors. A better solution is to modify regularizer along strong intensity variations and occluded areas. In addition, using neighborhood information with data constraint can better identify correspondence between image pairs than using only a pointwise data constraint. In this work, we present a novel motion estimation method that uses neighborhood dependent data constraint to better characterize local image structure. The method also uses ...


Automatic Recognition Of Smiling And Neutral Facial Expressions, Peiyao Li, S L. Phung, Abdesselam Bouzerdoum, Fok Hing Chi Tivive 2010 University of Wollongong

Automatic Recognition Of Smiling And Neutral Facial Expressions, Peiyao Li, S L. Phung, Abdesselam Bouzerdoum, Fok Hing Chi Tivive

Faculty of Informatics - Papers (Archive)

Facial expression is one way humans convey their emotional states. Accurate recognition of facial expressions via image analysis plays a vital role in perceptual human computer interaction, robotics and online games. This paper focuses on recognising the smiling from the neutral facial expression. We propose a face alignment method to address the localisation error in existing face detection methods. In this paper, smiling and neutral facial expression are differentiated using a novel neural architecture that combines fixed and adaptive non-linear 2-D filters. The fixed filters are used to extract primitive features, whereas the adaptive filters are trained to extract more ...


Fuzzy Logic-Based Image Fusion For Multi-View Through-The-Wall Radar, Cher Hau Seng, Abdesselam Bouzerdoum, Fok Hing Chi Tivive, Moeness G. Amin 2010 University of Wollongong

Fuzzy Logic-Based Image Fusion For Multi-View Through-The-Wall Radar, Cher Hau Seng, Abdesselam Bouzerdoum, Fok Hing Chi Tivive, Moeness G. Amin

Faculty of Informatics - Papers (Archive)

In this paper, we propose a new technique for image fusion in multi-view through-the-wall radar imaging system. As most existing image fusion methods for through-the-wall radar imaging only consider a global fusion operator, it is desirable to consider the differences between each pixel using a local operator. Here, we present a fuzzy logic-based method for pixel-wise image fusion. The performance of the proposed method is evaluated on both simulated and real data from through-the-wall radar imaging system. Experimental results show that the proposed method yields improved performance, compared to existing methods.


Automatic Classification Of Gpr Signals, W Shao, A Bouzerdoum, S L. Phung, L Su, B Indraratna, C Rujikiatkamjorn 2010 University of Wollongong

Automatic Classification Of Gpr Signals, W Shao, A Bouzerdoum, S L. Phung, L Su, B Indraratna, C Rujikiatkamjorn

Faculty of Informatics - Papers (Archive)

Ground penetrating radar has been widely used in many areas. However, the processing and interpretation of acquired signals remains a challenging task since it requires experienced users to manage the whole operations. In this paper, we propose an automatic classification system to categorise GPR signals based on magnitude spectrum amplitudes and support vector machines. The system is tested on a real-world GPR data set. The experimental results show that our system can correctly distinguish ground penetrating radar signals reflected by different materials.


Multi-Resolution Mean-Shift Algorithm For Vector Quantization, P L. M Bouttefroy, A Bouzerdoum, A Beghdadi, S L. Phung 2010 University of Wollongong

Multi-Resolution Mean-Shift Algorithm For Vector Quantization, P L. M Bouttefroy, A Bouzerdoum, A Beghdadi, S L. Phung

Faculty of Informatics - Papers (Archive)

The generation of stratified codebooks, providing a subset of vectors at different scale levels, has become necessary with the emergence of embedded coder/decoder for scalable image and video formats. We propose an approach based on mean-shift, invoking the multi-resolution framework to generate codebook vectors. Applied to the entire image, mean-shift is slow because it requires each sample to converge to a mode of the distribution. The procedure can be sped up with three simple assumptions: kernel truncation, code attraction and trajectory attraction. Here we propose to apply the mean-shift algorithm to the four image subbands generated by a DWT ...


Using Task Analysis To Design Intuitive Online Grocery Systems, Mark Freeman, Alison Freeman 2010 University of Wollongong

Using Task Analysis To Design Intuitive Online Grocery Systems, Mark Freeman, Alison Freeman

Faculty of Informatics - Papers (Archive)

This paper presents a normative task model for modelling user interactions with online grocery stores. It is envisaged that using task models will aid system developers in building better systems to meet users’ needs, and hereby creating better system design processes. This paper will discuss the three main areas of user experience when completing the process of adding a product to an online trolley: attempting to retrieve the product, receiving the results of the retrieval attempt, and adding the product to the trolley. The normative task model presented is expected to help in the future design of online grocery systems ...


Wavelet Based Nonlocal-Means Super-Resolution For Video Sequences, H Zheng, A Bouzerdoum, S L. Phung 2010 University of Wollongong

Wavelet Based Nonlocal-Means Super-Resolution For Video Sequences, H Zheng, A Bouzerdoum, S L. Phung

Faculty of Informatics - Papers (Archive)

Video sequence resolution enhancement became a popular research area during the last two decades. Although traditional super-resolution techniques have been successful in dealing with image sequences, many constraints such as global translation between frames, have to be imposed to obtain good performance. In this paper, we present a new wavelet-based nonlocal-means (WNLM) framework to bypass the motion estimation stage. It can handle complex motion changes between frames. Compared with the nonlocal-means (NLM) super-resolution framework, the proposed method provides better result in terms of PSNR and faster processing.


Adaptive Regularization For Image Restoration Using A Variational Inequality Approach, Matthew Kitchener, Abdesselam Bouzerdoum, Son Lam Phung 2010 University of Wollongong

Adaptive Regularization For Image Restoration Using A Variational Inequality Approach, Matthew Kitchener, Abdesselam Bouzerdoum, Son Lam Phung

Faculty of Informatics - Papers (Archive)

In this paper, a generalized image restoration method is formulated as a variational inequality problem, whose solution is obtained using a dynamic system approach. In this method, the restored image and the regularization parameter are obtained simultaneously. In particular, the optimum regularization parameter is determined adaptively, depending on noise and image content. The restoration problem is presented in a generalized form so that it maybe be implemented using different norms; only L1 and L2 norms have been implemented in this paper. A comparison based on experimental results shows that the proposed method achieves comparable if not better performance as some ...


The Co-Universal C*-Algebra Of A Row-Finite Graph, Aidan Sims 2010 University of Wollongong

The Co-Universal C*-Algebra Of A Row-Finite Graph, Aidan Sims

Faculty of Informatics - Papers (Archive)

Let $E$ be a row-finite directed graph. We prove that there exists a $C^*$-algebra $\Cr{E}$ with the following co-universal property: given any $C^*$-algebra $B$ generated by a Toeplitz-Cuntz-Krieger $E$-family in which all the vertex projections are nonzero, there is a canonical homomorphism from $B$ onto $\Cr{E}$. We also identify when a homomorphism from $B$ to $\Cr{E}$ obtained from the co-universal property is injective. When every loop in $E$ has an entrance, $\Cr{E}$ coincides with the graph $C^*$-algebra $C^*(E)$, but in general, $\Cr{E}$ is a quotient of $C^*(E)$. We investigate ...


Fpga-Based Signal Processing In An Optical Feedback Self-Mixing Interferometry System, Zongzhen Li, Yanguang Yu, Jiangtao Xi, Huiying Ye 2010 University of Wollongong

Fpga-Based Signal Processing In An Optical Feedback Self-Mixing Interferometry System, Zongzhen Li, Yanguang Yu, Jiangtao Xi, Huiying Ye

Faculty of Informatics - Papers (Archive)

Optical feedback Self-mixing Interferometry (OFSMI) can achieve a high-resolution displacement sensing and measurement by using advanced digital signal processing. However, most existing signal processing algorithms used for OFSMI signals are implemented on a PC by Matlab or other programming languages. In this case, the whole structure of OFSMI sensing system is incompact and the measurement is in low speed. The design trends in sensing systems are towarding to small size, high integration and fast real time processing. These trends require us to improve the existing OFSMI design. It is a good solution to apply Field-programmable gate arrays (FPGAs) technique onto ...


Quasi-Orthogonal Space-Time-Frequency Codes In Mb-Ofdm Uwb, Le Chung Tran, Alfred Mertins, Tadeusz A. Wysocki 2010 University of Wollongong

Quasi-Orthogonal Space-Time-Frequency Codes In Mb-Ofdm Uwb, Le Chung Tran, Alfred Mertins, Tadeusz A. Wysocki

Faculty of Informatics - Papers (Archive)

Quasi-Orthogonal Space-Time-Frequency Codes (QOSTFCs) will be examined in this paper to advance either data rate or error performance in recently proposed Space-Time-Frequency Coded Multiband OFDM Ultra-Wideband (STFC MB-OFDM UWB) communication systems. It is shown that QOSTFCs can provide signi¯cantly better error performance, compared to the conventional MB-OFDM UWB (without STFCs) and to the Orthogonal STFCs (OSTFCs) of the same order, at the same data rate, without increasing the total transmission power. Another form of the enhancement would be that QOSTFCs can provide higher data rates with the same error performance, compared to OSTFCs.


Usability As A Panacea, Mark Freeman, Matthew Bowden 2010 University of Wollongong

Usability As A Panacea, Mark Freeman, Matthew Bowden

Faculty of Informatics - Papers (Archive)

After implementation of a web-based application in a tertiary education environment, an expert review of this application was conducted. An analysis of the processes and results of the expert review of the web-based application is presented. The owners of the system implemented the recommendations of this expert review to resolve system issues. Through two rounds of expert evaluations, system modifications were made based on recommendations from the initial expert review. The concern that usability evaluations are used as a ‘cure-all solution’ to demonstrate to users that system owners are trying to resolve issues with the system is discussed. It should ...


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