Physical Sciences and Mathematics Commons^™

Combining Agent-Oriented Conceptual Modelling With Formal Methods, S. A. Vilkomir, Aditya K. Ghose, A. Krishna

Faculty of Informatics - Papers (Archive)

Agent-oriented conceptual modelling notations such as i* have received considerable recent attention as a useful approach to early-phase requirements engineering. Agent-oriented conceptual modelling notations are highly effective in representing requirements from an intentional stance and answering questions such as what goals exist, how key actors depend on each other and what alternatives must be considered. Formal methods such as those based on the Z notation offer a complementary set of representational facilities. We explore how these two otherwise disparate approaches might be used in a synergistic fashion.

Two Complex Orthogonal Space-Time Codes For Eight Transmit Antennas, Le Chung Tran, Jennifer Seberry, Yejing Wang, Beata J. Wysocki, Tadeusz A. Wysocki, Tianbing Xia, Ying Zhao

Faculty of Informatics - Papers (Archive)

Two new constructions of complex orthogonal space-time block codes of order 8 based on the theory of amicable orthogonal designs are presented and their performance compared with that of the standard code of order 8. These new codes are suitable for multi-modulation schemes where the performance can be sacrificed for a higher throughput.

Performance Evaluation Of A Proxy System For Providing Immersive Audio Communication To Massively Multi-Player Games, C. D. Nguyen, Farzad Safaei, P. Boustead

Faculty of Informatics - Papers (Archive)

In this paper, a distributed proxy architecture is introduced for the provisioning of an immersive audio communication service to massively multi-player online games. The immersive audio communication service enables each avatar to hear a realistic audio mix of conversations in its hearing range. In our earlier work, peer-to-peer and central server architectures have been proposed for this service. In this paper, a distributed proxy architecture with either using network multicast or unicast between proxies is introduced to address the limitations of the previous architectures. The main focus of this paper is to evaluate the bandwidth cost saving of network multicast …

Visual Perceptual Process Model And Object Segmentation, Wanqing Li, P. Ogunbona, Lei Ye, Igor Kharitonenko

Faculty of Informatics - Papers (Archive)

Modeling human visual process is crucial for automatic object segmentation that is able to produce consistent results to human perception. Based on the latest understanding of how human performs the task of extracting objects from images, we proposed a graph-based computational framework to model the visual process. The model supports the hierarchical nature of human visual perception and consists of the key steps of human visual perception including pre-attentive (pre-constancy) grouping, figure-and-ground organization, and attentive (post-constancy) grouping. A divide-and-conquer implementation of the model based on the concept of shortest spanning tree (SST) has demonstrated the potential of the model for …

A Recursive Overlay Multicast Algorithm For Distribution Of Audio Streams In Networked Games, M. Dowlatshahi, Farzad Safaei

Faculty of Informatics - Papers (Archive)

This paper aims to provide a fast multicast algorithm among a set of distributed proxies to enable the creation of realistic audio for networked games. We assume that each proxy is responsible for a group of clients. The proxy receives the audio packets from its clients and multicasts this audio to every other proxy that requires this audio for any of its attached clients. In crowded virtual environments, the number of multicast trees could be quite large and these undergoes continuous change as the avatars move in and out of each others hearing range. To reduce the effect of overhead …

Investigation And Modeling Of Traffic Issues In Immersive Audio Environments, J. Mcmahon, M. Rumsewicz, P. Boustead, Farzad Safaei

Faculty of Informatics - Papers (Archive)

A growing area of technical importance is that of distributed virtual environments for work and play. For the audio component of such environments to be useful, great emphasis must be placed on the delivery of high quality audio scenes in which participants may change their relative positions. In this paper we describe and analyze an algorithm focused on maintaining relative synchronization between multiple users of such an environment and examine the subjective quality of service achieved.

Resilience-Differentiation In Programmable Virtual Networks, F. Rosenbaum, S. Jha, P. Boustead, Farzad Safaei

Faculty of Informatics - Papers (Archive)

Service and application requirements on network resilience have increased over the past few years. New on-line services such as e-commerce and connection-oriented interactive real-time services require higher network resilience than the more traditional off-line services. Programmable virtual networks promise fast and easy provisioning of new services but no consideration to meet the diverse resilience requirements has been made. This paper discusses issues related to resilience-differentiation in programmable virtual networks. A set of general guidelines is presented that apply to resilience-differentiation in programmable virtual network architectures. A case study is used to illustrate how the proposed guidelines can be met by …

Location-Based Services: A Vehicle For It&T Convergence , Katina Michael

Faculty of Informatics - Papers (Archive)

Location-based services (LBS), more than any other mobile commerce application area has served to bring together information technology and telecommunications (IT&T) industries. While much has been written on the potential of LBS, literature on how it is a catalyst for digital convergence is scant. This paper identifies and explores the various levels of converging technologies in mobile commerce by using three LBS case studies. Through literal replication the findings indicate that IT&T technologies are converging at the infrastructure, appliance and application level. It is predicted that mCommerce applications will increasingly rely on industry convergence to achieve their desired outcomes.

The Social, Cultural, Religious And Ethical Implications Of Automatic Identification, Katina Michael, M G. Michael

Faculty of Informatics - Papers (Archive)

The number of automatic identification (auto-ID) technologies being utilized in eBusiness applications is growing rapidly. With an increasing trend toward miniaturization and wireless capabilities, auto-ID technologies are becoming more and more pervasive. The pace at which new product innovations are being introduced far outweighs the ability for citizens to absorb what these changes actually mean, and what their likely impact will be upon future generations. This paper attempts to cover a broad spectrum of issues ranging from the social, cultural, religious and ethical implications of auto-ID with an emphasis on human transponder implants. Previous work is brought together and presented …

Can The Love Of Learning Be Taught?, R. Nillsen

Faculty of Informatics - Papers (Archive)

This paper is an expanded version of a talk given at a Generic Skills Workshop at the University of Wollongong, and was originally intended for academic staff from any discipline and general staff with an interest in teaching. The issues considered in the paper include the capacity of all to learn, the distinction between learning as understanding and learning as information, the interaction between the communication and the content of ideas, the tension between perception and content in communication between persons, and the human functions of a love of learning. In teaching, the creation of a fear-free environment is emphasised, …

Flow Equivalence Of Graph Algebras, David A. Pask, Teresa G. Bates

Faculty of Informatics - Papers (Archive)

This paper explores the effect of various graphical constructions upon the associated graph C∗-algebras. The graphical constructions in question arise naturally in the study of flow equivalence for topological Markov chains. We prove that out-splittings give rise to isomorphic graph algebras, and in-splittings give rise to strongly Morita equivalent C∗-algebras. We generalize the notion of a delay as defined in (D. Drinen, Preprint, Dartmouth College, 2001) to form in-delays and out-delays. We prove that these constructions give rise to Morita equivalent graph C∗-algebras. We provide examples which suggest that our results are the most general possible in the setting of …

Fundamental Groupoids Of K-Graphs, David A. Pask, Iain F. Raeburn, John C. Quigg

Faculty of Informatics - Papers (Archive)

k-graphs are higher-rank analogues of directed graphs which were first developed to provide combinatorial models for operator algebras of Cuntz– Krieger type. Here we develop a theory of the fundamental groupoid of a kgraph, and relate it to the fundamental groupoid of an associated graph called the 1-skeleton. We also explore the failure, in general, of k-graphs to faithfully embed into their fundamental groupoids.

Methods Of Online Grocery Shopping: Linking And Searching, Mark B. Freeman

Faculty of Informatics - Papers (Archive)

There are two dominant methods for locating information or goods on websites and online systems: searching and linking. Most previous research on searching and linking methods has focused on generic websites dedicated to locating information, such as Yahoo, rather than the searching and linking mechanisms used in specific applications, such as online shopping. In contrast, this study assessed the searching and linking metaphors inherent in online grocery stores, where each website must provide efficient tools for locating products if they are to be successful e-commerce websites. Worldwide grocery sites were judged against a checklist of advanced search features, and the …

Lessons Learned From The Practice Of Mobile Health Application Development, Ping Yu, H. Yu

Faculty of Informatics - Papers (Archive)

This fast abstract briefly discusses lessons learned in terms of how to overcome limitations of PDA devices, effectively capture requirements for mobile health application development and effectively reengineer a desktop application on PDA. The limitation of PDA devices includes: (1) small screen size, which limits text-based data entry, reporting and browsing; (2) limited storage space and slow processing, which requires effective and efficient coding generation; (3) security limitations and inadequate third party application support, which poses challenge for application development. The corresponding strategies addressing the above challenges are: (1) providing check box, radio button, drop down list, text field, combo …

A Distributed Server Architecture For Providing Immersive Audio Communication To Massively Multiplayer Online Games, C. D. Nguyen, Farzad Safaei, P. Boustead

Faculty of Informatics - Papers (Archive)

This paper investigates the assignment of audio mixing operations to a geographically distributed set of servers to provide an immersive audio communication environment for massively multiplayer online games. The immersive audio communication service enables each avatar to hear a realistic audio mix of the conversations in its audible range. There are three primary delivery architectures for this service, namely, peer-to-peer, central server and distributed servers. We focus on the distributed server architecture, which partitions the virtual world into regions or locales and then assigns the computation associated with the creation of audio scenes for all avatars in each locale to …

On The Provision Of Immersive Audio Communication To Massively Multi-Player Online Games, C. D. Nguyen, Farzad Safaei, D. Platt

Faculty of Informatics - Papers (Archive)

This paper discusses issues in providing immersive audio communication to massively multi-player online games (MMOG). We focus on network and server architectures for creating immersive audio scenes for game clients. We examine advantages and limitations of several architectures, including central server, distributed servers, and peer-to-peer architectures. We focus on a dynamic centralized server architecture which is suitable for the current MMOG in terms of sealability at end users and resource efficiency. We propose algorithms to optimize the performance of a centralized server. Finally, a simulation study is carried out to evaluate the performance of our proposed centralized server architecture and …

Nonlinear Sigma Model For Odd-Frequency Triplet Superconductivity In Superconductor/Ferromagnet Structures, J E. Bunder, K B. Efetov

Faculty of Informatics - Papers (Archive)

No abstract provided.

Data Management For Large Scale Power Quality Surveys, Murray-Luke Peard, Sean T. Elphick, Victor W. Smith, Victor J. Gosbell, D A. Robinson

Faculty of Informatics - Papers (Archive)

For large scale power quality surveys, the management of the large amount of data generated is a major issue. This paper presents solutions to three main areas of data management, viz. a data interchange format, database design and data processing. Consideration of these issues has come about as a result of the Long Term National Power Quality Survey currently being conducted by the University of Wollongong, and reference is made to that specific application for illustrative purposes.

Secure Multimedia Authoring With Dishonest Collaborators, N. P. Sheppard, R. Safavi-Naini, P. Ogunbona

Faculty of Informatics - Papers (Archive)

Many systems have been proposed for protecting the intellectual property of multimedia authors and owners from the public at large, who have access to the multimedia only after it is published. In this paper, we consider the problem of protecting authors' intellectual property rights from insiders, such as collaborating authors and producers, who interact with the creative process before publication. We describe the weaknesses of standard proof-of-ownership watermarking approaches against dishonest insiders, and propose several possible architectures for systems that avoid these weaknesses. We further show how these architectures can be adapted for fingerprinting in the presence of dishonest insiders.

Usability/User Interface Design In Agile Processes, A. Fuller

Faculty of Informatics - Papers (Archive)

The increasing popularity of the “agile” software development methods has prompted claims that such methods compromise the usability of the delivered product. However, this need not be the case. While some authors have suggested remedial extensions or additions that run in parallel with the chosen method, we believe that any agile method, properly applied, will produce software equally as useable as that produced by any other method.

The aim of this paper is twofold. Firstly we present a survey of many of the arguments made in the literature, thus bringing together a number of differing concerns. Then we set out …

Signature-Based Document Retrieval, A. Chalechale, G. Naghdy, Alfred Mertins

Faculty of Informatics - Papers (Archive)

This paper presents a new approach for document image decomposition and retrieval based on connected component analysis and geometric properties of the labeled regions. The database contains document images with Arabic/Persian text combined with English text, headlines, ruling lines, trademark and signature. In particular, Arabic/Persian signature extraction is investigated using special characteristics of the signature that is fairly different from English signatures. A set of efficient, invariant and compact features is extracted for validation purposes using angular-radial partitioning of the signature region. Experimental results show the robustness of the proposed method.

Sketch-Based Image Retrieval Using Angular Partitioning, A. Chalechale, G. Naghdy, Alfred Mertins

Faculty of Informatics - Papers (Archive)

This paper presents a novel approach for sketch-based image retrieval based on low-level features. The approach enables measuring the similarity between a full color image and a simple black and white sketched query and needs no cost intensive image segmentation. The proposed method can cope with images containing several complex objects in an inhomogeneous background. Abstract images are obtained using strong edges of the model image and thinned outline of the sketched image. Angular-spatial distribution of pixels in the abstract images is then employed to extract new compact and effective features using Fourier transform. The extracted features are scale and …

Monitoring Of Wheel Dressing Operations For Precision Grinding, Li Xue, Fazel Naghdy, C. Cook

Faculty of Informatics - Papers (Archive)

In grinding operation, on-line process monitoring of dressing will ensure the quality of the grinding wheel and will achieve reproducible surface finish. The results of a study conducted to evaluate the feasibility and effectiveness of Acoustic Emission (AE) sensors in online monitoring of dressing is reported. Two aspects of the process are addressed. The first is the detection of undesired wheel conditions, such as an out-of-round wheel and wheel contour errors. The other is improving the surface finish of the ground workpiece by monitoring the dressing parameters. Experimental results indicate that AE signal can be effectively used to identify the …

Combinatorial Constructions Of 3- And 4-Secure Codes, Y. Wang, Jennifer Seberry, Beata J. Wysocki, Tadeusz A. Wysocki, Willy Susilo, Tianbing Xia, Y. Zhao, Le Chung Tran

Faculty of Informatics - Papers (Archive)

In this paper, 3- and 4-secure codes are constructed from combinatorial designs. Both constant weight and non-constant weight codes are shown.

Forensic Computing, X. Li, Jennifer Seberry

Faculty of Informatics - Papers (Archive)

Technology is rapidly changing the speed and manner in which people interact with each other and with the world. As technology helps criminals to operate more easily and quickly across borders, so law enforcement capability must continuously improve to keep one step ahead. Computer forensics has become a specialized and accepted investigative technique with its own tools and legal precedents that validate the discipline. Specially designed forensic software is also widely used during the whole process of computer forensic investigation. This article introduces computer forensic and computer evidence, introduces and compares some forensic software, and summarizes its likely future development.

Tolerance Of Control-Flow Testing Criteria, S. A. Vilkomir, K. Kapoor, J. P. Bowen

Faculty of Informatics - Papers (Archive)

Effectiveness of testing criteria is the ability to detect failure in a software program. We consider not only effectiveness of some testing criterion in itself but a variance of effectiveness of different test sets satisfied the same testing criterion. We name this property "tolerance" of a testing criterion and show that, for practical using a criterion, a high tolerance is as well important as high effectiveness. The results of empirical evaluation of tolerance for different criteria, types of faults and decisions are presented. As well as quite simple and well-known control-flow criteria, we study more complicated criteria: full predicate coverage, …

Reducing Redundancy In The Hypertree Decomposition Scheme, Peter Harvey, Aditya K. Ghose

Faculty of Informatics - Papers (Archive)

Hypertree decomposition is a powerful technique for transforming near-acyclic CSPs into acyclic CSPs. Acyclic CSPs have efficient, polynomial time solving techniques, and so these conversions are of interest to the constraints community. We present here an improvement on the opt-k-decomp algorithm for finding an optimal hypertree decomposition.

Fading Characteristics For Indoor Wireless Channels At 5 Ghz Unlicensed Bands, M. Carroll, Tadeusz A. Wysocki

Faculty of Informatics - Papers (Archive)

The paper reports on experiments undertaken at the University of Wollongong to characterise fading profiles of indoor wireless channels at the 5 GHz bands. The measurements were undertaken at different locations around the campus with results recorded for post-processing to calculate the Rician k-factor, the level crossing rate and the average fade duration.

Performance Measurement Of Watermark Embedding Patterns, R. Scealy, R. Safavi-Naini, N. P. Sheppard

Faculty of Informatics - Papers (Archive)

Segmented watermarking is an approach to multiple watermarking that can be used to acknowledge the contribution of multiple authors or to embed a fingerprint code-word, but is susceptible to cropping attacks that discard portions of the watermarked media. Careful selection of the watermark embedding pattern can increase the resilence of a segmented watermark in the presence of cropping attacks. In this paper, we consider performance measures for embedding patterns and compare the performance of several proposed embedding patterns using these measures.

Lie Analysis Of The Webster Horn Equation With Application To Audio Object Recognition, Tania M. Barrett, Ian S. Burnett, Jason Lukasiak

Faculty of Informatics - Papers (Archive)

The Webster horn equation describes the pressure wave in a duct of slowly varying cross section. We discuss symmetry reductions and exact solutions of the Webster horn equation using the classical Lie method of infinitesimals. The particular case of the exponential horn is examined and a complete set of reductions and solutions is formulated. The generation of a complete set of solutions using Lie analysis produces a set of group transformations. Particular attention is given to a new solution found, which contains an exponentially decaying Bessel function. The use of these group transformations as a tool for audio object recognition …