Physical Sciences and Mathematics Commons^™

Naturality Of Rieffel's Morita Equivalence For Proper Actions, Astrid An Huef, S Kaliszewski, Iain F. Raeburn, Dana P. Williams

Faculty of Informatics - Papers (Archive)

Suppose that a locally compact group G acts freely and properly on the right of a locally compact space T . Rieffel proved that if is an action of G on a C*-algebra A and there is an equivariant embedding of C₀(T ) in M(A), then the action α of G on A is proper, and the crossed product A⋊_α,rG is Morita equivalent to a generalised fixed-point algebra Fix(A,α ) in M(A)^α. We show that the assignment (A,α) → Fix(A,α ) extends …

A Mathematical Model For The Biological Treatment Of Industrial Wastewaters In A Cascade Of Four Reactors, Annette L. Worthy, Mark I. Nelson, Rubayyi Turki Alqahtani

Faculty of Informatics - Papers (Archive)

Many industrial processes, particularly in the food industry, produce slurriesor wastewaters containing high concentrations of biodegradable organicmaterials. Before these contaminated wastewaters can be dischargedthe concentration of these pollutants must be reduced. A method which has beenextensively employed to remove biodegradable organic matter is biologicaltreatment. In this process the wastewater (or slurry) is passed through abioreactor containing biomass which grows through consumption of thepollutants.The industrial treatment of wastewaters typically employs a reactor cascade.In a reactor cascade of n reactors the effluent stream from the ith reactor inthe cascade acts as the feed stream for the (i+1)th reactor, i.e. the nextreactor. The …

Initial Values In Estimation Procedures For State Space Models (Ssms), Raed Alzghool, Yan-Xia Lin

Faculty of Informatics - Papers (Archive)

In this paper, we will focus on State Space Models(SSMs), especially the stochastic volatility model, and lookfor a standard approach for assigning initial values in theQuasi-Likelihood (QL) and Asymptotic Quasi-Likelhood (AQL)estimation procedures.

A Spectral-Collocation Method For Pricing Perpetual American Puts With Stochastic Volatility, Song-Ping Zhu, Wenting Chen

Faculty of Informatics - Papers (Archive)

Based on the Legendre pseudospectral method, we propose a numerical treatment for pricing perpetual American put option with stochastic volatility. In this simple approach, a nonlinear algebraic equation system is first derived, and then solved by the Gauss–Newton algorithm. The convergence of the current scheme is ensured by constructing a test example similar to the original problem, and comparing the numerical option prices with those produced by the classical Projected SOR (PSOR) method. The results of our numerical experiments suggest that the proposed scheme is both accurate and efficient, since the spectral accuracy can be easily achieved within a small …

Understanding The Conducting States Of Active And Passive Switches In An Inverter Circuit Used For Power System Applications, Danny Sutanto, B.P. Divakar, K.W.E. Cheng

Faculty of Informatics - Papers (Archive)

Bi-directional inverter circuits are commonly used in many applications in power systems, such as in FACTS devices, energy storage systems and active power filters. Many power engineering students however find it difficult to understand the conducting states of the active switches (transistors, IGBTs) and the passive switches (the antiparallel diodes connected across the active switches). It seems a mystery to them that power can flow from a lower voltage ac system to a higher voltage dc system to charge the energy storage system. This paper proposes a simple chart that intuitively explains how to determine the states (either conducting or …

Building A System For Managing Clinical Pathways Using Digital Pens, Linda L. Dawson, Virginia Plummer, Stephen Weeding, Terri Harlem, Bob Ribbons, David Waterhouse

Faculty of Informatics - Papers (Archive)

Background: A research team from Monash University and Peninsula Health, Victoria is undertaking a trial of digital pen and paper technology for clinical pathway management. Digital pen and paper allows for the capture of images of handwritten documents using an embedded camera in the pen which is matched with special patterns of dots on the paper. These digitised images can be uploaded to a database for analysis. Objectives: Clinical pathways have been adopted in most Australian hospitals to document and manage multidisciplinary care across a variety of acute care environments. Analysis of the information collected in paper-based clinical pathway documents …

An Estimation Method For Feedback Level Factor C Of A Self-Mixing Interferometry System, Yuanlong Fan, Yanguang Yu, Jiangtao Xi, Joe F. Chicharo

Faculty of Informatics - Papers (Archive)

This paper presents a fast estimation method for feedback level factor C of a self-mixing interferometry (SMI) system. The reconstruction of a displacement waveform using a SMI signal needs to know a C value. However, it is difficult to maintain a constant C value during the reconstruction process. We study the features of the reconstructed displacement waveforms incorporating different pre-set C values and classify waveforms into two types. Bisection method is introduced in our method for fast estimating C value. The effectiveness of our proposed method has been verified by both simulation and experimental data.

Pbtrust: A Priority-Based Trust Model For Service Selection In General Service-Oriented Environments, Xing Su, Minjie Zhang, Yi Mu, Kwang Mong Sim

Faculty of Informatics - Papers (Archive)

How to choose the best service provider (agent), which a service consumer can trust in terms of the quality and success rate of the service in an open and dynamic environment, is a challenging problem in many service-oriented applications such as Internet-based grid systems, e-trading systems, as well as service-oriented computing systems. This paper presents a Priority-Based Trust (PBTrust) model for service selection in general service-oriented environments. The PBTrust is robust and novel from several perspectives. (1) The reputation of a service provider is derived from referees who are third parties and had interactions with the provider in a rich …

Information Retrieval And Social Tagging For Digital Libraries Using Formal Concept Analysis, Peter W. Eklund, Peter Goodall, Timothy Wray

Faculty of Informatics - Papers (Archive)

This paper reports a novel semantic web application developed to deliver a collaborative tagging system for a digital on-line museum. The key features of our application – called the Virtual Museum of the Pacific – concern the browsing and retrieval interface based on Formal Concept Analysis, the extensible distributed data model to support collaborative tagging and its web services implementation.

On The Combination Of Local Texture And Global Structure For Food Classification, Zhimin Zong, Duc Thanh Nguyen, Philip O. Ogunbona, Wanqing Li

Faculty of Informatics - Papers (Archive)

This paper proposes a food image classification method using local textural patterns and their global structure to describe the food image. In this paper, a visual codebook of local textural patterns is created by employing Scale Invariant Feature Transformation (SIFT) interest point detector with the Local Binary Pattern (LBP) feature. In addition to describing the food image using local texture, the global structure of the food object is represented as the spatial distribution of the local textural structures and encoded using shape context. We evaluated the proposed method on the Pittsburgh Fast-Food Image (PFI) dataset. Experimental results showed that the …

On Optimising Route Discovery For Multi-Interface And Power-Aware Nodes In Heterogeneous Manets, Huda Alaamri, Mehran Abolhasan, Tadeusz A. Wysocki, Justin Lipman

Faculty of Informatics - Papers (Archive)

This paper presents a new routing discovery strategy for heterogeneous MANETs. Node heterogeneity is modeled in terms of: types and number of different interfaces, power, and transmission ranges. Our proposed route discovery algorithm is implemented on the top of On-demand Tree-based Routing Protocol (OTRP) and hence it is called OTRP Heterogeneity-Aware (OTRP HA). OTRP HA utilizes node heterogeneity and optimizes route discovery to reduce overheads and ensures connectivities between different types of nodes with different interfaces. Each node makes its own decision to participate in the route discovery process according to its location, local density, and available resources. Simulation results …

The Curvhdr Method For Gating Flow Cytometry Samples, Ulrike Naumann, George Luta, Matthew P. Wand

Faculty of Informatics - Papers (Archive)

Background: High-throughput flow cytometry experiments produce hundreds of large multivariate samples of cellular characteristics. These samples require specialized processing to obtain clinically meaningful measurements. A major component of this processing is a form of cell subsetting known as gating. Manual gating is timeconsuming and subjective. Good automatic and semi-automatic gating algorithms are very beneficial to highthroughput flow cytometry.

Results: We develop a statistical procedure, named curvHDR, for automatic and semi-automatic gating. The method combines the notions of significant high negative curvature regions and highest density regions and has the ability to adapt well to human-perceived gates. The underlying …

Dynamic Trust Model For Federated Identity Management, Hao Gao, Jun Yan, Yi Mu

Faculty of Informatics - Papers (Archive)

The goal of federated identity management is to allow principals, such as identities and attributes, to be shared across trust boundaries based on established policies. Since current Single Sign-On (SSO) mechanism excessively relies on the specifications of Circle of Trust (CoT), the need for service collaboration from different domains is being addressed on CoT. For the motivating issue of the cross-domain SSO mechanism, we need an emergent dynamic trust list for calculating the trust parties, thus, the CoT specifications require an initial effort on enrolling members automatically to adapt to the dynamic open environment. In this paper, we propose a …

Data Security And Information Privacy For Pda Accessible Clinical-Log For Medical Education In Problem-Based Learning (Pbl) Approach, Rattiporn Luanrattana, Khin Than Win, John A. Fulcher

Faculty of Informatics - Papers (Archive)

Data security and information privacy are the important aspects to consider for the use of mobile technology for recording clinical experience and encounter in medical education. Objective: This study aims to address the qualitative findings of the appropriate data security and information privacy for PDA accessible clinical-log in problem-based learning (PBL) approach in medical education. Method: The semi-structured interviews were conducted with the medical faculty members, honorary clinical academics and medical education technology specialists. Results: Data security and information access plan were determined for managing clinical-log data. The results directed the guideline for the future development and implementation of clinical-log …

Finding Distinctive Facial Areas For Face Recognition, Ce Zhan, Wanqing Li, Philip O. Ogunbona

Faculty of Informatics - Papers (Archive)

One of the key issues for local appearance based face recognition methods is that how to find the most discriminative facial areas. Most of the existing methods take the assumption that anatomical facial components, such as the eyes, nose, and mouth, are the most useful areas for recognition. Other more elaborate methods locate the most salient parts within the face according to a pre-specified criterion. In this paper, a novel method is proposed to identify the discriminative facial areas for face recognition. Unlike the existing methods that only analyze the given face, the proposed method identifies the distinctive areas of …

Network Reconfiguration Using Psat For Loss, Essa-J-Abdul Zehra, Mahmoud Moghavvemi, Maher M.I. Hasim, Kashem Muttaqi

Faculty of Informatics - Papers (Archive)

Network reconfiguration in distribution system is realized by changing the status of sectionalizing switches, and is usually done for the purpose of loss reduction. Loss reduction can result in substantial benefits for a utility. Other benefits from loss reduction include increased system capacity, and possible deferment or elimination of capital expenditures for system improvements and expansion. There is also improved voltage regulation as a result of reducing feeder voltage drop. Research work included by this paper focuses on using branch exchange method to minimize losses and solve the problems over different radial configuration. Solution’s algorithm for loss minimization has been …

A New Approach To Harmonic Allocation For Mv Installations, Victor J. Gosbell, Robert A. Barr

Faculty of Informatics - Papers (Archive)

Distributors need to allocate a maximum allowed level of harmonic current to MV customers to keep voltage distortion acceptable. The paper describes a new approach, based on the concept of voltage droop, requiring much less calculation and data than required by the present approach based on an IEC technical report. The discrepancy between the new method and the present is studied by comparing some carefully selected scenarios. It is shown that the proposed method gives results within 20% of the standards-based approach which makes it a very attractive alternative for harmonic allocation.

Social Tagging For Digital Libraries Using Formal Concept Analysis, Timothy Wray, Peter W. Eklund

Faculty of Informatics - Papers (Archive)

This paper describes the Art Collection Ecosystem – an application that allows users to tag and serendipitously browse content using Formal Concept Analysis. Within this application, tags are derived from meta-data of artworks within an existing asset management system and are classified according to theories derived from social tagging behaviour.We present past and recent iterations of its design, where it is evaluated as a contextual comparison to a popular image tagging application, Flickr. Through the process of iterative design and user evaluation, we produce results are of interest to any applied research and development that involves the exploration of digital …

Estimating Shared Copy Number Aberrations For Array Cgh Data: The Linear-Median Method, Yan-Xia Lin, Veera Baladandayuthapani, V Bonato, K.-A. Do

Faculty of Informatics - Papers (Archive)

Motivation: Existing methods for estimating copy number variations in array comparative genomic hybridization (aCGH) data are limited to estimations of the gain/loss of chromosome regions for single sample analysis. We propose the linear-median method for estimating shared copy numbers in DNA sequences across multiple samples, demonstrate its operating characteristics through simulations and applications to real cancer data, and compare it to two existing methods.

Results: Our proposed linear-median method has the power to estimate common changes that appear at isolated single probe positions or very short regions. Such changes are hard to detect by current methods. This new …

Towards Dynamic Formation Of Temporal Constraints For The Service Level Agreements Negotiation, Azlan Ismail, Jun Yan, Jun Shen

Faculty of Informatics - Papers (Archive)

SLAs play an important role for the QoS-driven service composition. Meanwhile, the temporal constraints are one of the main elements in the management of SLA especially in specifying the validity period of the QoS offers. In practice, the temporal constraints should be generated dynamically by taking the resource capability of the provider into account. The generation should consider various parameters that influence the resource capability such as the expected duration of the required Web service, the amount of current utilization, the amount of available resources, the number of required time slots, etc. Therefore, this paper aims to elaborate this issue …

Optimisation Of Component Sizes For A Hybrid Remote Area Power Supply System, Saad M. Sayeef, Nishad Mendis, Kashem Muttaqi

Faculty of Informatics - Papers (Archive)

In this paper, an optimisation model for determination of the optimal sizes of various system components, including wind, diesel and energy storage, has been developed to obtain a reliable and cost-effective wind-diesel hybrid remote area power supply (RAPS) system. A linear programming based cost minimisation algorithm has been formulated for determination of optimal sizes of various components in a RAPS system with consideration of continually varying wind and system load. The system constraints, including power balance for both under-generation and over-generation scenarios, have been considered in the optimisation formulation. Optimisation model to minimize the total cost of the system based …

Dynamic Service Selection For Service Composition With Time Constraints, Azlan Ismail, Jun Yan, Jun Shen

Faculty of Informatics - Papers (Archive)

Service selection is a kind of planning approach that evaluates and selects from multiple services to form a composite plan. In service selection, we found one additional issue that has not been investigated yet namely time constraints consistency among composite services. This issue is significant because there are potential time constraints involved that might cause inconsistency between selected services although they can offer aggregated QoS that satisfy global requirements. Furthermore, there might be some unintended waiting time to be considered in the QoS aggregation. Thus, this paper contributes to the analysis on the problem caused by the time constraints and …

Dynamic Modelling Of Hydroelectric Turbine-Generator Unit Connected To A Hvdc System For Small Signal Stability Analysis, Yin Chin Choo, Ashish P. Agalgaonkar, Kashem Muttaqi, Sarath Perera, Michael Negnevitsky

Faculty of Informatics - Papers (Archive)

This paper presents the linearised small-signal dynamic modelling of hydroelectric turbine-generator (TG) unit with CIGRE first high-voltage direct current (HVDC) benchmark system in the synchronously rotating D-Q reference frame for small-signal stability analysis. The interaction behaviour between the hydroelectric unit and the dynamics and control of HVDC system is investigated utilising eigen-analysis,participation factor analysis and by conducting sensitivity studies. The computation of eigenvalues and eigenvectors for small signal stability analysis provides an invaluable insight onto the power system dynamic behaviour by characterising the damping and frequency of the system oscillatory modes. Theconsequences of different operating conditions, such as active and …

Fuzzy Control For Nonlinear Uncertain Electrohydraulic Active Suspensions With Input Constraint, Haiping Du, Nong Zhang

Faculty of Informatics - Papers (Archive)

This paper presents a Takagi-Sugeno (T-S) model-based fuzzy control design approach for electrohydraulic active vehicle suspensions considering nonlinear dynamics of the actuator, sprung mass variation, and constraints on the control input. The T-S fuzzy model is first applied to represent the nonlinear uncertain electrohydraulic suspension. Then, a fuzzy state feedback controller is designed for the obtained T-S fuzzy model with optimized H _infin performance for ride comfort by using the parallel-distributed compensation (PDC) scheme. The sufficient conditions for the existence of such a controller are derived in terms of linear matrix inequalities (LMIs). Numerical simulations on a full-car suspension model …

Allocated Harmonic Quantities As The Basis For Source Detection, Timothy J. Browne, Sarath Perera, Victor J. Gosbell

Faculty of Informatics - Papers (Archive)

A considerable body of literature examines assessment, from measurements, of whether it is the network or a customer installation which makes the greater contribution to harmonic distortion at a point of common coupling. However, the customer contribution to harmonic distortion at a point of common coupling depends heavily upon the definition chosen for that contribution. For example, expressing contributions as currents instead of voltages or vice versa may lead to large changes in results. Further, it can be shown that the harmonic voltage at the point of common coupling cannot be expressed independently of the network conditions, meaning that the …

Routing Metric For Multi-Interface And Power-Aware Nodes In Heterogenous Manets, Huda Mubarak Al Amri, Mehran Abolhasan, Tadeusz A. Wysocki

Faculty of Informatics - Papers (Archive)

This paper presents heterogeneity ratio (HR) as a new routing metric for heterogeneous MANETs. This metric is the ratio of number of powerful nodes to hop count that is used to select the best path to destination. Node heterogeneity is modeled in terms of: types and number of different interfaces, power, and transmission ranges. Our proposed routing metric is based on developing route discovery algorithm that is implemented on the top of on-demand tree-based routing protocol (OTRP)[2] to accommodate nodes heterogeneity. Simulation results show that using HR with OTRP heterogeneity aware outperforms other metrics like minimal hop count and maximal …

Strategies For Implementing A Converged Ict Regulator In Indonesia, Yudhistra Nughara, William Tibben

Faculty of Informatics - Papers (Archive)

This paper draws on a six month study that aimed to broadly clarify strategies for the IndonesianGovernment to address the issue of convergence. This paper reports on one aspect of this study thatmaps stakeholder policymaker opinions about a future converged regulator in Indonesia.Convergence refers to a trend in regulation that seeks to define a single regulatory structure fortelecommunications, broadcasting and information technology. In particular, the specific aims ofthis study were to examine regulatory structures with regard to two parameters derived from theInternational Telecommunications Union (ITU): the level of independence, and institutional design.Using benchmarking as a method, three case studies of …

Adaptive Task Allocation For P2p-Based E-Services Composition, Jun Shen, Shuai Yuan

Faculty of Informatics - Papers (Archive)

To effectively manage the task allocation, especially when handling with numerous different peers’ qualities, is one of the greatest challenges to be faced in order to guarantee the success of P2P-based e-services composition. In this context, various QoS descriptive frameworks and Web services technologies (such as WSDL and BPEL) are being considered as the most affordable solutions to promote the performance of decentralized e-services, through applying strategies like QoS ontologies and related optimization algorithms globally or locally. Nonetheless, most P2P-based service selection and composition approaches applied nowadays lack dynamism and autonomy. In this paper, we first propose an extension of …

Resource Price Turbulence And Macroeconomic Adjustment For A Resource Exporter: A Conceptual Framework For Policy Analysis, Grant M. Cox, Charles Harvie

Faculty of Informatics - Papers (Archive)

The increased demand for energy and other resources in global markets, particularly arising from therapidly developing economies of China and India, has resulted in considerable turbulence in resourceprices, and most obviously that of oil. The recent magnitude of change, both positive and negative, inresource prices and their macroeconomic implications is of considerable contemporary importance forboth resource importing and exporting economies. For a resource exporting economy, such as that ofAustralia, the resource price boom had a number of beneficial effects: increased government taxationrevenues, increased employment and higher wages in the resource and resource related sectors,increased spending in the domestic economy and …

Control Of Energy Storage Interface With A Bidirectional Converter For Photovoltaic Systems, K.N Hasan, M.E Haque, Michael Negnevitsky, Kashem Muttaqi

Faculty of Informatics - Papers (Archive)

Efficient energy storage is one of the greatest concerns for renewable power generation. This paper focuses on the control of a battery management system (BMS) for photovoltaic (PV) applications with a high efficiency bidirectional converter. The proposed BMS control strategy utilizes the dc bus power and battery state of charge (SOC) for the charging and discharging of the battery with a bidirectional converter. The bidirectional converter includes fewer components and switches, has less switching losses with zero voltage switching, and has high gain buck-boost operations. A new control algorithm of charging-discharging control for the battery storage system is proposed. The …