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Faculty of Informatics - Papers (Archive)

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A Novel Approach To Data Deduplication Over The Engineering-Oriented Cloud Systems, Zhe Sun, Jun Shen, Jianming Young Jan 2013

A Novel Approach To Data Deduplication Over The Engineering-Oriented Cloud Systems, Zhe Sun, Jun Shen, Jianming Young

Faculty of Informatics - Papers (Archive)

This paper presents a duplication-less storage system over the engineering-oriented cloud computing platforms. Our deduplication storage system, which manages data and duplication over the cloud system, consists of two major components, a front-end deduplication application and a mass storage system as back-end. Hadoop distributed file system (HDFS) is a common distribution file system on the cloud, which is used with Hadoop database (HBase). We use HDFS to build up a mass storage system and employ HBase to build up a fast indexing system. With a deduplication application, a scalable and parallel deduplicated cloud storage system can be effectively built up. …


Online Grocery Systems Design Through Task Analysis, Mark Freeman, Alison Freeman Jan 2011

Online Grocery Systems Design Through Task Analysis, Mark Freeman, Alison Freeman

Faculty of Informatics - Papers (Archive)

Purpose – Modelling users’ interactions online is envisaged to allow developers to increase the usability of online systems and will aid system developers in building better systems to meet users’ needs, hereby creating better system design processes. Design/methodology/approach – The normative task model that was developed in this paper was created through an expert review of 14 online grocery stores, using a reverse engineering technique to model the features of the stores’ ordering process. Findings – The research identified three main areas of user experience when undertaking the process of adding a product to an online trolley: attempting to retrieve …


Optimization Of Task Processing Schedules In Distributed Information Systems, Janusz R. Getta Jan 2011

Optimization Of Task Processing Schedules In Distributed Information Systems, Janusz R. Getta

Faculty of Informatics - Papers (Archive)

The performance of data processing in distributed information systems strongly depends on theefficient scheduling of the applications that access data at the remote sites. This work assumes atypical model of distributed information system where a central site is connected to a number ofremote and highly autonomous remote sites. An application started by a user at a central site isdecomposed into several data processing tasks to be independently processed at the remote sites.The objective of this work is to find a method for optimization of task processing schedules at acentral site. We define an abstract model of data and a system …


Investigating The Effect Of Participation-Limiting Structures On Outcomes Of E-Democracy Systems (Research In Progress), Rajeev Sharma Jan 2011

Investigating The Effect Of Participation-Limiting Structures On Outcomes Of E-Democracy Systems (Research In Progress), Rajeev Sharma

Faculty of Informatics - Papers (Archive)

Modern information systems provide a technical foundation for greater participation of citizens in the agenda-setting and decision-making processes of government. Information systems researchers and designers will need to address a number of issues to design IS applications for the effective functioning of evolving forms of democracy. This paper identifies a research agenda at the intersection of information systems research, economics and political science research and avenues for information systems researchers to contribute to the research agenda.


The Application Of Location Based Services In National Emergency Warning Systems: Sms, Cell Broadcast Services And Beyond, Anas Aloudat, Katina Michael Jan 2011

The Application Of Location Based Services In National Emergency Warning Systems: Sms, Cell Broadcast Services And Beyond, Anas Aloudat, Katina Michael

Faculty of Informatics - Papers (Archive)

Location-based services can be broadly defined as any service that provides information pertinent to the current location of an active mobile handset at a specific window of time, regardless of the underlying delivery technology used to convey its information. To date, the short message service and cell broadcast service have been utilised by several countries during emergencies, however the future indicates that these services while cost-effective today, will almost certainly be superseded in the next five to ten years by newer more powerful capabilities. The path forward in location-based emergency services in Australia is given against a backdrop of the …


A Preliminary Investigation Of Complex Adaptive Systems As A Model For Explaining Organisational Change Caused By The Introduction Of Health Information Systems, Kieren Diment, Ping Yu, Karin Garrety Jan 2011

A Preliminary Investigation Of Complex Adaptive Systems As A Model For Explaining Organisational Change Caused By The Introduction Of Health Information Systems, Kieren Diment, Ping Yu, Karin Garrety

Faculty of Informatics - Papers (Archive)

This paper documents the preliminary development of a framework for evaluating organisational change processes during the implementation of an electronic nursing documentation system in residential aged care facilities. It starts with a brief outline of organisational change processes. This is followed by a more detailed exposition of the principles underlying complex adaptive systems (CAS) theory, where we explain how mathematical concepts can be used to illuminate qualitative research approaches. Finally we present some preliminary findings on the facilitators and barriers for the introduction of the electronic documentation system, explained with reference to the CAS theory, based on analysis of interviews …


Supporting Developers In Complex Systems Modelling, Antonio A. Lopez-Lorca, Ghassan Beydoun, Rodrigo Martinez-Bejar, Holly Tootell Jan 2011

Supporting Developers In Complex Systems Modelling, Antonio A. Lopez-Lorca, Ghassan Beydoun, Rodrigo Martinez-Bejar, Holly Tootell

Faculty of Informatics - Papers (Archive)

Development of complex systems often requires building a large number of models with many interconnections and dependencies among them. The success of a project can be compromised by cognitive overload or limits of developers, who might miss relationships between elements of the models. Developing Multi-Agent Systems (MAS) is a typical example of where this may occur. Despite of its potential, this technology has not yet been widely adopted by industry due to its complexity and frequent errors in modelling activities. These errors typically propagate to later phases of the MAS development lifecycle, becoming costlier to fix and then lowering the …


A Multi-Method Approach To Evaluate Health Information Systems, Ping Yu Jan 2010

A Multi-Method Approach To Evaluate Health Information Systems, Ping Yu

Faculty of Informatics - Papers (Archive)

Systematic evaluation of the introduction and impact of health information systems (HIS) is a challenging task. As the implementation is a dynamic process, with diverse issues emerge at various stages of system introduction, it is challenge to weigh the contribution of various factors and differentiate the critical ones. A conceptual framework will be helpful in guiding the evaluation effort; otherwise data collection may not be comprehensive and accurate. This may again lead to inadequate interpretation of the phenomena under study. Based on comprehensive literature research and own practice of evaluating health information systems, the author proposes a multimethod approach that …


Using Task Analysis To Design Intuitive Online Grocery Systems, Mark Freeman, Alison Freeman Jan 2010

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 …


Monitoring Intelligent Distribution Power Systems: A Power Quality Plan, Neil R. Browne, Timothy J. Browne, Sean T. Elphick Jan 2010

Monitoring Intelligent Distribution Power Systems: A Power Quality Plan, Neil R. Browne, Timothy J. Browne, Sean T. Elphick

Faculty of Informatics - Papers (Archive)

Power system monitoring capabilities and requirements are evolving rapidly. The traditional monitoring framework in Australian distribution networks involves biannual readings of maximum demand at each distribution substation. As utilities respond to developments in metering and communications technology, automated collection and retrieval of quasi-real-time system data between substations and central repositories is now feasible. This gives network managers a significantly increased understanding of distribution network dynamic activity such as daily and seasonal load profiles. This leads to the increased ability of utilities to exploit metering data for power quality analysis purposes. This paper examines the scope for, and challenges associated with, …


Support Of Distribution System Using Distributed Wind And Pv Systems, Kai Zou, Ashish P. Agalgaonkar, Kashem Muttaqi, Sarath Perera, N Browne Jan 2009

Support Of Distribution System Using Distributed Wind And Pv Systems, Kai Zou, Ashish P. Agalgaonkar, Kashem Muttaqi, Sarath Perera, N Browne

Faculty of Informatics - Papers (Archive)

The application of renewable distributed generation (DG) could be considered as an alternative approach for distribution system expansion planning not only to reduce power loss and carbon emission, but also to improve system voltage profile. This paper investigates technical aspects relatedto voltage support and loss reduction in distribution systems with distributed wind and solar generation. The probabilistic wind, solar, and load models have been developed in order to address uncertain nature of wind speed, solar radiation, and load demand. Investigations have been carried out using Monte Carlo based probabilistic load flow analysis to estimate the probability distributions of system state …


Dynamic Universal Accumulators For Ddh Groups And Their Application To Attribute-Based Anonymous Credential Systems, Man Ho Au, Patrick P. Tsang, Willy Susilo, Yi Mu Jan 2009

Dynamic Universal Accumulators For Ddh Groups And Their Application To Attribute-Based Anonymous Credential Systems, Man Ho Au, Patrick P. Tsang, Willy Susilo, Yi Mu

Faculty of Informatics - Papers (Archive)

We present the first dynamic universal accumulator that allows (1) the accumulation of elements in a DDH-hard group G and (2) one who knows x such that y = gx has - or has not - been accumulated, where g generates G, to efficiently prove her knowledge of such x in zero knowledge, and hence without revealing, e.g., x or y. We introduce the Attribute-Based Anonymous Credential System, which allows the verifier to authenticate anonymous users according to any access control policy expressible as a formula of possibly negated boolean user attributes. We construct the system from our accumulator.


Control Of Energy Storage Interface With A Bidirectional Converter For Photovoltaic Systems, K.N Hasan, M.E Haque, Michael Negnevitsky, Kashem Muttaqi Jan 2008

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 …


Optimisation Of Distributed Generation Units And Shunt Capacitors For Economic Operation Of Distribution Systems, Kai Zou, Sarath Perera, Kashem Muttaqi, Ashish P. Agalgaonkar Jan 2008

Optimisation Of Distributed Generation Units And Shunt Capacitors For Economic Operation Of Distribution Systems, Kai Zou, Sarath Perera, Kashem Muttaqi, Ashish P. Agalgaonkar

Faculty of Informatics - Papers (Archive)

The integration of Distributed Generation (DG) units and shunt capacitors can be considered as an alternative approach for distribution system expansion planning not only to improve power supply quality and reliability, but also to defer major system updates. In this paper, the techno-economic issues of distribution system expansion planning with optimal sizing and siting of DG units and shunt capacitors are addressed. The minimisation of overall investment cost with the integration of DG units and shunt capacitors is assessed with the consideration of supply quality, reliability and energy loss. A new planning methodology by using Particle Swarm Optimisation (PSO) is …


Output Quality Evaluation Of Photovoltaic Systems With Different Current Control Methods Of Switch-Mode Converters, K. N. Hasan, Md Enamul Haque, Michael Negnevitsky, Kashem Muttaqi Jan 2008

Output Quality Evaluation Of Photovoltaic Systems With Different Current Control Methods Of Switch-Mode Converters, K. N. Hasan, Md Enamul Haque, Michael Negnevitsky, Kashem Muttaqi

Faculty of Informatics - Papers (Archive)

This paper presents a comparative assessment of the current control methods (CCM) of switch-mode converters for photovoltaic (PV) applications. In this paper, average current control, current programmed control, hysteresis current control and nonlinear carrier control methods are addressed considering input fluctuations and load variations for PV systems. Dynamic responses of PV systems are investigated and harmonic analysis is performed. Performances of the above current controllers are examined through simulation and the results are presented. The results show that the selection of different current control techniques depends on the working conditions and the area of applications.


Evaluating The Implementation Of Emr Systems From The Perspective Of Health Professionals, Yung-Yu Su, John A. Fulcher, Khin Than Win, Herng-Chia Chiu, Gui-Fen Chiu Jan 2008

Evaluating The Implementation Of Emr Systems From The Perspective Of Health Professionals, Yung-Yu Su, John A. Fulcher, Khin Than Win, Herng-Chia Chiu, Gui-Fen Chiu

Faculty of Informatics - Papers (Archive)

In health informatics, the "updated DeLone and McLean IS success model" is reviewed as a mature model in measuring health information system (HIS) success. This research provided an evaluation model to estimate the implementation of electronic medical records (EMR) systems from a health professional perspective by combined the updated DeLone and McLean IS success model, data quality management model, and EMR systems safety attributes. Based on evidence-based management (EBM), this research could be regarded as an empirical example for further EMR systems research since it not only provided a model to measure the Taiwanese EMR systems in two hospitals by …


The Largest Eigenvalue Characteristic Of Correlated Complex Wishart Matrices And Its Application To Mimo Mrc Systems, Xianyi Rui, Ronghong Jin, Junping Geng, Xiaojing Huang Jan 2007

The Largest Eigenvalue Characteristic Of Correlated Complex Wishart Matrices And Its Application To Mimo Mrc Systems, Xianyi Rui, Ronghong Jin, Junping Geng, Xiaojing Huang

Faculty of Informatics - Papers (Archive)

In this paper, we analyze statistical properties of the largest eigenvalue of correlated complex Wishart matrices. The results provide an analytical tool for the study of multiple-input multiple-output (MIMO) maximal ratio combining (MRC) systems in the presence of spatial fading correlation at the transmitter or receiver. Based on them, the exact closed-form expressions for the cumulative distribution function and the probability density function of the output signal-to-noise ratio are presented. The analytical results are validated by Monte Carlo simulations.


Nursing Information Systems: Applying Usability Testing To Assess The Training Needs For Nursing Students, Yiyu Qiu, Ping Yu Jan 2007

Nursing Information Systems: Applying Usability Testing To Assess The Training Needs For Nursing Students, Yiyu Qiu, Ping Yu

Faculty of Informatics - Papers (Archive)

Objective: In order to ensure the successful implementation of a nursing information system (NIS), nurses and nursing students must be adequately trained. In order to do this effectively, it is essential to understand their training needs. This study focuses on the training needs of nursing students in particular through the identification of the usage problems they encounter. Usability testing, which involves observing users' interaction with an NIS, overcomes the deficiencies of traditional approaches of training needs analysis such as interview and survey. The study applied usability test to assess training needs of nursing students to learn to use a specific …


Harmonic Impact Of Photovoltaic Inverters On Low Voltage Distribution Systems, Ahmed Latheef, D A. Robinson, Victor J. Gosbell, Victor W. Smith Jan 2006

Harmonic Impact Of Photovoltaic Inverters On Low Voltage Distribution Systems, Ahmed Latheef, D A. Robinson, Victor J. Gosbell, Victor W. Smith

Faculty of Informatics - Papers (Archive)

The number of installations of photovoltaic solar panels and associated inverter systems within residential premises is increasing. As these systems incorporate a power electronics front end, they will have an influence on the quality of supply in regards to voltage harmonics. This paper investigates the harmonic impact on an LV distribution feeder due to the installation of residential type grid connected photovoltaic inverter systems. To undertake the study an aggregated current source model is proposed for the photovoltaic inverter systems based on measurement data from available literature and the relevant international standards. A typical LV distribution feeder including load arrangements …


An Ontology-Based Approach For Expert And Knowledge Mining In Complex Multi-Agent Systems, Minjie Zhang, Xijin Tang, Quan Bai, Jifa Gu Jan 2006

An Ontology-Based Approach For Expert And Knowledge Mining In Complex Multi-Agent Systems, Minjie Zhang, Xijin Tang, Quan Bai, Jifa Gu

Faculty of Informatics - Papers (Archive)

Complex problems require diverse expertise and multiple techniques to solve. In order to solve such problems, complex multi-agent systems include numbers of heterogeneous agents, which may include both of human experts and autonomous agents, to work together toward some complex problems. Most complex multi-agent systems are working in open domains. Due to heterogeneities and dynamic working environments, expertise and capabilities of agents might not be well estimated and presented in the system. Therefore, how to discover useful knowledge from human and autonomous experts, make more accurate estimation for experts' capabilities and to find out suitable expert(s) to solve incoming problems …


Mindful It Adoption: Making The Right Strategic Decisions By Knowing Why And How To Adopt Enterprise Systems?, Valerie A. Baker, Tim Coltman Jan 2006

Mindful It Adoption: Making The Right Strategic Decisions By Knowing Why And How To Adopt Enterprise Systems?, Valerie A. Baker, Tim Coltman

Faculty of Informatics - Papers (Archive)

Corporate investment in enterprise level IT systems has been characterised by high rates of failure. The paper presents a knowledge based perspective to examine how firms adopt and implement enterprise systems in order to better understand how organisations can achieve reliable outcomes from such investments. The case presented explores the key decision stages of a major ERP investment, focusing on the strategic reasoning behind each decision. Particular attention is directed to the relationship between adoption know-why and implementation know-how to assess whether managers have been mindful or mindless in their investment decisions.


Scarcely Populated Uwb-Ir Systems With Interleaved Coding-Modulation On Multipath Fading Channels, Michal M. Pietrzyk, Keni Popovski, Tadeusz A. Wysocki, Beata J. Wysocki, Jos H. Weber Jan 2006

Scarcely Populated Uwb-Ir Systems With Interleaved Coding-Modulation On Multipath Fading Channels, Michal M. Pietrzyk, Keni Popovski, Tadeusz A. Wysocki, Beata J. Wysocki, Jos H. Weber

Faculty of Informatics - Papers (Archive)

Interleaved coding-modulation (ICM) is a recently proposed method for ultra-wideband impulse radio (UWB-IR) systems. ICM exploits the concept of chip interleaving, allowing to alleviate the problem of inter-symbol and inter-pulse interference commonly present in high data rate UWB-IR systems. In this paper, previous work on ICM is extended to scarcely populated multi-user scenarios. A novel design of a deterministic chip interleaver based on time-hopping hyperbolic congruence sequences is proposed. Furthermore, the main parameters of the random and hyperbolic interleavers are reviewed. The obtained results indicate that the proposed type of interleaver yields similar performance to random interleavers but with the …


Power System Applications Of Superconducting Magnetic Energy Storage Systems, X D. Xue, Eric Kw Cheng, Danny Sutanto Jan 2005

Power System Applications Of Superconducting Magnetic Energy Storage Systems, X D. Xue, Eric Kw Cheng, Danny Sutanto

Faculty of Informatics - Papers (Archive)

This study overviewed current researches on power system applications of SMES systems. Some key schematic diagrams of applications were given, too. Furthermore, the authors tried to present a few valuable suggestions for future studies of SMES applications to power systems.


Decision Aided Joint Compensation Of Clipping Noise And Nonlinearity For Mimo-Ofdm Systems, Shouyi Yang, Jiangtao Xi, Xiaomin Mu Jan 2005

Decision Aided Joint Compensation Of Clipping Noise And Nonlinearity For Mimo-Ofdm Systems, Shouyi Yang, Jiangtao Xi, Xiaomin Mu

Faculty of Informatics - Papers (Archive)

In this paper, we propose a new iterative approach to compensate the nonlinearity and clipping noise in multi-input multi-output orthogonal frequency division multiplexing (MlMO-OFDM) system with nonlinear channel. The proposed approach consists of two stages. Firstly a decision aided method is proposed to eliminate the nonlinearity introduced by high power transmit amplifier (HPA). Then this improved decision observations are employed to achieve the clipping noise compensation. The effectiveness of the proposed approach has been verified by computer simulations.


A Generalised Minimum Variance Controller For Time-Varying Systems, Zheng Li, Christian Schmid Jan 2005

A Generalised Minimum Variance Controller For Time-Varying Systems, Zheng Li, Christian Schmid

Faculty of Informatics - Papers (Archive)

In this paper, the problem of generalised minimum variance control of linear time-varying systems is studied. A time-varying optimal controller is developed for a standard controlled autoregressive moving average model using a cost function that is the sum of the plant output tracking error variance plus a penalty term of the squared manipulated variable.


Study Of Characteristics Of Effective Online Help Systems To Facilitate Nurses Interacting With Nursing Information Systems, Yiyu Qiu, Ping Yu Jan 2005

Study Of Characteristics Of Effective Online Help Systems To Facilitate Nurses Interacting With Nursing Information Systems, Yiyu Qiu, Ping Yu

Faculty of Informatics - Papers (Archive)

Topic area and paper objectives: Through identifying characteristics of Online Help System (OHS) that could facilitate nurses effectively interacting with information system, this paper proposes a framework that could guide the development of OHS written for a Nursing Information System (NIS). Background and concise literature review: User training is an important mechanism to guarantee the success of information system implementation. This is particularly true for a user group such as nurses. When faced with unfamiliar tasks, a user requires assistance to get the system to work. An OHS is supposed to be helpful in such situation. However, to date it …


Exploring End-User Perceptions Towards Mandated Deployment Of Pda-Based Health Information Systems Within Ambulatory Care, Jason P. Sargent, Lois Burgess, Joan Cooper, Carole Alcock, Damien Ryan Jan 2005

Exploring End-User Perceptions Towards Mandated Deployment Of Pda-Based Health Information Systems Within Ambulatory Care, Jason P. Sargent, Lois Burgess, Joan Cooper, Carole Alcock, Damien Ryan

Faculty of Informatics - Papers (Archive)

The impact of many well intentioned technology integration projects has not always been viewed favourably. In fact, many projects are destined to fail from the outset by not considering fundamental IT system inves tment risks (technical failure, data failure, user failure, organizational failure) [Lyytinen & Hirschiem, 1987]. With any new technology ‘an element of uncertainty exists in the minds of decision makers with respect to the successful adoption of them’ [Bagozzi et al, 1992]. Uncertainty towards adopting new technologies is not solely the domain of decision makers. Apart from chief technology and information officers, system administrators and help desk personnel, …


Flicker Transfer In Radial Power Systems, Sankika Tennakoon, Lakshal Perera, D A. Robinson, Sarath Perera Jan 2004

Flicker Transfer In Radial Power Systems, Sankika Tennakoon, Lakshal Perera, D A. Robinson, Sarath Perera

Faculty of Informatics - Papers (Archive)

Loads which exhibit continuous and rapid variations in their current can cause voltage fluctuations that are often referred to as flicker. One good example for such loads is arc furnaces which are usually fed by dedicated feeders from the high voltage busbars in transmission systems. The flicker generated from such loads will propagate to the upstream HV point of common coupling (PCC), and from there to the downstream through the transmission and sub transmission systems. This paper demonstrates how the generated flicker is propagated from the HV PCC to the downstream in radial networks exhibiting different levels of attenuation depending …


Harmonic Planning Levels For Australian Distribution Systems, Victor J. Gosbell, Victor W. Smith, D A. Robinson, W Miller Jan 2003

Harmonic Planning Levels For Australian Distribution Systems, Victor J. Gosbell, Victor W. Smith, D A. Robinson, W Miller

Faculty of Informatics - Papers (Archive)

A modelling technique is developed for determining the harmonic voltage distribution across a distribution system when there is an equitable distribution of harmonic emission. The harmonic voltages at the 132kV and 415V levels are fixed to values based on IEC Compatibility and Planning Levels and the intermediate voltages determined. Studies are made of six systems, typical of Australian distribution practice, to examine the effect of choice of voltage level and system parameters over the harmonic range of 2-40. Based on the study, harmonic Planning Levels are recommended for application to Australian distribution systems.


A Study Of Continuous Pq Disturbance Levels In Mv/Lv Distribution Systems, Victor J. Gosbell, D A. Robinson Jan 2003

A Study Of Continuous Pq Disturbance Levels In Mv/Lv Distribution Systems, Victor J. Gosbell, D A. Robinson

Faculty of Informatics - Papers (Archive)

Distribution Network Service Providers need to be aware of the general variation of PQ disturbances across their network, from the sites as diverse as the MV bus bar of a zone substation, the end of a MV feeder, and at the near and far ends of LV mains. This paper develops an understanding of PQ variations across such a system from survey results correlated with approximate analysis used to assign a PQ disturbance ranking to each site. The work will concentrate on continuous PQ disturbances, defined as those due to load current effects, for example voltage deviations, unbalance, fluctuations and …