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Faculty of Informatics - Papers (Archive)

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Articles 1051 - 1080 of 2013

Full-Text Articles in Physical Sciences and Mathematics

Buyer Preferences For Outsourced Logistics Services (3pl), Tim R. Coltman, Kate Hughes, Timothy M. Devinney, Stuart M. Whiting Jan 2006

Buyer Preferences For Outsourced Logistics Services (3pl), Tim R. Coltman, Kate Hughes, Timothy M. Devinney, Stuart M. Whiting

Faculty of Informatics - Papers (Archive)

Most work on supply chain design begins with cost, delivery time, quality and efficiency and frequently ignores the human factor interacting with that decision. In this study we explore the relative importance of various supply chain product components to reveal the decision-making trade-off that occurs when buyers select an outsourced service provider. Our research approach overcomes many of the limitations seen in prior studies that rely on simple rankings by survey respondents by identifying directly the customer’s utility for different service provider attributes. The results confirm the importance of various performance-level attributes and point us towards a new set of …

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Relative Cuntz-Krieger Algebras Of Finitely Aligned Higher-Rank Graphs, Aidan Sims Jan 2006

Relative Cuntz-Krieger Algebras Of Finitely Aligned Higher-Rank Graphs, Aidan Sims

Faculty of Informatics - Papers (Archive)

We define the relative Cuntz-Krieger algebras associated to finitely aligned higher-rank graphs. We prove versions of the gauge-invariant uniqueness theorem and the Cuntz-Krieger uniqueness theorem for relative Cuntz-Krieger algebras.

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Direct Sequence Modified Time Hopping Ppm Over Ultra Wideband S-V Channel, Peter James Vial, Beata J. Wysocki, Tadeusz A. Wysocki Jan 2006

Direct Sequence Modified Time Hopping Ppm Over Ultra Wideband S-V Channel, Peter James Vial, Beata J. Wysocki, Tadeusz A. Wysocki

Faculty of Informatics - Papers (Archive)

A three position Pulse Position Modulation (PPM) scheme is proposed for a Direct Sequence Time Hopping Ultra Wideband wireless communication system. The channel is based on the Saleh-Valenzuela model. We show that by adapting the Space Time Spreading technique to use three pulse positions in a single input single output system representing -2,0,2 an improvement in Bit Error Rate is achieved compared to sending the same bits using two pulse positions only. In addition, the bit access rate is doubled as two bits can be successfully sent in the same time using our proposed system.

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Community Websites And What Makes Them Sustainable: Evidence From Australia, Alison Norris, Mark B. Freeman Jan 2006

Community Websites And What Makes Them Sustainable: Evidence From Australia, Alison Norris, Mark B. Freeman

Faculty of Informatics - Papers (Archive)

Australia is leading the way in promoting the use of the Internet as a means of strengthening local communities. The Australian Domain Name Authority (auDA) has announced the release of Community Geographic Domain Names (CGDN), to be solely used by not-for-profit, self-funded local community groups. As Australian communities attempt to establish a management group and develop a website under this concept, they are faced with a range of issues. Longitudinal case study research has been conducted on three communities involved in a trial of the CGDN model, in the first research of this type. Based on data collected from the …

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Usability Of Online Grocery Systems: A Focus On Errors, Mark B. Freeman, Alison Norris, P. Hyland Jan 2006

Usability Of Online Grocery Systems: A Focus On Errors, Mark B. Freeman, Alison Norris, P. Hyland

Faculty of Informatics - Papers (Archive)

Recording of errors in regards to the usability of systems has traditionally focused on safety-critical systems and business support systems. This study applies Zapf et al.'s 'Taxonomy of Errors' to a non-work related context, an Online Grocery System. The taxonomy was found to show that similar types of errors were made by all users of such systems. However, the number of errors that were recorded by different user groups varied. This finding was in contrast to previous studies, and supported the common perception that beginner users make a greater number of errors than more experienced users.

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General Design Bayesian Generalized Linear Mixed Models, Yihua Zhao, John Staudenmayer, Brent Coull, M. Wand Jan 2006

General Design Bayesian Generalized Linear Mixed Models, Yihua Zhao, John Staudenmayer, Brent Coull, M. Wand

Faculty of Informatics - Papers (Archive)

Linear mixed models are able to handle an extraordinary range of complications in regression-type analyses. Their most common use is to account for within-subject correlation in longitudinal data analysis. They are also the standard vehicle for smoothing spatial count data. However, when treated in full generality, mixed models can also handle spline-type smoothing and closely approximate kriging. This allows for nonparametric regression models (e.g., additive models and varying coefficient models) to be handled within the mixed model framework. The key is to allow the ran dom effects design matrix to have general structure; hence our label general design. For continuous …

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T2-Fair: A Two-Tiered Time And Throughput Fair Scheduler For Multi-Rate Wlans, Kwan-Wu Chin Jan 2006

T2-Fair: A Two-Tiered Time And Throughput Fair Scheduler For Multi-Rate Wlans, Kwan-Wu Chin

Faculty of Informatics - Papers (Archive)

Low throughput due to unfairness is a key problem in multirate wireless local area networks. To promote fairness and hence throughput, T2-Fair groups flows according to their average data rate, provides each group fair time allocations and ensures throughput fairness for flows in each group. Since each group is allocated transmission times fairly, T2- Fair isolates high and low rate groups and prevents system capacity from being degraded by low rate flows. We have derived T2-Fair’s performance bounds analytically and investigated its performance using the ns-2 simulator in various scenarios with a mix of high and low rate flows. Our …

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Varying Microphone Patterns For Meeting Speech Segmentation Using Spatial Audio Cues, Eva Cheng, I. Burnett, Christian Ritz Jan 2006

Varying Microphone Patterns For Meeting Speech Segmentation Using Spatial Audio Cues, Eva Cheng, I. Burnett, Christian Ritz

Faculty of Informatics - Papers (Archive)

Meetings, common to many business environments, generally involve stationary participants. Thus, participant location information can be used to segment meeting speech recordings into each speaker’s ‘turn’. The authors’ previous work proposed the use of spatial audio cues to represent the speaker locations. This paper studies the validity of using spatial audio cues for meeting speech segmentation by investigating the effect of varying microphone pattern on the spatial cues. Experiments conducted on recordings of a real acoustic environment indicate that the relationship between speaker location and spatial audio cues strongly depends on the microphone pattern.

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Location-Based Services And The Price Of Security, Holly Tootell Jan 2006

Location-Based Services And The Price Of Security, Holly Tootell

Faculty of Informatics - Papers (Archive)

Location-based services (LBS) are one of many high- tech solutions to national security, providing advanced information capabilities. With their use comes a perceived increase in citizens having reduced access to services and information as well as waiving certain liberties in order for national security initiatives to be fully implemented. Focusing particularly on the role of LBS, this research will establish an understanding of the 'price' people pay for national security when it is achieved using LBS. The exchange of liberties for security will be illustrated by the results of the content analysis. This research provides insight in to how far …

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Implementation Of A Quasi-Digital Adc On Pld, Fu-Yuan Wang, Yong-Liang Li, Jiangto Xi, Joe F. Chicharo Jan 2006

Implementation Of A Quasi-Digital Adc On Pld, Fu-Yuan Wang, Yong-Liang Li, Jiangto Xi, Joe F. Chicharo

Faculty of Informatics - Papers (Archive)

This paper presents a new way to implement stochastic logic-based analog-to-digit converters (ADCs) on a programmable logic device (PLD) chip. The proposed implementation is almost all digitalized so that the design can be done by using hardware description language and the results can be easily downloaded into a PLD chip. Both simulation and hardware test results are given.

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Survey Estimation Under Informative Nonresponse With Follow-Up, Seppo Laaksonen, Ray Chambers Jan 2006

Survey Estimation Under Informative Nonresponse With Follow-Up, Seppo Laaksonen, Ray Chambers

Faculty of Informatics - Papers (Archive)

This article deals with survey estimation when there is partial follow-up of sample nonresponse. Two different approaches that make use of the follow-up data are presented, the first based on weighting and the other on prediction, with appropriate variance estimators developed for each case. A simulation evaluation using synthetic data and informative nonresponse is then used to compare these two approaches, as well as to contrast them with a simpler weighting approach that ignores the information obtained by the follow-up survey and treats the nonresponse as missing at random. Our results indicate that the new approaches lead to significant improvement …

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The Effects Of Knowledge Management On Information Sharing Practices: A Case Study On Nortel Networks, Katina Michael Jan 2006

The Effects Of Knowledge Management On Information Sharing Practices: A Case Study On Nortel Networks, Katina Michael

Faculty of Informatics - Papers (Archive)

In 1999 Nortel Networks deployed the Open Text Livelink knowledge management system (KMS). Livelink allowed for the centralization of key corporate applications and associated content at a global, regional, line-of-business and departmental level. Prior to the implementation of Livelink on an enterprise scale, the corporation’s 80,000 employees relied on fragmented departmental web pages which were scattered across 11 different Web servers making the task of finding information very difficult. This paper describes how the process of knowledge transfer at Nortel Networks changed with the deployment of Livelink and how it enabled the automation of workflows through the company’s Web-based Intranet. …

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Unlocking The Secrets Of Amazon: Understanding Tacit Knowledge And Its Implications For E-Business, William Tibben, Kratika Sangal, Soniya Gonsalves Jan 2006

Unlocking The Secrets Of Amazon: Understanding Tacit Knowledge And Its Implications For E-Business, William Tibben, Kratika Sangal, Soniya Gonsalves

Faculty of Informatics - Papers (Archive)

This paper explores the significance of tacit knowledge for e-business. Using Nonaka and Takeuchi's knowledge management framework the paper investigates the manner in which tacit knowledge is developed and used within an e-business case study, Amazon.com. Context and relationships emerge as fundamentally important factors in the productive use of tacit knowledge. In order to better understand the reasons why context and relationships should be important the paper extends Arrow's information-based approach to innovation. The paper argues that an understanding of information's private goods character, as opposed to its public goods character, opens up new perspectives on managing relationships and context …

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Developing A Culturally Specific E-Learning Website, Penelope Mcfarlane Jan 2006

Developing A Culturally Specific E-Learning Website, Penelope Mcfarlane

Faculty of Informatics - Papers (Archive)

The development of culturally influenced Websites for e-commerce has a great deal of research associated with it. Not a lot of work has been done on culturally specific Websites for e-learning. This paper will explore the theories of Hofstede, Hall and others as well as the web prototype theory of St Amant in the development of such sites for Singapore, Malaysia, Indonesia and Dubai. Sites for these countries have been developed for the Faculty of Informatics and student responses have been surveyed. It is felt that students would perform at a higher level if the e-learning interface was designed with …

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Scalable Delivery Of Immersive Communication Environment (Ice) Using Peer-To-Peer (P2p) Architecture, Ying Peng Que, P. Boustead, Farzad Safaei Jan 2006

Scalable Delivery Of Immersive Communication Environment (Ice) Using Peer-To-Peer (P2p) Architecture, Ying Peng Que, P. Boustead, Farzad Safaei

Faculty of Informatics - Papers (Archive)

In this work, we propose a peer-to-peer (P2P) voice delivery architecture for the support of an immersive communication environment (ICE). An ICE service allows multiple users in a distributed virtual environment (DVE) to exchange live voices which are rendered with the directional and distance cues corresponding to the users' positions in the DVE. Our architecture addresses the scalability issue in peer access bandwidth consumption encountered by the "brute force" full- mesh P2P architecture. On the other hand, our P2P architecture seeks a good balance between access bandwidth scalability and the voice quality delivered. The three key aspects of voice quality …

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Filter Games And Pathological Subgroups Of A Countable Product Of Lines, Taras Banakh, Peter Nickolas, Manuel Sanchis Jan 2006

Filter Games And Pathological Subgroups Of A Countable Product Of Lines, Taras Banakh, Peter Nickolas, Manuel Sanchis

Faculty of Informatics - Papers (Archive)

To each filter F on ω, a certain linear subalgebra A(F) of Rω, the countable product of lines, is assigned. This algebra is shown to have many interesting topological properties, depending on the properties of the filter F. For example, if F is a free ultrafilter, then A(F) is a Baire subalgebra of Rω for which the game OF introduced by Tkachenko is undetermined (this resolves a problem of Hernández, Robbie and Tkachenko); and if F1 and F2 are two free filters on ω that are not near coherent (such filters exist under …

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Linkages Between The Gauss Map And The Stern-Brocot Tree, Bruce Bates, Martin Bunder, Keith Tognetti Jan 2006

Linkages Between The Gauss Map And The Stern-Brocot Tree, Bruce Bates, Martin Bunder, Keith Tognetti

Faculty of Informatics - Papers (Archive)

We discover a bijective map between the Gauss Map and the left-half of the Stern-Brocot Tree. The domain of the Gauss Map is then extended to cover all reals, and the coverage of the Stern-Brocot Tree is extended to include all positive and negative rationals in a manner that preserves the map between the two constructions.

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An Open Source Approach To Medium-Term Data Archiving, Sherine M. Antoun, John Fulcher, Carole Alcock Jan 2006

An Open Source Approach To Medium-Term Data Archiving, Sherine M. Antoun, John Fulcher, Carole Alcock

Faculty of Informatics - Papers (Archive)

Medium- to long-term archiving of digital documents, beyond the lifespan of the authoring software/hardware, is a challenging problem. Magnetic and optical media are susceptible to environmental influences and deteriorate over time, often to the point where the archived documents can no longer be retrieved. Previous attempts to address this problem include migration and emulation, both of which have their attendant difficulties. It is the contention of the present study that an Open Source approach offers several advantages. More specifically, by archiving the Open Source application programs (in source code, not executable form) along with the documents in question, in both …

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Modeling Dual Polarization Wireless Fading Channels Using Quaternions, Beata J. Wysocki, Tadeusz A. Wysocki, Jennifer Seberry Jan 2006

Modeling Dual Polarization Wireless Fading Channels Using Quaternions, Beata J. Wysocki, Tadeusz A. Wysocki, Jennifer Seberry

Faculty of Informatics - Papers (Archive)

In the letter we describe signal transmitted between two dual-polarized antennas using a quaternion notation. The channel can then be modeled by a single quaternion gain, instead of a matrix of four complex gains as it is done in a classical approach. The model is very useful as it allows for a simple accommodation of any polarization twist between the transmit and receive antennas, as well as, modeling random fading in both polarizations with or without cross-polar scattering.

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The Importance Of Utilising Electronic Identification For Total Farm Management In Australia, Adam Trevarthen Jan 2006

The Importance Of Utilising Electronic Identification For Total Farm Management In Australia, Adam Trevarthen

Faculty of Informatics - Papers (Archive)

This paper aims to explore how Radio Frequency Identification (RFID) can be utilised on dairy farms to enhance total farm management. There is a growing worldwide trend for countries to implement whole-of-life traceability systems for livestock, and RFID is clearly the dominant technology being chosen to achieve this aim. In line with this global trend, and to meet the requirements of key trading partners (such as the EU), Australia has implemented the National Livestock Identification System (NLlS) to provide whole-of-life traceability for Iivestock - a system based on the use of RFID devices. As such, it is proposed that dairy …

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Subcarrier Allocation For Ofdma Wireless Channels Using Lagrangian Relaxation Methods, Gengfa Fang, Yi Sun, Jihua Zhou, Jinglin Shi, Zhongcheng Li, E. Dutkiewicz Jan 2006

Subcarrier Allocation For Ofdma Wireless Channels Using Lagrangian Relaxation Methods, Gengfa Fang, Yi Sun, Jihua Zhou, Jinglin Shi, Zhongcheng Li, E. Dutkiewicz

Faculty of Informatics - Papers (Archive)

In this paper, we propose a practically efficient Subcarrier Allocation scheme based on Lagrangian relaxation to solve the problem of subcarrier allocation in OFDMA wireless channels. The problem of subcarrier allocation is formulated into an Integer Programming (IP) problem, which is relaxed by replacing complicating constraints with Lagrange multipliers using Lagrangian Relaxation. A subgradient method is used to optimize the Lagrangian dual function and a heuristic is designed to obtain the feasible solution. Lagrangian Relaxation Subcarrier Allocation (LRSA) is proven to be of polynomial complexity and it provides bounds on the value of channel efficiency. Numerical results show that compared …

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Caso: A Framework For Dealing With Objectives In A Constraint-Based Extension To Agentspeak(L), Aniruddha Dasgupta, Aditya K. Ghose Jan 2006

Caso: A Framework For Dealing With Objectives In A Constraint-Based Extension To Agentspeak(L), Aniruddha Dasgupta, Aditya K. Ghose

Faculty of Informatics - Papers (Archive)

Incorporating constraints into a reactive BDI agent programming language can lead to better expressive capabilities as well as more efficient computation (in some instances). More interestingly, the use of constraint-based representations can make it possible to deal with explicit agent objectives (as distinct from agent goals) that express the things that an agent may seek to optimize at any given point in time. In this paper we extend the preliminary work of Ooi et.al in augmenting the popular Belief-Desire-Intention (BDI) language AgentSpeak( L) with constraint-handling capabilities. We present a slightly modified version of their proposal, in the form of the …

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Seamcad: Object-Oriented Modeling Tool For Hierarchical Systems In Enterprise Architecture, Lam-Son Le, Alain Wegmann Jan 2006

Seamcad: Object-Oriented Modeling Tool For Hierarchical Systems In Enterprise Architecture, Lam-Son Le, Alain Wegmann

Faculty of Informatics - Papers (Archive)

Enterprise Architecture (EA) requires modeling enterprises across multiple levels (from markets down to IT systems). Providing tool support for such models is a challenge (e.g. model containment hierarchy, navigation difficulties, problems to relate elements between different diagrams). In this paper, we identify the requirements that a CAD tool needs to satisfy to manage such hierarchical models. We then propose a solution to meet these requirements: SeamCAD - a tool designed to manage hierarchical models. We present the key features of SeamCAD and an overview of the modeling language it uses. The benefit of the proposed solution is tool support for …

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Evaluation Of Configuration Plans For Dgs In Developing Countries Using Tradeoff Analysis And Madm, Ashish Agalgaonkar, S. V. Kulkarni, S. A. Khaparde Jan 2006

Evaluation Of Configuration Plans For Dgs In Developing Countries Using Tradeoff Analysis And Madm, Ashish Agalgaonkar, S. V. Kulkarni, S. A. Khaparde

Faculty of Informatics - Papers (Archive)

Many developing countries have emphasis on DG technology for their generation expansion planning. The planning considerations and judicious choice of attributes is dictated by the prevailing conditions. With the increased complexities in DG planning options along with multiple attributes to be accounted, more sophisticated techniques are needed to arrive at the correct decisions by decision makers. The analytical hierarchy process (AHP) is proposed to identify the relative significance of the chosen attributes. Proper integration of different attributes can be achieved by linear additive utility function. The uncertainties are accounted using tradeoff analysis by co-relating normalized values of chosen attributes. The …

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Optimal Sizing Of Distributed Generators In Microgrid, Ashish Agalgaonkar, C. V. Dobariya, M. G. Kanabar, S. A. Khaparde, S. V. Kulkarni Jan 2006

Optimal Sizing Of Distributed Generators In Microgrid, Ashish Agalgaonkar, C. V. Dobariya, M. G. Kanabar, S. A. Khaparde, S. V. Kulkarni

Faculty of Informatics - Papers (Archive)

Hybrid optimization model for electric renewables (HOMER), developed by National Renewable Energy Laboratory (NREL), enables economic analysis for single source and hybrid distributed energy resources (DERs). However, current version of HOMER does not support microgrid analysis. In this paper, economic analyzer for distributed energy resources (EADER) is developed. It finds minimum cost of energy (COE) and optimal mix of DERs with multiple sources and sinks. In addition to single source distributed generator (DG) and hybrid DG, EADER is also capable to analyze microgrid. EADER results are validated for single source DG and hybrid DG with results obtained from HOMER for …

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Evaluation Of Configuration Plans For Dgs In Developing Countries Using Advanced Planning Techniques, Ashish Agalgaonkar, S. V. Kulkarni, S. A. Khaparde Jan 2006

Evaluation Of Configuration Plans For Dgs In Developing Countries Using Advanced Planning Techniques, Ashish Agalgaonkar, S. V. Kulkarni, S. A. Khaparde

Faculty of Informatics - Papers (Archive)

Many developing countries have emphasis on distributed generation (DG) technology for their generation expansion planning. The planning considerations and judicious choice of attributes are dictated by prevailing conditions. The attributes considered are capital costs, energy not served per annum, and profits from injecting power into the grid at peak load, all of which are important for a developing country. The uncertain futures considered are three possible loading conditions, which can be low, medium and high. Different scenarios (plans) are generated by various combinations of configurations. DGs can be configured as stand-alone mode, hybrid operation, or micro-grid formation with or without …

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Nonparametric Analysis Of Blocked Ordered Categories Data: Some Examples Revisited, Donald John Best, J. C. W Rayner, Olivier Thas Jan 2006

Nonparametric Analysis Of Blocked Ordered Categories Data: Some Examples Revisited, Donald John Best, J. C. W Rayner, Olivier Thas

Faculty of Informatics - Papers (Archive)

Nonparametric analysis for general block designs can be given by using the Cochran-Mantel-Haenszel (CMH) statistics. We demonstrate this with four examples and note that several well-known nonparametric statistics are special cases of CMH statistics.

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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 …

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A Compactly Generated Group Whose Hecke Algebras Admit No Bounds On Their Representations, Udo Baumgartner, Jacqueline Ramagge, George A. Willis Jan 2006

A Compactly Generated Group Whose Hecke Algebras Admit No Bounds On Their Representations, Udo Baumgartner, Jacqueline Ramagge, George A. Willis

Faculty of Informatics - Papers (Archive)

We construct a compactly generated, totally disconnected, locally compact group whose Hecke algebra with respect to any compact open subgroup does not have a C∗-enveloping algebra. 2000 Mathematics Subject Classification. 20C08.

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Benefits Of Ict Adoption And Use In Regional General Medical Practices: A Pilot Study, Robert Macgregor, Peter Hyland, Charles Harvie, Boon-Chye Lee, Andrew Dalley, Sangeetha Ramu Jan 2006

Benefits Of Ict Adoption And Use In Regional General Medical Practices: A Pilot Study, Robert Macgregor, Peter Hyland, Charles Harvie, Boon-Chye Lee, Andrew Dalley, Sangeetha Ramu

Faculty of Informatics - Papers (Archive)

This paper presents a pilot study of benefits derived from information and communications technology (ICT) adoption and use in medical practices in regional Australia. The study involved 122 regional medical practitioners. The results show that like the more general small businesssector, the perception of certain benefits is associated with the size of the practice (in terms of employee levels) and/ or the gender of the respondent practitioner.

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