Supporting disconnected operations in mobile computing

Mobile computing has enabled users to seamlessly access databases even when they are on the move. However, in the absence of readily available high-quality communication, users are often forced to operate disconnected from the network. As a result, software applications have to be redesigned to take advantage of this environment while accommodating the new challenges posed by mobility. In particular, there is a need for replication and synchronization services in order to guarantee availability of data and functionality, (including updates) in disconnected mode. To this end we propose a scalable and highly available data replication and management service. The proposed replication technique is compared with a baseline replication technique and shown to exhibit high availability, fault tolerance and minimal access times of the data and services, which are very important in an environment with low-quality communication links.

Enabling successful web-based information technology support for enterprise customers: a service provider perspective of stakeholder-based issues

An understanding by support organisations of the key factors enabling successful enterprise after-sales customer support provision when using Web-based Selfservice Systems (WSSs) is essential to making  improvements in such systems. This paper reports key stakeholder-oriented findings from an interpretive study of critical success factors (CSFs) for the transfer of after-sales support-oriented knowledge from an information technology (IT) service provider to enterprise customers when a WSS is used. The findings suggest that researchers and practitioners should consider WSSs within a complex network of service providers, business partners and customer firms. The paper also clearly points to a need for support organisations to engage in greater collaboration and integration of WSSs with enterprise customers and business partners.

Editorial : towards merging grid and pervasive computing

This special issue is in response to the increasing convergence between grids and pervasive computing, while different approaches exist, challenges and opportunities are numerous in this context (Parashar and Pierson, to appear). The research papers selected for this special issue represent recent progresses in the field, including works on mobile ad-hoc grids, service and data discovery, context-aware application building and context accuracy, and communication. All of these papers not only provide novel ideas and state-of-the-art techniques in the field, but also stimulate future research in the Pervasive Grid environment.

New educational service products : tertiary EC/EB education - the Asia-Pacific region

Electronic Commerce (EC) / Electronic Business (EB) has been (and is expected to continue to be) a dynamic, rapidly evolving area of technology, requiring skilled people with up-to-date knowledge and skills. The global community has required (and still requires) tertiary academic programs to prepare and train these people quickly. In the late nineties, following a tidal wave of tertiary EC program development in the United States, new tertiary programs began to appear in the Asia-Pacific (AP) region to satisfy this need, over a very short period of time. This research project aims to examine whether the development and effectiveness of tertiary EC/EB educational programs can be enhanced through employing a particular marketing paradigm. Four regions - Australia, New Zealand, Hong Kong SAR and the Republic of Singapore — were selected from the AP region, for this study. Based on a review of marketing literature, an inductive approach is adopted to build a model for new educational service product offerings. I also provide a description and comprehensive analysis of EC/EB education, and explore the model empirically, examining how it applies to the way EC education programs have been developed, to date. Essentially, this project consists of two major activities: theory building and theory testing – and is divided into three parts. Part 1: Preliminary study – literature review for theory building. This section of the thesis provides a literature review of the domains of curriculum development, EC/EB program development and management, EC/EB component models and new service product development. Part 2 : Understanding the marketplace – quantitative analysis. This section comprises five major surveys which provide an understanding of EC/EB education. Part 3 : In-depth analysis – qualitative research for theory testing. This section discusses the results of the multiple case studies of EC/EB degree programs undertaken over a five year period. The results of this project highlight both theoretical and practical aspects of the topic. In terms of the theoretical aspect, I provide a contribution to existing theory concerning the planning and development of new tertiary education programs. Research into academic course development in the past has tended to assume that all program development is pedagogically based and influenced. There is an assumption that people only develop academic programs and academic courses for pedagogic reasons. What this research project has done is to suggest that there are, in fact, many possible reasons for developing new programs and that, although these reasons might be pedagogic in nature, they can also be industry-focased, and market-oriented in the following ways: -the university is shaping the way it is perceived by the public – that is, the market; -the university is highlighting where its expertise lies. This led me to a form of new service product development consistent with the new image of the university. There is a clear need for diverse models for program development which accommodate the dynamic roles of modern universities. My research project develops such a model based on conditions in the Asia-Pacific region, and discusses findings arising from the overall project, which can be used to improve new educational program offerings in future, in both the Asia-Pacific and, I suggest, in other regions. This potential use of my findings highlights the practical contribution made by the research Project.

Curriculum history of business computing in Victorian tertiary institutions from 1960-1985

Fifty years ago there were no stored-program electronic computers in the world. Even thirty years ago a computer was something that few organisations could afford, and few people could use. Suddenly, in the 1960s and 70s, everything changed and computers began to become accessible. Today* the need for education in Business Computing is generally acknowledged, with each of Victoria's seven universities offering courses of this type. What happened to promote the extremely rapid adoption of such courses is the subject of this thesis. I will argue that although Computer Science began in Australia's universities of the 1950s, courses in Business Computing commenced in the 1960s due to the requirement of the Commonwealth Government for computing professionals to fulfil its growing administrative needs. The Commonwealth developed Programmer-in-Training courses were later devolved to the new Colleges of Advanced Education. The movement of several key figures from the Commonwealth Public Service to take up positions in Victorian CAEs was significant, and the courses they subsequently developed became the model for many future courses in Business Computing. The reluctance of the universities to become involved in what they saw as little more than vocational training, opened the way for the CAEs to develop this curriculum area.

Perceptions and misperceptions of computing careers

Two issues were addressed. 1. Women are underrepresented in computing courses and in the computing workplace. Despite almost two decades of recognition of the issue and of intervention to correct it, the proportion of women in computing continues to decline. 2. There is a shortage of people with appropriate skills and qualifications in computing, and, more specifically, a need for people with particular personality attributes. There is an increasing demand for computing personnel to have good communication and interpersonal skills, but the predominant personality types of computing people do not include these characteristics. The research relating to the underrepresentation of women was conducted as a series of interviews with university students, female computing professionals and secondary school girls. The main findings of these studies were: 1) schoolgirls are interested in careers that are interesting and varied and provide opportunities for interaction with others; 2) schoolgirls perceive computing as involving working alone; 3) women working in computing describe careers that are interesting, varied, and people-oriented; 4) tertiary computing students equated 'computing' with 'programming'; and 5) single interventions are unlikely to result in individuals in the targeted group deciding to study computing. The perception of schoolgirls that computing involves working alone, which is reinforced by many tertiary computing courses, suggested that the type of person who is likely to be attracted to computing is one who would prefer to work alone. It was predicted that schoolboys would have similar perceptions of computing. Thus, computing is likely to attract students who would prefer to work alone. For various social and stereotypical reasons addressed by previous research, these students will be predominantly male. In the final study, preferred Myers-Briggs Type Indicator and Strong Interest Inventory personality types were suggested for computer programmers, systems designers and systems analysts. The existing literature and the 'types' of 72 study participants tended to confirm that 1) certain personality types are overrepresented in computing; 2) these types are well suited to programming and design tasks; and 3) there is an underrepresentation of individuals who have the combination of analytical, communication and people skills that are required particularly of analysts but also of many others working in computing today. Interviews with participants supported the earlier findings that computing careers are perceived by students to be technical and involve working in isolation, but for many computing people this is not the reality.

Agent-based hybrid framework for decision making on complex problems

Electronic commerce and the Internet have created demand for automated systems that can make complex decisions utilizing information from multiple sources. Because the information is uncertain, dynamic, distributed, and heterogeneous in nature, these systems require a great diversity of intelligent techniques including expert systems, fuzzy logic, neural networks, and genetic algorithms. However, in complex decision making, many different components or sub-tasks are involved, each of which requires different types of processing. Thus multiple such techniques are required resulting in systems called hybrid intelligent systems. That is, hybrid solutions are crucial for complex problem solving and decision making. There is a growing demand for these systems in many areas including financial investment planning, engineering design, medical diagnosis, and cognitive simulation. However, the design and development of these systems is difficult because they have a large number of parts or components that have many interactions. From a multi-agent perspective, agents in multi-agent systems (MAS) are autonomous and can engage in flexible, high-level interactions. MASs are good at complex, dynamic interactions. Thus a multi-agent perspective is suitable for modeling, design, and construction of hybrid intelligent systems. The aim of this thesis is to develop an agent-based framework for constructing hybrid intelligent systems which are mainly used for complex problem solving and decision making. Existing software development techniques (typically, object-oriented) are inadequate for modeling agent-based hybrid intelligent systems. There is a fundamental mismatch between the concepts used by object-oriented developers and the agent-oriented view. Although there are some agent-oriented methodologies such as the Gaia methodology, there is still no specifically tailored methodology available for analyzing and designing agent-based hybrid intelligent systems. To this end, a methodology is proposed, which is specifically tailored to the analysis and design of agent-based hybrid intelligent systems. The methodology consists of six models - role model, interaction model, agent model, skill model, knowledge model, and organizational model. This methodology differs from other agent-oriented methodologies in its skill and knowledge models. As good decisions and problem solutions are mainly based on adequate information, rich knowledge, and appropriate skills to use knowledge and information, these two models are of paramount importance in modeling complex problem solving and decision making. Follow the methodology, an agent-based framework for hybrid intelligent system construction used in complex problem solving and decision making was developed. The framework has several crucial characteristics that differentiate this research from others. Four important issues relating to the framework are also investigated. These cover the building of an ontology for financial investment, matchmaking in middle agents, reasoning in problem solving and decision making, and decision aggregation in MASs. The thesis demonstrates how to build a domain-specific ontology and how to access it in a MAS by building a financial ontology. It is argued that the practical performance of service provider agents has a significant impact on the matchmaking outcomes of middle agents. It is proposed to consider service provider agents' track records in matchmaking. A way to provide initial values for the track records of service provider agents is also suggested. The concept of ‘reasoning with multimedia information’ is introduced, and reasoning with still image information using symbolic projection theory is proposed. How to choose suitable aggregation operations is demonstrated through financial investment application and three approaches are proposed - the stationary agent approach, the token-passing approach, and the mobile agent approach to implementing decision aggregation in MASs. Based on the framework, a prototype was built and applied to financial investment planning. This prototype consists of one serving agent, one interface agent, one decision aggregation agent, one planning agent, four decision making agents, and five service provider agents. Experiments were conducted on the prototype. The experimental results show the framework is flexible, robust, and fully workable. All agents derived from the methodology exhibit their behaviors correctly as specified.

Platform for reliable computing on clusters using group communications

Shared clusters represent an excellent platform for the execution of parallel applications given their low price/performance ratio and the presence of cluster infrastructure in many organisations. The focus of recent research efforts are on parallelism management, transport and efficient access to resources, and making clusters easy to use. In this thesis, we examine reliable parallel computing on clusters. The aim of this research is to demonstrate the feasibility of developing an operating system facility providing transport fault tolerance using existing, enhanced and newly built operating system services for supporting parallel applications. In particular, we use existing process duplication and process migration services, and synthesise a group communications facility for use in a transparent checkpointing facility. This research is carried out using the methods of experimental computer science. To provide a foundation for the synthesis of the group communications and checkpointing facilities, we survey and review related work in both fields. For group communications, we examine the V Distributed System, the x-kernel and Psync, the ISIS Toolkit, and Horus. We identify a need for services that consider the placement of processes on computers in the cluster. For Checkpointing, we examine Manetho, KeyKOS, libckpt, and Diskless Checkpointing. We observe the use of remote computer memories for storing checkpoints, and the use of copy-on-write mechanisms to reduce the time to create a checkpoint of a process. We propose a group communications facility providing two sets of services: user-oriented services and system-oriented services. User-oriented services provide transparency and target application. System-oriented services supplement the user-oriented services for supporting other operating systems services and do not provide transparency. Additional flexibility is achieved by providing delivery and ordering semantics independently. An operating system facility providing transparent checkpointing is synthesised using coordinated checkpointing. To ensure a consistent set of checkpoints are generated by the facility, instead of blindly blocking the processes of a parallel application, only non-deterministic events are blocked. This allows the processes of the parallel application to continue execution during the checkpoint operation. Checkpoints are created by adapting process duplication mechanisms, and checkpoint data is transferred to remote computer memories and disk for storage using the mechanisms of process migration. The services of the group communications facility are used to coordinate the checkpoint operation, and to transport checkpoint data to remote computer memories and disk. Both the group communications facility and the checkpointing facility have been implemented in the GENESIS cluster operating system and provide proof-of-concept. GENESIS uses a microkernel and client-server based operating system architecture, and is demonstrated to provide an appropriate environment for the development of these facilities. We design a number of experiments to test the performance of both the group communications facility and checkpointing facility, and to provide proof-of-performance. We present our approach to testing, the challenges raised in testing the facilities, and how we overcome them. For group communications, we examine the performance of a number of delivery semantics. Good speed-ups are observed and system-oriented group communication services are shown to provide significant performance advantages over user-oriented semantics in the presence of packet loss. For checkpointing, we examine the scalability of the facility given different levels of resource usage and a variable number of computers. Low overheads are observed for checkpointing a parallel application. It is made clear by this research that the microkernel and client-server based cluster operating system provide an ideal environment for the development of a high performance group communications facility and a transparent checkpointing facility for generating a platform for reliable parallel computing on clusters.

Is phase-specific, community-oriented treatment of early psychosis- an economically viable method of improving outcome?

Objective: The Early Psychosis Prevention and Intervention Centre (EPPIC) provides a comprehensive 'real-world' model of early intervention to young people experiencing an emerging psychotic disorder. A prospective study has already provided evidence of improved clinical outcome at 12 months after entry. The present study examined whether the service was also cost-effective.

Method: A cost-effectiveness analysis compared EPPIC with its immediate precursor service, from the perspective of the government funding agency. Only direct costs were included.

Results: EPPIC proved to be more cost-effective. The weighted average cost per patient for the first 12 months was cheaper (by äD 7110 per patient), while treatment outcomes were superior. The savings were due to the marked reduction in in-patient costs outweighing substantial increases in the costs of community care.

Conclusion: These results, while encouraging in terms of the further development of integrated, phase-specific intervention programmes for early psychosis, are not conclusive, and further research is required.

Knowledge transfer in enterprise IT support provision using web-based self-service

This research identified critical success factors and a staged model of knowledge transfer in the provision of after-sales information technology support to enterprise customers when Web-based Self-service systems are used. The research highlights the need for a relational, stakeholder-oriented approach that considers stakeholder interactions, knowledge flows, needs and capabilities.

Prototyping real-time systems using Petri net and object-oriented models

The objective of the research for this thesis is to develop techniques in order to build an executable model of a real-time system. This model is to be used early in the development of the system not only to detect errors in the specification of the system but also to validate expectations of the developer as to the operation of the system. A graphical specification of a real-time system called the transformation schema was chosen to be used to build the model. Two executable models of a real-time system are described.

Toolkit for constructing service replication systems

Distributed replication is the key to providing high availability, fault-tolerance, and enhanced performance. The thesis focuses on providing a toolkit to support the automatic construction of reliable distributed service replication systems. The toolkit frees programmers from dealing with network communications and replication control protocols.

A layered security approach for cloud computing infrastructure

This paper introduces a practical security model based on key security considerations by looking at a number of infrastructure aspects of Cloud Computing such as SaaS, Utility, Web, Platform and Managed Services, Service commerce platforms and Internet Integration which was introduced with a concise literature review. The purpose of this paper is to offer a macro level solution for identified common infrastructure security requirements. This model with a number of emerged patterns can be applied to infrastructure aspect of Cloud Computing as a proposed shared security approach in system development life cycle focusing on the plan-built-run scope.

Adaptive hierarchical scheduling policy for enterprise grid computing systems

In an enterprise grid computing environments, users have access to multiple resources that may be distributed geographically. Thus, resource allocation and scheduling is a fundamental issue in achieving high performance on enterprise grid computing. Most of current job scheduling systems for enterprise grid computing provide batch queuing support and focused solely on the allocation of processors to jobs. However, since I/O is also a critical resource for many jobs, the allocation of processor and I/O resources must be coordinated to allow the system to operate most effectively. To this end, we present a hierarchical scheduling policy paying special attention to I/O and service-demands of parallel jobs in homogeneous and heterogeneous systems with background workload. The performance of the proposed scheduling policy is studied under various system and workload parameters through simulation. We also compare performance of the proposed policy with a static space–time sharing policy. The results show that the proposed policy performs substantially better than the static space–time sharing policy.

Attributed publication and selection for web service-based distributed systems

With the emergence of cloud computing, the need for flexible and detailed publication and selection of services that expose cloud resources is greatly stressed. While dynamic attributes have improved the publication and selection of resources in distributed systems, the use of dynamic attributes is yet to be tried in Web services: a key element that makes cloud computing possible. We propose a new approach to Web service publication and selection using dynamic attributes shown in Web service WSDL documents, the most commonly accessed and used elements of Web services.