Generic Distribution Support for Programming Systems

This dissertation provides constructive proof, through the implementation of a middleware, that distribution transparency is practical, generic, and extensible. Fault tolerant distributed services can be developed by using the failure detection abilities of the middleware. By generic we mean that the middleware can be used for many different programming languages and paradigms. Distribution for each kind of language entity is done in terms of consistency protocols, which guarantee that the semantics of the entities are preserved in a distributed setting. The middleware allows new consistency protocols to be added easily. The efficiency of the middleware and the ease of integration are shown by coupling the middleware to a programming system, which encompasses the object oriented, the functional, and the concurrent-declarative programming paradigms. Our measurements show that the distribution middleware is competitive with the most popular distributed programming systems (JavaRMI, .NET, IBM CORBA)

Architecture for data exchange among partially consistent data models

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2002.Includes bibliographical references (leaves 75-76).by Eswar Venkat Ram Prasad Vemulapalli.S.M

COMPONENT TECHNOLOGIES AND THEIR IMPACT UPON SOFTWARE DEVELOPMENT

Software development is beset with problems relating to development productivity, resulting in projects delivered late and over budget. While the term software engineering was first introduced in the late sixties, its current state reflects no other engineering discipline. Component-orientation has been proposed as a technique to address the problems of development productivity and much industrial literature extols the benefits of a component-oriented approach to software development. This research programme assesses the use of component technologies within industrial software development. From this assessment, consideration is given to how organisations can best adopt such techniques. Initial work focuses upon the nature of component-orientation, drawing from the considerable body of industrial literature in the area. Conventional wisdom regarding componentorientation is identified from the review. Academic literature relevant to the research programme focuses upon knowledge regarding the assessment of software technologies and models for the adoption of emergent technologies. The method pays particular attention to literature concerning practitioner focussed research, in particular case studies. The application of the case study method is demonstrated. The study of two industrial software development projects enables an examination of specific propositions related to the effect of using component technologies. Each case study is presented, and the impact of component-orientation is each case is demonstrated. Theories regarding the impact of component technologies upon software development are drawn from case study results. These theories are validated through a survey of practitioners. This enabled further examination of experience in component-based development and also understanding how developers learn about the techniques. A strategy for the transfer of research findings into organisational knowledge focuses upon the packaging of previous experience in the use of component-orientation in such a way that it was usable by other developers. This strategy returns to adoption theories in light of the research findings and identifies a pattern-based approach as the most suitable for the research aims. A pattern language, placed in the context of the research programme, is developed from this strategy. Research demonstrates that component-orientation undoubtedly does affect the development process, and it is necessary to challenge conventional wisdom regarding their use. While component-orientation provides the mechanisms for increased productivity in software development, these benefits cannot be exploited without a sound knowledge base around the domain

Evaluating the adoption of enterprise application integration in multinational organisations

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.A review of normative literature, in the field of Information Systems (IS) integration, indicates that traditional approaches to applications integration have failed to result in flexible and maintainable IT infrastructures. In addressing this issue, a new technology called Enterprise Application Integration (EAI) has emerged and addresses most of integration problems by resulting in the development of reusable and manageable IT infrastructures. Enterprise application integration is a new research area with many research issues needing to be investigated. At this end, EAI adoption has not efficiently studied with organisations and researchers needing to understand and analyse EAI adoption. This work examines the introduction of enterprise application integration in multinational organisations and proposes a novel model for its adoption. The model is based on a comprehensive set of factors that influence the introduction of EAI in organisations. Since there is an absence of theoretical models for EAI adoption, the proposed model adapts factors that influence the adoption of other integration technologies such as Electronic Data Interchange (EDT). Additional factors like an evaluation framework that supports decision making have been considered by the author as factors that influence EAI adoption. In moving from the conceptual to the empirical, the work is based on a qualitative case study approach to examine the concepts of the proposed model for the adoption of EAI. In doing so, two case studies were conducted at multinational organisations and presented and analysed. However, during the empirical research complementary factors also emerged, which resulted in modifications being made to the previously presented conceptual model. In interpreting from empirical data, it appears that ten main factors influence the adoption of EAT namely: (a) benefits; (b) barriers; (c) costs; (d) internal pressures; (e) external pressures; (f) IT infrastructure; (g) IT sophistication; (h) an evaluation framework for the assessment of integration technologies; (i) evaluation framework for the assessment of EAT packages and, (j) support. The proposed model makes novel contribution at two levels. First, at the conceptual level, as it incorporates factors identified separately in previous studies as influencing adoption of other integration technologies. These factors are used for the development of a consistent model for the adoption and evaluation of EAT. Secondly, the concepts of the proposed model can be used for the adoption of inter-organisational information systems. The proposed model can be used as a decision-making tool to support management when taking decisions regarding the adoption of EAI. Additionally, it can be used by researchers to analyse and understand the adoption of application integration.This work is funded by the Brunel University Department of Information Systems and Computing

Clinical foundations and information architecture for the implementation of a federated health record service

Clinical care increasingly requires healthcare professionals to access patient record information that may be distributed across multiple sites, held in a variety of paper and electronic formats, and represented as mixtures of narrative, structured, coded and multi-media entries. A longitudinal person-centred electronic health record (EHR) is a much-anticipated solution to this problem, but its realisation is proving to be a long and complex journey. This Thesis explores the history and evolution of clinical information systems, and establishes a set of clinical and ethico-legal requirements for a generic EHR server. A federation approach (FHR) to harmonising distributed heterogeneous electronic clinical databases is advocated as the basis for meeting these requirements. A set of information models and middleware services, needed to implement a Federated Health Record server, are then described, thereby supporting access by clinical applications to a distributed set of feeder systems holding patient record information. The overall information architecture thus defined provides a generic means of combining such feeder system data to create a virtual electronic health record. Active collaboration in a wide range of clinical contexts, across the whole of Europe, has been central to the evolution of the approach taken. A federated health record server based on this architecture has been implemented by the author and colleagues and deployed in a live clinical environment in the Department of Cardiovascular Medicine at the Whittington Hospital in North London. This implementation experience has fed back into the conceptual development of the approach and has provided "proof-of-concept" verification of its completeness and practical utility. This research has benefited from collaboration with a wide range of healthcare sites, informatics organisations and industry across Europe though several EU Health Telematics projects: GEHR, Synapses, EHCR-SupA, SynEx, Medicate and 6WINIT. The information models published here have been placed in the public domain and have substantially contributed to two generations of CEN health informatics standards, including CEN TC/251 ENV 13606