An enhanced conceptual structure derivation

A novel and comprehensive methodology for derivation of enhanced conceptual structures is presented. The methodology meets the current state of research in semantic database modeling and it has proved particularly attractive for implementing an integrated tool for computer-assisted design. Present and anticipated user requirements on data (and pertinent statistics), as determining so called pre-canned function environment, are regarded as the fulcrum for all design stages and the verifier of most design decisions. The derivation process handles the extended range of semantic modeling constructs, such as: partial and total entities of a relationship, weak and regular relationships, n-ary, nested, recursive and nonunivocal relationships. A rigorous procedure for view modeling and integration is proposed and followed by a step-wise procedure for transforming collections of attributes, called primitive objects, into entities and relationships of a conceptual schema. A necessity for conceptual schema refinements (through abstractions and normalization) and for design feedbacks is exposed. A consistent set of examples is given in order to illustrate the underlying algorithms and to exemplify the semantics involved in the conceptual model. Finally, a very comprehensive list of references is provided in an attempt to make the report useful as a tutorial for more sophisticated readers (hence, some of the references only intrude on the corner of conceptual database design)

A physical schema derivation for network databases

A methodology for the design of a physical database schema in the network model environment is presented. The methodology is integrated with the conceptual and logical designs as presented inter alia in the earlier reports (Maciaszek, 1986; Maciaszek et ai., 1986a). As the physical design problem has the potential of being untractable in polynomial time; we have reduced its complexity in two orthogonal ways: (1) by applying a theory of separability on user views, and (2) by imposing strict ordering on design steps (with feedback). The methodology adheres to the latest standardization efforts for the network model and is consistent with the currently most recognized network Database Management Systems. The methodology is meant to serve as an initial and preliminary specification for a computer-assisted design tool, which - when integrated with other interactive tools for conceptual and logical designs - will be a component of the Intelligent Database Design Kit (IDDK). The IDDK is being developed for network and relational systems and is partly operational

From hubs via holons to an adaptive meta-architecture - the 'AD-HOC' approach

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An Investigation of Software Holons - the 'adHOCS' Approach

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Building Quality into Web Information Systems

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Managing complexity of enterprise information systems

The complexity of modern software is not that much in the size of systems as it is in the “wires” — in the linkages and communication paths between system components. The inter-component linkages create dependencies between distributed components that are difficult to understand and manage. The difficulty is inflated by the fact that components are frequently developed and managed by separate teams and by various component providers. This paper identifies main issues for successful management of complexity in large software projects. It uses the holon hypothesis to explain that all complex systems of a stable but evolvable character display hierarchic organization. The paper makes it clear that a complexity-aware architectural design paves the way for developing supportable systems. It makes it also clear that unless implementation is design-conformant and complexity -assured, the initial good intents may still result in an unsupportable system. Without rigorous project management, supported by tools able to compute and visualize complexity metrics, contemporary large software production risks delivering unsupportable systems.7 page(s

Adaptive integration of enterprise and B2B applications

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An Architectural style for trustworthy adaptive service based applications

Stakeholders demand trustworthy information systems. Trust is a subjective but strong belief in the ability of a system to perform dependably within a specified context defined by (necessarily changing) functional and nonfunctional requirements. Trust assumes satisfaction of various quality goals (including reliability, security, accuracy, efficiency, but also adaptability). A necessary condition for a trustworthy system is to build it based on a complexity-minimizing architectural style. This paper presents a layered/tiered architectural style for construction of service based applications such that dependencies between software elements are constrained to allow lifecycle management of software complexity. The presented style is an extension of the author's PCBMER (Presentation, Controller, Bean, Mediator, Entity, and Resource) meta-architecture for custom software systems.13 page(s

New Directions of Information Systems Development

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