2,414 research outputs found

    Application of object-orientation to HDL-based designs

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    The increase in the scale of VLSI circuits over the last two decades has been of great importance to the development process. To cope with this ever­growing design complexity. new development techniques and methodologies have been researched and applied. The early 90's have witnessed the uptake of a new kind of design methodology based on Hardware Description Languages (HDL). This methodology has helped to master the possibilities inherent in our ability to manufacture ever-larger designs. However. while HDL based design methodology is sufficient to address today's standard ASIC sizes, it reaches its limits when considering tomorrow's design scales. Already. RISC processor chip descriptions can contain tens of thousands of HDLlines. Object-Oriented design methodology has recently had a considerable Impact in the software design community as it is tightly coupled with the handling of complex systems. Object-Orientation concentrates on data rather than functions since. throughout the design process. data are more stable than functions. Methodologies for both hardware and software have been introduced through the application of HDLs to hardware design. Common design constructs and principles that have proved successful in software language development should therefore be considered in order to assess their suitability for HDLs based designs. A new methodology was created to emphasise on encapsulation. abstraction and classification of designs. using standard VHDL constructs. This achieves higher levels of modelling along with an Improved reusability through design inheritance. The development of extended semantics for integrating Object-Orientation in the VHDL language is described. Comparisons are made between the modelling abilities of the proposed extension and other competing proposals. A UNIX based Object-Oriented to standard VHDL pre-processor is described along with translation techniques and their issues related to synthesis and simulation. This tool permitted validation of the new design methodology by application to existing design problems

    IDEF method-based simulation model design and development

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    The purpose of this study is to provide an IDEF method-based integrated framework for a business process simulation model to reduce the model development time by increasing the communication and knowledge reusability during a simulation project. In this framework, simulation requirements are collected by a function modeling method (IDEF0) and a process modeling method (IDEF3). Based on these requirements, a common data model is constructed using the IDEF1X method. From this reusable data model, multiple simulation models are automatically generated using a database-driven simulation model development approach. The framework is claimed to help both requirement collection and experimentation phases during a simulation project by improving system knowledge, model reusability, and maintainability through the systematic use of three descriptive IDEF methods and the features of the relational database technologies. A complex semiconductor fabrication case study was used as a testbed to evaluate and illustrate the concepts and the framework. Two different simulation software products were used to develop and control the semiconductor model from the same knowledge base. The case study empirically showed that this framework could help improve the simulation project processes by using IDEF-based descriptive models and the relational database technology. Authors also concluded that this framework could be easily applied to other analytical model generation by separating the logic from the dataPeer Reviewe

    An Adaptive Integration Architecture for Software Reuse

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    The problem of building large, reliable software systems in a controlled, cost-effective way, the so-called software crisis problem, is one of computer science\u27s great challenges. From the very outset of computing as science, software reuse has been touted as a means to overcome the software crisis issue. Over three decades later, the software community is still grappling with the problem of building large reliable software systems in a controlled, cost effective way; the software crisis problem is alive and well. Today, many computer scientists still regard software reuse as a very powerful vehicle to improve the practice of software engineering. The advantage of amortizing software development cost through reuse continues to be a major objective in the art of building software, even though the tools, methods, languages, and overall understanding of software engineering have changed significantly over the years. Our work is primarily focused on the development of an Adaptive Application Integration Architecture Framework. Without good integration tools and techniques, reuse is difficult and will probably not happen to any significant degree. In the development of the adaptive integration architecture framework, the primary enabling concept is object-oriented design supported by the unified modeling language. The concepts of software architecture, design patterns, and abstract data views are used in a structured and disciplined manner to established a generic framework. This framework is applied to solve the Enterprise Application Integration (EM) problem in the telecommunications operations support system (OSS) enterprise marketplace. The proposed adaptive application integration architecture framework facilitates application reusability and flexible business process re-engineering. The architecture addresses the need for modern businesses to continuously redefine themselves to address changing market conditions in an increasingly competitive environment. We have developed a number of Enterprise Application Integration design patterns to enable the implementation of an EAI framework in a definite and repeatable manner. The design patterns allow for integration of commercial off-the-shelf applications into a unified enterprise framework facilitating true application portfolio interoperability. The notion of treating application services as infrastructure services and using business processes to combine them arbitrarily provides a natural way of thinking about adaptable and reusable software systems. We present a mathematical formalism for the specification of design patterns. This specification constitutes an extension of the basic concepts from many-sorted algebra. In particular, the notion of signature is extended to that of a vector, consisting of a set of linearly independent signatures. The approach can be used to reason about various properties including efforts for component reuse and to facilitate complex largescale software development by providing the developer with design alternatives and support for automatic program verification

    A ”Framework” for Object Oriented Frameworks Design

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    Object-oriented frameworks are established tools for domain-specific reuse. Many framework design patterns have been documented, e.g. reverse engineering framework architectures from conventionally built applications for a given domain. The framework development cycle generally evolves from open framework to closed application. We describe a more flexible component-based approach to framework design that stresses a common interface for ’plugging-in’ new components at different lifecycle stages. An analysis of framework-related user roles shows that the classical developer/end-user boundary is too rigid. We see the framework’s development as a continuum within which its ’actors’ can customise its behaviour. This both increases the system’s flexibility and reduces its maintenance requirement. A case study of three frameworks for different application domains illustrates the presented principles

    Considerations for a design and operations knowledge support system for Space Station Freedom

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    Engineering and operations of modern engineered systems depend critically upon detailed design and operations knowledge that is accurate and authoritative. A design and operations knowledge support system (DOKSS) is a modern computer-based information system providing knowledge about the creation, evolution, and growth of an engineered system. The purpose of a DOKSS is to provide convenient and effective access to this multifaceted information. The complexity of Space Station Freedom's (SSF's) systems, elements, interfaces, and organizations makes convenient access to design knowledge especially important, when compared to simpler systems. The life cycle length, being 30 or more years, adds a new dimension to space operations, maintenance, and evolution. Provided here is a review and discussion of design knowledge support systems to be delivered and operated as a critical part of the engineered system. A concept of a DOKSS for Space Station Freedom (SSF) is presented. This is followed by a detailed discussion of a DOKSS for the Lyndon B. Johnson Space Center and Work Package-2 portions of SSF
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