200 research outputs found

    Distributed simulation of building systems for legacy software reuse

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    The use of integrated building performance simulation can substantially help in improving a building design with regards to comfort levels and fuel consumption, while reducing emission of greenhouse gasses. However, the traditional tools that are closed for inter-communication, limit the modeler to use of components only available within that particular package. This paper gives an overview of distributed simulation approach that can alleviate above limitation. Each program can represent only a part of a building system that is able to model, exchanging the necessary information during the execution and bridging the gaps between the tools. Several important issues closely connected with its implementation, such as synchronization, are pointed out, and the sensitivity of a model on different coupling strategies is studied. The paper concludes with highlighting the gained flexibility in modeling and simulation of building performance that arises from the distributed approach

    Integrating modern business applications with objectified legacy systems

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    The encapsulation of legacy binaries using and XML-based approach with applications in ocean forecasting

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    Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2003.Includes bibliographical references (p. 85-87).This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.This thesis presents an XML-based approach for the encapsulation of legacy binaries. A method that utilizes XML documents to describe the various parameters and settings for the compilation and execution of an encapsulated binary is discussed. The binary is treated as a black-box component and the XML description for that binary contains relevant restrictions, such as input and output files and runtime parameters read in from the standard input stream. The proposed XML schema design constrains the aforementioned XML descriptions of binaries. The usage parameters for the binaries are expressed by such XML documents. A prototype system is then able to take any of these schema-conforming XML descriptions and display the relevant user controls in a graphical user interface (GUI). Instead of editing obscure script files, the user can make changes to build-time and runtime parameters for a binary using the presented system interface. After validating the user inputs, the system generates the required script files automatically and proceeds to compile and/or execute the binary. The Primary Equation Model binary of the Harvard Ocean Prediction System (HOPS) was successfully encapsulated using the presented approach. The customization and control of the binary's compilation and execution through a GUI was achieved.by Robert C. Chang.M.Eng

    Generic access to symbolic computing services

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    Symbolic computation is one of the computational domains that requires large computational resources. Computer Algebra Systems (CAS), the main tools used for symbolic computations, are mainly designed to be used as software tools installed on standalone machines that do not provide the required resources for solving large symbolic computation problems. In order to support symbolic computations an infrastructure built upon massively distributed computational environments must be developed. Building an infrastructure for symbolic computations requires a thorough analysis of the most important requirements raised by the symbolic computation world and must be built based on the most suitable architectural styles and technologies. The architecture that we propose is composed of several main components: the Computer Algebra System (CAS) Server that exposes the functionality implemented by one or more supporting CASs through generic interfaces of Grid Services; the Architecture for Grid Symbolic Services Orchestration (AGSSO) Server that allows seamless composition of CAS Server capabilities; and client side libraries to assist the users in describing workflows for symbolic computations directly within the CAS environment. We have also designed and developed a framework for automatic data management of mathematical content that relies on OpenMath encoding. To support the validation and fine tuning of the system we have developed a simulation platform that mimics the environment on which the architecture is deployed

    Integration of Legacy and Heterogeneous Databases

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    An agent-based service-oriented approach to evolving legacy software systems into a pervasive computing environment.

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    This thesis focuses on an Agent-Based Service-Oriented approach to evolving legacy system into a Pervasive Computing environment. The methodology consists of multiple phases: using reverse engineering techniques to comprehend and decompose legacy systems, employing XML and Web Services to transform and represent a legacy system as pervasive services, and integrating these pervasive services into pervasive computing environments with agent based integration technology. A legacy intelligent building system is used as a case study for experiments with the approach, which demonstrates that the proposed approach has the ability to evolve legacy systems into pervasive service environments seamlessly. Conclusion is drawn based on analysis and further research directions are also discussed

    Visual programming environments for multi-disciplinary distributed applications

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    A Problem Solving Environment is a complete, integrated computing environment for composing, compiling and running applications in a specific problem area or domain. A Visual Programming Environment is one possible front end to a problem solving environment. It applies the visual programming paradigms of "point and click" and "drag and drop", via a Graphical User Interface, to the various constituent components that are used to assemble an application. The aim of the problem solving environment presented here is to provide the ability to build up scientific applications by connecting, or plugging, software components together and to provide an intuitive way to construct scientific applications. Problem solving environments promise a totally new user environment for computational scientists and engineers. In this new paradigm, individual programs combined to solve a problem in their given area of expertise, are wrapped as components within an integrated system that is both powerful and easy to use. This thesis aims to address: problems in code reuse the combination of different codes in new ways and problems with underlying system familiarity and distribution. This is achieved by abstracting application composition using visual programming techniques. The work here focuses on a prototype environment using a number of demonstration problems from multi-disciplinary problem domains to illustrate some of the main difficulties in building problem solving environments and some possible solutions. A novel approach to code wrapping, component definition and application specification is shown, together with timing and usage comparisons that illustrate that this approach can be used successfully to help scientists and engineers in their daily work.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
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