429 research outputs found

    Open predicate path expressions for distributed environments: notation, implementation, and extensions

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    This dissertation introduces open predicate path expressions --a non-procedural, very-high-level language notation for the synchronization of concurrent accesses to shared data in distributed computer systems. The target environment is one in which resource modules (totally encapsulated instances of abstract data types) are the basic building blocks in a network of conventional, von Neumann computers or of functional, highly parallel machines. Each resource module will contain two independent submodules: a synchronization submodule which coordinates requests for access to the resource\u27s data and an access-mechanism submodule which localizes the code for operations on that data;Open predicate path expressions are proposed as a specification language for the synchronization submodule and represent a blend of two existing path notations: open path expressions and predicate path expressions. Motivations for the adoption of this new notation are presented, and an implementation semantics for the notation is presented in the form of dataflow graphs;An algorithm is presented which will automatically synthesize an open predicate path expression into a dataflow graph, which is then implemented by a network of communicating submodules written in either a sequential or an applicative language. Finally, an extended notation for the synchronization submodule is proposed, the purpose of which is to provide greater expressive power for certain synchronization problems which are difficult to specify using path expressions alone

    Experience with Process Modeling in the Marvel Software Development Environment Kernel

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    We have been working for several years on rule-based process modeling and the implementation of such models as part of the foundation for software development environments. We have defined a kernel, called MARVEL, for such an architecture and implemented several successive versions of the kernel and several small environments using the kernel. We have evaluated our results to date, and discovered several significant flaws and delineated several important open problems. Although the details are specific to rule-based process modeling, we believe that our insights will be valuable to other researchers and developers contemplating process modeling mechanisms

    Design of Mixed-Criticality Applications on Distributed Real-Time Systems

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    GRASP/Ada (Graphical Representations of Algorithms, Structures, and Processes for Ada): The development of a program analysis environment for Ada. Reverse engineering tools for Ada, task 1, phase 2

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    The study, formulation, and generation of structures for Ada (GRASP/Ada) are discussed in this second phase report of a three phase effort. Various graphical representations that can be extracted or generated from source code are described and categorized with focus on reverse engineering. The overall goal is to provide the foundation for a CASE (computer-aided software design) environment in which reverse engineering and forward engineering (development) are tightly coupled. Emphasis is on a subset of architectural diagrams that can be generated automatically from source code with the control structure diagram (CSD) included for completeness

    Towards a Reference Architecture with Modular Design for Large-scale Genotyping and Phenotyping Data Analysis: A Case Study with Image Data

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    With the rapid advancement of computing technologies, various scientific research communities have been extensively using cloud-based software tools or applications. Cloud-based applications allow users to access software applications from web browsers while relieving them from the installation of any software applications in their desktop environment. For example, Galaxy, GenAP, and iPlant Colaborative are popular cloud-based systems for scientific workflow analysis in the domain of plant Genotyping and Phenotyping. These systems are being used for conducting research, devising new techniques, and sharing the computer assisted analysis results among collaborators. Researchers need to integrate their new workflows/pipelines, tools or techniques with the base system over time. Moreover, large scale data need to be processed within the time-line for more effective analysis. Recently, Big Data technologies are emerging for facilitating large scale data processing with commodity hardware. Among the above-mentioned systems, GenAp is utilizing the Big Data technologies for specific cases only. The structure of such a cloud-based system is highly variable and complex in nature. Software architects and developers need to consider totally different properties and challenges during the development and maintenance phases compared to the traditional business/service oriented systems. Recent studies report that software engineers and data engineers confront challenges to develop analytic tools for supporting large scale and heterogeneous data analysis. Unfortunately, less focus has been given by the software researchers to devise a well-defined methodology and frameworks for flexible design of a cloud system for the Genotyping and Phenotyping domain. To that end, more effective design methodologies and frameworks are an urgent need for cloud based Genotyping and Phenotyping analysis system development that also supports large scale data processing. In our thesis, we conduct a few studies in order to devise a stable reference architecture and modularity model for the software developers and data engineers in the domain of Genotyping and Phenotyping. In the first study, we analyze the architectural changes of existing candidate systems to find out the stability issues. Then, we extract architectural patterns of the candidate systems and propose a conceptual reference architectural model. Finally, we present a case study on the modularity of computation-intensive tasks as an extension of the data-centric development. We show that the data-centric modularity model is at the core of the flexible development of a Genotyping and Phenotyping analysis system. Our proposed model and case study with thousands of images provide a useful knowledge-base for software researchers, developers, and data engineers for cloud based Genotyping and Phenotyping analysis system development
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