217,664 research outputs found

    Advanced technologies for Mission Control Centers

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    Advance technologies for Mission Control Centers are presented in the form of the viewgraphs. The following subject areas are covered: technology needs; current technology efforts at GSFC (human-machine interface development, object oriented software development, expert systems, knowledge-based software engineering environments, and high performance VLSI telemetry systems); and test beds

    Object oriented studies into artificial space debris

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    A prototype simulation is being developed under contract to the Royal Aerospace Establishment (RAE), Farnborough, England, to assist in the discrimination of artificial space objects/debris. The methodology undertaken has been to link Object Oriented programming, intelligent knowledge based system (IKBS) techniques and advanced computer technology with numeric analysis to provide a graphical, symbolic simulation. The objective is to provide an additional layer of understanding on top of conventional classification methods. Use is being made of object and rule based knowledge representation, multiple reasoning, truth maintenance and uncertainty. Software tools being used include Knowledge Engineering Environment (KEE) and SymTactics for knowledge representation. Hooks are being developed within the SymTactics framework to incorporate mathematical models describing orbital motion and fragmentation. Penetration and structural analysis can also be incorporated. SymTactics is an Object Oriented discrete event simulation tool built as a domain specific extension to the KEE environment. The tool provides facilities for building, debugging and monitoring dynamic (military) simulations

    Object-oriented development: knowledge base support for design

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    The research is conducted in the area of Software Engineering, with emphasis on the design phase of the Software Development Life Cycle (SDLC). The object-oriented paradigm is the point of departure. The investigation deals with the problem of creating support for the design phase of object-oriented system development. This support must be able to guide the system designer through the design process, according to a sound design method, highlight opportunities for prototyping and point out where to re-iterate a design step, for example. A solution is proposed in the form of a knowledge-based support system; In the prototype this support guides a designer partially through the first step of the System Design task for object-oriented design. The intention is that the knowledge-based system should capture the know-how of an expert system designer and assist an inexperienced system designer to create good designs

    An Object Oriented Paradigm for Requirements Specifications.

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    Software engineering defines a formalized five-step life-cycle for software development. These steps are: requirements specification, design, implementation, testing and maintenance. The requirements specification phase of the software development life-cycle is responsible for determining the functionality of the proposed system. In this work, a methodology is developed that enhances the generation of accurate requirements specifications, utilizing an object-oriented paradigm. This research realizes four objectives. First, the process of information transferral between the user and the specification team is enhanced. Second, a working base of knowledge containing the domain-specific information within the initial requirements document is established for use by the specification team. Third, techniques for evaluating the overall quality of the initial requirements document are addressed. Specifically, the problems associated with document ambiguity, completeness, consistency and structure are examined. Finally, a specification paradigm is defined utilizing this knowledge-based specification environment. The paradigm permits the automatic generation of an object-oriented specification model. This model may then be used as an input for the design phase. This paradigm defines a methodology for the establishment and evaluation of the knowledge-based specification environment. The environment permits the incorporation of an object-oriented development strategy into the specification process. In addition, the concept of information traceability throughout the specification process is enhanced

    Building ontologies in a domain oriented software engineering environment

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    Ontologies can be used in Domain Oriented Software Engineering Environments (DOSEEs) to organize and describe knowledge and to support management, acquisition and sharing of knowledge regarding some domain. However, ontology construction is not a simple task. Thus, it is necessary to provide tools that support ontology development. This paper discusses the use of ontologies to support domain-oriented software development in ODE, an Ontology-based software Development Environment, and presents ODEd, an ontology editor developed to satisfy the requirements for an ontology editor in a DOSEE. These requirements include the definition of concepts and relations using graphic representations, automatic generation of some classes of axioms, derivation of object frameworks from ontologies, and ontology instantiation and browsing.Eje: Ingeniería de Software y Bases de Datos (ISBD)Red de Universidades con Carreras en Informática (RedUNCI

    Network analysis of large scale object oriented software systems

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    PhD ThesisThe evolution of software engineering knowledge, technology, tools, and practices has seen progressive adoption of new design paradigms. Currently, the predominant design paradigm is object oriented design. Despite the advocated and demonstrated benefits of object oriented design, there are known limitations of static software analysis techniques for object oriented systems, and there are many current and legacy object oriented software systems that are difficult to maintain using the existing reverse engineering techniques and tools. Consequently, there is renewed interest in dynamic analysis of object oriented systems, and the emergence of large and highly interconnected systems has fuelled research into the development of new scalable techniques and tools to aid program comprehension and software testing. In dynamic analysis, a key research problem is efficient interpretation and analysis of large volumes of precise program execution data to facilitate efficient handling of software engineering tasks. Some of the techniques, employed to improve the efficiency of analysis, are inspired by empirical approaches developed in other fields of science and engineering that face comparable data analysis challenges. This research is focused on application of empirical network analysis measures to dynamic analysis data of object oriented software. The premise of this research is that the methods that contribute significantly to the object collaboration network's structural integrity are also important for delivery of the software system’s function. This thesis makes two key contributions. First, a definition is proposed for the concept of the functional importance of methods of object oriented software. Second, the thesis proposes and validates a conceptual link between object collaboration networks and the properties of a network model with power law connectivity distribution. Results from empirical software engineering experiments on JHotdraw and Google Chrome are presented. The results indicate that five considered standard centrality based network measures can be used to predict functionally important methods with a significant level of accuracy. The search for functional importance of software elements is an essential starting point for program comprehension and software testing activities. The proposed definition and application of network analysis has the potential to improve the efficiency of post release phase software engineering activities by facilitating rapid identification of potentially functionally important methods in object oriented software. These results, with some refinement, could be used to perform change impact prediction and a host of other potentially beneficial applications to improve software engineering techniques

    Declarative Representation of Programming Access to Ontologies

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    Abstract. Using ontologies in software applications is a challenging task due to the chasm between the logics-based world of ontologies and the object-oriented world of software applications. The logics-based repre-sentation emphasizes the meaning of concepts and properties, i.e., their semantics. The modeler in the object-oriented paradigm also takes into account the pragmatics, i.e., how the classes are used, by whom, and why. To enable a comprehensive use of logics-based representations in object-oriented software systems, a seamless integration of the two paradigms is needed. However, the pragmatic issues of using logic-based knowledge in object-oriented software applications has yet not been considered suffi-ciently. Rather, the pragmatic issues that arise in using an ontology, e.g., which classes to instantiate in which order, remains a task to be care-fully considered by the application developer. In this paper, we present a declarative representation for designing and applying programming ac-cess to ontologies. Based on this declarative representation, we have build OntoMDE, a model-driven engineering toolkit that we have applied to several example ontologies with different Characteristics.

    Extracting UML Class Diagrams from Object-Oriented Fortran: ForUML

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    Many scientists who implement computational science and engineering software have adopted the object-oriented (OO) Fortran paradigm. One of the challenges faced by OO Fortran developers is the inability to obtain high level software design descriptions of existing applications. Knowledge of the overall software design is not only valuable in the absence of documentation, it can also serve to assist developers with accomplishing different tasks during the software development process, especially maintenance and refactoring. The software engineering community commonly uses reverse engineering techniques to deal with this challenge. A number of reverse engineering-based tools have been proposed, but few of them can be applied to OO Fortran applications. In this paper, we propose a software tool to extract unified modeling language (UML) class diagrams from Fortran code. The UML class diagram facilitates the developers' ability to examine the entities and their relationships in the software system. The extracted diagrams enhance software maintenance and evolution. The experiments carried out to evaluate the proposed tool show its accuracy and a few of the limitations

    Iterative criteria-based approach to engineering the requirements of software development methodologies

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    Software engineering endeavours are typically based on and governed by the requirements of the target software; requirements identification is therefore an integral part of software development methodologies. Similarly, engineering a software development methodology (SDM) involves the identification of the requirements of the target methodology. Methodology engineering approaches pay special attention to this issue; however, they make little use of existing methodologies as sources of insight into methodology requirements. The authors propose an iterative method for eliciting and specifying the requirements of a SDM using existing methodologies as supplementary resources. The method is performed as the analysis phase of a methodology engineering process aimed at the ultimate design and implementation of a target methodology. An initial set of requirements is first identified through analysing the characteristics of the development situation at hand and/or via delineating the general features desirable in the target methodology. These initial requirements are used as evaluation criteria; refined through iterative application to a select set of relevant methodologies. The finalised criteria highlight the qualities that the target methodology is expected to possess, and are therefore used as a basis for de. ning the final set of requirements. In an example, the authors demonstrate how the proposed elicitation process can be used for identifying the requirements of a general object-oriented SDM. Owing to its basis in knowledge gained from existing methodologies and practices, the proposed method can help methodology engineers produce a set of requirements that is not only more complete in span, but also more concrete and rigorous

    Recovering Sequence Diagrams from Object-oriented Code

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    Software modernization is a current research area in the software industry intended to transform an existing software system to a new one satisfying new demands. The initiative Architecture-Driven Modernization (ADM) helps software developers in tackling reverse engineering, software evolution and, software modernization in general. To support modernization problems, the ADM Task Force has defined a set of metamodels such as KDM (Knowledge Discovery Metamodel), being the Eclipse-MDT MoDisco project the official support for software modernization. We propose the application of ADM principles to provide relevant model-based views on legacy systems. We describe a framework to reverse engineering models from object-oriented code. In this context, we show how to recover UML sequence diagrams from Java code. We validate our approach by using ADM standards and MoDisco platform. Our research can be considered a contribution to the MoDisco community; MoDisco does not support reverse engineering of sequence diagrams and, on the other hand, the MoDisco KDM Discover was used and enriched to obtain the required information for recovering interaction diagrams
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