344,396 research outputs found

    Steps Towards a Method for the Formal Modeling of Dynamic Objects

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    Fragments of a method to formally specify object-oriented models of a universe of discourse are presented. The task of finding such models is divided into three subtasks, object classification, event specification, and the specification of the life cycle of an object. Each of these subtasks is further subdivided, and for each of the subtasks heuristics are given that can aid the analyst in deciding how to represent a particular aspect of the real world. The main sources of inspiration are Jackson System Development, algebraic specification of data- and object types, and algebraic specification of processes

    Refinement and verification of concurrent systems specified in Object-Z and CSP

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    The formal development of large or complex systems can often be facilitated by the use of more than one formal specification language. Such a combination of languages is particularly suited to the specification of concurrent or distributed systems, where both the modelling of processes and state is necessary. This paper presents an approach to refinement and verification of specifications written using a combination of Object-Z and CSP. A common semantic basis for the two languages enables a unified method of refinement to be used, based upon CSP refinement. To enable state-based techniques to be used for the Object-Z components of a specification we develop state-based refinement relations which are sound and complete with respect to CSP refinement. In addition, a verification method for static and dynamic properties is presented. The method allows us to verify properties of the CSP system specification in terms of its component Object-Z classes by using the laws of the CSP operators together with the logic for Object-Z

    Region-Based Image Retrieval Revisited

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    Region-based image retrieval (RBIR) technique is revisited. In early attempts at RBIR in the late 90s, researchers found many ways to specify region-based queries and spatial relationships; however, the way to characterize the regions, such as by using color histograms, were very poor at that time. Here, we revisit RBIR by incorporating semantic specification of objects and intuitive specification of spatial relationships. Our contributions are the following. First, to support multiple aspects of semantic object specification (category, instance, and attribute), we propose a multitask CNN feature that allows us to use deep learning technique and to jointly handle multi-aspect object specification. Second, to help users specify spatial relationships among objects in an intuitive way, we propose recommendation techniques of spatial relationships. In particular, by mining the search results, a system can recommend feasible spatial relationships among the objects. The system also can recommend likely spatial relationships by assigned object category names based on language prior. Moreover, object-level inverted indexing supports very fast shortlist generation, and re-ranking based on spatial constraints provides users with instant RBIR experiences.Comment: To appear in ACM Multimedia 2017 (Oral

    Requirements analysis of the VoD application using the tools in TRADE

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    This report contains a specification of requirements for a video-on-demand (VoD) application developed at Belgacom, used as a trial application in the 2RARE project. The specification contains three parts: an informal specification in natural language; a semiformal specification consisting of a number of diagrams intended to illustrate the informal specification; and a formal specification that makes the requiremants on the desired software system precise. The informal specification is structured in such a way that it resembles official specification documents conforming to standards such as that of IEEE or ESA. The semiformal specification uses some of the tools in from a requirements engineering toolkit called TRADE (Toolkit for Requirements And Design Engineering). The purpose of TRADE is to combine the best ideas in current structured and object-oriented analysis and design methods within a traditional systems engineering framework. In the case of the VoD system, the systems engineering framework is useful because it provides techniques for allocation and flowdown of system functions to components. TRADE consists of semiformal techniques taken from structured and object-oriented analysis as well as a formal specification langyage, which provides constructs that correspond to the semiformal constructs. The formal specification used in TRADE is LCM (Language for Conceptual Modeling), which is a syntactically sugared version of order-sorted dynamic logic with equality. The purpose of this report is to illustrate and validate the TRADE/LCM approach in the specification of distributed, communication-intensive systems

    Object-oriented Programming Laws for Annotated Java Programs

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    Object-oriented programming laws have been proposed in the context of languages that are not combined with a behavioral interface specification language (BISL). The strong dependence between source-code and interface specifications may cause a number of difficulties when transforming programs. In this paper we introduce a set of programming laws for object-oriented languages like Java combined with the Java Modeling Language (JML). The set of laws deals with object-oriented features taking into account their specifications. Some laws deal only with features of the specification language. These laws constitute a set of small transformations for the development of more elaborate ones like refactorings

    European - North American - Russian Federation Inland ENC Harmonization Group

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    In 2003, the Inland ENC Harmonization Group (IEHG) was formed to agree upon specifications for Inland ENCs that are suitable for all known Inland ENC data requirements for safe and efficient navigation in European and North American inland waterways and rivers. In 2004, the IEHG expanded to include Russian Federation. It is expected that South America will join IEHG in the near future. The overall framework for international Inland ENC standards includes: - Use IHO S-57 Edition 3.1 ‘maritime’ ENC Product Specification, where applicable. - A minimum Inland ENC Product Specification that includes mandatory requirements for safety-of-navigation on inland waterways, worldwide. - An Inland ENC Encoding Guide that provides guidance on recommended object classes, attributes, and attribute values for encoding IENC data. - An Inland ENC Register for additional real-world, IENC object classes, attributes, and attribute values not already contained in IHO S-57Edition 3.1 Object Catalog. - Use of the Open ECDIS Forum (OEF) as a means of communication and for establishment of Register for Inland ENC object classes, attributes, and attribute values. - Align with the future IHO S-100 Geospatial Standard for hydrographic data. Depending on what IHO adopts as a future ‘maritime’ ENC Product Specification (S-101), the Inland ENC Product Specification may become an application “profile” consisting of a feature catalogue, an application schema, and encoding. Or, there may be a there may be a need for a separate Inland ENC Product Specification (e.g., S-102). This paper will briefly review the status to world-wide inland ENC coverage and implementation, and discuss the implications for expanding the scope of the hydrographic applications to meet new requirements

    LCM and MCM: specification of a control system using dynamic logic and process algebra

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    LCM 3.0 is a specification language based on dynamic logic and process algebra, and can be used to specify systems of dynamic objects that communicate synchronously. LCM 3.0 was developed for the specification of object-oriented information systems, but contains sufficient facilities for the specification of control to apply it to the specification of control-intensive systems as well. In this paper, the results of such an application are reported. The paper concludes with a discussion of the need for theorem-proving support and of the extensions that would be needed to be able to specify real-time properties
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