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data abstraction techniques in the validation of CSP-OZ specifications

Formal Aspects of Computing 2000年第3期12卷 147-164页

作者： Wehrheim, Heike Universität Oldenburg Fachbereich Informatik Oldenburg Germany Universität Oldenburg Fachbereich Informatik Postfach 2503 D-26111 Oldenburg Germany

CSP-OZ is an integrated formal method which combines the state-oriented specification language Object-Z with the process algebra CSP, thereby allowing a description of static as well as dynamic aspects of a system. Checking correctness of CSP-OZ specifications can be done via a translation into (FDR-)CSP, on which automatic verification can be performed with the FDR model checker if the state space of the resulting CSP process is not too large to be processed. This paper investigates how data abstraction techniques can be used to bring a translated specification within range of automatic verification.

关键词： Keywords: Integrated formal methods Verification data abstraction CSP-OZ

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data abstraction and Visualisation in Next Step: Experiences from a Government Services Delivery Trial

Data Abstraction and Visualisation in <i>Next Step</i>: Expe...

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IEEE International Congress on Big data

作者： Bista, Sanat Kumar Nepal, Surya Paris, Cecile CSIRO ICT Ctr Canberra ACT Australia

ISBN: (纸本)9780769550060

Online Communities offering support services from a government body can attract a large number of participants and thus grow quickly in terms of interaction volume. This big data can pose a challenge to the community members as well as moderators in reviewing the development of discussions and in understanding the social behaviour of the community. For the data to be useful, it is thus important to employ appropriate data abstraction and visualisation tools. We implemented a gamification based data abstraction and social behaviour based visualisation method in the context of Next Step, a year long trial conducted in partnership with the Australian Government Department of Human Services to deliver support services to citizens in a transitioning phase. The trial has been useful in drawing lessons that could be important for a scaled-up implementation of such government services. In this paper, we present our experiences from the implementation and discuss future prospects.

关键词： data abstraction data Visualisation Gamificaiton Online Community Government Services Delivery Social Behaviour

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FORMAL SPECIFICATION OF data abstraction IN FORTRAN 77 - ABSTRACT ARRAYS

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SOFTWARE ENGINEERING JOURNAL 1990年第3期5卷 151-159页

作者： COLBROOK, A SMYTHE, C UNIV SURREY DEPT ELECT & ELECT ENGNGUILDFORD GU2 5XHSURREYENGLAND

The emphasis of data organisation on the specification, design and implementation of large systems raises the question whether data abstraction may be applied to programming languages designed before the widespread use of such techniques. The data abstraction facilities available in FORTRAN 77 are considered, and it is shown that encapsulation is possible for simple data structures. An abstract array data structure is pecified and further refined to allow the definition of iterators. An example of this structure is implemented in FORTRAN 77. The introduction of a series of abstractions is thus made possible, which facilitates structured development and efficient maintenance.

关键词： formal specification FORTRAN 77 simple data structures maintenance data structures structured programming FORTRAN iterators encapsulation structured development programming languages Software engineering techniques abstract array data structure High level languages data abstraction File organisation data organisation

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data abstraction for Visual and Haptic Representations in Flow Visualization 22

Data Abstraction for Visual and Haptic Representations in Fl...

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28th ACM Symposium on Virtual Reality Software and Technology (VRST)

作者： Bhardwaj, Ayush Kang, Sungjoo Kim, Jin Ryong Univ Texas Dallas Richardson TX 75083 USA ETRI AI Res Lab Daejeon South Korea

ISBN: (纸本)9781450398893

This paper presents a new way of data abstraction for visual and haptic representations in immersive analytics using a mid-air haptic display. Visual and haptic abstraction is proposed to transform raw data (wind tunnel data) into another form of data for effective visual and haptic data mapping. Three main features are extracted: (i) Magnitude of Velocity, (ii) Recirculation Region, and (iii) Vorticity. For each feature, visual and haptic abstractions are defined based on data characterization and data reduction. A preliminary study shows a promising direction toward multimodal data interaction in immersive analytics.

关键词： Immersive analytics haptic data abstraction data transformation interactive data visualization

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A Relational Program Logic with data abstraction and Dynamic Framing

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ACM TRANSACTIONS ON PROGRAMMING LANGUAGES AND SYSTEMS 2022年第4期44卷 1–136页

作者： Banerjee, Anindya Nagasamudram, Ramana Naumann, David A. Nikouei, Mohammad IMDEA Software Inst Madrid Spain Stevens Inst Technol Hoboken NJ 07030 USA

In a paper published in 1972, Hoare articulated the fundamental notions of hiding invariants and simulations. Hiding: invariants on encapsulated data representations need not be mentioned in specifications that comprise the API of a module. Simulation: correctness of a new data representation and implementation can be established by proving simulation between the old and new implementations using a coupling relation defined on the encapsulated state. These results were formalized semantically and for a simple model of state, though the paper claimed this could be extended to encompass dynamically allocated objects. In recent years, progress has been made toward formalizing the claim, for simulation, though mainly in semantic developments. In this article, hiding and simulation are combined with the idea in Hoare's 1969 paper: a logic of programs. For an object-based language with dynamic allocation, we introduce a relational Hoare logic with stateful frame conditions that formalizes encapsulation, hiding of invariants, and couplings that relate two implementations. Relations and other assertions are expressed in first-order logic. Specifications can express a wide range of relational properties such as conditional equivalence and noninterference with declassification. The proof rules facilitate relational reasoning by means of convenient alignments and are shown sound with respect to a conventional operational semantics. A derived proof rule for equivalence of linked programs directly embodies representation independence. Applicability to representative examples is demonstrated using an SMT-based implementation.

关键词： Relational properties relational verification logics of programs data abstraction representation independence product programs automated verification

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KNOWLEDGE-BASED CLUSTERING APPROACH FOR data abstraction

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KNOWLEDGE-BASED SYSTEMS 1994年第2期7卷 103-113页

作者： SRIDHAR, V MURTY, MN Department of Computer Science and Automation Indian Institute of Science Bangalore 560 012 India

Clustering techniques have been used for data abstraction. data abstraction has many applications in the context of databases. Conceptual models are used to bridge the gap between the user's view of a database and the physical view of the database. Semantic models evolved to overcome the limitations of classical data models such as network and relational models. The paper uses a knowledge-based clustering algorithm to extend the abstractions, such as classification and association, which are employed in the semantic modeling of databases. The complexity of the proposed clustering algorithm is analysed. The ''tended semantic model can be used to design databases in which useful and interesting queries can be answered. The efficacy of the proposed knowledge-based clustering approach is examined in the context of a library database.

关键词： ASSOCIATION abstraction CLASSIFICATION abstraction CLUSTERING dataBASE COMPARISON data abstraction KNOWLEDGE-BASED CLUSTERING ALGORITHMS INCREMENTAL CLUSTERING ALGORITHMS ORDER-INDEPENDENT CLUSTERING ALGORITHMS SEMANTIC MODELS

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A FORTRAN PROGRAMMING METHODOLOGY BASED ON data abstraction

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COMMUNICATIONS OF THE ACM 1982年第10期25卷 686-697页

作者： ISNER, JF National Geodetic Survey Rockville MD

data abstraction has been an important consideration since the mid-1970s, with most research effort directed toward the development of experimental languages, formal specification techniques, and program verification schemes. The role of data abstraction in programming methodology, on the other hand, has received considerably less attention. In particular, the potential benefits of the application of data abstraction principles to conventional programming environments have been all but ignored. A programming methodology based on data abstraction and designed especially for the Fortran programming environment is presented here. © 1982, ACM. All rights reserved.

关键词： Parnas modules data abstraction information hiding programming methodology state-machine specification technique

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IMPLEMENTATION OF A CAPABILITY-BASED data abstraction

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IEEE TRANSACTIONS ON SOFTWARE ENGINEERING 1978年第1期4卷 56-64页

作者： ZELKOWITZ, MV LARSEN, HJ Department of Computer Science University of Maryland College Park MD with the Institute for Computer Sciences and Technology National Bureau of Standards

One important feature in programming language design is an appropriate data definitional facility. Criteria now recognized as important are the concepts of information hiding and data abstraction. The problem, however, is to embed these ideas into languages. Although including these ideas has often led to the design of a new language, that is not always necessary. Such facilities may be added to languages like PL/1 or Pascal. This report discusses the inclusion of such facilities within one such PL/1 compiler. While the resulting system does not have the optimal set of protection features, it does have several advantages: the base language is known to a large class of programmers, there are many such compilers already written, and the system achieves almost as much protection as is needed.

关键词： Pointer Variables data abstraction Infonnation Hiding Pascal PL 1

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Automatic Model-Based Generation of Parameterized Test Cases Using data abstraction

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ELECTRONIC NOTES IN THEORETICAL COMPUTER SCIENCE 2007年 191卷 25-48页

作者： Calame, Jens R. Ioustinova, Natalia van de Pol, Jaco Cent Wiskunde Informat Dept Software Engn Amsterdam Netherlands

Developing test suites is a costly and error-prone process. Model-based test generation tools facilitate this process by automatically generating test cases from system models. The applicability of these tools, however, depends on the size of the target systems. Here, we propose an approach to generate test cases by combining data abstraction, enumerative test generation and constraint-solving. Given the concrete specification of a possibly infinite system, data abstraction allows to derive an abstract system, which is finite and thus suitable for the automatic generation of abstract test cases with enumerative tools. To execute abstract test cases, we have to instantiate them with concrete data. For data selection we make use of constraint-solving techniques.

关键词： Conformance testing model-based testing test case generation data abstraction constraint-solving

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Adjudication rather than experience of data abstraction matters more in reducing errors in abstracting data in systematic reviews

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RESEARCH SYNTHESIS METHODS 2020年第3期11卷 354-362页

作者： E, Jian-Yu Saldanha, Ian J. Canner, Joseph Schmid, Christopher H. Le, Jimmy T. Li, Tianjing Johns Hopkins Bloomberg Sch Publ Hlth Ctr Clin Trials & Evidence Synth Dept Epidemiol Baltimore MD USA Brown Univ Ctr Evidence Synth Hlth Dept Hlth Serv Policy & Practice Primary Dept Epidemiol SecondarySch Publ Hlth Providence RI 02912 USA Johns Hopkins Sch Med Dept Surg Ctr Outcomes Res Baltimore MD USA Brown Univ Sch Publ Hlth Dept Biostat Ctr Evidence Synth Hlth Providence RI 02912 USA Univ Colorado Denver Dept Ophthalmol Sch Med 1675 Aurora CtF731 Aurora CO 80045 USA

Background During systematic reviews, "data abstraction" refers to the process of collecting data from reports of studies. The data abstractors' level of experience may affect the accuracy of data abstracted. Using data from a randomized crossover trial in which different data abstraction approaches were compared, we examined the association between abstractors' level of experience and accuracy of data abstraction. Methods We classified abstractors as "more experienced" if they had authored three or more published systematic reviews, and "less experienced" otherwise. Each abstractor abstracted data related to study design, baseline characteristics, and outcomes/results from six articles. We considered two types of errors: incorrect abstraction and errors of omission. We estimated the proportion of errors by level of experience using a binomial generalized linear mixed model. Results We used data from 25 less experienced and 25 more experienced data abstractors. Overall error proportions were similar for less experienced abstractors (21%) and more experienced abstractors (19%). Compared with less experienced abstractors, more experienced abstractors had a lower odds of errors for data items related to outcomes/results (adjusted odds ratio [OR] = 0.53;95% CI, 0.34-0.82) and potentially for data items related to study design (adjusted OR = 0.83;95% CI, 0.64-1.09) but a potentially higher odds of errors for items related to baseline characteristics (adjusted OR = 1.42;95% CI, 0.97-2.06). Conclusion Experience of data abstraction matters little. Errors are reduced by adjudication but still remain high for data items related to outcomes/results.

关键词： accuracy adjudication data abstraction errors experience systematic review

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