7423994
Computational Perspectives on Map Generalization
14219539
Characterisation and generalisation of cartographic lines using Delaunay triangulation
A method is presented for generalising cartographic lines using an approach based on determination of their structure. Constrained Delaunay triangulation is used to construct a skeleton of the space surrounding the lines and hence represent line features in terms of skeleton branches. Several statistical measures are used to characterise the triangulation branches. The measures enable selective generalisation of different types of line feature, leading to the possibility of user-specification of the style of generalisation. In our implementation of the approach, the triangulation is updated dynamically to allow both sides of multiple lines to be processed, while guaranteeing topological consistency between the resulting generalised lines.
36993113
A Collaborative Schema Integration System
Conceptual modelling as applied to database development can be described as a two stage process: schema modelling followed by schema integration. Schema modelling is the process of transforming individual user requirements into a conceptual schema: an implementation-independent map of data requirements. Schema integration is the process of combining individual conceptual schemas into a single, unified schema. Single-user tools for schema modelling have enjoyed much success partly because the process of schema modelling has become relatively well formalised. Although a number of formal approaches to conducting schema integration have been proposed, it appears that schema integration tools have not enjoyed the same level of success. This we attribute not so much to the problem of formalisation but to the inherent collaborative nature of schema integration work. This paper first discusses the importance of collaboration to schema integration work. It then describes SISIBIS, a demonstrator system employing the IBIS (Issue Based Information System) scheme to support collaborative database design.
26658779
Virtual architecture based on a binary relational model: A museum hypermedia application
38308402
Specification and Design of (Parallel) Programs
15085447
A Formal Basis for Some Dependability Notions
This paper shows how formal methods ideas can be used to clarify basic notions used in the field of dependability. Central to this endeavour is fixing a notion of system. Relationships between systems are also considered: in particular, the importance of the situation where one system is generated by another (possibly human) system is explored. The formalisation is used as a basis for definitions of the notions of fault, error and failure. Some applications to examples from the dependability literature and extensions of the basic model of system are also sketched.
6818472
Some Practical Problems and Their Influence on Semantics
This paper offers an assessment of what has been achieved in three decades of work on the semantics of programming languages and pinpoints some practical problems in computing which might stimulate further research. The examples sketched in this paper come from the author's own research on concurrent object oriented languages, from database practice, and from more speculative research on Internet issues.
41129929
The Atomic Manifesto
This paper is a manifesto for future research on "atomicity" in its many guises and is based on a five-day workshop on "Atomicity in System Design and Execution" that took place in Schloss Dagstuhl in Germany in April 2004.
42679892
Whither Formal Methods: A Plea To Investigate New Applications
[1] K. V. Hanford and C. B. Jones. Dynamic Syntax: A Concept for the Definition of the Syntax of Programming Languages, volume 7 of Annual Review in Automatic Programming. Pergamon Press, 1974. [2] D. Bjørner and C. B. Jones, editors. The Vienna Development Method: The Meta-Language, volume 61 of Lecture Notes in Computer Science. SpringerVerlag, 1978. [3] C. B. Jones. Software Development: A Rigorous Approach. Prentice Hall International, 1980. ISBN 0-13-821884-6. [4] D. Bjørner and C. B. Jones. Formal Specification and Software Development. Prentice Hall International, 1982. ISBN 0-13-329003-4. [5] H. Bekič and C. B. Jones, editors. Programming Languages and Their Definition: Selected Papers of H. Bekič, volume 177 of Lecture Notes in Computer Science. Springer-Verlag, 1984. [6] C. B. Jones. Systematic Software Development Using VDM. Prentice Hall International, 1986. ISBN 0-13-880717-5. [7] C. A. R. Hoare and C. B. Jones. Essays in Computing Science. Prentice Hall International, 1989. ISBN 0-13-284027-8. [8] C. B. Jones. Systematic Software Development using VDM. Prentice Hall International, second edition, 1990. ISBN 0-13-880733-7. [9] C. B. Jones and R. C. F. Shaw, editors. Case Studies in Systematic Software Development. Prentice Hall International, 1990. ISBN 0-13-116088-5. [10] C. B. Jones, K. D. Jones, P. A. Lindsay, and R. Moore. mural: A Formal Development Support System. Springer-Verlag, 1991. ISBN 3-540-19651-X. During time in industry, even significant items were not necessarily published externally: e.g. [178] was a complete defintion of Algol 60 using “functional semantics”; [187] introduced the concept of “implementation bias” [169] introduced the “exit” idea; [183] was the key output of the denotational semantics definition of PL/I which marks the start of VDM as a language defintion method.