205571678
A Prolog Rule-Based System for Cartographic Name Placement
Manual name placement is an extremely time consuming task and has been one of the most difficult aspects of the map production process to automate. It is complicated by the large number of rules required for the selection and placement of names. A hybrid Prolog/Fortrau rule-based system is described for placing names on a variety of map types. It uses a set of Prolog primitives for spatial search and name placement operations. The Ordnance Survey's 1:625000 scale digital dataset has been used to illustrate the application of rules for the selection of labels as well as for controlling their size and orientation. The application to other types of maps and diagrams is also briefly described.
7423994
Computational Perspectives on Map Generalization
9300744
Matching and aligning features in overlayed coverages
1. ABSTRACT The problems caused by locational error when overlaying spatial data from different sources have been recognised for some time, and much research has been directed towards finding solutions. In this paper we present a solution in the form of an algorithm that seeks to match and align semantically equivalent features prior to overlay. It is assumed that, because of locational error, semantically equivalent features will not always be geometrically equivalent. The technique has been developed to assist in the detection of change between multi-date vector-defined data sets. Initial results, obtained by applying our algorithm to land cover data, are presented. 1.1
8618172
Tentative steps toward a development method for interfering programs
Development methods for (sequential) programs that run in isolation have been studied elsewhere. Programs that run in parallel can interfere with each other, either via shared storage or by sending messages. Extensions to earlier development methods are proposed for the rigorous development of interfering programs. In particular, extensions to the specification method based on postconditions that are predicates of two states and the development methods of operation decomposition and data refinement are proposed. 41 references.
17181898
Constraining Inference in an Object-Based Design Model
This paper is the first of a series which are intended to contribute to tractable development methods for concurrent programs by exploring ways in which objectbased language concepts can be used to provide a compositional development method for concurrent programs. The property of a (formal) development method which gives the developmentprocess the potential for productivity is compositionality; interference is what makes it difficult to find compositional development methods for concurrent systems. This paper shows how object-based concepts can be used to provide a designer with control over interference; it also proposes a transformational style of development (for systems with limited interference) in which concurrency is introduced only in the final stages of design. The essential idea here is to show that certain object graphs limit interference.
22477823
A typed logic of partial functions reconstructed classically
This paper gives a comprehensive description of a typed version of the logic known as LPF. This logic is basic to formal specification and verified design in the software development method VDM. If appropriately extended to deal with recursively defined functions, the data types used in VDM, etc., it gives the VDM notation and its associated rules of reasoning. The paper provides an overview of the needed extensions and examines some of them in detail. It is shown how this nonclassical logic-and the extensions-can be reconstructed classically by embeddings into classical infinitary logic.
11004522
Program Specifications and Formal Development
33452389
Interference Revisited