A simple text processing tool which allows positioning of lines within a document is presented using the formal specification language Z. Implementation details such as the use of tab characters and newline sequences ...
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A simple text processing tool which allows positioning of lines within a document is presented using the formal specification language Z. Implementation details such as the use of tab characters and newline sequences are covered. The program has been implemented under the UNIX operating system. It is hoped that the use of similar techniques will become widespread in the field of software engineering.
Two systolic arrays for recursive digital filtering are presented. Both have a rectangular structure and produce output for a particular computation in consecutive cycles. Their performance is analyzed and the design ...
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Two systolic arrays for recursive digital filtering are presented. Both have a rectangular structure and produce output for a particular computation in consecutive cycles. Their performance is analyzed and the design tradeoffs are discussed.
Two classes of systolic array for the implementation of recursive digital filters are presented, which overcome some of the limitations of earlier designs. The trade-off resulting from varying the degree of pipelining...
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Two classes of systolic array for the implementation of recursive digital filters are presented, which overcome some of the limitations of earlier designs. The trade-off resulting from varying the degree of pipelining is discussed.
One of the concepts from topology that has found use in image processing is the so called Fundamental group of an image. A definition for the digital fundamental group of a binary picture was introduced by Kong in A d...
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One of the concepts from topology that has found use in image processing is the so called Fundamental group of an image. A definition for the digital fundamental group of a binary picture was introduced by Kong in A digital fundamental group [4]. This paper introduces a fundamental group for greyscale images. We also describe Poincare's classical method for computing a representation of the fundamental group and extend this to work with our greyscale version.
The study of computing is split at an early stage between the separate branches that deal with hardware and software;there is also a corresponding split in later professional specialisation. This paper explores the es...
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The study of computing is split at an early stage between the separate branches that deal with hardware and software;there is also a corresponding split in later professional specialisation. This paper explores the essential unity of the two branches and attempts to point to a common framework within which hardware-software codesigns can be expressed as a single executable specification, reasoned about, and transformed into implementations. We also describe a hardware/software co-design environment which has been built, and we show how designs can be realised within this environment. A rapid development cycle is achieved by using FPGAs to host the hardware components of the system. The architecture of a hardware platform for supporting experimental hardware/software co-designs is presented. A. particular example of a real-time video processing application built using this design environment is also described.
This paper discusses applications of a formal set-theoretic foundation for fuzzy set theory [23] to problems of approximate and uncertain reasoning, and also looks at other formalisms, such as the classical Alternativ...
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This paper discusses applications of a formal set-theoretic foundation for fuzzy set theory [23] to problems of approximate and uncertain reasoning, and also looks at other formalisms, such as the classical Alternative Set Theory 1.9) and its Intuitionistic version [21. 20] for uncertain reasoning. Formal definitions of these frameworks will be given. Many suggestions for semantic operations on values of formulae involving intermediate truth have been made;[41. 40] contain a survey of these. There are two main problems: how to reconcile the use of the linear order [0, 1. as the value space when in reality degrees of truth are often incomparable, and secondly, within this simplified range of values, to select operations which are both logically coherent with each other and intuitively reasonable. We will derive general semantic constraints on operations which will motivate the formal frameworks that we define.
We present a very general language for expressing tactic programs. The paper describes some essential tactic combinators (tacticals), and gives them a formal semantics. Those definitions are used to produce a complete...
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We present a very general language for expressing tactic programs. The paper describes some essential tactic combinators (tacticals), and gives them a formal semantics. Those definitions are used to produce a complete calculus for reasoning about tactics written in this language. The language is extended to cover structural combinators which enable the tactics to be precisely targeted upon particular sub-expressions.
This paper demonstrates how reduction to normal form can help in the design of a correct compiler for Dijkstra's guarded command language. The compilation strategy is to transform a source program, by a series of ...
This paper demonstrates how reduction to normal form can help in the design of a correct compiler for Dijkstra's guarded command language. The compilation strategy is to transform a source program, by a series of algebraic manipulations, into a normal form that describes the behaviour of a stored-program computer. Each transformation eliminates high-level language constructs in favour of lower-level constructs. The correctness of the compiler follows from the correctness of each of the algebraic transformations.
Acute abdominal pain is one of the most widely studied applications of computer-aided diagnosis. The usual approach is to apply Bayes' theorem with the assumption of conditional independence (''independenc...
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Acute abdominal pain is one of the most widely studied applications of computer-aided diagnosis. The usual approach is to apply Bayes' theorem with the assumption of conditional independence (''independence Bayes''). We compared various approaches to designing diagnostic programs for abdominal pain of suspected gynaecological origin. The methods range from statistical to knowledge-based. All programs were evaluated using a database of 1.270 cases collected retrospectively. Our results suggest that in this application no significant improvement in accuracy can be made by taking interactions into account, either by statistical or by knowledge-based means;independence Bayes is near-optimal. As far as accuracy is concerned, there appears to be little point in pursuing knowledge-based approaches. However, the ''nearest neighbours'' method using a new metric appears to be at least as accurate as independence Bayes. We argue that the nearest neighbours method is more suitable than independence Bayes for clinical use because of greater accountability.
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