摘要:

AbstractImage understanding is concerned with the elucidation of a computational base inherent in perceiving a three‐dimensional world using vision. This paper describes a low‐level (or early) vision software system, developed in the context of current collaborative research activities in image understanding, which goes some way toward fulfilling the goals of portability, ease of use, and general‐purpose extensibility. Since visual perception uses several types of disparate, but interrelated, information in some explicit cognitive organization, a central objective of the work is to represent this information in a coherent integrated manner which allows one interactively to investigate the properties of the interdependency between information

ISSN:0038-0644    

DOI:10.1002/spe.4380180502

出版商:John Wiley&Sons, Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractThe implementation of a virtual machine for X2, an object‐based programming language, is presented. The X2 virtual machine, is similar to the Smalltalk‐80 virtual machine, but X2 does not perform message look‐up. The implementation differs from most Smalitalk‐80 systems in that objects are paged and in the ability to save changes to an image instead of the whole image. These differences allow larger images to be

ISSN:0038-0644    

DOI:10.1002/spe.4380180503

出版商:John Wiley&Sons, Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractUsually a structured FORTRAN program is transformed into a standard FORTRAN program by means of a one‐pass preprocessor. In this case, several problems are caused by the many redundant continue and goto statements that a preprocessor generates. These problems include: (i) the generated FORTRAN program is not easy to read; (ii) the size of files to store the related programs becomes large; (iii) the total time increases for executing both the FORTRAN compiler and the output program itself.This paper presents a new scheme for constructing a one‐pass preprocessor that generates the optimized FORTRAN code by suppressing the redundant statements. By employing this scheme we have constructed our own preprocessors for Westran (one of the Structured FORTRAN languages) and Ratfor and measured these against the traditional preprocessors for the Westran and Ratfor languages.One of the results is as follows. The total time for users, namely ‘preprocessing time + FORTRAN compiling time’ is rather less than the traditional ones. This is due to the fact that to suppress the input/output of the redundant statements from/to files contributes to the decreasing of both preprocessing and compiling times, and this compensates completely the time‐overhead of the optimizatio

ISSN:0038-0644    

DOI:10.1002/spe.4380180504

出版商:John Wiley&Sons, Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractThis paper describes an exception detection and exception handling method for constructive algebraic specifications. A notation that supports exception handling is introduced. First, a safety function is provided for every sort. This function characterizes each object as being safe or unsafe. Secondly, axioms may contain markers that indicate when they are applicable.The proposed notation is a trade‐off between readability and capability to handle a large class of exceptional situations. The description of exception handling promotes a two‐step design method for constructive algebraic specifications. In a first step the specification is given with exception detection only; in a second step exception handling is superimpo

ISSN:0038-0644    

DOI:10.1002/spe.4380180505

出版商:John Wiley&Sons, Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractRun‐time program profiling is a valuable tool in understanding software efficiency. Techniques for obtaining profiles make assumptions that may result in misleading data. In the paper we illustrate flaws in two profiling systems: the Unix ‘Gprof’ family (including the packages ‘monitor’, ‘prof’ and ‘profil’), and the TI Explorer metering

ISSN:0038-0644    

DOI:10.1002/spe.4380180506

出版商:John Wiley&Sons, Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractA front‐end of an electronic CAD synthesis system is described. The synthesis system accepts a behavioural description of a digital system design written in VHSIC Hardware Description Language (VHDL) and produces the physical hardware, at the register transfer level, needed for realizing the specified behaviour. The synthesis system comprises three major subsystems: process‐graph analyser, design representation and the MIMOLA synthesis system. The process‐graph analyser is an optimization and parallelization tool. We show how optimizing techniques used for compilers are adapted to perform a similar optimization function for hardware synthesis. We present techniques that extend the parallelization of the sequential programs concept for doing control state partitioning. The technique is new because of the unique synthesis model that MIMOLA uses. Finally, we show how to integrate these concepts using a suitable intermediate behavioural representation called the process

ISSN:0038-0644    

DOI:10.1002/spe.4380180507

出版商:John Wiley&Sons, Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractA micro‐kernel that supports concurrent execution of C procedures within a single user process is described. A micro‐kernel provides only four primitives, which have been used to build a number of higher‐level abstractions, including support for distributed processing. The micro‐kernel differs from other efforts in that it is small and efficient, it is written entirely as a non‐privileged user program, and it provides fine‐grained unpredictable interleaving o

ISSN:0038-0644    

DOI:10.1002/spe.4380180508

出版商:John Wiley&Sons, Ltd.    

年代:1988

数据来源: WILEY

ISSN:0038-0644    

DOI:10.1002/spe.4380180509

出版商:John Wiley&Sons, Ltd.    

年代:1988

数据来源: WILEY

ISSN:0038-0644    

DOI:10.1002/spe.4380180510

出版商:John Wiley&Sons, Ltd.    

年代:1988

数据来源: WILEY

ISSN:0038-0644    

DOI:10.1002/spe.4380180501

出版商:John Wiley&Sons, Ltd.    

年代:1988

数据来源: WILEY