摘要:

AbstractWe herein describe a compiler generator, Rie, which is based on a one‐pass‐type attribute grammar. LR‐attributed grammars are one class of attribute grammars in which attribute evaluation can be performed in one pass during LR parsing without creating a parse tree. Rie was developed based on a variant of an LR‐attributed grammar called ECLR‐attributed grammar (equivalence class LR‐attributed grammar), in which equivalence relations are introduced into the LR‐attributed grammar. Rie generates a one‐pass compiler from a compiler description given in attribute grammar form. Many language processors have been developed using Rie. The generated compiler is only about 1.8 times slower than a handwritten compiler, which is fairly efficient for a compiler generated from form

ISSN:0038-0644    

DOI:10.1002/spe.4380250302

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractWe present a simple simulation of lift (or elevator) operation that has been developed as a prototype to address the need for the development of such systems. We first define the type of simulation that has been developed as a discrete‐event, dynamic, stochastic simulation. To do this, we present an overview of pertinent research in computer simulation, and identify some ambiguity in the use of terminology. We then describe the system that we have developed. Next we discuss the decisions taken in its realization, which are related to our research overview, and end by identifying some areas that we feel warrant further development. We believe that such a simulation can provide an important tool for the designers of lift systems. This prototype demonstrates its feasibilit

ISSN:0038-0644    

DOI:10.1002/spe.4380250303

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractThis paper presents an object‐oriented approach for the implementation of interactive systems. This approach applies the model‐view‐controller (MVC) paradigm, which is modified for the C++ environment. The modified paradigm is called MVC++. In this approach the design of interactive applications starts by constructing an object model that represents the key concepts of the problem domain. This object model does not contain any user interface elements. According to the MVC++ approach, the object model is called the model part of the application. Only after the model part has been created, is the user interface designed. A collection of user interface classes is called the view. The classes that connect the model and the view form the controller, which is designed to communicate with both the model and the view.The approach presented in this paper provides a number of benefits. Advantages of the original MVC approach are obtained in a standard C++ environment, the structure of applications becomes clear and stable, and reusability as well as readability of the classes increases. Reusability is achieved by employing a mechanism called ‘abstract partners’.The approach presented in this paper is being applied in the development of a large network management system with over one million lines of C++ code running in the XII en

ISSN:0038-0644    

DOI:10.1002/spe.4380250304

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractWe present a highly scalable approach to distributed parallel computing on workstations in the Internet which provides significant speed‐up to molecular biology sequence analysis. Recent developments show that smaller numbers of workstations connected via a local area network can be used efficiently for parallel computing. This work emphasizes scalability with respect to the number of workstations employed. We show that a massively parallel approach using several hundred workstations, dispersed over all continents, can successfully be applied for solving problems with low requirements on communication bandwidth. We calculated the optimal local alignment scores between a single genetic sequence and all sequences of a genetic sequence database using the ssearch code that is well known among molecular biologists. In a heterogeneous network with more than 800 workstations this job terminated after several minutes, in contrast to several days it would have taken on a single machin

ISSN:0038-0644    

DOI:10.1002/spe.4380250305

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractCADi began as a type‐checker for Z specifications, which were embedded within troff documents. In adding other functionality, such as expansion of schema calculus expressions, and alternative functionality, such as an embedding within LATEX documents, a more open architecture was created into which new tools can be added and alternative tools substituted. This paper gives an overview of CADiZ and describes its open architecture. Many of the ideas used in implementing CADiZ would be applicable to other language processing system

ISSN:0038-0644    

DOI:10.1002/spe.4380250306

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractApproximate string matching is used for spelling correction and personal name matching. In this paper we show how to use string matching techniques in conjunction with lexicon indexes to find approximate matches in a large lexicon. We test several lexicon indexing techniques, includingn‐grams and permuted lexicons, and several string matching techniques, including string similarity measures and phonetic coding. We propose methods for combining these techniques, and show experimentally that these combinations yield good retrieval effectiveness while keeping index size and retrieval time low. Our experiments also suggest that, in contrast to previous claims, phonetic codings are markedly inferior to string distance measures, which are demonstrated to be suitable for both spelling correction and personal name matchin

ISSN:0038-0644    

DOI:10.1002/spe.4380250307

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

ISSN:0038-0644    

DOI:10.1002/spe.4380250301

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY