An Improved Graphic Representation for Structured Program Design

In this paper,an improved graphic representation for Structured Program Design--N-S-Z (Nassi-Shneiderman-Zhou Diagram) is proposed.It not only preserves the advantages of the conventional graphic and non-graphic representations,but also adds some new features which will enhance the representative power of the original diagram.     

Digital signatures — An overview

To satisfy the requirements demanded by many of today's business transactions, a communications system must provide the capability for messages to be signed by digital signatures. Being dependent upon both the message and the originator, digital signatures can be used by the message recipient to prove to an impartial third party (judge or adjudicator) not only the identify of the message's originator but also the message's true content.Two types of digital signatures are investigated: true signatures, and arbitrated signatures. A true signature can be validated by anyone having the correct nonsecret (public) validation parameter, whereas an arbitrated signature must be validated by a trusted arbiter. Arbitrated signatures appear to be adequate if the sender and receiver both belong to a common organization. However, true signatures are usually required when the sender and receiver belong to different organizations.     

A High Resolution Chinese Character Generator

Font storage requirement is a crucial problem in developing Chinese typesettingsystem.A unique data compression technique is adopted in the system.Therepresentation of regular strokes and irregular strokes of Chinese characters and themethod for transforming the compressed representation into dot matrix are describedin the paper.The result is satisfactory,and the cost performance ratio of thetypesetting system is significantly improved by the technique.     

WAVEGIDE—An interactive waveguide program

WAVEGIDE is an interactive program which, when used in conjunction with IMSL's PDE/PROTRAN, can solve waveguide problems on arbitrary cross-sections, with variable permittivity and permeability. The user only has to answer a series of basic questions about his problem, posed in engineering terms, and all propagating modes in a specified interval are calculated, and the corresponding electric and magnetic fields are plotted.     

An interpreter for slips—An applicative language based on LAMBDA-Calculus

An applicative language based on the LAMBDA-Calculus is presented. The language, SLIPS (Small Language for Instruction Purposes), is described using the LAMBDA-Calculus as a metalanguage. A call-by-need mechanism of function invocation eliminates the drawbacks of both call-by-name and call-by-value. The system has been implemented in PASCAL.     

Local viewdata—An international CAL resource

Local viewdata, a heirarchical data structure, became available at low cost to schools during the latter part of 1984. Placing children in the roles of both information provider and user within a content-free software environment has already highlighted a number of interesting possibilities.The authors will illustrate a variety of case studies whereby such a system has been exploited by both teachers and their pupils in different parts of Europe. Apart from moving a step nearer to the global electronic village, the network provides an opportunity for children to look at their school in the community and become involved in information gathering, journalism and graphics design. The paper will be illustrated with examples of children's work.     

Program Constructionby Verifying Specification

A program construction method based on Gamma language is proposed.The problem to be solved is specified by first-order predicate logic and a semantic verification program is constructed directly from the specification.Ways for improving efficiency of the program are also studied.The method differs from the one proposed by Manna and Waldinger,where a program is extracted from the proof of the existence of an object meeting the given specification.On the other hand,it also differs from the classical one used for deriving Gamma programs of Banatre and Le metayes,which consists in decomposing the specification into an invariant and a termination conditon.     

Fault-tolerant Control Systems—An Introductory Overview

This paper presents an introductory overview on the development of fault-tolerant control systems. For this reason, the paper is written in a tutorial fashion to summarize some of the important results in this subject area deliberately without going into details in any of them. However, key references are provided from which interested readers can obtain more detailed information on a particular subject. It is necessary to mention that, throughout this paper, no efforts were made to provide an exhaustive coverage on the subject matter. In fact, it is far from it. The paper merely represents the view and experience of its author. It can very well be that some important issues or topics were left out unintentionally. If that is the case, the author sincerely apologizes in advance.After a brief account of fault-tolerant control systems, particularly on the original motivations, andthe concept of redundancies, the paper reviews the development of fault-tolerant control systems with highlights to several important issues from a historical perspective. The general approaches to fault-tolerant control has been divided into passive, active, and hybrid approaches. The analysis techniques for active fault-tolerant control systems are also discussed. Practical applications of fault-tolerant control are highlighted from a practical and industrial perspective. Finally, some critical issues in this area are discussed as open problems for future research/development in this emerging field.     

Online and multiplayer gaming — An overview

This paper gives a broad overview of the technology and market for on-line and multiplayer computer gaming. Some economic considerations and their influence on the choice of technologies are examined. Particular attention is given to the massively-multiplayer and persistent world type of games, and the special problems that arise in these environments. Lastly, some ongoing problems are investigated, particularly the thorny issue of cheating in multiplayer games.     

I—SATCHMORE：An Improvement of A—SATCHMORE

This paper presents an improvement of A-SATCHMORE (SATCHMORE with Availability).A-SATCHMORE incorporates relevancy testing and availability checking into SATCHMO to prune away irrelevant forward chaining.However ,considering every consequent atom of those non-Horn clauses being derivable,A-SATCHMORE may suffer from a potential explosion of the search space when some of such consequent atoms are actually underivable.This paper introduces a solution for this problem and shows its correctness.