一个消除GOTO语句的算法

在PASCAL到Modula-2的转换过程中,必须消除输入程序中存在的GOTO语句,转换程序消除GOTO语句(包括定义性标号)后,用循环语句、条件语句和布尔变量实现原有GOTO结构的功能。     

COBOL到Java源代码翻译中的数据类型转换*

提出了一种功能等价的类型封装和嵌套方法,可以有效地将COBOL数据描述映射到Java类型系统.该方法已在所开发的COBOL2Java翻译系统中进行应用,通过了近400万行的真实银行商用系统的测试.实验结果表明,此方法正确有效,并且提高了生成代码的执行效率和可读性.     

数据结构化编程:无数组和指针的程序设计

结构化程序设计为访问程序的指令引入了一种新的规范。在合适的编程语言中,这个规范可用不带GOTO的程序设计方法来描述。例如可以证明,对一种具有顺序、选择和重复等控制结构的编程语言,使用GOTO语句得到的任何操作效果.均能用同一语言的非GOTO语句实现。GOTO允许随机语句程序指令,而顺序、选择和重复则提供十分有限的、规范的访问方式。     

FORTRAN77结构程序设计(续三)

<正> 本书自始至终强调结构程序设计的方法;这些方法包括逐步求精、没有GOTO语句的程序设计(在条件循环中使用GOTO语句情况除外)、选择良好的变量名,等等。这些方法使得编写正确的程序更容易了。我们也给出了调试和查错程序的方法。在本章中,我们将汇集和扩展这些方法以确保程序的工作。     

COBOL报表程序自动生成系统

本文叙述一个在IBM/PC机上用PASCAL语言实现的VAX/COBOL报表程序自动生成系统,该系统具有比较强的表格绘制功能,同时生成COBOL报表程序中嵌套有对关系数据库RDB操纵语言RDO语句,能够实现对数据库中多个关系,多个字段同时交叉提取数据的操作。     

程序控制的流程

<正> ANS COBOL程序中的控制流程正常地是按程序员书写的顺序从一个语句传递到下一个语句。我们已学会用STOP RUN语句和GO TO语句来改变这个流程;在这章中,我们将学习使用另一个语句。这种语句有许多任选项,是程序员的一个极其有力的工具;这些任选项也简化了人们将面临的许多编码问题。 在本章中将学习使用的具体ANS COBOL     

IDMS环境下的程序设计

IDMS是国际数据处理领域内享有声誉的一个网状型数据库管理系统。它允许用户在其应用程序中通过数据操纵语句(DML)的语句请求数据库服务,随后用源语言的语句对检索到的数据库记录完成期望的处理。使用的宿主语言有COBOL,PL/1,汇编和FORTRAN。 本文企图说明各类DML语句功能并以 COBOL语句为例叙述在应用程序中检索与操纵数据库记录的方法。     

线程级猜测并行系统代码自动生成工具的设计与实现

虽然线程级猜测(Thread Level Speculation,TLS)执行机制可以简化多线程编程模型接口,并能获得较高的性能加速,但其并行程序的开发仍然比较困难。面向一个高效的软件TLS模型HEUSPEC,研究了代码自动生成工具C2H的设计与实现方法。具体包括3部分内容:首先,为HEUSPEC设计简单的标注语句,标注出可并行段的一些特征;其次,提出将标注语句和可并行段转换为猜测线程函数的算法;最后,设计生成HEUSPEC并行代码的算法。该方法已在开源编译器Clang上实现。面向Rodinia,OmpScr等基准程序的测试结果表明,C2H能够将带有简单标注语句的串行C代码转换为HEUSPEC并行代码,且其性能与手工编写的HEUSPEC并行代码的性能十分接近。     

PASCAL语言程序设计讲座(二) 第三章 分支结构

前一章我们已介绍了顺序结构的程序段以及赋值语句和读、写语句的用法。在顺序结构的程序段中,各语句是按书写的顺序逐条执行的。程序的实际流程是确定的,没有选择的余地。然而,实际问题常常要求根据某些判断结果来选取程序的实际执行的流程,这就在流程图中出现了所谓“分支”。在PASCAL语言中,实现分支功能的语句主要有IF语句和CASE语句。本章将通过介绍这些语句来阐明具有分支结构的程序段的构成和用途。此外,本章还将简述实现无条件转移的GOTO语句。在PC-PASCAL中还扩充了一些具有分支功能的语句,如BREAK语句和CYCLE语句等,由于它们与循环结构的程序段联系较密切,因此我们在下一章中再作讨论。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and     

Editorial:Brain-machine interface(BMI) and cyborg intelligence

正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate     

SCIENCE CHINA Information Sciences SUBJECT INDEX TO VOLUME 57(2014)

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Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate