Proving programs correct through refinement

Summary Program proving must be made applicable to all stages of program development. In particular, in the design phase, proving could prevent a program development based on erroneous or inconsistent design decisions, with its associated high cost of debugging. Furthermore, the proving activity itself would benefit from an early application in the development cycle of a program, because the proof of a program design seems to be simpler than the proof of the final, perhaps optimized, program. The Fisher-Galler algorithm will be used as an example for demonstrating the proof of a program design. An algebraic specification technique is used for describing the design. Details of the proof will be discussed.     

监控系统中控制软件的工程化设计与实现

主要探讨微机监控系统中控制软件的工程化设计方法,介绍了模块化程序设计和结构化程序设计的基本原理,具体分析了在电锅炉微机控制系统中,采用模块化程序设计和结构化的程序设计相结合的设计思路,给出了程序框图。实践证明,这是一种行之有效的方法,取得了很好的实际效果。     

基于MicroBlaze软核处理器的Bootloader设计

文章介绍了基于MicroBlaze软核处理器的Bootloader程序的设计,详细介绍了适用该程序的FPGA嵌入式系统的硬件配置及Bootloader程序设计的硬件逻辑设计流程和软件设计流程。该程序是在FPGA硬件配置完毕之后,在内部处理器上运行的一段启动代码,用来将FLASH中的用户程序传输至外部RAM,并引导嵌入式系统从用户程序中开始运行。它解决了使用大规模复杂应用程序的嵌入式系统的引导问题,已在实际中应用,具有良好的适应性。     

Incorporating codes of practice into reinforced concrete design programs

Changing the Code of Practice embodied in a reinforced concrete design program usually needs much expensive programming effort. A solution to this problem is described in which the Code-dependent sections of design programs are isolated and specified in a new problem-oriented language, developed for this task. Changing Codes in this program merely means changing the file of Code provisions. A simple beam design program, already run under five Codes, is described and some comparative design results are also shown.     

An interactive graphics program for teaching computer aided design of beams

A computer program developed for teaching flexural design of shafts to students taking machine design courses is described. The program utilizes conversational mode interaction via a storage tube graphics terminal and it includes interactive facilities for problem definition, analysis, evaluation and modification. Some experience in using this program is also presented.     

An exercise in program design using SIMULA class invariants

The concept of an invariant assertion has been shown by Hoare to be central to the problem of proving correctness of data representation in a program. A consequent approach for program design is to establish the parts of an overall invariant which characterize the components of the design. In this way it is feasible to synthesize a verified program. There is a gulf between verification theory and practical reality in this area, but the SIMULA class concept is close to the data representation technique required for such an approach. Some of the benefits and problems of this approach to design have been explored by the development of a SIMULA program to simulate a bounded delay resource allocation strategy in a job scheduling environment.     

TEFOOL/2: a program for theoretical drug design on microcomputers

TEFOOL/2, a program written in BASIC, is presented in this paper. The purpose of TEFOOL/2 is to provide people interested in drug design with an easy-to-handle program where some of the most important techniques in QSAR are included. The program permits the selection of the training series, performs regression calculations and searches for optimum substituents. The latter is achieved by using either a Hansch's strategy or geometrical procedures. The program is interactive and can be implemented on an IBM-PC or compatible microcomputer. Although TEFOOL/2 has been developed for its application in drug design studies, its great flexibility makes it suitable for application to any experimental design or optimization process.     

Two controlled experiments assessing the usefulness of designpattern documentation in program maintenance

Using design patterns is claimed to improve programmer productivity and software quality. Such improvements may manifest both at construction time (in faster and better program design) and at maintenance time (in faster and more accurate program comprehension). The paper focuses on the maintenance context and reports on experimental tests of the following question: does it help the maintainer if the design patterns in the program code are documented explicitly (using source code comments) compared to a well-commented program without explicit reference to design patterns? Subjects performed maintenance tasks on two programs ranging from 360 to 560 LOC including comments. The experiments tested whether pattern comment lines (PCL) help during maintenance if patterns are relevant and sufficient program comments are already present. This question is a challenge for the experimental methodology: A setup leading to relevant results is quite difficult to find. We discuss these issues in detail and suggest a general approach to such situations. A conservative analysis of the results supports the hypothesis that pattern-relevant maintenance tasks were completed faster or with fewer errors if redundant design pattern information was provided. The article provides the first controlled experiment results on design pattern usage and it presents a solution approach to an important class of experiment design problems for experiments regarding documentation     

A fortran program for the design of laminates with required mechanical properties

A FORTRAN 77 program for designing laminates with required mechanical properties is presented. This user-friendly program is developed for interactive use by users with either micro or mainframe computers to provide maximum flexibility and reduce the amount of inputting. The inputs required to the program are layer orthotropic unidirectional (UD) material properties and thickness and the desired laminate mechanical properties. The output is the optimum lamination that will provide these properties. This optimum is obtained by minimizing the difference between the calculated properties of trial laminates and the desired properties. The program allows such designed laminates to be unsymmetric in either geometry or material about the middle surface of a plate and consist of a specified number of different fibre-reinforced orthotropic layers. This program can either be used on its own for the purpose of designing laminated plates or be considered as a package-subroutine within a complex structural design package. As a demonstration of the use of the program, the design of a symmetric laminate is conducted to show how an optimal lay-up sequence can provide the required laminate mechanical properties determined by the design. A full listing of the program is given as an Appendix.     

CCS环境两次编程实现DSP串行EEPROM自举的方法

针对TI公司TMS320VC54系列DSP处理器独立运行需要程序自举引导的问题,介绍了一种利用CCS软件两次编程实现DSP通过SPI串行EEPROM完成程序代码自举的方法,给出了相应的硬件设计和软件编程思路,及以该方法实现DSP自举的实验.该方法硬件设计简单、成本低,而软件两次编程设计又方便DSP系统的在线编程调试和软件升级,可广泛用于程序代码不超过64K字节的DSP系统中.     

Advanced computer programs for drug dosing that combine pharmacokinetic and symbolic modeling of patients.

In this paper, we describe our design for advanced drug dosing programs that "reason" using a combination of Bayesian pharmacokinetic modeling and symbolic modeling of patient status and drug response. Our design is similar to the design of the Digitalis Therapy Advisor program, but extends this previous work by incorporating a Bayesian pharmacokinetic model, performing a "meta-level" analysis of drug concentrations to identify sampling errors and changes in pharmacokinetics, and including the results of this analysis in reasoning for dosing and therapeutic monitoring recommendations. The design has been implemented in a program for aminoglycoside antibiotics called Aminoglycoside Therapy Manager. The program is user-friendly and runs on low-cost general-purpose hardware. The initial validation study showed that the program was as accurate in predicting future drug concentrations as an expert using commercial Bayesian forecasting software and that its dosing recommendations were similar to those of an expert.     

用于农产品信息管理的RFID读写器设计

提出了一种适用于农产品信息管理的便携式RFID读写器设计方案。硬件设计主要包括控制模块、射频模块、供电管理模块和网络接口模块。软件设计主要包括射频通信程序、网络通信程序和主程序。给出了信息的处理方法。     

Design of flexible static program analyzers with PQL

Static program analyzers (SPA) are interactive tools that enhance program understanding during maintenance by answering queries about programs. Depending on the maintenance task in hand, SPAs must process different source programs and answer different types of program queries. Flexibility is, therefore, a desirable property of SPAs. The author describes a program query language, called PQL, that facilitates the design of flexible SPAs. PQL is a conceptual level, source language-independent notation to specify program queries and program views. In PQL, one can query global program design as well as search for detail code patterns. PQL queries are answered automatically by a query evaluation mechanism built into an SPA. Program design models and POL form the core of an SPA conceptual model. He based the SPA's architecture on this conceptual model. By separating the conceptual model from the implementation decisions, one can design SPAs that are customizable to the needs of the maintenance project at hand. Depending on criteria such as efficiency of query evaluation or simplicity of the SPA design, one can implement the same functional specifications of an SPA on a variety of program representations to meet the required criteria. Apart from its role in the design of SPAs, the conceptual model also allows one to rigorously study SPA functionality in the context of the underlying maintenance process and programmer behavior models, in isolation from tool implementation details     

TEC-XP16教学机浮点运算指令快速设计方法

为解决TEC-XP16教学机缺少浮点运算指令的问题,设计32 bit浮点加法、32 bit浮点减法、32 bit浮点乘法、32 bit浮点除法指令以及实现浮点运算的算法。为解决人工方式设计微程序和修改微程序控制器源程序效率低且容易出错等问题,提出一种能够由汇编语言程序自动生成微程序以及能够由微程序自动修改控制器ABEL语言源程序的方法。实验结果表明,所设计的32 bit浮点运算指令的功能是正确的,平均5 s之内就能根据汇编语言源程序自动生成微程序,平均2 s之内就能根据微程序等自动修改并生成控制器ABEL语言源程序。该方法也可推广到其他复杂指令的设计。     

PPCDS集成开发环境的设计与实现

PPCDS(并行程序概念设计系统)是一个将数据并行高层建模语言、并行识别方法、并行程序自动构造和人机交互界面技术集成在一起的并行程序设计环境,能简化并行程序设计,有效缩短并行程序开发周期,提高并行计算效率。PPCDS集成开发环境是PPCDS的重要组成部分,文中就PPCDS集成开发环境的设计和实现进行了简单介绍。     

AOP中方面冲突自动检测方法研究

为了解决面向方面编程中的方面冲突问题,在分析现有解决方法的基础上,提出了一种基于契约式设计的方面冲突自动检测方案。根据设计文档使用JML给方面和基础程序标注契约,利用契约转换程序生成契约检查程序,契约检查程序与面向方面的应用程序一起编译,生成包含契约检查的目标文件,从而在程序执行时,自动检测出方面与基础程序间的冲突以及方面与方面间冲突。该方案不破坏现有的应用程序,且无需重新设计编译器。通过一个实例表明该方案的可行性。     

Development and applications of an interactive digital filter design program

We have implemented an interactive digital filter design program in the HP 1000 computer at the Department of Electrical Engineering of the University of Washington. This program allows users to design different types of filters interactively with both amplitude and phase responses displayed on graphic devices. The performance of each designed filter can be evaluated conveniently before the best one is chosen and implemented for any particular application. This program can design recursive filters, e.g. Butterworth, Chebyshev and elliptic, or nonrecursive filters with one out of six different windows, i.e. rectangular, triangular, Hann, Hamming, Blackman and Kaiser. The main outputs from this program are coefficients of a transfer function of an analog filter, a digital filter, or both. Therefore, the design of both analog and digital filters is facilitated by using this program. The program is very simple to use and does not require background in analog or digital filter principles in order to run it. The program is written in standard FORTRAN and is about 30 kbytes in size excluding the graphics display routines. Since it uses standard FORTRAN, it can be easily transported to minicomputer and microcomputer systems that have a FORTRAN compiler and minimal graphics capabilities. This program is available for distribution to interested institutions and laboratories.     

CADSTEP: Computer-aided design of variable reluctance stepping motors

This paper describes a computer program package, called CADSTEP, for designing variable reluctance stepping motors. The performance specifications like stepping angle, stepping rate, output torque, number of phases, switching sequence, and saturation flux density, etc. form the inputs to the program. The program computes and prints out the dimensions of the motor from which manufacturing drawings may be prepared and the motor manufactured. The program is based on the step-by-step design procedure which in turn, has evolved from the general theory of variable reluctance stepping motors. This is the first time that such computer aided design program for VR stepping motors is being reported. The flow-chart for the program is given.     

KBE—Pascal:基于知识的程序编辑

KBE-Pascal是一种交互式的程序设计助手系统,其意图是程序员完成设计和实现的困难部分,由KBE-Pascal尽可能地帮助他。 KBE-Pascal的主要基础是格局,这是一种表示程序的方法,它抽去了程序的非基本特性,且明显地表示出算法的基本逻辑特性。 KBE-Pascal的设计目标是通过引用格局库中的断片,快速正确地构造程序。它的目标语言是Pascal。目前该系统由四部分组成:编码程序,用以产生对应于格局的程序正文;一个通用算法片断格局库;格局编辑程序,使得程序能通过修改格局而达到修改程序的目的;正文     

一个PASCAL自动驱动工具PADT的设计

程序自动驱动工具是一个重要的软件测试辅助工具，它能够有铲地辅助软件测试人员测试程序，从而提高软件测试效率。本文讨论了我们设计的一个PASCAL程序自动驱动工具PADT，PADT能够使自底向上渐增式的软件测试过程自动化－－辅助用户选择一个可测模块，并为该模块生成 一个测试程序TEST，通过运行TEST来达到测试该模块的目的。本文详细讨论了PADT的设计思想和实现方法。