需求分析的 Z 语言形式化方法

非形式化的需求规格说明容易产生歧义,导致所开发的软件系统不能满足用户的功能要求.Z语言是一种基于集合和一阶谓词逻辑的模式规约语言,可用于产生精确的需求规格说明.介绍了需求分析的Z语言形式化方法,并给出了一个通用堆栈的Z语言描述实例,同时指出这种形式化方法有待进一步研究的地方.     

微机仿真系统中形式化方法的应用

Z语言是一种广泛应用的形式化语言，适合于仿真实时软件系统的需求规格说明．通过微机系统仿真软件的Z规格说明，讨论了Z语言在实时系统开发中使用的一些方法、对典型问题的处理原则以及操作同时序关系的描述．     

Object-Z规格说明的结构模拟动画技术

形式化方法让软件需求的规格说明变得更加简洁精确,但是它的抽象难懂让用户难以确定形式规格说明中所叙述的用户需求就是他们所期望的.另外,大多的规格说明语言都是不可执行的,因此人们采用一种动画模拟的方式,将形式规格说明转换成一种可模拟执行的形式,从而帮助用户和规格说明者确认形式规格说明是否与用户的非形式化需求相一致.通过分析比较形式规格说明的两种动画策略———形式化程序合成和结构模拟的优缺点,决定使用结构模拟技术将Object-Z规格说明转换成SICStus Prolog可执行程序并加以执行,从而实现对Object-Z规格说明的确认.     

基于ＯＯＺＳ的ＵＭＬ类图形式化描述及其应用

统一建模语言UML是一种面向对象分析和设计过程中重要的建模工具。但由于UML缺乏精确的形式化语义,不利于对其所描述的需求进行进一步分析和验证。这一点上,形式化方法可与之互补。基于此,本文采用一种面向对象的、基于Z的扩展语言OOZS———结构化面向对象形式规格说明语言,对UML的类图进行了形式化描述,寻求一种在软件设计与系统建模过程中UML到OOZS的映射与转换机制,最后给出一个基于OOZS的UML类图的形式化描述实例,结果表明本文的研究工作在实践中是可行的。     

TCP协议的Z语言描述

计算机通信协议的开发难度随着复杂程度的增加而日益增大，潜在错误也越来越多，其中对协议规格说明理解的偏差是重要原因之一．因此需要对规格说明进行验证和确认，并对协议的实现进行一致性测试．一致性测试就是测试协议的实现是否与相关国际标准中的规格说明相一致．协议的规格说明主要是以自然语言描述的，对其进行形式化是为了精确描述协议，因而可减少这类错误的出现．Z语言是基于一阶谓词逻辑和集合论的形式规格说明语言，采用了严格的数学理论，可产生简明、精确、无歧义且可证明的规格说明．本文以TCP协议为例详细介绍了如何使用Z语言对协议进行形式化，为协议一致性测试打下基础．     

基于逻辑系统的用户需求功能规格说明语言及其应用

在基于谓词逻辑对知识的表示的基础上，用Unity逻辑系统对其加以扩充，形成一个小型的用户需求功能规格说明语言（Small problem Specification Language），用这种形式化的语言对电梯控制系统作出形式化的用户需求功能规格说明。     

Microsoft组件对象模型的形式化描述

基于组件的软件开发(CBD)是一种较为理想的软件开发方法,它根据组件标准,将独立开发的软件组件组合成应用.组件对象模型(COM)是目前最为流行的实现级组件软件协议,它是Microsoft关于如何建立组件和如何根据组件构造应用的一个规范,1995年公布的COM规格说明详细地定义了建立和使用COM组件应遵循的规则.然而该规格说明是非形式化的,这使得它缺乏逻辑的严密性,容易引起歧义.本文根据COM规格说明定义的规则,为其建立一个形式化的组件模型,模型反映了COM组件的本质,但省略了一些具体细节. 模型采用规格说明语言Z进行描述.     

代数规格说明语言ASL及到PROLOG的转换

本文讨论了代数规范说明技术及其到逻辑程序设计语言ＰＲＯＬＯＧ的转换。首先给出了一种基于抽象数据类型的代数规格说明语言ＡＳＬ：然后介绍了由ＡＳＬ描述的规格说明到ＰＲＯＬＯＧ转换　的形式化方法；在这种方法的基础上设计了一个自动转换系统，该系统接受ＡＳＬ语言描述的规格说明，通过转换规则，逐步将此规格说明转换成可执行的ＰＲＯＬＯＧ语言程序。     

多视点实时形式化方法的应用模式

RT-Z结合了Z的状态描述能力和Timed CSP对并发实时进程的描述能力,成为一种有效的实时并发软件的开发手段。RT-Z不但是一种规格说明语言,也可以用于建模．多视点的软件开发方法的研究从不同的视点观察系统,分离各自的关注点。简化了系统的设计．本文在形式化方法RT-Z的基础上扩充语法框架,以支持多视点工程的思想,充分利用形式化方法的精化推理机制,同时具有对实时约束的描述能力,可作为并发实时系统开发中的基本模式．     

关于功能规格说明的几个问题

本文从软件开发的瀑布式模型出发讨论了软件系统的功能规格说明的形式化问题,原型技术问题和功能规格说明语言应具有的特点,并给出若干实列.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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