人工智能中逻辑推论的探讨

本文从具体事例出发，解析了用直观推论、根据命题逻辑进行推论和谓词逻辑方法求解问题的思路和方法，在结束语中还提出了用于进行更接近人类推论逻辑的非单调逻辑，这是在设计高级知识信息处理系统时，需要加以研究的一个重要课题。     

命题逻辑的子句集中文字的分类

检测和消除命题逻辑公式中的冗余文字,是人工智能领域广泛研究的基本问题。针对命题逻辑的子句集中子句的划分,结合冗余子句和冗余文字的概念,将命题逻辑的子句集中的文字分为必需文字、有用文字和无用文字3类,并分别给出其定义。讨论3种文字与无冗余等价子集的性质,给出其等价子集的等价描述方法。得到题逻辑的子句集中必需文字、有用文字和无用文字的判定方法,借助子句集的可满足性得到3种文字与子句集的可满足性的等价条件。上述结果对命题逻辑中文字属性的判断提供了多种可选择方法,同时为命题逻辑公式的化简奠定了理论基础。     

基于CCS的软件规范描述及实例研究

软件规范描述方法主要是软件工程化的UML方法与形式化方法二类方法。论文主要给出了基于CCS的软件规范描述,首先根据系统需求画出进程派生树和迁移图,再根据操作语义和系统约束条件得到进程表达式,并用Java语言实现了系统原型代码。笔者的工作证明了CCS具有细节化地描述系统内部状态,便于系统软件实现的能力;在手工转换进程迁移图到进程表达式的基础上,提出了自动转换的进一步研究思路。     

多处理机信息处理系统设计

基于TMS320C80组成的一个多处理机信息处理系统,介绍了支持系统并行处理的硬件和软件设计,并提出了软硬件设计中的优化方法,最后,给出了一个描述多处理机信息处理系统工作过程的实例。     

基于SysML的无人侦察机需求描述方法研究

在装备论证与开发中,装备用户和研制设计人员间的需求描述往往难以沟通,造成研制工作的推迟和较大偏差.针对这种用户与研制方的需求交流障碍,借鉴SysML需求图建立武器装备需求描述的方法与步骤.主要分析了需求基本模型、需求导出模型、需求满足模型和需求验证模型等四类需求子模型.以无人侦察机需求为例,给出了基于SysML需求图对无人机顶层需求及其与设计参数之间的关系进行描述的方法.需求建模的结果表明,利用SysML需求图能够准确地对无人侦察机的需求进行描述,并且易于理解和操作.     

软件可靠性评估中 UML 应用

在开放环境下,软件规模日趋扩大,结构更加多元化,传统的基于状态的软件可靠性评估方法,状态空间膨胀增加了计算复杂度,而且不能对多种典型的系统结构进行很好的描述。为此,对传统的方法进行了改进,用UML的用例图分解系统,序列图描述子系统,并都作为软件可靠性分析的输入,通过自底向上的方法评估软件的可靠性,符合当前大规模复杂结构的软件系统可靠性评估。     

从时序图描述推导目标描述的方法研究

面向场景的需求建模方法自面世以来,在需求分析过程中被越来越广泛的使用.但是面向场景的需求分析方法在保证需求的一致性和完整性上存在着很大的困难.面向目标的需求分析方法,以目标需求为研究内容,目前已经成功的解决了需求完整性和一致性的判定问题.本文希望将场景描述转化为目标描述,然后通过保证目标的完整性和一致性来保证场景描述的完整性和一致性.因此,本文从场景的时序图描述出发,通过时序图的语义描述提出了一种时序图向操作目标集合的推导方法,并提供了判定推导等价的判定定理.     

基于Windows95平台的脑血流图信息处理系统的研制

本文介绍了已实现的脑血流图信息处理系统的主要组成、功能及在Ｗｉｎｄｏｗｓ９５平台上实现的方法。     

命题逻辑公式中的冗余子句及冗余文字

主要研究命题逻辑公式中的冗余子句和冗余文字。针对子句集中必需的、有用的、无用的子句,分别给出了一些等价描述方法,进而讨论子句集的无冗余等价子集。另外,得到了子句集中冗余文字的判别方法,借助可满足性给出了冗余子句的一种等价条件。上述结果为命题逻辑公式的化简奠定了一些理论基础。     

高校考试管理信息系统的设计和实现①

开发一个高校考试管理系统,包括考试、补考和重修。以UML建模驱动系统的开发过程,即使用用例图描述系统的需求,使用类图描述系统的静态结构,使用状态图描述系统的状态变化。使用C#和ASP.NET编程,系统运行在微软.NET框架上。     

并发系统中谓词行为图的行为时序逻辑表达

行为时序逻辑(TLA)组合时序逻辑与行为逻辑, 可以对并发系统进行描述与验证, 它引入动作和行为的概念, 使得系统和属性可用它的规约公式表示, 但存在用TLA描述复杂系统时TLA公式复杂且难以理解的不足。类似于状态转移图, 对于并发转移可以用谓词行为图进行图形化表示, 谓词行为图与行为时序逻辑规约具有相同的表达能力。介绍行为时序逻辑的语法、语义及简单推理规则, 用一个简单的实例说明使用谓词行为图去描述并发转移系统的有效性, 并用系统规约的TLA公式对谓词行为图表达能力进行证明, 表明两者具有等价性, 为描述和分析并发转换系统提供了一种可行的方法。     

Formal methods integration for the specification of dependable distributed systems

This paper describes a real-world case study in the specification and analysis of dependable distributed systems. The case study is an automated transport system with safety requirements. In order to manage the complexity of the problem of specifying the dynamic behavior of the whole system, a compositional approach is used, based on the integration of the trace logic of the Communicating Sequential Processes (CSP) theory, and stochastic Petri nets (SPNs). It is argued that the integration of different formal methods is a useful approach in the definition of practical engineering methodologies for the specification, design and analysis of complex dependable distributed systems.     

Falsification of combined invariance and reachability specifications in hybrid control systems

We propose an abstraction-based method that can be applied to falsify a class of computation tree logic (CTL) specifications that combine invariance and reachability requirements in terms of the discrete state of a hybrid control system. The fragment of CTL that we address is not expressible in ACTL^? (which includes LTL). The method involves applying supervisory control to a finite abstraction of the hybrid system to falsify the specification. For the class of systems that we consider, falsification of the specification implies a flaw in the design of the control and automation logic.     

Product design logic for an intelligent product modelling system

Recent research in CAD systems has been conducted to realize intelligent processing. Several CAD systems and product modelling systems have been developed using AI techniques. However, in order to develop more intelligent CAD systems, the design logic which connects the functional requirement to the geometric and the technological information of the designed product must be evaluated.

A product model used in such intelligent CAD systems has to include not only the geometric and the technological information of the product but also the designer's thought process which explains the design logic.

Design logic is generally divided into two parts. One is the generalized design logic which is commonly used in the conceptual design of mechanical products. The other is the product specified design logic which is used in the fundamental and detailed design phase. Different logic is applied to each product. This type of design logic is often used in modification design and compilation design, where the dimensions of parts have to be modified according to different functional requirements. When the dimensions and accuracies of the products are defined in connection with the functional requirements through design logic, the CAD system can automatically make decisions according to the given requirements. In this paper, suitable presentation formats and processing functions for these two types of design logic are discussed.

The importance of design logic in product modelling is proven through several case studies in this paper. As a conclusion, the intelligent product modelling system is developed, which should expedite the progress of design automation in the near future. In conceptual design, the design logic is processed in the modelling system and the product structure, with the technological information decided automatically from the functional requirement. Automation in the detailed design phase is also facilitated by the modelling system using the product specified design logic in the product model.     

一种基于多值逻辑的开放式逻辑软件设计方法

在工业控制系统中，将对逻辑测控过程的表述抽象成象值逻辑是一种准确而又便利的方法，同时，测控过程的多样性又使传统的利用程序设计语言中逻辑语句的软件设计方法很难适应对开放性的要求，本文提出一种适合多值逻辑处理的数据结构和代数系统，并以此为基础，构造逻辑描述式，实现组合多值逻辑和时序多值逻辑的开放式设计。     

系统动态行为语义模型及其形式描述

文中综述刻画系统动态行为的计算模型和形式化方法,包括算法模型,逻辑模型,基于进程代数的模型和方法,Ｉ／Ｏ自动化,Ｐｅｔｒｉ网及Ａｃｔｏｒ模型,并有针对性地本质上分析和比较它们在描述系统动态行为方面的特点和优劣。文事还着重剖析了基于网络环境下的分布对象计算系统的一些主要计算特征,包括交互,并发和分布等。     

面向媒体时序描述的带时间自动机的自动构造方法

依据有穷状态自动机模型,面向程序规范的并发系统和分布式系统测试方法的研究已经取得许多结果。由于特殊的实时和同步要求,这些结果不能直接应用于分布式多媒体软件系统的测试。为此,作者提出一种面向媒体对象时序描述的地间自动机（Ｔｉｍｅｄ ａｕｔｏｍａｔａ）的自动构造方法,根据带时间自动机,对分布式多媒体软件系统进行非确定性测试时,可以较容易地判断运行结果正确与否;在进行确定性测试时,可以辅助自动生成测试用     

RELAX: a language to address uncertainty in self-adaptive systems requirement

Self-adaptive systems have the capability to autonomously modify their behavior at run-time in response to changes in their environment. Self-adaptation is particularly necessary for applications that must run continuously, even under adverse conditions and changing requirements; sample domains include automotive systems, telecommunications, and environmental monitoring systems. While a few techniques have been developed to support the monitoring and analysis of requirements for adaptive systems, limited attention has been paid to the actual creation and specification of requirements of self-adaptive systems. As a result, self-adaptivity is often constructed in an ad-hoc manner. In order to support the rigorous specification of adaptive systems requirements, this paper introduces RELAX, a new requirements language for self-adaptive systems that explicitly addresses uncertainty inherent in adaptive systems. We present the formal semantics for RELAX in terms of fuzzy logic, thus enabling a rigorous treatment of requirements that include uncertainty. RELAX enables developers to identify uncertainty in the requirements, thereby facilitating the design of systems that are, by definition, more flexible and amenable to adaptation in a systematic fashion. We illustrate the use of RELAX on smart home applications, including an adaptive assisted living system.