A Formal Semantics for DAI Language NUML

1IntroductionAsE.H.Durfeestatesin[1]:Artificia1Inte1ligence(AI)hasemphasizedbuilding"stand-alonesystems"thatcansolveproblemswithminimalhelpfromothersystems(computerorman).Thesesystemshavetraditionallybeenbrittle,inthesensethattheyfailmiser-ablywhenpresentedwithproblemsevens1ightlyoutsideoftheir1imitedrangeofexpertise...Amorepowerful,extensiblestrategyforovercomingtheinherentboundsofintelligencepresentinanyfilliteAI(ornaturaI)systemistoputsysteminasocietyofsystems,sothatitcandrawonadiversec…     

基于任务的群体感知模型的形式化描述

群体感知理论和实现技术是计算机支持的协同工作中必不可少的组成部分。文章分析研究了群体感知理论研究工作的现状,介绍了一种基于任务的群体感知模型TAM。该模型通过对收集来的感知信息按基本要素“任务”进行分解、处理(加权)、再组合,精确描述群组任务的每个变化,并且获得相应的感知强度,有效地解决了现有的群体感知模型存在的不足。该文给出了该模型的建模思想和总体结构,并从该模型的基本概念、任务收集、任务分解、感知强度、任务整合等方面给出了该模型的形式化描述。文章最后讨论了在下一步研究中仍需解决的一些问题。     

TGM模型的RTL形式化描述

TGM模型是实时仿真参考模型的重要组成模型。它可以描述、构造实时系统行为。本文选取基于事件的RTL语言,形式化定义了TGM模型和其表现形式,如：断开子图、任务断开子图、非断开子图和沸合子图等。文章通过例子阐述了TGM模型描述能力。     

A Formal Semantics for the SmartFrog Configuration Language

System configuration languages are now widely used to drive the deployment and evolution of large computing infrastructures. Most such languages are highly informal, making it difficult to reason about configurations, and introducing an important source of failure. We claim that a more rigorous approach to the development and specification of these languages will help to avoid these difficulties and bring a number of additional benefits. In order to test this claim, we present a formal semantics for the core of the SmartFrog configuration language. We demonstrate how this can be used to prove important properties such as termination of the compilation process. To show that this also contributes to the practical development of clear and correct compilers, we present three independent implementations, and verify their equivalence with each other, and with the semantics. Supported by an extended example from a real configuration scenario, we demonstrate how the process of developing the semantics has improved understanding of the language, highlighted problem areas, and suggested alternative interpretations. This leads us to advocate this approach for the future development of practical configuration languages.     

一种可视查询语言OSVQL的设计与实现

该文基于对象结构提出了一种可视查询语言ＯＳＶＱＬ,给出了其若干定义,讨论了ＯＳＶＱＬ的设计思想与实现方法。     

平面设计中视觉语言的表现

文章阐述了视觉语言在平面设计中的重要地位。通过对平面设计三要素的分析,从文字、色彩、图形三个方面对视觉语言在平面设计中的表现形式进行论述。结合一些设计作品,介绍如何在实际平面设计中应用视觉语言。     

平面设计中的视觉语言

平面设计创作宗旨是向人们展示图画对人们生活的重要效用,因此在创作活动过程中不仅体现着对视觉语言的理解,同时也要对视觉语言进行升华,从而向人们快速有效地传播图画的主题思想。而视觉语言的使用是否确切、是否得当,很大程度上决定了设计信息是否能够得到准确而有效地传播。     

演绎型面向对象数据库管理系统形式模型研究

本文提出了一种研制演绎型面向对象数据库管理系统(DOODBMS)的理论基础,具体讨论了DOODBMS 的形式化描述、操作以及知识引入等问题,使得一方面,实现一般面向对象数据库管理系统(OODBMS)的功能,另一方面,又可获得OODBMS 的推理智能     

A Graph-Rewriting Visual Language for Database Programming

Textual database programming languages are computationally complete, but have the disadvantage of giving the user a non-intuitive view of the database information that is being manipulated. The visual languages developed in recent years have allowed naive users access to a direct representation of data, often in a graph form, but have concentrated on user interface rather than complex programming tasks. There is a need for a system which combines the advantages of both these programming methods.We describe an implementation of Spider, an experimental visual database programming language aimed at programmers. It uses a graph-rewriting paradigm as a basis for a fully visual, computationally complete language. The graphs it rewrites represent the schema and instances of a database.The unique graph-rewriting method used by Spider has syntactic and semantic simplicity. Its form of algorithmic expression allows complex computation to be easily represented in short programs. Furthermore, Spider has greater power than normally provided in textual systems, and we show that queries on the schema and associative queries can be performed easily and without requiring any additions to the language.     

建筑构件参数化建模语言PCML的设计和应用

针对三维建筑构件建模和应用的特点,提出一种用于描述建筑构件三维模型的方法--建筑构件参数化建模语言PCML.分析了PCML的设计目标,详细介绍了其语法构成与解释执行,并对构件各方面信息的描述方法做出说明.最后结合楼梯建筑构件类型,介绍其在三维设计软件EasyStructure中的具体应用.     

一个支持规约获取的形式规约语言

该文介绍了形式规约语言LFC设计的一些主要方面,并通过例子说明了LFC的一些特色。形式规约语言LFC是为支持软件形式规约的获取工作而开发的。该语言以一种新的递归函数,即定义在上下文无关语言上的递归函数为基础,以上下文无关语言为数据类型,在语言级支持规约获取。LFC语言已被用作形式规约获取系统SAQ的一部分。使用表明,LFC是一个能力强、易使用的语言,适合软件形式规约获取之用,并且适合其它一些用途。     

ConSpec – A Formal Language for Policy Specification

The paper presents ConSpec, an automata based policy specification language. The language trades off clean semantics to language expressiveness; a formal semantics for the language is provided as security automata. ConSpec specifications can be used at different stages of the application lifecycle, rendering possible the formalization of various policy enforcement techniques.     

A Formal Composition and Interaction Model for a Web Component Platform

A framework for components on the Web needs a formal model that captures essential concepts such as contractual information and service matching. We propose a typed π-calculus-based model for Web components that formalises an extension of the currently discussed Web Services framework. We address in particular activities in the stages of a component life cycle – such as matching, commitment, connection and interaction – that are part of the process that a component is involved in.     

A Formal Model for Experience–Aided Diagnosis

This paper presents a novel approach to model–based diagnosis. The approach addresses the two main problems that have prevented model–based diagnostic techniques from being widely used: computational complexity of abduction and inadequacies of device models. A model for automated diagnosis is defined that combines (1) deduction to rule out hypotheses, (2) abduction to generate hypotheses, and (3) induction to recall past experiences and account for potential errors in the device models. A review of the three forms of inference is provided, as well as a detailed analysis of the relationship between case–based reasoning and induction. The proposed model for diagnosis is used to characterize diagnostic errors and relate them to different types of errors in the device models. Experimental results are then described and used to assert the practicality and the usefulness of the approach. The model presented in this paper yields a practical method for solving hard diagnostic problems at a reasonable computational cost and provides a theoretical basis for overcoming the problem of partially incorrect device models.     

PML: Toward a High-Level Formal Language for Biological Systems

Documentation of knowledge about biological pathways is often informal and vague, making it difficult to efficiently synthesize the work of others into a holistic understanding of a system. Several researchers have proposed solving this problem by modeling pathways using formal languages, which have a precise and consistent semantics. While precise, many of these languages may be too low-level to model feasibly complex pathways. We have developed the Pathway Modeling Language (PML), a high-level language for modeling pathways. PML is based on a biological metaphor of molecules with binding sites and has special constructs for handling compartment changes in pathways. Our preliminary work has shown that PML's language constructs serve as a promising basis for modeling complex pathways in a readable and composable manner.     

Towards a Formal Basis for the Formal Development Method and the Ina Jo Specification Language

In carrying out SDC's Formal Development Method, one writes a specification of a system under design in the Ina Jo™ specification language and proves that the specification meets the requirements of the system. This paper develops an abstract machine model of what is specified by a level specification in an Ina Jo specification. It describes the state as defined by the front matter, computations as defined by initial states and transforms, and invariants, criteria, and constraints as properties of computations. The paper then describes a number of formal design methods and the kinds of abstractions that they require. For each of these kinds of abstractions, there is a characteristic relationship between refinements that should be proved as one is carrying out the method.     

用于描述网络拓扑的形式语言的研究

论述了应用随机线性文法及产生式描述计算机网络拓扑结构的方法.在该形式语言的描述中,设置了3个基元状态,通过对基元状态及各种状态规律的分析,准确地描述了网络中结点间通信及共享存储器的状态.同时,证明了用此方法在某种条件下从初始结点到终了结点间可以建立惟一的访问路径,并能避免冲突.此方法对计算机网络结点访问/冲突避免的研究具有一定的参考价值.