Diagram Chase in Relational System Development

We propose diagrammatic techniques for visualizing relational reasoning in formal methods like B or Z; in particular for induction and coinduction. These are similar to those for functional diagrams in category theory and inspired by rewriting theory. Diagrams are endowed with a simple algebraic semantics that imposes a convenient balance between expressive and algorithmic power. This makes the approach particularly suitable for mechanization and automation. Its usefulness for visual reasoning is illustrated by various examples.     

A logic-based model of intention formation and action for multi-agent subcontracting

We present a formalism for representing the formation of intentions by agents engaged in cooperative activity. We use a syntactic approach presenting a formal logical calculus that can be regarded as a meta-logic that describes the reasoning and activities of the agents. Our central focus is on the evolving intentions of agents over time, and the conditions under which an agent can adopt and maintain an intention. In particular, the reasoning time and the time taken to subcontract are modeled explicitly in the logic. We axiomatize the concept of agent interactions in the meta-language, show that the meta-theory is consistent and describe the unique intended model of the meta-theory. In this context we deal both with subcontracting between agents and the presence of multiple recipes, that is, multiple ways of accomplishing tasks. We show that under various initial conditions and known facts about agent beliefs and abilities, the meta-theory representation yields good results.     

Unity和Gamma之间的程序变换：一个实例研究

Ｇａｍｍａ，Ｕｎｉｔｙ都是面向问题描述的编程模型。文中我们提出了一种从Ｕｎｉｔｙ到Ｇａｍｍａ的语义等价的程序变换方法，进而我们证明，Ｇａｍｍａ比相应的Ｕｎｉｔｙ有更强的表达能力。同时，也提出了逆转换方法，把这些方法运用到排序问题中的实验结果表明，用转换机制以及把Ｕｎｉｔｙ作为Ｇａｍｍａ的实现层来编写有效的程序是一种可行的方法。     

Senses and Texts

This paper addresses the question of whether it is possible tosense-tag systematically, and on a large scale, and how we shouldassess progress so far. That is to say, how to attach each occurrenceof a word in a text to one and only one sense in a dictionary – aparticular dictionary of course, and that is part of the problem. Thepaper does not propose a solution to the question, though we havereported empirical findings elsewhere (Cowie et al., 1992;Wilks et al., 1996; Wilks and Stevenson, 1997), and intend to continue andrefine that work. The point of this paper is to examine two well-knowncontributions critically: The first (Kilgarriff, 1993), which is widelytaken to show that the task, as defined, cannot be carried outsystematically by humans and, secondly (Yarowsky, 1995), which claimsstrikingly good results at doing exactly that.     

对象组装及其关联语义的自动维持

讨论了对象组装概念及其对象关联语义的自动维持问题.在给出对象组装的模型之后,还对其语言描述、实现机制进行了阐述.它是基于专门用于组装的对象挂接,而不是常规对象接口.由此实现了面向问题域的对象间关联的动态建立和关联语义的自动维持,从而增加了对象建模的描述能力和使用的灵活性,降低了对象接口的实现和使用的复杂度.作为对象描述和对象作用的机制,它为软件IC的实现提出了新思想,其应用、规范和标准化将为软件设计的工业化生产提供新的设计技术.     

A semantics of sequence diagrams

We develop a formal semantics of sequence diagrams. The semantics is given in terms of our new temporal logic, named HDTL, which is designed to specify dynamically evolving systems. This approach allows to facilitate the generic feature of sequence diagrams as well as an automatic analysis, the identification of the instances of a sequence diagram over a trace.     

Agent Cooperation Based Control Integration by Activity-Sharing and Joint Intention

In this paper,a control integration method based on agent cooperation,called ASOJI,is proposed,which designs the architecture of integrated application systems in distributed computation environments as an agent community composed of nested agent fed-erations in three aspects:architecture style,agent cooperation,and composition semantics.Through defining activity-sharing-orented joint intention in the way of stepwise refinement,ASOJI can not only support the transparent specification of the architecture for software com-position,but also eliminate the gap between agent theory and the engineering realiztion of control integration.     

Internet Network Resource Information Model

The foundation of any network management systems is a database that contains information about the network resources relevant to the management tasks.A network information model is an abstraction of network resources,including both managed resources and managing resources,In the SNMP-based management framework,management information is defined almost exclusively from a “Device“ viewpoint,namely managing a network is equivalent to managing a collection of individual nodes.Aiming at making use of recent advances in distributed computing and in object-oriented analysis and design,the Internet management architecture can also be based on the Open Distributed Processing Reference Model(RM-ODP).The purpose of this article is to provide an Internet Network Resource Information Model.First,a layered management information architecture will be discussed.Then the Internet Network resource information model is presented.The information model is specified using object-Z.     

论动态数据结构的程序语义

在程序设计语言中，由于语言成份的语义描述不够完整，容易造成动态数据结构的使用混乱与错误，这些问题在编译程序中无法发现，并且在程序执行过程中也很难排除。本文针对这种情况，研究了如何正确刻划动态数据结构的程序语义问题。