LOTOS渐进细化设计方法在互斥访问系统中的应用

在复杂系统的设计流程中，每个设计阶段都要制定标准的设并方案以实现系统功能。渐进细化设计就是把设计流程中的设计方案和检验其能否实现一个特定功能分离开来。提出了渐进细化的概念，并将其应用于互斥访问系统中，同时用LOTOS规范进行描述。     

Bundle event structures: A revised cpo approach

Bundle event structures equipped with a partial order ? have been used to give a true concurrency denotational semantics for LOTOS. This model has also been extended by time and stochastic information. Unfortunately it fails to yield a complete partial order (cpo) as we illustrate by an example.We propose a subset of all bundle event structures such that it forms a cpo. This subset is closed under the usual operators on bundle event structures. And as a consequence these operators are continuous. Therefore, this subset can be used to give a denotational semantics of LOTOS.     

A tool supporting efficient model checking of concurrent specifications

We show a tool supporting efficient model checking of LOTOS programs. LOTOS is a well-known specification language for concurrent and distributed systems. The main functionality of the tool is the syntactic reduction of a program with respect to a logic formula expressing a property to be checked. The method is useful to reduce the state-explosion problem in model checking. The tool is integrated with the Concurrency Workbench of North Carolina. The tool also supports a windows user interface.     

Using Reason’s Model of Organisational Accidents in Formalising Accident Reports

This paper proposes a method for analysing what are called organisational accidents. The first step of the method involves using Reason’s model of organisational failures. This provides heuristic guidance in identifying both the active and latent conditions that lead to major failures. The second step involves applying formal methods to support a detailed analysis of each latent and active condition. The method is demonstrated on a case study: the railway accident at Watford Junction in the United Kingdom. Analysis of the formal model helps to identify organisational factors that might have prevented the accident. It also helps to identify weaknesses in the report itself. In particular we argue that a signalling standard was misunderstood, the consequences of which could lead to another serious accident.     

交互式用户界面的形式化描述与性质验证

随着人机交互技术的发展,计算机和用户之间的接口越来越自然,但用户界面管理系统内部的复杂度却大大地增加了.目前提出的新一代用户界面的模型大都停留在概念模型阶段,缺乏对模型的严格描述和证明.该文结合对基于自然交互方式的用户界面的研究成果,归纳出了一个交互式用户界面的通用模型.为了保证系统设计的正确性,文章讨论了如何使用形式化描述语言LOTOS(language of temporal ordering specification)和基于动作的时序逻辑ACTL(action based temporal log     

Comments on deriving protocol specifications from service specifications written in LOTOS

Summary. An algorithm by Kant, Higashino and Bochmann for service-based protocol synthesis in the standard specification language LOTOS is discussed. It is demonstrated that the transformations for distributed implementation of synchronised parallel execution and of disabling are not correct in a general case. Received: January 1998 / Accepted: January 1999     

测试目的引导的模型检测方法与技术研究

为了实现对伪代码的模型检测并且能够缓解模型检测中的状态空间爆炸问题,提出了测试目的引导的模型检测方法。该方法的基本思想是首先对伪代码进行模块划分并对每个模块进行建模,获取基本路径的集合并以流图的方式进行存储。然后利用自主开发的转换工具实现流图到国际标准语言LOTOS的转换。其次利用自主开发的辅助工具μ-演算编辑器对测试目的进行描述。最后使用模型检测工具验证被测程序是否满足测试目的。实验结果表明,测试目的引导的模型检测方法能够实现对伪代码的模型检测并且可以缓解状态空间爆炸问题。