Formal specification of concurrent systems

This paper presents a formal methodology for developing concurrent systems. We extend the Larch family of specification languages and tools with the CCS process algebra to support the specification and verification of concurrent systems. We present and follow a refinement strategy that relates an implementation in a programming language to a formal specification of such a system. We illustrate our methodology on an example that uses the preconditioned conjugate gradient method for solving a linear system of equations.     

Formal specification of non-functional properties of component-based software systems

Component-based software engineering (CBSE) is viewed as an opportunity to deal with the increasing complexity of modern-day software. Along with CBSE comes the notion of component markets, where more or less generic pieces of software are traded, to be combined into applications by third-party application developers. For such a component market to work successfully, all relevant properties of components must be precisely and formally described. This is especially true for non-functional properties, such as performance, memory foot print, or security. While the specification of functional properties is well understood, non-functional properties are only beginning to become a research focus. This paper discusses semantic concepts for the specification of non-functional properties, taking into account the specific needs of a component market. Based on these semantic concepts, we present a new specification language QML/CS that can be used to model non-functional product properties of components and component-based software systems.     

Formal interaction specification in public health surveillance systems using pi-calculus

This paper provides formal specification of interactions in typical public health surveillance systems involving healthcare agencies at local, state and federal levels. Although few standards exist for exchange of healthcare information, there is a general lack of formal models of the protocols involved in the interactions between the agencies. The quality of medical care provided is an end result of a well designed choreography of diverse services provided by different healthcare entities. One of the major challenges in this field appears to be explicit formal specification of such interactions. Such formal specification work is the first step leading to both design and verification of important properties of public healthcare systems. pi-calculus is a formal modeling technique for precise specification of semantics in interacting concurrent systems where mobility is involved. Two different configurations of public health surveillance systems are modelled using pi-calculus in this paper.     

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.     

Formal verification of multi-agent systems behaviour emerging from cognitive task analysis

The main goal of this paper is to present a novel formal approach to the verification of cognitive task analysis (CTA), an analytic tool that has been successfully used in the design of reactive behaviours, on multi-agent architectures. To achieve this, a formal logical system is developed, whose purpose is to formally check the possible success or failure of the resulting implementation. This logic's focus is on modelling an agent's behaviour based on her goals, perceptions and actions. The article starts by giving a brief introduction to current research in reactive systems and cognitive task analysis. Simple definitions are offered of the basic concepts in these fields: agent, object, reactive behaviour, control, etc. As illustration, the paper offers the results of applying CTA to a simple model of postal delivery. Then, the syntax and semantics of the proposed logic are defined. Finally, the logic is applied to the verification of some of the behaviours resulting of the previous CTA analysis.     

Formal methods for analysis of discrete systems using a specification language

A realization of an algorithm that translates an MSC diagram (an MSC document) into an event equivalent Petri net is described, and the correctness of the algorithm is proved. The net obtained in this way can be used to analyze properties of the original MSC document. The mentioned algorithm is a part of a system designed for verification and analysis of MSC documents. Translated from Kibernetika i Sistemnyi Analiz, No. 4, pp. 31–56, July–August 2009.     

Formal specification of hierarchical reports

The lattice of functional dependencies is constructed and studied. The role of functional dependencies in the specification of nondegenerate hierarchical reports is demonstrated. Formal tools for specification of hierarchical relations are introduced and analyzed.Translated from Kibernetika, No. 6, pp. 99–104, November–December, 1989.     

An event-driven high level model for the specification of laws in open multi-agent systems

The agent development paradigm poses many challenges to software engineering researchers, particularly when the systems are distributed and open. They have little or no control over the actions that agents can perform. Laws are restrictions imposed by a control mechanism to deal with uncertainty and to promote open system dependability. In this paper, we present a high level event-driven conceptual model of laws. XMLaw is an alternative approach to specifying laws in open multi-agent systems that presents high level abstractions and a flexible underlying event-based model. Thus XMLaw allows for flexible composition of the elements from its conceptual model and is flexible enough to accept new elements.     

工作流建模语言XPDL到CSP进程的转化研究

针对工作流定义标准语言XPDL缺乏形式化语义,提出了将XPDL描述转化为通信顺序进程(CSP)的方法,从而可以利用进程代数CSP理论以加强对工作流模型的语义描述分析检测。通过实例分析具体说明转化方法的有效性。     

Formal specification – an analytic tool for (management) information systems

Abstract. There appears to be a general consensus within the information systems literature that formal specification of software systems is an inappropriate response to the perceived general failure of information systems to meet user requirements. Such views would seem to be based primarily on the difficulty of constructing formal specifications – and on the difficulty of understanding such specifications once constructed. Research into the applicability of formal methods has therefore tended to concentrate on the needs and the context of software developers specializing in critical and extremely complex software such as operating systems, transaction processing monitors, or nuclear reactor protection. More recently, however, formal methods have been applied successfully in more conventional and commercial areas, such as the development of a CASE tool, indicating that many of the perceived disadvantages of formal methods are merely myths.
This paper discusses the differing research directions of the information systems and software engineering disciplines and suggests that significant beneflts may result from a synthesis of the two approaches. We further suggest that there is a serious danger that approaches which have been shown to have value in one of the two domains are automatically being ignored in the other as being 'irrelevant'. While each of the two areas ignores the contribution of the other, software systems will continue to be sub-optimal (in terms of relevance, as well as quality). We argue the relevance of formal specifications to the information systems discipline, illustrating the argument with a case study based within the IS domain.     

Formal specification and design time testing

It is shown how design time testing can be used in conjunction with formal specification. Emphasis is placed on the benefits of using an executable specification language OBJ, of having a design controlled by requirements specification, and of adherence to the regularity and uniformity hypotheses in dynamic validation. It is shown that such an approach offers positive benefits by providing early design validation and a controlled, disciplined design process     

Formal specification of geographic data processing requirements

A formal foundation for the specification of geographic data processing (GDP) requirements is established. Emphasis is on modeling data and knowledge requirements rather than processing needs. A subset of first-order logic is proposed as the principal means for constructing formalizations of the GDP requirements in a manner that is independent of the data representation. Requirements executability is achieved by selecting a subset of logic, compatible with the inference mechanisms available in Prolog. Concepts with GDP significance such as time, space, and accuracy are added for the formalization without losing Prolog implementability or separation of concerns. Rules of reasoning about time, space, and accuracy can be compactly stated in a subset of second-order predicate calculus and can be easily modified to meet the particular needs of a specific application. The feasibility of the approach is established with the aid of a prototype implementation of the formalism in Prolog. The implementation also provides the means for the graphical rendering of logical information on a high-resolution color display     

Formal specification of a display-oriented text editor

We present a formalization of the design of a display-oriented text editor. The formalization is rigorous enough to serve as a touchstone for the correctness of implementations of the editor and to permit various desirable properties of the design to be proven.The formalization is expressed in (slightly embellished) conventional mathematical notation whose unusual aspects are explained in the text.     

构件适应和组装的形式化语义描述

构件适应技术是基于构件的软件工程中一个很难解决的问题,分析了三种构件适应结构的应用条件,采用了形式化语义的方法描述和推导了与构件以及构件适应相关的问题,根据构件描述与应用需求描述动态地选择不同的适应层次来适应构件,从被适应的构件描述中推导出复合构件的描述,为构件适应的形式化分析、组装正确性检验提供了保证,并列出了一些值得进一步研究的问题。