The number of Web applications handling online transaction is increasing, but verification of the correctness of the Web application design has been done manually. This paper proposes a method for modeling Web applications using two finite-state automata, i.e., a page automaton which species Web page transitions, and an internal state automaton which species internal state transitions of the Web application. General assertions for checking Web application design are proposed, and a theoretical result for deadlock-freeness of Web application is also shown. An example Web application is modeled by the proposed method and checked using the model checker Spin.

We introduce an inheritance concept into a specification method of mobile and real-time systems in order to reuse and refine existing specifications. Reusability by inheritance is emphasized in this paper. We take multiple inheritance to enable to reuse several specifications at a time. An upper specification can be skillfully divided into inherited parts and non-inherited ones. Therefore, a necessary part of the specification can be reused for a lower specification. As an application, the FIPA contract net interaction protocol is specified incrementally by using our method. We have been developing support tools for specifications described using our proposed method.

Effective information services could be provided for users by investing meta-data in information sources and making software agents understand it. In this paper, we make better use of a collection (ontology) of meta-data in the semantic Web technology for the design of an e-learning system that enables to provide learners with a more effective education support. The learning domain is cryptography in network security. We define various concepts in the cryptographic domain and the relations among them as the ontology, and propose a way of utilizing it in the learning process. The strength of our ontology-based e-learning system is demonstrated through application examples of the prototype system that we have been developing.

We propose a formal method to maintain mobile systems placed on fluidal ambiences using a process calculus in this paper. Behavior of physically movable entities of mobile systems, e.g. mobile telephone systems and intelligent transport systems (ITSs), may be affected by their surrounding. We have focused on effects of ambiences to behavior of mobile systems and have introduced the notion of a field into a concurrent calculus /spl pi/F, an extension of /spl pi/-calculus, formalizes processes constrained by ambiences. Based on /spl pi/F, our maintenance method indicates us how an ambience should be recovered when it is damaged.

Communicating entities in a protocol specification communicate with each other and provide services to their users. Once the behaviours of the entities (specification of the protocol) are specified they are not changed. The entities provide a fixed set of services to their users. However, different users have different requirements and their requirements change often. The requirement changes in general are small in terms of the size of the behaviour expressions of the entities. Traditional protocol synthesis techniques have given considerable attention in construction of new protocols for fixed set of services but less attention to the attractive maintenance issue of protocol to adopt new protocol requirement changes. What is desirable is a protocol synthesis method which adopts new protocol requirement changes into the behaviours of entities or protocol specifications. In this paper, we propose a protocol synthesis method which adopts the new protocol requirement changes into the protocol specification. In this way, we can use existing protocol specifications and maintain them to adopt requirement changes. We use the formal specification language LOTOS to specify requirement changes and the behaviours of entities.

The problem of modifying an existing protocol specification of a communicating system in Labelled Transition System (LTS) based on changes of it's service specification in LTS is discussed. Two types of changes of a service specification are treated: addition of a behaviour expression to the service specification and deletion of some parts of the behaviour expression from the service specification. For each change, a modification method is proposed and a property of the method is shown. From the point of view of verification and validation of a specification, it is desirable to separate a changed part of the specification from the existing specification. Thus, especially for the former type of changes that is addition of a behaviour expression to the service specification, the method to express changes of the service specification by using a concurrent LTS is proposed. The method proposed in this paper is efficient and desirable when the size of the changed part of the service specification is small in terms of behaviour expressions.

An attempt is made to design a user-friendly software environment for protocol synthesis based on the FSM (finite state machine), and to show the validity of applying AI (artificial intelligence) techniques to the construction of such a system. For that purpose, the authors have first designed a user-friendly software environment, named SEPS, using the programming language C, which belongs to the procedural programming paradigm. The aim of SEPS is to help a protocol designer to easily design a protocol and avoid logical errors like unspecified receptions and state deadlocks. In order to enhance the productivity of protocol development, a user-friendly interface has been designed which employs the multiwindow mechanism and provides the graphic tools in this system. Consequently, a protocol designer without any experience in protocol synthesis can easily design a protocol without logical errors. The authors have also designed a knowledge-based software environment for protocol synthesis, named KSPS, using the expert system tool OPS83. KSPS has the same functions as SEPS. The advantages of KSPS over SEPS in terms of extension, modification, and maintenance of protocol development systems are shown.>

An intelligent support system, designed to make the development of protocols and communication software easy and user-friendly, is described. The support system is outlined and its accessories (the knowledge-based specification editor, the validation expert system, the software generation expert system, the conformance-testing expert system, and the protocol-conversion expert system) are described in detail. Artificial intelligence techniques are used in the design of each component of the support system. An example which demonstrates the functions of each component in the support system is given.>

A knowledge-based system for protocol synthesis named KSPS is presented. The aim of KSPS is to help the protocol designer design a protocol without logical errors, such as unspecified receptions and state deadlocks. KSPS consists of three major components: a knowledge base, a user interface, and an inference engine. The construction of the knowledge base and the user interface is examined. The knowledge of protocol synthesis represented in the production model and in the procedure programming model is embedded in the knowledge base. A user-friendly interface with a multiwindow mechanism is designed which provides the graphic tools in this system. Consequently, the protocol designer without experience in protocol synthesis can easily design a protocol without logical errors.>

An interactive synthesis algorithm, to construct two communicating finite-state machines (protocols), is presented. The machines exchange messages over two unidirectional FIFI (first-in first-out) channels when the function of the protocol has been given. The synthesis algorithm first constructs the global state transition graph (GSTG) of a protocol to be synthesized and then produces the protocol. It is based on a set of production rules and a set of deadlock avoidance rules, which guarantee that complete reception and deadlock freeness capabilities are provided in the interacting process. This synthesis algorithm prevents a designer from creating unspecified reception and nonexecutable transition, avoids the occurrence of deadlocks, and monitors for the presence of buffer overflow.>