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Atsushi TOGASHI Shigetomo KIMURA
This paper considers algebraic basic processes, a subset of communicating processes in CCS by Milner, and presents a synthesis algorithm to infer a process that satisfies the properties of the process, represented as fomulae in Hennessy-Milner Logic. The validity of the proposed algorithm can be stated that it synthesizes a process in the limit, which cannot be distinguished from the target one with respect to the strong equivalence.
Bhed Bahadur BISTA Zixue CHENG Atsushi TOGASHI Norio SHIRATORI
In communication protocols, the behaviour of a protocol entity is related to the behaviour of another protocol entity as they communicate under sets of communication rules (protocols). Thus, it is desirable to concentrate on the design of one protocol entity and generate the corresponding protocol entity automatically. Furthermore, it is desirable that the protocol is formal, precise and unambiguous that is, it is described using FDTs (Formal Description Techniques). In this paper, we propose a protocol synthesis algorithm in which, from a LOTOS specification of a single given entity, LOTOS specification of the corresponding peer entity is generated automatically. Unlike previous works, where FSMs (Finite State Machines) were used to synthesize protocols, we use LOTOS, which is one of FDTs developed by ISO, in our proposed synthesis algorithm. We prove that the generated protocol is logical errors free, collectively represented as deadlock free, if the given entity is in certain forms which are natural in the context of connunication protocols.
Kei HOMMA Satoru IZUMI Kaoru TAKAHASHI Atsushi TOGASHI
The number of Web applications handling online transaction is increasing, but verification of the correctness of Web application development has been done manually. This paper proposes a method for modeling, verifying and testing Web applications. In our method, a Web application is modeled using two finite-state automata, i.e., a page automaton which specifies Web page transitions, and an internal state automaton which specifies internal state transitions of the Web application. General properties for checking the Web application design are presented in LTL formulae and they are verified using the model checker Spin. Test cases examining the behavior of the Web application are also generated by utilizing the counterexamples obtained as the result of model checking. We applied our method to an example Web application to confirm its effectiveness.
Ushio YAMAMOTO Atsushi TOGASHI Norio SHIRATORI
This paper presents a support method for specifying communication systems. Generally, a set of requirements for a target system is partial and ambiguous to construct the whole system, namely it lacks certain necessary descriptions for the target system. To attack this problem, our method enables a designer to obtain such necessary descriptions from specifications stored in a knowledge base, namely by reusing specifications, and helps the designer to specify the target system completely. In our support method, we adopt labelled transition systems (LTSs) which are state transition graphs and are shared as a common notion by most FDTs. Therefore, our method is the common approach to FDTs. We propose a new idea about similarity berween LTSs, and propose an algorithm to suggest similar LTSs to the designer.