In our previous work, we proposed a method based on temporal logic for abstracting link structures consisting of cells pointing to one another. Cells are abstracted by abstract cells representing truth or falsity of each of the temporal formulas specified in advance, and an entire link structure is abstracted by a set of abstract cells. In this work, we tried to apply the method to analyze cellular automata. In order to abstract this new state of the link structure, we introduced the operations to split and merge abstract cells. By this method, we successfully analyzed simple one-dimensional (and two-dimensional) cellular automata. In this talk, we also explain the satisfiability of the two-way CTL (computation tree logic), which is used as a basis of the method.

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We present a method to generate a suffix trie st(p) from a naive O(mn) pattern matcher nm(p,t) and a text t by Generalized Partial Computation (GPC). The generated st(p) runs in O(m) time where m and n stand for the length of pattern p and text t, respectively. The size of st(p) is O(n) while the one of the residual program produced by a conventional partial evaluater is O(n²).

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LMNtal is a language model based on hierarchical graph rewriting. It is intended to allow uniform and concise description of various forms of computation including distributed processing.LMNtal is a multiset rewriting language featuring fine-grained concurrency. However, how to implement it correctly and efficiently is not clear because: (i) the multisets can be structuredusing membranes, (ii) each membrane can have its own set of local rewrite rules, and (iii) sets of rewrite rules can migrate.This paper describes the runtime system of a prototype LMNtal implementation that uses multiple stacks. The runtime system can be executed using multiple virtual machines, making it amenable todistributed implementation. The prototype is under development using Java and Ruby.

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We propose an approach to efficiently detect equalitiesamong SSA form expressions based on checking extended dominancerelation, called generalized dominance relation.Our technique checks the generalized dominance relationbased on the depth of control flow graph without up-edges.Since reachability to relevant points of dominance relation isexpected by the depth of the points, relevant points unreachablealong control flow graph edges can be ignored, and it is enoughto traverse dominator tree edges.We show the efficiency of our technique as compared with thedataflow analysis approach.

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When connecting and using two or more applications on a network, usually, a server is prepared in the center of a network. Each client communicates with other clients through a server. However, in such a network topology, if the number of clients increase, server will impossible to process message from clients. As an example, Using Remote Editing Protocol between the text editors connected in a ring, the whole edit state is held. We propose the method of enabling interactive editing between text editors.

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It is supposed that multiple bidders participate in auctions and every biddershould be treated fairly. We nowadays find online auctions everywhere, and itis desirable to verify their fairness property. The fairness can be consideredas the property that any bidder can not behave dishonestly and the propertythat bidders are never treated wrongfully. In this paper, we formalize auctionprotocols and the fairness properties to be verified by using the framework ofstrand space introduced by F.J.T.Fabrega. We also consider characteristics offairness properties and show that some of the properties can be considered asone of agreement properties which are most popular properties of securityprotocols.

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Security can be guaranteed with software specification which includes security requirements. Scenarios make it clear among stakeholders that concrete ways to defend from attacks when they are used on requirements elicitation. Furthermore, the scenarios give some actual cases for testing the software to detect the vulnerabilities. However, it is difficult for general users to describe a scenario with security requirements. In this paper the authors propose a method to guarantee the security with appending exceptional scenarios to the normal scenario; the exceptional scenarios are automatically generated and these express the behaviour of evil actors and the reactions against them. The evil actors are assumed to attack to the typical or system specific vulnerabilities.

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Proof-carrying authentication is a method for implementing general-purpose access control systems. In this method, a client requesting an access control sends a proof that he has a right to obtain the control, and a server checks the proof and gives the control to the client if the proof is correct. The burden at the server side is light because only a proof checker needs to be implemented. In this research, we are implementing proof-carrying authentication on cellular phones by building a transformer that generates a proof checker in Java from a description of a logical system expressed in logical framework. In this paper, we describe the overview of the transformer and a simple example application using proof-carrying authentication on cellular phones.

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Implementations of design patterns on object-oriented programming languages lack modularity of pattern codes and its invasive nature makes the participating classes mutually dependent. This alienates reuse of codes and obstruct software evolution. We proposed a role-based computation model Epsilon, which can modularize pattern codes of design pattens and reduce its invasive nature. Thus, it enhances reusability of design patterns and their participating classes. This leads to promotion of software evolution.

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JAAS is a basis for user-centric access control, and is an infrastructuresoftware to implement high-level security policy. It, however, requires someamount of programming as well as grant relationships stored declaratively ina policy file. Therefore, verifying that the high-level requirement is correclyimplemented in Java programs. This paper proposes to use Alloy, a formalspecification and analysis tool, for descriptions and verifications of high-levelsecurity policy with an example case of encoding LBAC on JAAS.

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We give a method for safety verification of real-time system by means of Linear Logic. Our method is applied especially to a system in which a number of agents and/or time constraint conditions can be changed dynamically. We illustrate a method to find a conjecture of safety condition in our framework, using a simple example.

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On a current online game systems, it use centralized server usually.However, if the game user increase to millions of units, in some case, A processing of the server becomes very slow and hinders game progress.So, we have proposed a framework using Agent.On some high spec PC, it operates the game process and network communication instead of video game machine.We suggest a communication protocol thatrealize online games and reduce trafficon the network between Agents which change dynamically.

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This paper presents a reasoning method on such a phenomenon thata property holding in some region is propagatedto another region.SRCC is an extention of RCC so that it can handle the integration of spatial and semantic data.In this paper,we present an algrithm that finds the spatial relationbetween the regionswhen the relative relation of the attibute of some region and that of anotheris given.Using the algorithm,we can determine the place where a newly introduced region is placed.In this paper,we show an application to a problem of propagation of the contamination.

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