*A space between the first name and last name, please enter



FacultyDepartment of Informatics / Graduate School of Science and Engineering Research
PositionAssociate Professor
Commentator Guide
Last Updated :2020/09/30

Education and Career


  •  - 1997 , Okayama University
  •  - 1997 , Okayama University, Graduate School, Division of Science and Technology
  •  - 1991 , Okayama University, Faculty of Engineering
  •  - 1991 , Okayama University, Faculty of Engineering

Research Activities

Research Areas

  • Informatics, Software
  • Informatics, Information theory

Research Interests

  • Semantics for Programming Languages

Published Papers

  • Hybrid Timed Ambient Calculus for Logistics Specification, Y.Fujisaka, K.Inamori, M.Higuchi, T. Kato, IPSJ Transactions on Programming, IPSJ Transactions on Programming, 10(4), 12 - 27, Jul. 2017 , Refereed
  • A Handling Management System for Freight with the Multiple Ambient Calculus and UHF RFID Tags, T. Hashimoto, T. Kato, M.Higuchi, IPSJ Transactions on Programming, IPSJ Transactions on Programming, 6(2), 1 - 12, Aug. 2013 , Refereed
  • A Conformance Decision System for Physical Distribution with the Ambient Calculus, 48(SIG10), 151 - 164, Jun. 2007

Conference Activities & Talks

  • The Implementation of Ambient Calculus with HORB for Mobile Agents, IIIS,   2003 08 , IIIS
    Summary:Ambient Calculus is a process algebra designed by Cardelli and Gordon of Microsoft Research for modeling mobile agents on network environments. They also proposed a basic implementation of the calculus in `Mobile Ambient Synchronization' though the ambient class only dealt with In and Out actions.Thus, we give the class extensions up to Open action,Replication and Communication primitives.Especially, the implementation includes a unique algorithm for the replication mechanism.Replication is the useful method that enables us to easily design server processes dealing with many demands from numerous clients. A naive implementation, however, would cause divergence of the number of processes. We propose a replication mechanism that does not generate infinite processes. As another feature of our implementation, ambients can bring several kind of applications, such as editor, file finder, and games with keeping running.
  • An Equivalence Relation for Typed Ambient Calculus, IIIS,   2002 08 , IIIS
    Summary:Ambient calculus is a process algebra designed for describing mobile processes. When we describe a network with ambients malicious processes can destroy nodes of the network or alter the construction of the network. Thus, a type system was introduced to ambient calculus so that we can give each node a desirable character that prevent malicious processes from cracking the network.The designers of the calculus defined an equational relation for untyped ambient calculus. Our revious work pointed out there exist identified processes up to the relation that have different properties, and it refined the relation so that we can discriminate those processes.This paper shows the original and our former relations are no longer available for typed ambient calculus and it presents another relation that is available for typed ambient calculus.
  • Formal Models of Mobile Concurrent Computations in Distributed Environments, SSGRR,   2000 07 , SSGRR
    Summary:Ambients represent the substances of movement and the fields of the ambients themselves. Having this hierarchy, this calculus can model various kinds of mobile computation. We found that an existing equational relation for ambient calculus can identify the processes which have different properties when we construct a choice operation consisting of only parallel and restricting primitives. We propos an equational relation which distinguish processes the existing equivalence identified.


  • The Semantics of Guarded Horn Clauses for Programs on Distributed Environment, Journal of Information Processing Society of Japan, 40, 1, 362, 373,   1999
  • A Domain for a Semantics of GHC for Programs on Distributed Environment, Journal of Information Processing Society of Japan, 38, 7, 1352, 1360,   1997
  • An OR-Compositional Semantics of Guarded Horn Clauses for Programs with Perpetual Processes, Journal of Information Processing Society of Japan, 37, 8, 1497, 1505,   1996

Research Grants & Projects

  • Freight Management Systems with the Ambient Calculus, We investigate a management system that ensures the correctness of cargo distribution in freight systems. The system determines the correctness by comparing the movement of containers, which is sensed by IC tags with formal models. These models are written in the ambient calculus and generated automatically based on several documents used in real freight systems. The ambient calculus is a formal description language that is suitable for representing freight systems with nested structures that dynamically change.
  • Study on Mobile Concurrent Computations in Distributed Environment
  • Study on Concurrent Programming Languages