Satoshi Amamiya

Kyushu University, Hukuoka, Fukuoka, Japan

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Publications (39)2.91 Total impact

  • Source
    Kousaku Kimura · Satoshi Amamiya · Tsunenori Mine · Makoto Amamiya
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    ABSTRACT: Peer-to-peer (P2P) communication and computing frame-works are important for constructing robust large-scale distributed sys-tems. Overlay network systems use distributed hash-table (DHT) to pro-vide scalable and efficient node search capabilities. However, the DHT-based method has a problem for the maintenance cost of dynamically changing large-scale-network, in which nodes are frequently joining and leaving. This paper proposes a novel technique of P2P communication path management. The proposed technique devises a robust semi-structured overlay network called Ordered Tree with Tuft (OTT for short). OTT provides not only efficient node searching, but also low-cost self-maintenance capabilities for the dynamically changing network. In this method, join-ing and leaving of a node are managed in O(1) with high probability. Furthermore, the proposed OTT-based technique can find and construct a path shorter than that on the normal ordered tree, by setting up bypass links between remote nodes on OTT.
    Full-text · Article · Jan 2012
  • Satoshi Amamiya · Makoto Amamiya · Ryuzo Hasegawa · Hiroshi Fujita
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    ABSTRACT: Current trend of research on multithreading processors is toward the chip multithreading (CMT), which exploits thread level parallelism (TLP) and improves performance of softwares built on traditional threading components, e.g., Pthread. There exist commercially available processors that support simultaneous multithreading (SMT) on multicore processors. But they are basically based on the conventional sequential execution model, and execute multiple threads in parallel under the control of OS that handles interruptions. Moreover, there exist few languages or programming techniques to utilize the multicore processors effectively. We are taking another approach to develop a multithreading processor, which is dedicated to TLP. Our processor, named Fuce, is based on the continuation-based multithreading. A thread is defined as a block of sequentially ordered instructions which are executed without interruption. Every thread execution is triggered only by the event called continuation. This paper first introduces the continuation-based multithread execution model and its processor architecture then gives multithreaded programming techniques and the continuation-based multithreading language system CML. Last, the performance of the Fuce processor is evaluated by means of the clock-level software simulation.
    No preview · Article · Feb 2009 · The Journal of Supercomputing
  • Tsunenori Mine · Akihiro Kogo · Satoshi Amamiya · Makoto Amamiya
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    ABSTRACT: This paper proposes two methods for improving the retrieval accuracy of the Agent-Community-based Peer-to-Peer information retrieval (ACP2P) method. One uses user feedbacks exchanged in a community. The other uses query-learning methods that make a middle agent to learn query-responder agent relationships. The latter methods are useful not only for improving the retrieval accuracy, but also for reducing communication loads. We conduct several experiments with test collections so that the evaluation can be done in an objective manner. The experimental results illustrate the validity of our proposed methods.
    No preview · Conference Paper · Jan 2009
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    ABSTRACT: Community-based collaboration support systems are useful for exchanging information on topics that community members are interested in. Most of them developed so far are based on server-client architecture and provide their services on Web servers. They require special administrative facilities, and ask users to upload their data on the systems. Furthermore, security mechanisms are not often provided for the communities. Considering these problems, we have been developing an Agent-Community-Network-based collaboration support system: in particular, a business-matching support system. Our system requires neither any special administrative facilities nor the need to upload user data to a special server. Furthermore, it supports secure peer-to-peer communication between users. It is implemented with a multi-agent Kodama framework.
    No preview · Chapter · Dec 2008
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    ABSTRACT: Business matching and collaboration support systems are useful, in particular for small-and-medium sized companies. Most of them developed so far are based on the server-client architecture and provide their services on Web servers. They require special administrative facilities, ask users to upload their data for matching between business needs and seeds, and leave to themselves peer-to-peer communication or ne- gotiation between matched companies. Considering these problems, we have been developing an agent-community- network-based business matching and collaboration support system. Our system requires neither any special adminis- trative facilities nor uploading user data to a special server. It furthermore supports secure peer-to-peer communication between users. It is implemented with multi-agent Kodama framework.
    Full-text · Conference Paper · Jan 2008
  • K. Kimura · S. Amamiya · T. Mine · M. Amamiya
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    ABSTRACT: A multi-agent system that consists of agents distributed in a network requires an application-level routing method using abstract identifiers such as agent names. We have accordingly proposed a routing method based on an Ordered-Tree-with-Tuft-shaped (OTT-shaped) overlay network. The method can maintain the network robustly and at low cost, and also make use of short-cuts between nodes to find shorter paths than those only found by the ordered tree of OTT. However it has a problem that the path-search cost by shortcuts is too expensive to achieve a reasonable success rate. This paper proposes our newly improved method that finds shorter-paths with both reasonable cost and high success rate of path-search by short-cuts and discusses some of experimental results achieved by software simulation. The results illustrate the validity of our proposed method.
    No preview · Article · Jan 2008
  • Satoshi Amamiya · Makoto Amamiya
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    ABSTRACT: In the near future, people will be able to access information and resources on the public open network environment. However, few current network environments seem to have unified method for protection of information and resource. This paper proposes a unified resource protection scheme on the basis of fusion of two multi-agent systems called Kodama and VPC. Kodama has the power of constructing flexible hierarchical logical spaces, and VPC has the ability to dynamically change its behavior according to the circumstance of user. As a protection scheme, two kinds of policies called public policy and private policy are introduced into the fused multi-agent system. Combination of these policies makes it possible to realize an open and secure information sharing system. We show practical sample applications using the scheme.
    No preview · Article · Apr 2007 · Journal of Ubiquitous Computing and Intelligence
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    ABSTRACT: We propose the Fuco architecture based on dataflow computing model. The goal of this architecture is fusion of communication and execution. The multiple thread execution model of the architecture takes the continuation-based multithreading model that manages dependency among fine-grain "uninterruptible" threads. In this paper, the continuation-based multithreading model constructs more resourceful parallel I/O processing cooperated with by processor and operating system. Our model is different from the conventional I/O processing model that handles "interrupt." We illustrate the continuation-based parallel I/O processing model.
    No preview · Article · Mar 2007
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    ABSTRACT: Fine-grained multithreading based on a natural model, such as dataflow model, is promising in achieving high efficiency and high programming productivity. In this paper, we discuss operating system issues for fine-grained multithread programs. We are developing an operating system called CEFOS based on a dataflow based computation model. A program on CEFOS consists of zero-wait threads which run to completion without suspension once started. Firing control among such threads is performed in a dataflow manner along with continuation relations in the program. Target platforms include Fuce processor, which is dedicated to fine-grained multithreading, and commodity processors such as Intel x86. In this paper, after introducing our basic model and our operating system model, we discuss implementation issues on Fuce and commodity platforms. The evaluation results indicate that our approach on commodity platforms is effective in reducing overheads while our approach on a special architecture naturally exploit parallelism even in I/O handling.
    Preview · Article · Jan 2007
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    ABSTRACT: Current trends of research on multithreading processors are the chip multithreading (CMT), which aims to exploit thread level parallelism (TLP) and to improve performance of software built onalltraditional threading components, e.g. pthreads. However, CMT is principally a straight forward extension of conventionalall symmetric multiprocessor (SMP) techniques, and it will suffer from the same limits to scalable multithreaded processing ifallit is built only on the traditional sequential-computation-based framework. Consideringallthese limitations of sequential-processor-basedallmultithreading, we are taking another approach to developing a multithreading processor dedicated to thread level parallelism(TLP). Our processor, named Fuce, is based on continuation-based multithreading. A thread is defined as a block of sequentially ordered instructions which areall executed exclusively. Every execution of a thread is triggered by one or more events, each of which is called continuation. The hardware cost and performance of the Fuce processor areallevaluated by means of a hardware implementation on FPGA and software simulation.
    No preview · Conference Paper · Jan 2007
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    ABSTRACT: Multi-tasking operating systems not only handle concurrent tasksbut also have concurrency and parallelism of various granularities in themselves. We claim that operating systems need to be developed based on a computation model that can deal with concurrency and parallelism of various granularities. In order to investigate this claim, we have been developing an operating system called CEFOS based on a dataflow-based computation model. A program for CEFOS consists of zero-waitthreads, each of which runs to completion without suspension once started. Synchronization between zero-wait threads is performed in a dataflow manner according to their continuation relations. Handler routines for I/O devices are also realized with zero-wait threads and executed under the continuation-based multithreading mechanism. We can eliminate "interrupts" that interfere with the execution ofinstruction streams in typical conventional approaches, and we can naturally handle concurrency and exploit parallelism in programs even for I/O-centric computation. In this paper, after introducing our model and our operating system based on the model, we discuss implementation issues on Fuce, which is a continuation-based multithreading processor dedicated to fine-grained multithreading. Then we evaluate the scalability of our system with the number of execution units and I/O devices.
    No preview · Conference Paper · Jan 2007
  • S. Amamiya · R. Hirana · M. Koshimura · H. Fujita · R. Hasegawa
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    ABSTRACT: In our previous works, we inroduced a higer intermidiate language called IML for the Fuce processor, and discussed special programming methods for stream processing on Fuce. However, without realization of the language HAL and its compiler, it is difficult to utilize the power of these tools. In this paper, we discuss the implementation techniques for constructing the HAL compiler including powerful optimization functionalities.
    No preview · Article · Sep 2006
  • R. Hasegawa · H. Fujita · S. Amamiya · M. Koshimura · M. Amamiya
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    ABSTRACT: In this paper, methods of concurrent programming on FUCE machine and language designs to implement them are studied. The idea of multi-thread processing on FUCE is far different from the others fitted to conventional computer systems. We have been developing a family of languages that are suitable for writing programs which should be executed efficiently on FUCE. The language features include several ways for handling synchronization, mutual exclusion, and stream processing. These should enable us to write more FUCE friendly programs, and a unique FUCE-OS in particular.
    No preview · Article · Mar 2006 · Research Reports on Information Science and Electrical Engineering of Kyushu University
  • S. Amamiya · R. Hasegawa · H. Fujita · M. Koshimura · M. Amamiya
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    ABSTRACT: In this paper, a language family designed for a FUCE machine is described. The FUCE hardware is viewed as a macro data-flow machine which actually executes "uninterruptable threads" on rather conventional but specially configured multiple processing elements. From the view point of programming languages, such architecture enables us to design and implement high level languages with minimum effort by utilizing conventional techniques or existing compiler tools. Intermediate languages of suitable abstraction in terms of some attached instructions and syntax sugars are very useful both for application programmers and system programmers. Also, a technique to automatically extract FUCE oriented threads from a usual C program is presented.
    No preview · Article · Mar 2006
  • T. Matsuzaki · S. Amamiya · M. Izumi · M. Amamiya
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    ABSTRACT: We are developing the FUCE processor based on the dataflow computing model. FUCE means FUsion of Communication and Execution. In order to execute many threads with multiple thread execution units efficiently, the FUCE processor executes multiple threads using the exclusive multi-thread execution model. The core concept of the exclusive multi-thread execution model is continuation based multi-thread execution, which is derived from dataflow computing. The FUCE processor unifies processing inside the processor and communication with processors outside as events, and executes the event as a thread. In this paper, we introduce the thread-programming model and the architecture of the FUCE processor and evaluate the hardware cost of a FUCE processor and the concurrency performance of a FUCE processor which we described in VHDL. As a result, we understood that the processor has concurrency capability when there is sufficient thread level parallelism.
    No preview · Article · Mar 2006
  • Source
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    ABSTRACT: Nowadays, development of processors which support concurrent multi-thread execution is becoming a trend. Most of these processors are aimed at exploiting instruc- tion level parallelism (ILP). But many researchers feel that the limits of ILP exploitation are rapidly being reached. In addition, exploiting more ILP makes the circuitry of proces- sor very complicated. We are taking another simpler ap- proach, and developing a processor focused only on thread level parallelism (TLP). Our processor is named Fuce. it is based on the continuation model which is derived from the dataflow computing model. In this paper, we introduce the core concepts of Fuce, the programming model for Fuce and an overview of Fuce architecture. We also show simu- lation results.
    Preview · Conference Paper · Jan 2006
  • S. Amamiya · M. Amamiya
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    ABSTRACT: In the near future, people will be able to access information and resources on the public open network environment. However, few current network environments seem to have unified method for protection of information and resource. This paper proposes a unified resource protection scheme on the basis of fusion of two multi-agent systems called Kodama and VPC. Kodama has the power of constructing flexible hierarchical logical spaces, and VPC has the ability to dynamically change its behavior according to the circumstance of user. As a protection scheme, two kinds of policies called public policy and private policy are introduced into the fused multi-agent system. Combination of these policies makes it possible to realize an open and secure information sharing system. We show practical sample applications using the scheme.
    No preview · Conference Paper · Aug 2005
  • Ken’ichi Takahashi · Satoshi Amamiya · Makoto Amamiya
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    ABSTRACT: Grid computing is promissing as an infrastructure that allows users to use distributed computer resources by simple connecting a computer to the network without special operation; just like connecting to the electricity, water or gas grid. In this paper, regarding resources as services, we propose a new architecture for realizing an environment in which users can use services that are in various locations through their portable terminals. In this architecture, a service is managed by an agent, which has two resource management spaces named the Public Zone and the Private Zone. The Public Zone is a space for realizing flexible public service use. The Private Zone is a space for protecting private user information. Moreover, agents are organized in a group called the community and are managed independently in each community. Thus, we realize both of flexible service use while protecting private information.
    No preview · Chapter · Jul 2005
  • T. Matsuzaki · S. Amamiya · M. Izumi · M. Amamiya
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    ABSTRACT: We are developing the Fuce processor based on the dataflow computing model. Fuce means fusion of communication and execution. In order to execute many threads with multiple thread execution units efficiently, the Fuce processor executes multiple threads using the exclusive multi-thread execution model. The core concept of the exclusive multi-thread execution model is continuation based multi-thread execution, which is derived from dataflow computing. The Fuce processor aims to fuse the intra-processor execution and inter-processor communication. The Fuce processor unifies processing inside the processor and communication with processors outside as events, and executes the event as a thread. In this paper, we introduce the architecture of the Fuce processor and evaluate the concurrency performance of a Fuce processor which we described in VHDL. As a result, we understood that the processor has concurrency capability when there is sufficient thread level parallelism.
    No preview · Conference Paper · Feb 2005
  • Kenichi Takahashi · Satoshi Amamiya · Makoto Amamiya
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    ABSTRACT: Grid computing is promissing as an infrastructure that allows users to use distributed computer resources by simple connecting a computer to the network without special operation; just like connecting to the electricity, water or gas grid. In this paper, regarding resources as services, we propose a new architecture for realizing an environment in which users can use services that are in various locations through their portable terminals. In this architecture, a service is managed by an agent, which has two resource management spaces named the Public Zone and the Private Zone. The Public Zone is a space for realizing flexible public service use. The Private Zone is a space for protecting private user information. Moreover, agents are organized in a group called the community and are managed independently in each community. Thus, we realize both of flexible service use while protecting private information.
    No preview · Conference Paper · Jan 2005