Arata Shinozaki

A high performance simulator system for a multiprocessor system based on a multi-way cluster

In the ubiquitous era, it is necessary to research on the architectures of multiprocessor system with high performance and low power consumption. A processor simulator developed in high level language is useful because of its easily changeable system architecture which includes application specific instruction sets and functions. However, there is a problem in processing speed that both PCs and workstations provide insufficient performance for the simulation of a multiprocessor system. In this research, a simulator for a multiprocessor system based on the multi-way cluster was developed. In the developed simulator system, one processor model consists of an instruction set simulator (ISS) process and several inter-processor communication processes. In order to get the maximization of the simulation performance, each processor model is assigned to the specific CPU on the multi-way cluster. Also, each inter-processor communication process is implemented using MPI library, which can minimize the CPU resource usage in a communication waiting state. The evaluation results of the processing and communication performance using a distributed application program such as JPEG encoding show that each ISS process in the developed simulator system consumes approximately 100% CPU resources for keeping enough inter-processor communication performance. This result means that the performance increases in proportion to the number of integrated CPUs on the cluster.

UMP-PerComp: A Ubiquitous Multiprocessor Network-Based Pipeline Processing Framework for Pervasive Computing Environments

Pervasive computing provides an attractive vision for the future of computing where contextual intelligent services will be available anywhere at any time. However, how to integrate distributed resources existed among heterogeneous devices to build pervasive applications that can constantly adapt to the highly dynamic computing environment is still a challenge. By analyzing the pipelining feature within a user task and exploiting the parallelism among ubiquitous processors, we propose UMP-PerComp, a ubiquitous multiprocessor-based pipeline processing architecture to support high performance pervasive application development. UMP-PerComp is an integrated comprehensive framework that makes the development of pervasive applications easier. It includes a set of common services such as context management, resource management, service migration, topology management, that help to build applications and directly simplify the task decoupling and service composition. We describe the design and implementation of UMP-PerComp in this paper. Besides, we develop a distributed JPEG encoding application successfully on the UMP-PerComp. Our experience confirms that UMP-PerComp is a flexible, scalable and practicable framework with high performance.

Multiprocessor Simulator System Based on Multi-way Cluster Using Double-buffered Model

In the ubiquitous era, it is necessary to research the architectures of multiprocessor system with high performance and low power consumption. A simulator developed in high level language is useful because of its easily changeable architecture, which includes application-specific instruction sets and functions. In this research, the basic framework for multiprocessor simulator system was constructed based on a multi- way cluster. Furthermore, this paper proposes and implements a double-buffered communication model to improve communication speed keeping independence from each processor model on the system. This model shows over 50% system performance improvement rate compared with the basic framework integrated with the single-buffered model. As the conclusion, the improved simulator system is suitable for the research of heterogeneous multiprocessor system.

A Gnutella inspired ubiquitous service discovery framework for pervasive computing environment

Pervasive computing, the new distributed computing paradigm aiming at providing services anywhere anytime, poses unique challenges on service management and discovery. In this paper, we propose a new pervasive computing framework named USDM-PerComp by using a Web service server/directory server (WSS/DS) based two-level hierarchical topology to address the challenges involved. DSs within USDM-PerComp autonomously form a peer-to-peer (P2P) overlay. We present a Gnutella inspired distributed algorithm to support service discovery over the resulted P2P overlay, and further implement a service crawler using mobile agent techniques to perform the discovery and invocation. With the service crawler, service composition could be done automatically and spontaneously without any user concern. Besides, we develop a distributed JPEG encoding application to verify the practicability of our proposal. Our experience confirms the scalability and flexibility of USDM-PerComp. The pervasive applications could be easily as well as efficiently created under USDM-PerComp environment.

Development of General-Purpose Processing Element and Network-Based Dataflow Processing System: Part One

This paper introduces a system, called Ubiquitous Multi-Processor (UMP) system, which constructs a dataflow network dynamically by connecting function-specific execution modules. We developed a general-purpose execution module (GP-PE) which performs an equivalent function to SS-PE by downloading the software library to improve the efficiency of development and reconfigure the function dynamically. This paper shows overhead time is 200ms caused by network communication among PEs using 1000 Base-T, on decentralized network where a client module, management modules, and calculation modules including GP-PE are deployed, comparing it with the system performance on a single PC. The experimental result presents the adaptability of GP-PE to UMP system in general use. Moreover, the ratio of the overhead time of the library to downloading time for general using is clarified. It becomes useful parameter to decide method of downloading DPL.

Network-Based Data Flow Processing System with Variable Data Granularity for Inter-module Communication

Integration of many functions in mobile devices often results in the insufficiency of computing resources and security problems. We utilize multiple computing modules distributed in the environment as external resources, and call this processor network system “UMP (Ubiquitous Multi Processor) system.” In our previous research, the basic architecture of a UMP system and its communication theory were verified. This paper evaluates the correlation between data granularity and system performance for applications with variable data granularity and verifies the usefulness of these parameters in dynamic scheduling necessary to construct intelligent systems. A JPEG encoding application was evaluated on the UMP system with six sub-functional modules. Optimization of data granularity shows 180% improvement of system performance. The experimental result shows that data granularity of inter-PE communication could be an important parameter in optimizing the system architecture and dynamic scheduling. Moreover, the result shows the possibility of further performance improvement through optimization of data granularity by focusing on individual modules.