13964619
Parallelization of Saprse Cholesky Factorization on an SMP Cluster
In this paper, we present parallel implementations of the sparse Cholesky factorization kernel in the SPLASH-2 programs to evaluate performance of a Pentium Pro based SMP cluster. Solaris threads and remote memory operations are utilized for intranode parallelism and internode communications, respectively. Sparse Cholesky factorization is a typical irregular application with a high communication to computation ratio and no global synchronization between steps. We efficiently parallelized using asynchronous message handling instead of lock-based mutual exclusion between nodes, because synchronization between nodes reduces the performance significantly. We also found that the mapping of processes to processors on an SMP cluster affects the performance especially when the communication latency can not be hidden.
217877
Relis-G: remote library install system for computational grids
When a grid user installs the library which is used by the GridRPC etc. to the servers distributed over a grid, the user needs to solve complicated and laborious problems, such as user's effort to input commands for remote operation, creation of an installation package of the library for heterogeneous server systems, avoidance of redundant compilation, and observance of administration policy of each server. In order to enable the user to solve these problems easily, we propose the remote library install system, Relis-G, which is highly portable and multipurpose in the grid. Besides the function for automatic remote library installation, this system offers functions, such as automatic creation of an installation package, automatic avoidance of redundant compilation, and automatic observance of administration policy of each server. Moreover, we confirmed that this system mitigated the above-mentioned user's burden greatly by operation tests.
16039028
Overlay Weaver: An overlay construction toolkit
A layered model of structured overlays has been proposed and it enabled development of a routing layer independently of higher-level services such as DHT and multicast. The routing layer has to include other part than a routing algorithm, which is essential for routing. It is routing process, which is common to various routing algorithms and can be decoupled from a routing algorithm. We demonstrated the decomposition by implementing an overlay construction toolkit Overlay Weaver. It facilitates implementation of routing algorithms and we could multiple well-known algorithms just in hundreds of lines of code with the toolkit. The decomposition also enables multiple implementations of the common routing process. Two implementations the toolkit provides perform iterative and recursive routing, respectively. Additionally, to our knowledge, the toolkit is the first feasibility proof of the layered model by supporting multiple algorithms and the higher-level services. Such modular design contributes to our goal, which is facilitation of rapid development of realistic routing algorithms and their application. We demonstrates that Overlay Weaver supports the goal by conducting large-scale tests and comparisons of algorithms on a single computer. The resulting algorithm implementations work on a real TCP/IP network as it is.
5670471
Design, implementation and performance evaluation of GridRPC programming middleware for a large-scale computational grid
This paper reports on the design, implementation and performance evaluation of a suite of GridRPC programming middleware called Ninf-G Version 2 (Ninf-G2). Ninf-G2 is a reference implementation of the GridRPC API, a proposed GGF standard. Ninf-G2 has been designed so that it provides 1) high performance in a large-scale computational Grid, 2) the rich functionalities which are required to adapt to compensate for the heterogeneity and unreliability of a Grid environment, and 3) an API which supports easy development and execution of Grid applications. Ninf-G2 is implemented to work with basic Grid services, such as GSI, GRAM, and MDS in the Globus Toolkit version 2. The performance ofNinf-G2 was evaluated using a weather forecasting system which was developed using Ninf-G2. The experimental results indicate that high performance can be attained even in relatively fine-grained task-parallel applications on hundreds of processors in a Grid environment.
16646144
Lessons learned through driving science applications in the PRAGMA grid
This paper describes the coordination, design and implementation of the PRAGMA Grid. Applications in genomics, quantum mechanics, climate simulation, organic chemistry and molecular simulation have driven the middleware requirements, and the PRAGMA Grid provides a mechanism for science and technology teams to collaborate, for grids to interoperate and for international users to share software beyond the essential, de facto standard Globus core. Several middleware tools developed by researchers within PRAGMA have been deployed in the PRAGMA grid and this has enabled significant insights, improvements and new collaborations to flourish. In this paper, we describe how human factors, resource availability and performance issues have affected the middleware, applications and the grid design. We also describe how middleware components in grid monitoring, grid accounting and grid file systems have dealt with some of the major characteristics of our grid. We also briefly describe a number of mechanisms that we have employed to make software easily available to PRAGMA and global grid communities.
951430
OpenGR: A directive-based grid programming environment
A new grid programming environment for remote procedure call (RPC) based master-worker type task parallelization is presented. The environment is realized through the use of a set of compiler directives, called OpenGR, and is implemented in the present study based on the Omni OpenMP compiler system and Ninf-G grid-enabled RPC system as a parallel execution mechanism. Using OpenGR directives, existing sequential applications can be readily adapted to the grid environment as master-worker parallel programs using the RPC architecture. The combination of OpenGR and OpenMP directives also allows for the hybrid parallelization of sequential programs, supporting both synchronous and asynchronous parallelism.
30858440
Vision based navigation system for autonomous mobile robot with global matching
We have previously developed a navigation system for an autonomous mobile robot. It can find the landmarks on the ceiling for navigation. However, when the robot fails to recognize a landmark, the robot can not calculate the self-position. So, the robot has to prepare for the behavior of error recovery. But an error that is not able to recover may occur. In such a case, the robot needs to relocate the self-position. In this paper, we define global matching as the behavior that is able to relocate the self-position and propose to use this module for the error recovery in HALAS (hierarchical adaptive and learning architecture system) that we have proposed as a hierarchical system.
42879781
Vision based navigation system by variable template matching for autonomous mobile robot
We have previously developed a navigation system for autonomous mobile robots. It can find landmarks on the ceiling to move and work. However, it is impossible to recognize landmarks when the size of landmark is different from the size of template. In such cases, the robot cannot continue to work. Therefore we proposed variable template matching (VTM) that makes it possible to recognize landmarks of different sizes. We realize VTM by using the optimization method called the evolution strategy (ES). The robot can recognize the landmark faster, inferring landmark parameters by binary density projection.