13995472
Grid PSE builder: a framework for building Web-based distributed PSE on grid
In order to provide a framework for building Web-based distributed PSEs (problem solving environment) on a grid, we have been designing and implementing grid PSE builder. By using grid PSE builder, PSE providers can easily build a PSE using existing large scale scientific-engineering application as PSE components, without specialized knowledge about Web security and programming. On the other hand, PSE user can access the PSE with highly secured way only by using a Web interface. We have built some Web application portals with existing applications by using grid PSE builder as a Web portal toolkit and it is possible to make existing applications into PSE components with only a small amount of work.
15968684
GEO Grid: Grid Infrastructure for Integration of Huge Satellite Imagery and Geoscience Data Setsets
We have designed Global Earth Observation(GEO) Grid, which is an infrastructure for archiving and processing huge satellite imagery and GIS geographical data sets. Users can immediately access the full archive and process the desired data areas on demand using the latest calibration and analysis algorithms through standardized web services interfaces on basic OGSA services. GEO Grid is based on four layers, hardware, virtual storage, application and data services, and user interface. Each layer has the potential for extendability. We constructed GEO Grid to process satellite data taken by ASTER launched at the end of 1999 as an EOS project.
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.
2787964
Implementation of Fault-Tolerant GridRPC Applications
A task parallel application is implemented with Ninf-G, a GridRPC system. A series of experiments are conducted on the Grid testbed in Asia Pacific for three months. Through tens of long executions, typical fault patterns were collected, and instability of the network throughput was determined to be a major reason of the faults. Several important points are stressed to avoid task throughput decline due to the fault-recovery operations: Timeout minimization for fault detection, background recovery, redundant task assignments, and so on. This study also issues a steer for design of the automated fault-tolerant mechanism in an upper layer of the GridRPC framework.
14481721
Dynamic Resource Allocation Based on On-the-Fly Reservation
Resource reservation is a vital issue for grid-enabled programs to execute smoothly. Instead of using metascheduling solutions to request grid resources statically, we are developing a tiny C++ library to reserve on-demand computing resources based on Globus Toolkit, local schedulers such as Maui, and SQLite database. The interface class is named CReservation in the library. At the time of preparing this paper, the only implementation available is for Maui scheduler. With such implementation classes, one can request, release, and monitor reservations of computing resources dynamically. To verify the simplicity, usability, and stability of current library, we have performed an in-depth case study with a grid enabled hybrid MD/QM (Molecular Dynamics/Quantum Mechanical) multi-scale simulation program. Our test shows that this library provides an easy and effective approach to manage resource reservations from within grid-enabled applications.
11192988
Design and Implementation of Distributed Task Sequencing on GridRPC
In the framework of GridRPC, a new function that allows direct data transfer between RPC servers is implemented for efficient execution of a Task Sequencing job in a grid environment. In Task Sequencing, RPC requires dependency between input and output parameters, which means output of a previous RPC becomes the input of the next RPC. In this study, the direct transfer of data is implemented using the grid filesystem without destroying the GridRPC programming model and without changing very many parts of the existing Ninf-G implementation. Our Task Sequencing API library analyzes RPC arguments to detect intermediate data after task submissions, and reports the information to GridRPC servers so that the intermediate data is created on the grid filesystem. Through our performance evaluation on LAN and on the Japan-US grid environment, it was verified that the function achieved performance improvement in distributed Task Sequencing.
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.
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.