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.
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.
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.
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.
7299459
The ninf portal: an automatic generation tool for grid portals
As the Grid proliferates as the next-generation computing infrastructure, a user interface in the form of "Grid Portals" is becoming increasingly important, especially for computational scientists and engineers. Although several Grid Portal toolkits have been proposed, portal developers still must build and deploy both the user interface and the application, which results in considerable programming efforts. We aim to ease this burden by generating a portal frontend (that constitutes of JSP and Java Servlets) from an XML document for the former, and a GridRPC system, Ninf-G for easily "gridifying" existing applications for the latter, and realizing their seamless integration. The resulting system, which we call the Ninf Portal, allowed concise description and easy deployment of a real Grid application with greatly small programming efforts.
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.
27048178
Mechanism and control of mobile pipeline maintenance robot with lazy tongs mechanism
A new type of mobile pipeline maintenance robot has been designed to clarify the feasibility of lazy tongs mechanism for adaptation to various size pipelines. The robot basically consists of three modules with two joints between modules and can move straight and spirally along the surface of pipeline. The robot can change its arm length in order to move on the pipeline of various size from 25 A to 100 A, and pass over obstacles such as reducer, diffuser, flange and other plant equipment. The control of the robot is so complicated that the modified dual control mode is introduced using the coordinate transformation matrix. By calculating the position and attitude of the robot under the control mode, the manoeuvrability of passing over a reducer is shown with experimental results.