Global Grids and Software Toolkits: A Study of Four Grid Middleware Technologies

Grid is an infrastructure that involves the integrated and collaborative use of computers, networks, databases and scientific instruments owned and managed by multiple organizations. Grid applications often involve large amounts of data and/or computing resources that require secure resource sharing across organizational boundaries. This makes Grid application management and deployment a complex undertaking. Grid middlewares provide users with seamless computing ability and uniform access to resources in the heterogeneous Grid environment. Several software toolkits and systems have been developed, most of which are results of academic research projects, all over the world. This chapter will focus on four of these middlewares--UNICORE, Globus, Legion and Gridbus. It also presents our implementation of a resource broker for UNICORE as this functionality was not supported in it. A comparison of these systems on the basis of the architecture, implementation model and several other features is included.Comment: 19 pages, 10 figure

Evaluation of the accuracy of a patient-specific instrumentation

Patient-specific instruments (PSI) has been introduced with the aim to reduce the overall costs of the implants, minimizing the size and number of instruments required, and also reducing surgery time. The aim of this study was to perform a review of the current literature, as well as to report about our personal experience, to assess reliability and accuracy of patient specific instrument system in total knee arthroplasty (TKA). A literature review was conducted of PSI system reviewing articles related to coronal alignment, clinical knee and function scores, cost, patient satisfaction and complications. Studies have reported incidences of coronal alignment ≥3° from neutral in TKAs performed with patient-specific cutting guides ranging from 6% to 31%. PSI seem not to be able to result in the same degree of accuracy as for the CAS system, while comparing well with standard manual technique with respect to component positioning and overall lower axis, in particular in the sagittal plane. In cases in which custom-made cutting jigs were used, we recommend performing an accurate control of the alignment before and after any cuts and in any further step of the procedure, in order to avoid possible outliers

Experimental Study of Remote Job Submission and Execution on LRM through Grid Computing Mechanisms

Remote job submission and execution is fundamental requirement of distributed computing done using Cluster computing. However, Cluster computing limits usage within a single organization. Grid computing environment can allow use of resources for remote job execution that are available in other organizations. This paper discusses concepts of batch-job execution using LRM and using Grid. The paper discusses two ways of preparing test Grid computing environment that we use for experimental testing of concepts. This paper presents experimental testing of remote job submission and execution mechanisms through LRM specific way and Grid computing ways. Moreover, the paper also discusses various problems faced while working with Grid computing environment and discusses their trouble-shootings. The understanding and experimental testing presented in this paper would become very useful to researchers who are new to the field of job management in Grid.Comment: Fourth International Conference on Advanced Computing & Communication Technologies (ACCT), 201

MPICH-G2: A Grid-Enabled Implementation of the Message Passing Interface

Application development for distributed computing "Grids" can benefit from tools that variously hide or enable application-level management of critical aspects of the heterogeneous environment. As part of an investigation of these issues, we have developed MPICH-G2, a Grid-enabled implementation of the Message Passing Interface (MPI) that allows a user to run MPI programs across multiple computers, at the same or different sites, using the same commands that would be used on a parallel computer. This library extends the Argonne MPICH implementation of MPI to use services provided by the Globus Toolkit for authentication, authorization, resource allocation, executable staging, and I/O, as well as for process creation, monitoring, and control. Various performance-critical operations, including startup and collective operations, are configured to exploit network topology information. The library also exploits MPI constructs for performance management; for example, the MPI communicator construct is used for application-level discovery of, and adaptation to, both network topology and network quality-of-service mechanisms. We describe the MPICH-G2 design and implementation, present performance results, and review application experiences, including record-setting distributed simulations.Comment: 20 pages, 8 figure

Inspiring Innovation

These accounts of the early lives, Navy appointments, and career accomplishments of the African American officers who followed in the trail that Vice Admiral Gravely blazed are offered to document the determination demonstrated and the successes achieved, under the often trying circumstances of bias encountered and obstacles that had to be overcome that the admiral mentioned in his formula for success.https://digital-commons.usnwc.edu/usnwc-van-beuren-les/1003/thumbnail.jp

The Architectural Design of Globe: A Wide-Area Distributed System

. Developing large-scale wide-area applications requires an infrastructure that is presently lacking entirely. Currently, applications have to be built on top of raw communication services, such as TCP connections. All additional services, including those for naming, replication, migration, persistence, fault tolerance, and security, have to be implemented for each application anew. Not only is this a waste of effort, it also makes interoperability between different applications difficult or even impossible. We present a novel, object-based framework for developing wide-area distributed applications. The framework is based on the concept of a distributed shared object, which has the characteristic feature that its state can be physically distributed across multiple machines at the same time. All implementation aspects, including communication protocols, replication strategies, and distribution and migration of state, are part of an object and are hidden behind its interface. The curren..