6061688
Mobile Agent Connection Establishment and Management (CEMA)—Message Exchange for Pervasive Computing Environments
Pervasive computing is an emerging technology that offers new possibilities to distributed computing and computer networking; it employs a wide variety of smart, ubiquitous devices throughout an individual's working and living environment. Mobile agents are software entities that can migrate between servers (mobile agent environments) of the network accomplishing various tasks on the behalf of their owners. The objective of this paper is to describe a test and prototyping environment for experimenting with mobile agents in pervasive environments. A prototype environment for a novel, proactive infrastructure is described for mobile agent assisted pervasive computing. In addition, a new message passing algorithm is provided for mobile agent connection establishment and management (CEMA). Simulation results show the performance of the proposed approach.
38463254
Locating and Ranking XML Documents Based on Content and Structure Synopses
We present a new framework for indexing, locating and ranking XML documents based on content and structural synopses extracted from the documents. Instead of indexing each single element or term in a document, we extract a structural summary and a small number of data synopses from the document, which are indexed in an efficient way suitable for query evaluation. Our query language is XPath extended with full-text search. The result of query evaluation is a ranked list of document locations that best match the query. We propose a novel aggregated ranking scheme, which is integrated into the query evaluation to score the documents based on those data synopses. Our experimental evaluation shows that our indexing scheme outperforms the standard XML indexing scheme based on inverted lists and our ranking scheme is effective in terms of precision and recall.
29185449
Performance Analysis and Scalability of the ThreadmanTM Thread Manager
15495414
A tool based methodology for development of automatically scalable and reusable parallel code
Program performance may be improved by efficiently programming some key sections of the software. We present a methodology for converting selected portions of source code into automatically scalable multithreaded routines, without forcing programmers to concentrate on parallel programming issues. These developed routines can be reused across various projects, operating systems and system architectures. To support this methodology two separate but tightly coupled tools have been developed -PARSA/sup (TM)/ software development environment (SDE) and the ThreadMan/sup (TM)/ thread manager. The SDE addresses programming issues by allowing a graphical object based approach to develop multithreaded routines that abstracts the users from parallel programming. ThreadMan manages the software developed using SDE. ThreadMan is a user-level thread manager that automatically spawns and schedules threads at runtime. Two examples have been developed using this methodology to demonstrate that there is virtually no degradation in performance when compared to sequential code, in a single processor system and scalability is achieved as the number of processors is increased.
697463
Interoperability Issues for a Secure Mobile Agent Platform
13161865
On the Reliability and Additional Overhead of Reliable On-Demand Multicast Routing Protocol for Mobile Ad Hoc Networks
Multicasting is the transmission of datagrams to a group of hosts identified by a single destination address, providing simple and efficient communication for group-oriented applications. Many applications currently envisioned for mobile ad hoc networks require multicasting. Several multicasting protocols have been proposed for mobile ad hoc networks, one of the most popular being the On Demand Multicast Routing Protocol. This paper provides a review of ad hoc multicast routing protocols, focusing on MAODV, ODMRP and a variation of ODMRP called reliable-ODMRP. NS-2 simulations are used to compare the reliability and overhead of MAODV, ODMRP, and R-ODMRP.
206967153
Iterative Joint Source-Channel Decoding of H.264 Compressed Video
This paper proposes an iterative joint source-channel decoding (IJSCD) scheme for the transmission of H.264 compressed video over a noisy channel. It uses channel coding along with H.264 semantic verification. The structure, selection of design parameters, and performance of the proposed IJSCD based on a rate-% recursive systematic convolutional (RSC) code over an AWGN channel are described and discussed as an illustrative example. In the example, for the same PSNR, the proposed IJSCD scheme offers a significant saving of 2.1dB in required channel SNR as compared to a system using the same RSC code alone. Furthermore, the performance can be improved by iterative decoding at the cost of increased delay. Hence, a tradeoff can be made between performance improvement and delay
17053048
Performance Testing of a Parallel Multiblock CFD Solver
A distributed-memory version of the OVERFLOW computational fluid dynamics code was evaluated on several parallel systems and compared with other approaches using test cases provided by the NASA-Boeing High-Speed Civil Transport program. A principal goal was to develop partitioning and load-balancing strategies that led to a reduction in computation time. We found multipartitioning, in which the aspect ratio of the multipartition is close to the aspect ratio of the grid zone, offered the best performance. The (uniprocessor) performance of the CRAY vector systems was superior to all other systems tested. However, the distributed-memory version when run on an SGI Origin system offers a price performance advantage over the CRAY vector systems.Performance on personal computer systems is promising but faces several hurdles.
9657478
Computational Electromagnetics and Parallel Dense Matrix Computations
We present computational results using CORAL, a parallel, three-dimensional, nonlinear magnetostatic code based on a volume integral equation formulation. A key feature of CORAL is the ability to solve, in parallel, the large, dense systems of linear equations that are inherent in the use of integral equation methods. Using the Chameleon and PSLES libraries ensures portability and access to the latest linear algebra solution technology.
62674005
Itinerant Agents for Mobile Computing
40980541
Object-oriented programming (abstract): how to “scale up” CS 1
This past June, the National Science Foundation sponsored a workshop devoted to exploring the topic of how to integrate object-oriented programming g (OOP) concepts into the undergraduate curriculum Participants were chosen based, in pm on papers and lab materials that were submitted demonstrating practical experience with teaching 00P to undergraduates. One of the many surprises (to the conveners) to come out of the workshop was the large number of attendees who advocated teaching 00P (in a variety of languages) in the fiist programming course for majors (CS 1), and who had developed interesting approaches for doing so.