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.
11624555
A Query Algebra for Fragmented XML Stream Data
The increased usage of mobile devices coupled with an unprecedented demand for information has pushed the scalability problem of pull-based data service to the focus. A broadcast model of streaming data over a wireless medium has been proposed as a viable alternative for information dissemination. In the streaming broadcast model, servers broadcast data in an asynchronous and unacknowledged mode while clients process personalized and complex queries locally, relieving the load on the server. We address the query processing of streamed XML data, which is fragmented into manageable chunks for easier synchronization. Although there has been some work done in defining algebras that model XQueries on XML documents, no work has been done in defining query algebras for fragmented XML stream data. We define a model for processing fragmented XML stream data, using the concept of holes and fillers. This model offers the flexibility required by the server to disseminate data in manageable fragments, whenever they become available, and to send repetitions, replacements and removal of fragments. We then present a query algebra for XQuery that operates on this streamed XML data model. The XML fragments are operated upon in a continuous pipelined fashion without the need of materializing the transmitted document at the client site.
36810175
A Multimedia Application using Mobile Agents for Establishing and Managing Streaming Audio Communications
Objective To be a part of an academic institution which has a strong and dedicated commitment to quality education and research.  Built a new UNIX Sun workstation network lab for the CS department. The lab is used for courses, mail and web service.
1557616
Optimizing Grid Scheduling Based on Local Cluster Scheduling Policies and Resource Availability
on the common paradigm of treating clusters as separate administrative domains. Clusters are grouped to form grids which participate in Virtual Organizations (VO) and share resources to meet common computing goals. Each cluster is a separate administrative domain and can choose to be a part of many VOs. Because of the nature of a VO, a cluster typically gives a higher preference to scheduling jobs for one VO over other VOs. In this paper we present a grid scheduling architecture which takes into consideration the current resource availability and scheduling policies of clusters at various sites. This architecture considers both hardware and software resources. The primary goal of this scheduler is to reduce the completion time of jobs by reducing the queuing time of jobs, also providing an increase in CPU utilization. We show the effect of our scheduling technique using a prototype implementation and compare the results against a typical grid scheduler based on random allocation of resources.
30423936
A scalable and self-adapting notification framework for healthcare information systems
There has been a great interest in publish/subscribe systems in recent years. This interest, coupled with the pervasiveness of lightweight electronic devices, such as cellular phones and PDAs, have opened a new arena in publish/subscribe networks. Currently, many broker overlay networks are static and never change in structure. Often, a network overlay structure is predefined or manually manipulated. We present a dynamic broker network in the context of disseminating critical labs and patient information in a Healthcare Information System (HIS). Our work builds upon previous network optimization research on ad-hoc publish/subscribe networks. Our framework utilizes user-defined heuristic cost functions to satisfy QoS constraints. We also address certain reliability issues by providing a scheduling algorithm to selectively retransmit information.
376625
Mobile Agents for Pervasive Computing Using a Novel Method of Message Passing
Pervasive computing is an emerging technology that brings new dimensions to distributed computing; it uses 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 or 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).
139273
Applications-driven parallel I/O
The authors investigate the needs of some massively parallel applications running on distributed-memory parallel computers at Argonne National Laboratory and identify some common parallel I/O operations. For these operations, routines were developed that hide the details of the actual implementation (such as the number of parallel disks) from the application, while providing good performance. An important feature is the ability for the application programmer to specify that a file be accessed either as a high-performance parallel file or as a conventional Unix file, simply by changing the value of a parameter on the file open call. These routines are examples of a parallel I/O abstraction that can enhance development, portability, and performance of I/O operations in applications. Some of the specific issues in their design and implementation in a distributed-memory toolset are discussed.
37714806
Parallel Solution of the Three-Dimensional, Time-Dependent Ginzburg-Landau Equation
The recent discovery of superconductivity in a class of copper-oxide compounds (the cuprate superconductors) at liquid nitrogen temperatures has generated a renewed interest in the magnetic properties of type-II superconductors. In our work, we are investigating these properties using the phenomenological time- dependent Ginzburg-Landau equation. This paper describes the parallelization of this equation.
15912029
A butterfly subdivision scheme for surface interpolation with tension control
A new interpolatory subdivision scheme for surface design is presented. The new scheme is designed for a general triangulation of control points and has a tension parameter that provides design flexibility. The resulting limit surface is C1 for a specified range of the tension parameter, with a few exceptions. Application of the butterfly scheme and the role of the tension parameter are demonstrated by several examples.
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.
666127
Changing the Game in Strategic Sourcing at Procter & Gamble: Expressive Competition Enabled by Optimization
Procter & Gamble put into practice CombineNets approach to building sourcing networks, called expressive competition. At its heart is a vision that looks past lowest-price reverse auctions and combinatorial package bidding toward a highly expressive commerce relationship with suppliers. It enables suppliers to make electronic offers that express rich forms of capabilities and efficiencies. As the buyer, P&G also uses an expressive language to state constraints and preferences. The detailed expressions of supply and demand are brought together via an advanced optimization engine to decide the optimal allocation of business to the suppliers. By March 2005, over a period of two and a half years, P&G had sourced over 3 billion through expressive commerce and seen 294.8 million (9.6 percent) in recommended savings. In the process, P&Gs suppliers benefited from the win-win approach: expressive competition matched demand to the most efficient means of production (rather than squeezing suppliers profit margins) and removed the exposure risks in making offers. Beyond direct monetary savings, the benefits included the redesign of supply networks with quantitative understanding of the trade-offs and the ability to implement in weeks instead of months.