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.
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.
6748545
Quality of Service Primitives for Operating System Support of Multimedia Applications
10614369
PICO: A Middleware Framework for Pervasive Computing
The pervasive information community organization is a framework for creating mission-oriented dynamic communities of autonomous software entities that perform tasks for users and devices. PICO's telemedicine example scenario demonstrates its potential as a simple, unique, and versatile middleware framework for pervasive computing.
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.
29185449
Performance Analysis and Scalability of the ThreadmanTM Thread Manager
6198667
CABOB: A Fast Optimal Algorithm for Combinatorial Auctions
Combinatorial auctions where bidders can bid on bundles of items can lead to more economical allocations, but determining the winners is NP-complete and inapproximable. We present CABOB, a sophisticated search algorithm for the problem. It uses decomposition techniques, upper and lower bounding (also across components), elaborate and dynamically chosen bid ordering heuristics, and a host of structural observations. Experiments against CPLEX 7.0 show that CABOB is usually faster, never drastically slower, and in many cases drastically faster. We also uncover interesting aspects of the problem itself. First, the problems with short bids that were hard for the first-generation of specialized algorithms are easy. Second, almost all of the CATS distributions are easy, and become easier with more bids. Third, we test a number of random restart strategies, and show that they do not help on this problem because the run-time distribution does not have a heavy tail (at least not for CABOB).
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.
16053840
Parallel computation of three-dimensional nonlinear magnetostatic problems
We describe a general-purpose parallel electromagnetic code for computing accurate solutions to large computationally demanding, 3D, nonlinear magnetostatic problems. The code, CORAL, is based on a volume integral equation formulation. Using an IBM SP parallel computer and iterative solution methods, we successfully solved the dense linear systems inherent in such formulations. A key component of our work was the use of the PETSc library, which provides parallel portability and access to the latest linear algebra solution technology.
20665084
Parallel performance of two applications in the Boeing high performance computing benchmark suite
Abstract We describe our work to evaluate the performance of the parallel versions of two floating-point-intensive engineering applications from Boeing's high performance computing benchmark suite (BHPCBS) on emerging RISC parallel systems and PC clusters. The first application is a computational fluid dynamics (CFD) code, OVERFLOW, developed by NASA and used by Boeing for analysis and design of advanced aircraft. The second application is a prototype of a computational electromagnetics (CEM) code, developed by Boeing and used for radar cross-section studies. The distributed memory parallel versions of both applications use the message passing interface (MPI) standard for message passing. The goal of our work was to determine whether RISC parallel systems and PC clusters, which offer high performance at low cost, may be able to meet Boeing's computing requirements in the future. We describe the test environments for the studies, discuss parallelization issues and strategies and present performance data for the two applications.
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.