14446925
Indexing and Searching XML Documents Based on Content and Structure Synopses
We present a novel framework for indexing and searching schema-less XML documents based on concise summaries of their structural and textual content. Our search query language is XPath extended with full-text search. We introduce two novel data synopsis structures that correlate textual with positional information in an XML document and improves query precision. In addition, we present a two-phase containment filtering algorithm based on these synopses that improves the searching process. Our experimental evaluation shows that our data synopses indexing scheme outperforms the standard XML indexing scheme based on inverted lists; the query evaluation based on our data synopses is more accurate than related approximate approaches that do not consider positional information; our two-phase containment filtering algorithm is more efficient than a single-phase brute force algorithm.
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.
6748545
Quality of Service Primitives for Operating System Support of Multimedia Applications
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.
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.
29185449
Performance Analysis and Scalability of the ThreadmanTM Thread Manager
29157947
Massively parallel computation of conservation laws
Abstract We present a new method for computing solutions of conservation laws based on the use of cellular automata with the method of characteristics. The method exploits the high degree of parallelism available with cellular automata and retains important features of the method of characteristics. It yields high numerical accuracy and extends naturally to adaptive meshes and domain decomposition methods for perturbed conservation laws. We describe the method and its implementation for a Dirichlet problem with a single conservation law for the one-dimensional case. Numerical results for the one-dimensional law with the classical Burgers nonlinearity or the Buckley-Leverett equation show good numerical accuracy outside the neighborhood of the shocks. The error in the area of the shocks is of the order of the mesh size. The algorithm is well suited for execution on both massively parallel computers and vector machines. We present timing results for an Alliant FX/8, Connection Machine Model 2, and CRAY X-MP.
35397691
Accomplishing More by Doing Less - Lessons from Spanish Language Instruction
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.
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.
15239156
Application of a hybrid genetic algorithm to airline crew scheduling
This paper discusses the development and application of a hybrid genetic algorithm to airline crew scheduling problems. The hybrid algorithm consists of a steady-state genetic algorithm and a local search heuristic. The hybrid algorithm was tested on a set of 40 real-world problems. It found the optimal solution for half the problems, and good solutions for 9 others. The results were compared to those obtained with branch-and-cut and branch-and-bound algorithms. The branch-and-cut algorithm was significantly more successful than the hybrid algorithm, and the branch-and-bound algorithm slightly better.