Results 1 - 10 of 56,110

Semantic Query Optimization in an Automata-Algebra Combined XQuery Engine over XML Streams

by Hong Su, Elke A. Rundensteiner, Murali Mani , 2004
"... Our Raindrop framework [6, 9] aims at tackling challenges of stream processing that are particular to XML. In contrast to the tuple-based or object-based data streams, XML streams are usually modeled as a sequence of primitive tokens, such as a start tag, an end tag or a PCDATA item. Unlike a self-c ..."
Abstract - Cited by 7 (2 self) - Add to MetaCart
-contained tuple or object whose semantics are completely determined by its own values, a token lacks semantics without the context provided by other tokens in the stream. This poses specific challenges for query processing over such XML streams. State-of-the-Art. Since the automata model was originally designed

Relational Databases for Querying XML Documents: Limitations and Opportunities

by Jayavel Shanmugasundaram, Kristin Tufte, Gang He, Chun Zhang, David DeWitt, Jeffrey Naughton , 1999
"... XML is fast emerging as the dominant standard for representing data in the World Wide Web. Sophisticated query engines that allow users to effectively tap the data stored in XML documents will be crucial to exploiting the full power of XML. While there has been a great deal of activity recently prop ..."
Abstract - Cited by 490 (9 self) - Add to MetaCart
that the relational approach can handle most (but not all) of the semantics of semi-structured queries over XML data, but is likely to be effective only in some cases. We identify the causes for these limitations and propose certain extensions to the relational

Tinydb: An acquisitional query processing system for sensor networks

by Samuel R. Madden, Michael J. Franklin, Joseph M. Hellerstein, Wei Hong - ACM Trans. Database Syst , 2005
"... We discuss the design of an acquisitional query processor for data collection in sensor networks. Acquisitional issues are those that pertain to where, when, and how often data is physically acquired (sampled) and delivered to query processing operators. By focusing on the locations and costs of acq ..."
Abstract - Cited by 609 (8 self) - Add to MetaCart
of acquiring data, we are able to significantly reduce power consumption over traditional passive systems that assume the a priori existence of data. We discuss simple extensions to SQL for controlling data acquisition, and show how acquisitional issues influence query optimization, dissemination

Semantic Query Optimization for XQuery over XML Streams

by Hong Su, Elke A. Rundensteiner, Murali Mani - In VLDB , 2005
"... We study XML stream-specific schema-based optimization. We assume a widely-adopted automata-based execution model for XQuery evaluation. Criteria are established regarding what schema constraints are useful to a particular query. How to apply multiple optimization techniques on an XQuery is then add ..."
Abstract - Cited by 14 (3 self) - Add to MetaCart
We study XML stream-specific schema-based optimization. We assume a widely-adopted automata-based execution model for XQuery evaluation. Criteria are established regarding what schema constraints are useful to a particular query. How to apply multiple optimization techniques on an XQuery

Sesame: A Generic Architecture for Storing and Querying RDF and RDF Schema

by Jeen Broekstra, Arjohn Kampman, Frank Van Harmelen , 2002
"... RDF and RDF Schema are two W3C standards aimed at enriching the Web with machine-processable semantic data. ..."
Abstract - Cited by 537 (11 self) - Add to MetaCart
RDF and RDF Schema are two W3C standards aimed at enriching the Web with machine-processable semantic data.

Models and issues in data stream systems

by Brian Babcock, Shivnath Babu, Mayur Datar, Rajeev Motwani, Jennifer Widom - IN PODS , 2002
"... In this overview paper we motivate the need for and research issues arising from a new model of data processing. In this model, data does not take the form of persistent relations, but rather arrives in multiple, continuous, rapid, time-varying data streams. In addition to reviewing past work releva ..."
Abstract - Cited by 770 (19 self) - Add to MetaCart
relevant to data stream systems and current projects in the area, the paper explores topics in stream query languages, new requirements and challenges in query processing, and algorithmic issues.

Ontologies: Silver Bullet for Knowledge Management and Electronic Commerce

by Dieter Fensel , 2007
"... Currently computers are changing from single isolated devices to entry points into a world wide network of information exchange and business transactions called the World Wide Web (WWW). Therefore support in the exchange of data, information, and knowledge exchange is becoming the key issue in cur ..."
Abstract - Cited by 643 (46 self) - Add to MetaCart
will play in knowledge management and in electronic commerce. In addition, I show how arising web standards such as RDF and XML can be used as

Dryad: Distributed Data-Parallel Programs from Sequential Building Blocks

by Michael Isard, Mihai Budiu, Yuan Yu, Andrew Birrell, Dennis Fetterly - In EuroSys , 2007
"... Dryad is a general-purpose distributed execution engine for coarse-grain data-parallel applications. A Dryad applica-tion combines computational “vertices ” with communica-tion “channels ” to form a dataflow graph. Dryad runs the application by executing the vertices of this graph on a set of availa ..."
Abstract - Cited by 730 (27 self) - Add to MetaCart
Dryad is a general-purpose distributed execution engine for coarse-grain data-parallel applications. A Dryad applica-tion combines computational “vertices ” with communica-tion “channels ” to form a dataflow graph. Dryad runs the application by executing the vertices of this graph on a set

Machine Learning in Automated Text Categorization

by Fabrizio Sebastiani - ACM COMPUTING SURVEYS , 2002
"... The automated categorization (or classification) of texts into predefined categories has witnessed a booming interest in the last ten years, due to the increased availability of documents in digital form and the ensuing need to organize them. In the research community the dominant approach to this p ..."
Abstract - Cited by 1658 (22 self) - Add to MetaCart
to this problem is based on machine learning techniques: a general inductive process automatically builds a classifier by learning, from a set of preclassified documents, the characteristics of the categories. The advantages of this approach over the knowledge engineering approach (consisting in the manual

Grid Information Services for Distributed Resource Sharing

by Karl Czajkowski , Steven Fitzgerald, Ian Foster, Carl Kesselman , 2001
"... Grid technologies enable large-scale sharing of resources within formal or informal consortia of individuals and/or institutions: what are sometimes called virtual organizations. In these settings, the discovery, characterization, and monitoring of resources, services, and computations are challengi ..."
Abstract - Cited by 703 (52 self) - Add to MetaCart
to incorporate individual entities into various information structures, such as aggregate directories that support a variety of different query languages and discovery strategies. These protocols can also be combined with other Grid protocols to construct additional higher-level services and capabilities
Results 1 - 10 of 56,110