Arens, Y.; Knoblock, C. A.; and Shen, W. 1996.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....and periodic information need. The InfoSleuth agents cooperate to populate the information needs of the domain events by accumulating and transforming data from a myriad of disparate data sources. InfoSleuth offers a metaphor beyond its counterparts in distributed information gathering, such as (Arens, Knoblock, Shen 1996; Garcia Molina et al. 1997; Levy, Srivastava, Kirk 1995) in that InfoSleuth is focused on loosely coupled components performing complex analysis and mined associations over the information space. Additional highlights of the InfoSleuth paradigm related to agent interaction are: ffl Community ....

Arens, Y.; Knoblock, C. A.; and Shen, W. 1996.

....in Picsel (Lattes Rousset 1998) Picsel is an information integration system over sources that are distributed and possibly heterogeneous. A first feature that distinguishes Picsel from existing integration information systems like Information Manifold (Y. Levy, Rajamaran, Ordille 1996) SIMS (Arens, Knoblock, Shen 1996), or Infomaster (Genesereth, Keller, Duschka 1997) is its full use of the combination of Datalog with description logics to represent both the domain of application and the contents of information sources. Note that Information Manifold already used Datalog extended with some features of ....

Arens, Y.; Knoblock, C. A.; and Shen, W.-M. 1996.

....(Research Statement) Jos e Luis Ambite Information Sciences Institute and Department of Computer Science University of Southern California ambite isi.edu My research interests are on flexible and efficient query processing in mediator systems. In the context of the SIMS (Arens et al. 1993; Arens, Knoblock, Shen 1996) and Ariadne (Knoblock et al. 1998) projects, we have applied a general framework for efficient highquality planning, called Planning by Rewriting (Ambite Knoblock 1997) to the problem of generating query plans in distributed and heterogeneous environments (Ambite Knoblock 1998) SIMS and ....

Arens, Y.; Knoblock, C. A.; and Shen, W.-M. 1996.

....Query planning Distributed query processing involves generating a plan that efficiently computes a user query. This plan is composed of data retrieval actions at diverse information sources and operations on this data. We used a simplified domain for the query planner (Sage) of the SIMS mediator (Arens, Knoblock, Shen 1996). We compare the performance and quality of the Sage planner and PBR for this domain, where the query plans are trees of join operations. 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 0 2 4 6 8 10 12 Schedule Length Number of Goals Sage BFS Sage DFS PBR Figure 9: Schedule Length Comparison In the query ....

Arens, Y.; Knoblock, C. A.; and Shen, W.-M. 1996.

....Systems. The views and conclusions contained in this paper are the authors and should not be interpreted as representing the official opinion or policy of any of the above organizations or any person connected with them. O. Duschka 1997) disco (Tomasic, Raschid, Valduriez 1997) sims (Arens, Knoblock, Shen 1996) and Ariadne (Ambite et al. 1998) a descendant of sims focusing on integrating Web sources. Such systems allow database like querying of semi structured Web sources through wrappers around the Web sources, and also provide integrated access to multiple data sources. The query response time for ....

....view over two sources of information about countries factbook country and country heads. The user queries the integrated view i.e. concepts in the domain model and the query planner in the agent generates plans to retrieve the requested information from one or more sources. Please refer to (Arens, Knoblock, Shen 1996) for a more detailed description of sims. Overall Optimization Approach Our approach to optimization is based on an idea described in (Arens Knoblock 1994) where we identify useful classes of information to materialize, materialize the data in these classes in a database local to the agent and ....

Arens, Y.; Knoblock, C. A.; and Shen, W.-M. 1996.

....include: choose source, infer equivalence, substitute definition, and decompose. The reformulation operators are used to rewrite the query expressed in domain terms into queries expressed in terms of the available information sources. The details of the reformulation operators are provided in (Arens, Knoblock, Shen 1996). Consider the operator shown in Table 3, which defines a join performed in the local system. This operator is used to achieve the goal of making some information available in the local knowledge base of the sims information mediator. It does this by partitioning the request into two subsets of ....

Arens, Y.; Knoblock, C. A.; and Shen, W.-M. 1996.

....complexity, namely, the ordering of data processing operators and the selection of relevant information sources for terms in a given query. Mediators need to provide mechanisms to resolve the semantic heterogeneity among the different sources. Our approach follows that of the SIMS mediator system (Arens, Knoblock, Shen 1996; Knoblock Ambite 1997) Briefly, SIMS assumes that a set of information sources such as databases, knowledge bases, web servers, etc. supply data about a particular application domain. The system designer specifies a global model of the application domain and defines the contents of the ....

....( n1 n2) with ( operators ( n3 (join q3 jc3 sq3a sq3b) n4 (join q4 jc4 sq4a sq4b) Figure 7: Join Swap Rewriting Rule erogeneous nature of the environment. As we explained earlier, a mediator needs to reconcile the semantic differences among the sources. A common approach (Arens, Knoblock, Shen 1996; Levy, Rajaraman, Ordille 1996; Kwok Weld 1996) is to define each source class as a logical formula over classes in a global domain model. In the SIMS mediator, for each class and set of attributes in the domain model the system automatically compiles axioms that describe how to obtain such ....

Arens, Y.; Knoblock, C. A.; and Shen, W.-M. 1996.

....each section, we also describe the AI methods that are used in modeling and query processing, and how the uniform representational scheme supports these methods. Approach to Information Integration Ariadne s approach to information integration is based heavily on the SIMS mediator architecture (Arens et al. 1996; Knoblock 1995) SIMS enables users to obtain information from multiple heterogeneous information sources. The framework consists of two parts: 1) a query planner executor that determines how to efficiently process a query given the set of available information sources and 2) wrappers that ....

Arens, Y.; Knoblock, C.A.; and Shen, W.M. 1996.

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