Subrahmanian, V., Adali, S., Brink, A., Emery, R., Lu, J., Rajput, A., Rogers, T., Ross, R., and Ward, C. Hermes: Heterogeneous reasoning and mediator system. http://www.cs.umd.edu/projects/hermes/publications/abstracts/hermes.html. Woo, T. and Lam, S. 1993. Authorizations in distributed systems: A new approach. Journal of Computer Security 2, 2,3, 107-136.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....relations, until the user is satisfied with the answer. The W3GDB approach is similar to that of the Information Manifold [15] in the sense that it describes information sources as local relations and maps those local relations to the global ones. Other systems (e.g. TSIMMIS [12] and HERMES [21]) concentrate on translating queries directly rather than by mapping local relations to global ones. But there are some important differences, having to do with common problems one faces in using such a system. First, when many sources are available on a topic, one needs to write many ....

V.S. Subrahmanian, S. Adali, A. Brink, R. Emery, J. Lu, A. Rajput, T. Rogers, R. Ross, and C. Ward. "HERMES: A Heterogeneous Reasoning and Mediator System. Tech. Report, U. of Maryland, 1995. 6

....to correlations, so we expect SJA (and SJA ) to generate excellent fusion query plans, even in the face of condition correlations. 4. 7 Fusion Queries in Existing Optimizers The expansion of the Web has led to mediator prototypes that combine information from multiple heterogeneous sources [4, 9, 13, 18, 28, 37, 68, 71]. Similarly, prototypes for integrating databases have been developed, and recently integration products are being released or announced [2, 5, 7, 26, 45] We note that there is a close connection between mediator based systems [79] and distributed database systems [53] Many mediator systems ....

....elimination becomes very expensive. This task takes time that is exponential in the number of the constituent SPJ subqueries, which in turn is exponential in the size of the original fusion query. Examples of systems in our first category are Information Manifold [41] TSIMMIS [55] HERMES [68] and Infomaster [23] Query processing in these systems is based on resolution [11, 24] which leads to the distribution of the join over the union. For example, Information Manifold would process our sample fusion query by generating nine datalog [75] subqueries, one for each of the nine ....

V.S. Subrahmanian et al. HERMES: A Heterogeneous Reasoning and Mediator System. http://www.cs.umd.edu/projects/hermes/overview/papers. January 1998.

.... integration from multiple data repositories (including semi structured and unstructured data) Examples include the TSIMMIS project at Stanford University [7] the SIMS project [17] the Ariadne project [26] at the University of Southern California, the Hermes project at the University of Maryland [23], NIMBLE a commercial system based on research at the University of Washington [20] and the TAMBIS project in UK [8] INDUS has been inspired by, and builds on previous work by several groups on data integration, and in particular, logic based and ontology based approaches to data integration ....

Subrahmanian, V.S., Sibel Adali, Anne Brink, James J. Lu, Adil Rajput, Timothy J. Rogers, Robert Ross, Charles Ward (2000). HERMES A Heterogeneous Reasoning and Mediator System.

....integrated information. Thereby, values of confidence or belief act as a basis for the calculation of a most promising fact to include into a common model. Examples for the use of annotated logics are the KAMEL language used in the KOMET approach [Calmet et al. 1993] and the HERMES project [Subrahmanian et al. 1995] . 3 Use of Mappings The task of integrating heterogeneous information sources put ontology in context. They cannot be perceived as standalone models of the world. They can rather be seen as the glue that puts together information of various kinds. Consequently, the relation of an ontology to ....

V. S. Subrahmanian, S. Adali, A. Brink, R. Emery, J. Lu, A. Rajput, T. Rogers, R. Ross, and C. Ward. Hermes: A heterogeneous reasoning and mediator system. Technical report, University of Maryland, 1995. 4

....information would have. In his seminal paper [3] Gio Wiederhold proposed the mediation architecture as a blueprint for the design of systems aimed at the intelligent integration of distributed, heterogeneous and autonomous sources. Most existing or proposed mediation systems (for example HERMES [14], TSIMMIS [2] Information Manifold [7] DISCO [15] and Context Interchange [1] comprise the three components of the mediation architecture. Facilitators provide user and application programming interfaces that This research was partially funded by grant R 252 000 064 107 from the National ....

....a wrapper interfacing an online bookstore may only support queries that indicate the name of the author or the title of the book searched, because this is the only interaction authorized by the form based Web interface. Therefore the optimizer must compose a plan under feasibility constraints [5, 9, 12, 14, 16]. Secondly, the optimizer must perform its optimization under cost models that estimate communication and source processing costs in a volatile environment, where none of these gures are precisely known nor can be controlled. For example (as we have all experienced as Web users) the response time ....

V. S. Subrahmanian et al. Hermes: A heterogeneous reasoning and mediator system. http://www.cs.umd.edu/projects/hermes/overview/paper, 1996.

.... retrieval systems (e.g. see [11 15] and Web based sources (e.g. see [16, 17] The techniques for building relational mediators are appropriate for rendering the structural (schema) heterogeneities of the sources transparent to the users (e.g. see the systems TSIMMIS [18] 7] HERMES [19], Information Manifold [6] Our work can complement these techniques so that to support approximate translations of values that are partially ordered. The difference with the approach presented in [20] is that in this approach the reasoning services for supporting translations have exponential ....

V. S. Subrahmanian, S. Adah, A. Brink, R. Emery, A. Rajput, R. Ross, T. Rogers, and C. Ward. "HERMES: A Heterogeneous Reasoning and Mediator System", 1996. (www.cs.umd.edu/projects/hermes/ overview/paper).

....external software: by now it is possible to integrate C, Tcl Tk and the ECLiPSe Data and Knowledge Base but it is planned to support other programming languages. Moreover it is under study how to extend the interface agents capabilities to make them real mediator agents, in the spirit of HERMES [16] and IMPACT [3] approaches. ....

V.S. Subrahmanian, S. Adali, A. Brink, R. Emery, J.J. Lu, A. Rajput, T.J. Rogers, R. Ross, and C. Ward. HERMES: Heterogeneous Reasoning and Mediator System, 1995.

....via wrapper s: components that translate queries from the language of the mediator into that of the ISs and the answers from the language or the data model of the IS into that of the mediator. The resulting architecture is depicted in gure 1. More information on mediators can be found e.g. in [6, 15]. Information source 1 Information source 2 Information source 3 Wrapper 1 Wrapper 2 Wrapper 3 Mediator User Figure 1 The mediator architecture The context of the work presented in this paper was provided by KOMET (Karlsruhe Open MEdiator Technology [1] a logic based me diator shell ....

V. S. Subrahmanian, S. Adal, A. Brink, R. Emery, J. J. Lu, A. Rajput, T. J. Rogers, R. Ross, and C. Ward. HERMES: A heterogeneous reasoning and mediator system. Technical report, University of Maryland, 1995.

....via wrapper s: components that translate queries from the language of the mediator into that of the ISs and the answers from the language of the IS into that of the mediator. The resulting architecture is depicted in the UML diagram of gure 1. More information on mediators can be found e.g. in [27, 12, 29]. The context of the work presented in this paper was provided by KOMET (Karlsruhe Open MEdiator Technology [4] a logic based mediator shell developed at the University of Karlsruhe. KOMET uses the declarative language KAMEL (KArlsruhe MEdiator Language) which is based on annotated logic. It ....

V. S. Subrahmanian, S. Adal, A. Brink, R. Emery, J. J. Lu, A. Rajput, T. J. Rogers, R. Ross, and C. Ward. HERMES: A heterogeneous reasoning and mediator system. Technical report, University of Maryland, 1995.

....information would have. In his seminal paper [3] Gio Wiederhold proposed the mediation architecture as a blueprint for the design of systems aimed at the intelligent integration of distributed, heterogeneous and autonomous sources. Most existing or proposed mediation systems (for example HERMES [14], TSIMMIS [2] Information Manifold [7] DISCO [15] and Context Interchange [1] comprise the three components of the mediation architecture. Facilitators provide user and application programming interfaces that This research was partially funded by grant R 252 000 064 107 from the National ....

....a wrapper interfacing an online bookstore may only support queries that indicate the name of the author or the title of the book searched, because this is the only interaction authorized by the form based Web interface. Therefore the optimizer must compose a plan under feasibility constraints [5, 9, 12, 14, 16]. Secondly, the optimizer must perform its optimization under cost models that estimate communication and source processing costs in a volatile environment, where none of these figures are precisely known nor can be controlled. For example (as we have all experienced as Web users) the response ....

V. S. Subrahmanian et al. Hermes: A heterogeneous reasoning and mediator system. http://www.cs.umd.edu/projects/hermes/overview/paper, 1996.

....Unfortunately, users are required to be familiar with standard terminology of the domain. In addition, users must query the databases using the Loom query language [19] which is not generally familiar and requires some understanding of the conceptual classes of the knowledge base. HERMES [35][2] also provides a mediated approach for integrating distributed information systems. Knowledge engineers define the domain mappings with a declarative, rule based language. A mediator compiler defines the semantic database integration to the system in an automated way. HERMES also provides a ....

V. S. Subrahmanian, S. Adali, A. Brink, R. Emery, J. J. Lu, A. Rajput, T. J. Rogers, R. Ross, and C. Ward, "HERMES: A Heterogeneous Reasoning and Mediator System", <http://www.cs.umd.edu//projects/hermes/overview/paper/index.html>, 1995.

.... of distinct information sources; f some tools for translation (to cope with syntactic relations) integration and mapping (to handle semantic relations) In the last few years, mediators based systems have become the reference architecture to integrate both structured semi structured data [13, 14, 15 and 16] Such systems are characterized by the presence of wrappers that are responsible of the translation of the data representation from the local model of the information source to the common one and of the queries from the common language to the information source language (fig. 1) ....

....the semantic relations are defined as views. Different mediators are needed to answer different queries or to build distinct relations among data. Existing systems in this class provide the programmer who has designed the mediator, tools to integrate domains, information and to handle conflicts [14, 17 and 18] Mediator Mediator Wrapper Wrapper Source Source Figure 1. A network of Mediators, Wrappers and Information Sources [19] In the latter approach to the design of mediator based systems, query formulation is an activity that stems out from the definition of an integrated schema ....

V. S. Subrahmanian, S. Adali, A. Brink, R. Emery, J. J. Lu, A. Rajput, T. J. Rogers, R. Ross, C. Ward, "HERMES: A Heterogeneous Reasoning and Mediator System", submitted for publication, 1998.

.... of distinct information sources; some tools for translation (to cope with syntactic relations) integration and mapping (to handle semantic relations) In the last few years, mediators based systems have become the reference architecture to integrate both structured semi structured data (Wie92, Sub98, Ham97 and Are93) Such systems are characterized by the presence of wrappers that are responsible of the translation of the data representation from the local model of the information source to the common one and of the queries from the common language to the information source language (fig. ....

....are defined as views. Different mediators are needed to answer different queries or to build distinct relations among data. Existing systems in this class provide the programmer who has designed the mediator, tools to integrate domains, information and to handle conflicts. Gar97, Lev96 and Sub98) In the latter approach to the of design mediator based systems, query formulation is an activity that stems out from the definition of an integrated schema requiring a partial or total unification of the local data models (Are93, Har97 and She88) In spite of the greatest number of prototypes ....

V. S. Subrahmanian, S. Adali, A. Brink, R. Emery, J. J. Lu, A. Rajput, T. J. Rogers, R. Ross, C. Ward, HERMES: A Heterogeneous Reasoning and Mediator System", submitted for publication, 1998. Available @ http://www.cs.umd.edu/projects/hermes/overview/paper

....called CASE tools [2] Nevertheless, completely automating this process is unrealistic for real world systems. Hence the need for computer based assistance tools which address several aspects of the development of FIS. Several CASE tools are now available for building FIS (e.g. 3] 4] 5] [6]) Many of them, however, appear to be limited in scope, and are generally dedicated to limited aspects of the FIS development. They do not attempt to integrate techniques and reasoning common to the integration process and the building of federation components, leaving the question of a general ....

....on the complexity and the heterogeneity of the source databases and on skill of the analyst. The tools must include a collection of basic techniques for the integration instead of a unique, automated, schema integrator. It must include a set of predefined functions for detecting conflicts [6]. Each federation is a new problem of its own, requiring specific reasoning and techniques. Integrating export schemas appears as a learning activity. The predefined functions should be easy to customize and to program, and, specific functions should be easy to develop. Solving syntactic, ....

V.S. Subrahmanian, S. Adali, A. Brink, R.E. J.ames J.L.A. Rajput, T.J. Rogers, R. Ross, Ch. Ward, "HERMES: Heterogeneous Reasoning and Mediator System", University of Maryland, 1995.

....mode of operation while our mediators are flexible as they allow multiple modes of operation. The techniques for building relational mediators are appropriate for rendering the structural (schema) heterogeneities of the sources transparent to the users (see the systems TSIMMIS [4] 7] HERMES [18], Information Manifold [13] However these approaches do not support approximate translation although there are many scenarios in which this functionality is necessary. One approach that considers approximate translations is [3] The queries considered there are boolean expressions of ....

V. S. Subrahmanian, S. Adah, A. Brink, R. Emery, A. Rajput, R. Ross, T. Rogers, and C. Ward. "HERMES: A Heterogeneous Reasoning and Mediator System", 1996. (www.cs.umd.edu/projects/hermes/ overview/paper).

No context found.

Subrahmanian, V., Adali, S., Brink, A., Emery, R., Lu, J., Rajput, A., Rogers, T., Ross, R., and Ward, C. Hermes: Heterogeneous reasoning and mediator system. http://www.cs.umd.edu/projects/hermes/publications/abstracts/hermes.html. Woo, T. and Lam, S. 1993. Authorizations in distributed systems: A new approach. Journal of Computer Security 2, 2,3, 107-136.

No context found.

V. S. Subrahmanian, S. Adali, A. Brink, R. Emery, J. Lu, A. Rajput, T. Rogers, R. Ross, and C. Ward. Hermes: A heterogeneous reasoning and mediator system. Technical report, University of Maryland, 1995.

No context found.

V. S. Subrahmanian, S. Adali, A. Brink, R. Emery, J. Lu, A. Rajput, T. Rogers, R. Ross, and C. Ward. Hermes: A heterogeneous reasoning and mediator system. Technical report, University of Maryland, 1995.

No context found.

V. S. Subrahmanian, S. Adali, A. Brink, R. Emery, J. Lu, A. Rajput, T. Rogers, R. Ross, and C. Ward. Hermes: A heterogeneous reasoning and mediator system. Technical report, University of Maryland, 1995.

No context found.

V. S. Subrahmanian, S. Adah, A. Brink, R. Emery, A. Rajput, R. Ross, T. Rogers, and C. Ward. "HERMES: A Heterogeneous Reasoning and Mediator System", 1996. (www.cs.umd.edu/projects/hermes/ overview/paper).

No context found.

V. Subrahmanian, S. Adali, A. Brink, J. Lu, A. Rajput, T. Rogers, R. Ross, and C. Ward. HERMES: Heterogeneous reasoning and mediator system. 1995.

No context found.

V. S. Subrahmanian, S. Adah, A. Brink, R. Emery, A. Rajput, R. Ross, T. Rogers, and C. Ward. "HERMES: A Heterogeneous Reasoning and Mediator System", 1996. (www.cs.umd.edu/projects/hermes/ overview/paper).

No context found.

V.S. Subrahmanian. Hermes: A heterogeneous reasoning and mediator system. University of Maryland, College Park, Draft, 1995.

No context found.

V. S. Subrahmanian, S. Adali, A. Brink, R. Emery, J. J. Lu, A. Rajput, T. J. Rogers, R. Ross, and C. Ward, HERMES: A Heterogeneous Reasoning and Mediator System, University of Maryland Technical Report, (1995) available at http://www.cs.umd.edu//projects/hermes/ publications/abstracts/hermes.html.

No context found.

V. S. Subrahmanian, S. Adali, A. Brink, R. Emery, J. J. Lu, A. Rajput, T. J. Rogers, R. Ross, and C. Ward, HERMES: A Heterogeneous Reasoning and Mediator System, University of Maryland Technical Report, (1995) available at http://www.cs.umd.edu//projects/hermes/ publications/ abstracts/ hermes.html.

First 50 documents  Next 50

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC