639197
An integrated and collaborative framework for business design: A knowledge engineering approach
Many large-scale endeavors, especially the ones that need to be performed on an occasional basis, are performed on a de novo basis. Whether one is designing a spacecraft or a dam, or launching a sales campaign, each endeavor tends to have a life of its own. Very little knowledge, if any, is transferred from one business or engineering design endeavor to a successive one. This paper describes an approach that involves the acquisition of raw information from the keystrokes entered by the user while performing the primary activity. Such information is distilled to produce knowledge for future use, without imposing additional burden on human users involved in the first endeavor or the succeeding endeavors. The paper also describes a complementary approach that significantly reduces the time and effort spent by human beings in articulating their requirements, and specifically, in terms of delineating the indifference points among a set of feasible alternatives. Both these approaches have been validated in a complex multi-organizational situation related to spacecrafts. The approaches can be applied, either singly or jointly, to a broad class of business and engineering scenarios. They incorporate the notion of automated knowledge acquisition, discovery, management, and dissemination. The proposed approach is discussed in the context of supporting workteams that are distributed both on geographic and temporal basis, thereby creating a "24-Hour Knowledge Factory" environment.
5958805
Selective and authentic third-party distribution of XML documents
Third-party architectures for data publishing over the Internet today are receiving growing attention, due to their scalability properties and to the ability of efficiently managing large number of subjects and great amount of data. In a third-party architecture, there is a distinction between the Owner and the Publisher of information. The Owner is the producer of information, whereas Publishers are responsible for managing (a portion of) the Owner information and for answering subject queries. A relevant issue in this architecture is how the Owner can ensure a secure and selective publishing of its data, even if the data are managed by a third-party, which can prune some of the nodes of the original document on the basis of subject queries and access control policies. An approach can be that of requiring the Publisher to be trusted with regard to the considered security properties. However, the serious drawback of this solution is that large Web-based systems cannot be easily verified to be secure and can be easily penetrated. For these reasons, we propose an alternative approach, based on the use of digital signature techniques, which does not require the Publisher to be trusted. The security properties we consider are authenticity and completeness of a query response, where completeness is intended with regard to the access control policies stated by the information Owner. In particular, we show that, by embedding in the query response one digital signature generated by the Owner and some hash values, a subject is able to locally verify the authenticity of a query response. Moreover, we present an approach that, for a wide range of queries, allows a subject to verify the completeness of query results.
18052775
Pricing of risk for loss guaranteed intra-domain internet service contracts
The Internet today offers primarily a best-effort service. Research and technology development efforts are currently underway to allow provisioning of better than best-effort Quality of Service (QoS) assurances. The residual uncertainty in QoS can be managed using pricing strategies. In this article, we develop a spot pricing framework for intra-domain expected bandwidth contracts with loss-based QoS guarantees. The framework builds on a nonlinear pricing scheme for cost recovery from earlier work and extends it to price risk. A utility-based options pricing approach is developed to account for the uncertainties in delivering loss guarantees. Application of options pricing techniques in Internet services provides a mechanism for fair risk sharing between the provider and the customer, and may be extended to price other uncertainties in QoS guarantees.
18656965
Integrating GIS and Imagery Through XML-Based Information Mediation
In this paper, we investigate a mediation-based approach to integrating information from geospatial information sources such as GIS's and databases of geo-referenced imagery. This approach is based on the use of XML to represent the information at the sources, by exporting XML Document Type Definitions (DTD's) associated with each source, and employing XML-based query languages to query integrated views of information at the mediator. Our goal is to enable users to issue a single query to the mediator, and provide the capability to return a result that seamlessly combines information from multiple sources. This paper describes issues in designing such a mediated system for geospatial data. Our notion of mediation for geospatial data is the "logical integration" of data achieved by creating correspondences between related spatial information, similar to the way mediation is done in "standard" databases. Thus, this notion of mediation does not depend on the development of spatial algorithms that operate on images or vector data and achieve "physical integration" through techniques such as image conflation. However, the mediator architecture does allow for the integration of physical integration techniques. The paper discusses issues related to wrapping of GIS and other geospatial sources and issues in querying such sources using an XML-based query language.
40714150
A semantic mediation approach for problems in computational molecular biology
As great amount of data are being produced and accumulated in life sciences, information access and consequent integration in analytical and computational methods become critical issues in order to conduct research. In this work we describe how the synergic combination of a high-level programmable planner engine and formal semantics are suitable to resolve many information integration problems in molecular biology.
10882098
Registering Scientific Information Sources for Semantic Mediation
In a conventional information mediation scenario it is assumed that all sources, including their schemas, are known before the integrated view is defined. We have found this assumption to be unrealistic for scientific information integration -new relevant sources are discovered quite frequently, and need to be integrated incrementally with an existing federation. In this paper, we address the issue of source registration, the mechanism by which a new information source "registers" its semantics with the mediator, such that not only new views can be defined with the newly joining source, but existing views can benefit from the source without any redefinition. We approach the problem in the framework of semantic (a.k.a. knowledge-based or model-based) mediation, a version of information integration where the sources cannot be integrated solely based on their own logical schema, but need additional domain knowledge at the mediator to "glue" them together. We solve the problem by introducing a process called contextualization, whereby a source specifies a set of axioms to express its own conceptual model relative to the mediator's knowledge base. To this end, we present a context specification language CSL that allows the user to specify this mapping, and illustrate how the mediator interprets a CSL specification to update its knowledge schema and preexisting views. The examples are derived from a real-world scenario involving an ongoing collaboration with several neuroscience groups.
575078
An Approach for Detecting Self-propagating Email Using Anomaly Detection
This paper develops a new approach for detecting self-propagating email viruses based on statistical anomaly detection. Our approach assumes that a key objective of an email virus attack is to eventually overwhelm mail servers and clients with a large volume of email traffic. Based on this assumption, the approach is designed to detect increases in traffic volume over what was observed during the training period. This paper describes our approach and the results of our simulation-based experiments in assessing the effectiveness of the approach in an intranet setting. Within the simulation setting, our results establish that the approach is effective in detecting attacks all of the time, with very few false alarms. In addition, attacks could be detected sufficiently early so that clean up efforts need to target only a fraction of the email clients in an intranet.