14311449
A software framework for matchmaking based on semantic web technology
An important objective of the Semantic Web is to make Electronic Commerce interactions more flexible and automated. To achieve this, standardization of ontologies, message content and message protocols will be necessary.In this paper we investigate how Semantic and Web Services technologies can be used to support service advertisement and discovery in e-commerce. In particular, we describe the design and implementation of a service matchmaking prototype which uses a DAML-S based ontology and a Description Logic reasoner to compare ontology based service descriptions. We also present the results of initial experiments testing the performance of this prototype implementation in a realistic agent based e-commerce scenario.
2448001
The Instance Store: DL Reasoning with Large Numbers of Individuals
We present an application – the Instance Store – aimed at solving some of the scalability problems that arise when reasoning with the large numbers of individuals envisaged in the semantic web. The approach uses well-known techniques for reducing description logic reasoning with individuals to reasoning with concepts. Crucial to the implementation is the combination of a description logic terminological reasoner with a traditional relational database. The resulting form of inference, although specialised, is sound and complete and sufficient for several interesting applications. Most importantly, the application scales to sizes (over 100,000s individuals) where all other existing applications fail. This claim is substantiated by a detailed empirical evaluation of the Instance Store in contrast with existing alternative approaches.
83373
Reasoning with large numbers of individuals moves on: extending the instance store
The Semantic Web [2] aims at enabling Web resources to be accessible to automated processes by adding “semantic annotations”—metadata (data about data) that describes their content. It is envisaged that the semantics in semantic annotations will be given by ontologies [8], which will provide a source of precisely defined terms (vocabularies) that are amenable to automated reasoning. A standard for expressing ontologies in the Semantic Web has already emerged: the ontology language OWL [4], which recently became a W3C proposed recommendation. One of the main features of OWL is that there is a direct correspondence between (two of the three “species” of) OWL and Description Logics (DLs) [12]. This means that reasoning procedures from DLs can be used in order to infer useful facts from ontology based annotations in OWL. In particular, since annotations are usually defined as individual instances of ontology classes, it is reasonable then to use ABox reasoning (the DL term for reasoning about individuals) to reason about annotations [3]. However, developing a practical ABox reasoner for such annotations is difficult. This difficulty arises not only from the computational complexity of ABox reasoning, but also from the fact that the number of annotations might be extremely large. On the one hand, the task of reasoning with large amounts of individuals is difficult even for the state-of-art optimised ABox reasoner RACER [9]. On the other hand, efficient management of very large volumes of data is well known to be a stronghold of relational databases. The approach of combining relational databases with Description Logics to deal with large amounts of data was, therefore, proposed in [11] which we call an Instance Store. The Instance Store provides an infrastructure for reasoning with large numbers of individuals. It combines a DL reasoner with a database in order to provide large scale storage of instance data, and sound and complete answers to instance retrieval queries for arbitrary query concepts. However, in order to simplify the integrated architecture, and to provide acceptable query answering performance, the current Instance Store only supports ABox axioms asserting that a given individual is an instance of a given (possibly complex) concept (e.g., John is an instance of the class of persons having at least one female child); but it forbids axiom assertions involving role relationships between pairs of individuals (e.g., an assertion that Mary is a child of John). Certainly, the idea of the Instance Store is not new, but, to the best of our knowledge, it is the first implementation of a general purposed role-free1 DL reasoner over individuals that is sound and complete, has reasonable response times. This claim is supported by presenting a variety of empirical test results [11] contrasting the Instance Store with the other existing techniques such as RACER.
46798
Lookahead Pathologies for Single Agent Search
Admissible and consistent heuristic functions are usually preferred in single-agent heuristic search as they guarantee optimal solutions with complete search methods such as A* and IDA*. Larger problems, however, frequently make a complete search intractable due to space and/or time limitations. In particular, a path-planning agent in a real-time strategy game may need to take an action before its complete search has the time to finish. In such cases, incomplete search techniques (such as RTA*, SRTA*, RTDP, DTA*) can be used. Such algorithms conduct a limited ply lookahead and then evaluate the states envisioned using a heuristic function. The action selected on the basis of such evaluations can be suboptimal due to the incompleteness of search and inaccuracies in the heuristic. It is usually believed that deeper lookahead increases the chances of taking the optimal action. In this paper, we demonstrate that this is not necessarily the case, even when admissible and consistent heuristic functions are used.
17573600
Two-way Web service: from interface design to interface verification
In this paper, we introduce a theoretical framework for two-way Web service (WS) interaction and interface design based on the concepts of operation reversal and XML type generalization. Under this theoretical framework, two generic types of interface solutions in two-way WS interaction, i.e. tightly coupled (TC) interface and loosely coupled (LC) interface, are formally defined and studied. The proposed theoretical framework is used to design, derive and verify WS interface for full duplex two-way WS interaction. An algorithm of interface verification is described that allows effective WS interface design and verification to support asynchronous two-way WS operation and event notification. The interface verification algorithm in our approach utilizes verification by derivation and verification by content to validate the client interface in two-way WS interaction. Use case studies are performed for both TC and LC interface solutions. A generic infrastructure based on two-way Web service application proxy (2SAP) is described and implemented. The proposed approach is applied to applications of realizing ECMA-348 for WS enablement of telecommunication.
8054797
Infinite Ensemble Learning with Support Vector Machines
Ensemble learning algorithms such as boosting can achieve better performance by averaging over the predictions of base hypotheses. However, existing algorithms are limited to combining only a finite number of hypotheses, and the generated ensemble is usually sparse. It is not clear whether we should construct an ensemble classifier with a larger or even infinite number of hypotheses. In addition, constructing an infinite ensemble itself is a challenging task. In this paper, we formulate an infinite ensemble learning framework based on SVM. The framework can output an infinite and nonsparse ensemble, and can be used to construct new kernels for SVM as well as to interpret some existing ones. We demonstrate the framework with a concrete application, the stump kernel, which embodies infinitely many decision stumps. The stump kernel is simple, yet powerful. Experimental results show that SVM with the stump kernel is usually superior than boosting, even with noisy data.
2365659
A Trajectory-Preserving Synchronization Method for Collaborative Visualization
In the past decade, a lot of research work has been conducted to support collaborative visualization among remote users over the networks, allowing them to visualize and manipulate shared data for problem solving. There are many applications of collaborative visualization, such as oceanography, meteorology and medical science. To facilitate user interaction, a critical system requirement for collaborative visualization is to ensure that remote users would perceive a synchronized view of the shared data. Failing this requirement, the user's ability in performing the desirable collaborative tasks would be affected. In this paper, we propose a synchronization method to support collaborative visualization. It considers how interaction with dynamic objects is perceived by application participants under the existence of network latency, and remedies the motion trajectory of the dynamic objects. It also handles the false positive and false negative collision detection problems. The new method is particularly well designed for handling content changes due to unpredictable user interventions or object collisions. We demonstrate the effectiveness of our method through a number of experiments
11582687
Web service enablement of communication services
In this paper, we introduce Web service application session services, WS-session, for Web service based application session management in communication. A two-way Web service framework is described. It supports the use of Web service in the situation of telecommunication where the communication endpoint can be both a client and a peer-to-peer server. We describe the interface design in two-way Web service interaction based on the concept of tightly coupled interface and loosely coupled interface solutions. The proposed approach provides full support of asynchronous outbound operations and event notifications in communication services. It is implemented in a research prototype system that provides both standard based (ECMA-348) services and Avaya service extensions. In addition, we investigated the integration of our proposed approach with BPEL4WS. It allows the user to create new services through a drag-n-drop based service creation environment (ECLIPSE/BPEL4WS). It leads to a paradigm of service creation through Web service composition. More sophisticated telecommunication services are created from composing the basic services.