Results 1 - 10
of
11
A probabilistic extension to ontology language owl
- In Proceedings of the 37th Hawaii International Conference On System Sciences (HICSS-37), Big Island
, 2004
"... With the development of the semantic web activity, ontologies become widely used to represent the conceptualization of a domain. However, none of the existing ontology languages provides a means to capture uncertainty about the concepts, properties and instances in a domain. Probability theory is a ..."
Abstract
-
Cited by 112 (3 self)
- Add to MetaCart
With the development of the semantic web activity, ontologies become widely used to represent the conceptualization of a domain. However, none of the existing ontology languages provides a means to capture uncertainty about the concepts, properties and instances in a domain. Probability theory is a natural choice for dealing with uncertainty. Incorporating probability theory into existing ontology languages will provide these languages additional expressive power to quantify the degree of the overlap or inclusion between two concepts, support probabilistic queries such as finding the most probable concept that a given description belongs to, and make more accurate semantic integration possible. One approach to provide such a probabilistic extension to ontology languages is to use Bayesian networks, a widely used graphic model for knowledge representation under uncertainty. In this paper, we present our on-going research on extending OWL, an ontology language recently proposed by W3C’s Semantic Web Activity. First, the language is augmented to allow additional probabilistic markups, so probabilities can be attached with individual concepts and properties in an OWL ontology. Secondly, a set of translation rules is defined to convert this probabilistically annotated OWL ontology into a Bayesian network. Our probabilistic extension to OWL has clear semantics: the Bayesian network obtained will be associated with a joint probability distribution over the application domain. General Bayesian network inference procedures (e.g., belief propagation or junction tree) can be used to compute P(C | e): the degree of the overlap or inclusion between a concept C and a concept represented by a description e. We also provide a similarity measure that can be used to find the most probable concept that a given description belongs to. 1.
A semantic description of 3D environments: a proposal based on Web standards
- in Proc. Web3D 2006
, 2006
"... While the number of virtual environments available on the net is constantly increasing, most of them are composed by a wide number of low-level geometric objects that lack any semantic description. Such situation prevents advanced uses of the data contained inside the environments, such as selection ..."
Abstract
-
Cited by 13 (6 self)
- Add to MetaCart
While the number of virtual environments available on the net is constantly increasing, most of them are composed by a wide number of low-level geometric objects that lack any semantic description. Such situation prevents advanced uses of the data contained inside the environments, such as selection and extraction of semantic objects or advanced queries that refer to high-level properties of the environment. Recently some attempts have been performed in order to annotate 3D environments using the descriptive capabilities of MPEG-7 standard. While the solutions proposed are interesting, there are still a number of issues to be solved, including the definition of scene-independent ontologies that can be useful in different situations (e.g., 3D world validation, semantic search through a set of worlds, etc.). This work proposes an alternate approach for associating semantic information to 3D worlds based on the integration of two web standards: the X3D language and the semantic web. The approach is characterized also by the definition of scene-independent ontologies and by the definition of semantic zones that complement the role of semantic objects for giving a complete description of the environment. In order to show the potentialities of such approach the paper will illustrate an application scenario characterized by the extraction of the semantic information from an X3D document and the associated ontology for generating a high-level and multilevel textual description of a tour through the 3D environment described by them.
Nonmonotonic Description Logic Programs: Implementation and Experiments
- In: Proc. of LPAR 2004, 3452 in LNAI
, 2005
"... Abstract. The coupling of description logic reasoning systems with other reasoning formalisms (possibly over the Web) is becoming an important research issue and calls for advanced methods and algorithms. Recently, several notions of description logic programs have been introduced, combining rule-ba ..."
Abstract
-
Cited by 12 (8 self)
- Add to MetaCart
(Show Context)
Abstract. The coupling of description logic reasoning systems with other reasoning formalisms (possibly over the Web) is becoming an important research issue and calls for advanced methods and algorithms. Recently, several notions of description logic programs have been introduced, combining rule-based semantics with description logics. Among them are nonmonotonic description logic programs (or dl-programs for short) which combine nonmonotonic logic programs with description logics under a generalized version of the answer-set and the well-founded semantics, respectively, which are the predominant semantics for nonmonotonic logic programs. In this paper, we consider some technical issues regarding an efficient implementation for both semantics, which has been realized in a working prototype exploiting the two state-of-art tools DLV and RACER. A major issue in this respect is efficient interfacing between the two reasoning systems at hand, for which we devised special methods. Such methods may fruitfully be used for the implementation of systems of similar nature. Reported experimentation activities with our prototype show that the methods we have developed are effective and are a key for highly optimized nonmonotonic dl-program engines. 1
Learning Consumer Preferences Using Semantic Similarity
, 2007
"... In online, dynamic environments, the services requested by consumers may not be readily served by the providers. This requires the service consumers and providers to negotiate their service needs and offers. Multiagent negotiation approaches typically assume that the parties agree on service content ..."
Abstract
-
Cited by 4 (1 self)
- Add to MetaCart
In online, dynamic environments, the services requested by consumers may not be readily served by the providers. This requires the service consumers and providers to negotiate their service needs and offers. Multiagent negotiation approaches typically assume that the parties agree on service content and focus on finding a consensus on service price. In contrast, this work develops an approach through which the parties can negotiate the content of a service. This calls for a negotiation approach in which the parties can understand the semantics of their requests and offers and learn each other’s preferences incrementally over time. Accordingly, we propose an architecture in which both consumers and producers use a shared ontology to negotiate a service. Through repetitive interactions, the provider learns consumers’ needs accurately and can make better targeted offers. To enable fast and accurate learning of preferences, we develop an extension to Version Space and compare it with existing learning techniques. We further develop a metric for measuring semantic similarity between services and compare the performance of our approach using different similarity metrics.
An Ontology of Interoperability in Inter-Enterprise Communities
"... Summary. The ability of a system to interoperate with another is a multi-dimensional concern which must be considered simultaneously from different perspectives and covering all the concerns relevant for different stakeholders. In this paper, we present a model of interoperability for service-based ..."
Abstract
-
Cited by 2 (0 self)
- Add to MetaCart
(Show Context)
Summary. The ability of a system to interoperate with another is a multi-dimensional concern which must be considered simultaneously from different perspectives and covering all the concerns relevant for different stakeholders. In this paper, we present a model of interoperability for service-based inter-enterprise computing environments which is based on the Ontology of Interoperability (OoI) developed under INTEROP-NoE and the Pilarcos framework for federated service communities. We propose a refined version of the OoI, generalizing the originally considered scope of interoperability and adding concepts required to address dynamic aspects in interoperability. The ontology is then specialized to the domain of federated service-based communities and we illustrate with some concrete examples how interoperability problems and solutions in that domain could be related to it. 1
Learning Consumer Preferences for Content-Oriented Negotiation ABSTRACT
"... Current approaches to e-commerce treat service price as the primary construct for negotiation. However, negotiation on price presupposes that other properties of the service have already been agreed upon. For many real life situations, a service consumer and a producer has a difficult time in unders ..."
Abstract
- Add to MetaCart
(Show Context)
Current approaches to e-commerce treat service price as the primary construct for negotiation. However, negotiation on price presupposes that other properties of the service have already been agreed upon. For many real life situations, a service consumer and a producer has a difficult time in understanding each other’s requirements and forming a consensus on the desired service. Accordingly, this paper develops a theory for automating service negotiation and provides the details of an implemented system. The theory combines important ideas from inductive logic learning with expressive representation of ontologies. Both consumers and producers share an ontology about the service of interest. Through repetitive interactions, producers learn consumers ’ needs accurately and can make better targeted counter offers. The developed system uses the well-known Wine ontology to demonstrate the negotiation of service needs. 1.
Paper currently under review – please contact the author for the most current version. Product Representation in the Semantic Web
"... Abstract. The machine-readable representation of products is probably the most important challenge on the road to business applications for the Semantic Web. This will not only help search engines provide more precise product search for human users, but can be expected to support a much higher degre ..."
Abstract
- Add to MetaCart
(Show Context)
Abstract. The machine-readable representation of products is probably the most important challenge on the road to business applications for the Semantic Web. This will not only help search engines provide more precise product search for human users, but can be expected to support a much higher degree of automation in general, which means basically the delegation of tasks to machines. Current descriptive languages for products and services, like UNSPSC (www.unspsc.org), the German approach eClass (www.eclass.de), and the eOTD (www.eotd.org) lack both the required coverage of concepts and semantic precision, and it is unclear how they shall be used in Semantic Web applications. One core problem with those traditional classification-based approaches is that in a Semantic Web context, the same document must be machine-readable by a huge number of different partners for a multiplicity of purposes. In other words, the data recipient and the data usage are not predetermined, which makes it difficult to reach consensus about suitable product classes. This paper develops the requirements for product representation in the Semantic Web, evaluates existing alternatives and describes a property-centric product description approach for the Semantic Web, based on the reuse of existing attribute libraries.
DEPARTMENT OF COMPUTER SCIENCE SERIES OF PUBLICATIONS C
"... Modelling framework for interoperability management in collaborative computing environments ..."
Abstract
- Add to MetaCart
(Show Context)
Modelling framework for interoperability management in collaborative computing environments
Simulation Model
"... atio he L truc equ mpl ane. l st cie and model components, and using ontology reasoners to search for models, automatically discover model unicat ldwide els to c achine ved by ng the In this case, the domain is an agricultural or natural resource sys-tem including hydrological, biological and physic ..."
Abstract
- Add to MetaCart
atio he L truc equ mpl ane. l st cie and model components, and using ontology reasoners to search for models, automatically discover model unicat ldwide els to c achine ved by ng the In this case, the domain is an agricultural or natural resource sys-tem including hydrological, biological and physical transforma-tions, and transport processes. The ontology in this domain includes concepts such as plant, soil profile, soil layer, water con-tent, nitrogen concentration, and many others. Ontologies attempt to precisely define each concept (what water concentration is, how it is measured), and much of this is expressed through relation-guage. While advances in programming languages, including object-oriented programming and even the most recent Unified Modeling Language (UML) methodologies (Ivar et al., 1998) such as Model-Driven Architecture (MDA) (Raistrick et al., 2004), have been used to improve the process, most modeling is still viewed from the standpoint of how to best implement software to realize the model. In ontology-based simulation, the problem of modeling is raised to the level where the software implementation and asso-ciated software engineering concerns are irrelevant to the model-ing process. Modeling becomes an abstract design problem in how best to represent knowledge about the system structure and
