Context-aware, ontology-based, service discovery

Service discovery is a process of locating, or discovering, one or more documents, that describe a particular service. Most of the current service discovery approaches perform syntactic matching, that is, they retrieve services descriptions that contain particular keywords from the user’s query. This often leads to poor discovery results, because the keywords in the query can be semantically similar but syntactically different, or syntactically similar but semantically different from the terms in a service description. Another drawback of the existing service discovery mechanisms is that the query-service matching score is calculated taking into account only the keywords from the user’s query and the terms in the service descriptions. Thus, regardless of the context of the service user and the context of the services providers, the same list of results is returned in response to a particular query. This paper presents a novel approach for service discovery that uses ontologies to capture the semantics of the user’s query, of the services and of the contextual information that is considered relevant in the matching process

Share Whatever You Like

To leverage proactive context-aware services for mobile handsets, an for the management, aggregation and distribution of information is required. This work presents a framework that has been developed to realize an extensible infrastructure in which personal information can be shared with others while on the go. Access control mechanisms restrict the distribution of data based on social relationships and the validity of context conditions

Speaker Identification and Assessment on the YOHO database

Within the CAVE project (Caller Verification in Banking and Telecommunication) we have done extensive research on speaker verification. However, speaker verification does not give sufficient information about inter-speaker relations, and that is one of the topics we want to investigate. So we decided to use speaker identification experiments to address the following two questions. Is there a reliable measure to classify speakers as resistant, dependable, unreliable or vulnerable? And can we construct a distance measure between speakers based on log likelihoods? And naturally, what is the relation between these two questions? First we will describe the speaker database and the HMM topologies. 1 Database description The database is the YOHO Speaker Verification Corpus. The particular vocabulary employed in this collection consists of two-digit numbers ("thirty-four", "sixty-one", etc), spoken continuously in sets of three (e.g. "36-45-89"): the so called combination-lock phrases. There ..

On The Independence Of Digits In Connected Digit Strings

One of the frequently used assumptions in Speaker Verification is that two speech segments (phonemes, subwords, words) are considered to be independent. And therefore, the log-likelihood of a test utterance is just the sum of the log-likelihoods of the speech segments in that utterance. This paper reports about cases in which this observation-independence assumption seems to be violated, namely for those test utterances which call a certain speech model more than once. For example, a pin code which contains a non-unique digit set performs worse in verification than a pin code which consists of four different digits. Results illustrate that violating the independence assumption too much might result in increasing EERs while more information (in form of digits) is added to the test utterance. 1. INTRODUCTION In Speaker Verification (SV) systems using passwords in the form of fixed or prompted digit strings it seems usual to compute the log-likelihood of a claimant being the true speaker..

Extending UDDI with Context-Aware Features Based on Semantic Service Descriptions

The web has evolved from the HTML-based repositories of text and images towards the current web services and semantic web developments. Web services are believed to help the integration of diverse applications while the semantic web promises to increase the "intelligence" of the web, enabling richer discovery, data integration, navigation and automation of tasks. A natural next step would be the combination of these developments, resulting in semantic web services. Another trend we observe is the development of next generation networks, such as GPRS and UMTS, which provide a richer environment as they will have access to information about the user�s, location, preferences and changing environment. With the aid of this information, service providers will be able to develop services that adapt to the user�s context. However, current web services technologies, based on WSDL and UDDI, do not provide a means for context-aware service discovery. In this paper we present the design and implementation of an enhanced UDDI server, capable of storage, matching and retrieval of semantically rich service profiles that contain contextual information. We also present a tool that facilitates the creation, publication and discovery of such service profiles