773 research outputs found
Tailoring temporal description logics for reasoning over temporal conceptual models
Temporal data models have been used to describe how data can evolve in the context of temporal databases. Both the Extended Entity-Relationship (EER) model and the Unified Modelling Language (UML) have been temporally extended to design temporal databases. To automatically check quality properties of conceptual schemas various encoding to Description Logics (DLs) have been proposed in the literature. On the other hand, reasoning on temporally extended DLs turn out to be too complex for effective reasoning ranging from 2ExpTime up to undecidable languages. We propose here to temporalize the âlight-weightâ DL-Lite logics obtaining nice computational results while still being able to represent various constraints of temporal conceptual models. In particular, we consider temporal extensions of DL-Lite^N_bool, which was shown to be adequate for capturing non-temporal conceptual models without relationship inclusion, and its fragment DL-Lite^N_core with most primitive concept inclusions, which are nevertheless enough to represent almost all types of atemporal constraints (apart from
covering)
Modeling Historical Social Networks Databases
Historical social networks are analyzed using prosopographical methods. Prosopography is a branch of historical research that focuses on the iden-tification of social networks that appear in historical sources. It aims to represent and to interpret histori-cal data, sourced from texts. Conceptual modeling imparts the capability to process these large data sets. This paper outlines a conceptual approach to design-ing a prosopographical database encompassing un-certainty. Our contribution is threefold: i) a generic certainty-based prosopographical conceptual model; ii) two meta-models with a mapping between them; iii) an illustrative example generating a customized pros-opographical relational model. Unlike past ap-proaches, our design process helps us to integrate disparate points of view as expressed in the proso-pography community. We apply our approach to the prosopographical database Studium Parisiense dedi-cated to members of Paris schools and university be-tween the twelfth and sixteenth centuries. This instan-tiation validates the usefulness of our approach
Context-sensitive user Interfaces for semantic services
Service-centric solutions usually require rich context to fully deliver and better reflect on the underlying applications. We present a novel use of context in the form of customized user interface services with the concept of User Interface as a Service (UIaaS). UIaaS takes user profiles as input to generate context-aware interface services. Such interface services can be used as context to augment semantic services with contextual information leading to UIaaS as a Context (UIaaSaaC). The added serendipitous benefit of the proposed concept is that the composition of a customized user interface with the requested service is performed by the service composition engine, as is the case with any other services. We use a special-purpose language (called User Interface Description Language (UIDL)) to model and realize user interfaces as services. We use a real-life e-government application, human services delivery for the citizens, as a proof-of-concept. We also present a comprehensive evaluation of the proposed approach using a functional evaluation and a nonfunctional evaluation consisting of an end user usability test and expert usability reviews
Multi-biometric templates using fingerprint and voice
As biometrics gains popularity, there is an increasing concern about privacy and misuse of biometric data held in central repositories. Furthermore, biometric verification systems face challenges arising from noise and intra-class variations. To tackle both problems, a multimodal biometric verification system combining fingerprint and voice modalities is proposed. The system combines the two modalities at the template level, using multibiometric templates. The fusion of fingerprint and voice data successfully diminishes privacy concerns by hiding the minutiae points from the fingerprint, among the artificial points generated by the features obtained from the spoken utterance of the speaker. Equal error rates are observed to be under 2% for the system where 600 utterances from 30 people have been processed and fused with a database of 400 fingerprints from 200 individuals. Accuracy is increased compared to the previous results for voice verification over the same speaker database
A logic programming framework for modeling temporal objects
Published versio
Towards active conceptual modelling for sudden events
There are a number of issues for information systems
which are required to collect data urgently that are
not well accommodated by current conceptual modelling
methodologies and as a result the modelling
step (and the use of databases) is often omitted. Such
issues include the fact that
âą the number of instances for each entity are relatively
low resulting in data definition taking a
disproportionate amount of effort,
âą the storage of data and the retrieval of information
must take priority over the full definition of
a schema describing that data,
âą they undergo regular structural change and are
thus subject to information loss as a result of
changes to the schemaâs information capacity,
âą finally, the structure of the information is likely
to be only partially known or for which there
are multiple, perhaps contradictory, competing
hypotheses as to the underlying structure.
This paper presents the Low Instance-to-Entity Ratio
(LItER) Model, which attempts to circumvent some
of the problems encountered by these types of application
and to provide a platform and modelling
technique to handle rapidly occurring phenomena.
The two-part LItER modelling process possesses an
overarching architecture which provides hypothesis,
knowledge base and ontology support together with
a common conceptual schema. This allows data to
be stored immediately and for a more refined conceptual
schema to be developed later. LItER modelling
also aims to facilitate later translation to EER, ORM
and UML models and the use of (a form of) SQL.
Moreover, an additional benefit of the model is that
it provides a partial solution to a number of outstanding
issues in current conceptual modelling systems.Sydney, NS
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