Search results for "Information Systems"
showing 10 items of 1926 documents
An Efficient and Secure Multidimensional Data Aggregation for Fog-Computing-Based Smart Grid
2021
International audience; The secure multidimensional data aggregation (MDA) has been widely investigated in smart grid for smart cities. However, previous proposals use heavy computation operations either to encrypt or to decrypt the multidimensional data. Moreover, previous fault-tolerant mechanisms lead to an important computation cost, and also a high communication cost when considering a separate identification phase. In this article, we propose an efficient and secure MDA scheme, named ESMA. Unlike existing schemes, the multidimensional data in ESMA are structured and encrypted into a single Paillier ciphertext and thereafter, the data are efficiently decrypted. For privacy preserving, …
Aggregation of the web performance of internal university units as a method of quantitative analysis of a university system: The case of Spain
2013
The aggregation of web performance (page count and visibility) of internal university units could constitute a more precise indicator than the overall web performance of the universities and, therefore, be of use in the design of university web rankings. In order to test this hypothesis, a longitudinal analysis of the internal units of the Spanish university system was conducted over the course of 2010. For the 13800 URLs identified, page count and visibility was calculated using the Yahoo API. The internal values obtained were aggregated by university and compared with the values obtained from the analysis of the university general URLs. The results indicate that, although the correlations…
Modeling and querying facts with period timestamps in data warehouses
2019
Abstract In this paper, we study various ways of representing and querying fact data that are time-stamped with a time period in a data warehouse. The main focus is on how to represent the time periods that are associated with the facts in order to support convenient and efficient aggregations over time. We propose three distinct logical models that represent time periods as sets of all time points in a period (instant model), as pairs of start and end time points of a period (period model), and as atomic units that are explicitly stored in a new period dimension (period∗ model). The period dimension is enriched with information about the days of each period, thereby combining the former tw…
Aligning Relational Schema and OWL Ontologies with Hidden Markov Model
2016
The problem of bridging the gap between relational schema and ontologies is actively investigated in the Semantic Web and business communities. The main motivations are the OBDA scenario, where a domain ontology allows to hidden the technical details of the db to end-users; and the persistent storage of ontologies in db for facilitating search and retrieval keeping the benefits of DBMSs such as security and integrity. In these cases, the ABox is usually stored into a db, and the TBox is maintained in an ontology; for this reason, schema alignment is a more significant problem than the instance matching one. The use of manual mappings is hard and expensive, especially for large representatio…
A framework for context-sensitive metadata description
2006
Expectations regarding the new generation of Web depend on the success of Semantic Web technology. Resource Description Framework (RDF) is a basis for explicit and machine-readable representation of semantics. However RDF is not suitable for describing dynamic and context-sensitive resources (eg. processes). We present the Context Description Framework (CDF) as an extension of the RDF by adding a 'TrueInContext' component to the basic RDF triple ('subject-predicate-object'), and consider contextual value as a container of RDF statements. We also add a probabilistic component, which allows multilevel contextual dependence descriptions as well as presumes possibility for Bayesian reasoning wi…
Semantic web service discovery system for road traffic information services
2015
Create a multi-agent platform for a traveller information system (FIPA standards).Extend Paulucci algorithm with the use of seven similarity measures.Weight the similarity measure according to semantic relation and parameter nature.Improved running-time with a filtering pre-process for non-functional parameters.Improved the recall by measuring the sibling relationship concepts. We describe a multi-agent platform for a traveller information system, allowing travellers to find the road traffic information web service (WSs) that best fits their requirements. After studying existing proposals for discovery of semantic WS, we implemented a hybrid matching algorithm, which is described in detail …
Self-service Ad-hoc Querying Using Controlled Natural Language
2016
The ad-hoc querying process is slow and error prone due to inability of business experts of accessing data directly without involving IT experts. The problem lies in complexity of means used to query data. We propose a new natural language- and semistar ontology-based ad-hoc querying approach which lowers the steep learning curve required to be able to query data. The proposed approach would significantly shorten the time needed to master the ad-hoc querying and to gain the direct access to data by business experts, thus facilitating the decision making process in enterprises, government institutions and other organizations.
Searching Silk Fabrics by Images Leveraging on Knowledge Graph and Domain Expert Rules
2021
The production of European silk textile is an endangered intangible cultural heritage. Digital tools can nowadays be developed to help preserving it, or even to make it more accessible for the public and the fashion industry. In this paper, we propose an image-based retrieval tool that leverages on a knowledge graph describing the silk textile production as well as rules formulated by experts of this domain. Out of several possible similarity scenarios, two have proven to work best and have been integrated into an exploratory search engine.
A Semantic Collaborative Clustering Approach Based on Confusion Matrix
2019
In this paper we discuss about a new images retrieval technique based on clustering. We argue that images don’t have an intrinsic meaning, but they can receive different interpretation. These images can complicate documents retrieval. However, users need a quick and direct access to documents. To answer this requirement, we propose a retrieval approach which use a collaborative clustering technique based on Confusion matrix.
A Web Centric Semantic Mediation Approach for Spatial Information Systems
2006
International audience; Semantic mediation is increasingly at the heart of the design of emerging webbased information systems, particularly spatial information systems thatrequire the integration or interoperation of a collection of heterogeneousdata sources. Ontologies are increasingly used to represent agreed semantic ofapplications by providing formal description models and related tools toexplicitly specify the conceptual entities of an application. Past research intraditional database integration has identified key issues in the resolution ofvarious structural and semantic conflicts. Recent research effort has extendedthis early research to address the interoperability of spatial info…