Search results for " retrieval."

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…

Large Scale Knowledge Matching with Balanced Efficiency-Effectiveness Using LSH Forest

2017

Evolving Knowledge Ecosystems were proposed to approach the Big Data challenge, following the hypothesis that knowledge evolves in a way similar to biological systems. Therefore, the inner working of the knowledge ecosystem can be spotted from natural evolution. An evolving knowledge ecosystem consists of Knowledge Organisms, which form a representation of the knowledge, and the environment in which they reside. The environment consists of contexts, which are composed of so-called knowledge tokens. These tokens are ontological fragments extracted from information tokens, in turn, which originate from the streams of information flowing into the ecosystem. In this article we investigate the u…

An interactive evolutionary approach for content based image retrieval

2009

Content Based Image Retrieval (CBIR) systems aim to provide a means to find pictures in large repositories without using any other information except its contents usually as low-level descriptors. Since these descriptors do not exactly match the high level semantics of the image, assessing perceptual similarity between two pictures using only their feature vectors is not a trivial task. In fact, the ability of a system to induce high level semantic concepts from the feature vector of an image is one of the aspects which most influences its performance. This paper describes a CBIR algorithm which combines relevance feedback, evolutionary computation concepts and ad-hoc strategies in an attem…

Part-of-speech labeling for Reuters database

2015

Even if the Vector Space Model used for document representation in information retrieval systems integrates a small quantity of knowledge it continues to be used due to its computational cost, speed execution and simplicity. We try to improve this document representation by adding some syntactic information such as the parts of speech. In this paper, we have evaluated three different tagging algorithms in order to select the most suitable tagger for using it to tag the Reuters dataset. In this work, we have evaluated the taggers using only five different parts of speech: noun, verb, adverb, adjective and others. We considered these particular tags being the most representative for describin…

Text mining of biomedical literature: doing well, but we could be doing better.

2015

SILKNOWViz: Spatio-Temporal Data Ontology Viewer

2019

Interactive visualization of spatio-temporal data is a very active area that has experienced remarkable advances in the last decade. This is due to the emergence of fields of research such as big data and advances in hardware that allow better analysis of information. This article describes the methodology followed and the design of an open source tool, which in addition to interactively visualizing spatio-temporal data that are represented in an ontology, allows the definition of what to visualize and how to do it. The tool allows selecting, filtering and visualizing in a graphical way the entities of the ontology with spatiotemporal data, as well as the instances related to them. The grap…

Estimating web site readability using content extraction

2009

Nowadays, information is primarily searched on the WWW. From a user perspective, the readability is an important criterion for measuring the accessibility and thereby the quality of an information. We show that modern content extraction algorithms help to estimate the readability of a web document quite accurate.

Optimized search strategy for detecting scientifically strong studies on treatment through PubMed.

2011

OBJECTIVE: To develop optimal MEDLINE search strategies for retrieving sound clinical studies of the etiology, prognosis, diagnosis, prevention, or treatment of disorders in adult general medicine. DESIGN: Analytic survey of operating characteristics of search strategies developed by computerized combinations of terms selected to detect studies meeting basic methodologic criteria for direct clinical use in adult general medicine. MEASURES: The sensitivities, specificities, precision, and accuracy of 134,264 unique combinations of search terms were determined by comparison with a manual review of all articles (the "gold standard") in ten internal medicine and general medicine journals for 19…

Improving Efficacy of PubMed Clinical Queries for Retrieving Scientifically Strong Studies on Treatment

2006

The authors evaluated the retrieval power of PubMed "Clinical Queries," narrow search string, about therapy in comparison with a modified search string to avoid possible retrieval bias. PubMed search strategy was compared to a slightly modified string that included the Britannic English term "randomised." The authors tested the two strings joined onto each of four terms concerning topics of broad interest: hypertension, hepatitis, diabetes, and heart failure. In particular, precision was computed for not-indexed citations. The added word "randomised" improved total citation retrieval in any case. Total retrieval gain for not-indexed citations ranged from 11.1% to 21.4%. A significant number…

2021

Health information-seeking behavior is the process of gathering information about health and disease and can be influential for health-related perception and behavior. University students are an important target group for prevention and health promotion and largely belong to an age group that is considered to play a leading role in propagating the SARS-CoV-2 epidemic in Germany. The paper deals with students' health information-seeking behavior before and during the corona crisis, aiming to give insights into its determinants and implications. Using the example of a large German comprehensive university and based on two cross-sectional surveys in the summer of 2019 (n = 4,351) and 2020 (n =…