Search results for "Retrieval"

Syntagmatic and Paradigmatic Associations in Information Retrieval

2003

It is shown that unconscious associative processes taking place in the memory of a searcher during the formulation of a search query in information retrieval — such as the production of free word associations and the generation of synonyms — can be simulated using statistical models that analyze the distribution of words in large text corpora. The free word associations as produced by subjects on presentation of stimulus words can be predicted by applying first-order statistics to the frequencies of word co-occurrences as observed in texts. The generation of synonyms can also be conducted on co-occurrence data but requires second-order statistics. Both approaches are compared and validated …

Graph-based exploration and clustering analysis of semantic spaces

2019

Abstract The goal of this study is to demonstrate how network science and graph theory tools and concepts can be effectively used for exploring and comparing semantic spaces of word embeddings and lexical databases. Specifically, we construct semantic networks based on word2vec representation of words, which is “learnt” from large text corpora (Google news, Amazon reviews), and “human built” word networks derived from the well-known lexical databases: WordNet and Moby Thesaurus. We compare “global” (e.g., degrees, distances, clustering coefficients) and “local” (e.g., most central nodes and community-type dense clusters) characteristics of considered networks. Our observations suggest that …

Reply from H. Ylönen

2011

Correction: Validation of Semantic Analyses of Unstructured Medical Data for Research Purposes.

2020

A solution to the stochastic point location problem in metalevel nonstationary environments.

2008

This paper reports the first known solution to the stochastic point location (SPL) problem when the environment is nonstationary. The SPL problem involves a general learning problem in which the learning mechanism (which could be a robot, a learning automaton, or, in general, an algorithm) attempts to learn a "parameter," for example, lambda*, within a closed interval. However, unlike the earlier reported results, we consider the scenario when the learning is to be done in a nonstationary setting. For each guess, the environment essentially informs the mechanism, possibly erroneously (i.e., with probability p), which way it should move to reach the unknown point. Unlike the results availabl…

Learning to Rank Images for Complex Queries in Concept-based Search

2018

Concept-based image search is an emerging search paradigm that utilizes a set of concepts as intermediate semantic descriptors of images to bridge the semantic gap. Typically, a user query is rather complex and cannot be well described using a single concept. However, it is less effective to tackle such complex queries by simply aggregating the individual search results for the constituent concepts. In this paper, we propose to introduce the learning to rank techniques to concept-based image search for complex queries. With freely available social tagged images, we first build concept detectors by jointly leveraging the heterogeneous visual features. Then, to formulate the image relevance, …

Top-k String Similarity Joins

2020

Top-k joins have been extensively studied in relational databases as ranking operations when every object has, among others, at least one ranking attribute. However, the focus has mostly been the case when the join attributes are of primitive data types (e.g., numerical values) and the join predicate is equality. In this work, we consider string objects assigned such ranking attributes or simply scores. Given two collection of string objects and a string similarity measure (e.g., the Edit distance), we introduce the top-k string similarity join () which returns k sufficiently similar pairs of objects with respect to a similarity threshold ϵ, which have the highest combined score computed by…

Additional file 2 of Efficacy and acceptability of pharmacological and non-pharmacological interventions for non-specific chronic low back pain: a pr…

2020

Additional file 2. MEDLINE search string.

Participation Costs and Inefficiency in Takeover Contests

2010

We consider a takeover in which risk neutral bidders incur private costs to participate to the auction. Supposing that valuations for target firm are common knowledge, we study the optimal strategy of bidders and analyze the takeover result when they get or not toeholds in the target firm. We found that bidder's decision of participation is endogenous. By analyzing bidder's condition of participation, we found that the probability that the potential bidder with the highest valuation will not participate to the control, exists. We show that this probability increases with the size of toeholds possessed by the bidder with low valuation. Nevertheless, the size of toeholds possessed by the bidd…

Familiar objects and memory color

1998

This research was supported in part by a grant from ADEIT- Universitat de Valencia and IMPIVA to M.D. de F.