Search results for " Retrieval"
showing 10 items of 1114 documents
Applying logistic regression to relevance feedback in image retrieval systems
2007
This paper deals with the problem of image retrieval from large image databases. A particularly interesting problem is the retrieval of all images which are similar to one in the user's mind, taking into account his/her feedback which is expressed as positive or negative preferences for the images that the system progressively shows during the search. Here we present a novel algorithm for the incorporation of user preferences in an image retrieval system based exclusively on the visual content of the image, which is stored as a vector of low-level features. The algorithm considers the probability of an image belonging to the set of those sought by the user, and models the logit of this prob…
Combining similarity measures in content-based image retrieval
2008
The purpose of content based image retrieval (CBIR) systems is to allow users to retrieve pictures from large image repositories. In a CBIR system, an image is usually represented as a set of low level descriptors from which a series of underlying similarity or distance functions are used to conveniently drive the different types of queries. Recent work deals with combination of distances or scores from different and usually independent representations in an attempt to induce high level semantics from the low level descriptors of the images. Choosing the best method to combine these results requires a careful analysis and, in most cases, the use of ad-hoc strategies. Combination based on or…
Employees' perceptions of high-performance work systems and innovative behaviour: The role of exploratory learning
2017
Abstract This paper analyses the influence of employees' perceptions of high-performance work systems (HPWSs) on employees' exploratory learning and innovative behaviour. Furthermore, the mediating role of exploratory learning in this relationship has also been studied. To achieve these objectives, a quantitative analysis was conducted with a sample of 304 researchers from the Spanish public sector. Results showed the relevance of employees' perceptions of HPWSs in promoting exploratory learning and employees' innovative behaviour. The mediating role of exploratory learning in the relationship was assessed. The paper mentions the importance of workers' perceptions on the implementation of H…
A statistical model for magnitudes and angles of wavelet frame coefficients and its application to texture retrieval
2014
Abstract This paper presents a texture descriptor based on wavelet frame transforms. At each position in the image, and for each resolution level, we consider both vertical and horizontal wavelet detail coefficients as the components of a bivariate random vector. The magnitudes and angles of these vectors are computed. At each level the empirical histogram of magnitudes is modeled by a Generalized Gamma distribution, and the empirical histogram of angles is modeled by a different version of the von Mises distribution that accounts for histograms with 2 modes. Each texture is characterized by few parameters. A new distance is presented (based on the Kullback–Leibler divergence) that allows g…
The Relevance of Genetic Factors in Tumor Therapy and the Underlying Pharmacogenetic Principles
2017
In the following chapter it is shown that only by the combination of pharmacological and genetic research programs new relevant findings of tumor formation and progression can be gained. This then lead to an improved and individualized therapy of the patients in the area of application.
Dr. Google, what can you tell me about homeopathy? Comparative study of the top10 websites in the United States, United Kingdom, France, Mexico and S…
2019
Users access to Google to find out about health issues is frequent among citizens. This research analyzes the best results of three generic searches on homeopathy, collected in four waves in five countries: Spain, France, Mexico, the United Kingdom, and the United States. Specifically, the fluctuation of the corpus ranking is studied, and a sample of the ten best-positioned pages in each country is taken to analyze their content (the authorship of the website, the stance of the effectiveness of homeopathy, the presence of controversy and the type of content). The results show that the ranking is stable; that the stance of homeopathy is linked to the state of public opinion in the country; t…
The predictive ability and value relevance of accounting measures
2011
Accepted version of an article published in the journal: International Journal of Economics and Accounting. Also available from the publisher at: http://dx.doi.org/10.1504/IJEA.2011.041894 Empirical accounting research sometimes assumes that the value relevance of accounting variables can be indirectly assessed by studying the ability of the variables to forecast future cash flow and earnings. This study investigates the relationships between short-term cash flow and earnings prediction tests and value relevance analyses. I find that earnings prediction tests might be good substitutes for value relevance analyses, whereas cash flow prediction tests merely provide indications with respect to…
Correlations of the nonexponentiality and state dependence of mechanical relaxations with bond connectivity in Ge-As-Se supercooled liquids
1992
We have studied the mechanical responses of supercooled Ge-As-Se liquids to flexural strains and temperature steps. The departures from exponential relaxation correlate well with the variations in connectivity. The structural state dependence of the mechanical relaxation, detected in pure and weakly cross-linked Se, is suppressed completely at the rigidity percolation threshold {l angle}{ital r}{sub {ital c}}{r angle}, where the liquid fragility is a minimum. The shapes of the decay functions of samples with the same {l angle}{ital r}{sub {ital c}}{r angle} but different compositions are not universal at {ital T}{sub {ital g}} probably because of chemical effects near the binary edges of th…
Application of Machine Learning Techniques in the Study of the Relevance of Environmental Factors in Prediction of Tropospheric Ozone
2010
This work presents a new approach for one of the main problems in the analysis of atmospheric phenomena, the prediction of atmospheric concentrations of different elements. The proposed methodology is more efficient than other classical approaches and is used in this work to predict tropospheric ozone concentration. The relevance of this problem stems from the fact that excessive ozone concentrations may cause several problems related to public health. Previous research by the authors of this work has shown that the classical approach to this problem (linear models) does not achieve satisfactory results in tropospheric ozone concentration prediction. The authors’ approach is based on Machin…
The Three Steps of Clustering in the Post-Genomic Era: A Synopsis
2011
Clustering is one of the most well known activities in scientific investigation and the object of research in many disciplines, ranging from Statistics to Computer Science. Following Handl et al., it can be summarized as a three step process: (a) choice of a distance function; (b) choice of a clustering algorithm; (c) choice of a validation method. Although such a purist approach to clustering is hardly seen in many areas of science, genomic data require that level of attention, if inferences made from cluster analysis have to be of some relevance to biomedical research. Unfortunately, the high dimensionality of the data and their noisy nature makes cluster analysis of genomic data particul…