0000000000195042
AUTHOR
Salvador Moreno-picot
A Linear Cost Algorithm to Compute the Discrete Gabor Transform
In this paper, we propose an alternative efficient method to calculate the Gabor coefficients of a signal given a synthesis window with a support of size much lesser than the length of the signal. The algorithm uses the canonical dual of the window (which does not need to be calculated beforehand) and achieves a computational cost that is linear with the signal length in both analysis and synthesis. This is done by exploiting the block structure of the matrices and using an ad hoc Cholesky decomposition of the Gabor frame matrix.
Clinicopathological analysis of 1571 cutaneous malignant melanomas in Valencia, Spain: factors related to tumour thickness.
Epidemiological studies on cutaneous melanoma in Mediterranean countries are scarce. Our aim was to perform a descriptive analysis of melanoma cases diagnosed in Valencia, Spain, and to evaluate the relationship between Breslow thickness and some clinical features. A total of 1571 patients with histologically confirmed cutaneous malignant melanoma diagnosed at the two main referral melanoma centres were evaluated retrospectively. For each patient the following clinical and pathological characteristics were selected: age, gender, anatomic site, histogenetic type, Breslow thickness, presence of ulceration, the stage, and symptoms such as bleeding, changes in size and colour, altered sensation…
A NSGA Based Approach for Content Based Image Retrieval
The purpose of CBIR Content Based Image Retrieval systems is to allow users to retrieve pictures related to a semantic concept of their interest, when no other information but the images themselves is available. Commonly, a series of images are presented to the user, who judges on their relevance. Several different models have been proposed to help the construction of interactive systems based on relevance feedback. Some of these models consider that an optimal query point exists, and focus on adapting the similarity measure and moving the query point so that it appears close to the relevant results and far from those which are non-relevant. This implies a strong causality between the low l…
Improving distance based image retrieval using non-dominated sorting genetic algorithm
Image retrieval is formulated as a multiobjective optimization problem.A multiobjective genetic algorithm is hybridized with distance based search.A parameter balances exploration (genetic search) or exploitation (nearest neighbors).Extensive comparative experimentation illustrate and assess the proposed methodology. Relevance feedback has been adopted as a standard in Content Based Image Retrieval (CBIR). One major difficulty that algorithms have to face is to achieve and adequate balance between the exploitation of already known areas of interest and the exploration of the feature space to find other relevant areas. In this paper, we evaluate different ways to combine two existing relevan…
An interactive evolutionary approach for content based image retrieval
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…
Searching for hidden sectors in multiparticle production at the LHC
Most signatures of new physics in colliders have been studied so far on the transverse plane with respect to the beam direction. In this work however we study the impact of a hidden sector beyond the Standard Model (SM) on inclusive (pseudo)rapidity correlations and moments of the multiplicity distributions, with special emphasis in the LHC results.
A hybrid multi-objective optimization algorithm for content based image retrieval
Abstract Relevance feedback methods in CBIR (Content Based Image Retrieval) iteratively use relevance information from the user to search the space for other relevant samples. As several regions of interest may be scattered through the space, an effective search algorithm should balance the exploration of the space to find new potential regions of interest and the exploitation of areas around samples which are known relevant. However, many algorithms concentrate the search on areas which are close to the images that the user has marked as relevant, according to a distance function in the (possibly deformed) multidimensional feature space. This maximizes the number of relevant images retriev…
Primary cutaneous melanoma in hidden sites is associated with thicker tumours — a study of 829 patients
The aim of this study was to determine if primary cutaneous melanomas in hidden anatomical sites were associated with thicker tumours. Retrospective medical data of 829 patients with melanomas diagnosed at our centre between January 1976 and July 1998 were recorded from our database. Three groups were defined according to the anatomical site of the primary melanoma: (1) visible areas (group 1: 493 patients); (2) visible areas only to the patients or to their partners in privacy (group 2: 281 patients); and (3) hidden areas (group 3: 55 patients). Univariate analysis indicated that patients with melanoma in hidden regions presented significantly thicker tumours (median for group 3: 2.25 vers…
Distance-based relevance feedback using a hybrid interactive genetic algorithm for image retrieval
Content-based image retrieval (CBIR) systems aim to provide a means to find pictures in large repositories without using any other information except the own content of the images, which is usually represented as a feature vector extracted from low-level descriptors. This paper describes a CBIR algorithm which combines relevance feedback, evolutionary computation concepts and distance-based learning in an attempt to reduce the existing gap between the high level semantic content of the images and the information provided by their low-level descriptors. In particular, a framework which is independent from the particular features used is presented. The effect of different crossover strategies…
Searching for a hidden sector in multiparticle production at LHC
A hidden sector beyond the Standard Model can show up in multiparticle production altering inclusive correlations and factorial cumulants of multiplicity distributions. In this report such a study is advocated with a special emphasis on the searches at LHC.
Efficient Analysis and Synthesis Using a New Factorization of the Gabor Frame Matrix
In this paper, we consider the case in which one needs to carry out Gabor analysis and synthesis on large signals using a short support analysis window and its corresponding, possibly longer canonical dual window, respectively. In this asymmetric context, we propose a novel factorization of the Gabor frame operator that exploits its strong and well-known structure and leads to a computational cost for synthesis, which is comparable to the one needed for short support analysis. The proposed factorization applies to any Gabor system with very mild conditions and leads to a potentially promising alternative to current synthesis algorithms in the case of short analysis windows whose support is …