Search results for "Descent"
showing 10 items of 99 documents
Learning spatial filters for multispectral image segmentation.
2010
International audience; We present a novel filtering method for multispectral satel- lite image classification. The proposed method learns a set of spatial filters that maximize class separability of binary support vector machine (SVM) through a gradient descent approach. Regularization issues are discussed in detail and a Frobenius-norm regularization is proposed to efficiently exclude uninformative filters coefficients. Experiments car- ried out on multiclass one-against-all classification and tar- get detection show the capabilities of the learned spatial fil- ters.
Unitary Space–Time Constellation Design Based on the Chernoff Bound of the Pairwise Error Probability
2008
Unitary space-time constellation design is considered for noncoherent multiple-antenna communications, where neither the transmitter nor the receiver knows the fading coefficients of the channel. By employing the Clarke's subdifferential theorem of the sum of the kappa largest singular values of a unitary matrix, we present a numerical optimization procedure for finding unitary space-time signal constellations of any dimension. The Chernoff bound of the pairwise error probability is used directly as a design criterion. The constellations are found by performing gradient descent search on a family ldquosurrogaterdquo functions that converge to the maximum pairwise error probability. The comp…
An optimality test for semi-infinite linear programming
1992
In this paper we present a test to characterize the optimal solutions for the continuous semi-infinite linear programming problem. This optimality characterization is a condition of Kuhn–Tucker type. The resolution of a linear program permits to check the optimality of a feasible point,to detect the unboundedness of the problem and to find descent directions. We give some illustrative examples. We show that the local Mangasarian–Fromovitz constraint qualification is almost equivalent to Slater qualification for this problem. Furthermore, it follows from our study that this optimality condition is always necessary for a wide class of semi-infinite linear programming problems
Optimisation non-lisse pour l'estimation de composants immunitaires cellulaires dans un environnement tumoral
2021
In this PhD proposal we will investigate new regularization methods of inverse problems that provide an absolute quantification of immune cell subpopulations. The mathematical aspect of this PhD proposal is two-fold. The first goal is to enhance the underlying linear model through a more refined construction of the expression matrix. The second goal is, given this linear model, to derive the best possible estimator. These two issues can be treated in a decoupled way, which is the standard for existing methods such as Cibersort, or as a coupled optimization problem (which is known as blind deconvolution in signal processing).
Rituales, descentramientos territoriales y niveles de identidad: La Semana Santa Marinera de Valencia
2011
The aim of this paper is to study how the processes of spatial and identity recomposition brought about by a globalized world affect traditional religious rituals, with particular reference to the <i>Semana Santa Marinera</i> processions in Valencia (Spain). Instead of the ritual giving rise to a single local identity, it can be seen that levels of local identity —while not disappearing— overlap more and more with increasingly vague new territorialities ranging from processional networks based on canon law to state-organized meetings. Media coverage of the ritual means that new virtual communities with no fixed territorial base are created, and the complexity of this phenomenon …
Differential geometric LARS via cyclic coordinate descent method
2012
We address the problem of how to compute the coefficient path implicitly defined by the differential geometric LARS (dgLARS) method in a high-dimensional setting. Although the geometrical theory developed to define the dgLARS method does not need of the definition of a penalty function, we show that it is possible to develop a cyclic coordinate descent algorithm to compute the solution curve in a high-dimensional setting. Simulation studies show that the proposed algorithm is significantly faster than the prediction-corrector algorithm originally developed to compute the dgLARS solution curve.
What is the best fitting function? Evaluation of lactate curves with common methods from the literature
2015
Using the lactate threshold for training prescription is the gold-standard, although there are several open questions. One open question is: What is the best fitting method for the load-lactate data points? This investigation re-analyses over 3500 lactate diagnostic datasets in swimming. Our evaluation software examines six different fitting methods with two different minimization criteria (RMSE and SE). Optimization of parameters of the functions is put in excecution with gradient descent. From a mathematical point of view, the double phase model, which consists of two linear regression lines, shows the least errors (RMSE min 0.254 ± 0.172; SE min 0.311 ± 0.210). However, this method canno…
Financiación autonómica : un elemento de tensión en la economía valenciana
2017
La financiación autonómica en España representa una fuente de tensión para la economía valenciana. La actualidad y polémica que suscitan su configuración y resultados hacen pertinente un análisis crítico del estado de la cuestión. Un primer apartado se dedica a revisar el proceso histórico de la financiación regional y sus principales debilidades. Un segundo apartado estudia las cifras de los modelos de 2002 y 2009, con especial atención al caso valenciano. De este modo, se constata que la economía valenciana recibe insuficientes recursos del sistema de financiación autonómica, hecho que pone en tela de juicio su capacidad de gasto en servicios públicos fundamentales. Asimismo, la escasez d…
: State monopoly and school decentralization: and exploration of Latin America.
2004
This article tries to investigate the decentralisation processes in the context of Latin American educational systems, as part of the operation of methods of providing school education. First of all, a number of theoretical categories linked to the provision of school education are established. Secondly, the article examines the four dominant conceptions of educational decentralisation in order to understand the role each of them has played in the countries that were reviewed. In this context and thirdly, the article proves the need to strictly understand the differences existing between decentralisation processes, in the context of state bureaucracy, in relation to the privatisation of edu…
Pràctica 3_34308
2018
El document forma part dels materials docents programats mitjançant l'ajut del Servei de Política Lingüística de la Universitat de València Presa de les mesures boxing de la muntura. Càlcul dels descentraments de les lents.