oalib

OALib Journal期刊

ISSN: 2333-9721

费用:99美元

投稿

匹配条件: “Príncipe” ,找到相关结果约1016条。
列表显示的所有文章,均可免费获取
第1页/共1016条
每页显示
Kernel Affine Projection Algorithms
Weifeng Liu,José C. Príncipe
EURASIP Journal on Advances in Signal Processing , 2008, DOI: 10.1155/2008/784292
Abstract: The combination of the famed kernel trick and affine projection algorithms (APAs) yields powerful nonlinear extensions, named collectively here, KAPA. This paper is a follow-up study of the recently introduced kernel least-mean-square algorithm (KLMS). KAPA inherits the simplicity and online nature of KLMS while reducing its gradient noise, boosting performance. More interestingly, it provides a unifying model for several neural network techniques, including kernel least-mean-square algorithms, kernel adaline, sliding-window kernel recursive-least squares (KRLS), and regularization networks. Therefore, many insights can be gained into the basic relations among them and the tradeoff between computation complexity and performance. Several simulations illustrate its wide applicability.
Maximum Correntropy Kalman Filter
Badong Chen,Xi Liu,Haiquan Zhao,José C. Príncipe
Statistics , 2015,
Abstract: Traditional Kalman filter (KF) is derived under the well-known minimum mean square error (MMSE) criterion, which is optimal under Gaussian assumption. However, when the signals are non-Gaussian, especially when the system is disturbed by some heavy-tailed impulsive noises, the performance of KF will deteriorate seriously. To improve the robustness of KF against impulsive noises, we propose in this work a new Kalman filter, called the maximum correntropy Kalman filter (MCKF), which adopts the robust maximum correntropy criterion (MCC) as the optimality criterion, instead of using the MMSE. Similar to the traditional KF, the state mean and covariance matrix propagation equations are used to give prior estimations of the state and covariance matrix in MCKF. A novel fixed-point algorithm is then used to update the posterior estimations. A sufficient condition that guarantees the convergence of the fixed-point algorithm is given. Illustration examples are presented to demonstrate the effectiveness and robustness of the new algorithm.
Nuevas estrategias terapéuticas en diabetes mellitus tipo 1
Barajas,M.; Príncipe,R. M.; Escalada,J.; Prósper,F.; Salvador,J.;
Anales del Sistema Sanitario de Navarra , 2008,
Abstract: the main determinant of the risk of complications from type 1 diabetes mellitus is the total lifetime blood glucose levels. to impact on the health and quality of life of individuals with diabetes, safe and effective methods of achieving and maintaining normoglycemia are needed. unfortunately, intensive insulin therapy does not achieve normal levels of blood glucose, is difficult to implement for many patients, and limited by the accompanying increased frequency of severe hypoglycemia. hence, the only way at present to restore permanently normoglycemia without hypoglycemia is to provide the patient with additional beta-cells. this can be achieved by transplanting an intact pancreas, or by transplanting islets. the shortage of functional beta-cells from available donors is one of the major limiting factors for the treatment of diabetes by islet transplantation. therefore, methods to preserve or even promote regeneration of the beta-cell mass are dearly needed. significant progress has been made over the last decade in stem cell biology. however, the quest for identification of stem cells has been hampered by the lack of appropriate research tools including assays that allow assess their differentiation potential in vitro and in vivo. therefore, new techniques are necessary in order to develop new therapeutic strategies based on stem cells for the treatment of diabetes mellitus type 1.
Nuevas estrategias terapéuticas en diabetes mellitus tipo 1 New therapeutic strategies for type 1 diabetes mellitus
M. Barajas,R. M. Príncipe,J. Escalada,F. Prósper
Anales del Sistema Sanitario de Navarra , 2008,
Abstract: El principal determinante del riesgo de complicaciones derivadas de la diabetes mellitus tipo 1 se debe a los altos niveles de glucosa en sangre mantenidos durante largo tiempo. Para conseguir un beneficio terapéutico en pacientes con diabetes mellitus es necesario desarrollar tratamientos que permitan de manera segura, efectiva y estable mantener la normoglucemia. Lamentablemente, el tratamiento de la diabetes mellitus tipo 1 mediante el aporte exógeno de insulina no es capaz de conseguir niveles estables de glucosa en sangre, de manera que con frecuencia se producen casos de severa hipoglucemia o hiperglucemia. Hasta la fecha la única solución para reestablecer de manera permanente la normoglucemia se consigue mediante el trasplante de páncreas o de islotes pancreáticos. Sin embargo, a medida que se incrementa el número de centros especializados en el trasplante de islotes, mayor es la necesidad de islotes para su trasplante. Así pues, el estudio de nuevas fuentes de células productoras de insulina así como de nuevos tratamientos que permitan preservar o incluso aumentar la masa de células beta en los pacientes con diabetes mellitus representa un objetivo de primera necesidad en este campo. En este sentido, en la última década ha habido un avance significativo en el campo de la biología de las células madre. Sin embargo, la identificación de células apropiadas para la generación de nuevas células beta, además del desarrollo de técnicas para la caracterización de estas células, así como de ensayos y modelos animales apropiados para probar su capacidad de diferenciación tanto in vitro como in vivo son de vital importancia para la puesta en marcha de nuevas estrategias terapéuticas basadas en la aplicación de las células madre para el tratamiento de la diabetes mellitus tipo 1. The main determinant of the risk of complications from type 1 diabetes mellitus is the total lifetime blood glucose levels. To impact on the health and quality of life of individuals with diabetes, safe and effective methods of achieving and maintaining normoglycemia are needed. Unfortunately, intensive insulin therapy does not achieve normal levels of blood glucose, is difficult to implement for many patients, and limited by the accompanying increased frequency of severe hypoglycemia. Hence, the only way at present to restore permanently normoglycemia without hypoglycemia is to provide the patient with additional beta-cells. This can be achieved by transplanting an intact pancreas, or by transplanting islets. The shortage of functional beta-cells from available donors is one of t
Statistical Coding and Decoding of Heartbeat Intervals
Fausto Lucena,Allan Kardec Barros,José C. Príncipe,Noboru Ohnishi
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0020227
Abstract: The heart integrates neuroregulatory messages into specific bands of frequency, such that the overall amplitude spectrum of the cardiac output reflects the variations of the autonomic nervous system. This modulatory mechanism seems to be well adjusted to the unpredictability of the cardiac demand, maintaining a proper cardiac regulation. A longstanding theory holds that biological organisms facing an ever-changing environment are likely to evolve adaptive mechanisms to extract essential features in order to adjust their behavior. The key question, however, has been to understand how the neural circuitry self-organizes these feature detectors to select behaviorally relevant information. Previous studies in computational perception suggest that a neural population enhances information that is important for survival by minimizing the statistical redundancy of the stimuli. Herein we investigate whether the cardiac system makes use of a redundancy reduction strategy to regulate the cardiac rhythm. Based on a network of neural filters optimized to code heartbeat intervals, we learn a population code that maximizes the information across the neural ensemble. The emerging population code displays filter tuning proprieties whose characteristics explain diverse aspects of the autonomic cardiac regulation, such as the compromise between fast and slow cardiac responses. We show that the filters yield responses that are quantitatively similar to observed heart rate responses during direct sympathetic or parasympathetic nerve stimulation. Our findings suggest that the heart decodes autonomic stimuli according to information theory principles analogous to how perceptual cues are encoded by sensory systems.
On the modelling of liquid steel processes
Goldschmit,M B.; Ferro,S. P.; Príncipe,R. J.; Coppola Owen,A. H.;
Latin American applied research , 2002,
Abstract: an iterative (k-l)-predictor / (e )- corrector algorithm that models turbulent flow was developed in previous publications. in this paper, the 3d finite element turbulent model was used to analyze the liquid steel movement produced by gravity force, inert gas stirring or electromagnetic force stirring.
Síndrome de Wolfram: relato de caso
Fontes, Bruno Machado;Chen, Jane;Príncipe, André Hasler;Sallum, Juliana M. Ferraz;Chicani, Carlos Filipe;
Arquivos Brasileiros de Oftalmologia , 2004, DOI: 10.1590/S0004-27492004000600023
Abstract: wolfram syndrome consists of the association of diabetes mellitus with optic atrophy. other common findings are deafness, urinary tract and neurological disorders. it is an autossomic recessive disease, with incomplete penetrance and variable expressivity. the aim of this case report is to describe a patient who presents all the characteristics of wolfram syndrome (didmoad syndrome). jfp, african - american, 23 years old, presents with diabetes mellitus and insipidus, optic atrophy, deafness, peripheral polyneuropathy, autonomic neuropathy, neurogenic bladder, urinary tract dilation with recurrent infections, and azoospermia. clinical examination, retinography, fluorescein angiogram, eletroretinography (erg) and visual evocated potencial (vep) revealed no retinal disorders and bilateral optic atrophy. wolfram syndrome must be remembered in cases of optic atrophy in association with diabetes, urinary disorders, or any of the described alterations.
Doen?a de Castleman Retroperitoneal: caso clínico e revis?o da literatura
Valle,Luísa; Pinto,Patrícia; Pimenta,Sofia; Dias,Manuela; Príncipe,Fernando; Sousa,Rui de;
Arquivos de Medicina , 2005,
Abstract: castleman′s disease is an atypical lymphoproliferative disorder, relatively rare, with chronic evolution and nonspecific symptoms. we report a case of retroperitoneal mixed histologic type castleman′s disease with cold haemolytic anemia as initial clinical manifestation. we also review the different subtypes, clinical presentation, diagnostic and therapeutic approach.
On the modelling of liquid steel processes
M B. Goldschmit,S. P. Ferro,R. J. Príncipe,A. H. Coppola Owen
Latin American applied research , 2002,
Abstract: An iterative (k-L)-predictor / (e )- corrector algorithm that models turbulent flow was developed in previous publications. In this paper, the 3D finite element turbulent model was used to analyze the liquid steel movement produced by gravity force, inert gas stirring or electromagnetic force stirring.
Approximate reconstruction of bandlimited functions for the integrate and fire sampler
Hans G. Feichtinger,José C. Príncipe,José Luis Romero,Alexander Singh Alvarado,Gino Angelo Velasco
Physics , 2009,
Abstract: In this paper we study the reconstruction of a bandlimited signal from samples generated by the integrate and fire model. This sampler allows us to trade complexity in the reconstruction algorithms for simple hardware implementations, and is specially convenient in situations where the sampling device is limited in terms of power, area and bandwidth. Although perfect reconstruction for this sampler is impossible, we give a general approximate reconstruction procedure and bound the corresponding error. We also show the performance of the proposed algorithm through numerical simulations.
第1页/共1016条
每页显示


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.