Search results for "tecnología."
showing 10 items of 861 documents
Non-convex distributed power allocation games in cognitive radio networks
2013
In this thesis, we explore interweave communication systems in cognitive radio networks where the overall objective is to maximize the sum-rate of each cognitive radio user by optimizing jointly both the detection operation based on sensing and the power allocation across channels, taking into account the influence of the sensing accuracy and the interference limitation to the primary users. The optimization problem is addressed in single and multiuser cognitive radio networks for both single-input single-output and multi-input multi-output channels. Firstly, we study the resource allocation optimization problem for single-input single-output single user cognitive radio networks, wherein th…
Upport vector machines for nonlinear kernel ARMA system identification.
2006
Nonlinear system identification based on support vector machines (SVM) has been usually addressed by means of the standard SVM regression (SVR), which can be seen as an implicit nonlinear autoregressive and moving average (ARMA) model in some reproducing kernel Hilbert space (RKHS). The proposal of this letter is twofold. First, the explicit consideration of an ARMA model in an RKHS (SVM-ARMA 2k) is proposed. We show that stating the ARMA equations in an RKHS leads to solving the regularized normal equations in that RKHS, in terms of the autocorrelation and cross correlation of the (nonlinearly) transformed input and output discrete time processes. Second, a general class of SVM-based syste…
Kernel-Based Framework for Multitemporal and Multisource Remote Sensing Data Classification and Change Detection
2008
The multitemporal classification of remote sensing images is a challenging problem, in which the efficient combination of different sources of information (e.g., temporal, contextual, or multisensor) can improve the results. In this paper, we present a general framework based on kernel methods for the integration of heterogeneous sources of information. Using the theoretical principles in this framework, three main contributions are presented. First, a novel family of kernel-based methods for multitemporal classification of remote sensing images is presented. The second contribution is the development of nonlinear kernel classifiers for the well-known difference and ratioing change detectio…
Preliminary results of the 2017 season in the Amazonian earthen structures known as geoglyphs.
2018
O trabalho realizado pela equipe de pesquisa multidisciplinar, liderada pela Universitat de Valencia Estudi General (UVEG) e a Universidade Federal do Acre (UFAC), de detalhamento da topografia, em especial na RESEX Chico Mendes, criou progresso significativo no conhecimento das estruturas de terra construídas na paisagem amazônica, conhecidas popularmente como geoglifos, no que se refere a aplicação de topografia de alta precisão para algumas das estruturas, compreensão geral fenômeno e aplicação de uma nova estratégia de pesquisa, com o auxílio de ferramentas como o Google Earth, Google Maps, GPX, OpenStreetMap e Lidar. Ainda há muito trabalho de campo a ser feito na Amazônia Ocidental, n…
The Information and Communication Technologies in the school sys-tem. A review of the research lines
2005
This paper offers a classification of research trends and perspectives about processes oriented to incorporate information and communication technologies (ICT) in schools. Identified are four research trends: a) studies about indicators of computers quantity in school systems; b) studies about computer effects in learning; c) studies about opinion, perspectives and attitudes of educational agents to ICT; and d) studies about computers' educational use in classroom and colleges. This paper finishes with a synthesis of current knowledge about projects and programs intended for the embodiment of ICT in school systems.
Tecnologías fotónicas y comunicaciones ópticas
1997
El presente trabajo tiene por objeto presentar una visión de las tecnologías fotónicas orientada fundamentalmente a su aplicación en telecomunicaciones.
University teaching and ICT. Materials online for training Cmap Tools
2013
En estas páginas presentamos una serie de materiales creados en un proyecto de elaboración de material de formación del profesorado universitario convocado por el Servicio de Formación Permanente de la Universitat de València. El objetivo fundamental del proyecto ha sido la creación de materiales en línea para aprender el funcionamiento del software libre Cmap Tools, elaborado por el Florida Institute for Human & Machine Cognition (IHMC). Los materiales de formación, desarrollados en la primera parte del proyecto, han consistido básicamente en la creación de vídeo tutoriales que muestran el procedimiento de descarga, instalación y las distintas utilidades del software y su aplicación a la d…
Role of cone-beam computed tomography (CBCT) in diagnosis and treatment planning of two-rooted maxillary lateral incisor with palatogingival groove. …
2020
Background: The embryonic root groove is an anatomical abnormality that starts in the cingulum and extends longitudinally down the long axis root towards the apex. This developmental anomaly is more frequently reported in maxillary lateral incisors. Gu YC in 2011 established three types of radicular grooves depending on its severity. According to this classification, type III presents a greater diagnostic and therapeutic complexity. The prevalence of palatogingival grooves in maxillary lateral incisors ranges from 1.9 to 14%. This case report provides valuable information about the diagnosis and treatment plan of palatogingival grooves with Cone-beam computed tomography (CBCT) scan. Case re…
La evaluación de los materiales didácticos digitales
2017
Este artículo presenta los resultados más relevantes obtenidos a partir de un estudio centrado en analizar las características pedagógicas y tecnológicas de una muestra de materiales de repositorios y plataformas de contenidos educativos digitales actualmente existentes en España destinados a la Educación Primaria tanto de plataformas de contenidos educativos comerciales como de repositorios institucionales públicos. El artículo presenta inicialmente algunas refexiones sobre algunos de los principales aspectos que, en nuestra opinión, deben caracterizar la evaluación de los materiales didácticos en el contexto de la sociedad digital. La metodología empleada en el estudio consistió en el aná…
Convergencia de medios y cambio social
2002
Publicación elaborada a partir de las transcripciones de las conferencias presentadas durante el "Congreso sobre Convergencia de Medios. Oportunidades para el acercamiento de Europa y América", que tuvo lugar en Madrid los días 13 y 14 de mayo de 2002.