2,789 research outputs found
Avances y retos en el campo de la Radiómica y Radiogenómica
RESUMEN
Desde hace tiempo ha surgido una nueva dirección en la investigación del cáncer que se centra en la relación entre:
- Radiómica: se basa en convertir las imágenes médicas a una dimensión superior de datos para crear una hipótesis y mejorar el soporte diagnóstico, pronóstico y previsión de respuesta a tratamientos
- Radiogenómica o genómica de imágenes: basada en que las imágenes biomédicas son producto de una alteración molecular y genética a nivel celular.
Como tal, los parámetros de imagen derivados del procesamiento y análisis de imágenes avanzados pueden reflejar las bases moleculares y genotípicas del tejido tumoral. En oncología, la radiogenómica puede permitir una caracterización y comprensión más profundas de la biología del tumor en su totalidad, incluida la captura de la heterogeneidad intrínseca del tumor que puede impulsar el desarrollo del tumor.
El objetivo de la radiogenómica es desarrollar biomarcadores de imágenes que incorporen características fenotípicas y genotípicas que puedan predecir el riesgo y los resultados del paciente y, por lo tanto, estratificar a los pacientes según riesgos, para una atención terapéutica más precisa.
Pero, por otro lado, hasta ahora, la mayoría de los estudios disponibles de radiómica y radiogenómica, son retrospectivos y presentan cohortes de pacientes pequeños y las conclusiones que pueden extraerse son algo limitadas para la práctica clínica.
Se han realizado investigaciones con diferentes tipos de cáncer siendo las más relevantes:
1) En cáncer de mama: Se ha evidenciado el potencial de asociación entre el tipo de realce en las secuencias dinámincas de la resonancia magnética con contraste de mama y los subtipos moleculares Luminal A, Luminal B y Oncotype DX.
2) En el cáncer de pulmón se ha observado correlación entre los fenotipos moleculares relacionados con la mutación del EGFR (receptor factor crecimiento epidérmico) y algunos hallazgos de imagen en tomografía computarizada.
3) Glioblastoma multiforme (GBM): han permitido una predicción clínica y molecular no invasiva.ABSTRACT
In recent years, a new direction in cancer research has emerged that focuses on the relationship between:
-Radiomics refers to the conversion of digital medical images to higher dimensional data and the subsequent mining for hypothesis generation and/or testing and ultimately an improved decision support
-The principle of radiogenomics is that biomedical images are the product of processes occurring at the genetic and molecular level. As such, imaging parameters derived from advanced image processing and analysis can reflect the underlying molecular and genotypic basis of the tissue in oncology, radiogenomics can enable a deeper characterization and understanding of tumor biology in its entirety, including capturing the intrinsic tumor heterogeneity that can drive tumor development
The goal of radiogenomics is to develop imaging biomarkers incorporating both phenotypic and genotypic metrics that can predict risk and patient outcomes and thereby better
stratify patients for more precise therapeutic care.
On the other hand, most of the available, radiogenomics and radiomics studies, are retrospective and feature small patient cohorts (< 100), and therefore the conclusions that can be drawn are somewhat limited for clinical practice.
Radiogenomic approaches in breast cancer, it has been showed the potential association between imaging and genomics by discovering a relationship between semi-automatically extracted imaging features describing MRI enhancement dynamics with Luminal A and Luminal B subtypes and Oncotype DX.
In lung cancer have showed a correlation between molecular phenotypes, EGFR mutation, and some imaging traits in lung computed tomography.
In GBM have the potential to predict clinical and molecular characteristics of tumors noninvasivelyUniversidad de Granada.Hospital Universitario Reina Sofí
Evolución de la televisión convencional: hacia una nueva forma de discurso. Twitch como la televisión del futuro
La Televisión convencional como actualmente la conocemos, ha sufrido cambios y
modificaciones en su manera de comunicar. Comenzó con dos canales nacionales, a lo que
se le fueron sumando otro tipo de cadenas con otra forma de discurso, entre los que hubo
alianzas y uniones.
Actualmente vivimos en una era en la que la Televisión se puede consumir de diferentes
formas y no solo a través del tradicional televisor. Lo que ha permitido generar contenido
audiovisual a través de otras plataformas que se encuentran inmersas en el mundo Digital.
Internet ha hecho que podamos ver de diferente forma aquello que la Televisión nos cuenta
a través de sus programas. Ofreciéndonos un amplio abanico de oportunidades para
consumir contenido audiovisual entre los que se encuentran algunas Redes Sociales como
Twitch.
Esta novedosa plataforma en crecimiento propone realizar conexiones con el usuario
mucho más estrechas a través de emisiones en directo, donde el creador de contenido de
cada uno de los canales que la conforman entabla conversaciones a través del chat con los
usuarios que se encuentran dentro del mismo.
Por ello, en la presente investigación se llevará a cabo un análisis de ambos soportes,
analizando Twitch y comparándola con la Televisión lineal y Digital, de una forma
cuantitativa, a través de herramientas que analizan cada medio y cualitativa, teniendo en
cuenta otros estudios realizados sobre la materia.Grado en Publicidad y Relaciones Pública
Influencia de las pruebas de acceso a la Universidad en la Enseñanza de la integral definida en el Bachillerato
La integral definida es considerada un tópico matemático central en el bachillerato. Un indicador empírico de este hecho son las pruebas de acceso a la universidad que masivamente proponen una cuestión, ejercicio o problema relacionado con esta noción matemática. En este trabajo describimos las configuraciones epistémicas de referencia en la institución y mostramos cómo se presenta esta noción en una muestra de libros de texto de editoriales de amplia difusión, así como el tipo de situaciones propuestas en las pruebas de acceso a la universidad. Se obtiene así una descripción de la realidad institucional con relación a la integral definida, que permite sugerir acciones para la mejora de procesos de estudio potenciales.The definite integral is considered a main topic in High School mathematics. An empirical evidence of this fact is the frequent use of it in the inclusion of a question, exercise or problem involving this mathematical notion in the university entrance examination. In this paper we describe the epistemic configurations which constitute a fundamental point of reference in High School; we also show how this topic is presented in several textbooks from major publishing companies; and, moreover, we analyse the type of proposed problems in the university entrance examinations. Thus we have an adequate description of the institutional attitude in relation to the teaching of the definite integral, which allows to suggest actions for the improvement of potential instructional processes
Soluciones para la gestión de regiones de memoria compartidas por varios hilos
La gestión de memoria dinámica es uno de los puntos más importantes dentro
de la implementación de java. Una vez que se ha almacenado un objeto en
tiempo de ejecución, el sistema hace un seguimiento del estado del objeto, y en
el momento en que se detecta que no se va a volver a utilizar ese objeto, el
sistema recupera el espacio ocupado de memoria para un uso futuro. Esta
gestión de la memoria dinámica hace que la programación en Java sea más
fácil, ya que el usuario no se debe preocupar de liberar el espacio ocupado por
los objetos (el equivalente de las funciones dispose en Pascal y free en C).
En este proyecto se estudian alternativas a las técnicas clásicas del reciclaje de
memoria con el fin de buscar una solución óptima compatible con la ejecución
de las aplicaciones de tiempo real crítico.
Proponemos distintos modelos basados todos en el uso del paradigma de una
región de memoria adicional introducida por RTSJ (Java para Tiempo Real): la
región Scoped. Las distintas formas de tratar estas regiones modelizarán las
reglas de comportamiento del programa y el modelo de programación, teniendo
cada una ciertas ventajas y desventajas aquí analizadas.
Una aproximación a una ejecución bajo modelos propuestos estará simulada
mediante una aplicación desarrollada en lenguaje Java, especificando las
distintas relaciones entre regiones Scoped que se establecen al crear y destruir
las regiones implicadas en la ejecución de un programa.
[ABSTRACT]
The performance of any programming language is limited both by the
compliance time of programs as his capacity to save memory with the result of
house different memory areas that interact on his execution. A basic element
here is the garbage collector, which will clear the memory of information not
necessary on every very moment.
This project is dedicated to study alternatives of this collector in order that
optimize the garbage collection of the programs.
We propose different models based on the use of a paradigm of an additional
memory area introduced by RTSJ: the Scoped Memory. The different ways of
use of these regions will represent rules behaviour of the program and the
programming model, having each one his advantages and inconvenients here
analyzed.
We estimate of the execution under the models proposed will be simulated with
an application developed on Java, specifying the relationships between Scoped
Memory stablished at the creating and deleting the regions implicated on the
application execution
Distributed Affine Projection Algorithm Over Acoustically Coupled Sensor Networks
[EN] In this paper, we present a distributed affine projection (AP) algorithm for an acoustic sensor network where the nodes are acoustically coupled. Every acoustic node is composed of a microphone, a processor, and an actuator to control the sound field. This type of networks can use distributed adaptive algorithms to deal with the active noise control (ANC) problem in a cooperative manner, providing more flexible and scalable ANC systems. In this regard, we introduce here a distributed version of the multichannel filtered-x AP algorithm over an acoustic sensor network that it is called distributed filtered-x AP (DFxAP) algorithm. The analysis of the mean and the mean-square deviation performance of the
algorithm at each node is given for a network with a ring topology and without constraints in the communication layer. The theoretical results are validated through several simulations. Moreover, simulations show that the proposed DFxAP outperforms the previously reported distributed multiple error filtered-x least mean
square algorithm.This work was supported in part by EU together with Spanish Government under Grant TEC2015-67387-C4-1-R (MINECO/FEDER), and in part by Generalitat Valenciana under PROMETEOII/2014/003.Ferrer Contreras, M.; Gonzalez, A.; Diego Antón, MD.; Piñero, G. (2017). Distributed Affine Projection Algorithm Over Acoustically Coupled Sensor Networks. IEEE Transactions on Signal Processing. 65(24):6423-6434. https://doi.org/10.1109/TSP.2017.2742987S64236434652
Affine Projection Algorithm Over Acoustic Sensor Networks for Active Noise Control
[EN] Acoustic sensor networks (ASNs) are an effective solution to implement active noise control (ANC) systems by using distributed adaptive algorithms. On one hand, ASNs provide scalable systems where the signal processing load is distributed among the network nodes. On the other hand, their noise reduction performance is comparable to that of their respective centralized processing systems. In this sense, the distributed multiple error filtered-x least mean squares (DMEFxLMS) adaptive algorithm has shown to obtain the same performance than its centralized counterpart as long as there are no communications constraints in the underlying ASN. Regarding affine projection (AP) adaptive algorithms, some distributed approaches that are approximated versions of the multichannel filtered-x affine projection (MFxAP) algorithm have been previously proposed. These AP algorithms can efficiently share the processing load among the nodes, but at the expense of worsening their convergence properties. In this paper we develop the exact distributed multichannel filtered-x AP (EFxAP) algorithm, which obtains the same solution as that of the MFxAP algorithm as long as there are no communications constraints in the underlying ASN. In the EFxAP algorithm each node can compute a part or the entire inverse matrix needed by the centralized MFxAP algorithm. Thus, we propose three different strategies that obtain significant computational saving: 1) Gauss Elimination, 2) block LU factorization, and 3) matrix inversion lemma. As a result, each node computes only between 25%¿60% of the number of multiplications required by the direct inversion of the matrix. Regarding the performance in transient and steady states, the EFxAP exhibits the fastest convergence and the highest noise level reduction for any size of the acoustic network and any projection order of the AP algorithm compared to the DMEFxLMS and two previously reported distributed AP algorithms.This work was supported by EU together with Spanish Government through RTI2018-098085B-C41 (MINECO/FEDER) and Generalitat Valenciana through PROMETEO/2019/109.Ferrer Contreras, M.; Diego Antón, MD.; Piñero, G.; Gonzalez, A. (2021). Affine Projection Algorithm Over Acoustic Sensor Networks for Active Noise Control. IEEE/ACM Transactions on Audio Speech and Language Processing. 29:448-461. https://doi.org/10.1109/TASLP.2020.3042590S4484612
Support for availability attributes in network slices in GANSO
Network slicing provides a way to define logically isolated networks over the same and shared physical infrastructure. This paper departs from previous work defining GST And Network Slice Operator (GANSO), a framework for automating the creation of network slices over SDN architectures, and proposes extensions to support the availability attribute as defined by the GSMA Generic Network Slice Template (GST). This new attribute is integrated and implemented within the GANSO framework, being validated through a set of experimental results.This work has been (partially) funded by H2020 EU/TW 5G-DIVE (Grant 859881) and H2020 5Growth (Grant 856709). It has been also funded by the Spanish State Research Agency (TRUE5G project, PID2019-108713RB-C52PID2019-108713RB-52/AEI/10.13039/501100011033
GPU Implementation of multichannel adaptive algorithms for local active noise control
© 2014 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksMultichannel active noise control (ANC) systems are commonly based on adaptive signal processing algorithms that require high computational capacity, which constrains their practical implementation. Graphics Processing Units (GPUs) are well known for their potential for highly parallel data processing. Therefore, GPUs seem to be a suitable platform for multichannel scenarios. However, efficient use of parallel computation in the adaptive filtering context is not straightforward due to the feedback loops. This paper compares two GPU implementations of a multichannel feedforward local ANC system working as a real-time prototype. Both GPU implementations are based on the filtered-x Least Mean Square algorithms; one is based on the conventional filtered-x scheme and the other is based on the modified filtered-x scheme. Details regarding the parallelization of the algorithms are given. Finally, experimental results are presented to compare the performance of both multichannel ANC GPU implementations. The results show the usefulness of many-core devices for developing versatile, scalable, and low-cost multichannel ANC systems.This work was supported by the European Union ERDF and Spanish Government under Project TEC2012-38142-C04, and Generalitat Valenciana under Project PROMETEO/2009/013. The associate editor coordinating the review of this manuscript and approving it for publication was Prof. Thushara D. Abhayapala.Lorente Giner, J.; Ferrer Contreras, M.; Diego Antón, MD.; Gonzalez, A. (2014). GPU Implementation of multichannel adaptive algorithms for local active noise control. IEEE Transactions on Audio, Speech and Language Processing. 22(11):1624-1635. https://doi.org/10.1109/TASLP.2014.2344852S16241635221
Control Effort Strategies for Acoustically Coupled Distributed Acoustic Nodes
[EN] This paper considers the effect of effort constraints on the behavior of an active noise control (ANC) system over a distributed network composed of acoustic nodes. A distributed implementation can be desirable in order to provide more flexible, versatile, and scalable ANC systems. In this regard, the distributed version of the multiple error filtered-x least mean square (DMEFxLMS) algorithm that allows collaboration between nodes has shown excellent properties. However, practical constraints need to be considered since, in real scenarios, the acoustic nodes are equipped with power constrained actuators. If these constraints are not considered within the adaptive algorithm, the control signals may increase and saturate the hardware devices, causing system instability. To avoid this drawback, a control effort weighting can be considered in the cost function of the distributed algorithm at each node. Therefore, a control effort strategy over the output signals at each node is used to keep them under a given threshold and ensuring the distributed ANC system stability. Experimental results show that, assuming ideal network communications, the proposed distributed algorithm achieves the same performance as the leaky centralized ANC system. A performance evaluation of several versions of the leaky DMEFxLMS algorithm in realistic scenarios is also included.This work has been supported by European Union ERDF together with Spanish Government through TEC2015-67387-C4-1-R project and Generalitat Valenciana through PROMETEOII/2014/003 project.Antoñanzas-Manuel, C.; Ferrer Contreras, M.; Diego Antón, MD.; Gonzalez, A. (2017). Control Effort Strategies for Acoustically Coupled Distributed Acoustic Nodes. Wireless Communications and Mobile Computing. 2017:1-15. https://doi.org/10.1155/2017/3601802S1152017Akyildiz, I. F., Weilian Su, Sankarasubramaniam, Y., & Cayirci, E. (2002). A survey on sensor networks. IEEE Communications Magazine, 40(8), 102-114. doi:10.1109/mcom.2002.1024422Yick, J., Mukherjee, B., & Ghosal, D. (2008). Wireless sensor network survey. Computer Networks, 52(12), 2292-2330. doi:10.1016/j.comnet.2008.04.002Puccinelli, D., & Haenggi, M. (2005). Wireless sensor networks: applications and challenges of ubiquitous sensing. IEEE Circuits and Systems Magazine, 5(3), 19-31. doi:10.1109/mcas.2005.1507522Xiaojiang Du, & Hsiao-Hwa Chen. (2008). Security in wireless sensor networks. IEEE Wireless Communications, 15(4), 60-66. doi:10.1109/mwc.2008.4599222Al Ameen, M., Liu, J., & Kwak, K. (2010). Security and Privacy Issues in Wireless Sensor Networks for Healthcare Applications. Journal of Medical Systems, 36(1), 93-101. doi:10.1007/s10916-010-9449-4Martinez, K., Hart, J. K., & Ong, R. (2004). Environmental sensor networks. Computer, 37(8), 50-56. doi:10.1109/mc.2004.91Segura-Garcia, J., Felici-Castell, S., Perez-Solano, J. J., Cobos, M., & Navarro, J. M. (2015). Low-Cost Alternatives for Urban Noise Nuisance Monitoring Using Wireless Sensor Networks. IEEE Sensors Journal, 15(2), 836-844. doi:10.1109/jsen.2014.2356342Flammini, A., Ferrari, P., Marioli, D., Sisinni, E., & Taroni, A. (2009). Wired and wireless sensor networks for industrial applications. Microelectronics Journal, 40(9), 1322-1336. doi:10.1016/j.mejo.2008.08.012Lopes, C. G., & Sayed, A. H. (2007). Incremental Adaptive Strategies Over Distributed Networks. IEEE Transactions on Signal Processing, 55(8), 4064-4077. doi:10.1109/tsp.2007.896034Cobos, M., Perez-Solano, J. J., Belmonte, O., Ramos, G., & Torres, A. M. (2016). Simultaneous Ranging and Self-Positioning in Unsynchronized Wireless Acoustic Sensor Networks. IEEE Transactions on Signal Processing, 64(22), 5993-6004. doi:10.1109/tsp.2016.2603972Llerena-Aguilar, C., Gil-Pita, R., Rosa-Zurera, M., Ayllón, D., Utrilla-Manso, M., & Llerena, F. (2016). Synchronization based on mixture alignment for sound source separation in wireless acoustic sensor networks. Signal Processing, 118, 177-187. doi:10.1016/j.sigpro.2015.06.023Elliott, S. J., & Nelson, P. A. (1993). Active noise control. IEEE Signal Processing Magazine, 10(4), 12-35. doi:10.1109/79.248551Elliott, S. J., Joseph, P., Bullmore, A. J., & Nelson, P. A. (1988). Active cancellation at a point in a pure tone diffuse sound field. Journal of Sound and Vibration, 120(1), 183-189. doi:10.1016/0022-460x(88)90343-4Joseph, P., Elliott, S. J., & Nelson, P. A. (1994). Near Field Zones of Quiet. Journal of Sound and Vibration, 172(5), 605-627. doi:10.1006/jsvi.1994.1202Kuo, S. M., & Morgan, D. R. (1999). Active noise control: a tutorial review. Proceedings of the IEEE, 87(6), 943-975. doi:10.1109/5.763310Burgess, J. C. (1981). Active adaptive sound control in a duct: A computer simulation. The Journal of the Acoustical Society of America, 70(3), 715-726. doi:10.1121/1.386908Elliott, S. J., & Boucher, C. C. (1994). Interaction between multiple feedforward active control systems. IEEE Transactions on Speech and Audio Processing, 2(4), 521-530. doi:10.1109/89.326611Grosdidier, P., & Morari, M. (1986). Interaction measures for systems under decentralized control. Automatica, 22(3), 309-319. doi:10.1016/0005-1098(86)90029-4Elliott, S., Stothers, I., & Nelson, P. (1987). A multiple error LMS algorithm and its application to the active control of sound and vibration. IEEE Transactions on Acoustics, Speech, and Signal Processing, 35(10), 1423-1434. doi:10.1109/tassp.1987.1165044Elliott, S. J., & Back, K. H. (1996). Effort constraints in adaptive feedforward control. IEEE Signal Processing Letters, 3(1), 7-9. doi:10.1109/97.475821Qiu, X., & Hansen, C. H. (2001). A study of time-domain FXLMS algorithms with control output constraint. The Journal of the Acoustical Society of America, 109(6), 2815-2823. doi:10.1121/1.1367247Rafaely, B., & Elliot, S. J. (2000). A computationally efficient frequency-domain LMS algorithm with constraints on the adaptive filter. IEEE Transactions on Signal Processing, 48(6), 1649-1655. doi:10.1109/78.845922Kozacky, W. J., & Ogunfunmi, T. (2013). An active noise control algorithm with gain and power constraints on the adaptive filter. EURASIP Journal on Advances in Signal Processing, 2013(1). doi:10.1186/1687-6180-2013-17Mosquera-Sánchez, J. A., Desmet, W., & de Oliveira, L. P. R. (2017). A multichannel amplitude and relative-phase controller for active sound quality control. Mechanical Systems and Signal Processing, 88, 145-165. doi:10.1016/j.ymssp.2016.10.036Rossetti, D. J., Jolly, M. R., & Southward, S. C. (1996). Control effort weighting in feedforward adaptive control systems. The Journal of the Acoustical Society of America, 99(5), 2955-2964. doi:10.1121/1.414877Antoñanzas, C., Ferrer, M., de Diego, M., & Gonzalez, A. (2016). Blockwise Frequency Domain Active Noise Controller Over Distributed Networks. Applied Sciences, 6(5), 124. doi:10.3390/app605012
Patrones de comportamiento en la transferencia de datos para identificar y evitar ataques en la red
El presente documento contiene información de investigación, la cual ha llegado al desarrollo de la tesis titulada "PATRONES DE COMPORTAMIENTO EN AL TRANSFERENCIA DE DATOS PARA IDENTIFICAR Y EVITAR ATAQUES EN LA RED". En busca de esto se desarrolla el presente trabajo de investigación. Análisis de protocolos de encriptación y algoritmos de cifrado, para el uso de estos en la implementación de un IDS/IPS (Sistema de Detección de Intrusos / Sistema de Protección de Intrusos) en una red virtual simulando a una organización y desde una red externa se realizará ataques a la red por medio de un Sniffer. En esta investigación se pretende demostrar cómo identificar y evitar los ataques a la red, en la transferencia de datos en una organización con y sin un IDS/IPS (Sistema de Detección de Intrusos / Sistema de Protección de Intrusos.)Tesi
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