Digital.CSIC
(14.269 recursos)
Repositorio institucional del Consejo Superior de Investigaciones Científicas.
Digital.CSIC es un depósito de documentos digitales, cuyo objetivo es organizar, archivar, preservar y difundir en modo de acceso abierto la producción intelectual resultante de la actividad investigadora del CSIC.
(IFA) Comunicaciones congresos
Mostrando recursos 1 - 20 de 37
1.
Electron-multiplying CCD astronomical photometry - Ferrero, Alejandro; Campos Acosta, Joaquín; Pons, Alicia
Electron Multiplying CCD is a CCD technology sensor reduces read-out noise to less than one electron. We
study the way the usage of this technology affects to the astronomical photometry and to the improvement
of the temporal resolution of the measurements. We show the effect of this technology on individual celestial
sources and in the limiting magnitude. We propose a criterion to choose the optimal EM gain for a specific
integration time. We explain a straightforward procedure to characterize the actual EM gain and the readout
noise expressed in photo-electrons for every software-displayed gain, and we applied this procedure to the Andor
Ixon DU-888E-C00-BV EMCCD.
2.
Linealización del Generador Auto-Shrinking e Implementación con FPGA - Pazo-Robles, M.E.; Fúster-Sabater, Amparo; Tinetti, F.G.
En este trabajo se presenta una modelización del generador Auto-Shrinking mediante autómatas celulares. La implementación del modelo ya linealizado puede llevarse a práctica mediante lógica FPGA. La linealidad y las propiedades de simetría que aparecen en este modelo celular pueden utilizarse de manera conveniente para el análisis y/o criptoanálisis de este tipo de generador criptográfico.
3.
APPLYING THE JOINT WIGNER TIME‐FREQUENCY DISTRIBUTION TO CHARACTERIZATION OF TRAIN‐AVERAGE PARAMETERS INHERENT IN THE PULSED LIGHT RADIATION OF SEMICONDUCTOR HETEROLASERS - Shcherbakov, Alexandre S.; Moreno Zarate, Pedro; Campos Acosta, Joaquin; Il'n, Yurij V.; Tarasov, Il'ya S.
We present an approach to the characterization of low‐power bright picosecond optical pulses with an internal frequency modulation in both time and frequency domains in practically important cases of exploiting semiconductor heterolasers operating in near‐infrared range in the active mode‐locking regime. This approach uses the joint Wigner time‐frequency distributions, which can be found for this regime due to involving the interferometric technique under consideration. In so doing, the modified scanning Michelson interferometers were chosen for shaping the field‐strength auto‐correlation functions peculiar to the above‐mentioned types of infrared light radiation. We consider in principle the key features of a new experimental...
4.
DETERMINING THE PARAMETERS OF PICOSECOND OPTICAL PULSES GENERATED BY THE ACTIVELY MODE‐LOCKED SEMICONDUCTOR HETEROLASERS - Shcherbakov, Alexandre S.; Kosarsky, Alexey Yu.; Campos Acosta, Joaquín; Moreno Zarate, Pedro
We make an attempt to develop a novel approach to experimental investigations of highrepetition‐
rate trains of picosecond optical pulses. For this purpose an opto‐electronic
system for detecting train‐average time parameters had been created. The scheme of this
system consists of optical auto‐correlator, electronic controller, and a set of the checking
units. The computer admits several regimes for operation: calibration of optical autocorrelator,
measuring cycle, and data processing and display. Initially, pulse trains arrive at
the optical auto‐correlator, i.e. at a two‐beam scanning Michelson interferometer, which
is formed by two total‐internal‐reflection prisms and a 50%‐mirror. The prismatic optical
circuit permits keeping out the backward scattering from basic reflecting...
5.
A NEW TECHNIQUE OF MEASURING LOW‐POWER PICOSECOND OPTICAL PULSE TRAINS - Muñoz Zurita, Ana Luz; Shcherbakov, Alexandre S.; Campos Acosta, Joaquín; Gómez Jiménez, Ramón
We present a theoretic approach to the characterization of low‐power bright ultrashort optical pulses with an internal frequency modulation simultaneously in both time and frequency domains. The analysis and computer simulations are applied to studying the capability of Wigner distribution to characterize solitary pulses in practically important case of the sech‐pulses. Then, the simplest two‐beam scanning Michelson interferometer is selected for shaping the field‐strength auto‐correlation function of low‐power picosecond pulse trains. We are proposing the key features of a new interferometric experimental technique for accurate and reliable measurements of the train‐average width as well as the value and sign of...
6.
Applying the triple correlation functions to characterizing high-frequency repetition trains of picosecond optical pulses - Muñoz Zurita, Ana L.; Shcherbakov, Alexandre S.; Campos Acosta, Joaquín
The triple correlation of an ordinary function on the real time is the integral of the product of that function with two independently shifted copies of itself. Triple correlation methods are frequently used in signal processing for treating signals that are corrupted by additive Gaussian noise; in particular, triple correlation techniques perform well when multiple observations of the signal are available and the signal may be translating in between the observations, e.g. a sequence of images of an object translating on a noisy background.
7.
Mejora del rango dinámico de un sensor Brillouin distribuido de temperatura y strain en fibra óptica mediante amplificación Raman - Rodríguez-Barrios, Félix; Martín-López, Sonia; Carrasco-Sanz, Ana; Corredera, Pedro; Hernanz, Mª Luisa; González-Herráez, Miguel
En el ámbito de la ingeniería civil, la monitorización del estado de sus infraestructuras, tanto en fase
de construcción como en fase de explotación resulta de gran interés social y económico. Para este
propósito tradicionalmente se han utilizado de manera casi exclusiva sensores de tipo eléctrico y
mecánico. En los últimos tiempos el uso de sensores ópticos ha proporcionado una solución de
compromiso para su instalación en ambientes en los que los sensores eléctricos presentan mermadas sus
capacidades óptimas, por ejemplo por el nivel de ruido electromagnético y los mecánicos resultan poco
prácticos y versátiles. En muchas aplicaciones, la necesidad de sensado de una elevada cantidad...
8.
Diseño y Construcción de un Novedoso Espectro-Gonio-Fotómetro - Rabal, Ana M.; Fontecha, José Luis; Pons, Alicia; Campos, Joaquín; Zafra, Rafael
Ser capaz de predecir y reproducir la apariencia de los objetos es un problema que tiene repercusiones
en múltiples áreas de actividad. Para llegar a resolver este problema es necesario especificar bien la
percepción de apariencia y basarla en medidas físicas. El concepto de apariencia está relacionado con el
color, el brillo, la translucidez y la textura de los objetos, por lo que la medida de la apariencia tiene que
estar relacionada con la de esas otras magnitudes.
9.
Criptosistemas basados en curvas hiperelípticas - Hernández Encinas, Luis
Presentado en el Primer Congreso Conjunto de Matemáticas RSME-SCM-SEIO-SEMA MAT.ES 2005, Universidad de Valencia, España, 31 de enero al 4 de febrero de 2005 (Eds., L. Hernández, A. Martín y G. Rodriguez).
10.
Una mirada al criptoanálisis actual: tendencias y casos prácticos - Fúster Sabater, Amparo
Presentado en el Primer Congreso Conjunto de Matemáticas RSME-SCM-SEIO-SEMA MAT.ES 2005, Universidad de Valencia, España, 31 de enero al 4 de febrero de 2005 (Eds., L. Hernández, A. Martín y G. Rodriguez).
11.
Evolución de los sistemas de cifrado basados en caos - Álvarez Marañón, Gonzalo
Presentado en el Primer Congreso Conjunto de Matemáticas RSME-SCM-SEIO-SEMA MAT.ES 2005, Universidad de Valencia, España, 31 de enero al 4 de febrero de 2005 (Eds., L. Hernández, A. Martín y G. Rodriguez).
12.
Linear Cellular Automata as Discrete Models for Generating Cryptographic Sequences - Fúster Sabater, Amparo; Caballero Gil, Pino
6 pages, 5 tables.-- This paper appeared at the Australasian Information Security Conference (AISC2008), Wollongong, Australia, January 2008.-- Later published as paper: http://digital.csic.es/handle/10261/11004
13.
Stream Cipher Design for MANets - Delgado, Óscar; Fúster Sabater, Amparo
4 pages.-- PACS nrs.: 89.20.Ff
; 07.05.Kf.-- Contributed to: Proc. of the International Conference on Computational Methods in Science and Engineering 2007 (ICCMSE 2007), Corfu, Greece, Sep 25-30, 2007 (T.E. Simos, G. Maroulis, eds).
17.
Usando la técnica MPR para la certificación de claves en MANETs - Hernández Goya, C.; Caballero Gil, Pino; Delgado, Óscar
9 pages, 4 figures.-- Contributed to: X Spanish Meeting on Cryptology and Information Security (Salamanca, Spain, Sep 2-5, 2008).
19.
Encryption of Images with 2-dimensional Cellular Automata - Hernández Encinas, Luis; Martín del Rey, Ángel; Hernández Encinas, Ascensión
6 pages, 4 figures.-- Communication presented at the 6th World Multiconference on Systemics, Cybernetics and Informatics and 8th International Conference on Information System Analysis and Synthesis (SCI/ISAS 2002, Orlando, Florida, Jul 14-18, 2002).
20.
Analysis of Structural Properties of Shrinking Generators as a Subset of Cellular Automata - Fúster Sabater, Amparo; Guía Martínez, Dolores de la; Caballero Gil, Pino
5 pages, 1 figure.-- Communication presented at the 6th World Multiconference on Systemics, Cybernetics and Informatics and 8th International Conference on Information System Analysis and Synthesis (SCI/ISAS 2002, Orlando, Florida, Jul 14-18, 2002).
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