Metabuscador

Filtrado por:

Temas

Año

2012 (3)
2010 (4)
2009 (8)
2007 (1)
2003 (3)
2002 (2)
Más...

Aproximadamente 21 registro(s) hasta el momento: (journal)

Mostrar 10 | 50 | 100 resultados por página

Recurso libre

Some activities on educational technology innovation in Physics, optics and telecommunications
Arribas Garde, Enrique - Beléndez Vázquez, Augusto - Nájera López, Alberto - Márquez Ruiz, Andrés - Villalba Montoya, José Manuel - Gallego Rico, Sergi - Ortuño Sánchez, Manuel - Francés Monllor, Jorge - Álvarez López, Mariela Lázara - Neipp López, Cristian - Pascual Villalobos, Inmaculada

Formato:	info:eu-repo/semantics/article
Enlaces:	The use of innovative technologies in education offers new possibilities that complement classroom teaching and may also help to improve the quality of education, enabling students to actively participate in the learning process. With this in mind, in 2009 the…
Fecha:	2012-10-01
Recurso:	RUA Docencia

Recurso libre

Left-handed metamaterial coatings for subwavelength-resolution imaging
Zapata Rodríguez, Carlos Javier - Pastor Calle, David - Martínez Martínez, Luis Enrique - Miret Marí, Juan José

Formato:	info:eu-repo/semantics/article
Enlaces:	We report on a procedure to improve the resolution of far-field imaging by using a neighboring high-index medium that is coated with a left-handed metamaterial. The resulting plot can also exhibit an enhanced transmission by considering proper conditions to retract…
Fecha:	2013-11-14
Recurso:	RUA Docencia

Recurso libre

Development of a unified FDTD-FEM library for electromagnetic analysis with CPU and GPU computing
Francés Monllor, Jorge - Bleda Pérez, Sergio - Gallego Rico, Sergi - Neipp López, Cristian - Márquez Ruiz, Andrés - Pascual Villalobos, Inmaculada - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	The present paper describes an optimized C++ library for the study of electromagnetics. The implementation is based on the Finite-Difference Time-Domain method for transient analysis, and the Finite Element Method for electrostatics. Both methods share the same core and are…
Fecha:	2013-05-07
Recurso:	RUA Docencia

Recurso libre

Retinal image quality assessment through a visual similarity index
Pérez Rodríguez, Jorge - Espinosa Tomás, Julián - Vázquez Ferri, Carmen - Mas Candela, David

Formato:	info:eu-repo/semantics/article
Enlaces:	Retinal image quality is commonly analyzed through parameters inherited from instrumental optics. These parameters are defined for ‘good optics’ so they are hard to translate into visual quality metrics. Instead of using point or artificial functions, we propose a quality…
Fecha:	2013-05-13
Recurso:	RUA Docencia

Recurso libre

Weighted Zernike polynomial fitting in steep corneas sampled in Cartesian grid
Espinosa Tomás, Julián - Pérez Rodríguez, Jorge - Mas Candela, David - Illueca Contri, Carlos

Formato:	info:eu-repo/semantics/article
Enlaces:	Surfaces with radial structure do not fit well to squared detectors or sampling matrices. Cartesian grid sampling provides a different density of nodes in sectors. Zernike polynomials are a complete set of orthogonal polynomials defined on a unit disk often…
Fecha:	2011-02-21
Recurso:	RUA Docencia

Recurso libre

Overmodulation control in the optimization of a H-PDLC device with ethyl eosin as dye
Ortuño Sánchez, Manuel - Riquelme Morell, Marina - Gallego Rico, Sergi - Márquez Ruiz, Andrés - Pascual Villalobos, Inmaculada - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	The response of a H-PDLC device is improved by means of a two-step method. First, component optimization—initiator system, crosslinker, and cosolvent—enables the diffraction efficiency of the hologram to be maximized. Second, the use of N-methyl-2-pyrrolidone in combination with N-vinyl-2-pyrrolidone prevents…
Fecha:	2013-12-04
Recurso:	RUA Docencia

Recurso libre

Spectral BRDF-based determination of proper measurement geometries to characterize color shift of special effect coatings
Ferrero Turrión, Alejandro - Rabal Almazor, Ana María - Campos Acosta, Joaquín - Martínez Verdú, Francisco Miguel - Chorro Calderón, Elísabet - Perales Romero, Esther - Pons Aglio, Alicia - Hernanz Sanjuán, María Luisa

Formato:	info:eu-repo/semantics/article
Enlaces:	A reduced set of measurement geometries allows the spectral reflectance of special effect coatings to be predicted for any other geometry. A physical model based on flake-related parameters has been used to determine nonredundant measurement geometries for the complete description…
Fecha:	2013-01-10
Recurso:	RUA Docencia

Recurso libre

Blinking kinematics description through non-invasive measurement
Pérez Rodríguez, Jorge - Espinosa Tomás, Julián - Doménech Amigot, Begoña - Mas Candela, David - Illueca Contri, Carlos

Formato:	info:eu-repo/semantics/article
Enlaces:	Spontaneous eye blinking is a complex process, which implies the joint actions of the eyelid muscles and the eye globe. These actions provoke the eyelid closure and simultaneous eye retraction into the orbit. Recently, the authors presented a non-invasive technique…
Fecha:	2011-02-16
Recurso:	RUA Docencia

Recurso libre

Axial irradiance and entropy of holographic optical elements under illumination with quasi-monochromatic light
Carretero López, Luis - Beléndez Vázquez, Augusto - Fimia Gil, Antonio

Formato:	info:eu-repo/semantics/article
Enlaces:	The chromatic sensitivity of holographic optical elements for use in optical interconnect systems is quantified using an entropy merit function. The influence of broad-band illumination on axial irradiance and intensity is studied showing that the best imaging point obtained with…
Fecha:	2009-02-02
Recurso:	RUA Docencia

Recurso libre

10.

Optimization of a fixation-free rehalogenating bleach for BB-640 holographic emulsion
Neipp López, Cristian - Pascual Villalobos, Inmaculada - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	Fixation-free rehalogenating bleaching is an interesting for the production of phase holograms. The shrinkage of the emulsion is reduced in comparison with other bleaching methods (reversal bleaching or rehalogenating bleaching with fixation). In this paper we present experimental results for…
Fecha:	2009-02-03
Recurso:	RUA Docencia

Recurso libre

11.

Tensorial split-field finite-difference time-domain approach for second- and third-order nonlinear materials
Francés Monllor, Jorge - Tervo, Jani - Márquez Ruiz, Andrés

Formato:	info:eu-repo/semantics/article
Enlaces:	The split-field finite-difference time-domain (SF-FDTD) method for one-dimensionally periodic structures is extended to include the coefficient-tensor description of second- and third-order nonlinear-optical media. A set of nonlinear equations related to the split-field values of the electric field is established. An…
Fecha:	2013-09-06
Recurso:	RUA Docencia

Recurso libre

12.

Fixation-free bleached silver halide transmission holograms recorded on Slavich PFG-01 red sensitive plates
Neipp López, Cristian - Beronich, Emiliano - Pascual Villalobos, Inmaculada - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	Bleaching is one of the most widely used techniques in the production of phase holograms of high quality on photographic emulsion, particularly in rehalogenating techniques without a fixation step. These techniques were very well understood when Agfa 8E75 HD emulsion…
Fecha:	2009-02-02
Recurso:	RUA Docencia

Recurso libre

13.

Diagnostic validity of clinical signs associated with a large exophoria at near
Cacho Martínez, Pilar - García Muñoz, Ángel - Ruiz Cantero, María Teresa

Formato:	info:eu-repo/semantics/article
Enlaces:	Purpose. To analyze the diagnostic validity of accommodative and binocular tests in a sample of patients with a large near exophoria with moderate to severe symptoms. Methods. Two groups of patients between 19 and 35 years were recruited from a…
Fecha:	2013-11-06
Recurso:	RUA Docencia

Recurso libre

14.

Characterization of a digital camera as an absolute tristimulus colorimeter
Martínez Verdú, Francisco Miguel - Pujol Ramo, Jaume - Capilla Perea, Pascual

Formato:	info:eu-repo/semantics/article
Enlaces:	An algorithm is proposed for the spectral and colorimetric characterization of digital still cameras (DSC) which allows them to be used as tele-colorimeters with CIE–XYZ color output, in cd/m2. The spectral characterization consists in the calculation of the color-matching functions…
Fecha:	2007-09-11
Recurso:	RUA Docencia

Recurso libre

15.

A two step method for recording holographic optical elements with partially coherent light
Pascual Villalobos, Inmaculada - Beléndez Vázquez, Augusto - Fimia Gil, Antonio

Formato:	info:eu-repo/semantics/article
Enlaces:	We propose a two step method which enables us to obtain transmission Holographic Optical Elements of high diffraction efficiency as well as a good signal-to-noise relation. By means of a device using partially coherent light, a master Holographic Optical Element…
Fecha:	2009-01-30
Recurso:	RUA Docencia

Recurso libre

16.

Clinical validation of an algorithm to correct the error in the keratometric estimation of corneal power for normal eyes
Piñero Llorens, David Pablo - Camps Sanchis, Vicente Jesús - Mateo Pérez, Verónica - Ruiz Fortes, Pedro

Formato:	info:eu-repo/semantics/article
Enlaces:	To validate clinically an algorithm for correcting the error in the keratometric estimation of corneal power by using a variable keratometric index of refraction (nk) in a normal healthy population.
Fecha:	2012-10-30
Recurso:	RUA Docencia

Recurso libre

17.

Thick phase holographic gratings recorded on BB-640 and PFG-01 silver halide materials
Neipp López, Cristian - Márquez Ruiz, Andrés - Pascual Villalobos, Inmaculada - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	Photographic emulsions are still widely used to record holographic optical elements. In particular, if high diffraction efficiencies are needed, phase volume holograms are preferably recorded on these emulsions. Two particular techniques producing high-quality volume phase holograms are fixation-free rehalogenating bleaching…
Fecha:	2009-01-30
Recurso:	RUA Docencia

Recurso libre

18.

Copying low spatial frequency holograms in silver halide emulsions: the influence of the bleach bath
Márquez Ruiz, Andrés - Pascual Villalobos, Inmaculada - Fimia Gil, Antonio - Beléndez Vázquez, Augusto - Campos Coloma, Juan - Yzuel Giménez, María Josefa

Formato:	info:eu-repo/semantics/article
Enlaces:	We present an available and low cost technique for the production of binary-phase diffractive optical elements designed by digital methods. We produce binary-amplitude holograms making use of a high-resolution graphic device. They are used as binary masks which are copied…
Fecha:	2009-05-20
Recurso:	RUA Docencia

Recurso libre

19.

Number of discernible colors for color-deficient observers estimated from the MacAdam limits
Perales Romero, Esther - Martínez Verdú, Francisco Miguel - Maciel Linhares, João Manuel - Cardoso Nascimento, Sérgio Miguel

Formato:	info:eu-repo/semantics/article
Enlaces:	We estimated the number of colors perceived by color normal and color-deficient observers when looking at the theoretic limits of object-color stimuli. These limits, the optimal color stimuli, were computed for a color normal observer and CIE standard illuminant D65,…
Fecha:	2011-09-20
Recurso:	RUA Docencia

Recurso libre

20.

Hybrid ternary modulation applied to multiplexing holograms in photopolymers for data page storage
Fernández Varó, Elena - Márquez Ruiz, Andrés - Gallego Rico, Sergi - Fuentes Rosillo, Rosa - García Llopis, Celia - Pascual Villalobos, Inmaculada

Formato:	info:eu-repo/semantics/article
Enlaces:	Holographic data storage is a new optical technology, which allows an important number of bits to be stored in a recording material. In this paper, holographic data pages were stored in a polyvinyl alcohol/acrylamide (AA) photopolymer layer, using a peristrophic…
Fecha:	2011-07-18
Recurso:	RUA Docencia

Recurso libre

21.

Low spatial frequency characterization of holographic recording materials applied to correlation
Márquez Ruiz, Andrés - Neipp López, Cristian - Beléndez Vázquez, Augusto - Campos Coloma, Juan - Yzuel Giménez, María Josefa - Fimia Gil, Antonio

Formato:	info:eu-repo/semantics/article
Enlaces:	Accurate recording of computer-generated holograms (CGH) on a phase material is not a trivial task. The range of available phase materials is large, and their suitability depends on the fabrication technique chosen to produce the hologram. We are particularly interested…
Fecha:	2009-01-30
Recurso:	RUA Docencia