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Aproximadamente 29 registro(s) hasta el momento: (journal)

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Recurso libre

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

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

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

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

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

Effect of the glass substrate on the efficiency of the different orders that propagate in a transmission sinusoidal diffraction grating
Neipp López, Cristian - Sheridan, John T. - Márquez Ruiz, Andrés - Gallego Rico, Sergi - Ortuño Sánchez, Manuel - Beléndez Vázquez, Augusto - Pascual Villalobos, Inmaculada

Formato:	info:eu-repo/semantics/article
Enlaces:	In this work we study the effect of the glass substrate on the efficiencies of the different orders that propagate inside a transmission sinusoidal diffraction grating. Holographic optical elements are usually recorded on a photosensitive medium deposited on to a…
Fecha:	2009-02-02
Recurso:	RUA Docencia

Recurso libre

Influence of the gaze-stabilizing eye movements on the quality of the retinal image of the human eye
Pons Moreno, Álvaro Máximo - Lorente Velázquez, Amalia - Illueca Contri, Carlos - Artigas Verde, José María - Felipe Marcet, Adelina

Formato:	info:eu-repo/semantics/article
Enlaces:	In this work we have studied the influence of the gaze stabilizing movements of the eye on the quality of the retinal image of the human eye obtained by double pass methods. The results obtained agree with the expected differences…
Fecha:	2007-10-16
Recurso:	RUA Docencia

Recurso libre

Optical surface reconstruction technique through combination of zonal and modal fitting
Espinosa Tomás, Julián - Mas Candela, David - Pérez Rodríguez, Jorge - Illueca Contri, Carlos

Formato:	info:eu-repo/semantics/article
Enlaces:	Videokeratometers and Scheimpflug cameras permit accurate estimation of corneal surfaces. From height data it is possible to adjust analytical surfaces that will be later used for aberration calculation. Zernike polynomials are often used as adjusting polynomials, but they have shown…
Fecha:	2010-05-03
Recurso:	RUA Docencia

Recurso libre

Refractive analysis of the human cornea through propagated fields
Illueca Contri, Carlos - Mas Candela, David - Pérez Rodríguez, Jorge - Pons Moreno, Álvaro Máximo - Artigas Verde, José María

Formato:	info:eu-repo/semantics/article
Enlaces:	A new technique for analysing the optical quality of the human cornea is presented. Corneal maps are obtained through keratographies and then converted into phase maps. The propagated fields generated from this surface are plotted and studied. It is shown…
Fecha:	2007-10-16
Recurso:	RUA Docencia

Recurso libre

10.

Fresnel diffraction in a theoretical eye: a fractional Fourier transform approach
Pons Moreno, Álvaro Máximo - Lorente Velázquez, Amalia - Illueca Contri, Carlos - Mas Candela, David - Artigas Verde, José María

Formato:	info:eu-repo/semantics/article
Enlaces:	In this work, we have applied the fractional Fourier transform to obtain the Fresnel diffraction patterns in a theoretical eye. The FRT approach to Fresnel diffraction is easily implemented in a Gullstrand-Emsley theoretical eye, and it allows us to obtain…
Fecha:	2007-10-16
Recurso:	RUA Docencia

Recurso libre

11.

Scale corrections for faster evaluation of convergent Fresnel patterns
Mas Candela, David - Espinosa Tomás, Julián - Pérez Rodríguez, Jorge - Illueca Contri, Carlos

Formato:	info:eu-repo/semantics/article
Enlaces:	Numerical calculation of Fresnel patterns through fast Fourier transforms usually requires an extremely large number of samples in order to fulfil the Nyquist sampling condition. In many applications, the cut-off frequency of the system is much below the limit fixed…
Fecha:	2007-10-02
Recurso:	RUA Docencia

Recurso libre

12.

Near-field light distributions propagated from human corneas: determination of relevant patterns
Mas Candela, David - Pérez Rodríguez, Jorge - Vázquez Ferri, Carmen - Hernández Poveda, Consuelo - Illueca Contri, Carlos

Formato:	info:eu-repo/semantics/article
Enlaces:	A procedure to determine the best image range of distances that can be obtained from an aphakic eye is presented. Corneal surfaces are calculated from videokeratographic data. Light distributions at different distances inside the eye are calculated with a near-field…
Fecha:	2007-10-16
Recurso:	RUA Docencia

Recurso libre

13.

Complete algorithm for the calculation light patterns inside the ocular media
Pérez Rodríguez, Jorge - Mas Candela, David - Illueca Contri, Carlos - Miret Marí, Juan José - Vázquez Ferri, Carmen - Hernández Poveda, Consuelo

Formato:	info:eu-repo/semantics/article
Enlaces:	Realistic mathematical models are of great importance for studying the optical performance of the human eye. Light propagation algorithms provide robust methods to calculate field distributions inside a homogeneous medium, and thus they can be applied to the study of…
Fecha:	2007-10-08
Recurso:	RUA Docencia

Recurso libre

14.

Custom designed dynamic videokeratometer
Mas Candela, David - Kowalska, Malgorzata A. - Espinosa Tomás, Julián - Kasprzak, Henryk T.

Formato:	info:eu-repo/semantics/article
Enlaces:	The human eye is a complex dynamic system that undergoes fine rotations and deformations. Usually information about the eye globe deformation and micromovements are averaged and lost when using commercial measuring devices, although they provide important information about the eye’s…
Fecha:	2010-02-25
Recurso:	RUA Docencia

Recurso libre

15.

Birefringence of cellotape: Jones representation and experimental analysis
Beléndez Vázquez, Augusto - Fernández Varó, Elena - Francés Monllor, Jorge - Neipp López, Cristian

Formato:	info:eu-repo/semantics/article
Enlaces:	In this paper we analyze a simple experiment to study the effects of polarized light. A simple optical system composed of a polarizer, a retarder (cellotape) and an analyzer is used to study the effect on the polarization state of…
Fecha:	2010-03-22
Recurso:	RUA Docencia

Recurso libre

16.

Colorimetric and spectral evaluation of the optical anisotropy of metallic and pearlescent samples
Chorro Calderón, Elísabet - Perales Romero, Esther - Martínez Verdú, Francisco Miguel - Campos Acosta, Joaquín - Pons Aglio, Alicia

Formato:	info:eu-repo/semantics/article
Enlaces:	The visual and optical anisotropies of metallic and pearlescent samples have been evaluated using a multi-gonio-spectrophotometer and by adapting a gonio-template over the instrument aperture for measuring the relative spectral reflectance factor when the sample is rotated around an axis…
Fecha:	2010-02-04
Recurso:	RUA Docencia

Recurso libre

17.

Silver halide (sensitized) gelatin in Agfa-Gevaert plates: the optimized procedure
Fimia Gil, Antonio - Beléndez Vázquez, Augusto - Pascual Villalobos, Inmaculada

Formato:	info:eu-repo/semantics/article
Enlaces:	Silver halide sensitized gelatin (SHSG) is one of the most promising techniques for the fabrication of transmission holographic optical elements, achieving relatively high sensitivity of photographic material with the low scattering and high light stability of dichromated gelatin. In this…
Fecha:	2009-02-02
Recurso:	RUA Docencia

Recurso libre

18.

Statistical model for noise gratings recorded in volume holograms
Carretero López, Luis - Fimia Gil, Antonio - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	A statistical model is used to study the formation of noise gratings in holograms and the mechanism that causes radiation scattering in them. The theoretical model presented describes noise scattering in terms of diffraction due to the high number of…
Fecha:	2009-02-03
Recurso:	RUA Docencia

Recurso libre

19.

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

20.

Corneal aberrometric and refractive performance of 2 intrastromal corneal ring segment models in early and moderate ectatic disease
Piñero Llorens, David Pablo - Alió y Sanz, Jorge L. - El Kady, Bassam - Pascual Villalobos, Inmaculada

Formato:	info:eu-repo/semantics/article
Enlaces:	Purpose: To evaluate and compare visual, refractive, and corneal aberrometric outcomes after implantation of 2 types of intrastromal corneal ring segments (ICRS) in eyes with early to moderate ectatic disease. Settings: Vissum Corporation-Instituto Oftalmológico de Alicante, Alicante, Spain. Methods: This…
Fecha:	2010-02-15
Recurso:	RUA Docencia

Recurso libre

21.

New method for comparing colour gamuts among printing technologies
Perales Romero, Esther - Chorro Calderón, Elísabet - Viqueira Pérez, Valentín - Martínez Verdú, Francisco Miguel - Otero Belmar, Susana - Gracia Bonache, Vicente de

Formato:	info:eu-repo/semantics/article
Enlaces:	The authors have developed a simple method to compare the colour gamuts of different industries (printing, textiles, plastics, etc.) based on representing the reproduced colours in constant lightness L* and hue hab* planes. This method allows the analysis of those
Fecha:	2008-10-31
Recurso:	RUA Docencia

Recurso libre

22.

Method for the characterization of hologram processing
Bányász, Istvan - Beléndez Vázquez, Augusto - Pascual Villalobos, Inmaculada - Fimia Gil, Antonio

Formato:	info:eu-repo/semantics/article
Enlaces:	A novel method for the characterization of the processing of both absorption and phase holograms is proposed. Differently from the previous models, the square root of the diffraction efficiency of the processed hologram was directly related to the amplitude of…
Fecha:	2009-02-02
Recurso:	RUA Docencia

Recurso libre

23.

High-efficiency silver-halide sensitized gelatin holograms with low absorption and scatter
Beléndez Vázquez, Augusto - Neipp López, Cristian - Flores, Marcos - Pascual Villalobos, Inmaculada

Formato:	info:eu-repo/semantics/article
Enlaces:	We report for the first time the results of a comparative performance study of silver-halide sensitized gelatin (SHSG) holograms recorded in the familiar Agfa 8E75 HD plates and the new BB-640 plates manufactured by Holographic Recording Technologies. High diffraction efficiency…
Fecha:	2009-02-03
Recurso:	RUA Docencia

Recurso libre

24.

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

25.

Holographic collimator of diameter 200 mm in silver halide sensitized gelatin
Beléndez Vázquez, Augusto - Pascual Villalobos, Inmaculada - Fimia Gil, Antonio

Formato:	info:eu-repo/semantics/article
Enlaces:	In this paper we present the theoretical analysis and experimental results of a holographic collimator made in silver halide sensitized gelatin. Diffraction efficiency up to 70% over the whole plate and wave aberration as low as 20-lambda in the maximum…
Fecha:	2009-02-09
Recurso:	RUA Docencia

Recurso libre

26.

Geometrical Optics and Riemannian Geometry
Carretero López, Luis - Mateos Álvarez, Felipe - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	The methods of differential geometry are used with the assumption that rays of light follow geodesic trajectories in a space whose metric is determined by the refraction index. Keeping this in mind, we show that these hypotheses are equivalent to…
Fecha:	2009-03-20
Recurso:	RUA Docencia

Recurso libre

27.

First-harmonic diffusion-based model applied to a polyvinyl-alcohol–acrylamide-based photopolymer
Neipp López, Cristian - Gallego Rico, Sergi - Ortuño Sánchez, Manuel - Márquez Ruiz, Andrés - Álvarez López, Mariela Lázara - Beléndez Vázquez, Augusto - Pascual Villalobos, Inmaculada

Formato:	info:eu-repo/semantics/article
Enlaces:	The photopolymerization diffusion models give accurate comprehension of the mechanism of hologram formation inside photopolymer materials. Although several models have been proposed, these models share the common assumption that there is an interplay between the processes of monomer polymerization and…
Fecha:	2009-01-22
Recurso:	RUA Docencia

Recurso libre

28.

Comparative study of bleaches applied to BB-640 plates
Neipp López, Cristian - Condeza, Shirley - Campos, Ana María - Pascual Villalobos, Inmaculada - Beléndez Vázquez, Augusto

Formato:	info:eu-repo/semantics/article
Enlaces:	The use of bleaching techniques is perhaps one of the most popular methods of creating phase holograms from holographic emulsions. In this paper we will study the influence of the different experimental conditions on the refractive index modulation created inside…
Fecha:	2009-01-30
Recurso:	RUA Docencia

Recurso libre

29.

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