ABSTRACT Computer graphics aim to create visual representations for screens, where depth is simulated. In contrast, Computed Generated Holograms (CGH) focus on encoding and recreating light patterns generate a true 3D holographic image that appears as physical object in space. Therefore, although both use digital models, the computation of CGHs necessitates additional phase‐related calculations, which turn escalate computational demands. These calculations often result excessively long...

In this article, we derive a physically-based model for simulating rainbows. Previous techniques rainbows have used either geometric optics (ray tracing) or Lorenz-Mie theory. theory is by far the most accurate technique as it takes into account optical effects such dispersion, polarization, interference, and diffraction. These are critical accurately. However, restricted to scattering spherical particles, cannot be applied real raindrops which nonspherical, especially larger raindrops. We...

Public procurement or tendering refers to the process followed by public authorities for of goods and services. In most developed countries, law requires provide online information ensure competitive as far possible, which adequate a nnouncement tenders is an essential requirement. addition, transparency laws being proposed in such countries are making monitoring contracts citizens fundamental right. This paper describes PPROC ontology, has been give support both processes, publication...

Abstract Motion blur is a fundamental cue in the perception of objects motion. This phenomenon manifests as visible trail along trajectory object and result combination relative motion light integration taking place film electronic cameras. In this work, we analyse mechanisms that produce recording devices methods can simulate it computer generated images. Light over time one most expensive processes to high‐quality renders, such, make an in‐depth review existing algorithms categorize them...

Abstract The object of this work is to analyse the computational aspects finite‐element method for elastic wave equations. necessary numerical techniques are analysed from point view accuracy, performance and storage requirements when implemented in scalar vector processors with large capacity. on an IBM 3090 facility. For implementation we consider five different time integration schemes (explicit implicit central difference, Houbolt, constant average acceleration Wilson), case, both direct...

Sustainable Development Goal 4 from the United Nations 2030 Agenda, focus on ensuring inclusive and equitable quality education promoting lifelong learning opportunities for all. Inclusive is a key component of sustainable development goal 4, assistive technology critical factor in achieving it. In this context, paper introduces an immersive virtual reality system with conversational skills processes. The idea work to provide motivate, educate, train students disabilities more way. order...

Optical encryption of information using Computer Generated Holograms (CGH) is a well-known discipline based on the modification phase pattern obtained from calculation hologram scene. This paper presents an evolution this technique adding random pixel permutation. The complete workflow described starting synthesis 3D scene by Graphics, its storage in CGH, and decryption process, showing results laboratory simulation. Special emphasis given to proposals related phase, allowing use, if...

This work presents an optical encryption process for various types of information related to 3D worlds (scenes) or 2D images, utilizing Computer-Generated Holograms (CGHs). It also introduces a modification the Dual Random Phase Encoding (DRPE) algorithm by incorporating pixel shuffling. proposal enables use either single key both shuffling and phase mask definition two independent keys. The latter option is particularly advantageous in applications that require involvement agents retrieve...

Abstract We present a novel method to estimate an approximation of the reflectance characteristics optically thick, homogeneous translucent materials using only single photograph as input. First, we approximate diffusion profile linear combination piecewise constant functions, approach that enables system minimization and maximizes robustness in presence suboptimal input data inferred from image. then fit smoother monotonically decreasing model, ensuring continuity on its first derivative....

The tourism sector in the province of Teruel (Aragon, Spain) is increasing rapidly. Although number domestic and foreign tourists continuously growing, there are some tourist attractions spread over a wide geographical area, which only visited by few people at specific times year. Additionally, having human guides everywhere speaking different languages unfeasible. An integrated solution based on smart interactive Embodied Conversational Agents (ECAs) combined with ontologies would overcome...

By means of fault population analysis (using the right dihedra, y‐R diagram and Etchecopar's methods), states stress in a number sites Cameras Massif (Northwestern Iberian Chain, Spain) nearby areas Ebro Basin have been determined. These used as framework order to infer model actual field that area during main stage Alpine compression (Oligocene‐lower Miocene). The three directions obtained (NW‐SE, NNE, NE‐SW) can be explained by single with horizontal σ 1 trending NNE vertical 2 , whose...

Several filtering techniques have been used to remove the effects of multipathing and modal contamination, isolate fundamental mode from Rayleigh wavetrains. Group velocity data are obtained by means multiple-filter technique. A time-variable filter has allowed influence noise as well interference produced higher modes be removed. Multiple is then again compute group velocities at each station. The interstation for wave estimated according two stations. Frequency-domain Wiener deconvolution...

A rigorous study of velocity dispersion surface waves generated by teleseismic events propagating across the Iberian Peninsula and traversing main geological units, has been carried out from a set selected analogue data, as digital records have only become available recently. Dispersed seismic signals obtained over period 16 years, between 1967 1982, at five stations having long-period instruments. In our study, we considered many earthquakes thus obtaining fairly good path coverage most...

Abstract Simulating the in‐water ocean light field is a daunting task. Ocean waters are one of richest participating media, where interacts not only with water molecules, but suspended particles and organic matter as well. The concentration each constituent greatly affects these interactions, resulting in very different hues. Inelastic scattering events such fluorescence or Raman imply energy transfers that usually neglected simulations. Our contributions this paper bio‐optical model...

This paper describes a novel extension of the photon mapping algorithm, capable handling both volume multiple inelastic scattering and curved light paths simultaneously. The is based on Full Radiative Transfer Equation (FRTE) Fermat's law, yields physically accurate, high-dynamic data than can be used for image generation or other simulation purposes, such as driving simulators, underwater vision lighting studies in architecture. Photons are traced into participating medium with varying...

We present a powerful technique to simulate and approximate caustics in images. Our algorithm is designed produce good results without the need painstakingly paint over pixels. The ability edit global illumination through image processing allows interaction with images at level which has not yet been demonstrated, significantly augments extends current image-based material editing approaches. show by means of set psychophysical experiments that resulting imagery visually plausible on par...