Desarrollo de un renderer 3D con path tracing

Actualmente es muy difícil obtener resultados gráficos realistas de manera fidedigna a la hora de renderizar escenas 3D. Muchas veces se utilizan muchos otros conceptos para intentar simular de la mejor manera posible, pero la realidad es que esos resultados, pese a ser muy buenos, no llegan a un nivel de hiper realismo suficiente. El objetivo principal de este proyecto es crear un renderer 3D que implemente la técnica del path tracing para conseguir renderizar una escena 3D simulando la iluminación de la manera más realista posible. Otros de los objetivos de este proyecto son aumentar los conocimientos en esta materia con la intención de que sirva para poder trabajar sobre ella en el futuro. Este proyecto va dirigido a todo aquel que tenga curiosidad acerca de la implementación de esta técnica y que le pueda servir de ayuda, no solo a nivel informativo, sino también en caso de querer implementar de forma propia esta técnica o alguna similar como puede ser el ray tracing. También está dirigido este trabajo a todo aquel que quiera realizar un renderizado de una escena 3D creada por él mismo. Para realizar este trabajo se utiliza la metodología iterativa e incremental que permite dividir el proyecto en pequeñas tareas las cuales se van añadiendo y mejorando poco a poco. Esta metodología permite llevar un mayor control sobre lo que ocurre en el proyecto y permite ir iterando el proyecto hasta llegar al resultado que se desea. El desarrollo de este proyecto ha sido llevado a cabo correctamente y se ha conseguido crear un editor que renderice escenas 3D utilizando la técnica del path tracing y permitiendo exportar este resultado en formato png. Al ser un editor, también se permite modificar ciertas características de los materiales para que el usuario pueda crear sus propias escenas. Finalmente, este proyecto ha sido realmente complejo de realizar, debido en parte a que pese a que hay mucha teoría sobre él y la mayoría de fórmulas para resolver el problema de la iluminación fueron descritas hace muchísimos años, la información sobre la implementación de esta técnica y cómo hacerlo correctamente es algo más escasa. Pese a esta falta de información a nivel práctico y que la planificación del proyecto no fue la adecuada, el resultado ha sido el que se describió en los objetivos al iniciar el proyecto

Strategies to unblock the n-GaAs surface when electrodepositing Bi from acidic solutions

Bismuth ultra-thin films grown on n-GaAs electrodes via electrodeposition are porous due to a blockade of the electrode surface caused by adsorbed hydrogen when using acidic electrolytes. In this study, we discuss the existence of two sources of hydrogen adsorption and e propose different routes to unblock the n-GaAs surface in order to improve Bi films compactness. Firstly, we demonstrate that increasing the electrolyte temperature provides ompact yet polycrystalline Bi films. Cyclic voltammetry scans indicate that this low crystal quality might be a result of the incorporation ofBi hydroxides within the Bi film as a result of the temperature increase. Secondly, we have illuminated the semiconductor surface to take advantage of photogenerated holes. These photocarriers oxidize the adsorbed hydrogen nblocking the surface, but also create pits at the substrate surface that degrade the Bi/GaAs interface and prevent an epitaxial growth. Finally, we show that performing a cyclic voltammetry scan before electrodeposition enables the growth of compact Bi ultra-thin films of high crystallinity on semiconductor substrates with a doping level low enough to perform transport measurements

Small Fluxgate Magnetometers: Development and Future Trends in Spain

In this paper, we give an overview of the research on fluxgate magnetometers carried out in Spain. In particular we focus in the development of the planar-type instruments. We summarize the fabrication processes and signal processing developments as well as their use in complex systems and space

Control of Animal Brucellosis — The Most Effective Tool to Prevent Human Brucellosis

The World Health Organization classifies brucellosis as one of the seven neglected endemic zoonosis which contribute to the perpetuation of poverty in developing countries. Although most of the developed countries are free from this important zoonosis, brucellosis has still a widespread distribution in the Mediterranean region, the Middle East, Central Asia, and parts of Latin America, making it a global problem. Nearly half a million of new cases of human brucellosis are reported each year around the world, in which animals (or products of animal origin) are the most likely source of infection. Brucella melitensis, the main etiologic agent of small ruminant brucellosis, is the most prevalent specie involved in cases of human disease in most parts of the world. Additionally, Brucella abortus (main responsible of bovine brucellosis) and Brucella suis (the most common etiological agent of porcine brucellosis) are often associated with human brucellosis. In animal production, brucellosis has a strong economic impact due not only to its direct consequences (e.g., reproductive failures) but also to indirect loses (e.g., trade restrictions). The problem of brucellosis could be considered a clear example of the need for a “One World, One Health” strategy, given that the only approach to achieve its control and subsequent eradication is the cooperation between public and animal health authorities. The prevention of human brucellosis cannot be achieved without the control of the disease in the animals, as exemplified by the impact that the early measures adopted in the beginning of the 20th century forbidding the consumption of goat milk had on the prevalence of the disease in the British soldiers in Malta. When the prevalence of the disease in the animal population is high or when eradication cannot be achieved due to other factors (e.g., lack of economic resources), its control in livestock must be the first objective. When deciding the optimal approach to tackle the disease, the prevalence of animal brucellosis is not the only parameter to consider by the decision makers since other epidemiological and economic aspects should be considered in order to implement the most adequate control strategy in each region. Cooperation between all stakeholders involved is a cornerstone in the success of any control strategy. Strict biosafety and management measures, vaccination, and test-and-slaughter strategy are recognized as the most effective strategies to control this pathology in livestock. The adequate combination of these measures depends on several factors that will determine the success of the eradication efforts. The present chapter will review the abovementioned measures for the control and eradication of brucellosis in livestock, focusing on the advantages and drawbacks of the diagnosis tools and immunization strategies currently available and evaluating new approaches based on the advance on the knowledge of different aspects of this disease and its etiological agents

Mixed effects of the atomic arrangement and surface chemistry on the electrodeposition of Bi thin films on n-GaAs substrates

We have studied the electrodeposition of Bi thin films on two GaAs orientations with different atomic arrangement and chemical composition, (110) and (111)B. The electrochemical properties of each substrate have been analyzed by means of cyclic voltammetries and current transients. Then, X-ray diffraction has been used to determine the crystal structure and quality of the Bi films, and atomic force microscopy images have provided information about the surface morphology. Finally, the Bi/GaAs interface has been electrically characterized by means of capacitance-voltage and current-voltage curves. In this study, we have been able to discriminate between the effect of surface chemistry and the arrangement of surface atoms. The former has a direct effect on the reduction process of Bi(III) ions and on the electrical properties of the Bi/GaAs interface, whereas the atoms arrangement at the substrate surface determines the texture and morphology of the Bi films

Evaluación de actividad física y sedentarismo a partir del fenotipo digital

El sedentarismo y los bajos niveles de actividad física son dos de los mayores factores de riesgo para numerosas enfermedades crónicas de gravedad. Sin embargo, estos conceptos son difíciles de medir de manera precisa debido al gran núumero de datos que se requiere para ello. Con este proyecto se pretende resolver este problema, desarrollando un sistema inform ático, alojado en la nube, que utiliza la huella digital de las personas para calcular estimadores realistas de su actividad y sedentarismo. Para poder llevar a cabo el proyecto ha sido necesario el estudio del funcionamiento de bases de datos NoSQL, de las estrategias y procesos de gestión de datos en proyectos con un gran volumen de estos, del funcionamiento de Docker y Kubernetes y, fi nalmente, de los conceptos médicos pertinentesA sedentary lifestyle and low levels of physical activity are two of the greatest risk factors for many serious chronic diseases. However, these concepts are di cult to measure accurately due to the large amount of data required to do so. The aim of this project is to solve this problem, developing an informatic system, hosted in cloud, which uses people's digital footprint to calculate realistic estimators of their activity and sedentarism. To carry out carry out the project, it's been necessary to study how NoSQL databases work, the data management strategies and processes in projects with a large volume of these, the operation of Docker and Kubernetes and, nally, the relevant medical concepts.Grado en Ingeniería Informátic

Control of magnetic properties of FeCo thin films grown by sputtering

Control of magnetic properties of FeCo thin films grown by sputterin

Influence of accelerometer signal filtering on automatic detection of gait impact parameters

[EN] Filtering the signal recorded by an accelerometer is essential to remove noise recorded by the sensor, but in order to calculate gait parameters properly, the choice of a suitable cutoff frequency of the filter is critical. This paper evaluates the influence of the filter cutoff frequency in the calculation of the parameters: vertical peak tibial acceleration and acceleration rate. The accelerometer signal filtering with low-pass filter with cutoff frequency below 50 Hz gives good results in the calculation of peak tibial acceleration but produces estimations of the acceleration rate below its real valueThis work has been sponsored by the Generalitat Valenciana: application 09.02.03.542.50.7 budget line T4015 grant from the “Conselleria de Educación, Cultura y Deporte”, aid for conducting R & D for emerging research groups corresponding to the call set out in Annex IX, the Order 64/2014, of July 31, the “Conselleria de Educación, Cultura y Deporte” (DOCV no. 7.332, of August 5, 2014). Record GV /2015/067.Camacho García, A.; Llinares Llopis, R.; Lucas-Cuevas, Á.; Pérez Soriano, P. (2016). Influence of accelerometer signal filtering on automatic detection of gait impact parameters. International Journal of Advancements in Digital Signal Processing. 3(1). http://hdl.handle.net/10251/94462S3

Turbulent statistics and coherent structures in an asymmetrically heated channel flow

A compressible direct numerical simulation (DNS) has been conducted to analyze the behavior of a fully developed turbulent channel flow. The problem has been set at mean friction Reynolds number Ret m = 400 submitted to a high-temperature gradient between the two walls (Thot/Tcold = 2).This work has been partially financially supported by the Ministerio de Economía y Competitividad, Secretaría de Estadod e Investigación, Desarrollo e Innovación, Spain (ref. PID2020-116937RB-C21 and PID2020-116937RB-C22). We also acknowledge Red Española de Supercomputación (RES) for awarding access to the MareNostrum IV machine based in Barcelona, Spain (IM-2022-3-0010).Peer ReviewedPostprint (published version

Room-temperature ferromagnetism in the mixtures of the TiO₂ and Co₃O₄ powders

We report here the observation of ferromagnetism (FM) at 300 K in mixtures of TiO₂ and Co₃O₄ powders despite the antiferromagnetic and diamagnetic characters of both oxides, respectively. The ferromagnetic behavior is found in the early stages of reaction and only for TiO₂ in anatase structure; no FM is found for identical samples prepared with rutile-TiO². Optical spectroscopy and x-ray absorption spectra confirm a surface reduction of octahedral Co^(+3) -> Co^(+2) in the mixtures which is in the origin of the observed magnetism