Face pose estimation with automatic 3D model creation for a driver inattention monitoring application

Texto en inglés y resumen en inglés y españolRecent studies have identified inattention (including distraction and drowsiness) as the main cause of accidents, being responsible of at least 25% of them. Driving distraction has been less studied, since it is more diverse and exhibits a higher risk factor than fatigue. In addition, it is present over half of the inattention involved crashes. The increased presence of In Vehicle Information Systems (IVIS) adds to the potential distraction risk and modifies driving behaviour, and thus research on this issue is of vital importance. Many researchers have been working on different approaches to deal with distraction during driving. Among them, Computer Vision is one of the most common, because it allows for a cost effective and non-invasive driver monitoring and sensing. Using Computer Vision techniques it is possible to evaluate some facial movements that characterise the state of attention of a driver. This thesis presents methods to estimate the face pose and gaze direction of a person in real-time, using a stereo camera as a basic for assessing driver distractions. The methods are completely automatic and user-independent. A set of features in the face are identified at initialisation, and used to create a sparse 3D model of the face. These features are tracked from frame to frame, and the model is augmented to cover parts of the face that may have been occluded before. The algorithm is designed to work in a naturalistic driving simulator, which presents challenging low light conditions. We evaluate several techniques to detect features on the face that can be matched between cameras and tracked with success. Well-known methods such as SURF do not return good results, due to the lack of salient points in the face, as well as the low illumination of the images. We introduce a novel multisize technique, based on Harris corner detector and patch correlation. This technique benefits from the better performance of small patches under rotations and illumination changes, and the more robust correlation of the bigger patches under motion blur. The head rotates in a range of ±90º in the yaw angle, and the appearance of the features change noticeably. To deal with these changes, we implement a new re-registering technique that captures new textures of the features as the face rotates. These new textures are incorporated to the model, which mixes the views of both cameras. The captures are taken at regular angle intervals for rotations in yaw, so that each texture is only used in a range of ±7.5º around the capture angle. Rotations in pitch and roll are handled using affine patch warping. The 3D model created at initialisation can only take features in the frontal part of the face, and some of these may occlude during rotations. The accuracy and robustness of the face tracking depends on the number of visible points, so new points are added to the 3D model when new parts of the face are visible from both cameras. Bundle adjustment is used to reduce the accumulated drift of the 3D reconstruction. We estimate the pose from the position of the features in the images and the 3D model using POSIT or Levenberg-Marquardt. A RANSAC process detects incorrectly tracked points, which are not considered for pose estimation. POSIT is faster, while LM obtains more accurate results. Using the model extension and the re-registering technique, we can accurately estimate the pose in the full head rotation range, with error levels that improve the state of the art. A coarse eye direction is composed with the face pose estimation to obtain the gaze and driver's fixation area, parameter which gives much information about the distraction pattern of the driver. The resulting gaze estimation algorithm proposed in this thesis has been tested on a set of driving experiments directed by a team of psychologists in a naturalistic driving simulator. This simulator mimics conditions present in real driving, including weather changes, manoeuvring and distractions due to IVIS. Professional drivers participated in the tests. The driver?s fixation statistics obtained with the proposed system show how the utilisation of IVIS influences the distraction pattern of the drivers, increasing reaction times and affecting the fixation of attention on the road and the surroundings

Face pose estimation with automatic 3D model creation for a driver inattention monitoring application

Texto en inglés y resumen en inglés y españolRecent studies have identified inattention (including distraction and drowsiness) as the main cause of accidents, being responsible of at least 25% of them. Driving distraction has been less studied, since it is more diverse and exhibits a higher risk factor than fatigue. In addition, it is present over half of the inattention involved crashes. The increased presence of In Vehicle Information Systems (IVIS) adds to the potential distraction risk and modifies driving behaviour, and thus research on this issue is of vital importance. Many researchers have been working on different approaches to deal with distraction during driving. Among them, Computer Vision is one of the most common, because it allows for a cost effective and non-invasive driver monitoring and sensing. Using Computer Vision techniques it is possible to evaluate some facial movements that characterise the state of attention of a driver. This thesis presents methods to estimate the face pose and gaze direction of a person in real-time, using a stereo camera as a basic for assessing driver distractions. The methods are completely automatic and user-independent. A set of features in the face are identified at initialisation, and used to create a sparse 3D model of the face. These features are tracked from frame to frame, and the model is augmented to cover parts of the face that may have been occluded before. The algorithm is designed to work in a naturalistic driving simulator, which presents challenging low light conditions. We evaluate several techniques to detect features on the face that can be matched between cameras and tracked with success. Well-known methods such as SURF do not return good results, due to the lack of salient points in the face, as well as the low illumination of the images. We introduce a novel multisize technique, based on Harris corner detector and patch correlation. This technique benefits from the better performance of small patches under rotations and illumination changes, and the more robust correlation of the bigger patches under motion blur. The head rotates in a range of ±90º in the yaw angle, and the appearance of the features change noticeably. To deal with these changes, we implement a new re-registering technique that captures new textures of the features as the face rotates. These new textures are incorporated to the model, which mixes the views of both cameras. The captures are taken at regular angle intervals for rotations in yaw, so that each texture is only used in a range of ±7.5º around the capture angle. Rotations in pitch and roll are handled using affine patch warping. The 3D model created at initialisation can only take features in the frontal part of the face, and some of these may occlude during rotations. The accuracy and robustness of the face tracking depends on the number of visible points, so new points are added to the 3D model when new parts of the face are visible from both cameras. Bundle adjustment is used to reduce the accumulated drift of the 3D reconstruction. We estimate the pose from the position of the features in the images and the 3D model using POSIT or Levenberg-Marquardt. A RANSAC process detects incorrectly tracked points, which are not considered for pose estimation. POSIT is faster, while LM obtains more accurate results. Using the model extension and the re-registering technique, we can accurately estimate the pose in the full head rotation range, with error levels that improve the state of the art. A coarse eye direction is composed with the face pose estimation to obtain the gaze and driver's fixation area, parameter which gives much information about the distraction pattern of the driver. The resulting gaze estimation algorithm proposed in this thesis has been tested on a set of driving experiments directed by a team of psychologists in a naturalistic driving simulator. This simulator mimics conditions present in real driving, including weather changes, manoeuvring and distractions due to IVIS. Professional drivers participated in the tests. The driver?s fixation statistics obtained with the proposed system show how the utilisation of IVIS influences the distraction pattern of the drivers, increasing reaction times and affecting the fixation of attention on the road and the surroundings

The role of slip transfer at grain boundaries in the propagation of microstructurally short fatigue cracks in Ni-based superalloys

Crack initiation and propagation under high-cycle fatigue conditions have been investigated for a polycrystalline Ni-based superalloy by in-situ synchrotron assisted diffraction and phase contrast tomography. The cracks nucleated along the longest coherent twin boundaries pre-existing on the specimen surface, that were well oriented for slip and that presented a large elastic incompatibility across them. Moreover, the propagation of microstructurally short cracks was found to be determined by the easy slip transfer paths across the pre-existing grain boundaries. This information can only be obtained by characterization techniques like the ones presented here that provide the full set of 3D microstructural information

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Prensa, propaganda electoral y comunismo en Costa Rica durante las décadas de 1930 y 19401

El propósito de este artículo es demostrar que en la denominada prensa “burguesa” y en la propaganda electoral de las décadas de 1930 y 1940 se configuraron discursos que, pese a su anticomunismo, favorecían tanto la inserción política y cultural del Partido Comunista de Costa Rica como la promoción del cambio social por vías institucionales. La presencia que tales discursos lograron en la esfera pública contribuyó a que la izquierda costarricense permaneciera como la única organización de su tipo en Centroamérica que, al no ser ilegalizada, pudo competir sistemáticamente en los comicios del período 1932-1948.The objective of this paper is to demonstrate that in the denominated “bourgeois” press and in the electoral propaganda of the 1930 and 1940 decades, were formed anti-Communist discourses that favored the political and cultural insertion of the Communist Party of Costa Rica, and promoted social change by institutional ways. The presence that such discourses reached in the public sphere, contributed that the Costa Rican left remained like the only organization of its kind in Central America that was not illegalized and, therefore, could compete systematically in the elections of the period 1932-1948

AER Neuro-Inspired interface to Anthropomorphic Robotic Hand

Address-Event-Representation (AER) is a communication protocol for transferring asynchronous events between VLSI chips, originally developed for neuro-inspired processing systems (for example, image processing). Such systems may consist of a complicated hierarchical structure with many chips that transmit data among them in real time, while performing some processing (for example, convolutions). The information transmitted is a sequence of spikes coded using high speed digital buses. These multi-layer and multi-chip AER systems perform actually not only image processing, but also audio processing, filtering, learning, locomotion, etc. This paper present an AER interface for controlling an anthropomorphic robotic hand with a neuro-inspired system.Unión Europea IST-2001-34124 (CAVIAR)Ministerio de Ciencia y Tecnología TIC-2003-08164-C03-02Ministerio de Ciencia y Tecnología TIC2000-0406-P4- 0

La cuestión de la frecuencia y el tipo de trato con inmigrantes: una aproximación a los efectos de las relaciones intergrupales sobre las actitudes hacia la inmigración

The goal of this report is to look in more depth at the effects that the relationships between indigenous people and immigrants can have on the attitudes of the former towards the latter. The study uses the results of a national opinion poll on the perception of Spaniards towards immigration. Following the traditional perspective of contact theory developed by G.W. Allport, two central questions are posed here: first, if more frequent contact between indigenous and immigrantcommunities brings with it a more positive perception of the migratoryphenomenon and second, if the type of relationship established between the two groups influences this perception. In other words, to what extent does intergroup contact contribute to reducing stereotypes and prejudices towards immigrants

El principio del debido proceso y la constitucionalización del derecho administrativo

La Constitución como norma de normas se encuentra en cada una de las ramas del derecho, y con el transcurrir del tiempo ha venido evolucionando el concepto de constitucionalización del derecho, bajo el presupuesto que toda norma que rija a una sociedad debe estar enmarcada en los principios constitucionales situación a la que no escapa la rama del derecho administrativo. Dentro de ese proceso de constitucionalización, cada día se han integrado en la normatividad los principios constitucionales con el fin de darle una mayor eficiencia y protección a los destinatarios de la norma, y uno de esos principios es el del debido proceso el cual se ha desarrollado a través de la jurisprudencia tanto constitucional como la del Consejo de Estado y la doctrina.The Constitution as the supreme law is in each of the areas of law, and with the passage of time has evolved the concept of constitutionalization of law, under the assumption that any rule governing a society should be framed on the principles constitutional situation that does not escape the branch of administrative law. Within this constitutional process, every day has been integrated into the norms of constitutional principles in order to give greater efficiency and protection to the recipients of the standard, and one of those principles is that of due process which has been developed through both constitutional jurisprudence of the State Council and doctrine

La frontera enquistada: el reino de Murcia a fines de la Edad Media

Con el final de las grandes conquistas del siglo XIII, la frontera con el recién creado reino de Granada quedó prácticamente estancada. El presente artículo estudia la situación del territorio murciano y el efecto que la presencia de la cercana frontera ejerció sobre él. Se hace referencia a organización del territorio, a la concentración de la población en grandes núcleos como Lorca, Caravaca, Cehegín y otros. Se alude también a la función que la frontera murciana ejerció, como lugar de refugio político, en el contexto de las luchas internas de la región entabladas en el siglo XV. Todo ello permite a los autores trazar un amplio parorama sobre la realidad de la región murciana durante el último siglo de la Edad Media e, incluso, analizar las repercusiones que tuvo para el territorio murciano la desaparición del reino nazarí de Granada tras su capitulación en 1492.With the end of the great conquest of the 13th century, the frontier with the recentIy founded Kingdom of Granada remained practically stagnant. The present article studies the situation in the Murcia territory and the effect the presence of this neigthboring border had in the area. A reference is made to the organization of the territory and to the concentration of populations in large centers like Lorca, Caravaca, and Cehegín among others. It al so alludes to the function the Murcian border served as a place of polítical refuge in relation to the internal disputes that defined the region during the 15th century. All of this allows the author to present a panorama of the reality of the Murcian region during the last century of the Middle Ages, and to analyze the repercussions that the disappearance of the Nazarí Kingdom of Granada had on the Murcian territory afier its surrender in 1492