52 resultados para Visão estéreo
Resumo:
A challenge that remains in the robotics field is how to make a robot to react in real time to visual stimulus. Traditional computer vision algorithms used to overcome this problem are still very expensive taking too long when using common computer processors. Very simple algorithms like image filtering or even mathematical morphology operations may take too long. Researchers have implemented image processing algorithms in high parallelism hardware devices in order to cut down the time spent in the algorithms processing, with good results. By using hardware implemented image processing techniques and a platform oriented system that uses the Nios II Processor we propose an approach that uses the hardware processing and event based programming to simplify the vision based systems while at the same time accelerating some parts of the used algorithms
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This work intends to show a new and few explored SLAM approach inside the simultaneous localization and mapping problem (SLAM). The purpose is to put a mobile robot to work in an indoor environment. The robot should map the environment and localize itself in the map. The robot used in the tests has an upward camera and encoders on the wheels. The landmarks in this built map are light splotches on the images of the camera caused by luminaries on the ceil. This work develops a solution based on Extended Kalman Filter to the SLAM problem using a developed observation model. Several developed tests and softwares to accomplish the SLAM experiments are shown in details
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Navigation based on visual feedback for robots, working in a closed environment, can be obtained settling a camera in each robot (local vision system). However, this solution requests a camera and capacity of local processing for each robot. When possible, a global vision system is a cheapest solution for this problem. In this case, one or a little amount of cameras, covering all the workspace, can be shared by the entire team of robots, saving the cost of a great amount of cameras and the associated processing hardware needed in a local vision system. This work presents the implementation and experimental results of a global vision system for mobile mini-robots, using robot soccer as test platform. The proposed vision system consists of a camera, a frame grabber and a computer (PC) for image processing. The PC is responsible for the team motion control, based on the visual feedback, sending commands to the robots through a radio link. In order for the system to be able to unequivocally recognize each robot, each one has a label on its top, consisting of two colored circles. Image processing algorithms were developed for the eficient computation, in real time, of all objects position (robot and ball) and orientation (robot). A great problem found was to label the color, in real time, of each colored point of the image, in time-varying illumination conditions. To overcome this problem, an automatic camera calibration, based on clustering K-means algorithm, was implemented. This method guarantees that similar pixels will be clustered around a unique color class. The obtained experimental results shown that the position and orientation of each robot can be obtained with a precision of few millimeters. The updating of the position and orientation was attained in real time, analyzing 30 frames per second
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This paper aims to build a notebook of activities that can help the teacher of elementary school mathematics. Topics covered are arithmetic and geometry and the activities proposed here were developed aiming print them a multicultural character. We take as a base line developed by Claudia Zaslavsky multiculturalism and reflected in his books "Games and activities worldwide" and "More games and activities worldwide." We structure our work around four themes: the symbol of the Olympic Games, the pyramids of Egypt, the Russian abacus abacus and Chinese. The first two themes allow you to explore basic concepts of geometry while the latter two themes allow us to explore numerical notation and arithmetic operations
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O objetivo deste trabalho é investigar a construção axiológica do riso na charge. Nesse gênero discursivo abordaremos a construção do riso, partindo da hipótese de que o riso constitutivo das relações dialógicas na charge é construído axiologicamente, ou seja, é um riso que presentifica enunciativamente e é por meio dele que chegamos ao axiológico, aos posicionamentos, ao ideológico. Para tanto, nos deteremos na investigação dos elementos verbo-visuais presentes na forma composicional como também do projeto de dizer constituidor/constituinte da forma arquitetônica. Tomamos como fundamento teórico-metodológico as formulações sobre linguagem advindas do Círculo de Bakhtin (2010, 2011, 1998) e outros tais como Faraco (2009), Brait (2009, 2006), Ponzio (2009) que comungam dessa concepção de linguagem. Especificamente sobre o gênero discursivo charge, nos reportamos a Ramos (2009, 2010, 2011) e Vergueiro (2009, 2010). Quanto ao riso, apoiamo-nos em autores como Possenti (2010), Minois (2003), Propp (1992), Bergson (2001), Skinner (2002), no entanto, tendo por principal referência a obra de Bakhtin sobre cosmovisão carnavalesca e riso (1997, 2010). Este trabalho se insere na área da Linguística Aplicada de perspectiva sócio-histórica e tem como tema linguagem, axiologia e riso
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The following work is to interpret and analyze the problem of induction under a vision founded on set theory and probability theory as a basis for solution of its negative philosophical implications related to the systems of inductive logic in general. Due to the importance of the problem and the relatively recent developments in these fields of knowledge (early 20th century), as well as the visible relations between them and the process of inductive inference, it has been opened a field of relatively unexplored and promising possibilities. The key point of the study consists in modeling the information acquisition process using concepts of set theory, followed by a treatment using probability theory. Throughout the study it was identified as a major obstacle to the probabilistic justification, both: the problem of defining the concept of probability and that of rationality, as well as the subtle connection between the two. This finding called for a greater care in choosing the criterion of rationality to be considered in order to facilitate the treatment of the problem through such specific situations, but without losing their original characteristics so that the conclusions can be extended to classic cases such as the question about the continuity of the sunrise
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The main goal of this work is analyze the way which the Natal City Prefecture was constructed as a place of subversion by those we call defenders of the order, in the period right after the outbreak of military coup in 1964. To reach it, the main resource of search was the Relatório Subversão no Rio Grande do Norte , document produced from the investigations realized in Natal City Prefecture as a result of the Commission of Inquiry s work, established by the governor Aluízio Alves to determine the subversion in Rio Grande do Norte s society. Based on the anti-comunist speech. That document introduces other image of the Prefecture, which activities developed by de second Djalma Maranhão administration (1961-1964), specially those developed in the educational area, as the campaign De Pé no Chão Também se Aprende a Ler , were considered subversive , communist , dangerous , threatening , names that served as backing to embed Natal City Prefecture in the general view about subversion existing in Rio Grande do Norte, according to the repression speech in this initial period of military regime. Key-words: 1964 Military Coup Natal City Prefecture
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In this thesis we tested evolutionary hypotheses, with empirically collected data, in a sample composed of pregnant Brazilian women. We consider that during pregnancy and soon after the baby's birth fundamental reproductive decisions take place, given the complete feminine involvement with the reproduction phenomenon. The results are presented in four empirical articles related to the history of female reproduction. The topics approached were mate selection, the life-history theory, the strategies of parental investment and postpartum depression. Data collection was accomplished through interviews with pregnant women and after the baby s birth, with a sample composed of women from two income classes (low income and middle class), in Natal, Brazil. With respect to mate selection, the results suggest that a real situation of reproductive mate selection shows significant differences when compared to the results obtained in studies involving potential mate selection (Article I). Considering the life-history theory, we have partially confirmed the hypothesis of the father`s absence influencing the development of the young female syndrome (Article II). In regard to parental investment strategies and the decrease of fatherhood uncertainty, we identified a larger attribution of the baby's resemblance after birth with the father, confirming our hypothesis (Article III). The results related to postpartum depression occurrence partially support the hypothesis that it is an evolutionary adaptation (Article IV). This thesis is part of a consolidation movement of Evolutionary Psychology in Brazil and it presents results on female reproductive history hitherto unpublished.
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Among placental mammals, primates are the only ones to present trichromatic color vision. However, the distribution of trichromacy among primates is not homogeneous: Old World primates shows an uniform trichromacy (with all individuals being trichromats) and New World primates exhibit a color vision polymorphism (with dichromatic males and dichromatic or trichromatic females). Visual ecology studies have investigated which selective pressures may have been responsible for the evolution of trichromacy in primates, diverging from the dichromat standard found in other mammals. Cues associated with foraging and the socio-reproductive status were analyzed, indicating a trichromatic advantage for the rapid detection of visually conspicuous objects against a green background. However, dichromats are characterized by an efficient capture of cryptic and camouflaged stimuli. These advantages regarding phenotype may be responsible for the maintenance of the visual polymorphism in New World primates and for the high incidence of color blindness in humans (standing around 8% in Caucasian men). An important factor that has not yet been experimentally taken into account is the predation risk and its effect on the evolution of trichromacy in primates. To answer this question, we prepared and edited pictures of animals with different coats: oncillas (Leopardus spp.), puma (Puma concolor) and ferret (Galictis cuja). The specimens were taxidermized and the photographs were taken in three different vegetation scenarios (dense forest, cerrado and grassland). The images of the predators were manipulated so that they fit into two categories of stimulus size (small or large). After color calibration and photo editing, these were presented to 40 humans (20 dichromats and 20 trichromats) by a computer program, which presented a set of four photos at a time (one picture containing the taxidermized animal amid the background vegetation and three depicting only the background vegetation) and recorded the response latency and success rate of the subjects. The results show a trichromatic advantage in detecting potential predators. The predator detection was influenced by the background, the predator species, the dimension of the stimulus and the observer s visual phenotype. As humans have a high rate of dyschromatopsias, when compared to wild Catarrhini or human tribal populations, it is possible that the increased rate of dichromats is a result of reduced pressure for rapid predator detection. Since our species came to live in more cohesive groups and resistant to attack by predators, with the advent of agriculture and the formation of villages, it is possible that the lower risk of predation has reduced the selection in favor of trichromats
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The study offers a global and interpretative view of the person-environment inter-action at André de Albuquerque Plaza, in Natal, RN, according to a descriptive-exploratory approach that aimed at learning about the space converted into place, as it is perceived and experienced by users, who attribute meaning to it. The main objective was to critically analyze the relationship person-plaza, based on data collected about users perception, utilization and ascribed meaning. I have employed an Environmental Psychology multi-method approach, including informal observations, interactive poster session, videotaping and interviews. The results indicated that the plaza, besides being a passage point, is also a spot of urban convergence for several groups, particularly taxi drivers, flanelinhas, skate boarders and students. In regard to the perception of the place, an overall positive evaluation of the plaza was verified, since people perceive selectively what interests them. In terms of usage, different groups of users presented diverse patterns of utilization, also observed in the attributed meanings. The plaza is a work place for taxi drivers and flanelinhas and a sports arena for the skate boarders, with a practical meaning for both groups. For students and other users it is a place for meeting and leisure, revealing a stronger affective quality, responsible for feelings of well being, tranquility and relaxation. The data so obtained could contribute for future government projects of intervention in those spaces, aiming at its preservation as an open spot among the concrete of city buildings, offering better quality of life, not only for today, but also for future generations
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The study aims to evaluate the quality of the work processes of the teams from the Family Health Strategy regarding the comprehensive health care for children, in the view of users in the state of Rio Grande do Norte. This is a cross-sectional observational evaluative research with quantitative approach. The primary data are part of the External Review from the Program of Improving Access and Quality of Primary Care (PMAQ) in 2012. 190 women were interviewed. The inclusion criteria was the presence in the clinic at the time of the survey, have attended the service in the last 12 months and be a mother or companion of a child up to two years old. A research protocol was developed in the dimensions of Growth and Development, Breastfeeding and nutrition, and health problems and its variables. The results revealed that mothers / companions who responded to the questionnaire 71% were aged between 18 and 35 years, 92.1% were literate, 96.3% had a monthly income and 62.6% received financial assistance from the government. As for the children, 39.4% were aged between 13 to 24 months. In promotion and prevention actions for children, 64.2% had consultation up to the 7th day of life, 91.1% underwent the screening test, 95.3% had a health handbook, 98.9% had a vaccine, 17.9% breastfed or breastfeed from 6 to 24 months. As for link and continuity of care, 86.8% of the children were accompanied by the same professional staff and 59.5% left with next consultation scheduled. In acute situations 42.4% of the children went to the health unit and 64% of these were attended. It is concluded that the actions involving prevention and health promotion of children in RN, are evaluated positively by the service users and meet the requirements of MS, as well as link and continuity of care. The weakness in access and reception of users is evident, indicating the need to adapt the service to the demand of health and planning actions to welcome all who seeks basic health unit-UBS
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In this work we propose a technique that uses uncontrolled small format aerial images, or SFAI, and stereohotogrammetry techniques to construct georeferenced mosaics. Images are obtained using a simple digital camera coupled with a radio controlled (RC) helicopter. Techniques for removing common distortions are applied and the relative orientation of the models are recovered using projective geometry. Ground truth points are used to get absolute orientation, plus a definition of scale and a coordinate system which relates image measures to the ground. The mosaic is read into a GIS system, providing useful information to different types of users, such as researchers, governmental agencies, employees, fishermen and tourism enterprises. Results are reported, illustrating the applicability of the system. The main contribution is the generation of georeferenced mosaics using SFAIs, which have not yet broadly explored in cartography projects. The proposed architecture presents a viable and much less expensive solution, when compared to systems using controlled pictures
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The objective of this research is to know the conscience, the sensibility and the interperformance's vision man-environment of some residents from Areado's slum, theirs attitudes and motivations to link individual and collectively with their environment seeking ransom the diferences and compare them in relacion of an scientific look. The study to the valorization of experience from individual or from the group consisted of humanist approach of Geography having the phenomenology as underlying philosophy. The theorical formulations manifested from ideas whole, detaching the effort to discipline the use at least these concepts: landscape, space, place and environment. Opposite the importance of knowing the interelation manenvironment, we insert more two concepts: topofilia (felling joins people to the place where they lives) and topophobia, because our preoccupations in the ambit of evironmental question, immediate to the human beings. The research had been developed from interview and percepition workshop, when the interviewed people answered about they understand what are environiment and Areado's environment. The gotten results allow a reflection about the evironmental thought thinking found there, constituting in subsidy to programs of evironmental education that be worried about local problems
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ABSTRACT This study aimed to evaluate the quality of prenatal Primary Care in Rio G rande do Norte, Brazil in 2012 under the program Improving Access and Quality of Primary Care. The study was cross - sectional, quantitative. Included 156 mothers of children under 2 years who received prenatal care at the health evaluated. We applied a ques tionnaire on profile, minimum queries, regularity of attendance, laboratory tests, vaccination, participation in educational activities, guidance received, clinical and obstetric procedures and prescription Ferrous sulphate and folic acid. The descriptive analysis of the criteria used Humanization Program Prenatal and Birth. The results showed that 92% of mothers had six or more visits; 85% with the same care was professional; 94% subsequent appointments scheduled. As for tests and procedures the percentage s were: Urine 98%; HIV - 96%; VDRL and 88%; 91% glucose; tetanus vaccination 93%; educational groups 56% with 36% participation, knowledge of the delivery location and 59% achievement breast exam 65%, 33% and preventive gynecological 43%; 98% supplemented wi th 96% Ferrous Sulfate and Folic Acid. It was concluded that there were advances in Rio Grande do Norte concerning assistance and there are weaknesses in the educational practices and conducting some minimal clinical examinations.
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This work presents an analysis of the behavior of some algorithms usually available in stereo correspondence literature, with full HD images (1920x1080 pixels) to establish, within the precision dilemma versus runtime applications which these methods can be better used. The images are obtained by a system composed of a stereo camera coupled to a computer via a capture board. The OpenCV library is used for computer vision operations and processing images involved. The algorithms discussed are an overall method of search for matching blocks with the Sum of the Absolute Value of the difference (Sum of Absolute Differences - SAD), a global technique based on cutting energy graph cuts, and a so-called matching technique semi -global. The criteria for analysis are processing time, the consumption of heap memory and the mean absolute error of disparity maps generated.