Um método para determinação da profundidade combinando visão estéreo e autocalibração para aplicação em robótica móvel

This work proposes a method to determine the depth of objects in a scene using a combination between stereo vision and self-calibration techniques. Determining the rel- ative distance between visualized objects and a robot, with a stereo head, it is possible to navigate in unknown environments. Stereo vision techniques supply a depth measure by the combination of two or more images from the same scene. To achieve a depth estimates of the in scene objects a reconstruction of this scene geometry is necessary. For such reconstruction the relationship between the three-dimensional world coordi- nates and the two-dimensional images coordinates is necessary. Through the achievement of the cameras intrinsic parameters it is possible to make this coordinates systems relationship. These parameters can be gotten through geometric camera calibration, which, generally is made by a correlation between image characteristics of a calibration pattern with know dimensions. The cameras self-calibration allows the achievement of their intrinsic parameters without using a known calibration pattern, being possible their calculation and alteration during the displacement of the robot in an unknown environment. In this work a self-calibration method based in the three-dimensional polar coordinates to represent image features is presented. This representation is determined by the relationship between images features and horizontal and vertical opening cameras angles. Using the polar coordinates it is possible to geometrically reconstruct the scene. Through the proposed techniques combination it is possible to calculate a scene objects depth estimate, allowing the robot navigation in an unknown environment

Um sistema de visão para navegação robusta de uma plataforma robótica semi-autônoma

Large efforts have been maden by the scientific community on tasks involving locomotion of mobile robots. To execute this kind of task, we must develop to the robot the ability of navigation through the environment in a safe way, that is, without collisions with the objects. In order to perform this, it is necessary to implement strategies that makes possible to detect obstacles. In this work, we deal with this problem by proposing a system that is able to collect sensory information and to estimate the possibility for obstacles to occur in the mobile robot path. Stereo cameras positioned in parallel to each other in a structure coupled to the robot are employed as the main sensory device, making possible the generation of a disparity map. Code optimizations and a strategy for data reduction and abstraction are applied to the images, resulting in a substantial gain in the execution time. This makes possible to the high level decision processes to execute obstacle deviation in real time. This system can be employed in situations where the robot is remotely operated, as well as in situations where it depends only on itself to generate trajectories (the autonomous case)

Correspondência estéreo usando imagens em multiresolução com profundidade variável

We propose a multi-resolution, coarse-to-fine approach for stereo matching, where the first matching happens at a different depth for each pixel. The proposed technique has the potential of attenuating several problems faced by the constant depth algorithm, making it possible to reduce the number of errors or the number of comparations needed to get equivalent results. Several experiments were performed to demonstrate the method efficiency, including comparison with the traditional plain correlation technique, where the multi-resolution matching with variable depth, proposed here, generated better results with a smaller processing time

Uma proposição para o cálculo de mapas de disparidade de imagens estéreo usando um interpolador neural baseado em funções de base radial

This study aims to seek a more viable alternative for the calculation of differences in images of stereo vision, using a factor that reduces heel the amount of points that are considered on the captured image, and a network neural-based radial basis functions to interpolate the results. The objective to be achieved is to produce an approximate picture of disparities using algorithms with low computational cost, unlike the classical algorithms

Implementação de rotinas computacionais básicas para cabeça estéreo robótica

O Laboratório de Sistemas Inteligentes do Departamento de Engenharia de Computação e Automação da Universidade Federal do Rio Grande do Norte - UFRN -tem como um de seus projetos de pesquisa -Robosense -a construção de uma plataforma robótica móvel. Trata-se de um robô provido de duas rodas, acionadas de forma diferencial, dois braços, com 5 graus de liberdade cada, um cinturão de sonares e uma cabeça estéreo. Como objetivo principal do projeto Robosense, o robô deverá ser capaz de navegar por todo o prédio do LECA, desviando de obstáculos. O sistema de navegação do robô, responsável pela geração e seguimento de rotas, atuará em malha fechada. Ou seja, sensores serão utilizados pelo sistema com o intuito de informar ao robô a sua pose atual, incluindo localização e a configuração de seus recursos. Encoders (sensores especiais de rotação) foram instalados nas rodas, bem como em todos os motores dos dois braços da cabeça estéreo. Sensores de fim-de-curso foram instalados em todas as juntas da cabeça estéreo para que seja possível sua pré-calibração. Sonares e câmeras também farão parte do grupo de sensores utilizados no projeto. O robô contará com uma plataforma composta por, a princípio, dois computadores ligados a um barramento único para uma operação em tempo real, em paralelo. Um deles será responsável pela parte de controle dos braços e de sua navegação, tomando como base as informações recebidas dos sensores das rodas e dos próximos objetivos do robô. O outro computador processará todas as informações referentes à cabeça estéreo do robô, como as imagens recebidas das câmeras. A utilização de técnicas de imageamento estéreo torna-se necessária, pois a informação de uma única imagem não determina unicamente a posição de um dado ponto correspondente no mundo. Podemos então, através da utilização de duas ou mais câmeras, recuperar a informação de profundidade da cena. A cabeça estéreo proposta nada mais é que um artefato físico que deve dar suporte a duas câmeras de vídeo, movimentá-las seguindo requisições de programas (softwares) apropriados e ser capaz de fornecer sua pose atual. Fatores como velocidade angular de movimentação das câmeras, precisão espacial e acurácia são determinantes para o eficiente resultado dos algoritmos que nesses valores se baseiam

Mapeamento robótico 2,5-D com representação em grade de ocupação-elevação

This work introduces a new method for environment mapping with three-dimensional information from visual information for robotic accurate navigation. Many approaches of 3D mapping using occupancy grid typically requires high computacional effort to both build and store the map. We introduce an 2.5-D occupancy-elevation grid mapping, which is a discrete mapping approach, where each cell stores the occupancy probability, the height of the terrain at current place in the environment and the variance of this height. This 2.5-dimensional representation allows that a mobile robot to know whether a place in the environment is occupied by an obstacle and the height of this obstacle, thus, it can decide if is possible to traverse the obstacle. Sensorial informations necessary to construct the map is provided by a stereo vision system, which has been modeled with a robust probabilistic approach, considering the noise present in the stereo processing. The resulting maps favors the execution of tasks like decision making in the autonomous navigation, exploration, localization and path planning. Experiments carried out with a real mobile robots demonstrates that this proposed approach yields useful maps for robot autonomous navigation

Serviços Bancários pela Internet: um Estudo de Caso Integrando a Visão de Competidores e Clientes

RAMOS, A. S. M. ; COSTA, F. S. P. R. . Serviços Bancários pela Internet: um estudo de caso integrando a visão de competidores e clientes. RAC. Revista de Administração Contemporânea, Rio de Janeiro - ANPAD, v. 4, n. 3, p. 133-154, 2000.

Humanização do atendimento à criança na atenção básica: visão dos profissionais

Objetivou-se compreender a humanização do atendimento à criança na Atenção Básica na visão dos profissionais. Estudo qualitativo, realizado em uma Unidade de Saúde da Família de Natal-RN, Brasil. Dezesseis profissionais responderam a um formulário contendo questões referentes ao atendimento à criança, à humanização e às práticas realizadas para humanizar o atendimento. Os dados foram categorizados por temas e analisados a partir dos princípios da Política Nacional de Humanização. Para os profissionais, humanizar o atendimento envolve acolher, escutar, aconselhar sobre o que está sendo realizado com a criança, valorizar a família, e tornar o sujeito ativo no atendimento, mesmo que de forma incipiente. A maioria dos profissionais descreveu atendimento que valorizava parte dos princípios da política de humanização, mesmo com dificuldades para implementá-los na rotina. Requer, portanto, estímulos e atualização dos profissionais para uma postura autocrítica sobre o atendimento

Gestão da cadeia de suprimento e vantagem competitiva: uma análise em setores industriais a partir da visão relacional

This work has as its main purpose to investigate the contribution of supply chain management in order to obtain competitive advantage by companies from the textile industry and from Ceará footwear industry, focusing its analysis mainly in the interorganizational relations (dyadic). For this, the theoretical referential contemplates different explanatory streams of the competitive advantage, detaching the relational perception of the resources theory, as well as, the main presuppositions of the supply chain management which culminates with the development of an analysis sample that runs the empirical study; the one which considers an expanded purpose of the supply chain which includes the government and the abetment institutions as institutional environment representatives. Besides supply chain management consideration as a competitive advantage source, the work also tried to identify other possible competitive advantage sources for the companies of the investigated sectors. It represents a study of multiple interpretive cases, having four cases as a total; meaning two cases in each one of the sectors, which used as a primary data collecting instrument a semi-structured interview schedule. Different methods were used for the data analysis, the content analysis and the constant comparison methods, the analytical procedure originated from the grounded theory research strategy, which were applied the Atlas/ti software recourse. Considering the theoretical referential and the used analysis sample, four basic categories of the work were defined, including its respective proprieties and dimensions: (1) characteristics concerning to the relationship with the supplier; (2) the company relations with the government; (3) the company relations with the abetment institutions and; (4) obtaining sources of competitive advantage. In general, the applied research in the footwear sector revealed that in the relationships of the researched companies related to its suppliers, there is a predominance of the partnership system and the main presuppositions of the supply chain management are applied which contributes for the acquisition of the relational competitive advantage; while in the textile sector, only some of these presuppositions are applied, with little contribution for the relational competitive advantage. The main resource which was accessed by the companies in both sectors through its relationships with the government and the abetment institutions are the tax incentives which, for the footwear companies, contribute for the acquisition of the temporary competitive advantage in relation to the contestants who do not own productive installations in the Northeast region, it also conducts to a competitive parity situation in relation to the contestants who own productive installations in the Northeast region and to the external market contestants; while for the companies of the textile sector, the tax incentives run the companies to a competitive parity situation in relation to its contestants. Furthermore, the investigated companies from the two sectors possess acquisition sources of the competitive advantage which collimate with different explanatory streams (industrial analysis, resources theory, Austrian school and the dynamic capabilities theory), although there is a predominance of the product innovation as a competitive advantage source in both sectors, due to the bond of these with the fashion tendencies

Marketing de relacionamento em um provedor de internet: um estudo comparativo que considera a visão gerencial e a percepção dos clientes

The current paper aims at analyzing customer retention in Internet provider services. For this study, we sought to understand what are the client's expectations regarding the services available and compare them with management perception in relation to the use of those services. Identifying the coherence level between the two points of view, management and client, it is possible to pinpoint how service is assessed in real conditions. Then, from this point on, a new vision can be implemented on available services, and new customer service strategies aiming at best serving to their expectation and need, can be rethought. The exploratory research was utilized. It was based on case study, and quantitative and qualitative methods were used. The quantitative method was done by applying the cluster technique with six variables of control derived from the six main services, whose definition was done through qualitative survey of the internal management team. Then, an structured interview with 443 clients, from a probabilistic sample of 800 costumers. The total number of active clients of the internet provider is of 10.677. Client perception in relation to services varied, if compared with the four services that were under the managerial metric method, this comparison showed a more positive evaluation than the real use of the service. Thus, it was observed that the value of each service available for the client depends on his/her perception of it, regardless of using or not the offered service. As a result, it is possible to understand which services offered by the company under study effectively contribute to a good client-company relationship, and the upkeep of those clients

Processos carioevolutivos na ordem tetraodontiformes: uma visão através de suas diferentes linhagens

Given the great diversity of fishes, the Order Tetraodontiformes stands to show genetic and morphological characteristics enough singular. The fishes of this order have a compact DNA which favors molecular studies, as well as comparisons with more basal species. Model of genome evolution, there are still many gaps in knowledge about their chromosomal patterns and how evolutionary rearrangements influence the marked variation in DNA content of this order. In view of this, we present cytogenetic analyzes of the species Acanthostracion quadricornis (Ostraciidae), A. polygonius (Ostraciidae) Melichthys niger (Balistidae) Cantherhines macrocerus (Monacanthidae) and C. pullus (Monacanthidae), Lagocephalus laevigatus, Colomesus psittacus and Canthigaster figueiredoi (Tetraodontidae), to contribute with cytogenetic data for this group. The analysis was performed by C-banding, Ag-RONs, coloring with base-specific fluorochromes DAPI-CMA3, restriction enzymes AluI, EcoRI, TaqI, PstI and HinfI and in situ hybridization with probes for ribosomal DNA 18S and 5S. The heterochromatic ultrastructure of A. quadricornis and A. polygonius revealed a outstanding heterochromatin content, which may indicate that the accumulation or loss of extensive heterochromatin content could be responsible for large variations in genomic content displayed in different Tetraodontiformes families. The species Cantherhines macrocerus, C. pullus (Monacanthidae) and Melichthys niger (Balistidae) shows a huge karyotypic similarity both numerically and structural. L. laevigatus showed similar cytogenetic features (2n = 44 and single RONs) to the species of the genus Takifugu, which reinforces the idea of their phylogenetic relationships. C. psittacus presented the highest diploid number described for the family (2n = 56) and large amount of HC, features that related with its sister family Diodontidae. Cytogenetic analysis in C. figueiredoi revealed heterochromatic polymorphisms, RONs multiple and Bs chromosomes. These events are rare in marine fishes, and are possibly associated with the strong restructuring and genomic reduction that this family has been suffered. These features, plus the morphological and molecular data suggests that these species share the same ancestral branch, with a possible monophyletic origin. In this study, new contributions to the knowledge of evolutionary patterns facing by Tetraodontiformes are provided and discussed under cytotaxonomyc, genomic and evolutionary perspectives.

A formação do pedagogo-professor no curso de pedagogia: limites e possibilidades na visão de professores formados no campus avançado de Patu da UERN

The inconclusive policies regarding the teaching background, specifically the Pedagogy Course, whose National Curricular Directives DCN were ratified by the Ministry of Education on April 4th 2006, have been causing protest from the various forces within the scope of the university, specifically in the Pedagogy Departments in which, through their professionals, express the several stands about the pedagogue profile, his/her professional acting field and a curriculum that meets the background needs of this professional. This paper tried to assess, from the viewpoint of the student who graduated from the Pedagogy Course and who acts in classroom in the first years of the Elementary School, to what extent this course meets the background needs of the professional who works as teacher. In specific terms it was this paper's objective to identify the most important background needs of teachers who graduated in Pedagogy, who act in the first years of the Elementary School; To list the contributions and limitations of the Pedagogy Course of CAJIM/UERN in the teachers' background, outlined by the graduates of the course; to raise suggestions for the improvement of the teachers' background in the Pedagogy Course of the CAJIM/UERN. In order to turn these objectives viable we opted for the qualitative approach in research, more precisely for the case study methodology, from which we used as instruments for the execution of the field work the observation in classrooms, semi-structured interviews which became the main instrument used for the data construction and analysis. The data analysis process took place through the content analysis technique based in Bardin (2000). The theoretical line is based on the studies from Schön (2000), Nóvoa (1997), Perrenoud (1993), Alarcão (2003), Ramalho (2003) we also used the National Curricular Directives which serve as current Parameter for the Pedagogy courses. The study indicated that the Pedagogy Course contributed for the personal and professional enrichment, however, difficulties in the theory-practice articulation are still present in the everyday life. The theoretical knowledge assimilated, though represent increments to the professional practice, are not enough to enable a pedagogical practice with excellence. There is a need to consider a curriculum in a dialectic perspective, configurator of social and cultural practices sustained by the reasoning as praxis, thus it must not be seen solely in a theoretical plan, mas as a process that builds itself between the acting and the reasoning.

Uma visão local de um projeto nacional: o curso mídias na educação

The essay "A local view of a national project: the course in Media Education" presents a research aimed at analyzing how the course Media in Education is being implemented by both Federal University of Rio Grande do Norte and State University of Rio Grande do Norte, with the intention of pointing out weaknesses in its use, which should be resolved in order to contribute to the design of other courses along these lines. Therefore, we performed a survey in which data collection, have used open questionnaires available in online pages created specifically for this purpose and administered to alumni and former participants, course participants and tutors from the two universities involved in the research. Through these questionnaires, we identified, especially, those aspects that negatively affect the provision of course related to the student's profile, the virtual learning environment where the course is hosted, the meetings, the contents and activities, the mentoring and the dropout, and the changes to improve the implementation of the course. The research collaborators are professors of public basic education. To understand the continuing education of teachers, conducted through distance education, using the virtual learning environment, we contextualize this from the nineties, in the context of the Brazilian educational reform took place in that decade. The Media in Education course is presented as a different proposition because it allows teachers to follow different pathways, materialized in the learning cycle. At the end of the study, we conclude that the implementation of this course, of the RN, the conditions for dialogue to happen, specifically, are not given

Avaliação de um programa de educação ambiental não formal: a Caravana Ecológica na visão dos participantes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

O acolhimento no ambulatório de um hospital universitário na visão de usuários

This present study of quantitative/qualitative approach, aims to analyze the outpatient care at the Hospital Universitário Onofre Lopes (HUOL), and, having as guide, the reception of the user. In this regard were invited and interviewed 20 users. Besides the interviews, conducted in a period of 45 days, in this same period of time was used a field diary for more significant notes of observations more significant. In the analysis, we drafted the socio-demographic profile of the group and identified their main complaints, problems and suggestions. For this, we have built graphics, tables and pictures, in addition to standing out their testimony, as a resource for better understanding of the subjective aspects. The theoretical reference consisted of documents from the Ministry of Health about the reception and humanization, and the studies of Merhy, Franco, Pinheiro, Matumoto, Mariotti, Teixeira, among others. The results show the ambulatory of HUOL as a privileged space and of credibility, where users commonly, find answers to their problems. However, these same users were unanimous in saying the difficulties they face in obtaining consultations, from the basic unit, until the hospital. Regarding the service, although they feel satisfied as for the assistance received, they list a series of problems, of structural relationship order: lack of visual signalling, information, wheelchairs, hygiene, in the waiting rooms that offer some comfort, besides the inattention of some professionals. In summary, in the study, undertaken now, we cannot say that there is in the reality studied, the reception, in its full meaning, but the HUOL as hospital-school, has all the potential to accomplish it