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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Effect of machine vision based traffic data collection accuracy on traffic noise

Nadella, Sunita January 2002 (has links)
No description available.
32

Adaptive Control of a Camera-Projection System using Vision-Based Feedback

Liao, Chwen Kai 15 April 2016 (has links)
This thesis derives an vision based feedback control strategy for a class of uncertain projector-camera systems that are used to animate two dimensional projected images on complex, three dimensional, articulated target objects. The target object of the robotic system is articulated using an open loop control strategy that generates a desired sequence of target poses that are designed using commercially available geometric modeling software. The ideal or desired image sequences are subsequently rendered in the geometric modeling software using an ideal camera/projector pose and ideal intrinsic parameter camera model. The rendered imagery from the ideal camera and projector pose are subsequently used to define tracking performance for the feedback control of the camera and projector. Uncertainty in actuator models of the camera and projector actuator subsystems in this paper includes contributions due to imprecision in camera pose and in intrinsic camera parameters. A feedback control strategy is derived that employs pixel coordinates of multiple tracked feature points in the target image sequence for pose estimation and tracking control problems. We establish sufficient conditions that guarantee the convergence and asymptotic stability of the pose estimation and tracking control problems for the class of uncertain, nonlinear systems studied in this thesis. Several numerical studies are summarized in the thesis that provide confidence in the derived theoretical results and further suggest robustness of the control strategy for the considered uncertainty class. / Master of Science
33

New Framework for Real-time Measurement, Monitoring, and Benchmarking of Construction Equipment Emissions

Heidari Haratmeh, Bardia 29 June 2014 (has links)
The construction industry is one of the largest emitters of greenhouse gases and health-related pollutants. Monitoring and benchmarking emissions will provide practitioners with information to assess environmental impacts and improve the sustainability of construction. This research focuses on real-time measurement of emissions from non-road construction equipment and development of a monitoring-benchmarking tool for comparison of expected vs. actual emissions. First, exhaust emissions were measured using a Portable Emission Measurement System (PEMS) during the operation of 18 pieces of construction equipment at actual job sites. Second-by-second emission rates and emission factors for carbon dioxide, carbon monoxide, nitrogen oxides, and hydrocarbons were calculated for all equipment. Results were compared to those of other commonly used emission estimation models. Significant differences in emission factors associated with different activities were not observed, except for idling and hauling. Moreover, emission rates were up to 200 times lower than the values estimated using EPA and California Air Resources Board (CARB) guidelines. Second, the resulting database of emissions was used in an automated, real-time environmental assessment system. Based on videos of actual construction activities, this system enabled real-time action recognition of construction operations. From the resulting time-series of activities, emissions were estimated for each piece of equipment and differed by only 2% from those estimated by manual action recognition. Third, the actual emissions were compared to estimated ones using discrete event simulation, a computational model of construction activities. Actual emissions were 28% to 144% of those estimated by manual action recognition. Results of this research will aid practitioners in implementing strategies to measure, monitor, benchmark, and possibly reduce air pollutant emissions stemming from construction. / Master of Science
34

Fatores de decisão de terceirização em tecnologia da informação

Mozzini, Silvia Helena Risch January 2011 (has links)
A prática da terceirização por parte das organizações é uma prática que vem sendo utilizada há muito tempo e tornou-se cada vez mais comum. O mesmo também ocorre em relação às atividades da área de Tecnologia da Informação, onde a terceirização vem assumindo um papel muito importante devido ao crescente do número de organizações que estão adotando essa prática, pelos altos valores envolvidos, ou ainda pelas formas e arranjos cada vez mais inovadores que estão se formando para o uso da terceirização em Tecnologia da Informação. Diversas são as razões que levam os executivos a terceirizar, parcial ou totalmente, suas diferentes atividades e serviços na área de Tecnologia da Informação, sendo muitos deles associados à redução de custos, melhoria da qualidade e foco nas atividades essenciais da organização. Os motivos pelos quais as organizações terceirizam têm sido foco de muitos estudos acadêmicos importantes, onde ainda são identificadas lacunas. Nesse contexto, esse trabalho tem como objetivo identificar os fatores que impactam no processo decisório de terceirização em Tecnologia da Informação. Diante disso, o principal objetivo desse trabalho é responder a seguinte questão: “que fatores devem ser considerados no processo decisório com relação à terceirização da Tecnologia da Informação?” O método utilizado é a pesquisa Survey realizada a partir de modelo validado apresentado pela literatura. O modelo precisou ser adaptado para a área de Tecnologia da Informação que resultou em um modelo contendo as dimensões Estratégia, Ambiente, Características do Processo de TI, Custos e Características dos Fornecedores de TI. O processo de validação e refinamento utilizou a Análise de Confiabilidade (Coeficiente Alfa de Cronbach) e a Análise Fatorial Fatorial Exploratória Discriminante. A partir do resultado dessas validações, foi identificada a possibilidade de diferentes arranjos de variáveis nas dimensões, porém manteve-se o padrão validado anteriormente sem contestação da literatura. A principal contribuição dessa pesquisa para a prática gerencial é o fornecimento de um instrumento de pesquisa que prevê a identificação dos fatores de determinantes para a decisão de terceirização em Tecnologia da Informação sob o ponto de vista do contratante. Esse modelo pode auxiliar executivos na decisão de terceirizar ou não suas atividades em Tecnologia da Informação. / The practice of Outsourcing by organizations has been used for years and it has become more and more common. The same has been occurring as to the activities of the area of Information Technology , where outsourcing has been occupying a relevant role due to the growing number of companies adopting this practice, the high amounts involved, or, still, the more and more innovating arrangements being formed for the utilization of outsourcing in Information Technology. There are many reasons for the executives to outsource, partial or totally, their different activities and services in the area of Information Technology, many of them associated to the reduction of costs, quality improvement and focus on the essential activities of the organization. The reasons why the organizations outsource have been the focus of many important academic studies, where many gaps are still identified. In this context, the aim of this work is to identify the factors that impact on the decision process of outsourcing in Information Technology. So, the main goal of this work is the answer for the following question: “which are the factors that shall be considered in the decision process relating to outsourcing of Information Technology".This work is a survey developed from a validated model presented by literature. The model had to be adapted to the area of Information Technology and resulted in a model containing the following dimensions: Strategy, Environment, Features of IT Process, Costs and Characteristics of IT Suppliers. The validation process and refining have used the Analysis of Reliability (Cronbach's Alpha Coefficient) and Discriminatory and Exploratory Factor Analysis. From the result of such validations, it has been identified the possibility of different arrangements of variables in the dimensions; however, it has been maintained the standard previously validated with no objection of literature. The main contribution of this survey for the managerial practice is the supply of a research tool which foresees the identification of determinant factors for outsourcing in Information Technology related to the contractor. The model may help the executives decide on the outsourcing of their activities related to Information Technology or not.
35

Vision-Based Localization and Guidance for Unmanned Aerial Vehicles

Conte, Gianpaolo January 2009 (has links)
The thesis has been developed as part of the requirements for a PhD degree at the Artificial Intelligence and Integrated Computer System division (AIICS) in the Department of Computer and Information Sciences at Linköping University.The work focuses on issues related to Unmanned Aerial Vehicle (UAV) navigation, in particular in the areas of guidance and vision-based autonomous flight in situations of short and long term GPS outage.The thesis is divided into two parts. The first part presents a helicopter simulator and a path following control mode developed and implemented on an experimental helicopter platform. The second part presents an approach to the problem of vision-based state estimation for autonomous aerial platforms which makes use of geo-referenced images for localization purposes. The problem of vision-based landing is also addressed with emphasis on fusion between inertial sensors and video camera using an artificial landing pad as reference pattern. In the last chapter, a solution to a vision-based ground object geo-location problem using a fixed-wing micro aerial vehicle platform is presented.The helicopter guidance and vision-based navigation methods developed in the thesis have been implemented and tested in real flight-tests using a Yamaha Rmax helicopter. Extensive experimental flight-test results are presented. / WITAS
36

Vision-based place categorization

Bormann, Richard Klaus Eduard 18 November 2010 (has links)
In this thesis we investigate visual place categorization by combining successful global image descriptors with a method of visual attention in order to automatically detect meaningful objects for places. The idea behind this is to incorporate information about typical objects for place categorization without the need for tedious labelling of important objects. Instead, the applied attention mechanism is intended to find the objects a human observer would focus first, so that the algorithm can use their discriminative power to conclude the place category. Besides this object-based place categorization approach we employ the Gist and the Centrist descriptor as holistic image descriptors. To access the power of all these descriptors we employ SVM-DAS (discriminative accumulation scheme) for cue integration and furthermore smooth the output trajectory with a delayed Hidden Markov Model. For the classification of the variety of descriptors we present and evaluate several classification methods. Among them is a joint probability modelling approach with two approximations as well as a modified KNN classifier, AdaBoost and SVM. The latter two classifiers are enhanced for multi-class use with a probabilistic computation scheme which treats the individual classifiers as peers and not as a hierarchical sequence. We check and tweak the different descriptors and classifiers in extensive tests mainly with a dataset of six homes. After these experiments we extend the basic algorithm with further filtering and tracking methods and evaluate their influence on the performance. Finally, we also test our algorithm within a university environment and on a real robot within a home environment.
37

Vision Based Obstacle Detection And Avoidance Using Low Level Image Features

Senlet, Turgay 01 April 2006 (has links) (PDF)
This study proposes a new method for obstacle detection and avoidance using low-level MPEG-7 visual descriptors. The method includes training a neural network with a subset of MPEG-7 visual descriptors extracted from outdoor scenes. The trained neural network is then used to estimate the obstacle presence in real outdoor videos and to perform obstacle avoidance. In our proposed method, obstacle avoidance solely depends on the estimated obstacle presence data. In this study, backpropagation algorithm on multi-layer perceptron neural network is utilized as a feature learning method. MPEG-7 visual descriptors are used to describe basic features of the given scene image and by further processing these features, input data for the neural network is obtained. The learning/training phase is carried out on specially constructed synthetic video sequence with known obstacles. Validation and tests of the algorithms are performed on actual outdoor videos. Tests on indoor videos are also performed to evaluate the performance of the proposed algorithms in indoor scenes. Throughout the study, OdBot 2 robot platform, which has been developed by the author, is used as reference platform. For final testing of the obstacle detection and avoidance algorithms, simulation environment is used. From the simulation results and tests performed on video sequences, it can be concluded that the proposed obstacle detection and avoidance methods are robust against visual changes in the environment that are common to most of the outdoor videos. Findings concerning the used methods are presented and discussed as an outcome of this study.
38

Fatores de decisão de terceirização em tecnologia da informação

Mozzini, Silvia Helena Risch January 2011 (has links)
A prática da terceirização por parte das organizações é uma prática que vem sendo utilizada há muito tempo e tornou-se cada vez mais comum. O mesmo também ocorre em relação às atividades da área de Tecnologia da Informação, onde a terceirização vem assumindo um papel muito importante devido ao crescente do número de organizações que estão adotando essa prática, pelos altos valores envolvidos, ou ainda pelas formas e arranjos cada vez mais inovadores que estão se formando para o uso da terceirização em Tecnologia da Informação. Diversas são as razões que levam os executivos a terceirizar, parcial ou totalmente, suas diferentes atividades e serviços na área de Tecnologia da Informação, sendo muitos deles associados à redução de custos, melhoria da qualidade e foco nas atividades essenciais da organização. Os motivos pelos quais as organizações terceirizam têm sido foco de muitos estudos acadêmicos importantes, onde ainda são identificadas lacunas. Nesse contexto, esse trabalho tem como objetivo identificar os fatores que impactam no processo decisório de terceirização em Tecnologia da Informação. Diante disso, o principal objetivo desse trabalho é responder a seguinte questão: “que fatores devem ser considerados no processo decisório com relação à terceirização da Tecnologia da Informação?” O método utilizado é a pesquisa Survey realizada a partir de modelo validado apresentado pela literatura. O modelo precisou ser adaptado para a área de Tecnologia da Informação que resultou em um modelo contendo as dimensões Estratégia, Ambiente, Características do Processo de TI, Custos e Características dos Fornecedores de TI. O processo de validação e refinamento utilizou a Análise de Confiabilidade (Coeficiente Alfa de Cronbach) e a Análise Fatorial Fatorial Exploratória Discriminante. A partir do resultado dessas validações, foi identificada a possibilidade de diferentes arranjos de variáveis nas dimensões, porém manteve-se o padrão validado anteriormente sem contestação da literatura. A principal contribuição dessa pesquisa para a prática gerencial é o fornecimento de um instrumento de pesquisa que prevê a identificação dos fatores de determinantes para a decisão de terceirização em Tecnologia da Informação sob o ponto de vista do contratante. Esse modelo pode auxiliar executivos na decisão de terceirizar ou não suas atividades em Tecnologia da Informação. / The practice of Outsourcing by organizations has been used for years and it has become more and more common. The same has been occurring as to the activities of the area of Information Technology , where outsourcing has been occupying a relevant role due to the growing number of companies adopting this practice, the high amounts involved, or, still, the more and more innovating arrangements being formed for the utilization of outsourcing in Information Technology. There are many reasons for the executives to outsource, partial or totally, their different activities and services in the area of Information Technology, many of them associated to the reduction of costs, quality improvement and focus on the essential activities of the organization. The reasons why the organizations outsource have been the focus of many important academic studies, where many gaps are still identified. In this context, the aim of this work is to identify the factors that impact on the decision process of outsourcing in Information Technology. So, the main goal of this work is the answer for the following question: “which are the factors that shall be considered in the decision process relating to outsourcing of Information Technology".This work is a survey developed from a validated model presented by literature. The model had to be adapted to the area of Information Technology and resulted in a model containing the following dimensions: Strategy, Environment, Features of IT Process, Costs and Characteristics of IT Suppliers. The validation process and refining have used the Analysis of Reliability (Cronbach's Alpha Coefficient) and Discriminatory and Exploratory Factor Analysis. From the result of such validations, it has been identified the possibility of different arrangements of variables in the dimensions; however, it has been maintained the standard previously validated with no objection of literature. The main contribution of this survey for the managerial practice is the supply of a research tool which foresees the identification of determinant factors for outsourcing in Information Technology related to the contractor. The model may help the executives decide on the outsourcing of their activities related to Information Technology or not.
39

Characterizing assistive shared control through vision-based and human-aware designs for wheelchair navigation assistance / Caractérisation d'une assistance par contrôle partagé : conception d'une solution basée vision d'aide à la navigation en environnement humain pour les fauteuils roulants

Karakkat Narayanan, Vishnu 23 November 2016 (has links)
Les premiers documents attestant l'utilisation d'une chaise à roues utilisée pour transporter une personne avec un handicap datent du 6ème siècle en Chine. À l'exception des fauteuils roulants pliables X-frame inventés en 1933, 1400 ans d'évolution de la science humaine n'ont pas changé radicalement la conception initiale des fauteuils roulants. Pendant ce temps, les progrès de l'informatique et le développement de l'intelligence artificielle depuis le milieu des années 1980 ont conduit inévitablement à la conduite de recherches sur des fauteuils roulants intelligents. Plutôt que de se concentrer sur l'amélioration de la conception sous-jacente, l'objectif principal de faire un fauteuil roulant intelligent est de le rendre le plus accessible. Même si l'invention des fauteuils roulants motorisés ont partiellement atténué la dépendance d'un utilisateur à d'autres personnes pour la réalisation de leurs actes quotidiens, certains handicaps qui affectent les mouvements des membres, le moteur ou la coordination visuelle, rendent impossible l'utilisation d'un fauteuil roulant électrique classique. L'accessibilité peut donc être interprétée comme l'idée d'un fauteuil roulant adaptée à la pathologie de l'utilisateur de telle sorte que il / elle soit capable d'utiliser les outils d'assistance. S'il est certain que les robots intelligents sont prêts à répondre à un nombre croissant de problèmes dans les industries de services et de santé, il est important de comprendre la façon dont les humains et les utilisateurs interagissent avec des robots afin d'atteindre des objectifs communs. En particulier dans le domaine des fauteuils roulants intelligents d'assistance, la préservation du sentiment d'autonomie de l'utilisateur est nécessaire, dans la mesure où la liberté individuelle est essentielle pour le bien-être physique et social. De façon globale, ce travail vise donc à caractériser l'idée d'une assistance par contrôle partagé, et se concentre tout particulièrement sur deux problématiques relatives au domaine de la robotique d'assistance appliquée au fauteuil roulant intelligent, à savoir une assistance basée sur la vision et la navigation en présence d'humains. En ciblant les tâches fondamentales qu'un utilisateur de fauteuil roulant peut avoir à exécuter lors d'une navigation en intérieur, une solution d'assistance à bas coût, basée vision, est conçue pour la navigation dans un couloir. Le système fournit une assistance progressive pour les tâches de suivi de couloir et de passage de porte en toute sécurité. L'évaluation du système est réalisée à partir d'un fauteuil roulant électrique de série et robotisé. A partir de la solution plug and play imaginée, une formulation adaptative pour le contrôle partagé entre l'utilisateur et le robot est déduite. De plus, dans la mesure où les fauteuils roulants sont des dispositifs fonctionnels qui opèrent en présence d'humains, il est important de considérer la question des environnements peuplés d'humains pour répondre de façon complète à la problématique de la mobilité en fauteuil roulant. En s'appuyant sur les concepts issus de l'anthropologie, et notamment sur les conventions sociales spatiales, une modélisation de la navigation en fauteuil roulant en présence d'humains est donc proposée. De plus, une stratégie de navigation, qui peut être intégrée sur un robot social (comme un fauteuil roulant intelligent), permet d'aborder un groupe d'humains en interaction de façon équitable et de se joindre à eux de façon socialement acceptable. Enfin, à partir des enseignements tirés des solutions proposées d'aide à la mobilité en fauteuil roulant, nous pouvons formaliser mathématiquement un contrôle adaptatif partagé pour la planification de mouvement relatif à l'assistance à la navigation. La validation de ce formalisme permet de proposer une structure générale pour les solutions de navigation assistée en fauteuil roulant et en présence d'humains. / Earliest records of a wheeled chair used to transport a person with disability dates back to the 6m century in China. With the exception of the collapsible X-frame wheelchairs invented in 1933, 1400 years of human scientific evolution has not radically changed the initial wheelchair design. Meanwhile, advancements in computing and the development of artificial intelligence since the mid-1980s has inevitably led to research on Intelligent Wheelchairs. Rather than focusing on improving the underlying design, the core objective of making a wheelchair intelligent is to make it more accessible. Even though the invention of the powered wheelchairs have partially mitigated a user's dependence on other people for their daily routines, some disabilities that affect limb movements, motor or visual coordination, make il impossible for a user to operate a common powered wheelchair. Accessibility can also thus be thought of as the idea, where the wheelchair adapts to the user malady such that he/she is able to utilize its assistive capabilities. While it is certain that intelligent robots are poised to address a growing number of issues in the service and medical care industries, it is important to resolve how humans and users interact with robots in order to accomplish common objectives. Particularly in the assistive intelligent wheelchair domain, preserving a sense of autonomy with the user is required, as individual agency is essential for his/her physical and social well-being. This work thus aims to globally characterize the idea of assistive shared control while particularly devoting the attention to two issues within the intelligent assistive wheelchair domain viz. vision-based assistance and human-aware navigation.Recognizing the fundamental tasks that a wheelchair user may have to execute in indoor environments, we design low­cost vision-based assistance framework for corridor navigation. The framework provides progressive assistance for the tasks of safe corridor following and doorway passing. Evaluation of the framework is carried out on a robotized off-the­shelf wheelchair. From the proposed plug and play design, we infer an adaptive formulation for sharing control between user and robot. Furthermore, keeping in mind that wheelchairs are assistive devices that operate in human environments, it is important to consider the issue of human-awareness within wheelchair mobility. We leverage spatial social conventions from anthropology to surmise wheelchair navigation in human environments. Moreover, we propose a motion strategy that can be embedded on a social robot (such as an intelligent wheelchair) that allows il to equitably approach and join a group of humans in interaction. Based on the lessons learnt from the proposed designs for wheelchair mobility assistance, we can finally mathematically formalize adaptive shared control for assistive motion planning. ln closing, we demonstrate this formalism in order to design a general framework for assistive wheelchair navigation in human environments.
40

Fatores de decisão de terceirização em tecnologia da informação

Mozzini, Silvia Helena Risch January 2011 (has links)
A prática da terceirização por parte das organizações é uma prática que vem sendo utilizada há muito tempo e tornou-se cada vez mais comum. O mesmo também ocorre em relação às atividades da área de Tecnologia da Informação, onde a terceirização vem assumindo um papel muito importante devido ao crescente do número de organizações que estão adotando essa prática, pelos altos valores envolvidos, ou ainda pelas formas e arranjos cada vez mais inovadores que estão se formando para o uso da terceirização em Tecnologia da Informação. Diversas são as razões que levam os executivos a terceirizar, parcial ou totalmente, suas diferentes atividades e serviços na área de Tecnologia da Informação, sendo muitos deles associados à redução de custos, melhoria da qualidade e foco nas atividades essenciais da organização. Os motivos pelos quais as organizações terceirizam têm sido foco de muitos estudos acadêmicos importantes, onde ainda são identificadas lacunas. Nesse contexto, esse trabalho tem como objetivo identificar os fatores que impactam no processo decisório de terceirização em Tecnologia da Informação. Diante disso, o principal objetivo desse trabalho é responder a seguinte questão: “que fatores devem ser considerados no processo decisório com relação à terceirização da Tecnologia da Informação?” O método utilizado é a pesquisa Survey realizada a partir de modelo validado apresentado pela literatura. O modelo precisou ser adaptado para a área de Tecnologia da Informação que resultou em um modelo contendo as dimensões Estratégia, Ambiente, Características do Processo de TI, Custos e Características dos Fornecedores de TI. O processo de validação e refinamento utilizou a Análise de Confiabilidade (Coeficiente Alfa de Cronbach) e a Análise Fatorial Fatorial Exploratória Discriminante. A partir do resultado dessas validações, foi identificada a possibilidade de diferentes arranjos de variáveis nas dimensões, porém manteve-se o padrão validado anteriormente sem contestação da literatura. A principal contribuição dessa pesquisa para a prática gerencial é o fornecimento de um instrumento de pesquisa que prevê a identificação dos fatores de determinantes para a decisão de terceirização em Tecnologia da Informação sob o ponto de vista do contratante. Esse modelo pode auxiliar executivos na decisão de terceirizar ou não suas atividades em Tecnologia da Informação. / The practice of Outsourcing by organizations has been used for years and it has become more and more common. The same has been occurring as to the activities of the area of Information Technology , where outsourcing has been occupying a relevant role due to the growing number of companies adopting this practice, the high amounts involved, or, still, the more and more innovating arrangements being formed for the utilization of outsourcing in Information Technology. There are many reasons for the executives to outsource, partial or totally, their different activities and services in the area of Information Technology, many of them associated to the reduction of costs, quality improvement and focus on the essential activities of the organization. The reasons why the organizations outsource have been the focus of many important academic studies, where many gaps are still identified. In this context, the aim of this work is to identify the factors that impact on the decision process of outsourcing in Information Technology. So, the main goal of this work is the answer for the following question: “which are the factors that shall be considered in the decision process relating to outsourcing of Information Technology".This work is a survey developed from a validated model presented by literature. The model had to be adapted to the area of Information Technology and resulted in a model containing the following dimensions: Strategy, Environment, Features of IT Process, Costs and Characteristics of IT Suppliers. The validation process and refining have used the Analysis of Reliability (Cronbach's Alpha Coefficient) and Discriminatory and Exploratory Factor Analysis. From the result of such validations, it has been identified the possibility of different arrangements of variables in the dimensions; however, it has been maintained the standard previously validated with no objection of literature. The main contribution of this survey for the managerial practice is the supply of a research tool which foresees the identification of determinant factors for outsourcing in Information Technology related to the contractor. The model may help the executives decide on the outsourcing of their activities related to Information Technology or not.

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