690 research outputs found

    New Global Referencing Approach in a Camera-LCD Micro Positioning System

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    The authors want to thank the cadet Guillaume Azzopardi for the assistance with the programming and test.In any precision manufacturing process, positioning systems play a very important role in achieving a quality product. As a new approach to current systems, camera-LCD positioning systems are a new technology that can provide substantial improvements enabling better accuracy and repeatability. However, in order to provide stability to the system a global positioning system is required. This paper presents an improvement of a positioning system based on the treatment of images on an LCD in which a new algorithm with absolute reference has been implemented. The method is based on basic geometry and linear algebra applied to computer vision. The algorithm determines the spiral center using an image taken at any point. Consequently, the system constantly knows its position and does not lose its reference. Several modifications of the algorithm are proposed and compared. The simulation and test of the algorithm provide an important improvement in the reliability and stability of the positioning system providing errors of microns for the calculation of the global position used by the algorithm

    Structure-from-Motion based vegetation modeling and shade estimation

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    Although three-dimensional (3-D) light dimension and range (LiDAR) point cloud datasets describing the structure of vegetation have proven to be highly useful for ecological modeling, the collection of such data is expensive. However, a new technology known as Structure-from-Motion, or SfM, has become available that can be used to create 3-D point cloud datasets for far less cost. A small unmanned aerial system (UAS), point and shoot digital camera, and Agisoft PhotoScan® (http://agisoft.com) software were used to create a highly dense 3-D SfM point cloud dataset representing a short reach of the Upper South Fork of the New River in Boone, NC. The quality of the 3-D SfM point cloud dataset was evaluated with an emphasis on how accurately vegetation was represented. Also, a digital surface model (DSM) based on the 3-D SfM point cloud dataset was used in conjunction with a solar ray tracing method to predict shade cast by vegetation in the study area. Overall, the results of this study suggest that SfM based point clouds representing vegetation are of a high enough quality to be used for ecological modeling purposes

    A study on virtual reality and developing the experience in a gaming simulation

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    A thesis submitted to the University of Bedfordshire in partial fulfilment of the requirements for the degree of Masters by ResearchVirtual Reality (VR) is an experience where a person is provided with the freedom of viewing and moving in a virtual world [1]. The experience is not constrained to a limited control. Here, it was triggered interactively according to the user’s physical movement [1] [2]. So the user feels as if they are seeing the real world; also, 3D technologies allow the viewer to experience the volume of the object and its prospection in the virtual world [1]. The human brain generates the depth when each eye receives the images in its point of view. For learning for and developing the project using the university’s facilities, some of the core parts of the research have been accomplished, such as designing the VR motion controller and VR HMD (Head Mount Display), using an open source microcontroller. The VR HMD with the VR controller gives an immersive feel and a complete VR system [2]. The motive was to demonstrate a working model to create a VR experience on a mobile platform. Particularly, the VR system uses a micro electro-mechanical system to track motion without a tracking camera. The VR experience has also been developed in a gaming simulation. To produce this, Maya, Unity, Motion Analysis System, MotionBuilder, Arduino and programming have been used. The lessons and codes taken or improvised from [33] [44] [25] and [45] have been studied and implemented

    Augmented Reality for Restoration/Reconstruction of Artefacts with Artistic or Historical Value

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    The artistic or historical value of a structure, such as a monument, a mosaic, a painting or, generally speaking, an artefact, arises from the novelty and the development it represents in a certain field and in a certain time of the human activity. The more faithfully the structure preserves its original status, the greater its artistic and historical value is. For this reason it is fundamental to preserve its original condition, maintaining it as genuine as possible over the time. Nevertheless the preservation of a structure cannot be always possible (for traumatic events as wars can occur), or has not always been realized, simply for negligence, incompetence, or even guilty unwillingness. So, unfortunately, nowadays the status of a not irrelevant number of such structures can range from bad to even catastrophic. In such a frame the current technology furnishes a fundamental help for reconstruction/restoration purposes, so to bring back a structure to its original historical value and condition. Among the modern facilities, new possibilities arise from the Augmented Reality (AR) tools, which combine the virtual reality (VR) settings with real physical materials and instruments. The idea is to realize a virtual reconstruction/restoration before materially acting on the structure itself. In this way main advantages are obtained among which: the manpower and machine power are utilized only in the last phase of the reconstruction; potential damages/abrasions of some parts of the structure are avoided during the cataloguing phase; it is possible to precisely define the forms and dimensions of the eventually missing pieces, etc. Actually the virtual reconstruction/restoration can be even improved taking advantages of the AR, which furnish lots of added informative parameters, which can be even fundamental under specific circumstances. So we want here detail the AR application to restore and reconstruct the structures with artistic and/or historical valu

    Guidance for benthic habitat mapping: an aerial photographic approach

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    This document, Guidance for Benthic Habitat Mapping: An Aerial Photographic Approach, describes proven technology that can be applied in an operational manner by state-level scientists and resource managers. This information is based on the experience gained by NOAA Coastal Services Center staff and state-level cooperators in the production of a series of benthic habitat data sets in Delaware, Florida, Maine, Massachusetts, New York, Rhode Island, the Virgin Islands, and Washington, as well as during Center-sponsored workshops on coral remote sensing and seagrass and aquatic habitat assessment. (PDF contains 39 pages) The original benthic habitat document, NOAA Coastal Change Analysis Program (C-CAP): Guidance for Regional Implementation (Dobson et al.), was published by the Department of Commerce in 1995. That document summarized procedures that were to be used by scientists throughout the United States to develop consistent and reliable coastal land cover and benthic habitat information. Advances in technology and new methodologies for generating these data created the need for this updated report, which builds upon the foundation of its predecessor

    The Use of Multiple Slate Devices to Support Active Reading Activities

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    Reading activities in the classroom and workplace occur predominantly on paper. Since existing electronic devices do not support these reading activities as well as paper, users have difficulty taking full advantage of the affordances of electronic documents. This dissertation makes three main contributions toward supporting active reading electronically. The first contribution is a comprehensive set of active reading requirements, drawn from three decades of research into reading processes. These requirements explain why existing devices are inadequate for supporting active reading activities. The second contribution is a multi-slate reading system that more completely supports the active reading requirements above. Researchers believe the suitability of paper for active reading is largely due to the fact it distributes content across different sheets of paper, which are capable of displaying information as well as capturing input. The multi-slate approach draws inspiration from the independent reading and writing surfaces that paper provides, to blend the beneficial features of e-book readers, tablets, PCs, and tabletop computers. The development of the multi-slate system began with the Dual-Display E-book, which used two screens to provide richer navigation capabilities than a single-screen device. Following the success of the Dual-Display E-book, the United Slates, a general-purpose reading system consisting of an extensible number of slates, was created. The United Slates consisted of custom slate hardware, specialized interactions that enabled the slates to be used cooperatively, and a cloud-based infrastructure that robustly integrated the slates with users' existing computing devices and workflow. The third contribution is a series of evaluations that characterized reading with multiple slates. A laboratory study with 12 participants compared the relative merits of paper and electronic reading surfaces. One month long in-situ deployments of the United Slates with graduate students in the humanities found the multi-slate configuration to be highly effective for reading. The United Slates system delivered desirable paper-like qualities that included enhanced reading engagement, ease of navigation, and peace-of-mind while also providing superior electronic functionality. The positive feedback suggests that the multi-slate configuration is a desirable method for supporting active reading activities

    Smart bus stop: people counting in a multi-view camera environment

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    As paragens de autocarros nos dias de hoje tem de estar cada vez mais ao serviço dos utentes, esta dissertação explora as ideias fundamentais sobre o que deve ser uma paragem de autocarro inteligente, reunindo num texto os conceitos mais utilizados e as mais recentes tecnologias sobre este tópico. Os fundamentos do que é uma paragem de autocarro inteligente são explorados, bem como a arquitetura de todo o sistema, não só a paragem propriamente dita. Ao analisar a bibliografia já existentes compreende-se que a paragem de autocarro não é uma entidade totalmente independente, pois esta está dependente de informação vinda de variadíssimas fontes. Assim sendo, a paragem de autocarro inteligente será um subsistema de um sistema muito mais complexo, composto pela própria paragem, pelo autocarro e por uma central. Em que a comunicação flui entre estes de forma a manter toda a informação do sistema atualizada em tempo real. O autocarro recolherá informação, como quantos passageiros tem abordo e a sua localização geográfica por exemplo. A central receberá toda a informação de todos os autocarros existentes assim como de todas as paragens de autocarro existentes. Por sua vez a paragem de autocarro, recolherá dados também, tais como quantas pessoas estão na paragem, temperatura, humidade, emissões de dióxido de carbono, ruido, entre outros. A paragem de autocarro deverá contar com um conjunto de interfaces de comunicação, tais como Bluetooth e/ou NFC, hi-fi e RFID ou Beacons, para que possam ser feitas comunicações com os utilizadores, com os autocarros e com a central. Deverá ter também ecrãs interativos que poderão ser acedidos usando gestos e/ou toque e/ou voz para que se possam efetuar as ações pretendidas. A informação não será apenas transmitida nos ecrãs interativos, será transmitida também através de som. A informação contida na paragem pode ser de todo o tipo, desde as rotas, horários, posição atual do próximo autocarro, assim como o número do mesmo, publicidade animada, etc. A paragem conta também com outras funcionalidades como conectores onde se possam carregar dispositivos móveis, aquecimento, iluminação controlada face à afluência de utilizadores e horário, um sistema de armazenamento de energia pois deverá contar com fontes de energia renováveis para que possa ser o mais autossustentável possível, e obviamente câmeras de vigilância para segurança dos utilizadores. Sendo o principal objetivo deste trabalho, o desenvolvimento de um algoritmo capaz de contar quantas pessoas se encontram na paragem de autocarro, através do processamento das imagens vindas de várias câmaras, o foco principal é explorar as tecnologias de visão computacional e como estas podem ser utilizadas dentro do conceito da paragem de autocarro inteligente. Uma vez que o mundo da visão computacional evoluiu muito nos últimos anos e as suas aplicações são quase ilimitadas, dai a sua implementação nas mais diversas áreas, como reconstrução de cenários, deteção de eventos, monitorização de vídeo, reconhecimento de objetos, estimativa de movimento, restauração de imagem, etc. Ao combinar os diferentes algoritmos das diferentes aplicações, podem ser criadas ferramentas mais poderosas. Assim sendo o algoritmo desenvolvido utiliza redes neuronais convulsionais para detetar todas as pessoas de uma imagem, devolvendo uma região de interesse. Essa região de interesse é processada em busca de caras e caso estas existam essa informação é guardada no perfil da pessoa. Isto é possível através da utilização de reconhecimento facial, que utiliza um algoritmo de Deep Learning (DL). Essa região de interesse também é convertida para uma escala de cinzentos e posteriormente para uma matriz, essa matriz será também guardada no perfil do utilizador. Está informação é necessária para que se possa treinar um modelo que utiliza algoritmos de aprendizagem de máquina (Support Vector Machine - SVM). Os algoritmos de DL e SVM são necessários para que se possa fazer a identificação dos utilizadores a cada imagem e para que se possa cruzar os vários perfis vindos das várias origens, para que possa eliminar os perfis repetidos. Com isto a mesma pessoa é contada as vezes que apareça nas imagens, em função do número de câmeras existentes na paragem. Assim sendo é preciso eliminar essas repetições de forma a ter um número de pessoas correto. Num ambiente controlado o algoritmo proposto tem uma taxa de sucesso elevada, praticamente sem falhas, mas quando testado no ambiente para o qual foi desenhado já não é bem assim, ou porque numa paragem de autocarro as pessoas estão em contante movimento ou porque ficam na frente umas das outras e não é possível visualizá-las a todas. Mesmo com muitas câmeras colocadas no local, acabam sempre por haver pontos mortos, devido à estrutura da paragem ou até mesmo devido ao meio, por exemplo árvores ou um carro mal-estacionado, etc.Bus stops nowadays have to be increasingly at the user’s service, this thesis explores the fundamentals ideas of what a Smart Bus Stop should be and bring all together into one concept using today’s technologies. Although the fundamentals of a Smart Bus Stop (SBS) are explored, the primary focus here is to explore computer vision technology and how they can be used inside the Smart Bus Stop concept. The world of computer vision has evolved a lot in recent years and its applications are almost limitless, so they have been incorporated into many different areas like scene reconstruction, event detection, video tracking, object recognition, motion estimation, image restoration, etc. When combining the different algorithms of the different applications more powerful tools can be created. This work uses a Convolutional Neural Network (CNN) based algorithm to detect people in a multi video feeds. It also counts the number of persons in the SBS, using facial recognition, using with Deep Learning algorithm, and Support Vector Machine algorithm. It is important to stress, these last two are used to keep track of the user and also to remove the repeated profiles gathered in the different video sources, since the SBS is in a multi-camera environment. Combining these technologies was possible to count how many people were in the SBS. In laboratory the propose algorithm presents an extremely high success rate, when applied to real bus stops que success rate decreases due to blind spots for instance

    Migrating characters: effective user guidance in instrumented environments

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    The work at hand deals with the conceptual design as well as with the realization of virtual characters, which, unlike previous works in this research area, are not limited to a use in virtual worlds. The presented Migrating Character approach on the contrary allows virtual characters to act and interact with the physical world. Different technical solutions allowing a Migrating Character to move throughout physical space, either completely autonomously or in conjunction with a user, are introduced and discussed as well as resulting implications for the characters behavior. While traditional virtual characters are acting in a well defined virtual world, Migrating Characters need to adapt to changing environmental setups in a very flexible way. A Migrating Character must be capable of determining these environmental changes by means of sensors. Furthermore, based on this data, an adequate adaptation of the characters behavior has to be realized. Apart from a theoretical discussion of the necessary enhancements of a virtual character when taking the step from virtual to real worlds, different exemplary Migrating Character implementations are introduced in the course of the work.Die vorliegende Arbeit beschäftigt sich mit dem konzeptuellen Entwurf und der technischen Realisierung von virtuellen Charakteren, die im Gegensatz zu bisherigen Arbeiten auf diesem Gebiet nicht auf den Einsatz in virtuellen Welten beschränkt sind. Der vorgestellte Migrating Character Ansatz erlaubt virtuellen Charakteren vielmehr in der physikalischen Welt zu agieren und zu interagieren. Verschiedene technische Lösungen, welche es einem Migrating Character ermöglichen sich in der physikalischen Welt autonom bzw. in Abhängigkeit vom Benutzer zu bewegen, sind ebenso Gegenstand der Arbeit wie eine ausführliche Diskussion der daraus für das Verhalten des virtuellen Charakters resultierenden Implikationen. Während sich traditionelle virtuelle Charaktere in einer wohl definierten virtuellen Umgebung bewegen, muss ein Migrating Character flexibel auf sich ändernde Umgebungsbedingungen reagieren. Aus sensorischer Sicht benötigt ein Migrating Character also die Fähigkeit eine sich ändernde physikalische Situation zu erkennen. Basierend auf diesen Daten muss weiterhin eine adäquate Anpassung des Verhaltens des Migrating Characters geschehen. Neben einer theoretischen Diskussion der notwendigen Erweiterungen eines virtuellen Charakters beim übergang von virtueller zu realer Umgebung werden auch exemplarische Migrating Character Implementierungen vorgestellt

    Design of an Autonomous Hovering Miniature Air Vehicle as a Flying Research Platform

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    This thesis, by developing a Miniature Aerial Vehicle (MAV) hovering platform, presents a practical solution to allow researchers and students to implement their theoretical methods for guidance and navigation in the real world. The thesis is not concerned with the development of guidance and navigation algorithms, nor is it concerned with the development of external sensors. There have been some recent advances in guidance and navigation towards developing algorithms and simple sensors for MAVs. The task of developing a platform to test such advancements is the subject of this thesis. It is considered a difficult and time consuming process due to the complexities of autonomous flight control and the strict size, weight and computational requirements of this type of system. It would be highly beneficial to be able to buy a platform specifically designed for this task that already possesses autonomous hovering capability and the expansion connectivity for interfacing your own custom developed sensors and algorithms. Many biological and computer scientists would jump at the opportunity to maximize their research by real world implementation. The development of such a system is not a trivial task. It requires a great deal of understanding in a broad range of fields including; Aeronautical, Microelectronic, Mechanical, Computer and Embedded Software Engineering in order to create a successful prototype. The challenge of this thesis was to design a research platform to enable easy implementation of external sensors and guidance algorithms, in a real world environment for research and education. The system is designed so it could be used for a broad range of testing experiments. After extensive research in current MAV and avionics design it became obvious in several areas the best available products were not sufficient to meet the needs of the proposed platform. Therefore it was necessary to custom design and build; sensors, a data acquisition system and a servo controller. The latter two products are available for sale by Jimonics (www.jimonics.com). It was then necessary to develop a complete flight control system with integrated sensors, processor and wireless communications network which is called ‘The MicroBrain’. ‘The MicroBrain’ board measures only 45mm x 35mm x 11mm and weighs ~11 grams. The coaxial contra-rotating MAV platform design provides a high level of mechanical stability to help minimise the control system complexity. The platform was highly modified from a commercially available remotely controlled helicopter. The system incorporates a novel collision protection system that was designed to also double as a mounting place for external sensors around its perimeter. The platform equipped with ‘The MicroBrain’ is capable of fully autonomous hover. This provides a great base for testing guidance and navigational sensors and algorithms by decoupling the difficult task of platform design and low-level stability control. By developing a platform with these capabilities the researcher can now focus on the guidance and navigation task, as the difficulties in developing a custom platform have been taken care of. This therefore promotes a faster evolution of guidance and navigational control algorithms for MAVs
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