Dissertationen zum Thema „Exploration and mapping“
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Mata, Roxana. „Persistent autonomous exploration, mapping and localization“. Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/113127.
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Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2017.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 103-106).
In this thesis, we investigate methods for exploration, persistent autonomy, and simultaneous localization and mapping tasks for an autonomous mobile robot with battery constraints. First, we present modifications to baseline frontier exploration on an occupancy grid that makes the robot's frontier exploration more efficient. Second, we describe the new software structure and recovery behavior for an autonomous robot to navigate to its dock despite errors of uncertainty in its map. Third, we implemented a landmark-based topological mapping method using a state-of-the-art toolbox that maps the environment using visually unique tags to compare with metric mapping methods. Our analysis shows that the robot explores its environment more efficiently using our method than with previous frontier exploration methods, and that graph based mapping outperforms metric mapping against ground-truth accuracy tests.
by Roxana Mata.
M. Eng.
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Valencia, Carreño Rafael. „Mapping, planning and exploration with Pose SLAM“. Doctoral thesis, Universitat Politècnica de Catalunya, 2013. http://hdl.handle.net/10803/117471.
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This thesis reports research on mapping, path planning, and autonomous exploration. These are classical problems in robotics, typically studied independently, and here we link such problems by framing them within a common SLAM approach, adopting Pose SLAM as the basic state estimation machinery. The main contribution of this thesis is an approach that allows a mobile robot to plan a path using the map it builds with Pose SLAM and to select the appropriate actions to autonomously construct this map.
Pose SLAM is the variant of SLAM where only the robot trajectory is estimated and where landmarks are only used to produce relative constraints between robot poses. In Pose SLAM, observations come in the form of relative-motion measurements between robot poses. With regards to extending the original Pose SLAM formulation, this thesis studies the computation of such measurements when they are obtained with stereo cameras and develops the appropriate noise propagation models for such case. Furthermore, the initial formulation of Pose SLAM assumes poses in SE(2) and in this thesis we extend this formulation to SE(3), parameterizing rotations either with Euler angles and quaternions. We also introduce a loop closure test that exploits the information from the filter using an independent measure of information content between poses. In the application domain, we present a technique to process the 3D volumetric maps obtained with this SLAM methodology, but with laser range scanning as the sensor modality, to derive traversability maps.
Aside from these extensions to Pose SLAM, the core contribution of the thesis is an approach for path planning that exploits the modeled uncertainties in Pose SLAM to search for the path in the pose graph with the lowest accumulated robot pose uncertainty, i.e., the path that allows the robot to navigate to a given goal with the least probability of becoming lost. An added advantage of the proposed path planning approach is that since Pose SLAM is agnostic with respect to the sensor modalities used, it can be used in different environments and with different robots, and since the original pose graph may come from a previous mapping session, the paths stored in the map already satisfy constraints not easy modeled in the robot controller, such as the existence of restricted regions, or the right of way along paths. The proposed path planning methodology has been extensively tested both in simulation and with a real outdoor robot.
Our path planning approach is adequate for scenarios where a robot is initially guided during map construction, but autonomous during execution. For other scenarios in which more autonomy is required, the robot should be able to explore the environment without any supervision. The second core contribution of this thesis is an autonomous exploration method that complements the aforementioned path planning strategy. The method selects the appropriate actions to drive the robot so as to maximize coverage and at the same time minimize localization and map uncertainties. An occupancy grid is maintained for the sole purpose of guaranteeing coverage. A significant advantage of the method is that since the grid is only computed to hypothesize entropy reduction of candidate map posteriors, it can be computed at a very coarse resolution since it is not used to maintain neither the robot localization estimate, nor the structure of the environment. Our technique evaluates two types of actions: exploratory actions and place revisiting actions. Action decisions are made based on entropy reduction estimates. By maintaining a Pose SLAM estimate at run time, the technique allows to replan trajectories online should significant change in the Pose SLAM estimate be detected. The proposed exploration strategy was tested in a common publicly available dataset comparing favorably against frontier based exploration
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Fan, Yuantao, und Maytheewat Aramrattana. „Exploration and Mapping of Warehouses Using QuadrotorHelicopters“. Thesis, Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-24007.
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The goal of this thesis work is mapping of warehouse infrastructure using AR.Drone, aquadro helicopter equipped with a wide angle camera as its main sensor for mapping.Parallel Tracking and Mapping algorithm is employed for localization and creationof 3D point cloud of corner feature in the environment. Our approach for mapping was adata fusion algorithm that combines point cloud data from PTAM with estimated pillarpositions extracted by multi-stage image analysis algorithm.The methods implemented in ROS and Matlab has been successfully tested in real warehouseenvironment. The system is capable of creating an accurate map if some factorsare controlled. Details of results and analysis of methods are provided.Automatic Inventory and Mapping of Stock
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Fåk, Joel, und Tomas Wilkinson. „Autonomous Mapping and Exploration of Dynamic Indoor Environments“. Thesis, Linköpings universitet, Reglerteknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-97609.
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This thesis describes all the necessary parts needed to build a complete system for autonomous indoor mapping in 3D. The robotic platform used is a two-wheeled Segway, operating in a planar environment. This, together with wheel odometers, an Inertial Measurement Unit (IMU), two Microsoft Kinects and a laptop comprise the backbone of the system, which can be divided into three parts: The localization and mapping part, which fundamentally is a SLAM (simultaneous localization and mapping) algorithm implemented using the registration technique Iterative Closest Point (ICP). Along with the map being in 3D, it also designed to handle the mapping of dynamic scenes, something absent from the standard SLAM design. The planning used by the system is twofold. First, the path planning - finding a path from the current position to a destination - and second, the target planning - determining where to go next given the current state of the map and the robot. The third part of the system is the control and collision systems, which while they have not received much focus, are very necessary for a fully autonomous system. Contributions made by this thesis include: The 3D map framework Octomap is extended to handle the mapping of dynamic scenes; A new method for target planning, based on image processing is presented; A calibration procedure for the robot is derived that gives a full six degree of freedom pose for each Kinect. Results show that our calibration procedure produces an accurate pose for each Kinect, which is crucial for a functioning system. The dynamic mapping is shown to outperform the standard occupancy grid in fundamental situations that arise when mapping dynamic scenes. Additionally, the results indicate that the target planning algorithm provides a fast and easy way to plan new target destinations. Finally, the entire system’s autonomous mapping capabilities are evaluated together, producing promising results. However, it also highlights some problems that limit the system’s performance such as the inaccuracy and short range of the Kinects or noise added and reinforced by the multiple subsystemsDetta exjobb beskriver delarna som krävs för att för bygga ett komplett system som autonomt kartlägger inomhusmiljöer i tre dimensioner. Robotplattformen är en Segway, som är kapabel att röra sig i ett plan. Segwayn, tillsammans med en tröghetssensor, två Microsoft Kinects och en bärbar dator utgör grunden till systemet, som kan delas i tre delar: En lokaliserings- och karteringsdel, som i grunden är en SLAM-algoritm (simultan lokalisering och kartläggning) baserad på registreringsmetoden Iterative Closest Point (ICP). Kartan som byggs upp är i tre dimensioner och ska dessutom hantera kartläggningen av dynamiska miljöer, något som orginalforumleringen av SLAM problemet inte klarar av. En automatisk planeringsdel, som består av två delar. Dels ruttplanering som går ut på att hitta en väg från sin nuvarande position till det valda målet och dels målplanering som innebär att välja ett mål att åka till givet den nuvarande kartan och robotens nuvarande position. Systemets tredje del är regler- och kollisionssystemen. Dessa system har inte varit i fokus i detta arbete, men de är ändå högst nödvändiga för att ett autonomt system skall fungera. Detta examensarbete bidrar med följande: Octomap, ett ramverk för kartläggningen i 3D, har utökats för att hantera kartläggningen av dynamiska miljöer; En ny metod för målplanering, baserad på bildbehandling läggs fram; En kalibreringsprocedur för roboten är framtagen som ger den fullständiga posen i förhållande till roboten för varje Kinect. Resultaten visar att vår kalibreringsprocedur ger en nogrann pose for för varje Kinect, vilket är avgörande för att systemet ska fungera. Metoden för kartläggningen av dynamiska miljöer visas prestera bra i grundläggande situationer som uppstår vid kartläggning av dynamiska miljöer. Vidare visas att målplaneringsalgoritmen ger ett snabbt och enkelt sätt att planera mål att åka till. Slutligen utvärderas hela systemets autonoma kartläggningsförmåga, som ger lovande resultat. Dock lyfter resultat även fram problem som begränsar systemets prestanda, till exempel Kinectens onoggranhet och korta räckvidd samt brus som läggs till och förstärks av de olika subsystemen.
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Alberts, Ernst Patrick. „Horizon mapping in exploration seismology using artficial intelligence“. Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272160.
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Fisher, Roderick John. „Pole-potential mapping and synthetic arrays in electrical exploration“. Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ59056.pdf.
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Wilson, Brenda G. „Exploration of mind mapping as an organizational change tool“. Thesis, Pepperdine University, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10100912.
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Mind mapping is a communication tool that has been around for decades though it is rarely discussed as a tool for facilitating organizational change. It is possible for this underutilized communication tool and the ever-present challenge of organizational change to work in harmony on a more consistent basis. This exploratory research asked Change Leaders and Change Participants about their current mind mapping usage or experience, and requested their input on the use of mind mapping for organizational change efforts. There were 76 Change Leaders and 11 others who self-described themselves as Change Participants who responded to a virtual data collection process. Overall change readiness levels were predominantly at the moderate level, 37% of Change Leaders and 45% of Change Participants, an encouraging statistic for organizations considering change. Respondents reported that mind mapping is mostly used as a personal tool for organization, planning events, setting goals, and writing papers. Change Leaders (n=20) who reported using mind mapping professionally, commented they used it primarily for communication and collaboration, and project and systems planning and design. Specific practices included coaching, clarifying objectives, evaluating and monitoring projects, assessing lessons learned, redesigning curriculum, realigning resources, setting expectations, objectives and goals, and establishing timelines. One study conclusion was that these change practitioners understood how change is inevitable, and indicated their willingness to actively participate. This makes it important for organizations to capitalize on change participants’ knowledge and enthusiasm to enable successful change and enhance employee well-being. Concluding that attitudes, behaviors, and feelings toward change vary based on the role one plays, Change Leaders can benefit from the efforts of Change Participants by simply respecting their role and knowledge and involving them in the entire process, from planning to implementation. It is a foregone conclusion that communication is essential for any change process regardless of what specific tool is used, but the importance of selecting an appropriate method(s) based on the situation, message, and the recipients is critical. Using mind mapping as a change management tool specifically designed for certain aspects of organizational change is highly recommended, as it allows for both linear and non-linear communication.
Keywords: mind mapping, organizational change, Organizational Change Readiness Assessment, OCRA, visual communication
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Gregory, R. G. „Soil gas emanometry and hydrothermal mineralisation in southwest England“. Thesis, University of Exeter, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.377311.
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Olson, Jacob Moroni. „Collaborative UAV Planning, Mapping, and Exploration in GPS-Denied Environments“. BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/8703.
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The use of multirotor UAVs to map GPS-degraded environments is useful for many purposes ranging from routine structural inspections to post-disaster exploration to search for survivors and evaluate structural integrity. Multirotor UAVs are able to reach many areas that humans and other robots cannot safely access. Because of their relatively short operational flight time compared to other robotic applications, using multiple UAVs to collaboratively map these environments can streamline the mapping process significantly. This research focuses on four primary areas regarding autonomous mapping and navigation with multiple UAVs in complex unknown or partially unknown GPS-denied environments: The first area is the high-level coverage path planning necessary to successfully map these environments with multiple agents. The second area is the lower-level reactive path planning that enables autonomous navigation through complex, unknown environments. Third, is the estimation framework that enables autonomous flight without the use of GPS or other global position sensors. Lastly, it focuses on the mapping framework to build a single dense 3D map of these environments with multiple agents flying simultaneously.
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Jiang, Dayou. „An exploration of BMSF algorithm in genome-wide association mapping“. Kansas State University, 2013. http://hdl.handle.net/2097/15505.
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Master of ScienceDepartment of Statistics
Haiyan Wang
Motivation: Genome-wide association studies (GWAS) provide an important avenue for investigating many common genetic variants in different individuals to see if any variant is associated with a trait. GWAS is a great tool to identify genetic factors that influence health and disease. However, the high dimensionality of the gene expression dataset makes GWAS challenging. Although a lot of promising machine learning methods, such as Support Vector Machine (SVM), have been investigated in GWAS, the question of how to improve the accuracy of the result has drawn increased attention of many researchers A lot of the studies did not apply feature selection to select a parsimonious set of relevant genes. For those that performed gene selections, they often failed to consider the possible interactions among genes. Here we modify a gene selection algorithm BMSF originally developed by Zhang et al. (2012) for improving the accuracy of cancer classification with binary responses. A continuous response version of BMSF algorithm is provided in this report so that it can be applied to perform gene selection for continuous gene expression dataset. The algorithm dramatically reduces the dimension of the gene markers under concern, thus increases the efficiency and accuracy of GWAS. Results: We applied the continuous response version of BMSF on the wheat phenotypes dataset to predict two quantitative traits based on the genotype marker data. This wheat dataset was previously studied in Long et al. (2009) for the same purpose but used only direct application of SVM regression methods. By applying our gene selection method, we filtered out a large portion of genes which are less relevant and achieved a better prediction result for the test data by building SVM regression model using only selected genes on the training data. We also applied our algorithm on simulated datasets which was generated following the setting of an example in Fan et al. (2011). The continuous response version of BMSF showed good ability to identify active variables hidden among high dimensional irrelevant variables. In comparison to the smoothing based methods in Fan et al. (2011), our method has the advantage of no ambiguity due to difference choices of the smoothing parameter.
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Knowles, Alia Karraz. „Mapping the subject : exploration of identity construction through autobiographical reflection“. Master's thesis, University of Cape Town, 2002. http://hdl.handle.net/11427/3591.
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BELO, FELIPE AUGUSTO WEILEMANN. „EXPLORATION AND VISUAL MAPPING ALGORITHMS DEVELOPMENT FOR LOW COST MOBILE ROBOTS“. PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2006. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=9142@1.
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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOAo mesmo tempo em que a autonomia de robôs pessoais e domésticos aumenta, cresce a necessidade de interação dos mesmos com o ambiente. A interação mais básica de um robô com o ambiente é feita pela percepção deste e sua navegação. Para uma série de aplicações não é prático prover modelos geométricos válidos do ambiente a um robô antes de seu uso. O robô necessita, então, criar estes modelos enquanto se movimenta e percebe o meio em que está inserido através de sensores. Ao mesmo tempo é necessário minimizar a complexidade requerida quanto a hardware e sensores utilizados. No presente trabalho, um algoritmo iterativo baseado em entropia é proposto para planejar uma estratégia de exploração visual, permitindo a construção eficaz de um modelo em grafo do ambiente. O algoritmo se baseia na determinação da informação presente em sub-regiões de uma imagem panorâmica 2-D da localização atual do robô obtida com uma câmera fixa sobre o mesmo. Utilizando a métrica de entropia baseada na Teoria da Informação de Shannon, o algoritmo determina nós potenciais para os quais deve se prosseguir a exploração. Através de procedimento de Visual Tracking, em conjunto com a técnica SIFT (Scale Invariant Feature Transform), o algoritmo auxilia a navegação do robô para cada nó novo, onde o processo é repetido. Um procedimento baseado em transformações invariáveis a determinadas variações espaciais (desenvolvidas a partir de Fourier e Mellin) é utilizado para auxiliar o processo de guiar o robô para nós já conhecidos. Também é proposto um método baseado na técnica SIFT. Os processos relativos à obtenção de imagens, avaliação, criação do grafo, e prosseguimento dos passos citados continua até que o robô tenha mapeado o ambiente com nível pré-especificado de detalhes. O conjunto de nós e imagens obtidos são combinados de modo a se criar um modelo em grafo do ambiente. Seguindo os caminhos, nó a nó, um robô pode navegar pelo ambiente já explorado. O método é particularmente adequado para ambientes planos. As componentes do algoritmo proposto foram desenvolvidas e testadas no presente trabalho. Resultados experimentais mostrando a eficácia dos métodos propostos são apresentados.
As the autonomy of personal service robotic systems increases so has their need to interact with their environment. The most basic interaction a robotic agent may have with its environment is to sense and navigate through it. For many applications it is not usually practical to provide robots in advance with valid geometric models of their environment. The robot will need to create these models by moving around and sensing the environment, while minimizing the complexity of the required sensing hardware. This work proposes an entropy-based iterative algorithm to plan the robot´s visual exploration strategy, enabling it to most efficiently build a graph model of its environment. The algorithm is based on determining the information present in sub-regions of a 2- D panoramic image of the environment from the robot´s current location using a single camera fixed on the mobile robot. Using a metric based on Shannon s information theory, the algorithm determines potential locations of nodes from which to further image the environment. Using a Visual Tracking process based on SIFT (Scale Invariant Feature Transform), the algorithm helps navigate the robot to each new node, where the imaging process is repeated. An invariant transform (based on Fourier and Mellin) and tracking process is used to guide the robot back to a previous node. Also, an SIFT based method is proposed to accomplish such task. This imaging, evaluation, branching and retracing its steps continues until the robot has mapped the environment to a pre-specified level of detail. The set of nodes and the images taken at each node are combined into a graph to model the environment. By tracing its path from node to node, a service robot can navigate around its environment. This method is particularly well suited for flat-floored environments. The components of the proposed algorithm were developed and tested. Experimental results show the effectiveness of the proposed methods.
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Mandelli, Marcelo Grandi. „Exploration of runtime distributed mapping techniques for emerging large scale MPSoCs“. Pontifícia Universidade Católica do Rio Grande do Sul, 2015. http://hdl.handle.net/10923/7585.
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Previous issue date: 2015MPSoCs with hundreds of cores are already available in the market. According to the ITRS roadmap, such systems will integrate thousands of cores by the end of the decade. The definition of where each task will execute in the system is a major issue in the MPSoC design. In the literature, this issue is defined as task mapping. The growth in the number of cores increases the complexity of the task mapping. The main concerns in task mapping in large systems include: (i) scalability; (ii) dynamic workload; and (iii) reliability. It is necessary to distribute the mapping decision across the system to ensure scalability. The workload of emerging large MPSoCs may be dynamic, i. e., new applications may start at any moment, leading to different mapping scenarios. Therefore, it is necessary to execute the mapping process at runtime to support a dynamic workload. Reliability is tightly connected to the system workload distribution. Load imbalance may generate hotspots zones and consequently thermal implications, which may result in unreliable system operation. In large scale MPSoCs, reliability issues get worse since the growing number of cores on the same die increases power densities and, consequently, the system temperature. The literature presents different task mapping techniques to improve system reliability. However, such approaches use a centralized mapping approach, which are not scalable. To address these three challenges, the main goal of this Thesis is to propose and evaluate distributed mapping heuristics, executed at runtime, ensuring scalability and a fair workload distribution. Distributing the workload and the traffic inside the NoC increases the system reliability in long-term, due to the minimization of hotspot regions. To enable the design space exploration of large MPSoCs the first contribution of the Thesis lies in a multi-level modeling framework, which supports different models and debugging capabilities that enrich and facilitate the design of MPSoCs. The simulation of lower level models (e. g. RTL) generates performance parameters used to calibrate abstract models (e. g. untimed models). The abstract models pave the way to explore mapping heuristics in large systems. Most mapping techniques focus on optimizing communication volume in the NoC, which may compromise reliability due to overload processors. On the other hand, a heuristic optimizing only the workload distribution may overload NoC links, compromising its reliability. The second significant contribution of the Thesis is the proposition of dynamic and distributed mapping heuristics, making a tradeoff between communication volume (NoC links) and workload distribution (CPU usage). Results related to execution time, communication volume, energy consumption, power traces and temperature distribution in large MPSoCs (144 processors) confirm the tradeoff hypothesis. Trading off workload and communication volume improves system reliably through the reduction of hotspots regions, without compromising system performance.
MPSoCs com centenas de processadores já estão disponíveis no mercado. De acordo com o ITRS, tais sistemas integrarão milhares de processadores até o final da década. A definição de onde cada tarefa será executada no sistema é um desafio importante na concepção de MPSoCs. Na literatura, tal desafio é definido como mapeamento de tarefas. O aumento do número de processadores aumenta a complexidade do mapeamento de tarefas. As principais preocupações em mapeamento de tarefas em grandes sistemas incluem: (i) escalabilidade; (ii) carga dinâmica de trabalho; e (iii) confiabilidade. É necessário distribuir a decisão do mapeamento pelo sistema para garantir escalabilidade. A carga de trabalho em MPSoCs pode ser dinâmica, ou seja, novas aplicações podem iniciar a execução a qualquer momento, levando a diferentes cenários de mapeamento. Portanto, é necessário executar o processo de mapeamento em tempo de execução para suportar uma carga de trabalho dinâmica. Confiabilidade é diretamente relacionada à distribuição da carga de trabalho no sistema. Desequilíbrio de carga pode gerar zonas de hotspots e implicações termais, que podem resultar em uma operação do sistema não confiável. Em MPSoCs de grande dimensão problemas de confiabilidade se agravam, uma vez que o crescente número de processadores no mesmo chip aumenta o consumo de energia e, consequentemente, a temperatura do sistema. A literatura apresenta diferentes técnicas de mapeamento de tarefas para melhorar a confiabilidade do sistema. No entanto, tais técnicas utilizam uma abordagem de mapeamento centralizado, a qual não é escalável. Em função destes três desafios, o principal objetivo desta Tese é propor e avaliar heurísticas de mapeamento distribuído, executadas em tempo de execução, garantindo escalabilidade e uma distribuição de carga de trabalho uniforme. Distribuir a carga de trabalho e o tráfego da NoC aumenta a confiabilidade do sistema no longo prazo, devido à minimização das regiões de hotspot. Para permitir a exploração do espaço de projeto em MPSoCs, a primeira contribuição desta Tese consiste em um ambiente de modelagem multi-nível, que suporta diferentes modelos e capacidades de depuração que enriquecem e facilitam o projeto de MPSoCs. A simulação de modelos de mais baixo nível (por exemplo, RTL) gera parâmetros de desempenho utilizados para calibrar modelos mais abstratos. Os modelos abstratos facilitam a exploração de heurísticas de mapeamento em grandes sistemas. A maioria das técnicas de mapeamento se concentram na otimização do volume comunicação na NoC, o que pode comprometer a confiabilidade, devido à sobrecarga de processadores. Por outro lado, uma heurística que visa a otimização apenas da distribuição de carga de trabalho pode sobrecarregar canais da NoC, comprometendo a sua confiabilidade. A segunda contribuição significativa desta Tese é a proposição de heurísticas de mapeamento dinâmico e distribuídos, fazendo um compromisso entre o volume de comunicação (canais da NoC) e distribuição de carga de trabalho (uso da CPU). Os resultados relacionados a tempo de execução, volume de comunicação, consumo de energia, distribuição de potência e temperatura em grandes MPSoCs (256 processadores) confirmam a hipótese deste compromisso. Fazer um compromisso entre carga de trabalho e volume de comunicação melhora a confiabilidade do sistema através da redução de regiões hotspots, sem comprometer o desempenho do sistema.
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Grandi, Mandelli Marcelo. „EXPLORATION OF RUNTIME DISTRIBUTED MAPPING TECHNIQUES FOR EMERGING LARGE SCALE MPSOCS“. Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS217/document.
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MPSoCs (systèmes multiprocesseurs sur puces) avec des centaines de cœurs sont déjà disponibles sur le marché. Selon le ITRS, ces systèmes intégreront des milliers de cœurs à la fin de la décennie. La définition du cœur, où chaque tâche sera exécutée dans le système, est une question majeure dans la conception de MPSoCs. Dans la littérature, cette question est définie comme allocation de tâches. La croissance du nombre de cœurs augmente la complexité de l'allocation de tâches. Les principales préoccupations en matière d'allocation de tâches dans des grands MPSoCs incluent: (i) l'évolutivité; (ii) la charge de travail dynamique; et (iii) la fiabilité. Il est nécessaire de distribuer la décision d'allocation de tâches à travers le système afin d'assurer l'évolutivité. La charge de travail de grands MPSoCs peut être dynamique, à savoir, de nouvelles applications peuvent commencer à tout moment, conduisant à différents scénarios d'allocation. Par conséquent, il est nécessaire d'exécuter le processus d'allocation à l'exécution pour soutenir une charge de travail dynamique. La fiabilité est étroitement liée à la distribution de la charge de travail du système. Un déséquilibre de charge peut générer des hotspots et autres implications thermiques, ce qui peut entraîner un fonctionnement peu fiable du système. Dans de grands MPSoCs, les problèmes de fiabilité empirent puisque l'augmentation du nombre de cœurs sur la même puce augmente la densité de puissance et, par conséquent, la température du système. La littérature présente différentes techniques d'allocation de tâches pour améliorer la fiabilité du système. Cependant, ces techniques utilisent des approches d'allocation centralisées, qui ne sont pas évolutives. Pour répondre à ces trois défis, l'objectif principal de cette Thèse est de proposer et évaluer des heuristiques d'allocation de tâches distribuées et dynamiques en assurant l'évolutivité et une distribution équitable de la charge de travail. Une distribution équitable de la charge de travail et du trafic du NoC (réseau sur puce) augmente la fiabilité du système dans le long terme, en raison de la minimisation des régions de hotspot. Pour permettre l'exploration de l'espace de conception de grands MPSoCs, la première contribution de cette Thèse se situe dans le cadre d'une modélisation multi-niveaux, qui prend en compte différents modèles et de capacités de débogage qui enrichissent et facilitent la conception des MPSoCs. La simulation de modèles de niveau inférieur (par exemple RTL) génère des paramètres de performance utilisés pour calibrer des modèles abstraits (sans précision d'horloge). Les modèles abstraits permettent d'explorer des heuristiques d'allocation de tâches dans de grands systèmes. La plupart des techniques d'allocation de tâches se focalisent sur l'optimisation du volume de communication, ce qui peut compromettre la fiabilité du système, en raison d'une surcharge des processeurs. D'autre part, une heuristique qui optimise seulement la distribution de la charge de travail peut surcharger le NoC et compromettre sa fiabilité. La deuxième contribution importante de cette Thèse est la proposition d'heuristiques d'allocation de tâches dynamiques et distribuées, qui réalisent un compromis entre le volume de communication (liens du NoC) et la distribution de la charge de travail (de l'utilisation des processeurs). Des résultats liés au temps d'exécution, au volume de la communication, à la consommation d'énergie, aux traces de puissance et à la distribution de la température dans les grands MPSoCs (144 processeurs) confirment l'hypothèse de compromis. Faire un compromis entre la réduction du volume de communication et une distribution équitable de la charge de travail améliore le système de manière fiable grâce à la réduction des régions de hotspots, sans compromettre la performance du systèmeMPSoCs with hundreds of cores are already available in the market. According to the ITRS roadmap, such systems will integrate thousands of cores by the end of the decade. The definition of where each task will execute in the system is a major issue in the MPSoC design. In the literature, this issue is defined as task mapping. The growth in the number of cores increases the complexity of the task mapping. The main concerns in task mapping in large systems include: (i) scalability; (ii) dynamic workload; and (iii) reliability. It is necessary to distribute the mapping decision across the system to ensure scalability. The workload of emerging large MPSoCs may be dynamic, i.e., new applications may start at any moment, leading to different mapping scenarios. Therefore, it is necessary to execute the mapping process at runtime to support a dynamic workload. Reliability is tightly connected to the system workload distribution. Load imbalance may generate hotspots zones and consequently thermal implications, which may result in unreliable system operation. In large scale MPSoCs, reliability issues get worse since the growing number of cores on the same die increases power densities and, consequently, the system temperature. The literature presents different task mapping techniques to improve system reliability. However, such approaches use a centralized mapping approach, which are not scalable. To address these three challenges, the main goal of this Thesis is to propose and evaluate distributed mapping heuristics, executed at runtime, ensuring scalability and a fair workload distribution. Distributing the workload and the traffic inside the NoC increases the system reliability in long-term, due to the minimization of hotspot regions. To enable the design space exploration of large MPSoCs the first contribution of the Thesis lies in a multi-level modeling framework, which supports different models and debugging capabilities that enrich and facilitate the design of MPSoCs. The simulation of lower level models (e.g. RTL) generates performance parameters used to calibrate abstract models (e.g. untimed models). The abstract models pave the way to explore mapping heuristics in large systems. Most mapping techniques focus on optimizing communication volume in the NoC, which may compromise reliability due to overload processors. On the other hand, a heuristic optimizing only the workload distribution may overload NoC links, compromising its reliability. The second significant contribution of the Thesis is the proposition of dynamic and distributed mapping heuristics, making a tradeoff between communication volume (NoC links) and workload distribution (CPU usage). Results related to execution time, communication volume, energy consumption, power traces and temperature distribution in large MPSoCs (144 processors) confirm the tradeoff hypothesis. Trading off workload and communication volume improves system reliably through the reduction of hotspots regions, without compromising system performance
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Xu, Fengliang. „Mapping and localization for extraterrestrial robotic explorations“. Connect to this title online, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1095695679.
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Thesis (Ph. D.)--Ohio State University, 2004.Document formatted into pages; contains xvi, 158 p. Includes bibliographical references. Abstract available online via OhioLINK's ETD Center; full text release delayed at author's request until 2005 Sep. 20.
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Mattisson, Andreas, und Mathias Börjesson. „Distributed exploration of virtual environments“. Thesis, Blekinge Tekniska Högskola, Avdelningen för programvarusystem, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-4261.
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In most games today the movements of computer players is controlled by a web of waypoints that have been predefined by the creators of the map, or automatically generated by an application on beforehand. This data is precompiled to save precious CPU cycles for the player of the game, but what if we want these computer players to be able to explore how to get around the map by themselves? How could this be done and how would the result change if we had several of these players cooperating to explore the map? We explore some of the possibilities for exploration and discovery of maps using approaches that is often found in robotics. We also look at what happens when there is a penalty for communicating between these computer players, and what effect different amounts of map coverage will have on the performance of them. By setting up a test environment inside an existing commercial computer game we developed a client side bot system that made it possible for us to test different parameters and settings. Based on the analysis of the test results we propose ways to describe and predict the effects of the number of bots and the communication rate, and we describe several ways of how to further advance on these ideas and experiments.
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Lakshminarayana, Avinash. „Evaluation Techniques for Mapping IPs on FPGAs“. Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/34645.
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The phenomenal density growth in semiconductors has resulted in the availability of billions
of transistors on a single die. The time-to-design is shrinking continuously due to aggressive
competition. Also, the integration of many discrete components on a single chip is growing
at a rapid pace. Designing such heterogeneous systems in short duration is becoming difficult
with existing technology. Field-Programmable Gate Arrays offer a good alternative in both
productivity and heterogeneity issues. However, there are many obstacles that need to be
addressed to make them a viable option. One such obstacle is the lack of early design space
exploration tools and techniques for FPGA designs. This thesis develops techniques to evaluate
systematically, the available design options before the actual system implementation.
The aspect which makes this problem interesting, yet complicated, is that a system-level
optimization is not linearly summable. The discrete components of a system, benchmarked
as best in all design parameters â speed, area and power, need not add up to the best
possible system. This work addresses the problem in two ways. In the first approach,
we demonstrate that by working at higher levels of abstraction, one can achieve orders of
improvement in productivity. Designing a system directly from its behavioral description is
an on-going effort in industry. Instead of focusing on design aspects, we use these methods to
develop quick prototypes and estimate the design parameters. Design space exploration needs
relative comparison among available choices and not accurate values of design parameters.
It is shown that the proposed method can do an acceptable job in this regard. The second
approach is about evolving statistical techniques for estimating the design parameters and
then algorithmically searching the design space. Specifically, a high level power estimation
model is developed for FPGA designs. While existing techniques develop power model for
discrete components separately, this work evaluates the option of generic power model for
multiple components.Master of Science
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Rodriguez-Gallegos, Hugo Benigno. „Exploration of Very High Spatial Resolution Data for Vegetation Mapping using Cartographic Ontologies: Identifying Life Forms to Mapping Formations“. Diss., The University of Arizona, 2009. http://hdl.handle.net/10150/194484.
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Vegetation mapping is often considered the process of identifying landscape patterns of individuals or clusters of species or life forms (LF). At the landscape scale, the larger pattern represented by individuals or clusters represents the conceptualization of "vegetation mapping" and can be used as a building block to describe an ecosystem. To represent these building blocks or LF a "common entity (CE)" concept is introduced to represent the components of Formations as described by the National Vegetation Classification (NVC) system. The NVC has established protocols to consistently represent plant communities and promote coordinated management, particularly across jurisdictional boundaries. However, it is not a universal standard and the methods of producing detailed maps of vegetation CE from very high spatial resolution (VHR) remote sensing data are important research questions.This research addressed how best to understand and represent plant cover in arid regions, the most effective methods of mapping vegetation cover using high spatial resolution data, how to assess the accuracy of these maps, and their value in establishing more standardized mapping protocols across ecosystems. Utilizing VHR products from the IKONOS and QuickBird sensors the study focused on the Coronado National Memorial and Chiricahua National Monument in Arizona and Los Ajos and Pinacate - Grand Desierto Biosphere Reserves in México. Individual CE were semi-automatically mapped incorporating spectral, textural and geostatistical variables. The results were evaluated across sensors, study sites, and input variables. In addition, multiple methods of acquiring field data for accuracy assessment were evaluated and then an evaluation was made of a semi-automatic determination of Formation based on CE.The results of the study suggest consistency across study sites using the IKONOSdata. A comparison between VHR products from the same place is feasible but sensor spectral differences may affect which derived bands would improve classification. CE classification procedures were not significantly different across sensors. The overall accuracy obtained for each Park was 59.5% for Chiricahua using QuickBird and 51.9% using IKONOS; at Pinacate 70.0% using IKONOS, and 55.9% for Ajos. Incorporating the geostatistical semi-variogram variables improved CE accuracy for some CE but not all.
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Tayob, Huda. „Exploring city spaces : an exploration into mapping practices and rule based design“. Master's thesis, University of Cape Town, 2010. http://hdl.handle.net/11427/19083.
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This paper has been written in 3 sections. With some adjustments, the first section is largely the theory paper, the second my technology paper, and the third an exploration of my design. These three sections have been written as disparate parts. Ideas and themes are carried through the three papers, but they do not read as a coherent whole. This year has been a journey into the city of Cape Town; an exploration of its complexity, vibrant city spaces and everyday life. This is essentially what this paper is about, and is a theme that is explored in all three sections in different ways- with the third drawing and building on the first two. I started with ideas of Lefebvre and the work of CHORA as a methodology for exploring the 'everyday practices' in the city- and moved through this to an engagement with rule based design and algorithmic architecture. The design chapter loops back to the beginning of the paper, and draws from and is informed by both the initial research, a'1d rule- based methodology. All three of these sections have been exploratory processes engaging with this set of ideas around complexity within the city. I do not see them as providing an answer as to how to design or explore cities, but rather as an attempt to engage with these very real questions. They are a series of ideas that have enabled me to see parts of the 'hidden world' within Cape Town, and explore this through ideas of the unknown and unimaginable in architecture.
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Kleiner, Alexander. „Mapping and exploration for search and rescue with humans and mobile robots“. [S.l. : s.n.], 2007.
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Hanson, Christopher Jon. „Exploration of the Gossypium raimondii Genome Using Bionano Genomics Physical Mapping Technology“. BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/6854.
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Cotton is a crop with a large global economic impact as well as a large, complex genome. Most industrial cotton production is from two tetraploid species (Gossypium hirsutum L. and Gossypium barbadense L.) which contain two subgenomes, specifically the AT and DT subgenomes. The DT subgenome is nearly half the size of the AT subgenome in tetraploid cotton and is closely related to an extant D-genome Gossypium species, G. raimondii Ulbr. Characterization of the structural variants present in diploid D-genome should provide greater insight into the evolution of the DT subgenome in the tetraploid cotton. Bionano (BNG) optical mapping uses patterns of fluorescent labels inserted at specific endonuclease sites to create physical maps of the genomes which can then be examined for structural variation. To develop optical maps in G. raimondii, we first developed a de novo PacBio long read sequence assembly of G. raimondii. This sequence assembly consisted of 2,379 contigs, an average contig length of 413 Kb and a contig N50 of 4.9 Mb. Using BNG technology, we developed two optical maps of the diploid D genome of G. raimondii. One was created using the Nt.BssSI endonuclease and one with the Nt.BspQI endonuclease. Using the BNG optical maps, the PacBio assembly was hybrid scaffolded into 100 scaffolds (+ 5 unscaffolded contigs) with an average scaffold length of 7.5 Mb and a scaffold N50 of 13.1 Mb. A comparison between the Nt. BssSI BNG optical map and the two sequence assemblies identified 3,195 structural variants. These were used to validate the accuracy of the reference sequence of G. raimondii and structural variants were used to create a new phylogeny of nine major cotton species.
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Ma, Donglin. „Exploration of Ray Mapping Methodology in Freeform Optics Design for Non-Imaging Applications“. Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/594394.
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This dissertation investigates various design metrologies on designing freeform surfaces for LED illumination applications. The major goal of this dissertation is to study designing freeform optical surfaces to redistribute the radiance (which can be simplified as intensity distribution for point source) of LED sources for various applications. Nowadays many applications, such as road lighting systems, automotive headlights, projection displays and medical illuminators, require an accurate control of the intensity distribution. Freeform optical lens is commonly used in illumination system because there are more freedoms in controlling the ray direction. Design methods for systems with rotational and translational symmetry were well discussed in the 1930's. However, designing freeform optical lenses or reflectors required to illuminate targets without such symmetries have been proved to be much more challenging. For the simplest case when the source is an ideal point source, the determination of the freeform surface in a rigorous manner usually leads to the tedious Monge-Ampère second order nonlinear partial different equation, which cannot be solved with standard numerical integration techniques. Instead of solving the differential equation, ray mapping is an easier and more efficient method in controlling one or more freeform surfaces for prescribed irradiance patterns. In this dissertation, we investigate the ray mapping metrologies in different coordinate systems to meet the integrability condition for generating smooth and continuous freeform surfaces. To improve the illumination efficiency and uniformity, we propose a composite ray mapping method for designing the total internal reflective (TIR) freeform lens for non-rotational illumination. Another method called "double pole" ray mapping method is also proposed to improve system performance. The ray mapping designs developed for the point source do not work well for extended sources, we have investigated different design methodologies including optimization method, deconvolution method and feedback modification method to design freeform optical surfaces for extended sources.
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Bender, Asher. „Autonomous Exploration of Large-Scale Natural Environments“. Thesis, The University of Sydney, 2013. http://hdl.handle.net/2123/9450.
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This thesis addresses issues which arise when using robotic platforms to explore large-scale, natural environments. Two main problems are identified: the volume of data collected by autonomous platforms and the complexity of planning surveys in large environments. Autonomous platforms are able to rapidly accumulate large data sets. The volume of data that must be processed is often too large for human experts to analyse exhaustively in a practical amount of time or in a cost-effective manner. This burden can create a bottleneck in the process of converting observations into scientifically relevant data. Although autonomous platforms can collect precisely navigated, high-resolution data, they are typically limited by finite battery capacities, data storage and computational resources. Deployments are also limited by project budgets and time frames. These constraints make it impractical to sample large environments exhaustively. To use the limited resources effectively, trajectories which maximise the amount of information gathered from the environment must be designed. This thesis addresses these problems. Three primary contributions are presented: a new classifier designed to accept probabilistic training targets rather than discrete training targets; a semi-autonomous pipeline for creating models of the environment; and an offline method for autonomously planning surveys. These contributions allow large data sets to be processed with minimal human intervention and promote efficient allocation of resources. In this thesis environmental models are established by learning the correlation between data extracted from a digital elevation model (DEM) of the seafloor and habitat categories derived from in-situ images. The DEM of the seafloor is collected using ship-borne multibeam sonar and the in-situ images are collected using an autonomous underwater vehicle (AUV). While the thesis specifically focuses on mapping and exploring marine habitats with an AUV, the research applies equally to other applications such as aerial and terrestrial environmental monitoring and planetary exploration.
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Ahsan, Nasir. „Combining Exploration and Exploitation in Active Learning“. Thesis, The University of Sydney, 2013. http://hdl.handle.net/2123/10144.
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This thesis investigates the active learning in the presence of model bias. State of the art approaches advocate combining exploration and exploitation in active learning. However, they suffer from premature exploitation or unnecessary exploration in the later stages of learning. We propose to combine exploration and exploitation in active learning by discarding instances outside a sampling window that is centered around the estimated decision boundary and uniformly draw sample from this window. Initially the window spans the entire feature space and is gradually constricted, where the rate of constriction models the exploration-exploitation tradeoff. The desired effect of this approach (CExp) is that we get an increasing sampling density in informative regions as active learning progresses, resulting in a continuous and natural transition from exploration to exploitation, limiting both premature exploitation and unnecessary exploration. We show that our approach outperforms state of the art on real world multiclass datasets. We also extend our approach to spatial mapping problems where the standard active learning assumption of uniform costs is violated. We show that we can take advantage of \emph{spatial continuity} in the data by geographically partitioning the instances in the sampling window and choosing a single partition (region) for sampling, as opposed to taking a random sample from the entire window, resulting in a novel spatial active learning algorithm that combines exploration and exploitation. We demonstrate that our approach (CExp-Spatial) can generate cost-effective sampling trajectories over baseline sampling methods. Finally, we present the real world problem of mapping benthic habitats where bathymetry derived features are typically not strong enough to discriminate the fine details between classes identified from high-resolution imagery, increasing the possiblity of model bias in active learning. We demonstrate, under such conditions, that CExp outperforms state of the art and that CExp-Spatial can generate more cost-effective sampling trajectories for an Autonomous Underwater Vehicle in contrast to baseline sampling strategies.
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Özkahraman, Özer. „Multi-Agent Control of Autonomous Surface Vehicles for Shallow Water Exploration and Depth Mapping“. Thesis, KTH, Robotik, perception och lärande, RPL, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-209948.
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Mapping is an enabler for further actions. With the map of an area available, it is possible to plan ahead. Maps of landmasses and heavily used deep waters have been produced and are in use but many shallow waters have been largely unmapped. This thesis proposes and examines two methods of control to produce depth maps of shallow waters using multiple autonomous surface vehicles. Assumptions about the environment are kept to a minimum and agents are expected to explore and map inside a given polygonal boundary. Gaussian process regression is used to guide the agents to areas with large uncertainty. A group of autonomous surface vehicles are used for experimental evaluation. Existing works in this area are compared with the method proposed in this thesis to evaluate map quality and time needed to create the map. Results show that one of the proposed methods is best suited for fast and raw map generation while the other strikes a good balance between accuracy and speed.Att ha tillgång till en karta över ett område är en förutsättning för många olika aktiviteter, och därför har det skapats allt mer exakta kartor över de flesta landområden. För hav och sjöar har man skapat mer ungefärliga djupkartor för att undvika grundstötningar för sjöfart. Grundare områden har däremot ofta undvikits av stora djupmätningsfartyg, och är därför i hög grad okarterade.I denna rapport föreslås och analyseras en metod för att kartera djupet i grunda områden med hjälp av en grupp autonoma ytfarkoster. Givet en polygon inom vilken man vill ha botten karterad skall gruppen autonomt söka av området med få ytterligare antaganden. Gaussiska processer används för att styra farkosterna mot områden med stora mätosäkerheter, och algoritmen utvärderas i riktiga experiment.Resultaten jämförs med befintliga metoders prestanda, med avseende på kartkvalitet och tid för kartering. Resultaten visar att en av de föreslagna metoderna är snabb men mindre noggrann, medan den andra ger en bättre avvägning mellan kvalitet och uppdragstid.
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Nguyen, Van Cuong. „Exploration de la cartographie par analyse d'association («Association Mapping») chez l'orge (Hordeum vulgare L.)“. Thesis, Université Laval, 2012. http://www.theses.ulaval.ca/2012/29300/29300.pdf.
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Kim, Jonghoek. „Simultaneous cooperative exploration and networking“. Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/39536.
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This thesis provides strategies for multiple vehicles to explore unknown environments in a cooperative and systematic manner. These strategies are called Simultaneous Cooperative Exploration and Networking (SCENT) strategies. As the basis for development of SCENT strategies, we first tackle the motion control and planning for one vehicle with range sensors. In particular, we develop the curve-tracking controllers for autonomous vehicles with rigidly mounted range sensors, and a provably complete exploration strategy is proposed so that one vehicle with range sensors builds a topological map of an environment. The SCENT algorithms introduced in
this thesis extend the exploration strategy for one vehicle to multiple vehicles.
The enabling idea of the SCENT algorithms is to construct a topological map of the environment, which is considered completely explored if the map corresponds to a complete Voronoi diagram of the environment. To achieve this, each vehicle explores its local area by incrementally expanding the already visited areas of the environment.
At the same time, every vehicle deploys communication devices at selected locations and, as a result, a communication network is created concurrently with a topological map. This additional network allows the vehicles to share information in a distributed manner resulting in an efficient exploration of the workspace.
The efficiency of the proposed SCENT algorithms is verified through theoretical investigations as well as experiments using mobile robots. Moreover, the resulting networks and the topological maps are used to solve coordinated multi-robot tasks,
such as capturing intruders.
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Thai, Ba chien. „Tone Mapping Operators for High Dynamic Range Images“. Thesis, Sorbonne Paris Cité, 2018. http://www.theses.fr/2018USPCD082.
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La conversion d'une image à grande gamme dynamique (HDR) en une image à faible gamme dynamique est étudiée de façon à garantir un rendu visuel de cette dernière de bonne qualité. La première contribution concerne le rehaussement de contraste de l'image mappée en utilisant une fonction linéaire par morceaux pour que l'égalisation d'histogramme soit ajustée à la "s-courbe" d'adaptation du système visuel humain. la deuxième et troisième contributions portent sur la préservation des détails de l'image HDR. Des approches multirésolution séparables et non séparables, basées sur des stratégies non oscillatoires, prenant en compte les singularités de l'image HDR dans la dérivation du modèle mathématique, sont proposées. La quatrième contribution non seulement préserve les détails mais également améliore le contraste de l'image HDR mappée. Un schéma de lifting séparable "presque optimal" est proposé. Il s'appuie sur une étape de prédiction adaptative des coefficients. Cette dernière repose sur une combinaison linéaire pondérée des coefficients voisins pour extraire les détails pertinents sur l'image HDR à chaque niveau de résolution. Un mappage linéaire par morceaux est ensuite appliqué à la reconstruction grossière. les résultats de simulation fournissent de bonnes performances en termes de qualité visuelle et de métrique TMQI (Tone Mapped Quality Index) par rapport aux approches de mise en correspondance tonale classiques. l'impact des paramètres TMQI sur la qualité visuelle des images mappées est discuté. Les paramètres proposés montrent une forte corrélation entre la métrique modifiée et la note moyenne d'opinionHe conversion of High Dynamic Range (HDR) image into Low Dynamic Range (LDR) image is investigated so that the visual rendering of the latter is of good quality. The first contribution focused on the contrast enhancement of the tone mapped image using a piecewise linear function as a non-uniform histogram equalization adjustment to mode! the "s-shaped" curve of the human visual adaptation. The second and third contributions are concerned with the details preservation of the HDR image on the tone mapped image. Separable and non-separable multiresolution approaches based on essential non-oscillatory strategies, taking into account the HDR image singularities in the mathematical mode! derivation, are proposed. The fourth contribution not only preserves details but also enhances the contrast of the HDR tone mapped image. A separable "near optimal" lifting scheme using an adaptive powerful prediction step is proposed. The latter relies on a linear weighted combination depending on the neighbouring coefficients to extract the relevant fin est details on the HDR image at each resolution level. A piecewise linear mapping is then applied on the coarse reconstruction. Simulation results provide good performance, both in terms of visual quality and Tone Mapped Quality Index (TMQI) metric, compared to existing competitive tone mapping approaches. The impact of the TMQI parameters on the visual quality of the tone mapped images is discussed. The proposed parameters show a strong correlation between the modified metric and
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Yang, Jin. „Exploration geochemical mapping in the north-eastern sector of the Morokweng impact structure, South Africa“. Thesis, University of the Western Cape, 2006. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_8373_1189147095.
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The Morokweng impact structure which is located in the North West province of South Africa, has attracted attention as a potential host for Ni-PGE mineralization. Geochemical exploration techniques using hydroxylamine partial extraction were used to determine the nature and source of surface geochemical anomalies known to occur in the overlying aeolian sang regolith. About 40 aeolian samples were taken from an area of about 35 square kilometer, located in the north eastern sector of the Morokweng impact structure. The samples were sieved to various grain size fractions and partially extracted using varying concentration of hydroxylamine hydrochloride at 50°
C.
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de, Pomereu Jean. „The exploration of 'indlandsis' : a cultural and scientific history of ice sheets to 1970“. Thesis, University of Exeter, 2015. http://hdl.handle.net/10871/18332.
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Despite their central importance to the Earth system, nowhere within the literatures of Polar Studies or the Humanities does there exist a comprehensive cultural and scientific history of ice sheets that takes into consideration both Greenland and Antarctica, or that is not constrained to a particular exploratory, technological, or geopolitical period or framing. My thesis addresses this lacunae by contributing a bi-polar, empirical history and analysis of the different scientific and cultural processes, transformations, and discontinuities through which ice sheets have been transformed from unexplored realms of the imagination, into tangible, material objects of investigation and meaning. Its scope extends from early Greek mapping to 1970. Within this timeframe, it identifies three broad phases in the perception of ice sheets. The first, preceding their earliest physical exploration, corresponds to the perception of ice sheets as one-dimensional realms defined and bounded by the human imagination. The second phase, associated with their early surface exploration between 1870 and 1930, corresponds to the perception of ice sheets as undifferentiated, two-dimensional 'topographies of absence', best characterized by their horizontal desolation. The third phase, triggered by the deployment of new technologies of sub-surface investigation such as seismic sounding, radio echo sounding (RES), and the practice of ice coring, corresponds to the perception of ice sheets as three-dimensional, super-massive, and interdependent objects of internal and material complexity. Although primarily rooted in archival research and the study of first hand textual and visual materials, my arguments and observations also draw on secondary literatures from the history of science and technology, geopolitics, visual culture, and the geography of space and place. These literatures allow me to contextualize and substantiate my analysis of historical processes within broader perspectives, notably Humboldtian science, Romanticism, visual abstraction, scientific imagery, and the Cold War.
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Wiik, Linus, und Jennie Bäcklin. „Collaborative Exploration of Unknown Terrain Utilizing Real-Time Kinematic Positioning“. Thesis, Linköpings universitet, Reglerteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-167103.
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Unmanned autonomous vehicles, airborne or terrestrial, can be used to solve many varying tasks in vastly different environments. This thesis describes a proposed collaboration between two types of such vehicles, namely unmanned aerial vehicles (UAVs) and unmanned ground vehicles (UGVs). The vehicles' objective is to traverse unknown terrain in order to access a target area. The exploration of the unknown terrain is in this thesis divided into three parts. These parts are terrain mapping, informative path planning (IPP) for the UAVs and path planning for the UGV. A Gaussian Process (GP) is used to model the terrain. The use of a GP map makes it possible to model spatial dependence and to interpolate data between measurements. Furthermore, sequential update of the map is achieved with a Kalman filter when new measurements are collected. In the second part, IPP is used to decide the best locations for the terrain height measurements. The IPP algorithm will prioritize measurements in locations with uncertain terrain height estimates in order to lower the overall map uncertainty. Finally, when the map is complete, the UGV plans an optimal path through the mapped terrain using A* graph search, while minimizing the total altitude difference for the path and respecting the map uncertainty. Collaborative behavior of autonomous vehicles requires highly accurate position estimates. In this thesis RTK is investigated and its accuracy and precision evaluated for the positioning of autonomous UAVs and UGVs through a series of experiments. The experiments range from stationary and dynamic accuracy to investigation of the consistency of the positioning estimates. The results are promising, RTK outperforms standard GNSS and can be used for centimeter-level accuracy when positioning a UAV in-flight. The proposed exploration algorithms are evaluated in simulations. The results show that the algorithms successfully solves the task of mapping and traversing unknown terrain. IPP makes the mapping of the unknown terrain efficient, which enables the possibility to use the resulting map to plan safe paths for the UGV. Traversing unknown terrain is hard for a single UGV but with the help from one or more UAVs the process is much more efficient. The use of multiple cooperating autonomous vehicles makes it possible to solve tasks complicated for the individual vehicle in an efficient manner.
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Keep, Stephanie Alexandra. „Space exploration mapping students' perception of the Smith College campus : a project based upon independent investigation /“. Click here for text online. Smith College School for Social Work website, 2007. http://hdl.handle.net/10090/986.
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Thesis (M.S.W.)--Smith College School for Social Work, Northampton, Mass., 2007Thesis submitted in partial fulfillment for the degree of Master of Social Work. Includes bibliographical references (leaves 60-62).
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Crosta, Alvaro Penteado. „Mapping of residual soils by remote sensing for mineral exploration in SW Minas Gerais State, Brazil“. Thesis, Imperial College London, 1990. http://hdl.handle.net/10044/1/47830.
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Cruz, Barbosa Raúl. „Generative manifold learning for the exploration of partially labeled data“. Doctoral thesis, Universitat Politècnica de Catalunya, 2009. http://hdl.handle.net/10803/78053.
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In many real-world application problems, the availability of data labels for supervised learning is rather limited. Incompletely labeled datasets are common in many of the databases generated in some of the currently most active areas of research. It is often the case that a limited number of labeled cases is accompanied by a larger number of unlabeled ones. This is the setting for semi-supervised learning, in which unsupervised approaches assist the supervised problem and vice versa.
A manifold learning model, namely Generative Topographic Mapping (GTM), is the basis of the methods developed in this thesis. The non-linearity of the mapping that GTM generates makes it prone to trustworthiness and continuity errors that would reduce the faithfulness of the data representation, especially for datasets of convoluted geometry. In this thesis, a variant of GTM that uses a graph approximation to the geodesic metric is first defined. This model is capable of representing data of convoluted geometries. The standard GTM is here modified to prioritize neighbourhood relationships along the generated manifold. This is accomplished by penalizing the possible divergences between the Euclidean distances from the data points to the model prototypes and the corresponding geodesic distances along the manifold. The resulting Geodesic GTM (Geo-GTM) model is shown to improve the continuity and trustworthiness of the representation generated by the model, as well as to behave robustly in the presence of noise.
The thesis then leads towards the definition and development of semi-supervised versions of GTM for partially-labeled data exploration. As a first step in this direction, a two-stage clustering procedure that uses class information is presented. A class information-enriched variant of GTM, namely class-GTM, yields a first cluster description of the data. The number of clusters defined by GTM is usually large for visualization purposes and does not necessarily correspond to the overall class structure. Consequently, in a second stage, clusters are agglomerated using the K-means algorithm with different novel initialization strategies that benefit from the probabilistic definition of GTM. We evaluate if the use of class information influences cluster-wise class separability. A robust variant of GTM that detects outliers while effectively minimizing their negative impact in the clustering process is also assessed in this context.
We then proceed to the definition of a novel semi-supervised model, SS-Geo-GTM, that extends Geo-GTM to deal with semi-supervised problems. In SS-Geo-GTM, the model prototypes are linked by the nearest neighbour to the data manifold constructed by Geo-GTM. The resulting proximity graph is used as the basis for a class label propagation algorithm. The performance of SS-Geo-GTM is experimentally assessed, comparing positively with that of an Euclidean distance-based counterpart and that of the alternative Laplacian Eigenmaps method. Finally, the developed models (the two-stage clustering procedure and the semi-supervised models) are applied to the analysis of a human brain tumour dataset (obtained by Nuclear Magnetic Resonance Spectroscopy), where the tasks are, in turn, data clustering and survival prognostic modeling.Resum de la tesi (màxim 4000 caràcters. Si se supera aquest límit, el resum es tallarà automàticament al caràcter 4000) En muchos problemas de aplicación del mundo real, la disponibilidad de etiquetas de datos para aprendizaje supervisado es bastante limitada. La existencia de conjuntos de datos etiquetados de manera incompleta es común en muchas de las bases de datos generadas en algunas de las áreas de investigación actualmente más activas. Es frecuente que un número limitado de casos etiquetados venga acompañado de un número mucho mayor de datos no etiquetados. Éste es el contexto en el que opera el aprendizaje semi-supervisado, en el cual enfoques no-supervisados prestan ayuda a problemas supervisados y vice versa. Un modelo de aprendizaje de variaciones (manifold learning, en inglés), llamado Mapeo Topográfico Generativo (GTM, en acrónimo de su nombre en inglés), es la base de los métodos desarrollados en esta tesis. La no-linealidad del mapeo que GTM genera hace que éste sea propenso a errores de fiabilidad y continuidad, los cuales pueden reducir la fidelidad de la representación de los datos, especialmente para conjuntos de datos de geometría intrincada. En esta tesis, una extensión de GTM que utiliza una aproximación vía grafos a la métrica geodésica es definida en primer lugar. Este modelo es capaz de representar datos con geometrías intrincadas. En él, el GTM estándar es modificado para priorizar relaciones de vecindad a lo largo de la variación generada. Esto se logra penalizando las divergencias existentes entre las distancias Euclideanas de los datos a los prototipos del modelo y las correspondientes distancias geodésicas a lo largo de la variación. Se muestra que el modelo Geo-GTM resultante mejora la continuidad y fiabilidad de la representación generada y que se comporta de manera robusta en presencia de ruido. Más adelante, la tesis nos lleva a la definición y desarrollo de versiones semi-supervisadas de GTM para la exploración de conjuntos de datos parcialmente etiquetados. Como un primer paso en esta dirección, se presenta un procedimiento de agrupamiento en dos etapas que utiliza información de pertenencia a clase. Una extensión de GTM enriquecida con información de pertenencia a clase, llamada class-GTM, produce una primera descripción de grupos de los datos. El número de grupos definidos por GTM es normalmente grande para propósitos de visualización y no corresponde necesariamente con la estructura de clases global. Por ello, en una segunda etapa, los grupos son aglomerados usando el algoritmo K-means con diferentes estrategias de inicialización novedosas las cuales se benefician de la definición probabilística de GTM. Evaluamos si el uso de información de clase influye en la separabilidad de clase por grupos. Una extensión robusta de GTM que detecta datos atípicos a un tiempo que minimiza de forma efectiva su impacto negativo en el proceso de agrupamiento es evaluada también en este contexto. Se procede después a la definición de un nuevo modelo semi-supervisado, SS-Geo-GTM, que extiende Geo-GTM para ocuparse de problemas semi-supervisados. En SS-Geo-GTM, los prototipos del modelo son vinculados al vecino más cercano a la variación construída por Geo-GTM. El grafo de proximidad resultante es utilizado como base para un algoritmo de propagación de etiquetas de clase. El rendimiento de SS-Geo-GTM es valorado experimentalmente, comparando positivamente tanto con la contraparte de este modelo basada en la distancia Euclideana como con el método alternativo Laplacian Eigenmaps. Finalmente, los modelos desarrollados (el procedimiento de agrupamiento en dos etapas y los modelos semi-supervisados) son aplicados al análisis de un conjunto de datos de tumores cerebrales humanos (obtenidos mediante Espectroscopia de Resonancia Magnética Nuclear), donde las tareas a realizar son el agrupamiento de datos y el modelado de pronóstico de supervivencia.
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Svensson, Martin. „Accelerated Volumetric Next-Best-View Planning in 3D Mapping“. Thesis, Linköpings universitet, Datorseende, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-111905.
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The Next-Best-View (NBV) problem plays an important part in automatic 3D object reconstruction and exploration applications. This thesis presents a novel approach of ray-casting in Occupancy Grid Maps (OGM) in the context of solving the NBV problem in a 3D-exploration setting. The proposed approach utilizes the structure of an octree-based OGM to perform calculations of potential information gain. The computations are significantly faster than current methods, without decreasing mapping quality. Performance, both in terms of mapping quality, coverage and computational complexity, is experimentally verified through a comparison with existing state-of-the-art methods using high-resolution point cloud data generated using time-of-flight laser range scanners. Current methods for viewpoint ranking focus either heavily on mapping performance or computation speed. The results presented in this thesis indicate that the proposed method is able to achieve a mapping performance similar to the performance-oriented approaches while maintaining the same low computation speed as more approximative methods.
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Chiconela, Domingos Rubão. „Geochemical exploration in tropical terrains with special reference to base metals“. Thesis, Rhodes University, 1996. http://hdl.handle.net/10962/d1005565.
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In tropical areas, the high rainfall induces severe-and pervasive weathering, producing a thick soil cover. The lithologies underneath may b~ recognised using geochemical mapping, which is based on certain elements that have the ability to differentiate between various lithologic units. Elements that are independent of the weathering process are normally selected for this purpose. The chemistry of mobility of base metals is an important factor to take into account when evaluating the mobility and distribution of these elements in a soil profile. Factors such as pH, Eh, organic material, clay minerals, Fe and Mn oxides are normally key aspects to be considered. When iron-rich rocks undergo deep weathering, lateritic profiles are developed. These are widespread in a belt bordering the equatorial zone, including the Brazilian shield, West and East Africa, parts of India and Northern Australia. In these profiles, the high rainfall promotes intense leaching of the different horizons. Where the pre-existing profiles are mostly preserved, the base metals are distributed throughout the profile: in the upper ferruginous horizon, goethite and hematite can adsorb large amounts of Mo, resulting in large dispersion halo. Other base metals such as Cu and Zn are less resistant in these freely-drained profiles and, therefore, they may be partly leached from the profile. In the lower horizons, Cu, ,zn, Ni and Co are retained, hosted in kaolinite and smectite, and thus, a high geochemical contrast will be identified in this horizon at the expense of a decline in the size of the dispersion haloes. The pre-existing profiles can be truncated, with a thin stone line developing at the contact between the lateritic profile and the recent soil. The conditions in these environments favour the retention of most of the pathfinder and target elements in all soil horizons, with the B horizon showing the highest contrast. If the primary rock is rich in AI, a bauxitic profile will be developed. The world distribution of bauxites closely resembles that of laterites. The behaviour of Co and Ni is very similar to that of iron during the bauxitization. Furthermore, the factors that induce residual enrichment of Al with removal of Fe in the soil profile will cause significant depletion of Co and Ni in these profiles. These metals are then concentrated at the base of the profile because of precipitation from downward percolating solutions. Many karst bauxite deposits in Southern Europe are enriched with Ni and Co in the basal horizon. Such horizon is mined as nickel ore in the bauxites of the Lokris region in Greece. Copper and molybdenum are strongly enriched.in bauxitic profiles. Concentration ratios are 8 and 3.2 for Cu and Mo respectively. Molybdenum is closely related to goethite and hematite, and therefore, the high concentration of Mo in a bauxitic profile will be consistent with the horizon where iron is concentrated. Copper concentrates at the base of the iron rich-horizon but also appears enriched in the saprolite together with Co. When sulphide bodies occur, in this environment, deep and penetrative weathering has resulted in considerable near-surface mobilization of iron and silica. The supergene alteration commonly obscures the identity of the primary sulphides at the surface. In this case, geochemical assessment of the resulting gossan has proved to be crucial in mineral exploration. A search in the secondary mineral assemblage, volatile and precious metals may lead to the information on the composition of the primary sulphide assemblage. The conclusion that will be reached is that if the geochemical properties (mobility, affinities with Fe or Mn oxides and/or clay minerals) of each of the base metals are understood, an appropriate sampling (optimum size-depth combination) will then be done. In such cases, a subdued, weak, but significant, geochemical response will be identified in the surface horizon.
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Vanapalli, Arun. „Montessori Grade 9 Students and Their Use of an Online Concept Mapping Website: A Case Study Exploration“. Thesis, Université d'Ottawa / University of Ottawa, 2019. http://hdl.handle.net/10393/39517.
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This study investigated the impact of an online concept mapping website (Concept Maps for Learning, or CMfL) designed to provide targeted formative feedback to students. The aims of this study were to determine the usefulness of CMfL for both teachers and students, as a tool for instruction and self-regulated learning. Additionally, the impacts of CMfL on supporting student learning were observed. This research site of this study was a Montessori high school, and the participating students were enrolled in the Ontario Grade 9 Academic Mathematics course. The educational philosophies deployed at the research site offered independence and flexibility to students with respect to how the Ontario Grade 9 Academic Mathematics course was approached, and therefore matched the self-regulated learning components of the study.
This study measured student achievement across three milestones over the data collection period to analyse any cognitive impact that CMfL had on the participating students. Metacognitive impacts, as well as the students’ perception of usefulness of CMfL, were measured through surveys that were administered at the milestone points. Usefulness of CMfL from the teacher’s perspective was determined through interviews with the teacher. The participating students and teacher were also provided with the opportunity to provide feedback on how CMfL could be improved through the aforementioned surveys and interviews, respectively.
The evidence collected over the study suggests that CMfL can be a useful tool for teaching and learning in a self-regulated environment, and that frequent engagement with CMfL may can support student learning. However, there is room for improvement that may increase student adoption and aid teaching strategy.
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Skabar, Andrew Alojz. „Inductive learning techniques for mineral potential mapping“. Thesis, Queensland University of Technology, 2001.
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Costa, Marco António Bernardino Raimundo. „Calibration, selection and mosaicing of SMART-1 AMIE images“. Master's thesis, Faculdade de Ciências e Tecnologia, 2013. http://hdl.handle.net/10362/10802.
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Dissertação para obtenção do Grau de Mestre em
Engenharia Electrotécnica e de ComputadoresSmall Missions for Advanced Research in Technology (SMART-1), represented European Space Agency (ESA) first mission to the moon. It fulfilled the goal of improving the scientific knowledge of earth’s natural satellite, while testing new technologies that had never been used in space exploration. Among the on board instruments of SMART-1 was the Advanced Moon micro-Imager Experiment (AMIE). It was an imaging equipment whose mission was to map the lunar surface providing state-of-the-art resolution. Containing six filters inside its visual scope AMIE allowed the study of the surface composition by multispectral imaging. This thesis aims at building a set of maps covering approximately all the Moon surface as it was mapped by the SMART-1 spacecraft, using the 31945 images captured by the AMIE instrument. During the Earth escape phase the instrument’s CCD was damaged by radiation, causing the accumulation of dark current and invalidating the laboratorial image calibration algorithm. The acquired dataset also suffered from scattered light that got beneath the CCD filters and reduced their contrast. In order to overcome this problem, a new calibration procedure was developed using the in-flight collected data and theoretical models, as well as a method to compensate for the reduced contrast in the filters. For building the lunar maps, the images were individually analysed and classified accordingly to their visual quality and grouped by their illumination conditions, allowing the creation of visually balanced maps. Image mosaicing and projection techniques were used to compensate the geometrical distortions and compose the calibrated images into a set of 88 maps of the Moon. Increasing the flexibility of the process, a comprehensive tool that allows the edition of the images in the mosaiced maps, as well as brightness and contrast correction and adjustment is also presented.
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Easton, Adam. „From mobile robot localisation to multi-robot exploration : a Gaussian approach to localisation and mapping in large environments“. Thesis, University of Oxford, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.442398.
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Hook, Simon John. „An evaluation of NS-001 and TIMS data for lithological mapping and mineral exploration in weathered vegetated terrain“. Thesis, Durham University, 1989. http://etheses.dur.ac.uk/6520/.
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This thesis evaluates the combined use of multispectral remotely sensed data from the 0.45-2.35µm and 8µm-12µm wavelength regions for lithological mapping and mineral exploration in weathered, vegetated terrain. The area studied is located in N. E. Queensland, Australia, and consists of a mixture of igneous, metamorphic and sedimentary rocks. The extrusive and intrusive igneous rocks of acid to intermediate composition are currently the focus of active exploration for gold mineralisation. The results from this study indicate data from the 0.45-2.35µm wavelength region are of more use for mineral exploration than data from the 8-12µm wavelength region in this terrain. Evaluation of data from the 0.45-2.35µm wavelength region resulted in the discovery of an area of epithermal alteration with potential for gold mineralisation at Blackfellow Mountain. Data from both wavelength regions proved useful for litholgical mapping but certain lithological units could only be discriminated with the data from the 8-12µm wavelength region. In order to obtain these results the data were reduced to physically meaningful parameters (reflectance, temperature and emittance). This necessitated the removal of radiometric and geometric distortions. The techniques used to remove these distortions are outlined, including two new methods for the removal of atmospheric effects from data from the 8-12µm wavelength region. After correction, the data from the 0.45-2.35µm wavelength region were analysed by a variety of techniques to extract the relevant reflectance information. These included compositing, channel ratios, log residuals, directed principal components and least squares fit residuals (LRES). The log residual and LRES techniques proved most effective for lithological mapping and mineral exploration respectively. The corrected data from the 8-12µm wavelength region were also analysed by several techniques for extracting emittance and temperature information. These techniques were the decorrelation stretch, model emittance calculation and thermal log residuals. The latter technique, developed during this study, proved most effective for lithological mapping.
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Chowdhury, Urmee. „An exploration of adult visitors' engagement in suburban neighbourhood park settings“. Thesis, Queensland University of Technology, 2022. https://eprints.qut.edu.au/235149/1/Urmee%2BChowdhury%2BThesis%281%29.pdf.
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Using an exploratory research design approach, this thesis aims to provide in-depth knowledge of adult visitors’ engagement in suburban neighbourhood parks. This research explored adult visitors’ behaviours and activities in park settings with integrated qualitative and quantitative analysis from the objective and subjective data. The findings revealed that adults engaged differently in the park spaces when compared by age groups, and multiple factors affecting park use could create opportunities for the social sustainability of the neighbourhood. The outcomes of this research are a contribution to park design and behavioural studies and have practical implications for leisure, urban and health studies.
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Farineau, Anne. „Diamonds in the Rough : Remote predictive mapping using multispectral satellite imagery for kimberlite exploration on northeast Banks Island, NT“. Thesis, Stockholms universitet, Institutionen för naturgeografi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-125966.
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This study demonstrates the use and limitations of Remote Predictive Mapping (RPM) as an aid to kimberlite exploration on northeast Banks Island, Northwest Territories, Canada. It focuses on the effectiveness of ASTER and Landsat 8 optical multi-spectral satellite imagery for discerning the spectral properties of different bedrock and surficial materials that outcrop or blanket the regional terrain. Statistical algorithms and digital image enhancement techniques were used to highlight patterns and anomalies within each scene in order to determine the range of materials and specific deposits (e.g., till, glaciofluvial) that could be the source of recovered kimberlite indicator minerals (KIMs) from stream sediment samples. Field inspection and sampling were in part guided by these patterns and anomalies. During the course of fieldwork, numerous outliers of the Pliocene Beaufort Formation fluvial sand and gravel deposits were discovered on upland surfaces in northeastern Banks Island. These outcrops sit well beyond (east) of any previous mapped Beaufort Fm. extents, and it is hypothesized that as they exist within catchments where Industry has recovered KIMs, they could be a source of bedrock-inherited KIMs. Field observations and spectral sampling using a portable spectroradiometer were integrated with ASTER and Landsat data to predict the spatial extents of Beaufort Fm. deposits. Using test and field-validated Beaufort Fm. sites, Spectral Angle Mapper (SAM) whole pixel spectral target detection was compared with Matched Filtering (MF), Mixture-Tuned Matched Filtering (MTMF) sub-pixel spectral target detection methods and Parallelepiped classification for ASTER scenes 1228 and 0686. Each method was also performed on ASTER scene 0541 to assess the potential for Quaternary sediment discrimination, using pixel ROIs from a field-validated glaciolacustrine deposit. The sub-pixel sensitivity of the MF/MTMF methods was determined to have the best potential for the discrimination of surficial materials on NE Banks Island. MF/MTMF also had the best results for discriminating Beaufort Fm. in scene 1228, but Parallelepiped classification was the most effective prediction method for scene 0686. These inconsistent results indicate spectral variability between Beaufort Fm. sites, a consideration for any further study in the region.
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Koorts, Christie. „A qualitative exploration and cognitive mapping of retail consumers sensitivity regarding the use of personal and behavioural information in relationship marketing tactics“. Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/97340.
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Thesis (MBA)--Stellenbosch University, 2015.ENGLISH ABSTRACT: In a global era of growing consumer economies, retailers rely extensively on the exploitation of consumers’ personal and behavioural information, in order to successfully execute and sustain their business models and strategic objectives. The gathering and mining of consumers’ personal and behavioural information represent tremendous potential in the application of relationship marketing tactics, towards consumer intimacy, and ultimately towards competitive advantage. However, in their quest to understand consumers better, retailers need to be acutely aware of consumers’ views regarding the gathering and use of their personal and behavioural information, in order to derive the associated benefits whilst mitigating the risk of alienating consumers. To this end, the main objective of this research assignment was to understand the thoughts and feelings of a selected sample of retail consumers, regarding the use of their personal and behavioural information in relationship marketing tactics. The research aim was achieved through a qualitative exploration of the thoughts and feelings of thirty millennial retail consumers who shared their individual views in written format and small group interviews. Cognitive mapping was used as the central technique for the coding and interpretation of written and interview data, depicting the central themes of consumer rationale, as well as the causal relationships of the concepts, which influenced their sentiment and decisions. The insights produced by the cognitive mappings were triangulated using additional techniques of sentiment analysis and word frequency analysis. The combination of research techniques produced robust overarching insights of universal value, coupled with insights of specific subtleties alluding to consumer groups with differentiated engagement needs. Universal insights included strong negative sentiment whenever consumer participants considered the possibility that retailers with whom they engage on the basis of their personal information could potentially share such personal information with third-party entities outside of their explicit or implicit relationship with a particular trusted retailer. Similarly, the personally intrusive nature of telemarketing as an engagement and communication channel was met with universal disdain at every mention thereof, clearly eliminating it as a viable channel for any retailer who would seek to build and sustain trusted consumer relationships. The sample of participants revealed four broad groups of millennial consumers, each with different preferences of engagement with retailers. The majority of the participants across two groups recognised a conditional and transactional basis for exchanging varying degrees of personal information for a variety of derived benefits. A small group of participants indicated a clear preference towards avoiding engagement on a personal basis and sharing of personal information with retailers. A similarly small group of participants exhibited general openness and willingness to engage retailers and share personal and behavioural information with little restraint or concern. The insights derived from this research assignment provide a solid foundational exploration for future research on the specific and related topics, whilst the application of the cognitive mapping technique provided profound multi-dimensional insights. Businesses stand to gain potential material benefit through the careful consideration of the terms of engagement with their consumers, as provided through the universal and specific insights of this research assignment.
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Sarraf, Niloufar. „Mapping the neural activities and affective dimensions of the ISP model: Correlates in the search exploration, formulation, and collection stages“. Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/127009/2/Niloufar_Sarraf_Thesis.pdf.
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The affective and neurological components of information retrieval system design have increasingly become an essential part of research in human-information interaction and interactive information retrieval. These sophisticated processes are composed of not only human cognitive processes but also emotional and neuropsychological responses. This research contributes three original findings to the field of Information Science, positioned in Neuro Information Science. This experimental research 1) mapped the neurophysiological dimensions of information search processes model, 2) integrated the three disciplines of Neuroscience, Information Science, and Cognitive Psychology, and 3) helped detect dimensions of emotions using EEG devices. This study collected brain frequencies through the EMOTIV EEG neuroheadset. The results indicated that there were clear differences in the brain frequencies/waves within different locations of the brain, depending on the ISP stage and the emotional state.
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Mahdoui, Chedly Nesrine. „Communicating multi-UAV system for cooperative SLAM-based exploration“. Thesis, Compiègne, 2018. http://www.theses.fr/2018COMP2447/document.
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Dans la communauté robotique aérienne, un croissant intérêt pour les systèmes multirobot (SMR) est apparu ces dernières années. Cela a été motivé par i) les progrès technologiques, tels que de meilleures capacités de traitement à bord des robots et des performances de communication plus élevées, et ii) les résultats prometteurs du déploiement de SMR tels que l’augmentation de la zone de couverture en un minimum de temps. Le développement d’une flotte de véhicules aériens sans pilote (UAV: Unmanned Aerial Vehicle) et de véhicules aériens de petite taille (MAV: Micro Aerial Vehicle) a ouvert la voie à de nouvelles applications à grande échelle nécessitant les caractéristiques de tel système de systèmes dans des domaines tels que la sécurité, la surveillance des catastrophes et des inondations, la recherche et le sauvetage, l’inspection des infrastructures, et ainsi de suite. De telles applications nécessitent que les robots identifient leur environnement et se localisent. Ces tâches fondamentales peuvent être assurées par la mission d’exploration. Dans ce contexte, cette thèse aborde l’exploration coopérative d’un environnement inconnu en utilisant une équipe de drones avec vision intégrée. Nous avons proposé un système multi-robot où le but est de choisir des régions spécifiques de l’environnement à explorer et à cartographier simultanément par chaque robot de manière optimisée, afin de réduire le temps d’exploration et, par conséquent, la consommation d’énergie. Chaque UAV est capable d’effectuer une localisation et une cartographie simultanées (SLAM: Simultaneous Localization And Mapping) à l’aide d’un capteur visuel comme principale modalité de perception. Pour explorer les régions inconnues, les cibles – choisies parmi les points frontières situés entre les zones libres et les zones inconnues – sont assignées aux robots en considérant un compromis entre l’exploration rapide et l’obtention d’une carte détaillée. À des fins de prise de décision, les UAVs échangent habituellement une copie de leur carte locale, mais la nouveauté dans ce travail est d’échanger les points frontières de cette carte, ce qui permet d’économiser la bande passante de communication. L’un des points les plus difficiles du SMR est la communication inter-robot. Nous étudions cette partie sous les aspects topologiques et typologiques. Nous proposons également des stratégies pour faire face à l’abandon ou à l’échec de la communication. Des validations basées sur des simulations étendues et des bancs d’essai sont présentéesIn the aerial robotic community, a growing interest for Multi-Robot Systems (MRS) appeared in the last years. This is thanks to i) the technological advances, such as better onboard processing capabilities and higher communication performances, and ii) the promising results of MRS deployment, such as increased area coverage in minimum time. The development of highly efficient and affordable fleet of Unmanned Aerial Vehicles (UAVs) and Micro Aerial Vehicles (MAVs) of small size has paved the way to new large-scale applications, that demand such System of Systems (SoS) features in areas like security, disaster surveillance, inundation monitoring, search and rescue, infrastructure inspection, and so on. Such applications require the robots to identify their environment and localize themselves. These fundamental tasks can be ensured by the exploration mission. In this context, this thesis addresses the cooperative exploration of an unknown environment sensed by a team of UAVs with embedded vision. We propose a multi-robot framework where the key problem is to cooperatively choose specific regions of the environment to be simultaneously explored and mapped by each robot in an optimized manner in order to reduce exploration time and, consequently, energy consumption. Each UAV is able to performSimultaneous Localization And Mapping (SLAM) with a visual sensor as the main input sensor. To explore the unknown regions, the targets – selected from the computed frontier points lying between free and unknown areas – are assigned to robots by considering a trade-off between fast exploration and getting detailed grid maps. For the sake of decision making, UAVs usually exchange a copy of their local map; however, the novelty in this work is to exchange map frontier points instead, which allow to save communication bandwidth. One of the most challenging points in MRS is the inter-robot communication. We study this part in both topological and typological aspects. We also propose some strategies to cope with communication drop-out or failure. Validations based on extensive simulations and testbeds are presented
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Vidal, Garcia Eduard. „Online 3D view planning for autonomous underwater exploration“. Doctoral thesis, Universitat de Girona, 2019. http://hdl.handle.net/10803/668814.
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Autonomous underwater vehicles are used nowadays in many applications. One of
the applications is mapping of a particular area of the ocean. Quen the robot
needs to cover the area of interest and no prior knowledge of the area to be
covered is avaialbe, a robotic exploration algorithm is used.
This thesis develops a robotic exploration algorithm for autonomous
underwater vehicles. The proposed algorithm allows the full exploration of a
2D or 3D environment, using acoustic sensors such as a scanning profiling sonar or a multibeam, and optical cameras.
The validity of the proposed algorithm is demonstrated through numerous
experiments carried out in different locations of the catalan coast, using
different vehicles and sensor suitesEls robots autònoms submarins s'utilitzen actualment en moltes aplicacions. Una d'elles és el mapeig d'una zona concreta de l'oceà. Quan el robot ha de cobrir la zona d'interès sense utilitzar informaciò prèvia sobre l'entorn a mapejar, s'utilitzen algorismes d'exploració robòtica. Aquesta tesi desenvolupa un algorisme d'exploració robòtica per a robots autònoms submarins. L'algorisme proposat permet explorar un entorn 2D o 3D en la seva totalitat, utilitzant sensors acústics, com per exemple un sonar perfilador o multifeix, i càmeres òptiques. La validesa de l'algorisme es demostra en experiments portats a terme a diferents entorns de la costa catalana, utilitzant múltiples vehicles i múltiples sensors
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Hamann, Maike. „Mapping social-ecological systems and human well-being : A spatial exploration of the links between people and the environment in South Africa“. Licentiate thesis, Stockholms universitet, Stockholm Resilience Centre, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-102860.
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It has become increasingly clear that dealing with present day environmental crises requires a holistic view that takes into account the interactions of social and ecological factors across multiple spatial and temporal scales. An example of where this new paradigm is being operationalized is the study of social-ecological systems. A substantial aspect of this growing research area aims to contribute to a more comprehensive understanding of the links between social-ecological systems, the ecosystem services they generate, and human well-being. This thesis summarizes the first part of a PhD project with the overall objective of unravelling some of these linkages using a mapping approach in South Africa, a country with high levels of social and ecological diversity. In the first paper, I present an approach to mapping social-ecological systems based on different bundles of ecosystem services. Mapping social-ecological systems has so far mainly been achieved by the overlay of separate social and ecological data. Here, I identify characteristic bundles of ecosystem services and use these bundle types as a proxy for different social-ecological systems in South Africa. The emergent pattern shows three distinct and spatially coherent systems that represent an overall low, medium and high level of ecosystem service use amongst households, and differs markedly from maps based on the overlay of social and ecological datasets. This approach not only identifies areas within South Africa where people are especially vulnerable to environmental changes that negatively affect ecosystem services, but also highlights areas in which distinctly different system dynamics operate in close proximity. It is especially in those areas where systems characterized by high and low dependence on ecosystem services lie side by side that nuanced and differentiated decision-making is required to sustainably manage ecosystem services in support of human well-being across all sectors of society. In the second paper I expand on the approach pioneered in Paper I by mapping human well-being bundles in South Africa. Mapping human well-being as bundles allows us to interrogate the trade-offs between different constituents of well-being at the sub-national scale, something that is not possible when measuring human well-being based on indicators or indices that reduce well-being to a single number. This approach also enables us to perform a spatial comparison between the levels of ecosystem service use (identified in Paper I) and human well-being, which signifies an important step forward in the development of quantitative tools for the analysis of the relationship between ecosystem services and human well-being at scales between the local and the national.Governance of ecosystem services under scenarios of change in southern and eastern Africa
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Merrick, Meg. „Opening Black Boxes and Following Traces: An Exploration of the Coalition for a Livable Future's Regional Equity Atlas Actor-World, 2003-2007“. PDXScholar, 2011. https://pdxscholar.library.pdx.edu/open_access_etds/298.
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Maps have longed been recognized as instruments of power and persuasion. With the recent proliferation of maps in the media and on the Internet has come an increasing desire among groups advocating for environmental and social change to have access to maps (the product) and mapping (the process) to more effectively promote their agendas. However, this is not as simple as it seems. Far from being neutral conduits of "truth," maps are constructed by a myriad of social interactions among heterogeneous actors (human and technical) that left unacknowledged can lead to an untapped potential of the power of maps. Adopting actor-network theory's (ANT) theoretical framework that accepts nonhuman entities as actors in the social, and its methodological protocols, this study contributes to the needed empirical evidence relating to the ways in which maps and mapping behave and function in society, particularly in the grassroots advocacy context and neighborhood scale, through a case study of the products, and thereby the process, of the Coalition for a Livable Future?s (CLF) Regional Equity Atlas four-year endeavor. The purpose of this study is to account for and expose the complexity of relations among data, technology, people, and organizations that underlie it and the ways in which these relations affected the atlas itself. Four interrelated themes emerge from this study. The first relates to CLF's contribution to equity mapping discourse including its participatory approach to equity mapping, its definition of equity, and the subsequent impacts of both of these things on the mapping process. The second relates more specifically to the contributions of the embedded ideologies that are integral to the GIS software that was used and the roles that they played. The third theme is the importance of process in community-based mapping projects and the recognition that they are social processes in the comprehensive sense that ANT theorists advocate. The fourth theme relates to how maps work, specifically, maps as maps versus the idea of maps.
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MacConville, Una. „Mapping a social landscape : an exploration of lay and professional understandings of a 'good death' and palliative care in an Irish setting“. Thesis, University of Bath, 2004. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.404710.
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This research has explored lay and professional understandings of a 'good death' and the spiritual dimension of care within a hospice in Ireland, and the extent to which culture shaped understanding. Palliative care has been largely developed in the UK and the U.S, societies with a strong emphasis on individualism, which is not present to the same extent in Ireland. No previous research has considered these aspects within palliative care in Ireland. The research has utilised a cartographic approach - as an organising principle, as a methodological approach and as a way of understanding the relationship between the individual and social aspects of a 'good death'. Death is an individual and a social experience in which family considerations and religious or spiritual beliefs play an important part. A central theme of relationship emerged in this research - relationships between the organisation, professional staff, the patient and the family all formed elements of a 'good death'. Spiritual care was considered as a role of accompaniment facilitated by a personal relationship between staff and the patient. Relationships were also shaped by the 'manners' of social engagement, and the location of care - at home, in the day care centre and in the inpatient unit - was influential. Palliative care professionals were visitors in the patient's home, and the patient and the family were visitors in the hospice. The person-centred approach of palliative care aided the formation of relationships; however, it also raised questions about their nature. This research has focused on the fine lines between aspects such as being person-centred and being too personal, between privacy and intrusion, observation and surveillance, communication and interrogation, and accompaniment and being led. The relationships between health care professionals and patients and family members have a cultural and historical specificity and these aspects have been explored.