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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Development of a synthetic vision system for general aviation

Wenger, Jason Christopher 01 January 2007 (has links)
Synthetic Vision is an aviation technology that uses databases and position estimation to establish a view of the database which provides an intuitive view that corresponds to the features of the outside world. The Synthetic Flight Bag is a low cost, portable system which implements synthetic vision, moving map, and route planning in a single software and hardware package. Human factors analysis was performed to identify appropriate functional requirements for the development of the system. Preliminary simulator testing identified requirements on screen size and mounting location with a mind to the cramped general aviation cockpit. Hardware survey identified appropriate computing platform targets. Hardware selected was a compact motherboard intended for embedded systems applications and graphics support. It was packaged into a custom-built avionics case, along with supporting power and I/O hardware. An LCD display with touch screen was designed and built, and represents the smallest, yet highest resolution display commercially available at this time. Software development led to a complete system with a primary flight display, multi function display, vertical profile display, and a menu and information system allowing for flight plan editing. A flight test aircraft was instrumented and outfitted with the Synthetic Flight Bag system. A ground simulator was also created for the purpose of training prior to flight test. VFR and IFR pilots participated in the study, and were evaluated on flight technical errors, workload, and eye movement. A flight test was performed, and results indicated that while the Synthetic Flight Bag system improves terrain awareness, it is not in its tested version a complete solution to the problem. The system was found to significantly improve the accuracy of flight, but was also found to increase workload in pilots not yet familiar with its operation. Several future improvements were identified, but the system as designed meets the project needs.
2

Implementation and evaluation of a general aviation synthetic vision display system

Burch, Douglas Paul January 2004 (has links)
No description available.
3

Performance Improvement Methods for Terrain Database Integrity Monitors and Terrain Referenced Navigation

Vadlamani, Ananth Kalyan 13 July 2004 (has links)
No description available.
4

On The Development Of In-Flight Autonomous Integrity Monitoring Of Stored Geo-Spatial Data Using Forward-Looking Remote Sensing Technology

Young, Steven D. 21 April 2005 (has links)
No description available.
5

Gradient-Based Steering for Vision-Based Crowd Simulation Algorithms / Gradient-Based Steering for Vision-Based Crowd Simulation Algorithms

TeÃfilo Bezerra Dutra 16 June 2015 (has links)
nÃo hà / Most recent crowd simulation algorithms equip agents with a synthetic vision component for steering. They offer promising perspectives by more realistically imitating the way humans navigate according to what they perceive of their environment. In this thesis, it is proposed a new perception/motion loop to steer agents along collision free trajectories that significantly improves the quality of vision-based crowd simulators. In contrast with previous solutions - which make agents avoid collisions in a purely reactive way - it is suggested exploring the full range of possible adaptations and to retain the locally optimal one. To this end, it is introduced a cost function, based on perceptual variables, which estimates an agentâs situation considering both the risks of future collision and a desired destination. It is then computed the partial derivatives of that function with respect to all possible motion adaptations. The agent adapts its motion to follow the steepest gradient. This thesis has thus two main contributions: the definition of a general purpose control scheme for steering synthetic vision-based agents; and the proposition of cost functions for evaluating the dangerousness of the current situation. Improvements are demonstrated in several cases. / Alguns dos algoritmos mais recentes para simulaÃÃo de multidÃo equipam agentes com um sistema visual sintÃtico para auxiliÃ-los em sua locomoÃÃo. Eles oferecem perspectivas promissoras ao imitarem de forma mais realista a forma como os humanos navegam de acordo com o que eles percebem do seu ambiente. Nesta tese, à proposto um novo laÃo de percepÃÃo/aÃÃo para dirigir agentes ao longo de trajetÃrias livres de colisÃes que melhoram significativamente a qualidade dos simuladores de multidÃo baseados em visÃo. Em contraste com abordagens anteriores - que fazem agentes evitarem colisÃes de maneira puramente reativa - à sugerida a exploraÃÃo de toda gama de adaptaÃÃes possÃveis e a retenÃÃo da que for Ãtima localmente. Para isto, à introduzida uma funÃÃo de custo, baseada em variÃveis de percepÃÃo, que estima a situaÃÃo atual do agente considerando tanto os riscos de futuras colisÃes como o destino desejado. SÃo entÃo computadas as derivadas parciais dessa funÃÃo com respeito a todas adaptaÃÃes de movimento possÃveis. O agente adapta seu movimento de forma a seguir o gradiente descendente. Esta tese possui assim duas principais contribuiÃÃes: a definiÃÃo de um esquema de controle de propÃsito geral para a orientaÃÃo de agentes baseados em visÃo sintÃtica; e a proposiÃÃo de funÃÃes de custo para avaliar o perigo da situaÃÃo atual. As melhorias obtidas com o modelo sÃo demonstradas em diversos casos.
6

Gradient-Based Steering for Vision-Based Crowd Simulation Algorithms / Gradient-Based Steering for Vision-Based Crowd Simulation Algorithms

Dutra, Teófilo Bezerra January 2015 (has links)
DUTRA, Teófilo Bezerra. Gradient-Based Steering for Vision-Based Crowd Simulation Algorithms. 2015. 122 f. Tese (Doutorado em Ciência da Computação)-Universidade Federal do Ceará, Fortaleza, 2015. / Submitted by Vitor Campos (vitband@gmail.com) on 2016-09-28T21:38:15Z No. of bitstreams: 1 2015_tese_tfdutra.pdf: 18611468 bytes, checksum: efc5f80ee6b8df68191af2bca394a07a (MD5) / Approved for entry into archive by Jairo Viana (jairo@ufc.br) on 2016-09-28T22:54:58Z (GMT) No. of bitstreams: 1 2015_tese_tfdutra.pdf: 18611468 bytes, checksum: efc5f80ee6b8df68191af2bca394a07a (MD5) / Made available in DSpace on 2016-09-28T22:54:58Z (GMT). No. of bitstreams: 1 2015_tese_tfdutra.pdf: 18611468 bytes, checksum: efc5f80ee6b8df68191af2bca394a07a (MD5) Previous issue date: 2015 / Most recent crowd simulation algorithms equip agents with a synthetic vision component for steering. They offer promising perspectives by more realistically imitating the way humans navigate according to what they perceive of their environment. In this thesis, it is proposed a new perception/motion loop to steer agents along collision free trajectories that significantly improves the quality of vision-based crowd simulators. In contrast with previous solutions - which make agents avoid collisions in a purely reactive way - it is suggested exploring the full range of possible adaptations and to retain the locally optimal one. To this end, it is introduced a cost function, based on perceptual variables, which estimates an agent’s situation considering both the risks of future collision and a desired destination. It is then computed the partial derivatives of that function with respect to all possible motion adaptations. The agent adapts its motion to follow the steepest gradient. This thesis has thus two main contributions: the definition of a general purpose control scheme for steering synthetic vision-based agents; and the proposition of cost functions for evaluating the dangerousness of the current situation. Improvements are demonstrated in several cases. / Alguns dos algoritmos mais recentes para simulação de multidão equipam agentes com um sistema visual sintético para auxiliá-los em sua locomoção. Eles oferecem perspectivas promissoras ao imitarem de forma mais realista a forma como os humanos navegam de acordo com o que eles percebem do seu ambiente. Nesta tese, é proposto um novo laço de percepção/ação para dirigir agentes ao longo de trajetórias livres de colisões que melhoram significativamente a qualidade dos simuladores de multidão baseados em visão. Em contraste com abordagens anteriores - que fazem agentes evitarem colisões de maneira puramente reativa - é sugerida a exploração de toda gama de adaptações possíveis e a retenção da que for ótima localmente. Para isto, é introduzida uma função de custo, baseada em variáveis de percepção, que estima a situação atual do agente considerando tanto os riscos de futuras colisões como o destino desejado. São então computadas as derivadas parciais dessa função com respeito a todas adaptações de movimento possíveis. O agente adapta seu movimento de forma a seguir o gradiente descendente. Esta tese possui assim duas principais contribuições: a definição de um esquema de controle de propósito geral para a orientação de agentes baseados em visão sintética; e a proposição de funções de custo para avaliar o perigo da situação atual. As melhorias obtidas com o modelo são demonstradas em diversos casos.
7

Algoritmo de vergencia para o controle de atenção de humanos virtuais

Carvalho, Schubert Ribeiro de 01 July 2005 (has links)
Orientador: Luiz Marcos Garcia Gonçalves / Dissertação (mestrado) - Universidade Estadual de Campinas. Instituto de Computação / Made available in DSpace on 2018-08-04T04:15:38Z (GMT). No. of bitstreams: 1 Carvalho_SchubertRibeirode_M.pdf: 2825282 bytes, checksum: 353ef9bd3c20fd58cf381620ea7f7f86 (MD5) Previous issue date: 2005 / Resumo: Os problemas de pesquisa mais comuns abordados na literatura sobre Humanos Virtuais são mais relacionados com a inserção e representação destes agentes gráficos no computador. Com o avanço das tecnologias e pesquisas nas áreas de computação gráfica e realidade virtual, novos problemas podem ser tratados, em relação as funcionalidades destes agentes virtuais. Atualmente, um dos principais desafios está associado ao desenvolvimento de humanos virtuais dotados de percepção visual realística. Um problema específico, referente a visão sintética destes agentes, é o controle da atenção, ou seja, definir e prover uma maneira eficiente e natural para que ele mude seu foco de atenção de uma posição corrente para outra no seu ambiente virtual. A coordenação dos movimentos da cabeça do agente, fazendo com que os olhos sejam fixados no objeto desejado, não é considerada uma tarefa trivial e está relacionada com a percepção de profundidade do ambiente. Neste trabalho, propomos um algoritmo de vergência, usado para o controle da atenção de humanos virtuais, onde o parâmetro de profundidade é obtido do Z-buffer. O controle dos movimentos da cabeça do humano virtual é executado com a realização de simples cálculos geométricos e no final do processo de vergência, os olhos são fixados corretamente em qualquer região de interesse do ambiente, passada previamente para o agente virtual / Abstract: Common research problems treated in literature about Virtual Humans are most related with insertion and representation of these graphic agents in computers. With techological advance and new researches in Computer Graphics and Virtual Reality, new problems can have place, related to the funcionality of the virtual agents. Currently, one of the main challenges is associated to development of virtual humans with realistic virtual perception and a specific problem that appears, related to synthetic vision in these agents, is the proper control of attention. That is, to define and provide an efficient and natural manner for it to change attentional focus from a current position to another one in its virtual environrnent. Coordination of head movements by way of fixation of eyes in a desired object is not considered a trivial task, being related to depth perception. In this work, we propose an algorithm for vergence, used for attention control in virtual humans, where the depth parameter is obtained from Z-buffer. Control of virtual human head movements is preformed with simple geometric calculations and at the end of vergence process the eyes are correctly fixed in any interest region of the environment, previously given to the virtual agent / Mestrado / Ciência da Computação / Mestre em Ciência da Computação
8

Characteristics of a real-time digital terrain database Integrity Monitor for a Synthetic Vision System

Campbell, Jacob January 2001 (has links)
No description available.
9

Hardware Design And Certification Aspects Of A Field Programmable Gate Array-Based Terrain Database Integrity Monitor For A Synthetic Vision System

Kakkeroda, Anupriya 18 December 2004 (has links)
No description available.
10

Modelagem de percepção de humanos virtuais baseada em dados geométricos e ray-casting

Pletsch, Eliéser Lourega 30 May 2006 (has links)
Made available in DSpace on 2015-03-05T13:56:58Z (GMT). No. of bitstreams: 0 Previous issue date: 30 / Nenhuma / Este trabalho apresenta um modelo de percepção de dados não visíveis (por exemplo, olfativas e auditivas) para humanos virtuais baseado em informações puramente geométricas existentes em ambientes virtuais. Esta proposta procurou contextualizar vários tópicos de pesquisa no que diz respeito a agentes autônomos em ambientes virtuais e suas capacidades de percepção. Procurou-se, através da área da visão sintética, encontrar métodos que pudessem ser generalizados para que outros sentidos pudessem ser simulados. O objetivo principal deste modelo é possibilitar que o agente possa identificar diferentes ocorrências de eventos dentro de um ambiente virtual, no que diz respeito às informações não necessariamente visuais, como por exemplo, a presença de cheiros ou barulhos. Para o modelo, foram buscados métodos que proporcionem um bom desempenho computacional e que sejam facilmente generalizados e implementados de maneira a prover métodos de percepção a multidões de humanos virtuais / This work presents a perception data model which deals with not visible information (such as hearing and smelling). This model is based on geometric information that exists in the virtual environment. This proposal also identifies several research topics related to autonomous agents in virtual environments and their perception abilities. Investigations in synthetic vision area allows to find methods that could be generalized in order to be used for other sensors. Therefore, the main objective of this model is to allow to the agents the possibility of identifying different events, into a virtual environment, not necessarily visual data. For instance, the presence of smell and noise. In addition, we propose methods which aims to provide a good computational performance and which can be generalized and implemented in a way that they can provide the perception methods to virtual human beings.

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