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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.
11

Avaliação da efetividade da protração maxilar com ancoragem intrabucal para correção da má oclusão classe III durante a fase de crescimento craniofacial / Evaluation of the effectiveness of maxilar protraction with intrabucal anchorage for the correction of male class III malocclusion during the phase of maxillary growth with intrabucal anchorage

Teodoro, Joana Teresa Guimarães [UNESP] 31 August 2018 (has links)
Submitted by Joana Teresa Guimarães Teodoro (jtg.teodoro@unesp.br) on 2018-10-19T12:24:39Z No. of bitstreams: 1 AVALIAÇÃO DA EFETIVIDADE DA PROTRAÇÃO MAXILAR COM ANCORAGEM INTRABUCAL PARA CORREÇÃO DA MÁ OCLUSÃO CLASSE III DURANTE A FASE DE CRESCIMENTO CRANIOFACIAL.pdf: 2222757 bytes, checksum: c102ed86466525d299b137781d839a62 (MD5) / Approved for entry into archive by Ana Paula Rimoli de Oliveira null (anapaula@foa.unesp.br) on 2018-10-19T12:44:20Z (GMT) No. of bitstreams: 1 teodoro_jtg_me_araca_int.pdf: 2222757 bytes, checksum: c102ed86466525d299b137781d839a62 (MD5) / Made available in DSpace on 2018-10-19T12:44:20Z (GMT). No. of bitstreams: 1 teodoro_jtg_me_araca_int.pdf: 2222757 bytes, checksum: c102ed86466525d299b137781d839a62 (MD5) Previous issue date: 2018-08-31 / Introdução: O tratamento da má oclusão Classe III em pacientes em crescimento é um desafio pela estabilidade e colaboração do paciente. A etilologia da Classe III pode ser por natureza esquelética, genética e fatores ambientais. Os aspectos encotrados são deficiência maxilar com mandíbula bem posicionada ou protruída da sua base ósseas, maxila bem posicionada com prognatismo mandibular ou a combinação de retrognatismo maxilar com prognatismo mandibular. A deficiência de maxila é frequentemente encontrada em pacientes com má oclusão Classe III sendo o tratamento indicado, a protração maxilar. Material e métodos: Foram selecionadas 8 crianças na faixa etária de 7 a 10 anos, com características faciais e esqueléticas para Classe III. Como terapêutica ortopédica, foi utilizado o aparelho expansor tipo Hyrax modificado com ganchos soldados na mesial dos segundos molares decíduos e primeiros molares permanentes. Para o inferior foi um arco lingual de Nance modificado com ganchos soldados na altura de caninos e segundos molares decíduos. O protocolo para disjunção maxilar com dois quartos de volta por dia em média de 7 a 10 dias, em seguida indicado o uso de elásticos para Classe III 3/16” de força média na primeira semana e a partir da segunda semana, elásticos 1/8” médio de cada lado da arcada até a correção da mordida cruzada anterior. Para a análise dos efeitos dentoesqueléticos foram usadas as teleradiografias iniciais (T1), as obtidas após a correção da MCA (T2) e as telerradiografias realizadas após três meses após a correção (T3). Resultados: De acordo com a mecânica proposta e metodologia aplicada, conclui-se que, no Aspecto dentoalveolar: 1.PlMx – constante, 1.NA – favorável, 1.NB – favorável, 1/.NS – constante, IMPA – favorável, 1/./1 - desfavorável. Posição da bases ósseas: SNA – desfavorável. SNB – favorável, Nperp-Pog – favorável, Nperp-A - constante. Posição maxilo mandibular: ANB – favorável, CoGn – favorável, Co-A – favorável. Análise vertical: AFAI – constante, FMA – desfavorável, SN.Go-Gn – favorável. Análise do perfil facial: ANL – favorável. Conclusão: A correção da Classe III provocou alterações dentoalveolares principalmente a vestibularização dos incisivos superiores; alterações esqueléticas sendo predominante a manutenção da posição mandibular e o perfil se modificou tornando-se mais convexo. / Introduction: Treatment of Class III malocclusion in growing patients is a challenge for patient stability and collaboration. Class III etiology may be by skeletal, genetic, and environmental factors. The aspects found are maxillary deficiency with well positioned or protruding mandible of its base bone, maxilla well positioned with mandibular prognathism or the combination of maxillary retrognathism with mandibular prognathism. Jaw deficiency is often found in patients with Class III malocclusion and the indicated treatment is maxillary protraction. Material and methods: We selected 8 children aged 7 to 10 years, with facial and skeletal characteristics for Class III. As an orthopedic therapy, the modified Hyrax type expander was used with welded hooks in the mesial of the second deciduous and first permanent molars. For the lower one was a lingual arch of Nance modified with welded hooks at the height of deciduous canines and second molars. The protocol for maxillary disjunction with two quarters of a turn in a mean of 7 to 10 days, then indicated the use of Class III 3/16 "elastic force in the first week and from the second week, elastic 1 / 8 "on each side of the arcade until the correction of the anterior crossbite. The initial teleradiographs (T1), those obtained after correction of the MCA (T2) and the cephalograms performed three months after the correction (T3) were used to analyze the dento-skeletal effects. Results: According to the proposed mechanics and applied methodology, it is concluded that, in the dentoalveolar aspect: 1.PlMx - constant, 1.NA - favorable, 1.NB - favorable, 1 / .NS - constant, IMPA - 1 /./ 1 - unfavorable. Position of the bony bases: SNA - unfavorable. SNB - favorable, Nperp-Pog - favorable, Nperp-A - constant. Mandibular maxillary position: ANB - favorable, CoGn - favorable, Co-A - favorable. Vertical analysis: AFAI - constant, FMA - unfavorable, SN.Go-Gn - favorable. Analysis of facial profile: ANL - favorable. Conclusion: Class III correction caused dentoalveolar changes, mainly vestibularization of maxillary incisors; skeletal changes being predominant the maintenance of the mandibular position, and the profile changed becoming more convex.
12

An Integrated Estimation-Guidance Approach for Seeker-less Interceptors

Saroj Kumar, G January 2015 (has links) (PDF)
In this thesis, the problem of intercepting highly manoeuvrable threats using seeker-less interceptors that operate in the command guidance mode, is addressed. These systems are more prone to estimation errors than standard seeker-based systems. Several non-linear and optimal estimation and guidance concepts are presented in this thesis for interception of randomly maneuvering targets by seeker-less interceptors. The key contributions of the thesis can be broadly categorized into six groups, namely (i) an optimal selection of bank of lters in interactive multiple model (IMM) scheme to cater to various maneuvers that are expected during the end-game, (ii) an innovative algorithm to reduce chattering phenomenon and formulate effective guidance algorithm based on 'differential game guidance law' (modi ed DGL), (iii) IMM/DGL and IMM/modified DGL based integrated estimation/guidance (IEG) strategy, (iv) sensitivity and robustness analysis of Kalman lters and ne tuning of lters in filter bank using innovation covariance, (v) Performance of tuned IMM/PN, tuned IMM/DGL and tuned IMM/modi ed DGL against various target maneuvers, (vi) Performance comparison with realistic missile model. An innovative generalized state estimation formulation has been proposed in this the-sis for accurately estimating the states of incoming high speed randomly maneuvering targets. The IMM scheme and an optimal selection of lters, to cater to various maneu-vers that are expected during the end-game, is described in detail. The key advantage of this formulation is that it is generic and can capture evasive target maneuver as well as straight moving targets in a uni ed framework without any change of target model and tuning parameters. In this thesis, a game optimal guidance law is described in detail for 2D and 3D engagements. The performance of the differential game based guidance law (DGL) is compared with conventional Proportional Navigation (PN) guidance law, especially for 3D interception scenarios. An innovative chatter removal algorithm is introduced by modifying the differential game based guidance law (modified DGL). In this algorithm, chattering is reduced to the maximum extent possible by introducing a boundary layer around the switching surface and using a continuous control within the boundary layer. The thesis presents performance of the modified DGL algorithm against PN and DGL, through a comparison of miss distances and achieved accelerations. Simulation results are also presented for varying fiight path angle errors. Apart from the guidance logic, two novel ideas have been presented following the evolving "integrated estimation and guidance" philosophy. In the rst approach, an in-tegrated estimation/guidance (IEG) algorithm that integrates IMM estimator with DGL law (IMM/DGL), is proposed for seeker-less interception. In this interception scenario, the target performs an evasive bang-bang maneuver, while the sensor has noisy measure-ments and the interceptor is subject to an acceleration bound. The guidance parameters (i.e., the lateral acceleration commands) are computed with the help of zero e ort miss distance. The thesis presents the performance of the IEG algorithm against combined IMM with PN (IMM/PN), through a comparison of miss distances. In the second ap-proach, a novel modi ed IEG algorithm composed of IMM estimator and modi ed DGL guidance law is introduced to eliminate the chattering phenomenon. Results from both of these integrated approaches are quite promising. Monte Carlo simulation results re-veal that modi ed IEG algorithm achieves better homing performance, even if the target maneuver model is unknown to the estimator. These results and their analysis o er an insight to the interception process and the proposed algorithms. The selection of lter tuning parameters puts forward a major challenge for scien-tists and engineers. Two recently developed metrics, based on innovation covariance, are incorporated for determining the filter tuning parameters. For predicting the proper combination of the lter tuning parameters, the metrics are evaluated for a 3D interception problem. A detailed sensitivity and robustness analysis is carried out for each type of Kalman lters. Optimal and tuned Kalman lters are selected in the IMM con guration to cater to various maneuvers that are expected during the end-game. In the interception scenario examined in this thesis, the target performs various types of maneuvers, while the sensor has noisy measurements and the interceptor is subject to acceleration bound. The tuned IMM serves as a basis for synthesis of e cient lters for tracking maneuvering targets and reducing estimation errors. A numerical study is provided which demonstrates the performance and viability of tuned IMM/modi ed DGL based modi ed IEG strategy. In this thesis, comparison is also performed between tuned IMM/PN, tuned IMM/DGL and tuned IMM/modi ed DGL in integrated estimation/guidance scheme. The results are illustrated by an extensive Monte Carlo simulation study in the presence of estimation errors. Simulation results are also presented for end game maneuvers and varying light path angle errors . Numerical simulations to study the aerodynamic e ects on integrated estimation/ guidance structure and its e ect on performance of guidance laws are presented. A detailed comparison is also performed between tuned IMM/PN, tuned IMM/DGL and tuned IMM/modi ed DGL in integrated estimation/guidance scheme with realistically modelled missile against various target maneuvers. Though the time taken to intercept is higher when a realistic model is considered, the integrated estimation/guidance law still performs better. The miss distance is observed to be similar to the one obtained by considering simpli ed kinematic models.
13

TELEMETRY IN THEATER MISSILE DEFENSE DEVELOPMENT

Toole, Michael T. 10 1900 (has links)
International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / Since the Gulf War, there has been significant interest in Theater Missile Defense (TMD) resulting in funding growth from tens of millions of dollars at the time of the Gulf War to $1.7 Billion in 1994. The Ballistic Missile Defense Organization (BMDO) has developed a Theater Missile Defense test and evaluation program that will assess technological feasibility and the degree to which system functionality and performance meet technical and operational requirements. The complexity of the TMD program necessitates a comprehensive test program which includes flight testing, ground testing, and modeling and simulation. This article will provide and overview the requirements and capabilities needed to satisfy these requirements. The data processing, and telemetry communities will play a major role in providing the expertise to support the development of the nation’s future Theater Missile Defense capabilities.

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