Orbits
Mostrando 1-12 de 185 artigos, teses e dissertações.
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1. Adjunctive Middle Turbinectomy for Endoscopic Medial Orbital Wall – Thyroid Eye Disease Decompression
Abstract Introduction Middle turbinate resection (MTR) is commonly performed during endonasal endoscopic sinus and skull base surgery. Objective The purpose of this study was to characterize the additional orbital soft-tissue volume expansion during endoscopic medial orbital wall decompression with adjunctive MTR. Methods A retrospective review of patient
International Archives of Otorhinolaryngology. Publicado em: 2022
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2. Computed tomography based analysis of the lamina papyracea variations and morphology of the orbit concerning endoscopic surgical approaches
Resumo Introdução: A avaliação radiológica é mandatória para avaliar o tipo de abordagem endoscópica no tratamento cirúrgico de doença nasossinusal e na reconstrução de fraturas antes de quaisquer modalidades de tratamento relacionadas à parede medial orbital. Objetivo: O objetivo foi proporcionar uma melhor compreensão das variações da lâ
Braz. j. otorhinolaryngol.. Publicado em: 07/11/2019
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3. A Precise Algorithm for Computing Sun Position on a Satellite
ABSTRACT: To meet the high precision sun tracking needs of a space deployable membrane solar concentrator and other equipment, an existing algorithm for accurately computing the sun position is improved. Firstly, compared with other theories, the VSOP (variation seculaires des orbits planetaires) 87 theory is selected and adopted to obtain the sun position i
J. Aerosp. Technol. Manag.. Publicado em: 26/08/2019
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4. REAL TIME PPP APPLIED TO AIRPLANE FLIGTHT TESTS
Abstract The availability in real time of GNSS satellites orbits, clock corrections and code and phase biases provided the possibility of application of Real Time Precise Point Positioning (RTPPP). This paper presents the methodology concerning RTPPP and application to kinematic trajectories of airplane flight tests, but without using the carrier phase bias.
Bol. Ciênc. Geod.. Publicado em: 10/07/2019
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5. Sensitivity Analysis of Flexible Rotor Subjected to Interval Uncertainties
Abstract This paper aims at analyzing the sensitivity of the structural response of flexible rotors subjected to uncertain interval parameters. The interval approach encompasses both an uncertainty and sensitivity analyses. The uncertainty analysis consists in computing the interval uncertain structural responses by using the global optimization method. The
Lat. Am. j. solids struct.. Publicado em: 13/05/2019
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6. Multi-objective Optimization Method For Repeat Ground-track Orbit Design Considering the Orbit Injection Error
ABSTRACT: Considering the adverse effects of orbit injection error, a novel repeat ground-track orbit redesign approach is proposed to reduce the fuel consumption caused by the orbital maneuvering from the injection orbit to the nominal orbit. By introducing the performance indexes of revisiting accuracy and orbit injection maneuvering fuel consumption, the
J. Aerosp. Technol. Manag.. Publicado em: 07/06/2018
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7. Analytical Solution for Optimal Low-Thrust Limited-Power Transfers Between Non-Coplanar Coaxial Orbits
ABSTRACT: In this paper, an analytical solution for time-fixed optimal low-thrust limited-power transfers (no rendezvous) between elliptic coaxial non-coplanar orbits in an inverse-square force field is presented. Two particular classes of maneuvers are related to such transfers: maneuvers with change in the inclination of the orbital plane and maneuvers wit
J. Aerosp. Technol. Manag.. Publicado em: 03/05/2018
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8. Periodic complex map germs and foliations
Abstract In this paper we study topological and analytical conditions on the orbits of a germ of diffeomorphism in the complex plane in order to obtain periodicity. In particular, we give a simple proof of a finiteness criteria for groups of analytic diffeomorphisms, stated in Brochero Martínez 2003. As an application, we derive some consequences about the
An. Acad. Bras. Ciênc.. Publicado em: 2017-12
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9. Analysis of the Dynamic Behavior of a Rotating Composite Hollow Shaft
Abstract In the present paper, a simplified homogenized beam theory is used in the context of a numerical investigation regarding the dynamic behavior of a rotating composite hollow shaft. For this aim, a horizontal flexible composite shaft and a rigid disc form the considered simple supported rotating system. The mathematical model of the rotor is derived f
Lat. Am. j. solids struct.. Publicado em: 2017-01
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10. Picosatellites for Maritime Security Applications - the Lambdasat Case
ABSTRACT: This study explores the potential deployment of small satellites for maritime interdiction and security applications by investigating the available solutions and formulating a generic proposal to optimize the use of those short-lived space assets in support of these operations. The operational background is analyzed with respect to the potential us
J. Aerosp. Technol. Manag.. Publicado em: 2015-12
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11. Uncertainty analysis of flexible rotors considering fuzzy parameters and fuzzy-random parameters
Abstract The components of flexible rotors are subjected to uncertainties. The main sources of uncertainties include the variation of mechanical properties. This contribution aims at analyzing the dynamics of flexible rotors under uncertain parameters modeled as fuzzy and fuzzy random variables. The uncertainty analysis encompasses the modeling of uncertain
Lat. Am. j. solids struct.. Publicado em: 2015-10
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12. Uncertainty analysis of a flexible rotor supported by fluid film bearings
AbstractThis paper is dedicated to the analyses of the effect of uncertain parameters on the dynamic behavior of a flexible rotor containing two rigid discs and supported by two fluid film bearings. A stochastic method has been extensively used to model uncertain parameters, i.e., the so-called Monte Carlo simulation. However, in the present contribution, th
Lat. Am. j. solids struct.. Publicado em: 2015-08