Results 181 to 190 of about 135,008 (218)
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Linear bearing device as a solution for optical navigation of fine needle procedures
Technology and Health Care, 2010Background: Optical navigation of needles < 1 mm diameter remains a challenging task. Bending of these tools is the limiting factor. Objective: To use a conventional optical navigation system for interventional fine needle procedures. Materials and methods: A novel custom-made device was constructed to guide the needle in the direction of the planned ...
Stüber, Volker +6 more
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Joint Line Changes After Navigation-Assisted Mobile-Bearing TKA
Orthopedics, 2009The purpose of this study was to analyze the clinical results of patients who underwent navigation-assisted cruciate ligament retention-type mobile-bearing total knee arthroplasty (TKA) according to joint line changes. From September 2004 to January 2006, cruciate ligament retention-type mobile-bearing TKAs were performed using a navigation system ...
Jae-Hyuk, Yang +3 more
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Trajectory characterizations for a discrete-time bearing-only navigation strategy
2008 16th Mediterranean Conference on Control and Automation, 2008In this paper we explore the geometry of a particular navigation scheme which guides a pursuer from a fixed initial position to a given fixed final position using a one-step look ahead strategy and using only bearing measurements. We explicitly characterize the optimal trajectories for the problem in terms of the Cramer-Rao bound such that the derived ...
Adrian N. Bishop, Pubudu N. Pathirana
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Observability Criteria and Unobservable Maneuvers for In-Orbit Bearings-Only Navigation
Journal of Guidance, Control, and Dynamics, 2014This paper provides an analytical derivation of the observability conditions for in-orbit bearings-only navigation that can also be used to solve for the conditions under which unobservable maneuvers occur. The derivation is performed in a rigorous yet relatively simple manner by attempting to solve for the initial conditions in a discrete formulation ...
Jonathan Grzymisch, Walter Fichter
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Computer Navigation: Improving Outcomes with Hard on Hard Bearings
2007The design and manufacture of ceramic implants has improved significantly over the last decade. Consequently the use of ceramic-on-ceramic bearings in total hip replacement has become increasingly popular with over 150,000 components having been implanted in Europe [1].
Robert G. Middleton +2 more
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One-step rendezvous guidance for improving observability in bearings-only navigation
Advances in Space Research, 2020Abstract In spacecraft rendezvous, bearings-only navigation generally suffers from a lack of observability in range direction. Therefore, dedicated orbital maneuvers are essential to improve the observability and meet the navigation requirement. This paper proposes a simple one-step guidance method for improving observability.
Sung-Hoon Mok +2 more
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Nonlinear pseudo-measurement filtering for in-orbit bearings-only navigation
IEEE Transactions on Aerospace and Electronic Systems, 2015In-orbit rendezvous is a key enabling technology for many space missions that already enjoys significant heritage. However, complex hardware is generally required in order to measure the relative range. Achieving rendezvous employing only bearing/angle measurements would simplify the relative navigation hardware currently required, increasing ...
Jonathan Grzymisch, Walter Fichter
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Navigated lower limb axis measurements: Influence of mechanical weight‐bearing simulation
Journal of Orthopaedic Research, 2007AbstractSuccessful outcomes following high tibial osteotomy (HTO) require precise realignment of the mechanical axis of the lower extremity. The inability to accurately assess the weight‐bearing axis intraoperatively may account for inappropriate degrees of correction with the osteotomy.
Daniel, Kendoff +7 more
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GES source localization and navigation based on discrete-time bearing measurements
52nd IEEE Conference on Decision and Control, 2013This paper addresses the problems of source localization and navigation based on discrete-time single direction measurements, in 3-D, in addition to relative velocity readings. For source localization, an agent aims at estimating the position of a source relative to itself, while for navigation the agents aims to estimate its own position assuming that
Pedro Batista +2 more
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Track initiation of bearings-only tracking based on ant navigation concept
Communications in Nonlinear Science and Numerical Simulation, 2010Abstract A novel heuristic track initiation method is developed for the bearing-only multi-sensor–multi-target tracking system, in which each target is assumed to move with a straight line. The key idea of the proposed method is derived from the ant navigation concept in its foraging life, which differs from the traditional ant colony optimization ...
Jihong Zhu, Benlian Xu, Zhiquan Wang
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