Results 171 to 180 of about 17,680 (216)
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Optimal probe position for precordial Doppler ultrasound in children
Pediatrics International, 2022AbstractBackgroundPrecordial Doppler ultrasound technology can be used to confirm correct peripheral intravenous access in children. Changes in precordial Doppler sound from the baseline after injecting normal saline are detected using a correct peripheral intravenous access.
Keisuke Nishida +2 more
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DOPPLER POSITIONING IN THE INDIAN OCEAN
Survey Review, 1983Abstract Many papers have been written on the theory of Doppler Satellite positioning techniques and equipment. In contrast the following article details the practical use of such instruments with reference to work carried out in the Indian Ocean.
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Tracking with converted position and Doppler measurements
SPIE Proceedings, 2011In many target tracking applications, estimation of target position and velocity is performed in Cartesian coordinates. Use of Cartesian coordinates for estimation stands in contrast to the measurements, which are traditionally the range, azimuth and elevation measurements of the spherical coordinate system.
Steven V. Bordonaro +2 more
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Doppler Effect in Positive Rays of Hydrogen
Nature, 1944THE Balmer lines in the spectra of the positive rays of hydrogen show Doppler displacement dλ given by the relation where λ is the wave-length of the light emitted by a neutral atom of the positive ray beam, moving with a velocity ν, the direction of motion of the atom making an angle θ with the direction of observation; c is the velocity of light.
B. DASANNACHARYA, G. K. DAS
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Review of Doppler satellite positioning in Canada
Bulletin Géodésique, 1976Canada has recently faced two geodetic problems. Existing control on land must be rapidly upraged for resource development and for the coming redefinition of North American networks. Geodetic methods of managing territorial and lease boundaries in the offshore region are required.
D. E. Wells +3 more
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Robust Positioning Based on Opportunistic Radio Sources and Doppler
2020 IEEE International Conference on Multisensor Fusion and Integration for Intelligent Systems (MFI), 2020Doppler shift measurements on opportunistic radio sources can be an alternative to GNSS in disturbed environments. Mobile measurements on a GSM base station indicate that the uncertainty is sufficiently low for vehicle positioning, provided that at least two sources are within range and that measurements are fused with an odometer and a rate gyro.
David Lindgren, Andreas Nordzell
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Doppler-Aided Algorithm for BeiDou Position
2013Real-time GNSS positioning rely mainly on pseudorange and carrier-phase. The pseudorange is not accurate because of a lot of noise and interference in environment. High-precision carrier-phase used to smooth pseudorange. While, when cycle slip occurs, the carrier-phase measurement is bias.
Dengyun Lei, Weijun Lu, DunShan Yu
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Ultrasonics, 1991
With a pulsed Doppler system, the recorded Doppler spectrum is expected to vary depending upon the sample volume size relative to the diameter of the vessel, the position of the sample volume in the vessel and the velocity profile. In the in vitro experiments described in this paper, the velocity profile was kept constant by using steady parabolic flow
Y F, Law +4 more
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With a pulsed Doppler system, the recorded Doppler spectrum is expected to vary depending upon the sample volume size relative to the diameter of the vessel, the position of the sample volume in the vessel and the velocity profile. In the in vitro experiments described in this paper, the velocity profile was kept constant by using steady parabolic flow
Y F, Law +4 more
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Improved Doppler Positioning Techniques for Stand-Off Scenarios
IEEE Transactions on Aerospace and Electronic Systems, 2020In “stand-off” scenarios, an estimate of the bearing to an emitter can be easily calculated from measurements of the received frequency, position, and velocity of receivers. This technique is only effective if the measured frequencies can be reliably associated with a single emitter that is far away.
Brian D. O. Anderson +1 more
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Doppler Echocardiographic Evaluation of Prosthetic Valves in Tricuspid Position
Asian Cardiovascular and Thoracic Annals, 2003Doppler echocardiographic characteristics of 29 normally functioning prosthetic valves (23 mechanical, 6 biological) and 8 obstructed mechanical prostheses in the tricuspid position are reported. In normally functioning prostheses, peak velocity, mean pressure gradient, and pressure-half time were 1.25 ± 0.18 m·sec
Shigeaki, Aoyagi +4 more
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