Results 221 to 230 of about 145,078 (261)

A Beam Domain Selection Method Based on the Conventional Beam Forming

Applied Mechanics and Materials, 2014
Beam forming technology is an important content in the study of underwater target positioning, can directly use beam forming technology to identify the target direction, but can be by beam forming of target signal enhancement, and then to deal with the enhanced signal.
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Time domain compressive beam forming of ultrasound signals

The Journal of the Acoustical Society of America, 2015
Ultrasound imaging is a wide spread technique used in medical imaging as well as in non-destructive testing. The technique offers many advantages such as real-time imaging, good resolution, prompt acquisition, ease of use, and low cost compared to other techniques such as x-ray imaging.
Guillaume, David, Jean-Luc, Robert, Bo, Zhang, Andrew F, Laine   +3 more
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Experimental Identification Technique of Nonlinear Beams in Time Domain

Nonlinear Dynamics, 1997
Abstract In previous papers the authors proposed a new experimental identification technique applicable to elastic structures. The proposed technique is based on the principle of harmonic balance, and can be classified as the frequency domain technique. The technique requires the excitation force to be periodic.
Yasuda, K., Kamiya, K.
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Transformation of pulsed nonideal beams in a four-dimension domain

Optics Letters, 1993
A tensor method is presented to treat the transformation of pulsed nonideal beams in a four-dimension spatiotemporal domain. The equivalent beamwidth, mean pulse duration, divergence, spectrum width, radius of curvature, and pulsed beam quality factor for arbitrary-amplitude profile pulsed beams are introduced.
Q, Lin, S, Wang, J, Alda, E, Bernabeu
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Beam domain PAPR reduction for massive MIMO downlink

2017 9th International Conference on Wireless Communications and Signal Processing (WCSP), 2017
This paper proposes a novel beam domain peak-to-average power ratio (PAPR) reduction scheme, named idle beam exploitation (IBE), in multi-beam systems, i.e., massive multi-input multi-output (MIMO) downlink based on angle division multiple access (ADMA) here.
Luyao Ni, Shi Jin 0002, Feifei Gao, Hai Lin 0001   +3 more
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Time-domain analysis of photon beams

Proceedings of the Physical Society, 1966
The analysis of photon beams in terms of the time intervals between photon counts is discussed; in particular, the cases of beats and of sinusoidal amplitude modulation are considered.
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True beam smoothing in the fractional Fourier transform domain

Journal of Modern Optics, 2003
Abstract The design of a diffractive optical element (DOE) for true beam smoothing in the fractional Fourier transform domain is described. Based on the Fresnel integrals, the intensity distribution on the output plane is calculated accurately and the discretization error of the spherical phase factor is avoided.
Tan Qiaofeng, Van Yingbai, Jin Guofan, Xu Duanyi   +3 more
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Stability for the beam equation with memory in non‐cylindrical domains

Mathematical Methods in the Applied Sciences, 2004
AbstractIn this paper, we prove the exponential decay as time goes to infinity of regular solutions of the problem for the beam equation with memory and weak damping where ${\hat{Q}}$ is a non‐cylindrical domains of ℝn+1 (n⩾1) with the lateral boundary ${\hat{\sum}}$ and α is a positive constant. Copyright © 2004 John Wiley & Sons, Ltd.
Ferreira, J., Santos, M. L., Matos, M. P.   +2 more
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Propagation of partially coherent pulsed beams in the spatiotemporal domain

Physical Review E, 2003
A generalized model to describe the spatiotemporal partially coherent pulsed beams is presented. The corresponding propagation formula is derived by using the partially coherent light theory. Based on this formula, we obtain a nonstationary generalized ABCD law (which illustrates the transformation of optical beams or pulses passing through media) to ...
Li-gang, Wang, Qiang, Lin, Hong, Chen, Shi-yao, Zhu   +3 more
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Nonlinear Beam Shaping in Domain Engineered Ferroelectric Crystals

Advanced Materials, 2019
AbstractDomain engineered ferroelectric crystals are a type of microstructure functional material that is used widely in the area of nonlinear optics. Herein, research processes in the area of nonlinear beam shaping using domain engineered crystals in the past decade are reviewed.
Xiaopeng Hu, Yong Zhang, Shining Zhu
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