Novel extraction method of the maximum variation-rate of State-of-Polarization vector from time-varying birefringence

2016 ◽  
Author(s):  
Yoshihiro KANDA ◽  
Hitoshi MURAI
Keyword(s):  
Extraction Method ◽  
Polarization Vector ◽  
Time Varying ◽  
Maximum Variation ◽  
State Of Polarization ◽  
Variation Rate

scholarly journals Effect of local PMD and PDL directional correlation on the principal state of polarization vector autocorrelation

2003 ◽  
Vol 11 (23) ◽  
pp. 3141 ◽  
Author(s):  
Liang Chen ◽  
Saeed Hadjifaradji ◽  
David Waddy ◽  
Xiaoyi Bao
Keyword(s):  
Polarization Vector ◽  
State Of Polarization

Robust Control for Uncertain Takagi–Sugeno Fuzzy Systems with Time-Varying Input Delay

2004 ◽  
Vol 127 (2) ◽  
pp. 302-306 ◽  
Author(s):  
Ho Jae Lee ◽  
Jin Bae Park ◽  
Young Hoon Joo
Keyword(s):  
Fuzzy Systems ◽  
Fuzzy Model ◽  
Input Delay ◽  
Time Varying ◽  
Convex Optimization Problem ◽  
Variation Rate ◽  
Mass Spring ◽  
Takagi Sugeno ◽  
Bounded Uncertainties ◽  
Norm Bounded Uncertainties

A control problem of Takagi–Sugeno fuzzy systems with a time-varying input delay and norm-bounded uncertainties is addressed. The input delay is well-known in making the closed-loop stabilization difficult. A sufficient condition for the robust fuzzy-model-based stabilization is derived based on the Lyapunov–Razumikhin stability theorem, without the assumption of the variation rate on the delay. A constructive design scheme is presented in the form of the iterative convex optimization problem. The effectiveness of the proposed method is demonstrated by a numerical simulation of a nonlinear mass-spring-damper system.

scholarly journals A time-varying wavelet phase extraction method using the wavelet amplitude spectra

2018 ◽  
Vol 6 (3) ◽  
pp. 10-18
Author(s):  
Peng Zhang ◽  
Yong-shou Dai ◽  
Yong-cheng Tan ◽  
Hongqian Zhang ◽  
Chunxian Wang
Keyword(s):  
Extraction Method ◽  
Phase Extraction ◽  
Time Varying ◽  
Amplitude Spectra

scholarly journals On the Double Doppler Effect Generated by Scatterer Motion

2011 ◽  
Vol 1 (1) ◽  
Author(s):  
Viet-Ha Pham ◽  
Mohamed Haj Taieb ◽  
Jean-Yves Chouinard ◽  
Sébastien Roy ◽  
Huu-Tue Huynh
Keyword(s):  
Velocity Distribution ◽  
Doppler Effect ◽  
Wireless Channels ◽  
Geometric Model ◽  
Doppler Frequency ◽  
Wireless Channel ◽  
Time Varying ◽  
Variation Rate ◽  
Channel Variation ◽  
Fixed Wireless

In a time-varying transmission channel, the received signals are subject to frequency shifts due to the Doppler effect. The Doppler frequency is dependent on the carrier frequency and channel variation rate. In a fixed wireless channel, the channel variations are caused by scatterer motion. In this paper, we investigate analytically the Doppler effects generated by scatterer motion under different scatterer velocity distributions using the ring-of-scatterers geometric model. The proposed model considers Doppler frequency components caused by scatterer mobility to both received and reflected signals at each scatterer, and therefore is called the double Doppler model. The analytical curves are compared and statistically tested with several measurement results published in the literature. At low scatterer speeds, e.g., generated by moving foliage, the exponential velocity distribution is an appropriate model to describe the time-varying nature of the fixed wireless channels. The curve fitting results also show that our analytical model better approaches the empirical curves than the single Doppler model does. However, further investigation is still needed to find a suitable scatterer velocity distribution that closely describes the double Doppler effect in fast-variation fixed wireless channels, e.g., caused by passing vehicles.

scholarly journals COMPARATIVE ANALYSIS OF THE PROPERTIES OF SODIUM NIOBATE AND SODIUM - LITHIUM NIOBATE CERAMICS

2021 ◽  
pp. 278-285
Author(s):  
Ольга Витальевна Малышкина ◽  
Кирилл Валерьевич Пацуев ◽  
Александра Ивановна Иванова ◽  
Майс Али
Keyword(s):  
Comparative Analysis ◽  
Lithium Niobate ◽  
Polarization Vector ◽  
Sodium Niobate ◽  
Ceramic Samples ◽  
State Of Polarization ◽  
Continuous Mass ◽  
Polarization Gradient ◽  
Individual Grains ◽  
Niobate Lithium

Авторами исследовано влияние температуры синтеза ниобата натрия, на состояние поляризации в образцах керамики чистого ниобата натрия и модифицированного литием. Проведено сравнительное исследование структуры и пироэлектрических свойств полученных образцов. Показано, что введение в качестве модификатора лития приводит к существенному изменению структуры в глубине образцов керамики на основе ниобата натрия. Если в глубине образцов чистого ни ниобата натрия, как и на поверхности, различаются отдельные зерна, то центральная часть керамики ниобата натрия-лития представляет собой сплошной массив, в котором отдельные зерна не наблюдаются. Во всех образцах, кроме чистого ниобата натрия, синтезированного двойным синтезом (первый при 650 °C, второй при 700 °C), установлено существование градиента поляризации по толщине образцов, направленного от стороны, соответствующей положительному концу вектора поляризации к стороне, соответствующей отрицательному концу вектора поляризации. The authors studied the effect of the temperature of sodium niobate synthesis on the state of polarization in ceramic samples of pure sodium niobate and modified with lithium. A comparative study of the structure and pyroelectric properties of the obtained samples has been carried out. It is shown that the introduction of lithium as a modifier leads to a significant change in the structure in the depth of ceramic samples based on sodium niobate. If in the depth of the pure sodium niobate samples, as well as on the surface, there are individual grains, then the central part of the sodium niobate-lithium niobate ceramics is a continuous mass in which individual grains are not observed. In all samples, except for pure sodium niobate, which was synthesized by double synthesis (the first at 650 °C, the second at 700 °C), the existence of a polarization gradient along the thickness of the samples was established. The gradient is directed from the side corresponding to the positive end of the polarization vector to the side corresponding to the negative end of the polarization vector.

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