- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE 2019 International Conference on Electrical, Communication, and Computer Engineering (ICECCE) - Swat, Pakistan (2019.7.24-2019.7.25)] 2019 International Conference on Electrical, Communication, and Computer Engineering (ICECCE) - Modeling and Analysis of Novel Tandem Solar Cells
摘要： While relay-based cooperative networks (widely known in the literature as cooperative communication), where relays only forward signals from the sources to the destination, have been extensively researched, fully cooperative systems have not been thoroughly examined. Unlike relay networks, in a fully cooperative network, each node acts as both a source node sending its own data and a relay forwarding its partner’s data to the destination. Mutual cooperation between neighboring nodes is believed to improve the overall system error performance, especially when space-time codes are incorporated. However, a comprehensive performance analysis of space-time-coded fully cooperative communication from all three perspectives, namely error performance, outage probability, and energy efficiency, is still missing. Answers to the commonly asked questions of whether, in what conditions, and to what extent the space-time-coded fully cooperative communication is better than direct transmission are still unknown. Motivated by this fact and inspired by the increasing popularity of healthcare applications in wireless body area networks (WBANs), this paper derives for the first time a comprehensive performance analysis of a decode-and-forward space-time coded fully cooperative communication network in Rayleigh and Rician fading channels in either identically or non-identically distributed fading scenario. Numerical analysis of error performance, outage probability, and energy efficiency, validated by simulations, show that fully cooperative communication is better than direct transmission from all three aspects in many cases, especially at a low-power and low signal-to-noise ratio regime, which is a typical working condition in WBANs.
关键词： symbol error rates,energy efficiency,MIMO,space-time codes,Rician,decode-and-forward,outage probability,wireless body area networks,Cooperative communication,Rayleigh
更新于2025-09-23 15:19:57
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[IEEE 2020 IEEE Texas Power and Energy Conference (TPEC) - College Station, TX, USA (2020.2.6-2020.2.7)] 2020 IEEE Texas Power and Energy Conference (TPEC) - Performance Evaluation of Photovoltaic Grid-connected Microgrid with Hybrid Energy Storage using Predictive Current Control
摘要： We propose and prove a theorem that allows the calculation of a class of functionals on Poisson point processes that have the form of expected values of sum–products of functions. In proving the theorem, we present a variant of the Campbell–Mecke theorem from stochastic geometry. We proceed to apply our result in the calculation of expected values involving interference in wireless Poisson networks. Based on this, we derive outage probabilities for transmissions in a Poisson network with Nakagami fading. Our results extend the stochastic geometry toolbox used for the mathematical analysis of interference-limited wireless networks.
关键词： interference,Wireless networks,time diversity,correlation,Poisson point process,Nakagami fading,stochastic geometry,Rayleigh fading
更新于2025-09-23 15:19:57
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Viscous Motion of Spherical Nanoparticles that Scatter Laser Radiation in the Rayleigh Regime
摘要： The mechanism of transverse radiation viscosity for nanospheres moving in laser ?eld is analyzed. It is demonstrated that in the process of light scattering by these particles besides the force Fs accelerating them in the direction of radiation propagation and the gradient force Fg that is due to the spatial inhomogeneity of the light ?eld, there are forces Fvisc that slow down the movement of particles in the transverse directions. These light viscosity forces are due to the Doppler shift in frequency of scattered radiation. The general expressions for these forces acting on particles that scatter radiation in the Rayleigh regime are derived and applied to estimate their e?ect on levitated nanospheres and also on slow electrons moving in the laser and magnetic ?elds. The possible experiments for observation the e?ects of light viscosity are discussed.
关键词： laser radiation,viscous motion,spherical nanoparticles,light viscosity forces,Rayleigh regime
更新于2025-09-23 15:19:57
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Numerical study on the laser ablative Rayleigha??Taylor instability
摘要： The laser ablative Rayleigh–Taylor instability plays an important role in the ignition of inertial re?nement fusion. An accurate simulation of this process is important to control the growth of ?ow instability during the implosion. In this paper, taking the simulations of the hydrodynamics, the laser energy deposition and the electronic thermal conductivity into consideration, a massively parallel laser ablative Rayleigh–Taylor instability code based on Euler method is developed. Some open source codes are used to improve the code development ef?ciency. The accuracy of the hydrodynamics simulation is tested by an analytical theory about the weakly nonlinear Rayleigh–Taylor instability with double interfaces. The benchmark of an one dimensional heat conductivity is used to test the accuracy of the thermal conductivity simulation. The laser ablative plane target and the laser ablative Rayleigh–Taylor instability are used to test the reliability of the code on the simulation of the whole laser ablative process. It is shown that the con?dence of our numerical simulation code is high and the code framework we designed is effective. It can be a basis on studying the problems about the laser ablative instability in inertial re?nement fusion.
关键词： Rayleigh–Taylor instability,Numerical simulation,Inertial con?nement fusion,Laser ablation
更新于2025-09-23 15:19:57
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Spherical particle absorption over a broad range of imaginary refractive index
摘要： This paper presents studies of the optical absorption cross section for homogeneous spheres of radius R interacting with light of wavelength λ as calculated with the Mie equations. Four regimes of behavior are disclosed: the Rayleigh Regime, the Geometric Regime, the Re?ection Regime, and a Crossover Regime. Two parameters govern these regimes, the imaginary part of the refractive index, κ, and the product of κ with the sphere size parameter kR where k = 2 π / λ, i.e. κkR . Simple, approximate functionalities on κ, k , sphere volume and projected geometric cross section are derived for these regimes. Interesting aspects of our observations include: Rayleigh absorption can apply to all particle sizes, Fresnel re?ection can occur for sub-wavelength spheres, and while κ is the agent of absorption, large κ can increase scattering to the detriment of absorption.
关键词： Absorption,Complex refractive index,Rayleigh theory,Mie theory
更新于2025-09-19 17:15:36
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Moment-based Approach for Statistical and Simulative Analysis of Turbulent Atmospheric Channels in FSO Communication
摘要： Free Space Optical (FSO) or wireless optical communication networks involve atmosphere as the channel, which at times can be turbulent in nature, thus degrading the system performance. These turbulent channels can be analysed by introducing various channel models and modulation techniques. Various researchers have analysed the performance by presenting different approaches for each type of channel model. In this paper, we present a uni?ed approach for the performance analysis of Log-normal, Nakagami-n (Rician) and Rayleigh statistical models by deriving the exact closed form expressions for average bit error probability and the outage probability of each model. It is achieved by using alternative form of Q-function and Gauss-Hermite Quadrature approximation to the moment-generating function of the output Signal-to-Noise Ratio (SNR). Further, de?nite expressions for each type of modulation technique are also derived to describe the channel fading in FSO communication system. The system of interest includes M-ary Phase Shift Keying (M-PSK) and M-ary Quadrature Amplitude Modulation (M-QAM) techniques. Moreover, the average output SNR, average received irradiance and the amount of fading (fading strength) are also expressed in simple closed forms for above mentioned turbulent channels. In addition to this, the performance of FSO system in presence of atmospheric turbulence and pointing errors is also investigated. The statistical model is examined for zero and nonzero boresight point errors modelled by Rayleigh and Rician distributions in Log-normal fading channel. The composite Log-normal PDFs along with asymptotic error rate and outage probability are also presented for such system. The effect of Tikhonov distributed phase noise arised due to BPSK modulation on BER performance is evaluated on three turbulent channels by deriving its closed-form expression using moment based approach.The mathematical analysis is veri?ed by comparing numerical results with Monte-Carlo Simulated values and graphs.
关键词： Rayleigh,SNR,BER,phase noise,Log-normal,Nakagami-n,path loss,outage probability,pointing errors
更新于2025-09-19 17:15:36
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Generalized Rayleigh surface waves in a piezoelectric semiconductor half space
摘要： In this paper, plane strain surface waves, also named generalized Rayleigh surface waves, in a transversely isotropic piezoelectric semiconductor half space are investigated. The governing equations of generalized Rayleigh surface waves include the equations of motion, Gauss’ law of electrostatics and the conservation of charge. Based on the basic theory of elastic-dynamic equations, the governing equations are deduced as equations related to the displacement, the electric potential and the perturbation of the carrier density and are solved analytically. We discuss dispersion curves and the attenuation tendency of generalized Rayleigh waves for real wave number cases. The results reveal that the semiconductor should lead to phase velocity decreasing, and the anomalous dispersion and damping of generalized Rayleigh waves. However, enough in-plane biasing electric field along the wave propagation should lead to the amplification of the waves. The influence of the out-plane biasing electric field is so slight that it can be omitted. These properties should be reproduced in the case of real frequencies. The results obtained may provide theoretical guidance for the design of high-performance surface acoustic wave devices made of piezoelectric semiconductors.
关键词： Damping,Piezoelectric semiconductor,Generalized Rayleigh surface,Biasing electric field
更新于2025-09-19 17:15:36
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Opto-acoustic effect of Au nanoparticles in water under irradiation of pulse laser
摘要： The cavitation bubbles in water generated by laser irradiated Au nanoparticles (NPs) exhibit potential applications in the photothermal therapy and enhancing photoacoustic imaging. The exploration of the related processes is crucial to improve the opto-acoustic efficiency that is important to these applications. Herein a model including the Mie theory, gas state equation, Rayleigh-Plesset equation, and sound pressure equation is established. Through this model, the volume and pressure of the bubble is obtained. The influences of laser flux and NP diameter to the volume and pressure of the bubble are simulated based on this model. The acoustic pressure of many Au NPs is obtained through the superposition of the opto-acoustic wave of a single Au NP, in which the Au NPs are assumed to be distributed randomly in the laser irradiation area. The opto-acoustic wave of many Au NPs is also investigated experimentally, which coincides with the theoretical analyses.
关键词： Rayleigh-Plesset equation,opto-acoustic effect,Cavitation bubble,Au nanoparticles
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Sozopol, Bulgaria (2019.9.6-2019.9.8)] 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - High peak and average power delivery from Fully-Aperiodic Large-Pitch-Fiber lasers (Invited)
摘要： A recently developed published approach to predict echo statistics is applied to clutter data that were collected with a midfrequency sonar and published in a separate independent study. This method explicitly accounts for the (?nite) number of unresolved scatterers, the statistics associated with the arbitrary scattering properties of the individual scatterers [but assumed to have identical echo probability density functions (pdfs) in this application], and beampattern effects which signi?cantly affect the echo statistics due to each scatterer being randomly located in the sonar beam. The data had been categorized according to whether they were associated with bottom structures, diffuse compact clutter, and compact nonstationary (moving) clutter. In this paper, the recently developed method is incorporated in a two-component mixed pdf (mixed with a Rayleigh distribution to account for the diffuse background) to model the statistics of the three classes of clutter. This is the ?rst such application of the model which had principally been validated only numerically. The degree to which the data are non-Rayleigh (heavy tailed) is reasonably predicted by the model and the number of scatterers per resolution cell is inferred for each type of clutter.
关键词： Beampattern,non-Rayleigh reverberation,clutter,reverberation statistics
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC) - Macao, Macao (2019.12.1-2019.12.4)] 2019 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC) - A Novel Cost-Effective AC-DC Power Supply for Indoor LED Lighting Applications
摘要： Differential-chaos-shift-keying cooperative communication (DCSK-CC) has attracted a great deal of attention in the past five years, because it can overcome the negative effect of wireless multipath fading. However, the conventional DCSK-CC system suffers from a major disadvantage of low data rate due to the resource consumption in cooperation. To address the issue, this paper proposes an efficient cooperative scheme, called partial-sequence CC (PS-CC) scheme, for the DCSK-CC system. In the PS-CC framework, the source and relays only transmit a partial chaotic sequence corresponding to one bit to the destination, while consuming the same transmission energy as DCSK-CC. To validate the feasibility of the DCSK PS-CC system, this paper carries out the error performance, diversity order, and data rate analyses under different cooperative conditions over multipath fading channels. Both numerical and simulated results show that the proposed PS-CC system outperforms the DCSK-based non-cooperative system and DCSK-CC systems over the range of signal-to-noise ratio under study. Moreover, the proposed system can enhance data rate and reduce the computational overhead of the relays as compared with the DCSK-CC system. In addition, it will be demonstrated that the DCSK PS-CC system preserves its advantages in typical ultra-wideband (UWB) channels. Overall, the PS-CC appears to be a desirable cooperative scheme for those applications featured by high-data-rate, low-power, and low-complexity, such as wireless sensor networks using the transmitted reference UWB technique.
关键词： multipath Rayleigh fading channel,partial-sequence cooperative communication (PS-CC),differential chaos shift keying (DCSK),User cooperation
更新于2025-09-19 17:13:59