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Exploration of the coupled lattice Boltzmann model based on a multiphase field model:A study of the solid-liquid-gas interaction mechanism in the solidification process

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Chinese Physics B 2024年第3期33卷 638-648页

作者：朱昶胜王利军高梓豪刘硕李广召 College of computer and communication Lanzhou University of TechnologyLanzhou 730050China State Key Laboratory of Gansu Advanced Processing and Recycling of Non-Ferrous Metal Lanzhou University of TechnologyLanzhou 730050China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China

A multiphase field model coupled with a lattice Boltzmann(PF-LBM)model is proposed to simulate the distribution mechanism of bubbles and solutes at the solid-liquid interface,the interaction between dendrites and bubbles,and the effects of different temperatures,anisotropic strengths and tilting angles on the solidified organization of the SCN-0.24wt.%butanedinitrile alloy during the solidification *** model adopts a multiphase field model to simulate the growth of dendrites,calculates the growth motions of dendrites based on the interfacial solute equilibrium;and adopts a lattice Boltzmann model(LBM)based on the shan-Chen multiphase flow to simulate the growth and motions of bubbles in the liquid phase,which includes the interaction between solid-liquid-gas *** simulation results show that during the directional growth of columnar dendrites,bubbles first precipitate out slowly at the very bottom of the dendrites,and then rise up due to the different solid-liquid densities and pressure *** bubbles will interact with the dendrite in the process of flow migration,such as extrusion,overflow,fusion and *** the case of wide gaps in the dendrite channels,bubbles will fuse to form larger irregular bubbles,and in the case of dense channels,bubbles will deform due to the extrusion of *** the simulated region,as the dendrites converge and diverge,the bubbles precipitate out of the dendrites by compression and diffusion,which also causes physical phenomena such as fusion and spillage of the *** results reveal the physical mechanisms of bubble nucleation,growth and kinematic evolution during solidification and interaction with dendrite growth.

关键词： multiphase field model lattice Boltzmann model(LBM) shan-Chen multiphase flow solidification organization

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Analysis on unit maximum capacity of orthogonal multiple watermarking for multimedia signals in B5G wireless communications

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Digital communications and Networks 2024年第1期10卷 38-44页

作者： Mianjie Li Senfeng Lai Jiao Wang Zhihong Tian Nadra Guizani Xiaojiang Du Chun shan School of Electronics and Information Guangdong Polytechnic Normal UniversityGuangzhou510665China Cyberspace Institute of Advanced Technology Guangzhou UniversityGuangzhou510006China Schoolof Electrical Engineering and computer Science Washington State UniversityPullmanWA99164USA Department of computer and Information Science Temple UniversityPhiladelphiaPA19122USA

Beyond-5G(B5G)aims to meet the growing demands of mobile traffic and expand the communication *** that intelligent applications to B5G wireless communications will involve security issues regarding user data and operational data,this paper analyzes the maximum capacity of the multi-watermarking method for multimedia signal hiding as a means of alleviating the information security problem of *** multiwatermarking process employs spread transform dither *** the watermarking procedure,Gram-Schmidt orthogonalization is used to obtain the multiple spreading ***,multiple watermarks can be simultaneously embedded into the same position of a multimedia ***,the multiple watermarks can be extracted without affecting one another during the extraction *** analyze the effect of the size of the spreading vector on the unit maximum capacity,and consequently derive the theoretical relationship between the size of the spreading vector and the unit maximum capacity.A number of experiments are conducted to determine the optimal parameter values for maximum robustness on the premise of high capacity and good imperceptibility.

关键词： B5G Multimedia information security Spread transform dither modulation Spreading vector measurement Unit maximum capacity

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Distributed generalized Nash equilibrium seeking:event-triggered coding-decoding-based secure communication

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Science China(Information Sciences) 2024年第7期67卷 271-284页

作者： Shaofu YANG Wenying XU Wangli HE Jinde CAO School of computer Science and Engineering Southeast University School of Mathematics Southeast University Key Laboratory of Advanced Control and Optimization for Chemical Processes East China University of Science and Technology

In this paper, we consider the distributed generalized Nash equilibrium(GNE) seeking problem in strongly monotone games. The transmission among players is implemented through a digital communication network with limited bandwidth. For improving communication efficiency or/and security, an event-triggered coding-decoding-based communication is first proposed, where the data(decision variable) are first mapped to a series of finite-level codewords and, only when an event condition is satisfied, then sent to the neighboring agents. Moreover, a distributed communication-efficient GNE seeking algorithm is constructed accordingly,and the overrelaxation scheme is further taken into consideration. Through primal-dual analysis, the proposed algorithm is proven to converge to a variational GNE with fixed step-sizes by recasting it as an inexact forward-backward iteration. Finally, numerical simulations illustrate the benefit of the proposed algorithms in terms of saving communication resources.

关键词： noncooperative games event-triggered communication coding-decoding quantization

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Efficient conversion of acoustic vortex using extremely anisotropic metasurface

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Frontiers of physics 2024年第4期19卷 257-264页

作者： Zhanlei Hao Haojie Chen Yuhang Yin Cheng-Wei Qiu shan Zhu Huanyang Chen Institute of Electromagnetics and Acoustics and Department of Physics College of Physical Science and TechnologyXiamen UniversityXiamen 361005China Department of Electrical and computer Engineering National University of Singapore4 Engineering Drive 3117583Singapore Department of Mechanical and Electrical Engineering Xiamen UniversityXiamen 361005China Pen-Tung Sah Institute of Micro-Nano Science and Technology Xiamen UniversityXiamen 361005China

Vortex wave and plane wave,as two most fundamental forms of wave propagation,are widely applied in various research ***,there is currently a lack of basic mechanism to enable arbitrary conversion between *** this paper,we propose a new paradigm of extremely anisotropic acoustic metasurface(AM)to achieve the efficient conversion from 2D vortex waves with arbitrary orbital angular momentum(OAM)to plane *** underlying physics of this conversion process is ensured by the symmetry shift of AM medium parameters and the directional compensation of ***,this novel phenomenon is further verified by analytical calculations,numerical demonstrations,and acoustic experiments,and the deflection angle and direction of the converted plane waves are qualitatively and quantitatively confirmed by a simple *** work provides new possibilities for arbitrary manipulation of acoustic vortex,and holds potential applications in acoustic communication and OAM-based devices.

关键词： efficient wave conversion vortex wave plane wave orbital angular momentum acoustic metasurface

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Movement-assisted service composition optimization in dynamic networks

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High Technology Letters 2013年第2期19卷 176-181页

作者：赵耀培 Yang Yang Mi Zhenqiang Department of computer and communication Engineering University of Science and Technology Beijing Department of Scientific Research Shan Dong Institute of Trade Union Administration Cadres

The mobility of service providers brings new features into the research of dynamic network based service *** an optimistic perspective,the mobility of services could benefit the optimization of service composition,if properly ***,the impacts of node mobility on the dynamic network based service composition are ***,a movement-assisted optimization method,namely MASCO,is proposed to improve the performance of the composited services by minimizing the length of data stream and the hop-counts of the service routes in the underlying *** correctness and efficiency of the proposed method are then verified through theoretical analysis and computer simulations.

关键词： service composition dynamic networks motion control service optimization re-versed current

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Improving the intensity and efficiency of compressed echo in rare-earth-ion-doped crystal

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Chinese Physics B 2016年第7期25卷 124-130页

作者：马秀荣梁裕卿王松张双根单云龙 Department of computer and communication Engineering Tianjin University of Technology Engineering Research Center of communication Devices and Technology Ministry of Education Tianjin Key Laboratory of Film Electronic and communication Devices

We investigate the intensity and efficiency of a compressed echo, which is important in arbitrary waveform generation（AWG）. A new model of compressed echo is proposed based on the optical Bloch equations, which exposes much more detailed parameters than the conventional model, such as the time delay of the chirp lasers, the nature of the rare-earth-iondoped crystal, etc. According to the novel model of compressed echo, we find that reducing the time delay of the chirp lasers and scanning the lasers around the center frequency of the inhomogeneously broadened spectrum, while utilizing a crystal with larger coherence time and excitation lifetime can improve the compressed echo＇s intensity and efficiency. The theoretical analysis is validated by numerical simulations.

关键词： intensity and efficiency compressed echo arbitrary waveform generation optical Bloch equations

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Adaptive Forward Error Correction with Cognitive Technology Mechanism for Video Streaming over Wireless Networks

Adaptive Forward Error Correction with Cognitive Technology ...

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2010 International Symposium on computer,communication, Control and Automation

作者： Hsiung-Yu Huang Tzu-Chi Huang Naveen Chilamkurti Rung-Shiang Cheng Ce-Kuen Shieh Institute of computer and communication Engineering NCKU dept.of Electronic Engineering Lunghwa university of Science and Technology dept.of computer Science and computer Engineering La Trobe university Melbourne dept of computer and communication kun shan university Institute of computer and communication Engineering Dept of EENCKU

ISBN: (纸本)9781424455652;9781424455669

Video streaming over wireless networks presents challenges associated with high packet loss rate *** lost transmission packets limit video streaming quality on the *** Forward Error Correction(FEC) mechanism has been proposed to recover lost ***,the FEC mechanism has to inject redundancy ***,congestion packet losses become critical when available bandwidth is *** propose an Adaptive Forward Error Correction with Cognitive technology(AFECC) mechanism to solve this *** AFECC mechanism uses cognitive technology to use frequency only when this does not incur interference or conflicts with *** AFECC utilizes a mathematical analytical model from which the appropriate FEC redundancy is *** AFECC mechanism does not have any self-induced congestion effects which can otherwise impede the timely recovery of video *** experimental results show that the AFECC mechanism outperforms conventional adaptive FEC mechanisms in reduced packet loss rate,increased throughput and higher Peak Signal to Noise Ratio(PSNR),

关键词： Cognitive Technology Forward Error Correction Video Streaming.

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Vortex localization and OAM selective conversion via cylindrical metagratings

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Chinese Optics Letters 2024年第3期22卷 137-141页

作者：郝占磊朱杉仇成伟徐亚东陈焕阳 Institute of Electromagnetics and Acoustics and Department of Physics College of Physical Science and TechnologyXiamen UniversityXiamen 361005China Department of Electrical and computer Engineering National University of SingaporeSingapore 117583Singapore School of Physical Science and Technology and Jiangsu Key Laboratory of Thin Films Soochow UniversitySuzhou 215006China

Vortex waves with orbital angular momentum(OAM)are a highly active research topic in various *** this paper,we design and investigate cylindrical metagratings(CMs)with an even number of unit cells that can efficiently achieve vortex localization and specific OAM selective *** multifunctional manipulation of vortex waves and the new OAM conservation law have further been confirmed through analytical calculations and numerical *** addition,we qualitatively and quantitatively determine the OAM range for vortex localization and the OAM value of vortex selective conversion and also explore the stability for performance and potential applications of the designed *** work holds potential applications in particle manipulation and optical communication.

关键词： vortex waves cylindrical metagratings vortex localization high-efficiency transmission vortex selective conversion

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Privacy-Preserving Deep Learning on Big Data in Cloud

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China communications 2023年第11期20卷 176-186页

作者： Yongkai Fan Wanyu Zhang Jianrong Bai Xia Lei Kuanching Li State Key Laboratory of Media Convergence and communication Communication University of ChinaBeijing 100024China Industrial and Commercial Bank of China Zhuhai Branch Zhuhai 519000China dept.of computer Science and Information Engineering Providence UniversityTaichung 43301China

In the analysis of big data,deep learn-ing is a crucial *** data analysis tasks are typically carried out on the cloud since it offers strong computer capabilities and storage ***-ertheless,there is a contradiction between the open nature of the cloud and the demand that data own-ers maintain their *** use cloud resources for privacy-preserving data training,a viable method must be found.A privacy-preserving deep learning model(PPDLM)is suggested in this research to ad-dress this preserving *** preserve data privacy,we first encrypted the data using homomorphic en-cryption(HE)***,the deep learn-ing algorithm’s activation function—the sigmoid func-tion—uses the least-squares method to process non-addition and non-multiplication operations that are not allowed by ***,experimental re-sults show that PPDLM has a significant effect on the protection of data privacy *** with Non-Privacy Preserving Deep Learning Model(NPPDLM),PPDLM has higher computational effi-ciency.

关键词： big data cloud computing deep learning homomorphic encryption privacy-preserving

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Multi-slots Wideband Cooperative Spectrum Sensing Based on Weighed Data Fusion in Cognitive Radio

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Journal of Harbin Institute of Technology(New Series) 2013年第1期20卷 1-7页

作者： Xin Liu Xiu-Hua Li Rong-Fei Fan Xue-Zhi Tan communication Research Centre Harbin Institute of Technology School of Electrical and Electronic Engineering Nanyang Technological University dept. of Electrical and computer Engineering University of Alberta

In order to avoid the interference to the primary user(PU), in this paper Cognitive Radio (CR) periodically senses the presence of PU, and during one period, CR can sense all the sub-channels based on weighed data fusion and then use all the idle channels decided by the coordinator. The local sensing time of CR is divided into multi-slots in which CR can sense any sub-channel. Through reasonably allocating the sensing slots and users by mathematic optimization, the proposed algorithm can improve the total throughput of CR. The optimization problem of the proposed scheme which seeks to maximize the throughput subject to the constraint of the detected performance of each sub-channel is proposed in order to choose the optimum local sense time and the number of the cooperative CRs. The simulation results indicate that the proposed scheme can obtain higher throughput than the conventional single-channel sense, and there are the optimum local sense time and the number of cooperative CRs to make the throughput reach maximum.

关键词： cognitive radio energy detection cooperative detection weighed data fusion thoughput

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