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Code Design and Latency Analysis of Distributed Matrix Multiplication with Straggling Servers in Fading Channels

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China Communications 2021年第10期18卷 15-29页

作者： ning liu Kuikui Li Meixia Tao School of Electronics Information and Electrical EngineeringShanghai Jiao Tong UniversityShanghai 200240China Huawei Technologies Co. Ltd.Shanghai 201206China Department of Electronic Engineering Shanghai Jiao Tong UniversityShanghai 200240China

This paper exploits coding to speed up computation offloading in a multi-server mobile edge computing(MEC)network with straggling servers and channel *** specific task we consider is to compute the product between a user-generated input data matrix and a large-scale model matrix that is stored distributively across the multiple edge *** key idea of coding is to introduce computation redundancy to improve robustness against straggling servers and to create communication redundancy to improve reliability against channel *** utilize the hybrid design of maximum distance separable(MDS)coding and repetition *** on the hybrid coding scheme,we conduct theoretical analysis on the average task uploading time,average edge computing time,and average output downloading time,respectively and then obtain the end-to-end task execution *** results demonstrate that when the task uploading phase or the edge computing phase is the performance bottleneck,the hybrid coding reduces to MDS coding;when the downlink transmission is the bottleneck,the hybrid coding reduces to repetition *** hybrid coding also outperforms the entangled polynomial coding that causes higher uplink and downlink communication loads.

关键词： mobile edge computing distributed matrix multiplication coded computing cooperative transmission

Low-complexity detection based on maximum cumulative measure and Laurent decomposition for multi-h CPM signal

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The Journal of China Universities of Posts and Telecommunications 2022年第6期29卷 64-72页

作者： Zheng Zhidong Yu Yanming liu ning Yuan Honggang Lou ning Institute of Systems Engineering Academy of Military SciencesBeijing 100082China

In order to solve the problem of high computational complexity in demodulation for multi-h continuous phase modulation(CPM) signal, a maximum cumulative measure combing with the Laurent decomposition(MCM-LD) scheme is proposed to reduce the number of the grid states and the required number of matched filters, which degrades the demodulation complexity at the *** advanced range telemetry(ARTM) Tier Ⅱ CPM signal is adopted to evaluate the performance in simulation. The results show that, compared with the traditional maximum likelihood sequence detection(MLSD), MCM-LD can respectively reduce the numbers of grid states and matched filters from 256 to 32 and 128 to 48 with negligible performance loss, which effectively degrades the computational complexity for multi-h CPM signal.

关键词： multi-h continuous phase modulation(CPM) Laurent decomposition(LD) maximum cumulative measure(CM) low-complexity demodulation

Psycho-visual modulation based information display:introduction and survey

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Frontiers of Computer Science 2021年第3期15卷 15-32页

作者： ning liu Zhongpai GAO Jia WANG Guangtao ZHAI Cooperative Medianet Innovation Center Shanghai Jiao Tong UniversityShanghai 200240China MoE Key Lab of Artificial Intelligence AI InstituteShanghai Jiao Tong UniversityShanghai 200240China Institute of Image Communication and Network Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Industry and academia have been making great efforts in improving refresh rates and resolutions of display devices to meet the ever increasing needs of consumers for better visual *** a result,many modem displays have spatial and temporal resolutions far beyond the discern capability of human visual ***,leading to the possibility of using those display-eye redundancies for innovative ***-ral/spatial psycho-visual modulation(TPVM/SPVM)was proposed to exploit those redundancies to generate multiple visual percepts for different viewers or to transmit non-visual data to computing devices without affecting normal *** paper reviews the STPVM technology from both conceptual and algorithmic perspectives,with exemplary applications in multiview display,display with visible light communication,*** possible future research directions are also identified.

关键词： information display human visual system spatial frequency temporal frequency non-negative matrix decomposition

Hybrid battery integrated by Zn-air and Zn-Co3O4 batteries at cell level

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Journal of Energy Chemistry 2020年第10期29卷 375-383页

作者： ning liu Honglu Hu Xinxin Xu Qiang Wang Department of Chemistry College of ScienceNortheastern UniversityShenyang 110819LiaoningChina Key Laboratory of Electromagnetic Processing of Materials MOENortheastern UniversityShenyang 110819LiaoningChina

The construction of Zn based hybrid battery through the combination of Zn-air and Zn-Co3O4 batteries at cell level is a feasible strategy to integrate high voltage,specific capacity and energy density in one power supply *** Zn based hybrid battery,an efficient cathode material with high specific capacitance and excellent ORR,OER activities is a vital component,which determines its performance in great *** this work,with Co based coordination polymer as precursor,oxygen vacancy-rich Co3 O4 based cathode material is *** this material Co3O4 particles with the size about 20 to 35 nm reside evenly in mesoporous carbon matrix doped by nitrogen *** OER,the overpotential of this cathode material is merely 330 m *** ORR proceeds with a typical four electron process with half wave achieving 0.76 *** charge/discharge at 1 A·g^-1,specific capacitance of this cathode material is 254.4 mAh·g^-*** current density increases to 20 A·g^-1,the specific capacitance still arrives at 122.5 mAh·g^-1 with nearly 50%*** on attractive performance of this cathode material,Zn based hybrid battery is *** discharge at 1 m A·cm-2,it presences two voltage platforms at 1.71 and 1.14 *** this situation,specific capacitance reaches 790 m Ah·g^-1 with energy density 928 Wh·kg^-*** battery shows promising stability after 300-cycle continuous test.

关键词： Zn based battery Hybrid battery Oxygen vacancy Electrocatalysis Co3O4

Indirect approach for predicting cutting force coefficients and power consumption in milling process

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Advances in Manufacturing 2022年第1期10卷 101-113页

作者： Kai-ning Shi ning liu Cong-Le liu Jun-Xue Ren Shan-Shan Yang Wei Chit Tan Key Laboratory of High Performance Manufacturing for Aero Engine Department of Mechanical EngineeringMinistry of Industry and Information TechnologyNorthwestern Polytechnical UniversityXi’an 710072People’s Republic of China Engineering Research Centre of Advanced Manufacturing Technology for Aero Engine Department of Mechanical EngineeringMinistry of EducationNorthwestern Polytechnical UniversityXi’an 710072People’s Republic of China Virtual Manufacturing Group Smart Manufacturing DivisionAdvanced Remanufacturing and Technology Centre3 Cleantech Loop#01-01CleanTech TwoSingapore 637143Singapore

Accurate energy consumption modeling is an essential prerequisite for sustainable ***,cutting-power-based models have garnered significant attention,as they can provide more comprehensive information regarding the machining energy consumption ***,their implementation is challenging because new cutting force coefficients are typically required to address new workpiece ***,cutting force coefficients are calculated at a high operation cost as a dynamometer must be ***,a novel indirect approach for estimating the cutting force coefficients of a new tool-workpiece pair is proposed *** key idea is to convert the cutting force coefficient calculation problem into an optimization problem,whose solution can be effectively obtained using the proposed simulated annealing ***,the cutting force coefficients for a new tool-workpiece pair can be estimated from a pre-calibrated energy consumption *** experiments performed using different machine tools clearly demonstrate the effectiveness of the developed *** studies with measured cutting force coefficients reveal the decent accuracy of the approach in terms of both energy consumption prediction and instantaneous cutting force *** proposed approach can provide an accurate and reliable estimation of cutting force coefficients for new workpiece materials while avoiding operational or economic problems encountered in traditional force monitoring methods involving ***,this study may significantly advance the development of sustainable manufacturing.

关键词： Sustainable manufacturing Cutting force coefficients Energy consumption Machining processSimulated annealing

RDX crystals with high sphericity prepared by resonance acoustic mixing assisted solvent etching technology

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Defence Technology（防务技术） 2023年第10期28卷 23-32页

作者： Dongjie Liao Qian liu Chunyan Li ning liu Mingchang Wang Chongwei An North University of China Taiyuan 030051China Yichang Testing Technique R&D Institute Yichang 443099China Xi'an Modern Chemistry Research Institute Xi'an 710065China

In order to obtain high-quality spherical RDX crystal particles,the RDX crystals were suspended in a mixed solvent of cyclohexanone and cyclohexane,subsequently a solvent etching study was carried out under the action of vibration/acoustic flow coupled flow field,which generated by resonance acoustic *** effects of solvent ratio,temperature,acceleration and experiment time on morphology as well as particle size of RDX crystals were *** only were the morphology,particle size distribution and crystal form of RDX crystals determined,but also the thermal decomposition performance and mechanical sensitivity of spherical RDX were examined and *** indicated that under the process of solvent/non-solvent volume ratio at 1:2,temperature of 40℃,acceleration of 40 g and experiment time of 4 h,α-type RDX crystal with sphericity of 0.92 can be ***,the median particle size(D_(50))of spherical RDX crystals is 215.8 μm with a unimodal particle size distribution(size span 1.34).For one thing,the thermal decomposition peak temperature of spherical RDX is about 2.5℃ higher than that of raw RDX,and apparent activation energy reaches 444.68 kJ/*** another thing,impact sensitivity and friction sensitivity of spherical RDX are 18.18% and 33.33% lower than that of raw RDX,*** demonstrates that safety of spherical RDX under thermal,impact and friction stimuli has been improved.

关键词： Resonance acoustic mixing Solvent etching RDX Sphericial explosive

Roll angular rate extraction based on modified spline-kernelled chirplet transform

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Defence Technology（防务技术） 2022年第5期18卷 876-890页

作者： Hui Zhao Zhong Su Qing Li Fu-chao liu ning liu School of Automation Beijing Institute of TechnologyBeijing100081China Beijing Key Laboratory of High Dynamic Navigation Technology Beijing Information Science and Technology UniversityBeijing100192China

The roll angular rate is much crucial for the guidance and control of the *** the high-speed rotation of the projectile brings severe challenges to the direct measurement of the roll angular ***,the radial magnetometer signal is modulated by the high-speed rotation,thus the roll angular rate can be achieved by extracting the instantaneous frequency of the radial magnetometer *** objective of this study is to find out a precise instantaneous frequency extraction method to obtain an accurate roll angular *** reach this goal,a modified spline-kernelled chirplet transform(MSCT)algorithm is proposed in this *** to the nonlinear frequency modulation characteristics of the radial magnetometer signal,the existing time-frequency analysis methods in literature cannot obtain an excellent energy concentration in the time-frequency plane,thereby leading to a terrible instantaneous frequency extraction ***,the MSCT can overcome the problem of bad energy concentration by replacing the short-time Fourier transform operator with the Chirp Z-transform operator based on the original spline-kernelled chirplet *** introduction of Chirp Z-transform can improve the construction accuracy of the transform *** the construction accuracy of the transform kernel determines the concentration of time-frequency distribution,the MSCT can obtain a more precise instantaneous *** performance of the MSCT was evaluated by a series of numerical simulations,high-speed turntable experiments,and real flight *** evaluation results show that the MSCT has an excellent ability to process the nonlinear frequency modulation signal,and can accurately extract the roll angular rate for the high spinning projectiles.

关键词： High spinning projectile Roll angular rate Time-frequency analysis Spline-kernelled chirplet transform Chirp Z-transform

Network selection policy in multi-radio access environment using stochastic control theory

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The Journal of China Universities of Posts and Telecommunications 2011年第4期18卷 98-103页

作者： WEI Yi-fei SONG Mei ZHANG Yong liu ning-ning School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

Network selection is crucial in improving the performance of heterogeneous wireless access systems. Most of previous work on network selection or radio resource allocation concentrates on the capability of each available network and ignores the time-varying nature of wireless media due to channel fading. However, the channel condition determines the state of each wireless network and plays a vital role in ensuring quality of service in multi-radio access environment. In this article, we propose a network selection policy using stochastic control theory considering the time-varying and stochastic character of wireless channels. The proposed scheme selects one network among different alternatives in each decision epoch according to the channel state of each network, which is modeled as finite-state Markov channel, with the objectives of increasing the data-rate, decreasing the bit error rate and minishing the delay. The procedure of network selection is formulated as a stochastic control problem, which can be solved using linear programming and primal-dual index heuristic algorithm. Simulation results are presented to show that network selection has great impact on the system performance, and the proposed scheme can improve the performance significantly.

关键词： network selection multi-radio finite-state Markov channel stochastic control

Mean Value on the Difference Between a Quadratic Residue and Its Inverse Modulo p

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Acta Mathematica Sinica,English Series 2007年第5期23卷 915-924页

作者： Hua ning liu Wen Peng ZHANG Department of Mathematics Northwest University Xi'an 710069 P. R. China

The main purpose of this paper is to use the generalized Bernoulli numbers, Gauss sums and the mean value theorems of Dirichlet L-functions between a quadratic residue and its inverse modulo p value formula. to study ... 详细信息

关键词： An integer and its inverse Bernoulli numbers Cochrane sums