检索结果-南通市图书馆

Stochastic Gradient Compression for Federated Learning over Wireless Network

在线全文

学校读者我要写书评

暂无评论

China Communications 2024年第4期21卷 230-247页

作者： lin Xiaohan Liu Yuan Chen Fangjiong Huang yang Ge Xiaohu School of Electronic and Information Engineering South China University of TechnologyGuangzhou 510641China Key Laboratory of Dynamic Cognitive System of Electromagnetic Spectrum Space Ministry of Industry and Information TechnologyNanjing University of Aeronautics and AstronauticsNanjing 210016China School of Electronic Information and Communications Huazhong University of Science and TechnologyWuhan 430074China

As a mature distributed machine learning paradigm,federated learning enables wireless edge devices to collaboratively train a shared AI-model by stochastic gradient descent(SGD).However,devices need to upload high-dimensional stochastic gradients to edge server in training,which cause severe communication *** address this problem,we compress the communication by sparsifying and quantizing the stochastic gradients of edge *** first derive a closed form of the communication compression in terms of sparsification and quantization ***,the convergence rate of this communicationcompressed system is analyzed and several insights are ***,we formulate and deal with the quantization resource allocation problem for the goal of minimizing the convergence upper bound,under the constraint of multiple-access channel *** show that the proposed scheme outperforms the benchmarks.

关键词： federated learning gradient compression quantization resource allocation stochastic gradient descent(SGD)

Modulation of charge in C_(9)N_(4) monolayer for a highcapacity hydrogen storage as a switchable strategy

在线全文

学校读者我要写书评

暂无评论

Frontiers of physics 2024年第4期19卷 47-55页

作者： lin Ju Junxian Liu Minghui Wang Shenbo yang Shuli Liu School of Physics and Electric Engineering Anyang Normal UniversityAnyang 455000China School of Mechanical Medical and Process EngineeringQueensland University of TechnologyBrisbane QLD 4001Australia Hongzhiwei Technology(Shanghai)Co.Ltd. 1599 Xinjinqiao RoadPudongShanghai 201206China

Developing advanced hydrogen storage materials with high capacity and efficient reversibility is a crucial aspect for utilizing hydrogen source as a promising alternate to fossil *** this paper,we have systematically investigated the hydrogen storage properties of neutral and negatively charged C_(9)N_(4) monolayer based on density functional theory(DFT).Our foundings indicate that injecting additional electrons into the adsorbent significantly boosts the adsorption capacity of C_(9)N_(4) monolayer to H2 *** gravimetric density of negatively charged C_(9)N_(4) monolayer can reach up to 10.80 wt% when fully covered with *** other hydrogen storage methods,the storage and release processes happen automatically upon introducing or removing extra ***,these operations can be easily adjusted through activating or deactivating the charging *** a result,the method is easily reversible and has tunable kinetics without requiring particular ***,C_(9)N_(4) is proved to be a suitable candidate for efficient electron injection/release due to its well electrical *** work can serve as a valuable guide in the quest for a novel category of materials for hydrogen storage with high capacity.

关键词： hydrogen storage C_(9)N_(4)monolayer charge modulation density functional theory

Cobalt doping amount determines dominant reactive species in peroxymonosulfate activation via porous carbon catalysts co-doped by cobalt and nitrogen

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第4期138卷 212-226页

作者： Xiang Li Limeng Wu Aiqin zhang Shaohua Wu Yan lin Chunping yang Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle Nanchang Hangkong UniversityNanchang 330063China Academy of Environmental and Resource Sciences School of Environmental Science and EngineeringGuangdong University of Petrochemical TechnologyMaoming 525000China College of Environmental Science and Engineering Hunan University and Key Laboratory of Environmental Biology and Pollution Control(Hunan University)Ministry of EducationChangsha 410082China

Switching the reaction routes in peroxymonosulfate(PMS)-based advanced oxidation processes have attracted much attention but remain ***,a series of Co-N/C catalysts with different compositions and structures were prepared by using bimetallic zeolitic imidazolate frameworks based on ZIF-8 and ZIF-67(x Zn/Co-ZIFs).Results show that Co doping amount could mediate the transformation of the activation pathway of PMS over CoN/*** Co doping amount was less than 10%,the constructed x Co-N/C/PMS system(x≤10%)was singlet oxygen-dominated reaction;however further increasing Co doping amount would lead to the generation and coexistence of sulfate radicals and high-valent cobalt,besides singlet ***,the nitrogen-coordinated Co(Co-NX)sites could serve as main catalytically active sites to generate singlet *** excess Co doping amount caused the formation of Co nanoparticles from which leached Co ions were responsible for the generation of sulfate radicals and high-valent *** to undoped N/C,Co doping could significantly enhance the catalytic *** 0.5%Co-N/C could achieve the optimum degradation(0.488 min^(-1))and mineralization abilities(78.4%)of sulfamethoxazole among the investigated Co-N/C catalysts,which was superior to most of previously reported *** addition,the application prospects of the two systems in different environmental scenarios(pH,inorganic anions and natural organic matter)were assessed and showed different degradation *** study provides a strategy to regulate the reactive species in PMS-based advanced oxidation process.

关键词： Peroxymonosulfate Sulfate radical Singlet oxygen Cobalt Zeolitic imidazolate framework Advanced oxidation process

3D interlocked all-textile structured triboelectric pressure sensor for accurately measuring epidermal pulse waves in amphibious environments

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第3期17卷 1923-1932页

作者： Shaobo Si Chenchen Sun Yufen Wu Jingjing Li Han Wang Yinggang lin Jin yang Zhong lin Wang Department of Optoelectronic Engineering Key Laboratory of Optoelectronic Technology and Systems Ministry of EducationChongqing UniversityChongqing 400044China College of Physics and Electronic Engineering Chongqing Normal UniversityChongqing 401331China Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijing 100083China School of Materials Science and Engineering Georgia Institute of TechnologyAtlantaGA 30332USA

The performance degradation and even damage of the e-textiles caused by sweat,water,or submersion during all-weather health monitoring are the main reasons that e-textiles have not been commercialized and routinized so ***,we developed an amphibious,high-performance,air-permeable,and comfortable all-textile triboelectric sensor for continuous and precise measurement of epidermal pulse waves during full-day *** on the principle of preparing gas by acid-base neutralization reaction,a one-piece preparation process of amphibious conductive yarn(ACY)with densely porous structures is *** innovative three-dimensional(3D)interlocking fabric knitted from ACYs(0.6 mm in diameter)and polytetrafluoroethylene yarns exhibit high sensitivity(0.433 V·kPa^(-1)),wide bandwidth(up to 10 Hz),and stability(>30,000 cycles).With these benefits,98.8%agreement was achieved between wrist pulse waves acquired by the sensor and a high-precision laser ***,the polytetrafluoroethylene yarn with good compression resilience provides sufficient mechanical support for the contact separation of the ***,the unique skeletonized design of the 3D interlocking structure can effectively relieve the water pressure on the sensor surface to obtain stable and accurate pulse waves(underwater depth of 5 cm).This achievement represents an important step in improving the practicality of e-textiles and early diagnosis of cardiovascular diseases.

关键词： triboelectric pressure sensor amphibious fabric interlocking fabric pulse wave measurement one-piece preparation method

Comparison of models to predict air infiltration rate of buildings with different surrounding environments

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Building Simulation 2024年第6期17卷 1007-1021页

作者： Shu Zheng Xiujiao Song lin Duanmu Yu Xue Xudong yang Department of Building Science Tsinghua UniversityBeijing100084China School of Civil Engineering Dalian University of TechnologyDalian116024China Shanxi Research Institute for Clean Energy Tsinghua UniversityTaiyuan030032China

The air infiltration rate of buildings strongly influences indoor environment and energy *** this study,several traditional methods for determining the air infiltration rate were compared,and their accuracy in different scenarios was ***,a method combining computational flow dynamics(CFD)with the Swami and Chandra(S-C)model was developed to predict the influence of the surrounding environment on the air infiltration *** buildings in Dalian,China,were selected:one with a simple surrounding environment and the other with a complex surrounding environment;their air infiltration rates were *** test results were used to validate the accuracy of the air infiltration rate solution models in different urban *** the building with a simple environment,the difference between the simulation and experimental results was 0.86%–22.52%.For the building with a complex environment,this difference ranged from 17.42%to 159.28%.We found that most traditional models provide accurate results for buildings with simple surrounding and that the simulation results widely vary for buildings with complex *** results of the method of combining CFD with the S-C model were more accurate,and the relative error between the simulation and test results was 10.61%.The results indicate that the environment around the building should be fully considered when calculating the air infiltration *** results of this study can guide the application of methods of determining air infiltration rate.

关键词： air infiltration rate models CFD simulation building surrounding air infiltration rate test

Stability-Considered Lane Keeping Control of Commercial Vehicles Based on Improved APF Algorithm

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2024年第1期37卷 114-129页

作者： Bin Tang Zhengyi yang Haobin Jiang Ziyan lin zhanxiang Xu Zitian Hu Automotive Engineering Research Institute Jiangsu UniversityZhenjiang 212013China

Regarding the lane keeping system,path tracking accuracy and lateral stability at high speeds need to be taken into account especially for commercial vehicles due to the characteristics of larger mass,longer wheelbase and higher mass *** improve the performance mentioned above comprehensively,the control strategy based on improved artificial potential field(APF)algorithm is *** the paper,time to lane crossing(TLC)is introduced into the potential field function to enhance the accuracy of path tracking,meanwhile the vehicle dynamics parameters including yaw rate and lateral acceleration are chosen as the repulsive force field *** lane keeping controller based on improved APF algorithm is designed and the stability of the control system is proved based on Lyapunov *** addition,adaptive inertial weight particle swarm optimization algorithm(AIWPSO)is applied to optimize the gain of each potential field *** co-simulation results indicate that the comprehensive evaluation index respecting lane tracking accuracy and lateral stability is reduced ***,the proposed control strategy is verified by the HiL *** provides a beneficial reference for dynamics control of commercial vehicles and enriches the theoretical development and practical application of artificial potential field method in the field of intelligent driving.

关键词： Lane keeping control Commercial vehicles Lateral stability Artificial potential field AIWPSO

Estimating Critical Clearing Time of Grid Faults Using DA of State-Reduction Model of Power Systems

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第2期10卷 807-820页

作者： yang Liu Zhongyang Chen Huanjin Yao lin Yi Q.H.Wu School of Electric Power Engineering South China University of TechnologyGuangzhou 510640China China Southern Power Grid Research Institute Guangzhou 510663China

This paper proposes a critical clearing time (CCT) estimation method by the domain of attraction (DA) of a state-reduction model of power systems using sum of squares (SOS) programming. By exploiting the property of the Jacobian matrix and the structure of the boundary of the DA, it is found the DA of the state-reduction model and that of the full model of a power system are topological isomorphism. There are one-to-one correspondence relationships between the number of equilibrium points, the type of equilibrium points, and solutions of the two system models. Based on these findings, an expanding interior algorithm is proposed with SOS programming to estimate the DA of the state-reduction model. State trajectories of the full model can be transformed to those of the state-reduction model by orthogonal or equiradius projection. In this way, CCT of a grid fault is estimated with the DA of the state-reduction model. The calculational burden of SOS programming in the DA estimation using the state-reduction model is rather small compared with using the full model. Simulation results show the proposed expanding interior algorithm is able to provide a tight estimation of DA of power systems with higher accuracy and lower time costs.

关键词： Critical clearing time domain of attraction expanding interior algorithm state-reduction model SOS programming

Filtration performance and modeling of granular bed for dust removal from coal pyrolytic vapors

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第1期65卷 35-42页

作者： Shuaiqiang yang lin Du Guangchao Ding Runguo Liu Wenli Song Songgeng Li State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Petrochemical Engineering Yan’an Vocational and Technical CollegeYan’an 716000China Sino-Danish College University of Chinese Academy of SciencesBeijing 100049China

Dust removal from pyrolytic vapors at high temperatures is an obstacle to the industrialization of the coal pyrolysis *** this work,a granular bed with expanded perlites as filtration media was designed and integrated into a 10 t·d^(–1)coal pyrolysis *** testing results showed that around 97.56%dust collection efficiency was *** a result,dust content in tar was significantly *** pressure drop of the granular bed maintained in the range of 356 Pa to 489 *** dust size in the effluent after filtration exhibited a bimodal distribution,which was attributed to the heterogeneity of the dust *** effects of filtration bed on pyrolytic product yields were also discussed.A modified filtration model based on the macroscopic phenomenological theory was proposed to describe the performance of the granular *** computation results were well agreed with the experimental data.

关键词： Granular bed filtration Dust removal Pyrolysis Filtration Fixed-bed

Dealuminated Hβ zeolite for selective conversion of fructose to furfural and formic acid

在线全文

学校读者我要写书评

暂无评论

Green Energy & Environment 2024年第2期9卷 311-320页

作者： Rui Li Qixuan lin Junli Ren Xiaobao yang Yingxiong Wang lingzhao Kong State Key Laboratory of Pulp and Paper Engineering School of Light Industry and EngineeringSouth China University of TechnologyGuangzhou510640China Institute of Coal Chemistry Chinese Academy of Sciences27 South Taoyuan RoadTaiyuan030001China CAS Key Laboratory of Low-Carbon Conversion Science and Engineering Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai201210China School of Environmental Science and Technology Suzhou University of Science and Technology Suzhou Jiangsu215009China

The fructose-to-furfural transformation is facing major challenges in the selectivity and high efficiency. Herein, we have developed a simple and effective approach for the selective conversion of fructose to furfural using Hβ zeolite modified by organic acids for dealuminization to regulate its textural and acidic properties. It was found that citric acid-dealuminized Hβ zeolite possessed high specific surface areas, wide channels and high Brønsted acid amount, which facilitated the selective conversion of fructose to furfural with a maximum yield of 76.2% at433 K for 1 h in the γ-butyrolactone(GBL)-H_(2)O system, as well as the concomitant formation of 83.0% formic acid. The^(13)C-isotope labelling experiments and the mechanism revealed that the selective cleavage of C1–C2 or C5–C6 bond on fructose was firstly occurred to form pentose or C5 intermediate by weak Brønsted acid, which was then dehydrated to furfural by strong Brønsted acid. Also this dealuminized Hβ catalyst showed the great recycling performance and was active for the conversion of glucose and mannose.

关键词： Fructose Dealuminated-Hb zeolite Selective conversion Furfural