检索结果-南通市图书馆

Gradient sparsification for efficient wireless federated learning with differential privacy

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第4期67卷 272-288页

作者： Kang WEI jun LI Chuan MA Ming DING Feng shu Haitao ZHAO Wen chen Hongbo ZHU School of Electronic and Optical Engineering Nanjing University of Science and Technology Zhejiang Lab Key Laboratory of Computer Network and Information Integration(Southeast University) Ministry of Education Data61 Commonwealth Scientific and Industrial Research Organisation School of Information and Communication Engineering Hainan University School of Communications and Information Engineering Nanjing University of Posts and Telecommunications School of Electronic Information and Electrical Engineering Shanghai Jiao Tong University

Federated learning(FL) enables distributed clients to collaboratively train a machine learning model without sharing raw data with each other. However, it suffers from the leakage of private information from uploading models. In addition, as the model size grows, the training latency increases due to the limited transmission bandwidth and model performance degradation while using differential privacy(DP)protection. In this paper, we propose a gradient sparsification empowered FL framework with DP over wireless channels, to improve training efficiency without sacrificing convergence performance. Specifically, we first design a random sparsification algorithm to retain a fraction of the gradient elements in each client’s local model, thereby mitigating the performance degradation induced by DP and reducing the number of transmission parameters over wireless channels. Then, we analyze the convergence bound of the proposed algorithm, by modeling a non-convex FL problem. Next, we formulate a time-sequential stochastic optimization problem for minimizing the developed convergence bound, under the constraints of transmit power, the average transmitting delay, as well as the client’s DP requirement. Utilizing the Lyapunov drift-plus-penalty framework, we develop an analytical solution to the optimization problem. Extensive experiments have been implemented on three real-life datasets to demonstrate the effectiveness of our proposed algorithm. We show that our proposed algorithms can fully exploit the interworking between communication and computation to outperform the baselines, i.e., random scheduling, round robin, and delay-minimization algorithms.

关键词： federated learning differential privacy gradient sparsification Lyapunov drift convergence analysis

同方期刊数据库

Numerical simulations for radon migration and exhalation behavior during measuring radon exhalation rate with closed-loop method

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第1期35卷 81-95页

作者： Ming Xia Yong-jun Ye shu-Yuan Liu School of Resources Environment and Safety Engineering University of South ChinaHengyang 421001China Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy University of South ChinaHengyang 421001China

Accurate measurements of the radon exhalation rate help identify and evaluate radon risk regions in the *** these measurement methods,the closed-loop method is frequently ***,traditional experiments are insufficient or cannot analyze the radon migration and exhalation patterns at the gas–solid interface in the accumulation *** CFD-based technique was applied to predict the radon concentration distribution in a limited space,allowing radon accumulation and exhalation inside the chamber intuitively and *** this study,three radon exhalation rates were defined,and two structural ventilation tubes were designed for the *** consistency of the simulated results with the variation in the radon exhalation rate in a previous experiment or analytical solution was *** effects of the vent tube structure and flow rate on the radon uniformity in the chamber;permeability,insertion depth,and flow rate on the radon exhalation rate and the effective diffusion coefficient on back-diffusion were *** on the results,increasing the inser-tion depth from 1 to 5 cm decreased the effective decay constant by 19.55%,whereas the curve-fitted radon exhalation rate decreased(lower than the initial value)as the deviation from the initial value increased by approximately 7%.Increasing the effective diffusion coefficient from 2.77×10^(-7) to 7.77×10^(-6) m^(2) s^(-1) made the deviation expand from 2.14 to 15.96%.The conclusion is that an increased insertion depth helps reduce leakage in the chamber,subject to notable back-diffusion,and that the closed-loop method is reasonably used for porous media with a low effective diffusion coefficient in view of the back-diffusion *** CFD-based simulation is expected to provide guidance for the optimization of the radon exhalation rate measurement method and,thus,the accurate measurement of the radon exhalation rate.

关键词： Radon exhalation Numerical simulation Accumulation chamber

维普期刊数据库

Thermoelectric transport properties of p-type Bi2Se3-Sb2Se3-In2Se3 high entropy compounds

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第7期43卷 3415-3421页

作者： Feng Jiang cheng-Liang Xia Yong-Bin Zhu jun Li Yue chen Wei-shu Liu Department of Materials Science and Engineering Southern University of Science and Technology Department of Mechanical Engineering The University of Hong Kong Guangdong Provincial Key Laboratory of Functional Oxide Materials and Devices Southern University of Science and Technology

The introduction of entropy concept into thermoelectric materials recently has attracted broad ***,we showed the phase diagram of the ternary systems of *** the high entropy compounds （HECs）,we have identified an in... 详细信息

关键词： Selenium compounds

Two different autorefractors for vision screening in children and adolescents

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2024年第2期17卷 331-338页

作者： Xiao-jun chen Lin-Jie Liu Bing Sun Dan-Dan Jiang shu-shu Zuo Yan-Hui Wang Chun-Hua Zhang Yan-Yan chen School of Optometry and Ophthalmology Wenzhou Medical UniversityWenzhou 325027Zhejiang ProvinceChina National Clinical Research Center for Ocular Diseases Eye HospitalWenzhou Medical UniversityWenzhou 325027Zhejiang ProvinceChina

AIM:To compare the consistency of two autorefractors(Tianle RM-9000 and Topcon KR-800)for school-age myopia children,and to provide a basis for largescale data analysis and ***:The refractive error in 909 subjects(age 4–18y)were measured using both autorefractors without *** data were analyzed using Fourier decomposition and the correlation coefficients,intraclass correlation coefficients(ICC),and Bland-Altman limits of agreement(LoA)for each parameter were ***:There was a strong correlation between the spherical equivalent(SE),sphere diopter(DS),and cylinder diopter(DC)readings of the Tianle RM-9000 and those of the Topcon KR-800,with correlation coefficient values of 0.98,0.98 and 0.83 and ICC values of 0.99,0.99 and 0.93,***,the correlation coefficients and ICC values of J0 and J45 were unreliable(R=-0.004,-0.034;both ICC<0.10).Bland-Altman analysis revealed that SE,DS,and DC measured by the Tianle RM-9000 were significantly biased toward myopia compared with the Topcon KR-800,and the mean differences were-0.072,-0.026,-0.091 D,respectively(all P<0.01).The minimum absolute value of the difference within the 95%LoA for SE,DS,and DC was 0.63 D,0.50 D,0.62 D,respectively;all these values were in the clinically acceptable *** J0 and J45,the mean differences were close to zero(P=0.43,0.84);however,the 95%LoA were relatively wide(J0 SD:0.53;95%CI:-1.00,1.10;J45 SD:0.52;95%CI:-1.00,1.00).CONCLUSION:The two autorefractors are consistent with each other,as the differences in SE,DS,and DC were within the clinically acceptable *** can compare the data measured by either device in different studies and use the two devices in the same study to generate a dataset that can be analyzed ***,the J0 and J45 vectors are unreliable and should not be used to assess astigmatism.

关键词： refractive error autorefractors school-age myopia children

Synthesis and characterization of iron clusters with an icosahedral [Fe@Fe12]16+ Core

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

National Science Review 2024年第4期11卷 123-129页

作者： Gan Xu Yun-shu Cui Xue-Lian Jiang Cong-Qiao Xu jun Li Xu-Dong chen Jiangsu Collaborative Innovation Center of Biomedical Functional Materials and Jiangsu Key Laboratory of New Power Batteries School of Chemistry and Materials Science Nanjing Normal University Department of Chemistry and Guangdong Provincial Key Laboratory of Catalytic Chemistry Southern University of Science and Technology Department of Chemistry and Engineering Research Center of Advanced Rare-Earth Materials of Ministry of Education Tsinghua University State Key Laboratory of Coordination Chemistry Nanjing University

Iron-metal clusters are crucial in a variety of critical biological and material systems,including metalloenzymes,catalysts,and magnetic storage ***,a synthetic high-nuclear iron cluster has been absent due to the extreme difficulty in stabilizing species with direct iron-iron *** this work,we have synthesized,crystallized,and characterized a（Tp*）4W4S12(Fe@Fe12) cluster(Tp*=tris（3,5-dimethyl-1-pyrazolyl）borate（1-）),which features a rare trideca-nuclear,icosahedral[Fe@Fe12] cluster core with direct multicenter iron-iron bonding between the interstitial iron（Fei） and peripheral irons（Fep）,as well as Fep…Fepferromagnetic *** chemistry studies reveal that the stability of the cluster arises from the 18-electron shell-closing of the [Fe@Fe12]16+core,assisted by its bonding interactions with the peripheral tridentate [（Tp*）WS3]4-ligands which possess both S→Fe donation and spin-polarized Fe-Wσ *** ground-state electron spin is theoretically predicted to be S=32/2 for the *** existence of low oxidation-state（OS～+1.23） iron in this compound may find interesting applications in magnetic storage,spintronics,redox chemistry,and cluster catalysis.

关键词： Fe13 cluster iron-sulfur cluster low-valence iron iron−iron bond high spin complex

Discovery of the choristodere Hyphalosaurus baitaigouensis from the Lower Cretaceous Jiufotang Formation of western Liaoning,China and its paleobiogeographic significance

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Palaeogeography 2024年第3期13卷 547-562页

作者： Li-jun Zhang shu-An Ji Hai-Chun Zhang South China Sea Culture Museum Hainan Tropical Ocean University Key Laboratory of Stratigraphy and Paleontology Ministry of Natural Resources Institute of Geology Chinese Academy of Geological Sciences State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment Chinese Academy of Sciences

The water-living reptile genus Hyphalosaurus was previously discovered in the Lower Cretaceous Yixian Formation bearing the middle Jehol Biota in western Liaoning, China. Two complete skeletons of Hyphalosaurus are reported for the first time from the Jiufotang Formation bearing the late Jehol Biota at two sites in western Liaoning. They show the typical characteristics of Hyphalosaurus baitaigouensis in terms of the contact between some cranial bones and the number of cervical and dorsal vertebrae, and therefore are assigned to H. baitaigouensis. This discovery extends the stratigraphic range of this species from the Yixian Formation to the overlying Jiufotang Formation. This paper further briefly compares the main characteristics of the two skeletons, summarizes the temporal and spatial distribution of Hyphalosaurus, and discusses the palaeogeographic evolution of western Liaoning at the middle and late Jehol Biota stages based on the aquatic habits of Hyphalosaurus and the geological background of western Liaoning. The analytical results show that the volcanic downwarped lakes, with distinct geographical divisions in western Liaoning during the deposition of the Yixian Formation, had not completely disappeared till the deposition of the Jiufotang Formation. The palaeo-lake in the Fuxin-Yixian Basin underwent the process of generation, expansion and shrinkage during the depositional period of the Yixian Formation and finally merged into a large lake. The palaeo-Dalinghe River,which connected the main basins in western Liaoning during the depositional period of the Jiufotang Formation, was formed simultaneously.

关键词： Western liaoning Jehol biota Jiufotang formation Hyphalosaurus baitaigouensis Palaeobiogeography

Mid-infrared Period–Luminosity Relations of Gaia DR3 Long Period Variables

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第7期24卷 59-73页

作者： Xiaohan chen Xiaodian chen Licai Deng shu Wang Tianlu chen Department of Physics College of ScienceTibet University Key Laboratory of Cosmic Rays (Tibet University) Ministry of Education CAS Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of Sciences School of Astronomy and Space Science University of the Chinese Academy of Sciences Department of Astronomy China West Normal University Institute for Frontiers in Astronomy and Astrophysics Beijing Normal University

Long period variable（LPV） stars are very promising distance indicators in the infrared bands. We selected asymptotic giant branch（AGB） stars in the Large and Small Magellanic Cloud（LMC and SMC） from the Gaia Data Release 3 LPV catalog, and classified them into oxygen-rich（O-rich） and carbon-rich（C-rich） AGB *** the Wide-field Infrared Survey Explorer database, we determined the W1-and W2-band period–luminosity relations（PLRs） for each pulsation-mode sequence of AGB stars. The dispersion of the PLRs of O-rich AGB stars in sequences C' and C is relatively small, around 0.14 mag. The PLRs of LMC and SMC are consistent in each sequence. In the W2 band, the PLR of large-amplitude C-rich AGB stars is steeper than that of small-amplitude C-rich AGB stars, due to their more circumstellar dust. By two methods, we find that some PLR sequences of O-rich AGB stars in the LMC are dependent on metallicity. The coefficients of the metallicity effect are β = –0.533 ± 0.213 mag dex1and β = –0.767 ± 0.158 mag dex1for sequence C in W1 and W2 bands, respectively. The significance of the metallicity effect in W1 band for the four sequences is 2.2-3.5σ. Both of these imply that distance measurements using O-rich Mira may need to take the metallicity effect into account.

关键词： infrared: stars stars: distances stars: variables: general

Boost VS_(2) electrochemical reactive kinetics by regulating crystallographic planes and coupling carbon matrix for high performance sodium-ion storage

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第1期43卷 98-112页

作者： Min Zeng Ming-Shan Wang Lin chen En-Zhi Li Zhen-Liang Yang Dan Zhou Hai-Jiao Xie jun-chen chen Zhi-Yuan Ma Bing-shu Guo Bo Yu Xing Li School of New Energy and Materials Southwest Petroleum UniversityChengdu 610500China Energy Storage Research Institute Southwest Petroleum UniversityChengdu 610500China Institute of Materials China Academy of Engineering PhysicsMianyang 621908China Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and TechnologyBeijingBeijing 100083China Hangzhou Yanqu Information Technology Co. Ltd.Hangzhou 310003China

Vanadium disulfide(VS_(2)) as a typical two-dimensional transition metal chalcogenide has excellent competitiveness for sodium-ion storage due to its wide layer spacing(0.575 nm),high theoretical capacity of 932mAh·g^(-1) originating from multi-electron electrochemical ***,continuous sodiation process accompanied by crystal structural evolution and collapse cause rapid capacity ***,novel few-layer VS_(2)nanosheets with open(001) crystal planes are in-situ constructed on reduced graphene oxide to solve these issues mentioned *** indicates that few-layer VS_(2)provides more Na^(+) storage activity due to the low Na^(+)surface migration energy barrier on exposed crystal(001)*** flexible and high electronic conductivity of carbon matrix also effectively builds multi-level buffer structure and electron transport kinetics to boost the Na^(+)insertion/conversion reactive activity on VS_(2) as well as Na^(+) pseudocapacitance storage kinetics on edges and defects of nano *** coupling effects result in high rate capability and long cycling stability as a battery/capacitor *** delivers conspicuous high energy density of 81 and 40 Wh·kg^(-1) at power density of 118 and 10,286W·kg^(-1),as well as 80% energy retention rate after 5000cycles,confirming its great application potential in sodiumbased storage devices.

关键词： Vanadium disulfide Reduced graphene oxide Anode Sodium-ion battery Sodium-ion capacitor

维普期刊数据库

Simultaneous type III congenital esophageal atresia and patent ductus arteriosus in a low-weight patient: A case report

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2024年第3期12卷 560-564页

作者： Yong-Yu Ma jun-Ru chen Shi-Wu Yang shu-Yu Wang Xin Cao jun Wu Faculty of Pediatrics Children’s Hospital Affiliated to Kunming Medical UniversityKunming 650103Yunnan ProvinceChina Department of Cardiothoracic Surgery Kunming Children’s HospitalKunming 650103Yunnan ProvinceChina

BACKGROUND We report a low-birth-weight child(1.8 kg)with neonatal type III congenital esophageal atresia(CEA)combined with symptomatic patent ductus arteriosus(PDA).After comprehensive evaluation,esophageal anastomosis was performed on postnatal day 11 after excluding surgical contraindications,and arterial catheter ligation was performed at the same *** surgery for CEA combined with PDA has not been clearly reported in the *** SUMMARY We report a 6-day-old female child with type III CEA and *** patient presented with foam at the mouth after birth,cough and shortness of breath after *** another hospital,she was considered to have neonatal pneumonia,neonatal jaundice and congenital heart disease and transferred to our *** iodine oil radiography of the esophagus and echocardiography we con-firmed diagnosis of CEA and *** diameter of the PDA was 8 mm,with obvious left to right *** performed right rear extrapleural orificium fistula ligation and esophageal anastomosis,and ligation of PDA via left axilla straight incision after 5 d of *** operations were successful,and the incision healed after 12 d,and the patient was *** re-examined the patient 1 mo after *** did not vomit when she ate rice *** angiography showed no stricture of the anastomotic *** patient weighed 3.2 *** For CEA patients with multiple risk factors,comprehensive,timely and accurate diagnosis and evaluation,and early treatment may improve prognosis.

关键词： Congenital esophageal atresia Patent ductus arteriosus Low weight One-stage operation Case report