检索结果-南通市图书馆

Deep learning methods for roping defect analysis in aluminum alloy sheets: prediction and grading

在线全文

学校读者我要写书评

暂无评论

Advances in Manufacturing 2024年第3期12卷 576-590页

作者： yuan-Zhe Hu Ru-Xue Liu Jia-Peng He Guo-Wei Zhou da-Yong Li State Key Laboratory of Mechanical Systems and Vibration Shanghai Jiao Tong UniversityShanghai200240People’s Republic of China School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240People’s Republic of China

Roping is a severe band-like surface defect that occurs in deformed aluminum alloy *** roping prediction and rating are essential for industrial ***,the authors introduced an artificial neural network(ANN)model to efficiently forecast roping behavior across the thickness of large regions with texture *** this study,the previously proposed ANN model for roping prediction is briefly reviewed,and a few-shot learning(FSL)-based method is developed for roping grading with limited *** consider the directionality of the roping patterns,the roping dataset constructed from experimental observations is transformed into the frequency domain for more compact characterization.A transfer-based FSL method is further presented for grade roping with manifold mixup regularization and the Sinkhorn mapping algorithm.A new component-focused representation is also implemented for data-processing,exploiting the close correlation between roping and power distribution in the frequency *** ultimate FSL method achieved an optimal accuracy of 95.65%in roping classification with only five training samples per class,outperforming four typical FSL *** FSL approach can be applied to grade the roping morphologies predicted by the ANN ***,the combination of prediction and grading using deep learning provides a new paradigm for roping analysis and control.

关键词： Roping Artificial neural network(ANN) Aluminum alloys Few-shot classification Surface morphology

Predicting submerged vegetation drag with a machine learning-based method

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

Journal of Hydrodynamics 2024年第3期36卷 534-545页

作者： Meng-yang Liu Hong-wu Tang Sai-yu yuan Jing Yan College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing210098China Key Laboratory of Hydrologic-Cycle and Hydrodynamic-System of Ministry of Water Resources Hohai UniversityNanjing210098China

Accurate estimation of the drag forces generated by vegetation stems is crucial for the comprehensive assessment of the impact of aquatic vegetation on hydrodynamic processes in aquatic *** coupling relationship between vegetation layer flow velocity and vegetation drag makes precise prediction of submerged vegetation drag forces particularly *** present study utilized published data on submerged vegetation drag force measurements and employed a genetic programming(GP)algorithm,a machine learning technique,to establish the connection between submerged vegetation drag forces and flow and vegetation *** using the bulk velocity,U,as the reference velocity scale to define the drag coefficient,C_(d),and stem Reynolds number,the GP runs revealed that the drag coefficient of submerged vegetation is related to submergence ratio(H^(*)),aspect ratio(d^(*)),blockage ratio(ψ^(*)),and vegetation density(λ).The relation between vegetation stem drag forces and flow velocity is implicitly embedded in the definition of C_(d).Comparisons with experimental drag force measurements indicate that using the bulk velocity as the reference velocity,as opposed to using the vegetation layer average velocity,U_(v),eliminates the need for complex iterative processes to estimate U_(v)and avoids introducing additional errors associated with U_(v)*** approach significantly enhances the model’s predictive capabilities and results in a simpler and more user-friendly formula expression.

关键词： Drag coefficient genetic programming algorithm submerged vegetation flow resistance cylinder array

Effects of Biostimulation-Bioaugmentation on Coastal Microbial Community in an in situ Mesocosm System

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

Journal of Ocean University of China 2024年第1期23卷 233-246页

作者： yuan Fangzheng ZHAO yangyong daI Yulai yang Wen ZHU Jinyong College of Marine Science Ningbo UniversityNingbo 315800China Zhejiang Easytest Environmental Technology Co. Ltd.Ningbo 315800China Hangzhou Academy of Agricultural Sciences Hangzhou 310024China

Globally,various types of pollution affect coastal waters as a result of human *** and biostimulation are effective methods for treating water ***,few studies have explored the response of coastal prokaryotic and eukaryotic communities to bioaugmentation and ***,a 28-day outdoor mesocosm experiment with two treatments(bioaugmentation-A and combined treatment of bioaugmentation and biostimulation-AS)and a control(untreated-C)were carried *** experiment was conducted in Meishan Bay to explore the composition,dynamics,and co-occurrence patterns of prokaryotic and eukaryotic communities in response to the A and AS using 16S rRNA and 18S rRNA gene amplicon *** treatment,Gammaproteobacteria and Epsilonproteobacteria were significantly increased in group AS compared to group C,while Flavobacteriia and Saprospirae were significantly *** was significantly reduced in AS compared to C,while Chrysophyta was significantly reduced in both AS and *** to C,the principal response curve analyses of the prokaryotic and eukaryotic communities both showed an increasing trend followed by a decreasing trend for ***,the trends of prokaryotic and eukaryotic communities in group A were similar to those in group AS compared with group C,but AS changed them more than A *** to the species weight table on principal response curves,a significant increase was observed in beneficial bacteria in prokaryotic communities,such as Rhodobacterales and Oceanospirillales,along with a decrease in autotrophs in eukaryotic communities,such as Chrysophyta and *** properties of network analysis reveal that A and AS complicate the interactions between the prokaryotic and eukaryotic ***,these findings expand our understanding of the response pattern of the bioaugmentation and biostimulation on coastal prokaryotic and eukaryotic communities.

关键词： prokaryotic community eukaryotic community bioaugmentation biostimulation coastal waters

Extraordinary hot extreme in summer 2022 over the yangtze River basin modulated by the La Nina condition under global warming

在线全文

学校读者我要写书评

暂无评论

Advances in Climate Change Research 2024年第1期15卷 21-30页

作者： Zhen LIAO Yu-Feng yuan yang CHEN Pan-Mao ZHAI State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China

A widespread and prolonged hot extreme hit the yangtze River basin in summer 2022,with 300 sites established new temperature records and nearly 96%stations endured more than 40 hot *** the perspective of the combination effect of the global warming and La Nina condition,potential mechanisms of the hot extreme were *** a record-breaking hot extreme was caused by an extremely strong and westward-shifted western Pacific subtropical high(WPSH).The global warming effect contributed primarily to the abnormal hot days in the yangtze River basin,coupled with the modulation of the La Nina *** sea surface temperature anomaly pattern under La Nina condition favored more convection activities over the western Pacific,encouraging an enhanced and westward-extended *** addition,an observation-based attribution analysis indicates that anthropogenic warming may increase the probability of such extensively persistent hot extremeby1.8 times.

关键词： Hot extreme The yangtze River basin Global warming Tropical Pacific forcing

Characterization of blueberry exosome-like nanoparticles and miRNAs with potential cross-kingdom human gene targets

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

Food Science and Human Wellness 2024年第2期13卷 869-878页

作者： yangfan Leng Liubin yang Siyi Pan Leilei Zhan Fang yuan College of Food Science and Technology Huazhong Agricultural UniversityWuhan 430070China Hubei Key Laboratory of Fruit&Vegetable Processing&Quality Control Huazhong Agricultural UniversityWuhan 430070China Wuhan GeneCreate Biological Engineering Co. Ltd.Wuhan 430070China

Edible plant derived exosome-like nanoparticles(ELNs)have been shown to have multiple nutraceutical ***,the diversity of plant materials makes the plant derived ELN study *** efforts are still needed to explore the feasible isolation methods of edible plant derived ELNs and the possible roles of food-derived ELNs in improving human *** this study,a size exclusion chromatography based method was compared with the traditional ultracentrifugation method to isolate blueberry derived ELNs(B-ELNs),and the miRNA profile of B-ELNs was analyzed by high-throughput sequencing.A total of 36 miRNAs were found to be enriched in B-ELNs compared with berry tissue,and their potential cross-kingdom human gene targets were further *** showed that size exclusion chromatography was effective for B-ELN *** most abundant miRNAs in B-ELNs mainly belonged to the miR166 family and miR396 *** gene prediction indicated that B-ELNs could potentially regulate pathways related to the human digestive system,immune system and infectious diseases.

关键词： Edible plant derived exosomes-like nanoparticles Size exclusion chromatography miRNA Target gene prediction Blueberry

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)

BDSec:Security Authentication Protocol for BeiDou-Ⅱ Civil Navigation Message

在线全文

学校读者我要写书评

暂无评论

China Communications 2024年第6期21卷 206-218页

作者： Wu Zhijun Zhang yuan yang Yiming Wang Peng Yue Meng School of Safety Science and Engineering Civil Aviation University of ChinaTianjin 300300China School of Electronic Information and Automation Civil Aviation University of ChinaTianjin 300300China

Due to the lack of authentication mechanism in BeiDou navigation satellite system(BDS),BD-Ⅱ civil navigation message(BDⅡ-CNAV) are vulnerable to spoofing attack and replay *** solve this problem,we present a security authentication protocol,called as BDSec,which is designed by using China’s cryptography Shangyong Mima(SM) series algorithms,such as SM2/4/9 and Zu Chongzhi(ZUC)*** BDSec protocol,both of BDⅡ-CNAV and signature information are encrypted using the SM4 algorithm(Symmetric encryption mechanism).The encrypted result is used as the subject authentication *** protocol applies SM9 algorithm(Identity-based cryptography mechanism) to protect the integrity of the BDⅡ-CNAV,adopts the SM2 algorithm(Public key cryptosystem) to guarantee the confidentiality of the important session information,and uses the ZUC algorithm(Encryption and integrity algorithm) to verify the integrity of the message authentication serial number and initial information and the information in authentication initialization sub-protocol *** results of the SVO logic reasoning and performance analysis show that BDSec protocol meets security requirements for the dual user identity authentication in BDS and can realize the security authentication of BDⅡ-CNAV.

关键词： BDII civil navigation messages(BDIICNAV) BeiDou navigation satellite system(BDS) identity-based cryptography mechanism navigation message authentication protocol(BDSec)

Understanding the Thermal Impedance of Silicone Rubber/Hexagonal Boron Nitride Composites as Thermal Interface Materials

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第3期42卷 352-363,I0008页

作者： yuan Ji Shi-da Han Hong Wu Shao-Yun Guo Feng-Shun Zhang Jian-Hui Qiu The State Key Laboratory of Polymer Materials Engineering Sichuan Provincial Engineering Laboratory of Plastic/Rubber Complex Processing TechnologyPolymer Research InstituteSichuan UniversityChengdu 610065China Institute of Chemical Materials China Academy of Engineering PhysicsMianyang 621900China Department of Mechanical Engineering Faculty of Systems Science and TechnologyAkita Prefectural UniversityAkita 015-0055Japan

Silicone rubber(SR) composites are most widely used as thermal interface materials(TIMs) for electronics heat dissipation. Thermal impedance as the main bottleneck limiting the performance of TIMs is usually neglected. Herein, the thermal impedance of SR composites loaded with different levels of hexagonal boron nitride(h-BN) as TIMs was elaborated for the first time by the ASTM D 5470 standard test and finite element analysis. It was found that elastic modulus and surface roughness of SR composites increased with the increase of h-BN content, indicating that the conformity was reduced. When the assembly pressure was 0.69 MPa, there existed an optimal h-BN content at which the contact resistance was minimum(0.39 K·cm^(2)·W^(-1)). Although the decreased bond line thickness(BLT) by increasing the assembly pressure was beneficial to reduce the thermal impedance, the proper assembly pressure should be selected to prevent the warpage of the contact surfaces and the increase in contact resistance, according to the compression properties of the SR composites. This study provides valuable insights into fabrication of high-performance TIMs for modern electronic device applications.

关键词： Thermal interface materials Hexagonal boron nitride Thermal impedance Surfaces

Extreme value theory applied to the auroral electrojet indices

在线全文

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2024年第2期8卷 375-381页

作者： Si Chen Hong yuan Yong Wei Guang yang FengZheng Yu Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094China Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

The study of extreme weather and space events has gained paramount importance in modern society owing to rapid advances in high *** and describing exceptional occurrences plays a crucial role in making decisive assessments of their potential impact on technical,economic,and social aspects in various *** research focuses on analyzing the hourly values of the auroral electrojet(AE)geomagnetic index from 1957 to 2019 by using the peak over threshold method in extreme value *** fitting the generalized Pareto distribution to extreme AE values,shape parameter indices were derived,revealing negative values that establish an upper bound for this time ***,it became evident that the AE values had reached a plateau,suggesting that extreme events exceeding the established upper limit are *** a result,although the need for diligent precautions to mitigate the consequences of such extreme events persists,surpassing the upper limit of AE values becomes increasingly *** is also possible to observe an aurora in the middle-and low-latitude regions during the maximum period of the AE index.

关键词： auroral electrojet indices extreme value theory extreme events