检索结果-南通市图书馆

Two-Staged Method for Ice Channel Identification Based on Image Segmentation and Corner Point Regression

China Ocean Engineering 2024年第2期38卷 313-325页

作者： DONG wen-bo ZHOU Li ding Shi-feng WANG Ai-ming CAI Jin-yan School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Identification of the ice channel is the basic technology for developing intelligent ships in ice-covered waters,which is important to ensure the safety and economy of navigation.In the Arctic,merchant ships with low ice class often navigate in channels opened up by icebreakers.Navigation in the ice channel often depends on good maneuverability skills and abundant experience from the captain to a large extent.The ship may get stuck if steered into ice fields off the channel.Under this circumstance,it is very important to study how to identify the boundary lines of ice channels with a reliable method.In this paper,a two-staged ice channel identification method is developed based on image segmentation and corner point regression.The first stage employs the image segmentation method to extract channel regions.In the second stage,an intelligent corner regression network is proposed to extract the channel boundary lines from the channel region.A non-intelligent angle-based filtering and clustering method is proposed and compared with corner point regression network.The training and evaluation of the segmentation method and corner regression network are carried out on the synthetic and real ice channel dataset.The evaluation results show that the accuracy of the method using the corner point regression network in the second stage is achieved as high as 73.33%on the synthetic ice channel dataset and 70.66%on the real ice channel dataset,and the processing speed can reach up to 14.58frames per second.

关键词： ice channel ship navigation identification image segmentation corner point regression

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Gradient sparsification for efficient wireless federated learning with differential privacy

引用

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

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Patterns and drivers of avian taxonomic and phylogenetic beta diversity in China vary across geographical backgrounds and dispersal abilities

引用

Zoological Research 2024年第1期45卷 125-135页

作者： Jian-Chao Liang Zhi-feng ding Chun-Lin Li Yi-Ming Hu Zhi-Xin Zhou Gan-wen Lie Xiao-Nan Niu wen-Bin Huang Hui-Jian Hu Xing-feng Si Guangdong Key Laboratory of Animal Conservation and Resource Utilization Guangdong Public Laboratory of Wild Animal Conservation and UtilizationInstitute of ZoologyGuangdong Academy of SciencesGuangzhouGuangdong 510260China School of Resources and Environmental Engineering Anhui UniversityHefeiAnhui 230601China Guangdong Eco-Engineering Polytechnic GuangzhouGuangdong 510520China Huizhou Institute of Forestry(Huizhou Botanical Garden Management Service Center) HuizhouGuangdong 516001China Administration of National Nature Reserve for Marine Ecology of Guangdong Nanpeng Islands ShantouGuangdong 515900China Zhejiang Zhoushan Archipelago Observation and Research Station Institute of Eco-ChongmingZhejiang Tiantong Forest Ecosystem National Observation and Research StationSchool of Ecological and Environmental SciencesEast China Normal UniversityShanghai 200241China

Geographical background and dispersal ability may strongly influence assemblage dissimilarity;however,these aspects have generally been overlooked in previous large-scale beta diversity studies.Here,we examined whether the patterns and drivers of taxonomic beta diversity(TBD)and phylogenetic beta diversity(PBD)of breeding birds in China vary across(1)regions on both sides of the Hu Line,which demarcates China’s topographical,climatic,economic,and social patterns,and(2)species with different dispersal ability.TBD and PBD were calculated and partitioned into turnover and nestedness components using a moving window approach.Variables representing climate,habitat heterogeneity,and habitat quality were employed to evaluate the effects of environmental filtering.Spatial distance was considered to assess the impact of dispersal limitation.Variance partitioning analysis was applied to assess the relative roles of these variables.In general,the values of TBD and PBD were high in mountainous areas and were largely determined by environmental filtering.However,different dominant environmental filters on either side of the Hu Line led to divergent beta diversity patterns.Specifically,climate-driven species turnover and habitat heterogeneity-related species nestedness dominated the regions east and west of the line,respectively.Additionally,bird species with stronger dispersal ability were more susceptible to environmental filtering,resulting in more homogeneous assemblages.Our results indicated that regions with distinctive geographical backgrounds may present different ecological factors that lead to divergent assemblage dissimilarity patterns,and dispersal ability determines the response of assemblages to these ecological factors.Identifying a single universal explanation for the observed pattern without considering these aspects may lead to simplistic or incomplete conclusions.Consequently,a comprehensive understanding of large-scale beta diversity patterns and effective planning of conservation strategies necessitate the

关键词： Beta diversity Environmental filtering Dispersal limitation Hu Line Species dispersal ability Breeding birds

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Nontraditional energy-assisted mechanical machining of difficult-to-cut materials and components in aerospace community:a comparative analysis

引用

International Journal of Extreme Manufacturing 2024年第2期6卷 190-271页

作者： Guolong Zhao Biao Zhao wenfeng ding Lianjia Xin Zhiwen Nian Jianhao Peng Ning He Jiuhua Xu College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016People’s Republic of China

The aerospace community widely uses difficult-to-cut materials,such as titanium alloys,high-temperature alloys,metal/ceramic/polymer matrix composites,hard and brittle materials,and geometrically complex components,such as thin-walled structures,microchannels,and complex surfaces.Mechanical machining is the main material removal process for the vast majority of aerospace components.However,many problems exist,including severe and rapid tool wear,low machining efficiency,and poor surface integrity.Nontraditional energy-assisted mechanical machining is a hybrid process that uses nontraditional energies(vibration,laser,electricity,etc)to improve the machinability of local materials and decrease the burden of mechanical machining.This provides a feasible and promising method to improve the material removal rate and surface quality,reduce process forces,and prolong tool life.However,systematic reviews of this technology are lacking with respect to the current research status and development direction.This paper reviews the recent progress in the nontraditional energy-assisted mechanical machining of difficult-to-cut materials and components in the aerospace community.In addition,this paper focuses on the processing principles,material responses under nontraditional energy,resultant forces and temperatures,material removal mechanisms,and applications of these processes,including vibration-,laser-,electric-,magnetic-,chemical-,advanced coolant-,and hybrid nontraditional energy-assisted mechanical machining.Finally,a comprehensive summary of the principles,advantages,and limitations of each hybrid process is provided,and future perspectives on forward design,device development,and sustainability of nontraditional energy-assisted mechanical machining processes are discussed.

关键词： difficult-to-cut materials geometrically complex components nontraditional energy mechanical machining aerospace community

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Highly Conductive Ag/pCF/MVQ Composite Rubber for Efficient Electromagnetic Interference Shielding

引用

Chinese Journal of Polymer Science 2024年第6期42卷 864-873页

作者： Yang Chen Xiao-Ming Shao Liang He Yi-Nuo Xu Qi-Yuan Yao ding feng wen-Cai Wang State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing100029China Key Laboratory of Beijing City for Preparation and Processing of Novel Polymer Materials Beijing University of Chemical TechnologyBeijing100029China Sino-german School of Engineering Qingdao University of Science and TechnologyQingdao266400China

In this study,flexible and highly conductive composite rubber at low filler content was successfully prepared through polydopamine-assisted electroless silver plating plus mechanical mixing.Firstly,carbon fibers(CF)were activated by polydopamine(PDA)to improve the surface activity by self-polymerization reaction.Next,because of the metal chelating ability of PDA,silver layer was firmly deposited on the surface of CF through a facile electroless silver plating method.Finally,flexible silver-plated carbon fibers(Ag/pCF)silicone rubber composites prepared by mechanical mixing.By using X-ray photoelectron spectroscopy(XPS)and X-ray diffraction(XRD),the chemical composition and crystal structure of Ag/pCF were examined,and scanning electron microscopy(SEM)was used to assess the surface morphology of the Ag/pCF.The results showed that a uniform and dense silver layer was formed on the surface of the CF,and the conductivity of the Ag/pCF could reach 7885 S/cm.It was noteworthy that the composite rubber filled with only 45 phr Ag/pCF had a high electromagnetic interference shielding effectiveness(100 dB)due to the low density and high aspect ratio of Ag/pCF.The composite rubber has excellent potential for application in the field of electromagnetic interference shielding.

关键词： Carbon fibers Polydopamine Electroless plating Silver Electromagnetic interference shielding

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Histological Features of Uterine Myometrial Dysfunction:Possible Involvement of Localized Inflammation

引用

Current Medical Science 2024年第3期44卷 633-641页

作者： Sheng-lan ZHU Hui-ting ZHANG Yuan-yuan DU Yi JIANG Shao-shuai WANG wen-cheng ding Ling feng National Clinical Research Center for Obstetrics and Gynecology Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430030China Department of Obstetrics and Gynecology Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430030China

Objective The latest perspective suggests that elevated levels of inflammation and cytokines are implicated in atonic postpartum hemorrhage.Lipopolysaccharide(LPS)has been widely used to induce inflammation in animal models.Therefore,this study aimed to induce uterine inflammation using LPS to investigate whether local inflammation triggers dysfunction and atrophy in the myometrium,as well as the potential underlying molecular mechanisms involved.Methods In vivo,an animal model was established by intraperitoneal injection of 300μg/kg LPS in rats on gestational day 21.Hematoxylin-eosin(H&E)staining and Masson staining were employed to determine morphological changes in the rat uterine smooth muscle.Enzyme-linked immunosorbent assay(ELISA)was used to detect inflammatory cytokines.Immunohistochemistry,tissue fluorescence,and Western blotting were conducted to assess the expression levels of the uterine contraction-related proteins Toll-like receptor 4(TLR4)and the nuclear factor kappa-B(NF-κB)signaling pathway.In vitro,human uterine smooth muscle cells(HUtSMCs)were exposed to 2μg/mL LPS to further elucidate the involvement of the TLR4/NF-κB signaling pathway in LPS-mediated inflammation.Results In this study,LPS induced uterine myometrial dysfunction in rats,leading to a disorganized arrangement,a significant increase in collagen fiber deposition,and widespread infiltration of inflammatory cells.In both in vivo animal models and in vitro HUtSMCs,LPS elevated IL-6,IL-1β,and TNF-αlevels while concurrently suppressing the expression of connexin 43(Cx43)and oxytocin receptor(OXTR).Mechanistically,the LPS-treated group exhibited TLR4 activation,and the phosphorylation levels of p65 and IκBαwere notably increased.Conclusion LPS triggered the TLR4/NF-κB signaling pathway,inducing an inflammatory response in the myometrium and leading to uterine myometrial dysfunction and uterine atony.

关键词： lipopolysaccharide inflammatory response TLR4 NF-κB myometrium

来源：

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

Effect of tungsten carbide particles on microstructure and mechanical properties of Cu alloy composite bit matrix

引用

Journal of Iron and Steel Research(International) 2024年第2期31卷 519-530页

作者： ding-qian Dong feng-yuan He Xin-hui Chen Hui Li Kai-hua Shi Hui-wen Xiong Xin Xiang Li Zhang College of Mechanical Engineering Sichuan University of Science and EngineeringZigong643000SichuanChina State Key Laboratory of Powder Metallurgy Central South UniversityChangsha410083HunanChina Zigong Cemented Carbide Co. Ltd.Zigong643011SichuanChina Material Corrosion and Protection Key Laboratory of Sichuan Province Sichuan University of Science and EngineeringZigong643000SichuanChina

Copper alloy composite bit matrix was prepared by pressureless vacuum infiltration,using at least one of the three kinds of tungsten carbide particles,for example,irregular cast tungsten carbide,monocrystalline tungsten carbide and sintered reduced tungsten carbide particles.The effects of powder particle morphology,particle size and mass fraction of tungsten carbide on the microstructure and mechanical properties of copper alloy composite were investigated by means of scanning electron microscopy,X-ray diffraction and abrasive wear test in detail.The results show that tungsten carbide morphology and particle size have obvious effects on the mechanical properties of copper alloy composites.Cast tungsten carbide partially dissolved in the copper alloy binding phase,and layers of Cu_(0.3)W_(0.5)Ni_(0.1)Mn_(0.1)C phase with a thickness of around 8–15μm were formed on the edge of the cast tungsten carbide.When 45%irregular crushed fine cast tungsten carbide and 15%monocrystalline cast tungsten carbide were used as the skeleton,satisfactory comprehensive performance of the reinforced copper alloy composite bit matrix was obtained,with the bending strength,impact toughness and hardness reaching 1048 MPa,4.95 J/cm^(2) and 43.6 HRC,respectively.The main wear mechanism was that the tungsten carbide particles firstly protruded from the friction surface after the copper alloy matrix was worn,and then peeled off from the matrix when further wear occurred.

关键词： Polycrystalline diamond compact Pressureless vacuum infiltration Copper alloy composite bit matrix Microstructure characterization Abrasive wear behavior

来源：

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

Management of retroperitoneal high-grade serous carcinoma of unknown origin:A case report

引用

World Journal of Clinical Cases 2024年第6期12卷 1190-1195页

作者： wen-Lin Hsieh Dah-Ching ding Department of Obstetrics and Gynecology Hualien Tzu Chi HospitalBuddhist Tzu Chi Medical FoundationTzu Chi UniversityHualien 970Taiwan Institute of Medical Sciences Tzu Chi UniversityHualien 970TaiwanTaiwan

BACKGROUND Retroperitoneal high-grade serous carcinoma(HGSC)of unknown origin is a sporadic tumor that can originate from ovarian cancer.Herein,we report the case of a woman with retroperitoneal HGSC of unknown origin and describe how she was diagnosed and treated.CASE SUMMARY A 71-year-old female presented with the tumor marker CA125 elevated to 1041.9 U/mL upon a regular health examination.Computed tomography revealed retroperitoneal lymph node enlargement.Subsequently,positron emission tomography scanning revealed lesions with increased F-18 fluorodeoxyglucose uptake at the nodes.As a result,she underwent laparoscopic lymph node resection,and pathology revealed metastatic adenocarcinoma with CK7(+),PAX8(+),WT1(+),PR(-),and p53 mutational loss of expression,indicating that the origin may be from the adnexa.The patient was admitted to our ward and underwent laparoscopic staging;however,the pathological results were negative.Under the suspicion of retroperitoneal HGSC of unknown origin,chemotherapy and targeted therapy were initiated.Tumor marker levels decreased after treatment.CONCLUSION We present a case of HGSC of unknown origin managed using retroperitoneal lymphadenectomy,staging surgery,chemotherapy,and targeted therapy.

关键词： High-grade serous carcinoma Retroperitoneum Origin Chemotherapy Lymph node Case report

来源：

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

Knowledge-embedded spatio-temporal analysis for euploidy embryos identification in couples with chromosomal rearrangements

引用

Chinese Medical Journal 2024年第6期137卷 694-703页

作者： Fangying Chen Xiang Xie Du Cai Pengxiang Yan Chenhui ding Yangxing wen Yanwen Xu feng Gao Canquan Zhou Guanbin Li Qingyun Mai Reproductive Medicine Center The First Affiliated Hospital of Sun Yat-sen UniversityGuangzhouGuangdong 510080China Guangdong Provincial Key Laboratory of Reproductive Medicine GuangzhouGuangdong 510080China School of Computer Science and Engineering Sun Yat-sen UniversityGuangzhouGuangdong 510006China Department of General Surgery(Colorectal Surgery) The Sixth Affiliated Hospital of Sun Yat-sen UniversityGuangzhouGuangdong 510655China Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases The Sixth Affiliated HospitalSun Yat-sen UniversityGuangzhouGuangdong 510655China Biomedical Innovation Center The Sixth Affiliated HospitalSun Yat-sen UniversityGuangzhouGuangdong 510655China Shanghai Artificial Intelligence Laboratory Shanghai 200232China

Background:The goal of the assisted reproductive treatment is to transfer one euploid blastocyst and to help infertile women giving birth one healthy neonate.Some algorithms have been used to assess the ploidy status of embryos derived from couples with normal chromosome,who subjected to preimplantation genetic testing for aneuploidy(PGT-A)treatment.However,it is currently unknown whether artificial intelligence model can be used to assess the euploidy status of blastocyst derived from populations with chromosomal rearrangement.Methods:From February 2020 to May 2021,we collected the whole raw time-lapse videos at multiple focal planes from in vitro cultured embryos,the clinical information of couples,and the comprehensive chromosome screening results of those blastocysts that had received PGT treatment.Initially,we developed a novel deep learning model called the Attentive Multi-Focus Selection Network(AMSNet)to analyze time-lapse videos in real time and predict blastocyst formation.Building upon AMSNet,we integrated additional clinically predictive variables and created a second deep learning model,the Attentive Multi-Focus Video and Clinical Information Fusion Network(AMCFNet),to assess the euploidy status of embryos.The efficacy of the AMCFNet was further tested in embryos with parental chromosomal rearrangements.The receiver operating characteristic curve(ROC)was used to evaluate the superiority of the model.Results:A total of 4112 embryos with complete time-lapse videos were enrolled for the blastocyst formation prediction task,and 1422 qualified blastocysts received PGT-A(n=589)or PGT for chromosomal structural rearrangement(PGT-SR,n=833)were enrolled for the euploidy assessment task in this study.The AMSNet model using seven focal raw time-lapse videos has the best real-time accuracy.The real-time accuracy for AMSNet to predict blastocyst formation reached above 70%on the day 2 of embryo culture,and then increased to 80%on the day 4 of embryo culture.Combing with 4 clinical features of couples,the AUC of A

关键词： Euploidy status Embryo Time-lapse imaging Deep learning Spatio-temporal analysis Preimplantation genetic testing for chromosomal structural rearrangement

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A generalization of Banach's lemma and its applications to perturbations of bounded linear operators

引用

Applied Mathematics(A Journal of Chinese Universities) 2024年第2期39卷 363-369页

作者： WANG Zi ding Jiu WANG Yu-wen School of Mathematics Sciences Harbin Normal UniversityHarbin 150025China School of Mathematics and Natural Sciences The University of Southern MississippiHattiesburg MS 39406-5043USA Academic Committee Harbin Institute of PetroleumHarbin 150027China

Let X be a Banach space and let P:X→X be a bounded linear operator.Using an algebraic inequality on the spectrum of P,we give a new sufficient condition that guarantees the existence of(I-P)^(-1) as a bounded linear operator on X,and a bound on its spectral radius is also obtained.This generalizes the classic Banach lemma.We apply the result to the perturbation analysis of general bounded linear operators on X with commutative perturbations.

关键词： Banach lemma spectral radius generalized inverse perturbation analysis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：