检索结果-南通市图书馆

Adaptive and augmented active anomaly detection on dynamic network traffic streams

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Information Technology & Electronic Engineering 2024年第3期25卷 446-460页

作者： Bin LI Yijie WANG Li cheng National Key Laboratory of Parallel and Distributed Computing College of ComputerNational University of Defense TechnologyChangsha 410073China College of System Engineering National University of Defense TechnologyChangsha 410073China

Active anomaly detection queries labels of sampled instances and uses them to incrementally update the detection model,and has been widely adopted in detecting network ***,existing methods cannot achieve desirable performance on dynamic network traffic streams because(1)their query strategies cannot sample informative instances to make the detection model adapt to the evolving stream and(2)their model updating relies on limited query instances only and fails to leverage the enormous unlabeled instances on *** address these issues,we propose an active tree based model,adaptive and augmented active prior-knowledge forest(A3PF),for anomaly detection on network trafic streams.A prior-knowledge forest is constructed using prior knowledge of network attacks to find feature subspaces that better distinguish network anomalies from normal *** one hand,to make the model adapt to the evolving stream,a novel adaptive query strategy is designed to sample informative instances from two aspects:the changes in dynamic data distribution and the uncertainty of *** the other hand,based on the similarity of instances in the neighborhood,we devise an augmented update method to generate pseudo labels for the unlabeled neighbors of query instances,which enables usage of the enormous unlabeled instances during model *** experiments on two benchmarks,CIC-IDS2017 and UNSW-NB15,demonstrate that A3PF achieves significant improvements over previous active methods in terms of the area under the receiver operating characteristic curve(AUC-ROC)(20.9%and 21.5%)and the area under the precision-recall curve(AUC-PR)(44.6%and 64.1%).

关键词： Active anomaly detection Network traffic streams Pseudo labels Prior knowledge of network attacks

薄膜铌酸锂光电器件与超大规模光子集成(特邀)

在线全文

学校读者我要写书评

暂无评论

中国激光 2024年第1期51卷 386-402页

作者：程亚华东师范大学物理与电子科学学院上海200241 中国科学院上海光学精密机械研究所强场激光物理国家重点实验室上海201800

近年来,薄膜铌酸锂光子集成技术发展极为迅速,其背后有着深刻的物理、材料、技术原因。单晶薄膜铌酸锂为解决光子集成芯片领域长期存在的低传输损耗、高密度集成以及低调制功耗需求提供了至今为止综合性能最优的解决方案。面向未来的新... 详细信息

近年来,薄膜铌酸锂光子集成技术发展极为迅速,其背后有着深刻的物理、材料、技术原因。单晶薄膜铌酸锂为解决光子集成芯片领域长期存在的低传输损耗、高密度集成以及低调制功耗需求提供了至今为止综合性能最优的解决方案。面向未来的新一代高速光电器件与超大规模光子集成芯片应用,本文回顾了薄膜铌酸锂光子技术的起源及其近期的快速发展,讨论了若干薄膜铌酸锂光子结构的加工技术,并展示了一系列当前性能最优的薄膜铌酸锂光子集成器件与系统,包括超低损耗可调光波导延时线、超高速光调制器、高效率量子光源,以及高功率片上放大器与片上激光器。这些器件以其体积小、质量轻、功耗低、性能好的综合优势,将对整个光电子产业产生难以估量的影响。

关键词：光子集成光波导光调制器微波光子学光量子集成器件薄膜薄膜铌酸锂

洋中脊动力学与俯冲带地震-岩浆-成矿事件远程效应

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

地学前缘 2024年第1期31卷 1-14页

作者：成秋明中国地质大学(北京)地质过程与矿产资源国家重点实验室北京100083 中国地质大学(北京)教育部深时数字地球前沿科学中心北京100083 中山大学地球科学与工程学院广东珠海519080

板块俯冲带和大陆岩浆弧的深部过程与极端地质事件之间存在密切的关系。板块俯冲与造山过程会导致地震、岩浆活动和成矿等事件的发生。这些极端事件的发生与俯冲过程中的壳幔相互作用、地幔楔形成、岩石圈部分熔融、构造-岩浆活动等因... 详细信息

板块俯冲带和大陆岩浆弧的深部过程与极端地质事件之间存在密切的关系。板块俯冲与造山过程会导致地震、岩浆活动和成矿等事件的发生。这些极端事件的发生与俯冲过程中的壳幔相互作用、地幔楔形成、岩石圈部分熔融、构造-岩浆活动等因素密切相关。然而,人们对洋中脊新生地壳的不均匀性或先天“缺陷”对以上的极端事件的长远影响和远程效应了解甚少。在洋中脊新的地壳形成过程中,由于受到板块扩张、压力降低、软流圈物质上涌等因素的作用,导致新生地壳温度升高、孔隙度和裂缝发育、密度降低、结构复杂的正反馈过程。因此,新生地壳在密度、强度、温度、厚度等方面存在非均质性。这些地壳的差异性将影响和决定板块在扩张和俯冲过程中的行为,并对板块俯冲作用形成的地震、岩浆和成矿等事件产生远程影响。以太平洋俯冲和安第斯造山带为例研究发现,板块运动速度、板块俯冲角度、板片撕裂、岩石圈厚度、Moho面深度等的突变与地震、火山和斑岩矿床的时空分布存在远程关联效应,这些认知对预测板块俯冲-碰撞带发生的极端地质事件的时空分布具有重要意义。

关键词：洋中脊板块俯冲地震火山成矿远程关联

Porous-DeepONet:Learning the Solution Operators of Parametric Reactive Transport Equations in Porous Media

在线全文

学校读者我要写书评

暂无评论

Engineering 2024年第8期39卷 94-103页

作者： Pan Huang Yifei Leng cheng Lian Honglai Liu State Key Laboratory of Chemical Engineering&Shanghai Engineering Research Center of Hierarchical Structure Nanomaterials School of Chemical EngineeringEast China University of Science and TechnologyShanghai 200237China School of Chemistry and Molecular Engineering East China University of Science and TechnologyShanghai 200237China Product Planning and New Auto Technologies Research Institute BYD Auto Industry Company LimitedShenzhen 518118China

Reactive transport equations in porous media are critical in various scientific and engineering disciplines,but solving these equations can be computationally expensive when exploring different scenarios,such as varying porous structures and initial or boundary *** deep operator network(DeepONet)has emerged as a popular deep learning framework for solving parametric partial differential ***,applying the DeepONet to porous media presents significant challenges due to its limited capability to extract representative features from intricate *** address this issue,we propose the Porous-DeepONet,a simple yet highly effective extension of the DeepONet framework that leverages convolutional neural networks(CNNs)to learn the solution operators of parametric reactive transport equations in porous *** incorporating CNNs,we can effectively capture the intricate features of porous media,enabling accurate and efficient learning of the solution *** demonstrate the effectiveness of the Porous-DeepONet in accurately and rapidly learning the solution operators of parametric reactive transport equations with various boundary conditions,multiple phases,and multiphysical fields through five *** approach offers significant computational savings,potentially reducing the computation time by 50–1000 times compared with the finite-element *** work may provide a robust alternative for solving parametric reactive transport equations in porous media,paving the way for exploring complex phenomena in porous media.

关键词： Porous media Reactive transport Solution operator DeepONet Neural network

Exploring Tourists’Low-carbon Cognition and Influencing Factors from the Dimension of Education Level

在线全文

学校读者我要写书评

暂无评论

Journal of Resources and Ecology 2024年第4期15卷 1083-1093页

作者： cheng Jinhong College of History and Tourism Culture Shanxi Normal UniversityTaiyuan 030031China

The cognition of low-carbon tourism among tourists is closely related to education *** this study,the degree of coordination of low-carbon cognition with different educational levels is assessed by the coupling model in Wutai Mountain,and the effect of each factor on low-carbon cognition is analyzed by the geographical *** results show that:(1)The six cognition aspects of low-carbon tourism gradually transition from the level of intermediate coordination to good coordination with the advancement of the education *** the low-level and lower-level tourists belong to the lag type of low-carbon visiting cognition,and the higher-level tourists belong to the lag type of low-carbon shopping cognition,while the high-level tourists show the lag type of low-carbon food cognition.(2)According to the individual factors and interactive effects in the geographical detector,each impacting factor has a decisive effect on tourists’cognition of low-carbon tourism,and the effect of any two factors after interaction shows either a double-factor or nonlinear *** findings of this study provide valuable practical implications for helping tourism destinations to educate tourists and improve their low-carbon tourism *** the same time,this study will provide theoretical standards for measuring tourists’cognition of low-carbon tourism,so as to enrich and improve the theoretical research related to low-carbon tourism.

关键词： low-carbon tourism cognitive differences education level model of coupling coordination degree Geo-detector

长三角区域大气污染协同治理网络结构及影响因素研究

在线全文

学校读者我要写书评

暂无评论

长江流域资源与环境 2024年第7期33卷 1529-1539页

作者：程进上海社会科学院生态与可持续发展研究所上海200020

基于长三角区域2018~2022年大气污染协同治理网络的数据样本,采用社会网络分析方法,对长三角区域大气污染协同治理网络结构进行研究。研究发现:(1)长三角区域大气污染协同治理网络密度总体上趋于增大,由最初的“强横向、弱纵向”的结构... 详细信息

基于长三角区域2018~2022年大气污染协同治理网络的数据样本,采用社会网络分析方法,对长三角区域大气污染协同治理网络结构进行研究。研究发现:(1)长三角区域大气污染协同治理网络密度总体上趋于增大,由最初的“强横向、弱纵向”的结构特点,逐渐演化出“强横向、强纵向”的特征。(2)长三角区域大气污染协同治理的行政主导特征显著,其网络结构具有明显的非梯度分布的层级特征,省级行政主体在网络结构中起关键主导作用。(3)区域大气污染协同治理网络结构受省级行政边界的影响较为明显,江苏、浙江和安徽三省范围内的城市各自形成了联系较为紧密的合作子集,省界内城市在开展大气污染协同治理方面表现出更加紧密的关系,跨省界的协同治理联系主要集中在省会城市或省界城市。(4)城市间距离、行政区划对大气污染协同治理关系的形成有显著影响。基于此,提出完善长三角区域合作“三级运作”结构模式、推动大气污染协同治理结构扁平化发展、增强跨区域大气污染协同治理纽带等政策建议。

关键词：长三角大气污染协同治理社会网络

使用深度学习在CTA扫描卷下实现主动脉夹层分类和直径测量的双功能系统

在线全文

学校读者我要写书评

暂无评论

Engineering 2024年第3期34卷 83-91页

作者： Zhihui Huang Rui Wang Hui Yu Yifan Xu cheng cheng Guangwei Wang Haosen Cao Xiang Wei Hai-Tao Zhang School of Artificial Intelligence and Automation&the MOE Engineering Research Center of Autonomous Intelligent Unmanned Systems&the State Key Laboratory of Intelligent Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China Division of Cardiovascular Surgery Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China Wuhan Children’s Hospital:Wuhan Women and Children Medical Care Center Tongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430010China

Acute aortic dissection is one of the most life-threatening cardiovascular diseases,with a high mortality *** prevalence ranges from 0.2%to 0.8%in humans,resulting in a significant number of deaths due to being missed in manual *** importantly,the aortic diameter—a critical indicator for surgical selection—significantly influences the outcomes of surgeries ***,it is an urgent yet challenging mission to develop an automatic aortic dissection diagnostic system that can recognize and classify the aortic dissection type and measure the aortic *** paper offers a dual-functional deep learning system called aortic dissections diagnosis-aiding system(DDAsys)that enables both accurate classification of aortic dissection and precise diameter measurement of the *** this end,we created a dataset containing 61190 computed tomography angiography(CTA)images from 279 patients from the Division of Cardiovascular Surgery at Tongji Hospital,Wuhan,*** dataset provides a slice-level summary of difficult-to-identify features,which helps to improve the accuracy of both recognition and *** system achieves a recognition F1 score of 0.984,an average classification F1 score of 0.935,and the respective measurement precisions for ascending and descending aortic diameters are 0.994 mm and 0.767 mm root mean square error(RMSE).The high consistency(88.6%)between the recommended surgical treatments and the actual corresponding surgeries verifies the capability of our system to aid clinicians in developing a more prompt,precise,and consistent treatment strategy.

关键词： Aortic dissections Computed tomography angiography Classification Deep learning

在线全文

学校读者我要写书评

暂无评论

SGTR事故工况下射流行为模拟实验研究

工程热物理学报 2024年第4期45卷 955-961页

作者：陈松徽程辉成松柏中山大学中法核工程与技术学院珠海519082 哈尔滨工程大学核科学与技术学院哈尔滨150001

蒸汽发生器传热管破口(SGTR)事故属于铅冷快堆(LFR)中一类较为严重的事故。在SGTR事故工况下,二回路冷却剂水会与一回路中的高温熔融铅铋合金直接接触,从而发生强烈的相互作用。为了进一步研究水射流在熔融铅铋中的注入行为,本研究设计... 详细信息

蒸汽发生器传热管破口(SGTR)事故属于铅冷快堆(LFR)中一类较为严重的事故。在SGTR事故工况下,二回路冷却剂水会与一回路中的高温熔融铅铋合金直接接触,从而发生强烈的相互作用。为了进一步研究水射流在熔融铅铋中的注入行为,本研究设计和搭建了液体射流两相流动可视化实验平台,并进行了一系列模拟实验。研究中首先探讨了沸腾(包含闪蒸)和非沸腾工况下的射流流型演化过程及规律,并定量分析了射流注入速率对最大注入深度的影响规律,最后基于实验数据运用Froude数理论对非沸腾工况下注入速度与最大注入深度进行了分析,并获得了无量纲半经验关系式。

关键词：铅冷快堆蒸汽发生器破口事故射流注入深度射流行为

被动式红外热像法研究古代建筑壁画裂隙病害动态成因

在线全文

学校读者我要写书评

暂无评论

光谱学与光谱分析 2024年第7期44卷 1952-1959页

作者：贺源刘成西北大学文化遗产学院陕西西安710127 西北大学文化遗产研究与保护技术教育部重点实验室陕西西安710127 中国-中亚人类与环境“一带一路”联合实验室陕西西安710127

红外热像法是文物保护领域广泛应用的无损检测方法之一。在目前的文物保护工作中,常利用主动式红外热像法对文物本体的病害状况和结构缺陷进行评估,而对被动式红外热像法的重视程度不足,且极少直接考察文物与赋存环境之间的动态作用关... 详细信息

红外热像法是文物保护领域广泛应用的无损检测方法之一。在目前的文物保护工作中,常利用主动式红外热像法对文物本体的病害状况和结构缺陷进行评估,而对被动式红外热像法的重视程度不足,且极少直接考察文物与赋存环境之间的动态作用关系。以辽宁义县奉国寺元代建筑壁画裂隙病害为例,探索被动式红外热像法研究“文物本体-赋存环境”交联耦合作用的可行性。在拍摄壁画表面红外热像照片从而获得更全面檐墙结构信息的基础上,分别对东、西墙中部纵向长裂隙以及北墙N1壁画整体开展连续红外热成像监测,并对裂隙、普通墙体表面和木骨处墙体表面进行温度测量;采用累积距平法和小波分析法对这些特征位置温度的变化趋势和周期波动性进行分析,从传热学角度对监测和分析结果进行定性讨论,区分壁画不同位置的传热影响模式,并结合裂隙产状特征对其形成过程进行初步判断。结果表明,壁画属多层不均匀结构,存在传热通路和结构强度上的差异;东、西墙的温度变化趋势具有相似性,而在波动信号及波动能量方面存在明显不同;裂隙的总体波动能量大于墙体,并与发育程度呈正相关;第一主周期的波动能量来源于气温的日变化,而次级主周期的波动能量可能与传热过程中的随机扰动有关,白天及日落后一段时间内的能量波动在传热影响中起到了关键作用;木骨与裂隙处的传热过程更快,随时间推移形成高温中心与横向传热趋势。裂隙病害的产生是材料对温度机械应变差异的结果,而传热影响途径有二:一是以檐墙为媒介的导热,二是通过檐柱处空气通道的对流换热;前者主要诱导生成间口内上下平行若干层的横向短裂隙组,后者则促进檐柱处纵向长裂隙的产生。该研究可为评估其他类型文物在复杂环境下的传热影响过程提供参考。

关键词：红外热成像壁画奉国寺病害机理传热影响