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An Algorithm for Cloud-based Web Service Combination Optimization Through Plant Growth Simulation
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作者 Li Qiang Qin Huawei +1 位作者 Qiao Bingqin Wu Ruifang 《系统仿真学报》 北大核心 2025年第2期462-473,共12页
In order to improve the efficiency of cloud-based web services,an improved plant growth simulation algorithm scheduling model.This model first used mathematical methods to describe the relationships between cloud-base... In order to improve the efficiency of cloud-based web services,an improved plant growth simulation algorithm scheduling model.This model first used mathematical methods to describe the relationships between cloud-based web services and the constraints of system resources.Then,a light-induced plant growth simulation algorithm was established.The performance of the algorithm was compared through several plant types,and the best plant model was selected as the setting for the system.Experimental results show that when the number of test cloud-based web services reaches 2048,the model being 2.14 times faster than PSO,2.8 times faster than the ant colony algorithm,2.9 times faster than the bee colony algorithm,and a remarkable 8.38 times faster than the genetic algorithm. 展开更多
关键词 cloud-based service scheduling algorithm resource constraint load optimization cloud computing plant growth simulation algorithm
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美国CLOUD法案数据跨境执法中的安全风险与中国的应对 被引量:2
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作者 廖明月 王佳宜 杨映雪 《图书馆论坛》 北大核心 2025年第1期128-137,共10页
数据是数字经济时代重要的国家战略资源,数据跨境流动亦是其中的重要一环。囿于犯罪活动呈现数字化和跨境化态势,数据跨境执法成为打击网络犯罪的重要手段,但基于执法目的的数据出境对数据存储国的影响重大。美国凭借“数据自由”话语... 数据是数字经济时代重要的国家战略资源,数据跨境流动亦是其中的重要一环。囿于犯罪活动呈现数字化和跨境化态势,数据跨境执法成为打击网络犯罪的重要手段,但基于执法目的的数据出境对数据存储国的影响重大。美国凭借“数据自由”话语体系通过CLOUD法案推出以“数据控制者标准”为核心的数据管辖模式,进而依托网络服务提供者实施“长臂管辖”,使得我国数据被动出境和被调取而引发的国家数据安全风险大幅提升。我国应将数据主权作为数据跨境流动的法理基础,探索控制数据安全风险的制度工具,包括基于国家主权调适“数据控制者”标准模式,完善数据跨境调取安全规则和审查机制,以阻断法限制单边数据跨境执法,对美国的相关“长臂管辖”进行有效制衡。 展开更多
关键词 数据跨境执法 安全风险 数据主权 cloud法案
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Control model for burning-bubble clouds formed by confined meltcast explosives under thermal stimulation
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作者 Zhi Li Zhuoping Duan +4 位作者 Zhiling Bai Jixuan Jiao Liji Xu Liansheng Zhang Fenglei Huang 《Defence Technology(防务技术)》 2025年第6期268-283,共16页
DNAN-based insensitive melt-cast explosives have been widely utilized in insensitive munition in recent years. When constrained DNAN-based melt-cast explosives are ignited under thermal stimulation, the base explosive... DNAN-based insensitive melt-cast explosives have been widely utilized in insensitive munition in recent years. When constrained DNAN-based melt-cast explosives are ignited under thermal stimulation, the base explosive exists in a molten liquid state, where high-temperature gases expand and react in the form of bubble clouds within the liquid explosive;this process is distinctly different from the dynamic crack propagation process observed in the case of solid explosives. In this study, a control model for the reaction evolution of burning-bubble clouds was established to describe the reaction process and quantify the reaction violence of DNAN-based melt-cast explosives, considering the size distribution and activation mechanism of the burning-bubble clouds. The feasibility of the model was verified through experimental results. The results revealed that under geometrically similar conditions, with identical confinement strength and aspect ratio, larger charge structures led to extended initial gas flow and surface burning processes, resulting in greater reaction equivalence and violence at the casing fracture.Under constant charge volume and size, a stronger casing confinement accelerated self-enhanced burning, increasing the internal pressure, reaction degree, and reaction violence. Under a constant casing thickness and radius, higher aspect ratios led to a greater reaction violence at the casing fracture.Moreover, under a constant charge volume and casing thickness, higher aspect ratios resulted in a higher internal pressure, increased reaction degree, and greater reaction violence at the casing fracture. Further,larger ullage volumes extended the reaction evolution time and increased the reaction violence under constant casing dimensions. Through a matching design of the opening threshold of the pressure relief holes and the relief structure area, a stable burning reaction could be maintained until completion,thereby achieving a control of the reaction violence. The proposed model could effectively reflect the effects of the intrinsic burning rate, casing confinement strength, charge size, ullage volume, and pressure relief structure on the reaction evolution process and reaction violence, providing a theoretical method for the thermal safety design and reaction violence evaluation of melt-cast explosives. 展开更多
关键词 Melt-cast explosives Non-shock-initiated reaction Self-sustaining enhanced combustion Burning-bubble cloud model Pressure relief area Reaction violence
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Link-16 anti-jamming performance evaluation based on grey relational analysis and cloud model
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作者 NING Xiaoyan WANG Ying +1 位作者 WANG Zhenduo SUN Zhiguo 《Journal of Systems Engineering and Electronics》 2025年第1期62-72,共11页
Anti-jamming performance evaluation has recently received significant attention. For Link-16, the anti-jamming performance evaluation and selection of the optimal anti-jamming technologies are urgent problems to be so... Anti-jamming performance evaluation has recently received significant attention. For Link-16, the anti-jamming performance evaluation and selection of the optimal anti-jamming technologies are urgent problems to be solved. A comprehensive evaluation method is proposed, which combines grey relational analysis (GRA) and cloud model, to evaluate the anti-jamming performances of Link-16. Firstly, on the basis of establishing the anti-jamming performance evaluation indicator system of Link-16, the linear combination of analytic hierarchy process(AHP) and entropy weight method (EWM) are used to calculate the combined weight. Secondly, the qualitative and quantitative concept transformation model, i.e., the cloud model, is introduced to evaluate the anti-jamming abilities of Link-16 under each jamming scheme. In addition, GRA calculates the correlation degree between evaluation indicators and the anti-jamming performance of Link-16, and assesses the best anti-jamming technology. Finally, simulation results prove that the proposed evaluation model can achieve the objective of feasible and practical evaluation, which opens up a novel way for the research of anti-jamming performance evaluations of Link-16. 展开更多
关键词 LINK-16 ANTI-JAMMING grey relational analysis(GRA) cloud model combination weights
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MatCloud-QE:基于云原生理念的高通量第一性原理计算程序包 被引量:1
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作者 杨小渝 郝德博 +3 位作者 舒城 许立芳 梁亚男 马新杰 《中国材料进展》 CAS CSCD 北大核心 2024年第11期1007-1015,共9页
国内开展第一性原理计算总是局限于某一两个商业软件,不仅需要软件使用许可,而且还需要下载、安装到本地,再通过人工部署到高性能计算集群才能开展使用,极大地限制了科研人员开展第一性原理计算。为了解决这个问题,作者团队基于Quantum ... 国内开展第一性原理计算总是局限于某一两个商业软件,不仅需要软件使用许可,而且还需要下载、安装到本地,再通过人工部署到高性能计算集群才能开展使用,极大地限制了科研人员开展第一性原理计算。为了解决这个问题,作者团队基于Quantum ESPRESSO第一性原理计算内核,进一步开发了高通量第一性原理计算加速算法、参数智能推荐算法、输入结构统一算法、自动后处理引擎、组件化引擎、图形化引擎、更多物性计算功能以及MatCloud+接口等算法程序,形成了具有云原生特点的第一性原理计算程序包:MatCloud-QE;进一步通过接入MatCloud+材料云,使用户仅通过浏览器就可在线开展第一性原理计算和数据自动化采集和管理,极大地方便了用户开展第一性原理计算以及高通量计算筛选,且无需软件使用许可。以面向太阳能电池应用的无机钙钛矿Rb_(1-x)Cs_(x)PbI3的材料特性的第一性原理计算为例,说明通过MatCloud+材料云平台使用MatCloud-QE第一性原理计算程序包可进行能隙、态密度和光学性质的计算,计算结果不仅和文献报道结果相符,且整个计算过程减少人工干预次数可达90%以上,极大地提高了效率。目前,MatCloud-QE第一性原理计算程序包深度集成在MatCloud+材料云平台,用户通过云端才能使用,该模式为用户提供了丰富的计算资源和一站式第一性原理计算服务。 展开更多
关键词 Matcloud-QE第一性原理计算程序包 Matcloud+材料云 第一性原理计算 高通量材料计算 云原生
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Cloud edge integrated security architecture of new cloud manufacturing system 被引量:1
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作者 ZHAO Longbo LI Bohu YUAN Haitao 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第5期1177-1189,共13页
With the rapid development of cloud manufacturing technology and the new generation of artificial intelligence technology,the new cloud manufacturing system(NCMS)built on the connotation of cloud manufacturing 3.0 pre... With the rapid development of cloud manufacturing technology and the new generation of artificial intelligence technology,the new cloud manufacturing system(NCMS)built on the connotation of cloud manufacturing 3.0 presents a new business model of“Internet of everything,intelligent leading,data driving,shared services,cross-border integration,and universal innovation”.The network boundaries are becoming increasingly blurred,NCMS is facing security risks such as equipment unauthorized use,account theft,static and extensive access control policies,unauthorized access,supply chain attacks,sensitive data leaks,and industrial control vulnerability attacks.Traditional security architectures mainly use information security technology,which cannot meet the active security protection requirements of NCMS.In order to solve the above problems,this paper proposes an integrated cloud-edge-terminal security system architecture of NCMS.It adopts the zero trust concept and effectively integrates multiple security capabilities such as network,equipment,cloud computing environment,application,identity,and data.It adopts a new access control mode of“continuous verification+dynamic authorization”,classified access control mechanisms such as attribute-based access control,rolebased access control,policy-based access control,and a new data security protection system based on blockchain,achieving“trustworthy subject identity,controllable access behavior,and effective protection of subject and object resources”.This architecture provides an active security protection method for NCMS in the digital transformation of large enterprises,and can effectively enhance network security protection capabilities and cope with increasingly severe network security situations. 展开更多
关键词 new cloud manufacturing system(NCMS) integrated cloud-edge-terminal security system architecture zero trust
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基于CloudSim的电力系统计算云原生模型与仿真方法 被引量:3
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作者 陈元榉 刘媛媛 +3 位作者 张延旭 蔡煜 胡春潮 蔡泽祥 《电力自动化设备》 EI CSCD 北大核心 2024年第9期189-196,204,共9页
分析基于云计算的电力系统计算过程是实现资源高效利用的基础。因此,提出一种基于CloudSim的电力系统计算的云原生建模与仿真方法。基于云原生技术阐述了电力系统计算架构的关键要素,提出基于CloudSim的电力系统计算架构的云原生模型,... 分析基于云计算的电力系统计算过程是实现资源高效利用的基础。因此,提出一种基于CloudSim的电力系统计算的云原生建模与仿真方法。基于云原生技术阐述了电力系统计算架构的关键要素,提出基于CloudSim的电力系统计算架构的云原生模型,分析电力云任务调配时的资源供需平衡问题。建立基于微服务的电力云任务模型,分析微服务的处理时序逻辑及其层级关系并生成微服务队列。据此提出微服务的动态调配模型,采用微服务-容器映射策略与实体动态整合策略,实现微服务在实体间的动态映射。利用CloudSim进行仿真分析,结果证明所提方法可行且有效,可为电力云计算的资源配置、任务调度等提供基本的仿真工具与方法。 展开更多
关键词 电力系统 cloudSim 云原生建模 电力系统计算架构 动态调配 时序逻辑 微服务队列
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Cloud control for IIoT in a cloud-edge environment 被引量:1
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作者 YAN Ce XIA Yuanqing +1 位作者 YANG Hongjiu ZHAN Yufeng 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第4期1013-1027,共15页
The industrial Internet of Things(IIoT)is a new indus-trial idea that combines the latest information and communica-tion technologies with the industrial economy.In this paper,a cloud control structure is designed for... The industrial Internet of Things(IIoT)is a new indus-trial idea that combines the latest information and communica-tion technologies with the industrial economy.In this paper,a cloud control structure is designed for IIoT in cloud-edge envi-ronment with three modes of 5G.For 5G based IIoT,the time sensitive network(TSN)service is introduced in transmission network.A 5G logical TSN bridge is designed to transport TSN streams over 5G framework to achieve end-to-end configuration.For a transmission control protocol(TCP)model with nonlinear disturbance,time delay and uncertainties,a robust adaptive fuzzy sliding mode controller(AFSMC)is given with control rule parameters.IIoT workflows are made up of a series of subtasks that are linked by the dependencies between sensor datasets and task flows.IIoT workflow scheduling is a non-deterministic polynomial(NP)-hard problem in cloud-edge environment.An adaptive and non-local-convergent particle swarm optimization(ANCPSO)is designed with nonlinear inertia weight to avoid falling into local optimum,which can reduce the makespan and cost dramatically.Simulation and experiments demonstrate that ANCPSO has better performances than other classical algo-rithms. 展开更多
关键词 5G and time sensitive network(TSN) industrial Internet of Things(IIoT)workflow transmission control protocol(TCP)flows control cloud edge collaboration multi-objective optimal scheduling
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Study on damage mechanism and damage distribution of the rear plate under impact of debris cloud
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作者 Chenyang Wu Xiaowei Chen Qiguang He 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第5期151-167,共17页
The debris cloud generated by the hypervelocity impact(HVI)of orbiting space debris directly threatens the spacecraft.A full understanding of the damage mechanism of rear plate is useful for the optimal design of prot... The debris cloud generated by the hypervelocity impact(HVI)of orbiting space debris directly threatens the spacecraft.A full understanding of the damage mechanism of rear plate is useful for the optimal design of protective structures.In this study,the hypervelocity yaw impact of a cylindrical aluminum projectile on a double-layer aluminum plate is simulated by the FE-SPH adaptive method,and the damage process of the rear plate under the impact of the debris cloud is analyzed based on the debris cloud structure.The damage process can be divided into the main impact stage of the debris cloud and the structural response of the rear plate.The main impact stage lasts a short time and is the basis of the rear plate damage.In the stage of structure response,the continuous deformation and inertial motion of the rear plate dominate the perforation of the rear plate.We further analyze the damage mechanism and damage distribution characteristics of the rear plate in detail.Moreover,the connection between velocity space and position space of the debris cloud is established,which promotes the general analysis of the damage law of debris cloud.Based on the relationship,the features of typical damage areas are identified by the localized fine analysis.Both the cumulative effect and structural response cause the perforation of rear plate;in the non-perforated area,cratering by the impact of hazardous fragments is the main damage mode of the rear plate. 展开更多
关键词 Damage of rear plate Debris cloud Secondary impact Hypervelocity yaw impact FE-SPH adaptive method
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A cloud model target damage effectiveness assessment algorithm based on spatio-temporal sequence finite multilayer fragments dispersion
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作者 Hanshan Li Xiaoqian Zhang Junchai Gao 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第10期48-64,共17页
To solve the problem of target damage assessment when fragments attack target under uncertain projectile and target intersection in an air defense intercept,this paper proposes a method for calculating target damage p... To solve the problem of target damage assessment when fragments attack target under uncertain projectile and target intersection in an air defense intercept,this paper proposes a method for calculating target damage probability leveraging spatio-temporal finite multilayer fragments distribution and the target damage assessment algorithm based on cloud model theory.Drawing on the spatial dispersion characteristics of fragments of projectile proximity explosion,we divide into a finite number of fragments distribution planes based on the time series in space,set up a fragment layer dispersion model grounded in the time series and intersection criterion for determining the effective penetration of each layer of fragments into the target.Building on the precondition that the multilayer fragments of the time series effectively assail the target,we also establish the damage criterion of the perforation and penetration damage and deduce the damage probability calculation model.Taking the damage probability of the fragment layer in the spatio-temporal sequence to the target as the input state variable,we introduce cloud model theory to research the target damage assessment method.Combining the equivalent simulation experiment,the scientific and rational nature of the proposed method were validated through quantitative calculations and comparative analysis. 展开更多
关键词 Target damage cloud model Fragments dispersion Effectiveness assessment Spatio-temporal sequence
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Research on BIM Model Reshaping Method Based on 3D Point Cloud Recognition
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作者 SHI Jin-yu YU Xian-feng +1 位作者 SI Zhan-jun ZHANG Ying-xue 《印刷与数字媒体技术研究》 CAS 北大核心 2024年第4期125-135,共11页
In view of the limitations of traditional measurement methods in the field of building information,such as complex operation,low timeliness and poor accuracy,a new way of combining three-dimensional scanning technolog... In view of the limitations of traditional measurement methods in the field of building information,such as complex operation,low timeliness and poor accuracy,a new way of combining three-dimensional scanning technology and BIM(Building Information Modeling)model was discussed.Focused on the efficient acquisition of building geometric information using the fast-developing 3D point cloud technology,an improved deep learning-based 3D point cloud recognition method was proposed.The method optimised the network structure based on RandLA-Net to adapt to the large-scale point cloud processing requirements,while the semantic and instance features of the point cloud were integrated to significantly improve the recognition accuracy and provide a precise basis for BIM model remodeling.In addition,a visual BIM model generation system was developed,which systematically transformed the point cloud recognition results into BIM component parameters,automatically constructed BIM models,and promoted the open sharing and secondary development of models.The research results not only effectively promote the automation process of converting 3D point cloud data to refined BIM models,but also provide important technical support for promoting building informatisation and accelerating the construction of smart cities,showing a wide range of application potential and practical value. 展开更多
关键词 3D point cloud RandLA-Net network BIM model OSG engine
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CT-CloudDetect:用于遥感卫星云检测的混合模型
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作者 方巍 陶恩屹 《遥感信息》 CSCD 北大核心 2024年第5期1-11,共11页
云检测是在遥感卫星云图中检测云的任务。近年来,人们提出了基于深度学习的云检测方法,并取得了良好的性能。然而,现有的基于深度学习的云检测模型大多还是基于卷积神经网络(convolutional neural network,CNN),由于卷积运算的固有局部... 云检测是在遥感卫星云图中检测云的任务。近年来,人们提出了基于深度学习的云检测方法,并取得了良好的性能。然而,现有的基于深度学习的云检测模型大多还是基于卷积神经网络(convolutional neural network,CNN),由于卷积运算的固有局部性,难以捕获长距离依赖关系。针对上述问题,文章提出一个基于CNN和ViT(Vision Transformer)的混合型云检测模型,并提出一种基于CNN和ViT的编码器,使网络具备捕捉局部和全局信息的能力。为了更好地融合语义和尺度不一致的特征,提出了一个双尺度注意力融合模块,通过注意力机制有选择地融合特征。此外,提出了轻量级路由解码器,该解码器通过路由结构降低模型复杂度。在3个公开云检测数据集上对模型进行了评估。大量实验表明,所提出的模型具有比现有模型更好的性能。 展开更多
关键词 深度学习 卷积神经网络 空间Vision Transformer 混合模型 云检测
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Cloud-based predictive adaptive cruise control considering preceding vehicle and slope information
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作者 GAO Bolin WANG Luyao +6 位作者 LI Shuyan WAN Keke WANG Xuepeng ZHANG Jin WANG Chen LIU Yanbin ZHONG Wei 《Journal of Systems Engineering and Electronics》 CSCD 2024年第6期1542-1562,共21页
With the advantage of exceptional long-range traffic perception capabilities and data fusion computational prowess,the cloud control system(CCS)has exhibited formidable poten-tial in the realm of connected assisted dr... With the advantage of exceptional long-range traffic perception capabilities and data fusion computational prowess,the cloud control system(CCS)has exhibited formidable poten-tial in the realm of connected assisted driving,such as the adap-tive cruise control(ACC).Based on the CCS architecture,this paper proposes a cloud-based predictive ACC(PACC)strategy,which fully considers the road slope information and the preced-ing vehicle status.In the cloud,based on the dynamic program-ming(DP),the long-term economic speed planning is carried out by using the slope information.At the vehicle side,the real-time fusion planning of the economic speed and the preceding vehi-cle state is realized based on the model predictive control(MPC),taking into account the safety and economy of driving.In order to ensure the safety and stability of the vehicle-cloud cooperative control system,an event-triggered cruise mode switching method is proposed based on the state of each sub-system of the vehicle-cloud-network-map.Simulation results indicate that the PACC system can still ensure stable cruising under delays and some complex conditions.Moreover,under normal conditions,compared to the ACC system,the PACC sys-tem can further improve economy while ensuring safety and improve the overall energy efficiency of the vehicle,thus achiev-ing fuel savings of 3%to 8%. 展开更多
关键词 predictive adaptive cruise control(PACC) cloud control system(CCS) economic driving
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基于CloudSat-CALIPSO数据的黄土高原地区云特征分析
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作者 尤丹丹 张淑花 +1 位作者 金存银 王倩茹 《高原气象》 CSCD 北大核心 2024年第3期583-594,共12页
云是地气系统的重要组成部分,为深入分析黄土高原地区云特征,利用2007-2016年搭载首部云探测雷达云卫星(CloudSat)与云-气溶胶激光雷达和红外探测者观测卫星(The Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation, C... 云是地气系统的重要组成部分,为深入分析黄土高原地区云特征,利用2007-2016年搭载首部云探测雷达云卫星(CloudSat)与云-气溶胶激光雷达和红外探测者观测卫星(The Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation, CALIPSO)资料,选取黄土高原半湿润、半干旱、干旱和寒旱四个区域,对云的宏、微观物理特征进行了分析。结果表明:(1)黄土高原各区域云出现频率年均值达到了55%以上,其中,春、夏季云出现频率最高,秋冬两季相对较低;半湿润区云出现频率高于其他区域,但其他三个区域云出现频率最高的月份均早于半湿润区。(2)各区域中单层云出现频率最高,占到总云量的60%以上,多层云中主要是双层云,约占总云量的25%。云层高度在不同区域表现为春、夏季节大于秋、冬季节,半湿润区的云层高度在四季均大于其他区域。各区域云几何厚度季节变化不显著,均在1~4 km之间,主要以薄云为主,且78.13%的云几何厚度不超过2 km。(3)各区域的云液态水含量年均值均达到了220.5 mg·m^(-3),约为冰水含量年均值的6.5倍,主要分布在8.5 km以下的高度层。随着高度的减小,液态水含量逐渐增多,其中半湿润区云液态水含量大于其他区域。各区域全年冰水含量占比较小,主要分布在16.5 km以下的高度层。(4)液滴有效半径在各区域的值主要集中在12~16μm,在半干旱区的春季出现了最大值,约为24μm;冰粒子有效半径最大值出现在半湿润区的夏季。液滴数浓度在各区域的值集中在60~80 cm^(-3),均小于冰粒子数浓度平均值,其峰值出现在各区域的夏季,冰粒子数浓度的峰值出现在半湿润和半干旱区的春季。该研究结果有助于深入认识黄土高原云的特征,为区域气候模式对黄土高原地区云特征的模拟提供一定的参考依据。 展开更多
关键词 黄土高原 cloudSat-CALIPSO 云垂直结构 宏微观物理特征
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基于PointCloudTransformer和优化集成学习的三维点云分类 被引量:2
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作者 于喜俊 段勇 《电子测量与仪器学报》 CSCD 北大核心 2024年第6期143-153,共11页
针对三维点云的不规则性和无序性所导致的难于提取特征并进行分类的问题,提出了一种融合深度学习和集成学习的三维点云分类方法。首先,训练深度学习点云分类网络PointCloudTransformer,并使用主干网络提取点云特征,进而训练基分类器,获... 针对三维点云的不规则性和无序性所导致的难于提取特征并进行分类的问题,提出了一种融合深度学习和集成学习的三维点云分类方法。首先,训练深度学习点云分类网络PointCloudTransformer,并使用主干网络提取点云特征,进而训练基分类器,获得基分类器集合;然后,针对集成学习算法设计基分类器选择模型,模型的优化目标为基分类器组合的差异性和平均总体精度。为了降低集成规模,本文基于增强后的白鲸优化算法提出了二元多目标白鲸优化算法,并使用该算法优化基分类器选择模型,获得集成剪枝方案集合;最后,采用多数投票法集成每个基分类器组合在测试集点云特征上的分类结果,获得最优基分类器组合,从而构建基于多目标优化剪枝的集成学习点云分类模型。在点云分类数据集上的实验结果表明,本文方法使用了更小的集成规模,获得了更高的集成精度,能够对多类别三维点云进行准确分类。 展开更多
关键词 三维点云分类 深度学习 集成学习 白鲸优化算法 多目标优化
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Cloudless-Training:基于serverless的高效跨地域分布式ML训练框架
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作者 谭文婷 吕存驰 +1 位作者 史骁 赵晓芳 《高技术通讯》 CAS 北大核心 2024年第3期219-232,共14页
跨地域分布式机器学习(ML)训练能够联合多区域的云资源协作训练,可满足许多新兴ML场景(比如大型模型训练、联邦学习)的训练需求。但其训练效率仍受2方面挑战的制约。首先,多区域云资源缺乏有效的弹性调度,这会影响训练的资源利用率和性... 跨地域分布式机器学习(ML)训练能够联合多区域的云资源协作训练,可满足许多新兴ML场景(比如大型模型训练、联邦学习)的训练需求。但其训练效率仍受2方面挑战的制约。首先,多区域云资源缺乏有效的弹性调度,这会影响训练的资源利用率和性能;其次,模型跨地域同步需要在广域网(WAN)上高频通信,受WAN的低带宽和高波动的影响,会产生巨大通信开销。本文提出Cloudless-Training,从3个方面实现高效的跨地域分布式ML训练。首先,它基于serverless计算模式实现,使用控制层和训练执行层的2层架构,支持多云区域的弹性调度和通信。其次,它提供一种弹性调度策略,根据可用云资源的异构性和训练数据集的分布自适应地部署训练工作流。最后,它提供了2种高效的跨云同步策略,包括基于梯度累积的异步随机梯度下降(ASGD-GA)和跨云参数服务器(PS)间的模型平均(MA)。Cloudless-Training是基于OpenFaaS实现的,并被部署在腾讯云上评估,实验结果表明Cloudless-Training可显著地提高跨地域分布式ML训练的资源利用率(训练成本降低了9.2%~24.0%)和同步效率(训练速度最多比基线快1.7倍),并能保证模型的收敛精度。 展开更多
关键词 跨地域分布式机器学习(ML)训练 跨云ML训练 分布式训练框架 serverless 跨云模型同步
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基于Cloude-Pottier目标分解和聚合的层次聚类算法的全极化SAR数据的非监督分类算法研究 被引量:20
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作者 曹芳 洪文 吴一戎 《电子学报》 EI CAS CSCD 北大核心 2008年第3期543-546,共4页
本文提出了一种新的基于Cloude-Pottier分解和聚合的层次聚类的全极化SAR(Synthetic Aperture Radar)数据的非监督分类算法.作者使用极化总功率SPAN来改进常规的初始化方法,并采用聚合的层次聚类算法对初始化结果进行类的合并,提高非监... 本文提出了一种新的基于Cloude-Pottier分解和聚合的层次聚类的全极化SAR(Synthetic Aperture Radar)数据的非监督分类算法.作者使用极化总功率SPAN来改进常规的初始化方法,并采用聚合的层次聚类算法对初始化结果进行类的合并,提高非监督分类器的性能.实验表明,该算法能获得有效的分类中心,分类结果明显优于常规的WishartH/α/A分类算法. 展开更多
关键词 cloude—Pottier分解 聚合的层次聚类 非监督分类 极化SAR
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利用CloudSat资料分析青藏高原、高原南坡及南亚季风区云高度的统计特征量 被引量:38
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作者 王胜杰 何文英 +2 位作者 陈洪滨 卞建春 王振会 《高原气象》 CSCD 北大核心 2010年第1期1-9,共9页
云与辐射的相互作用对全球的天气和气候变化过程有着重要的影响,不同高度的云有着不同的辐射强迫,获得云体高度及其在时空上的变化对研究全球气候的变化有着重要意义。本文利用云卫星上的云廓线雷达(CloudSat/CPR)2006年6月—2007年12... 云与辐射的相互作用对全球的天气和气候变化过程有着重要的影响,不同高度的云有着不同的辐射强迫,获得云体高度及其在时空上的变化对研究全球气候的变化有着重要意义。本文利用云卫星上的云廓线雷达(CloudSat/CPR)2006年6月—2007年12月期间的资料,对比分析了青藏高原、高原南坡和南亚季风区域不同云类的云顶、云底高度和云厚统计量。结果表明,在所研究区域单位面积上的云顶和云底高度变化具有一定的时空连续性,不同云类的云顶和云底高度存在不同的变化范围,且随着季节的改变均有明显的变化;同时各区域不同云类的云体厚度在夏季较大,冬季较小;各区域不同云类所占的比例(云量)也具有一定的季节变化规律。 展开更多
关键词 cloudSAT 青藏高原 云顶高度 云底高度 云体厚度
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基于概念格的Folksonomy知识组织研究——TagCloud的层级体系构建 被引量:7
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作者 滕广青 毕强 陈晓美 《情报学报》 CSSCI 北大核心 2012年第2期136-142,共7页
Folksonomy作为一种基于用户提交关键字的分类能够反映社群的群体知识背景和群体意识倾向,并在互联网知识组织领域受到人们的普遍关注。然而,在应用中,TagCloud的单一平面结构无法实现向下分层级的检索,并由于非热门Tag的“沉底”... Folksonomy作为一种基于用户提交关键字的分类能够反映社群的群体知识背景和群体意识倾向,并在互联网知识组织领域受到人们的普遍关注。然而,在应用中,TagCloud的单一平面结构无法实现向下分层级的检索,并由于非热门Tag的“沉底”容易形成社群的知识“窄”化等问题。为了解决Folksonomy应用中的这些问题,在对一般Folksonomy应用模式进行分析的基础上,通过形式概念分析技术构建Folksonomy网络应用模式中知识资源及其Tag的概念格,并在概念格的基础上导出了TagCloud的“形式层级”体系结构。讨论了“形式层级”体系的动态立体结构,及其对向下分层检索的支持,以及对非热门Tag的捕捞。 展开更多
关键词 概念格 FOLKSONOMY TAG cloud 形式层级
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Cloud Card对个人学习空间建设的新启示 被引量:9
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作者 郁晓华 黄沁 +1 位作者 张莹渊 祝智庭 《中国电化教育》 CSSCI 北大核心 2016年第2期41-48,共8页
近年来,个人学习空间建设走向实践研究,旨在为学习者提供智慧化学习环境。但由于数字资源组织仍然杂乱无序、适应性和联通性较差,学习工具难以满足学习者个性化需求,基于功能模块的数据服务难以支持真实性评价等原因,个人学习空间取得... 近年来,个人学习空间建设走向实践研究,旨在为学习者提供智慧化学习环境。但由于数字资源组织仍然杂乱无序、适应性和联通性较差,学习工具难以满足学习者个性化需求,基于功能模块的数据服务难以支持真实性评价等原因,个人学习空间取得的阶段性成效与预期尚存在较大距离。该文借鉴深层链接技术在Google、Twitter、Facebook等商业广告领域的成功经验,尝试将其新的发展延伸——Cloud Card引入到个人学习空间建设中。在对Cloud Card进行技术追溯和需求分析的基础上,详细阐述了Cloud Card的UI关联展现、流线型服务组织模式、底层隐形数据传递等特点,并从工具服务的情境化组织、学习过程的追踪、面向过程的真实性评价三个方面,重点探讨了Cloud Card在教育应用中的可行性和关键设计要素,以期能为"人人通"的实现与发展提供一种新的理念和技术路线,为个人学习空间建设助力。 展开更多
关键词 cloud CARD 个人学习空间 深层链接技术 教学情境 真实评价 人人通
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