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"Five steps four quadrants" modularized en bloc dissection technique for accessing hepatic hilum lymph nodes in laparoscopic pancreaticoduodenectomy 被引量:1
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作者 Xiao-Si Hu Yong Wang +5 位作者 Hong-Tao Pan Chao Zhu Shi-Lei Chen Hui-Chun Liu Qing Pang Hao Jin 《World Journal of Gastrointestinal Surgery》 SCIE 2024年第2期503-510,共8页
BACKGROUND Although en bloc dissection of hepatic hilum lymph nodes has many advantages in radical tumor treatment,the feasibility and safety of this approach for laparo-scopic pancreaticoduodenectomy(LPD)require furt... BACKGROUND Although en bloc dissection of hepatic hilum lymph nodes has many advantages in radical tumor treatment,the feasibility and safety of this approach for laparo-scopic pancreaticoduodenectomy(LPD)require further clinical evaluation and investigation.AIM To explore the application value of the"five steps four quadrants"modularized en bloc dissection technique for accessing hepatic hilum lymph nodes in LPD patients.METHODS A total of 52 patients who underwent LPD via the"five steps four quadrants"modularized en bloc dissection technique for hepatic hilum lymph nodes from April 2021 to July 2023 in our department were analyzed retrospectively.The patients'body mass index(BMI),preoperative laboratory indices,intraoperative variables and postoperative complications were recorded.The relationships between preoperative data and intraoperative lymph node dissection time and blood loss were also analyzed.RESULTS Among the 52 patients,36 were males and 16 were females,and the average age was 62.2±11.0 years.There were 26 patients with pancreatic head cancer,16 patients with periampullary cancer,and 10 patients with distal bile duct cancer.The BMI was 22.3±3.3 kg/m²,and the median total bilirubin(TBIL)concentration was 57.7(16.0-155.7)µmol/L.All patients successfully underwent the"five steps four quadrants"modularized en bloc dissection technique without lymph node clearance-related complications such as postoperative bleeding or lymphatic leakage.Correlation analysis revealed significant associations between preoperative BMI(r=0.3581,P=0.0091),TBIL level(r=0.2988,P=0.0341),prothrombin time(r=0.3018,P=0.0297)and lymph node dissection time.Moreover,dissection time was significantly correlated with intraoperative blood loss(r=0.7744,P<0.0001).Further stratified analysis demonstrated that patients with a preoperative BMI≥21.9 kg/m²and a TIBL concentration≥57.7μmol/L had significantly longer lymph node dissection times(both P<0.05).CONCLUSION The"five steps four quadrants"modularized en bloc dissection technique for accessing the hepatic hilum lymph node is safe and feasible for LPD.This technique is expected to improve the efficiency of hepatic hilum lymph node dissection and shorten the learning curve;thus,it is worthy of further clinical promotion and application. 展开更多
关键词 Five steps four quadrants Hepatic hilum lymph node Modularized en bloc clearance Laparoscopic pancreaticoduodenectomy
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Mobility edges and localization characteristics in one-dimensional quasiperiodic quantum walk
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作者 崔鑫辉 王慧敏 李志坚 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期156-160,共5页
We construct a one-dimensional quasiperiodic quantum walk to investigate the localization–delocalization transition.The inverse participation ratio and Lyapunov exponent are employed as two indexes to determine the m... We construct a one-dimensional quasiperiodic quantum walk to investigate the localization–delocalization transition.The inverse participation ratio and Lyapunov exponent are employed as two indexes to determine the mobility edge, a critical energy to distinguish the energy regions of extended and localized states. The analytical solution of mobility edge is obtained by the Lyapunov exponents in global theory, and the consistency of the two indexes is confirmed. We further study the dynamic characteristics of the quantum walk and show that the probabilities are localized to some specific lattice sites with time evolution. This phenomenon is explained by the effective potential of the Hamiltonian which corresponds to the phase in the coin operator of the quantum walk. 展开更多
关键词 quantum walk mobility edges QUASIPERIODICITY
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The Immense Impact of Reverse Edges on Large Hierarchical Networks
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作者 Haosen Cao Bin-Bin Hu +7 位作者 Xiaoyu Mo Duxin Chen Jianxi Gao Ye Yuan Guanrong Chen Tamás Vicsek Xiaohong Guan Hai-Tao Zhang 《Engineering》 SCIE EI CAS CSCD 2024年第5期240-249,共10页
Hierarchical networks are frequently encountered in animal groups,gene networks,and artificial engineering systems such as multiple robots,unmanned vehicle systems,smart grids,wind farm networks,and so forth.The struc... Hierarchical networks are frequently encountered in animal groups,gene networks,and artificial engineering systems such as multiple robots,unmanned vehicle systems,smart grids,wind farm networks,and so forth.The structure of a large directed hierarchical network is often strongly influenced by reverse edges from lower-to higher-level nodes,such as lagging birds’howl in a flock or the opinions of lowerlevel individuals feeding back to higher-level ones in a social group.This study reveals that,for most large-scale real hierarchical networks,the majority of the reverse edges do not affect the synchronization process of the entire network;the synchronization process is influenced only by a small part of these reverse edges along specific paths.More surprisingly,a single effective reverse edge can slow down the synchronization of a huge hierarchical network by over 60%.The effect of such edges depends not on the network size but only on the average in-degree of the involved subnetwork.The overwhelming majority of active reverse edges turn out to have some kind of“bunching”effect on the information flows of hierarchical networks,which slows down synchronization processes.This finding refines the current understanding of the role of reverse edges in many natural,social,and engineering hierarchical networks,which might be beneficial for precisely tuning the synchronization rhythms of these networks.Our study also proposes an effective way to attack a hierarchical network by adding a malicious reverse edge to it and provides some guidance for protecting a network by screening out the specific small proportion of vulnerable nodes. 展开更多
关键词 SYNCHRONIZABILITY Large hierarchical networks Reverse edges Information flows Complex networks
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Half-integer Shapiro steps in MgB_(2) focused He ion beam Josephson junctions
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作者 殷大利 蔡欣炜 +5 位作者 徐铁权 孙瑞宁 韩颖 张焱 王越 甘子钊 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第8期483-489,共7页
Half-integer microwave induced steps(Shapiro steps)have been observed in many different Josephson junction systems,which have attracted a lot of attention because they signify the deviation of current phase relation(C... Half-integer microwave induced steps(Shapiro steps)have been observed in many different Josephson junction systems,which have attracted a lot of attention because they signify the deviation of current phase relation(CPR)and uncover many unconventional physical properties.In this article,we first report the discovery of half-integer Shapiro steps in MgB_(2)focused He ion beam(He-FIB)Josephson junctions.The half-integer steps'dependence on microwave frequency,temperature,microwave power,and magnetic field is also analyzed.We find that the existence of half-integer steps can be controlled by the magnetic field periodically,which is similar to that of high temperature superconductor(HTS)grain boundary junctions,and the similarity of the microstructures between gain boundary junctions and He-FIB junctions is discussed.As a consequence,we mainly attribute the physical origin of half-integer steps in MgB_(2)He-FIB junctions to the model that a He-FIB junction is analogous to a parallel junctions'array.Our results show that He-FIB technology is a promising platform for researching CPR in junctions made of different superconductors. 展开更多
关键词 Josephson junction half-integer Shapiro steps MgB_(2) focused helium ion beam
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A Clean Switch Inner Mongolian town takes giant steps in transitioning to clean energy production
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作者 XIA YUANYUAN 《ChinAfrica》 2024年第5期34-36,共3页
Staff at the Ruichen Wanniu Livestock Farm in Jungar Zhao Town,Jungar Banner,Inner Mongolia,are consistently busy,even during important festivals.
关键词 CLEAN steps BANNER
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240 nm AlGaN-based deep ultraviolet micro-LEDs:size effect versus edge effect 被引量:2
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作者 Shunpeng Lu Jiangxiao Bai +6 位作者 Hongbo Li Ke Jiang Jianwei Ben Shanli Zhang Zi-Hui Zhang Xiaojuan Sun Dabing Li 《Journal of Semiconductors》 EI CAS CSCD 2024年第1期55-62,共8页
240 nm AlGaN-based micro-LEDs with different sizes are designed and fabricated.Then,the external quantum efficiency(EQE)and light extraction efficiency(LEE)are systematically investigated by comparing size and edge ef... 240 nm AlGaN-based micro-LEDs with different sizes are designed and fabricated.Then,the external quantum efficiency(EQE)and light extraction efficiency(LEE)are systematically investigated by comparing size and edge effects.Here,it is revealed that the peak optical output power increases by 81.83%with the size shrinking from 50.0 to 25.0μm.Thereinto,the LEE increases by 26.21%and the LEE enhancement mainly comes from the sidewall light extraction.Most notably,transversemagnetic(TM)mode light intensifies faster as the size shrinks due to the tilted mesa side-wall and Al reflector design.However,when it turns to 12.5μm sized micro-LEDs,the output power is lower than 25.0μm sized ones.The underlying mechanism is that even though protected by SiO2 passivation,the edge effect which leads to current leakage and Shockley-Read-Hall(SRH)recombination deteriorates rapidly with the size further shrinking.Moreover,the ratio of the p-contact area to mesa area is much lower,which deteriorates the p-type current spreading at the mesa edge.These findings show a role of thumb for the design of high efficiency micro-LEDs with wavelength below 250 nm,which will pave the way for wide applications of deep ultraviolet(DUV)micro-LEDs. 展开更多
关键词 ALGAN deep ultraviolet micro-LEDs light extraction efficiency size effect edge effect
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Air-Ground Collaborative Mobile Edge Computing:Architecture,Challenges,and Opportunities 被引量:1
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作者 Qin Zhen He Shoushuai +5 位作者 Wang Hai Qu Yuben Dai Haipeng Xiong Fei Wei Zhenhua Li Hailong 《China Communications》 SCIE CSCD 2024年第5期1-16,共16页
By pushing computation,cache,and network control to the edge,mobile edge computing(MEC)is expected to play a leading role in fifth generation(5G)and future sixth generation(6G).Nevertheless,facing ubiquitous fast-grow... By pushing computation,cache,and network control to the edge,mobile edge computing(MEC)is expected to play a leading role in fifth generation(5G)and future sixth generation(6G).Nevertheless,facing ubiquitous fast-growing computational demands,it is impossible for a single MEC paradigm to effectively support high-quality intelligent services at end user equipments(UEs).To address this issue,we propose an air-ground collaborative MEC(AGCMEC)architecture in this article.The proposed AGCMEC integrates all potentially available MEC servers within air and ground in the envisioned 6G,by a variety of collaborative ways to provide computation services at their best for UEs.Firstly,we introduce the AGC-MEC architecture and elaborate three typical use cases.Then,we discuss four main challenges in the AGC-MEC as well as their potential solutions.Next,we conduct a case study of collaborative service placement for AGC-MEC to validate the effectiveness of the proposed collaborative service placement strategy.Finally,we highlight several potential research directions of the AGC-MEC. 展开更多
关键词 air-ground architecture COLLABORATIVE mobile edge computing
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Mobility edges generated by the non-Hermitian flatband lattice
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作者 刘通 成书杰 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第2期417-420,共4页
We study the cross-stitch flatband lattice subject to the quasiperiodic complex potential exp(ix). We firstly identify the exact expression of quadratic mobility edges through analytical calculation, then verify the t... We study the cross-stitch flatband lattice subject to the quasiperiodic complex potential exp(ix). We firstly identify the exact expression of quadratic mobility edges through analytical calculation, then verify the theoretical predictions by numerically calculating the inverse participation ratio. Further more, we study the relationship between the real–complex spectrum transition and the localization–delocalization transition, and demonstrate that mobility edges in this non-Hermitian model not only separate localized from extended states but also indicate the coexistence of complex and real spectrum. 展开更多
关键词 NON-HERMITIAN QUASIPERIODIC mobility edge
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Edge enhanced depth perception with binocular meta-lens 被引量:2
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作者 Xiaoyuan Liu Jingcheng Zhang +5 位作者 Borui Leng Yin Zhou Jialuo Cheng Takeshi Yamaguchi Takuo Tanaka Mu Ku Chen 《Opto-Electronic Science》 2024年第9期4-13,共10页
The increasing popularity of the metaverse has led to a growing interest and market size in spatial computing from both academia and industry.Developing portable and accurate imaging and depth sensing systems is cruci... The increasing popularity of the metaverse has led to a growing interest and market size in spatial computing from both academia and industry.Developing portable and accurate imaging and depth sensing systems is crucial for advancing next-generation virtual reality devices.This work demonstrates an intelligent,lightweight,and compact edge-enhanced depth perception system that utilizes a binocular meta-lens for spatial computing.The miniaturized system comprises a binocular meta-lens,a 532 nm filter,and a CMOS sensor.For disparity computation,we propose a stereo-matching neural network with a novel H-Module.The H-Module incorporates an attention mechanism into the Siamese network.The symmetric architecture,with cross-pixel interaction and cross-view interaction,enables a more comprehensive analysis of contextual information in stereo images.Based on spatial intensity discontinuity,the edge enhancement eliminates illposed regions in the image where ambiguous depth predictions may occur due to a lack of texture.With the assistance of deep learning,our edge-enhanced system provides prompt responses in less than 0.15 seconds.This edge-enhanced depth perception meta-lens imaging system will significantly contribute to accurate 3D scene modeling,machine vision,autonomous driving,and robotics development. 展开更多
关键词 metasurfaces meta-lenses deep learning depth perception edge detection
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Sensitivity of forest phenology in China varies with proximity to forest edges
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作者 Weibin You Ziyi Xian +2 位作者 Guoyi Zhou Evgenios Agathokleous Zhen Yu 《Forest Ecosystems》 SCIE CSCD 2023年第6期647-655,共9页
Background:Shifts in forest phenological events serve as strong indicators of climate change.However,the sensitivity of phenology events to climate change in relation to forest origins has received limited attention.M... Background:Shifts in forest phenological events serve as strong indicators of climate change.However,the sensitivity of phenology events to climate change in relation to forest origins has received limited attention.Moreover,it is unknown whether forest phenology changes with the proximity to forest edge.Methods:This study examined the green-up dates,dormancy dates,time-integrated NDVI(LiNDVI,a measure of vegetation productivity in growing season),and their sensitivities to climatic factors along the gradients of distance(i.e.proximity)to forest edge(0–2 km)in China's natural forests(NF)and planted forests(PF).For the analysis,field-surveyed data were integrated with Moderate Resolution Imaging Spectroradiometer(MODIS)NDVI from 2000 to 2022.Results:Our results reveal that PF had earlier green-up dates,later dormancy dates,and higher LiNDVI than NF.However,green-up sensitivities to temperature were higher at the edges of NF,whereas no such pattern was observed in PF.Conversely,the sensitivity of dormancy dates remains relatively stable from the inner to the edge of both NF and PF,except for a quadratic change in dormancy date sensitivity to precipitation found in NF.Additionally,we found that the green-up sensitivity to temperature increased with decreasing proximity to edge in NF evergreen forests,while it showed the opposite trend in PF evergreen forests.Furthermore,we observed that the precipitation impact on green-up dates shifts from postponing to advancing from the inner to the edge of NF,whereas precipitation dominantly postpones PF's green-up dates regardless of the proximity to edge.The LiNDVI exhibits higher sensitivity to precipitation at the edge areas,a phenomenon observed in NF but not in PF.Conclusions:These results suggest that the responses of forests to climate change vary with the distance to the edge.With increasing edge forests,which results from fragmentation caused by global changes,we anticipate that desynchronized phenological events along the distance to the edge could alter biogeochemical cycles and reshape ecosystem services such as energy flows,pollination duration,and the tourism industry.Therefore,we advocate for further investigations of edge effects to improve ecosystem modelling,enhance forest stability,and promote sustainable tourism. 展开更多
关键词 Phenology sensitivity edge effects Planted forests Natural forests Climate change
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General mapping of one-dimensional non-Hermitian mosaic models to non-mosaic counterparts:Mobility edges and Lyapunov exponents
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作者 蒋盛莲 刘彦霞 郎利君 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第9期79-86,共8页
We establish a general mapping from one-dimensional non-Hermitian mosaic models to their non-mosaic counterparts.This mapping can give rise to mobility edges and even Lyapunov exponents in the mosaic models if critica... We establish a general mapping from one-dimensional non-Hermitian mosaic models to their non-mosaic counterparts.This mapping can give rise to mobility edges and even Lyapunov exponents in the mosaic models if critical points of localization or Lyapunov exponents of localized states in the corresponding non-mosaic models have already been analytically solved.To demonstrate the validity of this mapping,we apply it to two non-Hermitian localization models:an Aubry-Andre-like model with nonreciprocal hopping and complex quasiperiodic potentials,and the Ganeshan-Pixley-Das Sarma model with nonreciprocal hopping.We successfully obtain the mobility edges and Lyapunov exponents in their mosaic models.This general mapping may catalyze further studies on mobility edges,Lyapunov exponents,and other significant quantities pertaining to localization in non-Hermitian mosaic models. 展开更多
关键词 non-Hermitian mosaic model mosaic-to-non-mosaic mapping mobility edge Lyapunov exponent
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Mobility edges in one-dimensional finite-sized models with large quasi-periodic disorders
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作者 汤起芸 贺言 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第12期500-508,共9页
We study the one-dimensional tight-binding model with quasi-periodic disorders,where the quasi-period is tuned to be large compared to the system size.It is found that this type of model with large quasi-periodic diso... We study the one-dimensional tight-binding model with quasi-periodic disorders,where the quasi-period is tuned to be large compared to the system size.It is found that this type of model with large quasi-periodic disorders can also support the mobility edges,which is very similar to the models with slowly varying quasi-periodic disorders.The energy-matching method is employed to determine the locations of mobility edges in both types of models.These results of mobility edges are verified by numerical calculations in various examples.We also provide qualitative arguments to support the fact that large quasi-periodic disorders will lead to the existence of mobility edges. 展开更多
关键词 quasi-periodic disorders mobility edges Aubry–Andre model
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基于TeamSTEPPS理论的案例情景教学法在急诊护理团队培训中的应用
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作者 陈清清 黄赣英 +1 位作者 凡欣欣 沈小玲 《全科医学临床与教育》 2024年第1期85-87,共3页
急诊科具有危重患者多,突发状况多,医疗风险高等特点,目前国内大多数医院急诊科护士以团队形式开展工作,但临床工作中易出现职责分工不明确、配合不协调、组织抢救混乱等问题^([1])。团队培训是增强团队优质高效协作的重要途径^([2]),... 急诊科具有危重患者多,突发状况多,医疗风险高等特点,目前国内大多数医院急诊科护士以团队形式开展工作,但临床工作中易出现职责分工不明确、配合不协调、组织抢救混乱等问题^([1])。团队培训是增强团队优质高效协作的重要途径^([2]),为进一步提升急诊护理团队协作,保障患者安全,本次研究将前期基于提高医疗质量和患者安全的团队策略与工具(team strategies and tools to enhance performance and patient safety,TeamSTEPPS)理论构建的急诊护理团队培训方案^([3])进行临床应用,取得了较好的效果。现报道如下。 展开更多
关键词 急诊护理 急诊科护士 医疗风险 团队培训 step 团队协作 团队策略 患者安全
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基于Solid Edge自动生成数控加工图的二次开发研究
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作者 吴事谱 陆祉好 阳开应 《锅炉技术》 北大核心 2024年第4期21-26,共6页
基于Solid Edge软件平台,利用C#进行二次开发,设计出一款利用三维设计模型和组件图生成数控加工工艺图纸的批量设计软件,并详细展示了软件的工作流程、原理和关键技术。经应用验证,该软件具有出图快、信息匹配度高、适用模型范围广、操... 基于Solid Edge软件平台,利用C#进行二次开发,设计出一款利用三维设计模型和组件图生成数控加工工艺图纸的批量设计软件,并详细展示了软件的工作流程、原理和关键技术。经应用验证,该软件具有出图快、信息匹配度高、适用模型范围广、操作灵活、界面友好等优点,以此实现了车间的无纸化高效数据传输和敏捷生产。 展开更多
关键词 Solid edge 二次开发 数控加工图 轮廓图 C# 工程图 三维设计
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基于KubeEdge的全国气象监视数据采集软件设计
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作者 白金婷 罗飞 +5 位作者 孙超 张喜 罗谦 徐达 郭聪 段明静 《计算机技术与发展》 2024年第8期67-72,共6页
为解决气象综合业务实时监控系统(简称“天镜”)对全国气象监视数据采集汇聚安全性、高效性、灵活可管控能力不足的问题,更好地满足全国气象业务集中监视需求,基于“云边协同”的边缘计算KubeEdge架构设计并实现了“天镜”全国气象监视... 为解决气象综合业务实时监控系统(简称“天镜”)对全国气象监视数据采集汇聚安全性、高效性、灵活可管控能力不足的问题,更好地满足全国气象业务集中监视需求,基于“云边协同”的边缘计算KubeEdge架构设计并实现了“天镜”全国气象监视数据采集汇聚软件。国家级“天镜”采用KubeEdge内部通道传递应用程序的控制命令和状态信息,采用气象国省宽带网传输监视数据;采用脚本实现云边端离线自动部署;采用Harbor管理和分发镜像;基于KubeEdge的命令和状态信息实现节点、设备和任务的可视化管控,一体化管控全国边缘节点和采集任务,支持监视任务和数据上传的动态调整。实验结果表明,基于KubeEdge的全国气象监视数据采集汇聚软件有效提高了全国气象监视数据采集汇聚效率和灵活可管控能力,保障了数据传输的安全性。目前该软件已应用于各省(区、市)气象高质量发展通信网络指标评估、全国“天擎”集中监视、全国空间天气全链路状态监视,并取得了良好的业务效益。 展开更多
关键词 边缘计算 Kubeedge 云边协同 数据采集汇聚 灵活可管控 数据传输
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gEdge:基于容器技术的云边协同的异构计算框架
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作者 汪沄 汤冬劼 +2 位作者 郭开诚 戚正伟 管海兵 《计算机学报》 EI CAS CSCD 北大核心 2024年第8期1883-1900,共18页
由于按需灵活配置、高可用性、高资源利用率等优点,云计算技术成为过去十年的主流计算范式.随着万物互联时代的到来,单独依赖云计算技术已经无法满足数以亿计的IoT设备及其数据流量的需求.边缘计算可以被看作是云计算的进化,它因5G网络... 由于按需灵活配置、高可用性、高资源利用率等优点,云计算技术成为过去十年的主流计算范式.随着万物互联时代的到来,单独依赖云计算技术已经无法满足数以亿计的IoT设备及其数据流量的需求.边缘计算可以被看作是云计算的进化,它因5G网络和物联网的崛起而诞生.随着云游戏、VR技术以及人工智能技术在日常生活中的广泛运用,对计算资源的需求也在日渐增长.然而,受体积与功耗限制,处于边缘的节点设备算力较弱.本文提出了gEdge:一种基于容器技术的云边协同的异构计算框架.该框架通过GPU虚拟化技术,将云端的物理GPU资源分为多块虚拟GPU资源,按需为边缘节点提供GPU算力资源,并且对用户容器无感知.实验表明,使用gEdge框架使边缘节点使用的容器镜像体积降低了48.8%,容器启动时间降低了35.5%,平均相对运行速度提高了213%. 展开更多
关键词 图形处理器 虚拟化技术 容器技术 边缘计算 云边协同
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Security Implications of Edge Computing in Cloud Networks 被引量:1
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作者 Sina Ahmadi 《Journal of Computer and Communications》 2024年第2期26-46,共21页
Security issues in cloud networks and edge computing have become very common. This research focuses on analyzing such issues and developing the best solutions. A detailed literature review has been conducted in this r... Security issues in cloud networks and edge computing have become very common. This research focuses on analyzing such issues and developing the best solutions. A detailed literature review has been conducted in this regard. The findings have shown that many challenges are linked to edge computing, such as privacy concerns, security breaches, high costs, low efficiency, etc. Therefore, there is a need to implement proper security measures to overcome these issues. Using emerging trends, like machine learning, encryption, artificial intelligence, real-time monitoring, etc., can help mitigate security issues. They can also develop a secure and safe future in cloud computing. It was concluded that the security implications of edge computing can easily be covered with the help of new technologies and techniques. 展开更多
关键词 edge Computing Cloud Networks Artificial Intelligence Machine Learning Cloud Security
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IRS Assisted UAV Communications against Proactive Eavesdropping in Mobile Edge Computing Networks 被引量:1
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作者 Ying Zhang Weiming Niu Leibing Yan 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第1期885-902,共18页
In this paper,we consider mobile edge computing(MEC)networks against proactive eavesdropping.To maximize the transmission rate,IRS assisted UAV communications are applied.We take the joint design of the trajectory of ... In this paper,we consider mobile edge computing(MEC)networks against proactive eavesdropping.To maximize the transmission rate,IRS assisted UAV communications are applied.We take the joint design of the trajectory of UAV,the transmitting beamforming of users,and the phase shift matrix of IRS.The original problem is strong non-convex and difficult to solve.We first propose two basic modes of the proactive eavesdropper,and obtain the closed-form solution for the boundary conditions of the two modes.Then we transform the original problem into an equivalent one and propose an alternating optimization(AO)based method to obtain a local optimal solution.The convergence of the algorithm is illustrated by numerical results.Further,we propose a zero forcing(ZF)based method as sub-optimal solution,and the simulation section shows that the proposed two schemes could obtain better performance compared with traditional schemes. 展开更多
关键词 Mobile edge computing(MEC) unmanned aerial vehicle(UAV) intelligent reflecting surface(IRS) zero forcing(ZF)
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Moir patterns and step edges on few-layer graphene grown on nickel films
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作者 柯芬 尹秀丽 +6 位作者 佟鼐 林陈昉 刘楠 赵汝光 付磊 刘忠范 胡宗海 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第11期445-449,共5页
Few-layer graphene grown on Ni thin films has been studied by scanning tunneling microscopy. In most areas on the surfaces, moir6 patterns resulted from rotational stacking faults were observed. At a bias lower than 2... Few-layer graphene grown on Ni thin films has been studied by scanning tunneling microscopy. In most areas on the surfaces, moir6 patterns resulted from rotational stacking faults were observed. At a bias lower than 200 mV, only one sublattice shows up in regions without moir6 patterns while both sublattices are seen in regions with moir6 pattens. This phenomenon can be used to identify AB stacked regions. The scattering characteristics at various types of step edges are different from those of monolayer graphene edges, either armchair or zigzag. 展开更多
关键词 scanning tunneling microscopy few-layer graphene stacking order step edge
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A review on edge analytics:Issues,challenges,opportunities,promises,future directions,and applications
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作者 Sabuzima Nayak Ripon Patgiri +1 位作者 Lilapati Waikhom Arif Ahmed 《Digital Communications and Networks》 SCIE CSCD 2024年第3期783-804,共22页
Edge technology aims to bring cloud resources(specifically,the computation,storage,and network)to the closed proximity of the edge devices,i.e.,smart devices where the data are produced and consumed.Embedding computin... Edge technology aims to bring cloud resources(specifically,the computation,storage,and network)to the closed proximity of the edge devices,i.e.,smart devices where the data are produced and consumed.Embedding computing and application in edge devices lead to emerging of two new concepts in edge technology:edge computing and edge analytics.Edge analytics uses some techniques or algorithms to analyse the data generated by the edge devices.With the emerging of edge analytics,the edge devices have become a complete set.Currently,edge analytics is unable to provide full support to the analytic techniques.The edge devices cannot execute advanced and sophisticated analytic algorithms following various constraints such as limited power supply,small memory size,limited resources,etc.This article aims to provide a detailed discussion on edge analytics.The key contributions of the paper are as follows-a clear explanation to distinguish between the three concepts of edge technology:edge devices,edge computing,and edge analytics,along with their issues.In addition,the article discusses the implementation of edge analytics to solve many problems and applications in various areas such as retail,agriculture,industry,and healthcare.Moreover,the research papers of the state-of-the-art edge analytics are rigorously reviewed in this article to explore the existing issues,emerging challenges,research opportunities and their directions,and applications. 展开更多
关键词 edge analytics edge computing edge devices Big data Sensor Artificial intelligence Machine learning Smart technology Healthcare
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