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Enhanced Mechanism for Link Failure Rerouting in Software-Defined Exchange Point Networks
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作者 Abdijalil Abdullahi Selvakumar Manickam 《Computers, Materials & Continua》 SCIE EI 2024年第9期4361-4385,共25页
Internet Exchange Point(IXP)is a system that increases network bandwidth performance.Internet exchange points facilitate interconnection among network providers,including Internet Service Providers(ISPs)andContent Del... Internet Exchange Point(IXP)is a system that increases network bandwidth performance.Internet exchange points facilitate interconnection among network providers,including Internet Service Providers(ISPs)andContent Delivery Providers(CDNs).To improve service management,Internet exchange point providers have adopted the Software Defined Network(SDN)paradigm.This implementation is known as a Software-Defined Exchange Point(SDX).It improves network providers’operations and management.However,performance issues still exist,particularly with multi-hop topologies.These issues include switch memory costs,packet processing latency,and link failure recovery delays.The paper proposes Enhanced Link Failure Rerouting(ELFR),an improved mechanism for rerouting link failures in software-defined exchange point networks.The proposed mechanism aims to minimize packet processing time for fast link failure recovery and enhance path calculation efficiency while reducing switch storage overhead by exploiting the Programming Protocol-independent Packet Processors(P4)features.The paper presents the proposed mechanisms’efficiency by utilizing advanced algorithms and demonstrating improved performance in packet processing speed,path calculation effectiveness,and switch storage management compared to current mechanisms.The proposed mechanism shows significant improvements,leading to a 37.5%decrease in Recovery Time(RT)and a 33.33%decrease in both Calculation Time(CT)and Computational Overhead(CO)when compared to current mechanisms.The study highlights the effectiveness and resource efficiency of the proposed mechanism in effectively resolving crucial issues inmulti-hop software-defined exchange point networks. 展开更多
关键词 Link failure recovery Internet exchange point software-defined exchange point software-defined network multihop topologies
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香蕉枯萎病菌内源报告基因Foc4carS的鉴定及其应用
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作者 彭军 曾凡云 +5 位作者 王艳玮 漆艳香 丁兆建 王少伶 谢艺贤 张欣 《热带作物学报》 CSCD 北大核心 2024年第5期873-885,共13页
香蕉枯萎病是由尖孢镰刀菌古巴转化型(Fusarium oxysporum f. sp. cubense, Foc)引起的香蕉毁灭性土传病害,其中4号生理小种(Foc4)能感染几乎所有的香蕉品系,危害最严重。carS基因通过调控下游car结构基因参与调控镰刀菌类胡萝卜素的生... 香蕉枯萎病是由尖孢镰刀菌古巴转化型(Fusarium oxysporum f. sp. cubense, Foc)引起的香蕉毁灭性土传病害,其中4号生理小种(Foc4)能感染几乎所有的香蕉品系,危害最严重。carS基因通过调控下游car结构基因参与调控镰刀菌类胡萝卜素的生物合成,本研究克隆鉴定了Foc4carS基因(FOIG_05085),Foc4carS蛋白具有典型的RING-finger蛋白结构域。利用分割标记法(Split-marker PCR)获得Foc4carS基因的融合片段,同时构建含有Foc4carS基因sgRNA591序列的pUC-fFuCas9-HTBNLS-hph-Foc4carS基因编辑载体,通过PEG介导的原生质体转化获得该基因的敲除突变体、回补突变体以及基因编辑敲除体,并对敲除和回补突变体的生物学特性和致病力进行分析。结果显示:ΔFoc4carS突变体的菌落直径、产孢量和致病力等生物学表型与野生菌株Foc4无显著差异,而ΔFoc4carS突变体菌落颜色呈深橙色,Foc4carS基因的缺失影响了次生代谢产物类胡萝卜素的生物合成;基因编辑的ΔFoc4carS(HDR)突变体不论是再生筛选板还是继代后的PDA平板,其菌落均出现典型的深橙色,表明Foc4carS可作为内源报告基因,在香蕉枯萎菌Foc4中进行基因质粒型CRISPR/Cas9编辑可行。 展开更多
关键词 香蕉枯萎菌Foc4 Foc4carS基因 类胡萝卜素 基因敲除 CRISPR/Cas9基因编辑
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On Reliability-optimized Controller Placement for Software-Defined Networks 被引量:25
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作者 HU Yannan WANG Wendong GONG Xiangyang QUE Xirong CHENG Shiduan 《China Communications》 SCIE CSCD 2014年第2期38-54,共17页
By decoupling control plane and data plane,Software-Defined Networking(SDN) approach simplifies network management and speeds up network innovations.These benefits have led not only to prototypes,but also real SDN dep... By decoupling control plane and data plane,Software-Defined Networking(SDN) approach simplifies network management and speeds up network innovations.These benefits have led not only to prototypes,but also real SDN deployments.For wide-area SDN deployments,multiple controllers are often required,and the placement of these controllers becomes a particularly important task in the SDN context.This paper studies the problem of placing controllers in SDNs,so as to maximize the reliability of SDN control networks.We present a novel metric,called expected percentage of control path loss,to characterize the reliability of SDN control networks.We formulate the reliability-aware control placement problem,prove its NP-hardness,and examine several placement algorithms that can solve this problem.Through extensive simulations using real topologies,we show how the number of controllers and their placement influence the reliability of SDN control networks.Besides,we also found that,through strategic controller placement,the reliability of SDN control networks can be significantly improved without introducing unacceptable switch-to-controller latencies. 展开更多
关键词 software-defined Networking controller placement RELIABILITY networkoptimization
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CAR-T细胞治疗后复发/难治性多发性骨髓瘤患者的临床特征
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作者 王慧娟 陈文明 +1 位作者 耿传营 杨光忠 《中国癌症防治杂志》 CAS 2024年第5期549-553,共5页
目的分析嵌合抗原受体T(chimeric antigen receptor,CAR-T)细胞治疗后复发/难治多发性骨髓瘤(relapsed/refractory multiple myeloma,RRMM)患者的临床特征,初步探索此类患者未来可能的治疗策略。方法以2020年1月至2024年6月在首都医科... 目的分析嵌合抗原受体T(chimeric antigen receptor,CAR-T)细胞治疗后复发/难治多发性骨髓瘤(relapsed/refractory multiple myeloma,RRMM)患者的临床特征,初步探索此类患者未来可能的治疗策略。方法以2020年1月至2024年6月在首都医科大学附属北京朝阳医院住院治疗的RRMM患者为研究对象,分析CAR-T细胞治疗后复发的临床特征及生存情况。结果共收集14例符合条件的RRMM患者,均接受靶向BCMA的CAR-T细胞治疗,中位无进展生存时间为17个月(范围:3~47个月)。疾病复发进展时,1例仅表现为髓外复发,2例继发浆细胞白血病,11例为髓内复发;7例检查细胞遗传学,其中4例患者存在1个高危基因,1例患者存在2个高危基因。首次挽救治疗中,常用药物包括达雷妥尤单抗(6例)、泊马度胺(5例)、卡非佐米(3例),3例患者入组临床试验。13例患者可评价疗效,总有效率为61.5%(8/13),其中完全缓解率为30.8%(4/13),非常好的部分缓解率为23.1%(3/13)。中位随访时间为15个月(范围:1~32个月),中位无进展生存时间为7个月。截至末次随访,死亡6例,中位总生存期为32个月;1例患者出现第二肿瘤,类型为肺癌。结论接受CAR-T细胞治疗后RRMM患者常见多类药物耐药,挽救治疗疗效及预后不佳。 展开更多
关键词 多发性骨髓瘤 car-T细胞治疗 复发 难治 挽救治疗 预后
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A Survey: Typical Security Issues of Software-Defined Networking 被引量:12
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作者 Yifan Liu Bo Zhao +2 位作者 Pengyuan Zhao Peiru Fan Hui Liu 《China Communications》 SCIE CSCD 2019年第7期13-31,共19页
Software-Defined Networking (SDN) has been a hot topic for future network development, which implements the different layers of control plane and data plane respectively. Despite providing high openness and programmab... Software-Defined Networking (SDN) has been a hot topic for future network development, which implements the different layers of control plane and data plane respectively. Despite providing high openness and programmability, the “three-layer two-interface” architecture of SDN changes the traditional network and increases the network attack nodes, which results in new security issues. In this paper, we firstly introduced the background, architecture and working process of SDN. Secondly, we summarized and analyzed the typical security issues from north to south: application layer, northbound interface, control layer, southbound interface and data layer. Another contribution is to review and analyze the existing solutions and latest research progress of each layer, mainly including: authorized authentication module, application isolation, DoS/DDoS defense, multi-controller deployment and flow rule consistency detection. Finally, a conclusion about the future works of SDN security and an idealized global security architecture is proposed. 展开更多
关键词 software-defined NETWORKING network SECURITY global SECURITY SECURITY THREAT
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Quality of Service Improvement with Optimal Software-Defined Networking Controller and Control Plane Clustering 被引量:11
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作者 Jehad Ali Byeong-hee Roh 《Computers, Materials & Continua》 SCIE EI 2021年第4期849-875,共27页
The controller is indispensable in software-defined networking(SDN).With several features,controllers monitor the network and respond promptly to dynamic changes.Their performance affects the quality-of-service(QoS)in... The controller is indispensable in software-defined networking(SDN).With several features,controllers monitor the network and respond promptly to dynamic changes.Their performance affects the quality-of-service(QoS)in SDN.Every controller supports a set of features.However,the support of the features may be more prominent in one controller.Moreover,a single controller leads to performance,single-point-of-failure(SPOF),and scalability problems.To overcome this,a controller with an optimum feature set must be available for SDN.Furthermore,a cluster of optimum feature set controllers will overcome an SPOF and improve the QoS in SDN.Herein,leveraging an analytical network process(ANP),we rank SDN controllers regarding their supporting features and create a hierarchical control plane based cluster(HCPC)of the highly ranked controller computed using the ANP,evaluating their performance for the OS3E topology.The results demonstrated in Mininet reveal that a HCPC environment with an optimum controller achieves an improved QoS.Moreover,the experimental results validated in Mininet show that our proposed approach surpasses the existing distributed controller clustering(DCC)schemes in terms of several performance metrics i.e.,delay,jitter,throughput,load balancing,scalability and CPU(central processing unit)utilization. 展开更多
关键词 QUALITY-OF-SERVICE software-defined networking CONTROLLER hierarchical control plane clustering SCALABILITY
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BCMA CAR-T治疗复发/难治性多发性骨髓瘤患者的长期疗效和影响因素分析
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作者 喻敏 孔繁聪 +2 位作者 周玉兰 齐凌 李菲 《中国肿瘤临床》 CAS CSCD 北大核心 2024年第7期342-347,共6页
目的:评价靶向B细胞成熟抗原(B cell maturation antigen,BCMA)嵌合抗原受体T细胞(chimeric antigen receptor-T cell,CAR-T)治疗复发/难治性多发性骨髓瘤(relapsed/refractory multiple myeloma,R/R MM)的长期疗效和安全性。方法:回顾... 目的:评价靶向B细胞成熟抗原(B cell maturation antigen,BCMA)嵌合抗原受体T细胞(chimeric antigen receptor-T cell,CAR-T)治疗复发/难治性多发性骨髓瘤(relapsed/refractory multiple myeloma,R/R MM)的长期疗效和安全性。方法:回顾性分析2018年7月至2023年7月在南昌大学第一附属医院接受BCMA CAR-T细胞治疗20例R/R MM患者的临床资料,随访日期截至2023年12月31日。应用Kaplan-Meier生存分析评估患者总生存(overall survival,OS)率和无进展生存(progression-free survival,PFS)率,并统计相关不良反应。结果:20例R/R MM患者,既往中位治疗线数为3(2~6)线,客观缓解率(objective response rate,ORR)为75%,完全缓解(complete response,CR)率为50%;中位随访时间29个月,中位PFS为26个月。10例CR的患者中,5例在末次随访时仍处于缓解状态,缓解持续时间最短为6个月,最长48个月。亚组分析中,髓外浸润、17p缺失遗传学异常和肿瘤高负荷患者PFS显著更差(P<0.05)。细胞因子释放综合征(cytokine release syndrome,CRS)是CAR-T细胞治疗最常见的不良反应,发生率为90%,3~4级CRS的发生率为35%;远期不良反应少,未发生CAR-T细胞治疗相关死亡。结论:BCMA CAR-T细胞是当前R/R MM治疗的有效方案,不良反应可控。髓外浸润和肿瘤高负荷的患者治疗有效,但持久反应欠佳,如何进一步巩固和维持患者的疗效,值得进一步设计前瞻性的临床研究并探究其差异性。 展开更多
关键词 嵌合抗原受体修饰T细胞 复发/难治 多发性骨髓瘤
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Challenge-based collaborative intrusion detection in software-defined networking: An evaluation 被引量:4
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作者 Wenjuan Li Yu Wang +3 位作者 Zhiping Jin Keping Yu Jin Li Yang Xiang 《Digital Communications and Networks》 SCIE CSCD 2021年第2期257-263,共7页
Software-Defined Networking(SDN)is an emerging architecture that enables a computer network to be intelligently and centrally controlled via software applications.It can help manage the whole network environment in a ... Software-Defined Networking(SDN)is an emerging architecture that enables a computer network to be intelligently and centrally controlled via software applications.It can help manage the whole network environment in a consistent and holistic way,without the need of understanding the underlying network structure.At present,SDN may face many challenges like insider attacks,i.e.,the centralized control plane would be attacked by malicious underlying devices and switches.To protect the security of SDN,effective detection approaches are indispensable.In the literature,challenge-based collaborative intrusion detection networks(CIDNs)are an effective detection framework in identifying malicious nodes.It calculates the nodes'reputation and detects a malicious node by sending out a special message called a challenge.In this work,we devise a challenge-based CIDN in SDN and measure its performance against malicious internal nodes.Our results demonstrate that such a mechanism can be effective in SDN environments. 展开更多
关键词 software-defined networking Trust management Collaborative intrusion detection Insider attack Challenge mechanism
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On the use of the genetic programming for balanced load distribution in software-defined networks 被引量:3
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作者 Shahram Jamali Amin Badirzadeh Mina Soltani Siapoush 《Digital Communications and Networks》 SCIE 2019年第4期288-296,共9页
As a new networking paradigm,Software-Defined Networking(SDN)enables us to cope with the limitations of traditional networks.SDN uses a controller that has a global view of the network and switch devices which act as ... As a new networking paradigm,Software-Defined Networking(SDN)enables us to cope with the limitations of traditional networks.SDN uses a controller that has a global view of the network and switch devices which act as packet forwarding hardware,known as“OpenFlow switches”.Since load balancing service is essential to distribute workload across servers in data centers,we propose an effective load balancing scheme in SDN,using a genetic programming approach,called Genetic Programming based Load Balancing(GPLB).We formulate the problem to find a path:1)with the best bottleneck switch which has the lowest capacity within bottleneck switches of each path,2)with the shortest path,and 3)requiring the less possible operations.For the purpose of choosing the real-time least loaded path,GPLB immediately calculates the integrated load of paths based on the information that receives from the SDN controller.Hence,in this design,the controller sends the load information of each path to the load balancing algorithm periodically and then the load balancing algorithm returns a least loaded path to the controller.In this paper,we use the Mininet emulator and the OpenDaylight controller to evaluate the effectiveness of the GPLB.The simulative study of the GPLB shows that there is a big improvement in performance metrics and the latency and the jitter are minimized.The GPLB also has the maximum throughput in comparison with related works and has performed better in the heavy traffic situation.The results show that our model stands smartly while not increasing further overhead. 展开更多
关键词 software-defined networking OpenFlow Mininet OpenDaylight Load balancing
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Orchestrating Network Functions in Software-Defined Networks 被引量:2
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作者 Hongchao Hu Lin Pang +1 位作者 Zhenpeng Wang Guozhen Cheng 《China Communications》 SCIE CSCD 2017年第2期104-117,共14页
Software.defined networking(SDN) enables third.part companies to participate in the network function innovations. A number of instances for one network function will inevitably co.exist in the network. Although some o... Software.defined networking(SDN) enables third.part companies to participate in the network function innovations. A number of instances for one network function will inevitably co.exist in the network. Although some orchestration architecture has been proposed to chain network functions, rare works are focused on how to optimize this process. In this paper, we propose an optimized model for network function orchestration, function combination model(FCM). Our main contributions are as following. First, network functions are featured with a new abstraction, and are open to external providers. And FCM identifies network functions using unique type, and organizes their instances distributed over the network with the appropriate way. Second, with the specialized demands, we can combine function instances under the global network views, and formulate it into the problem of Boolean linear program(BLP). A simulated annealing algorithm is designed to approach optimal solution for this BLP. Finally, the numerical experiment demonstrates that our model can create outstanding composite schemas efficiently. 展开更多
关键词 software-defined network network function function orchestrating
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预后营养指数联合CAR、Alb对腹膜透析患者远期预后的预测价值
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作者 刘文佳 颜胜 陈越 《分子诊断与治疗杂志》 2024年第6期1044-1048,共5页
目的 评估预后营养指数(PNI)联合C反应蛋白/白蛋白比值(CAR)、血清白蛋白(Alb)对腹膜透析(PD)患者远期预后的预测价值。方法 分析纳入2019年1月至2024年1月在自贡市第一人民医院肾病内科接受PD治疗的终末期肾病患者102例,根据5年随访期... 目的 评估预后营养指数(PNI)联合C反应蛋白/白蛋白比值(CAR)、血清白蛋白(Alb)对腹膜透析(PD)患者远期预后的预测价值。方法 分析纳入2019年1月至2024年1月在自贡市第一人民医院肾病内科接受PD治疗的终末期肾病患者102例,根据5年随访期间PD患者生存结局分为死亡组(n=33)和生存组(n=69)。采用单因素及多因素Logistic回归分析影响PD患者远期预后的独立危险因素。绘制受试者工作特征(ROC)曲线评估PNI联合CAR、Alb对PD患者生存结局的预测价值。结果 与生存组相比,死亡组患者合并糖尿病、心血管疾病及腹膜炎并发症的比例较高,差异有统计学意义(χ^(2)=0.947,4.846,5.840);肾小球滤过率(eGFR)、PNI、Alb水平降低,差异有统计学意义(t=9.495,6.068,5.422);血清肌酐(SCR)、尿酸(UA)及CAR水平升高,差异有统计学意义(t=5.369,4.581,5.048),差异均有统计学意义(P<0.05)。Logistic回归分析显示,患者合并糖尿病、心血管疾病、CAR是PD患者死亡的独立危险因素(P<0.05),eGFR、PNI、Alb是PD患者死亡的独立保护因素(P<0.05)。ROC曲线分析显示,PNI、CAR、Alb联合预测的曲线下面积分别为0.928,显著高于单独预测(P<0.05)。结论 PNI、Alb水平降低及CAR升高是PD患者死亡的独立影响因素,三者均可为PD患者长期预后生存结局提供参考,且联合预测价值更高。 展开更多
关键词 腹膜透析 远期预后 预后营养指数 C反应蛋白/白蛋白比值 血清白蛋白
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Software-Defined Networking 被引量:2
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作者 Zhili Sun Jiandong Li Kun Yang 《ZTE Communications》 2014年第2期1-2,共2页
Software- defined networking (SDN) is a promising technology for next-generation networking and has attracted much attention from academics, network equipment manufacturer, network operators, and service providers. ... Software- defined networking (SDN) is a promising technology for next-generation networking and has attracted much attention from academics, network equipment manufacturer, network operators, and service providers. It has found center, and enterprise networks. applications in mobile, data The SDN architecture has a centralized, programmable control plane that is separate from the data plane. SDN also provides the ability to control and manage virtualized resources and networks without requiring new hardware technologies. This is a major shift in networking technologies. 展开更多
关键词 OpenFlow WORK NET software-defined Networking NFV
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A movement-assisted software-defined sensor network with NFV support 被引量:2
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作者 Yin Haohao Ding Cui +2 位作者 Yan Feng Xia Weiwei Shen Lianfeng 《Journal of Southeast University(English Edition)》 EI CAS 2018年第2期156-165,共10页
A flexible and controllable movement-assisted software-defined sensor network(MA-SDSN)based on the software-defined network(SDN)and network function virtualization(NFV)is proposed.First,a three-layer fundamental archi... A flexible and controllable movement-assisted software-defined sensor network(MA-SDSN)based on the software-defined network(SDN)and network function virtualization(NFV)is proposed.First,a three-layer fundamental architecture is proposed to overcome the inherent distributed management and rigidity of the conventional wireless sensor networks.Furthermore,the platform for research and development of MA-SDSN is established,and the dumb node(DN),the software-defined node(SN)and the movement-assisted node(MN)are designed and implemented.Then,the southbound application programming interface(API)is designed to provide a series of frames for communication between controllers and sensor nodes.The northbound API is developed and demonstrated overall and in detail.The functions of the controller are presented including topology discovery,dynamic networking,packet processing,mobility management and virtualization.Followed by the MA-SDSN network model,a Markov chain-based movement-assisted weighted relocation(MMWR)topology control algorithm is proposed to redeploy the MNs based on the node status and weight.Simulation results and analysis indicate that the proposed algorithm based on the MA-SDSN extends network lifetime with a lower average power consumption. 展开更多
关键词 software-defined sensor network network function virtualization movement-assisted topology control
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EARS: Intelligence-Driven Experiential Network Architecture for Automatic Routing in Software-Defined Networking 被引量:6
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作者 Yuxiang Hu Ziyong Li +2 位作者 Julong Lan Jiangxing Wu Lan Yao 《China Communications》 SCIE CSCD 2020年第2期149-162,共14页
Software-Defined Networking(SDN)adapts logically-centralized control by decoupling control plane from data plane and provides the efficient use of network resources.However,due to the limitation of traditional routing... Software-Defined Networking(SDN)adapts logically-centralized control by decoupling control plane from data plane and provides the efficient use of network resources.However,due to the limitation of traditional routing strategies relying on manual configuration,SDN may suffer from link congestion and inefficient bandwidth allocation among flows,which could degrade network performance significantly.In this paper,we propose EARS,an intelligence-driven experiential network architecture for automatic routing.EARS adapts deep reinforcement learning(DRL)to simulate the human methods of learning experiential knowledge,employs the closed-loop network control mechanism incorporating with network monitoring technologies to realize the interaction with network environment.The proposed EARS can learn to make better control decision from its own experience by interacting with network environment and optimize the network intelligently by adjusting services and resources offered based on network requirements and environmental conditions.Under the network architecture,we design the network utility function with throughput and delay awareness,differentiate flows based on their size characteristics,and design a DDPGbased automatic routing algorithm as DRL decision brain to find the near-optimal paths for mice and elephant flows.To validate the network architecture,we implement it on a real network environment.Extensive simulation results show that EARS significantly improve the network throughput and reduces the average packet delay in comparison with baseline schemes(e.g.OSPF,ECMP). 展开更多
关键词 software-defined networking(SDN) intelligence-driven experiential network deep reinforcement learning(DRL) automatic routing
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A Game-Theoretic Approach to Elastic Control in Software-Defined Networking 被引量:6
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作者 Hongchang Chen Guozhen Cheng Zhiming Wang 《China Communications》 SCIE CSCD 2016年第5期103-109,共7页
Elastic control could balance the distributed control plane in Software-Defined Networking(SDN). Dynamic switch migration has been proposed to achieve it. However, existing schemes mainly focus on how to execute migra... Elastic control could balance the distributed control plane in Software-Defined Networking(SDN). Dynamic switch migration has been proposed to achieve it. However, existing schemes mainly focus on how to execute migration operation, but not why. This paper designs a decision-making mechanism based on zero-sum game theory to reelect a new controller as the master for migrated switches. It first chooses a switch for migration in the heavy controller which invites its neighbors as the game players to compete for the master role of this switch in the game-playing field(GPF) which is an occasional and loose domain for game-playing. Second, based on the concept of GPF, we design a decentralized strategy to play the game and determine which player as the final master. We implement it by extending the Open Flow protocol. Finally, numerical results demonstrate that our distributed strategy can approach elastic control plane with better performance. 展开更多
关键词 software-defined networking master election game theory OpenFlow
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IL-7的诱导表达增强靶向GPC3 CAR-T细胞的增殖及体外抗肿瘤活性
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作者 龚福生 陈珊珊 +1 位作者 郑秋红 刘沁颖 《中国肿瘤生物治疗杂志》 CAS CSCD 北大核心 2024年第10期951-956,共6页
目的:探讨IL-7的诱导表达对靶向磷脂酰肌醇蛋白聚糖3(GPC3)嵌合抗原受体基因修饰T淋巴细胞(CAR-T细胞)的增殖和体外抗肿瘤活性的影响。方法:通过无缝克隆将GPC3 CAR序列片段插入GV400载体的Bam HⅠ/Eco RⅠ位置,构建第二代CAR慢病毒载体... 目的:探讨IL-7的诱导表达对靶向磷脂酰肌醇蛋白聚糖3(GPC3)嵌合抗原受体基因修饰T淋巴细胞(CAR-T细胞)的增殖和体外抗肿瘤活性的影响。方法:通过无缝克隆将GPC3 CAR序列片段插入GV400载体的Bam HⅠ/Eco RⅠ位置,构建第二代CAR慢病毒载体GPC3-BBZ及GPC3-BBZ-NFAT-IL-7,以293T细胞包装相应的慢病毒载体后,感染人T细胞制备CAR-T细胞。实验分为未转导T细胞(NT)组、GPC3-BBZ CAR-T细胞组、GPC3-BBZ-NFAT-IL-7 CAR-T细胞组。采用流式细胞术检测各组CAR-T细胞中CAR的表达水平,qPCR法检测经GPC3蛋白激活的CAR-T细胞中IL-7 m RNA的表达水平,细胞计数法检测CAR-T细胞在GPC3抗原刺激下的增殖能力,ELISA检测CAR-T细胞在受到肿瘤细胞刺激后IL-7、IFN-γ和TNF-α的分泌水平。应用实时细胞分析(RTCA)技术检测CAR-T细胞对人肝癌Huh-7细胞的杀伤作用。结果:成功构建慢病毒载体GPC3-BBZ和GPC3-BBZ-NFAT-IL-7,制备出靶向GPC3的CAR-T细胞。经GPC3抗原激活后,GPC3-BBZ-NFAT-IL-7 CAR-T细胞可有效表达IL-7 mRNA(P<0.01),其表现出更强的增殖能力(P<0.05)。与GPC3-BBZ CAR-T细胞相比,GPC3-BBZ-NFAT-IL-7 CAR-T细胞与GPC3阳性靶细胞Huh-7细胞共培养后,分泌更高水平的IL-7、IFN-γ和TNF-α(P<0.01或P<0.001)。RTCA结果显示,GPC3-BBZ-NFAT-IL-7 CAR-T细胞对GPC3阳性Huh-7细胞的杀伤活性显著高于GPC3-BBZ CAR-T细胞(P<0.05)。结论:成功制备可诱导表达IL-7的靶向GPC3的CAR-T细胞,IL-7的诱导表达增强靶向GPC3 CAR-T细胞的免疫活性,在体外展现出较强的肿瘤细胞杀伤能力。 展开更多
关键词 肝细胞癌 磷脂酰肌醇蛋白聚糖3 car-T细胞 IL-7 诱导表达
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儿童CD19 CAR-T细胞治疗相关B细胞再生障碍的临床意义和对策
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作者 卢俊 《临床儿科杂志》 CAS CSCD 北大核心 2024年第7期578-582,共5页
急性B系淋巴细胞白血病(B-ALL)患儿在CD 19 CAR-T细胞治疗后普遍发生B细胞再生障碍(BCA),BCA持续的时间长短对患者的免疫状态及预后会产生影响。对BCA的充分认识有助于临床医师科学、规范、合理地选择治疗策略,减少CAR-T治疗后白血病患... 急性B系淋巴细胞白血病(B-ALL)患儿在CD 19 CAR-T细胞治疗后普遍发生B细胞再生障碍(BCA),BCA持续的时间长短对患者的免疫状态及预后会产生影响。对BCA的充分认识有助于临床医师科学、规范、合理地选择治疗策略,减少CAR-T治疗后白血病患儿的感染机会,提高生活质量,改善预后。 展开更多
关键词 急性B系淋巴细胞白血病 CD 19 car-T B细胞再生障碍 儿童
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A Multi-Agent Reinforcement Learning-Based Collaborative Jamming System: Algorithm Design and Software-Defined Radio Implementation 被引量:1
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作者 Luguang Wang Fei Song +5 位作者 Gui Fang Zhibin Feng Wen Li Yifan Xu Chen Pan Xiaojing Chu 《China Communications》 SCIE CSCD 2022年第10期38-54,共17页
In multi-agent confrontation scenarios, a jammer is constrained by the single limited performance and inefficiency of practical application. To cope with these issues, this paper aims to investigate the multi-agent ja... In multi-agent confrontation scenarios, a jammer is constrained by the single limited performance and inefficiency of practical application. To cope with these issues, this paper aims to investigate the multi-agent jamming problem in a multi-user scenario, where the coordination between the jammers is considered. Firstly, a multi-agent Markov decision process (MDP) framework is used to model and analyze the multi-agent jamming problem. Secondly, a collaborative multi-agent jamming algorithm (CMJA) based on reinforcement learning is proposed. Finally, an actual intelligent jamming system is designed and built based on software-defined radio (SDR) platform for simulation and platform verification. The simulation and platform verification results show that the proposed CMJA algorithm outperforms the independent Q-learning method and provides a better jamming effect. 展开更多
关键词 multi-agent reinforcement learning intelligent jamming collaborative jamming software-defined radio platform
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Towards a Dynamic Controller Scheduling-Timing Problem in Software-Defined Networking 被引量:2
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作者 Zhenping Lu Fucai Chen +2 位作者 Guozhen Cheng Chao Qi Jianjian Ai 《China Communications》 SCIE CSCD 2017年第10期26-38,共13页
Controller vulnerabilities allow malicious actors to disrupt or hijack the Software-Defined Networking. Traditionally, it is static mappings between the control plane and data plane. Adversaries have plenty of time to... Controller vulnerabilities allow malicious actors to disrupt or hijack the Software-Defined Networking. Traditionally, it is static mappings between the control plane and data plane. Adversaries have plenty of time to exploit the controller's vulnerabilities and launch attacks wisely. We tend to believe that dynamically altering such static mappings is a promising approach to alleviate this issue, since a moving target is difficult to be compromised even by skilled adversaries. It is critical to determine the right time to conduct scheduling and to balance the overhead afforded and the security levels guaranteed. Little previous work has been done to investigate the economical time in dynamic-scheduling controllers. In this paper, we take the first step to both theoretically and experimentally study the scheduling-timing problem in dynamic control plane. We model this problem as a renewal reward process and propose an optimal algorithm in deciding the right time to schedule with the objective of minimizing the long-term loss rate. In our experiments, simulations based on real network attack datasets are conducted and we demonstrate that our proposed algorithm outperforms given scheduling schemes. 展开更多
关键词 software-defined networking network security controller
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TBDDoSA-MD:Trust-Based DDoS Misbehave Detection Approach in Software-defined Vehicular Network(SDVN) 被引量:1
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作者 Rajendra Prasad Nayak Srinivas Sethi +4 位作者 Sourav Kumar Bhoi Kshira Sagar Sahoo Nz Jhanjhi Thamer A.Tabbakh Zahrah A.Almusaylim 《Computers, Materials & Continua》 SCIE EI 2021年第12期3513-3529,共17页
Reliable vehicles are essential in vehicular networks for effective communication.Since vehicles in the network are dynamic,even a short span of misbehavior by a vehicle can disrupt the whole network which may lead to... Reliable vehicles are essential in vehicular networks for effective communication.Since vehicles in the network are dynamic,even a short span of misbehavior by a vehicle can disrupt the whole network which may lead to catastrophic consequences.In this paper,a Trust-Based Distributed DoS Misbehave Detection Approach(TBDDoSA-MD)is proposed to secure the Software-Defined Vehicular Network(SDVN).A malicious vehicle in this network performs DDoS misbehavior by attacking other vehicles in its neighborhood.It uses the jamming technique by sending unnecessary signals in the network,as a result,the network performance degrades.Attacked vehicles in that network will no longer meet the service requests from other vehicles.Therefore,in this paper,we proposed an approach to detect the DDoS misbehavior by using the trust values of the vehicles.Trust values are calculated based on direct trust and recommendations(indirect trust).These trust values help to decide whether a vehicle is legitimate or malicious.We simply discard the messages from malicious vehicles whereas the authenticity of the messages from legitimate vehicles is checked further before taking any action based on those messages.The performance of TBDDoSA-MD is evaluated in the Veins hybrid simulator,which uses OMNeT++and Simulation of Urban Mobility(SUMO).We compared the performance of TBDDoSA-MD with the recently proposed Trust-Based Framework(TBF)scheme using the following performance parameters such as detection accuracy,packet delivery ratio,detection time,and energy consumption.Simulation results show that the proposed work has a high detection accuracy of more than 90%while keeping the detection time as low as 30 s. 展开更多
关键词 software-defined vehicular network TRUST evaluator node denial of service misbehavior
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