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Introduction to a recently released dataset entitled CSNCD:A Comprehensive Dataset of Chinese Seismic Network 被引量:3
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作者 Yanru An 《Earthquake Research Advances》 CSCD 2024年第1期1-3,共3页
China and its adjacent regions are heavily affected by earthquake disasters,which has led to strong demand and vigorous development of the Chinese Seismic Network(CSN).Since 2004,China Earthquake Networks Center(CENC)... China and its adjacent regions are heavily affected by earthquake disasters,which has led to strong demand and vigorous development of the Chinese Seismic Network(CSN).Since 2004,China Earthquake Networks Center(CENC)has been authorized by China Earthquake Administration(CEA)to take charge of CSN management,mainly observing product output and quality control. 展开更多
关键词 SEISMIC EARTHQUAKE EARTHQUAKE
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Resource Allocation for IRS Assistedmm Wave Wireless Powered Sensor Networks with User Cooperation
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作者 Yonghui Lin Zhengyu Zhu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第1期663-677,共15页
In this paper,we investigate IRS-aided user cooperation(UC)scheme in millimeter wave(mmWave)wirelesspowered sensor networks(WPSN),where two single-antenna users are wireless powered in the wireless energy transfer(WET... In this paper,we investigate IRS-aided user cooperation(UC)scheme in millimeter wave(mmWave)wirelesspowered sensor networks(WPSN),where two single-antenna users are wireless powered in the wireless energy transfer(WET)phase first and then cooperatively transmit information to a hybrid access point(AP)in the wireless information transmission(WIT)phase,following which the IRS is deployed to enhance the system performance of theWET andWIT.We maximized the weighted sum-rate problem by jointly optimizing the transmit time slots,power allocations,and the phase shifts of the IRS.Due to the non-convexity of the original problem,a semidefinite programming relaxation-based approach is proposed to convert the formulated problem to a convex optimization framework,which can obtain the optimal global solution.Simulation results demonstrate that the weighted sum throughput of the proposed UC scheme outperforms the non-UC scheme whether equipped with IRS or not. 展开更多
关键词 Intelligent reflecting surface millimeter wave wireless powered sensor networks user cooperation resource allocation
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Research on Scheduling Strategy of Flexible Interconnection Distribution Network Considering Distributed Photovoltaic and Hydrogen Energy Storage
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作者 Yang Li Jianjun Zhao +2 位作者 Xiaolong Yang He Wang Yuyan Wang 《Energy Engineering》 EI 2024年第5期1263-1289,共27页
Distributed photovoltaic(PV)is one of the important power sources for building a new power system with new energy as the main body.The rapid development of distributed PV has brought new challenges to the operation of... Distributed photovoltaic(PV)is one of the important power sources for building a new power system with new energy as the main body.The rapid development of distributed PV has brought new challenges to the operation of distribution networks.In order to improve the absorption ability of large-scale distributed PV access to the distribution network,the AC/DC hybrid distribution network is constructed based on flexible interconnection technology,and a coordinated scheduling strategy model of hydrogen energy storage(HS)and distributed PV is established.Firstly,the mathematical model of distributed PV and HS system is established,and a comprehensive energy storage system combining seasonal hydrogen energy storage(SHS)and battery(BT)is proposed.Then,a flexible interconnected distribution network scheduling optimization model is established to minimize the total active power loss,voltage deviation and system operating cost.Finally,simulation analysis is carried out on the improved IEEE33 node,the NSGA-II algorithm is used to solve specific examples,and the optimal scheduling results of the comprehensive economy and power quality of the distribution network are obtained.Compared with the method that does not consider HS and flexible interconnection technology,the network loss and voltage deviation of this method are lower,and the total system cost can be reduced by 3.55%,which verifies the effectiveness of the proposed method. 展开更多
关键词 Seasonal hydrogen storage flexible interconnection AC/DC distribution network photovoltaic absorption scheduling strategy
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Edge computing oriented virtual optical network mapping scheme based on fragmentation prediction
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作者 何烁 BAI Huifeng +1 位作者 HUO Chao ZHANG Ganghong 《High Technology Letters》 EI CAS 2024年第2期158-163,共6页
As edge computing services soar,the problem of resource fragmentation situation is greatly worsened in elastic optical networks(EON).Aimed to solve this problem,this article proposes the fragmentation prediction model... As edge computing services soar,the problem of resource fragmentation situation is greatly worsened in elastic optical networks(EON).Aimed to solve this problem,this article proposes the fragmentation prediction model that makes full use of the gate recurrent unit(GRU)algorithm.Based on the fragmentation prediction model,one virtual optical network mapping scheme is presented for edge computing driven EON.With the minimum of fragmentation degree all over the whole EON,the virtual network mapping can be successively conducted.Test results show that the proposed approach can reduce blocking rate,and the supporting ability for virtual optical network services is greatly improved. 展开更多
关键词 elastic optical networks virtual optical network fragmentation self-awareness edge computing
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Construction and development of China digital seismological observation network 被引量:83
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作者 刘瑞丰 高景春 +4 位作者 陈运泰 吴忠良 黄志斌 徐志国 孙丽 《地震学报》 CSCD 北大核心 2008年第5期533-539,共7页
The seismological observation system in China has experienced rapid development over the Tenth Five-year Plan period. China Earthquake Administration (CEA) has completed the establishment of China digital seismologica... The seismological observation system in China has experienced rapid development over the Tenth Five-year Plan period. China Earthquake Administration (CEA) has completed the establishment of China digital seismological observation network. CEA has accomplished analog-to-digital conversion of the existing seismological observation systems and set up a number of new digital seismic stations. This indicates full digitization of seismological ob-servation in China. This paper presents an overview of the scale,layout principle and major functions of the up-dated national digital seismograph network,regional digital seismograph network,and digital seismograph net-work for volcano monitoring and mobile digital seismograph networks in China. 展开更多
关键词 地震台网 地震台阵 宽频带
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基于聚类的重复地震识别方法及应用
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作者 黄雅芬 李红谊 +2 位作者 李炎臻 葛慧颖 张盛中 《地球与行星物理论评(中英文)》 2025年第1期94-101,共8页
重复地震是指不同时期发生在断层同一位置的一组地震,表现为波形和震源机制上的高度相似.重复地震可用来探测断层深部形变、刻画断层行为、评估地震灾害.然而,重复地震的识别条件阈值设置尚没有统一的标准,常用的识别参数存在较大的主观... 重复地震是指不同时期发生在断层同一位置的一组地震,表现为波形和震源机制上的高度相似.重复地震可用来探测断层深部形变、刻画断层行为、评估地震灾害.然而,重复地震的识别条件阈值设置尚没有统一的标准,常用的识别参数存在较大的主观性,会导致识别重复地震存在误差.为解决上述问题,本研究利用基于机器学习中的层次聚类算法构建了一个自动高效的重复地震识别方法.首先采用波形并行互相关技术计算地震波形之间的互相关系数,结合S-P到时差方法估算地震震源之间的距离,再利用层次聚类方法将地震聚类,获得重复地震.本文将该方法应用至甘孜—玉树断裂带和东昆仑断裂带地区的地震活动,识别重复地震并估算断层滑动速率.在甘孜—玉树断裂带附近共识别出6组重复地震组,它们均沿甘孜—玉树断裂带走向布展,平均断层滑动速率为7.4 mm/a.东昆仑断裂带附近共识别出3组重复地震组,平均断层滑动速率为6.9 mm/a.沿东昆仑断裂东段,断层滑动速率呈现出速率向东逐渐降低的趋势,显示该区域复杂的动力作用过程.这些结果与野外地质观测和GPS大地测量结果较为一致.基于实际数据测试和验证,结果表明本文发展的基于聚类的识别重复地震方法具有自动、高效、便捷的特性,为准确识别重复地震提供了重要的基础资料,为分析断层活动性提供了重要约束. 展开更多
关键词 重复地震 聚类分析 甘孜—玉树断裂带 东昆仑断裂带
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Olfactory receptors in neural regeneration in the central nervous system
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作者 Rafael Franco Claudia Garrigós +3 位作者 Toni Capó Joan Serrano-Marín Rafael Rivas-Santisteban Jaume Lillo 《Neural Regeneration Research》 SCIE CAS 2025年第9期2480-2494,共15页
Olfactory receptors are crucial for detecting odors and play a vital role in our sense of smell,influencing behaviors from food choices to emotional memories.These receptors also contribute to our perception of flavor... Olfactory receptors are crucial for detecting odors and play a vital role in our sense of smell,influencing behaviors from food choices to emotional memories.These receptors also contribute to our perception of flavor and have potential applications in medical diagnostics and environmental monitoring.The ability of the olfactory system to regenerate its sensory neurons provides a unique model to study neural regeneration,a phenomenon largely absent in the central nervous system.Insights gained from how olfactory neurons continuously replace themselves and reestablish functional connections can provide strategies to promote similar regenerative processes in the central nervous system,where damage often results in permanent deficits.Understanding the molecular and cellular mechanisms underpinning olfactory neuron regeneration could pave the way for developing therapeutic approaches to treat spinal co rd injuries and neurodegenerative diseases like Alzheimer's disease.Olfa ctory receptors are found in almost any cell of eve ry orga n/tissue of the mammalian body.This ectopic expression provides insights into the chemical structures that can activate olfactory receptors.In addition to odors,olfactory receptors in ectopic expression may respond to endogenous compounds and molecules produced by mucosal colonizing microbiota.The analysis of the function of olfactory receptors in ectopic expression provides valuable information on the signaling pathway engaged upon receptor activation and the receptor's role in proliferation and cell differentiation mechanisms.This review explo res the ectopic expression of olfa ctory receptors and the role they may play in neural regeneration within the central nervous system,with particular attention to compounds that can activate these receptors to initiate regenerative processes.Evidence suggests that olfactory receptors could serve as potential therapeutic targets for enhancing neural repair and recovery following central nervous system injuries. 展开更多
关键词 adenosine receptors adrenergic receptors ectopic expression G proteincoupled receptors GLIA NEURONS
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Modeling and Defending Passive Worms over Unstructured Peer-to-Peer Networks 被引量:8
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作者 王方伟 张运凯 马建峰 《Transactions of Tianjin University》 EI CAS 2008年第1期66-72,共7页
Passive worms can passively propagate through embedding themselves into some sharing files, which can result in significant damage to unstructured P2P networks. To study the passive worm behaviors, this paper firstly ... Passive worms can passively propagate through embedding themselves into some sharing files, which can result in significant damage to unstructured P2P networks. To study the passive worm behaviors, this paper firstly analyzes and obtains the average delay for all peers in the whole transmitting process due to the limitation of network throughput, and then proposes a mathematical model for the propagation of passive worms over the unstructured P2P networks. The model mainly takes the effect of the network throughput into account, and applies a new healthy files dissemination-based defense strategy according to the file popularity which follows the Zipf distribution. The simulation results show that the propagation of passive worms is mainly governed by the number of hops, initially infected files and uninfected files. The larger the number of hops, the more rapidly the passive worms propagate. If the number of the initially infected files is increased by the attackers, the propagation speed of passive worms increases obviously. A larger size of the uninfected file results in a better attack performance. However, the number of files generated by passive worms is not an important factor governing the propagation of passive worms. The effectiveness of healthy files dissemination strategy is verified. This model can provide a guideline in the control of unstructured P2P networks as well as passive worm defense. 展开更多
关键词 network security unstructured peer-to-peer networks passive worms propagationmodel patch dissemination strategy
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The Improvement of Earthquake Real-Time Monitoring System of Chinese National Digital Seismic Network 被引量:3
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作者 GUO Tielong HUANG Zhibin ZHAO Bo 《Earthquake Research in China》 CSCD 2019年第4期596-604,共9页
The earthquake real-time monitoring system of the Chinese National Digital Seismic Network has been in operation since"the Ninth Five-year Plan"period,and the stability of the system has been well tested.In ... The earthquake real-time monitoring system of the Chinese National Digital Seismic Network has been in operation since"the Ninth Five-year Plan"period,and the stability of the system has been well tested.In recent years,with the continuous improvement of monitoring technology and increase of public demands,the original real-time monitoring system needs to be upgraded and improved in terms of timeliness,stability,accuracy and ease of operation.Therefore,by accessing a total of more than 1,000 seismic stations,reducing the seismic trigger threshold of the monitoring system,eliminating the false trigger stations and optimizing the seismic waveform display interface,the current earthquake monitoring demands can be satisfied on the basis of ensuring the stable operation of the system. 展开更多
关键词 Seismic monitoring Earthquake location Computer real-time processing
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Motor Fault Diagnosis Based on Short-time Fourier Transform and Convolutional Neural Network 被引量:41
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作者 Li-Hua Wang Xiao-Ping Zhao +2 位作者 Jia-Xin Wu Yang-Yang Xie Yong-Hong Zhang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2017年第6期1357-1368,共12页
With the rapid development of mechanical equipment, the mechanical health monitoring field has entered the era of big data. However, the method of manual feature extraction has the disadvantages of low efficiency and ... With the rapid development of mechanical equipment, the mechanical health monitoring field has entered the era of big data. However, the method of manual feature extraction has the disadvantages of low efficiency and poor accuracy, when handling big data. In this study, the research object was the asynchronous motor in the drivetrain diagnostics simulator system. The vibration signals of different fault motors were collected. The raw signal was pretreated using short time Fourier transform (STFT) to obtain the corresponding time-frequency map. Then, the feature of the time-frequency map was adap- tively extracted by using a convolutional neural network (CNN). The effects of the pretreatment method, and the hyper parameters of network diagnostic accuracy, were investigated experimentally. The experimental results showed that the influence of the preprocessing method is small, and that the batch-size is the main factor affecting accuracy and training efficiency. By investigating feature visualization, it was shown that, in the case of big data, the extracted CNN features can represent complex mapping relationships between signal and health status, and can also overcome the prior knowledge and engineering experience requirement for feature extraction, which is used by tra- ditional diagnosis methods. This paper proposes a new method, based on STFT and CNN, which can complete motor fault diagnosis tasks more intelligently and accurately. 展开更多
关键词 Big data Deep learning Short-time Fouriertransform Convolutional neural network MOTOR
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Sniffing Threat and Practices in IPv6 Networks 被引量:1
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作者 YI Xiushuang WEN Zhankao ZHANG Dengke 《Wuhan University Journal of Natural Sciences》 CAS 2006年第5期1389-1393,共5页
The IPv4 protocol suite is vulnerable to a variety of attacks. IPv6 security is in many ways the same as IPv4 security, the basic mechanisms for transporting packets across the network stay mostly unchanged, and the u... The IPv4 protocol suite is vulnerable to a variety of attacks. IPv6 security is in many ways the same as IPv4 security, the basic mechanisms for transporting packets across the network stay mostly unchanged, and the upper-layer protocols that transport the actual application data are mostly unaffected. This paper illustrates sniffing threat against IPv4 and then compares how the threat might influence an IPv6 networks. This is prefaced by a brief overview of current practices around the design of an IPv4 Internet edge network and then followed by a review of how that IPv4 edge network needs to evolve in order to secure the addition of IPv6. As IPv6 security is a large and complex subject, and also, IPv6 network is still at the very beginning stage and has not been fully examined in fact, this paper focus on the security requirements of medium edge networks. 展开更多
关键词 sniffing threat PRACTICE IPv6 Network
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Malicious Code Modeling and Analysis in Weighted Scale-Free Networks 被引量:2
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作者 WANG Changguang WANG Fangwei +1 位作者 ZHANG Yangkai MA Jianfengi 《Wuhan University Journal of Natural Sciences》 CAS 2007年第1期51-54,共4页
We study the detailed malicious code propagating process in scale-free networks with link weights that denotes traffic between two nodes. It is found that the propagating velocity reaches a peak rapidly then decays in... We study the detailed malicious code propagating process in scale-free networks with link weights that denotes traffic between two nodes. It is found that the propagating velocity reaches a peak rapidly then decays in a power-law form, which is different from the well-known result in unweighted network case. Simulation results show that the nodes with larger strength are preferential to be infected, but the hierarchical dynamics are not clearly found. The simulation results also show that larger dispersion of weight of networks leads to slower propagating, which indicates that malicious code propagates more quickly in unweighted scale-free networks than in weighted scale-free networks under the same condition. These results show that not only the topology of networks but also the link weights affect the malicious propagating process. 展开更多
关键词 malicious code weighted scale-free networks propagation model
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Topology-aware Overlay Multicast over IP Multicast Networks 被引量:1
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作者 陈逍 邵华钢 汪为农 《Journal of Shanghai Jiaotong university(Science)》 EI 2008年第1期91-96,共6页
Most existing overlay multicast approaches refuse to consider any network layer support no matter whether it is available or not. This design principle greatly increases the complexity of the routing algorithms and ma... Most existing overlay multicast approaches refuse to consider any network layer support no matter whether it is available or not. This design principle greatly increases the complexity of the routing algorithms and makes the overlay topologies incompatible with the underlying network. To address these issues, topology-aware overlay multicast over IP multicast networks (TOMIMN) was proposed as a novel overlay multicast protocol, which exploits the cooperation between end-hosts and IP multicast routers to construct a topology-aware overlay tree. Through a little modification to protocol independent multicast sparse mode (PIM-SM), a multicast router is able to receive registration from nearby group members and redirect passing-by join requests to them. Due to the multicast router's support, TOMIMN organizes its group members into an overlay multicast tree efficiently, which matches the physical network topology well. 展开更多
关键词 overlay networking network architecture overlay multicast
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A Study of Configuration Evolution of an Operational IP Backbone Network 被引量:1
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作者 Fuliang Li Jiahai Yang +3 位作者 Huijing Zhang Xingwei Wang Suogang Li Jianping Wu 《China Communications》 SCIE CSCD 2017年第6期88-97,共10页
Configuration errors are proved to be the main reasons for network interruption and anomalies.Many researchers have paid their attention to configuration analysis and provisioning,but few works focus on understanding ... Configuration errors are proved to be the main reasons for network interruption and anomalies.Many researchers have paid their attention to configuration analysis and provisioning,but few works focus on understanding the configuration evolution.In this paper,we uncover the configuration evolution of an operational IP backbone based on the weekly reports gathered from January 2006 to January 2013.We find that rate limiting and launching routes for new customers are configured most frequently.In addition,we conduct an analysis of network failures and find that link failures are the main causes for network failures.We suggest that we should configure redundant links for the links which are easy to break down.At last,according to the analysis results,we illustrate how to provide semi-automated configuration for rate limiting and adding customers. 展开更多
关键词 network measurement configuration evolution backbone network semi-automated configuration
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Graph Transformer for Communities Detection in Social Networks 被引量:2
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作者 G.Naga Chandrika Khalid Alnowibet +3 位作者 K.Sandeep Kautish E.Sreenivasa Reddy Adel F.Alrasheedi Ali Wagdy Mohamed 《Computers, Materials & Continua》 SCIE EI 2022年第3期5707-5720,共14页
Graphs are used in various disciplines such as telecommunication,biological networks,as well as social networks.In large-scale networks,it is challenging to detect the communities by learning the distinct properties o... Graphs are used in various disciplines such as telecommunication,biological networks,as well as social networks.In large-scale networks,it is challenging to detect the communities by learning the distinct properties of the graph.As deep learning hasmade contributions in a variety of domains,we try to use deep learning techniques to mine the knowledge from large-scale graph networks.In this paper,we aim to provide a strategy for detecting communities using deep autoencoders and obtain generic neural attention to graphs.The advantages of neural attention are widely seen in the field of NLP and computer vision,which has low computational complexity for large-scale graphs.The contributions of the paper are summarized as follows.Firstly,a transformer is utilized to downsample the first-order proximities of the graph into a latent space,which can result in the structural properties and eventually assist in detecting the communities.Secondly,the fine-tuning task is conducted by tuning variant hyperparameters cautiously,which is applied to multiple social networks(Facebook and Twitch).Furthermore,the objective function(crossentropy)is tuned by L0 regularization.Lastly,the reconstructed model forms communities that present the relationship between the groups.The proposed robust model provides good generalization and is applicable to obtaining not only the community structures in social networks but also the node classification.The proposed graph-transformer shows advanced performance on the social networks with the average NMIs of 0.67±0.04,0.198±0.02,0.228±0.02,and 0.68±0.03 on Wikipedia crocodiles,Github Developers,Twitch England,and Facebook Page-Page networks,respectively. 展开更多
关键词 Social networks graph transformer community detection graph classification
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Application-aware routing with QoS support in SDN networks 被引量:1
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作者 张泽鑫 Li Jun Wu Haibo 《High Technology Letters》 EI CAS 2016年第4期404-411,共8页
Software defined networking( SDN) offers programmable interface to effectively control their networks by decoupling control and data plane. The network operators utilize a centralized controller to deploy advanced net... Software defined networking( SDN) offers programmable interface to effectively control their networks by decoupling control and data plane. The network operators utilize a centralized controller to deploy advanced network management strategies. An architecture for application-aware routing which can support dynamic quality of service( Qo S) in SDN networks is proposed. The applicationaware routing as a multi-constrained optimal path( MCOP) problem is proposed,where applications are treated as Qo S flow and best-effort flows. With the SDN controller applications,it is able to dynamically lead routing decisions based on application characteristics and requirements,leading to a better overall user experience and higher utilization of network resources. The simulation results show that the improvement of application-aware routing framework on discovering appropriate routes,which can provide Qo S guarantees for a specific application in SDN networks. 展开更多
关键词 application aware software defined networking(SDN) networks quality of service(Qo S) multiple constraints path selection
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A Multiobjective Optimization Algorithm for QoS-Aware Path Selection in DiffServ and MPLS Networks
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作者 邵华钢 陈逍 汪为农 《Journal of Shanghai Jiaotong university(Science)》 EI 2006年第4期472-477,共6页
A multiobjective quality of service (QoS) routing algorithm was proposed and used as the QoS-aware path selection approach in differentiated services and multi-protocol label switching (DiffServ-MPLS) networks. It sim... A multiobjective quality of service (QoS) routing algorithm was proposed and used as the QoS-aware path selection approach in differentiated services and multi-protocol label switching (DiffServ-MPLS) networks. It simultaneously optimizes multiple QoS objectives by a genetic algorithm in conjunction with concept of Pareto dominance. The simulation demonstrates that the proposed algorithm is capable of discovering a set of QoS-based near optimal paths within in a few iterations. In addition, the simulation results also show the scalability of the algorithm with increasing number of network nodes. 展开更多
关键词 quality of service(QoS)-aware path selection MULTIOBJECTIVE optimization MULTI-PROTOCOL label switching(MPLS) DIFFERENTIATED services(DiffServ)
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A Distributed and Adaptive Framework for Provisioning QoS in IPv6 Networks
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作者 邵华钢 陈逍 汪为农 《Journal of Shanghai Jiaotong university(Science)》 EI 2008年第1期97-101,共5页
A distributed and adaptive framework (DAF) was proposed for provisioning quality of service (QoS) in IPv6 network. In DAF, per-flow admission control and resource reservation, in conjunction with a new IPv6 flow label... A distributed and adaptive framework (DAF) was proposed for provisioning quality of service (QoS) in IPv6 network. In DAF, per-flow admission control and resource reservation, in conjunction with a new IPv6 flow label mechanism, can be performed instantaneously in a fully distributed and independent fashion at the edge of network without hop-by-hop signaling. The flow label helps in resource reservation and packets forwarding for aggregated traffic on an edge-to-edge path basis. In addition, a bounded directional probing technique for DAF was designed to reconfigure resource reservation adaptively between every pair of edge router for aggregated traffic according to the fluctuation of its traffic load. The simulation results show that DAF provides QoS guarantees to individual flows with minimal overhead, as well as keeping the scalability characteristic like DiffServ. 展开更多
关键词 quality of service IPV6 integrated services (IntServ) differentiated services (DiffServ) admission control resource reservation
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Two-stage evolutionary algorithm for dynamic multicast routing in mesh network
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作者 Li ZHU Zhi-shu LI +1 位作者 Liang-yin CHEN Yan-hong CHENG 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第6期791-798,共8页
In order to share multimedia transmissions in mesh networks and optimize the utilization of network resources, this paper presents a Two-stage Evolutionary Algorithm (TEA), i.e., unicast routing evolution and multicas... In order to share multimedia transmissions in mesh networks and optimize the utilization of network resources, this paper presents a Two-stage Evolutionary Algorithm (TEA), i.e., unicast routing evolution and multicast path composition, for dynamic multicast routing. The TEA uses a novel link-duplicate-degree encoding, which can encode a multicast path in the link-duplicate-degree and decode the path as a link vector easily. A dynamic algorithm for adding nodes to or removing nodes from a multicast group and a repairing algorithm are also covered in this paper. As the TEA is based on global evaluation, the quality of the multicast path remains stabilized without degradation when multicast members change over time. Therefore, it is not necessary to rearrange the multicast path during the life cycle of the multicast sessions. Simulation results show that the TEA is efficient and convergent. 展开更多
关键词 Dynamic multicast ROUTING ENCODING Quality of Service (QoS) Evolution Genetic algorithm (GA)
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Comparison between different earthquake magnitudes determined by China Seismo-graph Network
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作者 刘瑞丰 陈运泰 +5 位作者 任枭 徐志国 孙丽 杨辉 梁建宏 任克新 《Acta Seismologica Sinica(English Edition)》 CSCD 2007年第5期497-506,共10页
By linear regression and orthogonal regression methods, comparisons are made between different magnitudes (local magnitude ML, surface wave magnitudes Ms and MsT, long-period body wave magnitude mB and short-period b... By linear regression and orthogonal regression methods, comparisons are made between different magnitudes (local magnitude ML, surface wave magnitudes Ms and MsT, long-period body wave magnitude mB and short-period body wave magnitude mb) determined by Institute of Geophysics, China Earthquake Administration, on the basis of observation data collected by China Seismograph Network between 1983 and 2004. Empirical relations between different magnitudes have been obtained. The result shows that: ① As different magnitude scales reflect radiated energy by seismic waves within different periods, earthquake magnitudes can be described more objectively by using different scales for earthquakes of different magnitudes. When the epicentral distance is less than 1000 km, local magnitude ME can be a preferable scale; In case M〈4.5, there is little difference between the magnitude scales; In case 4.5〈M〈6.0, mB〉Ms, i.e., Ms underestimates magnitudes of such events, therefore, mB can be a better choice; In case M〉6.0, Ms〉mB〉mb, both mB and mb underestimate the magnitudes, so Ms is a preferable scale for determining magnitudes of such events (6.0〈M〈8.5); In case M〉8.5, a saturation phenomenon appears in Ms, which cannot give an accurate reflection of the magnitudes of such large events; ② In China, when the epicentral distance is less than 1 000 km, there is almost no difference between ME and Ms, and thus there is no need to convert between the two magnitudes in practice; ③ Although Ms and Ms7 are both surface wave magnitudes, Ms is in general greater than Ms7 by 0.2~0.3 magnitude, because different instruments and calculation formulae are used; ④ mB is almost equal to mb for earthquakes around mB4.0, but mB is larger than mb for those of mB〉4.5, because the periods of seismic waves used for measuring mB and mb are different though the calculation formulae are the same. 展开更多
关键词 local earthquake magnitude surface wave magnitude body wave magnitude
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