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NeTrainSim:a network-level simulator for modeling freight train longitudinal motion and energy consumption
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作者 Ahmed S.Aredah Karim Fadhloun Hesham A.Rakha 《Railway Engineering Science》 EI 2024年第4期480-498,共19页
Although train modeling research is vast, most available simulation tools are confined to city-or trip-scale analysis, primarily offering micro-level simulations of network segments. This paper addresses this void by ... Although train modeling research is vast, most available simulation tools are confined to city-or trip-scale analysis, primarily offering micro-level simulations of network segments. This paper addresses this void by developing the Ne Train Sim simulator for heavy long-haul freight trains on a network of multiple intersecting tracks. The main objective of this simulator is to enable a comprehensive analysis of energy consumption and the associated carbon footprint for the entire train system. Four case studies were conducted to demonstrate the simulator's performance. The first case study validates the model by comparing Ne Train Sim output to empirical trajectory data. The results demonstrate that the simulated trajectory is precise enough to estimate the train energy consumption and carbon dioxide emissions. The second application demonstrates the train-following model considering six trains following each other. The results showcase the model ability to maintain safefollowing distances between successive trains. The next study highlights the simulator's ability to resolve train conflicts for different scenarios. Finally, the suitability of the Ne Train Sim for modeling realistic railroad networks is verified through the modeling of the entire US network and comparing alternative powertrains on the fleet energy consumption. 展开更多
关键词 Ne Train Sim Network train simulation Train longitudinal motion Energy consumption Carbon footprint
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3-D fracture network dynamic simulation based on error analysis in rock mass of dam foundation 被引量:4
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作者 ZHONG Deng-hua WU Han +2 位作者 WU Bin-ping ZHANG Yi-chi YUE Pan 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第4期919-935,共17页
Accurate 3-D fracture network model for rock mass in dam foundation is of vital importance for stability,grouting and seepage analysis of dam foundation.With the aim of reducing deviation between fracture network mode... Accurate 3-D fracture network model for rock mass in dam foundation is of vital importance for stability,grouting and seepage analysis of dam foundation.With the aim of reducing deviation between fracture network model and measured data,a 3-D fracture network dynamic modeling method based on error analysis was proposed.Firstly,errors of four fracture volume density estimation methods(proposed by ODA,KULATILAKE,MAULDON,and SONG)and that of four fracture size estimation methods(proposed by EINSTEIN,SONG and TONON)were respectively compared,and the optimal methods were determined.Additionally,error index representing the deviation between fracture network model and measured data was established with integrated use of fractal dimension and relative absolute error(RAE).On this basis,the downhill simplex method was used to build the dynamic modeling method,which takes the minimum of error index as objective function and dynamically adjusts the fracture density and size parameters to correct the error index.Finally,the 3-D fracture network model could be obtained which meets the requirements.The proposed method was applied for 3-D fractures simulation in Miao Wei hydropower project in China for feasibility verification and the error index reduced from 2.618 to 0.337. 展开更多
关键词 rock mass of dam foundation 3-D fracture network dynamic simulation fractal dimension error analysis relative absolute error(RAE) downhill simplex method
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Design for the simulation of space based information network 被引量:1
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作者 Zeng Bin Li Zitang Wang Wei 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2006年第2期443-449,共7页
Ongoing research is described that is focused upon modelling the space base information network and simulating its behaviours: simulation of spaced based communications and networking project. Its objective is to dem... Ongoing research is described that is focused upon modelling the space base information network and simulating its behaviours: simulation of spaced based communications and networking project. Its objective is to demonstrate the feasibility of producing a tool that can provide a performance evaluation of various eonstellation access techniques and routing policies. The architecture and design of the simulation system are explored. The algorithm of data routing and instrument scheduling in this project is described. Besides these, the key methodologies of simulating the inter-satellite link features in the data transmissions are also discussed. The performance of both instrument scheduling algorithm and routing schemes is evaluated and analyzed through extensive simulations under a typical scenario. 展开更多
关键词 space based information network network simulation inter-satellite link routing scheduling simulation
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Spanning tree-based algorithm for hydraulic simulation of large-scale water supply networks 被引量:1
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作者 Huan-feng DUAN Guo-ping YU 《Water Science and Engineering》 EI CAS 2010年第1期23-35,共13页
With the purpose of making calculation more efficient in practical hydraulic simulations, an improved algorithm was proposed and was applied in the practical water distribution field. This methodology was developed by... With the purpose of making calculation more efficient in practical hydraulic simulations, an improved algorithm was proposed and was applied in the practical water distribution field. This methodology was developed by expanding the traditional loop-equation theory through utilization of the advantages of the graph theory in efficiency. The utilization of the spanning tree technique from graph theory makes the proposed algorithm efficient in calculation and simple to use for computer coding. The algorithms for topological generation and practical implementations are presented in detail in this paper. Through the application to a practical urban system, the consumption of the CPU time and computation memory were decreased while the accuracy was greatly enhanced compared with the present existing methods. 展开更多
关键词 large-scale networks hydraulic simulation graph theory fundamental loop spanning tree EFFICIENCY
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Construction of Network Fault Simulation Platform and Event Samples Acquisition Techniques for Event Correlation
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作者 Su Yu-bei Wang Zhi +2 位作者 Cao Yang Huang Tian-xi Wang Li-na 《Wuhan University Journal of Natural Sciences》 EI CAS 2001年第3期670-674,共5页
Event correlation is one key technique in network fault management. For the event sample acquisition problem in event correlation, a novel approach is proposed to collect the samples by constructing network simulation... Event correlation is one key technique in network fault management. For the event sample acquisition problem in event correlation, a novel approach is proposed to collect the samples by constructing network simulation platform. The platform designed can set kinds of network faults according to user's demand and generate a lot of network fault events, which will benefit the research on efficient event correlation techniques. 展开更多
关键词 event correlation network fault simulation event sample
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A study on IP-based hierarchical routing strategy in network simulation
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作者 闫健恩 Zhang Zhaoxin Shen Yinghong 《High Technology Letters》 EI CAS 2017年第2期156-164,共9页
The intrinsic routing policy of NS2—a network simulation tool— based on flat or hierarchical address has the disadvantage such as small topology scale,high resource consumption,low efficiency and so on.This paper pr... The intrinsic routing policy of NS2—a network simulation tool— based on flat or hierarchical address has the disadvantage such as small topology scale,high resource consumption,low efficiency and so on.This paper proposes an IP based hierarchical routing strategy in network simulation to extend the topology scale and improve performance in simulating.Firstly,a stratification mechanism to identify IP address of nodes is described.Then,an algorithm of packet transmitting method(PTM) is presented for packet forwarding in the same subnet.Finally,algorithms of region partition(RP),routing computation based on region division(RCBRD) and routing distribution(RD) is proposed to implement regional segmentation,route calculation and route distribution for forwarding packets in different subnets respectively.The experiment results show that under the same condition,compared with plane address,the topology scale of the network simulation is extended two times and the consumption of time and memory during simulation is reduced by approximately 73%and 45.8% respectively.Compared with hierarchical address,the topology scale of the network simulation is expanded by more than 50%,and the consumption of time and memory is reduced by about 59.2% and 25% respectively.In addition,along with the growth of the node size,the proportion of reducing total simulation time and memory consumption would gradually increase. 展开更多
关键词 network simulation routing policy plane routing hierarchical routing
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Urban Growth Modeling Using Neural Network Simulation: A Case Study of Dongguan City, China
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作者 Xinmin Zhang 《Journal of Geographic Information System》 2016年第3期317-328,共12页
Dongguan is an important industrial city, located in the Pearl River Delta, South China. Recently, Dongguan city experienced a rapid urban growth with the locational advantage by transforming from traditional agricult... Dongguan is an important industrial city, located in the Pearl River Delta, South China. Recently, Dongguan city experienced a rapid urban growth with the locational advantage by transforming from traditional agricultural region to modern manufacturing metropolis. The urban transformation became the usual change in China under the background of urbanization which belongs to one trend of globalization in the 21st century. This paper tries to analyze urban growth simulation based on remotely sensed data of previous years and the related physical and socio-economic factors and predict future urban growth in 2024. The study examined and compared the land use/cover (LUC) changes over time based on produced maps of 2004, 2009, and 2014. The results showed that water and forest area decreased since the past years. In contrast, the urban land increased from 2004 to 2014, and this increasing trend will continue to the future years through the urbanization process. Having understood the spatiotemporal trends of urban growth, the study simulated the urban growth of Dongguan city for 2024 using neural network simulation technique. Further, the figure of merit (FoM) of simulated map of 2014 map was 8.86%, which can be accepted in the simulation and used in the prediction process. Based on the consideration of water body and forest, the newly growth area is located in the west, northeast, and southeast regions of Dongguan city. The finding can help us to understand which areas are going to be considered in the future urban planning and policy by the local government. 展开更多
关键词 Urban Growth Neural Network simulation Dongguan City
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Simulation Laboratory and Critical Appraisal of Development Tool
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作者 陈佳瑛 《电脑知识与技术》 2011年第7X期5256-5258,共3页
In order to carry out the different network question meaning the research to like the protocol interaction,the network dynamics' function,the measurable quantity waits for it is the necessary delivery is including... In order to carry out the different network question meaning the research to like the protocol interaction,the network dynamics' function,the measurable quantity waits for it is the necessary delivery is including.Thus,the network simulation may use in showing or quite interesting network performance and so on.Part two aim is provides the type of development tool,including consider such as cost,ease to use and limitations of software packages.The report is to meets the system specification requirement immediately the available component. 展开更多
关键词 network simulation development tool and component
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Simulation of natural gas transmission pipeline network system performance
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作者 Abraham Debebe Woldeyohannes Mohd Amin Abd Majid 《Journal of Energy and Power Engineering》 2009年第12期29-38,共10页
Simulation has proven to be an effective tool for analyzing pipeline network systems (PNS) in order to determine the design and operational variables which are essential for evaluating the performance of the system.... Simulation has proven to be an effective tool for analyzing pipeline network systems (PNS) in order to determine the design and operational variables which are essential for evaluating the performance of the system. This paper discusses the use of simulation for performance analysis of transmission PNS. A simulation model was developed for determining flow and pressure variables for different configuration of PNS. The mathematical formulation for the simulation model was derived based on the principles of energy conservation, mass balance, and compressor characteristics. For the determination of the pressure and flow variables, solution procedure was developed based on iterative Newton Raphson scheme and implemented using visual C++6. Evaluations of the simulation model with the existing pipeline network system showed that the model enabled to determine the operational variables with less than ten iterations. The performances of the compressor working in the pipeline network system xvhich includes energy consumption, compression ratio and discharge pressure were evaluated to meet pressure requirements ranging from 4000-5000 kPa at various speed. Results of the analyses from the simulation indicated that the model could be used for performance analysis to assist decisions regarding the design and optimal operations of transmission PNS. 展开更多
关键词 ENERGY transmission pipeline network: compressor station: natural gas: simulation
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Research of NS dataflow mechanism and its analyzer implementation
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作者 金烨 樊隽 《Journal of Southeast University(English Edition)》 EI CAS 2003年第1期44-48,共5页
This paper analyzes the main elements in NS network simulator, makes adetailed view of dataflow management in a link, a node, and an agent, respectively, and introducesthe information described by its trace file. Base... This paper analyzes the main elements in NS network simulator, makes adetailed view of dataflow management in a link, a node, and an agent, respectively, and introducesthe information described by its trace file. Based on the analysis of transportation and treatmentof different packets in NS, a dataflow state machine is proposed with its states exchange triggeringevents and a dataflow analyzer is designed and implemented according to it. As the machine statefunctions, the analyzer can make statistic of total transportation flux of a specified dataflow andoffer a general fluctuation diagram. Finally, a concrete example is used to test its performance. 展开更多
关键词 network simulation NS simulator dataflow analysis state machine
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RECURRENT NEURAL NETWORK-BASED PORTFOLIO INVESTMENT
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作者 郑丕谔 韩珊珊 《Transactions of Tianjin University》 EI CAS 2000年第2期141-145,共页
Instead of existing methods,a recurrent neural network is conceived to deal with three stages of portfolio management.Mainly,a deterministic annealing neural network is proposed for the approach to portfolio problem,w... Instead of existing methods,a recurrent neural network is conceived to deal with three stages of portfolio management.Mainly,a deterministic annealing neural network is proposed for the approach to portfolio problem,which is a kind of quadratic programming.Finally,through a real example,we verify that the neural network model proposed in this paper is a good tool to solve the portfolio problem. 展开更多
关键词 portfolio investment least risk simulated annealing neural network
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Redundancy Elimination in GPRS network 被引量:3
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作者 QIU Qin-long ZHANG Dong-mei +1 位作者 MA Jian ZHANG Da-jiang 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2006年第4期477-482,共6页
The mechanisms of TCP’s retransmission and reset will result in redundant packets. These redundant packets are often sent unnecessarily to the user over a slow last-hop link delaying useful traffic. This is a problem... The mechanisms of TCP’s retransmission and reset will result in redundant packets. These redundant packets are often sent unnecessarily to the user over a slow last-hop link delaying useful traffic. This is a problem for wide-area wireless links, such as General Packet Radio Service (GPRS), because unnecessary transmissions waste already limited radio bandwidth, battery power at the mobile terminal and incurs monetary cost due to charging by data volume. The paper first describes a GPRS model, then discusses how to eliminate the redundant packets in GPRS network and presents the simulation results in Network Simulation 2 (NS 2). The more traffic is, the more the network can benefit. In heavy traffic, it can even get more than 30% improvement in throughput. Average delay and loss percent are also lowered. 展开更多
关键词 GPRS TCP Redundancy Elimination Network simulation 2 (NS 2)
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Analysis and verification of network profile 被引量:3
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作者 Weiwei Chen Ning Huang +2 位作者 Yuqing Liu Ye Wang Rui Kang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第5期784-790,共7页
The elements of network profile are proposed.Based on the network traffic distribution model,the network profile includes the application request rate,the branch transfer probability,the ratio of application requests,... The elements of network profile are proposed.Based on the network traffic distribution model,the network profile includes the application request rate,the branch transfer probability,the ratio of application requests,and the probability distribution of the requested objects.Based on the evaluation method of network performance reliability,four simulation cases are constructed in OPNET software,and the results show the four elements of profile have impacts on the network reliability. 展开更多
关键词 system engineering network profile performance reliability network simulation.
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Combined heat and mass transfer by mixed convection MHD flow along a porous plate with chemical reaction in presence of heat source 被引量:1
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作者 J.ZUECO S.AHMED 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2010年第10期1217-1230,共14页
An exact and a numerical solutions to the problem of a steady mixed convective MHD flow of an incompressible viscous electrically conducting fluid past an infinite vertical porous plate with combined heat and mass tra... An exact and a numerical solutions to the problem of a steady mixed convective MHD flow of an incompressible viscous electrically conducting fluid past an infinite vertical porous plate with combined heat and mass transfer are presented.A uniform magnetic field is assumed to be applied transversely to the direction of the flow with the consideration of the induced magnetic field with viscous and magnetic dissipations of energy.The porous plate is subjected to a constant suction velocity as well as a uniform mixed stream velocity.The governing equations are solved by the perturbation technique and a numerical method.The analytical expressions for the velocity field,the temperature field,the induced magnetic field,the skin-friction,and the rate of heat transfer at the plate are obtained.The numerical results are demonstrated graphically for various values of the parameters involved in the problem.The effects of the Hartmann number,the chemical reaction parameter,the magnetic Prandtl number,and the other parameters involved in the velocity field,the temperature field,the concentration field,and the induced magnetic field from the plate to the fluid are discussed.An increase in the heat source/sink or the Eckert number is found to strongly enhance the fluid velocity values.The induced magnetic field along the x-direction increases with the increase in the Hartmann number,the magnetic Prandtl number,the heat source/sink,and the viscous dissipation.It is found that the flow velocity,the fluid temperature,and the induced magnetic field decrease with the increase in the destructive chemical reaction.Applications of the study arise in the thermal plasma reactor modelling,the electromagnetic induction,the magnetohydrodynamic transport phenomena in chromatographic systems,and the magnetic field control of materials processing. 展开更多
关键词 MHD perturbation technique network simulation method Eckert number mixed convection induced magnetic field viscous dissipation heat source/sink
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Design and Implementation of Distributed Self-Election Dynamic Array Honeypot System 被引量:1
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作者 石乐义 李婕 +1 位作者 韩煦 贾春福 《China Communications》 SCIE CSCD 2011年第4期109-115,共7页
Traditional honeypot is in fact a "passive proactive" defense mechanism because it may lose the value entirely once the adversary has detected the existence of the static trap and bypassed it.Our work focuse... Traditional honeypot is in fact a "passive proactive" defense mechanism because it may lose the value entirely once the adversary has detected the existence of the static trap and bypassed it.Our work focuses on a Self-Election dynamic honeypot framework which aims to bewilder attackers by coordinating and switching roles periodically to form a huge dynamic puzzle.In this paper,we discuss the UDP Spokesman synchronization scheme and the Self-Election coordination method,perform the framework simulation of the dynamic array honeypot with NS2,carry out the prototype implementation by Java,and then validate the effectiveness and feasibility on the simulation and prototype system.The promising results of applying this framework to mitigate the effects of attacks are shown and analyzed.Our work demonstrates that the Self-Election dynamic array honeypot system is feasible and effective for proactive network confrontation. 展开更多
关键词 HONEYPOT network confrontation self-election battle diagram network simulation
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Mathematical Model Validation of Search Protocols in MP2P Networks 被引量:1
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作者 Ajay Arunachalam Vinayakumar Ravi +2 位作者 Moez Krichen Roobaea Alroobaea Saeed Rubaiee 《Computers, Materials & Continua》 SCIE EI 2021年第8期1807-1829,共23页
Broadcasting is a basic technique in Mobile ad-hoc network(MANET),and it refers to sending a packet from one node to every other node within the transmission range.Flooding is a type of broadcast where the received pa... Broadcasting is a basic technique in Mobile ad-hoc network(MANET),and it refers to sending a packet from one node to every other node within the transmission range.Flooding is a type of broadcast where the received packet is retransmitted once by every node.The naive flooding technique,floods the network with query messages,while the random walk technique operates by contacting the subsets of every node’s neighbors at each step,thereby restricting the search space.One of the key challenges in an ad-hoc network is the resource or content discovery problem which is about locating the queried resource.Many earlier works have mainly focused on the simulation-based analysis of flooding,and its variants under a wired network.Although,there have been some empirical studies in peer-to-peer(P2P)networks,the analytical results are still lacking,especially in the context of P2P systems running over MANET.In this paper,we describe how P2P resource discovery protocols perform badly over MANETs.To address the limitations,we propose a new protocol named ABRW(Address Broadcast Random Walk),which is a lightweight search approach,designed considering the underlay topology aimed to better suit the unstructured architecture.We provide the mathematical model,measuring the performance of our proposed search scheme with different widely popular benchmarked search techniques.Further,we also derive three relevant search performance metrics,i.e.,mean no.of steps needed to find a resource,the probability of finding a resource,and the mean no.of message overhead.We validated the analytical expressions through simulations.The simulation results closely matched with our analyticalmodel,justifying our findings.Our proposed search algorithm under such highly dynamic self-evolving networks performed better,as it reduced the search latency,decreased the overall message overhead,and still equally had a good success rate. 展开更多
关键词 Search protocols random walk MANET P2P networks P2P MANET mathematical model peer-to-peer wireless ad hoc network FLOODING mobile P2P UNSTRUCTURED P2P NS-2 network simulator
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Decision Model of Knowledge Transfer in Big Data Environment 被引量:7
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作者 Chuanrong Wu Yingwu Chen Feng Li 《China Communications》 SCIE CSCD 2016年第7期100-107,共8页
A decision model of knowledge transfer is presented on the basis of the characteristics of knowledge transfer in a big data environment.This model can determine the weight of knowledge transferred from another enterpr... A decision model of knowledge transfer is presented on the basis of the characteristics of knowledge transfer in a big data environment.This model can determine the weight of knowledge transferred from another enterprise or from a big data provider.Numerous simulation experiments are implemented to test the efficiency of the optimization model.Simulation experiment results show that when increasing the weight of knowledge from big data knowledge provider,the total discount expectation of profits will increase,and the transfer cost will be reduced.The calculated results are in accordance with the actual economic situation.The optimization model can provide useful decision support for enterprises in a big data environment. 展开更多
关键词 big data knowledge transfer optimization simulation dynamic network
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A new algorithm for wireless sensor network based on NS-2 被引量:2
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作者 焦国太 孟庆丰 《Journal of Measurement Science and Instrumentation》 CAS 2013年第3期272-275,共4页
Considering wireless sensor network characteristics,this paper uses network simulator,version2(NS-2)algorithm to improve Ad hoc on-demand distance vector(AODV)routing algorithm,so that it can be applied to wireless se... Considering wireless sensor network characteristics,this paper uses network simulator,version2(NS-2)algorithm to improve Ad hoc on-demand distance vector(AODV)routing algorithm,so that it can be applied to wireless sensor networks.After studying AODV routing protocol,a new algorithm called Must is brought up.This paper introduces the background and algorithm theory of Must,and discusses the details about how to implement Must algorithm.At last,using network simulator(NS-2),the performance of Must is evaluated and compared with that of AODV.Simulation results show that the network using Must algorithm has perfect performance. 展开更多
关键词 wireless sensor networks routing protocol network simulator version 2 (NS-2) Must algorithmCLC number:TN926 Document code:AArticle ID:1674-8042(2013)03-0272-04
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Modeling and Generating Realistic Background Traffic by Hybrid Approach 被引量:2
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作者 QIAN Yaguan GUAN Xiaohui +1 位作者 JIANG Ming CEN Gang 《China Communications》 SCIE CSCD 2015年第10期147-157,共11页
One of the key challenges in largescale network simulation is the huge computation demand in fine-grained traffic simulation.Apart from using high-performance computing facilities and parallelism techniques,an alterna... One of the key challenges in largescale network simulation is the huge computation demand in fine-grained traffic simulation.Apart from using high-performance computing facilities and parallelism techniques,an alternative is to replace the background traffic by simplified abstract models such as fluid flows.This paper suggests a hybrid modeling approach for background traffic,which combines ON/OFF model with TCP activities.The ON/OFF model is to characterize the application activities,and the ordinary differential equations(ODEs) based on fluid flows is to describe the TCP congestion avoidance functionality.The apparent merits of this approach are(1) to accurately capture the traffic self-similarity at source level,(2) properly reflect the network dynamics,and(3) efficiently decrease the computational complexity.The experimental results show that the approach perfectly makes a proper trade-off between accuracy and complexity in background traffic simulation. 展开更多
关键词 network simulation background traffic ON/OFF models fluid flows self-similarity
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Ranking important nodes in complex networks by simulated annealing 被引量:3
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作者 Yu Sun Pei-Yang Yao +2 位作者 Lu-Jun Wan Jian Shen Yun Zhong 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第2期42-47,共6页
In this paper, based on simulated annealing a new method to rank important nodes in complex networks is presented.First, the concept of an importance sequence(IS) to describe the relative importance of nodes in comp... In this paper, based on simulated annealing a new method to rank important nodes in complex networks is presented.First, the concept of an importance sequence(IS) to describe the relative importance of nodes in complex networks is defined. Then, a measure used to evaluate the reasonability of an IS is designed. By comparing an IS and the measure of its reasonability to a state of complex networks and the energy of the state, respectively, the method finds the ground state of complex networks by simulated annealing. In other words, the method can construct a most reasonable IS. The results of experiments on real and artificial networks show that this ranking method not only is effective but also can be applied to different kinds of complex networks. 展开更多
关键词 complex networks node importance ranking method simulated annealing
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