This article presents a novel approach for the measurement and estimation of network traffic utilization between network nodes in heterogeneous environment. This research investigates performance evaluation of network...This article presents a novel approach for the measurement and estimation of network traffic utilization between network nodes in heterogeneous environment. This research investigates performance evaluation of network interface on heterogeneous services and technologies environment. This study proposes an enhanced equation to evaluate the performance of network interface via Little Law and Queuing theories to improve the evaluation algorithm. To get accuracy results on the performance of simulation model, it measures (verify and validate) data from Local Area Network (real network environment). This project uses network management tool to capture those data and Fluke Optiview device to generate traffic. As a result, this simulation model can provide a good approximation of the real traffic observed in the real network environment. Through laboratory and field experiments, the result shows that the model via simulation is capable of approximating the performance of network utilization and traffic over heterogeneous services and techniques within a minimum error range.展开更多
Dynamic bandwidth allocation(DBA)is an open and hot topic in the Ethernet passive optical network(EPON),which is regarded as one of the best choices for next-generation access networks.However,most proposed DBA scheme...Dynamic bandwidth allocation(DBA)is an open and hot topic in the Ethernet passive optical network(EPON),which is regarded as one of the best choices for next-generation access networks.However,most proposed DBA schemes ignore the quality of service(QoS)guarantee on maximum delay and delay jitter for the real-time traffic and the downstream bandwidth utilization under light upstream load in EPON.In this paper,a new DBA scheme,QoS guaranteed adaptive downstream bandwidth utilization(QoS-ADBU),is proposed.This scheme can provide better QoS assurance by determining the maximum transmission cycle time according to the maximum acceptable packet delay and delay jitter for real-time traffic.Besides,the downstream utilization can also be improved by adapting the polling frequency to downstream traffic load.展开更多
[Objectives]To explore the agricultural water resources utilization and management under the agricultural safety aim.[Methods]Fuzzy neural network algorithm was adopted.The evaluation model of agricultural water resou...[Objectives]To explore the agricultural water resources utilization and management under the agricultural safety aim.[Methods]Fuzzy neural network algorithm was adopted.The evaluation model of agricultural water resources utilization and management carrying capacity based on quantitative system was established.[Results]With the remarkable improvement of China's national income,great progress has been made in China's agricultural development.However,in the process of agricultural safety production,the problem of sustainable development has not been noticed,the problem of water resources exceeding the limit bearing capacity frequently occurs.[Conclusions]It is of great significance to effectively solve the problem of water resources utilization and management.In the feasibility test for the algorithm,further tests on various indicators show that the research is feasible.展开更多
The feasibility of using an ANN method to predict the mercury emission and speciation in the flue gas of a power station under un-tested combustion/operational conditions is evaluated. Based on existing field testing ...The feasibility of using an ANN method to predict the mercury emission and speciation in the flue gas of a power station under un-tested combustion/operational conditions is evaluated. Based on existing field testing datasets for the emissions of three utility boilers, a 3-layer back-propagation network is applied to predict the mercury speciation at the stack. The whole prediction procedure includes： collection of data, structuring an artificial neural network （ANN） model, training process and error evaluation. A total of 59 parameters of coal and ash analyses and power plant operating conditions are treated as input variables, and the actual mercury emissions and their speciation data are used to supervise the training process and verify the performance of prediction modeling. The precision of model prediction （ root- mean-square error is 0. 8 μg/Nm3 for elemental mercury and 0. 9 μg/Nm3 for total mercury） is acceptable since the spikes of semi- mercury continuous emission monitor （SCEM） with wet conversion modules are taken into consideration.展开更多
This paper develops a routing algorithm for delay-sensitive packet transmission in a low earth orbit multi-hop satellite network consists of micro-satellites. The micro-satellite low earth orbit （MS-LEO） network end...This paper develops a routing algorithm for delay-sensitive packet transmission in a low earth orbit multi-hop satellite network consists of micro-satellites. The micro-satellite low earth orbit （MS-LEO） network endures unstable link connection and frequent link congestion due to the uneven user distribution and the link capacity variations. The proposed routing algorithm, referred to as the utility maximizing routing （UMR） algorithm, improve the network utility of the MS-LEO network for carrying flows with strict end-to-end delay bound requirement. In UMR, first, a link state parameter is defined to capture the link reliability on continuing to keep the end-to-end delay into constraint; then, on the basis of this parameter, a routing metric is for- mulated and a routing scheme is designed for balancing the reliability in delay bound guarantee among paths and building a path maximizing the network utility expectation. While the UMR algo- rithm has many advantages, it may result in a higher blocking rate of new calls. This phenomenon is discussed and a weight factor is introduced into UMR to provide a flexible performance option for network operator. A set of simulations are conducted to verify the good performance of UMR, in terms of balancing the traffic distribution on inter-satellite links, reducing the flow interruption rate, and improving the network utility.展开更多
This article deals with the design of energy efficient water utilization systems allowing operation split. Practical features such as operating flexibility and capital cost have made the number of sub operations an im...This article deals with the design of energy efficient water utilization systems allowing operation split. Practical features such as operating flexibility and capital cost have made the number of sub operations an important parameter of the problem. By treating the direct and indirect heat transfers separately, target freshwater and energy consumption as well as the operation split conditions are first obtained. Subsequently, a mixed integer non-linear programming （MINLP） model is established for the design of water network and the heat exchanger network （HEN）. The proposed systematic approach is limited to a single contaminant. Example from literature is used to illustrate the applicability of the approach.展开更多
A strategy for water and wastewater minimization is developed for continuous water utilization systems involving fixed flowrate(non-mass-transfer-based)operations,based on the fictitious operations that is introduced ...A strategy for water and wastewater minimization is developed for continuous water utilization systems involving fixed flowrate(non-mass-transfer-based)operations,based on the fictitious operations that is introduced to represent the water losing and/or generating operations and a modified concentration interval analysis(MCIA) technique.This strategy is a simple,nongraphical,and noniterative procedure and is suitable for the quick yields of targets and the identification of pinch point location.Moreover,on the basis of the target method,a heuristic-based approach is also presented to generate water utilization networks,which could be demonstrated to be optimum ones. The proposed approaches are illustrated with example problems.展开更多
We study the tradeoff between network utility and network lifetime using a cross-layer optimization approach. The tradeoff model in this paper is based on the framework of layering as optimization decomposition. Our t...We study the tradeoff between network utility and network lifetime using a cross-layer optimization approach. The tradeoff model in this paper is based on the framework of layering as optimization decomposition. Our tradeoff model is the first one that incorporates time slots allocation into this framework. By using Lagrangian dual decomposition method, we decompose the tradeoff model into two subproblems： routing problem at network layer and resource allocation problem at medium access control （MAC） layer. The interfaces between the layers are precisely the dual variables. A partially distributed algorithm is proposed to solve the nonlinear, convex, and separable tradeoff model. Numerical simulation results are presented to support our algorithm.展开更多
A new approach, named TCP-I2NC, is proposed to improve the interaction between network coding and TCP and to maximize the network utility in interference-free multi-radio multi-channel wireless mesh networks. It is gr...A new approach, named TCP-I2NC, is proposed to improve the interaction between network coding and TCP and to maximize the network utility in interference-free multi-radio multi-channel wireless mesh networks. It is grounded on a Network Utility Maxmization (NUM) formulation which can be decomposed into a rate control problem and a packet scheduling problem. The solutions to these two problems perform resource allocation among different flows. Simulations demonstrate that TCP-I2NC results in a significant throughput gain and a small delay jitter. Network resource is fairly allocated via the solution to the NUM problem and the whole system also runs stably. Moreover, TCP-I2NC is compatible with traditional TCP variants.展开更多
The service and application of a network is a behavioral process that is oriented toward its operations and tasks, whose metrics and evaluation are still somewhat of a rough comparison, This paper describes sce- nes o...The service and application of a network is a behavioral process that is oriented toward its operations and tasks, whose metrics and evaluation are still somewhat of a rough comparison, This paper describes sce- nes of network behavior as differential manifolds, Using the homeomorphic transformation of smooth differential manifolds, we provide a mathematical definition of network behavior and propose a mathe- matical description of the network behavior path and behavior utility, Based on the principle of differen- tial geometry, this paper puts forward the function of network behavior and a calculation method to determine behavior utility, and establishes the calculation principle of network behavior utility, We also provide a calculation framework for assessment of the network＇s attack-defense confrontation on the strength of behavior utility, Therefore, this paper establishes a mathematical foundation for the objective measurement and precise evaluation of network behavior,展开更多
A novel backoff algorithm in CSMA/CA-based medium access control (MAC) protocols for clustered sensor networks was proposed. The algorithm requires that all sensor nodes have the same value of contention window (CW) i...A novel backoff algorithm in CSMA/CA-based medium access control (MAC) protocols for clustered sensor networks was proposed. The algorithm requires that all sensor nodes have the same value of contention window (CW) in a cluster, which is revealed by formulating resource allocation as a network utility maximization problem. Then, by maximizing the total network utility with constrains of minimizing collision probability, the optimal value of CW (Wopt) can be computed according to the number of sensor nodes. The new backoff algorithm uses the common optimal value Wopt and leads to fewer collisions than binary exponential backoff algorithm. The simulation results show that the proposed algorithm outperforms standard 802.11 DCF and S-MAC in average collision times, packet delay, total energy consumption, and system throughput.展开更多
In Wireless Mesh Networks (WMNs),the performance of conventional TCP significantly deteriorates due to the unreliable wireless channel.To enhance TCP performance in WMNs,TCP/LT is proposed in this paper.It introduces ...In Wireless Mesh Networks (WMNs),the performance of conventional TCP significantly deteriorates due to the unreliable wireless channel.To enhance TCP performance in WMNs,TCP/LT is proposed in this paper.It introduces fountain codes into packet reorganization in the protocol stack of mesh gateways and mesh clients.Furthermore,it is compatible with conventional TCP.Regarded as a Performance Enhancement Proxies (PEP),a mesh gateway buffers TCP packets into several blocks.It simultaneously processes them by using fountain encoders and then sends them to mesh clients.Apart from the improvement of the throughput of a unitary TCP flow,the entire network utility maximization can also be ensured by adjusting the scale of coding blocks for each TCP flow adaptively.Simulations show that TCP/LT presents high throughput gains over single TCP in lossy links of WMNs while preserving the fairness for multiple TCPs.As losses increase,the transmission delay of TCP/LT experiences a slow linear growth in contrast to the exponential growth of TCP.展开更多
It is promising to simultaneously develop multiple products through the combined utilization of seawater by solar chimney technology. A small scale experimental system was set up. The collector temperature, the seawat...It is promising to simultaneously develop multiple products through the combined utilization of seawater by solar chimney technology. A small scale experimental system was set up. The collector temperature, the seawater temperature, and the temperature and humidity of the airflow under the collector were measured. Thermal network analysis of the system was carried out. The results show that the airflow is nearly saturated at the entrance of the chimney, and the mean dry-bulb and wet-bulb temperatures of the airflow have increased by 8.4 ℃ and 9.6 ℃, respectively. The radiation heat transfer between the collector and the sky is the biggest heat loss in the system, which is up to 29.1% on average of the solar energy. However, the water evaporation heat is about 23.6% on average of the solar energy. To reduce the heat loss and enhance the water evaporation, it is necessary to reduce the emissivity and thermal conductivity of the collector and increase the evaporation areas.展开更多
This paper introduces a non-iterative algorithmic procedure to design water utilization networks with multiple contaminants in process plants. According to the water pinch analysis rules, the processes in water utiliz...This paper introduces a non-iterative algorithmic procedure to design water utilization networks with multiple contaminants in process plants. According to the water pinch analysis rules, the processes in water utilization systems were first divided into three groups, then water-supply priority algorithm was proposed. The results of case studies showed that the water networks designed by this method gave water consumption lower than that estimated by other approaches. In addition, the procedure was subject to no limitation on the problem scale.展开更多
The decision system based on network economy is the foundation of enterprise's making good winning in its market. This paper describes the decision makers' utility model based on network economy, considers the...The decision system based on network economy is the foundation of enterprise's making good winning in its market. This paper describes the decision makers' utility model based on network economy, considers the roles decision-makers not only play in the enterprises are decision making, coordinating, controlling and monitoring, but also they are mainly designers, executants and educators in the mode of network economy展开更多
In this paper,based on the utility preferential attachment,we propose a new unified model to generate different network topologies such as scale-free,small-world and random networks.Moreover,a new network structure na...In this paper,based on the utility preferential attachment,we propose a new unified model to generate different network topologies such as scale-free,small-world and random networks.Moreover,a new network structure named super scale network is found,which has monopoly characteristic in our simulation experiments.Finally,the characteristics of this new network are given.展开更多
This paper introduces the characteristics of TD-SCDMA, and analyzes some networking schemes and methods of multifrequency. For the 5 MHz frequency bandwidth, a frequency planning scheme containing three frequencies is...This paper introduces the characteristics of TD-SCDMA, and analyzes some networking schemes and methods of multifrequency. For the 5 MHz frequency bandwidth, a frequency planning scheme containing three frequencies is examined, and a simulation model is built to validate the performance of this scheme. Finally, this paper analyzes the advantages and disadvantages of the scheme, and proposes some directions for the future study of networking planning.展开更多
The High Speed Downlink Packet Access(HSDPA)technology is employed for the data service in the Time Division Synchronous Code Division Multiple Access(TD-SCDMA)mobile communication system.Theoretically,the HSDPA peak ...The High Speed Downlink Packet Access(HSDPA)technology is employed for the data service in the Time Division Synchronous Code Division Multiple Access(TD-SCDMA)mobile communication system.Theoretically,the HSDPA peak data throughput per Time Slot(TS)available in the terminals reaches 560kb/s.Since the data service often occurs indoors,flexible TS allocation between uplink and downlink is applied in TD-SCDMA networking.That is,TS1 and TS2 are uplink time slots and TS3,TS4,TS5 and TS6 are downlink time slots in the indoor cell;and symmetry TS allocation is made for the outdoor cell.In the intra-frequency cell network,it can cause intra-frequency interference between cells.So the research on the intra-frequency crossed time slots interference is done and the suggestions on the intra-frequency crossed time slots networking strategy are proposed in this paper.展开更多
In recent years, introduction of alternative energy sources such as solar energy is expected. Solar heat energy utilization systems are rapidly gaining acceptance as one of the best solutions to be an alternative ener...In recent years, introduction of alternative energy sources such as solar energy is expected. Solar heat energy utilization systems are rapidly gaining acceptance as one of the best solutions to be an alternative energy source. However, thermal energy collection is influenced by solar radiation and weather conditions. In order to control a solar heat energy utilization system as accurate as possible, it requires method of solar radiation estimation. This paper proposes the forecast technique of a thermal energy collection of solar heat energy utilization system based on solar radiation forecasting at one-day-ahead 24-hour thermal energy collection by using three different NN models. The proposed technique with application of NN is trained by weather data based on tree-based model, and tested according to forecast day. Since tree-based-model classifies a meteorological data exactly, NN will train a solar radiation with smoothly. The validity of the proposed technique is confirmed by computer simulations by use of actual meteorological data.展开更多
In Chinese traditional culture, ceramic culture is a very special cultural system With the advent of the era of network and the particularity of ceramic culture, Make the network native digital resources development a...In Chinese traditional culture, ceramic culture is a very special cultural system With the advent of the era of network and the particularity of ceramic culture, Make the network native digital resources development and utilization is especially important. The idea of Web3.0 make important ceramic culture network native digital resources ＂reasonable configuration＂, t o be more embody the value of academic research. In this paper, we＇ll discuss the conformity utilization of ceramic culture native digital resources based on the concept of WEB3.0.展开更多
文摘This article presents a novel approach for the measurement and estimation of network traffic utilization between network nodes in heterogeneous environment. This research investigates performance evaluation of network interface on heterogeneous services and technologies environment. This study proposes an enhanced equation to evaluate the performance of network interface via Little Law and Queuing theories to improve the evaluation algorithm. To get accuracy results on the performance of simulation model, it measures (verify and validate) data from Local Area Network (real network environment). This project uses network management tool to capture those data and Fluke Optiview device to generate traffic. As a result, this simulation model can provide a good approximation of the real traffic observed in the real network environment. Through laboratory and field experiments, the result shows that the model via simulation is capable of approximating the performance of network utilization and traffic over heterogeneous services and techniques within a minimum error range.
基金supported by the Tianjin Enterprise Innovation Fund under Grant No.08ZXCXGX17500
文摘Dynamic bandwidth allocation(DBA)is an open and hot topic in the Ethernet passive optical network(EPON),which is regarded as one of the best choices for next-generation access networks.However,most proposed DBA schemes ignore the quality of service(QoS)guarantee on maximum delay and delay jitter for the real-time traffic and the downstream bandwidth utilization under light upstream load in EPON.In this paper,a new DBA scheme,QoS guaranteed adaptive downstream bandwidth utilization(QoS-ADBU),is proposed.This scheme can provide better QoS assurance by determining the maximum transmission cycle time according to the maximum acceptable packet delay and delay jitter for real-time traffic.Besides,the downstream utilization can also be improved by adapting the polling frequency to downstream traffic load.
基金Supported by Special Scientific Research Program of Shaanxi Provincial Department of Education"Study on the Development of Farmer Water Use Cooperative Organizations from the Dual Perspectives of Social Capital and Organizational Structure"(13YJC790135)Project of Social Science Foundation of Shaanxi Province"Study on Development of Farmer Water Use Cooperative Organization in Guanzhong Irrigation Area Based on the Withdrawal Behavior of Members"(2016D026)Special Scientific Research Fund Project of Xianyang Normal University"Study on Member Heterogeneity and the Governance of Farmers Fund Mutual Aid Organizations"(14XYK056).
文摘[Objectives]To explore the agricultural water resources utilization and management under the agricultural safety aim.[Methods]Fuzzy neural network algorithm was adopted.The evaluation model of agricultural water resources utilization and management carrying capacity based on quantitative system was established.[Results]With the remarkable improvement of China's national income,great progress has been made in China's agricultural development.However,in the process of agricultural safety production,the problem of sustainable development has not been noticed,the problem of water resources exceeding the limit bearing capacity frequently occurs.[Conclusions]It is of great significance to effectively solve the problem of water resources utilization and management.In the feasibility test for the algorithm,further tests on various indicators show that the research is feasible.
基金The National Basic Research Program of China (973Program) (No.2006CB200302)the Natural Science Foundation of JiangsuProvince (No.BK2007224).
文摘The feasibility of using an ANN method to predict the mercury emission and speciation in the flue gas of a power station under un-tested combustion/operational conditions is evaluated. Based on existing field testing datasets for the emissions of three utility boilers, a 3-layer back-propagation network is applied to predict the mercury speciation at the stack. The whole prediction procedure includes： collection of data, structuring an artificial neural network （ANN） model, training process and error evaluation. A total of 59 parameters of coal and ash analyses and power plant operating conditions are treated as input variables, and the actual mercury emissions and their speciation data are used to supervise the training process and verify the performance of prediction modeling. The precision of model prediction （ root- mean-square error is 0. 8 μg/Nm3 for elemental mercury and 0. 9 μg/Nm3 for total mercury） is acceptable since the spikes of semi- mercury continuous emission monitor （SCEM） with wet conversion modules are taken into consideration.
基金supported by the National Natural Science Foundation of China (Nos. 61171069, 61231013)Innovative Research Groups of the Foundation of China (No. 60921001)
文摘This paper develops a routing algorithm for delay-sensitive packet transmission in a low earth orbit multi-hop satellite network consists of micro-satellites. The micro-satellite low earth orbit （MS-LEO） network endures unstable link connection and frequent link congestion due to the uneven user distribution and the link capacity variations. The proposed routing algorithm, referred to as the utility maximizing routing （UMR） algorithm, improve the network utility of the MS-LEO network for carrying flows with strict end-to-end delay bound requirement. In UMR, first, a link state parameter is defined to capture the link reliability on continuing to keep the end-to-end delay into constraint; then, on the basis of this parameter, a routing metric is for- mulated and a routing scheme is designed for balancing the reliability in delay bound guarantee among paths and building a path maximizing the network utility expectation. While the UMR algo- rithm has many advantages, it may result in a higher blocking rate of new calls. This phenomenon is discussed and a weight factor is introduced into UMR to provide a flexible performance option for network operator. A set of simulations are conducted to verify the good performance of UMR, in terms of balancing the traffic distribution on inter-satellite links, reducing the flow interruption rate, and improving the network utility.
基金Supported by the Major Project of National Natural Science Foundation of China （No.20409205） and National High Technology Research and Development Program of China （No.G20070040）.
文摘This article deals with the design of energy efficient water utilization systems allowing operation split. Practical features such as operating flexibility and capital cost have made the number of sub operations an important parameter of the problem. By treating the direct and indirect heat transfers separately, target freshwater and energy consumption as well as the operation split conditions are first obtained. Subsequently, a mixed integer non-linear programming （MINLP） model is established for the design of water network and the heat exchanger network （HEN）. The proposed systematic approach is limited to a single contaminant. Example from literature is used to illustrate the applicability of the approach.
文摘A strategy for water and wastewater minimization is developed for continuous water utilization systems involving fixed flowrate(non-mass-transfer-based)operations,based on the fictitious operations that is introduced to represent the water losing and/or generating operations and a modified concentration interval analysis(MCIA) technique.This strategy is a simple,nongraphical,and noniterative procedure and is suitable for the quick yields of targets and the identification of pinch point location.Moreover,on the basis of the target method,a heuristic-based approach is also presented to generate water utilization networks,which could be demonstrated to be optimum ones. The proposed approaches are illustrated with example problems.
基金supported by the Natural Science Foundation of China(No.60704046,60725312,60804067)the National 863 High Technology Research and Development Plan(No.2007AA04Z173,2007AA041201)
文摘We study the tradeoff between network utility and network lifetime using a cross-layer optimization approach. The tradeoff model in this paper is based on the framework of layering as optimization decomposition. Our tradeoff model is the first one that incorporates time slots allocation into this framework. By using Lagrangian dual decomposition method, we decompose the tradeoff model into two subproblems： routing problem at network layer and resource allocation problem at medium access control （MAC） layer. The interfaces between the layers are precisely the dual variables. A partially distributed algorithm is proposed to solve the nonlinear, convex, and separable tradeoff model. Numerical simulation results are presented to support our algorithm.
基金This work was supported by the State Key Program of Na- tional Nature Science Foundation of China under Grants No. U0835003, No. 60872087.
文摘A new approach, named TCP-I2NC, is proposed to improve the interaction between network coding and TCP and to maximize the network utility in interference-free multi-radio multi-channel wireless mesh networks. It is grounded on a Network Utility Maxmization (NUM) formulation which can be decomposed into a rate control problem and a packet scheduling problem. The solutions to these two problems perform resource allocation among different flows. Simulations demonstrate that TCP-I2NC results in a significant throughput gain and a small delay jitter. Network resource is fairly allocated via the solution to the NUM problem and the whole system also runs stably. Moreover, TCP-I2NC is compatible with traditional TCP variants.
文摘The service and application of a network is a behavioral process that is oriented toward its operations and tasks, whose metrics and evaluation are still somewhat of a rough comparison, This paper describes sce- nes of network behavior as differential manifolds, Using the homeomorphic transformation of smooth differential manifolds, we provide a mathematical definition of network behavior and propose a mathe- matical description of the network behavior path and behavior utility, Based on the principle of differen- tial geometry, this paper puts forward the function of network behavior and a calculation method to determine behavior utility, and establishes the calculation principle of network behavior utility, We also provide a calculation framework for assessment of the network＇s attack-defense confrontation on the strength of behavior utility, Therefore, this paper establishes a mathematical foundation for the objective measurement and precise evaluation of network behavior,
基金Project(60772088) supported by the National Natural Science Foundation of China
文摘A novel backoff algorithm in CSMA/CA-based medium access control (MAC) protocols for clustered sensor networks was proposed. The algorithm requires that all sensor nodes have the same value of contention window (CW) in a cluster, which is revealed by formulating resource allocation as a network utility maximization problem. Then, by maximizing the total network utility with constrains of minimizing collision probability, the optimal value of CW (Wopt) can be computed according to the number of sensor nodes. The new backoff algorithm uses the common optimal value Wopt and leads to fewer collisions than binary exponential backoff algorithm. The simulation results show that the proposed algorithm outperforms standard 802.11 DCF and S-MAC in average collision times, packet delay, total energy consumption, and system throughput.
基金supported by the State Key Program of National Nature Science Foundation of China under Grants No.U0835003,No.60872087
文摘In Wireless Mesh Networks (WMNs),the performance of conventional TCP significantly deteriorates due to the unreliable wireless channel.To enhance TCP performance in WMNs,TCP/LT is proposed in this paper.It introduces fountain codes into packet reorganization in the protocol stack of mesh gateways and mesh clients.Furthermore,it is compatible with conventional TCP.Regarded as a Performance Enhancement Proxies (PEP),a mesh gateway buffers TCP packets into several blocks.It simultaneously processes them by using fountain encoders and then sends them to mesh clients.Apart from the improvement of the throughput of a unitary TCP flow,the entire network utility maximization can also be ensured by adjusting the scale of coding blocks for each TCP flow adaptively.Simulations show that TCP/LT presents high throughput gains over single TCP in lossy links of WMNs while preserving the fairness for multiple TCPs.As losses increase,the transmission delay of TCP/LT experiences a slow linear growth in contrast to the exponential growth of TCP.
基金Supported by Tianjin Technological Development Program Project of China (No05YFGZSF02800 and No06YFSZSF04600)the Key Research Program of the National Eleventh Five-Year Plan of China (No 2006BAA04B03-03)
文摘It is promising to simultaneously develop multiple products through the combined utilization of seawater by solar chimney technology. A small scale experimental system was set up. The collector temperature, the seawater temperature, and the temperature and humidity of the airflow under the collector were measured. Thermal network analysis of the system was carried out. The results show that the airflow is nearly saturated at the entrance of the chimney, and the mean dry-bulb and wet-bulb temperatures of the airflow have increased by 8.4 ℃ and 9.6 ℃, respectively. The radiation heat transfer between the collector and the sky is the biggest heat loss in the system, which is up to 29.1% on average of the solar energy. However, the water evaporation heat is about 23.6% on average of the solar energy. To reduce the heat loss and enhance the water evaporation, it is necessary to reduce the emissivity and thermal conductivity of the collector and increase the evaporation areas.
文摘This paper introduces a non-iterative algorithmic procedure to design water utilization networks with multiple contaminants in process plants. According to the water pinch analysis rules, the processes in water utilization systems were first divided into three groups, then water-supply priority algorithm was proposed. The results of case studies showed that the water networks designed by this method gave water consumption lower than that estimated by other approaches. In addition, the procedure was subject to no limitation on the problem scale.
文摘The decision system based on network economy is the foundation of enterprise's making good winning in its market. This paper describes the decision makers' utility model based on network economy, considers the roles decision-makers not only play in the enterprises are decision making, coordinating, controlling and monitoring, but also they are mainly designers, executants and educators in the mode of network economy
基金The project partly supported by the State 0utstanding Youth Foundation under Grant No.70225005,National Natural Science Foundation of China under Grant Nos.70501005,70501004,and 70471088,the Natural Science Foundation of Beijing under Grant No.9042006,the Special Program for Preliminary Research of Momentous Fundamental Research under Grant No.2005CCA03900,the Innovation Foundation of Science and Technology for Excellent Doctorial Candidate of Beijing Jiaotong University under Grant No.48006
文摘In this paper,based on the utility preferential attachment,we propose a new unified model to generate different network topologies such as scale-free,small-world and random networks.Moreover,a new network structure named super scale network is found,which has monopoly characteristic in our simulation experiments.Finally,the characteristics of this new network are given.
文摘This paper introduces the characteristics of TD-SCDMA, and analyzes some networking schemes and methods of multifrequency. For the 5 MHz frequency bandwidth, a frequency planning scheme containing three frequencies is examined, and a simulation model is built to validate the performance of this scheme. Finally, this paper analyzes the advantages and disadvantages of the scheme, and proposes some directions for the future study of networking planning.
文摘The High Speed Downlink Packet Access(HSDPA)technology is employed for the data service in the Time Division Synchronous Code Division Multiple Access(TD-SCDMA)mobile communication system.Theoretically,the HSDPA peak data throughput per Time Slot(TS)available in the terminals reaches 560kb/s.Since the data service often occurs indoors,flexible TS allocation between uplink and downlink is applied in TD-SCDMA networking.That is,TS1 and TS2 are uplink time slots and TS3,TS4,TS5 and TS6 are downlink time slots in the indoor cell;and symmetry TS allocation is made for the outdoor cell.In the intra-frequency cell network,it can cause intra-frequency interference between cells.So the research on the intra-frequency crossed time slots interference is done and the suggestions on the intra-frequency crossed time slots networking strategy are proposed in this paper.
文摘In recent years, introduction of alternative energy sources such as solar energy is expected. Solar heat energy utilization systems are rapidly gaining acceptance as one of the best solutions to be an alternative energy source. However, thermal energy collection is influenced by solar radiation and weather conditions. In order to control a solar heat energy utilization system as accurate as possible, it requires method of solar radiation estimation. This paper proposes the forecast technique of a thermal energy collection of solar heat energy utilization system based on solar radiation forecasting at one-day-ahead 24-hour thermal energy collection by using three different NN models. The proposed technique with application of NN is trained by weather data based on tree-based model, and tested according to forecast day. Since tree-based-model classifies a meteorological data exactly, NN will train a solar radiation with smoothly. The validity of the proposed technique is confirmed by computer simulations by use of actual meteorological data.
文摘In Chinese traditional culture, ceramic culture is a very special cultural system With the advent of the era of network and the particularity of ceramic culture, Make the network native digital resources development and utilization is especially important. The idea of Web3.0 make important ceramic culture network native digital resources ＂reasonable configuration＂, t o be more embody the value of academic research. In this paper, we＇ll discuss the conformity utilization of ceramic culture native digital resources based on the concept of WEB3.0.
