With the rapid development of green communications,energy consumption issue plays more and more important role in cooperative communication strategies and communication systems.Based on cooperative transmission model,...With the rapid development of green communications,energy consumption issue plays more and more important role in cooperative communication strategies and communication systems.Based on cooperative transmission model,a cooperative user selection scheme is proposed in consideration of both energy efficiency and interference factor.With the proposed scheme,the selected cooperative user consumes less energy and receives less interference.Furthermore,the main factor is analyzed to affect system performance,including signal-to-noise ratio(SNR)of source user and cooperative user,distance between source user and cooperative user or base station(BS),and fading factor in the transmission model.Through the proposed scheme,energy consumption and influence of interference are jointly taken into account during the cooperative user selection process.Besides,bit error rate(BER)in proposed scheme is also superior to existing schemes.Simulation results are presented to show the performance improvement of the proposed scheme.展开更多
The spatial distribution of the energy flux, bottom boundary layer (BBL) energy dissipation, surface elevation amplitude and current magnitude of the major semidiurnal tidal constituents in the Bering Sea are examin...The spatial distribution of the energy flux, bottom boundary layer (BBL) energy dissipation, surface elevation amplitude and current magnitude of the major semidiurnal tidal constituents in the Bering Sea are examined in detail. These distributions are obtained from the results of a three-dimensional numerical simulation model (POM). Compared with observation data from seven stations, the root mean square errors of tidal height are 2.6 cm and 1.2 cm for M2 and N2 respectively, and those of phase-lag are 21.8~ and 15.8~ respectively. The majority of the tidal energy flux off the deep basin is along the shelf edge, although some of this flux crosses the shelf edge, especially in the southeast of the shelf break. The total M2 energy dissipation in the Bering Sea is 30.43 GW, which is about 10 times of that of N2 and $2. The semidiurnal tidal energy enters mainly to the Bering Sea by Samalga Pass, Amukta Pass and Seguam Pass, accounting more than 60% of the total energy entering the Being Sea from the Pacific.展开更多
The traditional evaluation of energy consumption mostly introduces pollutants as a negative economic output into evaluating model,ignoring the configuration relationship among the energy input,pollutants as well as ec...The traditional evaluation of energy consumption mostly introduces pollutants as a negative economic output into evaluating model,ignoring the configuration relationship among the energy input,pollutants as well as economic output.This paper considers the overall process of energy consumption and constructs an evaluation indication system of energy consumption level combined with endogenous pollutants based on entropytopsis method,then makes empirical research.The results show that China's energy consumption level presents a fluctuant rise in the premise of emission.Energy consumption level depends on the relationship among energy input,pollutants and economic output.The raise of energy consumption level should not increase economic output and reduce pollutant emission at the expense of environment.Finally,the whole paper puts forward the countermeasures to improve the overall level of energy consumption.展开更多
To understand the processes and energy dissipation performance caused by turbulence during the wave run-up over a stepped revetment,hydraulic model tests with steady flow conditions are conducted and correlated with u...To understand the processes and energy dissipation performance caused by turbulence during the wave run-up over a stepped revetment,hydraulic model tests with steady flow conditions are conducted and correlated with unsteady flow conditions of the wave run-up within a short time frame.Under irregular waves,the run-up reduction over a stepped revetment is dependent on the Iribarren number and decreases for decreasing Iribarren numbers.Velocity gradients are found to be similar in a steady and unsteady flow regime near the pseudo-bottom.展开更多
Energy saving is the nature of the optimal balance between the optimization of performance and energy consumption.Due to the node' s mobility of large-scale wireless sensor networks and the depletion of electrical en...Energy saving is the nature of the optimal balance between the optimization of performance and energy consumption.Due to the node' s mobility of large-scale wireless sensor networks and the depletion of electrical energy causing the failure of communication path and network segmentation mong nodes,and because energy consumption of nodes is mainly its communication, to design the routing with energy saving, low latency, extensibility and improving the fault-tolerance is particularly important.Based on the large-scale wireless sensor networks,mainly through introducing the methods of nonlinear modeling,this paper analyzes the fine-grained mapping between the system of energy consumption and software, builds and optimizes the software model of energy consumption and energy consumption-balance model of service quality, and commits to form an effective energy saving to lay a foundation for construction of low energy consumption of wireless sensor network. Research achievement has significant theoretical and application value in public safety, disaster prevention, ecological and environmental protection, urban management, smart home, intelligent transportation, medical and health care, industrial monitoring, green agriculture and other fields.展开更多
In this study, in order to investigate the power consumption of feed drive system, mathematical models for the single-axis experimental apparatus are developed. This apparatus can be driven by either of ball screw or ...In this study, in order to investigate the power consumption of feed drive system, mathematical models for the single-axis experimental apparatus are developed. This apparatus can be driven by either of ball screw or linear motor and it is possible to change the mechanical properties of such as grease viscosity of the table. Then, the power consumption is simulated by proposed method based on the mathematical model of feed drive systems and the simulated results are compared with the measured results of the experimental apparatus to confirm the validity of the proposed method. In addition, it is clarified that the energy usages of the feed drive system. The energy losses of the feed drive system are divided into the loss of each part and these energy losses are calculated by the proposed method. Then, it is investigated that the influence of the velocity and friction to the energy consumption of feed drive system. As the results, it is confirmed that proposed method can accurately predict the power consumption of the ball-screw feed drive system. It is also clarified that the energy usage for both of ball-screw and linear motor drive systems.展开更多
After the great east Japan earthquake in 2011, Japanese energy system has been expected to prioritize safety and trustworthiness. Now, distributed power systems are considered as one solution, but utilizing exhaust he...After the great east Japan earthquake in 2011, Japanese energy system has been expected to prioritize safety and trustworthiness. Now, distributed power systems are considered as one solution, but utilizing exhaust heat is an important task to be solved. The purpose of this study is to build a simulation model to harness waste heat of commercial buildings. We obtained two types of data: distributed power system in 1/15 scale model of supermarket, restaurant and real world energy consumption of the two buildings. Results showed cold cabinets, whose electricity was affected by temperatures outside and inside, consumed most in supermarket. While air conditioning, affected by air enthalpy of outside and inside, consumed most in restaurant. According to our simulation with gas engine, PV (photovoltaic) panel, PCM (phase change material), thermal storage, FCU (fan coil unit) and refrigerated cabinets in scale model, we could reduce 27% of CO_2 emission and 25% of running cost by selecting optimal size.展开更多
The key word for the design process of the photovoltaic tracking systems is the energetic efficiency. Using the tracking system, the photovoltaic panel follows the sun and increases the collected energy, but the drivi...The key word for the design process of the photovoltaic tracking systems is the energetic efficiency. Using the tracking system, the photovoltaic panel follows the sun and increases the collected energy, but the driving motors consume a part of this energy. In these terms, the optimization of the tracking systems became an important challenge in the modem research and technology. In this paper, a strategy for the dynamic optimization of the photovoltaic tracking systems is presented. The main task in optimization is to maximize the energetic gain by increasing the incoming solar radiation and minimizing the energy consumption for tracking. This strategy is possible by developing the virtual prototype of the tracking system, which is a control loop composed by the multi-body mechanical model connected with the dynamic model of the actuators and with the controller model. In this way, it is possible to optimize the tracking mechanism, choose the appropriate actuators, and design the optimal controller.展开更多
This paper discusses the design of the propulsion system of the UAQ4 (University of L'Aquila, model 4) magnetic levitating train which is used for transportation applications in urban environments. UAQ4 is the only...This paper discusses the design of the propulsion system of the UAQ4 (University of L'Aquila, model 4) magnetic levitating train which is used for transportation applications in urban environments. UAQ4 is the only magnetic levitating vehicle with resistance motion, except for aerodynamic drag and with energy consumption near zero at low speed. The feasibility of the system has been successfully verified and tested in the laboratory. Propulsion and braking are provided by a novel direct-current linear stepper motor, with the primary formed by permanent magnets distributed on central beam of the track, and the secondary by coils on board the vehicle, instead of the present alternate current linear motors that have well-known disadvantages. The motor working principles are described, and its performances are analyzed, by a finite element numerical model which allows modifying the most important parameters of the system. The main components of a full scale motor for urban transportation are measured and discussed.展开更多
Optimizing industrial structure is an important research object of human-economic geography, and it is also the object of government departments to strengthen macro-control. This has become even greater problem that C...Optimizing industrial structure is an important research object of human-economic geography, and it is also the object of government departments to strengthen macro-control. This has become even greater problem that China has entered the "new normal" in recent years. The study uses a multi-regional input-output model, with linear programming to build an optimal model of industrial structure as well as a model of optimization degree under the energy constraint. The results of the study revealed that:(1) the degree of optimization of industrial structure in Anhui Province is optimal(0.763), while that of Shanxi Province is the lowest(0.662);(2) the degree of optimization of industrial structure is negatively related to energy consumption per unit output value and the proportion of heavy industry; and(3) overall, central China should maintain or moderately increase the proportions of resource-based industry, greatly increase the proportions of manufacturing, including transport and telecommunications equipment, computers and other electronic equipment, and moderately reduce the proportions of smelting and pressing of metals and non-metal mineral products. In terms of service industries, the region should greatly increase the proportions of the production and supply of natural gas and tap water, moderately reduce or maintain the proportions of transport and storage as well as tourism, and maintain or moderately reduce the proportions of wholesale trade, retail trade and catering services.展开更多
基金Supported by the National Natural Science Foundation of China(No.61372089,61571021)Beijing Natural Science Foundation(No.4132019)
文摘With the rapid development of green communications,energy consumption issue plays more and more important role in cooperative communication strategies and communication systems.Based on cooperative transmission model,a cooperative user selection scheme is proposed in consideration of both energy efficiency and interference factor.With the proposed scheme,the selected cooperative user consumes less energy and receives less interference.Furthermore,the main factor is analyzed to affect system performance,including signal-to-noise ratio(SNR)of source user and cooperative user,distance between source user and cooperative user or base station(BS),and fading factor in the transmission model.Through the proposed scheme,energy consumption and influence of interference are jointly taken into account during the cooperative user selection process.Besides,bit error rate(BER)in proposed scheme is also superior to existing schemes.Simulation results are presented to show the performance improvement of the proposed scheme.
基金Supported by the Outstanding Middle-aged and Young Scientist Foundation in Shandong Province under Grant of No.2008BS06003National High Technology Research and development Program (863 Program) (No.2007AA06A403)National Nature Science Foundation under Grant of No.40706008
文摘The spatial distribution of the energy flux, bottom boundary layer (BBL) energy dissipation, surface elevation amplitude and current magnitude of the major semidiurnal tidal constituents in the Bering Sea are examined in detail. These distributions are obtained from the results of a three-dimensional numerical simulation model (POM). Compared with observation data from seven stations, the root mean square errors of tidal height are 2.6 cm and 1.2 cm for M2 and N2 respectively, and those of phase-lag are 21.8~ and 15.8~ respectively. The majority of the tidal energy flux off the deep basin is along the shelf edge, although some of this flux crosses the shelf edge, especially in the southeast of the shelf break. The total M2 energy dissipation in the Bering Sea is 30.43 GW, which is about 10 times of that of N2 and $2. The semidiurnal tidal energy enters mainly to the Bering Sea by Samalga Pass, Amukta Pass and Seguam Pass, accounting more than 60% of the total energy entering the Being Sea from the Pacific.
文摘The traditional evaluation of energy consumption mostly introduces pollutants as a negative economic output into evaluating model,ignoring the configuration relationship among the energy input,pollutants as well as economic output.This paper considers the overall process of energy consumption and constructs an evaluation indication system of energy consumption level combined with endogenous pollutants based on entropytopsis method,then makes empirical research.The results show that China's energy consumption level presents a fluctuant rise in the premise of emission.Energy consumption level depends on the relationship among energy input,pollutants and economic output.The raise of energy consumption level should not increase economic output and reduce pollutant emission at the expense of environment.Finally,the whole paper puts forward the countermeasures to improve the overall level of energy consumption.
基金part of the joint research project ‘wave STEPS’ funded by the German Federal Ministry of Education and Research(BMBF) through the German Coastal Engineering Research council(KFKI,03KIS108 and 03KIS119)
文摘To understand the processes and energy dissipation performance caused by turbulence during the wave run-up over a stepped revetment,hydraulic model tests with steady flow conditions are conducted and correlated with unsteady flow conditions of the wave run-up within a short time frame.Under irregular waves,the run-up reduction over a stepped revetment is dependent on the Iribarren number and decreases for decreasing Iribarren numbers.Velocity gradients are found to be similar in a steady and unsteady flow regime near the pseudo-bottom.
文摘Energy saving is the nature of the optimal balance between the optimization of performance and energy consumption.Due to the node' s mobility of large-scale wireless sensor networks and the depletion of electrical energy causing the failure of communication path and network segmentation mong nodes,and because energy consumption of nodes is mainly its communication, to design the routing with energy saving, low latency, extensibility and improving the fault-tolerance is particularly important.Based on the large-scale wireless sensor networks,mainly through introducing the methods of nonlinear modeling,this paper analyzes the fine-grained mapping between the system of energy consumption and software, builds and optimizes the software model of energy consumption and energy consumption-balance model of service quality, and commits to form an effective energy saving to lay a foundation for construction of low energy consumption of wireless sensor network. Research achievement has significant theoretical and application value in public safety, disaster prevention, ecological and environmental protection, urban management, smart home, intelligent transportation, medical and health care, industrial monitoring, green agriculture and other fields.
文摘In this study, in order to investigate the power consumption of feed drive system, mathematical models for the single-axis experimental apparatus are developed. This apparatus can be driven by either of ball screw or linear motor and it is possible to change the mechanical properties of such as grease viscosity of the table. Then, the power consumption is simulated by proposed method based on the mathematical model of feed drive systems and the simulated results are compared with the measured results of the experimental apparatus to confirm the validity of the proposed method. In addition, it is clarified that the energy usages of the feed drive system. The energy losses of the feed drive system are divided into the loss of each part and these energy losses are calculated by the proposed method. Then, it is investigated that the influence of the velocity and friction to the energy consumption of feed drive system. As the results, it is confirmed that proposed method can accurately predict the power consumption of the ball-screw feed drive system. It is also clarified that the energy usage for both of ball-screw and linear motor drive systems.
文摘After the great east Japan earthquake in 2011, Japanese energy system has been expected to prioritize safety and trustworthiness. Now, distributed power systems are considered as one solution, but utilizing exhaust heat is an important task to be solved. The purpose of this study is to build a simulation model to harness waste heat of commercial buildings. We obtained two types of data: distributed power system in 1/15 scale model of supermarket, restaurant and real world energy consumption of the two buildings. Results showed cold cabinets, whose electricity was affected by temperatures outside and inside, consumed most in supermarket. While air conditioning, affected by air enthalpy of outside and inside, consumed most in restaurant. According to our simulation with gas engine, PV (photovoltaic) panel, PCM (phase change material), thermal storage, FCU (fan coil unit) and refrigerated cabinets in scale model, we could reduce 27% of CO_2 emission and 25% of running cost by selecting optimal size.
文摘The key word for the design process of the photovoltaic tracking systems is the energetic efficiency. Using the tracking system, the photovoltaic panel follows the sun and increases the collected energy, but the driving motors consume a part of this energy. In these terms, the optimization of the tracking systems became an important challenge in the modem research and technology. In this paper, a strategy for the dynamic optimization of the photovoltaic tracking systems is presented. The main task in optimization is to maximize the energetic gain by increasing the incoming solar radiation and minimizing the energy consumption for tracking. This strategy is possible by developing the virtual prototype of the tracking system, which is a control loop composed by the multi-body mechanical model connected with the dynamic model of the actuators and with the controller model. In this way, it is possible to optimize the tracking mechanism, choose the appropriate actuators, and design the optimal controller.
文摘This paper discusses the design of the propulsion system of the UAQ4 (University of L'Aquila, model 4) magnetic levitating train which is used for transportation applications in urban environments. UAQ4 is the only magnetic levitating vehicle with resistance motion, except for aerodynamic drag and with energy consumption near zero at low speed. The feasibility of the system has been successfully verified and tested in the laboratory. Propulsion and braking are provided by a novel direct-current linear stepper motor, with the primary formed by permanent magnets distributed on central beam of the track, and the secondary by coils on board the vehicle, instead of the present alternate current linear motors that have well-known disadvantages. The motor working principles are described, and its performances are analyzed, by a finite element numerical model which allows modifying the most important parameters of the system. The main components of a full scale motor for urban transportation are measured and discussed.
基金National Natural Science Foundation of China,No.41271146,No.41201171
文摘Optimizing industrial structure is an important research object of human-economic geography, and it is also the object of government departments to strengthen macro-control. This has become even greater problem that China has entered the "new normal" in recent years. The study uses a multi-regional input-output model, with linear programming to build an optimal model of industrial structure as well as a model of optimization degree under the energy constraint. The results of the study revealed that:(1) the degree of optimization of industrial structure in Anhui Province is optimal(0.763), while that of Shanxi Province is the lowest(0.662);(2) the degree of optimization of industrial structure is negatively related to energy consumption per unit output value and the proportion of heavy industry; and(3) overall, central China should maintain or moderately increase the proportions of resource-based industry, greatly increase the proportions of manufacturing, including transport and telecommunications equipment, computers and other electronic equipment, and moderately reduce the proportions of smelting and pressing of metals and non-metal mineral products. In terms of service industries, the region should greatly increase the proportions of the production and supply of natural gas and tap water, moderately reduce or maintain the proportions of transport and storage as well as tourism, and maintain or moderately reduce the proportions of wholesale trade, retail trade and catering services.