In this paper,we study a class of dynamic games consisting of finite agents under a stochastic growth model with jumps.The jump process in the dynamics of the capital stock of each agent models announcements regarding...In this paper,we study a class of dynamic games consisting of finite agents under a stochastic growth model with jumps.The jump process in the dynamics of the capital stock of each agent models announcements regarding each agent in the game occur at Poisson distributed random times.The aim of each agent is to maximize her objective functional with mean-field interactions by choosing an optimal consumption strategy.We prove the existence of a fixed point related to the so-called consistence condition as the number of agents goes large.Building upon the fixed point,we establish an optimal feedback consumption strategy for all agents which is in fact an approximating Nash equilibrium which describes strategies for each agent such that no agent has any incentive to change her strategy.展开更多
This paper studies a problem of optimal investment and consumption with early retirement option under constant elasticity variation(CEV)model with finite horizon.Two risky assets are involved in the model with one fol...This paper studies a problem of optimal investment and consumption with early retirement option under constant elasticity variation(CEV)model with finite horizon.Two risky assets are involved in the model with one following geometric Brownian motion and the other a CEV model.This problem is a kind of two dimensional mixed control and optimal stopping problems with finite horizon.The existence and continuity of the optimal retirement threshold surfaces are proved and the working and retirement regions are characterized theoretically.Least-squares Monte-Carlo methods are developed to solve this mixed control and optimal stopping problem.The algorithms are well implemented and the optimal retirement threshold surfaces,optimal investment strategies and the optimal consumptions are drawn via examples.展开更多
Current power systems face significant challenges in supporting large-scale access to new energy sources,and the potential of existing flexible resources needs to be fully explored from the power supply,grid,and custo...Current power systems face significant challenges in supporting large-scale access to new energy sources,and the potential of existing flexible resources needs to be fully explored from the power supply,grid,and customer perspectives.This paper proposes a multi-objective electricity consumption optimization strategy considering the correlation between equipment and electricity consumption.It constructs a multi-objective electricity consumption optimization model that considers the correlation between equipment and electricity consumption to maximize economy and comfort.The results show that the proposed method can accurately assess the potential for electricity consumption optimization and obtain an optimal multi-objective electricity consumption strategy based on customers’actual electricity consumption demand.展开更多
The array of baffles protection structure is a flow resistance structure with good drainage,blocking,and intercepting effects on the rock avalanches.In this research,the physical model test on rock avalanches was cond...The array of baffles protection structure is a flow resistance structure with good drainage,blocking,and intercepting effects on the rock avalanches.In this research,the physical model test on rock avalanches was conducted.Three parameters(column spacing,row spacing,and a number of baffles)were used as indicators to determine the optimal layout of the array of baffles for energy efficiency consumption blocking.Then,the lattice Boltzmann numerical simulation method was used to build a numerical simulation model of rock avalanches-array of the baffles-hazard-bearing body to obtain the rock’s velocity attenuation and flow trajectory avalanches in the impact baffle protection structure.Finally,the results of the physical model test and the numerical simulation were mutually confirmed.The following conclusions were drawn through two methods of physical model test and numerical simulation.(1)The optimal layout parameters of array of baffles were determined as three rows of array of baffles(The number of baffles in each row is 7,8,9),column spacing Sc=3.5,and row spacing Sr=4.5.(2)Under the conditions of high baffle density(such as Sc=1.5,2.5),the rock avalanches would produce a certain degree of circumfluence,which would increase the fluid velocity by at least 24.5% over the average velocity,so the column spacing density should be increased appropriately to achieve the optimal effect of reducing the energy of rock avalanches.(3)In the event of a prototype grooved rock avalanches with a velocity close to 24.5 m/s and a flow depth of about 1.5 m,the three-row array of baffles protection with the parameters Sc^(*)=1.18 m and Sr^(*)=1.51 m could be arranged,playing the role of optimizing the array of baffles to guide the flow and block the energy consumption.LBM experiments can be used to replace laboratory experiments to some extent.Further Lattice Boltzmann method-Discrete element method(LBM-DEM)studies are required before applications to practical engineering.展开更多
The contradiction between the increasing material demand and resource,is the country has faced problems,to better solve the material demand and the contradiction between the environment and resources,is applied to the...The contradiction between the increasing material demand and resource,is the country has faced problems,to better solve the material demand and the contradiction between the environment and resources,is applied to the development of new energy,new energy,not only can alleviate people and resources,environment and resources,the contradiction between people and the environment,also can promote the sustainable development of world economy,HVAC technology has emerged a new generation of energysaving technology,HVAC has the characteristics of low consumption,low pollution,is a development of technology,to be promoted for environmentfriendly,resource-conserving society has an important role in promoting.This paper focuses on the HVAC technology,water source heat pump system operation control and energy consumption optimization,for the relevant personnel reference.展开更多
Currently,energy conservation draws wide attention in industrial manufacturing systems.In recent years,many studies have aimed at saving energy consumption in the process of manufacturing and scheduling is regarded as...Currently,energy conservation draws wide attention in industrial manufacturing systems.In recent years,many studies have aimed at saving energy consumption in the process of manufacturing and scheduling is regarded as an effective approach.This paper puts forwards a multi-objective stochastic parallel machine scheduling problem with the consideration of deteriorating and learning effects.In it,the real processing time of jobs is calculated by using their processing speed and normal processing time.To describe this problem in a mathematical way,amultiobjective stochastic programming model aiming at realizing makespan and energy consumption minimization is formulated.Furthermore,we develop a multi-objective multi-verse optimization combined with a stochastic simulation method to deal with it.In this approach,the multi-verse optimization is adopted to find favorable solutions from the huge solution domain,while the stochastic simulation method is employed to assess them.By conducting comparison experiments on test problems,it can be verified that the developed approach has better performance in coping with the considered problem,compared to two classic multi-objective evolutionary algorithms.展开更多
We consider the problem of inducing withdrawal reflex on a test subject by exposing the subject’s skin to an electromagnetic beam. Heat-sensitive nociceptors in the skin are activated wherever the temperature is abov...We consider the problem of inducing withdrawal reflex on a test subject by exposing the subject’s skin to an electromagnetic beam. Heat-sensitive nociceptors in the skin are activated wherever the temperature is above the activation temperature. Withdrawal reflex occurs when the activated volume reaches a threshold. Previously we studied static beams with 3 types of power density distribution: Gaussian, super-Gaussian, and flat-top. We found that the flaptop is the best and the Gaussian is the worst in their performance with regard to 1) minimizing the time to withdrawal reflex, 2) minimizing the energy consumption and 3) minimizing the maximum temperature increase. The less-than-desirable performance of Gaussian beams is attributed to the uneven distribution of power density resulting in low energy efficiency: near the beam center the high power density does not contribute proportionally to increasing the activated volume;outside the beam effective radius the low power density fails to activate nociceptors. To overcome the drawbacks of Gaussian beams, in this study, we revolve a Gaussian beam around a fixed point to make the power density more uniformly distributed. We optimize the performance over two parameters: the spot size of static beam and the radius of beam revolution. We find that in comparison with a static Gaussian beam, a revolving Gaussian beam can reduce the energy consumption, and at the same time lower the maximum temperature.展开更多
In the real-world environments,different individuals have different risk preferences.This paper investigates the optimal portfolio and consumption rule with a Cox–Ingersoll–Ross(CIR)model in a more general utility f...In the real-world environments,different individuals have different risk preferences.This paper investigates the optimal portfolio and consumption rule with a Cox–Ingersoll–Ross(CIR)model in a more general utility framework.After consumption,an individual invests his wealth into the financial market with one risk-free asset and multiple risky assets,where the short-term rate is driven by the CIR model and stock price dynamics are simultaneously influenced by random sources from both stochastic interest rate and stock market itself.The individual hopes to optimize their portfolios and consumption rules to maximize expected utility of terminal wealth and intermediate consumption.Risk preference of individual is assumed to satisfy hyperbolic absolute risk aversion(HARA)utility,which contains power utility,logarithm utility,and exponential utility as special cases.By using the principle of stochastic optimality and Legendre transform-dual theory,the explicit expressions of the optimal portfolio and consumption rule are obtained.The sensitivity of the optimal strategies to main parameters is analysed by a numerical example.In addition,economic implications are also presented.Our research results show that Legendre transform-dual theory is an effective methodology in dealing with the portfolio selection problems with HARA utility and interest rate risk can be completely hedged by constructing specific portfolios.展开更多
Magnetorheological(MR) cell with multi-coil was designed to enlarge the range of controllable transmission torque by increasing the effective length. Individual input current was proposed to maximize its potential for...Magnetorheological(MR) cell with multi-coil was designed to enlarge the range of controllable transmission torque by increasing the effective length. Individual input current was proposed to maximize its potential for reducing power consumption and generating large yield stress. Finite element analysis was performed to analyze magnetic field distribution, based on which a prototype MR cell was fabricated and tested to investigate the performance of various combinations of individual input currents. A good correlation was identified between experimental results and FEA predications. The results show that the power consumption can be reduced to 42.4%, maintaining large transmission torque, by distributing the total current(2 A) to three individual magnetic coils. In addition, optimal results of four input currents considering a multi-objective function are obtained by changing the weighting factor λ. The advantage of this design, such as lower power consumption and more control flexibility, makes it more competitive in engineering applications that require large energy consumption.展开更多
Pre-sowing mechanical tillage in crop fields is a primary task and important aspect of crop production.The interaction between the tillage components and the soil plays a crucial role in determining the energy consump...Pre-sowing mechanical tillage in crop fields is a primary task and important aspect of crop production.The interaction between the tillage components and the soil plays a crucial role in determining the energy consumption of tillage machinery.Therefore,it is essential to investigate soil-tool interaction mechanisms and optimize tool design for energy savings in soil cutting.The study employed the Smoothed Particle Hydrodynamics(SPH)method to investigate the soil cutting process of a typical rotary blade.The article describes the principles and modeling process of the SPH method in detail.It includes the selection of constitutive models,boundary treatments,and particle conversion.A high-precision soil-tool interaction model was established to analyze the deformation zone of the soil,cutting energy,cutting resistance,and soil particle movement.Orthogonal simulation experiments and response surface methodology were used to optimize key design parameters of the rotary blade considering both the reduction in cutting power consumption and the impact on the structural performance of the tool.The optimal parameters were determined as follows:a bending point included angle of 30°,a side cutting edge bending line direction angle of 51°,and a bending angle of 120°.These parameters resulted in a minimum power consumption of 0.181 kW while meeting the required structural performance.Finally,experiments were conducted on field rotary tillage,and the measured power consumption showed a deviation of 7.1%from the simulated power consumption.The optimized power consumption was reduced by 9.52%compared to the initial power consumption,validating the accuracy of the simulation process and the effectiveness of energy savings.展开更多
The explosive increase of smart devices and mobile traffic results intolerable network latency and degraded service to the end-users. in heavy burden on backhaul and core network, As a complement to core network, edge...The explosive increase of smart devices and mobile traffic results intolerable network latency and degraded service to the end-users. in heavy burden on backhaul and core network, As a complement to core network, edge network contributes to relieving network burden and improving user experience. To investigate the problem of optimizing the total consumption in an edge-core network, the system consumption minimization problem is fromulated, considering the energy consumption and delay. Given that the formulated problem is a mixed nonlinear integer programming (MNIP) , a low-complexity workload allocation algorithm is proposed based on interior-point method. The proposed algorithm has an extremely short running time in practice. Finally, simulation results show that edge network can significantly complement core network with much reduced backhaul energy consumption and delay.展开更多
To reduce network access latency, network traffic volume and server load, caching capacity has been proposed as a component of evolved Node B(e Node B) in the ratio access network(RAN). These e Node B caches reduce tr...To reduce network access latency, network traffic volume and server load, caching capacity has been proposed as a component of evolved Node B(e Node B) in the ratio access network(RAN). These e Node B caches reduce transport energy consumption but lead to additional energy cost by equipping every e Node B with caching capacity. Existing researches focus on how to minimize total energy consumption, but often ignore the trade-off between energy efficiency and end user quality of experience, which may lead to undesired network performance degradation. In this paper, for the first time, we build an energy model to formulate the problem of minimizing total energy consumption at e Node B caches by taking a trade-off between energy efficiency and end user quality of experience. Through coordinating all the e Node B caches in the same RAN, the proposed model can take a good balance between caching energy and transport energy consumption while also guarantee end user quality of experience. The experimental results demonstrate the effectiveness of the proposed model. Compared with the existing works, our proposal significantly reduces the energy consumption by approximately 17% while keeps superior end user quality of experience performance.展开更多
In this paper,a novel cooling control strategy as part of the smart energy system that can balance thermal comfort against building energy consumption by using the sensing and machine programming technology was invest...In this paper,a novel cooling control strategy as part of the smart energy system that can balance thermal comfort against building energy consumption by using the sensing and machine programming technology was investigated.For this goal,a general form of a building was coupled by the smart cooling system(SCS)and the consumption of energy with thermal comfort cooling of persons simulated by using the EnergyPlus software and compared with similar buildings without SCS.At the beginning of the research,using the data from a survey in a randomly selected group of hundreds and by analyzing and verifying the results of the specific relationship between the different groups of people in the statistical society,the body mass index(BMI)and their thermal comfort temperature were obtained,and the sample building was modeled using the EnergyPlus software.The result show that if an intelligent ventilation system that can calculate the thermal comfort temperature was used in accordance with the BMI of persons,it can save up to 35%of the cooling load of the building yearly.展开更多
This paper investigates the problem of fuel-efficient and safe control of autonomous vehicle platoons. We present a two-part hierarchical control method that can guarantee platoon stability with minimal fuel consumpti...This paper investigates the problem of fuel-efficient and safe control of autonomous vehicle platoons. We present a two-part hierarchical control method that can guarantee platoon stability with minimal fuel consumption. The first part vehicle controller is derived in the context of receding horizon optimal control by constructing and solving an optimization problem of overall fuel consumption. The Second part platoon controller is a complementation of the first part, which is given on the basis of platoon stability analysis. The effectiveness of the presented platoon control method is demonstrated by both numerical simulations and experiments with laboratory-scale Arduino cars.展开更多
Energy conservation is a critical problem in recently-emerging wireless sensor networks (WSNs). Pulse position modulation (PPM), as an exploring-worthy modulation format for energy efficiency, is tailored for WSNs...Energy conservation is a critical problem in recently-emerging wireless sensor networks (WSNs). Pulse position modulation (PPM), as an exploring-worthy modulation format for energy efficiency, is tailored for WSNs into two schemes, mono-mode PPM and multi-mode PPM, in this paper. Resorting to an idealized system model and a practical system model, which combine the power consumptions in transmission and reception modules of nodes with the idealized and real- istic battery characteristics, the battery energy efficiencies of mono-mode PPM and multi-mode PPM are evaluated and compared. To minimize the battery energy consumption (BEC), these schemes are further optimized in terms of constellation size M for a link in path-loss channels. Our analytical and numerical results show that considerable energy can be saved by multi-mode PPM; and the optimization performances of these schemes are noticeable at various communication distances though their optimization properties are different.展开更多
Top gas recycling oxygen blast furnace(TGR-OBF)process is a promising ironmaking process.The biggest challenge of the TGR-OBF in operation is the dramatic decrease of top gas volume(per ton hot metal),which once l...Top gas recycling oxygen blast furnace(TGR-OBF)process is a promising ironmaking process.The biggest challenge of the TGR-OBF in operation is the dramatic decrease of top gas volume(per ton hot metal),which once led to hanging-up and shutdowns in practice of the Toulachermet.In order to avoid this weakness,the strategy of medium oxygen blast furnace was presented.The maneuverable zone of the TGR-OBF was determined by the top gas volume,which should not be far from the data of the traditional blast furnace.The deviation of ±12.5% was used,and then the maneuverable blast oxygen content is from 0.30 to 0.47 according to the calculation.The flame temperature and the top gas volume have no much difference compared to those of the traditional blast furnace.The minimum carbon consumption of 357 kg per ton hot metal in the maneuverable zone occurs at the oxygen content of 0.30(fuel saving of 14%).In the unsteady evolution,the N2 accumulation could approach nearly zero after the recycling reached 6 times.Thus far,some TGR-OBF industrial trials have been carried out in different countries,but the method of medium oxygen enriched TGR-OBF has not been implemented,because the accumulation of N2 was worried about.The presented strategy of medium oxygen enriched TGR-OBF is applicable and the strategy with good operational performance is strongly suggested as a forerunner of the full oxygen blast furnace.展开更多
This paper develops a dynamic general equilibrium model to investigate the optimal level of capital income taxation in light of stochastic endogenous economic growth. Although endogenous human capital is incorporated ...This paper develops a dynamic general equilibrium model to investigate the optimal level of capital income taxation in light of stochastic endogenous economic growth. Although endogenous human capital is incorporated into our model, we restrict our investigation to the issue of optimal physical capital income tax; and the labor supply is also endogenously determined. This paper proves that the optimal capital income tax should be zero provided exogenous government expenditure on production; however, capital income should be taxed if we consider endogenous government consumption.展开更多
基金Supported by Natural Science Foundation of China(Grant No.11971368)the Key Research Program of Frontier Sciences,CAS(Grant No.QYZDB-SSW-SYS009)。
文摘In this paper,we study a class of dynamic games consisting of finite agents under a stochastic growth model with jumps.The jump process in the dynamics of the capital stock of each agent models announcements regarding each agent in the game occur at Poisson distributed random times.The aim of each agent is to maximize her objective functional with mean-field interactions by choosing an optimal consumption strategy.We prove the existence of a fixed point related to the so-called consistence condition as the number of agents goes large.Building upon the fixed point,we establish an optimal feedback consumption strategy for all agents which is in fact an approximating Nash equilibrium which describes strategies for each agent such that no agent has any incentive to change her strategy.
基金supported by the National Natural Science Foundation of China(Grant No.12071373)by the Fundamental Research Funds for the Central Universities of China(Grant No.JBK1805001)+1 种基金The work of J.Xing was supported by the National Natural Science Foundation of China(Grant No.12101151)by the Guizhou Key Laboratory of Big Data Statistical Analysis(Grant No.[2019]5103).
文摘This paper studies a problem of optimal investment and consumption with early retirement option under constant elasticity variation(CEV)model with finite horizon.Two risky assets are involved in the model with one following geometric Brownian motion and the other a CEV model.This problem is a kind of two dimensional mixed control and optimal stopping problems with finite horizon.The existence and continuity of the optimal retirement threshold surfaces are proved and the working and retirement regions are characterized theoretically.Least-squares Monte-Carlo methods are developed to solve this mixed control and optimal stopping problem.The algorithms are well implemented and the optimal retirement threshold surfaces,optimal investment strategies and the optimal consumptions are drawn via examples.
文摘Current power systems face significant challenges in supporting large-scale access to new energy sources,and the potential of existing flexible resources needs to be fully explored from the power supply,grid,and customer perspectives.This paper proposes a multi-objective electricity consumption optimization strategy considering the correlation between equipment and electricity consumption.It constructs a multi-objective electricity consumption optimization model that considers the correlation between equipment and electricity consumption to maximize economy and comfort.The results show that the proposed method can accurately assess the potential for electricity consumption optimization and obtain an optimal multi-objective electricity consumption strategy based on customers’actual electricity consumption demand.
基金funded by the National Natural Science Foundation of China(Grant No.41877266,No.41521002)the Science Foundation for Distinguished Young Scholars of Sichuan Province(Grant No.2020JDJQ0044)+2 种基金Scientific ResearchFoundation of Graduate School of Southeast University(Grant No.YBJJ 1844)Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX17_0130)CAS Original Innovation Program(Grant No.ZDBS-LY-DQC039)。
文摘The array of baffles protection structure is a flow resistance structure with good drainage,blocking,and intercepting effects on the rock avalanches.In this research,the physical model test on rock avalanches was conducted.Three parameters(column spacing,row spacing,and a number of baffles)were used as indicators to determine the optimal layout of the array of baffles for energy efficiency consumption blocking.Then,the lattice Boltzmann numerical simulation method was used to build a numerical simulation model of rock avalanches-array of the baffles-hazard-bearing body to obtain the rock’s velocity attenuation and flow trajectory avalanches in the impact baffle protection structure.Finally,the results of the physical model test and the numerical simulation were mutually confirmed.The following conclusions were drawn through two methods of physical model test and numerical simulation.(1)The optimal layout parameters of array of baffles were determined as three rows of array of baffles(The number of baffles in each row is 7,8,9),column spacing Sc=3.5,and row spacing Sr=4.5.(2)Under the conditions of high baffle density(such as Sc=1.5,2.5),the rock avalanches would produce a certain degree of circumfluence,which would increase the fluid velocity by at least 24.5% over the average velocity,so the column spacing density should be increased appropriately to achieve the optimal effect of reducing the energy of rock avalanches.(3)In the event of a prototype grooved rock avalanches with a velocity close to 24.5 m/s and a flow depth of about 1.5 m,the three-row array of baffles protection with the parameters Sc^(*)=1.18 m and Sr^(*)=1.51 m could be arranged,playing the role of optimizing the array of baffles to guide the flow and block the energy consumption.LBM experiments can be used to replace laboratory experiments to some extent.Further Lattice Boltzmann method-Discrete element method(LBM-DEM)studies are required before applications to practical engineering.
文摘The contradiction between the increasing material demand and resource,is the country has faced problems,to better solve the material demand and the contradiction between the environment and resources,is applied to the development of new energy,new energy,not only can alleviate people and resources,environment and resources,the contradiction between people and the environment,also can promote the sustainable development of world economy,HVAC technology has emerged a new generation of energysaving technology,HVAC has the characteristics of low consumption,low pollution,is a development of technology,to be promoted for environmentfriendly,resource-conserving society has an important role in promoting.This paper focuses on the HVAC technology,water source heat pump system operation control and energy consumption optimization,for the relevant personnel reference.
文摘Currently,energy conservation draws wide attention in industrial manufacturing systems.In recent years,many studies have aimed at saving energy consumption in the process of manufacturing and scheduling is regarded as an effective approach.This paper puts forwards a multi-objective stochastic parallel machine scheduling problem with the consideration of deteriorating and learning effects.In it,the real processing time of jobs is calculated by using their processing speed and normal processing time.To describe this problem in a mathematical way,amultiobjective stochastic programming model aiming at realizing makespan and energy consumption minimization is formulated.Furthermore,we develop a multi-objective multi-verse optimization combined with a stochastic simulation method to deal with it.In this approach,the multi-verse optimization is adopted to find favorable solutions from the huge solution domain,while the stochastic simulation method is employed to assess them.By conducting comparison experiments on test problems,it can be verified that the developed approach has better performance in coping with the considered problem,compared to two classic multi-objective evolutionary algorithms.
文摘We consider the problem of inducing withdrawal reflex on a test subject by exposing the subject’s skin to an electromagnetic beam. Heat-sensitive nociceptors in the skin are activated wherever the temperature is above the activation temperature. Withdrawal reflex occurs when the activated volume reaches a threshold. Previously we studied static beams with 3 types of power density distribution: Gaussian, super-Gaussian, and flat-top. We found that the flaptop is the best and the Gaussian is the worst in their performance with regard to 1) minimizing the time to withdrawal reflex, 2) minimizing the energy consumption and 3) minimizing the maximum temperature increase. The less-than-desirable performance of Gaussian beams is attributed to the uneven distribution of power density resulting in low energy efficiency: near the beam center the high power density does not contribute proportionally to increasing the activated volume;outside the beam effective radius the low power density fails to activate nociceptors. To overcome the drawbacks of Gaussian beams, in this study, we revolve a Gaussian beam around a fixed point to make the power density more uniformly distributed. We optimize the performance over two parameters: the spot size of static beam and the radius of beam revolution. We find that in comparison with a static Gaussian beam, a revolving Gaussian beam can reduce the energy consumption, and at the same time lower the maximum temperature.
基金This research is supported by National Natural Science Foundation of China(No.71671122)China Postdoctoral Science Foundation Funded Project(Nos.2014M560185 and 2016T90203)+1 种基金Humanities and Social Science Research Fund of Ministry of Education of China(Nos.11YJC790006 and 16YJA790004)Tianjin Natural Science Foundation of China(No.15JCQNJC04000).
文摘In the real-world environments,different individuals have different risk preferences.This paper investigates the optimal portfolio and consumption rule with a Cox–Ingersoll–Ross(CIR)model in a more general utility framework.After consumption,an individual invests his wealth into the financial market with one risk-free asset and multiple risky assets,where the short-term rate is driven by the CIR model and stock price dynamics are simultaneously influenced by random sources from both stochastic interest rate and stock market itself.The individual hopes to optimize their portfolios and consumption rules to maximize expected utility of terminal wealth and intermediate consumption.Risk preference of individual is assumed to satisfy hyperbolic absolute risk aversion(HARA)utility,which contains power utility,logarithm utility,and exponential utility as special cases.By using the principle of stochastic optimality and Legendre transform-dual theory,the explicit expressions of the optimal portfolio and consumption rule are obtained.The sensitivity of the optimal strategies to main parameters is analysed by a numerical example.In addition,economic implications are also presented.Our research results show that Legendre transform-dual theory is an effective methodology in dealing with the portfolio selection problems with HARA utility and interest rate risk can be completely hedged by constructing specific portfolios.
基金Projects(51175265,51305207)supported by the National Natural Science Foundation of China
文摘Magnetorheological(MR) cell with multi-coil was designed to enlarge the range of controllable transmission torque by increasing the effective length. Individual input current was proposed to maximize its potential for reducing power consumption and generating large yield stress. Finite element analysis was performed to analyze magnetic field distribution, based on which a prototype MR cell was fabricated and tested to investigate the performance of various combinations of individual input currents. A good correlation was identified between experimental results and FEA predications. The results show that the power consumption can be reduced to 42.4%, maintaining large transmission torque, by distributing the total current(2 A) to three individual magnetic coils. In addition, optimal results of four input currents considering a multi-objective function are obtained by changing the weighting factor λ. The advantage of this design, such as lower power consumption and more control flexibility, makes it more competitive in engineering applications that require large energy consumption.
基金supported by the National Key R&D Program of China-Science and Technology Innovation 2030 New Generation Artificial Intelligence(Grant No.2022ZD0115804)the Major Science and Technology Projects in Xinjiang Uygur Autonomous Region(Grant No.2022A02012-4)the Construction Project of Demonstration Platform for National New Materials Production&Application(Grant No.TC200H01X-5).
文摘Pre-sowing mechanical tillage in crop fields is a primary task and important aspect of crop production.The interaction between the tillage components and the soil plays a crucial role in determining the energy consumption of tillage machinery.Therefore,it is essential to investigate soil-tool interaction mechanisms and optimize tool design for energy savings in soil cutting.The study employed the Smoothed Particle Hydrodynamics(SPH)method to investigate the soil cutting process of a typical rotary blade.The article describes the principles and modeling process of the SPH method in detail.It includes the selection of constitutive models,boundary treatments,and particle conversion.A high-precision soil-tool interaction model was established to analyze the deformation zone of the soil,cutting energy,cutting resistance,and soil particle movement.Orthogonal simulation experiments and response surface methodology were used to optimize key design parameters of the rotary blade considering both the reduction in cutting power consumption and the impact on the structural performance of the tool.The optimal parameters were determined as follows:a bending point included angle of 30°,a side cutting edge bending line direction angle of 51°,and a bending angle of 120°.These parameters resulted in a minimum power consumption of 0.181 kW while meeting the required structural performance.Finally,experiments were conducted on field rotary tillage,and the measured power consumption showed a deviation of 7.1%from the simulated power consumption.The optimized power consumption was reduced by 9.52%compared to the initial power consumption,validating the accuracy of the simulation process and the effectiveness of energy savings.
基金supported by the National Science and Technology Major Project (2018ZX03001016)the China Ministry of Education-CMCC Research (MCM20160104 )the Beijing Municipal Science and Technology Commission Research (Z171100005217001)
文摘The explosive increase of smart devices and mobile traffic results intolerable network latency and degraded service to the end-users. in heavy burden on backhaul and core network, As a complement to core network, edge network contributes to relieving network burden and improving user experience. To investigate the problem of optimizing the total consumption in an edge-core network, the system consumption minimization problem is fromulated, considering the energy consumption and delay. Given that the formulated problem is a mixed nonlinear integer programming (MNIP) , a low-complexity workload allocation algorithm is proposed based on interior-point method. The proposed algorithm has an extremely short running time in practice. Finally, simulation results show that edge network can significantly complement core network with much reduced backhaul energy consumption and delay.
基金the National Natural Science Foundation of China(No.61502038)the Fundamental Research Funds for the Central Universities of China(No.023600-500110002)
文摘To reduce network access latency, network traffic volume and server load, caching capacity has been proposed as a component of evolved Node B(e Node B) in the ratio access network(RAN). These e Node B caches reduce transport energy consumption but lead to additional energy cost by equipping every e Node B with caching capacity. Existing researches focus on how to minimize total energy consumption, but often ignore the trade-off between energy efficiency and end user quality of experience, which may lead to undesired network performance degradation. In this paper, for the first time, we build an energy model to formulate the problem of minimizing total energy consumption at e Node B caches by taking a trade-off between energy efficiency and end user quality of experience. Through coordinating all the e Node B caches in the same RAN, the proposed model can take a good balance between caching energy and transport energy consumption while also guarantee end user quality of experience. The experimental results demonstrate the effectiveness of the proposed model. Compared with the existing works, our proposal significantly reduces the energy consumption by approximately 17% while keeps superior end user quality of experience performance.
文摘In this paper,a novel cooling control strategy as part of the smart energy system that can balance thermal comfort against building energy consumption by using the sensing and machine programming technology was investigated.For this goal,a general form of a building was coupled by the smart cooling system(SCS)and the consumption of energy with thermal comfort cooling of persons simulated by using the EnergyPlus software and compared with similar buildings without SCS.At the beginning of the research,using the data from a survey in a randomly selected group of hundreds and by analyzing and verifying the results of the specific relationship between the different groups of people in the statistical society,the body mass index(BMI)and their thermal comfort temperature were obtained,and the sample building was modeled using the EnergyPlus software.The result show that if an intelligent ventilation system that can calculate the thermal comfort temperature was used in accordance with the BMI of persons,it can save up to 35%of the cooling load of the building yearly.
基金supported by the National Natural Science Foundation of China(Grant Nos.61273107 and 61573077)Dalian Leading Talent(Grant No.841252)
文摘This paper investigates the problem of fuel-efficient and safe control of autonomous vehicle platoons. We present a two-part hierarchical control method that can guarantee platoon stability with minimal fuel consumption. The first part vehicle controller is derived in the context of receding horizon optimal control by constructing and solving an optimization problem of overall fuel consumption. The Second part platoon controller is a complementation of the first part, which is given on the basis of platoon stability analysis. The effectiveness of the presented platoon control method is demonstrated by both numerical simulations and experiments with laboratory-scale Arduino cars.
基金the National Natural Science Foundation of China (Grant Nos. 60642007 and 10374051)the Scientific Fundation of Guangxi Education Department of China (Grant No. [2002]316)
文摘Energy conservation is a critical problem in recently-emerging wireless sensor networks (WSNs). Pulse position modulation (PPM), as an exploring-worthy modulation format for energy efficiency, is tailored for WSNs into two schemes, mono-mode PPM and multi-mode PPM, in this paper. Resorting to an idealized system model and a practical system model, which combine the power consumptions in transmission and reception modules of nodes with the idealized and real- istic battery characteristics, the battery energy efficiencies of mono-mode PPM and multi-mode PPM are evaluated and compared. To minimize the battery energy consumption (BEC), these schemes are further optimized in terms of constellation size M for a link in path-loss channels. Our analytical and numerical results show that considerable energy can be saved by multi-mode PPM; and the optimization performances of these schemes are noticeable at various communication distances though their optimization properties are different.
基金supported by the National Key Technologies R&D Program of China(Grant No.2011BAE04B02)Key Technologies R&D Program of Beijing(Grant No.Z161100000716002)
文摘Top gas recycling oxygen blast furnace(TGR-OBF)process is a promising ironmaking process.The biggest challenge of the TGR-OBF in operation is the dramatic decrease of top gas volume(per ton hot metal),which once led to hanging-up and shutdowns in practice of the Toulachermet.In order to avoid this weakness,the strategy of medium oxygen blast furnace was presented.The maneuverable zone of the TGR-OBF was determined by the top gas volume,which should not be far from the data of the traditional blast furnace.The deviation of ±12.5% was used,and then the maneuverable blast oxygen content is from 0.30 to 0.47 according to the calculation.The flame temperature and the top gas volume have no much difference compared to those of the traditional blast furnace.The minimum carbon consumption of 357 kg per ton hot metal in the maneuverable zone occurs at the oxygen content of 0.30(fuel saving of 14%).In the unsteady evolution,the N2 accumulation could approach nearly zero after the recycling reached 6 times.Thus far,some TGR-OBF industrial trials have been carried out in different countries,but the method of medium oxygen enriched TGR-OBF has not been implemented,because the accumulation of N2 was worried about.The presented strategy of medium oxygen enriched TGR-OBF is applicable and the strategy with good operational performance is strongly suggested as a forerunner of the full oxygen blast furnace.
文摘This paper develops a dynamic general equilibrium model to investigate the optimal level of capital income taxation in light of stochastic endogenous economic growth. Although endogenous human capital is incorporated into our model, we restrict our investigation to the issue of optimal physical capital income tax; and the labor supply is also endogenously determined. This paper proves that the optimal capital income tax should be zero provided exogenous government expenditure on production; however, capital income should be taxed if we consider endogenous government consumption.