Gas hydrates now are expected to be one of the most important future unconventional energy resources. In this paper, researches on gas hydrate exploitation in laboratory and field were reviewed and discussed from the ...Gas hydrates now are expected to be one of the most important future unconventional energy resources. In this paper, researches on gas hydrate exploitation in laboratory and field were reviewed and discussed from the aspects of energy efficiency. Different exploiting methods and different types of hydrate reservoir were selected to study their effects on energy efficiencies. Both laboratory studies and field tests have shown that the improved technologies can help to increase efficiency for gas hydrate exploitation. And it also showed the trend that gas hydrate exploitation started to change from permafrost to marine. Energy efficiency ratio （EER） and energy return on energy invested （EROI） were introduced as an indicator of efficiency for natural gas hydrate exploitation. An energy-efficient hydrate production process, called ＂Hydrate Chain Energy System （HCES）＂, including treatment of flue gas, replacement of CH4 with CO2, separation of CO2 from CH4, and storage and transportation of CH4 in hydrate form, was proposed for future natural gas hydrate exploitation. In the meanwhile, some problems, such as mechanism of C02 replacement, mechanism of CO2 separation, CH4 storage and transportation are also needed to be solved for increasing the energy efficiency of gas hydrate exploitation.展开更多
The broad-leaved Korean pine(Pinus koraiensis) forest is one of the most biodiverse zonal communities in the North Temperate Zone and an important habitat for many endangered species.Broad-leaved Korean pine forests(B...The broad-leaved Korean pine(Pinus koraiensis) forest is one of the most biodiverse zonal communities in the North Temperate Zone and an important habitat for many endangered species.Broad-leaved Korean pine forests(BKPFs) are shrinking quickly due to deforestation and rapid urbanization. Thus, scientific protection strategies are urgently needed to change this status. Changbai Mountains contains one of the largest BKPFs and is considered a priority biodiversity conservation area in China. Guided by systematic conservation planning(SCP) methods and procedures, we chose representative species and communities in BKPFs ecosystem as priority conservation objects, and set quantitative conservation target, which is in the light of the biodiversity characteristic of BKPFs. The watershed area is used as planning unit. We used CPlan software to calculate the irreplaceability(Ir)value of each planning unit and the contribution value(Ti) of each conservation object to(1) assess the conservation efficiency;(2) identify the conservation gap of the existing conservation network. Then wecalculated a human disturbance index(HDI) for planning units in the conservation gaps and combine this with the Ir value to design three conservation scenarios to optimize the conservation network.Results show that planning units with high conservation value 14.16% of the total area, with3084.36 km2 were covered by the existing conservation network. 79.28% of planning units with high conservation value have not been protected which were concentrated mainly in the eight gap areas.Only 25.3% of protection objects achieved their conservation target with the existing conservation network. Conservation efficiency is low. Three conservation scenarios are constituted, each prioritizing a different aim:(1) ecological value;(2)species rescue; and(3) economical avoidance. The three conservation schemes potentially enable 93%,88% and 51% of conservation objects, respectively, to achieve identified conservation targets, thereby improving conservation efficiency significantly.展开更多
Understanding of how combinations of agronomic options can be used to improve the grain yield and nitrogen use efficiency（NUE） of winter wheat is limited. A three-year experiment involving four integrated management...Understanding of how combinations of agronomic options can be used to improve the grain yield and nitrogen use efficiency（NUE） of winter wheat is limited. A three-year experiment involving four integrated management strategies was conducted from 2013 to 2015 in Tai＇an, Shandong Province, China, to evaluate changes in grain yield and NUE. The integrated management treatments were as follows： current practice（T1）; improvement of current practice（T2）; high-yield management（T3）, which aimed to maximize grain yield regardless of the cost of resource inputs; and integrated soil and crop system management（T4） with a higher seeding rate, delayed sowing date, and optimized nutrient management. Seeding rates increased by 75 seeds m^-2 with each treatment from T1（225 seeds m^-2） to T4（450 seeds m^-2）. The sowing dates were delayed from T1（5 th Oct.） to T2 and T3（8 th Oct.）, and to T4 treatment（12 th Oct.）. T1, T2, T3, and T4 received 315, 210, 315, and 240 kg N ha^-1, 120, 90, 210 and 120 kg P2O5 ha^-1, 30, 75, 90, and 45 kg K2O ha^-1, respectively. The ratio of basal application to topdressing for T1, T2, T3, and T4 was 6：4, 5：5, 4：6, and 4：6, respectively, with the N topdressing applied at regreening for T1 and at jointing stage for T2, T3, and T4. The P fertilizers in all treatments were applied as basal fertilizer. The K fertilizer for T1 and T2 was applied as basal fertilizer while the ratio of basal application to topdressing（at jointing stage） of K fertilizer for both T3 and T4 was 6：4. T1, T2, T3, and T4 were irrigated five, four, four and three times, respectively. Treatment T3 produced the highest grain yield among all treatments over three years and the average yield was 9 277.96 kg ha^-1. Grain yield averaged across three years with the T4 treatment（8 892.93 kg ha^-1） was 95.85% of that with T3 and was 21.72 and 6.10% higher than that with T1（7 305.95 kg ha^-1） and T2（8 381.41 kg ha^-1）, respectively. Treatment T2 produced the highest NUE of all the integrated treatments. The NUE with T4 was 95.36% of that with T2 and was 51.91 and 25.62% higher than that with T1 and T3, respectively. The N uptake efficiency（UPE） averaged across three years with T4 was 50.75 and 16.62% higher than that with T1and T3, respectively. The N utilization efficiency（UTE） averaged across three years with T4 was 7.74% higher than that with T3. The increased UPE with T4 compared with T3 could be attributed mostly to the lower available N in T4, while the increased UTE with T4 was mainly due to the highest N harvest index and low grain N concentration, which consequently led to improved NUE. The net profit for T4 was the highest among four treatments and was 174.94, 22.27, and 28.10% higher than that for T1, T2, and T3, respectively. Therefore, the T4 treatment should be a recommendable management strategy to obtain high grain yield, high NUE, and high economic benefits in the target region, although further improvements of NUE are required.展开更多
A novel method to calculate fuel-electric conversion factor for full hybrid electric vehicle（HEV）equipped with continuously variable transmission（CVT）is proposed.Based on consideration of the efficiency of pivotal...A novel method to calculate fuel-electric conversion factor for full hybrid electric vehicle（HEV）equipped with continuously variable transmission（CVT）is proposed.Based on consideration of the efficiency of pivotal components,electric motor,system efficiency optimization models are developed.According to the target of instantaneous optimization of system efficiency,operating ranges of each mode of power-train are determined,and the corresponding energy management strategies are established.The simulation results demonstrate that the energy management strategy proposed can substantially improve the vehicle fuel economy,and keep battery state of charge（SOC）change in a reasonable variation range.展开更多
In this paper, we consider an insurance company which has the option of investing in a risky asset and a risk-free asset, whose price parameters are driven by a finite state Markov chain. The risk process of the insur...In this paper, we consider an insurance company which has the option of investing in a risky asset and a risk-free asset, whose price parameters are driven by a finite state Markov chain. The risk process of the insurance company is modeled as a diffusion process whose diffusion and drift parameters switch over time according to the same Markov chain. We study the Markov-modulated mean-variance problem for the insurer and derive explicitly the closed form of the efficient strategy and efficient frontier. In the case of no regime switching, we can see that the efficient frontier in our paper coincides with that of [10] when there is no pure jump.展开更多
Continuous-time Markowitz＇s by parameterizing a critical quantity. It mean-variance efficient strategies are modified is shown that these parameterized Markowitz strategies could reach the original mean target with a...Continuous-time Markowitz＇s by parameterizing a critical quantity. It mean-variance efficient strategies are modified is shown that these parameterized Markowitz strategies could reach the original mean target with arbitrarily high probabilities. This, in turn, motivates the introduction of certain stopped strategies where stock holdings are liquidated whenever the parameterized Markowitz strategies reach the present value of the mean target. The risk aspect of the revised Markowitz strategies are examined via expected discounted loss from the initial budget. A new portfolio selection model is suggested based on the results of the paper.展开更多
One of the most important aspects of current economical and social reality of each local and regional territory, and very much determinative for its economic development potential, is the nature of its territorial org...One of the most important aspects of current economical and social reality of each local and regional territory, and very much determinative for its economic development potential, is the nature of its territorial organization of the productive processes, as well as, the characteristics, and sophistication level, of the enterprise strategies that are functioning in it. This paper seeks to contribute to the ongoing discussion on the role of clusters as engines of economic and social development and sustainability of local and regional territories. Based on a study research methodology, we intend to answer to the following research questions： （1） What is the importance of clusters in the increment process of the local and regional conditions of governance and sustainability？ （2） How specific models of clusters＇ governance can contribute to greater territorial setting of enterprises and to increasing the sustainability of its development strategies？ （3） To what extent industrial public policies can increase the sustainability of development solutions for local and regional economies？展开更多
Ever since 2005, the US' shale oil and gas production growth and effective adjustment of domestic energy consumption mix have made it possible for the country to be less dependent upon imported energy and gain ene...Ever since 2005, the US' shale oil and gas production growth and effective adjustment of domestic energy consumption mix have made it possible for the country to be less dependent upon imported energy and gain energy independence. What should we learn from it to guarantee energy supply security? This paper tried to answer the question.展开更多
This study focuses on the development and analysis of a real-time updated operations strategy of a distributed energy system(DES).Owing to the relevant Chinese policy of electrical transmission and distribution,combin...This study focuses on the development and analysis of a real-time updated operations strategy of a distributed energy system(DES).Owing to the relevant Chinese policy of electrical transmission and distribution,combined cooling,heating,and power system(CCHP)and photovoltaic(PV)systems are not currently allowed.However,with the Chinese supply-side power grid reform,the permissions for connections between DESs and utilities are gradually evolving.By performing building simulation and using mixed integer linear programming(MILP),a real-time updated operation strategy of a DES is established.Then,considering the DES from Tianjin Eco-city as a case study,a comparative analysis between this updated strategy and the current operation strategy is performed by evaluating three factors:economic efficiency,energy consumption,and CO2 emission.The results show that the updated strategy can reduce 29.12%of electricity time-of-use cost,10.11%of total fuel consumption,and 18.40%of CO2 emission during the cooling season.Besides,a method of“rolling load forecasting”for DES by using Support vector regression machine(SVR)is proposed and discussed.The testing shows that the Mean Absolute Percentage Error(MAPE)is below 7.5%.And when the training sample is large,the particle swarm optimization algorithm can be used to shorten the modeling time of the air conditioning load forecasting model.展开更多
INTRODUCTION In recent years,the development of large-scale foundationmodels(LFMs)has made great advances.However,the high training costs and computational demands have long been a bottleneck for the widespread adopti...INTRODUCTION In recent years,the development of large-scale foundationmodels(LFMs)has made great advances.However,the high training costs and computational demands have long been a bottleneck for the widespread adoption of this technology.With technological advancements,this situation is undergoing a fundamental transformation.The recent release of DeepSeek-V31 has sparked extensive discussions.Through innovative architectural design and efficient training strategies,it has significantly reduced training costswhile achieving performance comparable to top-tier closed-source models.The pre-training cost of DeepSeek-V3is only$5.576 million,far lower than the hundreds ofmillions of dollars required formodels like GPT-4.As shwon in Figure 1,this breakthrough not onlymarks the democratization of LFM technology but also opens up opportunities for more small-and medium-sized enterprises and research institutions to participate in AI innovation.In the future,LFMs will no longer be a game for the few.展开更多
This paper studies a dynamic mean-variance portfolio selection problem with random liability in the affine interest rate environment, where the financial market consists of three assets: one risk-free asset, one risky...This paper studies a dynamic mean-variance portfolio selection problem with random liability in the affine interest rate environment, where the financial market consists of three assets: one risk-free asset, one risky asset and one zero-coupon bond. Assume that short rate is driven by affine interest rate model and liability process is described by the drifted Brownian motion, in addition, stock price dynamics is affected by interest rate dynamics. The investors expect to look for an optimal strategy to minimize the variance of the terminal surplus for a given expected terminal surplus. The efficient strategy and the efficient frontier are explicitly obtained by applying dynamic programming principle and Lagrange duality theorem. A numerical example is given to illustrate our results and some economic implications are analyzed.展开更多
The Green Revolution of the 1960s boosted crop yields in part through widespread production of semidwarf plant cultivars and extensive use of mineral fertilizers.The beneficial semidwarfism of cereal Green Revolution ...The Green Revolution of the 1960s boosted crop yields in part through widespread production of semidwarf plant cultivars and extensive use of mineral fertilizers.The beneficial semidwarfism of cereal Green Revolution cultivars is due to the accumulation of plant growth-repressing DELLA proteins,which increases lodging resistance but requires a high-nitrogen fertilizer to obtain high yield.Given that environmentally degrading fertilizer use underpins current worldwide crop production,future agricultural sustainability needs a sustainable Green Revolution through reducing N fertilizer use while boosting grain yield above what is currently achievable.Despite a great deal of research efforts,only a few genes have been demonstrated to improve N-use efficiency in crops.The molecular mechanisms underlying the coordination between plant growth and N metabolism is still not fully understood,thus preventing significant improvement.Recent advances of how plants sense,capture and respond to varying N supply in model plants have shed light on how to improve sustainable productivity in agriculture.This review focuses on the current understanding of root developmental and metabolic adaptations to N availability,and discuss the potential approaches to improve N-use efficiency in high-yielding cereal crops.展开更多
This paper deals with the solution concepts,scalarization and existence of solutions formultiobjective generalized game. The scalarization method used in this paper can characterizecompletely the solutions and be appl...This paper deals with the solution concepts,scalarization and existence of solutions formultiobjective generalized game. The scalarization method used in this paper can characterizecompletely the solutions and be applied to prove the existence of solutions for quasi-convexmultiobjective generalized game. On the other hand,a new concept of security strategy isintroduced and its existence is proved.At last,some relations between these solutions areestablished.展开更多
Tall buildings are being designed and built across a wide range of cities.A poorly designed tall building can tremendously increase the building’s appetite for energy.Therefore,this paper aims to determine the design...Tall buildings are being designed and built across a wide range of cities.A poorly designed tall building can tremendously increase the building’s appetite for energy.Therefore,this paper aims to determine the design strategies that help a high-rise office building to be more energy efficient.For this purpose,a comparative study on twelve case buildings in three climate groups(temperate,sub-tropical&tropical)was performed.The exterior envelope,building form and orientation,service core placement,plan layout,and special design elements like atria and sky gardens were the subject of investigation.effectiveness of different design strategies for reducing the cooling,heating,ventilation and electric lighting energy usage.Finally,lessons from these buildings’were defined for the three climates.Furthermore,a compari-son of building energy performance data with international benchmarks confirmed that in temperate and sub-tropical climates sustainable design strategies for high-rise buildings were performing well,as a result leading to lower energy consump-tion.However,for the tropics the design of high-rise buildings needs additional consideration.展开更多
基金supported by the National Natural Science Foundation of China (51176051 and 51106054)the Fundamental Research Funds for the Central University (2015ZM057, 2013ZZ0032 and 2014ZP0007)+1 种基金China Postdoctoral Science Foundation (2015M572321)the Petro China Innovation Foundation (2013D-5006-0107)
文摘Gas hydrates now are expected to be one of the most important future unconventional energy resources. In this paper, researches on gas hydrate exploitation in laboratory and field were reviewed and discussed from the aspects of energy efficiency. Different exploiting methods and different types of hydrate reservoir were selected to study their effects on energy efficiencies. Both laboratory studies and field tests have shown that the improved technologies can help to increase efficiency for gas hydrate exploitation. And it also showed the trend that gas hydrate exploitation started to change from permafrost to marine. Energy efficiency ratio （EER） and energy return on energy invested （EROI） were introduced as an indicator of efficiency for natural gas hydrate exploitation. An energy-efficient hydrate production process, called ＂Hydrate Chain Energy System （HCES）＂, including treatment of flue gas, replacement of CH4 with CO2, separation of CO2 from CH4, and storage and transportation of CH4 in hydrate form, was proposed for future natural gas hydrate exploitation. In the meanwhile, some problems, such as mechanism of C02 replacement, mechanism of CO2 separation, CH4 storage and transportation are also needed to be solved for increasing the energy efficiency of gas hydrate exploitation.
基金supported by the 12th fiveyear National Science and Technology plan of China (2012BAC01B03)
文摘The broad-leaved Korean pine(Pinus koraiensis) forest is one of the most biodiverse zonal communities in the North Temperate Zone and an important habitat for many endangered species.Broad-leaved Korean pine forests(BKPFs) are shrinking quickly due to deforestation and rapid urbanization. Thus, scientific protection strategies are urgently needed to change this status. Changbai Mountains contains one of the largest BKPFs and is considered a priority biodiversity conservation area in China. Guided by systematic conservation planning(SCP) methods and procedures, we chose representative species and communities in BKPFs ecosystem as priority conservation objects, and set quantitative conservation target, which is in the light of the biodiversity characteristic of BKPFs. The watershed area is used as planning unit. We used CPlan software to calculate the irreplaceability(Ir)value of each planning unit and the contribution value(Ti) of each conservation object to(1) assess the conservation efficiency;(2) identify the conservation gap of the existing conservation network. Then wecalculated a human disturbance index(HDI) for planning units in the conservation gaps and combine this with the Ir value to design three conservation scenarios to optimize the conservation network.Results show that planning units with high conservation value 14.16% of the total area, with3084.36 km2 were covered by the existing conservation network. 79.28% of planning units with high conservation value have not been protected which were concentrated mainly in the eight gap areas.Only 25.3% of protection objects achieved their conservation target with the existing conservation network. Conservation efficiency is low. Three conservation scenarios are constituted, each prioritizing a different aim:(1) ecological value;(2)species rescue; and(3) economical avoidance. The three conservation schemes potentially enable 93%,88% and 51% of conservation objects, respectively, to achieve identified conservation targets, thereby improving conservation efficiency significantly.
基金supported by the National Basic Research Program of China (2015CB150404)the Special Fund for Agro-scientific Research in the Public Interest, China (201203096)the Project of Shandong Province Higher Educational Science and Technology Program, China (J15LF07)
文摘Understanding of how combinations of agronomic options can be used to improve the grain yield and nitrogen use efficiency（NUE） of winter wheat is limited. A three-year experiment involving four integrated management strategies was conducted from 2013 to 2015 in Tai＇an, Shandong Province, China, to evaluate changes in grain yield and NUE. The integrated management treatments were as follows： current practice（T1）; improvement of current practice（T2）; high-yield management（T3）, which aimed to maximize grain yield regardless of the cost of resource inputs; and integrated soil and crop system management（T4） with a higher seeding rate, delayed sowing date, and optimized nutrient management. Seeding rates increased by 75 seeds m^-2 with each treatment from T1（225 seeds m^-2） to T4（450 seeds m^-2）. The sowing dates were delayed from T1（5 th Oct.） to T2 and T3（8 th Oct.）, and to T4 treatment（12 th Oct.）. T1, T2, T3, and T4 received 315, 210, 315, and 240 kg N ha^-1, 120, 90, 210 and 120 kg P2O5 ha^-1, 30, 75, 90, and 45 kg K2O ha^-1, respectively. The ratio of basal application to topdressing for T1, T2, T3, and T4 was 6：4, 5：5, 4：6, and 4：6, respectively, with the N topdressing applied at regreening for T1 and at jointing stage for T2, T3, and T4. The P fertilizers in all treatments were applied as basal fertilizer. The K fertilizer for T1 and T2 was applied as basal fertilizer while the ratio of basal application to topdressing（at jointing stage） of K fertilizer for both T3 and T4 was 6：4. T1, T2, T3, and T4 were irrigated five, four, four and three times, respectively. Treatment T3 produced the highest grain yield among all treatments over three years and the average yield was 9 277.96 kg ha^-1. Grain yield averaged across three years with the T4 treatment（8 892.93 kg ha^-1） was 95.85% of that with T3 and was 21.72 and 6.10% higher than that with T1（7 305.95 kg ha^-1） and T2（8 381.41 kg ha^-1）, respectively. Treatment T2 produced the highest NUE of all the integrated treatments. The NUE with T4 was 95.36% of that with T2 and was 51.91 and 25.62% higher than that with T1 and T3, respectively. The N uptake efficiency（UPE） averaged across three years with T4 was 50.75 and 16.62% higher than that with T1and T3, respectively. The N utilization efficiency（UTE） averaged across three years with T4 was 7.74% higher than that with T3. The increased UPE with T4 compared with T3 could be attributed mostly to the lower available N in T4, while the increased UTE with T4 was mainly due to the highest N harvest index and low grain N concentration, which consequently led to improved NUE. The net profit for T4 was the highest among four treatments and was 174.94, 22.27, and 28.10% higher than that for T1, T2, and T3, respectively. Therefore, the T4 treatment should be a recommendable management strategy to obtain high grain yield, high NUE, and high economic benefits in the target region, although further improvements of NUE are required.
基金Supported by the National Science and Technology Support Program(2013BAG12B01)Foundational and Advanced Research Program General Project of Chongqing City(cstc2013jcyjjq60002)
文摘A novel method to calculate fuel-electric conversion factor for full hybrid electric vehicle（HEV）equipped with continuously variable transmission（CVT）is proposed.Based on consideration of the efficiency of pivotal components,electric motor,system efficiency optimization models are developed.According to the target of instantaneous optimization of system efficiency,operating ranges of each mode of power-train are determined,and the corresponding energy management strategies are established.The simulation results demonstrate that the energy management strategy proposed can substantially improve the vehicle fuel economy,and keep battery state of charge（SOC）change in a reasonable variation range.
基金supported by National Basic Research Program of China(973 Program)(2007CB814905)the National Natural Science Foundation of China(10871102)the Research Fund for the Doctorial Program of Higher Education
文摘In this paper, we consider an insurance company which has the option of investing in a risky asset and a risk-free asset, whose price parameters are driven by a finite state Markov chain. The risk process of the insurance company is modeled as a diffusion process whose diffusion and drift parameters switch over time according to the same Markov chain. We study the Markov-modulated mean-variance problem for the insurer and derive explicitly the closed form of the efficient strategy and efficient frontier. In the case of no regime switching, we can see that the efficient frontier in our paper coincides with that of [10] when there is no pure jump.
基金supported by the National Natural Science Foundation of China (10571167)the National Basic Research Program of China (973 Program, 2007CB814902)+2 种基金the Science Fund for Creative Research Groups (10721101)supported by the Nomura Centrefor Mathematical Finance and the Oxford–Man Institute of Quantitative Financea start-up fund of the University of Oxford
文摘Continuous-time Markowitz＇s by parameterizing a critical quantity. It mean-variance efficient strategies are modified is shown that these parameterized Markowitz strategies could reach the original mean target with arbitrarily high probabilities. This, in turn, motivates the introduction of certain stopped strategies where stock holdings are liquidated whenever the parameterized Markowitz strategies reach the present value of the mean target. The risk aspect of the revised Markowitz strategies are examined via expected discounted loss from the initial budget. A new portfolio selection model is suggested based on the results of the paper.
文摘One of the most important aspects of current economical and social reality of each local and regional territory, and very much determinative for its economic development potential, is the nature of its territorial organization of the productive processes, as well as, the characteristics, and sophistication level, of the enterprise strategies that are functioning in it. This paper seeks to contribute to the ongoing discussion on the role of clusters as engines of economic and social development and sustainability of local and regional territories. Based on a study research methodology, we intend to answer to the following research questions： （1） What is the importance of clusters in the increment process of the local and regional conditions of governance and sustainability？ （2） How specific models of clusters＇ governance can contribute to greater territorial setting of enterprises and to increasing the sustainability of its development strategies？ （3） To what extent industrial public policies can increase the sustainability of development solutions for local and regional economies？
文摘Ever since 2005, the US' shale oil and gas production growth and effective adjustment of domestic energy consumption mix have made it possible for the country to be less dependent upon imported energy and gain energy independence. What should we learn from it to guarantee energy supply security? This paper tried to answer the question.
基金This study was supported by Scientific Research Project of Science and technology Commission of Shanghai Municipality(Grant No.18DZ1202700).
文摘This study focuses on the development and analysis of a real-time updated operations strategy of a distributed energy system(DES).Owing to the relevant Chinese policy of electrical transmission and distribution,combined cooling,heating,and power system(CCHP)and photovoltaic(PV)systems are not currently allowed.However,with the Chinese supply-side power grid reform,the permissions for connections between DESs and utilities are gradually evolving.By performing building simulation and using mixed integer linear programming(MILP),a real-time updated operation strategy of a DES is established.Then,considering the DES from Tianjin Eco-city as a case study,a comparative analysis between this updated strategy and the current operation strategy is performed by evaluating three factors:economic efficiency,energy consumption,and CO2 emission.The results show that the updated strategy can reduce 29.12%of electricity time-of-use cost,10.11%of total fuel consumption,and 18.40%of CO2 emission during the cooling season.Besides,a method of“rolling load forecasting”for DES by using Support vector regression machine(SVR)is proposed and discussed.The testing shows that the Mean Absolute Percentage Error(MAPE)is below 7.5%.And when the training sample is large,the particle swarm optimization algorithm can be used to shorten the modeling time of the air conditioning load forecasting model.
基金supported by the National Natural Science Foundation of China under grant nos.62206266 and 62372430the Youth Innovation Promotion Association CAS no.2023112.
文摘INTRODUCTION In recent years,the development of large-scale foundationmodels(LFMs)has made great advances.However,the high training costs and computational demands have long been a bottleneck for the widespread adoption of this technology.With technological advancements,this situation is undergoing a fundamental transformation.The recent release of DeepSeek-V31 has sparked extensive discussions.Through innovative architectural design and efficient training strategies,it has significantly reduced training costswhile achieving performance comparable to top-tier closed-source models.The pre-training cost of DeepSeek-V3is only$5.576 million,far lower than the hundreds ofmillions of dollars required formodels like GPT-4.As shwon in Figure 1,this breakthrough not onlymarks the democratization of LFM technology but also opens up opportunities for more small-and medium-sized enterprises and research institutions to participate in AI innovation.In the future,LFMs will no longer be a game for the few.
基金Supported by National Natural Science Foundation of China(71671122)China Postdoctoral Science Foundation Funded Project(2014M560185,2016T90203)+1 种基金Humanities and Social Science Research Fund of Ministry of Education of China(11YJC790006,16YJA790004)Tianjin Natural Science Foundation of China(15JCQNJC04000)
文摘This paper studies a dynamic mean-variance portfolio selection problem with random liability in the affine interest rate environment, where the financial market consists of three assets: one risk-free asset, one risky asset and one zero-coupon bond. Assume that short rate is driven by affine interest rate model and liability process is described by the drifted Brownian motion, in addition, stock price dynamics is affected by interest rate dynamics. The investors expect to look for an optimal strategy to minimize the variance of the terminal surplus for a given expected terminal surplus. The efficient strategy and the efficient frontier are explicitly obtained by applying dynamic programming principle and Lagrange duality theorem. A numerical example is given to illustrate our results and some economic implications are analyzed.
基金supported by the National Natural Science Foundation of China(32020103004,32170251)the Strategic Priority Research Program of Chinese Academy of Sciences(XDA24020309+1 种基金the Youth Innovation Promotion Association CAS(2019100)Key-Area Research and Development Program of Guangdong Province(2018B020202012)。
文摘The Green Revolution of the 1960s boosted crop yields in part through widespread production of semidwarf plant cultivars and extensive use of mineral fertilizers.The beneficial semidwarfism of cereal Green Revolution cultivars is due to the accumulation of plant growth-repressing DELLA proteins,which increases lodging resistance but requires a high-nitrogen fertilizer to obtain high yield.Given that environmentally degrading fertilizer use underpins current worldwide crop production,future agricultural sustainability needs a sustainable Green Revolution through reducing N fertilizer use while boosting grain yield above what is currently achievable.Despite a great deal of research efforts,only a few genes have been demonstrated to improve N-use efficiency in crops.The molecular mechanisms underlying the coordination between plant growth and N metabolism is still not fully understood,thus preventing significant improvement.Recent advances of how plants sense,capture and respond to varying N supply in model plants have shed light on how to improve sustainable productivity in agriculture.This review focuses on the current understanding of root developmental and metabolic adaptations to N availability,and discuss the potential approaches to improve N-use efficiency in high-yielding cereal crops.
文摘This paper deals with the solution concepts,scalarization and existence of solutions formultiobjective generalized game. The scalarization method used in this paper can characterizecompletely the solutions and be applied to prove the existence of solutions for quasi-convexmultiobjective generalized game. On the other hand,a new concept of security strategy isintroduced and its existence is proved.At last,some relations between these solutions areestablished.
文摘Tall buildings are being designed and built across a wide range of cities.A poorly designed tall building can tremendously increase the building’s appetite for energy.Therefore,this paper aims to determine the design strategies that help a high-rise office building to be more energy efficient.For this purpose,a comparative study on twelve case buildings in three climate groups(temperate,sub-tropical&tropical)was performed.The exterior envelope,building form and orientation,service core placement,plan layout,and special design elements like atria and sky gardens were the subject of investigation.effectiveness of different design strategies for reducing the cooling,heating,ventilation and electric lighting energy usage.Finally,lessons from these buildings’were defined for the three climates.Furthermore,a compari-son of building energy performance data with international benchmarks confirmed that in temperate and sub-tropical climates sustainable design strategies for high-rise buildings were performing well,as a result leading to lower energy consump-tion.However,for the tropics the design of high-rise buildings needs additional consideration.
