In order to solve the problem of the invalidation of thermal parameters andoptimal running, we present an efficient soft sensor approach based on sparse online Gaussianprocesses( GP), which is based on a combination o...In order to solve the problem of the invalidation of thermal parameters andoptimal running, we present an efficient soft sensor approach based on sparse online Gaussianprocesses( GP), which is based on a combination of a Bayesian online algorithm together with asequential construction of a relevant subsample of the data to specify the prediction of the GPmodel. By an appealing parameterization and projection techniques that use the reproducing kernelHubert space (RKHS) norm, recursions for the effective parameters and a sparse Gaussianapproximation of the posterior process are obtained. The sparse representation of Gaussian processesmakes the GP-based soft sensor practical in a large dataset and real-time application. And theproposed thermalparameter soft sensor is of importance for the economical running of the powerplant.展开更多
Some researchers, running instructors, and coaches have suggested that the "optimal" footstrike pattern to improve performance and reduce running injuries is to land using a mid-or forefoot strike. Thus, it ...Some researchers, running instructors, and coaches have suggested that the "optimal" footstrike pattern to improve performance and reduce running injuries is to land using a mid-or forefoot strike. Thus, it has been recommended that runners who use a rearfoot strike would benefit by changing their footstrike although there is little scientific evidence for suggesting such a change. The rearfoot strike is clearly more prevalent. The major reasons often given for changing to a mid-or forefoot strike are(1) it is more economical;(2) there is a reduction in the impact peak and loading rate of the vertical component of the ground reaction force; and(3) there is a reduction in the risk of a running-related injuries. In this paper,we critique these 3 suggestions and provide alternate explanations that may provide contradictory evidence for altering one's footstrike pattern.We have concluded, based on examining the research literature, that changing to a mid-or forefoot strike does not improve running economy, does not eliminate an impact at the foot-ground contact, and does not reduce the risk of running-related injuries.展开更多
This article deeply researched into the existent five problems and four main "bottlenecks" in the high-technologization of marine industry in China on the basis of analyzing the new trends in international m...This article deeply researched into the existent five problems and four main "bottlenecks" in the high-technologization of marine industry in China on the basis of analyzing the new trends in international marine problems and the necessity of implementing the strategy of developing China based on marine. This article brought up specific measures to the five "bottlenecks" according to the situations, and pointed out that new marine industry should be high-technologization and the traditional marine industry should be reformed by high-technique. The research results may provide the scientific basis for realizing the high-technologization of marine industry in China.展开更多
Considerable changes have taken place in commercial passenger air transport since the enactment of the 1978 Airline Deregulation Act in the US and the deregulation of airline networks that has occurred elsewhere. The ...Considerable changes have taken place in commercial passenger air transport since the enactment of the 1978 Airline Deregulation Act in the US and the deregulation of airline networks that has occurred elsewhere. The commercial and operational freedoms have led most of the larger carriers to develop hub-and-spoke networks, within which certain cities or metropolitan areas emerge as key nodes possessing tremendous advantages over other locations in the air transport system. This paper examines the nature of hub-and-spoke operations in air transportation services, and the benefits that accrue to a city or geographical region that is host to an airline hub. In particular, it looks into linkages between the air service hub and local economic development. Four potential types of impact of airports on the regional economy are defined and discussed. As an example, the assessment of the economic impacts of Cincinnati-Northern Kentucky International Airport (CVG), a major Delta Airlines hub, is introduced.展开更多
The degree of accuracy in predicting the photovoltaic power generation plays an important role in appropriate allocations and economic operations of the power plants based on the generating capacity data gathered from...The degree of accuracy in predicting the photovoltaic power generation plays an important role in appropriate allocations and economic operations of the power plants based on the generating capacity data gathered from the geographically separated photovoltaic plants through network. In this paper, a forecasting model is designed with an optimization algorithm which is developed with the combination of PSO （Particle Swarm Optimization） and BP （Back Propagation） neural network. The proposed model is further validated and the experiment results show that the predication model assures the prediction accuracy regardless the day type transitions and other relevant factors, in the proposed model, the prediction error rate is worth less than 20% in all different climatic conditions and most of the prediction error accuracy is less than 10% in sunny day, and whose precision satisfies the management requirements of the power grid companies, reflecting the significance of the proposed model in engineering applications.展开更多
In this paper,the authors have empirically analyzed the convergence in per capita GDP gap and the convergence in the variation of energy intensity with respect to the change of per capita GDP between China and eight d...In this paper,the authors have empirically analyzed the convergence in per capita GDP gap and the convergence in the variation of energy intensity with respect to the change of per capita GDP between China and eight developed countries.Then,the authors run a regression on the impact of decisive factors of economic growth on energy intensity and its change,so as to find out the economic mechanism of energy intensity gap changing with respect to the variation of economic growth.This study concludes that:First,there is a convergence in per capita GDP gap between China and the eight developed countries.With the convergence in per capita GDP gap,the energy intensity gap between China and eight different countries also converge,and the convergence rate of the latter is faster than that of the former,i.e.if the per capita GDP gap between China and the eight developed countries decreases by 1%,the energy intensity gap between them will correspondingly decrease by 1.552%.Second,the energy intensity decreases with the improvement of industrial structure,the rising of energy prices,the advances of technology,and the expansion of investment in fixed assets,and it slightly increases with the increase of FDI.Third,the energy intensity gap between China and eight developed countries narrows with the lessening of the difference in fixed assets investment,energy prices,and technological progress between China and eight developed countries,yet increases with the narrowing of the difference in FDI,and has no significant correlation with the difference in industrial structure.Fourth,the narrowing of difference in per capita GDP between China and the eight developed countries can result in the lessening of energy intensity gap,whose economic mechanism is that the decisive factors,such as difference in investment,technology,and the competition mechanism of prices,which can determine the difference in economic growth,can significantly affect the energy intensity gap.展开更多
Based on the statistical data from 1975 to 1997, we forecast the growth rate of coal consuming and the quantity in coming decade with the BP neuron network in the article.
Objectives:First-year college students had exposure to unhealthy lifestyle behaviors that correlate with a high prevalence of anxiety and depression.Regarding to the modifiable lifestyle behaviors factors,this study i...Objectives:First-year college students had exposure to unhealthy lifestyle behaviors that correlate with a high prevalence of anxiety and depression.Regarding to the modifiable lifestyle behaviors factors,this study investigated the prevalence and correlation of multiple lifestyle behaviors,anxiety and depression in a sample of Chinese first-year college students.Methods:Cross-sectional data were extracted from Residents eHealth app of health lifestyle behaviors survey from September to October 2019.Anxiety,depression,eating regular meals,consumption of snacks in-between meals,consumption of fruit,dessert and sugar-sweetened beverages,smoking and secondhand smoke exposure,consuming alcohol,physical activity,sedentary time were assessed by self-report.Socio-demographic including age,gender,education,family income,religion,and health condition were captured.Logistic regression was used to explore the association of multiple lifestyle behaviors,anxiety and depression.Results:Totally 1,017 participants were included in the study.The prevalence of anxiety and depression(from mild to severe) were 40.3% and 45.3%,respectively.In multivariable analyses,religion (believe in Buddhism,OR =2.438,95%CI:1.097-5.421;believe in Christian,OR =5.886,95%CI:1.604-21.597),gender (Female,OR =1.405,95%CI:1.001-1.971),secondhand smoke exposure (OR =1.089,95%CI:1.001-1.184),and eating regular meals (OR =0.513,95%C1:0.346-0.759) were associated with anxiety.Family income (OR =0.732,95%CI:0.596-0.898),eating regular meals (OR =0.641,95%CI:0.415-0.990),frequency of breakfast (OR =0.813,95%CI:0.690-0.959),with a chronic disease (OR =1.902,95%CI:1.335-2.712),and consumption of nocturnal snack (OR =1.337,95%CI:1.108-1.612) were associated with depression.Conclusions:These results highlighted the need for early lifestyle behavior intervention,especially modifying diet patterns considering the background of religion,health condition,and social-economic status in first-year college students to improve their mental health.展开更多
China′s economy and transport infrastructure have both experienced rapid development since 1978, and especially since 1990. Today, China is the second-largest economic entity in terms of GDP and has the largest high-...China′s economy and transport infrastructure have both experienced rapid development since 1978, and especially since 1990. Today, China is the second-largest economic entity in terms of GDP and has the largest high-speed rail(HSR) network and the second-largest expressway network in the world. This paper explores the relationship between accessibility and economic growth in China from 1990 to 2010. In the study, the basic research units include 333 prefecture-level cities and four municipalities. We explore a bivariate analysis framework of accessibility and economic growth, and their increase rates, to examine this relationship using long-term panel data. The results indicate that, first, accessibility and economic growth show a significant positive relationship using both cross-section and panel data, while the increase rate in accessibility and GDP indicate no significant relationship using cross-section data and a poor significant relationship using panel data. Second, the distributions of local advantage are uneven. Cities with low local advantage with respect to accessibility and GDP are mainly located in China′s eastern coastal region or the provincial capitals, while those with low local advantage in terms of their increase rates are located in the western region. Third, as China′s economic growth and transport networks have evolved, the distribution of local advantage shows little change in terms of accessibility and GDP, but a greater change in terms of their increase rates, which is largely influenced by the distribution of expressway and HSR networks.展开更多
Industries with network characteristics always have some special features, which differ from the ordinary business companies. Some scholars hold the theoretical viewpoint that these industries bear the characteristics...Industries with network characteristics always have some special features, which differ from the ordinary business companies. Some scholars hold the theoretical viewpoint that these industries bear the characteristics of natural monopoly, externality, measurement difficulty, etc. However, all these theories can explain why the network industries, especially prominent in transportation industries, are confronted with many difficulties in their process of reform and reorganization. But, there is something deep-seated that can explain why network industries such as railway, highway, aviation, telecommunication, water, gas, etc. have the characteristics of natural monopoly. The paper holds that： （1） Shared property in transportation industries such as the network infrastructure, station and marshalling yard, dispatch and control right, serves more than two enterprises or even hundreds of relative enterprises. （2） Shared property makes it possible for great amount of product quantity to share the sunken cost. Therefore, economy of scale and economy of scope thus exist in transportation sectors, which is called network economy. （3） From the input and output relationships in transportation industries with network features, there exists a law of increasing returns to scale, which is opposite to the classic economy theory that diminishing returns to scale will appear finally. Why？ It is because of the existence of shared property. Not only production cost, but also the transaction cost among transportation enterprises can be reduced. （4） We establish a quantitative model to testify the theory. The implication is that, the lack of incentive allocation is, if not all, one reason causing the usage inefficiency of the rights concerned. The low efficiency manifests in two aspects： the first one is the organization boundary, that is, transportation enterprises are not real enterprises at present. The second one is the so-called mixed task equilibrium of railway affairs. We haven＇t separated the shared property from the private ones.展开更多
文摘In order to solve the problem of the invalidation of thermal parameters andoptimal running, we present an efficient soft sensor approach based on sparse online Gaussianprocesses( GP), which is based on a combination of a Bayesian online algorithm together with asequential construction of a relevant subsample of the data to specify the prediction of the GPmodel. By an appealing parameterization and projection techniques that use the reproducing kernelHubert space (RKHS) norm, recursions for the effective parameters and a sparse Gaussianapproximation of the posterior process are obtained. The sparse representation of Gaussian processesmakes the GP-based soft sensor practical in a large dataset and real-time application. And theproposed thermalparameter soft sensor is of importance for the economical running of the powerplant.
文摘Some researchers, running instructors, and coaches have suggested that the "optimal" footstrike pattern to improve performance and reduce running injuries is to land using a mid-or forefoot strike. Thus, it has been recommended that runners who use a rearfoot strike would benefit by changing their footstrike although there is little scientific evidence for suggesting such a change. The rearfoot strike is clearly more prevalent. The major reasons often given for changing to a mid-or forefoot strike are(1) it is more economical;(2) there is a reduction in the impact peak and loading rate of the vertical component of the ground reaction force; and(3) there is a reduction in the risk of a running-related injuries. In this paper,we critique these 3 suggestions and provide alternate explanations that may provide contradictory evidence for altering one's footstrike pattern.We have concluded, based on examining the research literature, that changing to a mid-or forefoot strike does not improve running economy, does not eliminate an impact at the foot-ground contact, and does not reduce the risk of running-related injuries.
基金Under the auspices of the National Natural Science Foundation of China(No.40271029)
文摘This article deeply researched into the existent five problems and four main "bottlenecks" in the high-technologization of marine industry in China on the basis of analyzing the new trends in international marine problems and the necessity of implementing the strategy of developing China based on marine. This article brought up specific measures to the five "bottlenecks" according to the situations, and pointed out that new marine industry should be high-technologization and the traditional marine industry should be reformed by high-technique. The research results may provide the scientific basis for realizing the high-technologization of marine industry in China.
基金Under the auspices of Intramural Research Incentive Grant from the Office of the Senior Vice President for Research atUniversity of Louisville
文摘Considerable changes have taken place in commercial passenger air transport since the enactment of the 1978 Airline Deregulation Act in the US and the deregulation of airline networks that has occurred elsewhere. The commercial and operational freedoms have led most of the larger carriers to develop hub-and-spoke networks, within which certain cities or metropolitan areas emerge as key nodes possessing tremendous advantages over other locations in the air transport system. This paper examines the nature of hub-and-spoke operations in air transportation services, and the benefits that accrue to a city or geographical region that is host to an airline hub. In particular, it looks into linkages between the air service hub and local economic development. Four potential types of impact of airports on the regional economy are defined and discussed. As an example, the assessment of the economic impacts of Cincinnati-Northern Kentucky International Airport (CVG), a major Delta Airlines hub, is introduced.
基金the National Natural Science Foundation of China under Grant No.61261016，Wuhan Science and technology project for the Solar energy intelligent management system development and application demonstration
文摘The degree of accuracy in predicting the photovoltaic power generation plays an important role in appropriate allocations and economic operations of the power plants based on the generating capacity data gathered from the geographically separated photovoltaic plants through network. In this paper, a forecasting model is designed with an optimization algorithm which is developed with the combination of PSO （Particle Swarm Optimization） and BP （Back Propagation） neural network. The proposed model is further validated and the experiment results show that the predication model assures the prediction accuracy regardless the day type transitions and other relevant factors, in the proposed model, the prediction error rate is worth less than 20% in all different climatic conditions and most of the prediction error accuracy is less than 10% in sunny day, and whose precision satisfies the management requirements of the power grid companies, reflecting the significance of the proposed model in engineering applications.
文摘In this paper,the authors have empirically analyzed the convergence in per capita GDP gap and the convergence in the variation of energy intensity with respect to the change of per capita GDP between China and eight developed countries.Then,the authors run a regression on the impact of decisive factors of economic growth on energy intensity and its change,so as to find out the economic mechanism of energy intensity gap changing with respect to the variation of economic growth.This study concludes that:First,there is a convergence in per capita GDP gap between China and the eight developed countries.With the convergence in per capita GDP gap,the energy intensity gap between China and eight different countries also converge,and the convergence rate of the latter is faster than that of the former,i.e.if the per capita GDP gap between China and the eight developed countries decreases by 1%,the energy intensity gap between them will correspondingly decrease by 1.552%.Second,the energy intensity decreases with the improvement of industrial structure,the rising of energy prices,the advances of technology,and the expansion of investment in fixed assets,and it slightly increases with the increase of FDI.Third,the energy intensity gap between China and eight developed countries narrows with the lessening of the difference in fixed assets investment,energy prices,and technological progress between China and eight developed countries,yet increases with the narrowing of the difference in FDI,and has no significant correlation with the difference in industrial structure.Fourth,the narrowing of difference in per capita GDP between China and the eight developed countries can result in the lessening of energy intensity gap,whose economic mechanism is that the decisive factors,such as difference in investment,technology,and the competition mechanism of prices,which can determine the difference in economic growth,can significantly affect the energy intensity gap.
文摘Based on the statistical data from 1975 to 1997, we forecast the growth rate of coal consuming and the quantity in coming decade with the BP neuron network in the article.
基金This research did not receive any specific grant from funding agencies in the public,commercial,or not-for-profit sectors.
文摘Objectives:First-year college students had exposure to unhealthy lifestyle behaviors that correlate with a high prevalence of anxiety and depression.Regarding to the modifiable lifestyle behaviors factors,this study investigated the prevalence and correlation of multiple lifestyle behaviors,anxiety and depression in a sample of Chinese first-year college students.Methods:Cross-sectional data were extracted from Residents eHealth app of health lifestyle behaviors survey from September to October 2019.Anxiety,depression,eating regular meals,consumption of snacks in-between meals,consumption of fruit,dessert and sugar-sweetened beverages,smoking and secondhand smoke exposure,consuming alcohol,physical activity,sedentary time were assessed by self-report.Socio-demographic including age,gender,education,family income,religion,and health condition were captured.Logistic regression was used to explore the association of multiple lifestyle behaviors,anxiety and depression.Results:Totally 1,017 participants were included in the study.The prevalence of anxiety and depression(from mild to severe) were 40.3% and 45.3%,respectively.In multivariable analyses,religion (believe in Buddhism,OR =2.438,95%CI:1.097-5.421;believe in Christian,OR =5.886,95%CI:1.604-21.597),gender (Female,OR =1.405,95%CI:1.001-1.971),secondhand smoke exposure (OR =1.089,95%CI:1.001-1.184),and eating regular meals (OR =0.513,95%C1:0.346-0.759) were associated with anxiety.Family income (OR =0.732,95%CI:0.596-0.898),eating regular meals (OR =0.641,95%CI:0.415-0.990),frequency of breakfast (OR =0.813,95%CI:0.690-0.959),with a chronic disease (OR =1.902,95%CI:1.335-2.712),and consumption of nocturnal snack (OR =1.337,95%CI:1.108-1.612) were associated with depression.Conclusions:These results highlighted the need for early lifestyle behavior intervention,especially modifying diet patterns considering the background of religion,health condition,and social-economic status in first-year college students to improve their mental health.
基金National Natural Science Foundation of China(No.41371143,41171107)
文摘China′s economy and transport infrastructure have both experienced rapid development since 1978, and especially since 1990. Today, China is the second-largest economic entity in terms of GDP and has the largest high-speed rail(HSR) network and the second-largest expressway network in the world. This paper explores the relationship between accessibility and economic growth in China from 1990 to 2010. In the study, the basic research units include 333 prefecture-level cities and four municipalities. We explore a bivariate analysis framework of accessibility and economic growth, and their increase rates, to examine this relationship using long-term panel data. The results indicate that, first, accessibility and economic growth show a significant positive relationship using both cross-section and panel data, while the increase rate in accessibility and GDP indicate no significant relationship using cross-section data and a poor significant relationship using panel data. Second, the distributions of local advantage are uneven. Cities with low local advantage with respect to accessibility and GDP are mainly located in China′s eastern coastal region or the provincial capitals, while those with low local advantage in terms of their increase rates are located in the western region. Third, as China′s economic growth and transport networks have evolved, the distribution of local advantage shows little change in terms of accessibility and GDP, but a greater change in terms of their increase rates, which is largely influenced by the distribution of expressway and HSR networks.
文摘Industries with network characteristics always have some special features, which differ from the ordinary business companies. Some scholars hold the theoretical viewpoint that these industries bear the characteristics of natural monopoly, externality, measurement difficulty, etc. However, all these theories can explain why the network industries, especially prominent in transportation industries, are confronted with many difficulties in their process of reform and reorganization. But, there is something deep-seated that can explain why network industries such as railway, highway, aviation, telecommunication, water, gas, etc. have the characteristics of natural monopoly. The paper holds that： （1） Shared property in transportation industries such as the network infrastructure, station and marshalling yard, dispatch and control right, serves more than two enterprises or even hundreds of relative enterprises. （2） Shared property makes it possible for great amount of product quantity to share the sunken cost. Therefore, economy of scale and economy of scope thus exist in transportation sectors, which is called network economy. （3） From the input and output relationships in transportation industries with network features, there exists a law of increasing returns to scale, which is opposite to the classic economy theory that diminishing returns to scale will appear finally. Why？ It is because of the existence of shared property. Not only production cost, but also the transaction cost among transportation enterprises can be reduced. （4） We establish a quantitative model to testify the theory. The implication is that, the lack of incentive allocation is, if not all, one reason causing the usage inefficiency of the rights concerned. The low efficiency manifests in two aspects： the first one is the organization boundary, that is, transportation enterprises are not real enterprises at present. The second one is the so-called mixed task equilibrium of railway affairs. We haven＇t separated the shared property from the private ones.
