Economics literature has long overlooked an important economic phenomenon:Residents in large cities tend to save a smaller percentage of their disposable income than their peers in small and medium-sized cities.As an ...Economics literature has long overlooked an important economic phenomenon:Residents in large cities tend to save a smaller percentage of their disposable income than their peers in small and medium-sized cities.As an explanation for this phenomenon,this paper puts forth the hypothesis that:Residents in large cities purchase more services to increase their leisure time,which is reduced by longer commuting time than in small and medium-sized cities,thus lowering their household savings rate.We conducted an empirical study using panel data of China’s prefecture-level cities and urban household survey data,and employed an instrumental variable to address the endogeneity problem.The result confirmed the accuracy of the above hypothesis.In identifying the economic phenomenon and putting forth the hypothesis,this paper(i)creates a theoretical link between city size and household savings rate,which helps unravel the determinants of the urban household savings rate;(2)provides important implications for China’s policy-making on domestic consumption,urban populations,and industrial development.Priority should be given to developing large and medium-sized cities given the positive effects on domestic consumption and service sector development,and migrant labor shall not be barred from entering large and medium-sized cities to provide services to local residents.展开更多
Academics have yet to agree on the effectiveness of the precautionary saving theory in explaining Chinese households’saving behavior.With the Wenchuan megaearthquake of 2008 as an uncertain event to overcome the endo...Academics have yet to agree on the effectiveness of the precautionary saving theory in explaining Chinese households’saving behavior.With the Wenchuan megaearthquake of 2008 as an uncertain event to overcome the endogeneity problem of income volatility,this paper puts forward a brand-new hypothesis that"an earthquake influences household saving rate through its effects on expected income and the variance of expected income."Then,we employ propensity score matching-difference-in-differences(PSMDID)method,the systematic GMM methods,the synthetic control method,together with instrumental variable method,for an analysis of Chinese Household Income Project(CHIP)and inter-provincial data at the micro and macro levels,respectively.We find that the Wenchuan mega-earthquake was followed by an increase in the variance of household expected income in Sichuan and a significant rise in the household saving rate.Second,social protection is negatively correlated with expected income,and has a significant substitutive relationship with saving rate.This finding indirectly proves that the earthquake’s impact on the household saving rate is subject to the variance of expected income,shedding light on how the precautionary saving motivation works in the real world.展开更多
Cash flow statements suggest that China’s rising labor remuneration has had a major impact on its national savings rate since 2008.Accordingly,this paper proposes labor remuneration hypotheses to explain the evolving...Cash flow statements suggest that China’s rising labor remuneration has had a major impact on its national savings rate since 2008.Accordingly,this paper proposes labor remuneration hypotheses to explain the evolving trend of China’s national savings rate.We hypothesize that:(1)The certainty and predictability of household labor remuneration have led to excess sensitivity to consumption,with a corresponding decrease in the household savings rate;(2)rising household labor remuneration means a greater share of labor remuneration is paid by firms,resulting in a smaller corporate savings rate;(3)the increase in the payment of labor remuneration by firms as a share of national disposable income has resulted in the government spending more on social welfare and public services resulting in the government having a declining share of disposable income,less propensity to save,and a falling government savings rate.Using China’s provincial panel data of 2008-2016,we performed an empirical test with the minimum wage standard as the instrumental variable to verify the above hypothesis.To cope with economic growth pressures,China needs to shift from an investment-driven to a consumption-driven growth model and prioritize investment efficiency over quantity.展开更多
Since Piketty offered a new view of capital/income ratio, numerous attempts have been made to examine the relationship between return on capital, economic growth and the capital/income ratio. This paper attempts to sh...Since Piketty offered a new view of capital/income ratio, numerous attempts have been made to examine the relationship between return on capital, economic growth and the capital/income ratio. This paper attempts to shed new light on this field. More precisely, following recent literatures that pay attention to dynamics of external balance sheets of countries, we examine if Piketty’s results for large countries are robust for a country that takes the world rate of return on capital as given and whose savings rate increases gradually from negative value. It is revealed that for such a country, (1) Kuznets curve is drawn and (2) capital/income ratio decreases in accordance with a rise in savings rate and return on capital.展开更多
“” , “” “ ”, “” ; “ ”, “” : 2000, , , 1996—200630: The paper examines the micro-mechanism for the high savings rate in China from public finance view. We find that the self-interest of government...“” , “” “ ”, “” ; “ ”, “” : 2000, , , 1996—200630: The paper examines the micro-mechanism for the high savings rate in China from public finance view. We find that the self-interest of government has played an important role in the rising national savings rate since 2000. The improved SOE profitability has enhanced the government incentive to save for the investment. This has crowded out public expenditures on technology, education, medicare and social safety net. As a result, the private sector has to increase precautionary savings. The empirical study based on panel data of 30 provinces from 1996 to 2006 demonstrates that the savings rate of the public sector is positively related to SOE profitability, and the private sector savings rate is negatively related to the ratio of public expenditures to the disposable income of the public sector.View full textDownload full text展开更多
In an attempt to entice consumers to save less and spend more, China has focused on perfecting its social security system, reforming taxation and dividend-sharing proportion between the government and state-owned ente...In an attempt to entice consumers to save less and spend more, China has focused on perfecting its social security system, reforming taxation and dividend-sharing proportion between the government and state-owned enterprises. Liu Yuhui, Director of the China Economy Appraisal and Rating Center at the Institute of Finance and Banking, the Chinese Academy of Social Sciences, offered his insights in an Economic Observer article. Edited excerpts展开更多
The vehicle industry is always in search of breakthrough energy-saving and emission-reduction technologies.In recent years,vehicle intelligence has progressed considerably,and researchers are currently trying to take ...The vehicle industry is always in search of breakthrough energy-saving and emission-reduction technologies.In recent years,vehicle intelligence has progressed considerably,and researchers are currently trying to take advantage of these developments.Here we consider the case of many vehicles forming a queue,i.e.,vehicles traveling at a predetermined speed and distance apart.While the majority of existing studies on this subject have focused on the influence of the longitudinal vehicle spacing,vehicle speed,and the number of vehicles on aerodynamic drag and fuel economy,this study considers the lateral offset distance of the vehicle queue.The group fuel consumption savings rate is calculated and analyzed.As also demonstrated by experimental results,some aerodynamic benefits exist.Moreover,the fuel consumption saving rate of the vehicle queue decreases as the lateral offset distance increases.展开更多
By creating a two-sector intertemporal and intergenerational small open economy model,this paper investigates how real exchange rate responds to demographic shifts in the long term.The result shows that when the capit...By creating a two-sector intertemporal and intergenerational small open economy model,this paper investigates how real exchange rate responds to demographic shifts in the long term.The result shows that when the capital density of tradable goods sector exceeds that of non-tradable goods sector in a country,an increase in the country's elderly dependency rate(ODR) will cause its real exchange rate to appreciate.In addition,higher savings rate or per capita labor income means that real exchange rate is more responsive to ODR variations.We conducted an econometric test on our theoretical hypotheses using the data of 214 countries and regions during 1980-2013.Empirical result indicates that an increase of ODR will cause real exchange rate to appreciate.This result is robust and unaffected by sample grouping characteristics and differences.An increase in savings rate will significantly increase the ODR elasticity of real exchange rate.This conclusion is also significant and robust for overall samples and categorized samples(except for developed countries) and generally consistent with our theoretical hypothesis.However,our empirical research generally does not support the hypothesis that higher labor income increases the responsiveness of real exchange rate to ODR.This study is of great significance to unravel the effect of China's ageing population on the longterm variations of renminbi's exchange rate.展开更多
The level of saving not only influences the life of individuals, but also plays an important role in a country's development. Accordingly, the studying on saving is becoming a focus problem in modem life. In recent y...The level of saving not only influences the life of individuals, but also plays an important role in a country's development. Accordingly, the studying on saving is becoming a focus problem in modem life. In recent years, the personal saving rate in the United States has fallen sharply, but the personal saving rate in China is at an astoundingly high level. This paper studies this problem with the positive analysis method from the situation; the reasons of the saving rate disparity between the U.S. and .China, and put forward some proposals about how to deal with the saving problems.展开更多
A water-conducting polyacrylamide/montmorillonite coating was prepared by solutionblending.The coating was coated on fiber and then composited with polymer to form a composite film material that used for water saving ...A water-conducting polyacrylamide/montmorillonite coating was prepared by solutionblending.The coating was coated on fiber and then composited with polymer to form a composite film material that used for water saving and tree planting in arid and desert regions.The coating's water-conducting characteristics and dynamic self-adjusting behavior were investigated by Fourier transform infrared(FTIR)spectroscopy,thermal analysis(TG-DTA),and environmental scanning electron microscopy(ESEM).The results showed that the coating's water-conducting rate increased but water-retention capacity weakened with increasing montmorillonite content.The water-loss rate was positively related to temperature and negatively related to soil moisture.Water potential greatly influenced the water-conducting rate of the coating during its water conduction process.When the coating was at a low water potential,the montmorillonite particles interconnected and water was conducted quickly via montmorillonite layers,whereas when the coating was at a high potential,the montmorillonite particles disconnected and water was conducted slowly via the swelled polyacrylamide net structure.The rate can be regulated by changing the proportion of polyacrylamide and montmorillonite to guarantee a reasonable water supply for trees and make trees easier to survive.Thus,the survival rate of trees can be increased and the use of water resources can be significantly reduced.展开更多
Today the resources are becoming scarcer, which should not be regarded as unexhausted any more. Correspondingly, the production would be constrained by the scarcity of resources clearly. Then the economic researchers ...Today the resources are becoming scarcer, which should not be regarded as unexhausted any more. Correspondingly, the production would be constrained by the scarcity of resources clearly. Then the economic researchers would pay much more attention to reducing the consumption of natural resources in the future. Therefore this paper brings foreword the conception of elasticity ratio of resource consumption based on the concept of elasticity and analyzes the relationship between the parameters. For the certain relationships between the elasticity ratio of resource consumption and resource consumption, this paper will try to reveal, to keep economy growing while resource consumption reducing, what conditions should be met as to the relationships among resource productivity, its growth rate, energy saving efficiency, economic growth rate and elasticity ratio of resource consumption. This paper proves the relationship between the China's energy consumption and economy growth using statistic data from 1978 to 2003.展开更多
This paper presents a detailed analysis of the Chinese saving rate based on the flow offunds data. It finds that the most widely adopted view of precautionary saving, which is regarded as the top reason for maintainin...This paper presents a detailed analysis of the Chinese saving rate based on the flow offunds data. It finds that the most widely adopted view of precautionary saving, which is regarded as the top reason for maintaining a high saving rate in China, is misleading because this conclusion is drawn from the household survey data. In fact, the household saving rate has declined dramatically since the mid-1990s, as is observed from the flow of funds framework. The high national saving rate is attributed to the increasing shares of both government and corporation disposable incomes. Insufficient consumption demand is caused by the persistent decrease in percentage share of household to national disposable income. Governmentdirected income redistribution urgently needs to be improved to accelerate consumption, which in turn would make the Chinese economy less investment-led and help to reduce the current account surplus.展开更多
Centrifugal pumps are being widely used in many industrial and commercial applications.Many of these pumps are being operated at constant speed but could provide energy savings through adjustable speed operations.The ...Centrifugal pumps are being widely used in many industrial and commercial applications.Many of these pumps are being operated at constant speed but could provide energy savings through adjustable speed operations.The purpose of this study was to get the energy saving rates of the multistage centrifugal pump with variable speed conditions.For this investigation an experimental set up of variable flow and pressure system was made to get energy saving rates and numerical analyses are applied to validate the pump performance.The energy saving and therefore the cost saving depends on the specific duty cycle of which the machine operates.Duty cycle is the proportion of time during which a component,device and system is operated.The duty cycle segmented into different flow rates and weighting the average value for each segment by the interval time.The system was operated at 50%or less of the pump capacity.The input power of the system was carried out by pump characteristics curve of each operating point.The energy consumption was done by the product of specific duty cycle and the input power of the system for constant speed and variable speed drive operation.The total energy consumed for constant speed drive pump was 75,770 k W.hr and for variable speed drive pump was 31,700 k W.hr.The total energy saving of the system was 44,070 k W.hr or 58.16%annually.So,this paper suggests a method of implementing an energy saving on variable-flow and pressure system of the multistage centrifugal pump.展开更多
On the basis of the 1992-2003 flow of funds accounts for China released by the National Statistics Bureau, this article conducts a comparative analysis of the saving rates of the household, corporate and government se...On the basis of the 1992-2003 flow of funds accounts for China released by the National Statistics Bureau, this article conducts a comparative analysis of the saving rates of the household, corporate and government sectors from the perspective of income distribution and saving propensity. We found that although the household sector had the highest saving rate, it had actually trended downwards since 1992, as a result of falling labor compensation, property income and income from redistribution. Over this period, the corporate saving rate rose slowly, mainly because of a prolonged period of relatively low wage and interest costs rather than increased profitability. The government saving rate, which remained low in the last century, rose dramatically after 2000. The main reasons for this were the ever- increasing share of government disposable revenue in national income distribution via primary distribution and redistribution and the sector's increased saving propensity. Our policy recommendations suggest that in order to implement an economic development strategy centered on boosting domestic consumption, China should shift its economic focus to improving the income distribution structure and increasing household income. For this purpose, fiscal policies should be oriented toward increased public financing, public expenditure and social security expenditure and toward higher labor compensation based on increased productivity in the corporate sector. These aims should be taken as the objectives of national c regulation.展开更多
IEEE 802.16e is currently the latest broadband wireless access standard designed to support mobility. In mobile networks, how to control energy consumption is one of the most important issues for battery-powered mobil...IEEE 802.16e is currently the latest broadband wireless access standard designed to support mobility. In mobile networks, how to control energy consumption is one of the most important issues for battery-powered mobile stations. The standard proposes an energy saving mechanism named 'sleep mode' for conserving the power of mobile stations. According to the operation principle of the sleep mode for downlink traffic in the type I power saving class, considering the self-similar nature of massive multimedia data in wireless networks, a discrete-time batch arrival Geom^x/G/1 queuing model with a close-down time and multiple vacations is built. The batch size is supposed to be Pareto distributed. By employing an embedded Markov chain method, the average queue length and the average sojourn time of the system model are derived. Correspondingly, the performance measures are obtained of the energy saving rate and the average packet delay time for the sleep mode in the IEEE 802.16e. The numerical results demonstrate the dependency relationships between the system performance measures and the system parameters with different offered loads and different self-similar degrees. Furthermore, a cost model is developed to determine the optimum length of the close-down time for minimizing the total system cost.展开更多
基金This paper is a result of the major program of the Key Research Base for Humanities and Social Sciences of the Ministry of Education“Structural Transition,Urban Development and China’s Economic Growth”(Grant No.17JJD790005)sponsorships from the National Natural Science Foundation of China(NSFC)(Grant No.71841008,71833003,71863001)the Peak Program for Theoretical Economics at Fudan University。
文摘Economics literature has long overlooked an important economic phenomenon:Residents in large cities tend to save a smaller percentage of their disposable income than their peers in small and medium-sized cities.As an explanation for this phenomenon,this paper puts forth the hypothesis that:Residents in large cities purchase more services to increase their leisure time,which is reduced by longer commuting time than in small and medium-sized cities,thus lowering their household savings rate.We conducted an empirical study using panel data of China’s prefecture-level cities and urban household survey data,and employed an instrumental variable to address the endogeneity problem.The result confirmed the accuracy of the above hypothesis.In identifying the economic phenomenon and putting forth the hypothesis,this paper(i)creates a theoretical link between city size and household savings rate,which helps unravel the determinants of the urban household savings rate;(2)provides important implications for China’s policy-making on domestic consumption,urban populations,and industrial development.Priority should be given to developing large and medium-sized cities given the positive effects on domestic consumption and service sector development,and migrant labor shall not be barred from entering large and medium-sized cities to provide services to local residents.
文摘Academics have yet to agree on the effectiveness of the precautionary saving theory in explaining Chinese households’saving behavior.With the Wenchuan megaearthquake of 2008 as an uncertain event to overcome the endogeneity problem of income volatility,this paper puts forward a brand-new hypothesis that"an earthquake influences household saving rate through its effects on expected income and the variance of expected income."Then,we employ propensity score matching-difference-in-differences(PSMDID)method,the systematic GMM methods,the synthetic control method,together with instrumental variable method,for an analysis of Chinese Household Income Project(CHIP)and inter-provincial data at the micro and macro levels,respectively.We find that the Wenchuan mega-earthquake was followed by an increase in the variance of household expected income in Sichuan and a significant rise in the household saving rate.Second,social protection is negatively correlated with expected income,and has a significant substitutive relationship with saving rate.This finding indirectly proves that the earthquake’s impact on the household saving rate is subject to the variance of expected income,shedding light on how the precautionary saving motivation works in the real world.
基金sponsored by the Major Project of the Key Research Base of the Ministry of Education(Grant No.13JJD790036).
文摘Cash flow statements suggest that China’s rising labor remuneration has had a major impact on its national savings rate since 2008.Accordingly,this paper proposes labor remuneration hypotheses to explain the evolving trend of China’s national savings rate.We hypothesize that:(1)The certainty and predictability of household labor remuneration have led to excess sensitivity to consumption,with a corresponding decrease in the household savings rate;(2)rising household labor remuneration means a greater share of labor remuneration is paid by firms,resulting in a smaller corporate savings rate;(3)the increase in the payment of labor remuneration by firms as a share of national disposable income has resulted in the government spending more on social welfare and public services resulting in the government having a declining share of disposable income,less propensity to save,and a falling government savings rate.Using China’s provincial panel data of 2008-2016,we performed an empirical test with the minimum wage standard as the instrumental variable to verify the above hypothesis.To cope with economic growth pressures,China needs to shift from an investment-driven to a consumption-driven growth model and prioritize investment efficiency over quantity.
文摘Since Piketty offered a new view of capital/income ratio, numerous attempts have been made to examine the relationship between return on capital, economic growth and the capital/income ratio. This paper attempts to shed new light on this field. More precisely, following recent literatures that pay attention to dynamics of external balance sheets of countries, we examine if Piketty’s results for large countries are robust for a country that takes the world rate of return on capital as given and whose savings rate increases gradually from negative value. It is revealed that for such a country, (1) Kuznets curve is drawn and (2) capital/income ratio decreases in accordance with a rise in savings rate and return on capital.
文摘“” , “” “ ”, “” ; “ ”, “” : 2000, , , 1996—200630: The paper examines the micro-mechanism for the high savings rate in China from public finance view. We find that the self-interest of government has played an important role in the rising national savings rate since 2000. The improved SOE profitability has enhanced the government incentive to save for the investment. This has crowded out public expenditures on technology, education, medicare and social safety net. As a result, the private sector has to increase precautionary savings. The empirical study based on panel data of 30 provinces from 1996 to 2006 demonstrates that the savings rate of the public sector is positively related to SOE profitability, and the private sector savings rate is negatively related to the ratio of public expenditures to the disposable income of the public sector.View full textDownload full text
文摘In an attempt to entice consumers to save less and spend more, China has focused on perfecting its social security system, reforming taxation and dividend-sharing proportion between the government and state-owned enterprises. Liu Yuhui, Director of the China Economy Appraisal and Rating Center at the Institute of Finance and Banking, the Chinese Academy of Social Sciences, offered his insights in an Economic Observer article. Edited excerpts
基金This study was financially supported by the National Natural Science Foundation of China(52072156)the Postdoctoral Foundation of China(2020M682269).
文摘The vehicle industry is always in search of breakthrough energy-saving and emission-reduction technologies.In recent years,vehicle intelligence has progressed considerably,and researchers are currently trying to take advantage of these developments.Here we consider the case of many vehicles forming a queue,i.e.,vehicles traveling at a predetermined speed and distance apart.While the majority of existing studies on this subject have focused on the influence of the longitudinal vehicle spacing,vehicle speed,and the number of vehicles on aerodynamic drag and fuel economy,this study considers the lateral offset distance of the vehicle queue.The group fuel consumption savings rate is calculated and analyzed.As also demonstrated by experimental results,some aerodynamic benefits exist.Moreover,the fuel consumption saving rate of the vehicle queue decreases as the lateral offset distance increases.
基金the sponsorship of Major Project under the Special Foundation of the Ministry of Education for Basic University Research Funds Study on China's International Competitiveness under New-Type International Production System
文摘By creating a two-sector intertemporal and intergenerational small open economy model,this paper investigates how real exchange rate responds to demographic shifts in the long term.The result shows that when the capital density of tradable goods sector exceeds that of non-tradable goods sector in a country,an increase in the country's elderly dependency rate(ODR) will cause its real exchange rate to appreciate.In addition,higher savings rate or per capita labor income means that real exchange rate is more responsive to ODR variations.We conducted an econometric test on our theoretical hypotheses using the data of 214 countries and regions during 1980-2013.Empirical result indicates that an increase of ODR will cause real exchange rate to appreciate.This result is robust and unaffected by sample grouping characteristics and differences.An increase in savings rate will significantly increase the ODR elasticity of real exchange rate.This conclusion is also significant and robust for overall samples and categorized samples(except for developed countries) and generally consistent with our theoretical hypothesis.However,our empirical research generally does not support the hypothesis that higher labor income increases the responsiveness of real exchange rate to ODR.This study is of great significance to unravel the effect of China's ageing population on the longterm variations of renminbi's exchange rate.
文摘The level of saving not only influences the life of individuals, but also plays an important role in a country's development. Accordingly, the studying on saving is becoming a focus problem in modem life. In recent years, the personal saving rate in the United States has fallen sharply, but the personal saving rate in China is at an astoundingly high level. This paper studies this problem with the positive analysis method from the situation; the reasons of the saving rate disparity between the U.S. and .China, and put forward some proposals about how to deal with the saving problems.
基金Funded by the National Science Foundation of China(No.50772131)the National High-tech R&D Program of China(863Program)(No.2011AA322100)+1 种基金the Key Project of Chinese Ministry of Education(No.106086)the Fundmental Research Funds for the Central Universities(No.2010YJ05)
文摘A water-conducting polyacrylamide/montmorillonite coating was prepared by solutionblending.The coating was coated on fiber and then composited with polymer to form a composite film material that used for water saving and tree planting in arid and desert regions.The coating's water-conducting characteristics and dynamic self-adjusting behavior were investigated by Fourier transform infrared(FTIR)spectroscopy,thermal analysis(TG-DTA),and environmental scanning electron microscopy(ESEM).The results showed that the coating's water-conducting rate increased but water-retention capacity weakened with increasing montmorillonite content.The water-loss rate was positively related to temperature and negatively related to soil moisture.Water potential greatly influenced the water-conducting rate of the coating during its water conduction process.When the coating was at a low water potential,the montmorillonite particles interconnected and water was conducted quickly via montmorillonite layers,whereas when the coating was at a high potential,the montmorillonite particles disconnected and water was conducted slowly via the swelled polyacrylamide net structure.The rate can be regulated by changing the proportion of polyacrylamide and montmorillonite to guarantee a reasonable water supply for trees and make trees easier to survive.Thus,the survival rate of trees can be increased and the use of water resources can be significantly reduced.
基金the National Natural Sci-ence Foundation of China (Grant No.70673069)the Ministry of Education’s philosophy & social sciences research project (Grant No.05JZD00018)
文摘Today the resources are becoming scarcer, which should not be regarded as unexhausted any more. Correspondingly, the production would be constrained by the scarcity of resources clearly. Then the economic researchers would pay much more attention to reducing the consumption of natural resources in the future. Therefore this paper brings foreword the conception of elasticity ratio of resource consumption based on the concept of elasticity and analyzes the relationship between the parameters. For the certain relationships between the elasticity ratio of resource consumption and resource consumption, this paper will try to reveal, to keep economy growing while resource consumption reducing, what conditions should be met as to the relationships among resource productivity, its growth rate, energy saving efficiency, economic growth rate and elasticity ratio of resource consumption. This paper proves the relationship between the China's energy consumption and economy growth using statistic data from 1978 to 2003.
文摘This paper presents a detailed analysis of the Chinese saving rate based on the flow offunds data. It finds that the most widely adopted view of precautionary saving, which is regarded as the top reason for maintaining a high saving rate in China, is misleading because this conclusion is drawn from the household survey data. In fact, the household saving rate has declined dramatically since the mid-1990s, as is observed from the flow of funds framework. The high national saving rate is attributed to the increasing shares of both government and corporation disposable incomes. Insufficient consumption demand is caused by the persistent decrease in percentage share of household to national disposable income. Governmentdirected income redistribution urgently needs to be improved to accelerate consumption, which in turn would make the Chinese economy less investment-led and help to reduce the current account surplus.
基金supported by the Korea government through the Korea institute of Energy Technology Evaluation and Planning(KETEP)The grant number is 20132010101870 for the Promotion of Science
文摘Centrifugal pumps are being widely used in many industrial and commercial applications.Many of these pumps are being operated at constant speed but could provide energy savings through adjustable speed operations.The purpose of this study was to get the energy saving rates of the multistage centrifugal pump with variable speed conditions.For this investigation an experimental set up of variable flow and pressure system was made to get energy saving rates and numerical analyses are applied to validate the pump performance.The energy saving and therefore the cost saving depends on the specific duty cycle of which the machine operates.Duty cycle is the proportion of time during which a component,device and system is operated.The duty cycle segmented into different flow rates and weighting the average value for each segment by the interval time.The system was operated at 50%or less of the pump capacity.The input power of the system was carried out by pump characteristics curve of each operating point.The energy consumption was done by the product of specific duty cycle and the input power of the system for constant speed and variable speed drive operation.The total energy consumed for constant speed drive pump was 75,770 k W.hr and for variable speed drive pump was 31,700 k W.hr.The total energy saving of the system was 44,070 k W.hr or 58.16%annually.So,this paper suggests a method of implementing an energy saving on variable-flow and pressure system of the multistage centrifugal pump.
文摘On the basis of the 1992-2003 flow of funds accounts for China released by the National Statistics Bureau, this article conducts a comparative analysis of the saving rates of the household, corporate and government sectors from the perspective of income distribution and saving propensity. We found that although the household sector had the highest saving rate, it had actually trended downwards since 1992, as a result of falling labor compensation, property income and income from redistribution. Over this period, the corporate saving rate rose slowly, mainly because of a prolonged period of relatively low wage and interest costs rather than increased profitability. The government saving rate, which remained low in the last century, rose dramatically after 2000. The main reasons for this were the ever- increasing share of government disposable revenue in national income distribution via primary distribution and redistribution and the sector's increased saving propensity. Our policy recommendations suggest that in order to implement an economic development strategy centered on boosting domestic consumption, China should shift its economic focus to improving the income distribution structure and increasing household income. For this purpose, fiscal policies should be oriented toward increased public financing, public expenditure and social security expenditure and toward higher labor compensation based on increased productivity in the corporate sector. These aims should be taken as the objectives of national c regulation.
基金supported by the National Natural Science Foundation of China (10671170, 60773100)the Natural Science Foundation of Hebei Province (2009000475, 2008000864)
文摘IEEE 802.16e is currently the latest broadband wireless access standard designed to support mobility. In mobile networks, how to control energy consumption is one of the most important issues for battery-powered mobile stations. The standard proposes an energy saving mechanism named 'sleep mode' for conserving the power of mobile stations. According to the operation principle of the sleep mode for downlink traffic in the type I power saving class, considering the self-similar nature of massive multimedia data in wireless networks, a discrete-time batch arrival Geom^x/G/1 queuing model with a close-down time and multiple vacations is built. The batch size is supposed to be Pareto distributed. By employing an embedded Markov chain method, the average queue length and the average sojourn time of the system model are derived. Correspondingly, the performance measures are obtained of the energy saving rate and the average packet delay time for the sleep mode in the IEEE 802.16e. The numerical results demonstrate the dependency relationships between the system performance measures and the system parameters with different offered loads and different self-similar degrees. Furthermore, a cost model is developed to determine the optimum length of the close-down time for minimizing the total system cost.