On the basis of the analysis on the disadvantages of the original goal-setting about rock drivage, this paper defined the "life cycle quality". With project management theory and the Cobb-Douglas function, "quality...On the basis of the analysis on the disadvantages of the original goal-setting about rock drivage, this paper defined the "life cycle quality". With project management theory and the Cobb-Douglas function, "quality-cost and quality-price curve model" and the "total cost-period prediction model" were built. Then the goal-setting method of the balance among quality, cost and period of rock drivage was constructed by finding "life cycle cost" through "life cycle quality" using "quality-cost and quality-price curve model" and ensuring period through "life cycle cost" using "total cost-period prediction model" (hereinafter referred to as the "three goals balance method"). "Value contribution" which is the value of the contribution to a mine because of rock drivage, was found in the process of constructing the "quality-cost and quality-price curve model". An industrial test was done in coal mine A with the research results, staff footage efficiency improved by 24.24%, the period shortened by 14.3%, the "life cycle cost" dropped by 2.09%, the "life cycle quality price" improved by 3.29%, and value contribution increased by 25.3%. The result shows that the new goal method setting on the basis of coal mine profit maximization can ensure construc- tion period. At the same time, it can realize cost and quality objectives and the optimization and balance of relationship among them; rewarding excavation teams by "value contribution" can combine organizational goal with personal goal, it significantly raise the employee's work efficiency.展开更多
Medical education is an expensive activity.It is also a very long-term activity.Medical education interventions today will have impact up for 40 years into the future as today's medical students continue to practice ...Medical education is an expensive activity.It is also a very long-term activity.Medical education interventions today will have impact up for 40 years into the future as today's medical students continue to practice over a long career.The expense of medical education has led to a new interest in how to ensure maximum returns for educational investment.The new discipline of cost and value in medical education is clearly in its infancy with relatively few papers so far reporting rigorous results on the cost effectiveness or cost benefit or cost utility ratios of education interventions.展开更多
Nevada is one of the major states that are currently suffering from graffiti problem. It was estimated that graffiti costs Southern Nevada around $30 million per year. The major highway structures that were suffering ...Nevada is one of the major states that are currently suffering from graffiti problem. It was estimated that graffiti costs Southern Nevada around $30 million per year. The major highway structures that were suffering from graffiti were bridges, sound walls, retaining walls and traffic signs. Removing graffiti from these infrastructures was a big challenge to the maintenance division of Nevada Department of Transportation (NDOT). Thus, the department was looking for cost effective proactive countermeasures to prevent graffiti on highway infrastructure. This study first identified a spectrum of proactive countermeasures, and then evaluated them by conducting a cost-benefit analysis. Pedestrian fencing and chain link fence were found to be cost effective countermeasures for preventing graffiti on bridges and sound walls. However, for relative long sound walls, the chain link becomes less cost effective. Rat guard was found to be cost effective for road signs;however, it was more useful for traffic signs that are located in the area where the taggers cannot find the way to bypass the rat guard. Coating and landscaping were found to be cost effective for small structures. The security camera countermeasure was not cost effective at the locations where the reduction in graffiti was small. The software for spectrometers was relatively high cost and might hinder the cost effectiveness of this countermeasure. To reduce the cost of the software, developing the software internally could be adopted. And finally, the electronic database was recommended since it was not difficult to develop and maintain.展开更多
With the implementation of the policy of popularization of education, rural families make the choice of interests and behavior decisions through the calculation of their own benefits and costs, and gradually become th...With the implementation of the policy of popularization of education, rural families make the choice of interests and behavior decisions through the calculation of their own benefits and costs, and gradually become the main body of rural education investment decisions. The relationship between educational cost and income plays a major role in the rural family education investment. Based on the current situation of rural education in our country, this paper focuses on the risk of rural education investment and rural education costs and benefits, and then puts forward scientific, operational measures and suggestions.展开更多
Based on the fact that the software development cost is an important factorto control the whole project, we discuss the relationship between the software development cost andsoftware reliability according to the empir...Based on the fact that the software development cost is an important factorto control the whole project, we discuss the relationship between the software development cost andsoftware reliability according to the empirieal data collected from the development process. Byevolutionary modeling we get an empirical model of the relationship between cost and softwarereliability, and validate the estimate results with the empirical data.展开更多
In recent years, the sodium storage mechanism and performance optimization of FeS2 have been studied intensively. However, before the commercial application of FeS2, preconditions of low-cost, simple craft and scale p...In recent years, the sodium storage mechanism and performance optimization of FeS2 have been studied intensively. However, before the commercial application of FeS2, preconditions of low-cost, simple craft and scale production of nanoscale FeS2 are also essential. Based on above challenges, mesh-like FeS2/carbon tube/FeS2 composites are prepared simply from green, low-cost and renewable natural herb in this work. With the assistance of protogenetic interconnected carbon tube network(only 5.3 wt%), FeS2/carbon tube/FeS2 composites show high capacity(542.2 mA h g^-1), good stability(< 0.005% per cycle over 1000 cycles), and excellent rate performance(426.2 mA h g^-1 at 2 A g^-1).The outstanding electrochemical performance of FeS2/carbon tube/FeS2 composites may be attributed to the unique interconnected reticular structure, meaning that FeS2 nanoparticles are effectively immobilized by carbon tube network via physical encapsulation and chemical bonding.More importantly, this work may provide green and low cost preparation method for specially structured metal sulfides/carbon composites,which promotes their commercial utilization in environmentally friendly energy storage system.展开更多
We present a scheme for probabilistic remote preparation of multi-qubit with three-party from a sender to either of two receivers. The quantum channel is composed of a partial entangled tripartite GHZ state. We obtain...We present a scheme for probabilistic remote preparation of multi-qubit with three-party from a sender to either of two receivers. The quantum channel is composed of a partial entangled tripartite GHZ state. We obtain the successful totM probability of the scheme in the general case and special case, respectively. We also calculate total classical communication cost required in the RSP process with three-party in the general case and special case, respectively.展开更多
As the smart home is the end-point power consumer, it is the major part to be controlled in a smart micro grid. There are so many challenges for implementing a smart home system in which the most important ones are th...As the smart home is the end-point power consumer, it is the major part to be controlled in a smart micro grid. There are so many challenges for implementing a smart home system in which the most important ones are the cost and simplicity of the implementation method. It is clear that the major share of the total cost is referred to the internal controlling system network; although there are too many methods proposed but still there is not any satisfying method at the consumers' point of view. In this paper, a novel solution for this demand is proposed, which not only minimizes the implementation cost, but also provides a high level of reliability and simplicity of operation; feasibility, extendibility, and flexibility are other leading properties of the design.展开更多
AIM:To evaluate the changing trends and outcomes of colorectal cancer(CRC)surgery performed at a large single institution in Taiwan.METHODS:This study retrospectively analyzed 778patients who received colorectal cance...AIM:To evaluate the changing trends and outcomes of colorectal cancer(CRC)surgery performed at a large single institution in Taiwan.METHODS:This study retrospectively analyzed 778patients who received colorectal cancer surgery at E-Da Hospital in Taiwan from 2004 to 2009.These patients were from health examination,inpatient or emergency settings.The following attributes were analyzed in patients who had undergone CRC surgical procedures:gender,age,source,surgical type,tumor number,tumor size,number of lymph node metastasis,pathologic differentiation,chemotherapy,distant metastases,tumor site,tumor stage,average hospitalization cost and average lengths of stay(ALOS).The odds ratio and95%confidence intervals were calculated to assess the relative rate of change.Regression models were employed to predict average hospitalization cost and ALOS.RESULTS:The study sample included 458(58.87%)males and 320(41.13%)females with a mean age of64.53 years(standard deviation,12.33 years;range,28-86 years).The principal patient source came from inpatient and emergency room(96.02%).The principal tumor sites were noted at the sigmoid colon(35.73%)and rectum(30.46%).Most patients exhibited a tumor stage of 2(37.28%)or 3(34.19%).The number of new CRC surgeries performed per 100000 persons was12.21 in 2004 and gradually increased to 17.89 in 2009,representing a change of 46.52%.During the same period,the average hospitalization cost and ALOS decreased from$5303 to$4062 and from 19.7 to 14.4 d,respectively.The following factors were associated with considerably decreased hospital resource utilization:age,source,surgical type,tumor size,tumor site,and tumor stage.CONCLUSION:These results can be generalized to patient populations elsewhere in Taiwan and to other countries with similar patient profiles.展开更多
In this present paper, an inventory model with a generalised exponential decreasing demand is considered. A numerical example is used to illustrate the application of the model. Sensitivity analysis of the optimal sol...In this present paper, an inventory model with a generalised exponential decreasing demand is considered. A numerical example is used to illustrate the application of the model. Sensitivity analysis of the optimal solution with respect to various parameters is carried out to see the effect of parameter changes on the solution.展开更多
China's economic growth miracle despite complicated administrative approval formalities prompted us to raise the following question: ls it true that reforming administrative approval will promote economic growth? B...China's economic growth miracle despite complicated administrative approval formalities prompted us to raise the following question: ls it true that reforming administrative approval will promote economic growth? Based on our analysis on market entry, we discovered that reforming administrative approval will spur economic growth by reducing transaction cost for firms. Administrative approval may suppress social cost and propel China's economic growth; China's gradualist approval reforms may indeed propel economic growth by reducing transaction cost for firms. With the data of prefecture-level cities during 2000-2013 and data of companies listed on the SME board during 2010-2014, we tested the effects of approval reforms on economic growth and on transaction cost, and employed instrumental variable and PSM for the treatment of the endogeneity problem - all these tests led to robust and consistent results. Moreover, we discovered that difference in government policy implementation in the approval process is the root cause of corruption and rent seeking.展开更多
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
Medical education is associated with significant costs[1].These costs have led to a growing interest in how to deliver high quality or high quantity education on a limited budget.This in turn has led to an interest in...Medical education is associated with significant costs[1].These costs have led to a growing interest in how to deliver high quality or high quantity education on a limited budget.This in turn has led to an interest in how best to measure quantity,quality and cost and how to track these variables over time.The ultimate aim of the interest in cost and value in medical education is to展开更多
This paper analyzes the launch price of the launch vehicles, domestic and abroad, studies the status and trend of the low cost launch vehicles, and introduces two measures to reduce the cost by means of evolved and di...This paper analyzes the launch price of the launch vehicles, domestic and abroad, studies the status and trend of the low cost launch vehicles, and introduces two measures to reduce the cost by means of evolved and disruptive technologies, utilizing the concept of low cost manufacturing and operating modes as well. This paper also analyzes the launch strategies for small satellites such as piggyback, networking launch, and single launch with a small launch vehicle(SLV). Finally, the development trend of reusable launch vehicles is discussed as well as the development prospects for China's reusable launch vehicle.展开更多
The purpose of this paper is to expand Trivedi’s study on the influence of channel structure ,which based on product difference, to cost difference; and analyze the evolution course of channel structure under differe...The purpose of this paper is to expand Trivedi’s study on the influence of channel structure ,which based on product difference, to cost difference; and analyze the evolution course of channel structure under different conditions. We find that like product difference, cost difference have important influence on the choice of channel structure. This paper has improved the present result and provided proof for the choice of channel structure under different environments.展开更多
Many populations of the two-spotted spider mite, Tetranychus urticae Koch, have developed high levels of resistance to the pesticide abamectin in China and other countries. This study developed a near-isogenic line to...Many populations of the two-spotted spider mite, Tetranychus urticae Koch, have developed high levels of resistance to the pesticide abamectin in China and other countries. This study developed a near-isogenic line to understand better the inheritance, cross-resistance, and fitness costs associated with abamectin resistance in the field population of T. urticae in China. We introduced the trait that confers extremely high abamectin resistance in a field-collected population of T. urticae into a susceptible laboratory strain(IPP-SS) to generate an abamectin-resistant near-isogenic line(NIL-Aba).This process was carried out through multiple backcrossing to IPP-SS and via parthenogenesis and abamectin screening. Compared with IPP-SS, the NIL-Aba strain had a 25 147-fold resistance to abamectin and a high level of cross-resistance to bifenthrin(288.17-fold), an intermediate level to emamectin benzoate(42.57-fold), and low levels to bifenazate, chlorfenapyr, cyflumetofen, cyenopyrafen, and cyetpyrafen with resistance ranging from 3.18-to 9.31-fold.But it had no cross-resistance to profenofos. The resistance to abamectin in NIL-Aba was autosomal, incompletely dominant, and polygenic. Based on two sex life table parameters, no fitness cost was found in NIL-Aba. Establishing the NIL-Aba strain provides a reliable basis for an in-depth study of abamectin resistance in T. urticae. New information on toxicological characteristics and fitness cost should facilitate the management of abamectin resistance in field populations of T. urticae.展开更多
To understand the reason for the success of weeds,we investigated the energetic cost of leaf construction,and certain ecophysiological traits of rice and its dominant weeds.On physiological basis among all weeds,Caesu...To understand the reason for the success of weeds,we investigated the energetic cost of leaf construction,and certain ecophysiological traits of rice and its dominant weeds.On physiological basis among all weeds,Caesulia axillaris Roxburgh was found to be the most serious,followed by Echinochloa cruss-galli L.Beauv and Echinochloa colonum L.Link,while Fimbristylis miliaceae L.Vahl and Cyperus iria L.were moderate weeds of the rice fields.C.axillaris had the lowest leaf construction cost (LCC) both on a mass basis (1.15 g/g) and on a unit area basis (22.93 g/m2).Comparatively higher specific leaf area,photosynthetic rate,photosynthetic nitrogen use efficiency,leaf area ratio and leaf area index provided C.axillaris with further competitive advantage.Low LCC suggests that weeds utilize carbon resource more efficiently than the crop and potentially spend the saved energy on other competitive strategies viz.seed production,biomass production and high relative growth rate,which results in low crop yield and increase in weed seed bank.展开更多
We present a scheme for probabilistic remote preparation of the four-particle entangled W state by using four partial entangled two-particle states as the quantum channel. In this scheme, if Alice (sender) performs ...We present a scheme for probabilistic remote preparation of the four-particle entangled W state by using four partial entangled two-particle states as the quantum channel. In this scheme, if Alice (sender) performs four-particle projective measurements and Bob (receiver) adopts some appropriate unitary operation, the remote state preparation can be successfully realized with certain probability. The classical communication cost is also calculated. However, the success probability of preparation can be increased to 1 for four kinds of special states.展开更多
The purpose of this research was to assess money spent and calories consumed by college students from fast food restaurants located on and around a southern college campus. A convenience sample (n = 152) of undergradu...The purpose of this research was to assess money spent and calories consumed by college students from fast food restaurants located on and around a southern college campus. A convenience sample (n = 152) of undergraduate college students (aged 18 - 24) at a southern university participated in a survey that measured dietary intake from seven local fast food chains using a researcher developed food frequency questionnaire and a lifestyle behavior survey that collected data on health practices. A strong positive correlation was found between total monthly fast food expense and total monthly fast food caloric consumption (r(150) = 0.94, p t test comparing the mean monthly fast food restaurant expense males to females found a significant difference between the two groups (t(150) = 4.19, p < 0.05).The more money spent by college students contributed to a higher amount of calories consumed from fast food in a typical month. Future research needs to determine if college students are contributing to the high obesity rate and if limiting fast food restaurants on and around college campuses would help decrease fast food consumption in college students.展开更多
This paper analyzes the portfolio with inflation and transaction cost by broadening mean-variance model assumption. Based on the comparison between efficient frontier with and without transaction cost and inflation, t...This paper analyzes the portfolio with inflation and transaction cost by broadening mean-variance model assumption. Based on the comparison between efficient frontier with and without transaction cost and inflation, the conclusion is drawn that the new efficient frontier is revolving and the new investment strategy changes. Furthermore, we provide a numerical example based on real world data.展开更多
文摘On the basis of the analysis on the disadvantages of the original goal-setting about rock drivage, this paper defined the "life cycle quality". With project management theory and the Cobb-Douglas function, "quality-cost and quality-price curve model" and the "total cost-period prediction model" were built. Then the goal-setting method of the balance among quality, cost and period of rock drivage was constructed by finding "life cycle cost" through "life cycle quality" using "quality-cost and quality-price curve model" and ensuring period through "life cycle cost" using "total cost-period prediction model" (hereinafter referred to as the "three goals balance method"). "Value contribution" which is the value of the contribution to a mine because of rock drivage, was found in the process of constructing the "quality-cost and quality-price curve model". An industrial test was done in coal mine A with the research results, staff footage efficiency improved by 24.24%, the period shortened by 14.3%, the "life cycle cost" dropped by 2.09%, the "life cycle quality price" improved by 3.29%, and value contribution increased by 25.3%. The result shows that the new goal method setting on the basis of coal mine profit maximization can ensure construc- tion period. At the same time, it can realize cost and quality objectives and the optimization and balance of relationship among them; rewarding excavation teams by "value contribution" can combine organizational goal with personal goal, it significantly raise the employee's work efficiency.
文摘Medical education is an expensive activity.It is also a very long-term activity.Medical education interventions today will have impact up for 40 years into the future as today's medical students continue to practice over a long career.The expense of medical education has led to a new interest in how to ensure maximum returns for educational investment.The new discipline of cost and value in medical education is clearly in its infancy with relatively few papers so far reporting rigorous results on the cost effectiveness or cost benefit or cost utility ratios of education interventions.
文摘Nevada is one of the major states that are currently suffering from graffiti problem. It was estimated that graffiti costs Southern Nevada around $30 million per year. The major highway structures that were suffering from graffiti were bridges, sound walls, retaining walls and traffic signs. Removing graffiti from these infrastructures was a big challenge to the maintenance division of Nevada Department of Transportation (NDOT). Thus, the department was looking for cost effective proactive countermeasures to prevent graffiti on highway infrastructure. This study first identified a spectrum of proactive countermeasures, and then evaluated them by conducting a cost-benefit analysis. Pedestrian fencing and chain link fence were found to be cost effective countermeasures for preventing graffiti on bridges and sound walls. However, for relative long sound walls, the chain link becomes less cost effective. Rat guard was found to be cost effective for road signs;however, it was more useful for traffic signs that are located in the area where the taggers cannot find the way to bypass the rat guard. Coating and landscaping were found to be cost effective for small structures. The security camera countermeasure was not cost effective at the locations where the reduction in graffiti was small. The software for spectrometers was relatively high cost and might hinder the cost effectiveness of this countermeasure. To reduce the cost of the software, developing the software internally could be adopted. And finally, the electronic database was recommended since it was not difficult to develop and maintain.
文摘With the implementation of the policy of popularization of education, rural families make the choice of interests and behavior decisions through the calculation of their own benefits and costs, and gradually become the main body of rural education investment decisions. The relationship between educational cost and income plays a major role in the rural family education investment. Based on the current situation of rural education in our country, this paper focuses on the risk of rural education investment and rural education costs and benefits, and then puts forward scientific, operational measures and suggestions.
基金Supported by the National Natural Science Foun dation of China(60173063)
文摘Based on the fact that the software development cost is an important factorto control the whole project, we discuss the relationship between the software development cost andsoftware reliability according to the empirieal data collected from the development process. Byevolutionary modeling we get an empirical model of the relationship between cost and softwarereliability, and validate the estimate results with the empirical data.
基金supported by the Natural Science Foundation of China (Grant No. U1804126, U1804129, 21671205, 21771164 and 21701202)Key Scientific Research Projects of Universities in Henan Province (Grant No. 19A430032 and 18A430034)+2 种基金Program for Interdisciplinary Direction Team in Zhongyuan University of Technologythe Collaborative Innovation Centre of Henan Textile and Clothing Industrythe Innovation Scientists and Technicians Troop Construction Projects of Henan Province (Grant No. 164100510007 and CXTD2015018)
文摘In recent years, the sodium storage mechanism and performance optimization of FeS2 have been studied intensively. However, before the commercial application of FeS2, preconditions of low-cost, simple craft and scale production of nanoscale FeS2 are also essential. Based on above challenges, mesh-like FeS2/carbon tube/FeS2 composites are prepared simply from green, low-cost and renewable natural herb in this work. With the assistance of protogenetic interconnected carbon tube network(only 5.3 wt%), FeS2/carbon tube/FeS2 composites show high capacity(542.2 mA h g^-1), good stability(< 0.005% per cycle over 1000 cycles), and excellent rate performance(426.2 mA h g^-1 at 2 A g^-1).The outstanding electrochemical performance of FeS2/carbon tube/FeS2 composites may be attributed to the unique interconnected reticular structure, meaning that FeS2 nanoparticles are effectively immobilized by carbon tube network via physical encapsulation and chemical bonding.More importantly, this work may provide green and low cost preparation method for specially structured metal sulfides/carbon composites,which promotes their commercial utilization in environmentally friendly energy storage system.
基金National Natural Science Foundation of China under Grant Nos.60674040,10325523,and 10775048the National Fundamental Research Program of China under Grant No.2007CB925204China Postdoctoral Science Foundation
文摘We present a scheme for probabilistic remote preparation of multi-qubit with three-party from a sender to either of two receivers. The quantum channel is composed of a partial entangled tripartite GHZ state. We obtain the successful totM probability of the scheme in the general case and special case, respectively. We also calculate total classical communication cost required in the RSP process with three-party in the general case and special case, respectively.
文摘As the smart home is the end-point power consumer, it is the major part to be controlled in a smart micro grid. There are so many challenges for implementing a smart home system in which the most important ones are the cost and simplicity of the implementation method. It is clear that the major share of the total cost is referred to the internal controlling system network; although there are too many methods proposed but still there is not any satisfying method at the consumers' point of view. In this paper, a novel solution for this demand is proposed, which not only minimizes the implementation cost, but also provides a high level of reliability and simplicity of operation; feasibility, extendibility, and flexibility are other leading properties of the design.
文摘AIM:To evaluate the changing trends and outcomes of colorectal cancer(CRC)surgery performed at a large single institution in Taiwan.METHODS:This study retrospectively analyzed 778patients who received colorectal cancer surgery at E-Da Hospital in Taiwan from 2004 to 2009.These patients were from health examination,inpatient or emergency settings.The following attributes were analyzed in patients who had undergone CRC surgical procedures:gender,age,source,surgical type,tumor number,tumor size,number of lymph node metastasis,pathologic differentiation,chemotherapy,distant metastases,tumor site,tumor stage,average hospitalization cost and average lengths of stay(ALOS).The odds ratio and95%confidence intervals were calculated to assess the relative rate of change.Regression models were employed to predict average hospitalization cost and ALOS.RESULTS:The study sample included 458(58.87%)males and 320(41.13%)females with a mean age of64.53 years(standard deviation,12.33 years;range,28-86 years).The principal patient source came from inpatient and emergency room(96.02%).The principal tumor sites were noted at the sigmoid colon(35.73%)and rectum(30.46%).Most patients exhibited a tumor stage of 2(37.28%)or 3(34.19%).The number of new CRC surgeries performed per 100000 persons was12.21 in 2004 and gradually increased to 17.89 in 2009,representing a change of 46.52%.During the same period,the average hospitalization cost and ALOS decreased from$5303 to$4062 and from 19.7 to 14.4 d,respectively.The following factors were associated with considerably decreased hospital resource utilization:age,source,surgical type,tumor size,tumor site,and tumor stage.CONCLUSION:These results can be generalized to patient populations elsewhere in Taiwan and to other countries with similar patient profiles.
文摘In this present paper, an inventory model with a generalised exponential decreasing demand is considered. A numerical example is used to illustrate the application of the model. Sensitivity analysis of the optimal solution with respect to various parameters is carried out to see the effect of parameter changes on the solution.
文摘China's economic growth miracle despite complicated administrative approval formalities prompted us to raise the following question: ls it true that reforming administrative approval will promote economic growth? Based on our analysis on market entry, we discovered that reforming administrative approval will spur economic growth by reducing transaction cost for firms. Administrative approval may suppress social cost and propel China's economic growth; China's gradualist approval reforms may indeed propel economic growth by reducing transaction cost for firms. With the data of prefecture-level cities during 2000-2013 and data of companies listed on the SME board during 2010-2014, we tested the effects of approval reforms on economic growth and on transaction cost, and employed instrumental variable and PSM for the treatment of the endogeneity problem - all these tests led to robust and consistent results. Moreover, we discovered that difference in government policy implementation in the approval process is the root cause of corruption and rent seeking.
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Medical education is associated with significant costs[1].These costs have led to a growing interest in how to deliver high quality or high quantity education on a limited budget.This in turn has led to an interest in how best to measure quantity,quality and cost and how to track these variables over time.The ultimate aim of the interest in cost and value in medical education is to
文摘This paper analyzes the launch price of the launch vehicles, domestic and abroad, studies the status and trend of the low cost launch vehicles, and introduces two measures to reduce the cost by means of evolved and disruptive technologies, utilizing the concept of low cost manufacturing and operating modes as well. This paper also analyzes the launch strategies for small satellites such as piggyback, networking launch, and single launch with a small launch vehicle(SLV). Finally, the development trend of reusable launch vehicles is discussed as well as the development prospects for China's reusable launch vehicle.
基金Supported by the National Preeminence Youth Foundation of China(No.79275002)
文摘The purpose of this paper is to expand Trivedi’s study on the influence of channel structure ,which based on product difference, to cost difference; and analyze the evolution course of channel structure under different conditions. We find that like product difference, cost difference have important influence on the choice of channel structure. This paper has improved the present result and provided proof for the choice of channel structure under different environments.
基金funded by the National Natural Science Foundation of China (32072458)the earmarked fund for China Agriculture Research System (CARS-25)the Beijing Key Laboratory for Pest Control and Sustainable Cultivation of Vegetables, China, and the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences (CAAS-ASTIPIVFCAAS)。
文摘Many populations of the two-spotted spider mite, Tetranychus urticae Koch, have developed high levels of resistance to the pesticide abamectin in China and other countries. This study developed a near-isogenic line to understand better the inheritance, cross-resistance, and fitness costs associated with abamectin resistance in the field population of T. urticae in China. We introduced the trait that confers extremely high abamectin resistance in a field-collected population of T. urticae into a susceptible laboratory strain(IPP-SS) to generate an abamectin-resistant near-isogenic line(NIL-Aba).This process was carried out through multiple backcrossing to IPP-SS and via parthenogenesis and abamectin screening. Compared with IPP-SS, the NIL-Aba strain had a 25 147-fold resistance to abamectin and a high level of cross-resistance to bifenthrin(288.17-fold), an intermediate level to emamectin benzoate(42.57-fold), and low levels to bifenazate, chlorfenapyr, cyflumetofen, cyenopyrafen, and cyetpyrafen with resistance ranging from 3.18-to 9.31-fold.But it had no cross-resistance to profenofos. The resistance to abamectin in NIL-Aba was autosomal, incompletely dominant, and polygenic. Based on two sex life table parameters, no fitness cost was found in NIL-Aba. Establishing the NIL-Aba strain provides a reliable basis for an in-depth study of abamectin resistance in T. urticae. New information on toxicological characteristics and fitness cost should facilitate the management of abamectin resistance in field populations of T. urticae.
文摘To understand the reason for the success of weeds,we investigated the energetic cost of leaf construction,and certain ecophysiological traits of rice and its dominant weeds.On physiological basis among all weeds,Caesulia axillaris Roxburgh was found to be the most serious,followed by Echinochloa cruss-galli L.Beauv and Echinochloa colonum L.Link,while Fimbristylis miliaceae L.Vahl and Cyperus iria L.were moderate weeds of the rice fields.C.axillaris had the lowest leaf construction cost (LCC) both on a mass basis (1.15 g/g) and on a unit area basis (22.93 g/m2).Comparatively higher specific leaf area,photosynthetic rate,photosynthetic nitrogen use efficiency,leaf area ratio and leaf area index provided C.axillaris with further competitive advantage.Low LCC suggests that weeds utilize carbon resource more efficiently than the crop and potentially spend the saved energy on other competitive strategies viz.seed production,biomass production and high relative growth rate,which results in low crop yield and increase in weed seed bank.
基金supported by the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No.20060357003
文摘We present a scheme for probabilistic remote preparation of the four-particle entangled W state by using four partial entangled two-particle states as the quantum channel. In this scheme, if Alice (sender) performs four-particle projective measurements and Bob (receiver) adopts some appropriate unitary operation, the remote state preparation can be successfully realized with certain probability. The classical communication cost is also calculated. However, the success probability of preparation can be increased to 1 for four kinds of special states.
文摘The purpose of this research was to assess money spent and calories consumed by college students from fast food restaurants located on and around a southern college campus. A convenience sample (n = 152) of undergraduate college students (aged 18 - 24) at a southern university participated in a survey that measured dietary intake from seven local fast food chains using a researcher developed food frequency questionnaire and a lifestyle behavior survey that collected data on health practices. A strong positive correlation was found between total monthly fast food expense and total monthly fast food caloric consumption (r(150) = 0.94, p t test comparing the mean monthly fast food restaurant expense males to females found a significant difference between the two groups (t(150) = 4.19, p < 0.05).The more money spent by college students contributed to a higher amount of calories consumed from fast food in a typical month. Future research needs to determine if college students are contributing to the high obesity rate and if limiting fast food restaurants on and around college campuses would help decrease fast food consumption in college students.
文摘This paper analyzes the portfolio with inflation and transaction cost by broadening mean-variance model assumption. Based on the comparison between efficient frontier with and without transaction cost and inflation, the conclusion is drawn that the new efficient frontier is revolving and the new investment strategy changes. Furthermore, we provide a numerical example based on real world data.