Based on the principle of transient perturbation analysis,in this paper,a method to objectively determine the weather pattern formed by sea fog is provided.On the basis of the classification results,the circulation si...Based on the principle of transient perturbation analysis,in this paper,a method to objectively determine the weather pattern formed by sea fog is provided.On the basis of the classification results,the circulation situation,divergence and vertical velocity field,and the vertical profile of temperature and humidity are synthesized and analyzed.The basic characteristics of the circulation and physical field of sea fog under low pressure control(L type sea fog)are obtained,and the results are compared with the sea fog under the control of high pressure(H type sea fog):a)L type sea fogs potential height anomaly disturbance is mainly manifested in the low layer,and its average value is-65.66 gpm,gradually weakening upward;b)L type sea fogs inversion structure is weaker than H type sea fogs when it occurs,the fog layer is thicker and the high relative humidity level is high over the fog layer,while the H type sea fogs fog layer has a relatively obvious dry layer;c)L sea fog has three layers of structure at the vertical direction.The first layer 1000-950 hPa is convergence accompanied by weak rise and subsidence,the second layer 950-850 hPa is divergence accompanied by weak subsidence,and the third layer 850 to 500hPa is gradually strengthened.While there are two layer structures of the H type sea fog.1000 hPa is divergence accompanied by weak rising and sinking movement,950-500 hPa is a uniform subsidence movement.d)Probability density statistical analysis further quantified the vertical movement of L and H type sea fog and the distribution of relative humidity in each layer.These conclusions provide an important reference for forecasting the sea fog in the northwest of the Yellow Sea under the condition of low pressure circulation in summer.展开更多
The synthetic fuzzy assessing method is usually applied to sensory evaluation. The method has simple and reliable virtue, and it is consistent with objective evaluation results. Using this method, system status of pla...The synthetic fuzzy assessing method is usually applied to sensory evaluation. The method has simple and reliable virtue, and it is consistent with objective evaluation results. Using this method, system status of plating solution evaporator is evaluated, and the result is applied to compensate a fuzzy controller. Experimental results have shown the correctness and the validity of the proposed approach.展开更多
Whether environmental regulation can increase employment is still controversial in academic circles around the world.An important reason lies in the validity of an empirical method.Using China’s inter-provincial pane...Whether environmental regulation can increase employment is still controversial in academic circles around the world.An important reason lies in the validity of an empirical method.Using China’s inter-provincial panel data from 2003 to 2015 and the synthetic control method(SCM),this paper focuses on a test that was carried out on the basis of a quasi-natural experiment of the 2007 Emission Trading Pilot(ETP)policy.The test results show that the ETP policy has increased the average employment level by 3.25 percentage points and passed a robustness test.The robustness test using the regression control method(RCM)shows that the average employment level has risen by 3.21 percentage points.This means that the ETP policy has significantly increased employment.The paper also puts forward three policy recommendations:optimizing the trading system for emissions rights,encouraging companies to carry out cleaner production and innovation,and incorporating environmental performance assessments.展开更多
Background:At 10 a.m.on January 23,2020 Wuhan,China imposed a 76-day travel lockdown on its 11 million residents in order to stop the spread of COVID-19.This lockdown represented the largest quarantine in the history ...Background:At 10 a.m.on January 23,2020 Wuhan,China imposed a 76-day travel lockdown on its 11 million residents in order to stop the spread of COVID-19.This lockdown represented the largest quarantine in the history of public health and provides us with an opportunity to critically examine the relationship between a city lockdown on human mobility and controlling the spread of a viral epidemic,in this case COVID-19.This study aims to assess the causal impact of the Wuhan lockdown on population movement and the increase of newly confirmed COVID-19 cases.Methods:Based on the daily panel data from 279 Chinese cities,our research is the first to apply the synthetic control approach to empirically analyze the causal relationship between the Wuhan lockdown of its population mobility and the progression of newly confirmed COVID-19 cases.By using a weighted average of available control cities to reproduce the counterfactual outcome trajectory that the treated city would have experienced in the absence of the lockdown,the synthetic control approach overcomes the sample selection bias and policy endogeneity problems that can arise from previous empirical methods in selecting control units.Results:In our example,the lockdown of Wuhan reduced mobility inflow by approximately 60%and outflow by about 50%.A significant reduction of new cases was observed within four days of the lockdown.The increase in new cases declined by around 50%during this period.However,the suppression effect became less discernible after this initial period of time.A 2.25-fold surge was found for the increase in new cases on the fifth day following the lockdown,after which it died down rapidly.Conclusions:Our study provided urgently needed and reliable causal evidence that city lockdown can be an effective short-term tool in containing and delaying the spread of a viral epidemic.Further,the city lockdown strategy can buy time during which countries can mobilize an effective response in order to better prepare.Therefore,in spite of initial widespread skepticism,lockdowns are likely to be added to the response toolkit used for any future pandemic outbreak.展开更多
Generally fuzzy control system (FCS) is worked in washing machine. For the fuzzy set theory, membership functions are the building blocks. In a fuzzy set, fuzziness is determined by its membership functions. The shape...Generally fuzzy control system (FCS) is worked in washing machine. For the fuzzy set theory, membership functions are the building blocks. In a fuzzy set, fuzziness is determined by its membership functions. The shapes of membership functions are important, because it has an effect on fuzzy inference system. The shapes of membership functions can be triangular, trapezoidal and gaussian. The most widely used triangular membership function is used in this paper, because it can capture the short time period. In washing machine, open loop control system is found. This paper applies a fuzzy synthetic evaluation method (FSEM) for washing cloth in washing machine as FSEM can handle the multiple criteria with the help of evaluation matrix generated from membership function and weight matrix generated by Analytical Hierarchy Process (AHP). The purpose of this research is to minimize the wash time. By applying FSEM, we get a wash time which is less than that wash time got from applying the Mamdani approach in FCS. An example is given for illustration. For more reduction of wash time, statistical averaging method is also used. To reduce the wash time, statistical averaging method can be used in Mamdani approach also.展开更多
基金supported by National Natural Science Foundation of China(No.41576108 and No.41605006)Natural Science Foundation project of Shandong Province(No.ZR2016DB26).
文摘Based on the principle of transient perturbation analysis,in this paper,a method to objectively determine the weather pattern formed by sea fog is provided.On the basis of the classification results,the circulation situation,divergence and vertical velocity field,and the vertical profile of temperature and humidity are synthesized and analyzed.The basic characteristics of the circulation and physical field of sea fog under low pressure control(L type sea fog)are obtained,and the results are compared with the sea fog under the control of high pressure(H type sea fog):a)L type sea fogs potential height anomaly disturbance is mainly manifested in the low layer,and its average value is-65.66 gpm,gradually weakening upward;b)L type sea fogs inversion structure is weaker than H type sea fogs when it occurs,the fog layer is thicker and the high relative humidity level is high over the fog layer,while the H type sea fogs fog layer has a relatively obvious dry layer;c)L sea fog has three layers of structure at the vertical direction.The first layer 1000-950 hPa is convergence accompanied by weak rise and subsidence,the second layer 950-850 hPa is divergence accompanied by weak subsidence,and the third layer 850 to 500hPa is gradually strengthened.While there are two layer structures of the H type sea fog.1000 hPa is divergence accompanied by weak rising and sinking movement,950-500 hPa is a uniform subsidence movement.d)Probability density statistical analysis further quantified the vertical movement of L and H type sea fog and the distribution of relative humidity in each layer.These conclusions provide an important reference for forecasting the sea fog in the northwest of the Yellow Sea under the condition of low pressure circulation in summer.
文摘The synthetic fuzzy assessing method is usually applied to sensory evaluation. The method has simple and reliable virtue, and it is consistent with objective evaluation results. Using this method, system status of plating solution evaporator is evaluated, and the result is applied to compensate a fuzzy controller. Experimental results have shown the correctness and the validity of the proposed approach.
文摘Whether environmental regulation can increase employment is still controversial in academic circles around the world.An important reason lies in the validity of an empirical method.Using China’s inter-provincial panel data from 2003 to 2015 and the synthetic control method(SCM),this paper focuses on a test that was carried out on the basis of a quasi-natural experiment of the 2007 Emission Trading Pilot(ETP)policy.The test results show that the ETP policy has increased the average employment level by 3.25 percentage points and passed a robustness test.The robustness test using the regression control method(RCM)shows that the average employment level has risen by 3.21 percentage points.This means that the ETP policy has significantly increased employment.The paper also puts forward three policy recommendations:optimizing the trading system for emissions rights,encouraging companies to carry out cleaner production and innovation,and incorporating environmental performance assessments.
文摘Background:At 10 a.m.on January 23,2020 Wuhan,China imposed a 76-day travel lockdown on its 11 million residents in order to stop the spread of COVID-19.This lockdown represented the largest quarantine in the history of public health and provides us with an opportunity to critically examine the relationship between a city lockdown on human mobility and controlling the spread of a viral epidemic,in this case COVID-19.This study aims to assess the causal impact of the Wuhan lockdown on population movement and the increase of newly confirmed COVID-19 cases.Methods:Based on the daily panel data from 279 Chinese cities,our research is the first to apply the synthetic control approach to empirically analyze the causal relationship between the Wuhan lockdown of its population mobility and the progression of newly confirmed COVID-19 cases.By using a weighted average of available control cities to reproduce the counterfactual outcome trajectory that the treated city would have experienced in the absence of the lockdown,the synthetic control approach overcomes the sample selection bias and policy endogeneity problems that can arise from previous empirical methods in selecting control units.Results:In our example,the lockdown of Wuhan reduced mobility inflow by approximately 60%and outflow by about 50%.A significant reduction of new cases was observed within four days of the lockdown.The increase in new cases declined by around 50%during this period.However,the suppression effect became less discernible after this initial period of time.A 2.25-fold surge was found for the increase in new cases on the fifth day following the lockdown,after which it died down rapidly.Conclusions:Our study provided urgently needed and reliable causal evidence that city lockdown can be an effective short-term tool in containing and delaying the spread of a viral epidemic.Further,the city lockdown strategy can buy time during which countries can mobilize an effective response in order to better prepare.Therefore,in spite of initial widespread skepticism,lockdowns are likely to be added to the response toolkit used for any future pandemic outbreak.
文摘Generally fuzzy control system (FCS) is worked in washing machine. For the fuzzy set theory, membership functions are the building blocks. In a fuzzy set, fuzziness is determined by its membership functions. The shapes of membership functions are important, because it has an effect on fuzzy inference system. The shapes of membership functions can be triangular, trapezoidal and gaussian. The most widely used triangular membership function is used in this paper, because it can capture the short time period. In washing machine, open loop control system is found. This paper applies a fuzzy synthetic evaluation method (FSEM) for washing cloth in washing machine as FSEM can handle the multiple criteria with the help of evaluation matrix generated from membership function and weight matrix generated by Analytical Hierarchy Process (AHP). The purpose of this research is to minimize the wash time. By applying FSEM, we get a wash time which is less than that wash time got from applying the Mamdani approach in FCS. An example is given for illustration. For more reduction of wash time, statistical averaging method is also used. To reduce the wash time, statistical averaging method can be used in Mamdani approach also.
