Tolerance analysis is investigated under an environment of concurrent design in order to lead to optimized tolerance, as traditional tolerance analysis is often inefficient and liable to mistakes. Making full use of k...Tolerance analysis is investigated under an environment of concurrent design in order to lead to optimized tolerance, as traditional tolerance analysis is often inefficient and liable to mistakes. Making full use of knowledge in manufacturing tolerance analysis combined with the beta distribution model is introduced and applied. The use of beta distribution reflects fully actual capabilities in manufacture. Concurrent tolerance design is a manufacturing environment oriented design process paying more attention to influences or restraints on product design caused by such factors as the manufacturing process, machine capabilities, economy in manufacturing, etc. Process environment oriented tolerance analysis is more flexible making the designed results more practical and effective.展开更多
The bus operating characteristics are analyzed at the bus bay using the trajectories depending on the current status of buses. On this basis, a method for calculating the capacity of the bus bay is developed, which co...The bus operating characteristics are analyzed at the bus bay using the trajectories depending on the current status of buses. On this basis, a method for calculating the capacity of the bus bay is developed, which considers the queue probability, the dwell time distribution and the waiting time for a gap in the traffic stream at the curb lane. Then, the distribution model of the dwell time is developed using the survey data of Hangzhou city. And the log-normal distribution shows the best fitting performance. The capacities of the bus bay are computed with the Matlab program under different distribution parameters of the dwell time and different traffic volumes at the curb lane. The results show a large range of traffic capacity as the distribution parameters and traffic volumes change. Finally, the proposed model is validated by measurement and simulation, and the average relative errors between the calculated values and the measured and simulated values are 8.78% and 5.28%, respectively.展开更多
Reform dividends refer to the improvements in certain economic actors under the new, reformed institutional system as compared against the original system. Reform leads to greater economic growth potential by changing...Reform dividends refer to the improvements in certain economic actors under the new, reformed institutional system as compared against the original system. Reform leads to greater economic growth potential by changing the institutional environment, which in turn increases the vibrancy and innovation of economic actors. The most economically convenient system is also in actuality the most effective market economic system. Reform based on public and collective actions should be based on the following principle: if institutional reform is evolving towards the enhancement of economic convenience, then we can be sure that reform is embarking on the path of releasing dividends.展开更多
In order to provide important parameters for schedule designing, decision-making bases for transit operation management and references for passengers traveling by bus, bus transit travel time reliability is analyzed a...In order to provide important parameters for schedule designing, decision-making bases for transit operation management and references for passengers traveling by bus, bus transit travel time reliability is analyzed and evaluated based on automatic vehicle location (AVL) data. Based on the statistical analysis of the bus transit travel time, six indices including the coefficient of variance, the width of travel time distribution, the mean commercial speed, the congestion frequency, the planning time index and the buffer time index are proposed. Moreover, a framework for evaluating bus transit travel time reliability is constructed. Finally, a case study on a certain bus route in Suzhou is conducted. Results show that the proposed evaluation index system is simple and intuitive, and it can effectively reflect the efficiency and stability of bus operations. And a distinguishing feature of bus transit travel time reliability is the temporal pattern. It varies across different time periods.展开更多
To accurately capture the measurement of bus reliability and evaluate whether the transit system is properly operated an evaluation framework is established to assess the reliability of the transit system from differe...To accurately capture the measurement of bus reliability and evaluate whether the transit system is properly operated an evaluation framework is established to assess the reliability of the transit system from different stratifications including stops routes and network levels.The bus operation data of the Hefei city is analyzed as a case study.Comparison is conducted to show the improvement made by using the advanced method and an example of adding exclusive bus lanes to the existing bus route is provided. The proposed advanced method can avoid the shortcomings of the traditional method.For example the value of the reliability using the traditional coefficient of variation CV is not between 0 and 1 and the value of reliability can decrease with the increase in the transit headway etc. The case study shows that the advanced method can represent the real operation condition of the transit system and can be used to evaluate the transit headway reliability more reasonably.展开更多
Nowadays, geotextile tubes hydraulically filled with dredged materials have been used in the application of cofferdam, sea reclamation and deepwater channel regulation in China. The shape and mechanical behaviors duri...Nowadays, geotextile tubes hydraulically filled with dredged materials have been used in the application of cofferdam, sea reclamation and deepwater channel regulation in China. The shape and mechanical behaviors during the process of filling, consolidation and stacked are one of the main problems concemed by designers and researchers.This paper uses the method of elliptic integrals to study the behaviors of filling and deduces the regressive formulas of shape features and circumferential tension. The results show that the proposal regressive formulas are only the function of pressure at bottom; they are very convenient and suitable for the filling design. When the filling materials are sandy, the shape and mechanical behaviors nearly remain during the process of consolidation. The behaviors of stacked geotextile tubes are very complex, because they are involved in the properties of the filling material, geotextile and foundation.Using the commercial finite element analysis program ABAQUS, this paper establishes the entire 2- D finite element load model to investigate, which include the part of filling material, geotextile and foundation. The numerical results suggest that the maximun circumferential tension varies with the properties of filling materials and foundations, whereas the largest tensile force occurs during the filling process.展开更多
To improve the accuracy of real-time public transport information release system, a collaborative prediction model was proposed based on cyber-physical systems architecture. In the model, the total bus travel time was...To improve the accuracy of real-time public transport information release system, a collaborative prediction model was proposed based on cyber-physical systems architecture. In the model, the total bus travel time was divided into three parts: running time, dwell time and intersection delay time, and the data were divided into three categories of historical data, static data and real-time data. The bus arrival time was obtained by fusion computing the real-time data in perception layer together with historical data and static data in collaborative layer. The validity of the collaborative model was verified by the data of a typical urban bus line in Shanghai, and 1538 sets of data were collected and analyzed from three different perspectives. By comparing the experimental results with the actual results, it is shown that the experimental results are with higher prediction accuracy, and the collaborative prediction model adopted is able to meet the demand for bus arrival prediction.展开更多
To determinate the expressway capacity near a bus bay stop with an access, capacity models on the expressway near a bus stop with an access were developed on the basis of gap acceptance theory and queuing theory. Depe...To determinate the expressway capacity near a bus bay stop with an access, capacity models on the expressway near a bus stop with an access were developed on the basis of gap acceptance theory and queuing theory. Depending on a bus stop position to an entrance or an exit ramp, the capacity models were developed for four cases. Bus bay stops with overflow and bus bay stops without overflow were considered. A comparison of simulation experiment and model calculation was carried out. Results show that the suggested models have high accuracy and reliability, at bus arrival rate below 60 vehicles per hour(veh/h) or vehicle volumes at the entrance and the exit below 200 passenger cars units per hour(pcu/h), and there are no significant difference in the capacities for four cases. When bus arrival rate is above 240 veh/h, the capacities of all four cases will decline rapidly. With berth number increasing, the increasing of the capacities is no obvious for four cases. As the bus arrival rate and vehicle volumes at the entrance and the exit increase, bus stops located downstream of an entrance and upstream of an exit have a remarkably effect on the capacities. The latter case is much heavier than the former. Those results can be used to traffic design and optimization on urban expressway near a bus stop with an access.展开更多
Objective:Correctly understanding and evaluating the level of public risk perception toward public health emergencies not only helps experts and decision-makers understand the public’s preventative health behaviors t...Objective:Correctly understanding and evaluating the level of public risk perception toward public health emergencies not only helps experts and decision-makers understand the public’s preventative health behaviors to these emergencies but also enhances their risk information communication with the public.The aim of this study was to develop a risk perception scale for public health emergencies and test its validity and reliability during the coronavirus disease 2019(COVID-19)pandemic.Methods:Guided by the theoretical model of risk perception,an initial scale was generated through literature review,group meetings,resident interviews,and expert consultation.A pretest and item screening were then conducted to develop a formal risk perception scale for public health emergencies.Finally,the reliability and validity of the scale were validated through a questionnaire survey of 504 Chinese adults.Results:The final scale had 9 items.The content validity index of the scale was 0.968,and the content validity index of individual items ranged from 0.83 to 1.00.Three common factors,dread risk perception,severe risk perception,and unknown risk perception,were extracted for exploratory factor analysis,and together they explained 66.26%of the variance in the score.Confirmatory factor analysis showed that the model had a satisfactory fit,whereχ^(2)/df=1.384,the goodness-of-fit index(GFI)=0.989,root mean square error of approximation(RMSEA)=0.028,root mean square residual(RMR)=0.018,comparative fit index(CFI)=0.995,normed fit index(NFI)=0.982,and non-normed fit index(NNFI)=0.990.The correlations between dimensions ranged from 0.306 to 0.483(P<0.01).Cronbach’s a was 0.793 for the total scale and ranged between 0.687 and 0.801 for the individual dimensions.The split-half coefficient was 0.861 for the total scale and ranged from 0.727 to 0.856 for induvial dimensions.The test-retest coefficient was 0.846 for the total scale and ranged from 0.843 to 0.868 for induvial dimensions.Conclusion:The developed scale for the risk perception of public health emergencies showed acceptable levels of reliability and validity,suggesting that it is suitable for evaluating residents’risk perception of public health emergencies.展开更多
A highway was constructed in Jiangxi Province, China, through mountainous area. Some sections of the highway went through valleys where a soft clay layer of 6,8.5 m deep was encountered. A new explosive method was dev...A highway was constructed in Jiangxi Province, China, through mountainous area. Some sections of the highway went through valleys where a soft clay layer of 6,8.5 m deep was encountered. A new explosive method was developed and adopted for this project. In this method, blasting is used to remove and replace soft clay with crushed stones. Explosive charges are placed in the soil to be improved according to a certain pattern. Crushed stones are piled up behind the area where charges are installed. The explosion removes most of the soil in the exploded area and causes the pile of crushed stones to slide into the area where the soil is removed by blasting. A formular was suggested to calculate the charge weight used for improving a certain type of soil. The effectiveness of the method is evaluated using borehole exploration, plate load tests,and ground-probing radar tests.展开更多
Starting from Lie symmetry theory and combining with the approximate symmetry method, and using the package LieSYMGRP proposed by us, we restudy the perturbed Kuramoto-Sivashinsky (KS) equation. The approximate symm...Starting from Lie symmetry theory and combining with the approximate symmetry method, and using the package LieSYMGRP proposed by us, we restudy the perturbed Kuramoto-Sivashinsky (KS) equation. The approximate symmetry reduction and the infinite series symmetry reduction solutions of the perturbed KS equation are constructed. Specially, if selecting the tanh-type travelling wave solution as initial approximate, we not only obtain the general formula of the physical approximate similarity solutions, but also obtain several new explicit solutions of the given equation, which are first reported here.展开更多
Background Major infectious disease has become a serious threat to people’s health worldwide.As the world’s largest healthcare workforce and the core forces fighting against the epidemic,nurses are on the frontline ...Background Major infectious disease has become a serious threat to people’s health worldwide.As the world’s largest healthcare workforce and the core forces fighting against the epidemic,nurses are on the frontline of this battle.A number of ethical issues have given rise to numerous concerns that have largely affected nurses in different ways as they respond to the epidemic.In addition,excessive expectations from people can exert undue pressure,which can easily lead to burnout in nurses.Methods In this consensus,the expert panel method was used to develop and reach a consensus.The members involved in the formation of the consensus included an expert discussion panel and a consensus writing expert group,a methodologist,and four secretaries.After 16 rounds of online expert consultation and two rounds of expert panel meetings,the writing team analyzed and reviewed the 78 amendments suggested by the experts to develop a consensus on nursing ethics for prevention and control of major infectious disease outbreaks based on the ethical vision of life care.Results This expert consensus focuses on five essential domains:the responsibilities and rights of nurses,the nurse-patient relationship,the doctor-nurse relationship,and the relationship between society and nurses throughout the epidemic.Conclusions We hope this consensus can help nurses better understand and respond to the ethical issues and challenges in public health emergencies,and raise reasonable public expectations of the roles and responsibilities of nurses in these situations.展开更多
Natural monopoly,because of its spontaneous or natural characteristics, must have some mysterious causes of reasonableness.Thus,the regulations to its efficiency loss would have a different way compared to other monop...Natural monopoly,because of its spontaneous or natural characteristics, must have some mysterious causes of reasonableness.Thus,the regulations to its efficiency loss would have a different way compared to other monopolies. That the characteristics of natural monopoly,in the case of water industry, are that the infrastructure investments are very large,most of which are used to build the transportation system? The webs for transporting their products to their customers,and the products are identity goods or services.By examining the characteristics of natural monopoly,this paper proposed away to break upand remodel the industry of“natural monopoly”.The main clue of remodeling is that the governments,who represent the public and who have the power to control over public resources,should build and maintain a public web platform for the goods’ transportation uses, and break up the barrier ofthe entry so as to produce a market-oriented competitive structure.The running modeland the condition of remodeling are put forward and the cost-revenue analysis of the operation is briefly under consideration.展开更多
文摘Tolerance analysis is investigated under an environment of concurrent design in order to lead to optimized tolerance, as traditional tolerance analysis is often inefficient and liable to mistakes. Making full use of knowledge in manufacturing tolerance analysis combined with the beta distribution model is introduced and applied. The use of beta distribution reflects fully actual capabilities in manufacture. Concurrent tolerance design is a manufacturing environment oriented design process paying more attention to influences or restraints on product design caused by such factors as the manufacturing process, machine capabilities, economy in manufacturing, etc. Process environment oriented tolerance analysis is more flexible making the designed results more practical and effective.
基金The National High Technology Research and Development Program of China(863 Program)(No.2011AA110304)
文摘The bus operating characteristics are analyzed at the bus bay using the trajectories depending on the current status of buses. On this basis, a method for calculating the capacity of the bus bay is developed, which considers the queue probability, the dwell time distribution and the waiting time for a gap in the traffic stream at the curb lane. Then, the distribution model of the dwell time is developed using the survey data of Hangzhou city. And the log-normal distribution shows the best fitting performance. The capacities of the bus bay are computed with the Matlab program under different distribution parameters of the dwell time and different traffic volumes at the curb lane. The results show a large range of traffic capacity as the distribution parameters and traffic volumes change. Finally, the proposed model is validated by measurement and simulation, and the average relative errors between the calculated values and the measured and simulated values are 8.78% and 5.28%, respectively.
文摘Reform dividends refer to the improvements in certain economic actors under the new, reformed institutional system as compared against the original system. Reform leads to greater economic growth potential by changing the institutional environment, which in turn increases the vibrancy and innovation of economic actors. The most economically convenient system is also in actuality the most effective market economic system. Reform based on public and collective actions should be based on the following principle: if institutional reform is evolving towards the enhancement of economic convenience, then we can be sure that reform is embarking on the path of releasing dividends.
基金The Soft Science Research Project of Ministry of Housing and Urban-Rural Development of China (No. 2008-k5-14)
文摘In order to provide important parameters for schedule designing, decision-making bases for transit operation management and references for passengers traveling by bus, bus transit travel time reliability is analyzed and evaluated based on automatic vehicle location (AVL) data. Based on the statistical analysis of the bus transit travel time, six indices including the coefficient of variance, the width of travel time distribution, the mean commercial speed, the congestion frequency, the planning time index and the buffer time index are proposed. Moreover, a framework for evaluating bus transit travel time reliability is constructed. Finally, a case study on a certain bus route in Suzhou is conducted. Results show that the proposed evaluation index system is simple and intuitive, and it can effectively reflect the efficiency and stability of bus operations. And a distinguishing feature of bus transit travel time reliability is the temporal pattern. It varies across different time periods.
基金The National Basic Research Program of China(973 Program)(No.2012CB725402)the National Natural Science Foundation of China(No.51208099,50978057)
文摘To accurately capture the measurement of bus reliability and evaluate whether the transit system is properly operated an evaluation framework is established to assess the reliability of the transit system from different stratifications including stops routes and network levels.The bus operation data of the Hefei city is analyzed as a case study.Comparison is conducted to show the improvement made by using the advanced method and an example of adding exclusive bus lanes to the existing bus route is provided. The proposed advanced method can avoid the shortcomings of the traditional method.For example the value of the reliability using the traditional coefficient of variation CV is not between 0 and 1 and the value of reliability can decrease with the increase in the transit headway etc. The case study shows that the advanced method can represent the real operation condition of the transit system and can be used to evaluate the transit headway reliability more reasonably.
文摘Nowadays, geotextile tubes hydraulically filled with dredged materials have been used in the application of cofferdam, sea reclamation and deepwater channel regulation in China. The shape and mechanical behaviors during the process of filling, consolidation and stacked are one of the main problems concemed by designers and researchers.This paper uses the method of elliptic integrals to study the behaviors of filling and deduces the regressive formulas of shape features and circumferential tension. The results show that the proposal regressive formulas are only the function of pressure at bottom; they are very convenient and suitable for the filling design. When the filling materials are sandy, the shape and mechanical behaviors nearly remain during the process of consolidation. The behaviors of stacked geotextile tubes are very complex, because they are involved in the properties of the filling material, geotextile and foundation.Using the commercial finite element analysis program ABAQUS, this paper establishes the entire 2- D finite element load model to investigate, which include the part of filling material, geotextile and foundation. The numerical results suggest that the maximun circumferential tension varies with the properties of filling materials and foundations, whereas the largest tensile force occurs during the filling process.
基金Project(2011AA010101) supported by the National High Technology Research and Development Program of China
文摘To improve the accuracy of real-time public transport information release system, a collaborative prediction model was proposed based on cyber-physical systems architecture. In the model, the total bus travel time was divided into three parts: running time, dwell time and intersection delay time, and the data were divided into three categories of historical data, static data and real-time data. The bus arrival time was obtained by fusion computing the real-time data in perception layer together with historical data and static data in collaborative layer. The validity of the collaborative model was verified by the data of a typical urban bus line in Shanghai, and 1538 sets of data were collected and analyzed from three different perspectives. By comparing the experimental results with the actual results, it is shown that the experimental results are with higher prediction accuracy, and the collaborative prediction model adopted is able to meet the demand for bus arrival prediction.
基金Project(2012CB723303)supported by National Basic Research Program of China
文摘To determinate the expressway capacity near a bus bay stop with an access, capacity models on the expressway near a bus stop with an access were developed on the basis of gap acceptance theory and queuing theory. Depending on a bus stop position to an entrance or an exit ramp, the capacity models were developed for four cases. Bus bay stops with overflow and bus bay stops without overflow were considered. A comparison of simulation experiment and model calculation was carried out. Results show that the suggested models have high accuracy and reliability, at bus arrival rate below 60 vehicles per hour(veh/h) or vehicle volumes at the entrance and the exit below 200 passenger cars units per hour(pcu/h), and there are no significant difference in the capacities for four cases. When bus arrival rate is above 240 veh/h, the capacities of all four cases will decline rapidly. With berth number increasing, the increasing of the capacities is no obvious for four cases. As the bus arrival rate and vehicle volumes at the entrance and the exit increase, bus stops located downstream of an entrance and upstream of an exit have a remarkably effect on the capacities. The latter case is much heavier than the former. Those results can be used to traffic design and optimization on urban expressway near a bus stop with an access.
文摘Objective:Correctly understanding and evaluating the level of public risk perception toward public health emergencies not only helps experts and decision-makers understand the public’s preventative health behaviors to these emergencies but also enhances their risk information communication with the public.The aim of this study was to develop a risk perception scale for public health emergencies and test its validity and reliability during the coronavirus disease 2019(COVID-19)pandemic.Methods:Guided by the theoretical model of risk perception,an initial scale was generated through literature review,group meetings,resident interviews,and expert consultation.A pretest and item screening were then conducted to develop a formal risk perception scale for public health emergencies.Finally,the reliability and validity of the scale were validated through a questionnaire survey of 504 Chinese adults.Results:The final scale had 9 items.The content validity index of the scale was 0.968,and the content validity index of individual items ranged from 0.83 to 1.00.Three common factors,dread risk perception,severe risk perception,and unknown risk perception,were extracted for exploratory factor analysis,and together they explained 66.26%of the variance in the score.Confirmatory factor analysis showed that the model had a satisfactory fit,whereχ^(2)/df=1.384,the goodness-of-fit index(GFI)=0.989,root mean square error of approximation(RMSEA)=0.028,root mean square residual(RMR)=0.018,comparative fit index(CFI)=0.995,normed fit index(NFI)=0.982,and non-normed fit index(NNFI)=0.990.The correlations between dimensions ranged from 0.306 to 0.483(P<0.01).Cronbach’s a was 0.793 for the total scale and ranged between 0.687 and 0.801 for the individual dimensions.The split-half coefficient was 0.861 for the total scale and ranged from 0.727 to 0.856 for induvial dimensions.The test-retest coefficient was 0.846 for the total scale and ranged from 0.843 to 0.868 for induvial dimensions.Conclusion:The developed scale for the risk perception of public health emergencies showed acceptable levels of reliability and validity,suggesting that it is suitable for evaluating residents’risk perception of public health emergencies.
文摘A highway was constructed in Jiangxi Province, China, through mountainous area. Some sections of the highway went through valleys where a soft clay layer of 6,8.5 m deep was encountered. A new explosive method was developed and adopted for this project. In this method, blasting is used to remove and replace soft clay with crushed stones. Explosive charges are placed in the soil to be improved according to a certain pattern. Crushed stones are piled up behind the area where charges are installed. The explosion removes most of the soil in the exploded area and causes the pile of crushed stones to slide into the area where the soil is removed by blasting. A formular was suggested to calculate the charge weight used for improving a certain type of soil. The effectiveness of the method is evaluated using borehole exploration, plate load tests,and ground-probing radar tests.
基金The project supported by National Natural Science Foundations of China under Grant Nos. 10735030, 10475055, and 90503006; the Natural Science Research Plan in Shaanxi Province under Grant No. SJ08A09; the Research Fund of Postdoctoral of China under Grant No. 20070410727;the Research Found of Shaanxi Normal University
文摘Starting from Lie symmetry theory and combining with the approximate symmetry method, and using the package LieSYMGRP proposed by us, we restudy the perturbed Kuramoto-Sivashinsky (KS) equation. The approximate symmetry reduction and the infinite series symmetry reduction solutions of the perturbed KS equation are constructed. Specially, if selecting the tanh-type travelling wave solution as initial approximate, we not only obtain the general formula of the physical approximate similarity solutions, but also obtain several new explicit solutions of the given equation, which are first reported here.
基金Prevention&Control of COVID-19 Program of Soochow Securities,Grant/Award Number:JJ12700520Postgraduate Research&Practice Innovation Program of Jiangsu Province,Grant/Award Number:KYCX20_2684.
文摘Background Major infectious disease has become a serious threat to people’s health worldwide.As the world’s largest healthcare workforce and the core forces fighting against the epidemic,nurses are on the frontline of this battle.A number of ethical issues have given rise to numerous concerns that have largely affected nurses in different ways as they respond to the epidemic.In addition,excessive expectations from people can exert undue pressure,which can easily lead to burnout in nurses.Methods In this consensus,the expert panel method was used to develop and reach a consensus.The members involved in the formation of the consensus included an expert discussion panel and a consensus writing expert group,a methodologist,and four secretaries.After 16 rounds of online expert consultation and two rounds of expert panel meetings,the writing team analyzed and reviewed the 78 amendments suggested by the experts to develop a consensus on nursing ethics for prevention and control of major infectious disease outbreaks based on the ethical vision of life care.Results This expert consensus focuses on five essential domains:the responsibilities and rights of nurses,the nurse-patient relationship,the doctor-nurse relationship,and the relationship between society and nurses throughout the epidemic.Conclusions We hope this consensus can help nurses better understand and respond to the ethical issues and challenges in public health emergencies,and raise reasonable public expectations of the roles and responsibilities of nurses in these situations.
文摘Natural monopoly,because of its spontaneous or natural characteristics, must have some mysterious causes of reasonableness.Thus,the regulations to its efficiency loss would have a different way compared to other monopolies. That the characteristics of natural monopoly,in the case of water industry, are that the infrastructure investments are very large,most of which are used to build the transportation system? The webs for transporting their products to their customers,and the products are identity goods or services.By examining the characteristics of natural monopoly,this paper proposed away to break upand remodel the industry of“natural monopoly”.The main clue of remodeling is that the governments,who represent the public and who have the power to control over public resources,should build and maintain a public web platform for the goods’ transportation uses, and break up the barrier ofthe entry so as to produce a market-oriented competitive structure.The running modeland the condition of remodeling are put forward and the cost-revenue analysis of the operation is briefly under consideration.