By using cone-directed contingent derivatives, the unified necessary and sufficient optimality conditions are given for weakly and strongly minimal elements respectively in generalized preinvex set-valued optimization.
Purpose： The purpose of this study was to investigate the impact of acute exercise on reaction time and response preparation during a Go/No Go Task in children with attention deficit hyperactivity disorder （ADHD）. ...Purpose： The purpose of this study was to investigate the impact of acute exercise on reaction time and response preparation during a Go/No Go Task in children with attention deficit hyperactivity disorder （ADHD）. Methods： Nineteen children with ADHD （aged between 8 and 12 years old） undertook a 30-min intervention that consisted of treadmill running or video-watching presented in a counterbalanced order on different days. A Go/No Go Task was administrated after exercise or video-watching. Results： The results indicated a shorter reaction time and smaller contingent negative variation （CNV） 2 amplitude following exercise relative to the video-watching. For event related potential （ERP） analyses, greater CNV l and CNV 2 amplitudes in response to No Go stimuli in com- parison to Go stimuli was observed in the video-watching session only. Conclusion： These findings suggest that acute exercise may benefit children with ADHD by developing appropriate response preparation, particularly in maintaining a stable motor preparatory set prior to performing the given task.展开更多
World heritage possesses various kinds of use value and non-use value. Measuring the recreational value of world heritage sites is a key issue in the heritage tourism. This paper employs Contingent Valuation Method (C...World heritage possesses various kinds of use value and non-use value. Measuring the recreational value of world heritage sites is a key issue in the heritage tourism. This paper employs Contingent Valuation Method (CVM), which is an evaluation instrument on the basis of tourists′ attitude and preference, to measure the recreational value of Jiuzhaigou, one of the World Natural Heritage sites in China, and analyzes the biases in the survey. The results show that: 1) In 2009, Jiuzhaigou′s recreational value was 3.46×108 yuan (RMB), and the per capita Willingness to Pay (WTP) was 137.31 yuan by CVM. Compared with the results of other methods, this result is significantly low. 2) Among the factors that influence Jiuzhaigou tourists′ WTP, psychological perception factors have the greatest effect while demographic and socio-economic characteristics have a small effect on WTP. 3) The virtuality in CVM creates biases both from CVM itself and in the procedures that CVM was implemented. The former includes hypothetical bias, information bias, protest response bias, and strategic bias; and the latter includes the questionnaire design, population and sample definition, sampling and data processing. The paper analyses those biases and illustrates their potential in-fluences on the accuracy of CVM measurement. 4) Although there are various defects in CVM measurement, it is still an effective valuation method.展开更多
We estimate the willingness to pay （WTP） of Beijing and Shanghai residents for improving the air quality of the two cities from their levels prior to the 2008 Beijing Olympic Games to the level achieved during the O...We estimate the willingness to pay （WTP） of Beijing and Shanghai residents for improving the air quality of the two cities from their levels prior to the 2008 Beijing Olympic Games to the level achieved during the Olympics. The data are obtained from a contingent valuation study conducted through face-to-face interviews in June 2008 in Beijing and Shanghai prior to the Beijing Olympics, during which time there was intensive debate about Beijing＇s air quality. Residents in both cities are willing to pay more when they are more exposed to air pollution, when their disposable income increases, and when they have stronger beliefs that public opinion plays an important role in government policy making. Beijing residents are willing to pay more than Shanghai residents, due possibly to Beijing＇s poorer air quality. Overall, aggregate WTP for air quality improvement accounts for about 0.53% of the 2008 GDP in Beijing and 0.22% of the 2008 GDP in Shanghai.展开更多
BACKGROUND： Study results of event-refated potential in obsessive compulsive disorder （OCD） remain controversial, potentially as a result of different instruments utilized and their differing technical characterist...BACKGROUND： Study results of event-refated potential in obsessive compulsive disorder （OCD） remain controversial, potentially as a result of different instruments utilized and their differing technical characteristics. OBJECTIVE： To investigate the differences in several common event-related potentials, Le. contingent negative variations, P300, and mismatch negativity （MMN）, in OCD patients, depression patients, generalized anxiety disorder （GAD） patients, and healthy controls. DESIGN, TIME AND SETTING： A case-control study was performed in the Department of Electrophysiology, Shanghai Mental Health Center from May 2002 to December 2005. PARTICIPANTS： A total of 38 OCD patients, 20 depression patients, and 18 GAD patients, who were diagnosed according to the criteria of Chinese Classification of Mental Disorders （Version 3）, formulated by the Chinese Psychiatry Association, were selected from the Outpatient Department of Shanghai Mental Health Center. Patients with two or more the above diseases were excluded. In addition, 28 healthy people, gender and age matched, were selected as controls. METHODS： Contingent negative variations, P300, and MMN were recorded by a Nicolet Spirit Instrument. All electrodes were attached at Cz according to the Intemationa11020 system, with the mastoid leads as reference and Fpz as ground. MAIN OUTCOME MEASURES： Amplitude and latency of contingent negative variations, P300, and MMN. RESULTS： The contingent negative variations, P300, and MMN were different （P 〈 0.01）. OCD patients showed an increased MI amplitude compared with controls, depression, and GAD patients （P 〈 0.01）. Target P300 amplitudes were significantly lower in OCD, depression, and GAD patients compared with controls （P 〈 0.01）. Moreover, N2 latency and latency of MMN were prolonged in OCD and depression groups compared with controls （P 〈 0.05）. CONCLUSION： Event-related potentials were different in depression, GAD, and OCD patients and healthy controls. In parti展开更多
We examined the Hulun Lake protected area（HLPA）and tourist willingness to pay（WTP）for ecotourism resources using the contingent valuation method（CVM）.Eight hundred questionnaires were distributed in the HLPA and...We examined the Hulun Lake protected area（HLPA）and tourist willingness to pay（WTP）for ecotourism resources using the contingent valuation method（CVM）.Eight hundred questionnaires were distributed in the HLPA and 708 questionnaires were collected.To establish the relationship between variables and WTP,11 variables were incorporated into the model.Social trust factors and awareness factor were for the first time applied to the models,and two bid equations were obtained by the first and second bid.We found that tourist WTP for ecotourism resources in the HLPA was CNY 14 710 389 in 2010,indicating that tourists have a large WTP for protected area ecotourism resources.Most tourists（79.9%）were willing to pay for ecotourism resources and 21.1%tourists were unwilling to pay.The most common explanation for unwillingness to pay was that it was the government’s responsibility,influenced by special social and economic characteristics in China and indicating that Chinese residents lack resource protection awareness and participation.Income and the awareness of being in a protected area most significantly affected WTP.Trusting protected area authorities significantly affected WTP.Tourists’satisfaction affected WTP negatively in the first equation and WTP positively in the second equation.These results reveal that tourists had large WTP for ecotourism resources.To improve the WTP for ecotourism resources,the protected area management department could use third-party monitoring mechanisms and accounting systems to strengthen tourists’trust,and increase ecological education and modify the＂one site,several brands＂management system.展开更多
Water quality in China has seriously deteriorated in recent years. However, very few valuation studies have been conducted to estimate the monetary values associated with water quality changes. As a result, the decisi...Water quality in China has seriously deteriorated in recent years. However, very few valuation studies have been conducted to estimate the monetary values associated with water quality changes. As a result, the decision makers can hardly make rational choices with regard to investments in water quality improvement. This paper presents a valuation study conducted in Dali, Yunnan Province, which aims to estimate the total economic value of improving the water quality of Erhai Lake by one grade level. Both the contingent valuation method and the benefit transfer approach are employed in this study. The contingent valuation estimation strategy reveals that, on average, a household located in Dali is willing to pay about 27 yuan per month continuously for 5 years for the water quality improvement, equivalent to 1.7% of the household monthly income. The elasticity of willingness-to-pay with respect to income is estimated to be 0.28. The internal rate of economic return of the proposed pollution control project is estimated to be 13%. The benefit transfer exercise produces a similar estimation on willingness to pay （WTP） values, with a difference of less than 2% compared with the contingent valuation approach. The results indicate the potential reliability of using the benefit transfer approach for valuation estimations in Chinese provinces.展开更多
Human pressure on mountain resources poses certain threats to their natural and man-made environment. Although there are many parameters involved, one of the driving forces behind this situation is the emphasis given ...Human pressure on mountain resources poses certain threats to their natural and man-made environment. Although there are many parameters involved, one of the driving forces behind this situation is the emphasis given so far only to the market value of mountain goods and services, ignoring the true social and environmental costs of using mountain resources. Towards this direction, the use of non-market valuation techniques could prove to be beneficial. Bearing in mind the above remarks, the paper presents an application of the Contingent Valuation Method, which aims at estimating the monetary value of a mountain settlement’s vernacular architecture, namely Metsovo. For this purpose, the survey focuses on Metsovo visitors’ willingness to pay a single annual voluntary contribution to an institution that would be founded in order to undertake all necessary actions required to preserve the town’s traditional character. The results are very promising and indicate that vernacular architecture holds a significant economic value that could justify the implementation of appropriate policies towards the protection of vernacular settlements in mountain areas.展开更多
This paper deals with Henig globally efficiency in vector optimization involving generalized cone-preinvex set-valued mapping. Some properties of generalized cone-preinvex set-valued map are derived. It also disclose ...This paper deals with Henig globally efficiency in vector optimization involving generalized cone-preinvex set-valued mapping. Some properties of generalized cone-preinvex set-valued map are derived. It also disclose the closed relationships between Henig globally efficiency of generalized conepreinvex set-valued optimization problem and Henig globally efficiency of a kind of vector variational inequality.展开更多
Willingness to Pay(WTP),Willingness to Work(WTW)and Willingness to Accept Compensation(WTA)are the three quantitative criteria for assessing local ecological asset values for the social aspects of ecosystem services a...Willingness to Pay(WTP),Willingness to Work(WTW)and Willingness to Accept Compensation(WTA)are the three quantitative criteria for assessing local ecological asset values for the social aspects of ecosystem services and residents’willingness to contribute to and receive compensation for tourism ecology.The objectives of this study are to estimate the residents’willingness to pay,work and accept compensation for conservation at Sanjiangyuan National Park,and to analyze the relationship between residents’attitude towards tourism ecology and the ecological assets of the National Park based on a standard questionnaire survey.The dichotomous choice Contingent Valuation Method(CVM)was employed to determine the willingness.The survey conducted in 2018 collected WTP,WTW,WTA,socio-demFographical information,social trust and resident perceptions toward tourism impacts and relevant management strategies from 244 residents in two counties.Based on generalized linear modeling,income and education level are important for residents’WTP and WTA,but other social characteristics,such as gender and age,do not have significant effects.The social trust is found to be a significant factor on residents’willingness,despite the limitation on education level.Also,government funding is associated with residents’inclination to WTP,WTW and WTA,but the support levels differ among the two counties due to geographical and social heterogeneities.The estimated WTP,WTW and WTA for the Sanjiangyuan National Park in 2018 were 1.2448×10^(7) yuan,1.247×10^(6) hours and 2.3232×10^(7) yuan yr^(-1) based on the survey and published demographics.This study,for the first time,estimates the WTP,WTW and WTA for the Sanjiangyuan National Park and informs ecological conservation managers and policy makers.Ultimately,to maintain the long-term benefits arising from sustainable development,compensation should be specifically tailored and site-dependent,and development measures based on local resources should be adopted by governments to actively su展开更多
A kind of tangent derivative and the concepts of strong and weak * pseudoconvexity for a set-valued map are introduced. By the standard separation theorems of the convex sets and cones the optimality Fritz John condit...A kind of tangent derivative and the concepts of strong and weak * pseudoconvexity for a set-valued map are introduced. By the standard separation theorems of the convex sets and cones the optimality Fritz John condition of set-valued optimization under Benson proper efficiency is established, its sufficience is discussed. The form of the optimality conditions obtained here completely tally with the classical results when the set-valued map is specialized to be a single-valued map.展开更多
Ecological compensation is a powerful environmental economic tool for environmental protection in areas where drinking water sources are located. We established an ecological compensation accounting system based on re...Ecological compensation is a powerful environmental economic tool for environmental protection in areas where drinking water sources are located. We established an ecological compensation accounting system based on respondents＇ willingness to accept （WTA）. In this system, stakeholder preferences and the factors that influence them can be gauged effectively using logit and tobit models. We applied this accounting system to ecological compensation for the Miyun Reservoir, Beijing, China. The average WTA value for Miyun Reservoir residents was approximately 1186 CNY per family in 2012, which could be set as a suitable compensation standard, since it is slightly higher than the local protection cost. Thus, the annual total ecological compensation could be 58.73 million CNY. Distance from the reservoir, job types, and attitude to environmental protection were variables with significant effects on WTA. In addition, trends for individual preferences were identified via an analysis of key influential factors. The results suggest some useful information for establishing ecological compensation mechanisms for conservation of drinking water sources. Suggestions include popularizing the concept and meaning of ecological compensation among residents, setting different compensation levels based on distance from the reservoir, considering the requirements of farmers, and taking various in-kind and out-of-kind compensa- tion approaches.展开更多
In this paper, we concern the approaching condition of sliding mode control （SMC） with a Lipschitz switching surface that may be nonsmooth. New criteria on the relation between phase trajectories and an arbitrary Li...In this paper, we concern the approaching condition of sliding mode control （SMC） with a Lipschitz switching surface that may be nonsmooth. New criteria on the relation between phase trajectories and an arbitrary Lipschitz continuous surface are examined firstly. Filippov＇s differential inclusion is adopted to describe the dynamics of trajectories of the closed-loop system with SMC. Compared with Filippov＇s criteria for only smooth surface, new criteria are proposed by utilizing the cone conditions that allow the surface to be nonsmooth. This result also yields a new approaching condition of SMC design. Based on the new approaching condition, we develop the sliding mode controller for a class of nonlinear single-input single-output （SISO） systems, of which the switching surface is designed Lips- chitz continuous for the nonsmooth sliding motion. Finally, we provide a numerical example to verify the new design method.展开更多
Background： Around 2000 plant species occur naturally in Lorestan Province of which 250 species are medicinal and myrtle is one of them. Myrtle is a shrub whose leaves and fruits have medicinal value and thus, if man...Background： Around 2000 plant species occur naturally in Lorestan Province of which 250 species are medicinal and myrtle is one of them. Myrtle is a shrub whose leaves and fruits have medicinal value and thus, if managed and harvested properly, could produce sustained economic benefits. In recent years, however, over half of the myrtle site areas was destroyed, due to inappropriate management and excessive harvesting practices. Thus, coming up with a practical harvesting approach along with identifying those factors damaging the sites, seems to be very crucial. Methods： In our investigation, we calculated the conservation value per hectare of myrtle in the Dooreh forest area in Lorestan Province. Using the Contingent Valuation （CV） and Double Bounded Dichotomous Choice （DBDC） methods, we determined the willingness to pay （VVTP） for myrtle conservation. The VVTP was estimated with a Iogit model for which indices were obtained based on a maximum precision criterion. Results： The results showed that 86.67 per cent of people were willing to pay for the conservation of these myrtle sites. Average monthly WTP per family was calculated as $0.79. The annual conservation value in terms of WTP for the preservation of the myrtle sites in Dooreh was estimated as $102,525. Among the variables of the model presented, education had a positive impact, while the amount proposed for payment and family size had a negative impact on the WTP. Conclusions： Our estimate of the value of myrtle conservation should provide justification for policy makers and decision making bodies of natural resources to implement policies in order to conserve the natural sites of this species more effectively.展开更多
基金Supported by the National Natural Science Foundation of China (10571035)
文摘By using cone-directed contingent derivatives, the unified necessary and sufficient optimality conditions are given for weakly and strongly minimal elements respectively in generalized preinvex set-valued optimization.
基金particularly supported by the "Aim for the Top University Plan" of the National Taiwan Normal University and Ministry of Education,Taiwan,Chinaby the Ministry of Science and Technology (Taiwan,China) under grant NSC102-2410-H-003-128
文摘Purpose： The purpose of this study was to investigate the impact of acute exercise on reaction time and response preparation during a Go/No Go Task in children with attention deficit hyperactivity disorder （ADHD）. Methods： Nineteen children with ADHD （aged between 8 and 12 years old） undertook a 30-min intervention that consisted of treadmill running or video-watching presented in a counterbalanced order on different days. A Go/No Go Task was administrated after exercise or video-watching. Results： The results indicated a shorter reaction time and smaller contingent negative variation （CNV） 2 amplitude following exercise relative to the video-watching. For event related potential （ERP） analyses, greater CNV l and CNV 2 amplitudes in response to No Go stimuli in com- parison to Go stimuli was observed in the video-watching session only. Conclusion： These findings suggest that acute exercise may benefit children with ADHD by developing appropriate response preparation, particularly in maintaining a stable motor preparatory set prior to performing the given task.
基金Under the auspices of Sino-British Fellowship by the British Academy (No. SG-47266)National Natural Science Foundation of China (No. 40371030)
文摘World heritage possesses various kinds of use value and non-use value. Measuring the recreational value of world heritage sites is a key issue in the heritage tourism. This paper employs Contingent Valuation Method (CVM), which is an evaluation instrument on the basis of tourists′ attitude and preference, to measure the recreational value of Jiuzhaigou, one of the World Natural Heritage sites in China, and analyzes the biases in the survey. The results show that: 1) In 2009, Jiuzhaigou′s recreational value was 3.46×108 yuan (RMB), and the per capita Willingness to Pay (WTP) was 137.31 yuan by CVM. Compared with the results of other methods, this result is significantly low. 2) Among the factors that influence Jiuzhaigou tourists′ WTP, psychological perception factors have the greatest effect while demographic and socio-economic characteristics have a small effect on WTP. 3) The virtuality in CVM creates biases both from CVM itself and in the procedures that CVM was implemented. The former includes hypothetical bias, information bias, protest response bias, and strategic bias; and the latter includes the questionnaire design, population and sample definition, sampling and data processing. The paper analyses those biases and illustrates their potential in-fluences on the accuracy of CVM measurement. 4) Although there are various defects in CVM measurement, it is still an effective valuation method.
基金The paper is supported by the MOE （Ministry of Education in China） Project of Humanities and Social Sciences （No. 09YJC790182） and by the National Social Science Foundation of China （No. 10AZD015）. We thank Max Auffhammer, Soren Anderson, Li Gan, Timo Goeschl, Joe Herriges, Cathy Kling, Kerry Smith, and participants at the Global Environmental Challenges： the Role of China conference for their helpful comments. We thank Min Wang for excellent research assistance, Chunguang Cai, Ye Chen, and Jingjing Sun for help with focus groups, and the Beijing and Shanghai Branches of the National Statistics Bureau of China for assistance in implementation of our survey instruments. The usual disclaimer applies.
文摘We estimate the willingness to pay （WTP） of Beijing and Shanghai residents for improving the air quality of the two cities from their levels prior to the 2008 Beijing Olympic Games to the level achieved during the Olympics. The data are obtained from a contingent valuation study conducted through face-to-face interviews in June 2008 in Beijing and Shanghai prior to the Beijing Olympics, during which time there was intensive debate about Beijing＇s air quality. Residents in both cities are willing to pay more when they are more exposed to air pollution, when their disposable income increases, and when they have stronger beliefs that public opinion plays an important role in government policy making. Beijing residents are willing to pay more than Shanghai residents, due possibly to Beijing＇s poorer air quality. Overall, aggregate WTP for air quality improvement accounts for about 0.53% of the 2008 GDP in Beijing and 0.22% of the 2008 GDP in Shanghai.
基金the National Natural Science Foundation of China, No. 30770772, 30971046the Foundation of Shanghai Science and Technology Commission, No. 09411968200 the Major State Basic Research Development Program of China (973 program), No. S2009051026
文摘BACKGROUND： Study results of event-refated potential in obsessive compulsive disorder （OCD） remain controversial, potentially as a result of different instruments utilized and their differing technical characteristics. OBJECTIVE： To investigate the differences in several common event-related potentials, Le. contingent negative variations, P300, and mismatch negativity （MMN）, in OCD patients, depression patients, generalized anxiety disorder （GAD） patients, and healthy controls. DESIGN, TIME AND SETTING： A case-control study was performed in the Department of Electrophysiology, Shanghai Mental Health Center from May 2002 to December 2005. PARTICIPANTS： A total of 38 OCD patients, 20 depression patients, and 18 GAD patients, who were diagnosed according to the criteria of Chinese Classification of Mental Disorders （Version 3）, formulated by the Chinese Psychiatry Association, were selected from the Outpatient Department of Shanghai Mental Health Center. Patients with two or more the above diseases were excluded. In addition, 28 healthy people, gender and age matched, were selected as controls. METHODS： Contingent negative variations, P300, and MMN were recorded by a Nicolet Spirit Instrument. All electrodes were attached at Cz according to the Intemationa11020 system, with the mastoid leads as reference and Fpz as ground. MAIN OUTCOME MEASURES： Amplitude and latency of contingent negative variations, P300, and MMN. RESULTS： The contingent negative variations, P300, and MMN were different （P 〈 0.01）. OCD patients showed an increased MI amplitude compared with controls, depression, and GAD patients （P 〈 0.01）. Target P300 amplitudes were significantly lower in OCD, depression, and GAD patients compared with controls （P 〈 0.01）. Moreover, N2 latency and latency of MMN were prolonged in OCD and depression groups compared with controls （P 〈 0.05）. CONCLUSION： Event-related potentials were different in depression, GAD, and OCD patients and healthy controls. In parti
基金The National Natural Science Foundation of China(41301623,41671527)the China National Tourism Administration Tourism Young Expert Training Program(TYETP201519)the Program for Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region
文摘We examined the Hulun Lake protected area（HLPA）and tourist willingness to pay（WTP）for ecotourism resources using the contingent valuation method（CVM）.Eight hundred questionnaires were distributed in the HLPA and 708 questionnaires were collected.To establish the relationship between variables and WTP,11 variables were incorporated into the model.Social trust factors and awareness factor were for the first time applied to the models,and two bid equations were obtained by the first and second bid.We found that tourist WTP for ecotourism resources in the HLPA was CNY 14 710 389 in 2010,indicating that tourists have a large WTP for protected area ecotourism resources.Most tourists（79.9%）were willing to pay for ecotourism resources and 21.1%tourists were unwilling to pay.The most common explanation for unwillingness to pay was that it was the government’s responsibility,influenced by special social and economic characteristics in China and indicating that Chinese residents lack resource protection awareness and participation.Income and the awareness of being in a protected area most significantly affected WTP.Trusting protected area authorities significantly affected WTP.Tourists’satisfaction affected WTP negatively in the first equation and WTP positively in the second equation.These results reveal that tourists had large WTP for ecotourism resources.To improve the WTP for ecotourism resources,the protected area management department could use third-party monitoring mechanisms and accounting systems to strengthen tourists’trust,and increase ecological education and modify the＂one site,several brands＂management system.
文摘Water quality in China has seriously deteriorated in recent years. However, very few valuation studies have been conducted to estimate the monetary values associated with water quality changes. As a result, the decision makers can hardly make rational choices with regard to investments in water quality improvement. This paper presents a valuation study conducted in Dali, Yunnan Province, which aims to estimate the total economic value of improving the water quality of Erhai Lake by one grade level. Both the contingent valuation method and the benefit transfer approach are employed in this study. The contingent valuation estimation strategy reveals that, on average, a household located in Dali is willing to pay about 27 yuan per month continuously for 5 years for the water quality improvement, equivalent to 1.7% of the household monthly income. The elasticity of willingness-to-pay with respect to income is estimated to be 0.28. The internal rate of economic return of the proposed pollution control project is estimated to be 13%. The benefit transfer exercise produces a similar estimation on willingness to pay （WTP） values, with a difference of less than 2% compared with the contingent valuation approach. The results indicate the potential reliability of using the benefit transfer approach for valuation estimations in Chinese provinces.
文摘Human pressure on mountain resources poses certain threats to their natural and man-made environment. Although there are many parameters involved, one of the driving forces behind this situation is the emphasis given so far only to the market value of mountain goods and services, ignoring the true social and environmental costs of using mountain resources. Towards this direction, the use of non-market valuation techniques could prove to be beneficial. Bearing in mind the above remarks, the paper presents an application of the Contingent Valuation Method, which aims at estimating the monetary value of a mountain settlement’s vernacular architecture, namely Metsovo. For this purpose, the survey focuses on Metsovo visitors’ willingness to pay a single annual voluntary contribution to an institution that would be founded in order to undertake all necessary actions required to preserve the town’s traditional character. The results are very promising and indicate that vernacular architecture holds a significant economic value that could justify the implementation of appropriate policies towards the protection of vernacular settlements in mountain areas.
基金supported by the Natural Science Foundation of China under Grant No.11361001Ministry of Education Science and technology key projects under Grant No.212204+1 种基金the Natural Science Foundation of Ningxia under Grant No.NZ12207the Science and Technology key project of Ningxia institutions of higher learning under Grant No.NGY2012092
文摘This paper deals with Henig globally efficiency in vector optimization involving generalized cone-preinvex set-valued mapping. Some properties of generalized cone-preinvex set-valued map are derived. It also disclose the closed relationships between Henig globally efficiency of generalized conepreinvex set-valued optimization problem and Henig globally efficiency of a kind of vector variational inequality.
基金The National Key Research and Development Program(2017YFC0506501)The Program for Ecological Innovation Team in Minzu University of China(2020CXTD02)。
文摘Willingness to Pay(WTP),Willingness to Work(WTW)and Willingness to Accept Compensation(WTA)are the three quantitative criteria for assessing local ecological asset values for the social aspects of ecosystem services and residents’willingness to contribute to and receive compensation for tourism ecology.The objectives of this study are to estimate the residents’willingness to pay,work and accept compensation for conservation at Sanjiangyuan National Park,and to analyze the relationship between residents’attitude towards tourism ecology and the ecological assets of the National Park based on a standard questionnaire survey.The dichotomous choice Contingent Valuation Method(CVM)was employed to determine the willingness.The survey conducted in 2018 collected WTP,WTW,WTA,socio-demFographical information,social trust and resident perceptions toward tourism impacts and relevant management strategies from 244 residents in two counties.Based on generalized linear modeling,income and education level are important for residents’WTP and WTA,but other social characteristics,such as gender and age,do not have significant effects.The social trust is found to be a significant factor on residents’willingness,despite the limitation on education level.Also,government funding is associated with residents’inclination to WTP,WTW and WTA,but the support levels differ among the two counties due to geographical and social heterogeneities.The estimated WTP,WTW and WTA for the Sanjiangyuan National Park in 2018 were 1.2448×10^(7) yuan,1.247×10^(6) hours and 2.3232×10^(7) yuan yr^(-1) based on the survey and published demographics.This study,for the first time,estimates the WTP,WTW and WTA for the Sanjiangyuan National Park and informs ecological conservation managers and policy makers.Ultimately,to maintain the long-term benefits arising from sustainable development,compensation should be specifically tailored and site-dependent,and development measures based on local resources should be adopted by governments to actively su
文摘A kind of tangent derivative and the concepts of strong and weak * pseudoconvexity for a set-valued map are introduced. By the standard separation theorems of the convex sets and cones the optimality Fritz John condition of set-valued optimization under Benson proper efficiency is established, its sufficience is discussed. The form of the optimality conditions obtained here completely tally with the classical results when the set-valued map is specialized to be a single-valued map.
文摘Ecological compensation is a powerful environmental economic tool for environmental protection in areas where drinking water sources are located. We established an ecological compensation accounting system based on respondents＇ willingness to accept （WTA）. In this system, stakeholder preferences and the factors that influence them can be gauged effectively using logit and tobit models. We applied this accounting system to ecological compensation for the Miyun Reservoir, Beijing, China. The average WTA value for Miyun Reservoir residents was approximately 1186 CNY per family in 2012, which could be set as a suitable compensation standard, since it is slightly higher than the local protection cost. Thus, the annual total ecological compensation could be 58.73 million CNY. Distance from the reservoir, job types, and attitude to environmental protection were variables with significant effects on WTA. In addition, trends for individual preferences were identified via an analysis of key influential factors. The results suggest some useful information for establishing ecological compensation mechanisms for conservation of drinking water sources. Suggestions include popularizing the concept and meaning of ecological compensation among residents, setting different compensation levels based on distance from the reservoir, considering the requirements of farmers, and taking various in-kind and out-of-kind compensa- tion approaches.
文摘In this paper, we concern the approaching condition of sliding mode control （SMC） with a Lipschitz switching surface that may be nonsmooth. New criteria on the relation between phase trajectories and an arbitrary Lipschitz continuous surface are examined firstly. Filippov＇s differential inclusion is adopted to describe the dynamics of trajectories of the closed-loop system with SMC. Compared with Filippov＇s criteria for only smooth surface, new criteria are proposed by utilizing the cone conditions that allow the surface to be nonsmooth. This result also yields a new approaching condition of SMC design. Based on the new approaching condition, we develop the sliding mode controller for a class of nonlinear single-input single-output （SISO） systems, of which the switching surface is designed Lips- chitz continuous for the nonsmooth sliding motion. Finally, we provide a numerical example to verify the new design method.
文摘Background： Around 2000 plant species occur naturally in Lorestan Province of which 250 species are medicinal and myrtle is one of them. Myrtle is a shrub whose leaves and fruits have medicinal value and thus, if managed and harvested properly, could produce sustained economic benefits. In recent years, however, over half of the myrtle site areas was destroyed, due to inappropriate management and excessive harvesting practices. Thus, coming up with a practical harvesting approach along with identifying those factors damaging the sites, seems to be very crucial. Methods： In our investigation, we calculated the conservation value per hectare of myrtle in the Dooreh forest area in Lorestan Province. Using the Contingent Valuation （CV） and Double Bounded Dichotomous Choice （DBDC） methods, we determined the willingness to pay （VVTP） for myrtle conservation. The VVTP was estimated with a Iogit model for which indices were obtained based on a maximum precision criterion. Results： The results showed that 86.67 per cent of people were willing to pay for the conservation of these myrtle sites. Average monthly WTP per family was calculated as $0.79. The annual conservation value in terms of WTP for the preservation of the myrtle sites in Dooreh was estimated as $102,525. Among the variables of the model presented, education had a positive impact, while the amount proposed for payment and family size had a negative impact on the WTP. Conclusions： Our estimate of the value of myrtle conservation should provide justification for policy makers and decision making bodies of natural resources to implement policies in order to conserve the natural sites of this species more effectively.
