Based on optimization wharf structure type of triangle flame pier proposed, namely＂ Spatial triangular flame pier ＋ Big span bent which taking Slant supports＂ Simulating three-dimensional pier model of a variety of...Based on optimization wharf structure type of triangle flame pier proposed, namely＂ Spatial triangular flame pier ＋ Big span bent which taking Slant supports＂ Simulating three-dimensional pier model of a variety of conditions in the actual loading by structural finite element software. Under the guidance of the three-dimensional structure of the most unfavorable load combination algorithm, three-dimensional combination algorithm is applied to the new structure by the MATLAB software programming. Search and calculate the most unfavorable combination of action effects and the corresponding intemal force of the main member, checking the feasibility of the three-dimensional algorithms, Calculating the new wharf structure structural features and stability, Providing numerical reference for the design of this sort of wharf.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 support eco-tourism activities.展开更多
To predict the distortion of aerospace monolithic components, a model is established to simulate the numerical control (NC) milling process using 3D finite element method (FEM). In this model, the cutting layer is sim...To predict the distortion of aerospace monolithic components, a model is established to simulate the numerical control (NC) milling process using 3D finite element method (FEM). In this model, the cutting layer is simplified firstly. Then, the models of cutting force and cutting temperature are established to gain the cutting loads, which are applied to the mesh model of the part. Finally, a prototype of machining simulation environment is developed to simulate the milling process of a spar. Key factors influencing the distortion, such as initial residual stress, cutting loads, fixture layout, cutting sequence, and tool path are considered all together. The total distortion of the spar is predicted and an experiment is conducted to validate the numerical results. It is found that the maximum discrepancy between the simulation results and experiment values is 19.0%展开更多
Judice and Pires developed in recent years principal pivoting methods for the solving of the so called box linear complementarity problems (BLCPs) where the constraint matrices are restrictedly supposed to be of P ...Judice and Pires developed in recent years principal pivoting methods for the solving of the so called box linear complementarity problems (BLCPs) where the constraint matrices are restrictedly supposed to be of P matrices. This paper aims at presenting a new principal pivoting scheme for BLCPs where the constraint matrices are loosely supposed to be row sufficient.This scheme can be applied to the solving of convex quadratic programs subject to linear constraints and arbitrary upper and lower bound constraints on variables.展开更多
文摘Based on optimization wharf structure type of triangle flame pier proposed, namely＂ Spatial triangular flame pier ＋ Big span bent which taking Slant supports＂ Simulating three-dimensional pier model of a variety of conditions in the actual loading by structural finite element software. Under the guidance of the three-dimensional structure of the most unfavorable load combination algorithm, three-dimensional combination algorithm is applied to the new structure by the MATLAB software programming. Search and calculate the most unfavorable combination of action effects and the corresponding intemal force of the main member, checking the feasibility of the three-dimensional algorithms, Calculating the new wharf structure structural features and stability, Providing numerical reference for the design of this sort of wharf.
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 support eco-tourism activities.
基金Project (No. 50435020) supported by the National Natural Science Foundation of China
文摘To predict the distortion of aerospace monolithic components, a model is established to simulate the numerical control (NC) milling process using 3D finite element method (FEM). In this model, the cutting layer is simplified firstly. Then, the models of cutting force and cutting temperature are established to gain the cutting loads, which are applied to the mesh model of the part. Finally, a prototype of machining simulation environment is developed to simulate the milling process of a spar. Key factors influencing the distortion, such as initial residual stress, cutting loads, fixture layout, cutting sequence, and tool path are considered all together. The total distortion of the spar is predicted and an experiment is conducted to validate the numerical results. It is found that the maximum discrepancy between the simulation results and experiment values is 19.0%
文摘Judice and Pires developed in recent years principal pivoting methods for the solving of the so called box linear complementarity problems (BLCPs) where the constraint matrices are restrictedly supposed to be of P matrices. This paper aims at presenting a new principal pivoting scheme for BLCPs where the constraint matrices are loosely supposed to be row sufficient.This scheme can be applied to the solving of convex quadratic programs subject to linear constraints and arbitrary upper and lower bound constraints on variables.
