The rapid development of multimodal transportation system prompts travellers to choose multiple transportation modes, such as private vehicles or taxi, transit(subways or buses), or park-and-ride combinations for urba...The rapid development of multimodal transportation system prompts travellers to choose multiple transportation modes, such as private vehicles or taxi, transit(subways or buses), or park-and-ride combinations for urban trips. Traffic corridor is a major scenario that supports travellers to commute from suburban residential areas to central working areas. Studying their modal choice behaviour is receiving more and more interests. On one hand, it will guide the travellers to rationally choose their most economic and beneficial mode for urban trips. On the other hand, it will help traffic operators to make more appropriate policies to enhance the share of public transit in order to alleviate the traffic congestion and produce more economic and social benefits. To analyze the travel modal choice, a generalized cost model for three typical modes is first established to evaluate each different travel alternative. Then, random utility theory(RUT) and decision field theory(DFT) are introduced to describe the decision-making process how travellers make their mode choices. Further, some important factors that may influence the modal choice behaviour are discussed as well. To test the feasibility of the proposed model, a field test in Beijing was conducted to collect the real-time data and estimate the model parameters. The improvements in the test results and analysis show new advances in the development of travel mode choice on multimodal transportation networks.展开更多
Coal storing and loading have much more influence on coal quality. In the paper, a goal programming model has been constructed to determine the ideal quantity extracting from stockpile and silos and a quality control ...Coal storing and loading have much more influence on coal quality. In the paper, a goal programming model has been constructed to determine the ideal quantity extracting from stockpile and silos and a quality control model is inferred under the guidance of maximum theory of dispersed number and practice methods are given to meet production demand, with which a coal mine has achieved a better tech-economic result.展开更多
In this paper, an economic model was constructed to determine the optimal wolf population and distribution across the Northern Rocky Mountains. Both ecological and economic concepts were incorporated in an implicitly ...In this paper, an economic model was constructed to determine the optimal wolf population and distribution across the Northern Rocky Mountains. Both ecological and economic concepts were incorporated in an implicitly spatial social welfare maximization problem. This interdisciplinary model relies on multiple data sources, including current wolf population and distribution information, opportunity cost to local landowners, and contingent valuation studies to determine willingness-to-pay for wolves. Economic models tend to externalize ecological concerns and ecological models often omit the complex human dimensions of conservation policy. Accordingly, this model can serve as a guide for integrating best practices from both fields. The model presented here is sufficiently general to apply to wolves in other ecosystems and to other highly interacting species such as beavers and bison. The Northern Rocky Mountain wolf was used as an example of how this economic model works, but this model can be applied far more broadly.展开更多
Based on the theory of system dynamics, the paper analyzes the mechanism of socio-economic benefits of highway projects and establishes the system dynamics model of regional economic-highway development. Then taking J...Based on the theory of system dynamics, the paper analyzes the mechanism of socio-economic benefits of highway projects and establishes the system dynamics model of regional economic-highway development. Then taking Jinji(Tianjin--Jixian) Highway of Tianjin as an example, the errors of system simulation are tested, and the system dynamics model built is verified to be quite stable, which has a high performance. Through the comparison of simulation results with and without Jinji Highway, the paper simulates and predicts the socio-economie benefit of each year from 2003 to 2013. Thus the quantification evaluation of socio-economic benefit of highway project is realized and will provide the theory instructions for similar projects in the future.展开更多
The present research developed a bioeconomic model for control of Californian thistle (Cirsium arvense L. Scop.) in intensive, lowland sheep pastures in New Zealand. Production costs included two control methods: h...The present research developed a bioeconomic model for control of Californian thistle (Cirsium arvense L. Scop.) in intensive, lowland sheep pastures in New Zealand. Production costs included two control methods: herbicides and defoliation, with defoliation encompassing both physical means and biocontrol measures. The model was used to examine the economic value of a research programme into biological control of the weed, given several different future scenarios. These scenarios were high herbicide prices, a price premium for lamb raised without chemical herbicides, and development of herbicide resistance. The model results were used to estimate national impacts. If the only change in the agricultural sector was the cost of the biocontrol to the nation's farmers, the research programme to find an effective biocontrol agent had little economic impact. If other factors changed, such as the price of petroleum or levels of herbicide resistance in the weed. the model's results suggested that intensive sheep farming could grow or shrink by as much as NZ$219 million dollars over five years. In the latter case, having an alternative control method reduced potential losses and increased potential gains, resulting in a net benefit of between NZ$81 million and NZ$153 million. This work extended prior research in several ways. First. Californian thistle reproduces via root buds, which affected the modelling of weed behaviour. Secondly, the model allowed optimistation over continuous levels of weed control for two different methods. Thirdly, the model accounted for both weed control and damage to nitrogen-fixing clover from herbicide use. Finally, the research investigated optimal weed control in several different alternative future states.展开更多
Rational inter-industry allocation of environmental responsibilities has great significance to instituting effective policies on industrial environment and transforming the pattern of economic development. From the pe...Rational inter-industry allocation of environmental responsibilities has great significance to instituting effective policies on industrial environment and transforming the pattern of economic development. From the perspective of economic benefit and industrial linkage, this paper discusses the issue of inter-industry allocation of environmental responsibilities. Based on input-output model and three responsibility principles (producer responsibility, consumer responsibility and shared responsibility), this paper develops seven industrial environmental responsibility indicators and conducts an empirical analysis on the S02 emission responsibilities at China's industry level. Results indicate that all these indicators can avoid the double calculation of environmental responsibilities and results using different indicators have significant differences. Some industries such as power, heat production and supply may have little difference of the relative ranking of environmental responsibility under different indicators, but the magnitude of specific assumed responsibilities may have significant changes. Environmental responsibilities of some other industries (such as construction) may seem not important under certain indicators but can be among the most significant under some other indicators. More importantly, despite close connections between these indicators, they reflect different mechanisms of environmental responsibility allocation and have totally different policy significance.展开更多
This study provides basis information for estimating the feasibility of the environmental and ecological forestry construction project in the area. Through the survey in Miyun watershed, the economical benefits of car...This study provides basis information for estimating the feasibility of the environmental and ecological forestry construction project in the area. Through the survey in Miyun watershed, the economical benefits of carbon sequestration in five typical forest types have been studied by calculating the biomass from the timber accumulation data and converting to the money value. The results show that: in the duration of 100 years, at a discount rate of 5%, and 197 RMB yuan/t as the price of the carbon sequestration, the present value (PV) of the carbon sequestration in different forests are: 6900-9300 yuan/ha in Chinese pine forest,6100-8200 yuan/ha in oak forest, 4500-6100 yuan/ha in other broadleaf forests, 2300-3200 yuan/ha in shrubs and 1300-1800 yuan/ha in cypress forest. The annual mean economic benefit of carbon sequestration is 770-1040 yuan/ha. The pine forest has the highest carbon sequestration benefit, followed by oak forest, other broadleaf forest, shrubs, and cypress forest. If the land is suitable for all forests, pine forest and oak forest should be planted in order to sequestrate more carbon.展开更多
基金Project(2012CB725405)supported in part by National Basic Research Program of ChinaProject(2014BAG03B01)supported by the National Science and Technology Support Program,China+1 种基金Project(71301083)supported by the National Natural Science Foundation of ChinaProject(20131089307)supported by the Project Supported by Tsinghua University,China
文摘The rapid development of multimodal transportation system prompts travellers to choose multiple transportation modes, such as private vehicles or taxi, transit(subways or buses), or park-and-ride combinations for urban trips. Traffic corridor is a major scenario that supports travellers to commute from suburban residential areas to central working areas. Studying their modal choice behaviour is receiving more and more interests. On one hand, it will guide the travellers to rationally choose their most economic and beneficial mode for urban trips. On the other hand, it will help traffic operators to make more appropriate policies to enhance the share of public transit in order to alleviate the traffic congestion and produce more economic and social benefits. To analyze the travel modal choice, a generalized cost model for three typical modes is first established to evaluate each different travel alternative. Then, random utility theory(RUT) and decision field theory(DFT) are introduced to describe the decision-making process how travellers make their mode choices. Further, some important factors that may influence the modal choice behaviour are discussed as well. To test the feasibility of the proposed model, a field test in Beijing was conducted to collect the real-time data and estimate the model parameters. The improvements in the test results and analysis show new advances in the development of travel mode choice on multimodal transportation networks.
文摘Coal storing and loading have much more influence on coal quality. In the paper, a goal programming model has been constructed to determine the ideal quantity extracting from stockpile and silos and a quality control model is inferred under the guidance of maximum theory of dispersed number and practice methods are given to meet production demand, with which a coal mine has achieved a better tech-economic result.
文摘In this paper, an economic model was constructed to determine the optimal wolf population and distribution across the Northern Rocky Mountains. Both ecological and economic concepts were incorporated in an implicitly spatial social welfare maximization problem. This interdisciplinary model relies on multiple data sources, including current wolf population and distribution information, opportunity cost to local landowners, and contingent valuation studies to determine willingness-to-pay for wolves. Economic models tend to externalize ecological concerns and ecological models often omit the complex human dimensions of conservation policy. Accordingly, this model can serve as a guide for integrating best practices from both fields. The model presented here is sufficiently general to apply to wolves in other ecosystems and to other highly interacting species such as beavers and bison. The Northern Rocky Mountain wolf was used as an example of how this economic model works, but this model can be applied far more broadly.
基金Technology Plan Projects of Tianjin Planning Bureau(No.2010H3-0011)
文摘Based on the theory of system dynamics, the paper analyzes the mechanism of socio-economic benefits of highway projects and establishes the system dynamics model of regional economic-highway development. Then taking Jinji(Tianjin--Jixian) Highway of Tianjin as an example, the errors of system simulation are tested, and the system dynamics model built is verified to be quite stable, which has a high performance. Through the comparison of simulation results with and without Jinji Highway, the paper simulates and predicts the socio-economie benefit of each year from 2003 to 2013. Thus the quantification evaluation of socio-economic benefit of highway project is realized and will provide the theory instructions for similar projects in the future.
文摘The present research developed a bioeconomic model for control of Californian thistle (Cirsium arvense L. Scop.) in intensive, lowland sheep pastures in New Zealand. Production costs included two control methods: herbicides and defoliation, with defoliation encompassing both physical means and biocontrol measures. The model was used to examine the economic value of a research programme into biological control of the weed, given several different future scenarios. These scenarios were high herbicide prices, a price premium for lamb raised without chemical herbicides, and development of herbicide resistance. The model results were used to estimate national impacts. If the only change in the agricultural sector was the cost of the biocontrol to the nation's farmers, the research programme to find an effective biocontrol agent had little economic impact. If other factors changed, such as the price of petroleum or levels of herbicide resistance in the weed. the model's results suggested that intensive sheep farming could grow or shrink by as much as NZ$219 million dollars over five years. In the latter case, having an alternative control method reduced potential losses and increased potential gains, resulting in a net benefit of between NZ$81 million and NZ$153 million. This work extended prior research in several ways. First. Californian thistle reproduces via root buds, which affected the modelling of weed behaviour. Secondly, the model allowed optimistation over continuous levels of weed control for two different methods. Thirdly, the model accounted for both weed control and damage to nitrogen-fixing clover from herbicide use. Finally, the research investigated optimal weed control in several different alternative future states.
文摘Rational inter-industry allocation of environmental responsibilities has great significance to instituting effective policies on industrial environment and transforming the pattern of economic development. From the perspective of economic benefit and industrial linkage, this paper discusses the issue of inter-industry allocation of environmental responsibilities. Based on input-output model and three responsibility principles (producer responsibility, consumer responsibility and shared responsibility), this paper develops seven industrial environmental responsibility indicators and conducts an empirical analysis on the S02 emission responsibilities at China's industry level. Results indicate that all these indicators can avoid the double calculation of environmental responsibilities and results using different indicators have significant differences. Some industries such as power, heat production and supply may have little difference of the relative ranking of environmental responsibility under different indicators, but the magnitude of specific assumed responsibilities may have significant changes. Environmental responsibilities of some other industries (such as construction) may seem not important under certain indicators but can be among the most significant under some other indicators. More importantly, despite close connections between these indicators, they reflect different mechanisms of environmental responsibility allocation and have totally different policy significance.
文摘This study provides basis information for estimating the feasibility of the environmental and ecological forestry construction project in the area. Through the survey in Miyun watershed, the economical benefits of carbon sequestration in five typical forest types have been studied by calculating the biomass from the timber accumulation data and converting to the money value. The results show that: in the duration of 100 years, at a discount rate of 5%, and 197 RMB yuan/t as the price of the carbon sequestration, the present value (PV) of the carbon sequestration in different forests are: 6900-9300 yuan/ha in Chinese pine forest,6100-8200 yuan/ha in oak forest, 4500-6100 yuan/ha in other broadleaf forests, 2300-3200 yuan/ha in shrubs and 1300-1800 yuan/ha in cypress forest. The annual mean economic benefit of carbon sequestration is 770-1040 yuan/ha. The pine forest has the highest carbon sequestration benefit, followed by oak forest, other broadleaf forest, shrubs, and cypress forest. If the land is suitable for all forests, pine forest and oak forest should be planted in order to sequestrate more carbon.