This paper considers the problem of time varying congestion pricing to determine optimal time-varying tolls at peak periods for a queuing network with the interactions between buses and private cars.Through the combin...This paper considers the problem of time varying congestion pricing to determine optimal time-varying tolls at peak periods for a queuing network with the interactions between buses and private cars.Through the combined applications of the space-time expanded network(STEN) and the conventional network equilibrium modeling techniques,a multi-class,multi-mode and multi-criteria traffic network equilibrium model is developed.Travelers of different classes have distinctive value of times(VOTs),and travelers from the same class perceive their travel disutility or generalized costs on a route according to different weights of travel time and travel costs.Moreover,the symmetric cost function model is extended to deal with the interactions between buses and private cars.It is found that there exists a uniform(anonymous) link toll pattern which can drive a multi-class,multi-mode and multi-criteria user equilibrium flow pattern to a system optimum when the system's objective function is measured in terms of money.It is also found that the marginal cost pricing models with a symmetric travel cost function do not reflect the interactions between traffic flows of different road sections,and the obtained congestion pricing toll is smaller than the real value.展开更多
A simplified approach was proposed to analyze the negative skin friction calculation of special-shaped pile considering pile-soil interaction under surcharge. Based on the concentric cylinder shearing theory, consider...A simplified approach was proposed to analyze the negative skin friction calculation of special-shaped pile considering pile-soil interaction under surcharge. Based on the concentric cylinder shearing theory, considering the changes of pile shape(such as, taper angle and diameters of pile base, etc.), the load-transfer of special-shaped pile was built. The accuracy of the developed simplified approach was verified by numerical simulation model with the same condition. Then, the influence factors, such as, taper angles, the diameter of pile base, surcharge, and pile-soil interface parameters were analyzed and discussed. The results show that the developed simplified approach can calculate NSF of special-shaped pile under surcharge effectively. A limited parametric study indicates that in many practical situations special-shaped piles(such as belled wedge pile shown in this work) offer a design option that is more economical than traditional uniform cross-section piles.展开更多
Congestion pricing is an important component of urban intelligent transport system.The efficiency,equity and the environmental impacts associated with road pricing schemes are key issues that should be considered befo...Congestion pricing is an important component of urban intelligent transport system.The efficiency,equity and the environmental impacts associated with road pricing schemes are key issues that should be considered before such schemes are implemented.This paper focuses on the cordon-based pricing with distance tolls,where the tolls are determined by a nonlinear function of a vehicles' travel distance within a cordon,termed as toll charge function.The optimal tolls can give rise to:1) higher total social benefits,2) better levels of equity,and 3) reduced environmental impacts(e.g.,less emission).Firstly,a deterministic equilibrium(DUE) model with elastic demand is presented to evaluate any given toll charge function.The distance tolls are non-additive,thus a modified path-based gradient projection algorithm is developed to solve the DUE model.Then,to quantitatively measure the equity level of each toll charge function,the Gini coefficient is adopted to measure the equity level of the flows in the entire transport network based on equilibrium flows.The total emission level is used to reflect the impacts of distance tolls on the environment.With these two indexes/measurements for the efficiency,equity and environmental issues as well as the DUE model,a multi-objective bi-level programming model is then developed to determine optimal distance tolls.The multi-objective model is converted to a single level model using the goal programming.A genetic algorithm(GA) is adopted to determine solutions.Finally,a numerical example is presented to verify the methodology.展开更多
Academic research into service industries has explored the characteristics of interpersonal interactions between employees and customers, but there are few studies addressing the issues of consumer interaction with te...Academic research into service industries has explored the characteristics of interpersonal interactions between employees and customers, but there are few studies addressing the issues of consumer interaction with technology and its influence on the objectives and results of the operations subsystem. This study examines the elements of the service encounter, and the changes automation originates in them and their relationships. The paper also examines changes in the elements and results of the operations subsystem, as a result of automation. We propose that the customer's relationship with employees and/or technology and automated systems for the service impact the objectives and results of the operations subsystem, all of which could have an effect on the company's competitive position. The empirical study is focused on four industries, namely, toll motorways, car parks, carwash and video/DVD rental companies, in an attempt to identify objectives that lead companies to implement automated processes affecting the customer's relationship with the company. The hypotheses generated are contrasted with a structural equation modelling. The results confirm that the customer's relationship with employees and automated systems for the service impacts the objectives and results of the operations subsystem. Also, the results show how automation can enable firms simultaneously to achieve acceptable levels of flexibility and productivity, two dimensions that have traditionally been considered opposites.展开更多
For the optimum price problem of charging for effluent, this paper analyzes the optimal Pigovian Tax and the serious information asymmetry problem existing in the application process of optimal Pigovian Tax, which is ...For the optimum price problem of charging for effluent, this paper analyzes the optimal Pigovian Tax and the serious information asymmetry problem existing in the application process of optimal Pigovian Tax, which is predominant in theory. Then the bilevel system optimizing decision-making theory is applied to give bilevel linear programming decision-making model of charging for effluent, in which the government (environmental protection agency) acts as the upper level decision-making unit and the polluting enterprises act as the lower level decision-making unit. To some extent, the model avoids the serious information asymmetry between the government and the polluting enterprises on charging for effluent.展开更多
For resource poor and HIV victim urban and pre-urban dwellers in developing countries, home garden is vital to enhance food and nutrient security. The availability of both ground and surface water in Bahir Dar city of...For resource poor and HIV victim urban and pre-urban dwellers in developing countries, home garden is vital to enhance food and nutrient security. The availability of both ground and surface water in Bahir Dar city of Ethiopia propels many poor families to produce vegetable and fruit crop for home consumption and income generation. Productivity of fruits and vegetables has been seriously affected due to lack of high yield with good quality varieties, poor knowledge of agronomic practices, poor water and fertilizer managements to exploit the full potential benefits of home garden to the area. To minimize those gaps, resource poor and HIV victim women headed households were selected and model home garden were established to demonstrate improved production practices. Subsequent trainings and experience sharing focused on the different techniques of vegetable and fruit crops production and management, methods of compost preparation and how to generate income from home garden were provided. The seeds of lettuce, Swiss chard, head cabbage, kale, carrot and improved banana sucker and coffee seedlings were supplied for each model home garden. Based on the training and experiences gained, different vegetable growing structures, such as old plastic containers, wooden boxes, vegetable growing shelves made from locally available materials and old used car tier, and "food always in the house" (FAITH) gardening techniques were established to maximize the potential of home garden both vertically and horizontally. Within one growing season, participants produced plenty leafy vegetable for home consumption and they started to generate income by supplying fresh vegetable products to the local market. Nowadays, participants have been sharing their knowledge and experiences to new neighboring gardeners through their model home gardens. Therefore, the respective stakeholders should provide continuous technical and financial support to strengthen the established model home garden as a training center to disseminate improved production techniques for Bahir Dar city residents for the future.展开更多
The axial charges of the proton and N(1440) are studied in the framework of an extended constituent quark model (CQM) including qqqqq components. The cancellation between the contributions of qqq components and qq...The axial charges of the proton and N(1440) are studied in the framework of an extended constituent quark model (CQM) including qqqqq components. The cancellation between the contributions of qqq components and qqqqq components gives a natural explanation to the experimental value of the proton axial charge, which can not be well reproduced in the traditional CQM even after the SU(6) × O(3) symmetry breaking is taken into account. The experimental value of axial charge pins down the proportion of the qqqqq component in the proton to about 20%, which is consistent with the ones given by the strong decay widths and helicity amplitudes. Besides, an axial charge for N(1440) about 1 is predicted with 30% qqqqq component, which is obtained by the strong and electromagnetic decays.展开更多
Housing problem is the problem of livelihood. The problem of housing consumer behavior has become one of the main concern of the Government after more than 10 years the rapid development of real estate. This article i...Housing problem is the problem of livelihood. The problem of housing consumer behavior has become one of the main concern of the Government after more than 10 years the rapid development of real estate. This article is based on the logit model, integrated family net worth, family income, labor factors and so on. Results showed that housing in Shanghai have household net worth is the most critical, followed by labour income and labour force.展开更多
The author first constructs a Lie algebra ∑ :=∑(q, Wd) from rank 3 quantum torus, which is isomorphic to the core of EALAs of type Ad-1 with coordinates in quantum torus Cqd, and then gives the necessary and suff...The author first constructs a Lie algebra ∑ :=∑(q, Wd) from rank 3 quantum torus, which is isomorphic to the core of EALAs of type Ad-1 with coordinates in quantum torus Cqd, and then gives the necessary and sufficient conditions for the highest weight modules to be quasifinite nonzero central charges are Finally the irreducible Z-graded quasifinite ∑-modules with classified.展开更多
Using molecular dynamics simulation, we compared evaporation behavior of a tiny amount of water molecules adsorbed on solid surfaces with different dipole lengths, including surface dipole lengths of 1 fold, 2 folds, ...Using molecular dynamics simulation, we compared evaporation behavior of a tiny amount of water molecules adsorbed on solid surfaces with different dipole lengths, including surface dipole lengths of 1 fold, 2 folds, 4 folds, 6 folds and 8 folds of 0.14 nm and different charges from 0.1e to 0.9e. Surfaces with short dipole lengths (1-fold system) can always maintain hydrophobic character and the evaporation speeds are not influenced, whether the surface charges are enhanced or weakened; but when surface dipole lengths get to 8 folds, surfaces become more hydrophilic as the surface charge increases, and the evaporation speeds increase gradually and monotonically. By tuning dipole lengths from 1-fold to 8-fold systems, we confirmed non-monotonic variation of the evaporation flux (first increases, then decreases) in 4 fold system with charges (0.1e-0.7e), reported in our previous paper [S. Wang, et al., J. Phys. Chem. B 116 (2012) 13863], and also show the process from the enhancement of this unexpected non-monotonic variation to its vanishment with surface dipole lengths increasing. Herein, we demonstrated two key factors to influence the evaporation flux of a tiny amount of water molecules adsorbed on solid surfaces: the exposed surficial area of water aggregation from where the water molecules can evaporate directly and the attraction potential from the substrate hindering the evaporation. In addition, more interestingly, we showed extra steric effect of surface dipoles on further increase of evaporation flux for 2-folds, 4-folds, 6-folds and 8-folds systems with charges around larger than 0.7e. (The steric effect is first reported by parts of our authors [C. Wang, et al., Sci. Rep. 2 (2012) 358]). This study presents a complete physical picture of the influence of surface dipole lengths on the evaporation behavior of the adsorbed tiny amount of water.展开更多
基金The National High Technology Research and Development Program of China (863 Program) (No. 2007AA11Z202)the National Key Technology R & D Program of China during the 11th Five-Year Plan Period(No. 2006BAJ18B03)the Fundamental Research Funds for the Central Universities (No. DUT10RC(3) 112)
文摘This paper considers the problem of time varying congestion pricing to determine optimal time-varying tolls at peak periods for a queuing network with the interactions between buses and private cars.Through the combined applications of the space-time expanded network(STEN) and the conventional network equilibrium modeling techniques,a multi-class,multi-mode and multi-criteria traffic network equilibrium model is developed.Travelers of different classes have distinctive value of times(VOTs),and travelers from the same class perceive their travel disutility or generalized costs on a route according to different weights of travel time and travel costs.Moreover,the symmetric cost function model is extended to deal with the interactions between buses and private cars.It is found that there exists a uniform(anonymous) link toll pattern which can drive a multi-class,multi-mode and multi-criteria user equilibrium flow pattern to a system optimum when the system's objective function is measured in terms of money.It is also found that the marginal cost pricing models with a symmetric travel cost function do not reflect the interactions between traffic flows of different road sections,and the obtained congestion pricing toll is smaller than the real value.
基金Projects(51278170,U1134207)supported by the National Natural Science Foundation of ChinaProject(B13024)supported by the Program of Introducing Talents of Discipline to Universities,China
文摘A simplified approach was proposed to analyze the negative skin friction calculation of special-shaped pile considering pile-soil interaction under surcharge. Based on the concentric cylinder shearing theory, considering the changes of pile shape(such as, taper angle and diameters of pile base, etc.), the load-transfer of special-shaped pile was built. The accuracy of the developed simplified approach was verified by numerical simulation model with the same condition. Then, the influence factors, such as, taper angles, the diameter of pile base, surcharge, and pile-soil interface parameters were analyzed and discussed. The results show that the developed simplified approach can calculate NSF of special-shaped pile under surcharge effectively. A limited parametric study indicates that in many practical situations special-shaped piles(such as belled wedge pile shown in this work) offer a design option that is more economical than traditional uniform cross-section piles.
基金Projects (61304198,61374195) supported by the National Natural Science Foundation of ChinaProjects (2013M530159,2014T70351) supported by the China Postdoctoral Science Foundation
文摘Congestion pricing is an important component of urban intelligent transport system.The efficiency,equity and the environmental impacts associated with road pricing schemes are key issues that should be considered before such schemes are implemented.This paper focuses on the cordon-based pricing with distance tolls,where the tolls are determined by a nonlinear function of a vehicles' travel distance within a cordon,termed as toll charge function.The optimal tolls can give rise to:1) higher total social benefits,2) better levels of equity,and 3) reduced environmental impacts(e.g.,less emission).Firstly,a deterministic equilibrium(DUE) model with elastic demand is presented to evaluate any given toll charge function.The distance tolls are non-additive,thus a modified path-based gradient projection algorithm is developed to solve the DUE model.Then,to quantitatively measure the equity level of each toll charge function,the Gini coefficient is adopted to measure the equity level of the flows in the entire transport network based on equilibrium flows.The total emission level is used to reflect the impacts of distance tolls on the environment.With these two indexes/measurements for the efficiency,equity and environmental issues as well as the DUE model,a multi-objective bi-level programming model is then developed to determine optimal distance tolls.The multi-objective model is converted to a single level model using the goal programming.A genetic algorithm(GA) is adopted to determine solutions.Finally,a numerical example is presented to verify the methodology.
文摘Academic research into service industries has explored the characteristics of interpersonal interactions between employees and customers, but there are few studies addressing the issues of consumer interaction with technology and its influence on the objectives and results of the operations subsystem. This study examines the elements of the service encounter, and the changes automation originates in them and their relationships. The paper also examines changes in the elements and results of the operations subsystem, as a result of automation. We propose that the customer's relationship with employees and/or technology and automated systems for the service impact the objectives and results of the operations subsystem, all of which could have an effect on the company's competitive position. The empirical study is focused on four industries, namely, toll motorways, car parks, carwash and video/DVD rental companies, in an attempt to identify objectives that lead companies to implement automated processes affecting the customer's relationship with the company. The hypotheses generated are contrasted with a structural equation modelling. The results confirm that the customer's relationship with employees and automated systems for the service impacts the objectives and results of the operations subsystem. Also, the results show how automation can enable firms simultaneously to achieve acceptable levels of flexibility and productivity, two dimensions that have traditionally been considered opposites.
基金the National Social Science Foundation of China(Grant No.04BJY026).
文摘For the optimum price problem of charging for effluent, this paper analyzes the optimal Pigovian Tax and the serious information asymmetry problem existing in the application process of optimal Pigovian Tax, which is predominant in theory. Then the bilevel system optimizing decision-making theory is applied to give bilevel linear programming decision-making model of charging for effluent, in which the government (environmental protection agency) acts as the upper level decision-making unit and the polluting enterprises act as the lower level decision-making unit. To some extent, the model avoids the serious information asymmetry between the government and the polluting enterprises on charging for effluent.
文摘For resource poor and HIV victim urban and pre-urban dwellers in developing countries, home garden is vital to enhance food and nutrient security. The availability of both ground and surface water in Bahir Dar city of Ethiopia propels many poor families to produce vegetable and fruit crop for home consumption and income generation. Productivity of fruits and vegetables has been seriously affected due to lack of high yield with good quality varieties, poor knowledge of agronomic practices, poor water and fertilizer managements to exploit the full potential benefits of home garden to the area. To minimize those gaps, resource poor and HIV victim women headed households were selected and model home garden were established to demonstrate improved production practices. Subsequent trainings and experience sharing focused on the different techniques of vegetable and fruit crops production and management, methods of compost preparation and how to generate income from home garden were provided. The seeds of lettuce, Swiss chard, head cabbage, kale, carrot and improved banana sucker and coffee seedlings were supplied for each model home garden. Based on the training and experiences gained, different vegetable growing structures, such as old plastic containers, wooden boxes, vegetable growing shelves made from locally available materials and old used car tier, and "food always in the house" (FAITH) gardening techniques were established to maximize the potential of home garden both vertically and horizontally. Within one growing season, participants produced plenty leafy vegetable for home consumption and they started to generate income by supplying fresh vegetable products to the local market. Nowadays, participants have been sharing their knowledge and experiences to new neighboring gardeners through their model home gardens. Therefore, the respective stakeholders should provide continuous technical and financial support to strengthen the established model home garden as a training center to disseminate improved production techniques for Bahir Dar city residents for the future.
基金Support by National Natural Science Foundation of China under Grant No.10905077
文摘The axial charges of the proton and N(1440) are studied in the framework of an extended constituent quark model (CQM) including qqqqq components. The cancellation between the contributions of qqq components and qqqqq components gives a natural explanation to the experimental value of the proton axial charge, which can not be well reproduced in the traditional CQM even after the SU(6) × O(3) symmetry breaking is taken into account. The experimental value of axial charge pins down the proportion of the qqqqq component in the proton to about 20%, which is consistent with the ones given by the strong decay widths and helicity amplitudes. Besides, an axial charge for N(1440) about 1 is predicted with 30% qqqqq component, which is obtained by the strong and electromagnetic decays.
文摘Housing problem is the problem of livelihood. The problem of housing consumer behavior has become one of the main concern of the Government after more than 10 years the rapid development of real estate. This article is based on the logit model, integrated family net worth, family income, labor factors and so on. Results showed that housing in Shanghai have household net worth is the most critical, followed by labour income and labour force.
基金Project supported by the Post Doctorate Research Grant from the Ministry of Science and Technologyof China (No. 20060390526)the National Natural Science Foundation of China (No. 10601057)
文摘The author first constructs a Lie algebra ∑ :=∑(q, Wd) from rank 3 quantum torus, which is isomorphic to the core of EALAs of type Ad-1 with coordinates in quantum torus Cqd, and then gives the necessary and sufficient conditions for the highest weight modules to be quasifinite nonzero central charges are Finally the irreducible Z-graded quasifinite ∑-modules with classified.
基金Supported by National Natural Science Foundation of China under Grant Nos.11175230 and 11105088National Program on Key Basic Research Project under Grant No.2012CB932400Shanghai Supercomputer Center of China and Shanghai University Supercomputer (ZQ3000&4000)
文摘Using molecular dynamics simulation, we compared evaporation behavior of a tiny amount of water molecules adsorbed on solid surfaces with different dipole lengths, including surface dipole lengths of 1 fold, 2 folds, 4 folds, 6 folds and 8 folds of 0.14 nm and different charges from 0.1e to 0.9e. Surfaces with short dipole lengths (1-fold system) can always maintain hydrophobic character and the evaporation speeds are not influenced, whether the surface charges are enhanced or weakened; but when surface dipole lengths get to 8 folds, surfaces become more hydrophilic as the surface charge increases, and the evaporation speeds increase gradually and monotonically. By tuning dipole lengths from 1-fold to 8-fold systems, we confirmed non-monotonic variation of the evaporation flux (first increases, then decreases) in 4 fold system with charges (0.1e-0.7e), reported in our previous paper [S. Wang, et al., J. Phys. Chem. B 116 (2012) 13863], and also show the process from the enhancement of this unexpected non-monotonic variation to its vanishment with surface dipole lengths increasing. Herein, we demonstrated two key factors to influence the evaporation flux of a tiny amount of water molecules adsorbed on solid surfaces: the exposed surficial area of water aggregation from where the water molecules can evaporate directly and the attraction potential from the substrate hindering the evaporation. In addition, more interestingly, we showed extra steric effect of surface dipoles on further increase of evaporation flux for 2-folds, 4-folds, 6-folds and 8-folds systems with charges around larger than 0.7e. (The steric effect is first reported by parts of our authors [C. Wang, et al., Sci. Rep. 2 (2012) 358]). This study presents a complete physical picture of the influence of surface dipole lengths on the evaporation behavior of the adsorbed tiny amount of water.