In this paper,some refinements of norm equalities and inequalities of combination of two orthogonal projections are established.We use certain norm inequalities for positive contraction operator to establish norm ineq...In this paper,some refinements of norm equalities and inequalities of combination of two orthogonal projections are established.We use certain norm inequalities for positive contraction operator to establish norm inequalities for combination of orthogonal projections on a Hilbert space.Furthermore,we give necessary and sufficient conditions under which the norm of the above combination of o`rthogonal projections attains its optimal value.展开更多
To solve the Laplacian problems,we adopt a meshless method with the multiquadric radial basis function(MQRBF)as a basis whose center is distributed inside a circle with a fictitious radius.A maximal projection techniq...To solve the Laplacian problems,we adopt a meshless method with the multiquadric radial basis function(MQRBF)as a basis whose center is distributed inside a circle with a fictitious radius.A maximal projection technique is developed to identify the optimal shape factor and fictitious radius by minimizing a merit function.A sample function is interpolated by theMQ-RBF to provide a trial coefficient vector to compute the merit function.We can quickly determine the optimal values of the parameters within a preferred rage using the golden section search algorithm.The novel method provides the optimal values of parameters and,hence,an optimal MQ-RBF;the performance of the method is validated in numerical examples.Moreover,nonharmonic problems are transformed to the Poisson equation endowed with a homogeneous boundary condition;this can overcome the problem of these problems being ill-posed.The optimal MQ-RBF is extremely accurate.We further propose a novel optimal polynomial method to solve the nonharmonic problems,which achieves high precision up to an order of 10^(−11).展开更多
International oil and gas projects feature high capital-intensity, high risks and contract diversity. Therefore, in order to help decision makers make more reasonable decisions under uncertainty, it is necessary to me...International oil and gas projects feature high capital-intensity, high risks and contract diversity. Therefore, in order to help decision makers make more reasonable decisions under uncertainty, it is necessary to measure the risks of international oil and gas projects. For this purpose, this paper constructs a probabilistic model that is based on the traditional economic evaluation model, and introduces value at risk(VaR) which is a valuable risk measure tool in finance, and applies Va R to measure the risks of royalty contracts, production share contracts and service contracts of an international oil and gas project. Besides, this paper compares the influences of different risk factors on the net present value(NPV) of the project by using the simulation results. The results indicate:(1) risks have great impacts on the project's NPV, therefore, if risks are overlooked, the decision may be wrong.(2) A simulation method is applied to simulate the stochastic distribution of risk factors in the probabilistic model. Therefore, the probability is related to the project's NPV, overcoming the inherent limitation of the traditional economic evaluation method.(3) VaR is a straightforward risk measure tool, and can be applied to evaluate the risks of international oil and gas projects. It is helpful for decision making.展开更多
The need for Optimum Value benefit realization on Road Projects in developing countries has become topical. While the traditional Cost Control project management process only aligns actual costs with budgeted costs, V...The need for Optimum Value benefit realization on Road Projects in developing countries has become topical. While the traditional Cost Control project management process only aligns actual costs with budgeted costs, Value Engineering (VE) is a sustainable and systematic innovative methodology for establishing the best functional balance among desired features of a project. A Value Engineering (VE) study was conducted with the aim of examining the benefits associated with its use on Road Projects in Ghana. This study employed a two-stage research procedure: desk study and field research. The literature review identified the Optimum Value benefits associated with VE road project management technique as increased Confidence Level in Contract Compliance, reliable Implementation Level of Construction Delivery and enhanced Effectiveness Level of Project Sustainability. A quantitative survey research design based on a purposive sampling technique of selecting respondents was adopted. Employing closed-ended questions, 40 sets of questionnaires were issued to professionals in Road Infrastructure and Support Agencies (RISA) under the Ministry of Roads and Highways (MRH) in the Eastern Region of Ghana. At a response rate of 85%, descriptive statistical analysis (Means, Standard Deviations and Variances) and inferential statistical analysis of variance (ANOVA) test were used to process the data and determine whether there was any significant difference between VE benefit parameters and the groups of respondents. The results revealed that road professionals are familiar with the VE process but solely use Cost Control project management technique. Road professionals recognized the high Optimum Value benefits of professionally ethical Contract Compliance, efficient Construction Delivery and functionally viable Project Sustainability on VE road project management process.展开更多
Objective To recognize and assess the impact of the South-to-north Water Transfer Project (SNWTP) on the ecological environment of Xiangfan, Hubei Province, situated in the water-out area, and develop sound scientific...Objective To recognize and assess the impact of the South-to-north Water Transfer Project (SNWTP) on the ecological environment of Xiangfan, Hubei Province, situated in the water-out area, and develop sound scientific countermeasures. Methods A three-layer BP network was built to simulate topology and process of the eco-economy system of Xiangfan. Historical data of ecological environmental factors and socio-economic factors as inputs, and corresponding historical data of ecosystem service value (ESV) and GDP as target outputs, were presented to train and test the network. When predicted input data after 2001 were presented to trained network as generalization sets, ESVs and GDPs of 2002, 2003, 2004... till 2050 were simulated as output in succession. Results Up to 2050, the area would have suffered an accumulative total ESV loss of RMB 104.9 billion, which accounted for 37.36% of the present ESV. The coinstantaneous GDP would change asynchronously with ESV, it would go through an up-to-down process and finally lose RMB89.3 billion, which accounted for 18.71% of 2001. Conclusions The simulation indicates that ESV loss means damage to the capability of socio-economic sustainable development, and suggests that artificial neural networks (ANNs) provide a feasible and effective method and have an important potential in ESV modeling.展开更多
Both in developed and in developing countries, the construction industry is regarded as an economic investment activity without forgetting its significant relationship with national economic development due to its gre...Both in developed and in developing countries, the construction industry is regarded as an economic investment activity without forgetting its significant relationship with national economic development due to its great contributions to the national gross domestic product (GDP) of the country. Concerning construction processes, both risk management (RM) and value engineering (VE) techniques have commonalities from the beginning up to the completion of the project due to enhancing the project value/quality, meeting the project deadline, and reducing overall project cost. VE includes resolving the uncertainty of project objectives and ensuring that the project is delivered in a value for money way. The key point of RM is to solve the uncertainty of the project itself and its results to ensure that the specifications are achieved within the prescribed time, cost, and quality constraints. This review work is comparatively and collectively focus</span><span style="font-family:Verdana;">ed</span><span style="font-family:Verdana;"> on assessing the role of RM and VE tools for project successful delivery. It studies the points of difference and common features of the two aspects in terms of construction project delivery. So, this study concluded that in construction RM tool cannot be the chief aim of the all parties involved in the project execution because sometimes it produces itself negative results and reduces project management success. Therefore, RM needs a strong combination with VE due to the dependence of the target in identifying and assessing risks by considering the highest performance and lowest cost. The integration of RM and VE combination in a single study would avoid duplication of work and deliver better value for money thereby leading to better project outcomes.展开更多
This paper studies the consensus control of multiagent systems with binary-valued observations.An algorithm alternating estimation and control is proposed.Each agent estimates the states of its neighbors based on a pr...This paper studies the consensus control of multiagent systems with binary-valued observations.An algorithm alternating estimation and control is proposed.Each agent estimates the states of its neighbors based on a projected empirical measure method for a holding time.Based on the estimates,each agent designs the consensus control with a constant gain at some skipping time.The states of the system are updated by the designed control,and the estimation and control design will be repeated.For the estimation,the projected empirical measure method is proposed for the binary-valued observations.The algorithm can ensure the uniform boundedness of the estimates and the mean square error of the estimation is proved to be at the order of the reciprocal of the holding time(the same order as that in the case of accurate outputs).For the consensus control,a constant gain is designed instead of the stochastic approximation based gain in the existing literature for binary-valued observations.And,there is no need to make modification for control since the uniform boundedness of the estimates ensures the uniform boundedness of the agents’states.Finally,the systems updated by the designed control are proved to achieve consensus and the consensus speed is faster than that in the existing literature.Simulations are given to demonstrate the theoretical results.展开更多
In this paper,the optional and predictable projections of set-valued measurable processes are studied.The existence and uniqueness of optional and predictable projections of set-valued measurable processes are proved ...In this paper,the optional and predictable projections of set-valued measurable processes are studied.The existence and uniqueness of optional and predictable projections of set-valued measurable processes are proved under proper circumstances.展开更多
At present,with the rapid development of China's economy,the development of the construction industry has made a new breakthrough.Project management requires the construction industry to continuously play its role...At present,with the rapid development of China's economy,the development of the construction industry has made a new breakthrough.Project management requires the construction industry to continuously play its role and value in improving the ability of project management.Earned value method,which is an important way in the field of project management,enables whole project management to rise to a new height.The specific principle of earned value method will be elaborated by fully introducing the specific role of earned value method in engineering projects to provide a reference and basis for practitioners to improve their management ability.展开更多
A projected subgradient method for solving a class of set-valued mixed variational inequalities (SMVIs) is proposed when the mapping is not necessarily Lipschitz. Under some suitable conditions, it can be proven tha...A projected subgradient method for solving a class of set-valued mixed variational inequalities (SMVIs) is proposed when the mapping is not necessarily Lipschitz. Under some suitable conditions, it can be proven that the sequence generated by the method can strongly converge to the unique solution to the problem in the Hilbert spaces.展开更多
This article proves the existence of singular directions of value distribution theory for some transcendental holomorphic curves in the n-dimensional complex projective space P^n(C).. An example is given to compleme...This article proves the existence of singular directions of value distribution theory for some transcendental holomorphic curves in the n-dimensional complex projective space P^n(C).. An example is given to complement these results.展开更多
This paper introduces a novice solution methodology for multi-objective optimization problems having the coefficients in the form of uncertain variables. The embedding theorem, which establishes that the set of uncert...This paper introduces a novice solution methodology for multi-objective optimization problems having the coefficients in the form of uncertain variables. The embedding theorem, which establishes that the set of uncertain variables can be embedded into the Banach space C[0, 1] × C[0, 1] isometrically and isomorphically, is developed. Based on this embedding theorem, each objective with uncertain coefficients can be transformed into two objectives with crisp coefficients. The solution of the original m-objectives optimization problem with uncertain coefficients will be obtained by solving the corresponding 2 m-objectives crisp optimization problem. The R & D project portfolio decision deals with future events and opportunities, much of the information required to make portfolio decisions is uncertain. Here parameters like outcome, risk, and cost are considered as uncertain variables and an uncertain bi-objective optimization problem with some useful constraints is developed. The corresponding crisp tetra-objective optimization model is then developed by embedding theorem. The feasibility and effectiveness of the proposed method is verified by a real case study with the consideration that the uncertain variables are triangular in nature.展开更多
The singular value decomposition is derived when the Radon transform is restricted to functions which are square integrable on the unit ball in R-n with respect to the weight W-lambda(x). It fulfilles mainly by means ...The singular value decomposition is derived when the Radon transform is restricted to functions which are square integrable on the unit ball in R-n with respect to the weight W-lambda(x). It fulfilles mainly by means of the projection-slice theorem. The range of the Radon transform is spanned by products of Gegenbauer polynomials and spherical harmonics. The inverse transform of the those basis functions are given. This immediately leads to an inversion formula by series expansion and range characterizations.展开更多
China Seabuckthorn Ecological Project has been implemented for a decade (from 1999 to 2008) with an increasing seabuckthorn area of 1642.83 km2 in?the Sandstone Areas of Shanxi, Shaanxi and Inner Mongolia—the most se...China Seabuckthorn Ecological Project has been implemented for a decade (from 1999 to 2008) with an increasing seabuckthorn area of 1642.83 km2 in?the Sandstone Areas of Shanxi, Shaanxi and Inner Mongolia—the most serious soil erosion area in China. The vast artificial seabuckthorn forest’s value in environmental resource is assessed via 7 indicators on first-level, 15 indicators on secondary level and 35 indicators on third level in this research. As of 2008, the seabuckthorn environmental resource value is 10.017 billion RMB Yuan, which equals to 37.1 times of the project’s total investment of 0.27 billion RMB Yuan. It is proposed in this research that the external economical values such as soil and water conservation, windbreak and sand-fixation can be realized through relative national policies and taxes. Carbon-fixation and oxygen-producing value can be achieved through the international carbon trade.展开更多
This paper analyzed relative ecological value of several major plants in Minqin desert grassland using layered projection of plant canopy. The results showed that ecological functions of natural Nitraria tangutorum an...This paper analyzed relative ecological value of several major plants in Minqin desert grassland using layered projection of plant canopy. The results showed that ecological functions of natural Nitraria tangutorum and Ephedra sinica woods of a unit area were much better than those of artifi cial Haloxylon ammodendron woods, relative ecological value of N. tangutorum, E. sinica and Artemisia desertorum were much higher than that of artifi cial H. ammodendron woods. Layered projection explains clearly the ecological functions and relative ecological value of desert vegetation of the same coverage. It is inaccurate to indicate wind prevention and sand fi xation of desert vegetation in deserts using ecological function service value and ecological niche calculated on the basis of two-dimensional vegetation coverage, but three-dimensional projection degree should be applied to indicate ecological functions and relative ecological value of vegetation. Application of layered projection of plants in calculating ecological functions and relative ecological value of desert plants(vegetation) is the innovation point of this research.展开更多
Earned duration management(EDM)is a methodology for project schedule management(PSM)that can be considered an alternative to earned value management(EVM).EDM provides an estimation of devia-tions in schedule and a fin...Earned duration management(EDM)is a methodology for project schedule management(PSM)that can be considered an alternative to earned value management(EVM).EDM provides an estimation of devia-tions in schedule and a final project duration estimation.There is a key difference between EDM and EVM:In EDM,the value of activities is expressed as work periods;whereas in EVM,value is expressed in terms of cost.In this paper,we present how EDM can be applied to monitor and control stochastic pro-jects.To explain the methodology,we use a real case study with a project that presents a high level of uncertainty and activities with random durations.We analyze the usability of this approach according to the activities network topology and compare the EVM and earned schedule methodology(ESM)for PSM.展开更多
文摘In this paper,some refinements of norm equalities and inequalities of combination of two orthogonal projections are established.We use certain norm inequalities for positive contraction operator to establish norm inequalities for combination of orthogonal projections on a Hilbert space.Furthermore,we give necessary and sufficient conditions under which the norm of the above combination of o`rthogonal projections attains its optimal value.
基金supported by the the National Science and Technology Council(Grant Number:NSTC 112-2221-E239-022).
文摘To solve the Laplacian problems,we adopt a meshless method with the multiquadric radial basis function(MQRBF)as a basis whose center is distributed inside a circle with a fictitious radius.A maximal projection technique is developed to identify the optimal shape factor and fictitious radius by minimizing a merit function.A sample function is interpolated by theMQ-RBF to provide a trial coefficient vector to compute the merit function.We can quickly determine the optimal values of the parameters within a preferred rage using the golden section search algorithm.The novel method provides the optimal values of parameters and,hence,an optimal MQ-RBF;the performance of the method is validated in numerical examples.Moreover,nonharmonic problems are transformed to the Poisson equation endowed with a homogeneous boundary condition;this can overcome the problem of these problems being ill-posed.The optimal MQ-RBF is extremely accurate.We further propose a novel optimal polynomial method to solve the nonharmonic problems,which achieves high precision up to an order of 10^(−11).
基金supported by the Young Fund of Shanxi University of Finance and Economics(No.QN-2018002)National Natural Science Foundation of China(No.71774105)the Fund for Shanxi Key Subjects Construction(FSKSC)and Shanxi Repatriate Study Abroad Foundation(No.2016-3)
文摘International oil and gas projects feature high capital-intensity, high risks and contract diversity. Therefore, in order to help decision makers make more reasonable decisions under uncertainty, it is necessary to measure the risks of international oil and gas projects. For this purpose, this paper constructs a probabilistic model that is based on the traditional economic evaluation model, and introduces value at risk(VaR) which is a valuable risk measure tool in finance, and applies Va R to measure the risks of royalty contracts, production share contracts and service contracts of an international oil and gas project. Besides, this paper compares the influences of different risk factors on the net present value(NPV) of the project by using the simulation results. The results indicate:(1) risks have great impacts on the project's NPV, therefore, if risks are overlooked, the decision may be wrong.(2) A simulation method is applied to simulate the stochastic distribution of risk factors in the probabilistic model. Therefore, the probability is related to the project's NPV, overcoming the inherent limitation of the traditional economic evaluation method.(3) VaR is a straightforward risk measure tool, and can be applied to evaluate the risks of international oil and gas projects. It is helpful for decision making.
文摘The need for Optimum Value benefit realization on Road Projects in developing countries has become topical. While the traditional Cost Control project management process only aligns actual costs with budgeted costs, Value Engineering (VE) is a sustainable and systematic innovative methodology for establishing the best functional balance among desired features of a project. A Value Engineering (VE) study was conducted with the aim of examining the benefits associated with its use on Road Projects in Ghana. This study employed a two-stage research procedure: desk study and field research. The literature review identified the Optimum Value benefits associated with VE road project management technique as increased Confidence Level in Contract Compliance, reliable Implementation Level of Construction Delivery and enhanced Effectiveness Level of Project Sustainability. A quantitative survey research design based on a purposive sampling technique of selecting respondents was adopted. Employing closed-ended questions, 40 sets of questionnaires were issued to professionals in Road Infrastructure and Support Agencies (RISA) under the Ministry of Roads and Highways (MRH) in the Eastern Region of Ghana. At a response rate of 85%, descriptive statistical analysis (Means, Standard Deviations and Variances) and inferential statistical analysis of variance (ANOVA) test were used to process the data and determine whether there was any significant difference between VE benefit parameters and the groups of respondents. The results revealed that road professionals are familiar with the VE process but solely use Cost Control project management technique. Road professionals recognized the high Optimum Value benefits of professionally ethical Contract Compliance, efficient Construction Delivery and functionally viable Project Sustainability on VE road project management process.
文摘Objective To recognize and assess the impact of the South-to-north Water Transfer Project (SNWTP) on the ecological environment of Xiangfan, Hubei Province, situated in the water-out area, and develop sound scientific countermeasures. Methods A three-layer BP network was built to simulate topology and process of the eco-economy system of Xiangfan. Historical data of ecological environmental factors and socio-economic factors as inputs, and corresponding historical data of ecosystem service value (ESV) and GDP as target outputs, were presented to train and test the network. When predicted input data after 2001 were presented to trained network as generalization sets, ESVs and GDPs of 2002, 2003, 2004... till 2050 were simulated as output in succession. Results Up to 2050, the area would have suffered an accumulative total ESV loss of RMB 104.9 billion, which accounted for 37.36% of the present ESV. The coinstantaneous GDP would change asynchronously with ESV, it would go through an up-to-down process and finally lose RMB89.3 billion, which accounted for 18.71% of 2001. Conclusions The simulation indicates that ESV loss means damage to the capability of socio-economic sustainable development, and suggests that artificial neural networks (ANNs) provide a feasible and effective method and have an important potential in ESV modeling.
文摘Both in developed and in developing countries, the construction industry is regarded as an economic investment activity without forgetting its significant relationship with national economic development due to its great contributions to the national gross domestic product (GDP) of the country. Concerning construction processes, both risk management (RM) and value engineering (VE) techniques have commonalities from the beginning up to the completion of the project due to enhancing the project value/quality, meeting the project deadline, and reducing overall project cost. VE includes resolving the uncertainty of project objectives and ensuring that the project is delivered in a value for money way. The key point of RM is to solve the uncertainty of the project itself and its results to ensure that the specifications are achieved within the prescribed time, cost, and quality constraints. This review work is comparatively and collectively focus</span><span style="font-family:Verdana;">ed</span><span style="font-family:Verdana;"> on assessing the role of RM and VE tools for project successful delivery. It studies the points of difference and common features of the two aspects in terms of construction project delivery. So, this study concluded that in construction RM tool cannot be the chief aim of the all parties involved in the project execution because sometimes it produces itself negative results and reduces project management success. Therefore, RM needs a strong combination with VE due to the dependence of the target in identifying and assessing risks by considering the highest performance and lowest cost. The integration of RM and VE combination in a single study would avoid duplication of work and deliver better value for money thereby leading to better project outcomes.
基金supported by the National Natural Science Foundation of China(61803370,61622309)the China Postdoctoral Science Foundation(2018M630216)the National Key Research and Development Program of China(2016YFB0901902)
文摘This paper studies the consensus control of multiagent systems with binary-valued observations.An algorithm alternating estimation and control is proposed.Each agent estimates the states of its neighbors based on a projected empirical measure method for a holding time.Based on the estimates,each agent designs the consensus control with a constant gain at some skipping time.The states of the system are updated by the designed control,and the estimation and control design will be repeated.For the estimation,the projected empirical measure method is proposed for the binary-valued observations.The algorithm can ensure the uniform boundedness of the estimates and the mean square error of the estimation is proved to be at the order of the reciprocal of the holding time(the same order as that in the case of accurate outputs).For the consensus control,a constant gain is designed instead of the stochastic approximation based gain in the existing literature for binary-valued observations.And,there is no need to make modification for control since the uniform boundedness of the estimates ensures the uniform boundedness of the agents’states.Finally,the systems updated by the designed control are proved to achieve consensus and the consensus speed is faster than that in the existing literature.Simulations are given to demonstrate the theoretical results.
基金National Natural Science Foundation of China(1 9971 0 72 )
文摘In this paper,the optional and predictable projections of set-valued measurable processes are studied.The existence and uniqueness of optional and predictable projections of set-valued measurable processes are proved under proper circumstances.
文摘At present,with the rapid development of China's economy,the development of the construction industry has made a new breakthrough.Project management requires the construction industry to continuously play its role and value in improving the ability of project management.Earned value method,which is an important way in the field of project management,enables whole project management to rise to a new height.The specific principle of earned value method will be elaborated by fully introducing the specific role of earned value method in engineering projects to provide a reference and basis for practitioners to improve their management ability.
基金supported by the Key Program of National Natural Science Foundation of China(No.70831005)the National Natural Science Foundation of China(No.10671135)the Fundamental Research Funds for the Central Universities(No.2009SCU11096)
文摘A projected subgradient method for solving a class of set-valued mixed variational inequalities (SMVIs) is proposed when the mapping is not necessarily Lipschitz. Under some suitable conditions, it can be proven that the sequence generated by the method can strongly converge to the unique solution to the problem in the Hilbert spaces.
基金The project supported in part by the National Natural Science Foundation of China (10371091)
文摘This article proves the existence of singular directions of value distribution theory for some transcendental holomorphic curves in the n-dimensional complex projective space P^n(C).. An example is given to complement these results.
文摘This paper introduces a novice solution methodology for multi-objective optimization problems having the coefficients in the form of uncertain variables. The embedding theorem, which establishes that the set of uncertain variables can be embedded into the Banach space C[0, 1] × C[0, 1] isometrically and isomorphically, is developed. Based on this embedding theorem, each objective with uncertain coefficients can be transformed into two objectives with crisp coefficients. The solution of the original m-objectives optimization problem with uncertain coefficients will be obtained by solving the corresponding 2 m-objectives crisp optimization problem. The R & D project portfolio decision deals with future events and opportunities, much of the information required to make portfolio decisions is uncertain. Here parameters like outcome, risk, and cost are considered as uncertain variables and an uncertain bi-objective optimization problem with some useful constraints is developed. The corresponding crisp tetra-objective optimization model is then developed by embedding theorem. The feasibility and effectiveness of the proposed method is verified by a real case study with the consideration that the uncertain variables are triangular in nature.
文摘稀疏阵列布阵灵活,增大阵列孔径的同时还能减少阵元间耦合,但基于稀疏阵列的传统波达方向估计会导致角度模糊混叠,带来估计精度差和稳健性不足的问题。针对以上问题,提出一种适用于稀疏阵列波达方向估计的加权截断奇异值投影(weighted truncated singular value projection,WT-SVP)的鲁棒矩阵填充算法。在填充迭代过程中根据奇异值的大小分配权重,突出大奇异值包含的阵列信息,减少小奇异值中不必要的噪声信息,从而优化传统奇异值投影算法。该算法可以实现稀疏阵列的孔洞信息恢复,对不连续阵元充分利用,同时WT-SVP填充算法实现了稀疏阵列波达方向估计的高精度、高分辨以及在低信噪比、低快拍时的高鲁棒性。
文摘The singular value decomposition is derived when the Radon transform is restricted to functions which are square integrable on the unit ball in R-n with respect to the weight W-lambda(x). It fulfilles mainly by means of the projection-slice theorem. The range of the Radon transform is spanned by products of Gegenbauer polynomials and spherical harmonics. The inverse transform of the those basis functions are given. This immediately leads to an inversion formula by series expansion and range characterizations.
文摘China Seabuckthorn Ecological Project has been implemented for a decade (from 1999 to 2008) with an increasing seabuckthorn area of 1642.83 km2 in?the Sandstone Areas of Shanxi, Shaanxi and Inner Mongolia—the most serious soil erosion area in China. The vast artificial seabuckthorn forest’s value in environmental resource is assessed via 7 indicators on first-level, 15 indicators on secondary level and 35 indicators on third level in this research. As of 2008, the seabuckthorn environmental resource value is 10.017 billion RMB Yuan, which equals to 37.1 times of the project’s total investment of 0.27 billion RMB Yuan. It is proposed in this research that the external economical values such as soil and water conservation, windbreak and sand-fixation can be realized through relative national policies and taxes. Carbon-fixation and oxygen-producing value can be achieved through the international carbon trade.
基金Sponsored by Pilot Study of National 973 Plan(2014CB460611)The National Natural Science Fund(41261102)
文摘This paper analyzed relative ecological value of several major plants in Minqin desert grassland using layered projection of plant canopy. The results showed that ecological functions of natural Nitraria tangutorum and Ephedra sinica woods of a unit area were much better than those of artifi cial Haloxylon ammodendron woods, relative ecological value of N. tangutorum, E. sinica and Artemisia desertorum were much higher than that of artifi cial H. ammodendron woods. Layered projection explains clearly the ecological functions and relative ecological value of desert vegetation of the same coverage. It is inaccurate to indicate wind prevention and sand fi xation of desert vegetation in deserts using ecological function service value and ecological niche calculated on the basis of two-dimensional vegetation coverage, but three-dimensional projection degree should be applied to indicate ecological functions and relative ecological value of vegetation. Application of layered projection of plants in calculating ecological functions and relative ecological value of desert plants(vegetation) is the innovation point of this research.
基金financed by the Regional Government of Castille and Leon(Spain)with Grant(VA180P20).
文摘Earned duration management(EDM)is a methodology for project schedule management(PSM)that can be considered an alternative to earned value management(EVM).EDM provides an estimation of devia-tions in schedule and a final project duration estimation.There is a key difference between EDM and EVM:In EDM,the value of activities is expressed as work periods;whereas in EVM,value is expressed in terms of cost.In this paper,we present how EDM can be applied to monitor and control stochastic pro-jects.To explain the methodology,we use a real case study with a project that presents a high level of uncertainty and activities with random durations.We analyze the usability of this approach according to the activities network topology and compare the EVM and earned schedule methodology(ESM)for PSM.