[Objective] The aim was to better reveal the type of ecosystem service function of wetlands in Chao Lake and provide references for protection and man- agement, restoration and rebuilding of local wetland ecosystem. [...[Objective] The aim was to better reveal the type of ecosystem service function of wetlands in Chao Lake and provide references for protection and man- agement, restoration and rebuilding of local wetland ecosystem. [Method] The val- ues of ecosystem function was estimated by market value method, opportunity cost approach, replacement cost method, shadow engineering approach, travel cost method, hedonic pricing method and contingent value method. [Result] With wetland ecosystem service function value totals 4.968 billion yuan, the value of eco-environ- ment regulation and maintenance was the highest, followed by the value of cultural and social function. The value of material production was the least. The values of sub-functions can be concluded by comparison of service function va}ue and pro- portions, as follows： flood mitigation 〉water purification 〉water conservation 〉 tourism＆leisure〉material production〉scientific research and education〉water supply〉 biodiversity maintenance〉regulation on atmosphere constituents. [Conclusion] The re- search performed quantitative evaluations on ecosystem service function values of wetlands in Chao Lake and is of significance for specific development and protec- tion of local wetlands.展开更多
Based on the cross-layer design, the power-optimization problem of Macro-Femto Heterogeneous Networks （HetNets） has been formulated. The constraints of power and re-source block allocation in the physical layer, del...Based on the cross-layer design, the power-optimization problem of Macro-Femto Heterogeneous Networks （HetNets） has been formulated. The constraints of power and re-source block allocation in the physical layer, delay and target data rate in the medium ac-cess control layer, urgent queue length in the network layer, and packet error rate in the transport layer, have been considered. The original problem is non-deterministic polyno-mial time hard, which cannot be solved practi-cally. After the restrictions of upper layers are translated into constraints with physical layer parameters, and the integer restrictions are relaxed, the original problem can be decom- posed into convex optimization subproblems. The optimal solutions of resource block allo-cation and power allocation can be obtained by using the Lagrangian optimization. Simula-tion results show that the proposed scheme is better than both the round robin algorithm and the max-rain one in terms of energy efficiency, throughput and service fairness. The round robin algorithm and the max-min one only focus on the user fairness rather than quality of service fairness. Compared to the round robin scheme （the max-min one）, the proposed scheme improves the energy efficiency 58.85% （62.41%）, the throughput 19.09% （25.25%）, the service fairness 57.69% （35.48%）.展开更多
Ecosystem services are spatially heterogeneous and temporal variability, which results in trade-offs,synergies and neutrality. The trade-off is a key problem in ecosystem management and requires optimized decision-mak...Ecosystem services are spatially heterogeneous and temporal variability, which results in trade-offs,synergies and neutrality. The trade-off is a key problem in ecosystem management and requires optimized decision-making research. This paper reviews methods for identifying trade-offs and suggest future model developments. We conclude that(1) ecosystem service assessment depends on quantitative indicators and its modeling;(2)scenario analysis, multi-objective analysis and production possibility boundary are an effective means of ecosystem service trade-off decision-making;(3) future research needs to strengthen ecosystem service supply and demand flow and assist decision-making ecosystem mapping. Finally, integrated models should be developed to simulate and diagnose different scenarios and to optimize measures in land and ecosystem management for sustainability.展开更多
基金Supported by Anhui Environment Protection Scientific Research Program in 2014(201404)~~
文摘[Objective] The aim was to better reveal the type of ecosystem service function of wetlands in Chao Lake and provide references for protection and man- agement, restoration and rebuilding of local wetland ecosystem. [Method] The val- ues of ecosystem function was estimated by market value method, opportunity cost approach, replacement cost method, shadow engineering approach, travel cost method, hedonic pricing method and contingent value method. [Result] With wetland ecosystem service function value totals 4.968 billion yuan, the value of eco-environ- ment regulation and maintenance was the highest, followed by the value of cultural and social function. The value of material production was the least. The values of sub-functions can be concluded by comparison of service function va}ue and pro- portions, as follows： flood mitigation 〉water purification 〉water conservation 〉 tourism＆leisure〉material production〉scientific research and education〉water supply〉 biodiversity maintenance〉regulation on atmosphere constituents. [Conclusion] The re- search performed quantitative evaluations on ecosystem service function values of wetlands in Chao Lake and is of significance for specific development and protec- tion of local wetlands.
基金supported in part by the project of National Natural Science Foundation of China under Grant No. 61071075National Science and Technology Major Project of China under Grant No. 2010ZX03003-001-02+1 种基金National Science and Technology Major Project of China under Grant No. 2011ZX03004003the Chinese Ministry of Education in the project of the Fundamental Research Funds for the Central Universities under Grant No.2011YJS216
文摘Based on the cross-layer design, the power-optimization problem of Macro-Femto Heterogeneous Networks （HetNets） has been formulated. The constraints of power and re-source block allocation in the physical layer, delay and target data rate in the medium ac-cess control layer, urgent queue length in the network layer, and packet error rate in the transport layer, have been considered. The original problem is non-deterministic polyno-mial time hard, which cannot be solved practi-cally. After the restrictions of upper layers are translated into constraints with physical layer parameters, and the integer restrictions are relaxed, the original problem can be decom- posed into convex optimization subproblems. The optimal solutions of resource block allo-cation and power allocation can be obtained by using the Lagrangian optimization. Simula-tion results show that the proposed scheme is better than both the round robin algorithm and the max-rain one in terms of energy efficiency, throughput and service fairness. The round robin algorithm and the max-min one only focus on the user fairness rather than quality of service fairness. Compared to the round robin scheme （the max-min one）, the proposed scheme improves the energy efficiency 58.85% （62.41%）, the throughput 19.09% （25.25%）, the service fairness 57.69% （35.48%）.
基金National Key Research and Development Program of China(2017YFC0503803)National Natural Science Foundation of China(41867012)Qinghai Province Science and Technology Basic Condition Platform Construction Special Project(2018-ZJ-T09)
文摘Ecosystem services are spatially heterogeneous and temporal variability, which results in trade-offs,synergies and neutrality. The trade-off is a key problem in ecosystem management and requires optimized decision-making research. This paper reviews methods for identifying trade-offs and suggest future model developments. We conclude that(1) ecosystem service assessment depends on quantitative indicators and its modeling;(2)scenario analysis, multi-objective analysis and production possibility boundary are an effective means of ecosystem service trade-off decision-making;(3) future research needs to strengthen ecosystem service supply and demand flow and assist decision-making ecosystem mapping. Finally, integrated models should be developed to simulate and diagnose different scenarios and to optimize measures in land and ecosystem management for sustainability.
