Based on analysis of the change of land use and related social- economic factors in karst mountain areas of southwestern China, the index system characterizing land use change and its human driving forces in county sc...Based on analysis of the change of land use and related social- economic factors in karst mountain areas of southwestern China, the index system characterizing land use change and its human driving forces in county scale is put forward. Then the relationship of land use change and the driving forces is studied by statistic analysis to identify quantitatively the contribution of human forces and their differences in driving land use change. Moreover, taking the Luodian County as the case, a model simulating the annual change of cultivated land area under the driving of human forces is built. Result of the study will supply reference for the management of the relationship of man and land in karst mountain areas of southern- western China, and accumulate research experience for further study on land use/cover change.展开更多
In this study, a two-hop wireless sensor network with multiple relay nodes is considered where the amplify-and-forward(AF) scheme is employed. Two algorithms are presented to jointly consider interference suppression ...In this study, a two-hop wireless sensor network with multiple relay nodes is considered where the amplify-and-forward(AF) scheme is employed. Two algorithms are presented to jointly consider interference suppression and power allocation(PA) based on the minimization of the symbol error rate(SER) criterion. A stochastic gradient(SG) algorithm is developed on the basis of the minimum-SER(MSER) criterion to jointly update the parameter vectors that allocate the power levels among the relay sensors subject to a total power constraint and the linear receiver. In addition, a conjugate gradient(CG) algorithm is developed on the basis of the SER criterion. A centralized algorithm is designed at the fusion center. Destination nodes transmit the quantized information of the PA vector to the relay nodes through a limited-feedback channel. The complexity and convergence analysis of the proposed algorithms are carried out. Simulation results show that the proposed two adaptive algorithms significantly outperform the other previously reported algorithms.展开更多
基金Under the auspices of the National Natural Science Foundation of China !(No.49871037,59890200).
文摘Based on analysis of the change of land use and related social- economic factors in karst mountain areas of southwestern China, the index system characterizing land use change and its human driving forces in county scale is put forward. Then the relationship of land use change and the driving forces is studied by statistic analysis to identify quantitatively the contribution of human forces and their differences in driving land use change. Moreover, taking the Luodian County as the case, a model simulating the annual change of cultivated land area under the driving of human forces is built. Result of the study will supply reference for the management of the relationship of man and land in karst mountain areas of southern- western China, and accumulate research experience for further study on land use/cover change.
基金Project supported by the National Natural Science Foundation of China(Nos.61101103 and 61201230)the 5th Generation Mobile Communication Program in China(No.2014AA01A707)
文摘In this study, a two-hop wireless sensor network with multiple relay nodes is considered where the amplify-and-forward(AF) scheme is employed. Two algorithms are presented to jointly consider interference suppression and power allocation(PA) based on the minimization of the symbol error rate(SER) criterion. A stochastic gradient(SG) algorithm is developed on the basis of the minimum-SER(MSER) criterion to jointly update the parameter vectors that allocate the power levels among the relay sensors subject to a total power constraint and the linear receiver. In addition, a conjugate gradient(CG) algorithm is developed on the basis of the SER criterion. A centralized algorithm is designed at the fusion center. Destination nodes transmit the quantized information of the PA vector to the relay nodes through a limited-feedback channel. The complexity and convergence analysis of the proposed algorithms are carried out. Simulation results show that the proposed two adaptive algorithms significantly outperform the other previously reported algorithms.
