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Peng G.,Central South University | Peng G.,Key Laboratory of Metallogenic Prediction of Nonferrous Metals | Shen W.,Shanghai Ocean University | Han Z.,Shanghai Ocean University | Su W.,China Agricultural University
Sensor Letters | Year: 2011

In this paper, we present an approach that uses surface parameters retrieved from remote sensing to evaluate the tobacco planting suitability. In the processing, the Suitability Evaluation Index (SEI) with the spatial resolution of 100 m was established and used to estimate the tobacco planting suitability. The results show that, the area of tobacco planting is 11312 ha, and the area of the high suitable is 3745 ha in Mile county. The percentage between the area of tobacco planting in the high suitable and the area of tobacco planting in Mile County is only 33%. The spatial distribution of tobacco planting is very unreasonable and lopsided. The utility ratio of high quality land resources is very low. The overall rotation rate of Mile County is 80%, which has still a big gap to the target of 95%. © 2011 American Scientific Publishers. Source

Tang J.-T.,Key Laboratory of Metallogenic Prediction of Nonferrous Metals | Hu S.-G.,Key Laboratory of Metallogenic Prediction of Nonferrous Metals | Hu S.-G.,Central South University | Xiao X.,Key Laboratory of Metallogenic Prediction of Nonferrous Metals | Xiao X.,Central South University
Wutan Huatan Jisuan Jishu | Year: 2015

Audio magnetotelluric (AMT) sounding has become an important method for researching the Earth's electrical structure, which needs to collect the weak and vulnerable natural telluric signal. The stability of grounding resistance is an important factor that affects the accuracy of measurement. The paper has calculated the electric field and the response of the apparent resistivity and the phase under the condition of homogeneous half - space.which is based on the theory of the circuit representation of a telluric measurement. The study shows that the influence of grounding resistance changes on the electric field, the apparent resistivity and impedance phase can not be ignored, especially in the high - frequency. High ground resistance may bring errors of 50% to the electrode field and the phase error, and bring the greatest errors of 75% to the apparent resistivity. Source

Hu D.,Key Laboratory of Metallogenic Prediction of Nonferrous Metals | Hu D.,Central South University | Zhang K.-N.,Key Laboratory of Metallogenic Prediction of Nonferrous Metals | Zhang K.-N.,Central South University | He J.,Hunan University of Technology
International Journal of Earth Sciences and Engineering | Year: 2015

Making interpolation into the classical Kriging spatial interpolation for space-time expansion, and establishing the displacement prediction model of tunnel surrounding rock by space-time semivariogram; analyzing the relation of parameters and transformation, giving the calculation procedure and method for spatial and temporal interpolation. On that basis, space-time unification Kriging interpolation model is applied to predict the crown settlement displacement value within a certain scope at front of tunnel face at any time during the period of tunnel construction. Analyzing and comparing the relation of actual measurement and predicted displacement to time curve taking Sunanshan Tunnel as test object. Computed results show that the model can reflect the development and variation tendency of crown settlement and displacement better, indicating that the precision of spatial and temporal unification Kriging model meets code requirements and it is effective and feasible in displacement prediction of surrounding rock of actual tunnel project. © 2015 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved. Source

Zhou Y.-J.,Key Laboratory of Metallogenic Prediction of Nonferrous Metals | Zhou Y.-J.,Central South University | Deng C.-H.,Key Laboratory of Metallogenic Prediction of Nonferrous Metals | Deng C.-H.,Central South University
Zhongguo Youse Jinshu Xuebao/Chinese Journal of Nonferrous Metals | Year: 2012

The method of converting linear Gauss-Markov (GM) model to linear errors-in-variables (EIV) model was given, an ordinary total least squares (TLS) adjustment algorithm were introduced as an alternative method for converted EIV model. Extended TLS methods of weight TLS, mixed ordinary LS and TLS, constrained TLS estimators with computational schemes were introduced as well. A typical geodetic control network adjustment and a curve fitting data experiments are given to compare the adjustment results in accuracy and computation efficiency by TLS and traditional LS methods. The data experiments and theoretic analysis indicate that WTLS method is an optimal estimator for EIV model, reasonable TLS algorithms should be selected according to the function model and associated stochastic model in practical application. Source

Hu T.,Central South University | Hu T.,Key Laboratory of Metallogenic Prediction of Nonferrous Metals | Li D.-Q.,Central South University | Li D.-Q.,Key Laboratory of Metallogenic Prediction of Nonferrous Metals
Wutan Huatan Jisuan Jishu | Year: 2014

The superiority of the E-Ex mode of Wide field electromagnetic sounding method (WFEM) on near field and distinguishing ability of the structure with a thin layer with low resistance is discussed. More concerns were put on the 2D or 3D forward and inversion computation recently. While this paper set up several groups of 1D geological model containing low resistance thin layered structure, drawing the apparent resistivity curves, analyzing features of curves, and knowing the ability of distinguishing the low resistance with thin layer structure. And then compared with the one-dimensional numerical simulation results of CSAMT, the contrasted result shows the superiority of the E-E x mode of wide field electromagnetic sounding method on near field, and helps to know the aspects of wide field apparent resistivity. Source

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