A 3D stereotomography algorithm, which is derived from the 3D Cartesian coordinate, is applied for the first time to the deep-sea data acquired in the LH area, South China Sea, to invert a macro velocity model for pre...A 3D stereotomography algorithm, which is derived from the 3D Cartesian coordinate, is applied for the first time to the deep-sea data acquired in the LH area, South China Sea, to invert a macro velocity model for pre-stack depth migration. The successful implementation of stereotomography is highly dependent on the correct extraction of slowness components and the proper application of regularization terms. With the help of the structure tensor algorithm, a high-quality 3D stereotomography data space is achieved in a very efficient manner. Then, considering that the horizontal slowness in cross-line direction is usually unavailable for 3D narrow-azimuth data, the regularization terms must be enhanced to guarantee a stable convergence of the presented algorithm. The inverted model serves as a good model for the 3D pre-stack depth migration. The synthetic and real data examples demonstrated the robustness and effectiveness of the presented algorithm and the related schemes.展开更多
Stope mining design is a very important and complicated task in daily production design and technical management of an underground mine.Based on workface technology and human-computer interaction technology,this study...Stope mining design is a very important and complicated task in daily production design and technical management of an underground mine.Based on workface technology and human-computer interaction technology,this study introduces a method of 3D parametric design for the irregular structure of stope bottoms,and focuses on solving technical problems in surface modeling of stope bottom structure.Optimization of the minimum span length algorithm(MSLA) and the shortest path search algorithm(SPSA) is conducted to solve the problem of contour-line based instant modeling of stope bottom structures,which makes possible the 3D parametric design for irregular structure of stope bottom.Implementation process and relevant methods of the proposed algorithms are also presented.Feasibility and reliability of the proposed modeling method are testified in a case study.In practice,the proposed 3 D parameterization design method for irregular structure stope bottom proves to be very helpful to precise 3D parametric design.This method is capable of contributing to improved efficiency and precision of stope design,and is worthy of promotion.展开更多
Targeting the multicollinearity problem in dam statistical model and error perturbations resulting from the monitoring process, we built a regularized regression model using Truncated Singular Value Decomposition （T...Targeting the multicollinearity problem in dam statistical model and error perturbations resulting from the monitoring process, we built a regularized regression model using Truncated Singular Value Decomposition （TSVD）. An earth-rock dam in China is presented and discussed as an example. The analysis consists of three steps： multicollinearity detection, regularization pa- rameter selection, and crack opening modeling and forecasting. Generalized Cross-Validation （GCV） function and L-curve criterion are both adopted in the regularization parameter selection. Partial Least-Squares Regression （PLSR） and stepwise regression are also included for comparison. The result indicates the TSVD can promisingly solve the multicollinearity problem of dam regression models. However, no general rules are available to make a decision when TSVD is superior to stepwise regression and PLSR due to the regularization parameter-choice problem. Both fitting accuracy and coefficients＇ reasonability should be considered when evaluating the mode/reliability.展开更多
基金funded by China Natural Science Foundation(Nos.41574098 and 41630964)China key specialized project(No.2016ZX05026-001-03)
文摘A 3D stereotomography algorithm, which is derived from the 3D Cartesian coordinate, is applied for the first time to the deep-sea data acquired in the LH area, South China Sea, to invert a macro velocity model for pre-stack depth migration. The successful implementation of stereotomography is highly dependent on the correct extraction of slowness components and the proper application of regularization terms. With the help of the structure tensor algorithm, a high-quality 3D stereotomography data space is achieved in a very efficient manner. Then, considering that the horizontal slowness in cross-line direction is usually unavailable for 3D narrow-azimuth data, the regularization terms must be enhanced to guarantee a stable convergence of the presented algorithm. The inverted model serves as a good model for the 3D pre-stack depth migration. The synthetic and real data examples demonstrated the robustness and effectiveness of the presented algorithm and the related schemes.
基金Supported by the National High Technology Research and Development Programme of China(No.2011AA060407)Yunnan Province Science and Technology Innovation Platform Construction Plans,China(No.2010DH005)
文摘Stope mining design is a very important and complicated task in daily production design and technical management of an underground mine.Based on workface technology and human-computer interaction technology,this study introduces a method of 3D parametric design for the irregular structure of stope bottoms,and focuses on solving technical problems in surface modeling of stope bottom structure.Optimization of the minimum span length algorithm(MSLA) and the shortest path search algorithm(SPSA) is conducted to solve the problem of contour-line based instant modeling of stope bottom structures,which makes possible the 3D parametric design for irregular structure of stope bottom.Implementation process and relevant methods of the proposed algorithms are also presented.Feasibility and reliability of the proposed modeling method are testified in a case study.In practice,the proposed 3 D parameterization design method for irregular structure stope bottom proves to be very helpful to precise 3D parametric design.This method is capable of contributing to improved efficiency and precision of stope design,and is worthy of promotion.
基金Supported by the Research Project of Department of Water Resources of Zhejiang Province of China (No. RB1010)
文摘Targeting the multicollinearity problem in dam statistical model and error perturbations resulting from the monitoring process, we built a regularized regression model using Truncated Singular Value Decomposition （TSVD）. An earth-rock dam in China is presented and discussed as an example. The analysis consists of three steps： multicollinearity detection, regularization pa- rameter selection, and crack opening modeling and forecasting. Generalized Cross-Validation （GCV） function and L-curve criterion are both adopted in the regularization parameter selection. Partial Least-Squares Regression （PLSR） and stepwise regression are also included for comparison. The result indicates the TSVD can promisingly solve the multicollinearity problem of dam regression models. However, no general rules are available to make a decision when TSVD is superior to stepwise regression and PLSR due to the regularization parameter-choice problem. Both fitting accuracy and coefficients＇ reasonability should be considered when evaluating the mode/reliability.
