A goal-oriented adaptive finite element（FE） method for solving 3D direct current（DC） resistivity modeling problem is presented. The model domain is subdivided into unstructured tetrahedral elements that allow for ...A goal-oriented adaptive finite element（FE） method for solving 3D direct current（DC） resistivity modeling problem is presented. The model domain is subdivided into unstructured tetrahedral elements that allow for efficient local mesh refinement and flexible description of complex models. The elements that affect the solution at each receiver location are adaptively refined according to a goal-oriented posteriori error estimator using dual-error weighting approach. The FE method with adapting mesh can easily handle such structures at almost any level of complexity. The method is demonstrated on two synthetic resistivity models with analytical solutions and available results from integral equation method, so the errors can be quantified. The applicability of the numerical method is illustrated on a resistivity model with a topographic ridge. Numerical examples show that this method is flexible and accurate for geometrically complex situations.展开更多
针对大数据传输中的数据机密性、完整性和数据丢失等问题,提出一种基于简化数据加密标准(Simplified Data Encryption Standard,SDES)和双轮差错控制的大数据集成安全系统。使用SDES加密算法生成加密字符串,并设计意外数据丢失备份系统...针对大数据传输中的数据机密性、完整性和数据丢失等问题,提出一种基于简化数据加密标准(Simplified Data Encryption Standard,SDES)和双轮差错控制的大数据集成安全系统。使用SDES加密算法生成加密字符串,并设计意外数据丢失备份系统以提高机密性和防止意外数据丢失。基于双轮差错控制以较低的空间开销控制传输过程中包含的任意数量的离散或连续错误位,基于固定长度编码(Fixed Length Coding,FLC)的无损压缩技术来减少数据开销。该算法具有较高的AE值、熵和压缩百分比,具有提供更高的数据机密性和完整性的潜力。展开更多
基金supported by the National Natural Science Foundation of China (No. 41204055)the National Basic Research Program of China (No. 2013CB733203)the Opening Project (No. SMIL-2014-06) of Hubei Subsurface Multi-Scale Imaging Lab (SMIL), China University of Geosciences, Wuhan, China
文摘A goal-oriented adaptive finite element（FE） method for solving 3D direct current（DC） resistivity modeling problem is presented. The model domain is subdivided into unstructured tetrahedral elements that allow for efficient local mesh refinement and flexible description of complex models. The elements that affect the solution at each receiver location are adaptively refined according to a goal-oriented posteriori error estimator using dual-error weighting approach. The FE method with adapting mesh can easily handle such structures at almost any level of complexity. The method is demonstrated on two synthetic resistivity models with analytical solutions and available results from integral equation method, so the errors can be quantified. The applicability of the numerical method is illustrated on a resistivity model with a topographic ridge. Numerical examples show that this method is flexible and accurate for geometrically complex situations.
