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三维叠前傅里叶变换法模型并行算法 被引量:2
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作者 吴艳辉 张叔伦 +1 位作者 杨其强 田振平 《石油地球物理勘探》 EI CSCD 北大核心 2006年第1期8-12,共5页
本文应用傅里叶变换法模型算法实现三维叠前声波模型的并行计算,得到了三维合成地震记录,并且应用射线理论分析对此算法进行了验证。算法允许速度纵横向变化。三维叠前模型计算的最大困难是内存需求量和计算量庞大,算法的主要优点在于... 本文应用傅里叶变换法模型算法实现三维叠前声波模型的并行计算,得到了三维合成地震记录,并且应用射线理论分析对此算法进行了验证。算法允许速度纵横向变化。三维叠前模型计算的最大困难是内存需求量和计算量庞大,算法的主要优点在于各主体计算部分均采用快速傅里叶变换,成功地将向量化技术和复序列傅氏变换与实序列傅氏变换的关系用于二维、三维快速傅里叶变换(FFT),从而优化了程序,提高了计算效率并节省了内存。理论分析和实际试算表明:适当调节空间和时间采样间隔、震源子波的主频和长度,可减少因差分逼近微分引起的频散,得到更佳的模拟效果。利用消息传递并行编程环境和微机机群运行并行程序,大大提高了计算效率,节省了计算时间;同时将波场快照与速度剖面相结合,可以更好地观测到波的传播过程。模型试算得到的合成记录表明,此项算法可行且有效。 展开更多
关键词 三维快速傅里叶变换 傅里叶变换模型算法 频散 波场快照
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电子政务成本与效益问题分析 被引量:15
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作者 王宁红 《经济问题》 CSSCI 北大核心 2004年第2期27-29,共3页
电子政务的成本与效益分析是一项复杂的研究课题。电子政务的效益不仅包括经济效益,还包括社会效益。电子政务效益评估的复杂性和高难度,是当前电子政务建设出现参差不齐的主要因素之一。结合目前我国电子政务发展的实际,对电子政务成... 电子政务的成本与效益分析是一项复杂的研究课题。电子政务的效益不仅包括经济效益,还包括社会效益。电子政务效益评估的复杂性和高难度,是当前电子政务建设出现参差不齐的主要因素之一。结合目前我国电子政务发展的实际,对电子政务成本和效益进行了分析,给出了电子政务效益评价模型,提出了提高电子政务经济效益和社会效益的几个途径。 展开更多
关键词 电子政务 中国 成本-效益分析 经济效益 社会效益 行政管理 算法模型法 专家判定
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Optimization of support vector machine power load forecasting model based on data mining and Lyapunov exponents 被引量:7
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作者 牛东晓 王永利 马小勇 《Journal of Central South University》 SCIE EI CAS 2010年第2期406-412,共7页
According to the chaotic and non-linear characters of power load data,the time series matrix is established with the theory of phase-space reconstruction,and then Lyapunov exponents with chaotic time series are comput... According to the chaotic and non-linear characters of power load data,the time series matrix is established with the theory of phase-space reconstruction,and then Lyapunov exponents with chaotic time series are computed to determine the time delay and the embedding dimension.Due to different features of the data,data mining algorithm is conducted to classify the data into different groups.Redundant information is eliminated by the advantage of data mining technology,and the historical loads that have highly similar features with the forecasting day are searched by the system.As a result,the training data can be decreased and the computing speed can also be improved when constructing support vector machine(SVM) model.Then,SVM algorithm is used to predict power load with parameters that get in pretreatment.In order to prove the effectiveness of the new model,the calculation with data mining SVM algorithm is compared with that of single SVM and back propagation network.It can be seen that the new DSVM algorithm effectively improves the forecast accuracy by 0.75%,1.10% and 1.73% compared with SVM for two random dimensions of 11-dimension,14-dimension and BP network,respectively.This indicates that the DSVM gains perfect improvement effect in the short-term power load forecasting. 展开更多
关键词 power load forecasting support vector machine (SVM) Lyapunov exponent data mining embedding dimension feature classification
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Simulation of clinker grinding circuits of cement plant based on process models calibrated using GA search method 被引量:3
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作者 A.Farzanegan E.Ghasemi Ardi +1 位作者 A.Valian V.Hasanzadeh 《Journal of Central South University》 SCIE EI CAS 2014年第2期799-810,共12页
Particle size distributions of obtained samples from several sampling campaigns were determined and raw data were mass balanced before being used in simulation studies.After determination of breakage function,selectio... Particle size distributions of obtained samples from several sampling campaigns were determined and raw data were mass balanced before being used in simulation studies.After determination of breakage function,selection function,Bond work index,residence time distribution parameters,and Whiten's model parameters for air separators and diaphragms between the two compartments of tube ball mills,performance of the circuits was simulated for given throughputs and feed particle size distribution.Whiten's model parameters were determined by GA(genetic algorithm) toolbox of MATLAB software.Based on implemented models for modeling and simulation,optimization of circuits was carried out.It increased nearly 10.5% and 15.8% in fresh feed capacity input to each tube ball mill.In addition,circulating load ratios of circuits are modified to 118% and 127% from low level of 57% and 22%,respectively,and also cut points of air separators are adjusted at 30 and 40 μm from high range of 53 and 97 μm,respectively.All applications helped in well-operation and energy consumption reduction of equipments. 展开更多
关键词 cement plant clinker grinding genetic algorithm SIMULATION OPTIMIZATION
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An improved constrained model predictive control approach for Hammerstein-Wiener nonlinear systems 被引量:1
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作者 李妍 陈雪原 +1 位作者 毛志忠 袁平 《Journal of Central South University》 SCIE EI CAS 2014年第3期926-932,共7页
Many industry processes can be described as Hammerstein-Wiener nonlinear systems. In this work, an improved constrained model predictive control algorithm is presented for Hammerstein-Wiener systems. In the new approa... Many industry processes can be described as Hammerstein-Wiener nonlinear systems. In this work, an improved constrained model predictive control algorithm is presented for Hammerstein-Wiener systems. In the new approach, the maximum and minimum of partial derivative for input and output nonlinearities are solved in the neighbourhood of the equilibrium. And several parameter-dependent Lyapunov functions, each one corresponding to a different vertex of polytopic descriptions models, are introduced to analyze the stability of Hammerstein-Wiener systems, but only one Lyapunov function is utilized to analyze system stability like the traditional method. Consequently, the conservation of the traditional quadratic stability is removed, and the terminal regions are enlarged. Simulation and field trial results show that the proposed algorithm is valid. It has higher control precision and shorter blowing time than the traditional approach. 展开更多
关键词 Hammerstein-Wiener nonlinear systems model predictive control parameter-dependent Lyapunov functions stability linear matrix inequalities (LMIs)
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A multiple watermarks algorithm for image content authentication
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作者 蔡立军 李睿 易叶青 《Journal of Central South University》 SCIE EI CAS 2012年第10期2866-2874,共9页
A novel multiple watermarks cooperative authentication algorithm was presented for image contents authentication.This algorithm is able to extract multiple features from the image wavelet domain,which is based on that... A novel multiple watermarks cooperative authentication algorithm was presented for image contents authentication.This algorithm is able to extract multiple features from the image wavelet domain,which is based on that the t watermarks are generated.Moreover,a new watermark embedding method,using the space geometric model,was proposed,in order to effectively tackle with the mutual influences problem among t watermarks.Specifically,the incidental tampering location,the classification of intentional content tampering and the incidental modification can be achieved via mutual cooperation of the t watermarks.Both the theoretical analysis and simulations results validate the feasibility and efficacy of the proposed algorithm. 展开更多
关键词 multiple watermarks cooperation authentication wavelet transform image wavelet domain intentional contenttampering incidental modification
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Inverse procedure for determining model parameter of soils using real-coded genetic algorithm 被引量:3
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作者 李守巨 邵龙潭 +1 位作者 王吉喆 刘迎曦 《Journal of Central South University》 SCIE EI CAS 2012年第6期1764-1770,共7页
The hybrid genetic algorithm is utilized to facilitate model parameter estimation.The tri-dimensional compression tests of soil are performed to supply experimental data for identifying nonlinear constitutive model of... The hybrid genetic algorithm is utilized to facilitate model parameter estimation.The tri-dimensional compression tests of soil are performed to supply experimental data for identifying nonlinear constitutive model of soil.In order to save computing time during parameter inversion,a new procedure to compute the calculated strains is presented by multi-linear simplification approach instead of finite element method(FEM).The real-coded hybrid genetic algorithm is developed by combining normal genetic algorithm with gradient-based optimization algorithm.The numerical and experimental results for conditioned soil are compared.The forecast strains based on identified nonlinear constitutive model of soil agree well with observed ones.The effectiveness and accuracy of proposed parameter estimation approach are validated. 展开更多
关键词 parameter estimation real-coded genetic algorithm tri-dimensional compression test gradient-based optimization
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