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基于远场指标梯度的自学习波前控制模型 被引量:1
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作者 许振兴 杨平 +2 位作者 程涛 许冰 李和平 《中国激光》 EI CAS CSCD 北大核心 2020年第4期209-216,共8页
提出了基于远场指标梯度的自适应光学闭环控制模型,该模型使用递归最小二乘来稳定响应矩阵,通过远场指标的梯度信息快速自学习当前的系统状态。结果表明:该模型具有在线实时更新的特点,能够自适应H-S子孔径缺光或质心探测不理想的状态,... 提出了基于远场指标梯度的自适应光学闭环控制模型,该模型使用递归最小二乘来稳定响应矩阵,通过远场指标的梯度信息快速自学习当前的系统状态。结果表明:该模型具有在线实时更新的特点,能够自适应H-S子孔径缺光或质心探测不理想的状态,可在一定程度上改善控制性能。 展开更多
关键词 自适应光学 递归最小二乘 波前复原 场指标
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葫芦岛市春旱监测和春季第一场透雨指标的确定 被引量:5
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作者 汪丽新 《江西农业学报》 CAS 2010年第2期120-122,共3页
利用葫芦岛地区1959年到2005年3~5月的逐日气温和降水资料,确立了不同干旱程度下春季第一场透雨指标,并对春季干旱进行了分析。
关键词 春旱监测指标 春季第一透雨指标 春旱分析
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等效磁场与弯晶沟道辐射 被引量:5
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作者 罗诗裕 邵明珠 吴木营 《原子核物理评论》 CAS CSCD 北大核心 2003年第4期277-280,共4页
引入场指标和等效磁场概念,把粒子在弯晶沟道中的运动行为等效为回旋加速器中的粒子运动.结果表明,描写粒子的运动方程是一个非线性薛定谔方程.在小振幅近似下找到了系统的严格解和粒子振动周期,导出了瞬时辐射强度和最大辐射频率.
关键词 等效磁 弯晶 沟道辐射 椭圆函数 场指标 回旋加速器 非线性薛定谔方程 振动周期 瞬时辐射强度 最大辐射频率
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铺盖场场变趋稳后的场计算(续六)
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作者 徐尚璧 《水利科技与经济》 2008年第4期341-344,共4页
为粘土铺盖渗流场提供一种趋稳中测算场内多指标的测试算法。通过几则实例的测试粗算,说明了灌淤在耦合性场变中的主要地位。
关键词 耦合 趋稳 场指标 施测 试算
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地棘蛙素类似物的CoMFA和CoMSIA的3D-QSAR研究 被引量:1
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作者 刘春萍 李宏宇 张华北 《北京师范大学学报(自然科学版)》 CAS CSCD 北大核心 2004年第2期237-242,共6页
采用比较分子力场 (CoMFA)分析法和比较分子相似性指标场 (CoMSIA)分析法 ,进行偏最小二乘法 (PLS)分析 ,建立了地棘蛙素类化合物的三维构效模型 .通过验证 ,说明该系列化合物分子立体场、静电场、氢键场和疏水场的分布与生物活性之间... 采用比较分子力场 (CoMFA)分析法和比较分子相似性指标场 (CoMSIA)分析法 ,进行偏最小二乘法 (PLS)分析 ,建立了地棘蛙素类化合物的三维构效模型 .通过验证 ,说明该系列化合物分子立体场、静电场、氢键场和疏水场的分布与生物活性之间有良好的相关性 .用模型预测同系列测试集分子 ,结果与实验值偏差较小 .预测结果表明 ,该力场模型有一定的预测能力 .并得出了新的药效团定义模型 ,可用来指导设计新的地棘蛙素类化合物烟碱型乙酰胆碱配体 . 展开更多
关键词 地棘蛙素 比较分子力分析 比较分子相似性指标 三维定量构效关系 烟碱型乙酰胆碱受体
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Potential landfill site selection for solid waste disposal using GIS and multi-criteria decision analysis(MCDA) 被引量:9
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作者 S.Kapilan K.Elangovan 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第3期570-585,共16页
Proper solid waste disposal is an important socioeconomic concern for all developing countries.Municipalities have their own policies,individual approaches and methods to manage the solid wastes.They consider wastelan... Proper solid waste disposal is an important socioeconomic concern for all developing countries.Municipalities have their own policies,individual approaches and methods to manage the solid wastes.They consider wastelands outside the urban area as the best suitable for the solid waste disposal.Such improper site selection will create morphological changes that lead to environmental hazards in the urban and its surrounding areas.In this research,the site selection for urban solid waste disposal in the Coimbatore district used geographical information system(GIS)and multi-criteria decision analysis(MCDA).Thematic layers of lineament density,landuse/landcover,population density,groundwater depth,drainage density,slope,soil texture,geology and geomorphology were considered as primary criteria and weights for criteria,and sub-criteria were assigned by MCDA analysis.The resultant weight score was validated by consistency ratio so that the efficiency of the selected criteria was justified.The overlay analysis in GIS environment provides 17 potential zones in Coimbatore district,among which,four suitable sites were screened and refined with the help of field investigation and visual interpretation of satellite image.The result of landfill suitability map shows the effectiveness of the proposed method. 展开更多
关键词 municipal solid waste landfill site multi-criteria decision analysis remote sensing GIS Coimbatore
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Support pressure assessment for deep buried railway tunnels using BQ-index 被引量:6
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作者 WANG Ming-nian WANG Zhi-long +3 位作者 TONG Jian-jun ZHANG Xiao DONG Yu-cang LIU Da-gang 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第1期247-263,共17页
Estimation of support pressure is extremely important to the support system design and the construction safety of tunnels.At present,there are many methods for the estimation of support pressure based on different roc... Estimation of support pressure is extremely important to the support system design and the construction safety of tunnels.At present,there are many methods for the estimation of support pressure based on different rock mass classification systems,such as Q system,GSI system and RMR system.However,various rock mass classification systems are based on different tunnel geologic conditions in various regions.Therefore,each rock mass classification system has a certain regionality.In China,the BQ-Inex(BQ system)has been widely used in the field of rock engineering ever since its development.Unfortunately,there is still no estimation method of support pressure with BQ-index as parameters.Based on the field test data from 54 tunnels in China,a new empirical method considering BQ-Inex,tunnel span and rock weight is proposed to estimate the support pressure using multiple nonlinear regression analysis methods.And then the significance and necessity of support pressure estimation method for the safety of tunnel construction in China is explained through the comparison and analysis with the existing internationally widely used support pressure estimation methods of RMR system,Q system and GSI system.Finally,the empirical method of estimating the support pressure based on BQ-index was applied to designing the support system in the China’s high-speed railway tunnel—Zhengwan high-speed railway and the rationality of this method has been verified through the data of field test. 展开更多
关键词 rock mass classification support pressure deep buried tunnel field test multiple nonlinear regression analysis BQ-Index
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A Correction for Classic Performance Measures
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作者 Hayette Gatfaoui 《Chinese Business Review》 2012年第1期1-28,共28页
Non-normality in asset returns is now a common feature of financial markets. However, many practitioners as well as investors do still refer to classic risk adjusted performance measures to assess their investment. Fo... Non-normality in asset returns is now a common feature of financial markets. However, many practitioners as well as investors do still refer to classic risk adjusted performance measures to assess their investment. For example, Sharpe and Treynor ratios are designed for a Gaussian world. Then, employing them for a performance assessment prospect relative to the risk borne is a biased approach. If we look for consistency in risk assessment and in asset performance valuation, we need to look for robust methods or tools. Moreover, the well-known mathematical consistency and numerical tractability concerns drive our preference for simple methods. Under this setting, we propose to account in a simple way and to some extent for the skewness and kurtosis patterns describing the deviations from normality. We adjust therefore the classic Sharpe and Treynor ratios to asymmetries in the downside and upside deviations from the mean values of asset returns. Specifically, the adjusted Sharpe and Treynor ratios are weighted by the upside and downside deviation risks. Accounting for skewness and kurtosis changes generally the ranking of hedge fund performance. Moreover, the obtained adjusted performance measures capture well the skewness and/or kurtosis patterns in hedge fund returns depending on the targeted investment strategy 展开更多
关键词 hedge fund KURTOSIS PERFORMANCE Sharpe ratio SKEWNESS Treynor ratio
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The Effect of Word of Mouth in Customer Equity and Brand Equity
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作者 Guillermo Armelini 《Chinese Business Review》 2011年第3期205-216,共12页
In this paper the author examines the extent to which word of mouth (WOM) impact on customer equity and brand equity, two of the most popular metrics of marketing productivity. WOM is the most ancient and effective ... In this paper the author examines the extent to which word of mouth (WOM) impact on customer equity and brand equity, two of the most popular metrics of marketing productivity. WOM is the most ancient and effective communication tool because its low cost affects the efficiency in the allocation of marketing resources. After an extensive literature review, the author proposes several propositions to be tested in the future concerning how WOM might affect each element of brand equity and customer equity. 展开更多
关键词 word of mouth marketing productivity brand equity customer equity
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Factorial analysis of the effect of sugarbeet vinasses on agroecological indices in horticultural field
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作者 Miguel Angel Diez-Rojo Jose Antomo Lopez-Perez +3 位作者 Maria Rosa Gonzalez-Lopez Ana Piedra Buend Antonio Bello Gonzalo Almendros 《Journal of Agricultural Science and Technology》 2009年第8期31-39,共9页
The impact on soil of applying sugarbeet vinasses (V) was analyzed through a field experiment in horticulture greenhouse, arranged in a 23 factorial design. Two levels of three independent variables--application of ... The impact on soil of applying sugarbeet vinasses (V) was analyzed through a field experiment in horticulture greenhouse, arranged in a 23 factorial design. Two levels of three independent variables--application of V, use of polyethylene cover (PC) on the soil. and soil depth (D)---on various dependent variables were studied. Vinasses favoured crop yield and reduced the number of Meloidogyne incognita juveniles in soil. The concentrations ofN. P and K increased with the interaction VxD, with PC also increasing N concentration. The amounts of humic acids and humin decreased with D; fulvic acid concentration increased with V, but decreased with the interaction VxPC. Soil physical factors were improved mainly with D and V. Aromaticity of humic acid-like fractions increased ~'itb V. In general, V showed significant effects mainly on the topsoil, suggesting low leaching risks. The results indicate that the levels of the independent factors improving a group of variables were not the same that those contributing to another group. Therefore, their best combination should be determined for each scenario to achieve optimum agroecological performance. 展开更多
关键词 aggregate stability. biodisinfestation humic acid MELOIDOGYNE soil organic matter sugarbeet vinasses
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Estimating Field Source Parameters of Gravity Change in North China Based on the Euler Deconvolution Method
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作者 Liu Fang Zhu Yiqing Zhao Yunfeng 《Earthquake Research in China》 CSCD 2017年第2期247-256,共10页
Based on the absolute and relative gravity observations in North China from 2009 to 2014,spatial dynamic variations of the regional gravity field are obtained. We employed the Euler deconvolution method and the theore... Based on the absolute and relative gravity observations in North China from 2009 to 2014,spatial dynamic variations of the regional gravity field are obtained. We employed the Euler deconvolution method and the theoretical model to get the best estimates of parameters. Gravity field change caused by the depth and distribution in North China is calculated by back analysis. The results show the structural index that equals 1 is suitable for inversion of the gravity variation data. The inversion results indicate that the depths of anomaly field sources are spread over the Hetao fault. The research method of this paper can be used in the quantitative study on the field source and may shed new light on the interpretations of gravity change, and also provide quantitative basis for earthquake prediction index criterions based on the gravity change. 展开更多
关键词 Euler deconvolution Potential field inversion Gravity change Structural index North China
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Intensity measures for seismic liquefaction hazard evaluation of sloping site
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作者 陈志雄 程印 +2 位作者 肖杨 卢谅 阳洋 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第10期3999-4018,共20页
This work investigates the correlation between a large number of widely used ground motion intensity measures(IMs) and the corresponding liquefaction potential of a soil deposit during earthquake loading. In order to ... This work investigates the correlation between a large number of widely used ground motion intensity measures(IMs) and the corresponding liquefaction potential of a soil deposit during earthquake loading. In order to accomplish this purpose the seismic responses of 32 sloping liquefiable site models consisting of layered cohesionless soil were subjected to 139 earthquake ground motions. Two sets of ground motions, consisting of 80 ordinary records and 59 pulse-like near-fault records are used in the dynamic analyses. The liquefaction potential of the site is expressed in terms of the the mean pore pressure ratio, the maximum ground settlement, the maximum ground horizontal displacement and the maximum ground horizontal acceleration. For each individual accelerogram, the values of the aforementioned liquefaction potential measures are determined. Then, the correlation between the liquefaction potential measures and the IMs is evaluated. The results reveal that the velocity spectrum intensity(VSI) shows the strongest correlation with the liquefaction potential of sloping site. VSI is also proven to be a sufficient intensity measure with respect to earthquake magnitude and source-to-site distance, and has a good predictability, thus making it a prime candidate for the seismic liquefaction hazard evaluation. 展开更多
关键词 soil liquefaction liquefaction potential index intensity measure(IM) pore pressure generation seismic response prediction
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The entropy weight fuzzy comprehension evaluation of enterprise knowledge competitiveness
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作者 YU Lei WANG Shu-zhen 《Chinese Business Review》 2010年第2期46-50,共5页
With the constant development of knowledge-based economy, knowledge has become the core competitiveness of enterprise, which plays a vital role in the development of enterprise and market competition. It will be helpf... With the constant development of knowledge-based economy, knowledge has become the core competitiveness of enterprise, which plays a vital role in the development of enterprise and market competition. It will be helpful for enterprise managers to improve their knowledge competitiveness, if they can judge the advantage and disadvantage of knowledge competitiveness reasonably. According to the nature and the characteristic of knowledge competitiveness of enterprise, a system of evaluation index has been designed about the knowledge competitiveness of enterprise. Taking the enterprise A as an example, it is appraised by using fuzzy comprehension evaluation based on entropy weight, and has provided a new idea for the knowledge competitiveness of enterprise. 展开更多
关键词 knowledge competitiveness entropy weight fuzzy comprehension evaluation
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A practical framework for scenario-based optimal decision-making on water-deficient river ecological restoration in mining areas
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作者 Sen YU Ming-Yu WANG 《Journal of Coal Science & Engineering(China)》 2013年第4期566-572,共7页
Mining activities may cause serious damages to the river ecological environment in mining areas. It has been realized that challenging is faced for optimal decision-making on the river ecological restoration resulting... Mining activities may cause serious damages to the river ecological environment in mining areas. It has been realized that challenging is faced for optimal decision-making on the river ecological restoration resulting from system complexity, multi-objectives, long term restoration in which multiple stages may be needed to take, and difficulty in detailed process quan- tification. By analyzing and fully reflecting the differences between the central zone and surrounding zones of the restored river passing through the mining area, the comprehensive evaluation index systems of the central zone and surrounding zones are separately suggested firstly. Then a scenario-based optimization decision-making model for river ecological restoration in min- ing areas was established with taking advantages of spatial divisions and following procedure of first going through optimiza- tion by sub-region level, then optimizing by integration. Then, a framework for scenario-based optimal decision-making on water-deficient river ecological restoration in mining areas is proposed in which a multi-objective and multi-stage spatial division optimization method is considered to improve decision-making efficiency and enhance its practicability. It is indicated that this optimization framework is reasonable and practical, which is expected to offer reliable decision support in identifying the effective solutions on optimal management of the water-deficient river ecological restoration in mining areas. At the same time, it has implications in general land reclamation and ecological restoration in the mining areas. 展开更多
关键词 river ecological restoration optimization model scenario analysis
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Distribution of Market Share in the World Soft-Drink Industry
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作者 Femando Buendia Cristina Eccius 《Journal of Physical Science and Application》 2013年第2期123-126,共4页
The distribution of market shares within an industry is a relevant performance measure for managers and policy makers, for it allow to determine whether a given industry is competitive or not. Usually, the perfect com... The distribution of market shares within an industry is a relevant performance measure for managers and policy makers, for it allow to determine whether a given industry is competitive or not. Usually, the perfect competition model is the reference to judge the efficiency of markets. However, there is enough empirical evidence that shows that one of the most evident features of global firms is that both their size and market are Zipf-distributed. In this paper, we show that the distribution of market shares in the world cola-drink market is skewed, but it does not follow Zipf's law, thus it is inadequate to generalize it to any kind of market. 展开更多
关键词 Market share Zipf distribution market power.
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Demonstration Study on the Intrinsic Characteristic of Stock Complex Index on Shanghai Security Market
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《Journal of Systems Science and Information》 2006年第2期371-380,共10页
This paper takes the Shanghai Security market stock composite index as the research object, analyzes its intrinsic fractal essence characteristics by the application of fractal theory and the method, and computes the ... This paper takes the Shanghai Security market stock composite index as the research object, analyzes its intrinsic fractal essence characteristics by the application of fractal theory and the method, and computes the Hurst index, fractal dimension and correlated function of the highest prices of the complex index. Moreover, it studies characteristics of long term memory of the sample data and its variance along with time; study existence of chaotic attractors in data of the complex index by reconstructing the phase space of the index data. Finally, this paper carries on the related forecast demonstration study to the stock composite index. Results of the study have certain reference function to the actual problem. 展开更多
关键词 the shanghai stock market the stock composite index FRACTAL the Hurst index demonstration study
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