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Combination of Metal Shielding and Distance Estimation for Electromagnetic Compatibility Guarantee 被引量:1
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作者 Nguyen Duc Truong Tran Van Nghia +1 位作者 Bui Duc Chinh Ho Quang Quy 《Journal of Electromagnetic Analysis and Applications》 2019年第9期135-147,共13页
In this paper, a solution for electromagnetic compatibility guarantee based on the combination of metal shielding and circuit components distance estimation methods is presented. The electromagnetic noises generated f... In this paper, a solution for electromagnetic compatibility guarantee based on the combination of metal shielding and circuit components distance estimation methods is presented. The electromagnetic noises generated from a working radio-electronic unit can expand into the space and act on other around radio-electronic units. An EMC guaranteed radio-electronic unit by the suitable technique method will not cause the electromagnetic noise to others. In opposition, it will not be under electromagnetic action from another one. Due to the power of electromagnetic noise, the metal shielding, distance estimation or other technique methods should be used to guarantee EMC. Every method has own advantage as so as weakness for detail radio-electronic unit, so it is necessary to choose a suitable method to guarantee EMC for them, the combination of metal shielding and distance estimation is a choice, for example. The proposed solution has been evaluated by using CST (Computer Simulation Technology) software and EMxpertEHX analyzer in oscillator circuit context. The simulated results on CST show that the proposed solution decreases the electromagnetic radiation about of 39.1 dB at frequency 500 MHz in comparison to results when nothing electromagnetic compatibility methods are not used. The experimental results on the oscillator circuit are presented. The electromagnetic radiation reduction of the oscillator circuit is about of (25 - 30) dB. In comparison to individual metal shielding and distance estimation methods, the effectiveness of the proposed solution for electromagnetic compatibility guarantee is significantly increased. 展开更多
关键词 ELECTROMAGNETIC Compatibility ELECTROMAGNETIC RADIATION Metal SHIELDING distance estimation
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IN-SITU DISTANCE RESOLVED OPTICALLY TRANSPARENT THIN-LAYER MICROSCOPIC FTIR SPECTROELECTROCEMISTRY.ESTIMATION OF THE ELECTROCHEMICAL CONCENTRATION-DISTANCE PROFILE
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作者 Xiang Qin LIN Zhi Li LI Laboratory of Electroanalytical Chemistry,Changchun Institute of Appliese Chemistry,Chinese Academy of Sciences,Changchun 130022 《Chinese Chemical Letters》 SCIE CAS CSCD 1993年第4期355-358,共4页
An in-situ optically transparent thin-layer microscopic FTIR spectroelectro- chemical cell was constructed.Using this cell,we characterize a concentration-distance profile in the electrochemical diffusion thin-layer b... An in-situ optically transparent thin-layer microscopic FTIR spectroelectro- chemical cell was constructed.Using this cell,we characterize a concentration-distance profile in the electrochemical diffusion thin-layer by in-situ adjusting the focal point at different distances to the electrode surface. 展开更多
关键词 FTIR Pt IN-SITU distance RESOLVED OPTICALLY TRANSPARENT THIN-LAYER MICROSCOPIC FTIR SPECTROELECTROCEMISTRY.estimation OF THE ELECTROCHEMICAL CONCENTRATION-distance PROFILE
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Distance Estimation and Material Classification of a Compliant Tactile Sensor Using Vibration Modes and Support Vector Machine
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作者 S.R.GUNASEKARA H.N.T.K.KALDERA +1 位作者 N.HARISCHANDRA L.SAMARANAYAKE 《Instrumentation》 2019年第1期34-47,共14页
Many animals possess actively movable tactile sensors in their heads,to explore the near-range space.During locomotion,an antenna is used in near range orientation,for example,in detecting,localizing,probing,and negot... Many animals possess actively movable tactile sensors in their heads,to explore the near-range space.During locomotion,an antenna is used in near range orientation,for example,in detecting,localizing,probing,and negotiating obstacles.A bionic tactile sensor used in the present work was inspired by the antenna of the stick insects.The sensor is able to detect an obstacle and its location in 3 D(Three dimensional) space.The vibration signals are analyzed in the frequency domain using Fast Fourier Transform(FFT) to estimate the distances.Signal processing algorithms,Artificial Neural Network(ANN) and Support Vector Machine(SVM) are used for the analysis and prediction processes.These three prediction techniques are compared for both distance estimation and material classification processes.When estimating the distances,the accuracy of estimation is deteriorated towards the tip of the probe due to the change in the vibration modes.Since the vibration data within that region have high a variance,the accuracy in distance estimation and material classification are lower towards the tip.The change in vibration mode is mathematically analyzed and a solution is proposed to estimate the distance along the full range of the probe. 展开更多
关键词 VIBRATION based active TACTILE sensor Artificial Neural Network Support vector machines distance estimation VIBRATION MODES Euler-Bernoulli beam element
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Leading directions and effective distance of larch offspring dispersal at the upper treeline in the Northern and Polar Urals, Russia
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作者 P.A.Moiseev V.L.Semerikov +3 位作者 T.V.Semerikova D.S.Balakin I.B.Vorobiev S.O.Viuykhin 《Forest Ecosystems》 SCIE CSCD 2024年第5期603-617,共15页
Climate has changed sufficiently over the last 150 years and forced out upper treeline advance at the most studied sites around the world.The rate of advance has been extremely variable–from tens to hundreds meters i... Climate has changed sufficiently over the last 150 years and forced out upper treeline advance at the most studied sites around the world.The rate of advance has been extremely variable–from tens to hundreds meters in altitude.This is because the degree at which tree frontal populations respond to climate change depends on the complex interaction of biological and physical factors.The resulting stand pattern is the consequence of the interaction between dispersal and survival functions.A few publications have addressed the question of how this pattern is generated.In order to understand how the spatial structure of tree stands was formed at the upper limit of their distribution in the Ural Mountains,we assessed the distance and direction of dispersal of offspring from maternal individuals.We found that in frontal Larix sibirica Ledeb.populations,‘effective’dispersal of offspring ranges from 3 to 758 m(with a median of 20–33 m in open forest and 219 m in single-tree tundra in the Polar Urals and 107 m in open forest in the Northern Urals).We revealed that most of the offspring effectively dispersed not only in the direction of the prevailing winds,but also in the opposite direction up the slope,and the distance can reach 500–760 m.The data obtained can be used to develop an individual-based model which is capable of simulating in detail the dynamics of tree stands at the upper limit of their growth and reliably predicting the future position and pattern of treeline ecotone as growth conditions continue to improve in the face of observed climate change. 展开更多
关键词 Effective dispersal distance Upper treeline Parentage analysis Age estimation Terrestrial laser scanning Larix sibirica Ural mountains
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Asymptotic Normality Distribution of Simulated Minimum Hellinger Distance Estimators for Continuous Models 被引量:1
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作者 Andrew Luong Claire Bilodeau 《Open Journal of Statistics》 2018年第5期846-860,共15页
Certain distributions do not have a closed-form density, but it is simple to draw samples from them. For such distributions, simulated minimum Hellinger distance (SMHD) estimation appears to be useful. Since the metho... Certain distributions do not have a closed-form density, but it is simple to draw samples from them. For such distributions, simulated minimum Hellinger distance (SMHD) estimation appears to be useful. Since the method is distance-based, it happens to be naturally robust. This paper is a follow-up to a previous paper where the SMHD estimators were only shown to be consistent;this paper establishes their asymptotic normality. For any parametric family of distributions for which all positive integer moments exist, asymptotic properties for the SMHD method indicate that the variance of the SMHD estimators attains the lower bound for simulation-based estimators, which is based on the inverse of the Fisher information matrix, adjusted by a constant that reflects the loss of efficiency due to simulations. All these features suggest that the SMHD method is applicable in many fields such as finance or actuarial science where we often encounter distributions without closed-form density. 展开更多
关键词 Continuous DISTRIBUTION KERNEL Density estimATE CONTINUITY in PROBABILITY DIFFERENTIABILITY in PROBABILITY Hellinger distance
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RESEARCH OF THE MEAN COOK DISTANCE AND THE ROBUST ESTIMATE OF SCALE PARAMETER
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作者 Wang Zhizhong(Institute of Surverying Engineering and Land Information, Central SouthUniversity of Technology, Changsha 410083, China) 《Journal of Central South University》 SCIE EI CAS 1997年第1期61-64,共4页
Based on the principle of statistics and the research results by Zhu Jianjun, the paper establishesthe mean Cook distance of scale parameter and studies its properties. The paper still presents the robust estimate of ... Based on the principle of statistics and the research results by Zhu Jianjun, the paper establishesthe mean Cook distance of scale parameter and studies its properties. The paper still presents the robust estimate of scale parameter with minimum mean Cook distance and theoretically shows that scale parameter isnot "nuisance parameter" and it determined by the plus weight squared sums of the residuals of observations.A simple numerical example is given. 展开更多
关键词 COOK distance ROBUST estimATE SCALE PARAMETER
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A plotless density estimator with a Norton-Rice distribution for ordered distances
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作者 Steen Magnussen 《Journal of Forestry Research》 SCIE CAS CSCD 2021年第6期2385-2401,共17页
A Norton-Rice distribution(NRD)is a versatile,flexible distribution for k ordered distances from a random location to the k nearest objects.In a context of plotless density estimation(PDE)with n randomly chosen sample... A Norton-Rice distribution(NRD)is a versatile,flexible distribution for k ordered distances from a random location to the k nearest objects.In a context of plotless density estimation(PDE)with n randomly chosen sample locations,and distances measured to the k=6 nearest objects,the NRD provided a good fit to distance data from seven populations with a census of forest tree stem locations.More importantly,the three parameters of a NRD followed a simple trend with the order(1,…,6)of observed distances.The trend is quantified and exploited in a proposed new PDE through a joint maximum likelihood estimation of the NRD parameters expressed as a functions of distance order.In simulated probability sampling from the seven populations,the proposed PDE had the lowest overall bias with a good performance potential when compared to three alternative PDEs.However,absolute bias increased by 0.8 percentage points when sample size decreased from 20 to 10.In terms of root mean squared error(RMSE),the new proposed estimator was at par with an estimator published in Ecology when this study was wrapping up,but otherwise superior to the remaining two investigated PDEs.Coverage of nominal 95%confidence intervals averaged 0.94 for the new proposed estimators and 0.90,0.96,and 0.90 for the comparison PDEs.Despite tangible improvements in PDEs over the last decades,a globally least biased PDE remains elusive. 展开更多
关键词 Fixed-count sampling Spatial point pattern distance distributions Forest inventory Joint maximum likelihood estimation BIAS Root mean squared error COVERAGE
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A Fractal Compression Algorithm Based on Collage Distance Estimating and Compensating
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作者 He Xin Wei Xiaopeng Zhang Jianming Dalian University 116622, China 《Computer Aided Drafting,Design and Manufacturing》 2002年第1期32-36,共5页
A new fractal image compression scheme based on collage distance is explained, which can provide of the scheme two different compression codes containing their own unique collage distance sets and different types of s... A new fractal image compression scheme based on collage distance is explained, which can provide of the scheme two different compression codes containing their own unique collage distance sets and different types of similar transforms. The analysis and applications of the scheme indicate that it can be adopted as a suitable alternative for balancing between the distortion measure and compression ratio occurring in ordinary fractal compression method. 展开更多
关键词 data estimating fractal compression collage distance
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Diagnostics in generalized nonlinear models based on maximum L_q-likelihood estimation 被引量:1
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作者 徐伟娟 林金官 《Journal of Southeast University(English Edition)》 EI CAS 2013年第1期106-110,共5页
In order to detect whether the data conforms to the given model, it is necessary to diagnose the data in the statistical way. The diagnostic problem in generalized nonlinear models based on the maximum Lq-likelihood e... In order to detect whether the data conforms to the given model, it is necessary to diagnose the data in the statistical way. The diagnostic problem in generalized nonlinear models based on the maximum Lq-likelihood estimation is considered. Three diagnostic statistics are used to detect whether the outliers exist in the data set. Simulation results show that when the sample size is small, the values of diagnostic statistics based on the maximum Lq-likelihood estimation are greater than the values based on the maximum likelihood estimation. As the sample size increases, the difference between the values of the diagnostic statistics based on two estimation methods diminishes gradually. It means that the outliers can be distinguished easier through the maximum Lq-likelihood method than those through the maximum likelihood estimation method. 展开更多
关键词 maximum Lq-likelihood estimation generalized nonlinear regression model case-deletion model generalized Cook distance likelihood distance difference of deviance
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Method to reconnoiter pulse amplitude train for phased array radar based on Hausdorff distance 被引量:3
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作者 Chuan Sheng Yongshun Zhang +1 位作者 Wenlong Lu Junwei Xie 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2017年第6期1089-1097,共9页
This paper presents a method to estimate beam pointing of phased array radar by the pulse amplitude train, which is significant in radar electronic reconnaissance and electronic support measure. Firstly, the antenna p... This paper presents a method to estimate beam pointing of phased array radar by the pulse amplitude train, which is significant in radar electronic reconnaissance and electronic support measure. Firstly, the antenna patterns modeling of the phased array system is exploited to build the radar sweeping model and the signal propagation model. Secondly, the relationship between the variation of the radiated power and the antenna beam pointing angles in the given airspace is analyzed. Based on the above two points, the sample with obvious amplitude characteristics of the pulse amplitude train can be screened out after detecting the train peaks. Finally, the sample is matched to the subsequent pulse amplitude train based on the Hausdorff distance. The proposed methods have less prior knowledge and higher efficiency and are easier to process. By cross correlating the sample of the pulse amplitude train with the sample data of the antenna follow-up radiation, the probability of detection of the beam pointing direction becomes larger in case that the subsequent antenna beam returns to the specific position. 展开更多
关键词 beam pointing estimation antenna pattern pulse am plitude train Hausdorff distance
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Outlier Detection Based on Robust Mahalanobis Distance and Its Application 被引量:2
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作者 Xu Li Songren Deng +1 位作者 Lifang Li Yunchuan Jiang 《Open Journal of Statistics》 2019年第1期15-26,共12页
Classical Mahalanobis distance is used as a method of detecting outliers, and is affected by outliers. Some robust Mahalanobis distance is proposed via the fast MCD estimator. However, the bias of the MCD estimator in... Classical Mahalanobis distance is used as a method of detecting outliers, and is affected by outliers. Some robust Mahalanobis distance is proposed via the fast MCD estimator. However, the bias of the MCD estimator increases significantly as the dimension increases. In this paper, we propose the improved Mahalanobis distance based on a more robust Rocke estimator under high-dimensional data. The results of numerical simulation and empirical analysis show that our proposed method can better detect the outliers in the data than the above two methods when there are outliers in the data and the dimensions of data are very high. 展开更多
关键词 MCD estimATOR Rocke estimATOR OUTLIER Mahalanobis distance
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From Nonparametric Density Estimation to Parametric Estimation of Multidimensional Diffusion Processes 被引量:1
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作者 Julien Apala N’drin Ouagnina Hili 《Applied Mathematics》 2015年第9期1592-1610,共19页
The paper deals with the estimation of parameters of multidimensional diffusion processes that are discretely observed. We construct estimator of the parameters based on the minimum Hellinger distance method. This met... The paper deals with the estimation of parameters of multidimensional diffusion processes that are discretely observed. We construct estimator of the parameters based on the minimum Hellinger distance method. This method is based on the minimization of the Hellinger distance between the density of the invariant distribution of the diffusion process and a nonparametric estimator of this density. We give conditions which ensure the existence of an invariant measure that admits density with respect to the Lebesgue measure and the strong mixing property with exponential rate for the Markov process. Under this condition, we define an estimator of the density based on kernel function and study his properties (almost sure convergence and asymptotic normality). After, using the estimator of the density, we construct the minimum Hellinger distance estimator of the parameters of the diffusion process and establish the almost sure convergence and the asymptotic normality of this estimator. To illustrate the properties of the estimator of the parameters, we apply the method to two examples of multidimensional diffusion processes. 展开更多
关键词 Hellinger distance estimation MULTIDIMENSIONAL Diffusion Processes STRONG MIXING Process CONSISTENCE ASYMPTOTIC NORMALITY
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Hellinger distance based probability distribution approach to performance monitoring of nonlinear control systems 被引量:2
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作者 李晨 黄彪 钱锋 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第12期1945-1950,共6页
Control performance monitoring has attracted great attention in both academia and industry over the past two decades. However, most research efforts have been devoted to the performance monitoring of linear control sy... Control performance monitoring has attracted great attention in both academia and industry over the past two decades. However, most research efforts have been devoted to the performance monitoring of linear control systems, without considering the pervasive nonlinearities(e.g. valve stiction) present in most industrial control systems. In this work, a novel probability distribution distance based index is proposed to monitor the performance of non-linear control systems. The proposed method uses Hellinger distance to evaluate change of control system performance. Several simulation examples are given to illustrate the effectiveness of the proposed method. 展开更多
关键词 Control performance monitoring Kernel density estimation Hellinger distance Nonlinear system
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Studies on the High Resolution DOA Estimation for UUV Based on Synthetic Aperture Technique 被引量:3
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作者 杨旭东 黄建国 冯西安 《Defence Technology(防务技术)》 SCIE EI CAS 2009年第1期24-28,共5页
To increase the limited spatial processing gain of physical aperture of UUV(unmanned underwater vehicle) linear array and satisfy the demand of long distance target detection,a flank array based on the synthetic apert... To increase the limited spatial processing gain of physical aperture of UUV(unmanned underwater vehicle) linear array and satisfy the demand of long distance target detection,a flank array based on the synthetic aperture technique is introduced into UUV,and a modified beam domain passive synthetic aperture processing algorithm(BDPSA) suitable for the flank array is proposed concurrently,which sums the beamforming of linear array coherently for successive measurement after phase compensation to make the beam output peak corresponding to the expected target bearing,expand the array aperture effectively and improve the resolution.The simulation of detection probability and distinguishing probability for double targets within 1,1/2,1/3 and 1/4 beam-width shows that the method of BDPSA has lower SNR threshold for target distinguishing,improves the detection probability and distinguishing probability under low SNR,and realizes the long-distance and high resolution bearing estimation because of the obvious improvement of the spatial array gain. 展开更多
关键词 合成孔径技术 无人潜航器 高分辨率 DOA估计 无人水下航行器 线性阵列 检测概率 空间处理
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THE MEASURE OF MEAN COOK DISTANCE UNDER THE CONTAMINATED ERROR MODEL
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作者 Wang Zhizhong Zhu Jianjun (College of Resources, Environment and Civil Engineering, Central South University of Technology, Changsha 410083, China) 《Journal of Central South University》 SCIE EI CAS 1999年第2期115-119,共5页
Redefines the mean Cook distance under the contaminated error model. With the help of the mean Cook distance, the paper discusses the relationship between local influence of small perturbations and high leverage case.... Redefines the mean Cook distance under the contaminated error model. With the help of the mean Cook distance, the paper discusses the relationship between local influence of small perturbations and high leverage case. A new robust method for the adjustment of geodetic networks is proposed. The suggested method, a generalization of the robust method with the minimum mean Cook distance, is more efficient than the others. The basic feature of the method is that the equivalent weight functions of the robust estimates are determined according to the principle of statistics. 展开更多
关键词 ROBUST estimation COOK distance MAXIMUM LIKELIHOOD estimation
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Institutional Distance and CrossNational Income Gaps
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作者 黄新飞 舒元 徐裕敏 《China Economist》 2014年第2期76-89,共14页
ihis paper examines the root causes of current cross-national institutional difference from the perspective of national hetereogeneity and provides detailed explanations on the justification and effectiveness of using... ihis paper examines the root causes of current cross-national institutional difference from the perspective of national hetereogeneity and provides detailed explanations on the justification and effectiveness of using cross-national genetic distance as the instrumental variable (IV) of institutional difference. We combined 10,585 samples by pairing 146 countries and regions, created a cross-national institutional distance variable composed of 14 indicators from the World Bank and the Heritage Foundation in three aspects including differences of political system, economic system and institutional implementation attributes, and conducted a cross-section IV estimation for the long-term effect of institutional differences on cross-national income gaps using data between 1996 and 2010. Empirical results indicate that institutional difference has a long-term significant positive effect on cross-national income gaps and such an effect has a tendency to increase during sample period. With factors like human capital, geographical factor, language and religion under control, we still arrived at similar conclusions. The empirical results are demonstrated to be robust using different genetic distance measurement indicators and estimation methods. 展开更多
关键词 institutional distance cross-national income gap genetic distance nationalheterogeneity estimation of instrumental variable
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Combining Self-Organizing Map and Lipschitz Condition for Estimation in Direction of Arrival
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作者 Xiuhui Tan Peng Wang +2 位作者 Hongping Hu Rong Cheng Yanping Bai 《Open Journal of Applied Sciences》 2023年第7期1012-1028,共17页
There are many DOA estimation methods based on different signal features, and these methods are often evaluated by experimental results, but lack the necessary theoretical basis. Therefore, a direction of arrival (DOA... There are many DOA estimation methods based on different signal features, and these methods are often evaluated by experimental results, but lack the necessary theoretical basis. Therefore, a direction of arrival (DOA) estimation system based on self-organizing map (SOM) and designed for arbitrarily distributed sensor array is proposed. The essential principle of this method is that the map from distance difference of arrival (DDOA) to DOA is Lipschitz continuity, it indicates the similar topology between them, and thus Kohonen SOM is a suitable network to classify DOA through DDOA. The simulation results show that the DOA estimation errors are less than 1° for most signals between 0° to 180°. Compared to MUSIC, Root-MUSIC, ESPRIT, and RBF, the errors of signals under signal-to-noise ratios (SNR) declines from 20 dB to 2 dB are robust, SOM is better than RBF and almost close to MUSIC. Further, the network can be trained in advance, which makes it possible to be implemented in real-time. 展开更多
关键词 DOA estimation Kohonen SOM distance Difference of Arrival Topological Order Lipschitz Condition
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Likelihood and Quadratic Distance Methods for the Generalized Asymmetric Laplace Distribution for Financial Data 被引量:1
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作者 Andrew Luong 《Open Journal of Statistics》 2017年第2期347-368,共22页
Maximum likelihood (ML) estimation for the generalized asymmetric Laplace (GAL) distribution also known as Variance gamma using simplex direct search algorithms is investigated. In this paper, we use numerical direct ... Maximum likelihood (ML) estimation for the generalized asymmetric Laplace (GAL) distribution also known as Variance gamma using simplex direct search algorithms is investigated. In this paper, we use numerical direct search techniques for maximizing the log-likelihood to obtain ML estimators instead of using the traditional EM algorithm. The density function of the GAL is only continuous but not differentiable with respect to the parameters and the appearance of the Bessel function in the density make it difficult to obtain the asymptotic covariance matrix for the entire GAL family. Using M-estimation theory, the properties of the ML estimators are investigated in this paper. The ML estimators are shown to be consistent for the GAL family and their asymptotic normality can only be guaranteed for the asymmetric Laplace (AL) family. The asymptotic covariance matrix is obtained for the AL family and it completes the results obtained previously in the literature. For the general GAL model, alternative methods of inferences based on quadratic distances (QD) are proposed. The QD methods appear to be overall more efficient than likelihood methods infinite samples using sample sizes n ≤5000 and the range of parameters often encountered for financial data. The proposed methods only require that the moment generating function of the parametric model exists and has a closed form expression and can be used for other models. 展开更多
关键词 M-estimATORS CUMULANT Generating Function CHI-SQUARE Tests Generalized Hyperbolic Distribution SIMPLEX Pattern Search Variance Gamma Minimum distance VALUE at RISK Entropic VALUE at RISK European Call Option
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Application of Log Kriging on Estimated Reserves of the 10-9 Ore Body of Lutangba in the Gejiu Tin Deposits 被引量:2
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作者 DENG Ming-guo LI Wen-chang +5 位作者 LI Bo LI Li-hui JIANG Shun-de XIONG Guang-xu ZHANG Xue-shu YU Hai-jun 《Journal of China University of Mining and Technology》 EI 2007年第2期286-289,共4页
The approaches adopted so far in China to calculate reserves of ore deposits have largely been dependent on polygonal methods, including a cross-section method and a geological block method. However, for various reaso... The approaches adopted so far in China to calculate reserves of ore deposits have largely been dependent on polygonal methods, including a cross-section method and a geological block method. However, for various reasons, especially, the complexity of the geology, and the ore bodies, the deposits became gradually known as development and exploitation took place. There is a certain difference between the prospecting and mining, which will have a great impact on both geological and cutoff grade at the stage of geological mine construction and production. As much accurate information as possible on the spatial distribution patterns of ore bodies and global reserves is essential to improve the production efficiency and reduce production cost. The 10-9 ore body of Lutangba in the Gejiu Tin Deposits was selected as our research object, using a log Kriging and an inverse distance weighing method. In our paper the results are compared with the reserves calculated by the polygonal block method. The global estimate and estimation errors associated with each estimation method are discussed. 展开更多
关键词 log Kriging composite samples semi-variogram inverse distance weighing method reserves estimation Geiiu
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Distance Estimation in Ultrasound Images Using Specific Decorrelation Curves
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作者 DONG Fang ZHANG Dong +2 位作者 YANG Yan YANG Yue QIN Qianqing 《Wuhan University Journal of Natural Sciences》 CAS 2013年第6期517-522,共6页
Speckle decorrelation algorithm is a method using decorrelation curves to estimate the distance between two neighbor- ing ultrasound images. In this paper, we propose a new method to obtain specific decorrelation curv... Speckle decorrelation algorithm is a method using decorrelation curves to estimate the distance between two neighbor- ing ultrasound images. In this paper, we propose a new method to obtain specific decorrelation curves for distance estimation. First, several datasets of synthetic ultrasound (US) images are obtained by scanning different scatters. Second, based on the US datasets, we compute low-order moments and the elevational decorrelation curves. Finally, low-order moments are used to classify different scattering conditions. The suitable decorrelation curves can be acquired when the scattering style has been determined. With these steps, the relationship between low order moments and the decor- relation curves is established by the scattering conditions. This relationship proves to be efficient and applicable in the experiment section. The decorrelation curves chosen according to the rela- tionship also perform well in the distance estimation test. 展开更多
关键词 scattering condition low-order moments the decor-relation curves distance estimation
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