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Improvement of a new rotation function for molecular replacement by designing new scoring functions and dynamic correlation coefficient

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Chinese Physics B 2010年第10期19卷 354-359页

作者：江凡丁玮 Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Graduate School of the Chinese Academy of Sciences

A previously published new rotation function has been improved by using a dynamic correlation coefficient as well as two new scoring functions of relative entropy and mean-square-residues to make the rotation function more robust and independent of a specific set of weights for scoring and ranking. The previously described new rotation function calculates the rotation function of molecular replacement by matching the search model directly with the Patterson vector map. The signal-to-noise ratio for the correct match was increased by averaging all the matching peaks. Several matching scores were employed to evaluate the goodness of matching. These matching scores were then combined into a single total score by optimizing a set of weights using the linear regression method. It was found that there exists an optimal set of weights that can be applied to the global rotation search and the correct solution can be ranked in the top 100 or less. However, this set of optimal weights in general is dependent on the search models and the crystal structures with different space groups and cell parameters. In this work, we try to solve this problem by designing a dynamic correlation coefficient. It is shown that the dynamic correlation coefficient works for a variety of space groups and cell parameters in the global search of rotation function. We also introduce two new matching scores： relative entropy and mean-square-residues. Last but not least, we discussed a valid method for the optimization of the adjustable parameters for matching vectors.

关键词： molecular replacement rotation function global search correlation coefficient

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The Accuracy Analysis of Zero-lag correlation coefficient of Dual-Polarization Radar

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Chinese Journal of Electronics 2015年第1期24卷 212-217页

作者： ZHANG Wenwen YIN Fulian JIA Yunfeng Beijing Aerospace System Engineering Institute Information Engineering School Communication University of China

Dual polarization technology is gradually promoted in our country after Doppler weather radar network. It extends the capabilities of conventional Doppler radar, and can directly detect the differential reflectivity factor and the zero-lag correlation coefficient and so on which are related with the micro-physics characteristics of precipitation. Considering that small error may lead to erroneous judgments when identify the particle phase state with the zero-lag correlation coefficient for its values is close to each other at different phase states and is between0 and 1, the error mean value and mean square root of the zero-lag correlation coefficient are deduced at alternative transmission mode, and each parameter’s effect to the precision is analyzed. It not only provides a useful polarization variable for better identifying hydrometer phase state and clutter recognition, but also provides an practical way to estimate the zero-lag correlation coefficient and relevant.

关键词： Dual polarization Doppler radar Alternative transmission correlation coefficient Measurement accuracy.

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A correlation coefficient Approach for Evaluation of Stiffness Degradation of Beams Under Moving Load

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Computers, Materials & Continua 2019年第7期61卷 27-53页

作者： Thanh Q.Nguyen Thao T.D.Nguyen H.Nguyen-Xuan Nhi K.Ngo Laboratory of Applied Mechanics(LAM) Ho Chi Minh City University of TechnologyHo Chi Minh City740030Vietnam Saigon Hi-Tech Park Training Center Ho Chi Minh City715650Vietnam Ho Chi Minh City Department of Transportation and Communication Ho Chi Minh City710100Vietnam CIRTECH Institute Ho Chi Minh City University of Technology(HUTECH)Ho Chi Minh City717349Vietnam Department of Physical Therapy Graduate Institute of Rehabilitation ScienceChina Medical UniversityTaichung40402Taiwan

This paper presents a new approach using correlation and cross-correlation coefficients to evaluate the stiffness degradation of beams under moving *** theoretical study of identifying defects by vibration methods showed that the traditional methods derived from the vibration measurement data have not met the needs of the actual *** show that the correlation coefficients allow us to evaluate the degree and the effectiveness of the defects on *** the same time,the cross-correlation model is the basis for determining the relative position of *** results of this study are experimentally conducted to confirm the relationship between the correlation coefficients and the existence of the *** particular,the manuscript shows that the sensitivity of the correlation coefficients and cross-correlation is much higher than the parameters such as changes in stiffness(EJ)and natural frequency values(Δf).This study suggests using the above parameters to evaluate the stiffness degradation of beams by vibration measurement data in practice.

关键词： correlation coefficient cross-correlation vibration signal vibration amplitude frequency

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correlation Degree and correlation coefficient of Multi-Output Functions

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Wuhan University Journal of Natural Sciences 2005年第1期10卷 195-198页

作者： JUGui-zhi ZHAOYa-qun InstituteofInformationEngineering InformationEngineeringUniversityZhengzhou450002HenanChina InstituteofInformationEngineering InformationEngineeringUniversityZhengzhou450002HenanChina／／StateKayI.aboratoryofInformationSecurityChineseAcademyofScienceBeijing100039China

We present definitions of the correlation degree and correlation coefficient of multi-output functions. Two relationships about the correlation degree of multi-output functions are proved. One is between the correlation degree and independency, the other is between the correlation degree and balance. Especially the paper discusses the correlation degree of affine multioutput functions. We demonstrate properties of the correlation coefficient of multi-output functions. One is the value range of the correlation coefficient, one is the relationship between the correlation coefficient and independency, and another is the sufficient and necessary condition that two multi-output functions are equivalent to each other.

关键词： Key words multi output functions independency correlation degree balance correlation coefficient

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Stochastic resonance based on correlation coefficient in parallel array of threshold devices

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Journal of Southeast University(English Edition) 2006年第4期22卷 479-483页

作者：王友国吴乐南东南大学信息科学与工程学院

The phenomenon of stochastic resonance （SR） based on the correlation coefficient in a parallel array of threshold devices is discussed. For four representative noises： the Gaussian noise, the uniform noise, the Laplace noise and the Cauchy noise, when the signal is subthreshold, noise can improve the correlation coefficient and SR exists. The efficacy of SR can be significantly enhanced and the maximum of the correlation coefficient can dramatically approach to one as the number of the threshold devices in the parallel array increases. Two theorems are presented to prove that SR has some robustness to noises in the parallel array. These results further extend the applicability of SR in signal processing.

关键词： stochastic resonance correlation coefficient threshold array

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Study on Probability Plot correlation coefficient of the Log-Weibull Distribution

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Journal of Shanghai Jiaotong university(Science) 2015年第3期20卷 298-301页

作者：蒋仁言 Faculty of Automotive and Mechanical Engineering Changsha University of Science and Technology

The log-Weibull distribution is a variant of the three-parameter Weibull distribution. The probability plot of a distribution model is desired since it can help to decide on whether the model is appropriate for fitting a given dataset and can provide the initial estimate of the model parameters. The decision on the appropriateness of a distribution is somehow subjective. This paper presents a probability plot of the log-Weibull distribution(LWPP). The distribution of the probability plot correlation coefficient is studied. From this distribution, a lower confidence limit is determined for determining whether the probability plot correlation coefficient derived from a given data set is large enough. The appropriateness and usefulness of this study are illustrated by two real-world examples.

关键词： log-Weibull probability plot correlation coefficient lower confidence limit

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Theorem of Logarithm Expectation and Its Application to Prove Sample correlation coefficient as Unbiased Estimate

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Journal of Mathematics and System Science 2014年第9期4卷 605-608页

作者： Loc Nguyen Vietnam Institute of Mathematics Vietnam

In statistical theory, a statistic that is function of sample observations is used to estimate distribution parameter. This statistic is called unbiased estimate if its expectation is equal to theoretical parameter. Proving whether or not a statistic is unbiased estimate is very important but this proof may require a lot of efforts when statistic is complicated function. Therefore, this research facilitates this proof by proposing a theorem which states that the expectation of variable x 〉 0 is u if and only if the limit of logarithm expectation of x approaches logarithm of u. In order to make clear of this theorem, the research gives an example of proving correlation coefficient as unbiased estimate by taking advantages of this theorem.

关键词： Logarithm expectation correlation coefficient unbiased estimate

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correlation Degree and correlation coefficient of Multi-Output Functions

Correlation Degree and Correlation Coefficient of Multi-Outp...

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The 1st Chinese Conference on Trusted Computing and Information Security

作者： JU Gui-zhi, ZHAO Ya-qun Institute of Information Engineering, Information Engineering University, Zhengzhou 450002, Henan,China State Kay Laboratory of Information Security, Chinese Academy of Science, Beijing 100039,China

＜正＞ We present definitions of the correlation degree and correlation coefficient of multi-output functions. Two relationshipsabout the correlation degree of multi-output functions are proved. One is between the correlation degree and independency, the other is between the correlation degree and balance. Especiallythe paper discusses the correlation degree of affine multioutputfunctions. We demonstrate properties of the correlation coefficient of multi-output functions. One is the value range of the correlation coefficient, one is the relationship between the correlation coefficient and independency, and another is the sufficientand necessary condition that two multi-output functions are equivalent to each other.

关键词： multi-output functions independency correlation degree balance correlation coefficient

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基于EEMD、相关系数、排列熵和小波阈值去噪的新型水下声学信号去噪方法

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哈尔滨工程大学学报（英文版） 2024年第1期23卷 222-237页

作者：张玉燕杨志霞杜晓莉罗小元 Department of Instrument Science and Technology Yanshan UniversityQinhuangdao 066000China Department of Control Science and Engineering Yanshan UniversityQinhuangdao 066000China

The complexities of the marine environment and the unique characteristics of underwater channels pose challenges in obtaining reliable signals underwater,necessitating the filtration of underwater acoustic ***,an underwater acoustic signal denoising method based on ensemble empirical mode decomposition(EEMD),correlation coefficient(CC),permutation entropy(PE),and wavelet threshold denoising(WTD)is ***,simulation experiments are conducted using simulated and real underwater acoustic *** experimental results reveal that the proposed denoising method outperforms other previous methods in terms of signal-to-noise ratio,root mean square error,and *** proposed method eliminates noise and retains valuable information in the signal.

关键词： Ensemble empirical mode decomposition correlation coefficient Permutation entropy Wavelet threshold denoising Underwater acoustic signal denoising

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Three-Dimensional Sound Source Location Algorithm for Subsea Leakage Using Hydrophone

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China Ocean Engineering 2024年第2期38卷 326-337页

作者： LI Hao-jie CAI Bao-ping YUAN Xiao-bing KONG Xiang-di LIU Yong-hong Javed Akbar KHAN CHU Zheng-de YANG Chao TANG An-bang College of Mechanical and Electronic Engineering China University of PetroleumQingdao 266580China Shenzhen Urban Public Safety Technology Institute Shenzhen 518000China Institute of Hydrocarbon Recovery Universiti Teknologi PETRONASBandar Seri IskandarPerak Darul Ridzuan 32610Malaysia

Leakages from subsea oil and gas equipment cause substantial economic losses and damage to marine ecosystem,so it is essential to locate the source of the ***,due to the complexity and variability of the marine environment,the signals collected by hydrophone contain a variety of noises,which makes it challenging to extract useful signals for *** solve this problem,a hydrophone denoising algorithm is proposed based on variational modal decomposition(VMD)with grey wolf ***,the average envelope entropy is used as the fitness function of the grey wolf optimizer to find the optimal solution for the parameters K andα.Afterward,the VMD algorithm decomposes the original signal parameters to obtain the intrinsic mode functions(IMFs).Subsequently,the number of interrelationships between each IMF and the original signal was calculated,the threshold value was set,and the noise signal was removed to calculate the time difference using the valid signal obtained by ***,the arrival time difference is used to locate the origin of the *** localization accuracy of the method in finding leaks is investigated experimentally by constructing a simulated leak test rig,and the effectiveness and feasibility of the method are verified.

关键词： grey wolf optimizer variational modal decomposition mean envelope entropy correlation coefficient time difference of arrival

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