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The application of Gaussian distribution deconvolution method to separate the overlapping signals in the 2D NMR map
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作者 Kou-Qi Liu Zheng-Chen Zhang Mehdi Ostadhassan 《Petroleum Science》 SCIE EI CAS CSCD 2023年第3期1513-1520,共8页
The 2D NMR(T_(1)-T_(2))mapping technique,which can be used to separate different proton populations from various sources(hydroxyls,solid organic matter,free water,and free HC)has gained attention in petroleum industry... The 2D NMR(T_(1)-T_(2))mapping technique,which can be used to separate different proton populations from various sources(hydroxyls,solid organic matter,free water,and free HC)has gained attention in petroleum industry.To separate proton contributions,a fixed straight line is commonly employed to separate different regions representing proton sources on the map.However,some of these regions(Region 1 and 2)might overlap which makes extracting the NMR signal amplitude from these regions inaccurate.In order to solve this issue,in this study,we applied the Gaussian distribution deconvolution method to separate the T_(1)and T_(2)relaxation distributions and then derived the signal amplitude of each region instead of following the common fixed line approach.Next,we employed this method to analyze several shale samples from the literature and compared the results following both methods to verify our methodology.Finally,samples from the Bakken Shale were studied to separate signals from Region 1 and Region 2 and corelated the results with geochemical properties that were obtained from programmed(Rock Eval)pyrolysis.Results demonstrated an improvement in their relation when our approach is employed compared to the fixed line technique to differentiate signal from overlapping regions.This means the Gaussian distribution deconvolution method can be used with confidence to provide us with more accurate petrophysical and geochemical understanding of complex formations. 展开更多
关键词 2D NMR Signal amplitude gaussian distribution Shale formations
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Analytical Evaluation of Non-Elementary Integrals Involving Some Exponential, Hyperbolic and Trigonometric Elementary Functions and Derivation of New Probability Measures Generalizing the Gamma-Type and Gaussian-Type Distributions 被引量:1
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作者 Victor Nijimbere 《Advances in Pure Mathematics》 2020年第7期371-392,共22页
The non-elementary integrals involving elementary exponential, hyperbolic and trigonometric functions, <img src="Edit_699140d3-f569-463e-b835-7ccdab822717.png" width="290" height="22" ... The non-elementary integrals involving elementary exponential, hyperbolic and trigonometric functions, <img src="Edit_699140d3-f569-463e-b835-7ccdab822717.png" width="290" height="22" alt="" /><img src="Edit_bdd10470-9b63-4b2d-9cec-636969547ca5.png" width="90" height="22" alt="" /><span style="white-space:normal;">and <img src="Edit_e9cd6876-e2b8-45cf-ba17-391f054679b4.png" width="90" height="21" alt="" /></span>where <span style="white-space:nowrap;"><em>&#945;</em>,<span style="white-space:nowrap;"><em>&#951;</em></span><em></em></span> and <span style="white-space:nowrap;"><em>&#946;</em></span> are real or complex constants are evaluated in terms of the confluent hypergeometric function <sub>1</sub><em>F</em><sub>1</sub> and the hypergeometric function <sub>1</sub><em>F</em><sub>2</sub>. The hyperbolic and Euler identities are used to derive some identities involving exponential, hyperbolic, trigonometric functions and the hypergeometric functions <sub style="white-space:normal;">1</sub><em style="white-space:normal;">F</em><sub style="white-space:normal;">1</sub> and <sub style="white-space:normal;">1</sub><em style="white-space:normal;">F</em><sub style="white-space:normal;">2</sub>. Having evaluated, these non-elementary integrals, some new probability measures generalizing the gamma-type and Gaussian distributions are also obtained. The obtained generalized probability distributions may, for example, allow to perform better statistical tests than those already known (e.g. chi-square (<span style="white-space:nowrap;"><em>&#120;</em><sup>2</sup></span>) statistical tests and other statistical tests constructed based on the central limit theorem (CLT)), while avoiding the use of computational approximations (or methods) which are in general expensive and associated with numerical errors. 展开更多
关键词 non-Elementary Integrals Hypergeometric Function Confluent Hypergeometric Function Probability Measure Generalized Gamma-Type distributions Generalized gaussian-Type distributions
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The retrieval of the nonlinear random waves from the non-Gaussian characteristics of the sea surface elevation distribution
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作者 Liu Xin’an and Huang Peiji First Institute of Oceanography State Oceanic Administration Qtngdao 266003 China 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1993年第4期499-510,共12页
In this paper, without recourse to the nonlinear dynamical equations of the waves, the nonlinear random waves are retrieved from the non-Gaussian characteristic of the sea surface elevation distribution. The question ... In this paper, without recourse to the nonlinear dynamical equations of the waves, the nonlinear random waves are retrieved from the non-Gaussian characteristic of the sea surface elevation distribution. The question of coincidence of the nonlinear wave profile, spectrum and its distributions of maximum (or minimum) values of the sea surface elevation with results derived from some existing nonlinear theories is expounded under the narrow-band spectrum condition. Taking the shoaling sea wave as an example, the nonlinear random wave process and its spectrum in shallow water are retrieved from both the non-Gaussian characteristics of the sea surface elevation distribution in shallow water and the normal sea waves in deep water and compared with the values actually measured. Results show that they can coincide with the actually measured values quite well, thus, this can confirm that the method proposed in this paper is feasible. 展开更多
关键词 non-gaussian characteristic RETRIEVAL nonlinear random waves sea surface elevation distribution
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Estimation of Hourly and Daily Global Solar Radiation at Clear Days Using an Approach Based on Modified Version of Gaussian Distribution 被引量:4
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作者 S.M EI shazly 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1996年第3期349-358,共10页
The performance of two models,Jam and Baig,based on the modified version of Gaussian distribution function in estimating the daily total of global solar radiation and its distribution through the hours of the day from... The performance of two models,Jam and Baig,based on the modified version of Gaussian distribution function in estimating the daily total of global solar radiation and its distribution through the hours of the day from sunrise to sunset al any clear day is evaluated with our own measured data in the period from June 1992 to May 1993 in Qena Egypt The results show a high relative deviation of calculated values from measured ones,especially for Jain model,in the most hours of the day,except for those near to local noon.This misfit behavior is quite obvious in the early morning and late afternoon A new approach has been proposed in this paper to estimate the daily and hourly global solar radiation This model performs with very high accuracy on the recorded data in our region.The validity of this approach was verified with new measurements in some clear days in June and August 1994.The resultant very low relative deviation of the calculated values of global solar radiation from the measured ones confirms the high performance of the approach proposed in this work 展开更多
关键词 Glohal solar radiation . Measurements Models gaussian distribution function Statistical treatment
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Deterministic quantum key distribution based on Gaussian-modulated EPR correlations 被引量:1
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作者 何广强 曾贵华 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第6期1284-1289,共6页
This paper proposes a deterministic quantum key distribution scheme based on Gaussian-modulated continuous variable EPR correlations. This scheme can implement fast and efficient key distribution. The security is guar... This paper proposes a deterministic quantum key distribution scheme based on Gaussian-modulated continuous variable EPR correlations. This scheme can implement fast and efficient key distribution. The security is guaranteed by continuous variable EPR entanglement correlations produced by nondegenerate optical parametric amplifier. For general beam splitter eavesdropping strategy, the secret information rate ΔI = I(α, β)-I(α, ε) is calculated in view of Shannon information theory. Finally the security analysis is presented. 展开更多
关键词 quantum key distribution continuous variable EPR correlation gaussian modulation
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Derivation of Gaussian Probability Distribution: A New Approach 被引量:2
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作者 A. T. Adeniran O. Faweya +1 位作者 T. O. Ogunlade K. O. Balogun 《Applied Mathematics》 2020年第6期436-446,共11页
The famous de Moivre’s Laplace limit theorem proved the probability density function of Gaussian distribution from binomial probability mass function under specified conditions. De Moivre’s Laplace approach is cumbe... The famous de Moivre’s Laplace limit theorem proved the probability density function of Gaussian distribution from binomial probability mass function under specified conditions. De Moivre’s Laplace approach is cumbersome as it relies heavily on many lemmas and theorems. This paper invented an alternative and less rigorous method of deriving Gaussian distribution from basic random experiment conditional on some assumptions. 展开更多
关键词 De Moivres Laplace Limit Theorem Binomial Probability Mass Function gaussian distribution Random Experiment
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Mechanical properties of double-stranded DNA biofilm with Gaussian distribution 被引量:1
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作者 Heng-Song Tang Wei-Lie Meng Neng-Hui Zhang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2014年第1期15-19,共5页
In microcantilever-based label-free biodetection technologies, deflection changes induced by adsorptions of double-stranded DNA (dsDNA) molecules on Au-layer surface are greatly affected by the mechanical, thermal a... In microcantilever-based label-free biodetection technologies, deflection changes induced by adsorptions of double-stranded DNA (dsDNA) molecules on Au-layer surface are greatly affected by the mechanical, thermal and electrical properties of DNA biofilm. In this paper, the elastic properties of dsDNA biofilm are studied. First, the Parsegian's empirical potential based on a mesoscopic liq- uid crystal theory is employed to describe the interaction energy among coarse-grained DNA cylinders. Then, con- sidering a Gaussian distribution of DNA interaxial distance, the thought experiment method is used to derive an analyti- cal expression for Young's modulus of DNA biofilm with a stochastic packing pattern for the first time. Results show that Young's modulus of DNA biofilm is on the order of 10 MPa. These findings could provide a simple and effective method to evaluate the mechanical properties of soft biofilm on snbstrate. 展开更多
关键词 Double-stranded DNA. BiofilmElastic modu-lus - Cylinder model gaussian distribution
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Gaussian process assisted coevolutionary estimation of distribution algorithm for computationally expensive problems 被引量:1
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作者 罗娜 钱锋 +1 位作者 赵亮 钟伟民 《Journal of Central South University》 SCIE EI CAS 2012年第2期443-452,共10页
In order to reduce the computation of complex problems, a new surrogate-assisted estimation of distribution algorithm with Gaussian process was proposed. Coevolution was used in dual populations which evolved in paral... In order to reduce the computation of complex problems, a new surrogate-assisted estimation of distribution algorithm with Gaussian process was proposed. Coevolution was used in dual populations which evolved in parallel. The search space was projected into multiple subspaces and searched by sub-populations. Also, the whole space was exploited by the other population which exchanges information with the sub-populations. In order to make the evolutionary course efficient, multivariate Gaussian model and Gaussian mixture model were used in both populations separately to estimate the distribution of individuals and reproduce new generations. For the surrogate model, Gaussian process was combined with the algorithm which predicted variance of the predictions. The results on six benchmark functions show that the new algorithm performs better than other surrogate-model based algorithms and the computation complexity is only 10% of the original estimation of distribution algorithm. 展开更多
关键词 estimation of distribution algorithm fitness function modeling gaussian process surrogate approach
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A Gaussian Noise-Based Algorithm for Enhancing Backdoor Attacks
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作者 Hong Huang Yunfei Wang +1 位作者 Guotao Yuan Xin Li 《Computers, Materials & Continua》 SCIE EI 2024年第7期361-387,共27页
Deep Neural Networks(DNNs)are integral to various aspects of modern life,enhancing work efficiency.Nonethe-less,their susceptibility to diverse attack methods,including backdoor attacks,raises security concerns.We aim... Deep Neural Networks(DNNs)are integral to various aspects of modern life,enhancing work efficiency.Nonethe-less,their susceptibility to diverse attack methods,including backdoor attacks,raises security concerns.We aim to investigate backdoor attack methods for image categorization tasks,to promote the development of DNN towards higher security.Research on backdoor attacks currently faces significant challenges due to the distinct and abnormal data patterns of malicious samples,and the meticulous data screening by developers,hindering practical attack implementation.To overcome these challenges,this study proposes a Gaussian Noise-Targeted Universal Adversarial Perturbation(GN-TUAP)algorithm.This approach restricts the direction of perturbations and normalizes abnormal pixel values,ensuring that perturbations progress as much as possible in a direction perpendicular to the decision hyperplane in linear problems.This limits anomalies within the perturbations improves their visual stealthiness,and makes them more challenging for defense methods to detect.To verify the effectiveness,stealthiness,and robustness of GN-TUAP,we proposed a comprehensive threat model.Based on this model,extensive experiments were conducted using the CIFAR-10,CIFAR-100,GTSRB,and MNIST datasets,comparing our method with existing state-of-the-art attack methods.We also tested our perturbation triggers using various defense methods and further experimented on the robustness of the triggers against noise filtering techniques.The experimental outcomes demonstrate that backdoor attacks leveraging perturbations generated via our algorithm exhibit cross-model attack effectiveness and superior stealthiness.Furthermore,they possess robust anti-detection capabilities and maintain commendable performance when subjected to noise-filtering methods. 展开更多
关键词 Image classification model backdoor attack gaussian distribution Artificial Intelligence(AI)security
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Investigation of the inhomogeneous barrier height of an Au/Bi_4Ti_3O_(12)/n-Si structure through Gaussian distribution of barrier height
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作者 M.Gken M.Yildirim 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第12期538-543,共6页
A Au/Bi4Ti3O12/n-Si structure is fabricated in order to investigate its current voltage (IV) characteristics in a temperature range of 300 K-400 K. Obtained I-V data are evaluated by the thermionic emission (TE) t... A Au/Bi4Ti3O12/n-Si structure is fabricated in order to investigate its current voltage (IV) characteristics in a temperature range of 300 K-400 K. Obtained I-V data are evaluated by the thermionic emission (TE) theory. Zero-bias barrier height (Ф0) and ideality factor (n) calculated from I-V characteristics, are found to be temperature-dependent such that ФB0 increases with temperature increasing, whereas n decreases. The obtained temperature dependence of ФB0 and linearity in ФB0 versus the n plot, together with a lower barrier height and Richardson constant values obtained from the Richardson plot, indicate that the barrier height of the structure is inhomogeneous in nature. Therefore, I-V characteristics are explained on the basis of Caussian distribution of barrier height. 展开更多
关键词 BI4TI3O12 I-V characterization temperature dependence gaussian distribution
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What Is the Difference between Gamma and Gaussian Distributions?
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作者 Xiao-Li Hu 《Applied Mathematics》 2013年第2期285-289,共5页
An inequality describing the difference between Gamma and Gaussian distributions is derived. The asymptotic bound is much better than by existing uniform bound from Berry-Esseen inequality.
关键词 GAMMA distribution gaussian distribution Berry-Esseen INEQUALITY CHARACTERISTIC Function
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Heavy-Tailed Distributions Generated by Randomly Sampled Gaussian, Exponential and Power-Law Functions
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作者 Frederic von Wegner 《Applied Mathematics》 2014年第13期2050-2056,共7页
A simple stochastic mechanism that produces exact and approximate power-law distributions is presented. The model considers radially symmetric Gaussian, exponential and power-law functions inn= 1, 2, 3 dimensions. Ran... A simple stochastic mechanism that produces exact and approximate power-law distributions is presented. The model considers radially symmetric Gaussian, exponential and power-law functions inn= 1, 2, 3 dimensions. Randomly sampling these functions with a radially uniform sampling scheme produces heavy-tailed distributions. For two-dimensional Gaussians and one-dimensional exponential functions, exact power-laws with exponent –1 are obtained. In other cases, densities with an approximate power-law behaviour close to the origin arise. These densities are analyzed using Padé approximants in order to show the approximate power-law behaviour. If the sampled function itself follows a power-law with exponent –α, random sampling leads to densities that also follow an exact power-law, with exponent -n/a – 1. The presented mechanism shows that power-laws can arise in generic situations different from previously considered specialized systems such as multi-particle systems close to phase transitions, dynamical systems at bifurcation points or systems displaying self-organized criticality. Thus, the presented mechanism may serve as an alternative hypothesis in system identification problems. 展开更多
关键词 Heavy-Tailed distributionS Random Sampling gaussian EXPONENTIAL POWER-LAW
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Oversampling Method Based on Gaussian Distribution and K-Means Clustering
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作者 Masoud Muhammed Hassan Adel Sabry Eesa +1 位作者 Ahmed Jameel Mohammed Wahab Kh.Arabo 《Computers, Materials & Continua》 SCIE EI 2021年第10期451-469,共19页
Learning from imbalanced data is one of the greatest challenging problems in binary classification,and this problem has gained more importance in recent years.When the class distribution is imbalanced,classical machin... Learning from imbalanced data is one of the greatest challenging problems in binary classification,and this problem has gained more importance in recent years.When the class distribution is imbalanced,classical machine learning algorithms tend to move strongly towards the majority class and disregard the minority.Therefore,the accuracy may be high,but the model cannot recognize data instances in the minority class to classify them,leading to many misclassifications.Different methods have been proposed in the literature to handle the imbalance problem,but most are complicated and tend to simulate unnecessary noise.In this paper,we propose a simple oversampling method based on Multivariate Gaussian distribution and K-means clustering,called GK-Means.The new method aims to avoid generating noise and control imbalances between and within classes.Various experiments have been carried out with six classifiers and four oversampling methods.Experimental results on different imbalanced datasets show that the proposed GK-Means outperforms other oversampling methods and improves classification performance as measured by F1-score and Accuracy. 展开更多
关键词 Class imbalance OVERSAMPLING gaussian multivariate distribution k-means clustering
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A Normal Weighted Inverse Gaussian Distribution for Skewed and Heavy-Tailed Data
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作者 Calvin B. Maina Patrick G. O. Weke +1 位作者 Carolyne A. Ogutu Joseph A. M. Ottieno 《Applied Mathematics》 2022年第2期163-177,共15页
High frequency financial data is characterized by non-normality: asymmetric, leptokurtic and fat-tailed behaviour. The normal distribution is therefore inadequate in capturing these characteristics. To this end, vario... High frequency financial data is characterized by non-normality: asymmetric, leptokurtic and fat-tailed behaviour. The normal distribution is therefore inadequate in capturing these characteristics. To this end, various flexible distributions have been proposed. It is well known that mixture distributions produce flexible models with good statistical and probabilistic properties. In this work, a finite mixture of two special cases of Generalized Inverse Gaussian distribution has been constructed. Using this finite mixture as a mixing distribution to the Normal Variance Mean Mixture we get a Normal Weighted Inverse Gaussian (NWIG) distribution. The second objective, therefore, is to construct and obtain properties of the NWIG distribution. The maximum likelihood parameter estimates of the proposed model are estimated via EM algorithm and three data sets are used for application. The result shows that the proposed model is flexible and fits the data well. 展开更多
关键词 Inverse gaussian Finite Mixture Weighted distribution Mixed Model EM-ALGORITHM
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Research on Gaussian distribution preprocess method of infrared multispectral image background clutter
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作者 张伟 武春风 +1 位作者 邓盼 范宁 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2004年第5期513-515,共3页
This paper introduces a sliding-window mean removal high pass filter by which background clutter of infrared multispectral image is obtained. The method of selecting the optimum size of the sliding-window is based on ... This paper introduces a sliding-window mean removal high pass filter by which background clutter of infrared multispectral image is obtained. The method of selecting the optimum size of the sliding-window is based on the skewness-kurtosis test. In the end, a multivariate Gaussian distribution mathematical expression of background clutter image is given. 展开更多
关键词 infrared multispectral imagery background clutter Sliding-window mean removal Skewness-kurtosis test multivariate gaussian distribution
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Space Charge Effect of Bunched Beam With Gaussian Distribution
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作者 Chen, Yinbao Fu, Shinian +1 位作者 Huang, Zhibin Zhang, Zhenhai 《Chinese journal of nuclear physics》 EI 1995年第2期174-178,共5页
The nonlinear space charge effect of a bunched beam with Gaussian distribu-tion in the longitudinal direction is discussed.Some useful formulae are derived for cal-culating the potential induced by a cylinder model of... The nonlinear space charge effect of a bunched beam with Gaussian distribu-tion in the longitudinal direction is discussed.Some useful formulae are derived for cal-culating the potential induced by a cylinder model of space charge in the waveguide of alinac with different combinations of density distribution:Gaussian distribution in thelongitudinal direction versus Kapchinskij Vladimirskij,waterbag,parabolic andGaussian distribution in the transverse direction,rcspectively. 展开更多
关键词 gaussian distribution in the longitudinal direction SPACE CHARGE EFFECT Bunched BEAM
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Free Energy and Emittance Growth Caused by Bunched Beam With Gaussian Distribution in Longitudinal Direction in Linac
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作者 Huang Zhibin Chen Yinbao Fu Shinian China Institule of Atomic Energy,P.O.Box 275(17),Beijing 102413 《Chinese journal of nuclear physics》 1996年第4期236-243,共8页
The nonlinear space charge effect of bunched beam in linac is one of the important factors thatinduces the emittance growth due to the conversion of the field energy to kinetic energy.In this paper,us-ing a cylinder m... The nonlinear space charge effect of bunched beam in linac is one of the important factors thatinduces the emittance growth due to the conversion of the field energy to kinetic energy.In this paper,us-ing a cylinder model of space charge in linac,we derived the internal energy for a bunched beam withsome nonuniform space charge distributions,such as longitudinal Gaussian distribution combined withKapchinskij-Vladimirski1,waterbag,parabolic or Gaussian transverse distribution.And the emittancegrowth caused by the above distributions is worked out. 展开更多
关键词 —Emittance growth Longitudinal gaussian distribution TRANSVERSE NONUNIFORM distribution
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Cognitive-affective regulation process for micro-expressions based on Gaussian cloud distribution
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作者 Xiujun Yang Lun Xie +1 位作者 Jing Han Zhiliang Wang 《CAAI Transactions on Intelligence Technology》 2017年第1期56-61,共6页
In this paper, we explore the process of emotional state transition. And the process is impacted by emotional state of interaction objects. First of all, the cognitive reasoning process and the micro-expressions recog... In this paper, we explore the process of emotional state transition. And the process is impacted by emotional state of interaction objects. First of all, the cognitive reasoning process and the micro-expressions recognition is the basis of affective computing adjustment process. Secondly, the threshold function and attenuation function are proposed to quantify the emotional changes. In the actual environment, the emotional state of the robot and external stimulus are also quantified as the transferring probability. Finally, the Gaussian cloud distribution is introduced to the Gross model to calculate the emotional transitional probabilities. The experimental results show that the model in human-computer interaction can effectively regulate the emotional states, and can significantly improve the humanoid and intelligent ability of the robot. This model is consistent with experimental and emulational significance of the psychology, and allows the robot to get rid of the mechanical emotional transfer process. 展开更多
关键词 Micro-expression Cognitive-affective regulation gaussian cloud distribution Transferring probability Emotional intensity
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Analysis of Ocean Wave Characteristic Distributions Modeled by Two Different Transformed Functions 被引量:2
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作者 Duanfeng Han Ting Cui +3 位作者 Yingfei Zan Lihao Yuan Song Ding Zhigang Li 《Journal of Marine Science and Application》 CSCD 2019年第3期247-259,共13页
The probability distributions of wave characteristics from three groups of sampled ocean data with different significant wave heights have been analyzed using two transformation functions estimated by non-parametric a... The probability distributions of wave characteristics from three groups of sampled ocean data with different significant wave heights have been analyzed using two transformation functions estimated by non-parametric and parametric methods. The marginal wave characteristic distribution and the joint density of wave properties have been calculated using the two transformations, with the results and accuracy of both transformations presented here. The two transformations deviate slightly between each other for the calculation of the crest and trough height marginal wave distributions, as well as the joint densities of wave amplitude with other wave properties. The transformation methods for the calculation of the wave crest and trough height distributions are shown to provide good agreement with real ocean data. Our work will help in the determination of the most appropriate transformation procedure for the prediction of extreme values. 展开更多
关键词 Wave characteristic distributionS Transformed gaussian process Transformed FUNCTION PARAMETRIC METHOD non-PARAMETRIC METHOD Crossing-density FUNCTION
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Modeling Regional and Local-scale Permafrost Distribution in Qinghai-Tibet Plateau Using Equivalent-elevation Method 被引量:3
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作者 LI Jing SHENG Yu +5 位作者 WU Jichun WANG Jie ZHANG Bo YE Baisheng ZHANG Xiumin QIN Xiang 《Chinese Geographical Science》 SCIE CSCD 2012年第3期278-287,共10页
This study proposes an equivalent-elevation method to evaluate the integrated effects of latitude and elevation on regional and local-scale permafrost distribution in the Qinghai-Tibet Plateau,and to model the general... This study proposes an equivalent-elevation method to evaluate the integrated effects of latitude and elevation on regional and local-scale permafrost distribution in the Qinghai-Tibet Plateau,and to model the general permafrost-distribution patterns in regional and local-scale area.It is found that the Gaussian curve―an empirical model describing the relation between variations of altitudinal permafrost lower limit (PLL) and latitude in the Northern Hemisphere―could be applied in regional-and local-scale areas in the Qinghai-Tibet Plateau in a latitude-sensitive interval of 30°-50°N.The curve was then used to evaluate the latitudinal effect on permafrost distribution through transforming the latitudinal effect into a kind of altitudinal difference of PLL.This study then calculated the local equivalent-elevation value by overlaying the altitudinal difference of PLL onto real elevation at a certain location.The equivalent-elevation method was verified in an experimental subwatershed of the Qinghai-Tibet Plateau.However,feasibility of the method should be further tested in order to extend for future studies.The use of equivalent-elevation values can build a platform for comparing the regional general permafrost distribution in the plateau,and for basing further evaluations of local factors' effects on regional permafrost distribution. 展开更多
关键词 equivalent-elevation method permafrost distribution permafrost lower limit (PLL) gaussian curve plat- form function Qinghai-Tibet Plateau
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