期刊文献+
共找到2,435篇文章
< 1 2 122 >
每页显示 20 50 100
Neural network study of the nuclear ground-state spin distribution within a random interaction ensemble
1
作者 Deng Liu Alam Noor A +1 位作者 Zhen-Zhen Qin Yang Lei 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第3期216-227,共12页
The distribution of the nuclear ground-state spin in a two-body random ensemble(TBRE)was studied using a general classification neural network(NN)model with two-body interaction matrix elements as input features and t... The distribution of the nuclear ground-state spin in a two-body random ensemble(TBRE)was studied using a general classification neural network(NN)model with two-body interaction matrix elements as input features and the corresponding ground-state spins as labels or output predictions.The quantum many-body system problem exceeds the capability of our optimized NNs in terms of accurately predicting the ground-state spin of each sample within the TBRE.However,our NN model effectively captured the statistical properties of the ground-state spin because it learned the empirical regularity of the ground-state spin distribution in TBRE,as discovered by physicists. 展开更多
关键词 Neural network Two-body random ensemble Spin distribution of nuclear ground state
下载PDF
Efficient slope reliability analysis under soil spatial variability using maximum entropy distribution with fractional moments
2
作者 Chengxin Feng Marcos A.Valdebenito +3 位作者 Marcin Chwała Kang Liao Matteo Broggi Michael Beer 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第4期1140-1152,共13页
Spatial variability of soil properties imposes a challenge for practical analysis and design in geotechnical engineering.The latter is particularly true for slope stability assessment,where the effects of uncertainty ... Spatial variability of soil properties imposes a challenge for practical analysis and design in geotechnical engineering.The latter is particularly true for slope stability assessment,where the effects of uncertainty are synthesized in the so-called probability of failure.This probability quantifies the reliability of a slope and its numerical calculation is usually quite involved from a numerical viewpoint.In view of this issue,this paper proposes an approach for failure probability assessment based on Latinized partially stratified sampling and maximum entropy distribution with fractional moments.The spatial variability of geotechnical properties is represented by means of random fields and the Karhunen-Loève expansion.Then,failure probabilities are estimated employing maximum entropy distribution with fractional moments.The application of the proposed approach is examined with two examples:a case study of an undrained slope and a case study of a slope with cross-correlated random fields of strength parameters under a drained slope.The results show that the proposed approach has excellent accuracy and high efficiency,and it can be applied straightforwardly to similar geotechnical engineering problems. 展开更多
关键词 SLOPE random field Reliability analysis Maximum entropy distribution Latinized partial stratified sampling
下载PDF
Fully Distributed Learning for Deep Random Vector Functional-Link Networks
3
作者 Huada Zhu Wu Ai 《Journal of Applied Mathematics and Physics》 2024年第4期1247-1262,共16页
In the contemporary era, the proliferation of information technology has led to an unprecedented surge in data generation, with this data being dispersed across a multitude of mobile devices. Facing these situations a... In the contemporary era, the proliferation of information technology has led to an unprecedented surge in data generation, with this data being dispersed across a multitude of mobile devices. Facing these situations and the training of deep learning model that needs great computing power support, the distributed algorithm that can carry out multi-party joint modeling has attracted everyone’s attention. The distributed training mode relieves the huge pressure of centralized model on computer computing power and communication. However, most distributed algorithms currently work in a master-slave mode, often including a central server for coordination, which to some extent will cause communication pressure, data leakage, privacy violations and other issues. To solve these problems, a decentralized fully distributed algorithm based on deep random weight neural network is proposed. The algorithm decomposes the original objective function into several sub-problems under consistency constraints, combines the decentralized average consensus (DAC) and alternating direction method of multipliers (ADMM), and achieves the goal of joint modeling and training through local calculation and communication of each node. Finally, we compare the proposed decentralized algorithm with several centralized deep neural networks with random weights, and experimental results demonstrate the effectiveness of the proposed algorithm. 展开更多
关键词 distributed Optimization Deep Neural Network random Vector Functional-Link (RVFL) Network Alternating Direction Method of Multipliers (ADMM)
下载PDF
Effect of weak randomness flaws on security evaluation of practical quantum key distribution with distinguishable decoy states
4
作者 周雨 李宏伟 +5 位作者 周淳 汪洋 陆宜飞 江木生 张晓旭 鲍皖苏 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第5期254-260,共7页
Quantum key distribution provides an unconditional secure key sharing method in theory,but the imperfect factors of practical devices will bring security vulnerabilities.In this paper,we characterize the imperfections... Quantum key distribution provides an unconditional secure key sharing method in theory,but the imperfect factors of practical devices will bring security vulnerabilities.In this paper,we characterize the imperfections of the sender and analyze the possible attack strategies of Eve.Firstly,we present a quantized model for distinguishability of decoy states caused by intensity modulation.Besides,considering that Eve may control the preparation of states through hidden variables,we evaluate the security of preparation in practical quantum key distribution(QKD)scheme based on the weak-randomness model.Finally,we analyze the influence of the distinguishability of decoy state to secure key rate,for Eve may conduct the beam splitting attack and control the channel attenuation of different parts.Through the simulation,it can be seen that the secure key rate is sensitive to the distinguishability of decoy state and weak randomness,especially when Eve can control the channel attenuation. 展开更多
关键词 weak randomness quantum key distribution distinguishable decoy state
下载PDF
CONSISTENCY OF MLE OF THE PARAMETER OF EXPONENTIAL LIFETIME DISTRIBUTION FOR RANDOM CENSORING MODEL WITH INCOMPLETE INFORMATION 被引量:18
5
作者 YE ERHUA 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 1995年第4期379-386,共8页
In this paper, we have discussed a random censoring test with incomplete information, and proved that the maximum likelihood estimator(MLE) of the parameter based on the randomly censored data with incomplete informat... In this paper, we have discussed a random censoring test with incomplete information, and proved that the maximum likelihood estimator(MLE) of the parameter based on the randomly censored data with incomplete information in the case of the exponential distribution has the strong consistency. 展开更多
关键词 random censoring test with incomplete information exponential distribution maximum likelihood estimator consistency.
下载PDF
Optimization by Estimation of Distribution with DEUM Framework Based on Markov Random Fields 被引量:5
6
作者 Siddhartha Shakya John McCall 《International Journal of Automation and computing》 EI 2007年第3期262-272,共11页
This paper presents a Markov random field (MRP) approach to estimating and sampling the probability distribution in populations of solutions. The approach is used to define a class of algorithms under the general he... This paper presents a Markov random field (MRP) approach to estimating and sampling the probability distribution in populations of solutions. The approach is used to define a class of algorithms under the general heading distribution estimation using Markov random fields (DEUM). DEUM is a subclass of estimation of distribution algorithms (EDAs) where interaction between solution variables is represented as an undirected graph and the joint probability of a solution is factorized as a Gibbs distribution derived from the structure of the graph. The focus of this paper will be on describing the three main characteristics of DEUM framework, which distinguishes it from the traditional EDA. They are: 1) use of MRF models, 2) fitness modeling approach to estimating the parameter of the model and 3) Monte Carlo approach to sampling from the model. 展开更多
关键词 Estimation of distribution algorithms evolutionary algorithms fitness modeling Markov random fields Gibbs distri-bution.
下载PDF
Random Attractors for Stochastic Reaction-Diffusion Equations with Distribution Derivatives on Unbounded Domains 被引量:3
7
作者 Eshag Mohamed Ahmed Ali Dafallah Abdelmajid +1 位作者 Ling Xu Qiaozhen Ma 《Applied Mathematics》 2015年第10期1790-1807,共18页
In this paper, we prove the existence of random attractors for a stochastic reaction-diffusion equation with distribution derivatives on unbounded domains. The nonlinearity is dissipative for large values of the state... In this paper, we prove the existence of random attractors for a stochastic reaction-diffusion equation with distribution derivatives on unbounded domains. The nonlinearity is dissipative for large values of the state and the stochastic nature of the equation appears spatially distributed temporal white noise. The stochastic reaction-diffusion equation is recast as a continuous random dynamical system and asymptotic compactness for this demonstrated by using uniform estimates far-field values of solutions. The results are new and appear to be optimal. 展开更多
关键词 STOCHASTIC REACTION-DIFFUSION Equation random ATTRACTORS distribution DERIVATIVES Asymptotic Compactness Unbounded Domain
下载PDF
THE VALUE DISTRIBUTION OF RANDOM ANALYTIC DIRICHLET SERIES OF NEUTRAL GROWTH(I) 被引量:1
8
作者 丁晓庆 《Acta Mathematica Scientia》 SCIE CSCD 1999年第2期234-240,共7页
This paper deals with the value distribution of random Dirichlet series whose coefficients are a martingale difference sequence, and which is of neutral growth.
关键词 Value distribution random DIRICHLET series MARTINGALE DIFFERENCE sequence.
下载PDF
THE VALUE DISTRIBUTION OF RANDOM ANALYTIC DIRICHLET SERIES OF NEUTRAL GROWTH (Ⅱ) 被引量:1
9
作者 丁晓庆 《Acta Mathematica Scientia》 SCIE CSCD 2000年第4期504-510,共7页
This paper studies the value distribution of random analytic Dirichlet series f(s) = Zn()e-sn, where {Zn} is a sequence of independent random variables, n = 1 with moments zero, such that infE{Zn}/E1/2{Zn2≥ α > ... This paper studies the value distribution of random analytic Dirichlet series f(s) = Zn()e-sn, where {Zn} is a sequence of independent random variables, n = 1 with moments zero, such that infE{Zn}/E1/2{Zn2≥ α > 0. Suppose [h*(σ)]2 = n converges for any α > 0, and diverges for = 0. It is shown that if = ρ E (0, ), then with probability one, where β is a constant depending only upon the constant α. 展开更多
关键词 Value distribution exceptional value random Dirichlet series independent random variab
下载PDF
Distributed dynamic event-based finite-time dissipative synchronization control for semi-Markov switched fuzzy cyber-physical systems against random packet losses
10
作者 伍锡如 张煜翀 +1 位作者 张畑畑 张斌磊 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第10期328-342,共15页
This paper is concerned with the finite-time dissipative synchronization control problem of semi-Markov switched cyber-physical systems in the presence of packet losses, which is constructed by the Takagi–Sugeno fuzz... This paper is concerned with the finite-time dissipative synchronization control problem of semi-Markov switched cyber-physical systems in the presence of packet losses, which is constructed by the Takagi–Sugeno fuzzy model. To save the network communication burden, a distributed dynamic event-triggered mechanism is developed to restrain the information update. Besides, random packet dropouts following the Bernoulli distribution are assumed to occur in sensor to controller channels, where the triggered control input is analyzed via an equivalent method containing a new stochastic variable. By establishing the mode-dependent Lyapunov–Krasovskii functional with augmented terms, the finite-time boundness of the error system limited to strict dissipativity is studied. As a result of the help of an extended reciprocally convex matrix inequality technique, less conservative criteria in terms of linear matrix inequalities are deduced to calculate the desired control gains. Finally, two examples in regard to practical systems are provided to display the effectiveness of the proposed theory. 展开更多
关键词 cyber-physical systems finite-time synchronization distributed dynamic event-triggered mechanism random packet losses
下载PDF
THE STATIONARY DISTRIBUTION OF A CONTINUOUS-TIME RANDOM GRAPH PROCESS WITH INTERACTING EDGES 被引量:1
11
作者 韩东 《Acta Mathematica Scientia》 SCIE CSCD 1994年第S1期98-102,共5页
In previous papers, the stationary distributions of a class of discrete and continuoustime random graph processes with state space consisting of the simple and directed graphs on Nvenices were studied. In this paper, ... In previous papers, the stationary distributions of a class of discrete and continuoustime random graph processes with state space consisting of the simple and directed graphs on Nvenices were studied. In this paper, the random graph graph process is extended one impotent stepfurther by allowing interaction of edges. Similarly, We obtha the expressions of the stationarydistributions and prove that the process is ergodic under different editions. 展开更多
关键词 random graph prooes Minimum Q-process Stationary distribution Ergodicity.
下载PDF
Degree distribution of random birth-and-death network with network size decline 被引量:1
12
作者 张晓军 杨会兰 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第6期71-77,共7页
In this paper,we provide a general method to obtain the exact solutions of the degree distributions for random birthand-death network(RBDN) with network size decline.First,by stochastic process rules,the steady stat... In this paper,we provide a general method to obtain the exact solutions of the degree distributions for random birthand-death network(RBDN) with network size decline.First,by stochastic process rules,the steady state transformation equations and steady state degree distribution equations are given in the case of m ≥ 3 and 0 〈 p 〈 1/2,then the average degree of network with n nodes is introduced to calculate the degree distributions.Specifically,taking m = 3 for example,we explain the detailed solving process,in which computer simulation is used to verify our degree distribution solutions.In addition,the tail characteristics of the degree distribution are discussed.Our findings suggest that the degree distributions will exhibit Poisson tail property for the declining RBDN. 展开更多
关键词 random birth-and-death network(RBDN) Markov chain generating function degree distribution
下载PDF
Characterizing prediction errors of a new tree height model for cut-to-length Pinus radiata stems through the Burr TypeⅫdistribution
13
作者 Xinyu Cao Huiquan Bi +1 位作者 Duncan Watt Yun Li 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第6期1899-1914,共16页
Unlike height-diameter equations for standing trees commonly used in forest resources modelling,tree height models for cut-to-length(CTL)stems tend to produce prediction errors whose distributions are not conditionall... Unlike height-diameter equations for standing trees commonly used in forest resources modelling,tree height models for cut-to-length(CTL)stems tend to produce prediction errors whose distributions are not conditionally normal but are rather leptokurtic and heavy-tailed.This feature was merely noticed in previous studies but never thoroughly investigated.This study characterized the prediction error distribution of a newly developed such tree height model for Pin us radiata(D.Don)through the three-parameter Burr TypeⅫ(BⅫ)distribution.The model’s prediction errors(ε)exhibited heteroskedasticity conditional mainly on the small end relative diameter of the top log and also on DBH to a minor extent.Structured serial correlations were also present in the data.A total of 14 candidate weighting functions were compared to select the best two for weightingεin order to reduce its conditional heteroskedasticity.The weighted prediction errors(εw)were shifted by a constant to the positive range supported by the BXII distribution.Then the distribution of weighted and shifted prediction errors(εw+)was characterized by the BⅫdistribution using maximum likelihood estimation through 1000 times of repeated random sampling,fitting and goodness-of-fit testing,each time by randomly taking only one observation from each tree to circumvent the potential adverse impact of serial correlation in the data on parameter estimation and inferences.The nonparametric two sample Kolmogorov-Smirnov(KS)goodness-of-fit test and its closely related Kuiper’s(KU)test showed the fitted BⅫdistributions provided a good fit to the highly leptokurtic and heavy-tailed distribution ofε.Random samples generated from the fitted BⅫdistributions ofεw+derived from using the best two weighting functions,when back-shifted and unweighted,exhibited distributions that were,in about97 and 95%of the 1000 cases respectively,not statistically different from the distribution ofε.Our results for cut-tolength P.radiata stems represented the first case of any tree species where a non-normal error distribution in tree height prediction was described by an underlying probability distribution.The fitted BXII prediction error distribution will help to unlock the full potential of the new tree height model in forest resources modelling of P.radiata plantations,particularly when uncertainty assessments,statistical inferences and error propagations are needed in research and practical applications through harvester data analytics. 展开更多
关键词 Conditional heteroskedasticity Leptokurtic error distribution Skedactic function Nonlinear quantile regression Weighted prediction errors Serial correlation random sampling and fitting Nonparametric goodnessof-fit tests
下载PDF
Modeling random telegraph signal noise in CMOS image sensor under low light based on binomial distribution 被引量:2
14
作者 张钰 逯鑫淼 +2 位作者 王光义 胡永才 徐江涛 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第7期164-170,共7页
The random telegraph signal noise in the pixel source follower MOSFET is the principle component of the noise in the CMOS image sensor under low light. In this paper, the physical and statistical model of the random t... The random telegraph signal noise in the pixel source follower MOSFET is the principle component of the noise in the CMOS image sensor under low light. In this paper, the physical and statistical model of the random telegraph signal noise in the pixel source follower based on the binomial distribution is set up. The number of electrons captured or released by the oxide traps in the unit time is described as the random variables which obey the binomial distribution. As a result,the output states and the corresponding probabilities of the first and the second samples of the correlated double sampling circuit are acquired. The standard deviation of the output states after the correlated double sampling circuit can be obtained accordingly. In the simulation section, one hundred thousand samples of the source follower MOSFET have been simulated,and the simulation results show that the proposed model has the similar statistical characteristics with the existing models under the effect of the channel length and the density of the oxide trap. Moreover, the noise histogram of the proposed model has been evaluated at different environmental temperatures. 展开更多
关键词 random telegraph signal noise physical and statistical model binomial distribution CMOS image sensor
下载PDF
Analysis of random laser scattering pulse signals with lognormal distribution
15
作者 闫振纲 卞保民 +3 位作者 王绶玙 林颖璐 王春勇 李振华 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第6期246-256,共11页
The statistical distribution of natural phenomena is of great significance in studying the laws of nature. In order to study the statistical characteristics of a random pulse signal, a random process model is proposed... The statistical distribution of natural phenomena is of great significance in studying the laws of nature. In order to study the statistical characteristics of a random pulse signal, a random process model is proposed theoretically for better studying of the random law of measured results. Moreover, a simple random pulse signal generation and testing system is designed for studying the counting distributions of three typical objects including particles suspended in the air, standard particles, and background noise. Both normal and lognormal distribution fittings are used for analyzing the experimental results and testified by chi-square distribution fit test and correlation coefficient for comparison. In addition, the statistical laws of three typical objects and the relations between them are discussed in detail. The relation is also the non-integral dimension fractal relation of statistical distributions of different random laser scattering pulse signal groups. 展开更多
关键词 random pulse signal statistical self-similarity lognormal distribution laser scattering
下载PDF
The retrieval of the nonlinear random waves from the non-Gaussian characteristics of the sea surface elevation distribution
16
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
下载PDF
Seismic safety assessment with non-Gaussian random processes for train-bridge coupled systems
17
作者 Zhao Han Gao Lei +4 位作者 Wei Biao Tan Jincheng Guo Peidong Jiang Lizhong Xiang Ping 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2024年第1期241-260,共20页
Extensive high-speed railway(HSR)network resembled the intricate vascular system of the human body,crisscrossing mainlands.Seismic events,known for their unpredictability,pose a significant threat to both trains and b... Extensive high-speed railway(HSR)network resembled the intricate vascular system of the human body,crisscrossing mainlands.Seismic events,known for their unpredictability,pose a significant threat to both trains and bridges,given the HSR’s extended operational duration.Therefore,ensuring the running safety of train-bridge coupled(TBC)system,primarily composed of simply supported beam bridges,is paramount.Traditional methods like the Monte Carlo method fall short in analyzing this intricate system efficiently.Instead,efficient algorithm like the new point estimate method combined with moment expansion approximation(NPEM-MEA)is applied to study random responses of numerical simulation TBC systems.Validation of the NPEM-MEA’s feasibility is conducted using the Monte Carlo method.Comparative analysis confirms the accuracy and efficiency of the method,with a recommended truncation order of four to six for the NPEM-MEA.Additionally,the influences of seismic magnitude and epicentral distance are discussed based on the random dynamic responses in the TBC system.This methodology not only facilitates seismic safety assessments for TBC systems but also contributes to standard-setting for these systems under earthquake conditions. 展开更多
关键词 train-bridge coupled(TBC)system random vibration new point estimate method(NPEM) seismic safety assessment moment expansion approximation(MEA) non-Gaussian distributions
下载PDF
Statistical Distribution of Depth-Integrated Local Horizontal Momentum for Second-Order Random Ocean Waves in Finite Water Depth
18
作者 宋金宝 《海洋工程:英文版》 EI 2004年第3期381-389,共9页
Based on the second order random wave solutions of water wave equations in finite water depth, statistical distributions of the depth integrated local horizontal momentum components are derived by use of the charact... Based on the second order random wave solutions of water wave equations in finite water depth, statistical distributions of the depth integrated local horizontal momentum components are derived by use of the characteristic function expansion method. The parameters involved in the distributions can be all determined by the water depth and the wave number spectrum of ocean waves. As an illustrative example, a fully developed wind generated sea is considered and the parameters are calculated for typical wind speeds and water depths by means of the Donelan and Pierson spectrum. The effects of nonlinearity and water depth on the distributions are also investigated. 展开更多
关键词 statistical distribution depth-integrated local momentum second-order random waves water depth wave-number spectrum
下载PDF
Heavy-Tailed Distributions Generated by Randomly Sampled Gaussian, Exponential and Power-Law Functions
19
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
下载PDF
DISTRIBUTION LAW OF RANDOM UNBALANCE RESPONSE OF MULTISTAGE BLOWER
20
作者 Tan, Qing Zhong, Jue 《中国有色金属学会会刊:英文版》 EI CSCD 1998年第1期165-168,共4页
DISTRIBUTIONLAWOFRANDOMUNBALANCERESPONSEOFMULTISTAGEBLOWER①TanQingandZhongJueColegeofMechanicalandElectrical... DISTRIBUTIONLAWOFRANDOMUNBALANCERESPONSEOFMULTISTAGEBLOWER①TanQingandZhongJueColegeofMechanicalandElectricalEnginering,Centra... 展开更多
关键词 UNBALANCE distribution random experiment method vibration RESPONSE centrifugal BLOWER overcritical rotating speed autobalance technology working condition diagnosis
下载PDF
上一页 1 2 122 下一页 到第
使用帮助 返回顶部