期刊文献+
共找到27篇文章
< 1 2 >
每页显示 20 50 100
Underwater Image Classification Based on EfficientnetB0 and Two-Hidden-Layer Random Vector Functional Link
1
作者 ZHOU Zhiyu LIU Mingxuan +2 位作者 JI Haodong WANG Yaming ZHU Zefei 《Journal of Ocean University of China》 CAS CSCD 2024年第2期392-404,共13页
The ocean plays an important role in maintaining the equilibrium of Earth’s ecology and providing humans access to a wealth of resources.To obtain a high-precision underwater image classification model,we propose a c... The ocean plays an important role in maintaining the equilibrium of Earth’s ecology and providing humans access to a wealth of resources.To obtain a high-precision underwater image classification model,we propose a classification model that combines an EfficientnetB0 neural network and a two-hidden-layer random vector functional link network(EfficientnetB0-TRVFL).The features of underwater images were extracted using the EfficientnetB0 neural network pretrained via ImageNet,and a new fully connected layer was trained on the underwater image dataset using the transfer learning method.Transfer learning ensures the initial performance of the network and helps in the development of a high-precision classification model.Subsequently,a TRVFL was proposed to improve the classification property of the model.Net construction of the two hidden layers exhibited a high accuracy when the same hidden layer nodes were used.The parameters of the second hidden layer were obtained using a novel calculation method,which reduced the outcome error to improve the performance instability caused by the random generation of parameters of RVFL.Finally,the TRVFL classifier was used to classify features and obtain classification results.The proposed EfficientnetB0-TRVFL classification model achieved 87.28%,74.06%,and 99.59%accuracy on the MLC2008,MLC2009,and Fish-gres datasets,respectively.The best convolutional neural networks and existing methods were stacked up through box plots and Kolmogorov-Smirnov tests,respectively.The increases imply improved systematization properties in underwater image classification tasks.The image classification model offers important performance advantages and better stability compared with existing methods. 展开更多
关键词 underwater image classification EfficientnetB0 random vector functional link convolutional neural network
下载PDF
ON THE DISTRIBUTION OF VALUES AND DEFICIENT FUNCTION OF A GENERAL RANDOM INTEGRAL FUNCTION 被引量:2
2
作者 田范基 《Acta Mathematica Scientia》 SCIE CSCD 2001年第3期363-368,共6页
Under suitable conditions on {X-n}, the author obtains the important results: it is almost sure that the random integral function f(w) = Sigma (infinity)(n=0) X(n)z(n) (of finite positive order) has no deficient funct... Under suitable conditions on {X-n}, the author obtains the important results: it is almost sure that the random integral function f(w) = Sigma (infinity)(n=0) X(n)z(n) (of finite positive order) has no deficient function, and any direction is a Borel direction (without finite exceptional value) of f(w). 展开更多
关键词 random integral function deficient function order of growth
下载PDF
THE ANALYTICAL PROPERTIES FOR HOMOGENEOUS RANDOM TRANSITION FUNCTIONS 被引量:1
3
作者 胡迪鹤 邱育峰 《Acta Mathematica Scientia》 SCIE CSCD 2007年第1期180-192,共13页
The concepts of Markov process in random environment and homogeneous random transition functions are introduced. The necessary and sufficient conditions for homogeneous random transition function are given. The main r... The concepts of Markov process in random environment and homogeneous random transition functions are introduced. The necessary and sufficient conditions for homogeneous random transition function are given. The main results in this article are the analytical properties, such as continuity, differentiability, random Kolmogorov backward equation and random Kolmogorov forward equation of homogeneous random transition functions. 展开更多
关键词 Markov process in random environment random transition function homogeneous random transition function random Kohnogorov backward equation random Kohnogorov forward equation
下载PDF
Itopride therapy for functional dyspepsia:A meta-analysis 被引量:15
4
作者 Xuan Huang Bin Lv +2 位作者 Shuo Zhang Yi-Hong Fan Li-Na Meng 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第48期7371-7377,共7页
AIM:To evaluate the therapeutic effects of itopride vs other drugs(placebo,domperidone,mosapride) for functional dyspepsia(FD).METHODS:Randomized controlled trials(RCTs) of itopride for FD were retrieved from database... AIM:To evaluate the therapeutic effects of itopride vs other drugs(placebo,domperidone,mosapride) for functional dyspepsia(FD).METHODS:Randomized controlled trials(RCTs) of itopride for FD were retrieved from databases.Relevant information was extracted and analyzed,using the relative risk(RR) and weighted mean deviation,as appropriate.A random or fixed effect model was used,based on the heterogeneity of the included articles,and visual inspection of funnel plots was used to evaluate publication bias.RESULTS:Nine RCTs enrolling 2620 FD cases were included;1372 cases received itopride treatment and 1248 cases received placebo or other drugs(control groups).Compared with control groups,itopride had superior RR values of 1.11 [95%CI:(1.03,1.19),P = 0.006],1.21 [95%CI:(1.03,1.44),P = 0.02],and1.24 [95%CI:(1.01,1.53),P = 0.04] for global patient assessment,postprandial fullness,and early satiety,respectively.For the Leeds Dyspepsia Questionnaire score,the weighted mean deviation was-1.38 [95%CI:(-1.75,-1.01),P < 0.01].The incidence of adverse effects was similar in the itopride and control groups.The funnel plots for all indicators showed no evidence of publication bias.CONCLUSION:Itopride has good efficacy in terms of global patients assessment,postprandial fullness,and early satiety in the treatment of patients with FD and shows a low rate of adverse reactions.Itopride can greatly improve FD syndromes-score. 展开更多
关键词 Itopride functional dyspepsia Meta-analysis randomized controlled trials Prokinetic agents
下载PDF
QUANTITATIVE THEOREM AND SATURATION THEOREM FOR MULTIVARIATE RANDOMFUNCTIONS
5
作者 赵静辉 《Acta Mathematica Scientia》 SCIE CSCD 1997年第4期463-470,共8页
In this paper, we give the quantitative theorem and saturation theorem for random functions with compact convex parameter spaces.
关键词 random function quantitative theorem saturation theorem
下载PDF
ON MULTIPLE WIENER INTEGRAL EXPANSIONS FOR D'-VALUED NONLINEAR RANDOM FUNCTIONALS
6
作者 吴奖伦 《Acta Mathematica Scientia》 SCIE CSCD 1993年第2期220-228,共9页
In this paper, the multiple stochastic integral with respect to a Wiener D'-process is defined. And also it is shown that for a D'-valued nonlinear random functional there exists a sequence of multiple integra... In this paper, the multiple stochastic integral with respect to a Wiener D'-process is defined. And also it is shown that for a D'-valued nonlinear random functional there exists a sequence of multiple integral kernels such that the nonlinear functional can be expanded by series of multiple Wiener integrals of the integral kernels with respect to the Wiener D'-process. 展开更多
关键词 VALUED NONLINEAR RANDOM functionALS ON MULTIPLE WIENER INTEGRAL EXPANSIONS FOR D ONB
下载PDF
AFFINE TRANSFORMATION IN RANDOM ITERATED FUNCTION SYSTEMS
7
作者 XIONG Yong(熊勇) +1 位作者 SHI Ding-hua(史定华) 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2001年第7期820-826,共7页
Random iterated function systems (IFSs) is discussed, which is one of the methods for fractal drawing. A certain figure can be reconstructed by a random IFS. One approach is presented to determine a new random IFS, th... Random iterated function systems (IFSs) is discussed, which is one of the methods for fractal drawing. A certain figure can be reconstructed by a random IFS. One approach is presented to determine a new random IFS, that the figure reconstructed by the new random IFS is the image of the origin figure reconstructed by old IFS under a given affine transformation. Two particular examples are used to show this approach. 展开更多
关键词 FRACTAL random iterated function system affine transformation
下载PDF
WEIGHTED APPROXIMATION OF RANDOM FUNCTIONS
8
作者 YU JIARONG 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 1995年第4期361-366,共6页
Let (Ω, A, P) be a probability space, X(t, ω) a random function continuous in probability for t∈[0,+∞) or (-∞,+∞)(ω∈Ω), and F(t) a positive function continuous for t∈[0,+∞) or (-∞, +∞). If X(t, ω) and F(... Let (Ω, A, P) be a probability space, X(t, ω) a random function continuous in probability for t∈[0,+∞) or (-∞,+∞)(ω∈Ω), and F(t) a positive function continuous for t∈[0,+∞) or (-∞, +∞). If X(t, ω) and F(t) verify certain conditions, then there exists a sequence {Qn(t,ω)} of random polynomials such that we have almost surely: for t∈[0,+∞) or (-∞, +∞), lim|X(t, ω)-Qn(t, ω)|/F(t)=0. 展开更多
关键词 Random function continuous in probability weighted approximation.
下载PDF
Mean-square Almost Periodic Random Functions
9
作者 江利娜 张传义 《Northeastern Mathematical Journal》 CSCD 2007年第3期215-225,共11页
In this paper, we present a basic theory of mean-square almost periodicity, apply the theory in random differential equation, and obtain mean-square almost periodic solution of some types stochastic differential equat... In this paper, we present a basic theory of mean-square almost periodicity, apply the theory in random differential equation, and obtain mean-square almost periodic solution of some types stochastic differential equation. 展开更多
关键词 mean-square convergence mean-square almost periodic random function Ito integration
下载PDF
A Machine Learning Approach for Artifact Removal from Brain Signal
10
作者 Sandhyalati Behera Mihir Narayan Mohanty 《Computer Systems Science & Engineering》 SCIE EI 2023年第5期1455-1467,共13页
Electroencephalography(EEG),helps to analyze the neuronal activity of a human brain in the form of electrical signals with high temporal resolution in the millisecond range.To extract clean clinical information from E... Electroencephalography(EEG),helps to analyze the neuronal activity of a human brain in the form of electrical signals with high temporal resolution in the millisecond range.To extract clean clinical information from EEG signals,it is essential to remove unwanted artifacts that are due to different causes including at the time of acquisition.In this piece of work,the authors considered the EEG signal contaminated with Electrocardiogram(ECG)artifacts that occurs mostly in cardiac patients.The clean EEG is taken from the openly available Mendeley database whereas the ECG signal is collected from the Physionet database to create artifacts in the EEG signal and verify the proposed algorithm.Being the artifactual signal is non-linear and non-stationary the Random Vector Functional Link Network(RVFLN)model is used in this case.The Machine Learning approach has taken a leading role in every field of current research and RVFLN is one of them.For the proof of adaptive nature,the model is designed with EEG as a reference and artifactual EEG as input.The peaks of ECG signals are evaluated for artifact estimation as the amplitude is higher than the EEG signal.To vary the weight and reduce the error,an exponentially weighted Recursive Least Square(RLS)algorithm is used to design the adaptive filter with the novel RVFLN model.The random vectors are considered in this model with a radial basis function to satisfy the required signal experimentation.It is found that the result is excellent in terms of Mean Square Error(MSE),Normalized Mean Square Error(NMSE),Relative Error(RE),Gain in Signal to Artifact Ratio(GSAR),Signal Noise Ratio(SNR),Information Quantity(IQ),and Improvement in Normalized Power Spectrum(INPS).Also,the proposed method is compared with the earlier methods to show its efficacy. 展开更多
关键词 Random vector functional link network(RVFLN) information quantity(IQ) constrained independent component analysis(cICA)
下载PDF
RVFLN-based online adaptive semi-supervised learning algorithm with application to product quality estimation of industrial processes 被引量:5
11
作者 DAI Wei HU Jin-cheng +2 位作者 CHENG Yu-hu WANG Xue-song CHAI Tian-you 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第12期3338-3350,共13页
Direct online measurement on product quality of industrial processes is difficult to be realized,which leads to a large number of unlabeled samples in modeling data.Therefore,it needs to employ semi-supervised learnin... Direct online measurement on product quality of industrial processes is difficult to be realized,which leads to a large number of unlabeled samples in modeling data.Therefore,it needs to employ semi-supervised learning(SSL)method to establish the soft sensor model of product quality.Considering the slow time-varying characteristic of industrial processes,the model parameters should be updated smoothly.According to this characteristic,this paper proposes an online adaptive semi-supervised learning algorithm based on random vector functional link network(RVFLN),denoted as OAS-RVFLN.By introducing a L2-fusion term that can be seen a weight deviation constraint,the proposed algorithm unifies the offline and online learning,and achieves smoothness of model parameter update.Empirical evaluations both on benchmark testing functions and datasets reveal that the proposed OAS-RVFLN can outperform the conventional methods in learning speed and accuracy.Finally,the OAS-RVFLN is applied to the coal dense medium separation process in coal industry to estimate the ash content of coal product,which further verifies its effectiveness and potential of industrial application. 展开更多
关键词 semi-supervised learning(SSL) L2-fusion term online adaptation random vector functional link network(RVFLN)
下载PDF
A numerical simulation of seepage structure surface and its feasibility 被引量:3
12
作者 彭康 李夕兵 +1 位作者 王泽伟 刘爱华 《Journal of Central South University》 SCIE EI CAS 2013年第5期1326-1331,共6页
According to Cubic law and incompressible fluid law of mass conservation, the seepage character of the fracture surface was simulated with the simulation method of fractal theory and random Brown function. Furthermore... According to Cubic law and incompressible fluid law of mass conservation, the seepage character of the fracture surface was simulated with the simulation method of fractal theory and random Brown function. Furthermore, the permeability coefficient of the single fracture was obtained. In order to test the stability of the method, 500 simulations were conducted on each different fractal dimension. The simulated permeability coefficient was analyzed in probability density distribution and probability cumulative distribution statistics. Statistics showed that the discrete degree of the permeability coefficient increases with the increase of the fractal dimension. And the calculation result has better stability when the fractal dimension value is relatively small. According to the Bayes theory, the characteristic index of the permeability coefficient on fractal dimension P(Dfi| Ri) is established. The index, P(Dfi| Ri), shows that when the simulated permeability coefficient is relatively large, it can clearly represent the fractal dimension of the structure surface, the probability is 82%. The calculated results of the characteristic index verify the feasibility of the method. 展开更多
关键词 fractal theory numerical simulation representative elementary volume (REV) random brown function permeabilitycoefficient fractal dimension
下载PDF
Adaptive Control of Discrete-time Nonlinear Systems Using ITF-ORVFL 被引量:3
13
作者 Xiaofei Zhang Hongbin Ma +1 位作者 Wenchao Zuo Man Luo 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2022年第3期556-563,共8页
Random vector functional ink(RVFL)networks belong to a class of single hidden layer neural networks in which some parameters are randomly selected.Their network structure in which contains the direct links between inp... Random vector functional ink(RVFL)networks belong to a class of single hidden layer neural networks in which some parameters are randomly selected.Their network structure in which contains the direct links between inputs and outputs is unique,and stability analysis and real-time performance are two difficulties of the control systems based on neural networks.In this paper,combining the advantages of RVFL and the ideas of online sequential extreme learning machine(OS-ELM)and initial-training-free online extreme learning machine(ITFOELM),a novel online learning algorithm which is named as initial-training-free online random vector functional link algo rithm(ITF-ORVFL)is investigated for training RVFL.The link vector of RVFL network can be analytically determined based on sequentially arriving data by ITF-ORVFL with a high learning speed,and the stability for nonlinear systems based on this learning algorithm is analyzed.The experiment results indicate that the proposed ITF-ORVFL is effective in coping with nonparametric uncertainty. 展开更多
关键词 Adaptive control initial-training-free online learning algorithm random vector functional link networks
下载PDF
Laplace Transformation and Ergodic Potential Kernel for q-Process in Random Environment 被引量:2
14
作者 LU Ping HU Dihe 《Wuhan University Journal of Natural Sciences》 CAS 2007年第2期218-224,共7页
This paper introduces some concepts such as q- process in random environment, Laplace transformation, ergodic potential kernel, error function and some basic lemmas.We study the continuity and Laplace transformation o... This paper introduces some concepts such as q- process in random environment, Laplace transformation, ergodic potential kernel, error function and some basic lemmas.We study the continuity and Laplace transformation of random transition function. Finally, we give the sufficient condition for the existence of ergodic potential kernel for homogeneous q- processes in random environments. 展开更多
关键词 random transition function transition density func-tion in random environment q-process in random environment Laplace transformation ergodic potential kernel
下载PDF
Multiplicative Functions Resembling the Mobius Function 被引量:1
15
作者 Qing Yang LIU 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2023年第12期2316-2328,共13页
A multiplicative function f is said to be resembling the Mobius function if f is supported on the square-free integers,and f(p)=±1 for each prime p.We prove O-and Ω-results for the summatory function ∑_(n)≤x f... A multiplicative function f is said to be resembling the Mobius function if f is supported on the square-free integers,and f(p)=±1 for each prime p.We prove O-and Ω-results for the summatory function ∑_(n)≤x f(n)for a class of these f,and the point is that these O-results demonstrate cancellations better than the square-root saving.It is proved in particular that the summatory function is O(x^(1/3+ε))under the Riemann Hypothesis.On the other hand it is proved to be Ω(x^(1/4))unconditionally.It is interesting to compare these with the corresponding results for the Mobius function. 展开更多
关键词 Mobius function random multiplicative function ZETA-function
原文传递
Robust H_∞ control of piecewise-linear chaotic systems with random data loss
16
作者 张洪斌 于永斌 张健 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第8期191-199,共9页
This paper studies the problem of robust H∞ control of piecewise-linear chaotic systems with random data loss. The communication links between the plant and the controller are assumed to be imperfect (that is, data ... This paper studies the problem of robust H∞ control of piecewise-linear chaotic systems with random data loss. The communication links between the plant and the controller are assumed to be imperfect (that is, data loss occurs intermittently, which appears typically in a network environment). The data loss is modelled as a random process which obeys a Bernoulli distribution. In the face of random data loss, a piecewise controller is designed to robustly stabilize the networked system in the sense of mean square and also achieve a prescribed H∞ disturbance attenuation performance based on a piecewise-quadratic Lyapunov function. The required H∞ controllers can be designed by solving a set of linear matrix inequalities (LMIs). Chua's system is provided to illustrate the usefulness and applicability of the developed theoretical results. 展开更多
关键词 CHAOS H∞ control piecewise-linear systems piecewise-quadratic Lyapunov functions random data loss
下载PDF
Parametric characteristic of the random vibration response of nonlinear systems 被引量:2
17
作者 Xing-Jian Dong Zhi-Ke Peng +2 位作者 Wen-Ming Zhang Guang Meng Fu-Lei Chu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2013年第2期267-283,共17页
Volterra series is a powerful mathematical tool for nonlinear system analysis,and there is a wide range of nonlinear engineering systems and structures that can be represented by a Volterra series model.In the present... Volterra series is a powerful mathematical tool for nonlinear system analysis,and there is a wide range of nonlinear engineering systems and structures that can be represented by a Volterra series model.In the present study,the random vibration of nonlinear systems is investigated using Volterra series.Analytical expressions were derived for the calculation of the output power spectral density(PSD) and input-output cross-PSD for nonlinear systems subjected to Gaussian excitation.Based on these expressions,it was revealed that both the output PSD and the input-output crossPSD can be expressed as polynomial functions of the nonlinear characteristic parameters or the input intensity.Numerical studies were carried out to verify the theoretical analysis result and to demonstrate the effectiveness of the derived relationship.The results reached in this study are of significance to the analysis and design of the nonlinear engineering systems and structures which can be represented by a Volterra series model. 展开更多
关键词 Volterra series·Nonlinear system·Random vibration·Power spectrum density·Generalized frequency response functions
下载PDF
THE BRANCHING CHAIN WITH DRIFT IN SPACE-TIME RANDOM ENVIRONMENT(I):MODEL,MARKOV PROPERTY,MOMENTS
18
作者 胡迪鹤 胡晓予 《Acta Mathematica Scientia》 SCIE CSCD 2010年第5期1669-1678,共10页
There are three parts in this article. In Section 1, we establish the model of branching chain with drift in space-time random environment (BCDSTRE), i.e., the coupling of branching chain and random walk. In Section... There are three parts in this article. In Section 1, we establish the model of branching chain with drift in space-time random environment (BCDSTRE), i.e., the coupling of branching chain and random walk. In Section 2, we prove that any BCDSTRE must be a Markov chain in time random environment when we consider the distribution of the particles in space as a random element. In Section 3, we calculate the first-order moments and the second-order moments of BCDSTRE. 展开更多
关键词 branching chain with drift in space-time random enviromnent randombranching generating function local random transition generating function random drift law random branching law
下载PDF
Improved deep mixed kernel randomized network for wind speed prediction
19
作者 Vijaya Krishna Rayi Ranjeeta Bisoi +1 位作者 S.P.Mishra P.K.Dash 《Clean Energy》 EI CSCD 2023年第5期1006-1031,共26页
Forecasting wind speed is an extremely complicated and challenging problem due to its chaotic nature and its dependence on several atmospheric conditions.Although there are several intelligent techniques in the litera... Forecasting wind speed is an extremely complicated and challenging problem due to its chaotic nature and its dependence on several atmospheric conditions.Although there are several intelligent techniques in the literature for wind speed prediction,their accuracies are not yet very reliable.Therefore,in this paper,a new hybrid intelligent technique named the deep mixed kernel random vector functional-link network auto-encoder(AE)is proposed for wind speed prediction.The proposed method eliminates manual tuning of hidden nodes with random weights and biases,providing prediction model generalization and representation learning.This reduces reconstruction error due to the exact inversion of the kernel matrix,unlike the pseudo-inverse in a random vector functional-link network,and short-ens the execution time.Furthermore,the presence of a direct link from the input to the output reduces the complexity of the prediction model and improves the prediction accuracy.The kernel parameters and coefficients of the mixed kernel system are optimized using a new chaotic sine–cosine Levy flight optimization technique.The lowest errors in terms of mean absolute error(0.4139),mean absolute percentage error(4.0081),root mean square error(0.4843),standard deviation error(1.1431)and index of agreement(0.9733)prove the efficiency of the proposed model in comparison with other deep learning models such as deep AEs,deep kernel extreme learning ma-chine AEs,deep kernel random vector functional-link network AEs,benchmark models such as least square support vector machine,autoregressive integrated moving average,extreme learning machines and their hybrid models along with different state-of-the-art methods. 展开更多
关键词 deep neural network mixed kernel random vector functional network auto-encoder chaotic sine-cosine Levy flight optimization single and multistep wind speed prediction
原文传递
Quasimonotone random and stochastic functional differential equations with applications
20
作者 Xiaoming Bai Jifa Jiang Tianyuan Xu 《Science China Mathematics》 SCIE CSCD 2023年第9期2021-2056,共36页
In this paper, we study monotone properties of random and stochastic functional differential equations and their global dynamics. First, we show that random functional differential equations(RFDEs)generate the random ... In this paper, we study monotone properties of random and stochastic functional differential equations and their global dynamics. First, we show that random functional differential equations(RFDEs)generate the random dynamical system(RDS) if and only if all the solutions are globally defined, and establish the comparison theorem for RFDEs and the random Riesz representation theorem. These three results lead to the Borel measurability of coefficient functions in the Riesz representation of variational equations for quasimonotone RFDEs, which paves the way following the Smith line to establish eventual strong monotonicity for the RDS under cooperative and irreducible conditions. Then strong comparison principles, strong sublinearity theorems and the existence of random attractors for RFDEs are proved. Finally, criteria are presented for the existence of a unique random equilibrium and its global stability in the universe of all the tempered random closed sets of the positive cone. Applications to typical random or stochastic delay models in monotone dynamical systems,such as biochemical control circuits, cyclic gene models and Hopfield-type neural networks, are given. 展开更多
关键词 quasimonotone random and stochastic functional differential equations eventual strong mono-tonicity strong comparison theorems strong sublinearity random attractor global convergence to random equilibrium
原文传递
上一页 1 2 下一页 到第
使用帮助 返回顶部