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
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
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
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
To explore experimental quantization of stochastic chaos and exact wave tur-bulence in exponential oscillons,it is necessary to construct smooth random functions of time.In the current paper,we develop a new method of...To explore experimental quantization of stochastic chaos and exact wave tur-bulence in exponential oscillons,it is necessary to construct smooth random functions of time.In the current paper,we develop a new method of modeling stochastic variables described by a closed system of ordinary differential and algebraic equations.Primarily,oscillatory and pulsatory dynamic models pro-duced by the first triplet of copolar elliptic functions are studied from the view-point of the Hamiltonian and Newtonian dynamics.Secondly,the Hamilto-nian systems of the first triplet and the first triplet squared are meticulously investigated in the hyperbolic limit that results in oscillations and pulsations with rectangular and point pulses and a variable period.Thirdly,the relative Hamiltonian systems are used to develop two stochastic models of a random oscillatory cn-noise and a random pulsatory cn2-noise.Numerical experi-ments show that for the Bernoulli frequencies the random oscillatory cn-noise approaches a smooth random oscillatory variable with an unbounded period and the Gaussian probability distribution and the random pulsatory cn2-noise tends to a smooth random pulsatory variable with an unbounded period and the truncated Gaussian probability distribution as the number of elliptic modes approaches infinity.展开更多
This paper presents 3RVAV(Three-Round Voting with Advanced Validation),a novel Byzantine Fault Tolerant consensus protocol combining Proof-of-Stake with a multi-phase voting mechanism.The protocol introduces three lay...This paper presents 3RVAV(Three-Round Voting with Advanced Validation),a novel Byzantine Fault Tolerant consensus protocol combining Proof-of-Stake with a multi-phase voting mechanism.The protocol introduces three layers of randomized committee voting with distinct participant roles(Validators,Delegators,and Users),achieving(4/5)-threshold approval per round through a verifiable random function(VRF)-based selection process.Our security analysis demonstrates 3RVAV provides 1−(1−s/n)^(3k) resistance to Sybil attacks with n participants and stake s,while maintaining O(kn log n)communication complexity.Experimental simulations show 3247 TPS throughput with 4-s finality,representing a 5.8×improvement over Algorand’s committee-based approach.The proposed protocol achieves approximately 4.2-s finality,demonstrating low latency while maintaining strong consistency and resilience.The protocol introduces a novel punishment matrix incorporating both stake slashing and probabilistic blacklisting,proving a Nash equilibrium for honest participation under rational actor assumptions.展开更多
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
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
OBJECTIVE:To evaluate the effectiveness of a combined Traditional Chinese Medicine(TCM) therapy versus conventional treatment on adolescent idiopathic scoliosis.METHODS:One hundred twenty outpatients with mild and mod...OBJECTIVE:To evaluate the effectiveness of a combined Traditional Chinese Medicine(TCM) therapy versus conventional treatment on adolescent idiopathic scoliosis.METHODS:One hundred twenty outpatients with mild and moderate adolescent idiopathic scoliosis were randomly divided into a TCM group(TCMG)and a brace group(CG).TCMG patients underwent Daoyin,Tuina,and acupotomology therapies.CG patients were treated with a Milwaukee brace.Each patient's Cobb angle was measured after 12 and 24 months of treatment,and pulmonary function was determined after 12 months of treatment.Average electromyogram(AEMG) ratio of the surface electromyogram was measured after 6 and 12 months of treatment and followed-up after 18 and 24 months.RESULTS:The Cobb angle significantly decreased in both groups after 12 months of treatment compared with before treatment(P< 0.05).The percentages of original Cobb angle in TCMG and CG were51.4%and 47.8%(P > 0.05) after 12 months and62.5%and 34.7%(P < 0.05) after 24 months,respectively.Pulmonary function significantly improved after 12 months in TCMG(P < 0.05) but significantly decreased in CG(P < 0.05).The AEMG ratio was significantly lower(P < 0.01) and tended to remain at1 after stopping treatment in TCMG,but increased in CG(P<0.05).CONCLUSION:TCM combined therapy can prevent the progression of scoliosis.The AEMG ratio is a promising index that could replace radiography in the evaluation of treatment effect and progression in scoliosis.展开更多
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 ...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
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
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
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
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
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
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
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
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
This paper is concerned with the distribution of normalized zero-sets of random meromorphic functions.The normalization of the zero-set plays the same role as the counting function for a meromorphic function in Nevanl...This paper is concerned with the distribution of normalized zero-sets of random meromorphic functions.The normalization of the zero-set plays the same role as the counting function for a meromorphic function in Nevanlinna theory.The results generalize the theory of Shiffman and Zelditch on the distribution of the zeroes of random holomorphic sections of powers of positive Hermitian holomorphic line bundles.As in a very special case,our paper resembles a form of First Main Theorem in classical Nevanlinna Theory.展开更多
文摘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.
文摘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.
基金Supported by the NNSF of China (10371092)the Foundation of Wuhan University.
文摘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.
基金support of the National Key R&D Program of China(No.2022YFC2803903)the Key R&D Program of Zhejiang Province(No.2021C03013)the Zhejiang Provincial Natural Science Foundation of China(No.LZ20F020003).
文摘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.
基金The support of CAAM and the University of Mount Saint Vincent is gratefully acknowledged。
文摘To explore experimental quantization of stochastic chaos and exact wave tur-bulence in exponential oscillons,it is necessary to construct smooth random functions of time.In the current paper,we develop a new method of modeling stochastic variables described by a closed system of ordinary differential and algebraic equations.Primarily,oscillatory and pulsatory dynamic models pro-duced by the first triplet of copolar elliptic functions are studied from the view-point of the Hamiltonian and Newtonian dynamics.Secondly,the Hamilto-nian systems of the first triplet and the first triplet squared are meticulously investigated in the hyperbolic limit that results in oscillations and pulsations with rectangular and point pulses and a variable period.Thirdly,the relative Hamiltonian systems are used to develop two stochastic models of a random oscillatory cn-noise and a random pulsatory cn2-noise.Numerical experi-ments show that for the Bernoulli frequencies the random oscillatory cn-noise approaches a smooth random oscillatory variable with an unbounded period and the Gaussian probability distribution and the random pulsatory cn2-noise tends to a smooth random pulsatory variable with an unbounded period and the truncated Gaussian probability distribution as the number of elliptic modes approaches infinity.
文摘This paper presents 3RVAV(Three-Round Voting with Advanced Validation),a novel Byzantine Fault Tolerant consensus protocol combining Proof-of-Stake with a multi-phase voting mechanism.The protocol introduces three layers of randomized committee voting with distinct participant roles(Validators,Delegators,and Users),achieving(4/5)-threshold approval per round through a verifiable random function(VRF)-based selection process.Our security analysis demonstrates 3RVAV provides 1−(1−s/n)^(3k) resistance to Sybil attacks with n participants and stake s,while maintaining O(kn log n)communication complexity.Experimental simulations show 3247 TPS throughput with 4-s finality,representing a 5.8×improvement over Algorand’s committee-based approach.The proposed protocol achieves approximately 4.2-s finality,demonstrating low latency while maintaining strong consistency and resilience.The protocol introduces a novel punishment matrix incorporating both stake slashing and probabilistic blacklisting,proving a Nash equilibrium for honest participation under rational actor assumptions.
文摘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).
基金Supported by the National Natural Science Foundation of China (10371092)
文摘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.
基金Supported by Outstanding Youth Fund of the Administration of Traditional Chinese Medicine of Zhejiang Province,China(No.2012ZQ011)
文摘OBJECTIVE:To evaluate the effectiveness of a combined Traditional Chinese Medicine(TCM) therapy versus conventional treatment on adolescent idiopathic scoliosis.METHODS:One hundred twenty outpatients with mild and moderate adolescent idiopathic scoliosis were randomly divided into a TCM group(TCMG)and a brace group(CG).TCMG patients underwent Daoyin,Tuina,and acupotomology therapies.CG patients were treated with a Milwaukee brace.Each patient's Cobb angle was measured after 12 and 24 months of treatment,and pulmonary function was determined after 12 months of treatment.Average electromyogram(AEMG) ratio of the surface electromyogram was measured after 6 and 12 months of treatment and followed-up after 18 and 24 months.RESULTS:The Cobb angle significantly decreased in both groups after 12 months of treatment compared with before treatment(P< 0.05).The percentages of original Cobb angle in TCMG and CG were51.4%and 47.8%(P > 0.05) after 12 months and62.5%and 34.7%(P < 0.05) after 24 months,respectively.Pulmonary function significantly improved after 12 months in TCMG(P < 0.05) but significantly decreased in CG(P < 0.05).The AEMG ratio was significantly lower(P < 0.01) and tended to remain at1 after stopping treatment in TCMG,but increased in CG(P<0.05).CONCLUSION:TCM combined therapy can prevent the progression of scoliosis.The AEMG ratio is a promising index that could replace radiography in the evaluation of treatment effect and progression in scoliosis.
文摘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.
文摘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.
基金Project partially supported by the Young Scientists Fund of the National Natural Science Foundation of China(Grant No.60904004)the Key Youth Science and Technology Foundation of University of Electronic Science and Technology of China (Grant No.L08010201JX0720)
文摘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.
基金supported by the National Science Fund for Distinguished Young Scholars (11125209)the National Natural Science Foundation of China (10902068,51121063 and 10702039)+1 种基金the Shanghai Pujiang Program (10PJ1406000)the Opening Project of State Key Laboratory of Mechanical System and Vibration (MSV201103)
文摘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.
基金Supported by the NSFC(10371092,11771185,10871200)
文摘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.
基金Projects(61603393,61973306)supported in part by the National Natural Science Foundation of ChinaProject(BK20160275)supported by the Natural Science Foundation of Jiangsu Province,China+1 种基金Projects(2015M581885,2018T110571)supported by the Postdoctoral Science Foundation of ChinaProject(PAL-N201706)supported by the Open Project Foundation of State Key Laboratory of Synthetical Automation for Process Industries of Northeastern University,China
文摘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.
基金Project(50934006) supported by the National Natural Science Foundation of ChinaProject(CX2012B070) supported by Hunan Provincial Innovation Foundation for Postgraduate,ChinaProject(1343-76140000024) Supported by Academic New Artist Ministry of Education Doctoral Post Graduate in 2012,China
文摘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.
基金supported by the Ministry of Science and Technology of China(2018AAA0101000,2017YFF0205306,WQ20141100198)the National Natural Science Foundation of China(91648117)。
文摘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.
基金Supported by The Natural Science Foundation of Zhejiang Province of China,No. LY12H29002Traditional Chinese Medicine Science Foundation of Zhejiang Province of China,No. 2011ZB032
文摘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.
文摘This paper is concerned with the distribution of normalized zero-sets of random meromorphic functions.The normalization of the zero-set plays the same role as the counting function for a meromorphic function in Nevanlinna theory.The results generalize the theory of Shiffman and Zelditch on the distribution of the zeroes of random holomorphic sections of powers of positive Hermitian holomorphic line bundles.As in a very special case,our paper resembles a form of First Main Theorem in classical Nevanlinna Theory.
