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Computing large deviation prefactors of stochastic dynamical systems based on machine learning
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作者 李扬 袁胜兰 +1 位作者 陆凌宏志 刘先斌 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期364-373,共10页
We present a large deviation theory that characterizes the exponential estimate for rare events in stochastic dynamical systems in the limit of weak noise.We aim to consider a next-to-leading-order approximation for m... We present a large deviation theory that characterizes the exponential estimate for rare events in stochastic dynamical systems in the limit of weak noise.We aim to consider a next-to-leading-order approximation for more accurate calculation of the mean exit time by computing large deviation prefactors with the aid of machine learning.More specifically,we design a neural network framework to compute quasipotential,most probable paths and prefactors based on the orthogonal decomposition of a vector field.We corroborate the higher effectiveness and accuracy of our algorithm with two toy models.Numerical experiments demonstrate its powerful functionality in exploring the internal mechanism of rare events triggered by weak random fluctuations. 展开更多
关键词 machine learning large deviation prefactors stochastic dynamical systems rare events
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Effect of Froude similitude deviation on curved channel simulations: A case study in the Middle Yangtze River
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作者 Xiao-ting Yang Qian-qian Shang +3 位作者 Hui Xu Guo-bin Li Ya-jun Gao Qi-lin Yang 《Water Science and Engineering》 EI CAS CSCD 2023年第3期289-294,共6页
Froude similitude and friction similitude are the two crucial similarity conditions that are often used in physical-scale modeling of rivers.However,models often deviate from Froude similitude when dealing with real-w... Froude similitude and friction similitude are the two crucial similarity conditions that are often used in physical-scale modeling of rivers.However,models often deviate from Froude similitude when dealing with real-world situations.This study developed several fixed-bed river models with various curvatures to determine the effect of Froude similitude deviation on curved channel modeling.Models were constructed according to the characteristics of the Middle Yangtze River.Differences in longitudinal slope,transverse slope,and main stream line location were measured by varying Froude similitude deviation.The deviations of longitudinal slope and velocity were negligible because friction similitude was accounted for.The transverse slope varied significantly with the Froude similitude deviation,and the main stream line varied with the curvature and Froude similitude deviation.Formulae were derived to estimate the slope deviation.These analyses helped to clarify the feasibility of the method of Froude similitude deviation for curved channels. 展开更多
关键词 Fixed-bed river model Froude similitude deviation Flow movement Water surface slope Middle Yangtze river
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LARGE DEVIATIONS FOR TOP EIGENVALUES OFβ-JACOBI ENSEMBLES AT SCALING TEMPERATURES
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作者 雷良贞 马宇韬 《Acta Mathematica Scientia》 SCIE CSCD 2023年第4期1767-1780,共14页
Letλ=(λ_(1),…,λ_(n))beβ-Jacobi ensembles with parameters p_(1),p_(2),n andβ,withβvarying with n.Set■.Suppose that■and 0≤σγ<1.We offer the large deviation for p_(1)+p_(2)/p_(1)■λ_(i)whenγ>0 via the... Letλ=(λ_(1),…,λ_(n))beβ-Jacobi ensembles with parameters p_(1),p_(2),n andβ,withβvarying with n.Set■.Suppose that■and 0≤σγ<1.We offer the large deviation for p_(1)+p_(2)/p_(1)■λ_(i)whenγ>0 via the large deviation of the corresponding empirical measure and via a direct estimate,respectively,whenγ=0. 展开更多
关键词 β-Jacobi ensemble large deviation Wachter law extremal eigenvalue
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A LARGE DEVIATION PRINCIPLE FOR THE STOCHASTIC GENERALIZED GINZBURG-LANDAU EQUATION DRIVEN BY JUMP NOISE
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作者 王冉 张贝贝 《Acta Mathematica Scientia》 SCIE CSCD 2023年第2期505-530,共26页
In this paper,we establish a large deviation principle for the stochastic generalized Ginzburg-Landau equation driven by jump noise.The main difficulties come from the highly non-linear coefficient and the jump noise.... In this paper,we establish a large deviation principle for the stochastic generalized Ginzburg-Landau equation driven by jump noise.The main difficulties come from the highly non-linear coefficient and the jump noise.Here,we adopt a new sufficient condition for the weak convergence criterion of the large deviation principle,which was initially proposed by Matoussi,Sabbagh and Zhang(2021). 展开更多
关键词 large deviation principle weak convergence method stochastic generalized Ginzburg-Landau equation Poisson random measure
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A novel lattice model integrating the cooperative deviation of density and optimal flux under V2X environment
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作者 彭光含 罗春莉 +1 位作者 赵红专 谭惠丽 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第1期626-633,共8页
A novel lattice hydrodynamic model is proposed by integrating the cooperative deviation of density and optimal flux under vehicle to X(V2X) environment. According to the theoretical analysis, the stability conditions ... A novel lattice hydrodynamic model is proposed by integrating the cooperative deviation of density and optimal flux under vehicle to X(V2X) environment. According to the theoretical analysis, the stability conditions and the mKdV equations affected by the cooperative deviation of traffic information are explored. And the density wave, hysteresis loop and energy consumption of the traffic flow have been investigated via numerical simulation. The results indicate that the cooperative deviation of density and optimal flux can effectively alleviate the traffic congestion. More importantly, our new consideration can reduce fuel consumption and exhaust emission under the V2X environment. 展开更多
关键词 traffic flow lattice hydrodynamic model cooperative deviation
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Modified inferior oblique anterior transposition for dissociated vertical deviation combined with superior oblique palsy:A case report
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作者 Yao Zong Ze Wang +1 位作者 Wen-Lan Jiang Xian Yang 《World Journal of Clinical Cases》 SCIE 2023年第12期2796-2802,共7页
BACKGROUND Inferior oblique anterior transposition(IOAT)has emerged as an effective surgery in the management of dissociated vertical deviation(DVD)combined with superior oblique palsy(SOP).Traditional IOAT usually pr... BACKGROUND Inferior oblique anterior transposition(IOAT)has emerged as an effective surgery in the management of dissociated vertical deviation(DVD)combined with superior oblique palsy(SOP).Traditional IOAT usually provides satisfactory primary position alignment and simultaneously restricts the superior floating phenomenon.However,it also increases the risk of the anti-elevation syndrome and narrowing of the palpebral fissure in straight-ahead gaze,especially after the unilateral operation.CASE SUMMARY We report the outcomes of the modified unilateral IOAT in two patients with unilateral DVD combined with SOP.The anterior-nasal fibers of the inferior oblique muscle were attached at 9 mm posterior to the corneal limbus along the temporal board of the inferior rectus muscle,the other fibers were attached a further 5 mm temporal to the anterior-nasal fibers.Postoperatively,both hypertropia and floating were improved,and no obvious complications occurred.CONCLUSION In these cases,the modified unilateral IOAT was an effective and safe surgical method for treating DVD with SOP. 展开更多
关键词 Anterior transposition Inferior oblique muscles Dissociated vertical deviation Superior oblique palsy Anti-elevation syndrome Case report
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Application Research of an Intelligent Detection Algorithm for Vehicle Trajectory Route Deviation
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作者 Jianfei Luo Yadong Xing +2 位作者 Cheng Chen Weiqing Zhang Zhongcheng Wu 《Journal of Computer and Communications》 2023年第10期1-11,共11页
In the vehicle trajectory application system, it is often necessary to detect whether the vehicle deviates from the specified route. Trajectory planning in the traditional route deviation detection is defined by the d... In the vehicle trajectory application system, it is often necessary to detect whether the vehicle deviates from the specified route. Trajectory planning in the traditional route deviation detection is defined by the driver through the mobile phone navigation software, which plays a more auxiliary driving role. This paper presents a method of vehicle trajectory deviation detection. Firstly, the manager customizes the trajectory planning and then uses big data technologies to match the deviation between the trajectory planning and the vehicle trajectory. Finally, it achieves the supervisory function of the manager on the vehicle track route in real-time. The results show that this method could detect the vehicle trajectory deviation quickly and accurately, and has practical application value. 展开更多
关键词 Vehicle Positioning Terminal Vehicle Trajectory Route deviation Real-Time Segmentation Analysis Algorithm
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The Inheritance and Deviation of the Subjective Construction“You Bei X Dao(有被X到)”
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作者 YANG Yaqin 《Sino-US English Teaching》 2023年第2期80-84,共5页
Sentence“bei”(“被”字句)and“bei xx”(被xx)provide syntactic and semantic basis for the generation of the construction“You Bei X Dao(有被x到)”.They are in a continuum and have family similarity.The sentence“bei... Sentence“bei”(“被”字句)and“bei xx”(被xx)provide syntactic and semantic basis for the generation of the construction“You Bei X Dao(有被x到)”.They are in a continuum and have family similarity.The sentence“bei”is a typical member,while“bei xx”is an atypical member.Because the construction“You Bei X Dao”has a single function and less attention,it is at the edge of the continuum and is a marginal member.However,it has certain research value in the inheritance and innovation of“bei”and“bei xx”. 展开更多
关键词 “bei”sentence “bei xx” construction“You Bei X Dao” INHERITANCE deviation
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Assessment of Deviation in Quality of Steel Reinforcing Bars Used in Some Building Sites in Cameroon
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作者 Patrick Che Bame Bell Emmanuel Yamb Billong Ndigui 《World Journal of Engineering and Technology》 2023年第4期917-931,共15页
The present work evaluated the deviations in the quality of steel reinforcing bars in terms of markings, diameter, yield strength and ductility in order to facilitate the drawing up of a yield strength value for the C... The present work evaluated the deviations in the quality of steel reinforcing bars in terms of markings, diameter, yield strength and ductility in order to facilitate the drawing up of a yield strength value for the Cameroon National Annex to Eurocode 2. The methodology of the work started with the collection of steel samples from various active building project sites in four different towns viz: Bamenda, Douala, Maroua and Yaoundé and testing their tensile strength and elongation using a Universal Testing Machine and also carrying out the bending test. Results show that bars without marked manufacturer’s name fell all the tests. Other results show that 52% of all the steel had yield stresses below 400 Mpa and the highest deviation in the yield strengths was 22.50%. The study recommends that properly marked grade 500 steel bars should be adopted in the Cameroon national annex to Eurocode 2. 展开更多
关键词 Eurocode 2 National Annex Reinforcement Steel deviationS Yield Strengths
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Influence of highway space alignment continuous degradation in 3- dimensional space on autonomous vehicle trajectory deviation based on PreScan simulation
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作者 Xiao-Fei Wang Nathanael Melkisedek Coulibaly Qiang Zeng 《Digital Transportation and Safety》 2023年第2期77-88,共12页
The advent of autonomous vehicles(AVs)is expected to transform the current transportation system into a safe and reliable one.The existing infrastructures,operational criteria,and design method were developed to meet ... The advent of autonomous vehicles(AVs)is expected to transform the current transportation system into a safe and reliable one.The existing infrastructures,operational criteria,and design method were developed to meet the requirements of human drivers.However,previous studies have shown that in the traditional horizontal and vertical combined design methods,where the two-dimensional alignment elements change,there are varying changes in curvature and torsion,which cause the continuous degradation of the spatial curve and torsion.This continuous degradation will inevitably cause changes in the trajectory of Autonomous Vehicles(AVs),thereby affecting driving safety.Therefore,studying the characteristics of autonomous vehicles trajectory deviation has theoretical significance for optimizing highway alignment safety design.Driving simulation tests were performed by using PreScan and Simulink to calibrate the lateral deviation.A machine learning approach called the Gradient Boosting Decision Tree(GBDT)algorithm was implemented to build a model and express the relationship between space alignment parameters and lane deviation.The results showed that the AV’s driving trajectory is significantly affected by the space alignment factors when the vehicle is driving in the inner lane,the downhill section,and the left-turn section.These findings will provide a novel perspective for road safety research based on autonomous vehicle driving trajectories. 展开更多
关键词 Autonomous Vehicles(AVs) Trajectory deviation(TD) Traffic Safety Spatial Alignment Prescan CURVATURE TORSION
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LARGE DEVIATIONS AND MODERATE DEVIATIONS FOR m-NEGATIVELY ASSOCIATED RANDOM VARIABLES 被引量:8
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作者 胡亦钧 明瑞星 杨文权 《Acta Mathematica Scientia》 SCIE CSCD 2007年第4期886-896,共11页
M-negatively associated random variables, which generalizes the classical one of negatively associated random variables and includes m-dependent sequences as its particular case, are introduced and studied. Large devi... M-negatively associated random variables, which generalizes the classical one of negatively associated random variables and includes m-dependent sequences as its particular case, are introduced and studied. Large deviation principles and moderate deviation upper bounds for stationary m-negatively associated random variables are proved. Kolmogorov-type and Marcinkiewicz-type strong laws of large numbers as well as the three series theorem for m-negatively associated random variables are also given. 展开更多
关键词 negatively associated random variables stationary sequence strong law of large numbers large deviations moderate deviations
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MODERATE DEVIATIONS AND LARGEDE VIATIONS FOR A TEST OF SYMMETRY BASED ON KERNEL DENSITY ESTIMATOR 被引量:5
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作者 何晓霞 高付清 《Acta Mathematica Scientia》 SCIE CSCD 2008年第3期665-674,共10页
Let fn be a non-parametric kernel density estimator based on a kernel function K. and a sequence of independent and identically distributed random variables taking values in R. The goal of this article is to prove mod... Let fn be a non-parametric kernel density estimator based on a kernel function K. and a sequence of independent and identically distributed random variables taking values in R. The goal of this article is to prove moderate deviations and large deviations for the statistic sup |fn(x) - fn(-x) |. 展开更多
关键词 Symmetry test kernel estimator moderate deviations large deviations
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MODERATE DEVIATIONS FOR PARAMETER ESTIMATORS IN FRACTIONAL ORNSTEIN-UHLENBECK PROCESS 被引量:4
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作者 高付清 蒋辉 汪宝彬 《Acta Mathematica Scientia》 SCIE CSCD 2010年第4期1125-1133,共9页
We study moderate deviations for estimators of the drift parameter of the fractional Ornstein-Uhlenbeck process. Two moderate deviation principles are obtained.
关键词 Large deviations moderate deviations Ornstein-Uhlenbeck process
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MODERATE DEVIATIONS FROM HYDRODYNAMIC LIMIT OF A GINZBURG-LANDAU MODEL 被引量:2
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作者 王霞 高付清 《Acta Mathematica Scientia》 SCIE CSCD 2006年第4期691-701,共11页
The authors consider the moderate deviations of hydrodynamic limit for Ginzburg-Landau models. The moderate deviation principle of hydrodynamic limit for a specific Ginzburg-Landau model is obtained and an explicit fo... The authors consider the moderate deviations of hydrodynamic limit for Ginzburg-Landau models. The moderate deviation principle of hydrodynamic limit for a specific Ginzburg-Landau model is obtained and an explicit formula of the rate function is derived. 展开更多
关键词 Hydrodynamic limit large deviations moderate deviations Ginzburg-Landau model
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SMALL PERTURBATION CRAMER METHODS AND MODERATE DEVIATIONS FOR MARKOV PROCESSES 被引量:2
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作者 高付清 《Acta Mathematica Scientia》 SCIE CSCD 1995年第4期394-405,共12页
This paper presents a small perturbation Cramer method for obtaining the large deviation principle of a family of measures (β,ε> 0) on a topological vector space. As an application, we obtain the moderate deviati... This paper presents a small perturbation Cramer method for obtaining the large deviation principle of a family of measures (β,ε> 0) on a topological vector space. As an application, we obtain the moderate deviation estimations for uniformly ergodic Markov processes. 展开更多
关键词 Large deviations Cramer methods Markov processes moderate deviations.
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Geometric Deviation Modeling by Kinematic Matrix Based on Lagrangian Coordinate 被引量:1
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作者 LIU Weidong HU Yueming +1 位作者 LIU Yu DAI Wanyi 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2015年第5期1056-1066,共11页
Typical representation of dimension and geometric accuracy is limited to the self-representation of dimension and geometric deviation based on geometry variation thinking, yet the interactivity affection of geometric ... Typical representation of dimension and geometric accuracy is limited to the self-representation of dimension and geometric deviation based on geometry variation thinking, yet the interactivity affection of geometric variation and gesture variation of multi-rigid body is not included. In this paper, a kinematic matrix model based on Lagrangian coordinate is introduced, with the purpose of unified model for geometric variation and gesture variation and their interactive and integrated analysis. Kinematic model with joint, local base and movable base is built. The ideal feature of functional geometry is treated as the base body; the fitting feature of functional geometry is treated as the adjacent movable body; the local base of the kinematic model is fixed onto the ideal geometry, and the movable base of the kinematic model is fixed onto the fitting geometry. Furthermore, the geometric deviation is treated as relative location or rotation variation between the movable base and the local base, and it's expressed by the Lagrangian coordinate. Moreover, kinematic matrix based on Lagrangian coordinate for different types of geometry tolerance zones is constructed, and total freedom for each kinematic model is discussed. Finally, the Lagrangian coordinate library, kinematic matrix library for geometric deviation modeling is illustrated, and an example of block and piston fits is introduced. Dimension and geometric tolerances of the shaft and hole fitting feature are constructed by kinematic matrix and Lagrangian coordinate, and the results indicate that the proposed kinematic matrix is capable and robust in dimension and geometric tolerances modeling. 展开更多
关键词 geometry deviation geometry deviation representation kinematic matrix Lagrangian coordinate virtual joint
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LARGE DEVIATIONS AND MODERATE DEVIATIONS FOR SUMS OF NEGATIVELY DEPENDENT RANDOM VARIABLES 被引量:1
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作者 刘莉 万成高 冯艳钦 《Acta Mathematica Scientia》 SCIE CSCD 2011年第1期344-352,共9页
In this article, we obtain the large deviations and moderate deviations for negatively dependent (ND) and non-identically distributed random variables defined on (-∞, +∞). The results show that for some non-ide... In this article, we obtain the large deviations and moderate deviations for negatively dependent (ND) and non-identically distributed random variables defined on (-∞, +∞). The results show that for some non-identical random variables, precise large deviations and moderate deviations remain insensitive to negative dependence structure. 展开更多
关键词 Large deviation moderate deviation negative dependence non-identical distribution
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Deviation in Advertising English from a Stylistic Perspective
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作者 罗敏 《英语广场(学术研究)》 2012年第10期15-17,共3页
Advertising English is viewed as an English style with such functional factors as attention value, readability, memorability, selling power. Commercial advertisements are the major concern of this paper. Deviation, na... Advertising English is viewed as an English style with such functional factors as attention value, readability, memorability, selling power. Commercial advertisements are the major concern of this paper. Deviation, namely the violation to the norms of a language, frequently appears in advertisements and can meet requirements of the style of advertising English. Due to limited space, this paper focuses on deviation on the phonological, graphological, lexical, grammatical, and semantic level. Analyzing deviation in advertising English can promote readers' aesthetic and appreciative ability and encourage advertisers to create advertisements with more efficiency, novelty, innovation in more effective language. 展开更多
关键词 advertising English deviation STYLISTIC VIOLATION NORM
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CENTRAL LIMIT THEOREM AND MODERATE DEVIATIONS FOR A CLASS OF SEMILINEAR STOCHASTIC PARTIAL DIFFERENTIAL EQUATIONS
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作者 胡淑兰 李瑞囡 王新宇 《Acta Mathematica Scientia》 SCIE CSCD 2020年第5期1477-1494,共18页
In this paper we prove a central limit theorem and a moderate deviation principle for a class of semilinear stochastic partial differential equations, which contain the stochastic Burgers’ equation and the stochastic... In this paper we prove a central limit theorem and a moderate deviation principle for a class of semilinear stochastic partial differential equations, which contain the stochastic Burgers’ equation and the stochastic reaction-diffusion equation. The weak convergence method plays an important role. 展开更多
关键词 stochastic Burgers'equation stochastic reaction-diffusion equation large deviations moderate deviations
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Large Deviations and Moderate Deviations for the Chi-Square Test in Type Ⅱ Error
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作者 JIANG Hui GAO Fuqing 《Wuhan University Journal of Natural Sciences》 CAS 2008年第2期129-132,共4页
We study the asymptotics tot the statistic of chi-square in type Ⅱ error. By the contraction principle, the large deviations and moderate deviations are obtained, and the rate function of moderate deviations can be c... We study the asymptotics tot the statistic of chi-square in type Ⅱ error. By the contraction principle, the large deviations and moderate deviations are obtained, and the rate function of moderate deviations can be calculated explicitly which is a squared function. 展开更多
关键词 large deviations moderate deviations chi-square test
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