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Discovering context-aware conditional functional dependencies 被引量:1
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作者 Yuefeng DU Derong SHEN +2 位作者 Tiezheng NIE Yue KOU Ge YU 《Frontiers of Computer Science》 SCIE EI CSCD 2017年第4期688-701,共14页
Conditional functional dependencies(CFDs) are important techniques for data consistency. However, CFDs are limited to 1) provide the reasonable values for consistency repairing and 2) detect potential errors. This... Conditional functional dependencies(CFDs) are important techniques for data consistency. However, CFDs are limited to 1) provide the reasonable values for consistency repairing and 2) detect potential errors. This paper presents context-aware conditional functional dependencies(CCFDs) which contribute to provide reasonable values and detect po- tential errors. Especially, we focus on automatically discov- ering minimal CCFDs. In this paper, we present context rela- tivity to measure the relationship of CFDs. The overlap of the related CFDs can provide reasonable values which result in more accuracy consistency repairing, and some related CFDs are combined into CCFDs. Moreover, we prove that discover- ing minimal CCFDs is NP-complete and we design the pre- cise method and the heuristic method. We also present the dominating value to facilitate the process in both the precise method and the heuristic method. Additionally, the context relativity of the CFDs affects the cleaning results. We will give an approximate threshold of context relativity accord- ing to data distribution for suggestion. The repairing results are approved more accuracy, even evidenced by our empirical evaluation. 展开更多
关键词 conditional functional dependencies contextaware rules discovery
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Nonparametric inferences for kurtosis and conditional kurtosis
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作者 谢潇衡 何幼桦 《Journal of Shanghai University(English Edition)》 CAS 2009年第3期225-232,共8页
Under the assumption of strictly stationary process, this paper proposes a nonparametric model to test the kurtosis and conditional kurtosis for risk time series. We apply this method to the daily returns of S&P500 i... Under the assumption of strictly stationary process, this paper proposes a nonparametric model to test the kurtosis and conditional kurtosis for risk time series. We apply this method to the daily returns of S&P500 index and the Shanghai Composite Index, and simulate GARCH data for verifying the efficiency of the presented model. Our results indicate that the risk series distribution is heavily tailed, but the historical information can make its future distribution light-tailed. However the far future distribution's tails are little affected by the historical data. 展开更多
关键词 conditional probability density function (PDF) kernel estimate KURTOSIS conditional kurtosis heavy tail
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Linking Management and Riparian Physical Functions to Water Quality and Aquatic Habitat
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作者 Donald F. Kozlowski Robert K. Hall +1 位作者 Sherman R. Swanson Daniel T. Heggem 《Journal of Water Resource and Protection》 2016年第8期797-815,共19页
Stream and wetland riparian areas are able to sustain a state of resiliency based on the ecosystem’s ability to attain the functions of its ecological potential. This resiliency allows an area to provide and produce ... Stream and wetland riparian areas are able to sustain a state of resiliency based on the ecosystem’s ability to attain the functions of its ecological potential. This resiliency allows an area to provide and produce desired and valued water quality and aquatic habitat ecosystem services. Maintaining healthy aquatic and riparian habitats depends on “management” allowing for, or facilitating natural recovery of riparian functions. Altering grazing management practices in Maggie Creek lead to changes in riparian functionality, water quality, and aquatic habitat. Maggie Creek basin, historically renowned for its fishery, is one of only a few watersheds in Nevada capable of supporting Lahontan Cutthroat Trout (LCT) (Oncorhynchus clarkia ssp. Henshawi) meta-populations. Prior to 1993, the majority of Maggie Creek was grazed by cattle throughout the growing season. Decades of intensive grazing, water development, and road construction degraded aquatic and riparian habitats. By the early 1990’s, a majority of the Maggie Creek watershed was rated as nonfunctional or functional-at-risk condition with unstable banks, channel incision, loss of riparian vegetation, wide shallow channels, excessive erosion and deposition, reduced stream flows, and increased water temperatures. As mitigation for their 1993 South Operations Area Project mine dewatering, Newmont Mining Company, in cooperation with the Elko District Bureau of Land Management (BLM) and the Elko Land and Livestock Company, developed the Maggie Creek Watershed Restoration Project to enhance LCT habitat. The project was developed to enhance 82 miles of stream, 2000 acres of riparian habitat and 40,000 acres of upland watershed primarily through prescriptive livestock management. Beginning in 1994, grazing systems were implemented for portions of the perennial/intermittent streams. This greatly reduced the frequency and duration of hot season grazing on Maggie Creek and its tributaries. The objective of this paper is to compare 1994 and 2006 stream and wetland riparian assessments using proper functioning condition (PFC) protocol and water quality data. 展开更多
关键词 Ecosystem function Water Quality Non-Point Source Proper functioning Condition
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A NEW FORMULATION OF BERNSTEIN-BEZIER BASED SMOOTHNESS CONDITIONS FOR pp FUNCTIONS
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作者 Hong, Dong(Center for Approximation Theory, Texas A &M University, U.S. A) 《Analysis in Theory and Applications》 1995年第2期67-75,共9页
In this note, we establish a new formulation of smoothness conditions for piecewise polynomial (: =pp) functions in terms of the B-net representation in the general n-dimensional setting. It plays an important role fo... In this note, we establish a new formulation of smoothness conditions for piecewise polynomial (: =pp) functions in terms of the B-net representation in the general n-dimensional setting. It plays an important role for 2-dimensional setting in the constructive proof of the fact that the spaces of polynomial splines with smoothness rand total degree k≥3r+2 over arbitrary triangulations achieve the optimal approximation order with the approximation constant depending only on k and the smallest angle of the partition in [5]. 展开更多
关键词 A NEW FORMULATION OF BERNSTEIN-BEZIER BASED SMOOTHNESS CONDITIONS FOR pp functionS
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New smooth gap function for box constrained variational inequalities
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作者 张丽丽 李兴斯 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2013年第1期15-26,共12页
A new smooth gap function for the box constrained variational inequality problem (VIP) is proposed based on an integral global optimality condition. The smooth gap function is simple and has some good differentiable... A new smooth gap function for the box constrained variational inequality problem (VIP) is proposed based on an integral global optimality condition. The smooth gap function is simple and has some good differentiable properties. The box constrained VIP can be reformulated as a differentiable optimization problem by the proposed smooth gap function. The conditions, under which any stationary point of the optimization problem is the solution to the box constrained VIP, are discussed. A simple frictional contact problem is analyzed to show the applications of the smooth gap function. Finally, the numerical experiments confirm the good theoretical properties of the method. 展开更多
关键词 box constrained variational inequality problem (VIP) smooth gap function integral global optimality condition
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Approximate derivative-dependent functional variable separation for quasi-linear diffusion equations with a weak source
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作者 吉飞宇 杨春晓 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第10期67-72,共6页
By using the approximate derivative-dependent functional variable separation approach, we study the quasi-linear diffusion equations with a weak source ut = (A(u)Ux)x + eB(u, Ux). A complete classification of t... By using the approximate derivative-dependent functional variable separation approach, we study the quasi-linear diffusion equations with a weak source ut = (A(u)Ux)x + eB(u, Ux). A complete classification of these perturbed equations which admit approximate derivative-dependent functional separable solutions is listed. As a consequence, some approxi- mate solutions to the resulting perturbed equations are constructed via examples. 展开更多
关键词 quasi-linear diffusion equation approximate derivative-dependent functional separable solution approximate generalized conditional symmetry
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APPROXIMATION RATES OF ERROR DISTRIBUTION OF DOUBLE KERNEL ESTIMATES OF CONDITIONAL DENSITY
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作者 XueLiugen CaiGuoliang 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2000年第4期425-432,共8页
In this paper, the normal approximation rate and the random weighting approximation rate of error distribution of the kernel estimator of conditional density function f(y|x) are studied. The results may be used to... In this paper, the normal approximation rate and the random weighting approximation rate of error distribution of the kernel estimator of conditional density function f(y|x) are studied. The results may be used to construct the confidence interval of f(y|x) . 展开更多
关键词 conditional density function double kernel estimator random weighting method approximation rate.
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Joint probability distribution of winds and waves from wave simulation of 20 years (1989-2008) in Bohai Bay 被引量:9
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作者 Xiao-chen YANG Qing-he ZHANG 《Water Science and Engineering》 EI CAS CSCD 2013年第3期296-307,共12页
The joint probability distribution of wind speed and significant wave height in the Bohai Bay was investigated by comparing the Gurnbel logistic model, the Gumbel-Hougaard (GH) copula function, and the Clayton copul... The joint probability distribution of wind speed and significant wave height in the Bohai Bay was investigated by comparing the Gurnbel logistic model, the Gumbel-Hougaard (GH) copula function, and the Clayton copula function. Twenty years of wind data from 1989 to 2008 were collected from the European Centre for Medium-Range Weather Forecasts (ECMWF) database and the blended wind data of the Quick Scatterometer (QSCAT) satellite data set and re-analysis data from the United States National Centers for Environmental Prediction (NCEP). Several typhoons were taken into account and merged with the background wind fields from the ECMWF or QSCAT/NCEP database. The 20-year data of significant wave height were calculated with the unstructured-grid version of the third-generation wind wave model Simulating WAves Nearshore (SWAN) under extreme wind process conditions. The Gumbel distribution was used for univariate and marginal distributions. The distribution parameters were estimated with the method of L-moments. Based on the marginal distributions, the joint probability distributions, the associated return periods, and the conditional probability distributions were obtained. The GH copula function was found to be optimal according to the ordinary least squares (OLS) test. The results show that wind waves are the prevailing type of wave in the Bohai Bay. 展开更多
关键词 wind speed wave simulation joint probability distribution copula function conditional probability distribution
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SOLUTION OF DIFFERENT HOLES SHAPE BORDERS OF FIBRE REINFORCED COMPOSITE PLATES BY INTEGRAL EQUATIONS 被引量:3
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作者 LI Cheng ZHENG Yanping CHEN Zhongzhong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2007年第5期23-27,共5页
Accurate boundary conditions of composite material plates with different holes are founded to settle boundary condition problems of complex holes by conformal mapping method upon the nonhomogeneous anisotropic elastic... Accurate boundary conditions of composite material plates with different holes are founded to settle boundary condition problems of complex holes by conformal mapping method upon the nonhomogeneous anisotropic elastic and complex function theory. And then the two stress functions required were founded on Cauchy integral by boundary conditions. The final stress distributions of opening structure and the analytical solution on composite material plate with rectangle hole and wing manholes were achieved. The influences on hole-edge stress concentration factors are discussed under different loads and fiber direction cases, and then contrast calculates are carried through FEM. 展开更多
关键词 Fibre reinforced composite Accurate boundary conditions Mapping functions Complex hole shape Integral equations
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Estimated conditional score function for missing mechanism model with nonignorable nonresponse
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作者 CUI Xia ZHOU Yong 《Science China Mathematics》 SCIE CSCD 2017年第7期1197-1218,共22页
Missing data mechanism often depends on the values of the responses,which leads to nonignorable nonresponses.In such a situation,inference based on approaches that ignore the missing data mechanism could not be valid.... Missing data mechanism often depends on the values of the responses,which leads to nonignorable nonresponses.In such a situation,inference based on approaches that ignore the missing data mechanism could not be valid.A crucial step is to model the nature of missingness.We specify a parametric model for missingness mechanism,and then propose a conditional score function approach for estimation.This approach imputes the score function by taking the conditional expectation of the score function for the missing data given the available information.Inference procedure is then followed by replacing unknown terms with the related nonparametric estimators based on the observed data.The proposed score function does not suffer from the non-identifiability problem,and the proposed estimator is shown to be consistent and asymptotically normal.We also construct a confidence region for the parameter of interest using empirical likelihood method.Simulation studies demonstrate that the proposed inference procedure performs well in many settings.We apply the proposed method to a data set from research in a growth hormone and exercise intervention study. 展开更多
关键词 conditional score function empirical likelihood missing data nonignorabe nonresponse
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Conditional Log-Laplace Functional for a Class of Branching Processes in Random Environments
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作者 Hao WANG 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2015年第1期71-90,共20页
A conditional log-Laplace functional (CLLF) for a class of branching processes in random environments is derived. The basic idea is the decomposition of a dependent branching dynamic into a no-interacting branching ... A conditional log-Laplace functional (CLLF) for a class of branching processes in random environments is derived. The basic idea is the decomposition of a dependent branching dynamic into a no-interacting branching and an interacting dynamic generated by the random environments. CLLF will play an important role in the investigation of branching processes and superprocesses with interaction. 展开更多
关键词 Interacting superprocess conditional log-Laplace functional branching process in random environment Wong-Zakai approximation DUALITY
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Approximating Conditional Density Functions Using Dimension Reduction
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作者 Jian-qing Fan Liang Peng +1 位作者 Qi-wei Yao Wen-yang Zhang 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2009年第3期445-456,共12页
We propose to approximate the conditional density function of a random variable Y given a dependent random d-vector X by that of Y given θ^τX, where the unit vector θ is selected such that the average Kullback-Leib... We propose to approximate the conditional density function of a random variable Y given a dependent random d-vector X by that of Y given θ^τX, where the unit vector θ is selected such that the average Kullback-Leibler discrepancy distance between the two conditional density functions obtains the minimum. Our approach is nonparametric as far as the estimation of the conditional density functions is concerned. We have shown that this nonparametric estimator is asymptotically adaptive to the unknown index θ in the sense that the first order asymptotic mean squared error of the estimator is the same as that when θ was known. The proposed method is illustrated using both simulated and real-data examples. 展开更多
关键词 conditional density function dimension reduction Kullback-Leibler discrepancy local linear regression nonparametric regression Shannon's entropy
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Asymptotic properties of a nonparametric conditional density estimator in the local linear estimation for functional data via a functional single-index model
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作者 Fadila Benaissa Abdelmalek Gagui Abdelhak Chouaf 《Statistical Theory and Related Fields》 2022年第3期208-219,共12页
This paper deals with the conditional density estimator of a real response variable given a functional random variable(i.e.,takes values in an infinite-dimensional space).Specifically,we focus on the functional index ... This paper deals with the conditional density estimator of a real response variable given a functional random variable(i.e.,takes values in an infinite-dimensional space).Specifically,we focus on the functional index model,and this approach represents a good compromise between nonparametric and parametric models.Then we give under general conditions and when the variables are independent,the quadratic error and asymptotic normality of estimator by local linear method,based on the single-index structure.Finally,wecomplete these theoretical advances by some simulation studies showing both the practical result of the local linear method and the good behaviour for finite sample sizes of the estimator and of the Monte Carlo methods to create functional pseudo-confidence area. 展开更多
关键词 Mean squared error single functional index conditional density function nonparametric estimation local linear estimation asymptotic normality functional data
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Stokes flow before plane boundary with mixed stick-slip boundary conditions
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作者 N.AKHTAR G.A.H.CHOWDHURY S.K.SEN 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2011年第6期795-804,共10页
A general theorem for the Stokes flow over a plane boundary with mixed stick-slip boundary conditions is established. This is done by using a representation for the velocity and pressure fields in the three-dimensiona... A general theorem for the Stokes flow over a plane boundary with mixed stick-slip boundary conditions is established. This is done by using a representation for the velocity and pressure fields in the three-dimensional Stokes flow in terms of a biharmonic function and a harmonic function. The earlier theorem for the Stokes flow due to fundamental singularities before a no-slip plane boundary is shown to be a special case of the present theorem. Furthermore, in terms of the Stokes stream function, a corollary of the theorem is also derived, providing a solution to the problem of the axisymmetric Stokes flow along a rigid plane with stick-slip boundary conditions. The formulae for the drag and torque exerted by the fluid on the boundary are established. An illustrative example is given. 展开更多
关键词 Stokes flow Stokes stream function stick-slip boundary conditions harmonic function biharmonic function
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Likelihood Inference under Generalized Hybrid Censoring Scheme with Comp eting Risks
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作者 MAO Song SHI Yi-min 《Chinese Quarterly Journal of Mathematics》 2016年第2期178-188,共11页
Statistical inference is developed for the analysis of generalized type-Ⅱ hybrid censoring data under exponential competing risks model. In order to solve the problem that approximate methods make unsatisfactory perf... Statistical inference is developed for the analysis of generalized type-Ⅱ hybrid censoring data under exponential competing risks model. In order to solve the problem that approximate methods make unsatisfactory performances in the case of small sample size,we establish the exact conditional distributions of estimators for parameters by conditional moment generating function(CMGF). Furthermore, confidence intervals(CIs) are constructed by exact distributions, approximate distributions as well as bootstrap method respectively,and their performances are evaluated by Monte Carlo simulations. And finally, a real data set is analyzed to illustrate all the methods developed here. 展开更多
关键词 generalized type-Ⅱ hybrid scheme competing risks conditional moment generating function bootstrap method confidence intervals
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ASYMPTOTIC NORMALITY OF THE NONPARAMETRIC KERNEL ESTIMATION OF THE CONDITIONAL HAZARD FUNCTION FOR LEFT-TRUNCATED AND DEPENDENT DATA
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作者 Meijuan Ou Xianzhu Xiong Yi Wang 《Annals of Applied Mathematics》 2018年第4期395-406,共12页
Under some mild conditions, we derive the asymptotic normality of the Nadaraya-Watson and local linear estimators of the conditional hazard function for left-truncated and dependent data. The estimators were proposed ... Under some mild conditions, we derive the asymptotic normality of the Nadaraya-Watson and local linear estimators of the conditional hazard function for left-truncated and dependent data. The estimators were proposed by Liang and Ould-Sa?d [1]. The results confirm the guess in Liang and Ould-Sa?d [1]. 展开更多
关键词 asymptotic normality Nadaraya-Watson estimation local linear estimation conditional hazard function left-truncated data
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LOCAL POLYNOMIAL DOUBLE-SMOOTHING ESTIMATION OF A CONDITIONAL DISTRIBUTION FUNCTION WITH DEPENDENT
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作者 Mimi Hong Xianzhu Xiong 《Annals of Applied Mathematics》 2017年第4期364-378,共15页
Based on the idea of local polynomial double-smoother, we propose an estimator of a conditional cumulative distribution function with dependent and left-truncated data. It is assumed that the observations form a stati... Based on the idea of local polynomial double-smoother, we propose an estimator of a conditional cumulative distribution function with dependent and left-truncated data. It is assumed that the observations form a stationary a-mixing sequence. Asymptotic normality of the estimator is established. The finite sample behavior of the estimator is investigated via simulations. 展开更多
关键词 local polynomial double-smoother conditional cumulative distribution function left-truncated data a-mixing asymototic normality
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Existence and Uniqueness of Positive Solutions for Some Singular Boundary Value Problems with Linear Functional Boundary Conditions 被引量:2
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作者 Zeng Qin ZHAO Fu Shan LI 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2011年第10期2073-2084,共12页
By using the upper and lower solution method and fixed point theory, we investigate some nonlinear singular second-order differential equations with linear functional boundary conditions. The nonlinear term f(t, u) ... By using the upper and lower solution method and fixed point theory, we investigate some nonlinear singular second-order differential equations with linear functional boundary conditions. The nonlinear term f(t, u) is nonincreasing with respect to u, and only possesses some integrability. We obtain the existence and uniqueness of the C[0, 1] positive solutions as well as the C1 [0, 1] positive solutions. 展开更多
关键词 Linear functional boundary condition decreasing function positive solution upper and lower solution method fixed point theorem
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A necessary and sufficient condition for ternary majority functions being monotonic functions
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《Chinese Science Bulletin》 SCIE CAS 1998年第23期2018-2019,共2页
关键词 A necessary and sufficient condition for ternary majority functions being monotonic functions
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NECESSARY AND SUFFICIENT CONDITIONS FOR THE EXISTENCE OF LIAPUNOV FUNCTION OF LUR'E FORM WITH■≤0
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作者 仵永先 赵素霞 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 1990年第3期245-250,共6页
This paper is concerned with the problem of absolute stability for a control system with severalexecutive elements. Necessary and sufficient conditions are obtained for the existence of Liapunovfunction of Lur'e f... This paper is concerned with the problem of absolute stability for a control system with severalexecutive elements. Necessary and sufficient conditions are obtained for the existence of Liapunovfunction of Lur'e form with negative semi--definite derivative (i.e. V≤0). 展开更多
关键词 NECESSARY AND SUFFICIENT CONDITIONS FOR THE EXISTENCE OF LIAPUNOV function OF LUR’E FORM WITH
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