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
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
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
In order to avoid the discussion of equation (1.1), this paper employs the proof method of Liang (2012) to consider the re-weighted Nadaraya-Watson estimation of conditional density. The established results genera...In order to avoid the discussion of equation (1.1), this paper employs the proof method of Liang (2012) to consider the re-weighted Nadaraya-Watson estimation of conditional density. The established results generalize those of De Gooijer and Zerom (2003). In addition, this paper improves the bandwidth condition of Liang (2012).展开更多
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
A novel method is proposed to obtain the power spectra of hidden variables in a chaotic time series. By embedding the data in phase space , and recording the conditional probability density of points that the trajecto...A novel method is proposed to obtain the power spectra of hidden variables in a chaotic time series. By embedding the data in phase space , and recording the conditional probability density of points that the trajectory encounters as it evolves in the reconstructed phase space, it is possible to recover the power spectra of hidden variables in chaotic time series through a spectral analysis over the conditional probability density time series. The method is robust in the application to Lorenz system, 4 dimension Rssler system and rigid body motion by linear feedback system (LFRBM). Applying the method to the time series of sea surface temperature (SST) of the South China Sea, we obtained the power spectra of the wind speed (WS) from SST data. Furthermore, the results showed that there exists an important nonlinear interaction between the SST and the WS.展开更多
Based on the daily reanalysis data of NCEP / NCAR and by using the method of phase space reconstruction, the point conditional probability density of the subtropical high ridge index are determined and then used, toge...Based on the daily reanalysis data of NCEP / NCAR and by using the method of phase space reconstruction, the point conditional probability density of the subtropical high ridge index are determined and then used, together with their power spectra, to seek the correlation between them and individual monsoon-affecting factors and their power spectra. Through diagnosis, six indexes are discovered that have the most important effects on the subtropical high index. The results of the diagnosis indicate that the technique can identify the factors which are dynamically correlated. It can offer the basis in determining and choosing dynamic conceptual factors.展开更多
Let S be a periodic set in R and L2(S) be a subspace of L2(R). This paper investigates the density problem for multiwindow Gabor systems in L2(S) for the case that the product of time- frequency shift parameters...Let S be a periodic set in R and L2(S) be a subspace of L2(R). This paper investigates the density problem for multiwindow Gabor systems in L2(S) for the case that the product of time- frequency shift parameters is a rational number. We derive the density conditions for a multiwindow Gabor system to be complete (a frame) in L2(S). Under such conditions, we construct a multiwindow tight Gabor frame for L2 (S) with window functions being characteristic functions. We also provide a characterization of a multiwindow Gabor frame to be a Riesz basis for L2(S), and obtain the density condition for a multiwindow Gabor Riesz basis for L2 (S).展开更多
In this paper,the authors first introduce the tree-indexed Markov chains in random environment,which takes values on a general state space.Then,they prove the existence of this stochastic process,and develop a class o...In this paper,the authors first introduce the tree-indexed Markov chains in random environment,which takes values on a general state space.Then,they prove the existence of this stochastic process,and develop a class of its equivalent forms.Based on this property,some strong limit theorems including conditional entropy density are studied for the tree-indexed Markov chains in random environment.展开更多
A new method is proposed to inverse normalization data of hidden variables in a dynamical system by embedding a time series in multidimensional spaces and applying a normalization analysis to the conditional probabili...A new method is proposed to inverse normalization data of hidden variables in a dynamical system by embedding a time series in multidimensional spaces and applying a normalization analysis to the conditional probability density of points in the reconstructed phase spaces. The method is robust in the application to Lorenz system and 4-dimensional R?ssler system by testing quantitatively and qualitatively the correlation coefficient between inverse data and original data in time domain and in frequency domain, respectively. By applying the method to analyzing the South China Sea data, the normalization data of wind speed is extracted from the sea surface temperatu-re time series.展开更多
Statistical models using stochastic differential equations (SDEs) to describe dynamically evolving natural systems are appearing in the scientific literature with some regularity in recent years. In this study, the ...Statistical models using stochastic differential equations (SDEs) to describe dynamically evolving natural systems are appearing in the scientific literature with some regularity in recent years. In this study, the SDE mixed-effects parameter models based on a Vasicek non-homogeneous diffusion process are formulated. The breast height diameter- dependent drift function additionally depends on deterministic function that describes the dynamic of certain exogenous stand variables (crown height, eh, crown width Cw, mean breast height diameter, do, mean height, ho, age, A, soil fertility index SFI, stocking level, S) versus breast height diameter. The mixed-effects parameters SDE models included a random parameter that affected the models asymptote. The parameter estimators are evaluated by maximum likelihood procedure. The objective of the research was to develop a generalized mixed-effects parameters SDE heightdiameter models and to illustrate issues using dataset of Scots pine trees (Pinus sylvestris L.) in Lithuania with the breast height diameter outside the bark larger than 0cm. The parameters of all used models were estimated using an estimation dataset and were evaluated using a validation dataset. The new developed height diameter models are an improvement over exogenous stand variables, in that it can be calibrated to a new stand with observed height-diameter pairs, thus improving height prediction.展开更多
基金Supported by Natural Science Foundation of Beijing City and National Natural Science Foundation ofChina(2 2 30 4 1 0 0 1 30 1
文摘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) .
基金supported by US National Science Foundation grant DMS-0704337 National Natural Science Foundation of China(No.10628104)supported by an EPSRC research grant EP/C549058/1
文摘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.
文摘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.
基金supported by National Natural Science Foundation of China(No.11301084)Natural Science Foundation of Fujian Province(No.2014J01010)
文摘In order to avoid the discussion of equation (1.1), this paper employs the proof method of Liang (2012) to consider the re-weighted Nadaraya-Watson estimation of conditional density. The established results generalize those of De Gooijer and Zerom (2003). In addition, this paper improves the bandwidth condition of Liang (2012).
基金supported by the National Natural Science Foundation of China (Grant No.60773081)the Key Project of Shanghai Municipality (Grant No.S30104)
文摘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.
文摘A novel method is proposed to obtain the power spectra of hidden variables in a chaotic time series. By embedding the data in phase space , and recording the conditional probability density of points that the trajectory encounters as it evolves in the reconstructed phase space, it is possible to recover the power spectra of hidden variables in chaotic time series through a spectral analysis over the conditional probability density time series. The method is robust in the application to Lorenz system, 4 dimension Rssler system and rigid body motion by linear feedback system (LFRBM). Applying the method to the time series of sea surface temperature (SST) of the South China Sea, we obtained the power spectra of the wind speed (WS) from SST data. Furthermore, the results showed that there exists an important nonlinear interaction between the SST and the WS.
基金Research Foundation for Tropical and Marine Meteorology (200609)Natural Science Foundation of China (40375019)Key and Open Laboratory on Tropical Monsoon, China Meteorological Administration
文摘Based on the daily reanalysis data of NCEP / NCAR and by using the method of phase space reconstruction, the point conditional probability density of the subtropical high ridge index are determined and then used, together with their power spectra, to seek the correlation between them and individual monsoon-affecting factors and their power spectra. Through diagnosis, six indexes are discovered that have the most important effects on the subtropical high index. The results of the diagnosis indicate that the technique can identify the factors which are dynamically correlated. It can offer the basis in determining and choosing dynamic conceptual factors.
基金Supported by National Natural Science Foundation of China(Grant Nos.10901013and11271037)Beijing Natural Science Foundation(Grant No.1122008)Fundamental Research Funds for the Central Universities(Grant No.2011JBM299)
文摘Let S be a periodic set in R and L2(S) be a subspace of L2(R). This paper investigates the density problem for multiwindow Gabor systems in L2(S) for the case that the product of time- frequency shift parameters is a rational number. We derive the density conditions for a multiwindow Gabor system to be complete (a frame) in L2(S). Under such conditions, we construct a multiwindow tight Gabor frame for L2 (S) with window functions being characteristic functions. We also provide a characterization of a multiwindow Gabor frame to be a Riesz basis for L2(S), and obtain the density condition for a multiwindow Gabor Riesz basis for L2 (S).
基金supported by the National Natural Science Foundation of China(Nos.11571142,11971197,11601191)。
文摘In this paper,the authors first introduce the tree-indexed Markov chains in random environment,which takes values on a general state space.Then,they prove the existence of this stochastic process,and develop a class of its equivalent forms.Based on this property,some strong limit theorems including conditional entropy density are studied for the tree-indexed Markov chains in random environment.
基金the National Natural Science Foundation of China (Grant No.49476254).
文摘A new method is proposed to inverse normalization data of hidden variables in a dynamical system by embedding a time series in multidimensional spaces and applying a normalization analysis to the conditional probability density of points in the reconstructed phase spaces. The method is robust in the application to Lorenz system and 4-dimensional R?ssler system by testing quantitatively and qualitatively the correlation coefficient between inverse data and original data in time domain and in frequency domain, respectively. By applying the method to analyzing the South China Sea data, the normalization data of wind speed is extracted from the sea surface temperatu-re time series.
文摘Statistical models using stochastic differential equations (SDEs) to describe dynamically evolving natural systems are appearing in the scientific literature with some regularity in recent years. In this study, the SDE mixed-effects parameter models based on a Vasicek non-homogeneous diffusion process are formulated. The breast height diameter- dependent drift function additionally depends on deterministic function that describes the dynamic of certain exogenous stand variables (crown height, eh, crown width Cw, mean breast height diameter, do, mean height, ho, age, A, soil fertility index SFI, stocking level, S) versus breast height diameter. The mixed-effects parameters SDE models included a random parameter that affected the models asymptote. The parameter estimators are evaluated by maximum likelihood procedure. The objective of the research was to develop a generalized mixed-effects parameters SDE heightdiameter models and to illustrate issues using dataset of Scots pine trees (Pinus sylvestris L.) in Lithuania with the breast height diameter outside the bark larger than 0cm. The parameters of all used models were estimated using an estimation dataset and were evaluated using a validation dataset. The new developed height diameter models are an improvement over exogenous stand variables, in that it can be calibrated to a new stand with observed height-diameter pairs, thus improving height prediction.