In this paper, we employ the bifurcation method of dynamical systems to study the solitary waves and periodic waves of a generalized Boussinesq equations. All possible phase portraits in the parameter plane for the tr...In this paper, we employ the bifurcation method of dynamical systems to study the solitary waves and periodic waves of a generalized Boussinesq equations. All possible phase portraits in the parameter plane for the travelling wave systems are obtained. The possible solitary wave solutions, periodic wave solutions and cusp waves for the general Boussinesq type fluid model are also investigated.展开更多
Event-related potentials (ERP) is an important type of brain dynamics in human cognition research. However, ERP is often submerged by the spontaneous brain activity EEG, for its relatively tiny scale. Further more, th...Event-related potentials (ERP) is an important type of brain dynamics in human cognition research. However, ERP is often submerged by the spontaneous brain activity EEG, for its relatively tiny scale. Further more, the brain activities collected from scalp electrodes are often inevitably contaminated by several kinds of artifacts, such as blinks, eye movements, muscle noise and power line interference. A new approach to correct these disturbances is presented using independent component analysis (ICA). This technique can effectively detect and extract ERP components from the measured electrodes recordings even if they are heavily contaminated. The results compare favorably to those obtained by parametric modeling. Besides, auto-adaptive projection of decomposed results to ERP components was also given. Through experiments, ICA proves to be highly capable of ERP extraction and S/N ratio improving.展开更多
This paper presents the results of a research study carried out with students of China University of Geosciences to analyze the influence of readers' cognitive styles (field dependent/field neutral/field independe...This paper presents the results of a research study carried out with students of China University of Geosciences to analyze the influence of readers' cognitive styles (field dependent/field neutral/field independent) and reading strategies on their reading performance, including the total reading score, global inference questions, factual and detail questions, main idea questions, lexical inference questions. Results show the correlations between cognitive style and most of the reading questions are not statistically significant, except for the total reading scores and performance of global inference question. One-way ANOVA shows that there is significant difference between the FN and FD group in total reading score and global inference question. However, when the reading strategies have been partialled out of the correlations between cognitive style and reading scores, the remaining correlation with the total reading score and global inference and lexical inference reaches significance. This indicates the different information processing of FD/FI learners and the important role of direct reading strategies for all learners. Teachers can help their students become more effective readers by encouraging them to apply direct reading strategies, and apply different indirect reading strategies based on their different cognitive styles.展开更多
Normal copula with a correlation coefficient between-1 and 1 is tail independent and so it severely underestimates extreme probabilities. By letting the correlation coefficient in a normal copula depend on the sample ...Normal copula with a correlation coefficient between-1 and 1 is tail independent and so it severely underestimates extreme probabilities. By letting the correlation coefficient in a normal copula depend on the sample size, H¨usler and Reiss(1989) showed that the tail can become asymptotically dependent. We extend this result by deriving the limit of the normalized maximum of n independent observations, where the i-th observation follows from a normal copula with its correlation coefficient being either a parametric or a nonparametric function of i/n. Furthermore, both parametric and nonparametric inference for this unknown function are studied, which can be employed to test the condition by H¨usler and Reiss(1989). A simulation study and real data analysis are presented too.展开更多
基金The project supported by National Natural Science Foundation of China under Grant No. 10401022
文摘In this paper, we employ the bifurcation method of dynamical systems to study the solitary waves and periodic waves of a generalized Boussinesq equations. All possible phase portraits in the parameter plane for the travelling wave systems are obtained. The possible solitary wave solutions, periodic wave solutions and cusp waves for the general Boussinesq type fluid model are also investigated.
文摘Event-related potentials (ERP) is an important type of brain dynamics in human cognition research. However, ERP is often submerged by the spontaneous brain activity EEG, for its relatively tiny scale. Further more, the brain activities collected from scalp electrodes are often inevitably contaminated by several kinds of artifacts, such as blinks, eye movements, muscle noise and power line interference. A new approach to correct these disturbances is presented using independent component analysis (ICA). This technique can effectively detect and extract ERP components from the measured electrodes recordings even if they are heavily contaminated. The results compare favorably to those obtained by parametric modeling. Besides, auto-adaptive projection of decomposed results to ERP components was also given. Through experiments, ICA proves to be highly capable of ERP extraction and S/N ratio improving.
文摘This paper presents the results of a research study carried out with students of China University of Geosciences to analyze the influence of readers' cognitive styles (field dependent/field neutral/field independent) and reading strategies on their reading performance, including the total reading score, global inference questions, factual and detail questions, main idea questions, lexical inference questions. Results show the correlations between cognitive style and most of the reading questions are not statistically significant, except for the total reading scores and performance of global inference question. One-way ANOVA shows that there is significant difference between the FN and FD group in total reading score and global inference question. However, when the reading strategies have been partialled out of the correlations between cognitive style and reading scores, the remaining correlation with the total reading score and global inference and lexical inference reaches significance. This indicates the different information processing of FD/FI learners and the important role of direct reading strategies for all learners. Teachers can help their students become more effective readers by encouraging them to apply direct reading strategies, and apply different indirect reading strategies based on their different cognitive styles.
基金supported by the Simons FoundationNational Natural Science Foundation of China(Grant No.11171275)the Natural Science Foundation Project of CQ(Grant No.cstc2012jj A00029)
文摘Normal copula with a correlation coefficient between-1 and 1 is tail independent and so it severely underestimates extreme probabilities. By letting the correlation coefficient in a normal copula depend on the sample size, H¨usler and Reiss(1989) showed that the tail can become asymptotically dependent. We extend this result by deriving the limit of the normalized maximum of n independent observations, where the i-th observation follows from a normal copula with its correlation coefficient being either a parametric or a nonparametric function of i/n. Furthermore, both parametric and nonparametric inference for this unknown function are studied, which can be employed to test the condition by H¨usler and Reiss(1989). A simulation study and real data analysis are presented too.
