您选择的条件: 2019-04-22
  • Strengthened change point detection model for weak mean difference data

    分类: 统计学 >> 应用统计数学 提交时间: 2019-04-22

    摘要: Objective: The lifetime difference in adjacent parallel structure components becomes small as the number of components belonging to the same parallel structure increases. To infer the system structure, we must clarify the components that belong to the same parallel structure. Methods: A strengthened change point detection model (SCPDM) for weak mean difference data (WMDD) is established, which usually indicates that, as affected by a large variance, the mean difference in two subsignals for one data sequence becomes nonsignificant. For repeatedly retrievable WMDD, we performed two enhanced operations that doubled the mean difference by using the variance information and analyzed the asymptotic properties of the enhanced data. Then, we proposed an SCPDM based on the asymptotic results.Results: Finally, we compared the SCPDM with two other main change point detection models and verified that the SCPDM is superior to other models using WMDD change point detection by the simulation method.Limitations: This paper also have several limitations. First, we only discussed that are independent with normal distribution and single change point. Second, the reason why the relationship between and has an important influence on the accuracy of change point detection is not discussed in depth. We only defined the ratio boundary of WMDD by experience and simulation. Conclusions: Traditional change point detection models may become insensitive or ineffective for WMDD. We gave some asymptotic analysis and established a enhanced change point detection model (SCPDM) based on the asymptotic results. Compared with the traditional method, SCPDM can effectively detect the change point.

  • 对人类不良记忆的修饰:来自记忆再巩固的证据

    分类: 心理学 >> 生理心理学 提交时间: 2019-04-22

    摘要: 已经巩固的长时记忆被再次提取后,进入一个记忆的不稳定期,在此过程中,记忆可被更新,强化,削弱甚至抹除,这个过程称为再巩固。人类不良记忆再巩固研究揭示记忆激活后口服普萘洛尔 (propranolol) 或进行消退训练可削弱或抹除不良情绪记忆,此过程中涉及杏仁核、海马、前额叶皮层等脑区的参与及其构成的神经环路的调控。当前临床上利用再巩固原理可通过药物治疗、行为干预或无创脑部刺激的方法改变不良记忆。然而,由于其形成过程复杂并受多种因素影响,未来研究应尽可能模拟临床中人类不良记忆形成的复杂环境,深入探讨再巩固“边界问题”,推动实验室研究向临床应用的转化。