The scientists are dedicated to studying the detection of Alzheimer’s disease onset to find a cure, or at the very least, medication that can slow the progression of the disease. This article explores the effectivene...The scientists are dedicated to studying the detection of Alzheimer’s disease onset to find a cure, or at the very least, medication that can slow the progression of the disease. This article explores the effectiveness of longitudinal data analysis, artificial intelligence, and machine learning approaches based on magnetic resonance imaging and positron emission tomography neuroimaging modalities for progression estimation and the detection of Alzheimer’s disease onset. The significance of feature extraction in highly complex neuroimaging data, identification of vulnerable brain regions, and the determination of the threshold values for plaques, tangles, and neurodegeneration of these regions will extensively be evaluated. Developing automated methods to improve the aforementioned research areas would enable specialists to determine the progression of the disease and find the link between the biomarkers and more accurate detection of Alzheimer’s disease onset.展开更多
音符起始点是音乐特征信息中最基础的特征,也是高级音乐分析任务(如基频估计、节奏分析、节拍跟踪等)的前提.然而,目前大多数音符起始点检测算法的研究对象多以西洋乐(如钢琴、小提琴等)或人声为主,针对中国民乐的研究极为匮乏,其主要...音符起始点是音乐特征信息中最基础的特征,也是高级音乐分析任务(如基频估计、节奏分析、节拍跟踪等)的前提.然而,目前大多数音符起始点检测算法的研究对象多以西洋乐(如钢琴、小提琴等)或人声为主,针对中国民乐的研究极为匮乏,其主要原因是缺少高质量的带标注的数据集.为此,本文采集了古筝的部分考级曲目的音频,并在专家指导下对音符起始点加以标注,率先构建了一个带标签的包含3529条记录的古筝音符起始点数据集.此外,由于传统的神经网络特征预处理方法无法凸显古筝音符的起始点特征,本文提出了一种新型的特征平滑处理方法ELES(Extremum filtering based envelope smoothing),对训练数据的均值和标准差进行平滑处理,再经过标准化方法强化起始点特征,随后送入卷积神经网络进行训练.实验证明本文方法的准确性优于传统的基于音频信号处理的方法,并能够有效地检测出古筝的特殊技法和连续十六分音符的起始点.展开更多
The frequent and rapid onset of flash drought poses a serious threat to agriculture and ecosystems.Detecting human influences on flash droughts and estimating their future risks under climate change have attracted gre...The frequent and rapid onset of flash drought poses a serious threat to agriculture and ecosystems.Detecting human influences on flash droughts and estimating their future risks under climate change have attracted great attention.Focusing on a record-breaking flash drought event in the southeastern coastal region of China in summer 2020,the authors found that the suppression of convective precipitation and high temperature caused by the persistent high geopotential height anomalies and land-atmosphere dry coupling were important reasons for the rapid onset and strong intensity of the flash drought.Event attribution analysis with the latest CMIP6 data showed that anthropogenic climate change has not only increased the likelihood of an onset speed and intensity like those of the 2020 flash drought event,by about 93%±20%and 18%±15%,respectively,but also increased the chance of their simultaneous occurrence,by about 86%±38%,according to their joint probability distribution.Under a business-as-usual future scenario(SSP2-4.5),the likelihood of such an onset speed,intensity,and their simultaneous occurrence will further increase,by 85%±33%,49%±8%,and 81%±48%,respectively,as compared with current climate conditions.This study highlights the importance of anthropogenic climate change for accelerating and intensifying flash drought in the southeastern coastal region of China.展开更多
疑似预防接种异常反应(Adverse event following immunization,AEFI)被动监测是疫苗安全性评估的重要途径之一,通常采用传统的AEFI发生率比较或比例失衡分析方法检测可疑的疫苗安全性信号。近年来,基于反应发生时间间隔(Time-to-onset,T...疑似预防接种异常反应(Adverse event following immunization,AEFI)被动监测是疫苗安全性评估的重要途径之一,通常采用传统的AEFI发生率比较或比例失衡分析方法检测可疑的疫苗安全性信号。近年来,基于反应发生时间间隔(Time-to-onset,TTO)的检测方法应用于AEFI信号检测,且具有一定的优势和良好的检测能力。本文介绍了TTO间隔检测方法的原理、步骤和在AEFI信号检测中的应用,为中国疫苗上市后安全性评估提供参考。展开更多
文摘The scientists are dedicated to studying the detection of Alzheimer’s disease onset to find a cure, or at the very least, medication that can slow the progression of the disease. This article explores the effectiveness of longitudinal data analysis, artificial intelligence, and machine learning approaches based on magnetic resonance imaging and positron emission tomography neuroimaging modalities for progression estimation and the detection of Alzheimer’s disease onset. The significance of feature extraction in highly complex neuroimaging data, identification of vulnerable brain regions, and the determination of the threshold values for plaques, tangles, and neurodegeneration of these regions will extensively be evaluated. Developing automated methods to improve the aforementioned research areas would enable specialists to determine the progression of the disease and find the link between the biomarkers and more accurate detection of Alzheimer’s disease onset.
文摘音符起始点是音乐特征信息中最基础的特征,也是高级音乐分析任务(如基频估计、节奏分析、节拍跟踪等)的前提.然而,目前大多数音符起始点检测算法的研究对象多以西洋乐(如钢琴、小提琴等)或人声为主,针对中国民乐的研究极为匮乏,其主要原因是缺少高质量的带标注的数据集.为此,本文采集了古筝的部分考级曲目的音频,并在专家指导下对音符起始点加以标注,率先构建了一个带标签的包含3529条记录的古筝音符起始点数据集.此外,由于传统的神经网络特征预处理方法无法凸显古筝音符的起始点特征,本文提出了一种新型的特征平滑处理方法ELES(Extremum filtering based envelope smoothing),对训练数据的均值和标准差进行平滑处理,再经过标准化方法强化起始点特征,随后送入卷积神经网络进行训练.实验证明本文方法的准确性优于传统的基于音频信号处理的方法,并能够有效地检测出古筝的特殊技法和连续十六分音符的起始点.
基金supported by the National Natural Science Foundation of China[grant number 41875105]the National Key R&D Program of China[grant number 2018YFA0606002]the Natural Science Foundation of Jiangsu Province for Distinguished Young Scholars[grant number BK20211540]。
文摘The frequent and rapid onset of flash drought poses a serious threat to agriculture and ecosystems.Detecting human influences on flash droughts and estimating their future risks under climate change have attracted great attention.Focusing on a record-breaking flash drought event in the southeastern coastal region of China in summer 2020,the authors found that the suppression of convective precipitation and high temperature caused by the persistent high geopotential height anomalies and land-atmosphere dry coupling were important reasons for the rapid onset and strong intensity of the flash drought.Event attribution analysis with the latest CMIP6 data showed that anthropogenic climate change has not only increased the likelihood of an onset speed and intensity like those of the 2020 flash drought event,by about 93%±20%and 18%±15%,respectively,but also increased the chance of their simultaneous occurrence,by about 86%±38%,according to their joint probability distribution.Under a business-as-usual future scenario(SSP2-4.5),the likelihood of such an onset speed,intensity,and their simultaneous occurrence will further increase,by 85%±33%,49%±8%,and 81%±48%,respectively,as compared with current climate conditions.This study highlights the importance of anthropogenic climate change for accelerating and intensifying flash drought in the southeastern coastal region of China.
文摘疑似预防接种异常反应(Adverse event following immunization,AEFI)被动监测是疫苗安全性评估的重要途径之一,通常采用传统的AEFI发生率比较或比例失衡分析方法检测可疑的疫苗安全性信号。近年来,基于反应发生时间间隔(Time-to-onset,TTO)的检测方法应用于AEFI信号检测,且具有一定的优势和良好的检测能力。本文介绍了TTO间隔检测方法的原理、步骤和在AEFI信号检测中的应用,为中国疫苗上市后安全性评估提供参考。
