Results 11 to 20 of about 17,053 (160)

Synthesizing Empirical Research on Learner Metacognition in Second Language Writing

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT Despite considerable research interest in learner metacognition in second language (L2) writing, there is not yet a review that synthesizes the existing empirical findings and discusses their implications. To fill the void, this systematic review synthesized 39 empirical studies on learner metacognition in L2 writing and examined their salient
Chen Li, Icy Lee, Zhicheng Mao
wiley   +1 more source

基于多特征融合的电压致热型设备故障检测 附视频

open access: yesDianci bileiqi, 2022
大部分的电压致热型设备由于温升不明显,故障判断难度较大,并且红外图像受到背景复杂,尺寸多的影响,导致红外图像特征提取困难,另外,大多数现有的检测工作依靠人工判别,且存在判断分歧。目前,代替人工判别的研究中,许多只利用单一的特征来表征热图像中的故障特征。针对此类问题,笔者提出一种基于多特征融合的电压致热型设备故障提取方法。此方法将红外图像多故障目标检测算法和多特征融合算法相结合,建立动态决策准则。首先提取红外图像的三种典型特征,包括颜色、纹理和轮廓特征,继而通过融合算法(串行融合、并行融合和DCA ...
doaj  

Research on Sand Dumping Detection of Harbor Dredging Based on Signal Enhancement and Feature Extraction [PDF]

open access: yes, 2016
随着海洋经济发展,各国对港区建设和航道维护愈加重视。但是,在利益驱使下,疏浚驳船常常在非指定区倾倒泥沙,导致航道内泥沙淤积甚至断航,航道维护成本增加和生态坏境破坏。目前,国内普遍采用安装摄像头、吃水线检测等监控方法,但易受人为破坏和环境因素的影响无法获得好的效果。国外采用更改倾倒区和自然处理的手段并不适用于我国流域众多的国情。因此,航道管理部门急需一种非接触式、稳定可靠的监控手段,以保证疏浚工程作业的质量。 本文根据混浊海水声吸收的原理,周期性地发送和接收Chirp探测信号 ...
钟张婷
core  

Partisans' evaluations of unconstitutional legislative activity

open access: yesPolicy Studies Journal, EarlyView.
Abstract In this research note, we examine whether public evaluations of a policy depend on the constitutionality of the process by which that policy was passed. We observe whether people's views depend on accusations that a policy was passed in violation of a state constitution's single subject rule, and whether the effect of that accusation depends ...
Kevin K. Banda   +2 more
wiley   +1 more source

Dolphins whistle contour automatic extraction and recovery [PDF]

open access: yes, 2015
海豚是一种高智商的水生哺乳动物,它们使用自己独特的“语言”——哨声来进行互相交流。要想理解海豚的语言,就必须要对海豚哨声进行分析研究。当前对海豚哨声的分析研究大多是基于哨声语谱图进行的,但语谱图中哨声轮廓与背景噪声混合在一起,不仅导致目前对哨声的分割、提取等预处理都是用人工方式进行,同时也给后续的实验造增加了难度。如果对语谱图中的哨声轮廓进行去噪、特征提取和修复等自动化预处理,就能实时进行海豚哨声与背景噪声的分离,获得一个完整的海豚哨声轮廓。这不仅节约了人工提取花费的时间,也有利于海豚哨声的个体识别 ...
吴道曦
core  

Inversion of Net Photosynthetic Rate in Winter Rapeseed Based on UAV Multispectral Vegetation Indices and Texture Features

open access: yesFood and Energy Security, Volume 15, Issue 2, March/April 2026.
ABSTRACT Net photosynthetic rate (Pn) serves as a key indicator for evaluating plant growth and yield. In order to explore an effective method for monitoring winter rapeseed Pn using unmanned aerial vehicle (UAV) multispectral technology, the winter rapeseed was taken as the research object and the multispectral images were obtained through UAVs in ...
ChengYang Ni   +7 more
wiley   +1 more source

Design and Implementation of Face Recognition System Based on OpenCV and JavaCV [PDF]

open access: yes, 2016
随着计算机和互联网的不断发展,在人工智能领域思想理论取得了一系列的发展,作为人工智能领域中发展较为突出的人脸识别技术取得了较为快速的发展。随着国家经济急速的发展,在社会各个领域对人脸识别技术的要求不断增加。人脸识别技术应用领域广泛,可以毫不夸张的说几乎可以覆盖整个社会的各个方面。上至国家信息安全,下到民生建设都有广泛的应用领域。现如今的生活中主要使用输入密码、插卡、获取口令等方式来保护个人信息和财产安全,这些传统的方法具有安全性低、易忘、易丢等缺点。随着技术的发展这些传统验证方式受到新技术的挑战 ...
江桥
core  

Orthogonal Stimulus‐Responsive Ca3Ga2Ge3O12: Pr3+ for Real‐Time X‐Ray Dosimetry and Dynamic Information Encryption

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT Multimodal luminescent materials are crucial for advanced information encryption, real‐time dosimetry, and high‐resolution bioimaging, yet integrating orthogonal stimulus‐responsiveness into a single‐component system is challenging. Herein, we report a Pr3+‐doped Ca3Ga2Ge3O12 (CGGO: Pr3+) garnet phosphor that exhibits orthogonally addressable ...
Qi Chen   +10 more
wiley   +1 more source

基于面向对象和无人机影像的黄土高原丘陵区小流域梯田提取研究

open access: yesShuitu Baochi Xuebao, 2023
精确提取梯田对于水土保持动态监测和评价非常必要,建立黄土高原小流域梯田提取技术流程可为水土流失防治提供技术支持。以甘肃省天水市水土保持科学试验站坚家山小流域为研究区域,采用无人机影像数据,基于尺度参数评估工具以影像的纹理特征为输入层,确定最优分割尺度参数;选用光谱特征和可见光植被指数为分类特征,使用面向对象分类方法对梯田进行提取。结果表明:(1)以局部方差变化率101作为多尺度分割的尺度参数时,梯田边界明显,光谱、纹理和形状特征对于描绘梯田边界具有巨大的潜力;(2)采用可见光植被指数植被颜色指数 ...
张艳超   +3 more
doaj  

Classification of Gene Expression Data Based on Dimension Reduction [PDF]

open access: yes, 2015
利用基因芯片技术能够做到同时对多到数以万计的基因进行并行分析,随着该技术越来越成熟并得到广泛应用,现在已经有越来越多的基因表达数据测定出来,亟需处理,借助于计算机工具以及机器学习方法对这些大量数据进行分析是现在一个很重要的研究领域。其中,基因表达数据的分类研究是该领域的一个热点,通过分类能够帮助研究者发现正常细胞组织与疾病组织之间基因的本质差异,识别致病基因,对基因型疾病的临床诊断和治疗具有重要的意义。 基因表达数据具有“样本少、维数高、分布不平衡”的特点,这给分类带来了很多的困难和挑战 ...
李亮亮
core  

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