Results 31 to 40 of about 17,053 (160)

High nitrogen enrichment buffers plant photosynthesis against herbivory damage

open access: yesFunctional Ecology, Volume 40, Issue 1, Page 229-238, January 2026.
Read the free Plain Language Summary for this article on the Journal blog. Abstract Herbivorous insects and nitrogen deposition are key drivers of ecosystem productivity under global change. However, their combined effects on plant photosynthesis, particularly during insect outbreaks, remain poorly understood in natural ecosystems.
Yongqiang Zhang   +6 more
wiley   +1 more source

基于Gammatone滤波器组的齿轮系统侧隙诱发冲击特征提取

open access: yesJixie chuandong, 2015
齿侧间隙会引发齿间啮合冲击,影响齿轮传动的平稳性和可靠性。为了对故障冲击成分进行提取,提出了基于Gammatone滤波器组的特征提取方法。该方法借鉴听觉系统复杂语音信号识别过程中耳蜗基底膜的信号处理思想,采用与基底膜冲击响应、幅频特性相似的Gammatone滤波器组模型对齿轮系统故障信号进行时频分析,进而提取冲击特征。研究结果表明:Gammatone滤波器组具有对齿轮系统的非平稳瞬变振动信号进行时频分析的功能,该方法能够有效提取由于齿侧间隙引起的啮合冲击故障特征。
高洪波, 李允公, 于良会, 刘杰
doaj   +1 more source

高压断路器分合闸线圈电流信号特征提取与故障判别方法研究

open access: yesGaoya dianqi, 2015
高压断路器分合闸线圈电流信号特征提取在故障识别、检测及诊断方面都有重要的意义。文中提出采用小波分析与时域求极值点相结合的方法来获取高压断路器分合闸线圈电流信号特征值,并根据该特征值对断路器的故障判别方法做了探索性研究。实验结果表明,电流信号特征值提取方法是有效的,故障识别方法正确。
孙银山   +4 more
doaj  

Design and Implementation of Piano Playing Automatic Scoring System Based on BP Algorithm [PDF]

open access: yes, 2015
随着人们物质生活水平的不断提高,人们对精神生活的质量要求越来越高,钢琴学习也受到越来越多人的追捧。采用计算机技术对钢琴演奏技术进行自动评价,可以减轻钢琴学习负担,提高钢琴学习效果。 钢琴音乐的评价特征因素众多,评价方法模糊。根据钢琴音乐和计算机处理的特点,以及钢琴乐音自动评价的需求,选取短时平均幅度、短时平均过零率和短时平均幅度差三个钢琴乐音特征来对钢琴音乐进行评价。基于BP算法信息处理能力强,不确定性信息处理能力强等特点,采用BP算法来实现对钢琴音乐的自动评价 ...
吴蔚
core  

The Role of Uncertainty in the Policy Process: An Extension to the Multiple Streams Framework

open access: yesReview of Policy Research, Volume 43, Issue 1, January 2026.
ABSTRACT A core assumption of the Multiple Streams Framework proposes that agenda and policy change is more probable when a policy proposal worked out as a viable alternative in the policy stream is coupled with the political and/or problem stream in an open policy window.
Sebastian Hemesath, Georg Wenzelburger
wiley   +1 more source

基于振声时三维图的高压断路器机械故障诊断方法

open access: yesGaoya dianqi, 2014
分析高压断路器机械振动信号和声波信号的特性,针对现有诊断方法的不足,笔者提出了一种基于振声时三维图的高压断路器机械故障诊断方法,并给出了可行的诊断步骤和分析。此方法首先利用分级多时标信号对准的方法构建振声时三维图,然后提取断路器振声时三维图的包络,最后采用基于形状的分级特征向量提取方法构建支持向量机的输入向量进行故障诊断。其中,一级特征提取振声时三维图包络六面八角的特征向量,二级特征提取振声时三维图二维投影的区域弦的分布特征。实验结果表明,该方法诊断高压断路器机械故障能取得良好的效果。
张佩, 周秀萍
doaj  

3D reconstruction of train accident scene based on monocular image [PDF]

open access: yes, 2017
To help with making an emergency rescue plan for train accidents, a rapid 3D reconstruction method of train accident scene based on a monocular image was proposed.
Chang, J.   +4 more
core  

Role of forest edges and other seminatural linear landscape features in structuring wild bee habitat connectivity in intensively managed landscapes

open access: yesConservation Biology, Volume 39, Issue 6, December 2025.
Abstract Pollinator conservation schemes typically focus on conserving existing, restoring degraded, or creating new wild bee habitats. Their effectiveness depends on dispersal corridors enabling habitat colonization by bees. However, the role of seminatural linear landscape structures (LLS) in connecting pollinator communities across intensively ...
Markus A. K. Sydenham   +6 more
wiley   +1 more source

基于生成对抗网络的多特征融合去雾技术

open access: yes大数据
为提高图像清晰度,解决传统图像在去雾过程中存在的特征提取困难、去雾不彻底等问题,提出一种基于生成对抗网络的多特征融合端到端去雾网络。该网络由生成器和判别器组成,生成器采用编解码结构,通过多特征提取融合(MFEF)块提取多种感受野下的高维表征信息。判别器使用一系列卷积计算对生成图像和清晰图像进行特征差异分析,引导生成器输出更加真实的去雾图像。实验结果表明,该算法在有效消除雾霾干扰的同时,能够最大限度地保留图像的原始色调。与现有方法相比,该算法在峰值信噪比、结构相似性客观评价指标上分别提升了2.588 dB、
司亚中, 张旭龙, 杨帆, 王健宗, 程宁, 肖京
doaj   +1 more source

Design and Implementation of License Plate Localization System Based on Adaboost [PDF]

open access: yes, 2016
摘要 论文论述了车牌定位系统设计与实现的方法和过程,车牌定位是车牌识别系统中车牌定位、车牌分割、车牌号码识别三部分的第一个部分,好坏直接关系到整个系统识别率的高低,并且对识别速度有很大影响。 本文在理论研究上主要包括特征提取、算法选择、算法改进三个方面。在充分研究和理解Haar特征的基础上,提出了“回字形特征”和“非对称线性特征”两种类Haar特征。设计过程中选取四种原有Haar特征及本文提出的两种类Haar特征的六种特征为特征模版,以及对窗口大小和移动步长的优化选取生成了5571个特征 ...
屠楚楠
core  

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