Results 31 to 40 of about 106,544 (192)
Role of funders in embedding tests in conservation practice
Abstract Effective conservation practice requires decisions based on reliable and relevant evidence, but significant gaps in the evidence base exist. Incorporating well‐designed tests of the effectiveness of interventions for biodiversity in conservation projects is one of the best ways to scale up the rate of evidence generation.
Rebecca K. Smith +28 more
wiley +1 more source
针对现有光伏功率预测系统存在预测误差大的问题,文中结合实际工程经验,提出一种基于历史数据纵向匹配的功率预测方法。通过对电站历史数据进行预处理,排除失真数据,以时间和气象预测数据为条件对历史数据进行纵向查询,纵向匹配出预测日的光辐射系数曲线、功率输出综合系数曲线,实现对未来几小时或几天的功率预测。仿真实验与电站实际应用表明:该方法预测误差小,简单实用,有实际推广意义。
贺衬心 +4 more
doaj
Fast intra-prediction algorithm in H. 264(H. 264快速帧内预测算法)
在新制定的H. 264视频编解码标准中,帧内预测是一项重要的技术.它利用周围像素预测当前块来降低空间冗余,能极大地提高H. 264的编码效率.然而,帧内预测的4×4及16×16预测分别有9种和4种模式.为选出最佳模式,全搜索算法需要花费极大的计算量.为了降低帧内预测的复杂度,提出了一种快速帧内预测算法.该算法针对全I帧编码,充分利用了时域、空域及不同块大小间的相关性来预测当前块的最佳模式,并结合提前中止算法来减少不必要的模式选择计算.实验结果表明:与全搜索相比,文中提出的算法能减少50%〜75 ...
YANGLi-bo(杨黎波) +2 more
doaj +1 more source
Uncovering correlates of decline and critical refuges for a threatened terrestrial mammal
Abstract Globally, the geographic ranges of numerous species are contracting. Identifying spatiotemporal patterns of threat impact can illuminate why species decline in some parts of their range but persist in others. We developed a correlative approach to identify species’ response thresholds and locate ecological refuge areas associated with ...
Natalya M. Maitz +5 more
wiley +1 more source
软件复杂度的增加,导致菜单项数的激增,从而导致菜单交互过程中视觉搜索时间的增加和认知负荷的加重.论文研究了基于绝对分部的马尔科夫链预测模型(ADMCP)和多阶叠加的马尔科夫链预测模型(SPMCP),在不同Top-N下,对下一个可能选取的菜单项进行预测的预测能力.实验结果表明,ADMCP适用于预测项数Top-N大于5时的菜单项预测,而PSMCP适用于Top-N小于等于5时的菜单项预测.
陈渝, 谢天添, 林涛, 琚生根
doaj
Scientists’ warning on the global destruction of rock outcrop ecosystems
Abstract Rock outcrops are geological formations that harbor a highly specialized biota adapted to harsh environmental conditions that differ from their surrounding landscapes. They are globally distributed, especially in old, highly weathered landscapes, and can function as habitat islands containing high levels of endemism and distinct evolutionary ...
Luiza F. A. de Paula +19 more
wiley +1 more source
采集了某一时段国内某著名网站上针对某一指定话题的帖子,按时间周期构造了一个关于新增帖子数量的时间序列,利用混沌时间序列预测方法中的加权零阶局域预测法预测了该序列的变化趋势.仿真结果表明该预测趋势与实际趋势在短期内是基本一致的;短期预测误差明显小于长期预测误差.
胡朝浪 +4 more
doaj
Abstract Ecological niche models (ENMs) are used to assess the abiotic preferences of species by linking their occurrences to the environmental conditions in which they live. We developed a fossil‐informed ENM framework that integrates mid‐Holocene and modern occurrences to test niche stability and reconstruct abiotic niche characteristics for four ...
Claire. M. Williams +3 more
wiley +1 more source
气体绝缘组合电器(gas insulated switchgear,GIS)设备局部放电存在安全隐患,不容忽视。文中采用特高频法研究GIS中典型局部放电过程,建立局部放电缺陷模型,进行大量试验获得数据。提取数据得到局部放电特征量,并采用局部放电特征谱图研究局部放电的特征。对特征量进行筛选、分类,选取不同类型特征量代入自回归移动平均模型中对GIS局部放电发展趋势的预测情况进行分析研究。结果表明:①对于局部放电线性参量,ARMA预测模型可以对其发展趋势进行准确预测,整体预测误差值均在10%以下 ...
何金 +7 more
doaj
在前面我们知道了为什么可能运用加卸载响应比方法做地震预测,加卸载响应比方法不仅有坚实的理论基础,而且为实验室试验、数值计算以及过去的震例检测所证实。那么,在实际运用中,它真的有效吗? 尹祥础课题组将它用于地震中期预测已经取得了较好的效果,他们成功地预测过一些国内的地震,还成功地预测过一些国外的地震(美国,日本,土耳其等)。下面来看一些用加卸载响应比LURR预报地震成功的实例。 中国大陆: 早在1980年代后期,尹祥础课题组就用加卸载响应比方法对中外逾百个震例,从有感地震的4级~8 ...
尚嘉兰
core

