Results 21 to 30 of about 9,359 (164)
Factors That Influenced Coping With COVID‐19 During the Pandemic in Botswana
ABSTRACT This paper forms part of the broader Global South study, Personal and Family Coping with COVID‐19 in the Global South, which examines psychosocial and behavioral responses to the COVID‐19 pandemic. In Sub‐Saharan Africa, the pandemic posed significant psychological, social, and economic challenges, with important implications for preparedness ...
Magen Mhaka‐Mutepfa +3 more
wiley +1 more source
ABSTRACT The National Quality Infrastructure (NQI) in a given country provides the essential framework for quality assurance integrating standardization, metrology, accreditation, and conformity assessment to create the technical backbone for industry and trade. Hence, building a resilient NQI is fundamental to securing medicine quality, enabling local
Addisu Afrassa Tegegne +3 more
wiley +1 more source
Research of Underwater Acoustic Communication Signal Modulation Recognition and Its Implementation [PDF]
随着海洋开发、海洋权益维护、国防安全等领域信息获取和处理需求的不断提升,对水声通信信号的调制样式的自动识别研究成为重要的研究课题。然而目前无线领域常用的通信信号(BPSK,QPSK,MFSK,OFDM)的调制识别方法往往需要较多的调制参数作为先验知识(如精确载波频率、初始相位、符号速率)。由于水声信道的随机时-空-频变、窄带高噪、多途效应及多普勒频移等特性,使得上述这些先验知识在水声信号调制方式未知的情况下很难得到,因此,非合作水声通信信号的自动识别极具挑战性。 信号频谱是对信号在频域方面的一种描述 ...
江伟华
core
Abstract Henry George advocated for capturing land value increases for public ends. The active approach of public authorities organizing and financing land development can help capture higher land value increases, as Hartman and Spit indicate. However, this approach hardly happens in developing countries, where the coalition of private developers and ...
Nannan Xu
wiley +1 more source
针对支持向量机中参数选择严重影响分类效果的特点,提出采用差分进化算法对核函数g和惩罚因子c进行优化,得到最优的支持向量机模型,用于变压器的故障诊断。在简单介绍支持向量机的基础上,分析了采用差分进化算法对支持向量机优化的可行性。通过将收集的数据样本进行预处理,再利用差分进化的变异、交叉和选择对高斯径向基核函数进行优化,搜索出最优(c,g),并对得到的参数进行验证,获得最优的支持向量机模型。仿真实验表明,与SVM、GRID-SVM、GA-SVM、PSO-SVM相比,该方法误判率最低、全局寻优能力及鲁棒性较好。
贾立敬 +5 more
doaj
为在方案设计初期与工程造价相关信息很少的条件下,准确快速地预测住宅工程造价,在分析既往相关理论和方法优劣的基础上,选取支持向量机构建住宅工程造价预测模型,并通过主成分分析对原始数据进行降噪处理.选取住宅工程造价预测指标集与样本,对输入指标的数据进行主成分分析,消除指标相关性的同时对原始数据降维,将处理后的数据分别导入到“标准支持向量机”和“最小二乘支持向量机”模型中进行训练和预测,并对预测结果进行对比分析,选取较为合理的预测模型,通过参数寻优进一步优化预测效果.所构建预测模型的相对误差均控制在±7%以内,
QINZhongfu(秦中伏) +3 more
doaj +1 more source
Riesz basis-based reproducing kernel and SVM(基于Riesz基的再生核及支持向量机)
在支持向量机(SVM)技术中,再生核的选择起着重要作用.利用L2(R)中的一组Riesz基构造再生核,并将其推广到应用广泛的正交小波.在基于正交小波的再生核Hilbert空间中考虑函数的正则化逼近,对基于正交小波再生核的SVM结合小波分析进行探讨,得到SVM的离散逼近,离散细节均只与支持向量有关.
ZHOUDe-qiang(周德强) +1 more
doaj +1 more source
Research on Semisupervised Classification for Hyperspectral Image Based on Spectral-Spatial Feature [PDF]
高光谱遥感图像分类是图像研究领域的新热点问题,具有广泛的应用前景。随着近年来关注度的持续上升和研究投入的不断增加,已经取得一定的技术成果。然而,由于高光谱遥感图像本身的特殊性,使得其分类技术存在着维度高而训练集小、信息冗余、混合像素多等问题。针对这些问题,本文开展了基于谱域-空间特征的半监督高光谱图像分类方法研究,主要研究工作及创新点如下: 1.为了充分利用目标像素点的空间信息,提出将谱域和空间信息相结合的特征。目标像素点的空间信息包括:空间邻域像素点光谱信息和目标像素点自身空间位置信息 ...
尤雅萍
core
Modeling Methods and Influencing Factors for Age Estimation Based on DNA Methylation [PDF]
Age estimation based on tissues or body fluids is an important task in forensic science. The changes of DNA methylation status with age have certain rules, which can be used to estimate the age of the individuals.
Yi-hang HUANG, Wei-bo LIANG, Hui JIAN, Sheng-qiu QU
core +1 more source
Only 1541 (34.2%) of 4503 recognized non‐passerine bird species are held in ZIMS institutions worldwide. Approximately ~83% of the species kept globally are classified as non‐threatened and ~16% as threatened. To improve the conservation of threatened birds, a shift toward keeping threatened species should be considered within ex situ management ...
Anna Wahle +6 more
wiley +1 more source

