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线性回归模型的降维计算: 交互投影算法
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作者 童恒庆 《统计与决策》 北大核心 2000年第10期10-11,共2页
关键词 统计学 线性回归模型 降维计算 交互投影算法
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边界元法中区域积分的降维计算方法 被引量:1
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作者 袁政强 祝家麟 《数值计算与计算机应用》 CSCD 北大核心 2002年第4期241-245,共5页
§1.引言 边界元方法是在经典的积分方程法和有限元离散化技术的基础上发展起来的求解偏微分方程的数值计算方法.由于它在几何上的广泛适应性,输入数据的简单性以及在数值上的确定性,这种方法已广泛地应用于不同学科领域及各种工程... §1.引言 边界元方法是在经典的积分方程法和有限元离散化技术的基础上发展起来的求解偏微分方程的数值计算方法.由于它在几何上的广泛适应性,输入数据的简单性以及在数值上的确定性,这种方法已广泛地应用于不同学科领域及各种工程技术问题的数值计算,其基本的思想是利用Green公式和微分方程的基本解尽可能地把区域上的积分转化为边界上的积分. 展开更多
关键词 边界元法 区域积分 降维计算方法
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线性模型的降维计算与病态分离 被引量:2
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作者 童恒庆 《数值计算与计算机应用》 CSCD 北大核心 1997年第4期241-242,共2页
In this paper an iterative algorithm of alternating projection between two convex sets is proposed to calculate regression coefficient in linear model. The descent computation and ill-condition seperating of regressio... In this paper an iterative algorithm of alternating projection between two convex sets is proposed to calculate regression coefficient in linear model. The descent computation and ill-condition seperating of regression coefficient are realized. 展开更多
关键词 线性模型 降维计算 病态分离 参数估计
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弹性高斯束偏移PS成像降维高效计算方法
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作者 栗学磊 毛伟建 《世界地质》 CAS 2017年第4期1258-1267,共10页
给出了2D弹性高斯束偏移公式推导,该偏移实现了准确的波型分离,压制多波之间串扰噪音。将声波高斯束偏移的降维高效算法推广到弹性高斯束偏移PS成像,通过重新设计中心点慢度分量和偏移距慢度分量,改进了该降维高效算法,实现了PS成像的... 给出了2D弹性高斯束偏移公式推导,该偏移实现了准确的波型分离,压制多波之间串扰噪音。将声波高斯束偏移的降维高效算法推广到弹性高斯束偏移PS成像,通过重新设计中心点慢度分量和偏移距慢度分量,改进了该降维高效算法,实现了PS成像的降维高效计算。 展开更多
关键词 弹性介质 高斯束偏移 PS转换波 高效计算
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现场血流储备分数诊断性能对比验证与临床应用研究进展 被引量:1
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作者 王大震 朱胜松 +1 位作者 丁晓彤 俞梦越 《中国心血管病研究》 CAS 2022年第10期954-960,共7页
随着基于冠状动脉计算机断层扫描血管造影的血流储备分数(CT-FFR)的问世与普及,冠状动脉的评估已从影像学指导的解剖学时代进入无创功能学时代。冠状动脉无创功能学评估可以提高有创检查及治疗的精准性,但CT-FFR存在算法步骤较多、异地... 随着基于冠状动脉计算机断层扫描血管造影的血流储备分数(CT-FFR)的问世与普及,冠状动脉的评估已从影像学指导的解剖学时代进入无创功能学时代。冠状动脉无创功能学评估可以提高有创检查及治疗的精准性,但CT-FFR存在算法步骤较多、异地计算以及耗时较长等问题。近年来,新兴的现场CT-FFR技术不需要场外超级计算机的帮助,评估时间更短,经过多项研究的验证与有创FFR具有较好的一致性。本文就现场CT-FFR的对比验证和临床应用研究进展进行综述。 展开更多
关键词 现场血流储备分数 新型3D-计算流体力学 降维计算流体力学 机器学习 冠心病
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人脸检测与识别技术的研究分析
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作者 刘舒天 《科技资讯》 2023年第18期68-71,共4页
人脸检测与识别是一种常见管理手段,作为认定人员身份的工作方法,在各类管理系统中广泛应用。该文首先对人脸检测与识别技术进行简述,在此基础上结合企业管理工作,对其运用进行分析,包括运用框架、关键技术、基本流程等,并通过模拟分析... 人脸检测与识别是一种常见管理手段,作为认定人员身份的工作方法,在各类管理系统中广泛应用。该文首先对人脸检测与识别技术进行简述,在此基础上结合企业管理工作,对其运用进行分析,包括运用框架、关键技术、基本流程等,并通过模拟分析论证其优势。考虑到人脸检测与识别技术的运用仍得到较多关注,该文对其运用困境和发展方向进行了分析,以进一步推动该项服务技术的发展、应用优化。 展开更多
关键词 人脸检测 人脸识别技术 降维计算 检测方式
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Dimension-down iterative algorithm for the mixed transportation network design problem
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作者 陈群 姚加林 《Journal of Southeast University(English Edition)》 EI CAS 2012年第2期236-239,共4页
An optimal dimension-down iterative algorithm (DDIA) is proposed for solving a mixed (continuous/ discrete) transportation network design problem (MNDP), which is generally expressed as a mathematical programmin... An optimal dimension-down iterative algorithm (DDIA) is proposed for solving a mixed (continuous/ discrete) transportation network design problem (MNDP), which is generally expressed as a mathematical programming with equilibrium constraints (MPEC). The upper level of the MNDP aims to optimize the network performance via both the expansion of existing links and the addition of new candidate links, whereas the lower level is a traditional Wardrop user equilibrium (UE) model. The idea of the proposed DDIA is to reduce the dimensions of the problem. A group of variables (discrete/continuous) are fixed to altemately optimize another group of variables (continuous/discrete). Some continuous network design problems (CNDPs) and discrete network design problems (DNDPs) are solved repeatedly until the optimal solution is obtained. A numerical example is given to demonstrate the efficiency of the proposed algorithm. 展开更多
关键词 mixed network design problem (MNDP) dimension-down iterative algorithm (DDIA) mathematical programming with equilibrium constraint (MPEC)
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DIMENSIONALITY REDUCTION FOR HYPERSPECTRAL IMAGERY BASED ON FASTICA 被引量:4
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作者 Xin Qin Nian Yongjian +2 位作者 Li Xiu Wan Jianwei Su Linghua 《Journal of Electronics(China)》 2009年第6期831-835,共5页
The high dimensions of hyperspectral imagery have caused burden for further processing. A new Fast Independent Component Analysis (FastICA) approach to dimensionality reduction for hyperspectral imagery is presented. ... The high dimensions of hyperspectral imagery have caused burden for further processing. A new Fast Independent Component Analysis (FastICA) approach to dimensionality reduction for hyperspectral imagery is presented. The virtual dimensionality is introduced to determine the number of dimensions needed to be preserved. Since there is no prioritization among independent components generated by the FastICA,the mixing matrix of FastICA is initialized by endmembers,which were extracted by using unsupervised maximum distance method. Minimum Noise Fraction (MNF) is used for preprocessing of original data,which can reduce the computational complexity of FastICA significantly. Finally,FastICA is performed on the selected principal components acquired by MNF to generate the expected independent components in accordance with the order of endmembers. Experimental results demonstrate that the proposed method outperforms second-order statistics-based transforms such as principle components analysis. 展开更多
关键词 Hyperspectral imagery Dimensionality reduction Independent Component Analysis(ICA)
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Computationally Efficient 2DDOA Estimation for Uniform Planar Arrays:RDROOTMUSIC Algorithm 被引量:3
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作者 YE Changbo ZHU Beizuo +1 位作者 LI Baobao ZHANG Xiaofei 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2021年第4期685-694,共10页
The problem of two-dimensional direction of arrival(2D-DOA)estimation for uniform planar arrays(UPAs)is investigated by employing the reduced-dimensional(RD)polynomial root finding technique and 2D multiple signal cla... The problem of two-dimensional direction of arrival(2D-DOA)estimation for uniform planar arrays(UPAs)is investigated by employing the reduced-dimensional(RD)polynomial root finding technique and 2D multiple signal classification(2D-MUSIC)algorithm.Specifically,based on the relationship between the noise subspace and steering vectors,we first construct 2D root polynomial for 2D-DOA estimates and then prove that the 2D polynomial function has infinitely many solutions.In particular,we propose a computationally efficient algorithm,termed RD-ROOT-MUSIC algorithm,to obtain the true solutions corresponding to targets by RD technique,where the 2D root-finding problem is substituted by two one-dimensional(1D)root-finding operations.Finally,accurate 2DDOA estimates can be obtained by a sample pairing approach.In addition,numerical simulation results are given to corroborate the advantages of the proposed algorithm. 展开更多
关键词 uniform planar array(UPA) direction of arrival(DOA)estimation RD-ROOT-MUSIC algorithm
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