期刊文献+
共找到334篇文章
< 1 2 17 >
每页显示 20 50 100
Model-Free Feature Screening Based on Gini Impurity for Ultrahigh-Dimensional Multiclass Classification
1
作者 Zhongzheng Wang Guangming Deng 《Open Journal of Statistics》 2022年第5期711-732,共22页
It is quite common that both categorical and continuous covariates appear in the data. But, most feature screening methods for ultrahigh-dimensional classification assume the covariates are continuous. And applicable ... It is quite common that both categorical and continuous covariates appear in the data. But, most feature screening methods for ultrahigh-dimensional classification assume the covariates are continuous. And applicable feature screening method is very limited;to handle this non-trivial situation, we propose a model-free feature screening for ultrahigh-dimensional multi-classification with both categorical and continuous covariates. The proposed feature screening method will be based on Gini impurity to evaluate the prediction power of covariates. Under certain regularity conditions, it is proved that the proposed screening procedure possesses the sure screening property and ranking consistency properties. We demonstrate the finite sample performance of the proposed procedure by simulation studies and illustrate using real data analysis. 展开更多
关键词 Ultrahigh-Dimensional feature screening model-free Gini Impurity Multiclass Classification
在线阅读 下载PDF
Model-Free Feature Screening via Maximal Information Coefficient (MIC) for Ultrahigh-Dimensional Multiclass Classification
2
作者 Tingting Chen Guangming Deng 《Open Journal of Statistics》 2023年第6期917-940,共24页
It is common for datasets to contain both categorical and continuous variables. However, many feature screening methods designed for high-dimensional classification assume that the variables are continuous. This limit... It is common for datasets to contain both categorical and continuous variables. However, many feature screening methods designed for high-dimensional classification assume that the variables are continuous. This limits the applicability of existing methods in handling this complex scenario. To address this issue, we propose a model-free feature screening approach for ultra-high-dimensional multi-classification that can handle both categorical and continuous variables. Our proposed feature screening method utilizes the Maximal Information Coefficient to assess the predictive power of the variables. By satisfying certain regularity conditions, we have proven that our screening procedure possesses the sure screening property and ranking consistency properties. To validate the effectiveness of our approach, we conduct simulation studies and provide real data analysis examples to demonstrate its performance in finite samples. In summary, our proposed method offers a solution for effectively screening features in ultra-high-dimensional datasets with a mixture of categorical and continuous covariates. 展开更多
关键词 Ultrahigh-Dimensional feature screening model-free Maximal Information Coefficient (MIC) Multiclass Classification
在线阅读 下载PDF
Model-free feature screening for high-dimensional survival data 被引量:3
3
作者 Yuanyuan Lin Xianhui Liu Meiling Hao 《Science China Mathematics》 SCIE CSCD 2018年第9期1617-1636,共20页
With the rapid-growth-in-size scientific data in various disciplines, feature screening plays an important role to reduce the high-dimensionality to a moderate scale in many scientific fields. In this paper, we introd... With the rapid-growth-in-size scientific data in various disciplines, feature screening plays an important role to reduce the high-dimensionality to a moderate scale in many scientific fields. In this paper, we introduce a unified and robust model-free feature screening approach for high-dimensional survival data with censoring, which has several advantages: it is a model-free approach under a general model framework, and hence avoids the complication to specify an actual model form with huge number of candidate variables; under mild conditions without requiring the existence of any moment of the response, it enjoys the ranking consistency and sure screening properties in ultra-high dimension. In particular, we impose a conditional independence assumption of the response and the censoring variable given each covariate, instead of assuming the censoring variable is independent of the response and the covariates. Moreover, we also propose a more robust variant to the new procedure, which possesses desirable theoretical properties without any finite moment condition of the predictors and the response. The computation of the newly proposed methods does not require any complicated numerical optimization and it is fast and easy to implement. Extensive numerical studies demonstrate that the proposed methods perform competitively for various configurations. Application is illustrated with an analysis of a genetic data set. 展开更多
关键词 feature screening random censoring robustness sure independence screening ultra-high dimension
原文传递
Model-Free Ultra-High-Dimensional Feature Screening for Multi-Classified Response Data Based on Weighted Jensen-Shannon Divergence
4
作者 Qingqing Jiang Guangming Deng 《Open Journal of Statistics》 2023年第6期822-849,共28页
In ultra-high-dimensional data, it is common for the response variable to be multi-classified. Therefore, this paper proposes a model-free screening method for variables whose response variable is multi-classified fro... In ultra-high-dimensional data, it is common for the response variable to be multi-classified. Therefore, this paper proposes a model-free screening method for variables whose response variable is multi-classified from the point of view of introducing Jensen-Shannon divergence to measure the importance of covariates. The idea of the method is to calculate the Jensen-Shannon divergence between the conditional probability distribution of the covariates on a given response variable and the unconditional probability distribution of the covariates, and then use the probabilities of the response variables as weights to calculate the weighted Jensen-Shannon divergence, where a larger weighted Jensen-Shannon divergence means that the covariates are more important. Additionally, we also investigated an adapted version of the method, which is to measure the relationship between the covariates and the response variable using the weighted Jensen-Shannon divergence adjusted by the logarithmic factor of the number of categories when the number of categories in each covariate varies. Then, through both theoretical and simulation experiments, it was demonstrated that the proposed methods have sure screening and ranking consistency properties. Finally, the results from simulation and real-dataset experiments show that in feature screening, the proposed methods investigated are robust in performance and faster in computational speed compared with an existing method. 展开更多
关键词 Ultra-High-Dimensional Multi-Classified Weighted Jensen-Shannon Divergence model-free feature screening
在线阅读 下载PDF
A fast, accurate and dense feature matching algorithm for aerial images 被引量:2
5
作者 LI Ying GONG Guanghong SUN Lin 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2020年第6期1128-1139,共12页
Three-dimensional(3D)reconstruction based on aerial images has broad prospects,and feature matching is an important step of it.However,for high-resolution aerial images,there are usually problems such as long time,mis... Three-dimensional(3D)reconstruction based on aerial images has broad prospects,and feature matching is an important step of it.However,for high-resolution aerial images,there are usually problems such as long time,mismatching and sparse feature pairs using traditional algorithms.Therefore,an algorithm is proposed to realize fast,accurate and dense feature matching.The algorithm consists of four steps.Firstly,we achieve a balance between the feature matching time and the number of matching pairs by appropriately reducing the image resolution.Secondly,to realize further screening of the mismatches,a feature screening algorithm based on similarity judgment or local optimization is proposed.Thirdly,to make the algorithm more widely applicable,we combine the results of different algorithms to get dense results.Finally,all matching feature pairs in the low-resolution images are restored to the original images.Comparisons between the original algorithms and our algorithm show that the proposed algorithm can effectively reduce the matching time,screen out the mismatches,and improve the number of matches. 展开更多
关键词 feature matching feature screening feature fusion aerial image three-dimensional(3D)reconstruction
在线阅读 下载PDF
一种利用Screening加速技巧的Lasso算法
6
作者 邱俊洋 潘志松 +2 位作者 易磊 陶蔚 张梁梁 《计算机工程与应用》 CSCD 北大核心 2018年第4期135-140,共6页
Lasso(Least absolute shrinkage and selection operator)是目前广为应用的一种稀疏特征选择算法。经典的Lasso算法通过对高维数据进行特征选择一定程度上降低了计算开销,然而,求解Lasso问题目前仍面临诸多困难与挑战,例如当特征维数... Lasso(Least absolute shrinkage and selection operator)是目前广为应用的一种稀疏特征选择算法。经典的Lasso算法通过对高维数据进行特征选择一定程度上降低了计算开销,然而,求解Lasso问题目前仍面临诸多困难与挑战,例如当特征维数和样本数量非常大时,甚至无法将数据矩阵加载到主存储器中。为了应对这一挑战,Screening加速技巧成为近年来研究的热点。Screening可以在问题优化求解之前将稀疏优化结果中系数必然为0的无效特征筛选出来并剔除,从而极大地降低数据维度,在不损失问题求解精度的前提下,加速稀疏优化问题的求解速度。首先推导了Lasso的对偶问题,根据对偶问题的特性得出基于对偶多面投影的Screening加速技巧,最后将Screening加速技巧引入Lasso特征选择算法,并在多个高维数据集上进行实验,通过加速比、识别率以及算法运行时间三个指标验证了Screening加速技巧在Lasso算法上的良好性能。 展开更多
关键词 Lasso算法 screening加速技巧 稀疏特征选择 高维数据
在线阅读 下载PDF
基于一种距离相关的超高维生存数据Model-Free特征筛选 被引量:1
7
作者 潘莹丽 王昊宇 +1 位作者 喻佳丽 刘展 《湖北大学学报(自然科学版)》 CAS 2024年第1期122-132,共11页
随着大数据时代的来临,数据维度爆炸式增长,超高维数据的降维问题逐渐成为众多研究领域的热点话题。由于响应变量通常存在右删失,处理超高维完全数据的降维方法在右删失数据中将不再适用。本研究提出一种新的基于距离相关能有效处理超... 随着大数据时代的来临,数据维度爆炸式增长,超高维数据的降维问题逐渐成为众多研究领域的热点话题。由于响应变量通常存在右删失,处理超高维完全数据的降维方法在右删失数据中将不再适用。本研究提出一种新的基于距离相关能有效处理超高维右删失数据的特征筛选方法。首先利用距离相关系数计算每个协变量对响应变量的边际效应,建立与该系数有关的筛选指标,然后再根据事先确立的筛选准则进行特征筛选。提出的特征筛选方法不依赖任何模型结构假定,因此可以有效避免模型指定错误带来的不良后果。此外,该方法采用的距离协方差估计量是总体距离协方差的一个无偏估计,统计准确性和计算精度高。模拟和实证研究表明,提出的方法能在保留所有重要变量的前提下快速剔除与响应变量相关程度较弱的协变量,从而达到降低参数维数的目的。 展开更多
关键词 超高维数据 生存数据 距离相关 model-free特征筛选
在线阅读 下载PDF
Interpretable Machine Learning-Assisted High-Throughput Screening for Understanding NRR Electrocatalyst Performance Modulation between Active Center and C-N Coordination
8
作者 Jinxin Sun Anjie Chen +7 位作者 Junming Guan Ying Han Yongjun Liu Xianghong Niu Maoshuai He Li Shi Jinlan Wang Xiuyun Zhang 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第5期263-271,共9页
Understanding the correlation between the fundamental descriptors and catalytic performance is meaningful to guide the design of high-performance electrochemical catalysts.However,exploring key factors that affect cat... Understanding the correlation between the fundamental descriptors and catalytic performance is meaningful to guide the design of high-performance electrochemical catalysts.However,exploring key factors that affect catalytic performance in the vast catalyst space remains challenging for people.Herein,to accurately identify the factors that affect the performance of N2 reduction,we apply interpretable machine learning(ML)to analyze high-throughput screening results,which is also suited to other surface reactions in catalysis.To expound on the paradigm,33 promising catalysts are screened from 168 carbon-supported candidates,specifically single-atom catalysts(SACs)supported by a BC_(3)monolayer(TM@V_(B/C)-N_(n)=_(0-3)-BC_(3))via high-throughput screening.Subsequently,the hybrid sampling method and XGBoost model are selected to classify eligible and non-eligible catalysts.Through feature interpretation using Shapley Additive Explanations(SHAP)analysis,two crucial features,that is,the number of valence electrons(N_(v))and nitrogen substitution(N_(n)),are screened out.Combining SHAP analysis and electronic structure calculations,the synergistic effect between an active center with low valence electron numbers and reasonable C-N coordination(a medium fraction of nitrogen substitution)can exhibit high catalytic performance.Finally,six superior catalysts with a limiting potential lower than-0.4 V are predicted.Our workflow offers a rational approach to obtaining key information on catalytic performance from high-throughput screening results to design efficient catalysts that can be applied to other materials and reactions. 展开更多
关键词 electrochemical nitrogen reduction feature engineering high-throughput screening machine learning
在线阅读 下载PDF
Feature Screening and Error Variance Estimation for Ultrahigh-Dimensional Linear Model with Measurement Errors
9
作者 Hengjian Cui Feng Zou Li Ling 《Communications in Mathematics and Statistics》 2025年第1期139-171,共33页
In this paper,we mainly study the feature screening and error variance estimation in ultrahigh-dimensional linear model with errors-in-variables(EV).Given that sure independence screening(SIS)method by marginal Pearso... In this paper,we mainly study the feature screening and error variance estimation in ultrahigh-dimensional linear model with errors-in-variables(EV).Given that sure independence screening(SIS)method by marginal Pearson’s correlation learning may omit some important observation variables due to measurement errors,a corrected SIS called EVSIS is proposed to rank the importance of features according to their corrected marginal correlation with the response variable.Also,a corrected error variance procedure is proposed to accurately estimate the error variance,which could greatly attenuate the influence of measurement errors and spurious correlations,simultaneously.Under some regularization conditions,the proposed EVSIS possesses sure screening property and consistency in ranking and the corrected error variance estimator is also proved to be asymptotically normal.The two methodologies are illustrated by some simulations and a real data example,which suggests that the proposed methods perform well. 展开更多
关键词 Ultrahigh-dimensional linear model Measurement error feature screening Error variance estimation Sure screening property Asymptotic properties
原文传递
Dynamic Conditional Feature Screening:A High-Dimensional Feature Selection Method Based on Mutual Information and Regression Error
10
作者 Yi Zhao Guangming Deng 《Open Journal of Statistics》 2025年第2期199-242,共44页
Current high-dimensional feature screening methods still face significant challenges in handling mixed linear and nonlinear relationships,controlling redundant information,and improving model robustness.In this study,... Current high-dimensional feature screening methods still face significant challenges in handling mixed linear and nonlinear relationships,controlling redundant information,and improving model robustness.In this study,we propose a Dynamic Conditional Feature Screening(DCFS)method tailored for high-dimensional economic forecasting tasks.Our goal is to accurately identify key variables,enhance predictive performance,and provide both theoretical foundations and practical tools for macroeconomic modeling.The DCFS method constructs a comprehensive test statistic by integrating conditional mutual information with conditional regression error differences.By introducing a dynamic weighting mechanism,DCFS adaptively balances the linear and nonlinear contributions of features during the screening process.In addition,a dynamic thresholding mechanism is designed to effectively control the false discovery rate(FDR),thereby improving the stability and reliability of the screening results.On the theoretical front,we rigorously prove that the proposed method satisfies the sure screening property and rank consistency,ensuring accurate identification of the truly important feature set in high-dimensional settings.Simulation results demonstrate that under purely linear,purely nonlinear,and mixed dependency structures,DCFS consistently outperforms classical screening methods such as SIS,CSIS,and IG-SIS in terms of true positive rate(TPR),false discovery rate(FDR),and rank correlation.These results highlight the superior accuracy,robustness,and stability of our method.Furthermore,an empirical analysis based on the U.S.FRED-MD macroeconomic dataset confirms the practical value of DCFS in real-world forecasting tasks.The experimental results show that DCFS achieves lower prediction errors(RMSE and MAE)and higher R2 values in forecasting GDP growth.The selected key variables-including the Industrial Production Index(IP),Federal Funds Rate,Consumer Price Index(CPI),and Money Supply(M2)-possess clear economic interpretability,offering reliable support for economic forecasting and policy formulation. 展开更多
关键词 High-Dimensional feature screening Conditional Mutual Information Regression Error Difference Dynamic Weighting Dynamic Thresholding Macroeconomic Forecasting FRED-MD Dataset
在线阅读 下载PDF
基于光谱和时相特征筛选的黑龙江省2019—2023年主要粮食作物填图及其时空演变分析
11
作者 黄俊尧 吴骅 +3 位作者 张星星 黄佳鹏 程元良 文飞 《自然资源遥感》 北大核心 2026年第1期260-270,共11页
随着农业生产规模的扩展,遥感技术在作物监测中的应用逐渐取代了传统的人工调查手段,尤其是时序遥感数据为作物的高精度填图和时空演变分析提供了新的机遇。然而,现有的遥感方法常面临输入特征冗余和“维度灾难”问题,极大地影响了作物... 随着农业生产规模的扩展,遥感技术在作物监测中的应用逐渐取代了传统的人工调查手段,尤其是时序遥感数据为作物的高精度填图和时空演变分析提供了新的机遇。然而,现有的遥感方法常面临输入特征冗余和“维度灾难”问题,极大地影响了作物填图和时空演变分析的精度和效率。为解决这一问题,该文结合随机森林与层次聚类算法,提出了一种基于特征筛选的作物填图新方法。通过评估光谱和时相特征的重要性,剔除冗余特征并保留最具区分性的特征,结合机器学习技术,显著提升了作物填图及时空演变分析的效率。该方法基于优化后的特征集和随机森林分类器,生成了2019—2023年黑龙江省主要粮食作物的种植分布图,作物分类精度达到89.39%,Kappa系数为0.85,相比使用全时序的特征,分类时间缩短了85%,而精度仅下降了0.11百分点,表明该方法在作物填图中具有显著优势。在此基础上,进一步分析了黑龙江省主要粮食作物的时空演变趋势,结果显示水稻种植面积逐年减少,玉米种植面积呈增长趋势,而大豆种植面积保持稳定。该研究不仅为农业遥感监测提供了精确支持,而且为主要粮食作物的时空演变分析提供了可靠工具,在精细农业管理与粮食安全监测等方面具有重要应用潜力。 展开更多
关键词 作物分类 特征筛选 随机森林 Sentinel-2 黑龙江省
在线阅读 下载PDF
基于残差网络和改进特征的油气田作业施工监控画面检测算法研究
12
作者 刘晓天 谭龙华 +2 位作者 钱成 张军 王晨曦 《电子设计工程》 2026年第1期165-169,共5页
为提升油气田设备的使用效率并加快油田作业进度,设计了一种基于残差网络和改进特征的油气田作业施工监控画面检测算法。采用残差网络模型提取画面信息的改进特征,并通过对监控画面的匹配实现特征数据的初筛处理。根据改进特征下监控检... 为提升油气田设备的使用效率并加快油田作业进度,设计了一种基于残差网络和改进特征的油气田作业施工监控画面检测算法。采用残差网络模型提取画面信息的改进特征,并通过对监控画面的匹配实现特征数据的初筛处理。根据改进特征下监控检测目标的评估与定位标准,计算检测样本的均衡损失度值。实验结果表明,应用上述算法可在不同的监控画面清晰度下捕捉施工设备占用情况,最低占用率仅为26.9%,有助于提取油气田施工的细节信息。 展开更多
关键词 残差网络 改进特征 油气田施工 监控画面 画面检测
在线阅读 下载PDF
机器学习助力高效含能材料分子筛选与设计——基于主动学习的策略
13
作者 杨琳 张晓龙 +2 位作者 王鹤 周余伟 滕波涛 《燃料化学学报(中英文)》 北大核心 2026年第1期135-145,共11页
含能材料在军事和航天等领域应用广泛,但其发现与合成主要依赖“试错法”,严重制约了新型含能材料的研发与突破。本研究选取含能材料关键热力学性质——生成焓作为预测目标,提出一种融合主动学习策略与SMILES分子特征表示的机器学习构... 含能材料在军事和航天等领域应用广泛,但其发现与合成主要依赖“试错法”,严重制约了新型含能材料的研发与突破。本研究选取含能材料关键热力学性质——生成焓作为预测目标,提出一种融合主动学习策略与SMILES分子特征表示的机器学习构效关系模型。基于G4高精度量子化学方法构建了包含1447种气相含能分子的数据集,提取了93个SMILES有效描述符,建立了基于线性模型的气相生成焓初步预测模型。对从PubChem数据库中获取的221738种潜在含能分子进行了系统预测。进一步引入主动学习策略,对高误差样本迭代优化,得到了泛化能力更好的预测模型,该模型在典型含能分子上得到了验证。最终筛选出20个威力指数超过2.0倍TNT的候选分子,其中,大多数未见于现有已知含能材料库,显示出本研究在高性能含能材料发现方面的潜力,为新型含能材料的开发提供新策略与新途径。 展开更多
关键词 含能材料筛选 主动学习 SMILES特征 生成焓 爆炸热
在线阅读 下载PDF
基于注意力机制的文档图像屏摄鲁棒水印方法
14
作者 张小敏 赵军智 和红杰 《计算机科学》 北大核心 2026年第1期413-422,共10页
屏摄鲁棒的水印算法在版权保护、追踪溯源等领域具有重要意义。现有的抗屏摄鲁棒水印算法大多关注于自然图像,忽视了对文档图像的研究。文档载体本身的冗余信息较少,水印的鲁棒性和不可感知性很难得到平衡。为解决这一问题,提出了一种... 屏摄鲁棒的水印算法在版权保护、追踪溯源等领域具有重要意义。现有的抗屏摄鲁棒水印算法大多关注于自然图像,忽视了对文档图像的研究。文档载体本身的冗余信息较少,水印的鲁棒性和不可感知性很难得到平衡。为解决这一问题,提出了一种基于注意力机制的文档图像屏摄鲁棒水印方法。为提升水印的不可感知性,在编码器网络中引入注意力特征融合模块,实现浅层特征和深层特征的自适应聚合。为提高算法的鲁棒提取能力,在解码器网络中设计了自适应通道与空间注意力模块,突出通道和空间维度中与水印信息高度相关的特征。同时,在屏摄噪声模拟过程中设计了摩尔纹失真层,以提高算法抵抗真实摩尔纹干扰的鲁棒性能。实验结果显示,所提方法的平均PSNR为33.4 dB,SSIM为0.9885,RMSE为5.48,在多种屏摄场景的平均提取准确率可达99.49%。在图像质量和水印鲁棒性方面,均优于现有同类方法。 展开更多
关键词 屏摄鲁棒水印 文档图像 注意力特征融合 自适应通道与空间注意力 摩尔纹失真
在线阅读 下载PDF
基于因果增强改进LightGBM的风险筛查方法研究
15
作者 陈蓉 吴志杰 +1 位作者 刘娜 何炜琪 《环境科学学报》 北大核心 2026年第1期499-506,共8页
快速低成本评估污染场地的环境风险对于场地污染详查和污染治理具有重要意义.本研究基于场地污染源、迁移途径等业务数据,改进了LightGBM的特征选择方法,构建了风险筛查模型,并以广州制造业及电力、热力、燃气及水生产和供应业场地作为... 快速低成本评估污染场地的环境风险对于场地污染详查和污染治理具有重要意义.本研究基于场地污染源、迁移途径等业务数据,改进了LightGBM的特征选择方法,构建了风险筛查模型,并以广州制造业及电力、热力、燃气及水生产和供应业场地作为典型案例进行应用评估.结果表明:(1)基于因果增强改进的LightGBM的特征选择方法能够有效识别场地污染关键因子,减少特征维度的同时提升模型预测精度;(2)分别基于不同数量的关键指标,构建了初始LightGBM与因果增强改进的LightGBM模型.在使用44个关键指标时,模型达到最高的预准确度(91.17%),表明特征选择与模型优化相结合能够显著提高风险筛查分值的预测能力;(3)88个典型场地中,模型成功识别出79个风险场地,准确率达89.8%,实际应用效果良好.本研究改进后的风险筛查分值模型在污染场地风险评估中具有较高的预测精度,能够为场地污染快速识别、污染治理优先级提供决策支持. 展开更多
关键词 污染场地 风险筛查 特征选择 机器学习 LightGBM
原文传递
基于深度学习热力图回归的樱桃分级检测方法
16
作者 宋雪珺 高磊 郭晓霞 《食品与机械》 北大核心 2026年第1期72-78,共7页
[目的]解决樱桃筛选效率低、成本高的问题。[方法]提出一种基于热力图回归方法HRNet-YT,用于自动识别樱桃大小和果梗有无,实现高效筛选。HRNet-YT通过构建多个平行子网络实现多尺度信息融合,保持高分辨率表达,确保果梗和果萼关键点热力... [目的]解决樱桃筛选效率低、成本高的问题。[方法]提出一种基于热力图回归方法HRNet-YT,用于自动识别樱桃大小和果梗有无,实现高效筛选。HRNet-YT通过构建多个平行子网络实现多尺度信息融合,保持高分辨率表达,确保果梗和果萼关键点热力图的空间准确性。结合热力图技术捕捉丰富的上下文信息,并优化损失函数以提升模型的鲁棒性和精度。[结果]HRNet-YT-W48(384×288)在数据集上的检测准确率为87.3%,关键点平均精度(AP,OKS=0.5)为0.22。[结论]试验提出的方法在樱桃关键点检测任务中具有较高的准确性和适应性。 展开更多
关键词 深度学习 热力图回归 樱桃 分级检测 关键点检测 多尺度特征融合
在线阅读 下载PDF
ORB特征匹配的研究
17
作者 梁颖 《佳木斯大学学报(自然科学版)》 2026年第1期56-59,共4页
SLAM(Simultaneous Localization and Mapping,即时定位与地图构建)在机器人、无人机等行业起着重要作用,ORB-SLAM是其中的一个热门应用。其中的特征提取与匹配是SLAM最终能够获得准确定位与精确地图构建的基础,也是耗时、耗能较多的环... SLAM(Simultaneous Localization and Mapping,即时定位与地图构建)在机器人、无人机等行业起着重要作用,ORB-SLAM是其中的一个热门应用。其中的特征提取与匹配是SLAM最终能够获得准确定位与精确地图构建的基础,也是耗时、耗能较多的环节。为了进一步提高特征匹配效果,在ORB-SLAM2算法的基础上,在特征提取与特征匹配后,通过引入对特征点的匹配筛选环节,同时为了保证其实时性,采用具有强大并行能力的FPGA技术进行设计。最终在增加适当硬件资源的代价上,实现了较小的位姿相对误差。 展开更多
关键词 FPGA 特征提取 特征匹配 筛选
在线阅读 下载PDF
Accurate machine learning models based on small dataset of energetic materials through spatial matrix featurization methods 被引量:9
18
作者 Chao Chen Danyang Liu +4 位作者 Siyan Deng Lixiang Zhong Serene Hay Yee Chan Shuzhou Li Huey Hoon Hng 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第12期364-375,I0009,共13页
A large database is desired for machine learning(ML) technology to make accurate predictions of materials physicochemical properties based on their molecular structure.When a large database is not available,the develo... A large database is desired for machine learning(ML) technology to make accurate predictions of materials physicochemical properties based on their molecular structure.When a large database is not available,the development of proper featurization method based on physicochemical nature of target proprieties can improve the predictive power of ML models with a smaller database.In this work,we show that two new featurization methods,volume occupation spatial matrix and heat contribution spatial matrix,can improve the accuracy in predicting energetic materials' crystal density(ρ_(crystal)) and solid phase enthalpy of formation(H_(f,solid)) using a database containing 451 energetic molecules.Their mean absolute errors are reduced from 0.048 g/cm~3 and 24.67 kcal/mol to 0.035 g/cm~3 and 9.66 kcal/mol,respectively.By leave-one-out-cross-validation,the newly developed ML models can be used to determine the performance of most kinds of energetic materials except cubanes.Our ML models are applied to predict ρ_(crystal) and H_(f,solid) of CHON-based molecules of the 150 million sized PubChem database,and screened out 56 candidates with competitive detonation performance and reasonable chemical structures.With further improvement in future,spatial matrices have the potential of becoming multifunctional ML simulation tools that could provide even better predictions in wider fields of materials science. 展开更多
关键词 Small database machine learning Energetic materials screening Spatial matrix featurization method Crystal density Formation enthalpy n-Body interactions
在线阅读 下载PDF
Stable correlation and robust feature screening 被引量:2
19
作者 Xu Guo Runze Li +1 位作者 Wanjun Liu Lixing Zhu 《Science China Mathematics》 SCIE CSCD 2022年第1期153-168,共16页
In this paper,we propose a new correlation,called stable correlation,to measure the dependence between two random vectors.The new correlation is well defined without the moment condition and is zero if and only if the... In this paper,we propose a new correlation,called stable correlation,to measure the dependence between two random vectors.The new correlation is well defined without the moment condition and is zero if and only if the two random vectors are independent.We also study its other theoretical properties.Based on the new correlation,we further propose a robust model-free feature screening procedure for ultrahigh dimensional data and establish its sure screening property and rank consistency property without imposing the subexponential or sub-Gaussian tail condition,which is commonly required in the literature of feature screening.We also examine the finite sample performance of the proposed robust feature screening procedure via Monte Carlo simulation studies and illustrate the proposed procedure by a real data example. 展开更多
关键词 feature screening nonlinear dependence stable correlation sure screening property
原文传递
Feature Screening for Ultrahigh-dimensional Censored Data with Varying Coefficient Single-index Model 被引量:1
20
作者 Yi LIU 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2019年第4期845-861,共17页
In this paper, we study the sure independence screening of ultrahigh-dimensional censored data with varying coefficient single-index model. This general model framework covers a large number of commonly used survival ... In this paper, we study the sure independence screening of ultrahigh-dimensional censored data with varying coefficient single-index model. This general model framework covers a large number of commonly used survival models. The property that the proposed method is not derived for a specific model is appealing in ultrahigh dimensional regressions, as it is difficult to specify a correct model for ultrahigh dimensional predictors.Once the assuming data generating process does not meet the actual one, the screening method based on the model will be problematic. We establish the sure screening property and consistency in ranking property of the proposed method. Simulations are conducted to study the finite sample performances, and the results demonstrate that the proposed method is competitive compared with the existing methods. We also illustrate the results via the analysis of data from The National Alzheimers Coordinating Center(NACC). 展开更多
关键词 censored data consistency in ranking PROPERTY feature selection HIGH-DIMENSIONAL data sure screening PROPERTY VARYING COEFFICIENT single-index model
原文传递
上一页 1 2 17 下一页 到第
使用帮助 返回顶部