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LAD PARAMETER ESTIMATION of SaS BASED on SAMPLE CHARACTERISTIC FUNCTION
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作者 陈高波 《科技信息》 2010年第25期I0028-I0028,I0027,共2页
Parameter estimation to alpha stable distribution is difficult for without a explicit probability density function. On the base of sample characteristic function,an iterative LAD parameter estimation algorithm for SaS... Parameter estimation to alpha stable distribution is difficult for without a explicit probability density function. On the base of sample characteristic function,an iterative LAD parameter estimation algorithm for SaS is discussed. The example illustrates that the algorithm is feasible and efficient. 展开更多
关键词 概率 密度函数 计算方法 迭代参数
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Control of beam halo-chaos by sample function 被引量:1
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作者 白龙 张荣 +2 位作者 翁甲强 罗晓曙 方锦清 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第6期1226-1230,共5页
The K-V beam through an axisymmetric uniform-focusing channel is studied using the particle-core model. The beam halo-chaos is found, and a sample function controller is proposed based on mechanism of halo formation a... The K-V beam through an axisymmetric uniform-focusing channel is studied using the particle-core model. The beam halo-chaos is found, and a sample function controller is proposed based on mechanism of halo formation and strategy of controlling halo-chaos. We perform multiparticle simulation to control the halo by using the sample function controller. The numerical results show that our control method is effective. We also find that the radial ion density changes when the ion beam is in the channel: not only can the halo-chaos and its regeneration be eliminated by using the sample function control method, but also the density uniformity can be found at the beam's centre as long as an appropriate control method is chosen. 展开更多
关键词 beam halo-chaos sample function radial ion density uniform-focusing channel
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Frequentist and Bayesian Sample Size Determination for Single-Arm Clinical Trials Based on a Binary Response Variable: A Shiny App to Implement Exact Methods
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作者 Susanna Gentile Valeria Sambucini 《Open Journal of Statistics》 2024年第1期90-105,共16页
Sample size determination typically relies on a power analysis based on a frequentist conditional approach. This latter can be seen as a particular case of the two-priors approach, which allows to build four distinct ... Sample size determination typically relies on a power analysis based on a frequentist conditional approach. This latter can be seen as a particular case of the two-priors approach, which allows to build four distinct power functions to select the optimal sample size. We revise this approach when the focus is on testing a single binomial proportion. We consider exact methods and introduce a conservative criterion to account for the typical non-monotonic behavior of the power functions, when dealing with discrete data. The main purpose of this paper is to present a Shiny App providing a user-friendly, interactive tool to apply these criteria. The app also provides specific tools to elicit the analysis and the design prior distributions, which are the core of the two-priors approach. 展开更多
关键词 Binomial Proportion Frequentist and Bayesian Power functions Exact sample Size Determination Shiny App Two-Priors Approach
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Strong Consistency for the Kernal Estimates of the Random Window Width of the Density Function and its Derivatives Under Φ-Mixing Samples
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作者 樊家琨 《Chinese Quarterly Journal of Mathematics》 CSCD 1993年第3期52-56,共5页
In the paper,we study the strong uniform consistency for the kernal estimates of random window w■th of density function and its derivatives under the condition that the sequence{X_n}of the ■ are the identically Φ-m... In the paper,we study the strong uniform consistency for the kernal estimates of random window w■th of density function and its derivatives under the condition that the sequence{X_n}of the ■ are the identically Φ-mixing random variabks. 展开更多
关键词 Φ-mixing sample probability density function random window width kemal estimate strng uniform consistency
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SHANNON SAMPLING AND ESTIMATION OF BAND-LIMITED FUNCTIONS IN THE SEVERAL COMPLEX VARIABLES SETTING 被引量:1
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作者 高洁欣 钱涛 《Acta Mathematica Scientia》 SCIE CSCD 2005年第4期741-754,共14页
In this work the authors develop the n-dimensional sinc function theory in the several complex variables setting. In terms of the corresponding Paley-Wiener theorem the exact sinc interpolation and quadrature are esta... In this work the authors develop the n-dimensional sinc function theory in the several complex variables setting. In terms of the corresponding Paley-Wiener theorem the exact sinc interpolation and quadrature are established. Exponential convergence rate of the error estimates for band-limited functions in n-dimensional strips are obtained. 展开更多
关键词 Shannon sampling sinc function harmonic analysis
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Gyroscope Fault Diagnosis Using Fuzzy SVM to Unbalanced Samples 被引量:1
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作者 罗秋凤 张锐 +1 位作者 李勇 杨忠清 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2015年第1期16-21,共6页
A novel fuzzy support vector machine based on unbalanced samples(FSVM-US)is proposed to solve the high false positive rate problem since the gyroscope output is susceptible to unmanned aerial vehicle(UAV)airborne elec... A novel fuzzy support vector machine based on unbalanced samples(FSVM-US)is proposed to solve the high false positive rate problem since the gyroscope output is susceptible to unmanned aerial vehicle(UAV)airborne electromagnetic environment and the gyroscope abnormal signal sample is rather rare.Firstly,the standard deviation of samples projection to normal vector for SVM classifier hyper plane is analyzed.The imbalance feature expression reflecting the hyper plane shift for the number imbalance between samples and the dispersion imbalance within samples is derived.At the same time,the denoising factor is designed as the exponential decay function based on the Euclidean distance between each sample and the class center.Secondly,the imbalance feature expression and denoising factor are configured into the membership function.Each sample has its own weight denoted the importance to the classifier.Finally,the classification simulation experiments on the gyroscope fault diagnosis system are conducted and FSVM-US is compared with the standard SVM,FSVM,and the four typical class imbalance learning(CIL)methods.The results show that FSVM-US classifier accuracy is 12% higher than that of the standard SVM.Generally,FSVM-US is superior to the four CIL methods in total performance.Moreover,the FSVMUS noise tolerance is also 17% higher than that of the standard SVM. 展开更多
关键词 fault diagnosis GYROSCOPE fuzzy support vector machine(FSVM) unbalanced samples membership function
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On a Class of Generalized Sampling Functions
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作者 Yi Wang 《Analysis in Theory and Applications》 2014年第1期82-89,共8页
In this note, we discuss a class of so-called generalized sampling functions. These functions are defined to be the inverse Fourier transform of a family of piecewise constant functions that are either square integrab... In this note, we discuss a class of so-called generalized sampling functions. These functions are defined to be the inverse Fourier transform of a family of piecewise constant functions that are either square integrable or Lebegue integrable on the real number line. They are in fact the generalization of the classic sinc function. Two approaches of constructing the generalized sampling functions are reviewed. Their properties such as cardinality, orthogonality, and decaying properties are discussed. The interactions of those functions and Hilbert transformer are also discussed. 展开更多
关键词 Generalized sampling function sinc function non-bandlimited signal sampling the-orem Hilbert transform.
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Novel Stability Criteria for Sampled-Data Systems With Variable Sampling Periods 被引量:2
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作者 Hanyong Shao Jianrong Zhao Dan Zhang 《IEEE/CAA Journal of Automatica Sinica》 EI CSCD 2020年第1期257-262,共6页
This paper is concerned with a novel Lyapunovlike functional approach to the stability of sampled-data systems with variable sampling periods. The Lyapunov-like functional has four striking characters compared to usua... This paper is concerned with a novel Lyapunovlike functional approach to the stability of sampled-data systems with variable sampling periods. The Lyapunov-like functional has four striking characters compared to usual ones. First, it is time-dependent. Second, it may be discontinuous. Third, not every term of it is required to be positive definite. Fourth, the Lyapunov functional includes not only the state and the sampled state but also the integral of the state. By using a recently reported inequality to estimate the derivative of this Lyapunov functional, a sampled-interval-dependent stability criterion with reduced conservatism is obtained. The stability criterion is further extended to sampled-data systems with polytopic uncertainties. Finally, three examples are given to illustrate the reduced conservatism of the stability criteria. 展开更多
关键词 Lyapunov functional sampled-data systems sampling-interval-dependent stability
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Optimal Bayesian Sampling Plans Based on Hybrid Type-Ⅱ Censored Samples
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作者 CHENG Conghua CHENG Lijuan 《Journal of Donghua University(English Edition)》 EI CAS 2018年第1期58-64,共7页
The Bayesian sampling plans for exponential distributions are studied based on type-Ⅱ hybrid censored samples. The optimal Bayesian sampling plan is derived under a general loss function which includes the sampling c... The Bayesian sampling plans for exponential distributions are studied based on type-Ⅱ hybrid censored samples. The optimal Bayesian sampling plan is derived under a general loss function which includes the sampling cost, time-consuming cost, salvage value,and decision loss. It is employed to determine the Bayes risk and the corresponding optimal sampling plan. An explicit expression of the Bayes risk is derived. Furthermore,for the conjugate prior distribution,the closed-form formula of the Bayes decision rule can be obtained under either the linear or quadratic decision loss. 展开更多
关键词 Bayesian sampling plan Bayes risk decision function loss function hybrid censored sample
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Transfer Function Description of Multirate Sampling Systems
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作者 肖建 唐磊 《Journal of Modern Transportation》 1999年第2期141-147,共7页
Based on the sampler decomposition method and modified Z transform, this paper proposes a pulse transfer function matrix description of the multivariable multirate sampling systems. This multirate sampling system mode... Based on the sampler decomposition method and modified Z transform, this paper proposes a pulse transfer function matrix description of the multivariable multirate sampling systems. This multirate sampling system model has a simple structure, and can be used as a basis for the analysis and synthesis of the multirate sampling systems. 展开更多
关键词 multirate sampling system transfer function computer controlled system
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Model-data-driven seismic inversion method based on small sample data
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作者 LIU Jinshui SUN Yuhang LIU Yang 《Petroleum Exploration and Development》 CSCD 2022年第5期1046-1055,共10页
As sandstone layers in thin interbedded section are difficult to identify,conventional model-driven seismic inversion and data-driven seismic prediction methods have low precision in predicting them.To solve this prob... As sandstone layers in thin interbedded section are difficult to identify,conventional model-driven seismic inversion and data-driven seismic prediction methods have low precision in predicting them.To solve this problem,a model-data-driven seismic AVO(amplitude variation with offset)inversion method based on a space-variant objective function has been worked out.In this method,zero delay cross-correlation function and F norm are used to establish objective function.Based on inverse distance weighting theory,change of the objective function is controlled according to the location of the target CDP(common depth point),to change the constraint weights of training samples,initial low-frequency models,and seismic data on the inversion.Hence,the proposed method can get high resolution and high-accuracy velocity and density from inversion of small sample data,and is suitable for identifying thin interbedded sand bodies.Tests with thin interbedded geological models show that the proposed method has high inversion accuracy and resolution for small sample data,and can identify sandstone and mudstone layers of about one-30th of the dominant wavelength thick.Tests on the field data of Lishui sag show that the inversion results of the proposed method have small relative error with well-log data,and can identify thin interbedded sandstone layers of about one-15th of the dominant wavelength thick with small sample data. 展开更多
关键词 small sample data space-variant objective function model-data-driven neural network seismic AVO inversion thin interbedded sandstone identification Paleocene Lishui sag
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Synchronisation of chaotic systems using a novel sampled-data fuzzy controller
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作者 冯毅夫 张庆灵 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第1期33-41,共9页
This paper presents the synchronisation of chaotic systems using a sampled-data fuzzy controller and is meaningful for many physical real-life applications. Firstly, a Takagi-Sugeno (T-S) fuzzy model is employed to ... This paper presents the synchronisation of chaotic systems using a sampled-data fuzzy controller and is meaningful for many physical real-life applications. Firstly, a Takagi-Sugeno (T-S) fuzzy model is employed to represent the chaotic systems that contain some nonlinear terms, then a type of fuzzy sampled-data controller is proposed and an error system formed by the response and drive chaotic system. Secondly, relaxed LMI-based synchronisation conditions are derived by using a new parameter-dependent Lyapunov-Krasovskii functional and relaxed stabilisation techniques for the underlying error system. The derived LMI-based conditions are used to aid the design of a sampled-data fuzzy controller to achieve the synchronisation of chaotic systems. Finally, a numerical example is provided to illustrate the effectiveness of the proposed results. 展开更多
关键词 chaotic systems synchronisation sampled-data systems parameter-dependentLyapunov-Krasovskii functional
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Bayes Prediction of Future Observables from Exponentiated Populations with Fixed and Random Sample Size
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作者 Essam K. AL-Hussaini M. Hussein 《Open Journal of Statistics》 2011年第1期24-32,共9页
Bayesian predictive probability density function is obtained when the underlying pop-ulation distribution is exponentiated and subjective prior is used. The corresponding predictive survival function is then obtained ... Bayesian predictive probability density function is obtained when the underlying pop-ulation distribution is exponentiated and subjective prior is used. The corresponding predictive survival function is then obtained and used in constructing 100(1 – ?)% predictive interval, using one- and two- sample schemes when the size of the future sample is fixed and random. In the random case, the size of the future sample is assumed to follow the truncated Poisson distribution with parameter λ. Special attention is paid to the exponentiated Burr type XII population, from which the data are drawn. Two illustrative examples are given, one of which uses simulated data and the other uses data that represent the breaking strength of 64 single carbon fibers of length 10, found in Lawless [40]. 展开更多
关键词 Predictive Density And SURVIVAL functions One- And Two-sample Schemes BAYES PREDICTION Exponentiated Population. Exponentiated BURR Type XII Distribution Data Of Carbon Fibers
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不同温度热灭活处理临床血液样本对凝血功能及生化检测指标的影响
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作者 林丽文 吕慧 +3 位作者 唐娇 郭春杏 翚缨 韦梦思 《临床医学研究与实践》 2025年第2期81-84,共4页
目的探讨56℃30 min和65℃15 min干热灭活对临床血液样本凝血功能和生化检测指标的影响。方法收集覆盖各检测项目线性范围的临床血液标本60例,检测并比较灭活前和两种温度灭活后标本的凝血功能五项、电解质六项、肝功能八项以及肾功能... 目的探讨56℃30 min和65℃15 min干热灭活对临床血液样本凝血功能和生化检测指标的影响。方法收集覆盖各检测项目线性范围的临床血液标本60例,检测并比较灭活前和两种温度灭活后标本的凝血功能五项、电解质六项、肝功能八项以及肾功能三项指标。在实验前对这些指标的批内精密度进行评估。结果经检测,凝血功能五项、电解质六项、肝功能八项以及肾功能三项的批内精密度均符合要求。凝血功能五项的血浆样本在热灭活处理后发生凝固,无法进一步检测分析。电解质六项、肝功能八项和肾功能三项中,灭活1组和灭活2组的丙氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)、碱性磷酸酶(ALP)、γ-谷氨酰转移酶(GGT)水平与非灭活组比较,差异具有统计学意义(P<0.05);灭活1组和灭活2组的总蛋白(TP)、总胆红素(TBil)、直接胆红素(DBil)水平与非灭活组比较,差异无统计学意义(P>0.05);灭活1组与非灭活组的白蛋白(ALB)水平比较,差异无统计学意义(P>0.05);灭活2组与非灭活组的ALB水平比较,差异具有统计学意义(P<0.05)。结论抗凝血浆样本不适用于热灭活处理。不同实验室应用热灭活处理样本检测之前要经过验证。 展开更多
关键词 热灭活 血液样本 凝血功能 生化检测指标 批内精密度
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动态环境下改进BIT^(*)算法的机器人路径规划
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作者 王晓军 崔锡杰 李晓航 《计算机工程与应用》 北大核心 2025年第7期361-369,共9页
针对批量通知树算法在小样本中搜索路径成功率低、大样本中规划效率低、路径冗余节点多以及无法躲避未知障碍物的问题,提出动态环境批量通知树算法。利用改进批量采样点策略将样本点均匀等间距处理,并改进批量采样点数量以及偏置采样点... 针对批量通知树算法在小样本中搜索路径成功率低、大样本中规划效率低、路径冗余节点多以及无法躲避未知障碍物的问题,提出动态环境批量通知树算法。利用改进批量采样点策略将样本点均匀等间距处理,并改进批量采样点数量以及偏置采样点位置,弥补搜索路径成功率低的缺点;加入惩罚项改进启发式函数,弥补路径规划效率低的缺点;再引入路径拉伸优化减少路径长度以及冗余节点,缩小采样范围。面对未知障碍物,利用反向生长搜索树先验信息提出临时目标点选取策略,并结合改进随机点、转向角以及新节点的快速扩展随机树(RRT)算法,避免重规划路径过分偏离以及不能及时躲避。与其他算法进行对比,结果表明:动态环境批量通知树算法规划路径成功率和效率更高,路径长度和拐点数更少,躲避未知障碍物性能更高,重规划路径更接近全局路径。 展开更多
关键词 批量通知树算法 反向生长搜索树 批量采样点策略 启发式函数 快速扩展随机树(RRT)算法 路径重规划
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基于功能化COFs材料的样品前处理技术在新兴污染物中的研究进展
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作者 潘自宇 刘智敏 许志刚 《分析测试学报》 CAS 北大核心 2025年第1期12-24,共13页
新兴污染物因具有环境持久性、生物累积性、生物毒性以及在环境中痕量存在等特点而备受全球众多国家关注。因此,对环境、食品以及生物样品中的新兴污染物进行高灵敏检测至关重要。传统样品前处理技术存在耗时长、吸附剂用量大,以及对不... 新兴污染物因具有环境持久性、生物累积性、生物毒性以及在环境中痕量存在等特点而备受全球众多国家关注。因此,对环境、食品以及生物样品中的新兴污染物进行高灵敏检测至关重要。传统样品前处理技术存在耗时长、吸附剂用量大,以及对不稳定污染物的分析准确性差等缺点,因此,亟需开发设计具有高选择性、高传质效率的新型材料作为前处理技术的吸附剂,以实现新兴污染物的高选择、高灵敏检测。共价有机骨架材料(COFs),特别是功能化的COFs材料,因具有比表面积大、结构可设计、稳定且构筑基元丰富等诸多优点而被广泛用于新兴污染物的富集。该文主要综述了近年来功能化COFs材料的合成策略及其作为样品前处理吸附剂在环境、食品和生物样品中新兴污染物中的分析应用,并对该类材料的未来发展趋势进行了展望。 展开更多
关键词 新兴污染物 功能化COFs材料 样品前处理技术
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重新思考工业微小缺陷检测中的掩模降采样和回归损失函数
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作者 李刚 邵瑞 +3 位作者 李敏 万洪林 周鸣乐 韩德隆 《计算机辅助设计与图形学学报》 北大核心 2025年第1期176-184,共9页
针对PCB在生产过程中会出现短路、漏孔等缺陷,已有的损失函数和降采样算法存在定位不准确等导致缺陷检测收敛缓慢、检测结果不准确的问题,提出了一种基于掩模降采样和微小缺陷交并比损失的一阶段缺陷检测器.首先,提出基于面积损失的微... 针对PCB在生产过程中会出现短路、漏孔等缺陷,已有的损失函数和降采样算法存在定位不准确等导致缺陷检测收敛缓慢、检测结果不准确的问题,提出了一种基于掩模降采样和微小缺陷交并比损失的一阶段缺陷检测器.首先,提出基于面积损失的微小缺陷交并比损失函数,以进行更精确的微小缺陷回归定位;其次,提出基于动态掩模的降采样算法,以利于检测器在缩小参数矩阵尺寸过程中自动筛选重要特征、次要特征和噪声特征,提升缺陷检测器的特征提取能力.实验结果表明,提出的缺陷检测器在北京大学PCB缺陷数据集和Deep PCB数据集上可分别达到98.50%的mAP和99.02%的mAP,优于对比算法;提出的降采样算法使YOLOv5等检测器的mAP在北京大学PCB数据集中提升了1.6个百分点,提出的损失函数有利于YOLOv3和YOLOv4等检测器提升其在2个数据集上的检测准确率,展现出良好的鲁棒性. 展开更多
关键词 损失函数设计 降采样 缺陷检测 目标检测
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基于改进YOLOv5的复杂场景电动车头盔检测方法
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作者 韩东辰 张方晖 +3 位作者 王诗洋 段克盼 李宁星 王凯 《现代电子技术》 北大核心 2025年第1期123-129,共7页
佩戴电动车头盔是安全骑行的重要保障,对电动车驾乘人员佩戴头盔进行有效检测在保障驾乘人员安全方面具有重要意义。电动车头盔检测中存在目标之间相互遮挡、复杂背景干扰、头盔目标小等问题,现有方法尚不能满足复杂场景下电动车头盔检... 佩戴电动车头盔是安全骑行的重要保障,对电动车驾乘人员佩戴头盔进行有效检测在保障驾乘人员安全方面具有重要意义。电动车头盔检测中存在目标之间相互遮挡、复杂背景干扰、头盔目标小等问题,现有方法尚不能满足复杂场景下电动车头盔检测的要求,因此,提出一种改进YOLOv5的复杂场景电动车头盔识别方法。首先,提出一种新的主干网络结构ML-CSPDarknet53,增强网络的特征提取能力,引入轻量级上采样算子CARAFE,利用特征图语义信息扩大感受野;其次,搭建坐标卷积CoordConv模块,增强网络对空间信息的感知能力,并将WIoU v3作为边界框损失函数,降低低质量样本对模型性能的不利影响;最后,构建了内容丰富的头盔检测数据集对改进算法进行验证。实验结果表明,改进后算法相较于原算法在精确度、召回率、mAP@0.5、mAP@0.5:0.95上分别提升了2.9%、3.0%、3.4%和2.2%,并且性能优于其他主流检测算法,满足复杂道路交通场景下电动车驾乘人员头盔检测的任务要求。 展开更多
关键词 头盔检测 改进YOLOv5 复杂场景 目标遮挡 特征提取 上采样 坐标卷积 损失函数
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基于Sigmoid函数归一化的多光谱指数特征在油茶林遥感识别和样本迁移研究中的应用
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作者 章海亮 王宇 +5 位作者 胡梅 张译之 张晶 詹白勺 刘雪梅 罗微 《光谱学与光谱分析》 北大核心 2025年第4期1159-1167,共9页
遥感影像分析中,多光谱指数特征的归一化处理对于提高分类精度和模型的泛化能力至关重要。采用Google Earth Engine(GEE)平台,以Sentinel-1 SAR雷达遥感影像和Sentinel-2 A光学遥感影像为数据源,通过计算纹理特征、地形特征、极化特征和... 遥感影像分析中,多光谱指数特征的归一化处理对于提高分类精度和模型的泛化能力至关重要。采用Google Earth Engine(GEE)平台,以Sentinel-1 SAR雷达遥感影像和Sentinel-2 A光学遥感影像为数据源,通过计算纹理特征、地形特征、极化特征和Sigmoid函数归一化前后的多光谱指数特征构建不同的分类场景,采用随机森林、梯度提升树、支持向量机和朴素贝叶斯4种机器学习分类器进行分类实验,分析对光谱指数特征进行归一化处理是否有利于油茶林识别。将构建的卷积神经网络(CNN)和结合Bi-LSTM模块的深度学习模型与机器学习分类器进行比较,分析不同模型对油茶林识别效果。以吉安市2021年五种土地类型样本点为基础,将适合油茶林识别的分类场景应用到不同年份(2019年、2020年、2022年、2023年)的样本迁移中,分析各年份油茶林面积增量与空间分布。结果表明,归一化后的光谱指数特征与随机森林相结合对油茶林识别精度最高,整体精度(OA)为99.02%,Kappa系数为0.9837,油茶林用户精度(UA)为95.31%,油茶林生产者精度(PA)为93.74%;研究中CNN系列的深度学习模型对油茶林识别精度略低于随机森林分类器,其中结合Bi-LSTM模块的深度学习模型的整体精度(OA)为98.69%,Kappa系数为0.9713油茶林用户精度(UA)为94.96%,油茶林生产者精度(PA)为93.17%;2021年吉安市油茶林种植面积达184.4881万亩,其中遂川县占27.67%,为面积最大县;油茶林种植分布由地势高向地势低递减,种植地点多位于家庭农户附近的山坡地和自留地,油茶林种植面积逐年增加。研究所提出的油茶林提取方法能够为实现油茶林动态监测与管理提供帮助,所提出的样本迁移方法能有效减少样本采集和标注成本。 展开更多
关键词 Sentinel影像 油茶 SIGMOID函数 Google Earth Engine 样本迁移
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非整周期采样下的相敏接收器相位差测量方法研究
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作者 刁艳美 陈美玲 《仪表技术与传感器》 北大核心 2025年第2期109-115,共7页
相敏接收器相位差计算精度容易受谐波及非整周期采样影响,不利于轨道区段状态的判断。文中提出一种非整周期的高精度相位差计算方法。首先使用简化格型自适应滤波器对采样信号进行小步长、快速收敛的滤波,求出采样信号实际频率;其次,对... 相敏接收器相位差计算精度容易受谐波及非整周期采样影响,不利于轨道区段状态的判断。文中提出一种非整周期的高精度相位差计算方法。首先使用简化格型自适应滤波器对采样信号进行小步长、快速收敛的滤波,求出采样信号实际频率;其次,对齐采样数据,使其整周期化;然后,对2路信号进行Hilbert变换,利用互相关函数及反三角函数得出相位差;最后,进行实验测试。结果表明:该方法能够在长持续时间下准确追踪被采样信号频率,能有效抑制端点效应,相位差计算结果误差小于0.000 1°。 展开更多
关键词 相敏接收器 非整周期采样 相关函数 相位差计算
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