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Estimation of the probability of informed trading models via an expectation‑conditional maximization algorithm
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作者 Montasser Ghachem Oguz Ersan 《Financial Innovation》 2025年第1期1860-1896,共37页
The estimation of the probability of informed trading(PIN)model and its extensions poses significant challenges owing to various computational problems.To address these issues,we propose a novel estimation method call... The estimation of the probability of informed trading(PIN)model and its extensions poses significant challenges owing to various computational problems.To address these issues,we propose a novel estimation method called the expectation-conditional-maximization(ECM)algorithm,which can serve as an alternative to the existing methods for estimating PIN models.Our method provides optimal estimates for the original PIN model as well as two of its extensions:the multilayer PIN model and the adjusted PIN model,along with its restricted versions.Our results indicate that estimations using the ECM algorithm are generally faster,more accurate,and more memory-efficient than the standard methods used in the literature,making it a robust alternative.More importantly,the ECM algorithm is not limited to the models discussed and can be easily adapted to estimate future extensions of the PIN model. 展开更多
关键词 expectation conditional-maximization algorithm ECM PIN model MPIN Multilayer probability of informed trading Adjusted PIN model Maximum-likelihood estimation Private information Information asymmetry
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Parallel Expectation-Maximization Algorithm for Large Databases
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作者 黄浩 宋瀚涛 陆玉昌 《Journal of Beijing Institute of Technology》 EI CAS 2006年第4期420-424,共5页
A new parallel expectation-maximization (EM) algorithm is proposed for large databases. The purpose of the algorithm is to accelerate the operation of the EM algorithm. As a well-known algorithm for estimation in ge... A new parallel expectation-maximization (EM) algorithm is proposed for large databases. The purpose of the algorithm is to accelerate the operation of the EM algorithm. As a well-known algorithm for estimation in generic statistical problems, the EM algorithm has been widely used in many domains. But it often requires significant computational resources. So it is needed to develop more elaborate methods to adapt the databases to a large number of records or large dimensionality. The parallel EM algorithm is based on partial Esteps which has the standard convergence guarantee of EM. The algorithm utilizes fully the advantage of parallel computation. It was confirmed that the algorithm obtains about 2.6 speedups in contrast with the standard EM algorithm through its application to large databases. The running time will decrease near linearly when the number of processors increasing. 展开更多
关键词 expectation-maximization (EM) algorithm incremental EM lazy EM parallel EM
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考虑旅客期望出行时间的列车时刻表与停站方案一体化优化
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作者 梁辉 景云 +1 位作者 戴邵杰 吴明泽 《铁道学报》 北大核心 2026年第2期1-8,共8页
设计满足旅客需求的列车时刻表对铁路运营方具有重要意义。旅客出行路径不仅受列车时刻表的影响,还受到列车停站方案的限制。考虑旅客期望出行时间,研究分钟客流需求下的高速铁路列车时刻表、停站方案和旅客路径一体化优化问题。设计列... 设计满足旅客需求的列车时刻表对铁路运营方具有重要意义。旅客出行路径不仅受列车时刻表的影响,还受到列车停站方案的限制。考虑旅客期望出行时间,研究分钟客流需求下的高速铁路列车时刻表、停站方案和旅客路径一体化优化问题。设计列车-旅客耦合时空网络,并在此基础上建立以旅客总出行时间成本最小的0-1整数线性规划模型。基于模型特点,采用拉格朗日松弛对列车安全间隔约束和列车服务能力约束进行松弛分解。以京沪高铁北京南—济南西区段为实际场景,通过构建一个包含40列列车和210组旅客的案例验证所提出模型和算法的有效性。此外,对旅客时间偏离系数进行灵敏度分析,并采用列车受限策略进一步提升算法的求解效率。 展开更多
关键词 高速铁路 列车时刻表 旅客期望出发时间 0-1整数规划模型 拉格朗日松弛
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漂移算法在视敏度检查中的应用
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作者 刘建廷 项华中 +2 位作者 马乐飞 程慧 王冰城 《光学仪器》 2026年第1期53-63,共11页
为了实现对受测者视敏度的精确测量,建立了一种结合概率分布与均值漂移算法的视敏度检测系统。该系统利用均值漂移算法沿数据密度递增方向探索聚类中心的特性,结合概率分布理论,精确计算不同视敏度水平对应的视敏度概率。通过反复迭代,... 为了实现对受测者视敏度的精确测量,建立了一种结合概率分布与均值漂移算法的视敏度检测系统。该系统利用均值漂移算法沿数据密度递增方向探索聚类中心的特性,结合概率分布理论,精确计算不同视敏度水平对应的视敏度概率。通过反复迭代,不断更新探索点并使其向概率密度较高的区域移动,直至找到最符合受测者实际视敏度水平的点。在系统实现过程中,算法可根据受测者响应实时调整视标的尺寸,通过持续地将当前观测值向其数学期望或均值方向调整,经过多轮迭代使概率分布逐渐贴近实际视敏度分布。实验结果表明,在3个实验场景中,即使在错误发生频率最高的情况下,该算法的平均误差率也仅为0.0083,基本满足视敏度测量的稳定可靠、鲁棒性高、抗干扰能力强等要求。 展开更多
关键词 概率分布 数学期望 均值漂移算法 视敏度
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品牌标识如何减少算法“负能”?算法自适应性与字母标识的交互效应
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作者 姚琦 肖文强 蒯玲 《外国经济与管理》 北大核心 2026年第4期78-96,共19页
由于算法透明度不足,企业开始主动公布产品算法信息以吸引消费者,但消费者通常对产品中所应用的算法持谨慎态度,这影响了算法控制产品的市场接受度。本文认为算法和品牌字母标识之间存在交互效应,并开展了一项行为实验和四项实验室实验... 由于算法透明度不足,企业开始主动公布产品算法信息以吸引消费者,但消费者通常对产品中所应用的算法持谨慎态度,这影响了算法控制产品的市场接受度。本文认为算法和品牌字母标识之间存在交互效应,并开展了一项行为实验和四项实验室实验进行验证。具体而言,实验1a和实验1b表明高(低)自适应算法控制产品,采用大写(小写)字母品牌标识,会引发更高的购买意愿和下载行为;实验2a探讨了产品绩效预期的中介作用,并进一步检验了交互效应对支付意愿的影响;实验2b发现当提供产品算法解释时,算法自适应性与字母标识的交互效应会削弱;实验3探讨了品牌标识字母间距的调节作用,当字母间距宽松(vs.紧凑)时,算法自适应性与品牌字母标识的交互对消费者反应的积极影响会削弱。 展开更多
关键词 算法控制产品 算法自适应性 字母大小写 产品绩效预期 字母间距
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期望因子驱动下的K-means初始聚类中心优化算法研究
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作者 冯鑫 檀丁 李明峰 《现代电子技术》 北大核心 2026年第6期89-93,共5页
合理的初始聚类中心是提升K-means算法聚类效果和避免局部最优的关键。为了确定合理的初始聚类中心,文中提出一种期望因子驱动下的K-means初始聚类中心优化算法。首先,设计期望因子驱动下的网格划分标准来衡量样本点密度因素,并采用欧... 合理的初始聚类中心是提升K-means算法聚类效果和避免局部最优的关键。为了确定合理的初始聚类中心,文中提出一种期望因子驱动下的K-means初始聚类中心优化算法。首先,设计期望因子驱动下的网格划分标准来衡量样本点密度因素,并采用欧氏距离衡量样本点距离因素;其次,引入权重系数约束密度因素和距离因素,综合考虑两种因素以优化初始聚类中心的选取,增强全局搜索能力和提升聚类效果;最后,提出中心相距和的概念来衡量初始聚类中心的优化效果。在UCI数据集Iris、Seeds和Wine上的对比实验结果表明,所提算法的中心相距和相较于传统K-means算法分别减小75%、52%、58%,误差平方和分别减小15%、7%、6%,准确率分别提升20%、19%、24%,性能优于其他改进算法。实验结果证明,所提算法能够有效优化初始聚类中心,提高聚类效果和聚类结果稳定性。 展开更多
关键词 初始聚类中心 优化算法 K-MEANS 期望因子 网格划分 权重系数
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基于双高斯分布混合的可解释自适应鲁棒神经网络建模方法
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作者 刘鑫 李琪琪 代伟 《自动化学报》 北大核心 2026年第3期463-480,共18页
工业过程数据常常受到混合噪声干扰,传统基于单一重尾分布的鲁棒建模方法在处理混合噪声问题时,在准确性与可解释性方面均存在一定局限.基于此,提出一种混合双高斯分布的可解释鲁棒自适应建模方法.该方法首先采用随机配置算法构建基础... 工业过程数据常常受到混合噪声干扰,传统基于单一重尾分布的鲁棒建模方法在处理混合噪声问题时,在准确性与可解释性方面均存在一定局限.基于此,提出一种混合双高斯分布的可解释鲁棒自适应建模方法.该方法首先采用随机配置算法构建基础的随机配置网络学习模型,确定模型的隐含层节点数、输入权重和偏置;其次为保证模型对混合噪声的鲁棒性,构建双高斯分布(一大一小方差)加权组合而成的噪声表征模型;随后利用期望最大化算法自适应迭代学习随机配置网络输出权值和混合高斯模型噪声参数,最终形成基于双高斯分布混合鲁棒建模方法.该方法具有以下优势:噪声模型能够通过参数自适应学习逼近实际混合噪声特性,其中大方差高斯分量负责对异常噪声进行粗调,小方差高斯分量则用于精细拟合主体噪声,从而增强模型的可解释性;在网络模型输出权值估计过程中,通过为每个输出数据点自适应分配惩罚权重,保障模型的鲁棒性能.为验证所提方法的有效性,分别在函数仿真、基准数据集和工业实例上设计多组对比实验,结果均表明所提方法具备良好的可靠性与实用性. 展开更多
关键词 随机配置网络 双高斯分布混合 鲁棒建模方法 期望最大化算法
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基于自适应滤波算法的电能计量设备故障自适应溯源识别
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作者 杨晓坤 戚成飞 +2 位作者 肖娜 郑思达 高帅 《兰州大学学报(自然科学版)》 北大核心 2026年第1期20-26,共7页
为提高电能计量设备故障的识别效果,提出基于最小均方误差(LMS)自适应滤波算法的电能计量设备故障自适应溯源识别方法,能够精准发现引发电能计量设备故障的原因.求解滤波器对电能计量设备输入、输出信号的反馈信息获取预估误差,自动更... 为提高电能计量设备故障的识别效果,提出基于最小均方误差(LMS)自适应滤波算法的电能计量设备故障自适应溯源识别方法,能够精准发现引发电能计量设备故障的原因.求解滤波器对电能计量设备输入、输出信号的反馈信息获取预估误差,自动更新滤波器参数,通过LMS算法确定横向滤波器的最佳抽头权值,实现电能计量设备数据的降噪.构建了基于有符号定向图-故障网络图的电能计量设备故障溯源模型,利用有符号定向图层分析降噪后的数据,体现电力系统中某设备出现失常时,其他设备受到的相关影响;利用故障网络图层表达设备发生故障时,其内部的扩展过程,阐述故障模式的制衡关系,实现电能计量设备故障的溯源识别.结果表明,该方法能够实现电能计量设备数据的降噪,使噪声峰值接近于0;故障识别中的数据丢失<40次,识别时间<15 ms,可提高电力设备故障的溯源识别效果. 展开更多
关键词 滤波算法 电能计量 设备故障 溯源识别 预期响应 抽头权向量
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基于遗传算法的装备数量规划方法
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作者 曹凯 刘星宇 +2 位作者 贺绍飞 许兴顺 池嘉诚 《指挥控制与仿真》 2026年第1期126-133,共8页
针对装备体系设计中面临的装备数量规划问题,基于美国国防部体系架构框架给出了“任务-能力-类型-型号”四层装备体系构建方法和流程,采用层次分析法完成了装备体系各要素权重分配,基于期望能力构建了装备能力差距函数并给出了装备期望... 针对装备体系设计中面临的装备数量规划问题,基于美国国防部体系架构框架给出了“任务-能力-类型-型号”四层装备体系构建方法和流程,采用层次分析法完成了装备体系各要素权重分配,基于期望能力构建了装备能力差距函数并给出了装备期望能力及实际能力的计算方法,基于此构建了以装备体系总能力差距最小为优化目标、以装备数量和研发投入为约束条件的装备数量规划模型,并给出了遗传算法求解方法。针对典型仿真算例,设计了保障装备体系并规划得到了各型装备数量,验证了该方法的可行性和有效性。 展开更多
关键词 装备体系 数量规划 层次分析法 期望能力 遗传算法
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块序正则化最大期望值重建算法β值对前列腺癌Al^(18)F-PSMA-11 PET/CT图像质量及半定量参数准确性的影响
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作者 彭新华 朱研佳 +3 位作者 朱湘 张利卜 王健 戴东 《中国医学装备》 2026年第1期34-39,共6页
目的:分析块序正则化最大期望值(BSREM)重建算法不同β值重建对^(18)F-氟化铝-前列腺特异性膜抗原-11(Al^(18)FPSMA-11)PET/CT图像质量参数和半定量参数的影响,经Al^(18)F-PSMA-11显像剂获取最佳图像质量和准确半定量参数的β值。方法:... 目的:分析块序正则化最大期望值(BSREM)重建算法不同β值重建对^(18)F-氟化铝-前列腺特异性膜抗原-11(Al^(18)FPSMA-11)PET/CT图像质量参数和半定量参数的影响,经Al^(18)F-PSMA-11显像剂获取最佳图像质量和准确半定量参数的β值。方法:回顾性分析2022年7月至2023年11月就诊于天津医科大学肿瘤医院,经病理诊断为前列腺癌并且在本院行Al^(18)F-PSMA-11 PET/CT检查的23例患者的56个病灶,所有图像分别选择有序子集最大化(OSEM)算法重建和BSREM算法重建。BSREM选择不同的β值:β100、β200、β300、β400、β500、β600、β700、β800、β900和β1000进行重建。视觉分析由两名医师对所有图像进行独立评分。测量两种重建方法后的图像噪声(Noise)、信噪比(SNR)、信号背景比(SBR)、最大标准化摄取值(SUV_(max))。分析β100~β1000的Noise、SNR、SBR及SUV_(max)变化,并结合视觉分析结果评价Al^(18)F-PSMA-11 PET/CT BSREM重建β值对图像质量和半定量参数的影响。结果:23例患者BSREM重建算法图像随β值上升Noise水平整体呈现下降趋势(Q=227.13,P<0.001),β100和β200时Noise水平高于OSEM重建(Z=-4.20,-2.54,P<0.05)。随β值上升所有病灶的SNR整体呈递增趋势(Q=305.33,P<0.001),β100时SNR与OSEM重建的SNR比较差异无统计学意义(P>0.05),β200~β1000时SNR高于OSEM重建,差异均有统计学意义(Z=-2.446,-3.920,-5.839,-6.089,-6.464,-6.446,-6.196,-5.562,-5.821,P<0.05)。β600~β1000相邻值间SNR比较差异均无统计学意义(P>0.05),SNR趋于平稳。所有病灶SBR随β值上升逐渐下降,β600时与OSEM重建SBR差异无统计学意义(P>0.05)。β700~β1000时SBR低于OSEM重建,差异均有统计学意义(Z=-1.098,-2.196,-3.250,-4.321,P<0.05),β700~β1000相邻值间SBR比较差异均无统计学意义(P>0.05),SBR趋于平稳。SUV_(max)随β值增加逐渐下降(Q=529.99,P<0.001),β100~β500时SUV_(max)高于OSEM重建,差异均有统计学意义(Z=-5.607,-4.714,-3.589,-2.625,-1.357,P<0.05)。β600和β700时SUV_(max)与OSEM重建比较差异无统计学意义(P>0.05)。β800~β1000时SUV_(max)低于OSEM重建(Z=-2.107,-3.188,-4.268,P<0.05)。视觉评分结果显示,BSREM重建算法β100~β300、β900和β1000图像质量低于OSEM重建,β400和β800图像质量近似于OSEM重建,β500~β700图像质量显著优于OSEM重建。结论:BSREM重建β值影响Al^(18)F-PSMA-11 PET/CT图像Noise、SNR、SBR及SUV_(max),且影响图像质量和诊断水平,而最适重建β值建议为600。 展开更多
关键词 前列腺特异性膜抗原 正电子发射型计算机体层显像(PET/CT) 块序正则化最大期望值(BSREM)重建算法 图像质量 β值
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A multi-target tracking algorithm based on Gaussian mixture model 被引量:4
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作者 SUN Lili CAO Yunhe +1 位作者 WU Wenhua LIU Yutao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2020年第3期482-487,共6页
Since the joint probabilistic data association(JPDA)algorithm results in calculation explosion with the increasing number of targets,a multi-target tracking algorithm based on Gaussian mixture model(GMM)clustering is ... Since the joint probabilistic data association(JPDA)algorithm results in calculation explosion with the increasing number of targets,a multi-target tracking algorithm based on Gaussian mixture model(GMM)clustering is proposed.The algorithm is used to cluster the measurements,and the association matrix between measurements and tracks is constructed by the posterior probability.Compared with the traditional data association algorithm,this algorithm has better tracking performance and less computational complexity.Simulation results demonstrate the effectiveness of the proposed algorithm. 展开更多
关键词 multiple-target tracking Gaussian mixture model(GMM) data association expectation maximization(EM)algorithm
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Novel method for extraction of ship target with overlaps in SAR image via EM algorithm 被引量:1
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作者 CAO Rui WANG Yong 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第4期874-887,共14页
The quality of synthetic aperture radar(SAR)image degrades in the case of multiple imaging projection planes(IPPs)and multiple overlapping ship targets,and then the performance of target classification and recognition... The quality of synthetic aperture radar(SAR)image degrades in the case of multiple imaging projection planes(IPPs)and multiple overlapping ship targets,and then the performance of target classification and recognition can be influenced.For addressing this issue,a method for extracting ship targets with overlaps via the expectation maximization(EM)algorithm is pro-posed.First,the scatterers of ship targets are obtained via the target detection technique.Then,the EM algorithm is applied to extract the scatterers of a single ship target with a single IPP.Afterwards,a novel image amplitude estimation approach is pro-posed,with which the radar image of a single target with a sin-gle IPP can be generated.The proposed method can accom-plish IPP selection and targets separation in the image domain,which can improve the image quality and reserve the target information most possibly.Results of simulated and real mea-sured data demonstrate the effectiveness of the proposed method. 展开更多
关键词 expectation maximization(EM)algorithm image processing imaging projection plane(IPP) overlapping ship tar-get synthetic aperture radar(SAR)
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DOA estimation and mutual coupling calibration with the SAGE algorithm 被引量:4
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作者 Xiong Kunlai Liu Zhangmeng +1 位作者 Liu Zheng Jiang Wenli 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2014年第6期1538-1543,共6页
In this paper, a novel algorithm is presented for direction of arrival(DOA) estimation and array self-calibration in the presence of unknown mutual coupling. In order to highlight the relationship between the array ... In this paper, a novel algorithm is presented for direction of arrival(DOA) estimation and array self-calibration in the presence of unknown mutual coupling. In order to highlight the relationship between the array output and mutual coupling coefficients, we present a novel model of the array output with the unknown mutual coupling coefficients. Based on this model, we use the space alternating generalized expectation-maximization(SAGE) algorithm to jointly estimate the DOA parameters and the mutual coupling coefficients. Unlike many existing counterparts, our method requires neither calibration sources nor initial calibration information. At the same time,our proposed method inherits the characteristics of good convergence and high estimation precision of the SAGE algorithm. By numerical experiments we demonstrate that our proposed method outperforms the existing method for DOA estimation and mutual coupling calibration. 展开更多
关键词 Array self-calibration Convergence Direction of arrival estima-tion Mutual coupling Space alternating generalized expectation-maximization algorithm
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A Coordinated Search Algorithm for a Lost Target on the Plane
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作者 Sundus Naji Al-Aziz Abd Al-Aziz Hosni El-Bagoury W.Afifi 《Computer Systems Science & Engineering》 SCIE EI 2022年第1期127-137,共11页
Concepts in search theory have developed since World War II.The study of search plans has found considerable interest among searchers due to its wide applications in our life.Searching for lost targets either located ... Concepts in search theory have developed since World War II.The study of search plans has found considerable interest among searchers due to its wide applications in our life.Searching for lost targets either located or moved is often a time-critical issue,especially when the target is very important.In many commercial and scientific missions at sea,it is of crucial importance to find lost targets underwater.We illustrate a technique known as coordinated search,that completely characterizes the search for a randomly located target on a plane.The idea is to avoid wasting time looking for a missing target.Two searchers or robots start from the center of a circle to search out a lost target,the first searcher looks for the target on the right side of the circular area,and the second one looks for it on the left side.The time taken to detect the target is obtained by assuming the target’s position has a symmetric distribution.The procedures to facilitate the detection of the target are presented as an algorithm and as a flow-chart.An application demonstrates the applicability of this search technique and the associated decrease in search cost.Its effectiveness is illustrated by numerical results,which indicates considerable promise. 展开更多
关键词 expected value sensors lost target coordinated search search algorithm lost ship
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The Distribution Search:An O(n) Expected Time Search
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《Wuhan University Journal of Natural Sciences》 CAS 1996年第2期167-170,共4页
Provided an algorithm for the distribution search and proves the time complexity of the algorithm. This algorithm uses a mathematical formula to search n elements in the sequence of n elements in O(n)expected time,and... Provided an algorithm for the distribution search and proves the time complexity of the algorithm. This algorithm uses a mathematical formula to search n elements in the sequence of n elements in O(n)expected time,and experimental reesult proves that distribution search is superior to binary search. 展开更多
关键词 the distribution search the algorithm design a mathematical formula analysis of the complexity O(n)expected time
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Probabilistic, Statistical and Algorithmic Aspects of the Similarity of Texts and Application to Gospels Comparison
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作者 Soumaila Dembele Gane Samb Lo 《Journal of Data Analysis and Information Processing》 2015年第4期112-127,共16页
The fundamental problem of similarity studies, in the frame of data-mining, is to examine and detect similar items in articles, papers, and books with huge sizes. In this paper, we are interested in the probabilistic,... The fundamental problem of similarity studies, in the frame of data-mining, is to examine and detect similar items in articles, papers, and books with huge sizes. In this paper, we are interested in the probabilistic, and the statistical and the algorithmic aspects in studies of texts. We will be using the approach of k-shinglings, a k-shingling being defined as a sequence of k consecutive characters that are extracted from a text (k ≥ 1). The main stake in this field is to find accurate and quick algorithms to compute the similarity in short times. This will be achieved in using approximation methods. The first approximation method is statistical and, is based on the theorem of Glivenko-Cantelli. The second is the banding technique. And the third concerns a modification of the algorithm proposed by Rajaraman et al. ([1]), denoted here as (RUM). The Jaccard index is the one being used in this paper. We finally illustrate these results of the paper on the four Gospels. The results are very conclusive. 展开更多
关键词 SIMILARITY Web MINING Jaccard SIMILARITY RU algorithm Minhashing Data MINING Shingling Bible’s GOSPELS Glivenko-Cantelli expectED SIMILARITY STATISTICAL Estimation
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A Complex Algorithm for Solving a Kind of Stochastic Programming
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作者 Yunpeng Luo Xinshun Ma 《Journal of Applied Mathematics and Physics》 2020年第6期1016-1030,共15页
Considering that the probability distribution of random variables in stochastic programming usually has incomplete information due to a perfect sample data in many real applications, this paper discusses a class of tw... Considering that the probability distribution of random variables in stochastic programming usually has incomplete information due to a perfect sample data in many real applications, this paper discusses a class of two-stage stochastic programming problems modeling with maximum minimum expectation compensation criterion (MaxEMin) under the probability distribution having linear partial information (LPI). In view of the nondifferentiability of this kind of stochastic programming modeling, an improved complex algorithm is designed and analyzed. This algorithm can effectively solve the nondifferentiable stochastic programming problem under LPI through the variable polyhedron iteration. The calculation and discussion of numerical examples show the effectiveness of the proposed algorithm. 展开更多
关键词 Stochastic Programming with Recourse Probability Distribution with Linear Partial Information Maximized Minimum expectation Complex algorithm
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Parameter Estimation of RBF-AR Model Based on the EM-EKF Algorithm 被引量:6
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作者 Yanhui Xi Hui Peng Hong Mo 《自动化学报》 EI CSCD 北大核心 2017年第9期1636-1643,共8页
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The Fuzzy Modeling Algorithm for Complex Systems Based on Stochastic Neural Network
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作者 李波 张世英 李银惠 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2002年第3期46-51,共6页
A fuzzy modeling method for complex systems is studied. The notation of general stochastic neural network (GSNN) is presented and a new modeling method is given based on the combination of the modified Takagi and Suge... A fuzzy modeling method for complex systems is studied. The notation of general stochastic neural network (GSNN) is presented and a new modeling method is given based on the combination of the modified Takagi and Sugeno's (MTS) fuzzy model and one-order GSNN. Using expectation-maximization(EM) algorithm, parameter estimation and model selection procedures are given. It avoids the shortcomings brought by other methods such as BP algorithm, when the number of parameters is large, BP algorithm is still difficult to apply directly without fine tuning and subjective tinkering. Finally, the simulated example demonstrates the effectiveness. 展开更多
关键词 Complex system modeling General stochastic neural network MTS fuzzy model expectation-maximization algorithm
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基于TLF-YOLOv8的堆叠垃圾实例分割算法 被引量:1
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作者 李利 梁晶 +2 位作者 陈旭东 潘红光 寇发荣 《科学技术与工程》 北大核心 2025年第5期2009-2018,共10页
相较于一般场景下的图像实例分割,复杂堆叠场景下的实例分割受到严重遮挡、同类别待测物体堆叠等复杂情况的影响,使得其实例分割具有更大的难度。针对具有复杂堆叠场景下的垃圾实例分割问题,提出了一种融合YOLOv8与双层特征网络策略的... 相较于一般场景下的图像实例分割,复杂堆叠场景下的实例分割受到严重遮挡、同类别待测物体堆叠等复杂情况的影响,使得其实例分割具有更大的难度。针对具有复杂堆叠场景下的垃圾实例分割问题,提出了一种融合YOLOv8与双层特征网络策略的实例分割算法。首先,在数据预处理部分进行特征数据分层,并通过双层图卷积网络(graph convolutions network,GCN)实现双分支特征融合,减弱堆叠情况对被遮挡物体特征的影响,从而解决复杂堆叠遮挡下的实例分割问题。同时,为了解决同类待测物体易混淆的问题,融入了软阈值化非极大值抑制算法和新的交并比算法。最后,根据应用场景和数据集的复杂性,优化了主干网络部分的特征提取模块,并在主干网络部分引入了多尺度注意力机制,有效提高了模型的检测性能。实验使用遮挡垃圾分类实例分割数据集,实验结果表明该方法的平均准确率、交并比阈值为0.5时的平均准确率(AP_(50))、交并比为0.5~0.95时的平均准确率(AP_(50~95))等指标较之前的其他方法更优。相较于原YOLOv8算法,检测AP_(50)提高了7.9%,分割AP_(50)提高了5.4%,具有更好的检测和分割效果。 展开更多
关键词 垃圾堆叠 双层特征解耦融合 YOLOv8算法 软阈值化非极大值抑制 动态非单调聚焦机制 期望最大化注意力
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