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变分自编码器低质量数据生成原因剖析
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作者 张建光 郭双乐 +2 位作者 曹吉朋 左瑞龙 齐长志 《衡水学院学报》 2023年第4期20-24,共5页
从数学角度对变分自编码器目标函数下界和网络结构进行了研究,指出变分自编码器所生成的样本质量低的两个原因:1)由于识别模型qφ(z|x)表达能力的限制使得后验分布pθ(z|x)偏离目标分布,导致最大化证据下限时没有能够保证最大化对数似然... 从数学角度对变分自编码器目标函数下界和网络结构进行了研究,指出变分自编码器所生成的样本质量低的两个原因:1)由于识别模型qφ(z|x)表达能力的限制使得后验分布pθ(z|x)偏离目标分布,导致最大化证据下限时没有能够保证最大化对数似然;2)变分自编码器中条件分布pθ(x|z)对应的网络结构把生成数据x和隐变量z之间的概率依赖关系近似为函数依赖关系,即把一个显示概率生成模型用一个隐式概率生成模型来近似实现。该结论为进一步研究和改进变分自编码器以及设计其他生成模型提供了理论支撑。 展开更多
关键词 变分自编码器 生成模型 重参数化
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Matched Field Localization Based on CS-MUSIC Algorithm 被引量:1
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作者 guo shuangle TANG Ruichun +1 位作者 PENG Linhui JI Xiaopeng 《Journal of Ocean University of China》 SCIE CAS 2016年第2期254-260,共7页
The problem caused by shortness or excessiveness of snapshots and by coherent sources in underwater acoustic positioning is considered.A matched field localization algorithm based on CS-MUSIC(Compressive Sensing Multi... The problem caused by shortness or excessiveness of snapshots and by coherent sources in underwater acoustic positioning is considered.A matched field localization algorithm based on CS-MUSIC(Compressive Sensing Multiple Signal Classification) is proposed based on the sparse mathematical model of the underwater positioning.The signal matrix is calculated through the SVD(Singular Value Decomposition) of the observation matrix.The observation matrix in the sparse mathematical model is replaced by the signal matrix,and a new concise sparse mathematical model is obtained,which means not only the scale of the localization problem but also the noise level is reduced;then the new sparse mathematical model is solved by the CS-MUSIC algorithm which is a combination of CS(Compressive Sensing) method and MUSIC(Multiple Signal Classification) method.The algorithm proposed in this paper can overcome effectively the difficulties caused by correlated sources and shortness of snapshots,and it can also reduce the time complexity and noise level of the localization problem by using the SVD of the observation matrix when the number of snapshots is large,which will be proved in this paper. 展开更多
关键词 MUSIC算法 匹配场定位 矩阵奇异值分解 多重信号分类法 数学模型 水声定位 MUSIC 时间复杂度
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Optimal tracking control for linear time-delay large-scale systems with persistent disturbances 被引量:1
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作者 Tang Ruichun Ma Huamin +1 位作者 guo shuangle Ren Lijie 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第5期1058-1064,共7页
An optimal tracking control (OTC) problem for linear time-delay large-scale systems affected by external persistent disturbances is investigated. Based on the internal model principle, a disturbance compensator is c... An optimal tracking control (OTC) problem for linear time-delay large-scale systems affected by external persistent disturbances is investigated. Based on the internal model principle, a disturbance compensator is constructed. The system with persistent disturbances is transformed into an augmented system without persistent disturbances. The original OTC problem of linear time-delay system is transformed into a sequence of linear two- point boundary value (TPBV) problems by introducing a sensitivity parameter and expanding Maclaurin series around it. By solving an OTC law of the augmented system, the OTC law of the original system is obtained. A numerical simulation is provided to illustrate the effectiveness of the proposed method. 展开更多
关键词 optimal tracking control sensitivity approach time-delay large-scale system persistent disturbance
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基于加速稳健特征的视频运动识别技术分析
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作者 郭双乐 张建光 《电子技术(上海)》 2023年第11期158-159,共2页
阐述加速稳健特征(Speeded Up Robust Features,SURF)和运动边界直方图(Motion Boundary Histograms,MBH)分别是图像识别和运动识别中最流行的特征方法,它们之间存在互补特性,探讨将这两种特征有效结合,提出动态加速稳健特征(Motion Spe... 阐述加速稳健特征(Speeded Up Robust Features,SURF)和运动边界直方图(Motion Boundary Histograms,MBH)分别是图像识别和运动识别中最流行的特征方法,它们之间存在互补特性,探讨将这两种特征有效结合,提出动态加速稳健特征(Motion Speeded-Up Robust Features,MoSURF)用于视频分析和运动识别。与现有方法相比,该方法在识别准确性和特征提取速度方面都取得了较好的效果。 展开更多
关键词 图像识别 运动识别 加速稳健特征 视频分析
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