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基于K-SVD-OMP的稀疏表示方法在电力负荷预测中的应用 被引量:15
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作者 李军 李世昌 《电机与控制学报》 EI CSCD 北大核心 2020年第9期156-164,172,共10页
针对中期或短期电力负荷预测,提出一种基于稀疏表示的特征提取建模方法。为构建预测模型,将历史电力负荷等数据构成具有时延的输入—输出数据对,将时延输入数据向量作为初始字典,采用K均值—奇异值分解(K-SVD)算法将其进行稀疏分解与变... 针对中期或短期电力负荷预测,提出一种基于稀疏表示的特征提取建模方法。为构建预测模型,将历史电力负荷等数据构成具有时延的输入—输出数据对,将时延输入数据向量作为初始字典,采用K均值—奇异值分解(K-SVD)算法将其进行稀疏分解与变换至稀疏域以得到学习后的字典。进一步,由正交匹配追踪(OMP)算法获取相应的稀疏编码向量,再将该向量作为核极限学习机(KELM)的输入来构建全局回归模型。为了验证该方法的有效性,将所提出的方法用于不同地区的中期或短期电力负荷预测中,在同等条件下还与单一KELM、支持向量机(SVM)、极限学习机(ELM)方法以及非字典学习的其他稀疏表示建模方法进行了比较。实验结果表明,不同的稀疏表示建模方法均能取得很好的预测效果,其中所提方法具有更好的预测效果,显示出其有效性。 展开更多
关键词 负荷预测 稀疏表示 特征提取 k均值—奇异值分解 正交匹配追踪 核极限学习机
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Impulsive component extraction using shift-invariant dictionary learning and its application to gear-box bearing early fault diagnosis 被引量:4
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作者 ZHANG Zhao-heng DING Jian-ming +1 位作者 WU Chao LIN Jian-hui 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第4期824-838,共15页
The impulsive components induced by bearing faults are key features for assessing gear-box bearing faults.However,because of heavy background noise and the interferences of other vibrations,it is difficult to extract ... The impulsive components induced by bearing faults are key features for assessing gear-box bearing faults.However,because of heavy background noise and the interferences of other vibrations,it is difficult to extract these impulsive components caused by faults,particularly early faults,from the measured vibration signals.To capture the high-level structure of impulsive components embedded in measured vibration signals,a dictionary learning method called shift-invariant K-means singular value decomposition(SI-K-SVD)dictionary learning is used to detect the early faults of gear-box bearings.Although SI-K-SVD is more flexible and adaptable than existing methods,the improper selection of two SI-K-SVD-related parameters,namely,the number of iterations and the pattern lengths,has an adverse influence on fault detection performance.Therefore,the sparsity of the envelope spectrum(SES)and the kurtosis of the envelope spectrum(KES)are used to select these two key parameters,respectively.SI-K-SVD with the two selected optimal parameter values,referred to as optimal parameter SI-K-SVD(OP-SI-K-SVD),is proposed to detect gear-box bearing faults.The proposed method is verified by both simulations and an experiment.Compared to the state-of-the-art methods,namely,empirical model decomposition,wavelet transform and K-SVD,OP-SI-K-SVD has better performance in diagnosing the early faults of a gear-box bearing. 展开更多
关键词 gear-box bearing fault diagnosis shift-invariant k-means singular value decomposition impulsive component extraction
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