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基于改进LightGBM的交通模式识别算法 被引量:6
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作者 熊苏生 《计算机与现代化》 2018年第10期68-73,126,共7页
针对交通模式识别中非步行交通模式识别精度低的问题,提出一种改进后的Light GBM算法结合移动端的交通模式分类方法。该方法首先对数据集进行了滤波处理,选取了三轴加速度计、陀螺仪和磁力计这3种传感器数据的时域和频域特征作为模式识... 针对交通模式识别中非步行交通模式识别精度低的问题,提出一种改进后的Light GBM算法结合移动端的交通模式分类方法。该方法首先对数据集进行了滤波处理,选取了三轴加速度计、陀螺仪和磁力计这3种传感器数据的时域和频域特征作为模式识别特征量,然后通过采用Filter相关性度量CFS算法对特征进行打分排序,选择最优特征集,最后识别过程采用分层识别算法和基于居民出行规则与一阶隐马尔科夫链改进的K-lightGBM识别算法对交通模式进行识别,同时采用部分传统算法进行对比实验。实验结果表明,该方法不仅能识别多种交通模式,而且对居民的交通模式识别的平均准确率较高,达到了94%。 展开更多
关键词 传感器 CFS 一阶隐马尔科夫链 LightGBM算法 交通模式识别
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HMM-based noise estimator for speech enhancement
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作者 许春冬 夏日升 +2 位作者 应冬文 李军锋 颜永红 《Journal of Beijing Institute of Technology》 EI CAS 2014年第4期549-556,共8页
A noise estimator was presented in this paper by modeling the log-power sequence with hidden Markov model (HMM). The smoothing factor of this estimator was motivated by the speech presence probability at each freque... A noise estimator was presented in this paper by modeling the log-power sequence with hidden Markov model (HMM). The smoothing factor of this estimator was motivated by the speech presence probability at each frequency band. This HMM had a speech state and a nonspeech state, and each state consisted of a unique Gaussian function. The mean of the nonspeech state was the estimation of the noise logarithmic power. To make this estimator run in an on-line manner, an HMM parameter updated method was used based on a first-order recursive process. The noise signal was tracked together with the HMM to be sequentially updated. For the sake of reliability, some constraints were introduced to the HMM. The proposed algorithm was compared with the conventional ones such as minimum statistics (MS) and improved minima controlled recursive averaging (IM- CRA). The experimental results confirms its promising performance. 展开更多
关键词 noise estimation hidden markov model CONSTRAINTS first-order recursive process speech enhancement
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