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要实现采矿机组的智能化,必须对采矿机械的位姿进行实时准确地控制。由于开采工作面环境复杂,可选用捷联惯性导航技术来实现对采矿机械的监测。光纤陀螺作为捷联惯导系统的核心元件,其随机噪声制约着惯性导航系统的精度。传统的建模滤波及小波消噪方法由于其自身的局限性,不能保证准确性和去噪效果。所以结合经验模态分解(Empirical Mode Decomposition,EMD),提出了Hausdorff距离(Hausdorff Distance,HD)筛选准则与阈值滤波相结合的去噪算法。该算法以本征模态函数(Intrinsic Mode Function,IMF)与原始信号概率密度函数(Probability Density Function,PDF)的Hausdorff距离为判别依据,对所有IMF进行筛选,之后引入阈值对筛选出的IMF进行滤波处理,最后将其与余项重构。通过试验比较了软硬阈值的滤波效果,确定了该算法采用硬阈值。为验证算法的有效性,将该算法与其他3种方法进行比较,仿真信号与实测陀螺静态漂移数据的试验结果表明了该方法的优越性,能够有效降低陀螺的各项随机误差。 相似文献
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用投影变换的方法进行了成像声纳采集的水声图像特征提取与识别。阐述了Radon与扇束投影变换的特点及二者关系,并提出了一种基于图像边缘Radon变换的水声图像矩特征提取和识别方法。首先使用一种形态学边缘提取算子和细化算法提取二维图像中目标的轮廓,构造目标轮廓在Radon变换空间的平移、比例和旋转矩不变量,并应用于三类水下物体的分类识别中,实验仿真结果表明该方法在运算速度上优于Hu’s不变矩和图像目标面Radon投影空间不变矩,具有很好的性能和较高的实用价值。 相似文献
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动态挖掘算法考虑顾客随时间变化的动态行为轨迹的特性,采取动态追踪,以顾客的动态行为轨迹为依据实现对顾客的个性化推荐。由于行为轨迹中时间段划分跨度对推荐源数据实用价值存在影响,故提出了时间约束定义,同时完成了该算法中自动学习功能的实现。实验结果表明,基于该算法的推荐系统有较高的推荐准确度。 相似文献
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剩余活性污泥碱性发酵液用于厌氧交替好氧-缺氧序批式反应器生物除磷脱氮的碳源的研究(英文) 总被引:3,自引:0,他引:3
Activated sludge process has been widely used to remove phosphorus and nitrogen from wastewater. However, the nitrogen and phosphorus removal is sometimes unsatisfactory due to the low influent COD. Another problem with the activated sludge process is that large amount of waste activated sludge is produced, which needs further treatment. In this study, the waste activated sludge alkaline fermentation liquid was used as the main carbon source for phosphorus and nitrogen removal under anaerobic followed by alternating aerobic-anoxic conditions, and the results were compared with those using acetic acid as the carbon source. The use of alkaline fermentation liquid not only affected the transformations of phosphorus, nitrogen, intracellular polyhydroxyalkanoates and glycogen, but also led to higher removal efficiencies for phosphorus and nitrogen compared with acetic acid. It was observed that ammonium was completely removed with either alkaline fermentation liquid or acetic acid as the carbon source. However, the former resulted in higher removal efficiencies for phosphorus (95%) and nitrogen (82%), while the latter showed lower ones (87% and 74%, respectively). The presence of a large amount of propionic acid in the alkaline fermentation liquid was one possible reason for its higher phosphorus removal efficiency. Exogenous instead of endogenous denitrification was the main pathway for nitrogen removal with the alkaline fermentation liquid as the carbon source, which was responsible for its higher nitrogen removal efficiency. It seems that the alkaline fermentation liquid can replace acetic acid as the carbon source for phosphorus and nitrogen removal in anaerobic followed by alternating aerobic-anoxic sequencing batch reactor. 相似文献
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长尾理论视角下基于DCA 的网络自助出版推荐系统 总被引:1,自引:1,他引:0
随着自助出版系统文本规模的迅速增长,选用合理的推荐技术有利于"长尾"文本的发掘和价值实现。针对自助出版文本,设计了基于有向图的聚类算法DCA(Directed Graph Clustering Algorithm),将聚类看成是确定对象的过程,根据词间信息传递量的大小选定特征词集对文本进行聚类。为改善"长尾"文本聚类的有效性,文中所述系统设置了浮动相似度阙值及推荐公共池。实验结果表明,较之K-Means算法,该算法有较强的自适应性和通用性,能有效地运用到自助出版文本的个性化推荐系统领域。 相似文献
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为解决时域和频域盲解卷积算法在时延长的情况下计算量大、不适于水声信道的实时计算问题,本文研究了一种基于二阶统计量的时域与频城相结舍的快速盲解卷积算法.该算法首先对接收数据进行分段,段内数据进行分块处理,并给出一个新的在宽带情况下的代价函数表达范式;然后采用自然梯度法调整自适应权矩阵,进行块内数据离线、段闻数据在线更新的自适应滤波,以获得源信号的估计.仿真结果表明,该方法结合了宽带和窄带算法的优点,对于线性豢积混合的接收数据取得了很好的分离效果,且计算量小,更适于在实时信号处理中应用. 相似文献