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81.
提出了一种基于相关向量机的MEMS陀螺仪随机漂移预测方法。针对MEMS陀螺仪随机漂移误差的非线性、不确定性等特点,建立了相关向量机预测模型,并采用EM算法获得模型的参数。针对随机漂移的混沌特性,利用相空间重构技术,将重构后的漂移序列作为输入变量进行模型的训练和预测。训练和测试结果均表明,该方法具有很好的预测效果,优于常用的时间序列分析法和支持向量机法。利用预测结果对随机漂移进行补偿,有效地提高了陀螺的使用精度。  相似文献   
82.
在宽带波束形成中,若干扰信号从主瓣方向进入,会引起主瓣畸变、旁瓣电平抬高,从而使波束性能严重恶化。为了解决波束形成中的这些问题,研究了一种基于协方差矩阵重构和特征投影预处理(EMP)的宽带波束形成算法。该算法首先通过EMP算法求取阻塞矩阵,对接收信号进行干扰相消预处理阻塞掉主瓣干扰;然后通过相干信号子空间(CSM)方法、协方差矩阵重构求取合理的协方差矩阵;最后进行波束形成。在主瓣干扰、旁瓣干扰同时存在的情况下,该算法能够自适应地阻塞主瓣干扰、抑制旁瓣干扰,解决了存在主瓣干扰情况下宽带波束形成的波形畸变问题。计算机仿真验证了该算法有效性。  相似文献   
83.
秦福建  桂莉 《炭素技术》2007,26(3):47-49
在预焙阳极生产中,卧式连续混捏机曾经大量应用,使用效果良好。目前艾立许混捏机以其简化机械设计、降低维修及操作成本等许多独特的优点,在铝电解炭阳极生产中也得到大量应用。通过对原有卧式混捏机设备增加艾立许冷却系统,可以使两种设备得到最佳组合,可提高阳极质量,取得良好效益。  相似文献   
84.
二郎山滑坡坡脚挡墙破坏及修复技术研究   总被引:1,自引:0,他引:1  
王浩  岳建伟  王全才  潘登 《人民长江》2017,48(15):71-75
二郎山1号滑坡位于龙胆溪左岸,滑坡前缘采用了坡脚挡墙防冲刷工程,10 a之后位于龙胆溪凹岸部分坡脚挡墙破坏。针对坡脚挡墙破坏形成的原因,对比分析了目前常用冲刷防护结构的局限性,提出了采用台坎式挡墙新组合结构进行修复,组合结构主要由挡土墙、墙底抗滑键、墙脚台坎以及耐磨肋组成。介绍了组合结构设计计算方法,并通过造价分析说明台坎式挡墙结构与其它防冲刷相比在经济上具有明显优越性,可为其它同类地质灾害防治提供参考。  相似文献   
85.
We introduce order-k α-hulls and α-shapes – generalizations of α-hulls and α-shapes. Being also a generalization of k-hull (known in statistics as “k-depth contour”), order-k α-hull provides a link between shape reconstruction and statistical depth. As a generalization of α-hull, order-k α-hull gives a robust shape estimation by ignoring locally up to k outliers in a point set. Order-k α-shape produces an “inner” shape of the set, with the amount of “digging” into the points controlled by k. As a generalization of k-hull, order-k α-hull is capable of determining “deep” points amidst samples from a multimodal distribution: it correctly identifies points which lie outside clusters of samples.The order-k α-hulls and α-shapes are related to order-k Voronoi diagrams in the same way in which α-hulls and α-shapes are related to Voronoi diagrams. This implies that order-k α-hull and α-shape can be readily built from order-k Voronoi diagram, and that the number of different order-k α-shapes for all possible values of α is proportional to the complexity of order-k Voronoi diagram.  相似文献   
86.
87.
The linear reconstruction measure (LRM), which determines the nearest neighbors of the query sample in all known training samples by sorting the minimum L2-norm error linear reconstruction coefficients, is introduced in this paper. The intuitive interpretation and mathematical proofs are presented to reveal the efficient working mechanism of LRM. Through analyzing the physical meaning of coefficients and regularization items, we find that LRM provides more useful information and advantages than the conventional similarity measure model which calculates the distance between two entities (i.e. conventional point-to-point, C-PtP). Inspired by the advantages of LRM, the linear reconstruction measure steered nearest neighbor classification framework (LRM-NNCF) is designed with eight classifiers according to different decision rules and models of LRM. Evaluation on several face databases and the experimental results demonstrate that these proposed classifiers can achieve greater performance than the C-PtP based 1-NNs and competitive recognition accuracy and robustness compared with the state-of-the-art classifiers.  相似文献   
88.
The paper studies a 3D fingerprint reconstruction technique based on multi-view touchless fingerprint images. This technique offers a solution for 3D fingerprint image generation and application when only multi-view 2D images are available. However, the difficulties and stresses of 3D fingerprint reconstruction are the establishment of feature correspondences based on 2D touchless fingerprint images and the estimation of the finger shape model. In this paper, several popular used features, such as scale invariant feature transformation (SIFT) feature, ridge feature and minutiae, are employed for correspondences establishment. To extract these fingerprint features accurately, an improved fingerprint enhancement method has been proposed by polishing orientation and ridge frequency maps according to the characteristics of 2D touchless fingerprint images. Therefore, correspondences can be established by adopting hierarchical fingerprint matching approaches. Through an analysis of 440 3D point cloud finger data (220 fingers, 2 pictures each) collected by a 3D scanning technique, i.e., the structured light illumination (SLI) method, the finger shape model is estimated. It is found that the binary quadratic function is more suitable for the finger shape model than the other mixed model tested in this paper. In our experiments, the reconstruction accuracy is illustrated by constructing a cylinder. Furthermore, results obtained from different fingerprint feature correspondences are analyzed and compared to show which features are more suitable for 3D fingerprint images generation.  相似文献   
89.
It has been recently shown in Ren et al. (2010) that by collecting noise-contaminated time series generated by a coupled-oscillator system at each node of a network, it is possible to robustly reconstruct its topology, i.e. determine the graph Laplacian. Restricting ourselves to linear consensus dynamics over undirected communication networks, in this paper we introduce a new dynamic average consensus least-squares algorithm to locally estimate these time series at each node, thus making the reconstruction process fully distributed and more easily applicable in the real world. We also propose a novel efficient method for separating the off-diagonal entries of the reconstructed Laplacian, and examine several concepts related to the trace of the dynamic correlation matrix of the coupled single integrators, which is a distinctive element of our network reconstruction method. The theory is illustrated with examples from computer, power and transportation systems.  相似文献   
90.
提出了一种基于距离变换、形态重构和分水岭算法的图像分割算法。将一幅图像通过距离变换得到距离灰度图,与形态重构算法结合,得到颗粒图像的标识点图,用标识点图对距离灰度图进行分割,再用分水岭变换对分割后的距离灰度图进行变换。试验表明,该算法能有效合理地解决粘连或者重叠颗粒等物体的分割。  相似文献   
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