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91.
为了解决骨骼参数难以测量的问题,提出一种利用网格分割结果计算参数的方法.首先对骨骼网格模型在提取少量特征点的基础上进行语义分割;然后将分割得到的模板借助基于Laplacian变形的非刚性配准,指导同类骨骼模型实现快速兼容性分割;最后结合网格分割结果及特征点计算出骨骼的主要形态参数.实验结果表明,该方法仅需少量的用户交互就能获得较好的测量效果,结合模板的策略也支持大批量骨骼模型的参数测定. 相似文献
92.
Peng Geng Min Huang Shuaiqi Liu Jun Feng Peina Bao 《Multimedia Tools and Applications》2016,75(17):10583-10593
The curvelet transform can represent images at both different scales and different directions. Ripplet transform, as a higher dimensional generalization of the curvelet transform, provides a new tight frame with sparse representation for images with discontinuities along C2 curves. However, the ripplet transform is lack of translation invariance, which causes the pseudo-Gibbs phenomenon on the edges of image. In this paper, the cycle spinning method is adopted to suppress the pseudo-Gibbs phenomena in the multifocus image fusion. On the other hand, a modified sum-modified-laplacian rule based on the threshold is proposed to make the decision map to select the ripplet coefficient. Several experiments are executed to compare the presented approach with other methods based on the curvelet, sharp frequency localized contourlet transform and shearlet transform. The experiments demonstrate that the presented fusion algorithm outperforms these image fusion works. 相似文献
93.
This paper proposes a novel method to quantify the error of a nominal normalized right graph symbol (NRGS) for an errors-in-variables (EIV) system corrupted with bounded noise. Following an identification framework for estimation of a perturbation model set, a worst-case v-gap error bound for the estimated nominal NRGS can be first determined from \textit{a priori} and \textit{a posteriori} information on the underlying EIV system. Then, an NRGS perturbation model set can be derived from a close relation between the v-gap metric of two models and ${\rm H}_\infty$-norm of their NRGSs' difference. The obtained NRGS perturbation model set paves the way for robust controller design using an ${\rm H}_\infty$ loop-shaping method because it is a standard form of the well-known NCF (normalized coprime factor) perturbation model set. Finally, a numerical simulation is used to demonstrate the effectiveness of the proposed identification method. 相似文献
94.
In this paper, a quasi-Newton-type optimized iterative learning control (ILC)
algorithm is investigated
for a class of discrete linear time-invariant systems. The proposed learning
algorithm is to update the learning gain matrix by a quasi-Newton-type matrix instead of the
inversion of the plant. By means of the mathematical inductive method, the monotone
convergence of the proposed algorithm is analyzed, which shows
that the tracking error monotonously converges to zero after a
finite number of iterations. Compared with the existing optimized ILC
algorithms, due to the superlinear convergence of quasi-Newton method, the proposed learning law operates with a faster
convergent rate and is robust to the ill-condition of the
system model, and thus owns a wide range of applications.
Numerical simulations demonstrate the validity and
effectiveness. 相似文献
95.
96.
王庚 《数字社区&智能家居》2013,(6):1325-1326
随着我国的科技事业的快速进步,越来越多的科技项目不断的被研发和生产,其中计算机通信工程的建设和完善始终和百姓的生活有着紧密的联系。在日常生活中,电话、手机已相当的普及,这样一些方面就是得益于通信工程作出突出贡献。该文中,我们将着力介绍计算机网络通讯在运行中存在的问题,以及就这些问题我们提出了相应的建议和改进策略。 相似文献
97.
Yongli Hu Fuqing Duan Baocai Yin Mingquan Zhou Yanfeng Sun Zhongke Wu Guohua Geng 《Multimedia Tools and Applications》2013,64(2):345-364
3D face reconstruction from skull has been investigated deeply by computer scientists in the past two decades because it is important for identification. The dominant methods construct 3D face from the soft tissue thickness measured at a set of landmarks on skull. The quantity and position of the landmarks are very vital for 3D face reconstruction, but there is no uniform standard for the selection of the landmarks. Additionally, the acquirement of the landmarks on skull is difficult without manual assistance. In this paper, an automatic 3D face reconstruction method based on a hierarchical dense deformable model is proposed. To construct the model, the skull and face samples are acquired by CT scanner and represented as dense triangle mesh. Then a non-rigid dense mesh registration algorithm is presented to align all the samples in point-to-point correspondence. Based on the aligned samples, a global deformable model is constructed, and three local models are constructed from the segmented patches of the eye, nose and mouth. For a given skull, the globe and local deformable models are iteratively matched with it, and the reconstructed facial surface is obtained by fusing the globe and local reconstruction results. To validate the presented method, a measurement in the coefficient domain of a face deformable model is defined. The experimental results indicate that the proposed method has good performance for 3D face reconstruction from skull. 相似文献
98.
空气阻力系数对水滴运动及蒸发的影响 总被引:1,自引:0,他引:1
应用喷灌条件下水滴的运动、蒸发及分布模型对水滴的飞行时间、飞行距离以及蒸发率进行了预测,并对5种空气阻力系数计算公式 (Bird、Park、Fukui、伊沙叶夫、Wallis) 求得的预测值和实测值进行了比较。结果表明:应用Bird、Wallis、Fukui公式预测的水滴飞行时间与实测值随水滴直径的变化趋势一致,应用Park和伊沙叶夫公式求得的水滴飞行时间预测值与实测值的相对误差最小;5种阻力系数公式均能较准确地预测水滴飞行距离,其中Park公式的预测精度最高;5种阻力系数公式对于单个水滴蒸发率的预测结果与实测值之间的平均相对误差在26.1%~30.2%之间;5种阻力系数公式对总蒸发率的预测影响不明显,预测值与实测值之间的平均相对误差在15.2%~17.5%之间。建议在水滴运动和蒸发计算中采用Park阻力系数公式。 相似文献
99.
100.
Lihong Huang 《Asian journal of control》2013,15(4):1158-1167
This paper considers a class of delayed neural networks with discontinuous neuron activations. Based on the theory of differential equations with discontinuous right‐hand sides, some novel sufficient conditions are derived that ensure the existence and global exponential stability of the equilibrium point. Moreover, by adopting the concept of convergence in measure, convergence behavior for the output is discussed. The obtained results are independent of the delay parameter and can be thought of as a generalization of previous results established for delayed neural networks with Lipschtz continuous neuron activations to the discontinuous case. Finally, we give a numerical example to illustrate the effectiveness and novelty of our results by comparing our results with those in the early literature. 相似文献