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991.
Multi-Scale Gaussian Processes: a Novel Model for Chaotic Time Series Prediction 总被引:1,自引:0,他引:1 下载免费PDF全文
Based on the classical Gaussian process (GP) model, we propose a multi-scale Gaussian process (MGP) model to predict the existence of chaotic time series. The MGP employs a covariance function that is constructed by a scaling function with its different dilations and translations, ensuring that the optimal hyperparameter is easy to determine. Moreover, the scaling function with its different dilations and translations can form a set of complete bases, resulting in the fact that the MGP can acquire better prediction performance than the GP. The experiments can lead to the following conclusions: (i) The MGP gives a relatively better prediction performance in comparison with the classical GP model. (ii) The prediction performance of the MGP is competitive with support vector machine (SVM). They give better performance as compared to the radial basis function networks. 相似文献
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描述了PtS i512×512CCD红外探测器用集成式杜瓦和斯特林制冷机组件的集成,包括斯特林制冷机的选择、集成杜瓦的设计、芯片封装和组件的试验结果与分析,组件可靠性设计和考核,并给出了PtS i512×512CCD用ID-CA组件的性能参数。 相似文献
995.
基于混凝土模型试验,对涂敷层的传感光纤的裂缝复用能力进行了定量分析,得到了传感光纤和工程结构裂缝夹角在30°,45°,60°时的复用能力与裂缝宽度的关系曲线。对由软性材料构成的光纤涂敷层来说,光纤的复用能力随涂敷层厚度的增加而增大,在与裂缝夹角成45°时,二次涂敷粗光纤的复用能力约为细光纤的5倍,表明光纤敷层对光纤裂缝监测的复用能力具有较大影响。对这种影响的机理进行了理论分析和试验研究,发现当混凝土开裂时,光纤沿混凝土界面的滑移是光纤涂敷层影响光纤裂缝复用能力的主要原因,在光纤与裂缝夹角成45°时,这一影响占60%以上。 相似文献
996.
Numerical Simulation for Coherent and Partially Coherent Beam Propagation through Atmospheric Turbulence 下载免费PDF全文
Propagation properties of coherent and partially coherent beams in atmospheric turbulence are investigated respectively by using numerical simulation It is found that a partially coherent beam has a spreading larger than a coherent beam. However, from the point view of relative beam spreading and intensity scintillation, a partially coherent beam is less affected than the corresponding coherent beam, which may be the most important virtue of partially coherent beams that could be utilized to improve the performance of laser engineering. The beam wandering is almost independent of the degree of the source coherence. More aperture averaging occurs when beam becomes more coherent. 相似文献
997.
FU Ying-Shuang JI Shuai-Hua ZHANG Tong CHEN Xi JIA Jin-Feng XUE Qi-Kun MA Xu-Cun 《中国物理快报》2010,27(6):160-163
We demonstrate the importance of interface modification on improving electron confinement by preparing Pb quantum islands on Si(111) substrates with two different surface reconstructions, i.e., Si(111)-7 ×7 and Si(111)- Root3×Root3-Pb (hereafter, 7 ×7 and R3). Characterization with scanning tunneling microscopy/spectroscopy shows that growing Pb films directly on a 7 × 7 surface will generate many interface defects, which makes the lifetime of quantum well states (QWSs) strongly dependent on surface locations. On the other hand, QWSs in Pb films on an R3 surface are well defined with small variations in linewidth on different surface locations and are much sharper than those on the 7 × 7 surface. We show that the enhancement in quantum confinement is primarily due to the reduced electron-defect scattering at the interface. 相似文献
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The associated production of Z boson and a pair of new quarks at the Large Hadron Collider (LHC) is studied. The cross sections for both sequential fermions and vector-like fermions are presented. It is found that for sequential fermions the cross sections can reach 1 - 10^2 /b for heavy quark mass mQ from 1000 GeV to 200 GeV. For vector-like quarks, the cross sections are suppressed by mixing parameter sin OL. Focusing on process pp → b'b', we investigate the possibility of detecting the 6l 4- 2j signal. For a b' with light mass and a large branching ratio of b' → bZ, it is found that only several signal events ( parton level ) can be produced with 1000 fb^-1 integrated luminosity. Although the signal events are rare, all the final states are produced centrally and multi lepton final states are clear at hadron collider, which could be easily detected. 相似文献
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We investigate the possibility of probing R-parity violating interactions in forward-backward asymmetries, and conclude that the Tevatron collider is the best place to measure new interactions involving the first generation of quarks. With additional down type squark ~dk contributions, the charge asymmetry in e+e— events around Z-pole mass region at the Tevatron will be sensitive to R-parity violating couplings λ’11k, which was inaccessible to the LEP Qfb had inclusive measurement. Assuming no apparent deviation from SM prediction is observed, λ’11k〈 0.19 at 95% C.L. with squark mass Mdk=100 GeV can be derived. 相似文献