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131.
提出了一种新的基于支持向量机的混沌时间序列预测方法,该方法利用平均场理论使支持向量机的学习过程变得简单高效。同时由于该方法将支持向量机的参数近似为高斯分布的,因此采用平均场理论能够容易的求解这些参数,这样获得的支持向量机的参数比传统的基于二次规划的算法更加精确,而且学习速度更快。最后利用该方法对嵌入维数与模型的泛化能力关系进行了探讨,并利用Mackey-Glass时间序列对该方法进行了验证,结果表明:该预测方法能精确地预测混沌时间序列,而且在混沌时间序列的嵌入维数未知时也能取得比较好的预测效果.这一结论预示着平均场支持向量机是一种研究混沌时间序列的有效方法. 相似文献
132.
Navasardyan T Adams GS Ahmidouch A Angelescu T Arrington J Asaturyan R Baker OK Benmouna N Bertoncini C Blok HP Boeglin WU Bosted PE Breuer H Christy ME Connell SH Cui Y Dalton MM Danagoulian S Day D Dodario T Dunne JA Dutta D El Khayari N Ent R Fenker HC Frolov VV Gan L Gaskell D Hafidi K Hinton W Holt RJ Horn T Huber GM Hungerford E Jiang X Jones M Joo K Kalantarians N Kelly JJ Keppel CE Kubarovski V Li Y Liang Y Malace S Markowitz P McGrath E McKee P Meekins DG Mkrtchyan H Moziak B 《Physical review letters》2007,98(2):022001
A large data set of charged-pion (pi+/-) electroproduction from both hydrogen and deuterium targets has been obtained spanning the low-energy residual-mass region. These data conclusively show the onset of the quark-hadron duality phenomenon, as predicted for high-energy hadron electroproduction. We construct several ratios from these data to exhibit the relation of this phenomenon to the high-energy factorization ansatz of electron-quark scattering and subsequent quark-->pion production mechanisms. 相似文献
133.
Shenmin Zhu Jingjing Guo Junping Dong Zhaowen Cui Tao Lu Chenglin Zhu Di Zhang Jun Ma 《Ultrasonics sonochemistry》2013,20(3):872-880
This study synthesized Fe3O4 nanoparticles of 30–40 nm by a sonochemical method, and these particles were uniformly dispersed on the reduced graphene oxide sheets (Fe3O4/RGO). The superparamagnetic property of Fe3O4/RGO was evidenced from a saturated magnetization of 30 emu/g tested by a sample-vibrating magnetometer. Based on the testing results, we proposed a mechanism of ultrasonic waves to explain the formation and dispersion of Fe3O4 nanoparticles on RGO. A biosensor was fabricated by modifying a glassy carbon electrode with the combination of Fe3O4/RGO and hemoglobin. The biosensor showed an excellent electrocatalytic reduction toward H2O2 at a wide, linear range from 4 × 10?6 to 1 × 10?3 M (R2 = 0.994) as examined by amperometry, and with a detection limit of 2 × 10?6 M. The high performance of H2O2 detection is attributed to the synergistic effect of the combination of Fe3O4 nanoparticles and RGO, promoting the electron transfer between the peroxide and electrode surface. 相似文献
134.
Aimed at the complex information in videos and low detection efficiency, an actions detection model based on neighboring Gaussian structure and 3D LARK features is put forward. We exploit a double hierarchical multi-structure space–time statistical matching model (DMSM) in temporal action localization. First, a neighboring Gaussian structure is presented to describe the multi-scale structural relationship. Then, a space–time statistical matching method is proposed to achieve two similarity matrices on both large and small scales, which combines double hierarchical structural constraints in model by both the neighboring Gaussian structure and the 3D LARK local structure. Finally, the double hierarchical similarity is fused and analyzed to detect actions. Besides, the multi-scale composite template extends the model application into multi-view. Experimental results of DMSM on the complex visual tracker benchmark data sets and THUMOS 2014 data sets show the promising performance. Compared with other state-of-the-art algorithm, DMSM achieves superior performances. 相似文献
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136.
为了提高超声波多普勒法测量复杂流体流量的精度,针对流体的超声回波频率的复杂性,本文研究多普勒流速测量中的频偏提取方法。以傅里叶分析为理论基础,设计了硬件电路并获得代表回波平均频率的信号,然后以该信号作为输入,以数字鉴频法获得回波多普勒频移。基于该方法设计了一种超声多普勒流量测量系统,实验结果显示:油水混合流体流量的测量误差在3%以内,从而证实了此频偏提取方法的有效性。 相似文献
137.
Ever since the pioneering work of Bardeen, Cooper and Schrieffer in the 1950s, exploring novel pairing mechanisms for fermion superfluids has become one of the central tasks in modern physics. Here, we investigate a new type of fermion superfluid with hybridized s- and p-wave pairings in an ultracold spin-1/2 Fermi gas. Its occurrence is facilitated by the co-existence of comparable s- and p-wave interactions, which is realizable in a two-component 40K Fermi gas with close-by s- and p-wave Feshbach resonances. The hybridized superfluid state is stable over a considerable parameter region on the phase diagram, and can lead to intriguing patterns of spin densities and pairing fields in momentum space. In particular, it can induce a phase-locked p-wave pairing in the fermion species that has no p-wave interactions. The hybridized nature of this novel superfluid can also be confirmed by measuring the s- and p-wave contacts, which can be extracted from the high-momentum tail of the momentum distribution of each spin component. These results enrich our knowledge of pairing superfluidity in Fermi systems, and open the avenue for achieving novel fermion superfluids with multiple partial-wave scatterings in cold atomic gases. 相似文献
138.
波分复用技术是当今光纤通信系统中的关键技术之一。具有增加光纤通信系统容量的巨大潜力,集成光学复用技术对于单模光纤通信系统特别重要本文给出了一种集成光学复用器件的设计和制作,这种集成光学滤波器是在之切LiNbO3衬底上用非对称钛扩散条波导定向耦合器构成,它适于1.32μm和1.55μm波长耦合滤波。为了使单模光纤和条波导有效耦合,我们研制出了硅V型槽,并给出了一种光纤与波导的连接结构。提供了一种切实可行的途径。 相似文献
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140.