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1.
Christian Soize Roger Ghanem 《International journal for numerical methods in engineering》2022,123(1):268-290
The probabilistic learning on manifolds (PLoM) introduced in 2016 has solved difficult supervised problems for the “small data” limit where the number N of points in the training set is small. Many extensions have since been proposed, making it possible to deal with increasingly complex cases. However, the performance limit has been observed and explained for applications for which N is very small and for which the dimension of the diffusion-map basis is close to N. For these cases, we propose a novel extension based on the introduction of a partition in independent random vectors. We take advantage of this development to present improvements of the PLoM such as a simplified algorithm for constructing the diffusion-map basis and a new mathematical result for quantifying the concentration of the probability measure in terms of a probability upper bound. The analysis of the efficiency of this extension is presented through two applications. 相似文献
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In recent years, the light field (LF) as a new imaging modality has attracted wide interest. The large data volume of LF images poses great challenge to LF image coding, and the LF images captured by different devices show significant differences in angular domain. In this paper we propose a view prediction framework to handle LF image coding with various sampling density. All LF images are represented as view arrays. We first partition the views into reference view (RV) set and intermediate view (IV) set. The RVs are rearranged into a pseudo sequence and directly compressed by a video encoder. Other views are then predicted by the RVs. To exploit the four dimensional signal structure, we propose the linear approximation prior (LAP) to reveal the correlation among LF views and efficiently remove the LF data redundancy. Based on the LAP, a distortion minimization interpolation (DMI) method is used to predict IVs. To robustly handle the LF images with different sampling density, we propose an Iteratively Updating depth image based rendering (IU-DIBR) method to extend our DMI. Some auxiliary views are generated to cover the target region and then the DMI calculates reconstruction coefficients for the IVs. Different view partition patterns are also explored. Extensive experiments on different types LF images also valid the efficiency of the proposed method. 相似文献
3.
将糙米分别进行干法和湿法微粉碎,与谷朊粉以4:1比例混合,制备糙米面团和面包,研究干法和湿法微粉碎对糙米面团和面包品质的影响。结果表明,经干法和湿法微粉碎后糙米粉颗粒细度显著降低,湿法粉碎糙米粉破损淀粉含量较少。干法粉碎糙米粉面团结构致密,弹性和黏性升高,糙米面包比容降低,硬度和耐咀性增强,弹性降低。随着粉碎时间的延长,湿法粉碎糙米粉-谷朊粉面团的黏性和弹性先升高后降低,面团网络结构更加紧密,其面包的比容与黏性和弹性变化规律一致,面包耐咀性和硬度增加,弹性降低。干法粉碎15 min(微粉A),湿法粉碎40 min(微粉X)时,糙米面包的比容最大,硬度和弹性适中,面包的品质较好。 相似文献
4.
Analysis of the convective heat transfer and flow behavior around two counter‐rotating side‐by‐side cylinders 下载免费PDF全文
This study presents details of the heat and fluid flow around two counter‐rotating cylinders. For this goal, three different nondimensional gap spaces such as G/D = 1.5, 2.0, and 3.0 are examined in the constant Reynolds number of 200 and Prandtl number of 7.0. In addition, computations are carried out at various nondimensional rotating speeds (R.S) in the range from 0 to 4. The obtained results are validated against the available data in the open literature for stationary cases. The results showed that the flow structure, vortex shedding process, and exerted forces on the cylinders strongly depended on the R.S and G/D. Reductions of the drag coefficients are observed for both cylinders with increasing the R.S due to suppression of the wake downstream of the cylinders at low R.S and eliminating the vortex shedding process at high R.S. Finally, it is demonstrated that, regardless of the G/D value, increasing the R.S diminishes dramatically the convective heat exchange rate between the cylinders and fluid flow. 相似文献
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