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71.
Tobias Siems Marc Hellmuth Volkmar Liebscher 《Journal of computational and graphical statistics》2019,28(2):290-298
Within a Bayesian retrospective framework, we present a way of examining the distribution of changepoints through a novel set estimator. For a given level, α, we aim at smallest sets that cover all changepoints with a probability of at least 1 ? α. These so-called smallest simultaneous credible regions, computed for certain values of α, provide parsimonious representations of the possible changepoint locations. In addition, combining them for a range of different α’s enables very informative yet condensed visualizations. Therewith we allow for the evaluation of model choices and the analysis of changepoint data to an unprecedented degree. This approach exhibits superior sensitivity, specificity, and interpretability in comparison with highest density regions, marginal inclusion probabilities, and confidence intervals inferred by stepR. While their direct construction is usually intractable, asymptotically correct solutions can be derived from posterior samples. This leads to a novel NP-complete problem. Through reformulations into an Integer Linear Program we show empirically that a fast greedy heuristic computes virtually exact solutions. Supplementary material for this article is available online. 相似文献
72.
Study of nonholonomic motion planning needs further research into the global properties of linear constraints in state space.
The global properties of constraints, which contain the holonomicity and the nonholonomicity by regions, the existence of
the isolated integral manifolds and the singular points and so on, have essential influence on motion planning. By analysis
of the point sets in total space, the complete sketch of the global properties of linear constraints in state space is obtained,
which can directly be applied to motion planning.
Project supported by the National Natural Science Foundation of China and Doctoral Programme Foundation Institution of High
Education of China. 相似文献
73.
Water absorbed by nylons appears to be partitioned into interlamellar and interfibrillar spaces. The amount of water in the interfibrillar region remains essentially unchanged with increasing draw ratio, whereas that in the interlamellar regions decreases with draw ratio; the latter accounts for the decrease in the water uptake in the drawn fibers. These results suggest that the amount of the amorphous material in the interfibrillar regions remains unchanged during drawing, and the increase in the crystallinity during drawing results from the incorporation of the amorphous chain segments in the interlamellar regions into the crystalline lamellae. Further, the interfibrillar water is more tightly bound than the interlamellar water. The length of the longitudinal channels into which water diffuses is about the same as that of the fibrils, and increases from ca. 1500 to 2000 Å upon drawing. The longitudinal channels are highly oriented even in undrawn fibers, and their misorientation increases from 5° to 15° upon drawing. These channels can be described as surface fractals of dimension 3.4–3.6. © 1994 John Wiley & Sons, Inc. 相似文献
74.
具有外部输入和偏差的细胞神经网络的完全稳定性 总被引:2,自引:0,他引:2
本文证明了对于由两个细胞组成的细胞神经网络,外部输入和偏差不影响网络的稳定平衡点的存在性和完全稳定性. 相似文献
75.
In this paper, we study a rational function which plays an important role in several problems of interest (eigenvalue problems,
linear control theory, ... ). Our main interest is to determine zero-free regions. We also derive upper and lower bounds for
this function.
Communicated by T.L. Freeman 相似文献
76.
L.M. Ruan H. Qi L.H. Liu H.P. Tan 《Journal of Quantitative Spectroscopy & Radiative Transfer》2004,86(4):343-352
In this paper the radiative transfer in one-dimensional and two-dimensional cylindrical medium is simulated by the Monte-Carlo (M-C) method. Our results agree with the previous ones very well. It indicates that our cylindrical M-C model is creditable. In this paper, the partition allocation method of radiative heat transfer in participating cylindrical media is presented, in which every sub-domain is isolated by imaginary black wall at certain equivalent temperature and overlaps each other. The stitched results of all sub-domains can predict the results of a whole zone accurately. The partitioned treatment by overlap regions can achieve reasonable result, save memory efficiently, and compute parallel. 相似文献
77.
78.
Paul G. Mezey 《Theoretical chemistry accounts》1981,58(4):309-330
The space of internal coordinates of a molecular system is partitioned into catchment regions of various critical points of the energy hypersurface. The partitioning is based on an ordering of steepest descent paths into equivalence classes. The properties of these catchment regions and their boundaries are analyzed and the concepts of chemical structure, reaction path and reaction mechanism are discussed within the framework of the Born-Oppenheimer and energy hypersurface approximations. Relations between catchment regions and the chemically important reactive domains of energy hypersurfaces, as well as models for branching of reaction mechanisms, caused by instability domainsD
, 1, are investigated. 相似文献
79.
80.
本文报道的是作者利用分子作为介质,通过非线性光学过程(四波和频,三次谐波)在真空紫外波段产生宽带可调谐相干光的理论和实验研究及其结果,实验产生的宽波段可调谐激光输出为建成完备的小型真空紫外激光光源奠定了基础。此文还报道了作者用该光源在XUV波希成功测量分子转动温度的方法和结果。 相似文献