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Ohne Zusammenfassung 相似文献
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Alois Smolka 《Monatshefte für Chemie / Chemical Monthly》1885,6(1):915-926
Ohne Zusammenfassung 相似文献
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Simply generated families of trees are described by the equation T(z) = ϕ(T(z)) for their generating function. If a tree has n nodes, we say that it is increasing if each node has a label ∈ { 1,…,n}, no label occurs twice, and whenever we proceed from the root to a leaf, the labels are increasing. This leads to the concept of simple families of increasing trees. Three such families are especially important: recursive trees, heap ordered trees, and binary increasing trees. They belong to the subclass of very simple families of increasing trees, which can be characterized in 3 different ways. This paper contains results about these families as well as about polynomial families (the function ϕ(u) is just a polynomial). The random variable of interest is the level of the node (labelled) j, in random trees of size n ≥ j. For very simple families, this is independent of n, and the limiting distribution is Gaussian. For polynomial families, we can prove this as well for j,n → ∞ such that n − j is fixed. Additional results are also given. These results follow from the study of certain trivariate generating functions and Hwang's quasi power theorem. They unify and extend earlier results by Devroye, Mahmoud, and others. © 2007 Wiley Periodicals, Inc. Random Struct. Alg., 2007 相似文献
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This paper presents an analytic approach to the construction cost of fringe-balanced binary search trees. In [7], Mahmoud used a bottom-up approach and an urn model of Pólya. The present method is top-down and uses differential equations and Hwang's quasi-power theorem to derive the asymptotic normality of the number of rotations needed to construct such afringe balanced search tree. We also obtain the exact expectation and variance with this method. Although Pólya's urn model is no longer needed, we also present an elegant analysis of it based on an operator calculus as in [4].This research was supported by the Austrian Research Society (FWF) under the project number P12599-MAT. 相似文献
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E Wenisch C Tauer A Jungbauer H Katinger M Faupel P G Righetti 《Journal of chromatography. A》1990,516(1):133-146
Isoforms of human monoclonal antibodies against the gp-41 of AIDS virus and of human recombinant superoxide dismutase have been purified to homogeneity by isoelectric focusing (IEF) in a multi-compartment electrolyser with isoelectric, immobiline membranes. This system allows the processing of large sample volumes and gram-scale protein loads and can resolve isoforms as close as 0.001 in pI difference. The purification progress was usually monitored by analytical IEF in immobilized pH gradients (IPG). Capillary zone electrophoresis (CZE) was applied to the monitoring of the content of each chamber of the electrolyser. CZE was found to be superior in terms of speed of analysis and quantification (but only by UV reading at 200-210 nm, i.e., in the region of the peptide bond) but, notwithstanding the millions of theoretical plates reported, was no match for the resolving power of IPGs, at least for protein analysis. When compared also with chromatofocusing, the resolving power decreases in the order IPG greater than CZE much greater than chromatofocusing. 相似文献