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991.
992.
This article presents sufficient conditions, which provide almost sure (a.s.) approximation of the superposition of the random processes S(N(t)), when càd-làg random processes S(t) and N(t) themselves admit a.s. approximation by a Wiener or stable Lévy processes. Such results serve as a source of numerous strong limit theorems for the random sums under various assumptions on counting process N(t) and summands. As a consequence we obtain a number of results concerning the a.s. approximation of the Kesten–Spitzer random walk, accumulated workload input into queuing system, risk processes in the classical and renewal risk models with small and large claims and use such results for investigation the growth rate and fluctuations of the mentioned processes. 相似文献
993.
Paula?Reis Luísa?Canto e Castro Sandra?Dias M.?Ivette?GomesEmail author 《Methodology and Computing in Applied Probability》2015,17(1):189-206
In reliability theory any coherent system can be represented as either a series-parallel or a parallel-series system. Its lifetime can thus be written as the minimum of maxima or the maximum of minima. For large-scale coherent systems it is sensible to assume that the number of system components goes to infinity. Then, the possible non-degenerate extreme value laws either for maxima or for minima are eligible candidates for the system reliability or at least for the finding of adequate lower and upper bounds for the reliability. The identification of the possible limit laws for the system reliability of homogeneous series-parallel (or parallel-series) systems has already been done under different frameworks. However, it is well-known that in most situations such non-degenerate limit laws are better approximated by an adequate penultimate distribution. Dealing with regular and homogeneous parallel-series systems, we assess both theoretically and through Monte-Carlo simulations the gain in accuracy when a penultimate approximation is used instead of the ultimate one. 相似文献
994.
Yuri?E.?GliklikhEmail author Olga?O.?Zheltikova 《Methodology and Computing in Applied Probability》2015,17(1):91-105
The paper is devoted to a brief introduction into the theory of equations and inclusions with mean derivatives and to investigation of a special type of such inclusions called inclusions of geometric Brownian motion type. The existence of optimal solutions maximizing some cost criteria, is proved. 相似文献
995.
996.
Christopher?L.?DancyEmail author Frank?E.?Ritter Keith?A.?Berry Laura?C.?Klein 《Computational & Mathematical Organization Theory》2015,21(1):90-114
Adding a physiological representation to a cognitive architecture offers an attractive approach to modeling the effects of stress on cognition. We introduce ACT-R/Φ, an extended version of the ACT-R cognitive architecture that includes an integrative model of physiology. The extension allows the representation of how physiology and cognition interact. This substrate was used to represent potential effects of a startle response and task-based stress during a mental arithmetic (subtraction) task. We compare predictions from two models loaded into the new hybrid architecture to models previously developed within ACT-R. General behavior differed between models in that the ACT-R/Φ models had dynamic declarative memory noise over the course of the task based on varying epinephrine levels. They attempted more subtractions but were less accurate; this more closely matched human performance than the previous ACT-R models. Using ACT-R/Φ allows a more tractable integration of current physiological and cognitive perspectives on stress. ACT-R/Φ also permits further exploration of the interaction between cognition and physiology, and the emergent effects on behavior caused by the interaction among physiological subsystems. This extension is useful for anyone exploring how the human mind can occur in and be influenced by the physical universe. 相似文献
997.
We show how to reduce the general formulation of the mass–angular momentum–charge inequality, for axisymmetric initial data of the Einstein–Maxwell equations, to the known maximal case whenever a geometrically motivated system of equations admits a solution. It is also shown that the same reduction argument applies to the basic inequality yielding a lower bound for the area of black holes in terms of mass, angular momentum, and charge. This extends previous work by the authors (Cha and Khuri, Ann Henri Poincaré, doi: 10.1007/s00023-014-0332-6, arXiv:1401.3384, 2014), in which the role of charge was omitted. Lastly, we improve upon the hypotheses required for the mass–angular momentum–charge inequality in the maximal case. 相似文献
998.
Yuta Suzuki Tetsuhiro NemotoShun-ichi Nakano Zengduo ZhaoYuta Yoshimatsu Yasumasa Hamada 《Tetrahedron letters》2014
A novel method for synthesizing 4,5-fused tricyclic quinoline derivatives based on an acid-promoted intramolecular Friedel–Crafts allenylation of anilines. Using aryl group-substituted propargyl alcohol derivatives with a meta-substituted N-Boc aniline unit as substrates, a four-step reaction sequence involving an acid-promoted intramolecular Friedel–Crafts allenylation of anilines, an acid-promoted intramolecular C–N bond formation, deprotection of the Boc group, and air oxidation proceeded in a single pot, producing the corresponding 4,5-fused tricyclic quinoline derivatives in 31–84% yield. 相似文献
999.
Tomohito Morosaki Tsubasa Suzuki Wei‐Wei Wang Shigeru Nagase Takayoshi Fujii 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(36):9723-9725
Electronic effects on the central carbon atom of carbone, generated by the replacement of the SIV ligand of carbodisulfane (CDS) with other chalcogen ligands (Ph2E, E=S or Se), were investigated. The carbones Ph2E→C←SPh2(NMe) [E=S( 1 ) or Se( 2 )] were synthesized from the corresponding salts, and their molecular structures and electronic properties were characterized. The carbone 2 is the first carbone containing selenium as the coordinated atom. DFT calculations revealed the electronic structures of 1 and 2 , which have two lone pairs of electrons at the carbon center. The trend in HOMO energy levels, estimated by cyclic voltammetry measurements, for the carbones and CDS follows the order of 2 > 1 >CDS. Analysis of a doubly protonated dication and trication complex revealed that the central carbon atom of 2 behaves as a four‐electron donor. 相似文献
1000.
Takashi Maoka Miho Takemura Harukuni Tokuda Nobutaka Suzuki Norihiko Misawa 《Tetrahedron letters》2014
In order to produce a novel keto-carotenoid in Escherichia coli, we introduced the marine bacterial carotenoid ketolase gene (crtW) into pathway-engineered E. coli producing carotenoids of plant origin, which carried the lycopene biosynthesis genes (crtE, crtB, and crtI) from soil bacterium Pantoea ananatis and the liverwort Marchantia polymorpha genes that encode lycopene β-cyclase (MpLCYb), lycopene ε-cyclase (MpLCYe), and β-carotenoid hydroxylase (MpBHY). A novel keto-carotenoid (1) was produced by these carotenoid biosynthesis genes in E. coli along with α-echinenone, adonirubin, and adonixanthin. The structure of 1 was determined as (3S,6′R)-3-hydroxy-β,ε-caroten-4-one based on Uv–vis, MS, 1H NMR, and CD spectral data. This compound was named 4-ketozeinoxanthin and showed anti-tumor-promoting activity. 相似文献