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91.
In this paper, we continue the research by Serletis [Random walks, breaking trend functions, and the chaotic structure of the velocity of money, J. Bus. Econ. Stat. 13 (1995) 453-458] and Serletis and Shintani [Chaotic monetary dynamics with confidence, J. Macroeconomics 28 (2006) 228-252] by applying the method of detrended fluctuation analysis (DFA)—introduced by Peng et al. [Mosaic organization of DNA nucleotides, Phys. Rev. E 49 (1994) 1685-1689] and adapted to the analysis of long-range correlations in economic data by Uritskaya [Forecasting of magnitude and duration of currency crises based on analysis of distortions of fractal scaling in exchange rate fluctuations, Noise and fluctuations in econophysics and finance, Proc. SPIE 5848 (2005) 17-26; Fractal methods for modeling and forecasting of currency crises, in: Proceedings of the fourth International Conference on Modeling and Analysis of Safety and Risk in Complex Systems, SPbSU Press, St.Petersburg, 2005, pp. 210-215]—to investigate the dynamical structure of United States money and velocity measures. We use monthly data over the time period from 1959:1 to 2006:2, at each of the four levels of monetary aggregation, M1, M2, M3, and MZM, making comparisons among simple-sum, Divisia, and currency equivalent (CE) methods of aggregation. The results suggest that the sum and Divisia monetary aggregates are more appropriate for measuring long-term tendencies in money supply dynamics while the CE aggregates are more sensitive measures of short-term processes in the economy. 相似文献
92.
Apostolos Giannopoulos Vitali D. Milman Antonis Tsolomitis 《Journal of Functional Analysis》2005,223(1):86-108
Sharpening work of the first two authors, for every proportion λ∈(0,1) we provide exact quantitative relations between global parameters of n-dimensional symmetric convex bodies and the diameter of their random ⌊λn⌋-dimensional sections. Using recent results of Gromov and Vershynin, we obtain an “asymptotic formula” for the diameter of random proportional sections. 相似文献
93.
Apostolos Beligiannis 《Algebras and Representation Theory》2002,5(5):483-525
Our aim in this paper is to develop a theory of purity and to prove in a unified conceptual way the existence of almost split morphisms, almost split sequences and almost split triangles in abstract homotopy categories, a rather omnipresent class of categories of interest in representation theory. Our main tool for doing this is the classical Brown representability theorem. 相似文献
94.
Auslander-Reiten Triangles, Ziegler Spectra and Gorenstein Rings 总被引:1,自引:0,他引:1
Apostolos Beligiannis 《K-Theory》2004,32(1):1-82
We investigate (existence of) Auslander—Reiten triangles in a triangulated category in connection with torsion pairs, existence of Serre functors, representability of homological functors and realizability of injective modules. We also develop an Auslander—Reiten theory in a compactly generated triangulated category and we study the connections with the naturally associated Ziegler spectrum. Our analysis is based on the relative homological theory of purity and Brown's Representability Theorem. Our main interest lies in the structure of Auslander—Reiten triangles in the full subcategory of compact objects. We also study the connections and the interplay between Auslander—Reiten theory, pure-semisimplicity and the finite type property, Grothendieck groups, and we give applications to derived categories of Gorenstein rings. 相似文献
95.
Alissandratos A Baudendistel N Hauer B Baldenius K Flitsch S Halling P 《Chemical communications (Cambridge, England)》2011,47(2):683-685
The enzyme catalysed esterification of starch and fatty acids with terminal triple bonds is described. This material can be used as an acceptor for azide containing molecules, through azide/alkyne cycloaddition. The potential is illustrated by the production of fluorescently-labelled starch, and a biotinylated derivative which can bind streptavidin. 相似文献
96.
97.
Ioannis Matiatos Apostolos Alexopoulos 《Isotopes in environmental and health studies》2013,49(4):512-529
The present study examines the isotopic and hydrochemical composition of 18 inland spring waters and 3 coastal karstic spring waters, covering the period between October 2005 and March 2008. The stable isotopes (18O, 2H) processing has revealed the absence of significant evaporation phenomena and that the origin of fresh water samples is meteoric. Using 18O values in rainfall waters, an average line of isotopic depletion with altitude has been constructed, extracting a rate of?0.45‰/100 m as typical for the study area. Furthermore, the mean altitude of recharge of the springs has been estimated by plotting the groundwater sampling points on a δ18O versus altitude diagram. Hydrochemistry results have shown that the dissolution of carbonate, flysch and ophiolitic formations defines the hydrochemical characteristics of groundwater. Moreover, seawater intrusion in the coastal area is significantly high, causing the water in the three karstic springs to be brackish. 相似文献
98.
Degradation of 4-hydroxybenzoic acid by combined ultrasound irradiation and catalytic wet peroxide oxidation 总被引:5,自引:0,他引:5
Nikolopoulos AN Igglessi-Markopoulou O Papayannakos N 《Ultrasonics sonochemistry》2004,11(3-4):183-186
The aim of this study is to explore the potential benefits from the combined use of ultrasound irradiation and catalytic wet peroxide oxidation for the degradation of 4-hydroxybenzoic acid (4-HBA). The target compound degradation was studied under direct and indirect sonication, while silent conditions were employed as reference. The catalyst, a mixed (Al-Fe) pillared clay named FAZA, was in the form of powder and of extrudates. In the case of extrudates it was observed that ultrasound improves the catalyst performance due to reduction of diffusion resistance, thereby increasing the conversion after 4 h by 12-15 times. Increasing the initial concentration of 4-HBA was found to lead to lower conversion. The combined ultrasonic/catalytic process appears very promising for environmental applications. 相似文献
99.
100.
George A. Alexiou Anastasia Zikou Spyridon Tsiouris Anna Goussia Paraskevi Kosta Athanasios Papadopoulos Spyridon Voulgaris Pericles Tsekeris Athanasios P. Kyritsis Andreas D. Fotopoulos Maria I. Argyropoulou 《Magnetic resonance imaging》2014