123,462 research outputs found
Chelonus ocellatus ALEXEEV 1971
No full textChelonus ocellatus ALEXEEV 1971 M a t e r i a l e x a m i n e d: Mazandaran province: Savadkooh, 1, July 2005. G e n e r a l d i s t r i b u t i o n Crimea, Middle Asia, Turkey (AYDOGDU & BEYARSLAN 2002).Published as part of Sakenin, H., Naderian, H., Samin, N., Rastegar, J., Tabari, M., Papp, J. & I, Northern, 2012, On a collection of Braconidae (Hymenoptera) from northern Iran, pp. 1319-1330 in Linzer biologische Beiträge 44 (2) on page 1323, DOI: 10.5281/zenodo.533526
Chelonus ocellatus ALEXEEV 1971
No full textChelonus ocellatus ALEXEEV 1971 M a t e r i a l: Mazandaran province: Savadkooh, Alasht (3), September 2003. G e n e r a l d i s t r i b u t i o n: Crimea,MiddleAsia, Turkey.Published as part of Ghahari, H., Fischer, M., Cetin, O., Beyarslan, A. & Ostovan, H., 2010, A contribution to the braconid wasps (Hymenoptera: Braconidae) from the forests of northern Iran, pp. 621-634 in Linzer biologische Beiträge 42 (1) on page 626, DOI: 10.5281/zenodo.533280
On the Singular Spectrum of Powers and Products of Random Matrices
No full textAlexeev NV, Götze F, Tikhomirov AN. On the Singular Spectrum of Powers and Products of Random Matrices. DOKLADY MATHEMATICS. 2010;82(1):505-507
ASYMPTOTIC DISTRIBUTION OF SINGULAR VALUES OF POWERS OF RANDOM MATRICES
No full textAlexeev N, Götze F, Tikhomirov A. ASYMPTOTIC DISTRIBUTION OF SINGULAR VALUES OF POWERS OF RANDOM MATRICES. LITHUANIAN MATHEMATICAL JOURNAL. 2010;50(2):121-132.Let x be a complex random variable such that Ex = 0, E|x|(2) = 1, and E|x|(4) infinity EFN(m)(x) of the empirical distribution function F-N((m))(x) = N-1 Sigma(N)(k=1) I{lambda(k) <= x}, where I {A} stands for the indicator function of an event A. With m = 1, our result turns to a well- known result of Marchenko and Pastur [V. Marchenko and L. Pastur, The eigenvalue distribution in some ensembles of random matrices, Math. USSR Sb., 1:457- 483, 1967]
Income Distribution and Price Controls: Targeting a Social Safety Net During Economic Transition
No full textDuring the ongoing post-communist economic transitions, the relative well-being of many people is changing rapidly, and governments are not well positioned to accurately measure individual living standards. Under such circumstances, continued price controls over basic consumer goods within the state sector, and the associated queuing, can form a serviceable device for targeting poor people for subsidies. With a fixed-price state sector and free-price parallel markets, rich people might choose to avoid queues and shop in the free markets, while poor people would prefer to pay low nominal prices and queue in the state sector. The targeting of subsidies through queues, therefore, can be accomplished even if the government has no information on individual income or living standards. When the alternative to price controls is a poorly targeted explicit social safety net, the resource cost of queues might be more than compensated for by an improvement in the targeting of subsidies.price controls, tax evasion, queue-rationing, economic transition, income distribution
A generating functional approach to the Hubbard model
No full textThe method of generating functional, suggested for
conventional systems by Kadanoff and Baym, is generalized to the
case of strongly correlated systems, described by the Hubbard X
operators. The method has been applied to the Hubbard model with
arbitrary value U of the Coulomb on-site interaction. For the
electronic Green's function constructed for
Fermi-like X operators, an equation using variational
derivatives with respect to the fluctuating fields has been
derived and its multiplicative form has been determined. The
Green's function is characterized by two quantities: the self
energy Σ and the terminal part Λ. For them we have
derived the equation using variational derivatives, whose
iterations generate the perturbation theory near the atomic limit.
Corrections for the electronic self-energy Σ are calculated
up to the second order with respect to the parameter W/U (W
width of the band), and a mean field type approximation was
formulated, including both charge and spin static fluctuations.
This approximation is actually equivalent to the one used in the
method of Composite Operators, and it describes an insulator-metal
phase transition at half filling reasonably well.
The equations for the Bose-like Green's functions have been
derived, describing the collective modes: the magnons and
doublons. The main term in this equation represents variational
derivatives of the electronic Green's function with respect to the
corresponding fluctuating fields. The properties of the poles of
the doublon Green's functions depend on electronic filling. The
investigation of the special case n=1 demonstrates that the
doublon Green's function has a soft mode at the wave vector
, indicating possible instability of the
uniform paramagnetic phase relatively to the two sublattices
charge ordering. However this instability should compete with an
instability to antiferromagnetic ordering.
The generating functional method with the X operators could be
extended to the other models of strongly correlated systems
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Обобщенная квантовая гидродинамика
No full textThis paper addresses the fundamental principles of generalized Boltzmann physical kinetics, as a part of non-local physics. It is shown that the theory of transport processes (including quantum mechanics) can be considered in the frame of unified theory based on the non-local physical description. The paper can be considered also as comments and prolongation of the materials published in the known author’s monograph (Boris V. Alexeev, Generalized Boltzmann Physical Kinetics. Elsevier. 2004).В статье рассматриваются фундаментальные принципы обобщенной Больцмановской физической кинетики как составной части нелокальной физики. Установлено, что теория процессов переноса (включая квантовую механику) может быть рассмотрена в рамках универсальной теории, основанной на нелокальном физическом описании. Статья может рассматриваться как продолжение исследований, опубликованных в известной монографии автора (Boris V. Alexeev, Generalized Boltzmann Physical Kinetics. Elsevier. 2004)
A Note on Measuring the Unofficial Economy in the Former Soviet Republics
No full textThis note argues that the most commonly used estimates of the size of the unofficial economies in the former Soviet republics are flawed. Most important, they are based on calculations that disregard the variation in unofficial economic activity across space in the pre-transition Soviet Union. In addition, these estimates appear to understate the size of the unofficial economies in these countries. We propose alternative estimates and find that they are more strongly related to the institutional factors commonly used to explain the size of the unofficial sector. Our estimates also show that the size of a country's pre-transition unofficial economy is an important predictor of its size during the transition. This suggests that the size of the unofficial economy is to a large extent a historical phenomenon only partly determined by contemporary institutional factors.A Note on Measuring the Unofficial Economy in the Former Soviet Republics
- …
