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Найдено 54 550 публикаций
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Статья
Старикова И. В. Philosophia Mathematica. 2018. Vol. 26. No. 2. P. 161-183.
Добавлено: 15 июня 2018
Статья
Sidorkin A. M. Journal of Philosophy of Education. 2001. Vol. 35. No. 1. P. 21-30.
Добавлено: 16 сентября 2013
Статья
Zvyagina A. I., Melnikova E. K., Averin A. A. et al. Carbon. 2018. Vol. 134. P. 62-70.
Добавлено: 16 июля 2018
Статья
Odesskii A., Feigin B. L. International Mathematics Research Notices. 1997. No. 11. P. 531-539.
Добавлено: 1 июня 2010
Статья
Zlotnik A. A., Koltsova N. Computational Methods in Applied Mathematics. 2013. Vol. 13. No. 2. P. 119-138.

An initial-boundary value problem for the 1D self-adjoint parabolic equation on the half-axis is solved. We study a broad family of two-level finite-difference schemes with two parameters related to averages both in time and space. Stability in two norms is proved by the energy method. Also discrete transparent boundary conditions are rigorously derived for schemes by applying the method of reproducing functions. Results of numerical experiments are included as well.

Добавлено: 6 апреля 2013
Статья
Marshall I., Wojciechowski S., Fordy A. Physics Letters A. 1986. No. 113A. P. 395-400.
Добавлено: 30 октября 2010
Статья
Babenko M. A. Theory of Computing Systems. 2010. No. 46(1). P. 59-79.
Let G be an undirected graph and be a collection of disjoint subsets of nodes. Nodes in T 1∪⋅⋅⋅∪T k are called terminals, other nodes are called inner. By a TeX -path we mean a path P such that P connects terminals from distinct sets in TeX and all internal nodes of P are inner. We study the problem of finding a maximum cardinality collection ℘ of TeX -paths such that at most two paths in ℘ pass through any node. Our algorithm is purely combinatorial and has the time complexity O(mn 2), where n and m denote the numbers of nodes and edges in G, respectively.
Добавлено: 17 декабря 2010
Статья
Zlotnik A.A., Zlotnik I.A. Doklady Mathematics. 2017. Vol. 95. No. 2. P. 129-135.

A new fast direct algorithm for implementing a finite element method (FEM) of order on rectangles as applied to boundary value problems for Poisson-type equations is described that extends a well-known algorithm for the case of difference schemes or bilinear finite elements (n = 1). Its core consists of fast direct and inverse algorithms for expansion in terms of eigenvectors of one-dimensional eigenvalue problems for an nth-order FEM based on the fast discrete Fourier transform. The amount of arithmetic operations is logarithmically optimal in the theory and is rather attractive in practice. The algorithm admits numerous further applications (including the multidimensional case).

Добавлено: 28 февраля 2017
Статья
Larisa Komosko, Mikhail Batsyn, Pablo San Segundo . et al. Journal of Combinatorial Optimization. 2016. No. 4. P. 1665-1677.
Добавлено: 13 июля 2015
Статья
Babenko M. A., Artamonov S. European Journal of Combinatorics. 2018. P. 3-23.

A perfect 2-matching in an undirected graph G=(V,E) is a function x:E→0,1,2 such that for each node v∈V the sum of values x(e) on all edges e incident to v equals 2. If supp(x)=e∈E∣x(e)≠0 contains no triangles then x is called triangle-free. Polyhedrally speaking, triangle-free 2-matchings are harder than 2-matchings, but easier than usual 1-matchings. Given edge costs c:E→R + , a natural combinatorial problem consists in finding a perfect triangle-free matching of minimum total cost. For this problem, Cornuéjols and Pulleyblank devised a combinatorial strongly-polynomial algorithm, which can be implemented to run in O(VElogV) time. (Here we write V, E to indicate their cardinalities |V|, |E|.) If edge costs are integers in range [0,C] then for both 1- and 2-matchings some faster scaling algorithms are known that find optimal solutions within O(Vα(E,V)logVElog(VC)) and O(VElog(VC)) time, respectively, where α denotes the inverse Ackermann function. So far, no efficient cost-scaling algorithm is known for finding a minimum-cost perfect triangle-free2-matching. The present paper fills this gap by presenting such an algorithm with time complexity of O(VElogVlog(VC)).

Добавлено: 1 марта 2018
Статья
Akhmedov E., Popov F. Journal of High Energy Physics. 2015. Vol.  1509. No.  1509. P. 085.
Добавлено: 6 октября 2015
Статья
V.A. Vassiliev. Arnold Mathematical Journal. 2015. Vol. 1. No. 2. P. 201-209.
Добавлено: 19 января 2016
Статья
Glutsyuk A. Panoramas and Synthèses. 2011. Vol. 34. P. 149-202.
Добавлено: 9 марта 2013
Статья
Kishimoto T., Yuri Prokhorov, Zaidenberg M. Osaka Journal of Mathematics. 2014. Vol. 51. No. 4. P. 1093-1113.

We address the following question: When an affine cone over a smooth Fano threefold admits an effective action of the additive group? In this paper we deal with Fano threefolds of index 1 and Picard number 1. Our approach is based on a geometric criterion from our previous paper, which relates the existence of an additive group action on the cone over a smooth projective variety X with the existence of an open polar cylinder in X. Non-trivial families of Fano threefolds carrying a cylinder were found in loc. cit. Here we provide new such examples.

Добавлено: 10 октября 2013
Статья
Cheltsov I., Park J., Won J. Journal of the European Mathematical Society. 2016. Vol. 18. No. 7. P. 1537-1564.

We show that affine cones over smooth cubic surfaces do not admit non-trivial Ga-actions.

Добавлено: 1 июля 2016
Статья
Arzhantsev I., Timashev D. Transformation Groups. 2001. Vol. 6. No. 2. P. 101-110.
Добавлено: 8 июля 2014
Статья
Braverman A., Finkelberg M. V., Kazhdan D. Springer Proceedings in Mathematics & Statistics. 2012. Vol. 9. P. 17-29.
Добавлено: 5 февраля 2013
Статья
Frenkel E., Feigin B. L. Communications in Mathematical Physics. 1990. Vol. 128. No. 1. P. 161-189.
Добавлено: 2 июня 2010
Статья
Gorsky E., Mazin M., Vazirani M. Transactions of the American Mathematical Society. 2016. Vol. 368. No. 12. P. 8403-8445.
Добавлено: 14 февраля 2015
Статья
Gaifullin S. A. Sbornik Mathematics. 2008. Vol. 199. No. 3. P. 319-339.
Добавлено: 17 декабря 2014
Статья
Krishna K., Tarasov A. American Economic Journal: Microeconomics. 2016. Vol. 8. No. 2. P. 215-252.

This paper identifies a new reason for giving preferences to the disadvantaged using a model of contests. There are two forces at work: the e§ort e§ect working against giving preferences and the selection e§ect working for them. When education is costly and easy to obtain (as in the U.S.), the selection e§ect dominates. When education is heavily subsidized and limited in supply (as in India), preferences are welfare reducing. The model also shows that unequal treatment of identical agents can be welfare improving, providing insights into when the counterintuitive policy of rationing educational access to some subgroups is welfare improving.

Добавлено: 2 октября 2015