242 research outputs found
Fundamental solution of the problem of linear programming and method of its determination
The idea of a fundamental solution to a problem in linear programming is introduced. A method of determining the fundamental solution and of applying this method to the solution of a problem in linear programming is proposed. Numerical examples are cited
Решение транспортных задач ПС-методом при ограничениях на переменные
The research considers transportation problems of linear programming where restrictions (greater or less) are imposed on some variables. If the first restriction doesn’t create an additional complexity then an excessive restrictions on variables require a special approach. It has been shown that these tasks could be solved applying PC-method proposed by the author.В работе рассматриваются открытые транспортные задачи линейного программирования, в которых на некоторые переменные положено ограничение больше или меньше. Если первое ограничение не создает дополнительных трудностей при решении задачи, то ограничения сверху на переменные требуют особого подхода. Показано, что такие задачи достаточно хорошо решаются с помощью предложенного автором ПС-метода
Crystal Undulator As A Novel Compact Source Of Radiation
A crystalline undulator (CU) with periodically deformed crystallographic
planes is capable of deflecting charged particles with the same strength as an
equivalent magnetic field of 1000 T and could provide quite a short period L in
the sub-millimeter range. We present an idea for creation of a CU and report
its first realization. One face of a silicon crystal was given periodic
micro-scratches (grooves), with a period of 1 mm, by means of a diamond blade.
The X-ray tests of the crystal deformation have shown that a sinusoidal-like
shape of crystalline planes goes through the bulk of the crystal. This opens up
the possibility for experiments with high-energy particles channeled in CU, a
novel compact source of radiation. The first experiment on photon emission in
CU has been started at LNF with 800 MeV positrons aiming to produce 50 keV
undulator photons.Comment: Presented at PAC 2003 (Portland, May 12-16
Conversion of wooden structures into porous SiC with shape memory synthesis
Synthesis of structured silicon carbide materials can be accomplished using wooden materials as the carbon source, with various silicon impregnation techniques. We have explored the low cost synthesis of SiC by impregnation of carbon from wood with SiO gas at high temperatures, which largely retains the structure of the starting wood (shape memory synthesis). Suitably structured, porous SiC could prove to be an important type of catalyst support material. Shape memory synthesis (SMS) has earlier been tried on high surface area carbon materials. Here we have made an extensive study of SMS on carbon structures obtained from different types of wood. © 2011 Elsevier Ltd and Techna Group S.r.l
Experimental Study For The Feasibility Of A Crystalline Undulator
We present an idea for creation of a crystalline undulator and report its
first realization. One face of a silicon crystal was given periodic
micro-scratches (trenches) by means of a diamond blade. The X-ray tests of the
crystal deformation due to given periodic pattern of surface scratches have
shown that a sinusoidal shape is observed on both the scratched surface and the
opposite (unscratched) face of the crystal, that is, a periodic sinusoidal
deformation goes through the bulk of the crystal. This opens up the possibility
for experiments with high-energy particles channeled in crystalline undulator,
a novel compact source of radiation.Comment: 12 pages, 4 figure
Orientation and symmetries of Alexandrov spaces with applications in positive curvature
We develop two new tools for use in Alexandrov geometry: a theory of ramified
orientable double covers and a particularly useful version of the Slice Theorem
for actions of compact Lie groups. These tools are applied to the
classification of compact, positively curved Alexandrov spaces with maximal
symmetry rank.Comment: 34 pages. Simplified proofs throughout and a new proof of the Slice
Theorem, correcting omissions in the previous versio
Experimental Reconstruction of Lomonosov's Discovery of Venus's Atmosphere with Antique Refractors During the 2012 Transit of Venus
In 1761, the Russian polymath Mikhail Vasilievich Lomonosov (1711-1765)
discovered the atmosphere of Venus during its transit over the Sun's disc. In
this paper we report on experimental reenactments of Lomonosov's discovery with
antique refractors during the transit of Venus June 5-6, 2012. We conclude that
Lomonosov's telescope was fully adequate to the task of detecting the arc of
light around Venus off the Sun's disc during ingress or egress if proper
experimental techniques as described by Lomonosov in his 1761 report are
employed.Comment: 14 pages, 9 figure
A simple proof of Perelman's collapsing theorem for 3-manifolds
We will simplify earlier proofs of Perelman's collapsing theorem for
3-manifolds given by Shioya-Yamaguchi and Morgan-Tian. Among other things, we
use Perelman's critical point theory (e.g., multiple conic singularity theory
and his fibration theory) for Alexandrov spaces to construct the desired local
Seifert fibration structure on collapsed 3-manifolds. The verification of
Perelman's collapsing theorem is the last step of Perelman's proof of
Thurston's Geometrization Conjecture on the classification of 3-manifolds. Our
proof of Perelman's collapsing theorem is almost self-contained, accessible to
non-experts and advanced graduate students. Perelman's collapsing theorem for
3-manifolds can be viewed as an extension of implicit function theoremComment: v1: 9 Figures. In this version, we improve the exposition of our
arguments in the earlier arXiv version. v2: added one more grap
Asymptotically Extrinsic Tamed Submanifolds
We study, from the extrinsic point of view, the structure at infinity of open
submanifolds, ϕ : Mm → Mn(κ) isometrically immersed in the real space forms of
constant sectional curvature κ ≤ 0.We shall use the decay of the second fundamental
form of the so-called tamed immersions to obtain a description at infinity of the
submanifold in the line of the structural results in Greene et al. (Int Math Res Not
1994:364–377, 1994) and Petrunin and Tuschmann (Math Ann 321:775–788, 2001)
and an estimation from below of the number of its ends in terms of the volume growth
of a special class of extrinsic domains, the extrinsic balls.Vicent Gimeno: Work partially supported by the Research Program of University Jaume I Project UJI-B2016-07, and DGI -MINECO Grant (FEDER) MTM2013-48371-C2-2-P. Vicente Palmer: Work partially supported by the Research Program of University Jaume I Project UJI-B2016-07, DGI -MINECO Grant (FEDER) MTM2013-48371-C2-2-P, and Generalitat Valenciana Grant PrometeoII/2014/064. G. Pacelli Bessa: Work partially supported by CNPq- Brazil grant # 301581/2013-4
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