85 research outputs found
A new representation for the partition function of the six vertex model with domain wall boundaries
We obtain a new representation for the partition function of the six vertex
model with domain wall boundaries using a functional equation recently derived
by the author. This new representation is given in terms of a sum over the
permutation group where the partial homogeneous limit can be taken trivially.
We also show by construction that this partition function satisfies a linear
partial differential equation.Comment: 14 pages, v2: added references, accepted for publication in J. Stat.
Mec
Analysis of model for assessing the road train movement stability
In this paper, we conduct a mathematical analysis of the model of ensuring the road trains movement stability by changing the design of coupling devices to determine the critical characteristic parameters of the road trains, which result in the loss of en-route directional stability under external action. The concept of the model was to separate the process of yawing of the road trains and its elements (due to external perturbing action) on the highway into several typical stages. The main parameters of the stages (the displacement amplitude and rotation angle of the road trains elements in relation to the driving direction) were determined based on the initial conditions of the road trains movement, the force and duration of the external action. The most dangerous areas of external action application to the road trains were determined in this paper. The maximum permissible exposure limit should not exceed 0.5-1.0% of the road trains trailer momentum, with duration having the greater effect than the amount of impact. The results obtained can be used in mechanical engineering to improve the road trains performance. © Published under licence by IOP Publishing Ltd
Model for assessing the road train stability movement
Road trains (RT) are the main transport in agriculture. However, their accident rate is quite high. In the vehicles movement research their design characteristics and operating modes are mainly improved. The main way to reduce the accident rate remains the speed limit. The authors proposed methods (confirmed by the issued patents) for ensuring the stability of the RT movement by changing the design of trailer devices. The purpose of this work is to form a mathematical model for assessing the stability of the RT movement in the presence of side effects (modeling of sharp turns, impacts). Methods of analysis and synthesis, mathematical analysis, and vector geometry were applied. The process of RT yawing on the highway is split into a number of stages, for which the laws of changing its geometry and kinematics are formulated. Side effect leads to increase in the RT impulse (lateral oscillations increase the speed), or to a violation of stability (the movement amplitude goes beyond the highway or tipping). This model can be used to analyze the stability of the RT movement and evaluate methods to influence it in order to reduce the probability of accidents. © 2020 Published under licence by IOP Publishing Ltd
Assessment of biodamage resistance of various concrete grades
© 2016, International Journal of Pharmacy and Technology. All rights reserved.At estimation of modern mineral construction materials resistance to Aspergillus niger; Aureobasidium pullulans; Trichoderma sp. it was shown that 28-day exposure of test samples with micromycetes according to GOST 310.4-81 does not reduce their chemical stability coefficient. Analysis of growth rate of selected micromycetes in solid Czapeck-Daux medium allows to relate them to r-strategists. At cultivation of microscopic fungi in liquid Czapeck-Daux medium one-, two-and tribasic (acetic, oxalic, apple and citric) organic acids were identified. High rate of micromycetes growth and formation of wide range of organic acids during their growth gives the basis for supposition that at long-lasting contact of microscopic fungi with construction materials the damage of the latter cannot be excluded
Fluctuations and skewness of the current in the partially asymmetric exclusion process
We use functional Bethe Ansatz equations to calculate the cumulants of the
total current in the partially asymmetric exclusion process. We recover known
formulas for the first two cumulants (mean value of the current and diffusion
constant) and obtain an explicit finite size formula for the third cumulant.
The expression for the third cumulant takes a simple integral form in the limit
where the asymmetry scales as the inverse of the square root of the size of the
system, which corresponds to a natural separation between weak and strong
asymmetry.Comment: 21 pages, 3 figure
Slow drowning of Tibetan grasslands fenced in by Beijing
The initiative that led to pasture being fenced off is part of a string of Chinese grassland policies. Although Tibet has its own regional government, policies concerning what is called the Tibet Autonomous Region are effectively handed down from the Chinese government in Beijing. This article traces the degradation of grasslands and with it, nomadic culture, due to fencing the land. It is becoming clear that grassland privatization, which was introduced to protect the environment, is causing biodiversity loss and a decline in grassland quality. Due to climate change, meltwater submerges the highlands and snowstorms hit trapped herds; shrinking glaciers defrost soil, increasing flow into mountain lakes
On two-point boundary correlations in the six-vertex model with DWBC
The six-vertex model with domain wall boundary conditions (DWBC) on an N x N
square lattice is considered. The two-point correlation function describing the
probability of having two vertices in a given state at opposite (top and
bottom) boundaries of the lattice is calculated. It is shown that this
two-point boundary correlator is expressible in a very simple way in terms of
the one-point boundary correlators of the model on N x N and (N-1) x (N-1)
lattices. In alternating sign matrix (ASM) language this result implies that
the doubly refined x-enumerations of ASMs are just appropriate combinations of
the singly refined ones.Comment: v2: a reference added, typos correcte
Долгосрочные онкологические и функциональные результаты робот-ассистированной радикальной простатэктомии
Prostate cancer (РСа), being one of the leading causes of cancer mortality in men in Russia and in a number of other countries of the world, remains an urgent problem for modern oncourology, and the choice of surgical method is an important task for a surgeon. Such a pronounced interest in robot-assisted radical prostatectomy (RARP) in patients is driven by good tolerance and effectiveness of these surgical interventions, despite the fact that radical prostatectomy is considered to be the "gold standard" for treatment of patients with clinically localized РСа with regard to European Association of Urology data. The long-term oncological and functional results and the quality of life of patients after RARP deserve close attention and thorough study. According to the data presented in this article, it is obvious that RARP is the preferred method for surgical treatment of РСа, since oncological and functional results in the long-term follow-up are comparable to the results after radical prostatectomy, and according to some authors, these results are superior to the results of radical prostatectomy. The results of the study will allow to continue further introduction of RARP into clinical practice and its popularization as a method of surgical treatment of patients with localized PCa, which will reduce the length of hospital stay of patients, accelerate their medical and social rehabilitation, and improve the quality of medical care.The amount of data on the study of distant oncological and functional results of RARP as well as its superiority over other treatment methods is limited in medical literature, which prompted us to conduct our own research. Currently the urological clinic of the A.I. Evdokimov Moscow State University of Medicine and Dentistry continues work aimed at studying the longterm results of RARP in the first patients in Russia.Рак предстательной железы (РПЖ), являясь одной из ведущих причин онкологической смертности у мужчин в России и ряде других стран, остается актуальной проблемой современной онкоурологии, а выбор метода хирургического лечения - важной задачей для хирурга. Выраженный интерес к робот-ассистированной радикальной простатэктомии (РАРП) обусловлен хорошей переносимостью и эффективностью этого оперативного вмешательства, несмотря на то что радикальная простатэктомия является «золотым стандартом» лечения пациентов с клинически локализованным РПЖ, по данным Европейской ассоциации урологов. Отдаленные онкологические и функциональные результаты и качество жизни пациентов после РАРП заслуживают пристального внимания.Согласно приведенным в настоящей статье данным, очевидно, что РАРП считается предпочтительным методом хирургического лечения РПЖ. При этом онкологические и функциональные результаты в долгосрочном наблюдении сопоставимы с результатами радикальной простатэктомии, а по данным некоторых авторов, превосходят их. Результаты проведенного исследования позволят продолжить внедрение в клиническую практику и популяризировать РАРП как метод хирургического лечения пациентов с локализованным РПЖ, что сократит продолжительность пребывания больных в стационаре, ускорит медицинскую и социальную реабилитацию пациентов, повысит качество оказания медицинской помощи пациентам.Ограниченное количество данных в медицинской литературе, посвященных изучению отдаленных онкологических, функциональных результатов РАРП, побудило нас к проведению собственного исследования. В настоящее время в урологической клинике Московского государственного медико-стоматологического университета им. А.И. Евдокимова продолжается работа, направленная на изучение отдаленных результатов РАРП у первых пациентов в России
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