2,230 research outputs found
COVID-19 Dynamics: A Heterogeneous Model
No full textThe mathematical model reported here describes the dynamics of the ongoing coronavirus disease 2019 (COVID-19) epidemic, which is different in many aspects from the previous severe acute respiratory syndrome (SARS) epidemic. We developed this model when the COVID-19 epidemic was at its early phase. We reasoned that, with our model, the effects of different measures could be assessed for infection control. Unlike the homogeneous models, our model accounts for human population heterogeneity, where subpopulations (e.g., age groups) have different infection risks. The heterogeneous model estimates several characteristics of the epidemic more accurately compared to the homogeneous models. According to our analysis, the total number of infections and their peak number are lower compared to the assessment with the homogeneous models. Furthermore, the early-stage infection increase is little changed when population heterogeneity is considered, whereas the late-stage infection decrease slows. The model predicts that the anti-epidemic measures, like the ones undertaken in China and the rest of the world, decrease the basic reproductive number but do not result in the development of a sufficient collective immunity, which poses a risk of a second wave. More recent developments confirmed our conclusion that the epidemic has a high likelihood to restart after the quarantine measures are lifted. © Copyright © 2021 Gerasimov, Lebedev, Lebedev and Semenycheva
Unemployment Benefits and Unemployment Rates of Low-Skilled and Elder Workers in West Germany: A Search Equilibrium Approach
No full textApproach Author & abstract Download 16 References 1 Citations Related works & more Corrections Author Listed: Launov, Andrey ([email protected]) (University of Kent) Wolff, Joachim ([email protected]) (Institute for Employment Research (IAB), Nuremberg) Klasen, Stephan ([email protected]) (University of Göttingen) Registered: Stephan Klasen Abstract In this paper we investigate whether the extension of the entitlement to unemployment benefits in the mid 80s can explain the increase in the unemployment rates of unskilled and elder workers in western Germany. To answer this question we estimate a version of the Burdett-Mortensen search equilibrium model and analyze how workers’ search behaviour responded to these reforms. We try both nonparametric and fully-parametric estimation methods and identify the cases in which the nonparametric approach cannot be applied. We find that the entitlement reforms are largely responsible for the increase of unemployment among unskilled workers
Unemployment Benefits and Unemployment Rates of Low-Skilled and Elder Workers in West Germany: A Search Equilibrium Approach
No full textApproach Author & abstract Download 16 References 1 Citations Related works & more Corrections Author Listed: Launov, Andrey ([email protected]) (University of Kent) Wolff, Joachim ([email protected]) (Institute for Employment Research (IAB), Nuremberg) Klasen, Stephan ([email protected]) (University of Göttingen) Registered: Stephan Klasen Abstract In this paper we investigate whether the extension of the entitlement to unemployment benefits in the mid 80s can explain the increase in the unemployment rates of unskilled and elder workers in western Germany. To answer this question we estimate a version of the Burdett-Mortensen search equilibrium model and analyze how workers’ search behaviour responded to these reforms. We try both nonparametric and fully-parametric estimation methods and identify the cases in which the nonparametric approach cannot be applied. We find that the entitlement reforms are largely responsible for the increase of unemployment among unskilled workers
Saltikov-Shedrin's traditions in literary creation of Andrey Platonov
No full textIn this article the author throws light on connections between the creative work of Andrey Platonov and satire of Mikhail Saltikov-Shedrin. Author deduces similarity of the destinies of two Great Russian writers; she notifies likeness of their literary stylistics, unity of their literary characters and vehicles
Kontorovich-Lebedev Integrals in Electromagnetic Scattering and Radiation Problems
No full textThe paper explains the Kontorovich-Lebedev (KL) integral convergence issues from the viewpoint of the KL integral transformation and presents a version of the KL method which is particularly well suited for solving problems of radiation and scattering of waves with real-valued wave numbers. The approach treats the KL integrals as analytic functions of the wave number and uses the fact that the KL integrals improve their convergence as the imaginary part of the wave number grows. During the construction of a solution the wave number is assumed to be purely imaginary to ensure convergence of the involved field representations. Once the solution is constructed, the integral representation is analytically continued to a desired, for example, real, value of the wave number. The paper shows that the pole singularity in the KL integrand function is to be understood in the principal value sense. For practical evaluation of the solution, one may transform the KL integral into either a series of Bessel functions or a Sommerfeld integral. The former representation is particularly useful in the low-frequency limit, whereas the latter is ideally suited for deriving high-frequency approximations of the wave fields
In memory of Andrey A. Aleksandrov (1946?2015)
No full textOn March, 17th, 2015 professor Andrey A. Alexandrov, the chief of functional cardiology department at Endocrinology Research Centre passed away. Andrey A. Alexandrov graduated from 2nd Moscow Medical Institute in 1971. In 1979 finished his PhD and in 1989 his doctoral research on topic ?Hormonal regulation and carbohydrate metabolism in patients with heart attack?. From 1999 to present time was the Chief of cardiology department at Endocrinology Research Centre. Alexandrov is the author of more than 420 publications, he supervised 13 PhDs and 1 doctoral research. We will remember him as a high level professional, great scientist, talented teacher and charming person.
Andrey Kiselev: the life and the legend
No full textThis article is devoted to Andrey Kiselev, probably the most well-known Russian author of mathematics textbooks. His books remained in schools for nearly one hundred years, and his name became legendary, symbolizing the “good old days” when all was supposedly well with mathematics education. Meanwhile, even in Russia, let alone abroad, many aspects of Kiselev’s life are little known. Their study facilitates a better understanding of the complicated nature of the development of Russian and Soviet mathematics education, including the connection between them and seemingly distant social-political issues. The present article undertakes such a study. The author draws on his Russian publications, materials from Russian archives, and other primary sources
BOOK REVIEW “DIARY OF AN INVASION, BY ANDREY KURKOV (2022)”
No full textDiary of An Invasion is a book written by Ukrainian author Andrey Kurkov in 2022. Written mostly during the first semester of 2022, the book is a chronological and personal diary that recounts Kurkov’s experience in Ukraine, during the initial months of the Russian invasion
Applying the Kontorovich-Lebedev transform to the analysis of electromagnetic diffraction by wedges
No full textThe presence of edges on the surface of a target may considerably influence the scattered field. The corresponding edge corrections are derived from the solution of the canonical problem of diffraction by an infinite wedge. If the refraction index takes different values inside and outside the wedge, no closed-form solution has been found so far despite multiple attempts and the use of a broad variety of methods. The Kontorovich-Lebedev transform has been successfully applied in the past to a number of scalar problems of diffraction by wedges. This paper applies the method to a vector problem of electromagnetic diffraction by a dielectric wedge. The boundary-value problem is reduced to a system of singular integral equations. It is shown that the equations can be approximately solved by perturbation method when the refraction index is near unity
Andrey Muraviev’s The Russian Vilnius
No full textThe article is an attempt to present the impressions of Andrey Muraviev, religious writer,
theologian, poet, playwright, church and state activist, from his stay in Vilnius in 1863, on the basis of his work entitled The Russian Vilnius. It consists of six essays on Vilnius religious monuments: the Chapel of Our Lady of Ostra Brama, St. Paraskeva Orthodox church, Orthodox cathedral of Our Most Holy Lady, Orthodox church of translation of St Nicholas’ relics, Holy Trinity cathedral, Holy Spirit church and monastery complex. The author was only interested in monuments which would document the city’s connections to Russia and Orthodox Christianity. His reflections might be considered as a literary justification for the program of Russification of the north-west country, developed by the writer’s brother, Mikhail, who went down in Polish historical memory as Veshatiel
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