482 research outputs found
Competing ideologies of Russia's civil society
Many analysts and public opinion makers in the West conflate the notions of Russia’s non-systemic liberal opposition and the country’s civil society. Indeed, despite garnering the support of a minority of Russia’s population, non-systemic liberal opposition represents a well-organized civic group with a clearly articulated agenda and the ability to take action. Yet, does Russia’s civil society end there? A closer look at the country’s politics shows that Russia has a substantial conservative-traditionalist faction that has also developed agenda for action and formulated opinions. This group is anti-liberal rather than illiberal ideologically and pro-strong state/pro a geopolitically independent Russia rather than pro-Kremlin politically. The interaction between liberal and conservative civic groups represents the battle of meanings, ideas, and ethics, and ultimately determines the future trajectory of Russia’s evolution. Thus, the analysis of Russia’s civil society must represent a rather more nuanced picture than a mere study of the liberal non-systemic opposition. This article will examine the complexity of Russia’s civil society scene with reference to the interplay between the liberal opposition and conservative majority factions. The paper will argue that such complexity stems from ideological value pluralism that falls far beyond the boundaries of the liberal consensus, often skewing our understanding of political practice in Russia
Numerical integration of Heath-Jarrow-Morton model of interest rates
We propose and analyze numerical methods for the Heath-Jarrow-Morton (HJM)
model. To construct the methods, we first discretize the infinite dimensional
HJM equation in maturity time variable using quadrature rules for approximating
the arbitrage-free drift. This results in a finite dimensional system of
stochastic differential equations (SDEs) which we approximate in the weak and
mean-square sense using the general theory of numerical integration of SDEs.
The proposed numerical algorithms are computationally highly efficient due to
the use of high-order quadrature rules which allow us to take relatively large
discretization steps in the maturity time without affecting overall accuracy of
the algorithms. Convergence theorems for the methods are proved. Results of
some numerical experiments with European-type interest rate derivatives are
presented.Comment: 48 page
A Block Circulant Embedding Method for Simulation of Stationary Gaussian Random Fields on Block-regular Grids
We propose a new method for sampling from stationary Gaussian random field on
a grid which is not regular but has a regular block structure which is often
the case in applications. The introduced block circulant embedding method
(BCEM) can outperform the classical circulant embedding method (CEM) which
requires a regularization of the irregular grid before its application.
Comparison of BCEM vs CEM is performed on some typical model problems.Comment: [17 pages, 8 figures] We added Remarks 2.1, 3.1, 3.2, and Example 1.3
and removed the Appendix which is now summarized in Remark 2.
On the Definition of Effective Permittivity and Permeability For Thin Composite Layers
The problem of definition of effective material parameters (permittivity and
permeability) for composite layers containing only one-two parallel arrays of
complex-shaped inclusions is discussed. Such structures are of high importance
for the design of novel metamaterials, where the realizable layers quite often
have only one or two layers of particles across the sample thickness. Effective
parameters which describe the averaged induced polarizations are introduced. As
an explicit example, we develop an analytical model suitable for calculation of
the effective material parameters and
for double arrays of electrically small electrically polarizable scatterers.
Electric and magnetic dipole moments induced in the structure and the
corresponding reflection and transmission coefficients are calculated using the
local field approach for the normal plane-wave incidence, and effective
parameters are introduced through the averaged fields and polarizations. In the
absence of losses both material parameters are purely real and satisfy the
Kramers-Kronig relations and the second law of thermodynamics. We compare the
analytical results to the simulated and experimental results available in the
literature. The physical meaning of the introduced parameters is discussed in
detail.Comment: 6 pages, 5 figure
Stable and fast semi-implicit integration of the stochastic Landau-Lifshitz equation
We propose new semi-implicit numerical methods for the integration of the
stochastic Landau-Lifshitz equation with built-in angular momentum
conservation. The performance of the proposed integrators is tested on the 1D
Heisenberg chain. For this system, our schemes show better stability properties
and allow us to use considerably larger time steps than standard explicit
methods. At the same time, these semi-implicit schemes are also of comparable
accuracy to and computationally much cheaper than the standard midpoint
implicit method. The results are of key importance for atomistic spin dynamics
simulations and the study of spin dynamics beyond the macro spin approximation.Comment: 24 pages, 5 figure
Probabilistic methods for the incompressible navier-stokes equations with space periodic conditions
We propose and study a number of layer methods for Navier-Stokes equations (NSEs) with spatial periodic boundary conditions. The methods are constructed using probabilistic representations of solutions to NSEs and exploiting ideas of the weak sense numerical integration of stochastic differential equations. Despite their probabilistic nature, the layer methods are nevertheless deterministic. © ?Applied Probability Trust 2013
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