National Research University – Higher School of Economics

About: National Research University – Higher School of Economics is a education organization based out in Moscow, Russia. It is known for research contribution in the topics: Population & Computer science. The organization has 12873 authors who have published 23376 publications receiving 256396 citations.

Waveguide-integrated single- and multi-photon detection at telecom wavelengths using superconducting nanowires

Abstract: We investigate single- and multi-photon detection regimes of superconducting nanowire detectors embedded in silicon nitride nanophotonic circuits. At near-infrared wavelengths, simultaneous detection of up to three photons is observed for 120 nm wide nanowires biased far from the critical current, while narrow nanowires below 100 nm provide efficient single photon detection. A theoretical model is proposed to determine the different detection regimes and to calculate the corresponding internal quantum efficiency. The predicted saturation of the internal quantum efficiency in the single photon regime agrees well with plateau behavior observed at high bias currents.

Common and Unique Features of Schwartz’s and Inglehart’s Value Theories at the Country and Individual Levels:

Abstract: This article examines commonalities and differences in the value theories proposed by Ronald Inglehart and Shalom Schwartz. A systematic review of previous findings was conducted. Then, we showed, with a joint multidimensional scaling (MDS) analysis, that Schwartz’s Embeddedness versus Autonomy dimension tends to lie at the diagonal of the Inglehart Cultural Map of the World, suggesting that in order to be autonomous/open, individuals need to have both self-expressive and secular-rational values, whereas being embedded /conservative involves both traditional and survival values. Two distinct regions of Schwartz’s values (one at each level) which are missed by Inglehart’s instrument were identified. At the same time, an MDS plot revealed that, at the individual level, Inglehart’s Survival values are not captured by the Schwartz’s items included. The obtained structures at the two levels of analysis were shown to be remarkably similar (Tucker’s Φ > .90).

Fractal Folding and Medium Viscoelasticity Contribute Jointly to Chromosome Dynamics

Abstract: Chromosomes are key players of cell physiology, their dynamics provides valuable information about its physical organization. In both prokaryotes and eukaryotes, the short-time motion of chromosomal loci has been described with a Rouse model in a simple or viscoelastic medium. However, little emphasis has been put on the influence of the folded organization of chromosomes on the local dynamics. Clearly, stress propagation, and thus dynamics, must be affected by such organization, but a theory allowing us to extract such information from data, e.g., on two-point correlations, is lacking. Here, we describe a theoretical framework able to answer this general polymer dynamics question. We provide a scaling analysis of the stress-propagation time between two loci at a given arclength distance along the chromosomal coordinate. The results suggest a precise way to assess folding information from the dynamical coupling of chromosome segments. Additionally, we realize this framework in a specific model of a polymer whose long-range interactions are designed to make it fold in a fractal way and immersed in a medium characterized by subdiffusive fractional Langevin motion with a tunable scaling exponent. This allows us to derive explicit analytical expressions for the correlation functions.

Everyone Hates Privatization, but Why? Survey Evidence from 28 Post-Communist Countries

Abstract: A 2006 survey of 28,000 individuals in 28 post-communist countries reveals overwhelming support for revising privatization, but also that most respondents prefer to leave firms in private hands. We test whether individuals support revising privatization primarily due to a preference for state property or due to concerns about the legitimacy of privatization. We find that a lack of human capital and privately owned assets affects the support for revising privatization primarily via a preference for state property over private property; whereas transition-related hardships influence support for revising privatization via both a preference for state property and concerns about the illegitimacy of privatization. These results suggest the value of analyses that not only link respondent traits with support for policy, but that also probe the motivations that underpin this support.

A note on linearized reformulations for a class of bilevel linear integer problems

Abstract: We consider reformulations of a class of bilevel linear integer programs as equivalent linear mixed-integer programs (linear MIPs). The most common technique to reformulate such programs as a single-level problem is to replace the lower-level linear optimization problem by Karush–Kuhn–Tucker (KKT) optimality conditions. Employing the strong duality (SD) property of linear programs is an alternative method to perform such transformations. In this note, we describe two SD-based reformulations where the key idea is to exploit the binary expansion of upper-level integer variables. We compare the performance of an off-the-shelf MIP solver with the SD-based reformulations against the KKT-based one and show that the SD-based approaches can lead to orders of magnitude reduction in computational times for certain classes of instances.