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.

Optical Single-Photon Detection in Micrometer-Scale NbN Bridges

Abstract: The success of superconducting single-photon detectors has recently led to theoretical analysis of the impact of photons on a current-carrying superconductor, accompanied by the emergence of resistance due to vortices. Based on this analysis, a device unlike the standard long, narrow variety is developed, enabling operation close to the intrinsic critical pair-breaking current of the superconductor. These devices, which can be as wide as a few $\ensuremath{\mu}$m, clearly show single-photon detection for optical wavelengths from 408 to 1550 nm, making them compatible with optical fibers and promising for next-generation large-area detectors for quantum optics applications.

Triadic Formal Concept Analysis and triclustering: searching for optimal patterns

Abstract: This paper presents several definitions of "optimal patterns" in triadic data and results of experimental comparison of five triclustering algorithms on real-world and synthetic datasets. The evaluation is carried over such criteria as resource efficiency, noise tolerance and quality scores involving cardinality, density, coverage, and diversity of the patterns. An ideal triadic pattern is a totally dense maximal cuboid (formal triconcept). Relaxations of this notion under consideration are: OAC-triclusters; triclusters optimal with respect to the least-square criterion; and graph partitions obtained by using spectral clustering. We show that searching for an optimal tricluster cover is an NP-complete problem, whereas determining the number of such covers is #P-complete. Our extensive computational experiments lead us to a clear strategy for choosing a solution at a given dataset guided by the principle of Pareto-optimality according to the proposed criteria.

Predictors of (in)efficiencies of Healthcare Expenditure Among the Leading Asian Economies – Comparison of OECD and Non-OECD Nations

Abstract: Purpose The goal of this study was to assess the effectiveness of healthcare spending among the leading Asian economies. Methods We have selected a total of nine Asian nations, based on the strength of their economic output and long-term real GDP growth rates. The OECD members included Japan and the Republic of Korea, while the seven non-OECD nations were China, India, Indonesia, Malaysia, Pakistan, the Philippines, and Thailand. Healthcare systems efficiency was analyzed over the period 1996-2017. To assess the effectiveness of healthcare expenditure of each group of countries, the two-way fixed effects model (country- and year effects) was used. Results Quality of governance and current health expenditure determine healthcare system performance. Population density and urbanization are positively associated with a healthy life expectancy in the non-OECD Asian countries. In this group, unsafe water drinking has a statistically negative effect on healthy life expectancy. Interestingly, only per capita consumption of carbohydrates is significantly linked with healthy life expectancy. In these non-OECD Asian countries, unsafe water drinking and per capita carbon dioxide emissions increase infant mortality. There is a strong negative association between GDP per capita and infant mortality in both sub-samples, although its impact is far larger in the OECD group. In Japan and South Korea, unemployment is negatively associated with infant mortality. Conclusion Japan outperforms other countries from the sample in major healthcare performance indicators, while South Korea is ranked second. The only exception is per capita carbon dioxide emissions, which have maximal values in the Republic of Korea and Japan. Non-OECD nations' outcomes were led by China, as the largest economy. This group was characterized with substantial improvement in efficiency of health spending since the middle of the 1990s. Yet, progress was noted with remarkable heterogeneity within the group.

Study of the lineshape of the χc1 (3872) state

Abstract: A study of the lineshape of the χc1(3872) state is made using a data sample corresponding to an integrated luminosity of 3 fb-1 collected in pp collisions at center-of-mass energies of 7 and 8 TeV with the LHCb detector. Candidate χc1(3872) and ψ(2S) mesons from b-hadron decays are selected in the J/ψπ+π- decay mode. Describing the lineshape with a Breit-Wigner function, the mass splitting between the χc1(3872) and ψ(2S) states, Δm, and the width of the χc1(3872) state, ΓBW, are determined to be Δm=185.598±0.067±0.068 MeV,ΓBW=1.39±0.24±0.10 MeV, where the first uncertainty is statistical and the second systematic. Using a Flatte-inspired model, the mode and full width at half maximum of the lineshape are determined to be mode=3871.69-0.04-0.13+0.00+0.05 MeV,FWHM=0.22-0.06-0.13+0.07+0.11 MeV. An investigation of the analytic structure of the Flatte amplitude reveals a pole structure, which is compatible with a quasibound D0D¯*0 state but a quasivirtual state is still allowed at the level of 2 standard deviations.

Quantum continuous $\mathfrak{gl}_{\infty}$: Tensor products of Fock modules and $\mathcal{W}_{n}$-characters

Abstract: We construct a family of irreducible representations of the quantum continuous gl∞ whose characters coincide with the characters of representations in the minimal models of the Wn-algebras of gln type. In particular, we obtain a simple combinatorial model for all representations of the Wn-algebras appearing in the minimal models in terms of n interrelating partitions.