1,792 research outputs found
Economic tomography: the possibility to anticipate and respond to socio-economic crises
The article discusses an approach based on an original hypothesis related to the peculiarities of Russia’s development (on the one hand, its scale, the Russian mentality and a certain closeness of the economy; on the other hand, a significant dominant resource and human potential, and, as a consequence, a genuine role in the global economic community), the diagnosis of which (at the level of the well-being of individuals and inhabited areas) can be used to identify crises, provide an early assessment of threats to socio-economic development of regions as well as help to evaluate the state of the region over a 3 to 5 year period. In other words, in order to ensure that executives have enough time to mount a sufficiently rapid response to the crises and administrative errors and to reduce the impact of emerging threats. The aim of this paper is to present theoretical and methodological tools for the recognition of the early stages of emerging threats, allowing fewer losses to be experienced during the crisis period. Simulation experiments were carried out for the purpose of classifying previously occurring social and economic crises (9 possible variants were reviewed) and mathematically processed trajectories of change in the main indicators for the well-being of individuals and inhabited areas, taking the influence of various factors into account. On the basis of the authors’ proposed approach (referred to as economic tomography) an attempt is made to comprehensively assess the state of sample representative regions of Russia.The research has been supported by the Russian Science Foundation (project № 14–18–00574 'Information-analytical system "Anticrisis:" diagnostics of the regions, threat assessment and scenario forecasting for the preservation and strengthening of economic security and well-being of Russia')
Russia’s Birth Rate Dynamics Forecasting
This article covers contemporary issues of Russia’s population reproduction, their causes and the state policy aimed to overcome the same. The urgency to fulfill the task related to assessment of the most probable future dynamics of Russia’s population birth rate in the context of a low child-woman ratio, and subject to an impact of pronatalist policies implemented by the state, is justified. In order to fulfill the task based on the crude birth rate behavior probability distribution function, a probabilistic assessment of future dynamics of Russia’s population reproduction has been carried out. Based on a modernized method suggested by Hurst, the following two forecasting paths of the crude birth rate dynamics have been built: the first path conforms to the scenario where a value of the crude birth rate is to tend to values between 8–10.5 births/1,000 people (probability is 0.182), in particular, through a negative external impact, the second path is to tend to values between 13–16.5 births/1,000 people (probability — 0.618), in particular, through a positive external impact. Notwithstanding that these scenarios significantly differ from each other, the paths of the crude birth rate dynamics for 2015–2041, corresponding to the reliable prediction time, forecasted according to the abovementioned scenarios, are virtually identical. The analysis of the findings allowed for the conclusion that the state demographic policy is not capable of having a significant impact on the future dynamics of the birth rate, substantially determined by the current situation and conjuncture shifts. These conclusions confirm the view prevailing in academic circles and suggesting that the state regulation of Russia’s demographic situation should be primarily focused on the improvement in health and a rise in the life expectancy of the population.The research has been prepared with the support of the Russian Science Foundation grant (Project No. 14-18-00574 “Information and analytic systems “Anticrisis”: diagnostics of the regions, threat evaluation and scenario forecasting to preserve and reinforce the welfare of Russia”)
Vertical-external-cavity surface-emitting lasers and quantum dot lasers
The use of cavity to manipulate photon emission of quantum dots (QDs) has
been opening unprecedented opportunities for realizing quantum functional
nanophotonic devices and also quantum information devices. In particular, in
the field of semiconductor lasers, QDs were introduced as a superior
alternative to quantum wells to suppress the temperature dependence of the
threshold current in vertical-external-cavity surface-emitting lasers
(VECSELs). In this work, a review of properties and development of
semiconductor VECSEL devices and QD laser devices is given. Based on the
features of VECSEL devices, the main emphasis is put on the recent development
of technological approach on semiconductor QD VECSELs. Then, from the viewpoint
of both single QD nanolaser and cavity quantum electrodynamics (QED), a
single-QD-cavity system resulting from the strong coupling of QD cavity is
presented. A difference of this review from the other existing works on
semiconductor VECSEL devices is that we will cover both the fundamental aspects
and technological approaches of QD VECSEL devices. And lastly, the presented
review here has provided a deep insight into useful guideline for the
development of QD VECSEL technology and future quantum functional nanophotonic
devices and monolithic photonic integrated circuits (MPhICs).Comment: 21 pages, 4 figures. arXiv admin note: text overlap with
arXiv:0904.369
Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV
The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8 TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum
- …