446 research outputs found
Electronic structure and magnetic anisotropy of CrO_2
The problem of importance of strong correlations for the electronic
structure, transport and magnetic properties of half--metallic ferromagnetic
CrO_2 is addressed by performing density functional electronic structure
calculations in the local spin density approximation (LSDA) as well as using
the LSDA+U method. It is shown that the corresponding low--temperature
experimental data are best fitted without accounting for the Hubbard U
corrections. We conclude that the ordered phase of CrO$_2 is weakly correlated.Comment: 5 pages, 7 EPS figures, in RevTex forma
Determinants of households’ credit behavior in Russia
Purpose: The main goal of this work is to substantiate the need to consider microeconomic statistics when analyzing consumer lending to the population, as well as implementing approaches to modeling household credit behavior at the micro level.
Design/Methodology/Approach: The article proposes and implements a comprehensive statistical approach that allows identifying the specificity of the influence of demographic, socio-economic characteristics of households on their credit activity.
Findings: The article states that loan borrowings are more often found in households with children of preschool age who are in relatively high-income groups, who much more often inform about cash incomes that do not correspond to the declared level of consumption. Members of these households are more likely to work. The age range of borrowers expanded during the study period, and no prevalence of any age group was observed.
Practical Implications: This result is of great practical importance, since, as already indicated, in assessing the solvency of the borrower, credit organizations are mainly focused on individual characteristics.
Originality/value: It was found that the hypothesis that individual characteristics are important determinants of household lending activity has not been confirmed. And variables that characterize households significantly affect their credit behavior.peer-reviewe
Electronic Structure and Magnetic Properties of Solids
We review basic computational techniques for simulations of various magnetic
properties of solids. Several applications to compute magnetic anisotropy
energy, spin wave spectra, magnetic susceptibilities and temperature dependent
magnetisations for a number of real systems are presented for illustrative
purposes.Comment: Review article; To appear in Journal of Computational Crystallograph
Usporedba QSPR modela zasnovanih na vodikom-popunjenim molekularnim grafovima i na grafovima atomskih orbitala
QSPR models are studied for normal boiling points of alkanes, alkylbenzenes, and polyaromatic hydrocarbons, in terms of optimized correlation weights of local invariants of the hydrogen- -filled graphs (HFGs) and of the graphs of atomic orbitals (GAOs). Morgan extended connectivities of the zeroth, first, and second order of the HFGs and GAOs were employed. The best QSPR model obtained is based on optimized correlation weights of the extended connectivity of the first order of the GAO. The statistical characteristics of this model are: n = 70, r superscript(2) = 0.9988, s = 5.8 °C, F = 57437 (training set); n = 70, r superscript(2) = 0.9985, s = 6.7 °C, F = 45154 (test set).Istraživani su QSPR modeli za normalnu točku vrelišta alkana, alkilbenzena i poliaromatskih ugljikovodika, zasnovani na optimiziranim korelacijskim te`inama lokalnih invarijanti vodikom-popunjenih molekularnih grafova (HFG) i grafova atomskih orbitala (GAO). Primjenjeni su Morganovi indeksi proširene povezanosti nultoga, prvoga i drugoga reda, kako za HFG tako i za GAO. Najbolji QSPR model je dobiven na osnovi optimiziranih korelacijskih težina za proširenu povezanost prvoga reda za GAO. Statističke karakteristike ovoga modela su: n = 70, r superscript(2) = 0.9988, s = 5.8 °C, F = 57437 (training set); n = 70, r superscript(2) = 0.9985, s = 6.7 °C, F = 45154 (test set)
The problem of attracting and keeping the youth in the Far East of Russia
Освещается проблема демографии современного Дальнего Востока России – отток населения, в том числе молодежи, определяются возможные пути решения данной проблемы. По мнению авторов, решать ее необходимо по двум направлениям – развитие рынка труда в регионе и обеспечение молодежи жильем.Shows the problem of the demographics of the Far East of Russia – directions of solving this problem. According to the authors, it must be solved on two fronts – the development of the labour market in the region and the provision of housing for youth
Control optimization for asynchronized switched motor of mine hoist plant using Bellman – Lyapunov method
У статті розглядається задача синтезу нелінійного регулятора швидкості асинхронізованого вентильного двигуна. Для знаходження оптимального закону управління, використаний метод Беллмана - Ляпунова з використанням концепції методу «занурення». Здійснено моделювання та зроблений порівняльний аналіз електропривода зі стандартним ПІ - регулятором, а також з синтезованим оптимальним регулятором.The problem of synthesis of nonlinear speed controller asynchronized switched motor is considered. To find the optimal control law by, the method of Bellman - Lyapunov by concept of "immersion" is used. Modeling and comparative analysis of the system with the standard PI - controller, as well as the synthesized regulators are made.В статье рассматривается задача синтеза нелинейного регулятора скорости асинхронизированного вентильного двигателя. Для нахождения оптимального закона управления, использован метод Беллмана - Ляпунова с использованием концепции метода «погружения». Осуществлено моделирование и произведен сравнительный анализ электропривода со стандартным ПИ - регулятором, а также с синтезированным оптимальным регулятором
QSAR Model for Cytotoxicity of Silica Nanoparticles on Human Embryonic Kidney Cells1
Abstract A predictive model for cytotoxicity of 20 and 50 nm silica nanoparticles has been built using so-called optimal descriptors as mathematical functions of size, concentration and exposure time. These parameters have been encoded into 31 combinations 'concentration-exposure-size'. The calculation has been carried out by means of the CORAL software ( http://www.insilico.eu/coral/ ) using three random splits of the obtained systems into training and test sets. The statistical quality of the best model for cell viability (%) of cultured human embryonic kidney cells (HEK293) exposed to different concentrations of silica nanoparticles measured by MTT assay is satisfactory
Advancement of predictive modeling of zeta potentials (ζ) in metal oxide nanoparticles with correlation intensity index (CII)
It was expected that index of the ideality of correlation (IIC) and correlation intensity index (CII) could be used as possible tools to improve the predictive power of the quantitative model for zeta potential of nanoparticles. In this paper, we test how the statistical quality of quantitative structure-activity models for zeta potentials (ζ, a common measurement that reflects surface charge and stability of nanomaterial) could be improved with the use of these two indexes. Our hypothesis was tested using the benchmark data set that consists of 87 measurements of zeta potentials in water. We used quasi-SMILES molecular representation to take into consideration the size of nanoparticles in water and calculated optimal descriptors and predictive models based on the Monte Carlo method. We observed that the models developed with utilization of CII are statistically more reliable than models obtained with the IIC. However, the described approach gives an improvement of the statistical quality of these models for the external validation sets to the detriment for the training sets. Nevertheless, this circumstance is rather an advantage than a disadvantage
Implementation of PLC-based optimal control system of rotor wheel motors with the concept of Pearson method
Розглянуто можливість реалізації оптимального керування електродвигуном роторного колеса при використанні програмованих логічних контролерів. Вибрано функціонал якості, при якому забезпечується висока якість регулювання швидкості і суттєво спрощується процедура аналітичного конструювання. Синтезовано закон оптимального керування методом динамічного програмування з використанням концепції методу Пірсона. Зроблено аналіз виконання теореми Котельникова - Шеннона при використанні програмованого логічного контролера і реалізації в ньому отриманого закону управління.The possibility of implementing the optimal control by rotor wheel motors using programmable logic controllers is considered. Functional of quality, which ensures high quality control and a greatly simplified procedure for analytical design, is selected. Optimal control law by dynamic programming method using the concept of Pearson is synthesized. The analysis of the implementation of the Kotelnikov-Shennon theorem by using a programmable logic controller and realization of obtained control law is produced.Рассмотрена возможность реализации оптимального управления электродвигателем роторного колеса при использовании программируемых логических контроллеров. Выбран функционал качества, при котором обеспечивается высокое качество регулирования скорости и существенно упрощается процедура аналитического конструирования. Синтезирован закон оптимального управления методом динамического программирования с использованием концепции метода Пирсона. Произведен анализ выполнения теоремы Котельникова - Шеннона при использовании программируемого логического контроллера и реализации в нем полученного закона управления
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