Determination of the Optimal Number of Realizations of the Modulating Sequence of the PSK-n signal Necessary for Estimating the Error Probability per Symbol Caused by the ISI Produced by Linear Selective Systems

© 2018 IEEE. the problem of estimation of the optimal number of realizations for necessary PSK-n modulating sequence to estimate symbol error rate caused by ISI produced by linear selective systems is considered in the paper. Estimation of the optimal realization number for this case is carried out based on numerical simulation of communicating channel. Dependencies, which allow to estimate value of specific number of optimal of realization per discrete state, are shown in the article, appropriate recommendations are provided

Interpretation of the results of thermohydrodynamic studies of vertical wells that operate on multibed deposits

© 2014, Pleiades Publishing, Ltd. A mathematical model for describing thermohydrodynamic processes in a “vertical well-multibed deposit” system was developed. A method for determining the filtration and thermophysical parameters of a multibed deposit and flow rates of interlayers is proposed. The curves of changes in the bottomhole temperature in a vertical borehole that were measured after its startup are used as the initial information

Determination of Filtration Properties of a Deformable Porous-Fractured Bed from the Results of Hydrodynamic Investigations of Horizontal Wells

© 2014, Springer Science+Business Media New York. A computational algorithm has been proposed for interpretation of results of hydrodynamic investigations of horizontal wells in unsteady regimes of filtration in deformable porous-fractured beds. The proposed approach makes it possible to evaluate the dependence of the permeability coefficient of fractures on pressure. A study has been made of the dynamics of change in the bottom-hole pressure after bringing a horizontal well into production and shutting it down in the nonlinear elastic regime of filtration of the fluid in a porous-fractured bed

World population estimates and projections: Data and methods

In work results of the carried-out demographic forecasting as in general for the world and by certain parts of the world (Africa, South America, North America, Asia, Europe) are provided. It allowed to carry out at the same time the analysis of the population growth dynamics by groups of the countries "North" - "South". The analysis of the world population dynamics and certain parts of the world during 1950 - 2010 allowed to carry out the forecast of the world population and certain parts of the world before 2050. In work methods of regression and correlation analysis were applied. The received results in case of the various options choice like the approximating functions differ in the high level of the actual compliance and calculated values, i.e. insignificant errors of approximation,in case of high significance value of results (p>0.05). In the course of forecasting it was revealed that in the first half of the 21st century population growth will continue. This growth will be extremely uneven both on continents, and over groups of the countries. As a result of globalization processes the stage of demographic transition will be entered by all countries of the world (though differentiation in this plan will be very essential). In the second half of the century the period of demographic stabilization at the planetary level will begin

Bright ultra-broadband fiber-based biphoton source

In this Letter, we report a first experimental realization of bright ultra-broadband (180 THz) fiber-based biphoton source with widely spectrally separated signal and idler photons. Such a two-photon source is realized due to the joint use of broadband phase-matching of interacting light waves and high optical nonlinearity of a silica-core photonic crystal fiber. The high performance of the developed fiber source identifies it as an important and useful tool for a wide range of optical quantum applications

Thermohydrodynamic studies of vertical wells with hydraulic fracturing of a reservoir

© 2017, Pleiades Publishing, Ltd.A mathematical model to describe thermohydrodynamic processes in the system “oil reservoir–hydraulic fracture” is developed. A method for determining filtration and thermophysical parameters of the reservoir and fracture is proposed. Curves of the change of the downhole temperature and pressure are used as initial information

Determination of the Parameters of the Hole Bottom Zone of a Vertical Well from the Results of Thermodynamic Investigations

© 2016, Springer Science+Business Media New York.A computational algorithm for estimating the parameters of the hole bottom zone from the results of measuring pressure and temperature at the bottom hole of a vertical well is suggested. The ambiguity of determining the permeability and of the hole bottom zone radius depending on the original information is shown

Thermohydrodynamic investigations of vertical wells operating in multilayer reservoirs

A mathematical model is constructed to describe the thermohydrodynamic processes in "vertical well - multilayer reservoir" system. A new approach to estimate the filtration parameters and flow rates of interlayers is proposed. The curves of the bottomhole temperature variations taken after the bringing the vertical well into production are used as the source data

Hydrodynamic studies of horizontal wells

A new technology is suggested for performance of hydrodynamic studies in horizontal wells using comprehensive off-line instrumentation. The interpretation procedure for the outcome of such studies has been developed based on the regularizalion methods

Syphilis epidemiology in 1994–2013, molecular epidemiological strain typing and determination of macrolide resistance in Treponema pallidum in 2013–2014 in Tuva Republic, Russia

© 2016 APMIS. Published by John Wiley & Sons LtdThe incidence of syphilis in the Tuva Republic (geographical centre of Asia), Russia has been exceedingly high historically. No detailed examinations and no molecular investigations of Treponema pallidum strains transmitted in the Tuva Republic, or in general, in Russia, were published internationally. We examined the syphilis epidemiology in 1994–2013, and the molecular epidemiology and macrolide resistance in T. pallidum strains in 2013–2014 in the Tuva Republic. Among 95 mainly primary or secondary syphilis patients, the arp, tpr, tp0548 and 23S rRNA genes in 85 polA gene-positive genital ulcer specimens were characterized. The syphilis incidence in Tuva Republic peaked in 1998 (1562), however declined to 177 in 2013. Among the 70 (82%) completely genotyped specimens, six molecular strain types were found. Strain type 14d/f accounted for 91%, but also 14c/f, 14d/g, 14b/f, 14i/f, 9d/f, and 4d/f were identified. Two (2.4%) specimens contained the 23S rRNA A2058G macrolide resistance mutation. This is the first internationally published typing study regarding T. pallidum in Russia, performed in the Tuva Republic with the highest syphilis incidence in Russia. The two molecular strain types 4d/f and 9d/f have previously been described only in Eastern and Northern China and for the first time, macrolide-resistant syphilis was described in Russia