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Search Results: 1 - 10 of 505 matches for " Alla Romanova "
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A Numerov-Crank-Nicolson-Strang scheme with discrete transparent boundary conditions for the Schr?dinger equation on a semi-infinite strip
Alexander Zlotnik,Alla Romanova
Mathematics , 2013,
Abstract: We consider an initial-boundary value problem for a 2D time-dependent Schr\"odinger equation on a semi-infinite strip. For the Numerov-Crank-Nicolson finite-difference scheme with discrete transparent boundary conditions, the Strang-type splitting with respect to the potential is applied. For the resulting method, the uniqueness of a solution and the uniform in time $L^2$-stability (in particular, $L^2$-conservativeness) are proved. Due to the splitting, an effective direct algorithm using FFT in the direction perpendicular to the strip is developed to implement the splitting method for general potential. Numerical results on the tunnel effect for smooth and rectangular barriers together with the practical error analysis on refining meshes are included as well.
A splitting higher order scheme with discrete transparent boundary conditions for the Schr?dinger equation in a semi-infinite parallelepiped
Bernard Ducomet,Alexander Zlotnik,Alla Romanova
Physics , 2013,
Abstract: An initial-boundary value problem for the $n$-dimensional ($n\geq 2$) time-dependent Schr\"odinger equation in a semi-infinite (or infinite) parallelepiped is considered. Starting from the Numerov-Crank-Nicolson finite-difference scheme, we first construct higher order scheme with splitting space averages having much better spectral properties for $n\geq 3$. Next we apply the Strang-type splitting with respect to the potential and, third, construct discrete transparent boundary conditions (TBC). For the resulting method, the uniqueness of solution and the unconditional uniform in time $L^2$-stability (in particular, $L^2$-conservativeness) are proved. Owing to the splitting, an effective direct algorithm using FFT (in the coordinate directions perpendicular to the leading axis of the parallelepiped) is applicable for general potential. Numerical results on the 2D tunnel effect for a P\"{o}schl-Teller-like potential-barrier and a rectangular potential-well are also included.
The Development of the Public-Private Partnership Concept in Economic Theory  [PDF]
Alla Mostepaniuk
Advances in Applied Sociology (AASoci) , 2016, DOI: 10.4236/aasoci.2016.611028
Abstract: The paper is aimed at the historical research of the approaches to identify the concept of public-private partnership and support its necessity in various conditions and countries by representatives of different scientific economic schools. Using methods of analyzing and interpreting of historical conditions and evidences as well as original scientific papers, the key stages of public-private partnership concept historical development were discovered and described.
Planktonic Foraminifera Diversity in the Sea of Okhotsk and Correlation to Past Climate Change  [PDF]
A. Romanova, N. Iurchenko
Journal of Geoscience and Environment Protection (GEP) , 2014, DOI: 10.4236/gep.2014.23011
Abstract:

80 sediment stations and 4 sediment cores collected in the Sea of Okhotsk were used in this study in order to reveal additional proxy for past climate reconstruction based on planktonic foraminifera. Variation in diversity indices (Simpson, Shannon and equitability indices) along the sea became additional criteria for 5 biogeographical provinces based on planktonic foraminifera. All of them show different structure aspects of the planktonic foraminifera assemblages that is very informative in cases of high relative abundance of N. pachyderma sin. and influence of carbonate dissolution factor. During the last 100 ky the diversity indices were changed and we can assume the migration of biogeographical provinces borders: borders of the Northern province were mov- ed to the central part in cold MIS 2, 4, structure of assemblages during MIS 3, 5 was close to the modern Central province but characterized by low total foraminiferal abundance in the sediments. The Simpson and Shannon indices are more sensitive to changes in structure of planktonic foraminifera assemblages when equitability index varies lightly during the Late Pleistocene-Holocene.

Superlexical versus lexical prefixes
Eugenia Romanova
Nordlyd : Troms? University Working Papers on Language & Linguistics / Institutt for Spr?k og Litteratur, Universitetet i Troms? , 2004,
Abstract: This paper is intended to justify the classification of all the Rus- sian prefixes into lexical and superlexical. It gives semantic and syntactic criteria for distinguishing between the two groups, includ- ing: the idiosyncratic or spatial lexical meaning versus operator-like function; the (in)ability to measure over objects and events; the (in)ability to stack; the (in)ability of a host verb to form secondary imperfective; attaching to (a)telic stems; the (in)ability to change the argument structure of a host verb. Applying these criteria results in finer gradation within the group of superlexical prefixes. It is ac- counted for by their different syntactic positions with respect to vP. At the end of the paper I speculate about the effect this architecture can have on the prefixation of unaccusative and unergative verbs.
Samara epidemiological research of myasthenia gravis
Т.V. Romanova
Saratov Journal of Medical Scientific Research , 2012,
Abstract: The aim of the study was to analyze epidemiological and demographic characteristics of patients with myasthenia gravis in the Samara region. Material and methods. Data of electronic register of Regional myasthenic center containing information about 340 patients were used. Prevalence of myasthenia gravis in area made up 9,7; average annual disease over the last 10 years — 0,73 per 100000. Results. The data obtained are comparable with the global characteristics of the disease, but higher than the figures of some domestic researches. Conclusion. Confirms the fact that in regions where work specialized myasthenic centers, epidemiological parameters are always higher.
Regionalist Origins of Centralisation in Ukraine
Valentyna Romanova
Sfera Politicii , 2012,
Abstract: Regionalism in Ukraine is often perceived as a threat for territorial integrity and democratisation. However, Ukrainian regionalist parties, that call for severe decentralisation during electoral campaigns, tend to promote centralisation when in national office. Indeed, their pre-electoral and post-electoral positions on the centre-periphery relations significantly differ. Strong regionalist parties follow their pre-electoral agendas mainly for effective bargaining with strong centralist parties. When in national office, they promote centralisation, which is beneficial for territorial interest groups they represent – territorially bounded heavy industries that require central investment.
Analysis of Scheduling Problem on Two Machines with Partial Precedence Order on the Set of Jobs
Anna Romanova
Mathematics , 2014,
Abstract: In this paper, we consider an NP-hard problem of scheduling a set of jobs of equal processing time on two machines, given a partial precedence order on the set of jobs, with an objective to minimize the makespan. An approximation algorithm is proposed for this problem with a tight approximation bound. Polynomial solvability of the problem is proved in the case when each job on the first machine is in precedence relation with two jobs on the second machine.
Thinning of Emulsion Water-in-Oil Films Stabilized with Modified Aluminum Hydroxide under Influence of Applied Pressure Drop  [PDF]
Alla V. Nushtaeva
Soft (Soft) , 2014, DOI: 10.4236/soft.2014.31002
Abstract:

The results of studies of thinning free water-in-oil emulsion films stabilized by solid particles by the Applied Pressure Drop Technique (APDT) are reported. The quasi-equilibrium film thickness achieved by slow increasing the pressure drop was smaller than the rupture thickness obtained by sharp increasing the pressure. It is shown that non-equilibrium films ruptured with thicknesses corresponding to adjustment of the packing of solid particles in the films. It is supposed that the restructuring package is the cause of the earlier breakthrough of the film.

Introduction of Fertigation in Sugarcane Production for Optimization of Water and Fertilizers Use  [PDF]
Daffa Alla Mohamed Abdel Wahab
Agricultural Sciences (AS) , 2014, DOI: 10.4236/as.2014.511102
Abstract: A fertigation experiment was conducted during 2009/2010 and 2010/2011 seasons under com-mercial field conditions in Kenana Sugar Scheme, Sudan (latitude 13.10’N and longitude 32.40’E) in heavy clay soils, with 65% clay, 24% silt, 11% sand and pH 7.5 - 8.5. The primary objective of this study was to compare different strategies for timing of injection, to develop management practices on the efficient use of water and fertilizers in production of sugarcane, maximize yield, and improve quality. In both seasons four treatments were studied in a randomized complete block design with three replications as: Injection of the dissolved urea (46% N) during entire irrigation time (100%), during the first half of the irrigation time, during the second half of the irrigation time, and Mechanical application of urea. The first three treatments were applied with the third irrigation cycle through the irrigation water so that nitrogen fertilizer in form of dissolved urea (46% N) was injected in irrigation water by means of pressure differential tank system which is based on the principle of a pressure differential being created by a valve and flow regulator forcing and injecting a varying amount of dissolved fertilizer into the irrigation water. In the fourth treatment the fertilizer spreader and rigid tine cultivator were used for urea application just before the third irrigation event. The reference evapotranspiration (ETo) and the amount of water required for irrigating sugarcane plants were calculated according to its phenological stages using Peman-Monteith approach. The results of this study support the general finding that the injection during the entire irrigation (100% of the irrigation) produced the best distribution uniformity of added urea. In this study, injection during the first half of the irrigation was not statistically different from injection during 100% of the irrigation.
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