Lietuvos matematikos rinkinys
https://www.journals.vu.lt/LMR
<p><span data-contrast="auto">Founded in 1961. Publishes articles presenting new and important events in all areas of mathematics.</span><span data-ccp-props="{"335559731":0}"> </span></p>Vilniaus universiteto leidykla / Vilnius University PressltLietuvos matematikos rinkinys0132-2818<p>Please read the Copyright Notice in <a href="http://www.zurnalai.vu.lt/informacijos-mokslai/journalpolicy">Journal Policy</a>. </p>On H(D)-valued random elements
https://www.journals.vu.lt/LMR/article/view/34744
<p>There is not abstract.</p>
ArticlesAntanas Laurinčikas
Copyright (c) 2001 Antanas Laurinčikas
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2001-12-172001-12-1763263610.15388/LMR.2001.34744On the stability of one characterization of the stable distributions
https://www.journals.vu.lt/LMR/article/view/34743
<p>As early as 1923, Georg P6lya wrote: ``The Gaussian error law possesses the property that it remains valid under a linear combination of errors. The Gaussian error law can be characterized by this property to some extent – it is the only law that admits steadiness with respect to linear combinations of errors''. The idea of using linear combinations of random variables to characterize the stable distributions has been extended by P. Levy. We investigate the stability of this characterization.</p>
ArticlesOlga YanushkevichieneRomanas Yanushkevichius
Copyright (c) 2001 Olga Yanushkevichiene | Romanas Yanushkevichius
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2001-12-172001-12-1762663110.15388/LMR.2001.34743Asymptotic expansion for the density function of the series scheme of a random variables in the large deviation in Cramer zone
https://www.journals.vu.lt/LMR/article/view/34742
<p>In this work, the expansion of the density function of series schemes of independent variables <em>ξ</em><sup>(<em>n</em>)</sup><sub>1</sub>,<em>ξ</em><sup>(<em>n</em>)</sup><sub>2 </sub>,..., <em>ξ</em><sup>(<em>n</em>)</sup><em>j,</em> <sub> </sub> with means <strong>E</strong><em>ξ</em><sup>(<em>n</em>)</sup><em>j</em> = 0, and dispersions σ<sup>(<em>n</em>)2</sup><sub><em>j</em></sub> = <strong>E</strong><em>ξ</em><sup>(<em>n</em>)2</sup><em>j </em> has been obtained in the Cramer zone of large deviations. The result was obtained, based on General Lemma 6.1 [2] by joining the methods of characteristic functions and cumulants. The work broadens theory of sums of random variables [1] and in special case improves S.A. Book [5] results of sums of random variables with weights.</p>
ArticlesDovilė DeltuvienėLeonas Saulis
Copyright (c) 2001 Dovilė Deltuvienė | Leonas Saulis
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2001-12-172001-12-1762062510.15388/LMR.2001.34742Kornya approximation for dependent indicators
https://www.journals.vu.lt/LMR/article/view/34741
<p>There is not abstract.</p>
ArticlesVydas Čekanavičius
Copyright (c) 2001 Vydas Čekanavičius
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2001-12-172001-12-1761561910.15388/LMR.2001.34741Asymptotical investigation of extreme terms of the variational series
https://www.journals.vu.lt/LMR/article/view/34740
<p>In asymptotics of extreme terms of the variational series is presented. The volume of the sample is random and normalization or nonlinear.</p>
ArticlesAlgimantas Aksomaitis
Copyright (c) 2001 Algimantas Aksomaitis
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2001-12-172001-12-1761161410.15388/LMR.2001.34740Calculation of the transient heat distribution on the plate by the finite element method
https://www.journals.vu.lt/LMR/article/view/34739
<p>The paper deals with the analysis problem of transient heat distribution on the plate. The external surfaces of the plate are subject to the heat transfer by convection with time dependent fluid temperature. The efficiency of the numerical results is illustrated by the solution of the problem of a cooled plate.</p>
ArticlesSigita Turskienė
Copyright (c) 2001 Sigita Turskienė
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2001-12-172001-12-1760360810.15388/LMR.2001.34739Stating and solving digital image similarity problem
https://www.journals.vu.lt/LMR/article/view/34738
<p>Digital image similarity problem is posed. Necessary conditions (criterion) for the existence of similar digital d-dimensional images are formulated and proved. Areas of application of the criterion are mentioned.</p>
ArticlesNerijus MorkevičiusJonas Valantinas
Copyright (c) 2001 Nerijus Morkevičius | Jonas Valantinas
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2001-12-172001-12-1759660210.15388/LMR.2001.34738Modelling of vehicle motion control
https://www.journals.vu.lt/LMR/article/view/34737
<p>The problem is to calculate the path trajectory and sequence of control signals for a vehicle following a wire in the floor. Motion of the vehicle is determined by system of differential equations. Fourth-order Runge–Kutta adaptive method was used for solving of the obtained system of the differential equations.</p>
ArticlesNarimantas Listopadskis
Copyright (c) 2001 Narimantas Listopadskis
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2001-12-172001-12-1759159510.15388/LMR.2001.34737Time alignment in speech and speaker recognition
https://www.journals.vu.lt/LMR/article/view/34736
<p>Time scale alignment problems in speech and speaker recognition by voice are investigated. Dynamic programming approach to solution of this problem is discussed.</p>
ArticlesAntanas LipeikaJoana Lipeikienė
Copyright (c) 2001 Antanas Lipeika | Joana Lipeikienė
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2001-12-172001-12-1758459010.15388/LMR.2001.34736Investigation of the stability of a metal cutting process
https://www.journals.vu.lt/LMR/article/view/34735
<p>There is not abstract.</p>
ArticlesJolanta JanutėnienėDonatas Švitra
Copyright (c) 2001 Jolanta Janutėnienė | Donatas Švitra
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2001-12-172001-12-1757858310.15388/LMR.2001.34735The mathematical model of the menstrual cycle with time delay depending on the researched function
https://www.journals.vu.lt/LMR/article/view/34734
<p>There is not abstarct.</p>
ArticlesRasa GrigolienėGintaras PridotkasKostas BučysDonatas Švitra
Copyright (c) 2001 Rasa Grigolienė | Gintaras Pridotkas | Kostas Bučys | Donatas Švitra
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2001-12-172001-12-1757357710.15388/LMR.2001.34734Optimisation of parameters of vibration control process by applying rheological dynamic model
https://www.journals.vu.lt/LMR/article/view/34733
<p>The process of vibration control in question is investigated when the sediment is described in terms of rheologic body. The summarised dynamic and mathematical models of the vibration control are presented. In the partial case the sediment is described in terms of elastic-tough-plastic body. It is assumed that the vibration power is directed to the surface under cleaning at a certain angle therefore the process is analysed in tangent and normal directions. There is detennined optimum criteria for the vibration control process. The solution of the system is presented for the case when the angle of the influence power <em>θ </em>= 1. There are presented the main characteristics of the process and conclusions on it.</p>
ArticlesRimantas DidžgalvisAntanas SudintasIrena Tiknevičienė
Copyright (c) 2001 Rimantas Didžgalvis | Antanas Sudintas | Irena Tiknevičienė
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2001-12-172001-12-1756757210.15388/LMR.2001.34733Модель динамики реактора, учитывающая влияние запаздывающих нейтронов
https://www.journals.vu.lt/LMR/article/view/34732
<p>There is not abstract.</p>
ArticlesKostas BučysRasa GrigolienėDonatas Švitra
Copyright (c) 2001 Kostas Bučys | Rasa Grigolienė | Donatas Švitra
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2001-12-172001-12-175б156610.15388/LMR.2001.34732Nash equilibria in the context of convex sets
https://www.journals.vu.lt/LMR/article/view/34730
<p>Nash equilibria (<em>α, β</em>), <em>α ></em><em> </em><strong>O</strong>, <em>β > </em><strong>O,</strong> are investigated in bimatrix (3 x 3) game. Necessary and sufficient conditions for existing of such Nash equilibria are obtained (in theorems 4 and 8), and the algorithms for calculating them too. Some ideas of convex analysis are employed.</p>
ArticlesDaina Sūdžiūtė
Copyright (c) 2001 Daina Sūdžiūtė
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2001-12-172001-12-1755255810.15388/LMR.2001.34730Mathematical modelling criminality in Lithuania in a context of the East European countries
https://www.journals.vu.lt/LMR/article/view/34729
<p>One of the most sensitive indicators of a moral and social state of society is criminality. The paper examines the criminality trends in Lithuania in a respect of the East European countries.<br>Dynamic series allows to decrease differences in crime registration systems and to distinguish the main trends in the rate of criminality. General tendencies of criminality in Lithuania are the same as in Bulgaria, Hungary or Poland. The analysis of differences between the criminality in Lithuania and the average criminality rates in Bulgaria, Hungary and Poland is fulfilled using linear regression model.</p>
ArticlesVitalija Rudzkienė
Copyright (c) 2001 Vitalija Rudzkienė
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2001-12-172001-12-1754855110.15388/LMR.2001.34729The mathematical modeling of counter-attack
https://www.journals.vu.lt/LMR/article/view/34644
<p>There is not abstract.</p>
ArticlesAlbertas PincevičiusRimantas-Jonas RakauskasGintautas MisevičiusSvajonė Vašterienė
Copyright (c) 2001 Albertas Pincevičius | Rimantas-Jonas Rakauskas | Gintautas Misevičius | Svajonė Vašterienė
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2001-12-172001-12-1754254710.15388/LMR.2001.34644Population projection: a parametric approach
https://www.journals.vu.lt/LMR/article/view/34643
<p>There is not abstract.</p>
ArticlesRemigijus LapinskasRamunė Verikaitė
Copyright (c) 2001 Remigijus Lapinskas | Ramunė Verikaitė
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2001-12-172001-12-1753854110.15388/LMR.2001.34643Accuracy analysis of different components evaluation of time series
https://www.journals.vu.lt/LMR/article/view/34642
<p>Mathematical models for decomposing and forecasting of time series are analysed in this paper. Sometimes we have the situations when we don't get good result describing time series by standard components (trend, cyclical, seasonal). It is often happened with economic indicators. For example, the method of evaluation is changed or economic crisis has happened. Inclusion of new variables – intervention variables – can help with these problems. There is investigation of model accuracy depending on accuracy of evaluation of different components. Time series of different structure were simulated for imitation of real situations. Estimation of time series models with intervention variables and traditional components was done by program Demetra.</p>
ArticlesVitalija Klokova
Copyright (c) 2001 Vitalija Klokova
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2001-12-172001-12-1753353710.15388/LMR.2001.34642Application of finite-difference methods to parameter identification of agroecological models
https://www.journals.vu.lt/LMR/article/view/34641
<p>A typical parameter identification problem arisen in agroecological modeling is described and a finite difference method to solve an appropriate inverse problem is proposed. The method supposes the direct solution of an initial-boundary problem by finite difference scheme and then uses a non-linear optimization routine for parameter estimation. The derived recurrent formulas allow the accumulation of values of gradient and Hessian matrices while solving the direct problem. The software algorithm is described and some numerical results are given for the particular soil heat transfer parameter estimation exercise using the field treatment data collected at the Lithuanian Institute of Agriculture.</p>
ArticlesNatalija JuščenkoVitalijus Denisov
Copyright (c) 2001 Natalija Juščenko | Vitalijus Denisov
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2001-12-172001-12-1752653210.15388/LMR.2001.34641On the transition probabilities confidence interval evaluation in the syndromic analysis
https://www.journals.vu.lt/LMR/article/view/34640
<p>A confidence interval evaluation problem of transition probabilities is considered.</p>
ArticlesAlgimantas BikelisSigitas DapkūnasMečislovas MeilūnasDanutė Stoškuvienė
Copyright (c) 2001 Algimantas Bikelis | Sigitas Dapkūnas | Mečislovas Meilūnas | Danutė Stoškuvienė
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2001-12-172001-12-1751952510.15388/LMR.2001.34640On solving the plastoelastic problen in space of the commutative matrixes
https://www.journals.vu.lt/LMR/article/view/34638
<p>A method for calculating mechanical parameters of multilayer structural elements (MSE) and their layers in elastic and plastoelastic zones are presented and grounded in the case of axial stretching. The method of diagonal matrices is proposed to define the parameters of MSE's and their layers. In the elastic zone, MCE's are completely defined by two matrices: that of the modulus of elasticity and layer cross-section areas. In the plastoelastic zone, by the matrix of the layer crosssection areas and a diagonal matrix-function that defines <em>σ</em> - <em>ε</em> diagrams of the layers. In the case of stretching, the above mentioned matrices make up a commutative group with respect to product operation which makes it possible to obtain compact expressions for the required parameters that do not depend on the number of layers and are analogous to scalar ones (a single-layer case). This kind of calculation methods enables us to compute the values of axial stiffness and normal stress as well as the quantity of limiting axial load or the zones areas of elastic and plastoelastic deformation, when the diagrams <em>σ</em> - <em>ε</em><em> </em>of deformation materials composing it correspond to that diagram that of plastoelastic and elastically-strengthening materials.</p>
ArticlesVytautas Kleiza
Copyright (c) 2001 Vytautas Kleiza
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2001-12-172001-12-1751151610.15388/LMR.2001.34638Symmetrical splitting scheme for nonlinear Shrödinger equation
https://www.journals.vu.lt/LMR/article/view/34637
<p>In this paper we consider one-dimensional nonlinear Shrödinger equation. The equation includes an absorption term and the solution is periodically amplified in order to compensate the lose of the energy. We present a finite difference approximation by a symetrical splitting scheme. The convergence of the discrete solution is proved.</p>
ArticlesRaimondas ČiegisVioleta Pakenienė
Copyright (c) 2001 Raimondas Čiegis | Violeta Pakenienė
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2001-12-172001-12-1750451010.15388/LMR.2001.34637On one problem with non-local boundary conditions
https://www.journals.vu.lt/LMR/article/view/34636
<p>In this article two problems with non-local boundary conditions are analysed: stationary diffusion problem with constant coeficients and non-local boundary condition, and stationary diffusion problem with additional convection term and non-local boundary condition. Finite difference schemes are constructed and investigated. The sufficient conditions for the existence of an unique solution are obtained.</p>
ArticlesRaimondas ČiegisOlga ŠtikonienėOlga Suboč
Copyright (c) 2001 Raimondas Čiegis | Olga Štikonienė | Olga Suboč
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2001-12-172001-12-1749750310.15388/LMR.2001.34636Смешанные билинейные дискретные решения
https://www.journals.vu.lt/LMR/article/view/34635
<p>There is not abstract.</p>
ArticlesVilius Bistrickas
Copyright (c) 2001 Vilius Bistrickas
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2001-12-172001-12-1749349610.15388/LMR.2001.34635Procedure for finding estimate of convergence rate
https://www.journals.vu.lt/LMR/article/view/34634
<p>Here is presented one method for finding convergence rate estimate of probability function.</p>
ArticlesRobertas VilkasAlgimantas Aksomaitis
Copyright (c) 2001 Robertas Vilkas | Algimantas Aksomaitis
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2001-12-172001-12-1748549010.15388/LMR.2001.34634Discriminant analysis of multivariate spatial regressions
https://www.journals.vu.lt/LMR/article/view/34633
<p>There is not abstract.</p>
ArticlesKęstutis DučinskasJūratė Šaltytė
Copyright (c) 2001 Kęstutis Dučinskas | Jūratė Šaltytė
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2001-12-172001-12-1747848410.15388/LMR.2001.34633Statistical analysis of congenital anomlies in children in Lithuania
https://www.journals.vu.lt/LMR/article/view/34632
<p>Trends, prevalence and some influential (risk) factors of congenital anomlies in children in Lithuania are investigated using logistic regression model.</p>
ArticlesMarijus RadavičiusJurgis SušinskasAlgirdas Utkus
Copyright (c) 2001 Marijus Radavičius | Jurgis Sušinskas | Algirdas Utkus
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2001-12-172001-12-1746947710.15388/LMR.2001.34632Discriminant space for mixtures of elliptical distributions in classification problem
https://www.journals.vu.lt/LMR/article/view/34631
<p>There is not abstract.</p>
ArticlesMarius Radavičius
Copyright (c) 2001 Marius Radavičius
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2001-12-172001-12-1746346810.15388/LMR.2001.34631Calibrated estimators of the ratio
https://www.journals.vu.lt/LMR/article/view/34629
<p>There is not abstract.</p>
ArticlesAlesandras Plikusas
Copyright (c) 2001 Alesandras Plikusas
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2001-12-172001-12-1745746210.15388/LMR.2001.34629New tests for symmetry
https://www.journals.vu.lt/LMR/article/view/34628
<p>A new class of tests for symmetry of random variables is considered. This class is based on the empirical characteristic function. Tests from this class are compared with the classical Sign test using graphical display of <em>P </em>values. It is easy to extend this approach to the multivariate case.</p>
ArticlesVytautas Maniušis
Copyright (c) 2001 Vytautas Maniušis
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2001-12-172001-12-1745145610.15388/LMR.2001.34628