Lietuvos matematikos rinkinys https://www.journals.vu.lt/LMR <p>Publish articles presenting new and important events in all areas of mathematics.</p> lt-LT <p>Please read the Copyright Notice in&nbsp;<a href="http://www.zurnalai.vu.lt/informacijos-mokslai/journalpolicy">Journal Policy</a>.&nbsp;</p> remigijus.leipus@mif.vu.lt (Remigijus Leipus) vigintas.stancelis@kf.vu.lt (Vigintas Stancelis) Fri, 15 Nov 2019 00:00:00 +0000 OJS 3.1.2.1 http://blogs.law.harvard.edu/tech/rss 60 Editorial Board and Table of Contents https://www.journals.vu.lt/LMR/article/view/14945 Copyright (c) 2019 Lietuvos matematikos rinkinys http://creativecommons.org/licenses/by/4.0 https://www.journals.vu.lt/LMR/article/view/14945 Wed, 13 Nov 2019 00:00:00 +0000 A derivation-loop method for temporal logic https://www.journals.vu.lt/LMR/article/view/14953 <p><span style="background-color: #ffffff; color: #000000; font-family: &amp;quot; noto sans&amp;quot;,arial,helvetica,sans-serif; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; -webkit-text-stroke-width: 0px; white-space: normal; word-spacing: 0px;">Various types of calculi (Hilbert, Gentzen sequent, resolution calculi, tableaux) for propositional linear temporal logic (PLTL) have been considered in the literature. Cutfree Gentzen-type sequent calculi are convenient tools for backward proof-search search of formulas and sequents. In this paper we present a cut-free Gentzen type sequent calculus for PLTL with the operator </span></p> Romas Alonderis | Haroldas Giedra Copyright (c) 2019 Lietuvos matematikos rinkinys http://creativecommons.org/licenses/by/4.0 https://www.journals.vu.lt/LMR/article/view/14953 Tue, 12 Nov 2019 00:00:00 +0000 Functional approach to analysis of daily tax revenues https://www.journals.vu.lt/LMR/article/view/14948 <p><span style="background-color: #ffffff; color: #000000; font-family: &amp;quot; noto sans&amp;quot;,arial,helvetica,sans-serif; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; -webkit-text-stroke-width: 0px; white-space: normal; word-spacing: 0px;">We present a functional data analysis approach to modeling and analyzing daily tax revenues. The main features of daily tax revenue we need to extract are some patterns within calendar months which can be used for prediction. As standard seasonal time series techniques cannot be used due to varying number of banking days per calendar month and presence of seasonality between and within months we interpret monthly tax revenues as curves obtained from daily data. Standard smoothing techniques and registration taking into account time variability are used for data preparation.</span></p> Jovita Gudan | Alfredas Račkauskas Copyright (c) 2019 Lietuvos matematikos rinkinys http://creativecommons.org/licenses/by/4.0 https://www.journals.vu.lt/LMR/article/view/14948 Tue, 12 Nov 2019 00:00:00 +0000 Intellectual need for mathematical knowledge https://www.journals.vu.lt/LMR/article/view/14955 <p><span style="background-color: #ffffff; color: #000000; font-family: &amp;quot; noto sans&amp;quot;,arial,helvetica,sans-serif; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; -webkit-text-stroke-width: 0px; white-space: normal; word-spacing: 0px;">Harel’s [2] notion of intel lectual need is refined by employing Davis’ [1] findings<br>about interesting propositions in social sciences. A few hypothetical examples of how this<br>revised definition might aid in planning mathematics lessons which provide meaningfulness<br>for the students are presented.</span></p> <p>&nbsp;</p> Vytautas Miežys Copyright (c) 2019 Lietuvos matematikos rinkinys http://creativecommons.org/licenses/by/4.0 https://www.journals.vu.lt/LMR/article/view/14955 Tue, 12 Nov 2019 00:00:00 +0000 Why do we teach the mathematics that we do? https://www.journals.vu.lt/LMR/article/view/14957 <p><span style="background-color: #ffffff; color: #000000; font-family: &amp;quot; noto sans&amp;quot;,arial,helvetica,sans-serif; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; -webkit-text-stroke-width: 0px; white-space: normal; word-spacing: 0px;">Due to the changes of education system the school mathematics in Lithua-nia have acquired the elements of commercial-administrative mathematics of ancient times. Among other consequences the opportunities of school children to achieve the standards of mathematical reasoning are limited.</span></p> Rimas Norvaiša Copyright (c) 2019 Lietuvos matematikos rinkinys http://creativecommons.org/licenses/by/4.0 https://www.journals.vu.lt/LMR/article/view/14957 Wed, 13 Nov 2019 00:00:00 +0000 The minimizer for the second order differential problem with the integral condition https://www.journals.vu.lt/LMR/article/view/14951 <p><span style="background-color: #ffffff; color: #000000; font-family: &amp;quot; noto sans&amp;quot;,arial,helvetica,sans-serif; font-size: 14px; font-style: normal; font-variant: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; -webkit-text-stroke-width: 0px; white-space: normal; word-spacing: 0px;">In this paper, we investigate the best fit solution for the second order differential problem with one initial and other integral conditions. We obtain the representation of that minimizer and present an example.</span><span style="background-color: #ffffff;">paration.</span></p> Gailė Paukštaitė Copyright (c) 2019 Lietuvos matematikos rinkinys http://creativecommons.org/licenses/by/4.0 https://www.journals.vu.lt/LMR/article/view/14951 Tue, 12 Nov 2019 00:00:00 +0000 Revised linear convolution https://www.journals.vu.lt/LMR/article/view/14959 <p><span style="background-color: #ffffff;">It is assumed that linear time-invariant (LTI) system input signal samples are updated by a sensor in real time. It is urgent for every new input sample or for small part of new samples to update an ordinary convolution as well. The idea is that well-known convolution sum algorithm, used to calculate output signal, should not be recalculated with every new input sample. It is necessary just to modify the algorithm, when the new input sample renew the set of previous samples. Approaches in time and frequency domains are analyzed. An example of computation of the convolution in time area is presented.</span></p> <p>&nbsp;</p> Rimantas Pupeikis Copyright (c) 2019 Lietuvos matematikos rinkinys http://creativecommons.org/licenses/by/4.0 https://www.journals.vu.lt/LMR/article/view/14959 Tue, 12 Nov 2019 00:00:00 +0000