Ribiniai pavojaus skirstiniai tinklinėse sistemose

The subject of this work is the analysis of hazard distribution in the network systems. In the age when transport flows in the railway and road systems, information flows in the internet channels, etc. intensify, hazard distribution in the network systems becomes a more relevant and important issue.  In the paper various theoretical hazard type distributions in the network systems are analysed. Mathematical model of hazard distribution and accumulation in the nodes of the network was created.Santraukos nėra

Kvazigardelinių atsitiktinių dydžių serijų sumų skirstinių asimptotinė analizė

We consider the formal asymptotic expansion of probability distribution of the sums of independent random variables. The approximation was made by using infinitely divisible probability distributions.  Diskretų k-matį atsitiktinį vektorių ξ = (ξ1, ξ2, . . . , ξk) vadinsime kvazigardeliniu, jeigu jo koordinatės ξ1, . . . , ξk yra kvazigardeliniai atsitiktiniai dydžiai ξi, t. y. ξi įgyja reikšmes (βi, νi) = β1iν1i + · · · + βkiiνkii, νji = 0,±1,±2, . . . , βji > 0 ir vektoriausβi = (β1i, . . . , βkii) koordinatės yra tiesiškai nesurištos racionalių skaičių kūne. Yra įrodyta, kad vietoje kvazigardelinio vektoriaus ξ1, galima nagrinėti gardelinį atsitiktinį vektorių θ= (θ1, . . . , θm) erdvėje Rm, kur m = k1 + k2 + · · · + kk. Toliau mes kalbėsime apie kvazigardelinius atsitiktinius vektorius, kurių klasei priklauso ir gardeliniai atsitiktiniai vektoriai (žiūr. [1]). &nbsp

Asimptotiniai skleidiniai normalinės aproksimacijos atveju

We consider the asymptotic behavior of the convolution P*n(A\sqrt{n}) of a k-dimensional probability distribution P(A) as n \to  \infty for A from the \sigma-algebra M of Borel subsets of Euclidian space Rk or from its subclasses.  Nagrinėjame k-mačio tikimybinio skirstinio P(A) sąsūkos P*n(A\sqrt{n}) asimptotinį elgesį, kai n \to  \infty ir A priklauso Euklido erdvės Rk poaibių  \sigma-algebrai M arba jos siauresniems poaibiams

The Criticality Measure of Energy Systems

AbstractNational security, economic growth and population welfare depends on the safe and reliable functioning of various infrastructures very much. The disruptions in one of the infrastructures often are transferred to the other dependent infrastructures. Thus, it could have considerably negative effects for the functionality of the country's basic administration. The critical infrastructure is defined by an asset, system, part thereof or technical networks composed of different sectors. The paper presents the assessment method of critical infrastructure modelling and elements’ criticality of the energy system. The criticality of infrastructure element is described by other systems elements functionality reduction when considered element is affected by disruption or out of order. Assessment of system ability to perform its functions is implemented by authors developed model, when energy supply is interrupted or system element is out of order. In the analysed model energy sector is composed of heat and power systems. The optimization methods were used to simulate real system (to implement allocation of demands of heat and electricity for generation technologies)

Sustainable development and energy security level after Ignalina NPP shutdown

The paper presents the investigation of the impact of Ignalina Nuclear Power Plant (NPP) shutdown on Lithuanian energy security. The system of energy security indicators, covering technical, economic and socio-political aspects is presented. The integral characteristic of these indicators shows the level of energy security. The paper analyses the Lithuanian energy security level in 2007. To make a comparison, the energy security level in 2010, after the shutdown of Ignalina NPP, when Lithuanian Power Plant in Elektrėnai becomes the main electricity producer, is forecasted. Two alternatives are analysed: Lithuanian Power Plant uses either gas or heavy fuel oil for electricity production. The security level of each indicator, each indicator block and the total security level are presented as the result. Energy security indicators, which increased or decreased after the shutdown of Ignalina NPP, are analysed, including the indicators which have had the greatest impact on the change in energy security level. The influence of Ignalina NPP shutdown on CO2 emissions is presented. Also, electricity generating costs for different types of electricity production at a different discount rate are presented

Criticality assessment of energy infrastructure

After the last major accidents in the energy sector of the last decade (USA and Canada (2003), India (2012), Russian-Ukrainian (2009)), energy infrastructure criticality assessment has become one of the most important issues. It has become the topical subject of the economy and national security in all countries. There is no single measure unit for the assessment of critical infrastructure with respect to “interdependency” among critical infrastructure sectors. This paper proposes to use criticality of infrastructure element as a measure to assess the importance of considered element to the normal activity of all sectors of infrastructure. The pilot numerical simulation of heat and electricity infrastructure was performed to demonstrate the implementation of the application of developed method for the assessment of infrastructure functionality and criticality

Safety and Security of Energy Supply in Lithuania by Vaida Matuziene and Juozas Augutis; Strategic Insights, v. 7 issue 1 (February 2008)

This article appeared in Strategic Insights, v.7 issue 1 (February 2008)Approved for public release; distribution is unlimited

Energy security analysis and energy security level assessment

The paper presents an investigation on the development of energy security analysis and energy security level assessment technology. Energy security analysis in this work includes energy system risks investigation, modeling of different disturbances and consequences assessment. Methodology of energy security analysis based on both deterministic ant probabilistic models. It allows assessing of various uncertainties, identifying the most dangerous scenarios and critical energy infrastructure. The system of energy security indicators, covering technical, economic and socio-political aspects, is introduced. The security indicator is a special index which gives numerical values to important issues for security of energy sector. In the paper, each indicator is described by presenting the title, comments, factual and threshold, pre-critical and critical state values. The integral characteristics of these indicators show the level of energy security and in order to identify it, a point system assessment scale is used. The methodology developed in this paper is applied for the assessment of the Lithuanian energy security level in different scenarios. The paper presents analysis of the impact of Ignalina Nuclear Power Plant (NPP) shutdown on Lithuanian energy security. The paper analyses the Lithuanian energy security level in 2007 and, to make a comparison, in 2010 after the shutdown of Ignalina NPP, in 2014 when in Lithuania will be built LNG terminal and in 2016 when the power lines to Poland and Sweden will be constructed. A separate study in this work is dedicated to the influence of the planed nuclear power plant on Lithuanian energy security level. Acknowledgements: This research was funded by a grant for project “Lithuania energy security analysis and assessment of the energy security level” (No. ATE-1/2012) from the Research Council of LithuaniaMatematikos ir statistikos katedraVytauto Didžiojo universiteta

Festive speech delivered to the VMU Senate on april 26, 2019

Vytauto Didžiojo universiteto rektoriaus kalboje, skirtoje VDU atkūrimo trisdešimtmečiui, apžvelgiami svarbiausi šio universiteto atkūrimo momentai, jo išskirtinumas to meto sąlygomis ir kiekvieno iš trijų gyvavimo dešimtmečių ypatybės bendrosios Lietuvos aukštojo mokslo ir studijų politikos fone. Tekstas baigiamas vertybinėmis ateities VDU gairėmisIn a speech delivered by the Rector of Vytautas Magnus University (VMU) on the 30th anniversary of its re-establishment, the most important moments in the re-establishment process are highlighted. The Rector also brings out the uniqueness of this event given the conditions prevalent at that time as well as the character of each of the three decades of VMU’s existence against the background of the general political condition of Lithuanian higher education, scholarship, and studies. The text ends with VMU’s ethical guidelines for the futureMatematikos ir statistikos katedraVytauto Didžiojo universiteta