1,720,984 research outputs found
The criticality assessment of energy systems critical infrastructure.
No full textThis dissertation research helped to develop a new evaluation methodology of energy infrastructure systems criticality, which for the first time takes into account the interrelationships among the elements of the systems, the reliability, the risk, and random operation of the systems. The evaluation of criticality is carried out as regarded by the consumers. The developed methodology and models helped to identify the Lithuanian energy system infrastructure elements (and their groups) that have the highest criticality for energy systems. The designed methodology and models for the evaluation of criticality of critical energy infrastructures allow complete identification of the critical elements and their groups of the systems that have the highest criticality for energy systems, taking into account the random operation of the entire system. The findings of the research complement the critical infrastructure (energy system) evaluation and modeling theory with new methods. On the basis of the findings, the criticality of aggregated Lithuanian energy system was evaluated, groups of critical elements were identified, and the impact of gas development scenarios on the criticality of energy systems was evaluated
Kalba, pasakyta iškilmingame VDU Senato posėdyje 2019 metų balandžio 26 dieną
Get PDFn 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 future.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 gairėmis
Pensinio amžiaus žmonių beveik dvigubai daugiau nei jaunimo
No full textVytauto Didžiojo universitetas / Vytautas Magnus UniversityGamtos ir tech.mokslų tyr.institut / Research Institute of Natural and Technological Science
Karas su COVID - 19 dar nesibaigė
No full textMatematikos ir statistikos katedra / Department of Mathematics and StatisticsInformatikos fakultetas / Faculty of InformaticsVytauto Didžiojo universitetas / Vytautas Magnus Universit
Data analysis with uncertainty evaluation for the Ignalina NPP RBMK-1500 gas-gap closure evaluation
No full textThis paper presents data analysis with uncertainty evaluation for Ignalina NPP Unit I RBMK-1500 reactor core lifetime analysis. The closure of the gas gap between the pressure tubes and the graphite bricks is one of the criteria for the evaluation of the reactor core lifetime. The rate of closure of the approximately 1.5mm gaps between the pressure tubes and the graphite is largely a function of accumulated fast neutron dose and graphite operating temperatures. Historical approaches to this problem are briefly discussed and more thorough data analysis performing probabilistic model is presented. For the graphite behaviour the ABAQUS code was used. Non-linear changes of graphite have high influence for further forecast. With the data used for the calculations it was performed uncertainty analysis. It showed confidence in the results.Informatikos fakultetas / Faculty of InformaticsVytauto Didžiojo universitetas / Vytautas Magnus Universit
Mathematical modelling of security of energy supply disturbance scenarios
No full textTomo antraštė: 6th annual conference of young scientists on energy issues (CYSENI 2009), Kaunas, Lithuania, 28-29 May 2009Security of energy supply is extremely important for each country energy development. It depends not only on energy production and infrastructure but also on technical, economical, political and environmental impact. Energy security covers many fields, whereas threats to energy system can be various and consequences have impact to all areas of country’s economy. Mathematical model for consequence scenarios of energy supply potential disturbances, such as technical failure of energy system, natural disasters and catastrophes, terrorism acts, reduction of energy supply, economical blockades, economical and political crisis, etc. is analysed in the paper. Consequences of disturbances used in methodology are technical, economical and socio-political. Development of the model is based on mathematical methods (Markov chains and processes) analysing consequence scenarios of disturbances, performing probabilistic and frequency analysis. In the paper, developed mathematical model of energy system disturbance consequence analysis is presented.Matematikos ir statistikos katedra / Department of Mathematics and StatisticsInformatikos fakultetas / Faculty of InformaticsVytauto Didžiojo universitetas / Vytautas Magnus Universit
Safety and Security of Energy Supply in Lithuania by Vaida Matuziene and Juozas Augutis; Strategic Insights, v. 7 issue 1 (February 2008)
Get PDFThis article appeared in Strategic Insights, v.7 issue 1 (February 2008)Approved for public release; distribution is unlimited
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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