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Investigation on Lithuanian Railway and Water (Sea) Transport Interaction in the Carriage of Goods by International Routes
No full textBaigiamojo darbo tikslas – ištirti geležinkelių ir vandens (jūrų) transporto sąveiką, organizuojant tarptautinius krovinių vežimus, Lietuvoje. Nustatyti esamą situaciją bei numatyti galimas tobulinimo galimybes. Analitinėje dalyje yra nagrinėjami moksliniai literatūros šaltiniai geležinkelių ir vandens (jūrų) transporto sąveikos klausimais, taip pat analizuojama panaudojimo praktika pasaulyje bei Lietuvoje. Mokslo literatūros šaltinių pagrindu yra suformuluota problema bei iškelta darbo hipotezė, kuriai patikrinti naudotas kiekybinis tyrimas apklausos metodu. Projektinėje darbo dalyje, įvertinant analitinės bei tiriamosios dalies duomenis, yra sukurtas geležinkelių ir vandens (jūrų) transporto sąveikos organizavimo modelis, vežant krovinius tarptautiniais maršrutais. Sukurto modelio praktiniam patikrinimui yra naudojamas ekspertinis vertinimas, kurio rezultatai yra pateikiami projektinės dalies pabaigoje. Remiantis analitine bei tiriamąja dalimis yra pateikiamos išvados bei pasiūlymai. Darbą sudaro įvadas, analitinė, tiriamoji bei projektinė dalys, išvados, pasiūlymai, literatūros šaltinių sąrašas ir priedai. Darbo apimtis be priedų yra 74 psl., 31 iliustracija, 11 lentelių, 47 informaciniai šaltiniai.The purpose of the final master thesis is to analyze railway and water (sea) transport interaction in Lithuania, organizing international cargo carriage. To determine existing situation and envisage possible improvement possibilities. The analytical part deals with scientific literature on issues of railway and water (sea) transport interactions, as well as analysis of usage practices in the world and in Lithuania. On the basis of scientific literature, the problem is formulated and the work hypothesis is put forward, which is used to verify the quantitative research used by the survey method. In the project part of the thesis, considering the data of the analytical and research part, a model of organization of railway and water (sea) transport interconnection was created, for the transportation of goods on international routes. An expert evaluation is used for practical testing of the developed model, the results of which are presented at the end of the project section. Based on the analytical and research parts, conclusions and suggestions are presented. This thesis consists of introduction, analytical, research and project parts, conclusions, suggestions, list of references and attachments. The volume of the thesis without attachments is 74 p., 31 pictures, 11 tables, 47 sources of information
The assessment of logistics sector role on EU-27 economic growth during COVID-19 pandemic
No full textThis study focuses on evaluation the role of logistics and transport industry on the economic growth of EU-27 during the COVID-19 pandemic. The evaluation found a positive correlation between government spending to transport infrastructure, employment level, and freight transportation by road, railway and economic growth. Regression analyses showed that in 2019 the impact of logistics industry and economic growth of EU-27 countries insignificant, and in 2020 – statistically significant between public expenditure, employment rate in EU-27 economies. This study also found that some variables, such as the length of rail freight and transportation by air did not have a significant impact on economic growth of EU-27 during pandemics.Taip / Yes
Credit default modeling and prediction
No full textFinansų institucijos, prieš priimdamos sprendimą ar suteikti paskolą, vertina kredito riziką. Atsiradus tarpusavio skolinimo platformoms, rizika egzistuoja ne tik bankams, bet ir privatiems asmenims. Čia iškyla problema - ar paprastas žmogus, investuodamas tokioje platformoje, supranta riziką ir moka ją įvertinti? Analizuojant tarpusavio skolinimo platformos duomenis ir pritaikant regresinę analizę bei duomenų koreliacijas, atrenkami tinkamiausi kintamieji. Kredito įsipareigojimų nevykdymo modeliai sudaromi naudojant logistinę regresiją ir dirbtinius neuroninius tinklus. Ieškant geriausio modelio pastebima, kad naudojamas 10 metų laikotarpis yra per ilgas, ir optimaliu parenkamas 3 metų intervalas. Sudarytų modelių rezultatų tikslumas yra panašus, tačiau logistinę regresiją išrenkame geriausiu modeliu dėl jos paprastumo.Finance institutions assess credit risk before taking a decision to grant a loan. After introduction of peer-to-peer lending platforms, not only banks, but also individuals hold credit risk. The problem is – does ordinary person investing in such platform understands the risk and knows how to evaluate it? When analysing data from peer-to-peer lending platform, regression analysis and data correlations are used to select most suitable variables. Afterwards, credit default models are created using logistic regression and artificial neural networks. When looking for the best model, it is noticeable that the 10 year period is too long and the 3 year interval is chosen as an optimal one. The accuracy of both models is similar, but logistic regression is chosen as the best model because of its simplicity
Quality assessment of biogas-producing macroalgae from Azov Sea and Šventoji River
No full textThe decline of fossil fuels, the increase in greenhouse gases, and the global demand for energy are driving the search for alternative energy sources. Anaerobic digestion is a promising technology because it can convert organic biomass into biogas. As the climate warms, there is an increase in the biomass of plant origin in water bodies, and ecosystems are unable to clean themselves. The novelty of the work is that it determines the energetic values of macroalgae growing in the Sea of Azov and freshwater bodies using theoretical and experimental methods. This work aims to show that macroalgae and aquatic plants can be an excellent raw material for biogas production. By mixing them with co-substrates such as cattle manure, higher biogas and methane yields can be obtained. When Cladophora glomerata and Enteromorpha intestinalis macroalgae are mixed with cattle manure, the biogas yield is up to 458.8 mL/gVS and 397.9 mL/gVS, respectively. Methane concentration remained high and reached 62.4–64.1%. The obtained research results show the high energy value of biogas and the energy potential of biomass. Macroalgae increased the energy potential of biogas to 22.9 MJ/m3, and the energy potential of biomass reached 2.40 MJ/Kg. Due to its high energy value, biogas produced from the considered substrates can be an excellent alternative to fossil fuels. Integrating aquatic macroalgae into anaerobic digestion is a promising approach for a waste-free marine and freshwater system.iss. 19vol. 1
Dynamic probing data analysis in coarse soils
No full textBaigiamajame magistro darbe nagrinėjami dinaminio zondavimo metu išmatuoti duomenys. Apžvelgtas dinaminio zondavimo bandymas, pagrindiniai principai, kuriais remiantis atliekamas bandymas. Pateiktas sąryšis ir koreliacijos koeficientas tarp zondavimo užfiksuotų pagreičių ir grunto kūginio stiprio vandeningame ir nevandeningame grunte. Taip pat sąryšis tarp grunto atsako ir kūginio stiprio vandeningame ir nevandeningame grunte. Išnagrinėjus gautus bandymo rezultatus, pateikiamos baigiamojo darbo išvados. Darbą sudaro 7 dalys: įvadas, literatūros apžvalga, dinaminis zondavimas, atliktas tyrimas, bandymo rezultatai, išvados, literatūros sąrašas. Darbo apimtis – 50 p. teksto be priedų, 24 iliustr., 4 lent., 36 bibliografiniai šaltiniai.This thesis examines the dynamic probing during the measured data. Overlooked dynamic probing test, the basic principles on which the test is performed. The above relationship and the correlation coefficient between the probe and the ground accelerations recorded cone strength watery and waterless ground. Also, the relationship between the soil response and cone strength watery and waterless ground. An examination of test results, conclusions. The work consists of 7 parts: introduction, literature review, dynamic probing, study, test results, conclusions, references. Work size - 50 p. text without appendixes, 24 pictures., 4 tables., 36 bibliographical entries. Appendixes included
Experimental investigation of a near-field focusing performance of the IP-Dip polymer based 2D and 3D Fresnel zone plate geometries fabricated using 3D laser lithography coated with hyperbolic dispersion surface layered metamaterial
No full textHerein we investigate the character of the near-field emission of a two- (2D) and novel three-dimensional (3D) probe geometries fabricated using 3D direct laser writing lithography. Near-field scans in x–y and y–z planes were measured both before and after the deposition of hyperbolic dispersion metamaterial (HMM) to further verify the directional propagation of the high wave-vector components present in the vicinity of the structures. Additional computational and theoretical characterization forewent the actual experimental measurements, showing a promising performance, particularly for the 3D Fresnel zone plate (FZP). Overall, the experimental data documents a subwavelength resolution with a significant signal enhancement in the focal spot of the 3D FZP and highly subwavelength depth of focus.iss. 17vol. 1
Investigation of the possibilities of using air removed from the premises for an air-water heat pump.
No full textStraipsnyje analizuojamos šilumos siurblio „oras–vanduo“ sistemos, įrengtos daugiabučiame ir administraciniame pastatuose, naudojančios iš patalpų ištraukiamą orą. Tiriamasis objektas – Vilniaus daugiabutyje įrengta tokio tipo sistema. Išanalizavus šią sistemą, siekiama ją pritaikyti plačiau – administracinės paskirties pastatui. Šiuo tikslu sudaromi skaitiniai modeliai abiejų pastatų atvejais, taikant „EnergyPRO“ programinę įrangą. Atlikus modeliavimo skaičiavimus, pateikiami energinių rodiklių rezultatai ir įvertinamos įvairių sistemų pritaikymo galimybės.The article analyzes air-water heat pump systems in multi-apartment residential and administrative buildings, the heat source of which is air extracted from the premises. An existing real system installed in an apartment building in Vilnius is reviewed. After analyzing this system, the aim is to apply it more broadly – to an administrative building. For this purpose, numerical models for both buildings are created using “EnergyPRO” software. After the simulation calculations, the results of the energy indicators are presented, and the application possibilities of various systems are evaluated
Identification of pressure pulsation spectrum in a hydraulic system with a vibrating proportional valve /
No full textIn this paper, attention was focused on identifying the components of the amplitude-frequency spectrum of pressure pulsations in a hydraulic system in which an external low-frequency mechanical vibration was subjected to a proportional hydraulic directional control valve. It was observed that an operating machine or device equipped with hydraulic valves is a source of mechanical vibrations with a wide frequency spectrum. The influence of these vibrations on the pressure pulsation spectrum was analysed, identifying the components resulting from the forcing of the directional control valve spool. In addition, it was noted that the pressure pulsation spectrum includes components resulting from the pulsation of the displacement pump output feeding the hydraulic system. A description of these spectrum components was also made and, using the solution superposition method, the components of the pressure pulsation spectrum over a wide frequency range were identified.iss. 00vol. 0
Study of the strongly coupled Tamm-plasmon polariton states in the surface lattice array of gold nano-bumps
No full textThe strong coupling between the Tamm and surface plasmon polariton (SPP) in 1D photonic crystals (PCs) with gold lattice array was investigated by total internal reflection ellipsometry (TIRE). An optical dispersion and propagation characteristics of plasmons in 1D PCs with uniform gold layer and lattice array were studied using two coupled oscillator model. The assessed propagation length for SPP and TPP components in the hybrid polaritonic mode for nanostructures with a uniform gold layer was įSPP § 5.5-6.5 ȝm and įTPP § 6.5-9.5 ȝm, respectively. Meanwhile, the periodic gold surface lattice showed longer propagation length for the SPP component (įSPPlattice § 7-10.5 ȝm), and a shorter length for TPP (įTPPlattice § 5.5-8.5 ȝm). When surface lattice resonances are used in conjunction with the strong coupling regime, losses are reduced, resulting in increased propagation length and better coherence properties of such plasmonic excitations
Efficiency of digital economy in the context of sustainable development: DEA–Tobit approach
No full textThe paper aims at measuring the efficiency of the digital economy in EU countries. For that purpose, data envelopment analysis (DEA) is used. Sub-dimensions of the Digital Economy and Society Index (DESI) are used as inputs and the Sustainable Development Goals Index (SDGI) as an output. The results revealed that Bulgaria, Italy and Romania are the most efficient digital economies in terms of human capital; Belgium, Bulgaria, Cyprus, Croatia, Estonia, Finland, Greece, Lithuania, Poland and Portugal in terms of connectivity; Bulgaria, Hungary and Romania in terms of integration of digital technology; and Romania in terms of digital public services. The result of tobit regression analysis showed that not all the indicators of the DESI dimensions positively influence the efficiency of the digital economy.iss. 2vol. 3