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Transporto priemonių galimybes įvertinančių maršruto sudarymo algoritmų tyrimas
No full textThe main aim of Master Thesis is to perform extensive capacitated vehicle routing problem algorithms analysis and suggest an open source implementation. The aim is achieved by performing a capacitated vehicle routing problem algorithms analytical review, architectural review of best performing HGSADC algorithm and creating an open source implementation. Finally, two computational benchmarks of an implemented open source algorithm are presented comparing results to the original HGSADC version and other open-source CVRP algorithms. The thesis consists of 39 pages of text without appendixes, 15 figures, 2 tables, 50 reference entries, 1 appendixMagistro baigiamojo darbo tikslas - ištirti transporto priemonių galimybes įvertinančio maršruto sudarymo algoritmo (angl. Capacitated Vehicle Routing Problem; CVRP) tobulinimo galimybes, pasiūlyti ir ištirti algoritmo modifikacijas. Iškeltiems uždaviniams įvykdyti buvo atlikta analitinė CVRP algoritmų apžvalga, išanalizuota efektyviausio dabartinio metodo HGSADC architektūra ir sukurta jį įgyvendinanti atvirojo kodo implementacija. Atlikti eksperimentiniai bandymai lyginant sukurtą algoritmą tiek su HGSADC autoriaus skelbiamais rezultatais, tiek su kitais atvirojo kodo CVRP algoritmais. Sukurtas algoritmas rodo geriausius rezultatus tarp atvirojo kodo CVRP algoritmų, tačiau ženkliai atsilieka nuo rezulatų, skelbiamų HGSADC straipsnyje. Darbo apimtis: 39 psl. teksto be priedų, 15 iliustr., 2 lentelės, 50 bibliografinių šaltinių, 1 priedas
Optimisation model of production processes as an example of the cosmetics sector
No full textIn 2020, Europe reached 76.7 billion people. EUR of cosmetics sales in the retail market and according to this indicator is the largest market for cosmetic products in the world. 500 million European consumers use cosmetics and personal care products every day to protect their health and improve their well-being. With the high demand for cosmetic products, companies must ensure that products are produced at the right time and in the right quantities. However, in cosmetic manufacturing processes, inevitable losses occur in the supply chain and various losses in production that slow the shipments of cosmetic products. Continuous improvement of production processes, cost reduction measures, and quality assurance are necessary measures to obtain maximum profit and remain competitive. The object of the study is to improve production processes in the cosmetics sector. The purpose of the article is to identify the main problems of production processes in the cosmetics sector and to create a model for improving production processes. To achieve the goal, the following tasks are set: perform an analysis of scientific literature related to the improvement of the production process of the cosmetics sector; to choose appropriate research methods that will help identify the problems of improving production processes in the cosmetics sector; to present a model for improving cosmetic product manufacturing processes in cosmetic manufacturing companies. Research methods: analysis of scientific literature, observation method, expert assessment
Research into Aspheric Lenses Clean Production Technology
No full textBaigiamajame magistro darbe nagrinėjama poliravimo greičio ir įrankio spaudimo įtaka paviršiaus formos nuokrypiams ir paviršiaus šiurkštumui. Aprašyta naudota metodika, įrankiai ir įranga, eksperimentui pasirinkta medžiaga – lydytas kvarcas. Atlikta kitų panašaus pobūdžio tyrimų apžvalga. Atlikti eksperimentiniai poliravimo tyrimai, išmatuoti formos nuokrypiai ir paviršiaus šiurkštumo parametrai, gauti rezultatai išanalizuoti taikant programinę įrangą, pateiktos išvados. Ištirta, kad poliravimo greitis ir spaudimas turi didelę įtaką gautam rezultatui, nustatyti optimalūs parametrai poliravimui. Darbą sudaro šios dalys: įvadas, tyrimų apžvalga, tyrimo įranga ir metodika, rezultatai ir jų analizė, išvados ir siūlymai, literatūros sąrašas. Darbo apimtis – 45 p. teksto be priedų, 39 iliustr., 12 lent., 20 bibliografinių šaltinių. Atskirai pridedami darbo priedai.The purpose of this paper is to study polishing tool pressure and speed effect to aspherical lens form precision and rougness parameters. Lenses from fused silica with 60 mm focal lenght was polished with cerium oxyde suspension during experiment. Experimental polishing researches were made, surface form irregularity and roughness parameters measured , results of experiments analyzed using software, It was established that the polishing speed and pressure have a significant impact on the polishing results, the optimal technological parameters were determined. Structure: Introduction, review of literature, methodology of research, results of research and their analysis, conclusions and suggestions, references. Thesis consist of: 45 p. text without appendixes,39 pictures, 12 tables, 20 bibliographical resources. Appendixes are included
Improvement of Production Planning Process in the Printing Industrial Companies
No full textBaigiamajame magistro darbe nagrinėjami pagrindiniai gamybos planavimo tobulinimo būdai. Teorinėje dalyje nagrinėjama mokslinė literatūra, siekiant nustatyti gamybos valdymo ir tobulinamo priemones. Taip pat išnagrinėta kaip gamybos planavimą apibrėžia skirtingi autoriai ir kokie yra planavimo metodai. Nagrinėjant planavimo tobulinimo aspektus, aprašyti netechnologiniai tobulinimo metodai ir ketvirtosios pramonės revoliucijos dedamosios, kurios naudojamos gamybos planavimo procesui tobulinti. Empirinio tyrimo metu atlikta tipinio atvejo analizė, ištirta, kokia įtaką daro planavimo tobulinimo įrankių panaudojimas bei pateikiami poligrafinių įmonių planavimo ekspertų apklausos rezultatai. Remiantis tyrimo rezultatais sudarytas poligrafinės įmonės gamybos planavimo tobulinimo modelis bei pateikiamos išvados ir pasiūlymai, kaip tobulinti gamybos planavimo procesą. Darbą sudaro 3 dalys: gamybos planavimo tobulinimo poligrafijos įmonėje teoriniai aspektai, poligrafijos pramonės gamybos planavimo empirinis tyrimas ir universalus planavimo tobulinimo modelis, skirtas poligrafijos pramonės įmonėms. Darbo apimtis – 77 p. teksto be priedų; 27 iliustr., 2 lent., 74 bibliografiniai šaltiniai.The master thesis examines the main aspects of production planning. In the theoretical part, the planning process is explained based on scientific literature. Non-technological improvement methods and the fourth industrial revolution components, as a tool for the improvement of the production planning process, are established. The results of the survey of the production planning experts are presented in the empirical research. Also, the impact of production planning improvement tools in a typical polygraphic company is studied. Based on the research results, a model for improvement of production planning in polygraphic companies is presented and the suggestions on planning improvement are concluded. The thesis consists of 3 parts: theoretical aspects of production planning improvement in printing companies, empirical research of polygraphic production planning and a universal planning improvement model for printing industry. The thesis consists of 77 pages without annexes, 27 pictures, 2 tables, 74 bibliographical entries
Case Study of Abandoned (not used) Industrial Buildings Coversion for Public Needs
No full textApleisti (nebenaudojami) gamybinės paskirties pastatai Lietuvoje ir užsienio šalyse yra aktuali problema miestuose, susiduriančiuose su neefektyviu teritorijų užstatymu. Šiame magistro darbe analizuojami apleisti (nebenaudojami) gamybos paskirties pastatai ir jų pritaikymo visuomeniniams poreikiams galimybės, pasitelkiant konversijos procesą. Darbą sudaro įvadas, trys dalys, išvados ir priedai. Pirmojoje darbo dalyje nagrinėjama apleistų pastatų ir teritorijų atsiradimo problematika. Antrojoje darbo dalyje suformuojamasma apibendrintas apleistų gamybinės paskirties pastatų (teritorijų) konversijos alternatyvų vertinimo modelis, apžvelgiamos konversijos alternatyvos, jų palyginimui pasirenkami daugiakriteriai vertinimo metodai. Trečiojoje dalyje pateikiamas ekspertinis vertinimas konversijos variantų rodiklių reikšmingumų nustatymui. Palyginama 10 atrinktų konversijos projektų įvairiose šalyse naudojant daugiakriterius vertinimo metodus ARAS, COPRAS ir SAW. Darbo apimtis – 82 puslapiai. Darbe yra 31 sunumeruota formulė, 31 paveikslėlis, 22 lentelės ir 83 bibliografinės nuorodos.Abandoned (not used) industrial buildings are important issue in Lithuania and foreign countries especially in cities facing with inefficient territorial development. The thesis analyzes abandoned industrial buildings‘ adaptive reuse, reasons of their occurrence and adaptation possibilities for public needs. Thesis‘ structure consist of: introduction, three chapters, conclusions and appendixes. The first chapter analyzes problems of abandoned industrial buildins and territories. The second chapter consist of general model for conversion of abandoned industrial buildings (territories), conversion alternatives is presented and multi-criteria evaluation methods are selected for alternatives comparison. In the third chapter expert evaluation and multicriteria methods ARAS, COPRAS and SAW are applied to compare ten executed adaptive reuse projects in different countries. The scope of the thesis – 82 pages, 31 numbered equations, 31 pictures, 22 tables and 83 sources of literature
Comparative Analysis of the Applicability of Five Clustering Algorithms for Market Segmentation
No full textCustomer communication is important in maintaining business sustainability, which can be tremendously improved by market segmentation. Clustering is a powerful tool to carry out market segmentation in an effective way. As every algorithm has its advantages and disadvantages, may be susceptible to the data peculiarities and change its effectiveness depending on it, for marketing it is vital to understand which techniques work better on mixed data, and which show poor results or are not applicable at all. This paper represents a comparative analysis on five clustering algorithms (k-means, BIRCH, agglomerative hierarchical clustering, DBSCAN and OPTICS), which represent three different approaches in clustering: centroid-based, connectivity-based and density-based approach. Using an open-source dataset with the data that describe hotel customers we evaluated the effectiveness of the aforementioned algorithms in extracting customer groups. For clustering quality evaluation, we used Davies-Bouldin score and Silhouette score, and after that visualized the results. As a result, we made a complete comparison of clustering algorithms and revealed the advantage of agglomerative hierarchical clustering over other algorithms. Also, we proved the significant benefit from using Gower's distance with density-based algorithms and loss with connectivity-based algorithm when dealing with mixed data. Finally, we summarized obtained results to make a conclusion about the applicability of each algorithm.Taip / Ye
Use of macroalgae in a three-stage bioreactor for the biogas production
No full textAn excess of macroalgae growing in water bodies is an environmental problem, as it is difficult to remove the excessive amounts of them in natural ways. It was observed previously that mixing macroalgae with the other organic substrates can produce high yields of biogas (mostly methane). Cladophora glomerata, macroalgae growing in the Lithuanian freshwaters, was used for this purpose. They were mixed with cattle manure and an activated sewage sludge as source of microorganisms for the biogas production in a three-stage bioreactor. Bradford, Folch or Dinitro Salicylic Acid (DNS) methods were used for the determination of concentrations of total proteins, lipids, and glucose (reduced sugars), respectively. Concentrations of those were determined at different bioreactor organic loads: 2.87, 4.06 and 8.13 kg VS/m3 d. The highest total lipid concentration (6.69%) was reached when the organic load was 8.13 kg VS/m3 d. The average biogas yield at this load was 198.7±2.2 L/Kg VSadded, and the methane yield was 154.1±5.4 L CH4/Kg VSadded. Concentration of reduced sugards decreased from 9.68 to 6.67% during this proccess indicating that some of it has been consumed by microorganisms. The lowest total protein concentration (1.12%) was found when the organic load of the bioreactor was 4.06 kg VS/m3 d. The decreased concentration of total proteins showed the activity of microorganisms during which the yield of biogas and methane increased to 386.4±3.8 L/Kg VSadded and 281.5±8.2 L CH4/Kg VSadded, respectively. Our studies have shown that the yield of biogas and methane in a three-stage bioreactor depends on the organic load of the bioreactor. Such dependence was determined by the concentration of glucose, fat and protein in the substrate. This project has received funding from the Research Council of Lithuania (LMTLT, grant number S-LU-22-2) and Ministry of Education and Science of Ukraine
Possibilities of Legislative and Economic Support for Electromobility in Slovakia
No full textThe transport sector generates almost 25% of European greenhouse gas emissions and is the city’s leading cause of air pollution. Almost 90% of urban dwellers in the European Union are exposed to harmful levels of air pollutants. Around 95% of vehicles on European roads still use fossil fuels. The transport policy of the European Union aims to reduce greenhouse gas emissions by 20% by 2030 and by 60% by 2050 compared to 1990 values. One of the means of achieving these goals is the use of electric cars. This article aims to process the current state of passenger and small freight electric vehicles registered in the Slovak Republic and to compare them with other countries. This article proposes measures that would support electromobility in Slovakia. These proposals are based on an analysis of weaknesses in legislation, taxes, and fees. Currently, several forms of electromobility support are used. They aim to overcome obstacles preventing the successful implementation of electromobility in practice. These are direct subsidies for electric vehicles or relief from taxes and fees. Individual governments or self-governments also provide non-financial benefits to motivate residents to use electric cars largely.Operational Program Integrated Infrastructure 2014–2020Taip / YesEuropean Regional Development FundInnovative Solutions for Propulsion, Power and Safety Components of Transport Vehicle
Kapinės už miesto, miške. Katalikų laidojimo kraštovaizdžiai XIX a. Vilniuje :
No full textIšvirkščias miestas. Visuomenės veidrodis. Atminties kraštovaizdis. Meno ir istorijos sodas. Moralės akademija. Žmonių muziejus. Tai prasmės ir funkcijos, XIX a. pradžioje įžvelgtos naujai įrengiamose kapinėse tiek Vilniuje, tiek Vakarų Europoje. Dr. Eglė Bazaraitė monografijoje Kapinės už miesto, miške dekonstruoja trejų Vilniaus katalikų kapinių – Rasų, Bernardinų ir Saulės – erdvinę struktūrą, brėžia paraleles ir išryškina prieštaras su to laiko kapinėmis krikščioniškame Europos branduolyje. Monografijoje į katalikų laidojimo kraštovaizdžius žvelgiama pasitelkiant architektūrines priemones, pristatant šias miesto teritorijas kaip daugiasluoksnį erdvinį konstruktą, suformuotą istorinių bei kultūrinių kontekstų
Biblioteka informuoja, 2023 Nr. 46 (638)
No full textNaujai į Web of Science ir Scopus įtrauktų Vilnius Gedimino technikos darbuotojų publikacijų sąrašai ir kitos bibliotekos aktualijos.46 (638)202