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Neskaidrių atitvarų apšiltinimo įtaka gyvenamųjų pastatų vėsinimo poreikiams Nigerijoje
No full textA building envelope’s thermal performance significantly impacts cooling energy consumption, especially in
countries with very hot climates like Nigeria. Non-transparent envelope insulation, including walls, roofs, and floors,
is important in reducing heat gain, improving indoor thermal comfort, and regulating indoor temperature. This study
examines the traditional 3-layer uninsulated wall constructed in Nigeria. It compares it to an insulated 4-layered wall
using different insulation materials to evaluate the influence of non-transparent envelope insulation on the cooling demand
of residential buildings in Nigeria. By analysing different insulation materials and thicknesses, this study assesses
their effectiveness in minimising cooling loads. The research considers key climatic factors such as solar radiation and
ambient temperature to determine insulation strategies for energy efficiency. Findings indicate that properly insulated,
non-transparent envelopes can reduce indoor temperatures and cooling energy demand in residential buildings. However,
some factors like material selection and installation also influence the overall performance of these buildings. This
study highlights the importance of adopting energy-efficient envelope designs to enhance sustainability and reduce dependence
on mechanical cooling systems. These insights could significantly contribute to developing new practices for
improving energy efficiency in Nigeria’s residential building construction and renovation sector.Pastato atitvarų šiluminės charakteristikos daro
reikšmingą poveikį vėsinimo energijos suvartojimui, ypač šalyse,
kuriose vyrauja labai karštas klimatas, pavyzdžiui, Nigerijoje.
Neskaidrių pastato atitvarų ‒ sienų, stogų ir grindų ‒ apšiltinimas yra svarbi priemonė šilumos prieaugiui mažinti,
patalpų šilumos komfortui gerinanti ir vidaus temperatūrai
reguliuoti. Šiame tyrime lyginama tradicinė trijų sluoksnių
neapšiltinta siena su izoliuota keturių sluoksnių siena, naudojant
skirtingas izoliacines medžiagas. Tikslas ‒ įvertinti neskaidrių
atitvarų apšiltinimo įtaką gyvenamųjų pastatų vėsinimo
energijos sąnaudoms Nigerijos. Analizuojant skirtingas
izoliacines medžiagas ir storius, vertinamas jų efektyvumas
mažinant vėsinimo apkrovas. Tyrimo rezultatai rodo, kad tinkamai
izoliuotos neskaidrios atitvaros gali sumažinti patalpų
temperatūrą ir vėsinimo energijos poreikį gyvenamuosiuose
pastatuose. Vis dėlto galutinį efektyvumą taip pat lemia tokie
veiksniai kaip medžiagų pasirinkimas ir jų montavimo kokybė.
Tyrimas pabrėžia, kad energiją taupančių konstrukcijų
taikymas yra būtinas siekiant didesnio tvarumo bei mažesnės
priklausomybės nuo mechaninių vėsinimo sistemų.Taip / Ye
Research on Hybrid Image Storage Models to Ensure Data Security and Privacy
No full textThis paper addresses the growing challenge of secure and efficient image storage using hybrid architectures that combine local and cloud resources. We propose and compare three architectural models with integrated encryption mechanisms (AES-256, RSA, and a bitwise method). A multi-criteria decision analysis identifies Microsoft Azure as the optimal cloud platform. Experimental results, based on entropy, pixel correlation, encryption time, and storage overhead, demonstrate the trade-offs between performance and security. The proposed models can serve as a basis for scalable and secure hybrid image storage systems.Taip / Ye
Biblioteka informuoja, 2025 Nr. 24 (721)
No full textNaujai į Web of Science ir Scopus įtrauktų Vilnius Gedimino technikos darbuotojų publikacijų sąrašai ir kitos bibliotekos aktualijos.24 (721)202
Biblioteka informuoja, 2025 Nr. 9 (706)
No full textNaujai į Web of Science ir Scopus įtrauktų Vilnius Gedimino technikos darbuotojų publikacijų sąrašai ir kitos bibliotekos aktualijos.9 (706)202
The 22nd International Workshop on Piezoelectric Materials and Applications in Actuators. Abstract Proceedings
No full textThis book constitutes the abstracts of presentations presented for the 22nd International Workshop on Piezoelectric Materials and Applications in Actuators – IWPMA 2025, which is being held in Vilnius from July 1 to July 3
2025 and organized by Vilnius Gediminas Technical University – VILNIUS TECH.
The aim of the conference is to provide a platform for sharing knowledge and fostering collaboration in the
field of piezoelectric materials and their applications. It seeks to disseminate current research findings across
this inherently multidisciplinary domain. Beyond presenting scientific advancements, the conference also serves
to connect researchers and industry representatives from around the world, encouraging lasting international
cooperation and future joint initiatives.Ne / N
Ways to improve job satisfaction among medical personnel in the healthcare system: the case of Georgia
No full textThe sustainable development of any modern country is ensured by a healthy society. The healthcare sector is
one of the most important components of a country’s social policy, as public health directly affects the labor potential
and well-being of its citizens.
Goals and objectives. Modern medicine, along with continuous development, creates significant opportunities for the
prevention and eventual cure of various diseases. In this process, the education, responsibility and job satisfaction of
medical personnel play a vital and relevant role. Our scientific research focuses on identifying the main factors that
determine the job satisfaction of medical personnel, studying its current state and developing strategies for its improvement.
Research results. Our research has shown that the job satisfaction of medical personnel is directly proportional to the
degree of satisfaction with the medical services received by the patient. Satisfaction from patient care is most influenced
by work experience (Chi-square = 17.032, P = 0.002). Besides, 53.1% of the interviewed medical staff are satisfied
with the training and development programs offered by the organization, 47% positively evaluate collaboration among
colleagues, and 41.5% are satisfied with the organization’s support in international activities.
Conclusion. The findings and recommendations will help managers of healthcare organizations develop appropriate
strategies to improve job satisfaction and overall organizational effectiveness.Taip / Ye
DI algoritmų taikymas projektuojamojo erdvės laiko PM₁₀ ir oro taršai modeliuoti
No full textWithout a doubt, air pollution is one of the most serious issues confronting our world today, which presents
significant health and environmental risks, exacerbating respiratory ailments and contributing to climate change. Air
pollutants’ spatial and temporal variability is the basis for effective air quality management, necessitating more accurate
predictive models. The study aims to assess particulate matter of a diameter smaller than 10 μm (PM₁₀) forecasts using
the European Union’s Space Copernicus program mission of monitoring the atmosphere and tracking air pollutants,
the Sentinel-5 Precursor satellite (5P) TROPOspheric Monitoring Instrument (TROPOMI), coupled with meteorological
variables and observations from air quality monitoring stations. Root mean square error (RMSE) and mean absolute
error (MAE) measure the model’s accuracy. The study integrated machine learning algorithms and diverse datasets to
enable precise spatial modelling of PM₁₀ concentrations using a geographic information system (GIS). The results obtained
peak accuracy during the heating season validation yielded an RMSE of 4.52 μg/m³, MSE of 20.44 (μg/m³)², and
MAE of 3.30 μg/m³, while testing resulted in an RMSE of 4.38 μg/m³, MSE of 19.21 (μg/m³)², and MAE of 3.19 μg/m³.Oro tarša yra viena iš rimčiausių šių dienų pasaulio
problemų. Ji kelia didelį pavojų žmonių sveikatai ir aplinkai,
skatina kvėpavimo takų ligas ir prisideda prie klimato
kaitos. Oro teršalų identifikavimas ir oro kokybės valdymas
yra svarbiausi veiksniai siekiant tikslesnio taršos prognozavimo
ir modeliavimo. Tyrimo tikslas – įvertinti kietųjų dalelių,
kurių skersmuo mažesnis nei 10 μm (PM₁₀), koncentracijas ir
atlikti jų prognozavimą, remiantis Europos Sąjungos „Copernicus“
programos duomenimis. Naudojami Sentinel-5P palydovo
troposferos stebėjimo instrumento „Tropomi“ duomenys,
gauti iš stebėjimo stočių, išsidėsčiusių visoje Europoje.
Sukurto modelio tikslumas vertinamas pagal vidutinę kvadratinę
(RMSE) ir vidutinę absoliutinę (MAE) paklaidas. Tyrime
taikomi mašininio mokymosi algoritmai, naudojant įvairius
duomenų rinkinius. Pasitelkus geografinių informacinių sistemų
(GIS) įrankius, atliktas erdvinis PM₁₀ koncentracijų modeliavimas.Taip / Ye
Comparison of chambers of agriculture in the Baltic States
No full textThe chambers of agriculture play a crucial role in shaping agricultural policy, supporting rural development,
and representing the interests of farmers and agribusinesses in rural areas. This research provides a comparative
analysis of the Chambers of agriculture in Lithuania, Latvia, and Estonia, focusing on their historical development,
governance structures, legal frameworks, membership principles, and relationships with public authorities. Although
all three Baltic States transitioned from planned to market economies after the collapse of the Soviet Union, the reestablishment
of chambers of agriculture took place in different years. In Lithuania as early as 1991, Estonia followed
in 1996, and Latvia re-established its Chamber in 1999. The research highlights differences in membership models, financial
structures, and engagement with government institutions. Estonia demonstrates a more integrated and efficient
Chamber model, with higher participation rates. Lithuania and Latvia, despite having similar frameworks, show lower
membership engagement and economic impact. The findings focus on the best practices for enhancing the effectiveness
of agricultural chambers, particularly in post-Soviet economies undergoing institutional transformations.Taip / Ye
Driving factors for the transformation to sustainable entrepreneurship in small and medium production companies
No full textSmall and medium enterprises (SMEs) are significant contributors to economic growth. Being the most
represented group of enterprises, SMEs can carry the greatest weight in contributing to sustainable development by
transforming into sustainable entrepreneurship (SE). However, SMEs are substantially limited in resources, and to assist
SMEs, first and foremost, it is important to understand what facilitates the transformation. Thus, the study’s objective
was to identify driving factors for transformation to SE in production SMEs. A monographic literature review
was conducted to provide a comprehensive summary of the latest research. Further, as a result of the secondary data
and the content analysis methods, 6 driving and 7 assisting factors were identified that support the central feature of
transformation to SE – the ability to find new opportunities. Based on the connections among the discovered factors,
the authors developed an Innovation-Driven Development (IDD) conceptual framework. The framework illustrates the
pathway to SE for production SMEs.Taip / Ye
Research of parameters of railway noise barriers
No full textSiekiant užtikrinti tvarią geležinkelių transporto plėtrą, būtina sumažinti riedmenų skleidžiamą triukšmą. Žemos triukšmo mažinimo sienutės, veiksmingai slopinančios rato ir bėgio sąveikoje kylantį riedėjimo triukšmą, gali būti tinkama priemonė triukšmui mažinti geležinkelių keliuose, kuriuose riedmenų važiavimo greitis neviršija 250 km/h. Tačiau, siekiant padidinti jų veiksmingumą, tokias sienutes reikėtų taikyti esant tam tikroms sąlygoms bei tinkamai parinkti jų techninius parametrus.
Disertacijos tikslas siekiant sumažinti riedėjimo skleidžiamo triukšmo poveikį aplinkai, pateikti rekomendacijas žemoms triukšmo mažinimo sienutėms taikyti tiesiuose geležinkelių bėgių kelio ruožuose bei žemos triukšmo mažinimo sienutės parinkimo algoritmą. Darbe sprendžiami keli pagrindiniai uždaviniai: triukšmo sienučių įneštinio silpninimo nustatymas atliekant eksperimentą ir riedmenų, judančių skirtingais važiavimo greičiais, skleidžiamo triukšmo mažinimo skirtingo aukščio triukšmo sienučių veiksmingumo palyginimas modeliuojant.
Disertaciją sudaro įvadas, trys skyriai, išvados, literatūros sąrašas ir keturi priedai. Įvade pristatoma tyrimo problema, aprašomas darbo aktualumas ir tyrimų objektas, darbo tikslas ir uždaviniai, tyrimų metodika, darbo mokslinis naujumas, darbo rezultatų praktinė reikšmė ir ginamieji teiginiai, pateikiama disertacijos struktūra. Pirmame skyriuje atliekama literatūros analizė. Aprašyti rato ir bėgio sąveikos sukeliamo triukšmo mechanizmas bei modeliai, išnagrinėtas geležinkelių bėgių kelio skleidžiamo triukšmo teisinis reglamentavimas, aptarti moksliniai tyrimai geležinkelių bėgių kelio skleidžiamo triukšmo mažinimo tematika. Remiantis užsienio šalių patirtimi bei įvertinus Lietuvos sąlygas, sudarytas žemos triukšmo mažinimo sienutės taikymo modelis. Antrame skyriuje atlikta riedmenų važiavimo greičio ir geležinkelių skleidžiamo triukšmo lygio koreliacijos analizė, parengtas eksperimentinio tyrimo planas ir metodikos. Trečiame skyriuje atliktas triukšmo mažinimo priemonių veiksmingumo įvertinimas daugiakriteriu metodu. Siekiant nustatyti įvairaus aukščio bei ilgio triukšmo mažinimo sienučių veiksmingumą, atlikti eksperimentiniai triukšmo mažinimo sienutės įneštinio silpninimo lauko sąlygomis bei skaitinio modeliavimo CadnaA paketo programa tyrimai. Atlikta statistinė žemų triukšmo mažinimo sienučių parametrų, darančių įtaką įneštinio silpninimo vertėms, analizė.
Disertacijos tema paskelbti 7 straipsniai: 2 mokslo žurnaluose, įtrauktuose į Web of Science duomenų bazę, 1 recenzuojamame mokslo žurnale, 1 tarptautinės konferencijos medžiagoje, referuojamoje Web of Science duomenų bazėje, bei 3 kituose tarptautinių ir respublikinės konferencijų leidiniuose.Sustainable development of rail transport requires adequate mitigation of the noise emitted by rolling stock. Low noise barriers, which effectively mitigate rolling noise arising from the rail/wheel interaction, are a suitable means of noise reduction on railways where the speed of rolling stock does not exceed 250 km/h. However, to ensure their effectiveness, such barriers should be applied under certain conditions, and their technical parameters should be properly selected.
The dissertation aims to present recommendations for applying low-noise barriers in straight sections of railway tracks and an algorithm to select a low-noise barrier to reduce the impact of rolling noise on the environment. The work addresses several main tasks: determines the insertion loss of a noise barrier by experiment and uses numerical simulation to compare the effectiveness of different height noise barriers in mitigating the noise of rolling stocks moving at different speeds. The dissertation consists of an Introduction, three chapters, conclusions, and references. The introduction formulates the research problem, describes the relevance of the work and the object of research, formulates the aim and tasks of the work, describes the research methodology, the scientific novelty of the work, the practical significance of the work results and defended statements, and presents the structure of the dissertation. The first chapter revises the used literature. It describes the mechanism and models of the noise caused by the wheel/rail interaction, examines the legal regulation of the noise emitted by the railway track, and examines scientific research on mitigating the noise emitted by the railway track. Based on the experience of foreign countries and after evaluating the conditions of Lithuania, a model of applying a low noise barrier has been created. The second chapter analyses the correlation between rolling stock speed and the level of noise emitted by railways and suggests methods of experimental research. The third chapter evaluates the effectiveness of noise mitigation measures using a multi-criteria method. Experimental studies of noise barriers in field conditions and numerical modelling using the CadnaA package were carried out to determine the effectiveness of noise barriers of various sizes in mitigating the noise emitted by the railway track. A statistical analysis of the low noise barrier parameters that influence the insertion loss values was performed.
Seven scientific articles were published on the topic of the dissertation: two in scientific journals included in the Web of Science, one in a reviewed scientific journal, one in the Web of Science Proceedings database publications, and three in the scientific conference publications