VGTU Journals (Vilnius Gediminas Technical University - Vilnius Tech)
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Evaluation of the low-cost depth cameras for non-destructive testing
No full textThe primary aim of this paper is to assess the effectiveness of a low-cost stereo (depth) camera as a non-destructive tool for the detection and measurement of cracks in concrete surfaces. The experiment was carried out on four concrete beams with cracks, created with different concrete mixes. The mixes of the four beams were made up of lightweight aggregates with 12% of normal weight aggregates. One beam was used as a reference without fibers, while 3D steel fiber reinforcement, 5D steel fibers reinforcement, and a hybrid fibers mix of 5D steel fiber and synthetic were used for the other three beams. The cracks in the beams were measured manually followed by taking their stereo images with a ZED camera. The ZED images were processed to produce 3D models of the concrete surfaces, which are useful for crack measurement in a three-dimensional framework. The project results are particularly significant in the measurement of all three dimensions (length, width and depth), with less than a 10% error between the actual and the experimental procedure. Relatively, multiple differential approaches gave a less accurate result of a 15% error mainly due to syntax errors. Results suggest that the ZED depth camera is an effective tool for robust detection and measurement of cracks in concrete surfaces
Creativity in contemporary higher education in the context of the artificial intelligence expansion
No full textIn the paper it is discussed what are the potential possibilities to foster creativity in contemporary higher education in the context of the artificial intelligence expansion based on theoretical analysis of sources and the findings of a pilot empiric study. The aim of this paper is to discuss aspects for potential development of creativity in higher education in the context of the artificial intelligence expansion. The objectives are organized around the research question: what are the aspects of studies in the context the artificial intelligence expansion that students in higher education experience and note today as relevant for their studies (potentially – for professional activity)? Methods of critical analyses of references, theoretical considerations, reflections on authors’ personal experiences, and a pilot empiric study, involving respondents/students, were employed for the development of the paper. Results of an empiric study are presented together with the conclusions that students in higher education conceptualise expansion of the artificial intelligence quite broadly and to a major degree – optimistically, with some attention on creativity and quite extensive attention to changes in culture
Problem-based learning in developing students’ communicative skills and creativity in teaching English for specific purposes
No full textTertiary education uses a variety of teaching methods to cater for different learning styles, encourage critical thinking, and prepare students for real-world challenges. Common methods include lectures, seminars, independent study, and collaborative learning. This diversity reflects the complexity of higher education and helps to create a dynamic learning environment that fosters lifelong learning and critical thinking skills. Problem-based learning, a prominent teaching method, focuses students on an inquiry-based approach, presenting them with real-life problems that require the application of knowledge, critical thinking, creative approach, and collaboration. Problem-based learning is very effective in teaching English for specific purposes at tertiary level because it involves students in projects that require the use of the target language, thus enhancing language acquisition and fostering communicative skills. This method benefits students by promoting active learning, improving communication, encouraging creativity, and developing problem-solving skills. A study at Vilnius Gediminas Technical University, Lithuania, involving students from creative and technical fields, found that most students found problem-based learning beneficial, although creativity students were more enthusiastic. The results suggest that while problem-based learning improves understanding of both theoretical and practical aspects of study programmes, technical students are more sceptical about the effectiveness of problem-based learning. Despite some negative attitudes on the part of some students, problem-based learning remains a valuable tool in English for specific purposes education, supporting the development of language and professional skills
The creativity of monuments: the case of bistable Belarusian identity
No full textDuring the last decades, Belarus has experienced a wave of monument construction, i.e., the monuments as creative practices through which certain historical, cultural and political meanings are constructed and articulated. The process confirms some scientists’ insights that the Belarusian identity is actively created today. However, the scientists who are interested in its construction on a practical level have not paid attention to the process of monument creation in Belarus as it also creates and articulates state identity. The analysis of the monument-making process has revealed that three identity narratives co-exist in Belarus: national-cultural and two political-historical ones, i.e., commonality with Russia and political independence from Russia. The potential contradiction of these political-historical narratives shows that the Belarusian identity is in a dichotomous and uncertain state. Although the spread of the political independence from Russia narrative allows us to talk about the existence of an independent national identity of Belarus (one of the most prominent manifestations was the mass protests in 2020, unpredicted by many scientists) in parallel with the existence of a strong historical-political narrative of commonality with Russia, the identity of Belarus remains in a bistable condition. For this reason, the further development of the Belarusian identity remains uncertain in the long-term perspective
How does the collaborative innovation network in construction industry evolve? Evidence from China
No full textTechnology innovation in the construction industry involves collaboration among multiple innovation organizations which formed an intricate collaborative innovation network (CIN). To understand the evolution characteristics of structural characteristics of CIN in China’s construction industry and to clarify the collaborative patterns among innovation organizations, the CIN were analyzed in terms of overall network characteristics and local collaborative patterns by using the social network analysis (SNA) and network motif analysis (NMA), respectively based on the data of projects winning the China’s Science and Technology Award in Construction (CSTAC) in 2004–2021. The results indicate that the CIN became larger but less connected and exhibited scale-free and small-world characteristics during the study period. There is a giant component in the CIN, which is gradually increasing in size and becoming more cohesive. China Academy of Building Research which had the highest degree centrality and closeness centrality and Tongji University which had the largest betweenness centrality had an important position in CIN. The main collaborative innovation mode in China’s construction industry is collaboration between enterprises, followed by collaboration between enterprise-university, which has an increasing share. The results help organizations clarify their position in the CIN and inform their development of co-innovation partners
An evaluation study on immigrants′ transport system adaptation behaviour: Turkey example
No full textGlobal migration patterns have led to significant population shifts, particularly in regions such as Turkey, which has experienced a substantial influx of immigrants due to political crises, economic instability, and armed conflicts. This study examines the adaptation behaviour of immigrants to Turkey′s transport system, identifying key challenges, expectations, and integration patterns. Using survey data from immigrants in Turkey, the study explores the role of demographic factors, prior transport experiences, and socio-economic conditions in shaping mobility choices. The findings indicate that while many aspects of Turkey′s transport system are familiar to immigrants, significant barriers such as high travel costs, unclear traffic signage, and language-related difficulties hinder complete adaptation. Younger, higher-educated immigrants and those from culturally similar backgrounds demonstrate a faster integration process, whereas older immigrants and those with limited educational backgrounds face more significant obstacles. Statistical analyses, including multiple linear regression and decision tree classifier, reveal that age is the most significant predictor of long-term transport adaptation. Additionally, the study highlights that as the duration of stay increases, immigrants exhibit a higher reliance on public transportation, with ownership of private vehicles gradually rising among long-term residents. The research underscores the need for policy interventions, such as reducing transport costs, improving multilingual signage, and offering integration programs to enhance immigrant mobility. These insights provide valuable guidance for policymakers, urban planners, and transport authorities striving to develop more inclusive and efficient transport systems
Artificial intelligence as applied to classifying epoxy composites for aircraft
No full textThe problem of classification of epoxy composites used for the manufacture of aircraft structures is solved by machine learning methods: neural network, reinforced trees and random forests. Classification metrics were obtained for each method used. Parameters such as precision, recall, F1 score and support were determined. The neural network classifier demonstrated the highest results. Boosted trees and random forests showed slightly lower results than the neural network method. At the same time, the classification metrics were high enough in each case. Therefore, machine learning methods effectively classify epoxy composites. The results obtained are in good agreement with the experimental ones. The prediction accuracy score obtained using each method was greater than 0.88
Bitcoin: a Ponzi scheme or an emerging inflation-fighting asset?
No full textUnder the dual impact of the COVID-19 pandemic and the Russian-Ukrainian conflict, the excessive stimulation of monetary policy continuously pushes up global inflation (INF). Therefore, this article explores whether Bitcoin can serve as a safe haven for INF. We apply the rolling-window Granger causality test to solve the issue of parameter instability in vector autoregression (VAR) systems and investigate the time-varying interaction between INF and Bitcoin price (BP). The negative influence of INF on BP means a high inflation shock causes BP to decline, indicating that Bitcoin cannot be a safe asset against INF. This is because investors have decreased their willingness to hold Bitcoin under the high INF expectations and cause BP to fall. This finding is not supported by the Intertemporal Capital Asset Pricing Model, emphasising that INF positively impacts BP. Conversely, BP has positive and negative impacts on INF. The positive effect highlights the effectiveness of Bitcoin in predicting INF fluctuations, but economic factors could undermine this effectiveness. In the context of economic stagnation and market turmoil, investors can adjust their portfolio investments based on Bitcoin. The government should utilise the trend of BP to regulate the dynamics of INF to reduce uncertainty in the financial system.
First published online 30 August 202
Debt or equity? Financial impacts of R&D support across firm demographics
No full textThis study utilizes data from Korea’s Research and Development (R&D) grant program to examine the impact of receiving an R&D grant on a firm’s ability to obtain external financing, taking into account the heterogeneous effects based on firm size and characteristics. By employing the propensity score matching method, we establish the causal effect of R&D support on financing and discover that R&D grants have differential effects on debt and equity financing. Our findings indicate that larger firms are more likely to acquire subsequent debt financing, whereas small firms that receive R&D grants exhibit an increased likelihood of securing equity financing, particularly among young firms. Furthermore, we identify a certification effect of R&D grants, implying that such grants may serve as indicators of the potential success of small, young firms in the market. Collectively, this study illuminates the role of R&D grants in firms’ financing decisions, providing valuable insights for policymakers and firms seeking to secure external financing.
First published online 12 December 202
Fuel prices and economic activity: time and frequency analysis for selected European countries
No full textThe effects of fuel prices on economic activity are still being investigated, as oil and gas are critical inputs in the production process. This study examines the relationship between fuel prices and macroeconomic aggregates both in the time domain and frequency domain in three selected countries of Germany and Poland as net oil importers and Norway as a net oil exporter for the period 1995Q1–2021Q3. The causal relationships between these macroeconomic variables are first examined using a conventional Granger causality test for the time domain and then the Breiutung–Candelon test based on the vector autoregression model for the frequency domain, which are estimated separately for the long-term, business cycle, and short-term components obtained by applying the boosted Hodrick–Prescott filter. This study demonstrates that the predictability of fuel prices for macroeconomic aggregates differs across various frequencies. Although the patterns of causality differ across countries depending on whether it is oil-importing or oil-exporting and the level of economic development and energy mix, this relationship is found to be important for slowly and fast fluctuating components but to different degrees in each country.
First published online 15 April 202