1. Development of Methodology for Estimation of Energy-Efficient Building Renovation Using Application of MINLP-Optimized Timber–Glass Upgrade ModulesMaja Lešnik Nedelko, Stojan Kravanja, Miroslav Premrov, Vesna Žegarac Leskovar, 2025, izvirni znanstveni članek Opis: Vertical addition to already-existing structures is an approach to energy-efficient building renovation. It presents an opportunity for the densification of built-up areas and the construction of new usable spaces. While many studies have dealt with the subject of renovating buildings with a focus on energy efficiency, far fewer studies have specifically examined the potential of vertically extending existing buildings, an approach which could be introduced in new sustainable building policies. The objective of this study is to redevelop optimal timber–glass upgrade modules, considering the ideal proportions of glazing for all cardinal directions, by using discrete Mixed-Integer Non-Linear Programming optimization. The novelty of the suggested method resides in the synchronous optimization of the upgrade modules’ daylighting and energy-efficiency performance, resulting in the creation of optimization methods that can determine the optimal glazing proportions for all cardinal directions and incorporate rational design and window measurement. The impact of the developed Mixed-Integer Non-Linear Programming-optimized upgrade modules is compared to previously designed optimized upgrade modules. Finally, a methodology for estimating the energy efficiency of building renovations incorporating vertical additions using the timber–glass upgrade modules was developed, supporting the quick assessment of the reduction in hybrid buildings’ energy consumption for heating and cooling according to boundary conditions, presuming that they undergo the suggested renovations. The findings are applicable (not exclusively) to Slovenia’s residential building stock, which makes up around 20% of the country’s current housing stock and was mainly constructed between 1946 and 1970. This offers a substantial opportunity to improve the overall sustainability and energy efficiency of the country’s housing stock. The proposed approach offers a holistic solution to drive sustainable development in the built environment by incorporating all three pillars of sustainability (environmental, social, and economic). Ključne besede: energy efficient building renovation, energy efficiency, building vertical addition, timber–glass upgrade modules, mixed-integer non-linear programming, MINLP, optimization, visual comfort, energy sustainability Objavljeno v DKUM: 16.01.2025; Ogledov: 0; Prenosov: 3
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2. Comparison of different modulation control strategies for wireless power transfer systemJure Domajnko, Oto Težak, Mitja Truntič, Nataša Prosen, 2025, izvirni znanstveni članek Opis: When designing a wireless power transfer system, overall system efficiency is one of the key parameters. The efficiency depends on several parameters, which also includes control modulation, used for excitation of the transmitter coil. However, how much the modulation technique impacts the efficiency is studied rarely. In this paper, we compare the three most popular control modulation techniques for transmitter voltage of a wireless power transfer system. First, the theory behind the methods is presented by highlighting the difference between them and their implementation. The methods are implemented, together with a linear PI control scheme, to evaluate the efficiency and performance of each of the methods. Finally, the practical tests were performed, under different output power levels, in order to evaluate the practical performance of each modulation strategy further Ključne besede: inductive power transfer, full-bridge inverter, inverter modulation comparison, efficiency comparison Objavljeno v DKUM: 08.01.2025; Ogledov: 0; Prenosov: 5
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3. Information communication technology and supply chain efficiency in manufacturing SMES in Bulawayo Province in ZimbabweSithokozile Bafana, Simba Mutsvangwa, Felix Chari, 2024, izvirni znanstveni članek Opis: There has been a global plummeting trend of failure in most manufacturing Small and Medium Enterprises (SMEs) due to purported supply chain inefficiency. It is imperative for clothing manufacturing SMEs in developing nations like Zimbabwe, with reference to Bulawayo Province, which lacks digitization to integrate Information and Communication Technology (ICT) solutions into their supply chain operations to improving efficiency and maintain competitiveness in the global market. Thus, the purpose of the study was to evaluate ICT and supply chain efficiency in the clothing manufacturing SMEs in Bulawayo Province. Employing the pragmatic approach, data were collected using semi-structured questionnaires from a sample of 107 from a total population of 147 that were triangulated with 15 interviews from clothing manufacturing SMEs in Bulawayo. A simple linear regression analysis through Ordinary Least Squares was conducted to test the relationship between ICT and supply chain efficiency. The results show that ICT has a positive and statistically significant effect on cost performance, agility and delivery performance in Bulawayo clothing manufacturing SMEs. By prioritizing ICT adoption, managers can achieve better cost management, increased responsiveness to market demands, and enhanced delivery capabilities. It is recommended that clothing manufacturing SMEs in Bulawayo should embrace the ICT. Further studies should examine the relationship between ICT and supply chain efficiency in manufacturing SMEs across different industries and nations. Ključne besede: information and communication technology, supply chain efficiency, SMEs (small and medium enterprises), material requirement planning Objavljeno v DKUM: 17.12.2024; Ogledov: 0; Prenosov: 3
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4. The Economic efficiency of micro biogas plants: ǂa ǂSustainable Energy solution in Slovenia - Case studyPeter Vindiš, Karmen Pažek, Jernej Prišenk, Črtomir Rozman, 2024, izvirni znanstveni članek Opis: This paper presents a simulation model for determining the most suitable type of microbiogas plant for small local communities on Slovenian farms, focusing on the efficient processing of organic waste. This model uses various input parameters, including different types and quantities of slurry and corn silage. Four different scenarios were developed to represent potential plant sizes, each evaluated using key economic indicators: net present value, breakthrough price, and internal rate of return. A scenario sensitivity analysis was conducted to assess the effects of changes in investment costs, fluctuations in energy prices, and the addition of corn silage to the anaerobic digestion process. The results highlight significant differences in economic viability across the scenarios, with some demonstrating positive financial outcomes and shorter payback periods and others indicating potential financial risks and longer recovery times under certain conditions. The analysis suggests that smaller micro biogas plants may struggle to achieve profitability without optimizing input ratios or reducing costs, whereas larger plants show more favorable economic indicators, provided certain conditions are met. Furthermore, the economic efficiency improves when adding maize silage to the fermentor mixture. Ključne besede: micro biogas plant, biogas, economic efficiency, simulation Objavljeno v DKUM: 27.11.2024; Ogledov: 0; Prenosov: 5
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5. Gender differences in work satisfaction, work engagement and work efficiency of employees during the COVID-19 pandemic : the case in SloveniaMaja Rožman, Simona Sternad Zabukovšek, Samo Bobek, Polona Tominc, 2021, izvirni znanstveni članek Opis: The COVID-19 pandemic and the resultant lockdown has caused massive economic disruption, leading businesses to make a rapid transition and take a new approach to business strategy. Therefore, the aim of the paper is to examine if there are statistically significant gender differences in work satisfaction, work engagement, and work efficiency among employees who work from home during the COVID-19 pandemic. Further, the paper aims to identify the importance of individual dimensions of work satisfaction, work engagement, and work efficiency, and gender differences perspective. The research is based on a survey of 785 employees in Slovenian companies. The factor analysis and the t-test for two independent samples were used to test the research hypotheses. Findings: The results show significant gender differences in work satisfaction, work engagement, and work efficiency among employees who work from home during the COVID-19 pandemic. The paper provides change management insights and recommendations to assist companies in minimizing the negative impact of the COVID-19 pandemic on their employees. Ključne besede: work satisfaction, work engagement, work efficiency, employees, COVID-19 Objavljeno v DKUM: 14.10.2024; Ogledov: 0; Prenosov: 12
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6. Defining a sustainable supply chain for buildings Off-Site envelope thermal insulation solutions : proposal of a methodology to investigate opportunities based on a context analysisMiriam Benedetti, Carlos Herce, Matteo Sforzini, Tiziana Susca, Claudia Toro, 2024, pregledni znanstveni članek Opis: External wall thermal insulation is one of the most effective solutions on the market to increase energy efficiency in the built environment. Off-Site Construction (OSC), through better control of the various parameters involved, can bring important advantages, such as the reduction of construction time, the improvement of product and process quality, etc. In the last years, the rapidly growing demand for thermal insulation systems, stimulated also by tax incentives, has generated a unique situation in Italy compared to the rest of Europe, also leading to a considerable fragmentation of the supply chain with several players involved (component and system manufacturers, distributors, and installers). The complexity of such context makes Italy an extremely challenging and insightful case study for a supply chain and sustainability study, also considering the fact that the energy efficiency of the Italian building stock represents a crucial challenge to achieve the country's energy saving goals since 40% of final energy consumption derives from buildings and 75% of the building stock presents a low energy performance (energy labels E, F and G). This article presents both an analysis of the Italian market of manufacturers of building envelope thermal insulation solutions, highlighting the different players in the supply chain in terms of number, type, and marketed products and solutions, and a focus on sustainable and recycled materials. The study also aims to define a methodology to investigate the state of play and opportunities for industrialisation of this market and its bottlenecks. In the article, a questionnaire is proposed to collect information and opinions on the spread of OSC and the perception of companies and professionals regarding the advantages and disadvantages of industrializing the sector. A first validation of the survey is presented in the form of industrial focus groups. Ključne besede: supply chain sustainability, industrial energy efficiency, off-site construction, construction industrialisation, sustainable building materials, modular buildings Objavljeno v DKUM: 01.10.2024; Ogledov: 0; Prenosov: 3
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7. Differences in subject-specific competences between Slovenian and Italian physical education teachersMarjeta Kovač, Bojan Leskošek, Gregor Jurak, Miha Marinšek, Miloš Tul, 2021, izvirni znanstveni članek Opis: This cross-sectional study was designed to analyse the differences between the subject-specific competences of Slovenian and Italian physical education (PE) teachers. The participants, 669 Slovenian and 484 Italian PE teachers, evaluated their professional competences with a self-administered questionnaire on a four-level Likert scale. A t-test for independent samples indicates differences in the self-evaluations of the majority of subject-specific competences between both groups. However, in almost all items, Slovenian PE teachers evaluate their competences higher. A multivariate analysis of variance, used to identify the role of some socio-demographic factors (state, gender, years of service), shows that the state has the highest impact on the differences between self-efficiency of both groups (p<0.001, Eta2=0.531). The greatest differences (Cohen's d > 0.8) are observed on those competences that relate to some of the narrower aspects of PE didactics. The reasons for the perceived differences can be found in some historical and social events, length of education, the different orientation of PE teacher education programmes, and the different responses of both countries to educational policies. The present study outcomes may aid in updating initial PE teacher training and designing a creative system of continuous professional development. Ključne besede: physical education, educators, self-efficiency, cross-cultural study Objavljeno v DKUM: 04.09.2024; Ogledov: 41; Prenosov: 4
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8. The technical efficiency of Tunisian ports : comparing data envelopment analysis and stochastic frontier analysis scoresRabeb Kammoun, 2018, izvirni znanstveni članek Opis: Maritime transportation for Tunisia plays an important role in trade exchange with other countries. Therefore, the objective of this paper is to measure the efficiency scores of 7 seaports in Tunisia by applying the Stochastic Frontier Analysis (SFA) with Cobb-Douglas production function and Data envelopment analysis (DEA) with CCR and BCC models. The annual data collected cover the 2007-2017 period for each port. Thus, the sample size for the analysis comprises a total of 77 observations. The empirical result shows that the total average scores of operating efficiency scores were DEA-BCC (0.746)>SFACD (0.536)>DEA-CCR (0.334) from 2007 to 2017. Given these results, the port of Gabes can be considered as the best efficient port in the 3 models (DEA-BCC, DEACCR and SFA-CD). Ključne besede: efficiency, data envelopment analysis (DEA), stochastic frontier analysis (SFA), Tunisian seaports Objavljeno v DKUM: 22.08.2024; Ogledov: 44; Prenosov: 4
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9. Appropriately organized work and employees’ concerns related to work from home during the COVID-19 pandemic : the case in SloveniaMaja Rožman, Vesna Čančer, 2022, izvirni znanstveni članek Opis: Purpose: The main aim of the paper is to establish the effects of appropriately organized work as well as the effects of the employees' concerns related to work during the COVID-19 pandemic on work efficiency and work satisfaction among employees working from home during this period. The empirical research includes 619 employees in Slovenia, who participated in the survey during the COVID-19 pandemic.
Design/methodology/approach: Structural equation modeling was used in exploring the effects between constructs.
Findings: Based on the results, the authors found that appropriately organized work during the COVID-19 pandemic has a positive effect not only on the work efficiency of employees who work from home during the COVID-19 pandemic in Slovenia but also on their work satisfaction. Also, based on the results, the authors found that the employees' concerns related to work during the COVID-19 pandemic have a negative effect on the work efficiency and on the work satisfaction of employees who work from home during this period in Slovenia.
Originality/value: The COVID-19 pandemic dramatically changed the way we live and work; therefore, this paper contributes to the creation of new working conditions and employee management during and also after the COVID-19 pandemic. Ključne besede: COVID-19 pandemic, appropriately organized work, work efficiency, work satisfaction, employees` concerns Objavljeno v DKUM: 03.07.2024; Ogledov: 117; Prenosov: 9
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10. The interplay of restaurant SMEs' entrepreneurial and environmental characteristics, management of the requisite assets, and operational efficiencyTanja Planinc, Marko Kukanja, Anja Žnidaršič, 2022, izvirni znanstveni članek Opis: Background/Purpose: SMEs are subject to different factors in the business environments that influence their business performance. Considering the importance of restaurants’ environmental characteristics, entrepreneurs can also, through their entrepreneurial characteristics, influence SMEsʼ management of the requisite assets (MRA). Accordingly, this study examines the influence of restaurant SMEs’ entrepreneurial (self-efficacy, orientation, and demographics) and environmental (location, size, and competition) characteristics on MRA and, consequently, on SMEs’ operational efficiency.
Methods: Primary data relating to the environmental (location, size, and competition) and entrepreneurial (self-efficacy, orientation, and demographic) characteristics were obtained using a survey questionnaire, while the secondary data were obtained from SMEs’ official financial reports. The sample consists of 266 restaurant SMEs in the Republic of Slovenia. Efficiency was analysed using data envelopment analysis (DEA), and structural equation modelling (SEM) was used to test the research model.
Results: The results indicate that environmental characteristics have a much more significant impact on MRA than entrepreneurial characteristics. Entrepreneurial self-efficacy and most demographic characteristics (age, gender, education, and experience) proved not to influence significantly MRA and, consequently, SMEs’ operational efficiency.
Conclusion: SMEs’ external environment is generally not directly influenced by managerial decisions. Therefore, it is critical to strengthen the influence of the internal environment through an active development of entrepreneurial characteristics, which could result in a more effective MRA and higher efficiency. The conclusion provides suggestions for future research and valuable information for entrepreneurs, academia, and policymakers. Ključne besede: SMEs, restaurant industry, Slovenia, efficiency, environmental and entrepreneurial characteristics, requisite assets Objavljeno v DKUM: 28.06.2024; Ogledov: 418; Prenosov: 17
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