1. Experimental and numerical investigation of the fire behavior of double-glass building integrated photovoltaic modules with PVB interlayersWanning Yu, Lizhong Yang, Xinyang Wang, Dimeng Lai, Grunde Jomaas, Kim M. Liew, Xiaoyu Ju, 2026, original scientific article Abstract: Amid rising global energy demands and environmental concerns, energy-efficient, or ‘green’, buildings are becoming mandatory in building regulations worldwide. In that context, building-integrated photovoltaics (BIPV), which merge photovoltaic (PV) modules with architectural design, are gaining widespread adoption. To assess fire safety aspects of BIPV, the fire performance of double-glass PV modules with polyvinyl butyral (PVB) encapsulation in BIPV façade systems was studied experimentally and numerically. More specifically, fire experiments were conducted under varying radiative heat fluxes to evaluate thermal degradation, fire behavior, and toxic gas emissions. Key parameters, including ignition time, heat release rate per unit area (HRRPUA), mass loss rate (MLR), and gas composition, were analyzed. The results confirm that a higher external heat flux markedly reduces ignition time while increasing HRRPUA and MLR for BIPV, which is in line with results for other materials. The primary toxic gases emitted during combustion were CO, CO2, H2, and SO2, with CO and CO2 emissions rising significantly at elevated heat fluxes. To complement the experimental results, a numerical model coupling transient heat conduction and pyrolysis kinetics was developed to predict the pre-ignition thermal response of the multilayer structure. The model employed layer discretization and temperature-dependent boundaries, demonstrating close agreement with experimental data. Therefore, it enabled systematic analyses of the sensitivity of PV module material flammability to incident radiative heat fluxes, material properties, and geometric configurations. This combined experimental and numerical approach offers a predictive framework for assessing fire risks and optimizing the fire safety design of BIPV systems.
Keywords: fire behavior, combustion stages, PV modules, heat conduction pyrolysis model, module toxicity, fire safety
Published in DiRROS: 13.01.2026; Views: 266; Downloads: 189
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2. Exploring module interactions in modular CMA-ES across problem classesAna Nikolikj, Tome Eftimov, 2025, original scientific article Abstract: This study presents an in-depth analysis of module importance within the modular CMA-ES (modCMA-ES) algorithm using exploratory data analysis and large-scale benchmarking across the BBOB suite. Rather than introducing new algorithms, our contribution lies in uncovering how individual modules and their interactions influence optimization performance across diverse black-box problem classes. We evaluate 324 modCMA-ES variants across 24 problem classes using functional ANOVA (f-ANOVA) to quantify the variance in performance attributable to individual, pairwise, and triplet module interactions. Results reveal substantial variation in module importance across problem classes and highlight strong alignment between module interaction patterns and high-level landscape features, particularly multi-modality. Further, we demonstrate that configuring only the most important modules — identified via f-ANOVA — achieves performance comparable to or better than the single-best solver, especially in high-dimensional settings. This analysis, conducted at both low (5D) and high (30D) dimensions, offers actionable insights into module interactions within the mod-CMA-ES framework.
Keywords: module importance, empirical study, black-box optimization, benchmarking
Published in DiRROS: 20.08.2025; Views: 660; Downloads: 308
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3. Generalization ability of feature-based performance prediction models : a statistical analysis across benchmarksAna Nikolikj, Ana Kostovska, Gjorgjina Cenikj, Carola Doerr, Tome Eftimov, 2024, published scientific conference contribution Abstract: This study examines the generalization ability of algorithm performance prediction models across various bench-mark suites. Comparing the statistical similarity between the problem collections with the accuracy of performance prediction models that are based on exploratory landscape analysis features, we observe that there is a positive correlation between these two measures. Specifically, when the high-dimensional feature value distributions between training and testing suites lack statistical significance, the model tends to generalize well, in the sense that the testing errors are in the same range as the training errors. Two experiments validate these findings: one involving the standard benchmark suites, the BBOB and CEC collections, and another using five collections of affine combinations of BBOB problem instances.
Keywords: meta-learning, single-objective optimization, module importance
Published in DiRROS: 16.09.2024; Views: 1265; Downloads: 653
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5. Invariants of multi-linkoidsBoštjan Gabrovšek, Neslihan Gügümcü, 2023, original scientific article Abstract: In this paper, we extend the definition of a knotoid to multilinkoids that consist of a finite number of knot and knotoid components. We study invariants of multi-linkoids, such as the Kauffman bracket polynomial, ordered bracket polynomial, the Kauffman skein module, and the $T$-invariant in relation with generalized $\Theta$-graphs.
Keywords: knotoid, multi-linkoid, spatial graph, Kauffman bracket polynomial, Kauffman bracket skein module, theta-curve, theta-graph
Published in DiRROS: 15.03.2024; Views: 1117; Downloads: 609
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6. Development of an advanced methodology for assessing the environmental impacts of refurbishmentsTajda Potrč Obrecht, Sabina Jordan, Andraž Legat, Marcella Ruschi Mendes Saade, Alexander Passer, 2022, published scientific conference contribution Abstract: The refurbishment of the building stock is one of the key tasks for reducing the future environmental emissions in building sector. The assessment of the environmental impacts (EI) of refurbishments with LCA methodology remains a challenge. In the current practice, the refurbishment is threated as the beginning of the new lifecycle and all the impacts associated with the previous life cycle are generally neglected. The exclusion of materials and components used prior to the refurbishment produces a data gap at the end-of-life since information about materials that remained in the building after the refurbishment are missing. Furthermore, no information about what impacts have already been considered in the past bears the risk that some of the impacts are double-counted. In order to overcome these problems, an advanced methodology for the assessment of the embodied impacts in the case of refurbishment was developed that combines two sub-methodologies that can also be used separately. The first submethodology is used for remodelling the input data in order to make them time corresponding. The second sub-methodology is used for the assessment of the EI in the residual value of building materials and components and is including the allocation of EI between the life cycle before and after the refurbishment. The combination of the two sub-methodologies enables a more realistic and accurate assessment of the environmental impacts. The methodology is illustrated on the case on the case of a façade refurbishment. Five different allocation approaches are investigated and the residual value is calculated after a selected time period before and after the refurbishment. For all the inputs time-corresponding data is modelled and used. The study showed that for the life cycle before the refurbishment the EI and the residual value are generally higher if time-corresponding data is used since the EI of the electricity mix are higher. It turned out that the use of different allocation approaches is favouring either the use of recycled or reused materials or the recycling of the materials at the end. The PEF and the cut-off approach with module D are both enhancing the circular economy. It can be assumed that they are likely to prevail in the future.
Keywords: LCA, refurbishment, allocation, module D, dynamic LCA
Published in DiRROS: 31.01.2024; Views: 1551; Downloads: 819
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