1. The influence of health claims and nutritional composition on consumers' yoghurt preferencesKrista Miklavec, Igor Pravst, Klaus G. Grunert, Marija Klopčič, Jurij Pohar, 2015, izvirni znanstveni članek Ključne besede: health claims, biotin, probiotics, conjoint analysis, cluster analysis
Objavljeno v DiRROS: 28.11.2025; Ogledov: 103; Prenosov: 57
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2. Recent theoretical and practical contributions to the OR environment and CEJOR from the perspective of SSI-SORJanez Povh, Lidija Zadnik Stirn, Janez Žerovnik, 2025, izvirni znanstveni članek Povzetek: The article summarizes the research topics published in this special issue. The pa- pers in this issue are based on the selected and peer-reviewed papers from the 17th International Symposium on Operations Research in Slovenia – SOR’23, which took place in Bled, Slovenia (https://arhiv.fov.um.si/sor23/), September 20–22, 2023. In addition, we examined the 27 research papers in the last two SSI-SOR CEJOR special issues, 16 in the Cent Eur J Oper Res 31, issue 3, 2023, and 11 in this CEJOR special issue, and grouped them into clusters using keywords ac- cording to the methodology published by Kastrin et al. (2021) Methodologies and applications for resilient global development from the aspect of SDI-SOR. The clusters show the main and niche topics presented and, on the one hand, illustrate the European and international state of the art in the field of OR over the last five years and, on the other hand, can serve as a stimulus for further work on upcoming strategic OR topics.
Ključne besede: operations research, SOR conferences, Slovenia, cluster analysis
Objavljeno v DiRROS: 19.06.2025; Ogledov: 402; Prenosov: 257
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3. Application of multivariate statistical methods for determining geochemical trends of elements on the territory of SloveniaRobert Šajn, Mateja Gosar, Jasminka Alijagić, Tamara Teršič, 2024, izvirni znanstveni članek Povzetek: The main objective of this study is to map multi-element geochemical anomalies in soil on a regional scale. We aimed to determine and evaluate the baseline geochemical values and main geochemical trends in soil that may serve as reference values against any future changes. A total of 817 topsoil samples (0–10 cm) were collected in a 5 × 5 km grid and analyzed for 35 elements using ICP-ES after multi-acid digestions (HClO4/HNO3/HCl/HF) and 53 elements using ICP-MS after modified aqua regia digestion (HCl/HNO3/H2O). The analytical results for the two different digestion methods (multi-acid digestion vs. aqua regia) were also compared for each chemical element. Multivariate statistical methods were applied to identify the geochemical trends and main sources of trace elements over the territory of Slovenia. Based on these results, seven natural and one mixed natural/anthropogenic geochemical association were established. The contents and trends of the determined factors are presented according to 8 natural units, 4 drainage areas, and geological units characteristic of Slovenia. The identified anthropogenic geochemical association combines toxic elements (Ag, Bi, Cd, Hg, P, Pb, S, Sn, and Zn). Increased values of these elements can be found in mining areas and metallurgic centers, in Quaternary sediments of the Sava River, and Adriatic Basin as the consequence of past mining activities and in the Julian Alps, where their origin could be connected to the atmospheric deposition.
Ključne besede: soil, geochemical mapping, distribution of geochemical elements, factor analysis, cluster analysis
Objavljeno v DiRROS: 04.01.2024; Ogledov: 1211; Prenosov: 427
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4. Statistical approach to interpretation of geochemical data of stream sediment in Pleše mining areaSimona Jarc, 2022, izvirni znanstveni članek Povzetek: The Ba, Pb and Zn ore deposit Pleše near Ljubljana is one of the formerly productive mines. The stream sediments were sampled and analysed by XRF to establish the effect of grain size, mineralization, and downstream location of sampling sites on geochemical composition based on various statistical analyses. Statistical analyses of the geochemical data confirm the impact of mineralization. The parametric t-test, non-parametric Mann-Whitney test and cluster analysis showed only minor differences in the geochemical composition of the samples with different grain sizes (< 0.063 mm and 0.063-2 mm). The parametric and non-parametric correlation coefficients as well as cluster analysis indicate that the contents of Si, Al, K, Rb, and Fe are associated with weathered rock forming minerals such as micas, and clay minerals, whereas Nb and Zr are associated with minerals resistant to weathering. Ca and Mg are associated with carbonates. S, Ba, Sr, Pb, Zn, and Mn indicate local mineralization with sulphates and sulphides. The results of the t-test and analysis of variance, Mann-Whitney tests and Kruskal-Wallis ANOVA of the groups established by the cluster analysis confirm that the contents of Ba, Pb and Sr have a statistically significant influence on the classification of the cluster group - i.e., the influence of sediment mineralization. There are no differences in elemental contents in the sediment samples downstream. The statistical approach to evaluate the geochemical data has proven useful and provides a good basis for further interpretation.
Ključne besede: ANOVA, t-test, correlation, cluster analysis, XRF, mineralization
Objavljeno v DiRROS: 18.01.2023; Ogledov: 1729; Prenosov: 776
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