241. The optimal kinematic model of the performance of the clear hip circle to handstand on the uneven bars : a case studyEmilija Petković, Saša Veličković, Edvard Kolar, Ratko Stanković, Daniel Stanković, 2023, original scientific article Abstract: The aim of this research was to define the optimal kinematic parameters of performance of the Clear hip circle to handstand on uneven bars (KOVT). The optimal kinematic model defined in this case study represents an example of the successful performance of the Clear hip circle to handstand on the uneven bars. The exercise was performed at the 39th and 40th World Cup in Artistic gymnastics in Maribor (SLO). The kinematic parameters were specified by the APAS 3-D video system (Ariel Dynamics Inc., San Diego, CA), using 16 anthropometric reference points and 8 body segments (Foot, Ankle, Knee joint, Hip joint, Wrist, Elbow joint, Shoulder joint and Head), in which one of the points represents the center of gravity of the body. The female gymnasts (N=15), mean age 17.5 yrs, who performed one Clear hip circle on the uneven bars performed two KOVTs in their gymnastics routine, while the rest performed one KOVT on the uneven bars, mean age 17.5. The main method in this research was kinematic, and the additional one was statistical. Optimizing the technique of successful performance of the KOVT is important for detecting different styles of the technique that occur in female gymnasts. Keywords: gymnastics, female gymnasts, kinematics, technique analysis Published in DiRROS: 20.11.2024; Views: 105; Downloads: 56 Full text (1,02 MB) This document has many files! More... |
242. Bootstrap percolation in strong products of graphsBoštjan Brešar, Jaka Hedžet, 2024, original scientific article Abstract: Given a graph $G$ and assuming that some vertices of $G$ are infected, the $r$-neighbor bootstrap percolation rule makes an uninfected vertex $v$ infected if $v$ has at least $r$ infected neighbors. The $r$-percolation number, $m(G,r)$, of $G$ is the minimum cardinality of a set of initially infected vertices in $G$ such that after continuously performing the $r$-neighbor bootstrap percolation rule each vertex of $G$ eventually becomes infected. In this paper, we consider percolation numbers of strong products of graphs. If $G$ is the strong product $G_1\boxtimes \cdots \boxtimes G_k$ of $k$ connected graphs, we prove that $m(G,r)=r$ as soon as $r\le 2^{k-1}$ and $|V(G)|\ge r$. As a dichotomy, we present a family of strong products of $k$ connected graphs with the $(2^{k-1}+1)$-percolation number arbitrarily large. We refine these results for strong products of graphs in which at least two factors have at least three vertices. In addition, when all factors $G_i$ have at least three vertices we prove that $m(G_1 \boxtimes \dots \boxtimes G_k,r)\leq 3^{k-1} -k$ for all $r\leq 2^k-1$, and we again get a dichotomy, since there exist families of strong products of $k$ graphs such that their $2^{k}$-percolation numbers are arbitrarily large. While $m(G\boxtimes H,3)=3$ if both $G$ and $H$ have at least three vertices, we also characterize the strong prisms $G\boxtimes K_2$ for which this equality holds. Some of the results naturally extend to infinite graphs, and we briefly consider percolation numbers of strong products of two-way infinite paths. Keywords: bootstrap percolation, strong product of graphs, infinite path Published in DiRROS: 20.11.2024; Views: 98; Downloads: 49 Full text (649,39 KB) This document has many files! More... |
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244. Variations in the nutritional profile and colour parameters of sweet potato varieties with different flesh colours : Effects of cropping system, mulching and growing seasonLovro Sinkovič, Mohamed Neji, Nataša Kunstelj, Barbara Pipan, Vladimir Meglič, 2024, original scientific article Keywords: Sweet potato, Flesh colour, Nutritional profile, Cropping system, Genetic makeup, Linear discriminant analysis Published in DiRROS: 19.11.2024; Views: 155; Downloads: 2593 Full text (4,05 MB) |
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248. The effectiveness of neuromuscular training warm-up program for injury preventionin adolescent male basketball playersArmin Paravlić, Peter Bakalár, Katarina Puš, Saša Pišot, Miloš Kalc, Kaja Teraž, Luka Šlosar, Manca Peskar, Uroš Marušič, Boštjan Šimunič, 2024, original scientific article Abstract: This study evaluated the effects of a neuromuscular training (NMT) warm-up program on injury incidence,neuromuscular function, and program adherence, maintenance and acceptance in adolescent basketballplayers. A total of 275 players from 20 Slovenian teams (15 ± 1.7 years of age), were randomized into anintervention group (IG, n=129) and a control group (CG, n=146). Over three months, the IG incorporatedNMT into their warm-ups, while the CG followed their usual practice. Measurements of body anthro-pometry, muscle contractile properties, and balance were taken before and after the intervention. Also,the injury incidence, training adherence and maintenance were reported. Both groups showed improvedbalance, with no significant difference between them. However, IG demonstrated reduced delay times inspecific muscles, indicating improved neuromuscular function. Injury prevalence proportion (%) duringthe whole study period was higher in the control group compared to intervention (IG: 10.9% vs. CG:23.3%), and incidence rate. Moreover, the incidence rate ratio for sustaining an injury was 2.6 on average(ranging from 0.88 to 7.07 for tendon and muscle injuries, respectively), indicating significantly lowerinjury risk in IG than CG. These findings highlight the effectiveness of NMT warm-ups in reducing injuryrisk and enhancing neuromuscular function, emphasizing the value of structured injury preventionstrategies in youth sports. Keywords: muscle contractile properties, balance, injury prevalence, training adherence Published in DiRROS: 18.11.2024; Views: 169; Downloads: 93 Full text (895,08 KB) This document has many files! More... |
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250. A multiphase eigenvalue problem on a stratified Lie groupDebajyoti Choudhuri, Leandro S. Tavares, Dušan Repovš, 2024, original scientific article Abstract: We consider a multiphase spectral problem on a stratified Lie group.We prove the existence of an eigenfunction of $(2, q)$-eigenvalue problem on a bounded domain. Furthermore, we also establish a Pohozaev-like identity corresponding to the problem on the Heisenberg group. Keywords: multiphase spectral problem, stratified Lie group, Heisenberg group, left invariant vector field, (2, q)-eigenvalue problem Published in DiRROS: 15.11.2024; Views: 183; Downloads: 82 Full text (334,31 KB) This document has many files! More... |