Search Results (223)

In this paper, we address the problem of intelligent operation of Distribution Static Synchronous Compensators (D-STATCOMs) in power distribution systems to reduce energy losses and CO₂ emissions while improving system operating conditions. In addition, we consider the entire set of constraints inherent in the operation of such networks in an environment with D-STATCOMs. To solve such a problem, we used three master–slave methodologies based on sequential programming methods. In the proposed methodologies, the master stage solves the problem of intelligent D-STATCOM operation using the continuous versions of the Monte Carlo (MC) method, the population-based genetic algorithm (PGA), and the Particle Swarm Optimizer (PSO). The slave stage, for its part, evaluates the solutions proposed by the algorithms to determine their impact on the objective functions and constraints representing the problem. This is accomplished by running an Hourly Power Flow (HPF) based on the method of successive approximations. As test scenarios, we employed the 33- and 69-node radial test systems, considering data on power demand and CO₂ emissions reported for the city of Medellín in Colombia (as documented in the literature). Furthermore, a test system was adapted in this work to the demand characteristics of a feeder located in the city of Talca in Chile. This adaptation involved adjusting the conductors and voltage limits to include a test system with variations in power demand due to seasonal changes throughout the year (spring, winter, autumn, and summer). Demand curves were obtained by analyzing data reported by the local network operator, i.e., Compañía General de Electricidad. To assess the robustness and performance of the proposed optimization approach, each scenario was simulated 100 times. The evaluation metrics included average solution quality, standard deviation, and repeatability. Across all scenarios, the PGA consistently outperformed the other methods tested. Specifically, in the 33-node system, the PGA achieved a 24.646% reduction in energy losses and a 0.9109% reduction in CO₂ emissions compared to the base case. In the 69-node system, reductions reached 26.0823% in energy losses and 0.9784% in CO₂ emissions compared to the base case. Notably, in the case of the Talca feeder—particularly during summer, the most demanding season—the PGA yielded the most significant improvements, reducing energy losses by 33.4902% and CO₂ emissions by 1.2805%. Additionally, an uncertainty analysis was conducted to validate the effectiveness and robustness of the proposed optimization methodology under realistic operating variability. A total of 100 randomized demand profiles for both active and reactive power were evaluated. The results demonstrated the scalability and consistent performance of the proposed strategy, confirming its effectiveness under diverse and practical operating conditions. Full article

The calculation and evaluation of wave loads represent a critical component in the design process of offshore wind turbines, which is of significant value for ensuring the safety and stability of offshore wind turbines during operation. In recent years, as the offshore wind power industry has extended into deep-sea areas, wind turbines and their foundation structures have gradually increased in scale. Due to the continuously growing diameter of fixed foundation structures, the wave loads they endure can no longer be evaluated solely by traditional methods. This study simplifies the monopile foundation structure of wind turbines into an upright circular cylinder. The open-source CFD platform OpenFOAM is employed to establish a numerical wave tank, and large eddy simulation (LES) models are used to conduct numerical simulations of its force-bearing process in wave fields. Through this approach, the hydrodynamic loads experienced by the single-cylinder structure in wave fields and the surrounding wave field data are obtained, with further investigation into its hydrodynamic characteristics under different wave environments. By analyzing the wave run-up distribution around cylinders of varying diameters and their effects on incident waves, a more suitable value range for traditional theories in engineering design applications is determined. Additionally, the variation laws of horizontal wave loads on single-cylinder structures under different parameter conditions (such as cylinder diameter, wave steepness, water depth, etc.) are thoroughly studied. Corresponding hydrodynamic load coefficients are derived, and appropriate wave force calculation methods are established to address the impact of value errors in hydrodynamic load coefficients within the transition range from large-diameter to small-diameter cylinders in traditional theories on wave force evaluation. This contributes to enhancing the accuracy and practicality of engineering designs. Full article

Background: Recess provides a valuable opportunity for physical activity for students at school. However, there is no clear evidence regarding the effects of running a mile daily on schoolchildren’s physical fitness. The objective of this study was to identify and evaluate the effects of running a mile daily during recess in a school setting over a 12-week period. Methods: The study included 68 students (39 boys and 29 girls) aged 13 to 16 years (14.45 ± 1.08) from secondary education (Spain). Participants were randomly assigned to one of three groups. Intervention Group 1 (IG1): one-mile run once per week (22 students). Intervention Group 2 (IG2): one-mile runs three times per week (21 students). Intervention Group 3 (IG3): one-mile runs five times per week (25 students). Physical fitness was assessed using the following tests: Broad jump (lower limb strength); Sit and Reach (lower limb flexibility); 4 × 10 m shuttle runs (speed, agility, and coordination); 10 × 5 m shuttle runs (displacement speed); 20 m shuttle run (Course Navette) (cardiorespiratory endurance). Results: Broad jump: No overall post-intervention differences were observed (p > 0.05), but there were pre-existing gender differences [boys outperform girls in IG2 and IG3 (p < 0.05)] that widened after the program, even appearing in IG1 (p = 0.031). Sit and Reach: No overall changes occurred (p > 0.05), but gender differences emerged in IG3 after the intervention [girls outperformed boys (p < 0.050)], and IG3 boys showed a decrease in flexibility after the program (p = 0.041). The 4 × 10 m shuttle runs: Initial differences between IG1 vs. IG3 disappeared after the intervention, with an overall increase in test time (p > 0.005). Pre-existing gender differences decreased, except in IG2 (boys remained faster; p < 0.001). The 10 × 5 m shuttle runs: Significant improvements were observed in all post-intervention groups (p = 0.003), with the greatest gains in IG3 boys (p < 0.001) and IG1 girls (p = 0.003). The 20 m shuttle run: Significant improvements occurred in IG1 and IG3 (p < 0.005), particularly in IG3 boys (p = 0.002) and IG1 girls (p = 0.019). Conclusions: Although effects varied by fitness component, intervention frequency, and gender, daily mile running was shown to be a viable strategy for improving aspects of fitness in adolescents, particularly endurance and speed, even at lower frequencies. Full article

Neuromuscular gait deficits in children with autism spectrum disorder (ASD) are often overlooked. High-intensity training protocols may improve running performance, but their efficacy in pediatric populations is underexplored. This study evaluates the impact of a high-intensity running protocol on locomotor performance in neurotypical and neurodivergent children (children with ASD). Spatiotemporal gait characteristics (speed, stride frequency, stride length, and duty factor), gait symmetry (symmetry ratio), and kinematics were assessed for ten neurodivergent children (10–15 years old) during a 15 m sprint. Locomotor costs (cost of locomotion, transport, and locomotion per stride) were analyzed in six neurodivergent participants (11–14 years old) via open-flow respirometry during treadmill running. Participants completed a 5–12 week, twice-weekly program; neurotypical participants served as a control group. Neurodivergent and neurotypical children exhibited baseline differences in spatiotemporal variables. Following training, neurodivergent participants demonstrated statistically significant improvements in spatiotemporal metrics and locomotor costs. Differences in symmetry between the two groups were not present pre- or post-program. These findings highlight the efficacy of high-intensity running programs in improving sensorimotor function and coordination in children with ASD. This program provides valuable insights into gross motor rehabilitation for neurodivergent children, supporting its potential as an effective intervention. Full article

This study aimed to examine whether managerial changes and their training methodology influence the physical attributes of soccer players and determine if these changes significantly impact the overall physical performance of the team. Twenty-seven male elite-level football players competing in the Eastern Mediterranean region (age: 28.12 ± 5.5 years, height: 179.3 ± 6.25 cm, body mass: 75.8 ± 6.6 kg) participated in this study. To analyze the impact of managerial changes on elite football players’ physical performance, this study evaluated and compared physical attributes during weekly microcycles and official games across three different coaching regimes over an entire season. Data were collected using a 10 Hz GPS tracking technology and included the following external load (EL) parameters: total distance, high metabolic load distance, high-speed running, sprint distance, accelerations, and decelerations. A one-way Analysis of Variance (ANOVA) was utilized to assess differences in physical performance across the three coaching methods. Significant differences were evident in high metabolic load distance during games [F(2,27) = 7.59, p < 0.05]. High-speed running distance also varied significantly across the three coaching regimes, both during training sessions [F(2,27) = 5.89, p < 0.05] and games [F(2,27) = 4.31, p < 0.05]. Furthermore, sprint distance showed significant differences during training [F(2,27) = 4.62, p < 0.05] and games [F(2,27) = 3.37, p < 0.05]. The findings of this study suggest that managerial changes can have a significant effect on the physical performance of soccer players. The results highlight the importance of aligning coaching strategies with physical conditioning techniques for optimizing performance. These findings provide a deeper understanding of the potential benefits and risks associated with managerial changes in professional soccer. Nevertheless, a limitation in this study is that all metrics of EL were interpreted as absolute values rather than relative-based threshold values, which may affect the interpretation of the players’ physical capacities. Full article

This study investigated the impact of varying the number of small goals on elite female soccer players’ decision-making, technical–tactical skills, running performance, and perceived exertion during game-based situations (GBSs). Sixteen national female players (aged 22.33 ± 2.89 years) participated in three conditions within an 8vs8 game without a goalkeeper (45 × 40 m), each featuring a different number of small goals (1.2 × 0.8 m): (i) 1 small goal (1G); (ii) 2 small goals (2G); and (iii) 3 small goals (3G). Sensors to track players’ positioning, perceived exertion, and notational analysis were used to evaluate player performance. The results indicated that players covered a greater distance at low intensity during the 2G condition compared to both 1G (p = 0.024) and 3G (p ≤ 0.05). Conversely, the 3G condition promoted a higher distance covered at high intensity compared to 2G (p ≤ 0.05). The 1G condition resulted in fewer accelerations (2G, p = 0.003; 3G, p < 0.001) and decelerations (2G, p = 0.012) compared to conditions with additional goals. However, there were no statistically significant effects on technical–tactical actions. Notably, a trend toward improved decision-making was observed in the 1G condition compared to 2G (ES = −0.64 [−1.39; 0.11]) and a longer ball possession duration compared to 3G (ES = −0.28 [−0.71; 0.16]). In conclusion, coaches working with elite female soccer players can strategically vary the number of goals to achieve specific physical aims (i.e., using 2G to emphasize acceleration and deceleration or 3G to promote high-intensity distance) with minimal effects on their perceived fatigue, technical–tactical variables, and decision-making. Full article

The aim of this study was to examine the influence of biological maturation on young football players adaptations and monitor and analyse variations in external (EL) and internal load (IL) during a running-based HIIT programme, according to the players’ maturity status. A total of 41 players (13.9 ± 0.7 years) participated, divided into an experimental group (EG) (n = 19) and a control group (CG) (n = 22). Acceleration (5 m and 30 m) and intermittent endurance (vIFT via the 30-15 IFT test) were assessed before and after eight weeks of intervention. EL and IL load variables and the rating of perceived exertion (RPE) were recorded. The results showed better initial performance in advanced maturity status players (post-PHV). Players from the EG had significant improvements in the 5 m and 30 m sprints and in the vIFT, whereas the CG only showed significant improvements in the 30 m sprint. Post-PHV players perceived less intensity (RPE) and thus, less IL than players with a delayed maturity status (pre-PHV). The pre-PHV group also exhibited significant improvements in the 30 m sprint and vIFT. However, no significant interaction effect (time × maturational group) was detected for any variable. These findings underscore the importance of considering maturity status in performance evaluation, training load prescription, and adaptations. Full article

Limited access to education in rural areas of Senegal is a structural barrier to human development and equal opportunities. The Bicycles for Education project, promoted by the Utopia Foundation—Bicycles Without Borders (BSF), aims to improve the educational participation of young people aged 12 to 21 by providing bicycles to facilitate their travel to school. In this study, the GRITS research group from the University of Barcelona externally evaluates the impact of the project on improving access to education, reducing gender inequalities, and the associated socioeconomic as well as community benefits. A qualitative approach based on individual interviews (n = 23), focus groups (n = 6) and group interviews (n = 8) was used, with a total of 80 participants, including students, families, teachers, project coordinators, and institutional managers. The analysis was carried out through thematic coding and content analysis, identifying four main axes: educational impact, gender equity, economic effects, and community transformation. The results show that the provision of bicycles throughout the school year led to increased school attendance and punctuality, improvements in academic performance, a reduction in social inequalities, gender inequalities in access to education, and a decrease in household costs associated with transport and food. In addition, there has been a cultural transformation in the perception of cycling as a viable means of mobility and a change in those communities where the project has been running for more than a decade. Full article

In recent years, the importance of developing the tourism sector and diversifying income sources has grown in the Gulf Cooperation Council (GCC) countries. This paper estimates the impact of tourism industry development on income equality in the GCC region from the first quarter of 2014 to the fourth quarter of 2023. Furthermore, this paper evaluates the existence of the Kuznets curve and its implications for income distribution. To achieve these objectives, this study employs panel cointegration tests and the cross-sectionally augmented autoregressive distributed lag (CS-ARDL) model. The dataset combines quarterly data from the World Bank and national statistical agencies, including indicators such as tourism revenue, international arrivals, government effectiveness, and education expenditure (used as a proxy for income equality). The results indicate that tourism revenue (TOU) has a significant and positive long-run effect on income equality (0.14%). In the short run, the squared term of tourism revenue (TOU2) becomes significant and positive (0.01%), but the findings do not support the Kuznets curve hypothesis. Furthermore, the number of international travelers (TRAV) has a negative and significant effect in the long run, while government effectiveness (GE) is negative and significant in both the long and short run. A key limitation of the study lies in the use of education expenditure as a proxy for income equality, due to the unavailability of consistent inequality metrics across the GCC countries. Full article

(1) Background: Dynamic knee valgus (DKV) is a common biomechanical risk factor for knee injuries, particularly in sports involving high-intensity movements, such as basketball. While neuromuscular control and structural alignment contribute to DKV, recent evidence indicates that lower limb muscle power (LLMP) and cardiorespiratory fitness (CRF) may significantly influence DKV. This study aims to examine the relationship among LLMP, CRF, and DKV in adolescent basketball athletes. (2) Methods: A total of 104 adolescent basketball athletes (63.5% boys), 12 to 17 years old (13.87 ± 1.46 years) participated in this study. Anthropometric and demographic characteristics such as sex, age, height, weight, and body mass index (BMI) were recorded. The Counter Movement Jump (CMJ) was used for the evaluation and prediction of the LLMP, the 20 m shuttle run test (20mSRT) was used for the evaluation and prediction of CRF, and the single-leg drop jump (SLDJ) was used for the evaluation of DKV via a two-dimensional (2D) kinematic analysis. Statistical analysis included Pearson and Spearman correlations, as well as multiple linear regression, to determine the relationship among LLMP, CRF, and DKV. (3) Results: A statistical analysis revealed strong correlations among LLMP, CRF, and DKV. Pearson’s correlation coefficients demonstrated significant associations between the VO₂max and frontal plane projection angle (FPPA) (r = 0.78, p < 0.001), as well as between LLMP and FPPA (r = 0.82, p < 0.001). Multiple linear regression analysis showed that VO₂max and LLMP together accounted for 85% of the variance in FPPA (R² = 0.85, p < 0.001). (4) Conclusions: The findings highlight that both aerobic capacity and lower limb muscle power significantly contribute to knee valgus control among adolescent basketball players. Implementing training programs focused on improving lower limb muscle power and cardiorespiratory fitness may enhance knee stability and reduce the risk of lower limb injuries. Given the strong predictive value of VO₂max and LLMP for knee control, targeted training programs focusing on neuromuscular conditioning and aerobic capacity may be effective for injury prevention. Full article

Arthrogenic muscle inhibition (AMI) is a neuromuscular impairment commonly observed following anterior cruciate ligament reconstruction (ACLR). This condition, characterized by persistent quadricep inhibition due to altered afferent feedback, significantly impacts neuromuscular recovery, delaying return to running and sport. Despite advancements in rehabilitation strategies, AMI may persist for months or even years after ACLR, leading to muscle strength asymmetries, altered biomechanics, and an increased risk of reinjury. The mechanisms underlying AMI involve both peripheral (joint effusion, mechanoreceptor dysfunction) and central (corticospinal inhibition, neuroplasticity alterations) components, which collectively hinder voluntary muscle activation and movement control. AMI alters gait mechanics, reduces knee stability, and promotes compensatory patterns that increase injury risk. Current return-to-sport protocols emphasize strength symmetry and functional performance but often neglect neuromuscular deficits. A comprehensive assessment integrating neuromuscular, biomechanical, and proprioceptive evaluations is needed at specific stages to optimize rehabilitation and minimize reinjury risk. Future research should explore targeted interventions such as neuromuscular stimulation, cognitive–motor training, and advanced gait analysis to mitigate AMI’s impact and facilitate a safer, more effective return to sport. Full article

Background: Running-related injuries are often associated with biomechanical inefficiencies, particularly in the sagittal and frontal planes. This study evaluates the effects of three interventions—reduced heel-to-toe drop (HTD) shoes, increased cadence, and inversion foot orthoses—on key kinematic parameters: ankle dorsiflexion, knee flexion, and hip adduction (measured at foot strike and at their respective peak joint angles during the stance phase). Methods: Nineteen recreational runners (ten males and nine females; mean ± SD: age 26.4 ± 4.3 years; height 174.2 ± 7.8 cm; weight 68.3 ± 9.6 kg; BMI 22.5 ± 2.1 kg/m²) participated in a 3D motion capture study under five experimental conditions: baseline (10 mm HTD, no cadence adjustment, no foot orthoses), full intervention (5 mm HTD, +10% cadence, orthoses), and three partial interventions: HTD combined with orthoses, HTD combined with increased cadence, and cadence increase alone. Kinematic changes were analyzed for statistical significance. Results: The full intervention significantly increased ankle dorsiflexion at foot strike (from 8.11° to 10.44°; p = 0.005) and reduced peak knee flexion (from 45.43° to 43.07°; p = 0.003). Cadence adjustments consistently produced improvements, while orthoses and HTD alone showed effects on ankle flexion only. Conclusions: Combining structural (HTD and orthoses) and dynamic (cadence) modifications optimizes running biomechanics, providing evidence-based strategies for injury prevention and performance enhancement. Full article

Running-induced fatigue affects several biomechanical parameters, and yet few studies are focused on the acceleration spikes’ asymmetries. This study aimed to evaluate the effects of a 30 min run on lower limbs spikes’ asymmetries. Eighteen recreational runners (35.6 ± 7.5 years; seven women) performed a treadmill running protocol at a moderate speed and acceleration spikes’ asymmetries and kinematic (temporal) parameters were measured via accelerometers—on the tibias and sacrum—and photogrammetry. Acceleration spikes’ parameters were continuously measured and averaged per minute to assess the relationship between fatigue and acceleration spike asymmetries via a linear regression model. Right tibial acceleration spikes increased over time (r = 0.9; p < 0.001) and left tibia spikes decreased (r = 0.78; p < 0.001), with a rise in tibial load asymmetry from 9% to 25% at the end (r = 0.98; p < 0.001). This study suggest that fatigue affects the acceleration spikes of the two legs differently, with increasingly greater acceleration spikes in the right (dominant) leg. These findings should be considered, as greater asymmetries are related to overuse injuries and lower efficiency. Also, in studies focusing on running mechanics with fatigue, it is recommended that researchers collect data from both limbs, and not only from the right (dominant) leg. Full article

Background/Objectives: The Rhenish German draught horse is an endangered German horse breed, originally used as working horse in agriculture. Therefore, the objective of this study was to evaluate the breed’s genetic diversity using pedigree and genomic data in order to analyze classical and ancestral pedigree-based inbreeding, runs of homozygosity, ROH islands, and consensus ROH. Methods: We studied the genome-wide genotype data of 675 Rhenish German draught horses and collated pedigree-based inbreeding coefficients for these horses. The final dataset contained 64,737 autosomal SNPs. Results: The average number of ROH per individual was 43.17 ± 9.459 with an average ROH length of 5.087 Mb ± 1.03 Mb. The average genomic inbreeding coefficient F_ROH was 0.099 ± 0.03, the pedigree-based classical inbreeding coefficient F_PED 0.016 ± 0.021, and ancestral inbreeding coefficients ranged from 0.03 (F_{a_Kal}) to 0.51 (Ahc). Most ROH (55.85%) were classified into the length category of 2–4 Mb, and the minority (0.43%) into the length category of >32 Mb. The effective population size (N_e) decreased in the last seven generations (~65 years) from 189.43 to 58.55. Consensus ROH shared by 45% of the horses were located on equine chromosomes 3 and 7, while ROH islands exceeding the 99th percentile threshold were identified on chromosomes 2, 3, 5, 7, 9, 10, and 11. These ROH islands contained genes associated with morphological development (HOXB cluster), fertility (AURKC, NLRP5, and DLX3), muscle growth, and skin physiology (ZNF gene cluster). Conclusions: This study highlights how important it is to monitor genetic diversity in endangered populations with genomic data. The results of this study will help to develop breeding strategies to ensure the conservation of the German Rhenish draught horse population and show whether favorable alleles from the overrepresented candidate genes within ROH were transmitted to the next generation. Full article

Background/Objectives: In recent years, molecular diagnosis has become increasingly critical in identifying human pathogens with unknown genes. Methods: An innovative approach, the fuzzy-based preference ranking organization method for enrichment evaluation (PROMETHEE) technique, one of the most effective multi-criteria decision-making (MCDM) methods, was used to evaluate criteria, including portability, generation type, max read/run, max output data/run, processing time/run, read length, accuracy, diagnostic sensitivity, test minimum loading volume, test cost/run, instrument cost, error rate, throughput capability, ability to sequence the large whole genome, small whole genome, and exome and large panel, mutation detection ability, whole-genome sequencing with single-stranded sequencing, and single-stranded sequencing accuracy, to determine the most suitable sequencing technology. Results: Based on the analysis, the Avidite Base Chemistry (ABC), Nanopore, and Illumina sequencing platforms sequentially emerged as the most favorable options based on their net flows of 0.0346, 0.0041, and 0.0003, respectively. Conclusions: Our findings provide important data to facilitate the selection of genome detection technologies. Through the use of innovative approaches, complex evaluations can be analyzed and the right choices can be made. Importantly, the technique has a degree of subjectivity, so varying conditions may lead to different findings. Full article