Search Results (17)

The exponential growth of machine learning (ML) applications in smart grid (SG) research over the past decade has generated a vast and fragmented body of literature that lacks systematic synthesis. This study addresses that gap by presenting a comprehensive bibliometric and science mapping analysis of the ML–smart grid (MLSG) research landscape to date, drawing on 4156 peer-reviewed publications indexed in the Elsevier Scopus database from 2009 to 2025. The principal contributions of this study are fourfold. First, it provides a rigorous quantitative mapping of MLSG publication growth from one document in 2009 to 1163 publications in 2025, representing a growth rate of 116,200%, thereby establishing a definitive baseline for tracking future scholarly development in the field. Second, it identifies the key actors driving MLSG research, including the most prolific authors (Nadeem Javaid, Alsabaan M.), leading institutions (King Saud University, Tennessee Technological University), and dominant nations (India, China, United States), which offers researchers and funding bodies actionable intelligence on collaboration opportunities and research leadership. Third, through keyword co-occurrence and cluster analysis, the study maps the three dominant thematic hotspots structuring current MLSG research—Smart Grid Security, Power Load Forecasting, and Advanced Energy Management—providing a structured intellectual framework that can guide future research prioritization. Fourth, the study delivers a critical thematic literature review of these three hotspots, synthesizing the most impactful ML methodologies and applications reported across 4156 publications, including deep learning-based intrusion detection, ensemble forecasting models, and reinforcement learning-driven energy management. Collectively, these contributions offer a robust evidence base for researchers, policymakers, and industry practitioners seeking to navigate, benchmark, and advance the field of ML-enabled smart grid systems. Full article

Background: Isokinetic strength of the knee joint represents a significant determinant of athletic performance and injury prevention; however, its relationship with explosive performance in young female athletes remains insufficiently explored. The aim of the study was to analyze the relationships between isokinetic strength of the knee joint at different angular velocities and explosive jumping performance in young female athletes. Methods: The research sample consisted of 13 young female athletes enrolled in sport-oriented educational programs specializing in athletics. Explosive lower-limb power was assessed using performance tests for countermovement jump (CMJ), countermovement jump free arms (CMJ FAs) and squat jump (SJ) administered with the Chronojump system. Isokinetic strength of the knee flexors and extensors was assessed using the Humac Norm dynamometer in the concentric mode at angular velocities of 60°/s, 180°/s, and 300°/s. Peak torque, the ipsilateral H:Q ratio, and bilateral asymmetries were evaluated. Pearson’s correlation coefficient was used to analyze the relationships between the investigated parameters. Results: The strongest relationships with explosive performance were observed for hamstring strength at an angular velocity of 180°/s, where significant high correlations were identified with performance in the CMJ (r = 0.693), CMJ FA (r = 0.754), and SJ (r = 0.713). In contrast, quadriceps strength demonstrated predominantly low to moderate associations with jumping performance, while no significant correlations were confirmed at an angular velocity of 300°/s. Bilateral asymmetries of the knee extensors and flexors were generally low, ranging approximately between 7 and 10%, whereas the values of the ipsilateral H:Q ratio were within the physiological range of approximately 50–55%. Conclusions: The results suggest that the ability to generate force at higher contraction velocities, particularly in the hamstrings, is significantly associated with explosive performance in young female athletes. At the same time, isokinetic strength assessment appears to be an appropriate tool for evaluating muscular strength, muscle balance, and potential asymmetries in youth sports. However, explosive performance cannot be explained solely by the level of maximal muscular strength, but rather by a complex interaction of neuromuscular and biomechanical factors. Full article

Afforestation of post-agricultural land is one of the most important challenges of modern forestry, posed by economic demand and climate protection. Unfortunately, stands introduced on such degraded soils are not sustainable and their productive value is limited. The present study tested the effects of two substances—Humac and Alginite—on the community structure of mesostigmatid mites colonizing plots overgrown by Platanus × acerifolia (Aiton) Willd, also comparing them with the mite communities of arable field and 64-year-old stands of Pinus sylvestris L. and Quercus robur L. growing on post-agricultural land. A total of 306 mite individuals were recorded, belonging to 45 taxa and 14 families. The results indicate a moderately positive effect of Humac fertilization on the mite communities studied. A similar impact has not been demonstrated for Alginite. In contrast, all parameters studied (density, species richness and diversity of mite communities) reached the highest values in the P. sylvestris stand. Humac application harmonizes Mesostigmata mite community structures between young and older stands and may be considered a beneficial practice for the afforestation of former agricultural land. Full article

Non-Native Tree Species (NNTs) play crucial roles in global and European forests. However, in the Czech Republic, NNTs represent a tiny fraction of the forested areas due to limited research on their potential use. The country is actively afforesting abandoned agricultural lands; NNTs which are already tested and certified could enhance the country’s forestry system. This study aimed to evaluate the initial growth of Castanea sativa, Platanus acerifolia, and Corylus colurna under three soil treatments on abandoned agricultural soil, evaluate the survival and mortality of the tree species, and further compare the soil dynamics among the three ecosystems to describe the initial state and short-term changes in the soil environment. The research plot was set in the Doubek area, 20 km East of Prague. Moreover, soil-improving materials, Humac (1.0 t·ha⁻¹) and Alginite (1.5 t·ha⁻¹), were established on the side of the control plot at the afforested part. The heights of plantations of tree species were measured from 2020 to 2024. Furthermore, 47 soil samples were collected at varying depths from three ecosystems (afforested soil, arable land, and old forest) in 2022. A single-factor ANOVA was run, followed by a post hoc test. The result shows that the Control-C plot (Castanea Sativa + Platanus acerifolia + Corylus colurna + agricultural soil without amendment) had the highest total growth (mean annual increment in the year 2024) for Castanea sativa (KS = 40.90 ± a21.61) and Corylus colurna (LS = 55.62 ± 59.68); Alginite-A (Castanea Sativa + Platanus acerifolia + Corylus colurna + Alginite) did best for Platanus acerifolia (PT = 39.85 ± 31.52); and Humac-B (Castanea Sativa + Platanus acerifolia + Corylus colurna + Humac) had the lowest growth. Soil dynamics among the three ecosystems showed that the old forest (plot two) significantly differs from arable soil (plot one), Humac and Platanus on afforested land (plot three), Platanus and Alginite on afforested land (plot four), and Platanus without amendment (plot five) in horizon three (the subsoil or horizon B) and in horizon four (the parent material horizon or horizon C). Results document the minor response of plantations to soil-improving matters at relatively rich sites, good growth of plantations, and initial changes in the soil characteristics in the control C plot. We recommend both sparing old forests and the afforestation of abandoned agricultural soils using a control treatment for improved tree growth and sustained soil quality. Further studies on the species’ invasiveness are needed to understand them better. Full article

Spring wheat was grown on a loess-derived Luvisol under the conditions of two farming systems (conventional and organic) and five forecrops (sugar beet, spring barley, red clover, winter wheat, and oat) over the period 2021–2023. In the conventional system, mineral NPK fertilization and pesticides (herbicides, fungicide, insecticide, and retardant) were applied at the recommended rates for wheat. Mechanical weed control was also used (double harrowing). In the organic system, the organic fertilizer Humac Agro was applied and the fields under the wheat were harrowed twice. No plant protection products were used under organic farming conditions. The organic system was proven to have an effect on reducing spring wheat yield, on average by 23%, compared to the conventional system (the grain yield was, respectively, 4.59 t ha⁻¹ compared to 5.96 t ha⁻¹). In spite of the lower yield potential, the organic cultivation of spring wheat significantly improved the quality and health-promoting parameters of this cereal grain. Except for the total nitrogen and potassium content, the organic system contributed to a significant increase in the grain content of total dietary fiber (by 0.89 p.p.), o-dihydroxyphenols (by about 19%), and polyphenols (by about 12%), and increased the content of the following elements: Se, Mg, Ca, Cu, Mn, Fe, and Zn. Among the forecrops, red clover and sugar beet had the most beneficial effect on grain quality (including the amino acid composition and EAAI index), followed by oat (especially under organic farming conditions). The other wheat forecrops (spring barley and winter wheat) clearly deteriorated the yield and quality of spring wheat grain. To sum up the obtained research results, appropriate management of organic spring wheat cultivation (forecrop sugar beet or red clover, Humac Agro fertilizer) contributes to high grain nutritional quality relative to the conventional system and also reduces the yield gap relative to conventional farming. Full article

Background/Aims: Asymmetry of the internal (IR) and external (ER) shoulder rotators can increase the risk of injuries in judokas. Discrete analyses are usually performed in time series data, but they can have biases by removing trends, so other approaches have been proposed to avoid these biases such as statistical parametric mapping (SPM) and principal component analysis (PCA). This study analyzed the asymmetry in the shoulder rotators in female judokas, comparing dominant (D) vs. non-dominant (ND) upper limbs. Methods: For this, 11 elite athletes (age: 20.1 ± 2.9 yrs.; experience: 4.0 ± 0.5 yrs.; body mass: 66.0 ± 14.6 kg; height: 1.6 ± 0.1 m; BMI: 24.8 ± 4.3 kg/m²), were evaluated in an isokinetic dynamometer (Cybex^® Humac/Norm Dynamometer CSMI, 502140, Stoughton, MA, USA). All participants performed the concentric (CON/CON) isokinetic evaluations of internal and external rotation of the shoulder in 60°/s and 180°/s angular velocities. Results: There was no significative asymmetry between IR vs. ER at 60°/s; similar results were observed at 180°/s when analyzed by PCA or SPM methods (p > 0.05 for all comparison). There was no difference between peak torque at 60°/s or 180°/s (p > 0.05 for all comparison). Conclusions: no asymmetry was observed in IR and ER in elite female athletes, regardless of the analysis method. Full article

Background: Headache is one of the leading causes of disability in the world. Neck proprioception, pain, and postural control are interconnected in both healthy individuals and those with chronic neck pain. This study examines the effects of proprioceptive training using a gaze direction recognition task on postural stability and pain in cervicogenic headache patients. Methods: Patients with cervicogenic headache (n = 34, age: 35–49 y) were randomized into a control group (CON), receiving only selected physical therapy rehabilitation or to an experimental group (EXP), performing proprioceptive training using a gaze direction recognition task plus selected physical therapy rehabilitation. Both programs consisted of 24, 60 min long sessions over 8 weeks. Postural stability was assessed by the modified clinical test of sensory integration of balance (mCTSIB) and a center of pressure test (COP) using the HUMAC balance system. Neck pain was assessed by a visual analog scale. Results: In all six tests, there was a time main effect (p < 0.001). In three of the six tests, there were group by time interactions so that EXP vs. CON improved more in postural stability measured while standing on foam with eyes closed normalized to population norms, COP velocity, and headache (all p ≤ 0.006). There was an association between the percent changes in standing on foam with eyes closed normalized to population norms and percent changes in COP velocity (r = 0.48, p = 0.004, n = 34) and between percent changes in COP velocity and percent changes in headache (r = 0.44, p = 0.008, n = 34). Conclusions: While we did not examine the underlying mechanisms, proprioceptive training in the form of a gaze direction recognition task can improve selected measures of postural stability, standing balance, and pain in cervicogenic headache patients. Full article

Continuous monitoring of lower extremity muscles is necessary, as the muscles support many human daily activities, such as maintaining balance, standing, walking, running, and jumping. However, conventional electromyography and physiological cross-sectional area methods inherently encounter obstacles when acquiring precise and real-time data pertaining to human bodies, with a notable lack of consideration for user comfort. Benefitting from the fast development of various fabric-based sensors, this paper addresses these current issues by designing an integrated smart compression stocking system, which includes compression garments, fabric-embedded capacitive pressure sensors, an edge control unit, a user mobile application, and cloud backend. The pipeline architecture design and component selection are discussed in detail to illustrate a comprehensive user-centered STIMES design. Twelve healthy young individuals were recruited for clinical experiments to perform maximum voluntary isometric ankle plantarflexion contractions. All data were simultaneously collected through the integrated smart compression stocking system and a muscle force measurement system (Humac NORM, software version HUMAC2015). The obtained correlation coefficients above 0.92 indicated high linear relationships between the muscle torque and the proposed system readout. Two-way ANOVA analysis further stressed that different ankle angles (p = 0.055) had more important effects on the results than different subjects (p = 0.290). Hence, the integrated smart compression stocking system can be used to monitor the muscle force of the lower extremities in isometric mode. Full article

In recent years, products containing humic acids have been increasingly used in agriculture to improve soil parameters. Quantifying their impact on soil quality is, therefore, of key importance. This study seeks to evaluate the impact of the commercial humic acid product (HA) on the hydrophysical parameters of sandy and clayey soils sampled from different sites in Slovakia. Specifically, the study hypothesizes that humic amendment will enhance particle density (ρ_s), dry bulk density (ρ_d), porosity (Φ), saturated hydraulic conductivity (K_s), soil water repellency (SWR), and water retention capacity in sandy and clayey soils. The results of the laboratory measurements were analyzed using NCSS statistical software at a statistical significance of p < 0.05. In sandy soil, there was a statistically significant decrease in ρ_d and K_s and an increase in Φ and a contact angle (CA) after the application of 1 g/100 cm³ HA. At a dose of 6 g/100 cm³ HA, the values of ρ_s, ρ_d, and K_s decreased, and the Φ and CA values increased. In clayey soil, the K_s value significantly decreased by −35.5% only after the application of 6 g/100 cm³ HA. The addition of HA increased the full water capacity (FWC) and available water capacity (AWC) of clayey and sandy soils. The positive influence of HA on the studied soil parameters was experimentally confirmed, which can be beneficial, especially for their use in agricultural production. Full article

This study assessed the between-session reliability of the FysioMeter H-station when measuring isometric quadriceps and hamstrings strength and H/Q (hamstring/quadriceps) ratio, and the concurrent validity when compared to an isokinetic dynamometer (ID). Sixteen young males and three females (25.6 ± 1.7 years old) performed maximum quadriceps and hamstring contractions using the H-station and the Humac NORM ID over two sessions. Between-session reliability was evaluated by comparing scores from the first and the second session. Concurrent validity was assessed by comparing scores from the H-station with the Humac NORM ID. The H-station showed excellent relative reliability for the quadriceps, hamstring, and the H/Q ratio with ICC2.1 ranging from 0.89 to 0.91. The relative reliability of the Humac NORM was good to moderate for the quadriceps, hamstring, and the H/Q ratio with ICC2.1 ranging from 0.89 to 0.91. Acceptable absolute reliability of the H-station was found across quadriceps, hamstring, and H/Q measures (coefficient of variance (CV) = 7.2 to 9.3%, limit of agreement (LOA) = 20.0 to 24.3%). The validity of the H-station was large for hamstring strength (r = 0.79) and moderate for quadriceps strength (r = 0.69) and H/Q ratio (r = 0.39) compared to the Humac NORM ID. Bland–Altman plots showed LOAs ranging from 37.9 to 59.5%. The results indicate that the H-station can be used to make reliable assessments of relative changes in maximum isometric quadriceps and hamstring strength. Full article

The yield potential of switchgrass was verified by testing seven cultivars in a small-scale experiment carried out from 2018 to 2022 on Gleyic Fluvisol under Central European conditions. The treatments are as follows: pre-sowing (i/HA) soil humic preparation Humac AGRO (based on leonardite) with an ameliorative dose of 1000.0 kg ha⁻¹ or (ii/NPK) basic nutrition with a dose of 220.0 kg ha⁻¹ NPK; an annual dose of 70 kg ha⁻¹ N was applied to both treatments (HA, NPK) and compared to (iii/UC) untreated control. A dry matter (DM) yield of 9.02 t ha⁻¹ was achieved in the total average, which varied from 0.05 t ha⁻¹ to 60.64 t ha⁻¹. The yield was affected mainly by years (F-ratio 106.64), then by nutrition (F-ratio 79.03), followed by cultivars (F-ratio 56.87), and finally by replications (F-ratio 0.00). Switchgrass productivity increased according to the utility year; however, the driest year (2020—388 mm, 2021—372 mm, and 2022—288 mm) changed the order of the three full utility years (12.44, 19.13, and 7.73 t ha⁻¹ DM, respectively). HA gives the highest DM yield of 13.69 t ha⁻¹ on average with values of 9.19 and 4.19 for NPK and UC, respectively. The cultivars order was EG 1101 ˃ BO Master ˃ EG 1102 ˃ Kanlow ˃ Alamo ˃ Carthage ˃ NJ Ecotype (21.15, 12.48, 8.14, 7.70, 6.34, 4.47, and 2.89 t ha⁻¹ DM when ranking average yield or 60.64, 45.20, 29.92, 29.15, 17.87, 9.86, and 5.93 t ha⁻¹ DM when ranking maximal yields). Full article

Background and Objectives: The purpose of this study was twofold: (1) to examine strength asymmetries in elite athletes of different sports and (2) to examine the magnitude of asymmetries between elite and u18 athletes. Materials and Methods: A total of 254 athletes participated in this study. For the first purpose of the study, the group consisted of adult professional male basketball players (n = 30), elite male (n = 30) and female soccer players (n = 20), male futsal players (n = 30), elite male goalkeepers (n = 22), and professional female volleyball players (n = 20). For the second purpose, male youth goalkeepers (n = 22), youth female (n = 20) and male soccer players (n = 30), and youth male basketball players (n = 30) were compared to the adult athletes of the same sport. Asymmetries were measured utilizing a Humac Norm and Rehabilitation device. Testing included three maximal concentric flexion and extension repetitions at an angular speed of 60°/s. The differences in asymmetries were assessed using ANOVA followed by an LS means post-hoc analysis. An independent samples t-test was used to identify the differences between adult and youth players. Results: It was indicated that none of the groups demonstrated asymmetries greater than 10%, other than the elite female soccer players and female volleyball players. Significant differences were demonstrated between youth and adult soccer players (males and females), with the adult groups demonstrating increased asymmetries. Conclusions: Special consideration should be given to female soccer players and volleyball players, as soccer and volleyball practice and competition at the professional level may induce greater lower -limb asymmetries. The isokinetic parameters can be useful for planning strength and conditioning interventions in order to reduce or prevent those imbalances. Additional unilateral and bilateral jumping testing is encouraged for the verification of imbalances. Full article

The effective use of digestate as exogenous organic matter to enhance soil carbon sequestration depends on the balance between labile and recalcitrant organic carbon, which is influenced by the type of feedstock, the fermentation process, and the fraction (liquid, solid) of the fermented product used. In this work, in order to change the ratio of labile to stable carbon in the resulting fertiliser, the digestate was mixed with organic carbon-rich supplements: biochar and Humac (a humic acid-rich substance). The pot experiment was carried out under controlled conditions with maize (Zea mays L.) in soil amended with the digestate (D), which was incubated with Humac (H), biochar (B), or a combination of both (D + B + H) before the application. Digestate enriched with Humac showed improved short-term nutrient (carbon, phosphorus, nitrogen) transformation, as indicated by soil enzyme activity and the highest maize biomass production of. Total carbon content, C:N ratio, short-term respiration activity, and nitrification were most enhanced by digestate enriched with either biochar or combined biochar + Humac). Long-term nitrogen mineralization was mostly enhanced by digestate + Humac, as indicated by amino-acid-induced respiration and urease activity. Short-term positive effects of digestate + biochar (eventually + Humac) on catabolism were proven, whereas their long-term effects on nutrient mineralization were negative (i.e., biochar-mediated immobilization, sequestration), which should be the focus of further research in future. Full article

Co-composting of raw manure with other organic sources has recently gained the attention of the scientific community. In the present study, raw manure and manures enriched with humic substances (Humac) or biochar were co-composted to improve their physico-chemical properties. We conducted an experiment including variants consisting of soil amended with manure (M), manure + Humac (M + H), manure + biochar (M + B), and unamended (control). Soil physico-chemical, biological, and plant properties were assessed altogether. All matured manures differed from each other physico-chemically (nutrient content) and in microbial composition, and hence their effects on the observed parameters. Compared to control, the soil respiration and enzyme activities related to N and P mineralization were enhanced due to the amendment of either manure or enriched manures. The M + H treatment resulted in higher pH of the manures as compared to other treatments, whereas the M + B and M treatments revealed the highest C_org contents of the final product, which was negatively correlated with HA:FA. In the same manner, M + H and M + B were the most prominent treatments, causing higher variations in basal soil respiration. The same treatments resulted in the highest percent increase values of soil enzymes related to C, N, and P, which further show the potential of manure modification as a viable option to boost soil fertility and health. Full article

Background: The HUMAC Balance System (HBS) offers valid measurement of balance, and the arm crank exercise test (ACE) is a valid measure of physiological capacity. Neither have been used to evaluate associations between balance and physiological capacity in lower-limb amputees. Methods: Thirty-five participants with lower-limb amputations were recruited. Standing balance (center of pressure) was evaluated during eyes opened (EO) and eyes closed (EC) conditions using the HBS. Participants performed ACE graded exercise testing (GXT) to evaluate aerobic capacity. Spearman’s rho was used to identify relationships between variables. Cut-points for three groups were generated for time on ACE. Mann–Whitney U tests were used to explore significant differences in variables of balance and ACE between low and high performers. Results: Relationships between variables of eyes open displacement (EOD), eyes open velocity (EOV), eyes closed displacement (ECD), and eyes closed velocity (ECV) were significant (p < 0.05), and high performers with EO also performed best with EC. Longer exercise times were significantly associated with increased HR_peak, VO_2peak, VE_peak, and RER_peak (p < 0.05). HR_peak (143.0 ± 30.6 b/min), VO_2peak (22.7 ± 7.9 and 10.6 ± 4.7 mL/kg/min), VE_peak (80.2 ± 22.2 and 33.2 ± 12.7 L/min), and RER_peak (1.26 ± 0.08 and 1.13 ± 0.11) were significantly greater in high performers than low performers, respectively (p < 0.05). There was no significant association among VO_2peak and any balance task variables; however, there were significant associations between some balance and physiological variables. Conclusions: Findings differentiated high and low performers; however, participants were still well below able-bodied norms of physical capacity. Training to mitigate deconditioning is suggested. Full article