PURPOSE This study optimized stopword removal to enhance topic modeling performance. We propose an objective method combining normalized pointwise mutual information (NPMI) with median-based term frequency–inverse document frequency (TF–IDF) to automatically generate stopwords. METHODS Using text data from 443 research papers on “Taekwondo sparring,” we selected stopword candidates based on NPMI and identified 30 words with the lowest TF–IDF scores. We examined the impact of removing 1–30 stopwords on u_mass coherence scores. RESULTS The NPMI–TF–IDF method significantly improved coherence (R² = .456; p < .001). However, excessive removal led to diminishing returns, with the optimal coherence score (−11.442) achieved at 200 stopwords. In contrast, manually selected stopwords yielded a lower coherence score (−16.001). The findings indicate that integrating TF–IDF with NPMI effectively preserves meaningful words and outperforms PMI2 and PMI3 approaches. CONCLUSIONS Manual stopword selection can reduce reproducibility. Optimizing stopword removal based on domain-specific characteristics is essential. Future research should validate this method across diverse fields to establish a more generalizable standard.
PURPOSE This study examined levels of safety knowledge and practice among recreational sports participants, focusing particularly on impacts of gender, age, injury experience, and exercise-level profile. In sports environments, understanding these factors is essential for developing targeted strategies to promote safe behaviors. METHODS Survey data from 7725 participants engaged in regular recreational sports activities were analyzed. Latent Profile Analysis was employed to categorize participants based on their injury experience and exercise levels, resulting in two profiles: Group 1 (moderate or severe injury experience with intermediate exercise levels) and Group 2 (mild injury experience with beginner exercise levels). Three-way ANOVA was then used to evaluate relationships between these profiles and safety knowledge and practice levels. RESULTS Results revealed significant differences across sex, age, and profile groups. Compared with women, men demonstrated higher levels of safety knowledge and practice, which were likely influenced by greater exposure to high-intensity sports and risk-taking tendencies. Adolescents exhibited the highest levels of safety knowledge and practice linked to structured safety education, but these levels declined in early adulthood and then increased again in middle age due to growing health awareness and preventive motivations. Furthermore, participants in Group 1 consistently showed higher levels of safety knowledge and practice than those in Group 2, highlighting injury experience’s role in shaping safety behaviors. CONCLUSIONS These findings underscore the importance of developing gender-specific safety education programs, age-appropriate interventions, and training initiatives tailored to beginning participants. Future research should evaluate these strategies’ long-term impact on safety practices and injury prevention in diverse sports settings.
PURPOSE The purpose of this study was to investigate the association of physical activity level with insomnia severity (Normal, Subthreshold, Moderate and Severe) in adolescents and to use it as a basis for insomnia prevention. METHODS This study was conducted on a cohort of 50 adolescents under the age of 20 (19 males, 31 females) recruited from Hospital N in Incheon, Korea. Participants were categorized into groups according to the severity of insomnia in both males and females using the Korean version of the Insomnia Severity Index-Korean (ISI-K). The Korean version of the International Physical Activity Questionnaire was also used to calculate participants’ weekly moderate and vigorous physical activity. RESULTS The participants’ characteristics did not differ by insomnia severity in males, but there were significant differences in weight (p=.008), BMI (p=.019), SBP (p=.004), and DBP (p=.019) in females by insomnia severity. In male adolescents, there was no significant difference in the amount of physical activity by insomnia severity, but there was a trend toward decreased amount of physical activity with increasing severity. Among female adolescents, there were significant differences in the amount of physical activity by insomnia severity: moderate (p<.05), high (p<.05), and moderate-high (p<.05). In the unadjusted model, adolescents who did not meet the recommended amount of physical activity (150 minutes per week) were more likely to have insomnia (OR=4.67, 95% CI=1.34–16.24) than those who met the recommended amount of physical activity. The model after adjusting for covariates (gender and body mass index) also showed an association between the recommended amount of physical activity and insomnia (OR=3.94, 95% CI=1.17–13.28). Negatice correlations was found between insomnia index and moderate-to-vigorous physical activity (r=–.357, p=.013). CONCLUSIONS Adolescents are approximately 4.67 times more likely to suffer from insomnia if they do not meet physical activity recommendations, and there was a negative correlation between the insomnia index and moderate-to-vigorous physical activity, suggesting that physical activity should be increased to reduce the insomnia index.
PURPOSE This study aimed to investigate the effects of an 8-week unstable surface Pilates training on physical fitness, abdominal muscle thickness, lumbar isokinetic muscle function, and pain in women aged 30–40 who are living a sedentary lifestyle and experiencing nonspecific low back pain. METHODS The training group (TR, n = 15) performed Pilates using small apparatuses on an unstable surface for 50 min/session, three sessions per week for 8 weeks, whereas the control group (n = 13) maintained their usual living pattern during the same intervention period. RESULTS 1) The body weight, body mass index, percent body fat, and fat mass decreased significantly in the TR, 2) whereas the hand grip strength, trunk extension, sit-andreach, and modified Schober test scores improved significantly. 3) The thickness of the external oblique, internal oblique, and transversus abdominis increased significantly in the TR. 4) Lumbar isokinetic flexor strength per body weight increased significantly in the TR. The endurance and endurance per body weight of the lumbar isokinetic extensor and lumbar isokinetic flexor also significantly increased in the TR. 5) The Korean Oswestry disability index (KODI) and the visual analog scale (VAS) score decreased significantly in the TR. 6) Significant negative correlations were found between the change rates in the KODI and nondominant hand grip strength, external oblique thickness, transversus abdominis thickness, and lumbar isokinetic extensor endurance. A significant negative correlation was found between the change rates in the VAS score and external oblique thickness. CONCLUSIONS The results revealed that the 8-week unstable surface Pilates training was beneficial in improving physical fitness, abdominal muscle thickness, lumbar isokinetic muscle function, disabilityindex, and pain levels in women aged 30–40 years who were having a sedentary lifestyle and experiencing nonspecific low back pain.
PURPOSE This study reviews the operational status of the four courses that comprise the 'International Referee Development Program' in 2022 and 2023, analyzes participant satisfaction and feedback, and derives policy implications for the program’s future direction from the perspective of its operators. METHODS To achieve the study objectives, a literature review was conducted, survey items were developed, and expert meetings were held. RESULTS The four sub-courses within the 'International Referee Development Program' were analyzed by comparing modifications made between 2022 and 2023, evaluating satisfaction survey results, and identifying operational improvements. From the operators’ perspective, the study emphasized the urgency of conducting a comprehensive review of the scope of sports included in the referee development program, establishing clear evaluation criteria for selecting and monitoring focus areas, enforcing sanctions for dropouts under the current format and maximizing outcomes through long-term support. CONCLUSIONS It is expected that by establishing more macro-level and practical key performance indicators (KPIs) under the guidance of the Ministry of Culture, Sports, and Tourism and the Korea Sports Promotion Organization, the program’s continuity and direction will be maintained, even in the event of changes in responsible personnel.
PURPOSE This study examines changes in sport-team employees’ job satisfaction over their tenure and how these are moderated by their organizational identification and team identification, formed through their concurrent roles as fan and employee. METHODS A total of 292 sport-team employees participated in a survey, and their self-reported tenure length served as the time variable. This study estimated the nonlinear pattern of job satisfaction and tested the moderating effects of dual identification using generalized additive mixed models with random effects at the individual level. RESULTS Job satisfaction followed a honeymoon–hangover–rebound curve, rising during the first 0–29.4 months, declining between 29.4 and 76.8 months, and increasing again after 76.8 months. Higher levels of organizational and team identification positively moderated this pattern. CONCLUSIONS Applying a time-based job satisfaction model from organizational behavior to the sport management setting extends the model’s generalizability. This study empirically demonstrated that the fan–employee dual identification can significantly amplify or attenuate the job satisfaction pattern, highlighting the need for sport organizations to develop human resource strategies specific to one’s tenure phase.
PURPOSE Despite the public’s strong interest in sport, most clubs lack a stable revenue stream tied to their fanbase. Instead, much of their operating budget depends on parent companies and local governments, leaving many with accumulated deficits and capital impairments. This study develops a financial distress prediction model using sport clubs’ financial data and identifies the main determinants of capital impairment to propose improvement strategies. METHODS Financial data from clubs classified under the “Sport Club Operation” sector of the Korean Standard Industrial Classification were collected from 2011 to 2023. After preprocessing, a logistic regression–based prediction model was built and used to analyze factors influencing capital impairment. RESULTS Of the eight independent variables examined, the current asset ratio and working capital to total assets significantly affected capital impairment at the 5% level. CONCLUSIONS Stakeholders in professional sport clubs should focus on securing net working capital by reducing current liabilities rather than merely increasing current assets. To address deficits, clubs must strengthen their internal financial structure, while governments and institutions should provide effective policy support to ease chronic financial distress.
PURPOSE This study was conducted to investigate the effects of a 12-week walkingbased exercise program with square stepping exercise (SSE) on chronic pain and sleep in community-dwelling Korean older adults. METHODS A total of 42 older adults who had not participated in a registered exercise program in the past 3 months were included, among whom 20 participants in the exercise group engaged in a walking exercise program once a week for 60 min per session for 12 weeks. Repeated measures two-way analysis of variance was used to analyze pre- and postinterventions data on chronic pain and sleep. RESULTS The exercise group showed a significant improvement in the chronic pain score after the intervention (2.0 ± 1.4 vs 1.4 ± 0.8, p < .05). Similarly, there was a significant difference in the Korean version of the Pittsburgh Sleep Quality Index score in the exercise group after the intervention (6.1 ± 1.8 vs 4.9 ± 2.6, p < .05). CONCLUSIONS The walking-based exercise program with SSE is an effective intervention for alleviating chronic pain and simultaneously improving sleep quality in older adults. Our study suggests that a walking-based exercise program, which includes varied stepping patterns, could be a viable approach for addressing societal challenges, including the increasing healthcare expenses due to chronic pain or sleep disorders in a super-aging society.
PURPOSE Previous research has rarely examined foot segment motion and muscle activity simultaneously in relation to foot type. Therefore, this study aimed to investigate how foot type influences segmental foot kinematics and lower limb biomechanics during walking. METHODS Fifty-eight healthy adults were sorted into normal group (NG), pes planus group (PPG), or pes cavus group (PCG) using the Foot Posture Index, navicular drop, normalized navicular height, and normalized instep height. Furthermore, three-dimensional foot kinematics and lower limb muscle activity were recorded during 12-meter, self-paced walking using an optical motion capture system and surface electromyography. Kinematic analysis during the stance phase included measurement of joint angles and ranges of motion (ROM) for the following segments: foot relative to the shank, forefoot relative to the midfoot, lateral forefoot relative to the midfoot, medial forefoot relative to the midfoot, and hallux relative to the medial forefoot. Moreover, muscle activity analysis included the tibialis anterior, peroneus longus, and medial and lateral heads of the gastrocnemius. RESULTS Compared with the NG and PPG, the PCG exhibited greater ROMs in the frontal plane for the forefoot relative to the midfoot and medial forefoot relative to the midfoot. Additionally, the PPG exhibited a greater ROM in the frontal plane for the hallux relative to the medial forefoot compared with the NG. The intersegmental angles according to foot type demonstrated distinct kinematic differences between the PPG and NG in the transverse plane, specifically in the forefoot relative to the midfoot and medial forefoot relative to the midfoot relationships. However, no significant differences were observed in lower limb muscle activity during the stance phase. CONCLUSIONS This study provides insights into kinematic changes according to foot type during walking. Moreover, the findings of this study may deepen our understanding of the intrinsic risk factors for lower extremity injuries and tissue stress associated with variations in foot type.
PURPOSE This study compares the effects of video group and metaverse group counseling for student athletes to analyze differences in immersion, sychological skills learning effects, and each approach’s participation experiences. METHODS Twenty-four high school archery students were divided into three groups: a metaverse experimental, a video comparison, and a control group. For the experimental and comparative groups, 10 non-face-to-face psychological skills training sessions were conducted. With the control group, results were compared and analyzed by measuring psychological skills and social presence pre- and post-training. Additionally, analysis of the qualitative effects of psychological skills training was performed. RESULTS The psychological skill test’s quantitative analysis of the video comparison group showed a more significant effect in anxiety control factors than the metaverse experimental and the control groups. Moreover, in the social presence test, both the metaverse and the video groups showed significant differences in social presence and satisfaction; furthermore, Scheff post-verification results showed that the two environments’ satisfaction was significantly higher than that of the control group. Qualitative analysis confirmed that the metaverse and video groups experienced psychological, technical, and relational changes in common. CONCLUSIONS Although the metaverse group using avatars was likely to increase immersion, both the video and the metaverse groups were effective in psychological skills training, suggesting that the training effect may vary depending on the non- face-to-face environment’s stability and participation method. Future studies should examine effects of applying the metaverse platform to sports psychological skills training and various psychological support activities by solving the metaverse environment’s technical limitations.
