• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.30 no.2
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• pp.13-26
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• 2024

Background: The most common form of injury in soccer is a hamstring strain. Eccentric bias exercises are crucial for reducing injury risk and improving sprinting performance. The purpose of this study was to compare a 4-week hip-dominant hamstring strengthening exercise program (HDE) with a knee-dominant hamstring strengthening exercise program (KDE) in youth soccer players. Method: The sample (n=31) was randomly divided into two groups: HDE (n=17) and KDE (n=14), with soccer players in HDE performing hip joint-dominant hamstring strengthening exercises and those in KDE performing knee joint-dominant hamstring strengthening exercises. Each intervention was conducted three times per week for four weeks. The outcome measures included the hamstring strength test (isometric strength test, eccentric strength test), knee joint range of motion (90/90 active knee extension; AKE) test, lower limb function test Y-balance test and Agility T-test. Results: Following the intervention, both groups showed significant improvement in isometric and eccentric hamstring strength on both dominant and non-dominant sides (p<.05). The AKE test showed significant improvement in the dominant leg (p<.05) and non-dominant leg only in KDE. The agility test significantly improved in HDE (p<.05). There was a slight improvement in the Y-balance test score; however, the difference was not statistically significant. There were no differences between the two groups in the values before, and after the intervention for all items. Conclusion: The hip-dominant and knee-dominant hamstring strengthening exercise should be coordinated and used based on the environment during hamstring injury prevention training.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.208-209
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• 2016

This study explores how bargaining power and partnership effect on the SCM main results namely flexibility, agility, and control of uncertainty. To test the suggested model, this study used a data set generated from online and offline survey. The 140 sets of data collected, which companies use SCM, were tested against the model using SPSS 23 and smartPLS 3.2.3. The results of this study are as follows. First, Bargaining power had an effect on partnership. Second, partnership had an effect on the SCM agility, flexibility, control of uncertainty.

• Journal of Auto-vehicle Safety Association
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• v.13 no.1
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• pp.6-13
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• 2021

This paper presents yaw moment control for modification of steering characteristic in rear-driven vehicle with front in-wheel motors (IWMs). The proposed control algorithm is designed to modify yaw rate response of the test vehicle. General approach for modification of steering characteristic is to define the desired yaw rate and track the yaw rate. This yaw rate tracking method can cause the chattering problem because of the IWM actuator response. Large overshoot and settling time in IWM torque response can amplify the oscillation in control input and yaw rate. To resolve these problems, open-loop IWM controller for cornering agility was designed to modify the understeer gradient of the vehicle. The proposed algorithm has been investigated via the computer simulations and the vehicle tests. The performance evaluation has been conducted on dry asphalt using E-segment test vehicle. The performance of the proposed algorithm has been compared to general yaw rate tracking algorithm in the vehicle tests. It has been shown that the proposed control law improved the cornering agility without chattering problem.

• Journal of Aerospace System Engineering
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• v.12 no.3
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• pp.86-96
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• 2018

The High Agility and Remote Control Camera System Can-Satellite ($HA+RC^2S$ CanSat) proposed in this study is a satellite designed by the authors of this work and submitted as an entry in the 2017 CanSat competition in Goheung gun, Jeonnam, Korea. The primary mission of this work is to develop a high agility camera system (HACS) that can obtain high quality images in the air. This objective is achieved by using a tuned mass damper (TMD) to attenuate the residual vibration that occurs immediately after rotating the camera. The secondary objective is to obtain a self-image of CanSat in the air using a remote control self-camera system (RCSS) that is wirelessly controlled using a joystick from a ground station. This paper describes the development process of the $HA+RC^2S$ CanSat, including mission definition, system design, manufacturing, function and performance tests carried out on the ground, and final launch test.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.11 no.3
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• pp.233-242
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• 2016

Startup must be agile and be able to handle extreme changes, survive unpredicted threats, and capitalize on emerging business opportunities. Agile teams continually sense changes for competitive action and marshal the necessary knowledge. While team members share their knowledge, there must be emerging various type of conflicts in teams. This study examines the relationship among the conflict, knowledge sharing and agility in startup context. At the same time, we tested the roles of shard vision both moderating variable between conflict and knowledge sharing, and antecedent for knowledge sharing. Different two types of conflict, task conflict and relationship conflict, knowledge sharing, agility, and different impact of shared vision are identified from literatures and tested. 182 data points were collected from under 5-year old startup's representatives to test these hypotheses. PLS data analysis indicated that the task conflict and shard vision positively effect on knowledge sharing, and then knowledge sharing has statistically significant effect on agility. And the impact of conlict has been weakened by shared vision's moderating effect. Based on the results, we proposed practically several team management skills for startup managers, leaders and stakeholder, and explained theoretical contributions.

• Journal of Korean Academy of Nursing
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• v.26 no.4
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• pp.833-852
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• 1996

Regular long term dance movement could be one of ways to induce improvement of psychophysiological variables, resulting in improvement of quality of life. However, there have been few studies to evaluate the effect of dance movement training on both physiological and psychological variables in the elderly. This study was focused to determine the effect of Korean traditional dance movement training on psychophysiological variables-body weight, body fat, lean body mass, muscle strength, muscle endurance, flexibility, agility, resting heart rate and blood pressure, depression and life satisfaction-in Korean elderly women. Thirty four subjects, aged between 65 and 75years who have normal cognition, sensory function, cerebellum function, cardiovascular function, participated in this study. Seventeen experimental group subjects were selected from E-elderly university in Kyung Gi province, and Seventeen control group subjects were selected from N-welfare facility in Seoul City. Seventeen experimental group subjects participated for 12weeks dance movement program. Korean traditional dance movement program was developed on the basis of Korean traditional dance and music by the author. The program consisted of approximately 50minutes of dance, 3times a week for 12weeks. During 50minutes workout, there were 15minutes of warm-up dancing, 25minutes of conditioning dance and 10minutes of cool-down dancing. The intensity for the conditioning phase was at between 60% and 65% of age-adjusted maximum heart rates. The body weight, body fat, lean body mass, muscle strength(grip strength, leg strength), muscle endurance, flexibility, agility, resting heart rate and blood pressure, depression and life satis-faction were measured prior to and following the experimental treatment. The participants in dance movement were interviewed focusing on subjective feeling following 12 week's regular dance movement. Data were analyzed with mean, standard deviation, percentage of change, X²-test, t-test, and ANCOVA test using SPSS PC/sup +/ program. Subjective feeling was categorized into cognitopsy-chological and physiological responses. Results were obtained as follows : 1) The body weight (F=15.52, p=.000), body fat (F=18.33, p=.000) and lean body mass (F=7.28, p=.011) of the experimental group were significantly lower than those of the control group following the dance movement training. 2) The leg strength (F=30.96, p=.000), muscle endurance (F=9.06, p=.005), agility(F=44.92, 000), flexibility(F=6.84, p=.014) of the experimental group were significantly higher than those of the control group following the dance movement training. There was no significant difference of grip strength(F=.43, p=.515) between experimental and control groups. 3) The heart rate(F=26.96, p=.000), systolic (F=10.40, p=.000) and diastolic(F=3.99, p=.005) blood pressure at rest of the experimental group were significantly lower than those of the control group following the dance movement training. 4) No significant difference of score of depression (F=3.49, p=.071) was observed between experimental and control groups. 5) Score of life satisfaction of experimental group was remarkably higher than that of control group following 12weeks of dance movement training (p<0.05). 6) Thematic responses about the dance movement following the training were positive. "I feel good" was the most frequent among cognitopsychological responses and "I feel lightness of body" was the most frequent among physiological responses. The results suggest that Korean traditional dance movement training can improve psychophysiological variables of Korean elderly.

• Journal of the Ergonomics Society of Korea
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• v.24 no.4
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• pp.15-21
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• 2005

Use of a glove made of materials with a low elasticity decreases the performance of the hand such as agility, dexterity, range of motion, and grip strength. The present study examined if the adverse effects of a low-elastic glove can be reduced by a design which accommodates the changes of hand surface lengths by hand motion. Two glove designs which provide patches of elastic cloth and pleats at the finger joints and knuckle were developed by considering the hand surface length changes, and then compared with two conditions(bare hand and conventional glove design that does not consider the dynamic characteristics of the hand dimensions) in terms of completion time in peg board insertion task, maximum grip strength, discomfort in hand motion, discomfort in force exertion, and overall discomfort by 24 right-handed participants. The test results confirmed that wearing of a glove significantly reduced the agility and grip strength capability of the hand and indicated that the novel designs were effective to lessen the performance decreases compared to the conventional design. Also, of the glove designs, the pleat glove design was found most preferred for both better hand performance and less subjective discomfort.

• Journal of muscle and joint health
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• v.16 no.1
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• pp.26-35
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• 2009

Purpose: The purpose of this study was to investigate the effects of Tai Chi exercise program on physical fitness, pain, and self-efficacy in patients with osteoarthritis. Method: A preexperimental research design was applied to 22 subjects who dwelled at a welfare institution in C-city and agreed to participate in this study. The Tai Chi exercise was conducted with a duration of 60 minutes per session twice a week for 9 weeks. Outcome measures were physical fitness($VO_{2}max$, strength, flexibility, foot power, agility, balance), pain, and self-efficacy. Data were analyzed by descriptive statistics and paired t-test. Result: After participating in the Tai Chi exercise program, the subjects showed significant improvements in strength, agility, balance, pain and self-efficacy. But there were no significant differences in $VO_{2}max$, flexibility and foot power. Conclusion: The results showed that Tai Chi exercise would partially improve physical fitness and be effective for pain reduction and self efficacy as well. Further studies are needed to confirm the effects of Tai Chi exercise on physical fitness.

• Journal of the Korean Applied Science and Technology
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• v.36 no.2
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• pp.541-550
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• 2019

This study is aimed to find out the effect of PAPS-D on physical fitness of developmental disabled students who participated of Inline skate program. The subject of this study was 10 middle and high school students diagnosed as developmental disability. The subject attended a total of 32 classes twice a week for 16 weeks and the class was 1 hour each time. Improvement of physical fitness was assessed based on PAPS-D program developed by the Department of Education science in 2016 except for obesity measurement; cardio pulmonary function (walking in 6 minutes), flexibility (seated forward bend, clasped hand behind the back), muscle function (sit-up) and agility (standing long jump). To find out the interaction between control group and experimental group, two-way repeated measure ANOVA was used. As a result, there was a statistically significant relation in cardio pulmonary function and agility but not in flexibility and muscle function. 3 variables (cardio pulmonary function, flexibility and muscle function) among 4 variables showed positive effect of Inline skate program on physical fitness while one variable which was agility showed decreased result in post-test. Based on the results of three variables that were found to have improved in the pre post-examination, the result of this study indicates positive effect of Inline skating program on physical fitness of developmentally disabled students.

• Journal of muscle and joint health
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• v.19 no.2
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• pp.210-222
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• 2012

Purpose: This study examined the effects of taekwondo exercise program on the physical function, fitness and quality of life in women with osteoarthritis. Methods: With nonequivalent control group quasi-experimental design, 17 outpatients with osteoarthritis were recruited from June to August, 2010. The subjects were divided into 14 in experimental group and 13 in control group. The taekwondo exercise program was consisted of public taekwondo gymnastics with stretching movement and carried out every 60 minutes, 2 times a week for 12 weeks. Physical fitness of sit up, sit and reach, and agility, KWOMAC, and quality of life were measured. Data were analyzed by t-test and Mann-Whitney test using SPSS program. Results: After the intervention, the physical fitness for muscle endurance (Z=-4.40, p<.001), flexibility (Z=-2.75, p=.006), and agility (Z=-1.95, p=.050) were significantly improved in the experimental group. The mean scores of KWOMAC in the experimental group were significantly decreased (Z=-2.94, p=.003) and the mean difference of quality of life in the experimental group was also significantly increased than that of the control group (Z=-3.50, p<.001). Conclusion: The taekwondo exercise program may have affirmative effects on physical fitness, physical function, and quality of life in women with osteoarthritis.