• Korean Journal of Applied Biomechanics
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• v.13 no.2
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• pp.175-183
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• 2003

The purpose of this study was to analyze the kinetic energy of putter head and ball movements during the process of impact. Highly skilled 5 golfers(less than 1 handicap) participated in this study and the target distance was 3 m. Movements of ball and putter head were recorded with 2 VHS video cameras(60 Hz, 1/500 s shutter speed). Small control object($18.5{\times}18.5{\times}78.5\;cm$) was used in this sdtuldy. Analyzing the process of impact, putter was digitized before 0.0835 s and after 0.0835 s of impact. Ball was digitized 0.1336 s after impact. The results showed that the maximum speed was appeared at Impact and prolonged for a while. Contact point of the club head was within 0.7 cm to the z axis. After contacting the club head, the ball was moved above the ground level(slide) and returned to the ground with sliding and rolling. After contacting the ground, the speed of ball was relied on the surface of the ground. During impact, 70% of kinetic energy of club head has been transferred to the ball.

• Physical Therapy Rehabilitation Science
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• v.12 no.2
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• pp.149-154
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• 2023

Objective: This study is designed to investigate the effect of ankle joint position on hip extensor muscle activity when bridging exercise in sagittal plane. Design: Cross-sectional study Methods: The subjects were recruited from 20 healthy adult men. The subjects performed three types of bridging exercises (normal bridging, ankle dorsiflexion bridging, ankle plantar flexion bridging) three times for five seconds with a rest of 15 seconds between measurements and two minutes of rest between each motion. The target muscles were the gluteus maximus, biceps femoris, soleus, and tibialis anterior. A surface electromyography was used to measure the muscle activity of these muscles. Results: The results show there was no statistically significant difference between the three types of exercise in the gluteus maximus muscle activity. However, the biceps femoris showed a significant difference between the three types of exercises (p<0.05). Conclusions: In conclusion, when the three different bridging exercises were performed by adding ankle motion to normal bridging exercise, there was a significant difference in the muscle activity of the gluteus maximus relative to the biceps femoris muscle activity in the order of the ankle dorsiflexion bridging, normal bridging, and ankle plantar flexion bridging exercise. Therefore, this could be an effective option for a bridging exercise if applied to patients with a weak gluteal muscle and shortening of the hamstring muscle in further studies.

• Physical Therapy Rehabilitation Science
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• v.13 no.2
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• pp.240-249
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• 2024

Objective: The objective of this study is to evaluate various research that have examined dynamic knee valgus and to pinpoint a straightforward, clinically practical 2D assessment method for dynamic knee valgus that is user-friendly. Design: A literature review Methods: This literature review was conducted in Pubmed, MEDLINE^® and Google Scholar with the following key words: Knee valgus angle, Knee valgus evaluation, Knee valgus assessment, Dynamic knee valgus. After removing duplicate studies, 53 articles were initially chosen using this method, with 17 studies ultimately meeting the selection criteria. Results: Based on the comprehensive review of various studies, the Single Leg Squat (SLS) was identified as the most popular test method, followed by the Single Leg Landing (SLL) as the next most common test method. The Frontal Plane Projection Angle (FPPA) method was the most representative method for measuring dynamic knee valgus (DKV) during these tests. SLS was found in a total of 10 studies, while SLL was found in 7 studies. Conclusions: The most commonly proposed test for assessing DKV is measuring the SLS using the FPPA method. However, when applied to individuals without knee pathology, the discriminative power of this method may be limited. This suggests the need for further research to explore alternative methods for assessing DKV in this population.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5148-5154
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• 2012

The purpose of this study was to analyze the kinematic characteristics of the thrower's center of mass (COM) and the shot that her performance hits record high for the 29th National Athletic Competition. Two S-VHS video cameras were used to visualize. The Direct Linear Transformation technique was employed to paint a clear picture in the three dimensional coordination. Kwon3D was used to analyze the data. The results showed that release velocity and height were 13.73 m/s and 198.6 cm(119% by height ratio), respectively, which is considered as peak performance comparing an extensive review of previous literature on the shot put. Release angle was $34^{\circ}$, which is lower than the previous studies. The path of thrower's center of mass is needed to travel in a release direction during the flight phase. The vertical movement of the thrower's center of mass during the driving should be controlled. At release, the perfact timing is required without vertical and horizontal movements of the thrower's center of mass.

• Korean Journal of Clinical Pharmacy
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• v.30 no.1
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• pp.11-18
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• 2020

Background: Nivolumab and pembrolizumab are antagonists of the programmed death-ligand 1 (PD-L1) receptor that function as immuno-oncological agents. This study aimed to evaluate the safety and efficacy of nivolumab and pembrolizumab in elderly patients in outpatient settings. Methods: The safety and efficacy of nivolumab and pembrolizumab were compared retrospectively among patients at the Veterans Health Service (VHS) Medical Center in Seoul, South Korea, from September 1, 2017 to August 25, 2018. Results: Eighty-seven patients were selected for the study. The median progression-free survival was 63 days for nivolumab (95% confidence interval (CI), [14 to 282]) vs. 243 days for pembrolizumab (95% CI, [22 to 348]) (p =0.04). The objective response rate (ORR) was 0% in the nivolumab group vs 5.6% in the pembrolizumab group (p =0.310). All the patients exhibited treatment-related adverse effects. More than 89% of the patients exhibited diseases of the gastrointestinal (GI) tract. Pneumonia, of grades three or higher, was the most common adverse effect, followed by weakness and anorexia. Conclusions: There was no statistically significant difference between the nivolumab group and the pembrolizumab group with respect to the ORR. The incidence and severity of the adverse effects in this study were higher than those of previous studies; however, these adverse effects are generally manageable in a real-world clinical setting. Further randomized controlled studies will be necessary to confirm these results in elderly patients.

• Korean Journal of Applied Biomechanics
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• v.18 no.1
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• pp.53-62
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• 2008

The purpose of this research was to analyze the kinematics of the 205B movement in platform diving. For the experiment, 2 athlete from the national diving team were chosen as the subject and two S -VHS video cameras were used. For this diving players preparing for the olympics participated. It was shown that the mean total took $1.112{\pm}0.12s$. In order to perform better, the divers time must be increased, at take off and rotation must be done high up and the horizontal distance must be shorted to main entrance of the water. To enter the water safely, the jump has to be high, the horizontal speed slow and the vertical speed as fast as possible. At E1 the lower limbs change in speed should decrease and after the rotation begins at E2. At take off, the jump is more important than the rotation for the performance of the dive. At take off, the trunk angular velocity was high, and this was needed to jump high for moment of inertia for rotation because for efficient jumping the upper body has to spread out and increase the height of the center of mass.

• Journal of the Korean Society of Physical Medicine
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• v.11 no.2
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• pp.17-24
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• 2016

PURPOSE: This study aimed to evaluate the effects of health-promoting behaviors on the subjective well-being of a physical therapist. METHODS: Survey data were collected from 247 physical therapists in Daejeon city. The baseline for health-promoting behaviors was determined using Health Promoting Lifestyle Profile (HPLP), subjective well-being was determined using Positive Affect and Negative Affect Schedule (PANAS), quality of life was measured using the SF-36 (Short-Form 36), and pain level was determined using the Quadruple Visual Analogue Scale (QVAS). Health-promoting behaviors and related factors were analyzed using an average comparative analysis (t-test), and the factors relevant to subjective well-being and health-promoting behaviors were evaluated using correlation analysis (Pearson's correlation coefficient). Factors affecting health-promoting behaviors were evaluated using stepwise multiple regression analysis (stepwise multiple regression). RESULTS: The mean score for health-promoting behavior was 3.73, with emotional support having the highest score (3.90) and regular meals having the lowest score (3.16 points; p<0.01). Health-promoting behavior was significantly correlated with positive emotions and negative emotions are subjective well-being, negative emotions and pain were noted (p<0.01). Health-promoting behaviors showed a significant correlation with quality of life (r=0.04), positive emotions (r=0.21; p<0.01), negative emotions (r=0.16; p<0.05), and pain level (r=0.016). The results of this study showed that health-promoting behaviors are significant predictors of subjective well-being in physical therapists (p<0.01). CONCLUSION: Physical therapists have to maintain their health by avoiding infections. Regular exercise is the most important factor among all health-promoting behaviors.

• Korean Journal of Applied Biomechanics
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• v.13 no.3
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• pp.47-65
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• 2003

The purpose of this study was to investigate the differences of the kinematical and the kinetical factors that calculated from preflight to postflight of salto forward straight 3/2 turn motion between skitters and less-skitters. four S-VHS video cameras operating at 60Hz were used to record the performances. five elite male gymnasts were participated in this study as subjects. three-dimensional coordinates of 20 body landmarks during each trial were collected using a Direct Linear Transformation method. The digitized body landmarks were smoothed using a Butterworth second order with low pass digital filter and a cutoff frequency of 10Hz. 1. A skitter, got a high score for performance, showed shorter time and faster horizontal velocity than a less-skitter at the board contact. also, a skitter extended quickly his knee and hip joint after contacting board for preflight phase. 2. A skitter revealed faster time and horizontal velocity the vault from taking off board than a less-skiller. A skitter took a long time and high distance to get the vertical peak compared with a less-skiller. 3. For the second phase, a skitter, who executes the most optimal motions among the subjects, displayed a long flight time, a high height, and a far flight distance as well as maintaining consistent horizontal speed even at the peak of post flight. On the other side, a less-scorer displayed a slow vertical velocity, distance and a short time at the point of take-off from vault as well as low height at the peak of post flight.

• Korean Journal of Applied Biomechanics
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• v.14 no.2
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• pp.85-103
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• 2004

This study was conducted to determine what effects would the midsole hardness of running shoes have on shoe flex angle and maximum propulsive force. Furthermore, the relationship between the shoes flex angle and maximum propulsive force was elucidated in order to provide basic data for developing running shoes to improve sports performances and prevent injuries. The subjects employed in the study were 10 college students majoring in physical education who did not have lower limbs injuries for the last one year and whose running pattern was rearfoot strike pattern of normal foot. The shoes used in this study had 3different hardness, shore A 40(soft), 50(medium) and 60(hard). The subjects were asked to run at a speed of $4{\pm}0.08m/sec$, and their movements were videotaped with 2 S-VHS video-cameras and measured with a force platform. And the following results were obtained after analyzing and comparing the variables. 1. Although the minimum angle of shoes flex angle was estimated to appear at SFA4, it appeared at SFA2 except in those shoes with the hardness of 40. 2. The minimum angle of shoes flex angle was $145.1^{\circ}$ with barefoot. Among the shoes with different hardness, it was the smallest when the hardness was 50 at $149.9^{\circ}$. The time to the minimum angle was 70.7% of the total ground contact time. 3. Maximum propulsive force according to midsole hardness was the largest when the hardness was 50 at $1913.9{\pm}184.3N$. There was a low correlation between maximum propulsive force and shoes flex angle.

• Journal of Broadcast Engineering
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• v.8 no.3
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• pp.306-316
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• 2003

When a cinema being composed of 24 frames/sec is converted to NTSC video or TV program, several fields we repeated to have 60 fields/sec, which is called the telecine or 3:2 pull-down. Hence, when encoding the telecine NTSC video into MPEG format, if we convert it into the original 24 frames/sec Progressive cinema, then we can save 20% of bits compared to the case of encoding all the 60 fields. In this Paper, we propose an algorithm for performing the inverse telecine by using the properties of the frames. Specifically, the algorithm exploits the fact that there Is much Inconsistency between the even and odd fields in the case of telecine frame, which results in high magnitude at the Nyquist frequency In the vertical direction. The experiment shows that the proposed algorithm performs very well regardless of the quality of video with a very few computations, whereas the conventional motion based method requires much computational complexity and its performance is degraded when the video is of low (eg. VHS) quality.