• 한국전문물리치료학회지
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• 제24권4호
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• pp.11-19
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• 2017

Background: Methods for exercising serratus anterior (SA) and upper trapezius (UT) muscles are important for the recovery of patients with various shoulder disorders, yet the efficacy of closed or open kinetic chain exercises have not yet been evaluated. Objects: The purpose of this study was to compare the activation of the SA and UT muscles during scapular protraction considering both closed and open kinetic chain exercises. Methods: Thirty subjects were randomly divided into experimental groups (closed kinetic chain exercise) and control groups (open kinetic chain exercise) in which scapular protraction was performed at $90^{\circ}$ or $125^{\circ}$ shoulder flexion. Electromyographic activity data were collected from the SA and UT muscles per position and exercise method. Results: Separate mixed 2-way analysis of variance showed significant differences in the activation of the SA (F1,28=6.447, p=.017) and the UT (F1,28=35.450, p=.001) muscles between the groups at $90^{\circ}$ and $125^{\circ}$ shoulder flexion. Also, the SA/UT ratio measures at $90^{\circ}$ and $125^{\circ}$ shoulder flexion significantly differed between the groups (F1,28=15.457, p=.001). That is, the closed chain exercise was more effective than open chain exercise for strengthening the SA muscle and controlling the UT muscle, $125^{\circ}$ of shoulder joint was more effective than $90^{\circ}$. Conclusion: The findings suggest that scapular protraction with shoulder $125^{\circ}$ flexion at the closed kinetic chain exercise may be more effective in increasing SA muscle activation and decreasing UT muscle activation as well as increasing the SA/UT ratio than open kinetic chain exercise.

• 한국소음진동공학회논문집
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• 제21권12호
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• pp.1152-1158
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• 2011

In this paper a configuration of the load evaluation device for the tilting actuator using hydraulic power is presented, which makes it possible to measure the force action on the tilting actuator. It is possible to measure only current using the conventional electro-mechanical actuator when the bogie is in the process of the tilting. This makes impossible to measure the force acting on the tilting actuator. In order to overcome this problem a kinetic mechanism test system using hydraulic cylinder is proposed. The system are consisted of hydraulic cylinder for the tilting actuation, control system to control hydraulic power, sensors to measure for force and displacement and monitoring system for the user interface.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권2호
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• pp.142-148
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• 2005

This paper proposes a cell age model for Penicillium chrysogenum fed-batch cultivation to supply a qualitative insight into morphology-associated dynamics. The average ages of the segregated cell populations, such as growing cells, non-growing cells and intact productive cells, were estimated by this model. A combined model was obtained by incorporating the aver-age ages of the cell sub-populations into a known but modified segregated kinetic model from literature. For simulations, no additional effort was needed for parameter identification since the cell age model has no internal parameters. Validation of the combined model was per-formed by 20 charges of industrial-scale penicillin cultivation. Meanwhile, only two charge-dependent parameters were required in the combined model among approximately 20 parameters in total. The model is thus easily transformed into an adaptive model for a further application in on-line state variables prediction and optimal scheduling.

• The Journal of Korean Physical Therapy
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• 제27권5호
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• pp.345-350
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• 2015

Purpose: This study was conducted to determine the effects of ankle joint position during closed kinetic chain (CKC) exercise on knee extensor strength and balance in patients with chronic stroke. Methods: Sixteen patients with chronic stroke participated in the study. Participants were randomly assigned to two groups: $15^{\circ}$ ankle joint plantar flexion group (n=8) and ankle joint neutral group (n=8) during CKC exercise. All participants underwent conventional physical therapy for 30 minutes. In addition, the experimental group ($15^{\circ}$ ankle joint plantar flexion group) and control group (ankle joint neutral group) participated in a 20-minute CKC exercise program. In both groups exercise was performed three times a week for four weeks. Outcomes including knee extensor strength and balance ability (Five times sit-to-stand test, Timed up and go test, and Balancia) were measured before and after exercise. Results: Significant differences in knee extensor strength and balance ability were observed between pre- and post-exercise in all groups (p<0.05). The improvement of knee extensor strength and dynamic balance was significantly higher in the experimental group than in the control group (p<0.05). Conclusion: These findings demonstrated that $15^{\circ}$ ankle joint plantar flexion during closed kinetic chain exercise is effective in improvement of knee extensor strength and dynamic balance in patients with chronic stroke.

• The Journal of Korean Physical Therapy
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• 제28권2호
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• pp.65-70
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• 2016

Purpose: The aim of this study was to determine the effects of electromyographic (EMG)-Biofeedback using closed kinetic chain exercise (EB-CKCE) on quadriceps angle (Q-angle) and quadriceps muscle activation and muscle activation ratio in subjects with patellofemoral pain syndrome and to provide fundamental information on rehabilitation exercise in patellofemoral pain syndrome. Methods: Thirty participants who met the criteria were included. The subjects were randomly divided into three groups: control group (Group I, n=10), semi-squat exercise group (Group II, n=10), and EMG-Biofeedback using closed kinetic chain exercise group (Group III, n=10). Intervention was provided to each group for eight weeks (three times per week; 30 minutes per day). Subjects were measured on Q-angle and quadriceps muscle activation. Results: Significant difference in Q-angle and quadriceps muscle activation was observed in groups II and III compared with control group I (p<0.01). Results of post-hoc analysis showed a significant difference in Q-angle and quadriceps muscle activation in on group III compared with groups I and II. Conclusion: Findings of this study suggest that closed kinetic chain exercise using EMG-Biofeedback that provides real-time biofeedback information on muscle contraction may have a beneficial effect on improvement of Q-angle and quadriceps muscle activation in patellofemoral pain syndrome.

• 전기학회논문지
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• 제63권5호
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• pp.597-607
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• 2014

This paper proposes active power control and frequency support control schemes of wind turbine generation system by using modified Maximum Power Point Tracking(MPPT) of Permanent Magnet Synchronous Generator(PMSG). Most wind turbine generation system is completely decoupled from the power system and power output control with pitch control. According to the frequency deviation, however, MPPT control can not contribute to the frequency change of the power system due to its active power output control. For solving this, the de-loaded(DL) control scheme is constructed for the frequency support control, which is based on applying the active power output control in the rotor speed control of PMSG. The rotor speed by used in the proposed DL control scheme is increased more than the optimal rotor speed of MPPT, and then this speed improvement increases the saved kinetic energy(KE). In order to show the effectiveness of the proposed control scheme, the case studies have been performed using the PSCAD/EMTDC. The results show that the proposed active power output control scheme(DL control and KE discharge control) works properly and the frequency response ability of the power system can be also improved with the frequency support of wind farm.

• Journal of Microbiology and Biotechnology
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• 제13권3호
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• pp.332-337
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• 2003

Enzyme kinetics data play a vital role in the design of reactors and control of processes. In the present study, kinetic studies on pectinases were carried out. Partially purified polymethylgalacturonase (PMG) and polygalacturonase (PG) were the two pectinases studied. The plot of initial rate vs. initial substrate concentration did not follow the conventional Michaelis-Menten kinetics, but substrate inhibition was observed. For PMG, maximum rate was attained at an initial pectin concentration of 3 g/l, whereas maximum rate was attained when the initial substrate concentration of 2.5 g/l of polygalacturonic acid for PG I and PG II. The kinetic data were fitted to five different kinetic models to explain the substrate inhibition effect. Among the five models tested, the combined mechanism of protective diffusion limitation of both high and inhibitory substrate concentrations (semi-empirical model) explained the inhibition data with 96-99% confidence interval.

• 대한물리의학회지
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• 제9권2호
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• pp.223-231
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• 2014

PURPOSE: The aim of this study was to investigate the effect of closed and open kinetic exercises on knee extensor strength and balance in patients with early stroke. METHODS: Thirty patients with early stroke participated in the study. Participants were randomly assigned to three groups: an open kinetic chain (OKC) exercise group (n=10), a closed kinetic chain (CKC) exercise group (n=10), and a control group (n=10). All participants received conventional physical therapy for 30 minutes. In addition, the two experimental groups (OKC and CKC) participated in a 30-minute knee strengthening training program. Training for the experimental groups was carried out three times a week for four weeks. Outcomes such as knee extensor strength and balance ability (Tetrax, Functional Reaching Test, Timed Up and Go Test) were measured before and after training. RESULTS: There were significant differences in knee extensor strength and balance ability between the pre- and post-treatment of all groups (p<.05). The improvement of knee extensor strength was significantly higher in the OKC group than in the other groups (p<.05), and the improvement of dynamic balance was significantly higher in the CKC group than in the other groups (p<.05). CONCLUSION: These results showed that both open and closed kinetic chain exercises are effective in the improvement of knee extensor strength and balance ability. This study suggests that open and closed kinetic exercise training is an effective training for strength and balance in patients with early stroke.

• 한국전문물리치료학회지
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• 제31권1호
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• pp.40-47
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• 2024

Background: Single-leg squat (SLS)s are commonly used as assessment tool and closed kinetic exercises are useful for assessing performance of the lower extremities. Pronated feet are associated with foot pressure distribution (FPD) during daily activities. Objects: To compare the FPD during SLSs between groups with pronated and normal feet. Methods: This cross-sectional study included 30 participants (15 each in the pronated foot and control groups) are recruited in this study. The foot posture index was used to distinguish between the pronated foot and control groups. The Zebris FDM (Zebris Medical GmbH) stance analysis system was used to measure the FPD on the dominant side during a SLS, which was divided into three phases. A two-way mixed-model ANOVA was used to identify significant differences in FPD between and within the two groups. Results: In the hallux, the results of the two-way mixed-model ANOVAs revealed a significant difference between the group and across different phases (p < 0.05). The hallux, and central forefoot were significantly different between the group (p < 0.05). Moreover, significant differences across different phases were observed in the hallux, medial forefoot, central forefoot, lateral forefoot, and rearfoot (p < 0.05). The post hoc t-tests were conducted for the hallux and forefoot central regions. In participants with pronated foot, the mean pressure was significantly greater in hallux and significantly lower, in the central forefoot during the descent and holding phases. Conclusion: SLSs are widely used as screening tests and exercises. These findings suggest that individuals with pronated feet should be cautious to avoid excessive pressure on the hallux during the descent-to-hold phase of a SLS.

• 대한의용생체공학회:의공학회지
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• 제28권6호
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• pp.744-749
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• 2007

Kinematic and kinetic analysis has been performed for Soft Golf swings utilizing realistic three dimensional computer simulations based on three dimensional motion tracking data. Soft Golf is a newly developed recreational sport in South Korea aimed to become a safe and easy-to-learn sport for all ages. The advantage of Soft Golf stems from lighter weight of the club and much larger area of the sweet spot. This paper tries to look into kinematic and kinetic aspects of soft golf swings compared to regular golf swing and find the advantages of lighter Soft Golf clubs. For this purpose, swing motions of older aged participants were captured and kinematic analysis was performed for various kinematic parameters such as club head velocity, joint angular velocity, and joint range of motions as a pilot study. Kinetic analysis was performed by applying kinematic data to computer simulation models constructed from anthropometric database and the measurements from the participants. The simulations were solved using multi-body dynamics solver. Firstly, the kinematic parameters such as joint angles were obtained by solving inverse dynamics problem based on motion tracking data. Secondly, the kinetic parameters such as joint torques were obtained by solving control dynamics problem of making joint torque to follow pre-defined joint angle data. The results showed that mechanical loadings to major joints were reduced with lighter Soft Golf club.