• Proceedings of the KIEE Conference
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• summer
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• pp.485-487
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• 2004

High-voltage gas-insulated circuit-breaker must interrupt short-circuit current successfully when breakdown occurs in electric power system. Among many test-duties, Basic Terminal fault T100a(BTF T100a) is the one of the severest duties because of its high DC component of short-circuit current. In this paper, we developed 245kV 50kA gas circuit breaker using control circuits to reduce DC component while interrupting short-circuit current, then got good performance through high-power tests in Korea Electrotechnology Research Institute(KERI) and KEMA

• Proceedings of the KIEE Conference
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• 2006.11a
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• pp.335-336
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• 2006

초고압 지중송진선로에 적용되는 가교절연케이블은 전기적 특성의 우수성과 유지보수의 용이성 때문에 확대적용되고 있다. 345kV급 지중송전선로는 장거리 계통에 적용이 되고 있으며, 이에 따라 접속재 부분의 개발이 중요하게 되었다. 현재 154kV용 PMJ는 자체 개발되어 실계통에 설치 운용되고 있다. 345kV급 PMJ개발에 앞서 220kV급 가교절연 송전선로용 PMJ를 자체 설계 및 제조하여 세계적인 인증기간인 KEMA에서 제품의 신뢰성 인증을 받았다.

• Proceedings of the KIEE Conference
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• 2006.11a
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• pp.337-338
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• 2006

초고압 지중송전선로에 적용되는 가교절연 케이블은 전기적 측성의 우수성과 유지보수의 용이성 때문에 확대적용되고 있다. 345kV급 지중송전선로는 장거리 계통에 적용이 되고 있으며, 이에 따라 접속재부분의 개발도 중요하게 되었다. 배전선로에 사용되던 Plug-in 종단접속재를 송전용 가스중종단접속재(EBG)에 적용함으로써 선로 결합 시에 사용되는 부품의 수를 줄이고, 작업공정의 단순화를 이룰 수 있었다. 아직 국내제품으로는 초고압 Plug-in 종단접속재가 실계통에 적용된 경우는 없으나 이번 220kV용 Plug-in 종단접속재를 개발함으로서 당사의 기술력 확보를 이룰 수 있었으며, PMJ와 마찬가지로 세계적인 인증기간인 네덜란드 KEMA에서 제품에 대한 신뢰성 인증을 받았다.

• The Journal of Korean Physical Therapy
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• v.31 no.3
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• pp.147-150
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• 2019

Purpose: The purpose of this study was to compare the reliability of unilateral hip abductor strength assessment in side-lying with break and make test in subjects with pelvic drop. Hip abduction muscles are very important in the hip joint structures. Therefore, it is essential to evaluate their strength in a reliable way. Methods: Twenty-five subjects participated in this study. Unilateral isometric hip abductor muscle strength was measured in side-lying, with use of a specialized tensiometer using smart KEMA system for make test, of a hand held dynamometer for break test. Coefficients of variation, and intra class correlation coefficients were calculated to determine test-retest reliability of hip abductor strength. Results: In make test, maximal hip abductor strength in the side-lying position was significantly higher compared with break test (p<0.05). Additionally, Test-retest reliability of hip abductor strength measurements in terms of coefficients of variation (3.7% for make test, 16.1% for break test) was better in the side-lying position with make test. All intraclass correlation coefficients with break test were lower than make test (0.90 for make test, 0.73 for break test). Conclusion: The side-lying body position with make test offers more reliable assessment of unilateral hip abductor strength than the same position with break test. Make test in side-lying can be recommended for reliable measurement of hip abductor strength in subjects with pelvic drop.

• The Journal of Korean Physical Therapy
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• v.31 no.4
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• pp.222-227
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• 2019

Purpose: This study examined the influence of longitudinal arch on the strength and muscle activity of the abductor hallucis in the standing position in subjects with and without navicular drop signs. Methods: A sample of 34 subjects with and without navicular drop signs between 22 and 28 years of age were enrolled in this study. The strength and muscle activity of the abductor hallucis was measured using a tensiometer. The Smart KEMA System and electromyography device was used on the subjects with and without navicular drop signs. Two groups were classified using the navicular drop test to identify the longitudinal arch of the foot. The strength of the abductor hallucis was evaluated in standing, both with and without an external arch support condition. The two-way mixed ANOVA was used. The level of statistical significance was set to ${\alpha}=0.05$. Results: The strength and muscle activity of the abductor hallucis in standing was significantly higher with external arch support than that without the external arch support in the group with navicular drop signs. There was no significant difference in the abductor hallucis strength and muscle activity with and without external arch support in the subjects without navicular drop signs. Conclusions: The strength and muscle activity of the abductor hallucis in standing can be influenced by the external arch support in the group with navicular drop signs. The strength measurement of the abductor hallucis in standing should be separately performed in conditions with and without longitudinal arch of foot.

• Journal of International Academy of Physical Therapy Research
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• v.11 no.4
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• pp.2178-2183
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• 2020

Background: Trunk flexor-extensor muscles' co-activation and upright posture are important for spinal stability. Abdominal bracing and maximal expiration are being used as exercises to excel torso co-contraction. However, no study has on comparison of the effect of this exercise on multifidus in the upright sitting posture. Objectives: This study aims to verify the effectiveness of abdominal bracing and expiration maneuvers in lumbo-pelvic upright sitting. Design: Cross-sectional study. Methods: Eighteen healthy women were recruited for this study. The multifidus muscle thickness of all subjects was measured in three sitting conditions (lumbo-pelvic upright sitting, lumbo-pelvic upright sitting with abdominal bracing, and lumbo-pelvic upright sitting with maximum expiration) using ultrasound. One-way repeated measure analysis of variance was used for the evaluation. Results: Compared to lumbo-pelvic upright sitting, lumbo-pelvic upright sitting with abdominal bracing and lumbo-pelvic upright sitting with maximum expiration were associated with significantly increment of muscle thickness. There was no significant difference in muscle thickness between lumbo-pelvic upright sitting with abdominal bracing and lumbo-pelvic upright sitting with maximum expiration. Conclusion: Abdominal bracing and maximum expiration could be beneficial to increasing lumbar multifidus thickness in lumbo-pelvic upright sitting.

• Journal of International Academy of Physical Therapy Research
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• v.11 no.4
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• pp.2173-2177
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• 2020

Background: Shoulder horizontal abduction in the prone position (SHAP) has been reported as an effective exercise to strengthen the lower trapezius. However, the effects of pre-emptive scapular posterior tilt on scapular muscle activity and scapulohumeral movements during SHAP have not been examined. Objectives: To examine the effect of the addition of scapular posterior tilt on muscle activity of the trapezius and posterior deltoid, and scapular posterior tilt and shoulder horizontal abduction, during SHAP. Design: Cross-sectional study. Methods: Fifteen healthy male subjects performed two types of SHAP: general and modified SHAP (SHAP combined with pre-emptive scapular posterior tilt). To perform modified SHAP, pre-emptive scapular posterior tilt training was performed prior to the modified SHAP. Muscle activity of the middle and lower trapezius and posterior deltoid, and the amount of scapular posterior tilt and shoulder horizontal abduction, were measured during two types of SHAP. Results: Muscle activity of the lower trapezius and scapular posterior tilt was significantly increased during the modified SHAP, while muscle activity of the posterior deltoid and the amount of shoulder horizontal abduction were significantly decreased. However, the middle trapezius muscle activity did not change during the modified SHAP. Conclusion: The SHAP with pre-emptive scapular posterior tilt can be useful to strengthen the lower trapezius.

• Journal of the Korean Society of Physical Medicine
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• v.12 no.1
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• pp.75-81
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• 2017

PURPOSE: The purpose of this study was to compare the activity of the abductor hallucis (AbdH) muscle during short foot exercise (SFE) using foot orthosis (SFE-FO) and the windlass effect (SFO-WE) while sitting and in a one-leg standing position. METHODS: We recruited fourteen subjects with normal feet for this study. Surface electromyography (EMG) was used to measure the muscle activity of the AbdH muscle during SFE, SFE-FO, and SFE-WE while sitting and in a one-leg standing position. Three trials consisting of a 5 s hold for each of the three exercises were performed to measure the EMG activity of the AbdH muscle. Exercise type and position were randomly assigned. Two-way repeated-measures ANOVA was used to analyze the effects of exercise type (SFE vs. SFE-FO vs. SFE-WE) and position (sitting vs. one-leg standing position) on AbdH muscle activity. A statistical significance was set at ${\alpha}=.05$. RESULTS: The EMG activity of AbdH muscle in the SFE-WE exercise was significantly greater than that during SFE and SFE-FO in both exercise positions (p<.001). In addition, the EMG activity of the AbdH muscle in the one-leg standing position was significantly higher than that while sitting (p<.001) during all three exercises. CONCLUSION: These results suggest that SFE-WE is a more effective strengthening exercise than SFE or SFE-FO for activating the AbdH muscle.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.6
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• pp.169-176
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• 2010

Substation Automation System is basically operating throughout communicative services among IEC 61850 based devices. So, minimum requirement in order to install the system in the substation is to verify server and client conformance of IEDs and HMIs according to the IEC 61850 standard. Even though UCA IUG issued IEC 61850 conformance test procedures for both the server and the client, Much of the test is limited to IEDs as server and there is no client-only testing tool except KEMA server test tool sets. this study aims to develop IEC 61850 client testing system for verifying the full communication conformance of the substation automation system and this paper describes the design and implementation of the testing system.

• Physical Therapy Korea
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• v.27 no.4
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• pp.272-277
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• 2020

Background: Forward head posture (FHP) is common postural malalignment. FHP is described relatively extension to upper cervical and lower cervical is relatively flexion. Although several researchers mentioned the lower cervical flexion posture in FHP, most of the studies related to FHP is focused on the deep cervical flexor function. Objects: The purposes of present study is to compare the cervical strength (upper cervical extension [UCE], lower cervical extension [LCE], upper cervical flexion [UCF], lower cervical flexion [LCF]) between individuals with and without FHP. Methods: Fifty-one participants are recruited. Participants who have the craniovertebral angle (CVA) less than 48 degree were classified to the FHP group (n = 24) and the others were included in without FHP group (n = 27). The cervical strength (UCE, LCE, UCF, LCF) were measured using Smart KEMA strength sensor and the strength data was normalized by body weight. All strength measurement conducted at head and neck neutral position in sitting. Independent t-test was used to compare the cervical strength between individuals with and without FHP. Results: The mean value of CVA was greater in without FHP group than with FHP group (p < 0.000). The strength value of UCF (p < 0.002) and LCE (p < 0.001) was significant less in FHP group than without FHP group. But no significant differences were seen in the LCF and UCE strength between two groups. Conclusion: UCF and LCE weakness in FHP group should be considered to evaluate and manage the individuals with FHP.