전류연속 모드로 동작하는 탭인덕터 부스트 컨버터의 설계

강정일(Jeong-il Kang),한상규(Sang-Kyoo Han),한종희(Jonghee Han) 전력전자학회 2013 전력전자학술대회 논문집 Vol.2013 No.11

컴퓨터 타이핑 작업 시 목과 어깨의 멀리건테이핑 적용효과 분석

강정일(Jeong-Il Kang),박준수(Jun-Soo Park) 한국엔터테인먼트산업학회 2016 한국엔터테인먼트산업학회논문지 Vol.10 No.1

본 연구는 VDT 증후군에 대한 테이핑의 예방효과를 검증하고 일상생활의 작업능률을 향상시킬 수 있는 방안을 제시하고자, 성인 남성 30명을 대상으로 실험군 15명, 대조군 15명으로 무작위 표본 추출하여, 실험군은 어깨관절 정렬을 위해 비탄력 테이프를 적용하고, 대조군은 테이핑을 적용하지 않은 상태에서 각각 근전도를 이용하여 목근육(목빗근)과 어깨 주위 근육(위등세모근, 앞어깨세모근, 중간어깨세 모근)들을 측정하여, 30분 간 타이핑 작업을 시행한 후 비교 분석하였다. 그 결과 그룹 내 근활성도 변화는 실험군은 위등세모근을 제외한 나머지 근육들에서 유의한 차이가 나타나 근활성도가 증가하였고(p<.001)(p<.01), 대조군은 모든 근육들에서 유의한 차이가 나타나 근활성도가 증가하였으며(p<.001), 그룹 간 변화는 위등세모근에서 유의한 차이가 있었다(p<.001). 그룹 내 중앙주파수 변화는 실험군은 위등세모근을 제외한 나머지 근육들에서 유의한 차이가 나타나 중앙주파수가 감소하였고(p<.01)(p<.001), 대조군은 모든 근육들에서 유의한 차이가 나타나 중앙주파수가 감소하였으며(p<.05)(p<.001), 그룹 간 변화는 위등세모근에서 통계학적으로 유의한 차이가 있었다(p<.05). 따라서 타이핑 작업 시 어깨관절의 테이핑 적용이 어깨뼈의 안정성을 증진시키고 그 결과 어깨뼈의 안정성에 기여하는 위등세모근의 근활성도와 근피로도가 유지되는 효과가 있음을 알 수 있었으며, 향후 연구에서는 테이핑 적용방법에 따른 효과를 좀 더 객관적으로 검증하는 연구가 더 필요하다고 사료된다. This study aims to verify the preventive effects of taping for VDT syndrome and present methods to improve work efficiency in everyday lives. To achieve this purpose, 30 male adults were randomly sampled and assigned into experiment group of 15 individuals and control group of 15 individuals. The experiment group were provided c-tape for shoulder joint alignment and the control group were not provided the tape, and neck muscle (sternocleidomastoid muscle) and shoulder muscle (upper trapezius, frontal deltoid muscle, and intermediate deltoid muscle) were measured by using electromyogram after typing on the computer for 30 minutes. As a result, in terms of changes in muscle activity within groups, experiment group showed a significant difference in muscles other than upper trapezius, which led to increase in muscle activity (p<.001)(p<.01), and control group showed a significant difference in all muscles, which led to increase in muscle activity (p<.001), and in terms of changes between both groups, there was a significant difference in upper trapezius(p<.001). In terms of changes in median frequency within groups, experiment group showed a significant difference in muscles other than upper trapezius, which led to reduction in median frequency (p<.01)(p<.001), and control group showed a significant difference in all muscles, which led to reduction in median frequency (p<.05)(p<.001), and changes between groups showed a statistically significant difference in upper trapezius (p<.05). Therefore, it was found that application of taping onto shoulder joint while typing on the computer improved stability in shoulder bone. This suggests that such an application has effects to maintain muscle activity and muscle fatigue of upper trapezius that contributes to stability in shoulder bone. Future studies need to verify the effects of taping more objectively.

새로운 위상전이 병렬입력/직렬출력 모듈화를 적용한 듀얼 컨버터

강정일(Jeong-il Kang),노정욱(Chung-wook Roh),한상규(Sang-Kyoo Han),윤명중(Myung-Joong Youn) 전력전자학회 2000 전력전자학술대회 논문집 Vol.2000 No.11

A new phase shift PWM parallel-input/series-output modularized dual converter is proposed in this paper, This converter is operated with a fixed duty ratio and its output voltage is regulated by phase shift between each module, Since the operating duty ratio of each module is fixed, it is sufficient to implement a simple open loop drive circuitry for each module and the cost of total system can be much reduced, The operation of the converter is analyzed in this paper and verified by computer simulation

자가 신장운동이 전방머리자세를 동반한 만성 목통증 환자의 자세개선에 미치는 영향

강정일 ( Jeong-il Kang ),정대근 ( Dae-keun Jeong ),박승규 ( Seung-kyu Park ),양대중 ( Dae-jung Yang ),김제호 ( Je-ho Kim ),문영준 ( Young-jun Moon ),백승윤 ( Seung-yun Baek ) 대한물리의학회 2020 대한물리의학회지 Vol.15 No.3

PURPOSE: The purpose of this study was to provide clinical basic data to reduce pain and improve function by comparing neck muscle activity and neck alignment using self-stretching and passive stretching exercises for chronic neck pain caused by forward head posture. METHODS: The subjects were divided into 15 subjects assigned to perform self-stretching exercise and 15 subjects assigned to perform passive stretching exercise. The intervention was conducted for a total of 4 weeks. The muscle activity in the neck was measured by surface electromyography (EMG) before intervention, and craniovertebral and cranial rotation angles were measured by X-ray. The 4-week intervention was conducted and the above items re-measured in the same manner and analyzed. RESULTS: Muscle activity within both groups after intervention using self-stretching or passive stretching exercise was significantly different (p < .05)(p < .01). Neck alignment of both groups was significantly different (p < .001)(p < .01). Further, muscle activities of the upper trapezius and splenius capitis muscles showed significant differences (p<.05). Lastly, neck alignment showed statistically significant difference (p < .05). CONCLUSION: Self-stretching exercise activated motor nerves as a posture correction exercise, thereby improving inhibition of muscle activity, muscle contraction delay, and pathological conditions of the muscle. For future research, interventions of self-stretching exercise will be needed for patients with chronic back pain accompanied by forward head posture, and various clinical studies on postural improvement of forward head posture by maintaining a normal muscle tone state are needed.

정상 노년층의 동심성 및 편심성 수축 시 대뇌 피질신경원 흥분도 비교

강정일,최현,Kang, Jeong-Il,Choi, Hyun 대한물리치료학회 2012 대한물리치료학회지 Vol.24 No.4

Purpose: This study was designed to analyze the differences in cerebral cortex activity of the elderly after extracting the movement related cortical potentials (MRCPs) from electroencephalogram (EEG) during a concentric and eccentric contraction of the elbow joint flexors, and entering them into the brain-mapping program to make the images. Methods: Right-dominant normal elderly people were divided into an eccentric contraction group and a concentric contraction group. Then, their MRCPs were measured using EEG and sEMG, during an eccentric and concentric contraction. Then, they were converted into images using the brain-mapping program. Results: Eccentric contraction group's $C_3$ and Cz showed statistically higher mean values of MRCP positive potential than the concentric contraction group. Conclusion: Researching a cerebral cortex activity, using MRCP, would provide basic data for clinical neuro-physiological researches on aging or neural plasticity of patients with a central nervous system injury.

전신진동을 결합한 스쿼트운동이 중증 만성폐쇄성폐질환 환자의 폐기능과 넙다리네갈래근 활성도에 미치는 영향

강정일 ( Jeong-il Kang ),정대근 ( Dae-keun Jeong ) 대한물리의학회 2020 대한물리의학회지 Vol.15 No.4

PURPOSE: This study aimed to propose an exercise technique that helps improve the skeletal muscle function while suppressing the symptoms of respiratory distress, by mediating squat exercises in whole-body vibration for patients with severe COPD, and comparing the post intervention pulmonary function and activity of quadriceps. METHODS: Totally, 21 patients with severe COPD were randomly assigned to two groups through clinical sampling: experimental group I included 11 patients (Squat exercise combined with whole-body vibration exercise), and experimental group II included 10 patients (Only squat exercise). Before intervention, we measured pulmonary function using a pulmonary function tester, muscle activity of quadriceps using surface EMG, and gait ability using the 6MWT. RESULTS: Comparison of intra-group changes in both experimental groups showed a significant increase in the activity of rectus femoris, vastus medialis, and vastus lateralis, and also in the 6MWT. Intra-group comparisons also revealed significant difference in the activity of rectus femoris, vastus medialis, and vastus lateralis (p < .05). CONCLUSION: Squat exercise combined with wholebody vibration significantly increased the activity of the quadriceps muscle, suggesting that this intervention helps maintain the function of skeletal muscles and prevent muscle atrophy. Therefore, studies to develop protocols using whole body vibration in clinical practice as an exercise method can safely be performed in severe COPD patients, as considered necessary.

자기관찰훈련을 병행한 복합적 균형운동이 뇌졸중 환자의 균형과 보행에 미치는 영향

강정일 ( Jeong-il Kang ),정대근 ( Dae-keun Jeong ),백승윤 ( Seung-yun Baek ) 대한물리의학회 2023 대한물리의학회지 Vol.18 No.3

PURPOSE: This study aimed to provide the basic data necessary for rehabilitation by identifying the effects of complex balance exercises combined with self-observation training on balance and gait improvement in stroke patients. METHODS: This study assigned 20 people randomly into two groups: the control and experimental groups. The experimental group (10 subjects) underwent self-observation training-combined complex balance exercise. The control group (10 subjects) underwent complex balance exercises. A pretest of the balance ability and walking ability of both groups was performed. The interventions were conducted for 30 minutes three times a week for four weeks, and post-tests were conducted four weeks after all interventions were completed. RESULTS: There was a significant difference between the experimental and control groups according to the increase in Berg Balance Sale within the group and a statistically significant difference by a decrease in 10MWT (p < .01). On the other hand, there was a significant difference only in the change in Berg Balance Sale between the two groups (p < .05). CONCLUSION: Combined balance exercise combined with self-observation training and combined balance exercise alone positively affected the Berg Balance Sale and 10MWT in both groups. On the other hand, in the results between groups, there was a statistically significant difference in Berg Balance Sale in complex balance exercise combined with self-observation training. Therefore, self-observation training should be used for the rapid social rehabilitation of stroke patients.

전기자동차 응용을 위한 DC-DC 컨버터의 설계 및 제어

강정일(Jeong-il Kang),노정욱(Chung-Wook Roh),이성세(Gun-Woo Moon),문건우(Sung-Sae Lee),윤명중(Myung-Joong Youn) 전력전자학회 2002 전력전자학술대회 논문집 Vol.- No.-

In the fuel-cell electric vehicle system, the low-voltage output of unit fuel-cell demands a number of cells to be stacked in series to produce a DC link voltage which is high enough to drive the vehicle inverter system. However, this increases the complexity of the fuel-cell control system This paper presents a design of high-efficiency boost converter emplying the average current-mode control, which is able to convert a low voltage of a fuel-cell generator with a small number of unit cells to a stable and high DC link voltage for electric vehicle applications

불안정한 지지면에서 양측성 과제운동이 뇌졸중 환자의 다리 근활성도와 균형에 미치는 영향

강정일 ( Jeong-il Kang ),정대근 ( Dae-keun Jeong ),백승윤 ( Seung-yun Baek ) 대한물리의학회 2023 대한물리의학회지 Vol.18 No.3

PURPOSE: This study assessed the influence of bilateral coordination exercises on unstable support surfaces on leg muscle activation and balance in stroke patients. METHODS: Two groups were recruited for comparison: an experimental group of 10 individuals who performed bilateral coordination exercises on unstable surfaces and a control group of 10 individuals who performed the same exercises on stable surfaces. All participants were assigned randomly. Pre-tests were conducted to measure the leg muscle activation and balance levels of the participants prior to the experiment. The intervention was comprised of three 30-minute weekly sessions for four weeks, followed by a post-test after the four-week period. RESULTS: Significant differences were identified within the experimental group in relation to all muscles (p < .01) and balance (p < .05). Within the control group, significant differences were identified in relation to the rectus femoris muscle, biceps femoris muscle, and balance (p < .05). Significant differences between the two groups were only observed in relation to the tibialis anterior and soleus muscles (p < .05). CONCLUSION: Only the tibialis anterior and soleus muscles showed significant differences between the two groups. This effectiveness may be attributed to using an ankle strategy to maintain body balance during exercise on unstable surfaces.

맥켄지운동이 만성 목통증 환자의 목주위 근육 피로도와 목 장애지수에 미치는 영향

강정일 ( Jeong-il Kang ),백승윤 ( Seung-yun Baek ),정대근 ( Dae-keun Jeong ) 대한물리의학회 2019 대한물리의학회지 Vol.14 No.4

PURPOSE: This study tries attempted to provide basic clinical data to reduce pain and improve function by comparing the muscle fatigue of the superficial neck muscles and neck disability index (NDI) by performing McKenzie exercise or passive stretching exercise for chronic neck pain patients. METHODS: Sixteen chronic neck pain patients were selected and divided into the McKenzie group (n=8) and passive stretching group (n=8). The intervention program was performed three times a week for four weeks. The time for one exercise was 30 minutes. Before the intervention, the muscle fatigue the superficial neck muscles and NDI were measured. They were measured again after four weeks using the same method. RESULTS: The median frequency of the superficial neck muscles increased significantly in the McKenzie group and passive stretching group (p<.05). The NDI of both the McKenzie group and the passive stretching group decreased significantly. A comparison of the groups, revealed a significant difference in only the median frequency values of the upper trapezius muscle and splenius capitis muscle (p<.05). The NDI values of both groups were similar. CONCLUSION: Both McKenzie exercise and passive stretching exercises showed a significant difference in the degree of fatigue and NDI. McKenzie exercise delayed the replace of the fast twitch fibers which helped improve the muscle fatigue of the upper trapezius muscle and splenius capitis muscle. On the other hand, additional studies applying more variables for the muscle function to improve the symptom of chronic neck pain patients will be needed.