• 한국지반신소재학회논문집
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• 제10권2호
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• pp.55-66
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• 2011

본 논문에서는 Back-to-Back(BTB) 보강토 옹벽의 파괴메커니즘에 관한 연구내용을 다루었다. 이를 위해 모형실험과 불연속체 해석(Discrete Element Method, DEM)을 도입한 수치해석을 수행하였다. 먼저 축소모형실험에서는 일반적으로 시공되는 Back-to-Back 보강토 옹벽을 1/10로 축소하여 1-g 모델을 구축한 후 자중만으로 파괴에 도달하도록 하였으며 보강재의 길이변화에 따른 파괴 메커니즘을 고찰하였다. 아울러 모형실험 결과를 토대로 검증된 DEM 해석모델을 이용하여 다양한 시공조건에 대한 해석을 수행하여 BTB 옹벽의 폭 및 보강재 길이에 따른 파괴 메커니즘을 고찰하고 그 결과를 현재 적용되는 FHWA 설계기준과 비교하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.905_906
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• 2009

본 논문은 한전 전력연구원이 주관하고 명지대학교와 (주)효성이 참여하는 연구과제의 결과물로써 다중펄스 컨버터와 PWM 컨버터로 구성된 20MVA급 Back-to-Back STATCOM의 시스템 구성 및 제어 동작특성에 대하여 정리하였다. 한전 전력연구원과 (주)효성이 국책과제를 통해 순수 국내기술로 개발한 10MVA급 다중펄스 STATCOM의 활용방안으로 10MVA급 PWM STATCOM 1기를 추가하여 두 STATCOM 각각의 DC link단을 연계시킨 20MVA급 Back-to-Back STATCOM을 구성하고 제어 알고리즘을 개발하였다. 또한 PSCAD/EMTDC 소프트웨어를 이용하여 개발한 Back-to-Back STATCOM의 제어 및 동작특성을 분석하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전력기술부문
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• pp.66-68
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• 2006

본 논문은 펄스 삽입 보조 회로를 갖고 있는 12-펄스 브리지 4대를 사용한 36-펄스 back-to-back 전압원 컨버터를 제안한다. 제안된 back-to-back 전압원 컨버터는 교류 연계점에서 유효전력과 무효전력의 독립적인 제어가 가능하다. 펄스 수를 증가하는 원리는 이론적 접근을 사용하여 분석되었다. 제안된 시스템의 동작 타당성은 PSCAD/EMTDC 소프트웨어의 시뮬레이션을 통해 검증되었다. 하드웨어 구현 타당성을 검증하기 위해 축소모형을 제작하고 실험에 의해 분석하였다. 제안된 back-to-back 전압원 컨버터는 HVDC와 FACTS 장치로 널리 사용될 수 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전력기술부문
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• pp.6-8
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• 2005

본 논문은 펄스 삽입 보조 회로를 갖고 있는 12-펄스 브리지 4대를 사용한 36-펄스 back-to-back 전압원 컨버터를 제안한다. 제안된 back-to-back 전압원 컨버터는 교류 연계점에서 유효전력과 무효전력의 독립적인 제어가 가능하다. 펄스 수를 증가하는 원리는 이론적 접근을 사용하여 분석되었다. 제안된 시스템의 동작 타당성은 PSCAD/EMTDC 소프트웨어의 시뮬레이션을 통해 검증되었다. 제안된 back-to-back 전압원 컨버터는 HVDC와 FACTS 장치로 널리 사용될 수 있다.

• 한국직업건강간호학회지
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• 제13권1호
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• pp.48-58
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• 2004

Purpose: To identify the factors which are related to compensated low back pain disability. These include individual. workplace. economic and injury factors. Method: Data collection was performed at 13 office of Korea Labor Welfare Corporation and 29 hospitals from 23th June to 4th August 2003. This study used 212 workers with compensated low back pain. Result: From the bivariate analysis, industry kind, type of employment, rest schedule, Job control, compensation, payment of company, diagnosis, cause of occupational injury, duration of compensated low back pain, pattern of pain, operation, other injury is related to low back pain disability. From the multiple regression analysis, rest schedule, compensation, diagnosis, pattern of pain, other injury have statistically significant effect on the low back pain disability. Conclusion: In order to reduce low back pain disability, occupational rehabilitation nursing intervention is necessary to workers with compensated low back pain.

• International Journal of Railway
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• 제6권3호
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• pp.107-111
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• 2013

In order to constrain the railway roadbed settlement which causes track irregularity, and thus threats running stability and ride quality, advanced Back-to-Back (BTB) reinforced retaining wall was numerically analyzed as railway roadbed structure. This study is intended to improve conventional Back-to-Back reinforced retaining wall as the technology which would reduce the roadbed settlement in a way of constraining the lateral displacement of its prestressed vertical facing and inducing arching effects in roadbed (backfill) placed between masonry diaphragm wall and vertical facing. As a result of numerical analysis, it was found that the roadbed settlement was reduced by 10% due to the prestressed vertical facing and embedded masonry diaphragm wall of the advanced Back-to-Back reinforced retaining wall system.

• 성인간호학회지
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• 제20권2호
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• pp.269-279
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• 2008

Purpose: The study was to examine the effect of lumbar stabilization exercise on back pain, physical fitness, sleep, and depression in middle-aged women who have chronic back pain. Methods: With one group pre-post test design, 18 subjects who have had more than 6 months of back pain were recruited by convenience sampling in D metropolitan area. Lumbar stabilization exercise was based on Tai Chi for back pain program developed by Lam(2003). This program was mainly focusing on strengthening lumbar stabilizing muscle for one hour per session, twice a week for 20 weeks. Degree of back pain, back pain disability, sleep, and depression were measured at three time points(pretest, 12 weeks, and 20 weeks) by a structured study questionnaire. Physical fitness variables including waist flexibility, mobility, and back muscle strength were measured three times at health promotion center located in the university hospital. Data were analyzed by frequency, descriptive statistics, and repeated measures of ANOVA. Results: Mean age of subjects was 52 years(SD = 6.4). Most of them(90%) had suffered from back pain more than one year and 67% was taking medicine to relieve their back pain. Results showed that back pain score and disability score were not significantly decreased after the exercise. On physical fitness variables, however, waist flexibility(F = 3.50, p = .04) and mobility(F = 3.31, p = .04) were improved after the exercise. Quality of sleep(F = 4.48, p = .03) was improved gradually and depression scores were also decreased(F = 3.12, p = .05) after the exercise. Conclusion: This lumbar stabilization exercise was not able to reduce chronic back pain, but could improve physical fitness and psycho-social variables for community dwelling women who have chronic back pain. Further study is needed to replicate this exercise with control group to confirm the positive effect.

• 한방재활의학과학회지
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• 제23권2호
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• pp.85-94
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• 2013

Objectives : This study aims to contribute to developing new pattern identification based on searches regarding pattern identification of low back pain, which is used in thesis both in Korea and China. Methods : First of all, we searched thesis concerning pattern identification of low back pain from RISS, OASIS, Korean traditional knowledge portal, CNKI. Results : 1. There were overall 34 thesis, consist of 18 Korean thesis(13 clinical papers and 5 analytical papers) and 9 Chinese thesis(7 clinical papers and 9 analytical papers). 2. 10 of 11 Korean thesis used more than 9 patterns for pattern identification, 9 of 14 Chinese thesis used less than 4 patterns for pattern identification of low back pain. 3. Patterns, which were repeatedly used in Korea, were 腎虛腰痛(Kidney deficiency low back pain), 濕熱腰痛(Dampness-heat low back pain), 寒濕腰痛(Cold-dampness low back pain), 痰飮腰痛(Phlegm-fluid retention low back pain), 風腰痛(Wind low back pain), 食積腰痛(Food accumulation low back pain), 濕腰痛(Dampness low back pain), 挫閃腰痛(Sprain low back pain), 瘀血腰痛(Static blood low back pain), 氣腰痛(Qi low back pain). 4. Patterns, which were repeatedly used in China, were 腎虛腰痛(Kidney deficiency low back pain), 濕熱腰痛(Dampness-heat low back pain), 寒濕腰痛(Cold-dampness low back pain), 氣滯血瘀腰痛(Blood stasis due to qi stagnation low back pain). Conclusions : Based on these results, it is considered that an advanced type of pattern identification of low back pain should be made or existing type needs to be practically and objectively improved.

• The Journal of Korean Physical Therapy
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• 제12권1호
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• pp.87-99
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• 2000

A study was conducted in order to determine back pain experience status of elementary. junior and senior high school teachers and the factors affecting their knowledge of back pain and physical therapy from April 2 through June 30, 1999 in major big cities and small and medium towns. Questionnaires were sent to 924 teachers and the collected daa were analyzed. The results summarized are as follows ; 1. $46.3\%$ of the respondents had experienced back pain, and $47.0\%$ of females, $62.0\%$ of the people over 50years old, $57.4\%$ of junior high school teachers, $47.5%$ of teachers of art and physical education, $46.9\%$ of married persons, $47.8\%$ of the people living in medium or small towns, and $58.6\%$ of the persons whose economic status was low han experienced back pains, $58.9\%$ of respondents who were not healthy, and $49.3\%$ of those who did not drink alcohol, $47.9\%$ of nonsmokers, and $49.1\%$ of those who slept on ondol had experienced back pains. $76.7\%$ of the respondents got health information on back pains from health professionals. 2. An average level of the respondents en physical therapy was $14.95\pm8.32$ points out of 44 and it was 34 points when converted to 100. The knowledge levels of males,. elementary teachers, married persons, those teaching students far more than 20 hours a week, smokers, those who did not drink, those who exercised regularly, and those who had experienced back pains were higher than those in other groups. The knowledge level of those who had experienced back pain prevention education was $18.88\pm8.88$ points and the difference between those with experience and those without experience was statistically significant. The depression level of those who got 40 pome on back pains, and physical therapy was higher than other group(p<0.001). 3, Depression levels of teachers on back pains and physical therapy related knowledge was higher in those with back pains than those without back pains(p<0.01). 4. The factors affecting experience of back pains were back pain related age, economic status, health status, smoking, style of kitchen, sown of information on back pain, and back pain prevention education. (p<0.001), 5. The factors affecting the knowledge on physical therapy were general knowledge levels on back pains, position when tilling, and moving heavy stuffs, driving position, sources of information on back pain prevention, type of bed, age, and health status, and the explanation power of those factors was $45.2\%$.

• 전자공학회논문지B
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• 제29B권4호
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• pp.58-65
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• 1992

In this paper new back propagation algorithm which adds neurons to hidden layer is proposed. this proposed algorithm is applied to the pattern recognition of written number coupled with back propagation algorithm through omitting redundant learning. Learning rate and recognition rate of the proposed algorithm are compared with those of the conventional back propagation algorithm and the back propagation through omitting redundant learning. The learning rate of proposed algorithm is 4 times as fast as the conventional back propagation algorithm and 2 times as fast as the back propagation through omitting redundant learning. The recognition rate is 96.2% in case of the conventional back propagation algorithm, 96.5% in case of the back propagation through omitting redundant learning and 97.4% in the proposed algorithm.