• Proceedings of the KIEE Conference
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• 2005.10a
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• pp.79-81
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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 접압원 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.

• Journal of muscle and joint health
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• v.21 no.2
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• pp.114-124
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• 2014

Purpose: The purpose of this study was to explore the effects of the 8-weeks back pain management program (consisted of exercise and education for back pain) in patients with chronic low back pain. Methods: A total of 20 subjects who visited the pain clinic in a university hospital were randomly assigned either to a experimental or a control group. Ten subjects in the experimental group carried out the back pain management program for 8 weeks, and 10 in the control group did not. Results: After the back pain management program, back pain and disability were significantly reduced, and back pain management behavior and back muscle strength were significantly increased in the experimental group. However, radiating pain and flexibility were not significantly changed after the back pain management program. Conclusion: Findings of this study indicated that the 8-weeks back pain management program had favorable effects on back pain, degree of disability, back pain management behavior, and back muscle strength in patients with chronic low back pain. Future research needs to examine the optimal intensity and frequency of back muscle strengthen exercise, and the lasting effects of education for back pain.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.4
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• pp.748-755
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• 2009

This paper proposes a 18-step back-to-back voltage source converter using four sets of 3-Level converter module with auxiliary circuit to increase the number of steps. The proposed back-to-back voltage source converter has an independent control capability of active power and reactive power at the interconnected ac system. The operational feasibility of proposed system was verified through computer simulations with PSCAD/EMTDC software. The feasibility of hardware implementation was verified through experimental results with a scaled hardware model. The proposed back-to-back converter can be widely applied for interconnecting the renewable energy source to the power grid.

• The Journal of Korean Physical Therapy
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• v.14 no.1
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• pp.169-176
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• 2002

The purpose of this study were to measured peak torque of lumbar extensor at various degrees and to compare with the choronic low back pain patients and healthy subjects back extensor peak torque. Research subject are fifty choronic low back pain patients and fifty healthy subjects are Dong-a university hospital visited to 2000, January since 1999, august none lumbosacral traumal past history and neurologic disorder that is twenty generation, thirty generation, forty generation, fifty generation, sixty generation in healthy subjects and twenty generation, thirty generation, forty generation, fifty generation, sixty generation in cause choronic low back pain patients. The result were as follows. 1. There were each generation choronic low back pain patients and healthy subjects back extensor peak torque are consideration (p<.05). 2. Twenty generation was all degree of angle in lumbar extention peak torque in choronic low back pain patients back extensor are lower than healthy subjects(p<.05). 3. Thirty generation was all degree of angle in lumbar extention peak torque in choronic low back pain patients back extensor are lower than healthy subjects(p<.05). 4. Forty generation was all degree of angle in lumbar extention peak torque in choronic low back pain patients back extensor are lower than healthy subjects(p<;.05). 5. Fifty generation was all degree of angle in lumbar extention peak torque in choronic low back pain patients back extensor are lower than healthy subjects(p<.05). 6. Sixty generation was all degree of angle in lumbar extention peak torque in choronic low back pain patients back extensor are lower than healthy subjects(p<.05).

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.3
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• pp.102-108
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• 2006

This paper proposes a 36-pulse back-to-back voltage source converter using four sets of 12-pulse bridges with pulse-Interleaving auxiliary circuit. The proposed back-to-back voltage source converter has an independent control capability of active power and reactive power at the at connection point. The principle of increasing the number of pulses was analyzed using theoretical approach. The operational feasibility of proposed system was verified through computer simulations with PSCAD/EMTDC software. The proposed back-to-back converter can be widely used for the HVDC and FACTS devices.

• Physical Therapy Korea
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• v.3 no.3
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• pp.59-66
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• 1996

The purpose of this study was to assess the biomechanical effects of corset and back brace for low back pain syndroms patients. The subjects of this study were 69 patients with low back pain syndroms who had been hospitalized or were visited out-patient department of the rehabilitation hospital, college of medicine, Yonsei University, from October 5, 1995 through November 5, 1995. Clinical results and datum were obtained by phone calls and chart reviews of low back pain patients. The results were as follows: 1) Fifty - nine subjects recovered over a good grade (85.6%). 2) The standing workers had a little effect of brace for low back pain. 3) After using a corset and back brace, the test of SLR increased from 36.23% to 72.47%, and the ability of ambulation improved from 40.57% to 85.5%. In conclusion, the biomechanical effects of corset and back brace for low back pain patients were found to be decrease pains and improve posture and ADL function.

• Journal of Korean Physical Therapy Science
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• v.13 no.2
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• pp.27-36
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• 2006

The purpose of this study would like to analyze statically significant difference for low back-pain frequency of mother after development-disability children. Seven nursery children with disability conducted survey from 122 mothers cared children with disability. Survey data was obtained from April 14. 2006 to May 23. 2006. The results were as follows: According to walking-existence, assistance walking, and disability-degree, low back pain incidence frequency of mothers were statically significant difference, (p<0.05). Low back pain incidence frequency of walker-ability population was 51.4%, but low back pain incidence frequency of walker-disability population was 80.0%. then low back pain incidence frequency of mothers to walking-existence was differed amount. Disabled not statically significant difference to encephalopathy and disability-type1 and disability -type2 (p>0.05). children with disability-degree and assistance walking benchmarked low back pain disability-measure. Low back pain degree not relevancy statically significant. Physical load was statically significant difference between Oswestry's low back pain score and reach effect to child-cared(p<0.05). As development-children with disability of disable degree, Mother appeared to highly low back pain frequency rate and appeared to large reach effect child-cared owing to physical load of low back pain. So hereafter, location and person request to approach with more clinical and objectively. As approach result, it will help to stress solution of children with disability owing to develop to low back pain class and family capable strengthening program and so on.

• Women's Health Nursing
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• v.10 no.1
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• pp.8-14
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• 2004

Purpose: The purpose of this study was to look into back pain, pain disability, labour pain, and related areas of pain experienced by postpartum women. Method: A survey about pain including a Visual Analogue Scale (VAS), Oswestry pain disability, and pain drawing was used in a descriptive research method on 98 women 2-3 days after delivery. Result: 57.1% of those surveyed reported experiencing back pain before pregnancy. 75.5% reported experiencing back pain during pregnancy. The average starting time of back pain for pregnant women was 2.9 months into pregnancy. 48.8% reported the most severe back pain in the last trimester of pregnancy, while most women complained of left and right pubic pain and lumbar area pain during pregnancy. Statistical relations were calculated and menstrual symptoms (F=5.938, p=0.004), back pain prior to pregnancy (F=4.714, p=0.000), back pain during pregnancy (F=-3.429, p=0.001), and back pain disability prior to pregnancy (F=-1.994). Conclusion: There is a relation in postpartum women's back pain between back pain prior to pregnancy and back pain during pregnancy. Pelvic examinations early in pregnancy can determine if back pain will change for the worse or relapse. Therefore, the application of a pain relieving nursing intervention is needed.

• Journal of the Korean Geosynthetics Society
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• v.10 no.2
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• pp.55-66
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• 2011

This paper presents the results of an investigation on the failure mechanism of geosynthetic reinforced soil walls in back-to-back configuration using 1-g reduced-scale model tests as well as discrete element method-based numerical investigation. In the 1-g reduced scale model tests, 1/10 scale back-to-back walls were constructed so that the wall can be brought to failure by its own weight and the effect of reinforcement length on the failure mechanism was investigated. In addition, a validated discrete element method-based numerical model was used to further investigate the failure mechanism of back-to-back walls with different boundary conditions. The results were then compared with the failure mechanisms defined in the FHWA design guideline.

• International Journal of Railway
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• v.6 no.3
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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.