• 대한관절경학회지
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• 제16권2호
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• pp.153-159
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• 2012

목적: 본 연구의 목적은 슬관절 내측 반월상 연골판 후방 부착부 파열 환자에 대해 관절경적 견인 봉합술을 시행한 후 임상적 및 방사선학적 5년 추시 결과를 보고하고자 한다. 대상 및 방법: 2001년 1월부터 2005년 5월까지 본원에서 내측 반월상 연골판 후방 부착부 파열로 진단받고 관절경적 견인 봉합술을 시행한 환자 중 5년 이상 추적 관찰이 가능하였던 30예를 대상으로 하였다. 평균 추시 기간은 76개월(60-90개월)이었다. 임상적 결과는 Lysholm knee score로 확인하였고 방사선학적 결과는 단순 방사선 사진을 이용한 Kellgren-Lawrence 분류를 이용하였으며, 전예에서 2차 관절경 수술을 시행하였다. 외상, 비만, 내반 변형 및 수술 시기 등과 임상적 결과를 비교 분석하였다. 결과: 임상적 결과는 수술 전 Lysholm knee score 평균 55점에서 5년 추시 시 평균 86점으로 호전을 보였고, 방사선학적 추시 검사 결과 23예에서 관절 간격의 유지 및 호전 소견 보였으며, 7예에서 관절 간격이 감소되는 등의 퇴행성 변화가 있었고, 그 중 1예에서 골 관절염의 진행 소견으로 추후 인공 관절 치환술을 시행하였다. 결론: 관절경적 견인 봉합술을 시행하여 최소 5년 추시에서 27예(90%)에서 양호 이상의 좋은 결과를 얻었으며 내반 각도가 클수록 임상적으로 호전되는 정도는 유의하게 낮았다.

• 대한소아치과학회지
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• 제21권2호
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• pp.533-539
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• 1994

The mandibular buccal frenum is a fold of mucous membrane at the posterior labial vestibule, that attaches the lips and the cheeks to the alveolar mucosa, gingiva, and underlying periosteum. The buccal frenum becomes a problem if its attachment is too close to the marginal gingiva. It may then pull on healthy gingiva, encourge plaque formation and interfere with tooth brushing. Heavy buccal frenum mucogingivally results in insufficient attached gingiva, inadequate vestibular depth and high frenum attachment and also difficulty in eruption of mandibular second premolar. Frenectomy in various forms has been used for many years to remove the influence of the frenum. Unfortunately, the results are not always ideal and there is often postoperative relapse because of muscle pull. In this treatment, frenotomy was used in conjuction with autogenous free gingival graft with the object of removing the influence of the buccal frenum and creating an adequate and stable width of attached gingiva. We observed decrease in muscle pull, adequate width of attached gingiva and increased vestibular depth in addition to progressive eruption of second premolar. Periodic follow-up is needed for evaluation of relapse, grafting gingiva and also space regaining for second premolar.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.478-481
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• 2004

An experimental investigation on the relationship between corrosion of reinforcement and bond strength in pull-out test specimen has been conducted to establish the allowable limit of rust of reinforcement in the construction field. The reinforcing bars used in this study were rusted before embedded in pull-out test specimen. The first component of this experiment is to make reinforcing bar rust electrically based on Faraday's theory to be 2, 4, 6, 8 and $10\%$ of reinforcing bar weight. For estimation of the amount of rust by weight, Clarke's solution and shot blasting were adopted and compared. Parameters also include 24 and 45MPa of concrete compressive strengths and diameter of reinforcing bar (16, 19 and 25mm). Pull-out tests were carried out according to KS F 2441 and ASTM C 234. Results show that up to $2\%$ of rust increases the bond strength regardless of concrete strength and diameter of reinforcing bar. As expected, the bond strength increases as compressive strength of concrete increases and the diameter of bar decreases.

• Journal of Power Electronics
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• 제11권5호
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• pp.632-638
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• 2011

This paper presents a cascaded coil flux control based on a Current Source Parallel Resonant Push-Pull Inverter (CSPRPI) for Induction Heating (IH) applications. The most important problems associated with current source parallel resonant inverters are start-up problems and the variable response of IH systems under load variations. This paper proposes a simple cascaded control method to increase an IH system's robustness to load variations. The proposed IH has been analyzed in both the steady state and the transient state. Based on this method, the resonant frequency is tracked using Phase Locked Loop (PLL) circuits using a Multiplier Phase Detector (MPD) to achieve ZVS under the transient condition. A laboratory prototype was built with an operating frequency of 57-59 kHz and a rated power of 300 W. Simulation and experimental results verify the validity of the proposed power control method and the PLL dynamics.

• 산업경영시스템학회지
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• 제15권25호
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• pp.63-74
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• 1992

This study proposes D- shortage control system which is a convenient tool for cooperative companies to reduce shortages which frequently break out between the manufacturing companies and the cooperative companies. On the ground of theoretical analysis of MRP and JIT system, D- shortage control system sets up a schedule that secures the delivery date by precedent scheduling( D-) comparing with MRP It also syncronizes business, production and release, and builds the pull system comparing with JIT. The factors causing shotages are the scheduling absurdity and the controlling absurdity. The scheduling absurdity can be settled by the calculating required quantity method of MRP and the controlling absurdity can be settled by daily control of business, production and pruchasing fuctions by the pull system of JIT. And the inventory and the WIP can be reduced by the operating of PULL system and by the settlement of D- shortage control practices. The Application of D- shortage control system, therefore, enables the rationalization of logistics and reduces the inventory And it leads to the reinforced competitiveness and the security of subsistence of manufacturer by the cost ruduction, the reduction of financial difficulty, and the insurance of the delivery date.

• Archives of Plastic Surgery
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• 제46권3호
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• pp.277-281
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• 2019

Recto-vaginal fistulas are difficult to treat due to their high recurrence rate. Currently, no single surgical intervention is universally regarded as the best treatment option for recto-vaginal fistulas. We present a case of recurrent recto-vaginal fistula surgically treated with a gracilis pull-through flap. The surgical goals in this patient were complete excision of the recto-vaginal fistula and introduction of fresh, vascularized muscle to seal the fistula. A defunctioning colostomy was performed 1 month prior to the present procedure. The gracilis muscle and tendon were mobilized, pulled through the freshened recto-vaginal fistula, passed through the anus, and anchored externally. Excess muscle and tendon were trimmed 1 week after the procedure. Follow-up at 4 weeks demonstrated complete mucosal coverage over an intact gracilis muscle, and no leakage. At 8 weeks post-procedure, the patient resumed sexual intercourse with no dyspareunia. At 6 months post-procedure, her stoma was closed. The patient reported transient fecal staining of her vagina after stoma reversal, which resolved with conservative treatment. The fistula had not recurred at 20 months post-procedure. The gracilis pull-through flap is a reliable technique for a scarred vagina with an attenuated recto-vaginal septum. It can function as a well-vascularized tissue plug to promote healing.

• Advances in pediatric surgery
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• 제10권1호
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• pp.1-8
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• 2004

A re-pull-through operation for Hirschsprung's disease is performed when the primary operation has failed because of the remnant or acquired aganglionosis, anastomotic stricture and/or fistula. The purpose of this study is to review our experience of the re-pull-through procedure for Hirschsprung's disease. From May 1978 to July 2003, 26 patients who underwent re-pull-through operations at the Department of Pediatric Surgery, Seoul National University Children's Hospital, were studied retrospectively by means of chart review as well as telephone interview. The mean age at primary operation and re-operation were llmonths (2 months - 10 years) and 43 months (1 year - 23 years 3 months), respectively. Initial operation for Hirschsprung's disease was Duhamel's procedure in 17, Swenson's in 6 and Soave's 3. Causes of failure of primary operation were remains of secondary aganglionic segment (n=23), vascular arcade injury (n= 1), rectoperineal fistula (n=2, due to mesenteric torsion and poor blood supply), Mean interval between the primary operation and the re-operation was 34 months (6 months-22 years). Reoperation methods were Soave's in 12, Duhamel's in 8, APSP (abdomino-posterosagittal pull-through procedure) in 5, and Swenson's in 1 case. In 2 cases of repeated rectoperineal fistula or rectourethral fistula, re-APSP were performed 3 times, respectively. A total of 29 re-pull-through operations were performed. Postoperative complications were wound infection (n=1), adhesive ileus (n=1), rectoperineal fistula (n=3), rectourethral fistula (n=2), and death due to pulmonary embolism (n=1). Mean follow up period of reoperation was 78 months (1 month-23years). In current state, 2 patients have an ileostomy because of repeated rectoperineal fistula and rectourethral fistula. Of the remaining 23 patients, 21(91 %) are totally continent with or without minimal soiling. Reoperation for Hirschsprung's disease was effective and safe for the patients complicated to the initial pull-through operation.

• 한국응용곤충학회지
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• 제58권3호
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• pp.209-218
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• 2019

본 연구는 시설토마토 재배지에서 push-pull 전략을 이용해 담배가루이와 천적곤충의 행동을 제어함으로써 담배가루이(Bemisia tabaci)를 친환경적으로 방제하기 위한 기술을 개발하고자 수행하였다. 담배가루이는 노란색에 유인율이 가장 높았으며, 520 nm의 광원에는 유인반응을 복합광원인 450 + 660 nm의 광원에는 회피반응을 보였다. 천적곤충인 담배장님노린재(Cyrtopeltis tenuis)와 미끌애꽃노린재(Orius laevigatus)는 모두 520 nm의 광원에 가장 높은 유인반응을 보였다. 휘발성 물질로는 ocimene과 carvacrol에 대해 기피반응을, methyl isonicotinate에는 유인반응을 보였다. 토마토 온실에 메밀을 투입하였을 경우 천적곤충인 담배장님노린재의 밀도는 무처리 대비 15일간 약 16배로 높게 유지되었다. Push-pull 세부전략들을 종합 처리한 결과, 처리 50일 경과 후 담배가루이의 트랩당 밀도는 무처리 대비 3배 이상 낮게 나타났으며, 이에 따른 시기별 방제효과는 시간이 경과함에 따라 증가하는 경향을 보인 가운데 최고 68.7%였다.

• 한국전자통신학회논문지
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• 제15권5호
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• pp.889-896
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• 2020

일반적으로 스텝 업(Step-up) 컨버터는 Boost 컨버터, Buck-Boost 컨버터, Flyback 컨버터, Push-Pull 컨버터 등 다양하며 이 중에서 Boost 컨버터는 매우 간단한 형태로 가장 널리 사용되는 스텝 업(Step-up) 컨버터이다. 하지만, Boost 컨버터는 DCM 동작, 큰 리플 문제 및 RHPZ 문제 등을 가지고 있다. 이러한 문제를 해결하기 위해 새로운 Topology를 적용한 컨버터들이 제시되었는데 그 중 KY 컨버터는 Boost 컨버터의 DCM 동작, 큰 리플 문제 및 RHPZ 문제 등을 개선하였다. 그러나 기존의 KY 컨버터는 Boost 컨버터보다 전압 이득이 상대적으로 낮은 단점이 있다. 따라서 본 논문에서는 기존의 KY 컨버터의 장점이 있으면서 낮은 전압 이득 문제를 해결한 새로운 Topology의 KY 컨버터를 제안하였다.

• International Journal of Aeronautical and Space Sciences
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• 제12권1호
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• pp.84-91
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• 2011

A finite element analysis for the wing and landing gear of a composite target-drone air vehicle was performed. For the wing analysis, two load cases were considered: a 5g symmetric pull-up and a -1.5g symmetric push-over. For the landing gear analysis, a sinking velocity of 1.4 m/s at a 2g level landing condition was taken into account. MSC/NASTRAN and LS-DYNA were utilized for the static and dynamic analyses, respectively. Finite element results were verified by the static test of a prototype wing under a 6g symmetric pull-up condition. The test showed a 17% larger wing tip deflection than the finite element analysis. This difference is believed to come from the material and geometrical imperfections incurred during the manufacturing process.