• 항공우주기술
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• 제9권1호
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• pp.78-83
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• 2010

본 연구에서는 높은 양력을 얻기 위하여 플랩 형상 최적 설계를 시도하였다. 플랩 형태는 플랩 중에서 가장 효율이 좋은 파울러 플랩(fowler flap)이다. 플랩 설계는 최적화 기법을 활용하여 진행하였고 최적화의 초기 형상은 general aviation airfoil과 Wentz 등이 개발한 플랩이다. 최적화 방법으로는 반응면 기법 (Response Surface Method)이 사용되었으며, Hicks-Henne 형상함수가 사용되었고, GA(W)-1 익형과 fowler flap이 조합된 형상의 유동장에 대하여 Navier-Stokes 해석을 수행하였다. 상용 최적화 프로그램인 Visual-Doc, 격자 생성 프로그램인 Gambit/Tgrid, 그리고 유동해석에는 Fluent를 이용하였다. 플랩의 윗면 형상과 gap에 대한 최적화를 수행하여 착륙조건에서의 양력이 증가하였다. 초기 형상과 최적화된 형상의 공력특성 변화를 관찰하기 위하여 항우연의 1m 풍동에서 시험을 수행하였다. 최적화된 형상은 대체로 예측치와 비슷한 경향을 보이나, 이른 실속이 관찰되었다. 또한, 날개와 플랩 간의 간격을 설계치보다 좁혀 줌으로써 양력특성이 향상됨을 알 수 있었는데, 이는 설계시 사용된 난류 모델의 영향이라 판단된다.

• Archives of Reconstructive Microsurgery
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• 제5권1호
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• pp.80-91
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• 1996

A free rectus abdominis flap can include a variable amount of muscle length depending on recipient site requirements. There is also great flexibility in flap design in terms of size, orientation of its axis, and the level of its location over the muscle. It is safe to design the skin island across the midline. Though skin islands designed over the most inferior portion of the abdomen have not always proved reliable when based on the superior epigastric artery, free flaps based on the inferior pedicle can be successfully designed in this area. As free flap based on the inferior epigastric vessels, this flap has been useful for large head and neck defects following ablative procedures, for facial contour restoration as a buried flap, for upper extremity defects, for lower extremity defects such as coverage of grade III tibial fractures and for breast reconstruction. A free rectus abdominis muscle or myocutaneus flap was used in 8 patients. The operations were performed between Sep. of 1994 and April of 1996. The patients were tongue cancer 1 case, chronic facial palsy 1 case, unilateral breast reconstruction 1 case, upper and lower extremity injury 5 cases. The free rectus abdominis muscle flaps were 4 cases and the free myocutaneous flaps were 4 cases. There was no failure of the flap, except one partial necrosis. One case of the skin grafts on the muscle flap was regrafted. One case of reoperation due to venous thrombosis was performed. In tongue cancer patient, a orocutaneous fistula was occurred, but conservative treatment and secondandry skin graft were done. In conclusion, a free rectus abdominis flap has many advantages such as a long and constant pedicle, easy dissection, enough soft tissue available, scar on the donor site to be hiddened, no need for changing position. So we think that this flap is the most useful one for small or moderate sized defects on the various sites.

• Archives of Plastic Surgery
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• 제50권6호
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• pp.586-592
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• 2023

Background One-stage reconstruction with "thin perforator flaps" has been attempted to salvage limbs and restore function. The deep inferior epigastric perforator (DIEP) flap is a commonly utilized flap in breast reconstruction (BR). The purpose of this study is to present the versatility of DIEP flaps for the reconstruction of large defects of the extremities. Methods Patients with large tissue defects on extremities who were treated with thin DIEP flaps from January 2016 to January 2018 were included. They were minimally followed up for 36 months. We analyzed the etiology and location of the soft tissue defect, flap design, anastomosis type, outcome, and complications. We also considered the technical differences in the DIEP flap between breast and extremity reconstruction. Results Overall, six free DIEP flaps were included in the study. The flap size ranged from 15 × 12 to 30 × 16 cm². All flaps were transversely designed similar to a traditional BR design. Three flaps were elevated with two perforators. Primary closure of the donor site was possible in all cases. Five flaps survived with no complications. However, partial necrosis occurred in one flap. Conclusion A DIEP flap is not the first choice for soft tissue defects, but it should be considered for one-stage reconstruction of large defects when the circulation zone of the DIEP flap is considered. In addition, this flap has many advantages over other flaps such as provision of the largest skin paddle, low donor site morbidity with a concealed scar, versatile supercharging technique, and a long pedicle.

• Advances in aircraft and spacecraft science
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• 제2권3호
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• pp.329-343
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• 2015

This study aimed to observe the effect of a novel concept (referred to as the flap extension) implemented on the leading edge of the flap of a three element high lift device. The high lift device, consisting of a flap, main element and slat is designed around an Airbus research profile for sufficient take off and landing performance of a large commercial aircraft. The concept is realised on the profile and numerically optimised to achieve an optimum geometry. Two different optimisation approaches based on Genetic Algorithm optimisations are used: a zero order approach which makes simplifying assumptions to achieve an optimised solution: as well as a direct approach which employs an optimisation in ANSYS DesignXplorer using RANS calculations. Both methods converge to different optimised solutions due to simplifying assumptions. The solution to the zero order optimisation showed a decreased stall angle and decreased maximum lift coefficient against angle of attack due to early stall onset at the flap. The DesignXplorer optimised solution matched that of the baseline solution very closely. The concept was seen to increase lift locally at the flap for both optimisation methods.

• 대한치과의사협회지
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• 제48권8호
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• pp.607-614
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• 2010

Reconstruction after ablative oral cancer surgery is challenging mission. Soft tissue and hard tissue could be resected in case of advanced oral cancer. The final goal of oral reconstruction is to gain normal swallowing, chewing and speech. Nowadays, free flap reconstruction after oral cancer resection is more popular than pedicled flap. Microsurgical reconstruction with free flap could be used effectively in complicated cases of oral cavity defect. However, complications could be happened. So not only meticulous preoperative study about the extent of defects but also the donor site dressing after surgery were performed to prevent postoperative complication. The most favorite free flap for soft tissue reconstruction is radial forearm flap. It has a lot of advantages such as pliable, hairless, reliable vessels, appropriate diameter of radial artery and diverse flap design. And the most popular free flap for jaw reconstruction is free fibular flap. In this article, we report the classification of flap for reconstruction and reveal the pits and falls of radial forearm free flap and free fibular flap.

• 한국항공우주학회지
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• 제46권7호
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• pp.542-550
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• 2018

본 논문에서는 헬리콥터의 전진비행시 발생하는 허브 진동 하중 저감을 위해 설계된 능동 뒷전 플랩이 장착된 SNUF 블레이드의 무베어링 주 로터 적용 설계에 대해 살펴보았다. 이를 위해 EDISON의 박벽 복합재료 회전보 진동해석 프로그램(CORBA77_MEMB)을 이용하여 유연보의 단면 설계가 이루어졌다. 다물체 동역학 해석 프로그램 DYMORE를 이용하여 단면 설계에 따른 블레이드 동특성 및 능동 뒷전 플랩을 이용한 하중 제어의 특성을 예측하였다.

• 대한두경부종양학회지
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• 제21권2호
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• pp.190-195
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• 2005

Background and Objectives: Fibula is the flap of choice for reconstruction of wide mandible defects after tumor ablation surgery. In mandible reconstruction, restoring the mandible frame to provide mandibular contour and dental arch while restoring masticatory function are important. Even though vascularized fibula can be osteotomized freely, proper design and flap insetting is not easy because of its three dimensional structure and difference in design according to the defect sites. We reviewed patients who underwent mandible reconstruction with fibular flaps according to the defect sites and suggest proper modification methods of fibular flap according to the various defects sites after tumor ablation surgery. Materials and Methods: Twelve consecutive mandible reconstruction with fibular free flaps were performed for defects after tumor ablation surgery. Patients were classified into 4 groups according to the type of mandibular defect(Group 1 : defect on central segment including symphysis, Group 2 : defect on lateral segment(with or without central segment) confined to body, Group 3 : defect on body and ascending ramus that does not include the condyle, Group 4 : defect including the condyle). Results: We suggest different modification methods of fibular free flap for each patient group. Group 1, 3 ; contour by using multiple closing wedge osteotomy. Group 2 ; single or double barrel reconstruction without wedge osteotomy. Group 4 ; contour using single or multiple wedge osteotomy and condylar reconstruction with costochondral graft. Conclusion: Fibular free flaps can be contoured to any desired shape after multiple osteotomies to restore various mandibular defects. It is a reliable and versatile method for reconstruction of mandibular defects after tumor ablation surgery.

• International Journal of Aerospace System Engineering
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• 제4권1호
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• pp.13-21
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• 2017

In this paper, we present some results on performance analysis for flap actuation system of aircraft. For this, by utilizing MATLAB/Simulink solution, which is widely used physical model-based design tool, we particularly construct the architecture of the analysis model consisting of the main three phases: 1)commanding and outer-controlling the flap angle through flight control computer; 2)generating hydraulic/mechanical power through control module and power drive unit; 3)transmitting torque and actuating the flap through torque tube and rotary geared actuators. For mimicking the motion of the actual flap, we apply each mechanical component, which is already being used in actual aircraft, to our performance analysis model so that it guarantees the congruency of the simulation results. That is, we reflect the actual specifications of flap hardware and software as parameters of the model. Finally, simulation results are presented to illustrate the model.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2005년도 춘계학술대회 논문집
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• pp.35-40
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• 2005

선박의 조종운동은 선체와 프로펠러 그리고 타의 연성 운동의 결과로서 선박 조종성능을 향상시키기 위해서는 각 요소의 적절한 평가 및 보완이 필요하다. 본 연구에서는 조종성능 향상 기법의 일례로 특수타의 일종인 플랩타 주위의 유동특성을 유동가시화 시험기법과 PIV 해석을 이용하여 알아본다.

• Ocean and Polar Research
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• 제42권4호
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• pp.293-301
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• 2020

Blades of tidal stream turbines have to sustain many different loads during operation in the underwater environment, so securing their structural safety is a key issue. In this study, we focused on periodic loads due to wave orbital motion and propose a load reduction method with a blade design. The flap of an airplane wing is a well-known structure designed to increase lift, and it can also change the load distribution on the wing through deflection. For this reason, we adopted a passive flap structure for the load reduction and investigated its effectiveness by an analytical method based on the blade element moment theory. Flap torsional stiffness required for the design of the passive flap can be obtained by calculating the flap moment based on the analytic method. Comparison between a flapped and a fixed blade showed the effect of the flap on load reduction in a high amplitude wave condition.