• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.9
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• pp.753-760
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• 2007

In a 3-D flapping motion, the spanwise flow is generated while the wing is moved on the stroke plane. And at the end of each stroke, the rotational circulation is generated due to a wing rotation. In this study, to evaluate the effect of spanwise flow and wing rotation on the aerodynamic characteristics in 3-D flap 753ping motion, a 3-D flapping motion was compared with a 2-D translating motion. In each flapping motion, the aerodynamic forces were measured with respect to the angles of attack and Reynolds number. The aerodynamic forces generated by 2-D translating motion were higher than those generated by 3-D flapping motion. While the lift of 3-D flapping motion was increased until the angle of attack $60^{\circ}$ at mid-stroke, the lift generated by 2-D translating motion was decreased above the angle of attack 40° at mid stroke. Also, at the end of each stroke, the aerodynamic forces were increased rapidly due to wing rotation.

• Archives of Plastic Surgery
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• v.36 no.5
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• pp.642-648
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• 2009

Purpose: Hexadactyly without thumb is a rare congenital anomaly of the hand where six triphalangeal digits are symmetrically distributed without thumb. Contrary to mirror hands, triphalangeal six digits are symmetrically distributed on each side at the midline with well - differentiated carpal bones, extensor tendons, one ulnar and one radius. The authors developed a new surgical technique based on a three - dimensional concept to correct the hexadactyly and applied to 2 cases of hexadactyly with good functional and aesthetic results. Here we document the surgical technique and its result. Methods: A 16 month old male patient visited our clinic with chief complaints of bilateral hexadactyly deformity. On physical examination most radial first and second digits showed no opposition and adduction motion on both side hands. Radiography showed 6 triphalangeal digits with normal development of carpal, radial and ulnar bone. Right side abnormality was corrected by removal of most radial side extra - digit, rotation and migration of 2nd ray to thumb position and creation of 1st web by transposing a mid - palm based rectangular palmar flap as in Snow & Littler procedure which has been being applied for correction of 1st web syndactyly in cleft hand deformity. Seven months later, left side abnormality was also corrected with the same procedure. Results: Postoperative appearances of the both hands were satisfactory. Flexion, extension, opposition and grasping were possible with the pollicized 2nd ray. Pinching power was 3.0 kg 15 months after surgery and 2.5 kg 22 months after in right hand respectively. Conclusion: In correction of hexadactyly deformity, satisfactory aesthetic and relevant functional results can be expected with authors' newly developed technique: removal of most radial digit, rotation and migration of 2nd digit to thumb position as well as creation of the 1st web space by transposition of mid - palm based rectangular flap.

• Archives of Craniofacial Surgery
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• v.22 no.1
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• pp.11-16
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• 2021

Background: Nasal septal cartilage is used to obtain favorable aesthetic and functional outcomes in rhinoplasty, but is often difficult to harvest or the harvested amount is insufficient. Therefore, the objective of this study is to introduce how to harvest septal cartilage optimally without losing and use harvested cartilage efficiently. Methods: From March 2015 to January 2020, we tried to harvest as much septal cartilage as possible while maintaining the L-strut in 30 patients. A spreader flap and septal rotation suture were used instead of a spreader graft. Also in patients who needed a spreader graft and septal extension graft, a spreader graft was used on one side and a one-piece spreader graft combined with a septal extension graft was performed on the other side. For tip plasty, a columella septal suture was performed first. Postoperative patient satisfaction was assessed using the Rhinoplasty Outcome Examination questionnaire. Results: No serious complications were observed. The patient satisfaction score was 50% or above in 27 patients (90%) and less than 50% in only three patients (10%). The average score was 81.5 points. Conclusion: For septal cartilage deficiency, a spreader flap, the septal rotation suture, or onepiece spreader graft combined with a septal extension graft was used. The nasal tip was sufficiently rotated using the columellar septal suture technique first. These techniques made it possible to obtain good aesthetic outcomes using only septal cartilage, without harvesting other cartilage.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.12
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• pp.881-887
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• 2015

The stiffness and natural frequencies for blades, flexbeam, and torque tube of bearingless rotor system are measured to determine the material input properties such as mass distributions and stiffness distribution for the rotor dynamics and load analysis. The flap stiffness, lag stiffness, and torsional stiffness are calculated by measuring section strain or twist angle, gages position, and applied loads through bending and twist tests. The modal tests are undertaken to find out the natural frequencies for flap, lag, torsion modes in non-rotating conditions. The stiffness values and mass properties are tuned and updated to match prediction frequencies to the measured frequencies. The rotorcraft comprehensive code(CAMRAD II) is used to analyze the natural frequencies of the specimens. The analysis results with the updated material properties agree well with the measured frequencies. The updated properties will be used to analyze the rotor stability, dynamic characteristics and loads for the rotor rotation test in a whirl tower.

• Korean Journal of Head & Neck Oncology
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• v.7 no.2
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• pp.92-98
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• 1991

Numerous mycoutaneous island flaps or free flaps have been used to reconstruct a defect which resulted from the wide resection of tumor mass in head and neck region. Since the curative resection of tumor usually include muscles and bones as well as skin and mucosa, the anatomical and functional restoration of the defect depend on which and what amount of tissues were provided to cover the defect; good aesthetic appearance subsequently follows the result. Furthermore, a simultaneous neck nodes dissection usually results in exposure of major neck vessels., which should be protected with sufficient padding. The ideal method to reconstruct a defect in the head and neck region requires a sufficient coverage by muscle layer with good vascularity, a wide arc of rotation, and minimization of donor site defect. The pectoralis major myocutaneous flap which was first decribed by Ariyan and lateral trapezius myocutaneous flap by Demergasso meet these criteria. We describe the use of these myocutaneous flaps in reconstruction of mandible and oral cavity.

• Archives of Plastic Surgery
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• v.35 no.1
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• pp.92-95
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• 2008

Purpose: Heterotopic ossification in pressure sore patients is reported to rarely develop, but once it occurs, it frequently causes joint stiffness and mobilization restriction. The aim of this article is to report our experience of atypical bone growing at femur neck fracture site with chronic, extensive pressure sore in patient with paraplegia secondary to spinal injury. Methods: A 28-year-old male patient presented with atypical bone growth at femur neck fracture site with pressure sore. He had undergone atypical growth bone removal and separation of united iliac bone and femur, and then pressure sore was covered by advanced rotation flap. Results: The patient mobilized hip joint and rode in a wheelchair. Complications such as dehiscence, infection, hematoma and flap necrosis did not occur. Conclusion: We experienced successful correction of atypical bone growth removal and recovery of pressure sore. We report our experience of atypical bone growth of fracture site and the related literature was reviewed.

• Archives of Plastic Surgery
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• v.39 no.4
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• pp.360-366
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• 2012

Background Coverage of defects of the pretibial area remains a challenge for surgeons. The difficulty comes from the limited mobility and availability of the overlying skin and soft tissue. We applied variable pedicled perforator flaps to overcome the disadvantages of local flaps and free flaps on the pretibial area. Methods Eight patients who had the defects in the anterior tibial area were enrolled. Retrospective data were obtained on patient demographics, cause, defect location, defect size, flap dimension, originating artery, pedicle length, pedicle rotation, complication, and postoperative result. The raw surface created following the flap elevation was covered with a split thickness skin graft. Results Posterior tibial artery-based perforator flaps were used in five cases and peroneal artery-based perforator flaps in three cases. The mean age was 54.3 and the mean period of follow-up was 6 months. The average size of the flaps was 63.8 $cm^2$, with a range of 18 to 135 $cm^2$. There were no major complications. No patients had any newly developed functional deficit of the lower leg. Conclusions We suggest that pedicled perforator flaps can be an alternative treatment modality for covering pretibial defects as a simple, safe and versatile procedure.

• Journal of Yeungnam Medical Science
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• v.3 no.1
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• pp.237-241
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• 1986

In clinical microsurgery, limitation of space often prohibits rotation of a double clamp in an end-to-end anastomosis, or shortage of length of the secondary vessel in an end-to-side anastomosis does not allow visualization of the back wall. In these situation, back wall repair is extremely difficult. To overcome this problem, we use continuous suture technique without rotation of double clamp for end-to-end and end-to-side anastomosis of the 40 rat femoral arteries. After continuous sutures for microarterial anastomosis, the following results were obtained: Continuous sutures are useful in anastomosis where there is unavoidable limited access to the posterior wall and for some of the larger vessels now being anastomosed in free flap and other reconstructive surgery.

• Archives of Plastic Surgery
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• v.32 no.5
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• pp.667-670
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• 2005

Congenital facial cleft is a rare entity and appears along by the line of different processes of the facial development. An isolated cleft of the nose has been reported not often in the literature. We treated a patient with an isolated nasal cleft associated with undefined cranial anomaly. On 3D CT scan was seen a bony cleft traversing the pyriform aperture lateral to the anterior nasal spine. The nasal septum and frontal process of the maxilla were intact. There also was found bilateral bony defects in the frontal bone and bilateral frontal boss. The nasal cleft and frontal defect and boss were corrected by two stages: anterior two-third of the cranial vault with bilateral frontal boss was remodeled at the age of two years and the nasal cleft was repaired with a local rotation flap at age 3.

• Journal of Chest Surgery
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• v.22 no.5
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• pp.851-856
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• 1989

Initial successful treatment of postpneumonectomy empyema depends to a large extent on adequate dependent drainage of the empyema sac and the use of antibiotics. But definite control of the infected space remains a disturbing and controversial area in the field of thoracic surgery. A 55-year-old man had a right pneumonectomy for tuberculosis with the development of postoperative thoracic empyema and in October 1973. Postoperatively, an empyema developed and the condition was managed with closed drainage and an open window thoracostomy. He was transferred to our institution in October 1988, and underwent thoracoplasty for the obliteration of the empyema space, resulting in a remaining space. The remaining space after thoracoplasty was obliterated by myoplasty using a rotation flap of splitted pectoralis major muscle three months later. He was discharged with uneventful course 12 days after operation, and continues to do well 3 months following operation. Our experience shows that thoracoplasty and myoplasty offer an effective alternative method of management of post-pneumonectomy empyema.