• Transactions of the KSME C: Technology and Education
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• v.3 no.3
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• pp.183-191
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• 2015

In this study, the finite element analysis was carried out to investigate dynamic characteristics of the AGF(Active Gurney Flap) which is under development for reducing vibration and noise of the helicopter rotor system. The Gurney flap is a kind of small flat plate, mounted normal to the lower surface of the airfoil near to the trailing edge. An electric motor, L-shaped linkages and flap parts were integrated into a rotor bade, and 3~5/rev control was given to the AGF to reduce the vibration in the fixed frame. Thus, an explicit time integration method was adopted to investigate the dynamic response of the AGF with considering both centrifugal force due to the rotor rotation and active control input, and it can be seen that the vertical displacement of the AGF was satisfied to meet the design requirement.

• Korean Journal of Cleft Lip And Palate
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• v.8 no.1
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• pp.31-37
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• 2005

In alveolar deformity of cleft patient, the flap design is very important to make the functional and esthetic outcome. Especially in bilateral cleft alveolus with wide defect, deficiency of covering tissue is a greatest problem. Wound dehiscence may develop oronasal fistula of palatal and labial region and loss of the bone graft. We report 2 cases with bilateral cleft alveolus. In both case, bilateral buccal mucosal flap was used for closure of bilateral cleft alveolus with wide defect. The one was operated with iliac bone graft according to secondary grafting method, the other was closed without bone grafting. The patient was 3 years old. So, secondary alveolar bone graft will be required some years later for the establishment of bony continuity and esthetic advantage. In both cases, we found the entire soft tissue closure without the lack of covering flap. In these case, the closure of alveolus defect was accomplished successfully by the use of bilateral buccal mucosal flap. There was no complication, secondary fistula. The most important thing is the tension-free closure of the bilateral buccal mucosal flap. So, we report these cases with literatures.

• Archives of Plastic Surgery
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• v.36 no.4
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• pp.422-427
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• 2009

Purpose: Breast cancer is second most common cancer in women. Almost of patients with breast cancer treated with mastectomy undergoes breast reconstruction. Nipple reconstruction is an important step in breast reconstruction. Many surgeons have investigated of nipple reconstruction using the flap technique after breast reconstruction with the autologous tissue. The objective of this study is to evaluate the results of nipple reconstruction using the C - V flap technique after breast reconstruction with the only breast expander. Methods: From April 2006 to May 2008, the authors treated 17 patients of nipple reconstruction using C - V flap technique, who were received breast reconstruction with the only breast expander. We have predicted decrease of the size of reconstructed nipple and designed flap a little larger than wanted nipple size. Nipple splint was applied for 4 - 6 months for minimizing decrease of the size of reconstructed nipple. The diameter and height of the reconstructed nipple were measured and patient's satisfaction score was assessed. Results: Mean follow-up duration was 12.5 months. Among the 17 patients, the average absorption rate by height of nipple was 47.0%. Partial necrosis was noted in 1 case, and treated well with conservative management. There was no other significant complications noted. Patient's satisfactory score was assessed by the height, design and location of the nipple. The average of satisfaction score was 85%, 68%, 62% and total average was 83%. Conclusion: The authors experienced 17 patients of nipple reconstruction using the C - V flap technique after breast reconstruction with the only breast expander. The absorption rate of the size of the nipple, complications and patient's satisfactory score of this study were similar to those of nipple reconstruction after breast reconstruction with the autologous tissue. It is expected that nipple reconstruction after breast reconstruction with the only breast expander is safe and reliable. It is considered that a long - term study is necessary.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.33 no.5
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• pp.203-216
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• 2021

Analyzing various wave interactions with oscillating wave surge converters (OWSC) is essential because they must be operated efficiently under a wide range of wave conditions and designed to extract optimal wave energy. In the conceptual design and development stage of OWSC, numerical analysis can be a good alternative as a design tool. This study performed a numerical analysis on the behavioral characteristics of the inverted triangle flap against the incident waves using open source CFD to examine the essential behavioral attributes of OWSC. Specifically, the behavioral characteristics of the structure were studied by calculating the free water surface displacement and the flap rotation angle near the inverted triangular flap according to the change of the period under the regular wave conditions. By comparing and examining the numerical analysis results with the hydraulic model experiments, the validity of the analysis performed and the applicability in analyzing the wave-structure interactions related to OWSC was verified. The numerical analysis result confirmed that the hydrodynamic behavior characteristic due to the interactions of the wave and the inverted triangle flap was well reproduced.

• Wind and Structures
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• v.2 no.2
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• pp.119-125
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• 1999

The ZG Bridge(preliminary design), with unfavorable aerodynamic stability characteristics, is a truss-stiffened suspension bridge, its critical wind speed of flutter instability is much lower than that of code requirement, In the present paper, based on both aerostatic and aeroelastic section model wind tunnel test, not only effects of some aerodynamic means on aerodynamic stability of its main girder are investigated, but also such effective aerodynamic means of it as flap and plate-like center stabilizer are concluded.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.4
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• pp.286-292
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• 2012

The lateral upper arm flap (LUAF) was initially described by in 1982 by Song et al. as a simple skin flap, addressing the availability of cutaneous nerves for anastomoses. Katsaros et al., reported the use of a lateral upper arm skin flap, but also considered using it as a composite graft. The LUAF for the oral and maxillofacial reconstruction has several advantages over other flaps, such as constant anatomy, good color match and texture, thin design and plasticity. There is no functional limitation in the donor arm, such as strength and extension, and donor defects can be closed primarily with a linear scar, even when a flap of up to 8 cm in width is taken. For a better understanding of LUAF as a routine reconstructive option in moderate defect of maxillofacial region, the constant anatomical findings must be learned and memorized by young doctors during the specialized training course for the Korean national board of oral and maxillofacial surgery. This article review the anatomical basis of LUAF with Korean language.

• Archives of Plastic Surgery
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• v.41 no.1
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• pp.50-56
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• 2014

Background The aim of this study was to determine the efficacy of lateral intercostal artery perforator-based adipofascial free flaps for facial reconstruction in patients with facial soft tissue deficiency. Methods We conducted a retrospective study of five consecutive patients diagnosed with facial soft tissue deficiency who underwent operations between July 2006 and November 2011. Flap design included the area containing the perforators. A linear incision was made along the rib, which had the main intercostal pedicle. First, we dissected below Scarpa's fascia as the dorsal limit of the flap. Then, the adipofascial flap was elevated from the medial to the lateral side, including the perforator that pierces the serratus anterior muscle after emerging from the lateral intercostal artery. After confirming the location of the perforator, pedicle dissection was performed dorsally. Results Dominant perforators were located on the sixth to eighth intercostal space, and more than four perforators were found in fresh-cadaver angiography. In the clinical case series, the seventh or eighth intercostal artery perforators were used for the free flaps. The mean diameter of the pedicle artery was 1.36 mm, and the mean pedicle length was 61.4 mm. There was one case of partial fat necrosis. No severe complications occurred. Conclusions This is the first study of facial contour reconstruction using lateral intercostal artery perforator-based adipofascial free flaps. The use of this type of flap was effective and can be considered a good alternative for restoring facial symmetry in patients with severe facial soft tissue deficiency.

• Journal of the Korean Society for Railway
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• v.14 no.4
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• pp.327-332
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• 2011

As the preceding research for the design of gangway in the next generation high speed train, the aero-acoustic noise at the gangway is calculated. For this purpose, the shape of gangway with mud flaps is assumed as the two-dimensional cavity. Then, 5 gap sizes between mud flaps of gangway are selected and parametric study is performed according to the gap sizes. From this study, the aerodynamic features such as vortex shedding, pressure, etc. are computed. Also, the aero-acoustic properties of tonal noise and overall noise are analyzed at the 3 locations of microphone and the relation between the gap size of mud flap and the noise level is assessed. Through this study, it is shown that the noise characteristics of base and specific models are better than those of other models.

• Smart Structures and Systems
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• v.14 no.4
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• pp.659-678
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• 2014

The study is aimed at investigating the feasibility of a high TRL solution for a wing flap segment characterized by morphable camber airfoil and properly tailored to be implemented on a real-scale regional transportation aircraft. On the base of specific aerodynamic requirements in terms of target airfoil shapes and related external loads, the structural layout of the device was preliminarily defined. Advanced FE analyses were then carried out in order to properly size the load-carrying structure and the embedded actuation system. A full scale limited span prototype was finally manufactured and tested to: ${\bullet}$ demonstrate the morphing capability of the conceived structural layout; ${\bullet}$ demonstrate the capability of the morphing structure to withstand static loads representative of the limit aerodynamic pressures expected in service; ${\bullet}$ characterize the dynamic behavior of the morphing structure through the identification of the most significant normal modes. Obtained results showed high correlation levels with respect to numerical expectations thus proving the compliance of the device with the design requirements as well as the goodness of modeling approaches implemented during the design phase.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.49 no.2
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• pp.91-95
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• 2023

This study examined the effects of a vertical incision on postoperative edema after third molar extraction. The study design was that of a comparative split-mouth approach. Evaluation was performed via magnetic resonance imaging (MRI). Two patients with homogeneous bilateral impacted mandibular third molars were enrolled. These patients underwent facial MRI within 24 hours after simultaneous extraction surgery. Modified triangular flap and enveloped flap incisions were made. Postoperative edema was evaluated by MRI and was assessed according to anatomical space. The two pairs of homogeneous extractions demonstrated that vertical incisions were associated qualitatively and quantitatively with extensive postoperative edema. The edema associated with these incisions spread toward the buccal space, beyond the buccinator muscle. In conclusion, a vertical incision with mandibular third molar extraction was related to edema in the buccal space and the fascial space, which contributed to clinical facial swelling.