• 한국항공운항학회지
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• 제19권3호
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• pp.1-9
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• 2011

In this paper, a conceptual design process for Very Light Jet aircraft has been proposed incorporating aircraft safety certification. During the proposed design process, satisfaction of the airworthiness certification for an intermediate resulting aircraft configuration is evaluated and then redesigns are carried out if necessary and until the designed aircraft configuration satisfies the airworthiness requirements. Certification database has been developed using FAR 23, AC 23, KAS 23, and CS 23 as the airworthiness certification. Based on the developed certification database Design Certifcation Related Table has been produced to use the airworthiness requirements as design constraints in the propsed design process. Using Quality Function Deployment the design variables for a redesign are carefully selected and a design optimization is performed. To demonstrate the feasibility and effectiveness of rapid aircraft conceptual design using the proposed approach, a Very Light Jet design optimization including a redesign of wing flap has been performed and the design results have been presented.

• Archives of Plastic Surgery
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• 제34권4호
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• pp.441-447
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• 2007

Purpose: Various kinds of local flap or free flap have been used for coverage for soft tissue defects with bone exposure over the ankle and dorsum of foot. Adipofascial flaps, nourished by vascular plexuses of the subcutaneous tissue and deep fascia originating from the local perforators of the major vessels, appear particularly to be indicated for the reconstruction of these areas. Our experience with this flap on the dorsum of foot and ankle has also been quite encouraging. Methods: The design of the flap is determined by the size and the location of the defect. The base of the flap is chosen depending on the availability of the soft tissue around the defect. The ratio of the area of the flap to the area of the base wound be more reliable to predict the survival of the turnover flap by the conventional length-to-width ratio. Nineteen patients with defect over the dorsum of the foot and ankle were resurfaced with adipofascial turn-over flaps and skin graft. Results: The average age of the patients was 38.2 years(3 - 81 years). The flap size was from $2{\times}3cm$ to $8{\times}5cm$. The average follow-up time was 6 months. All flaps survived completely except one case who suffered distal necrosis of the flap. The additional skin graft was required for partial skin loss in the five cases. Other functional impairment was not noted. Conclusion: Dissection of the local adipofascial turnover flap is quite easy, quick, requires less time and sacrifice of surrounding muscle itself, and maintains major arteries. In most cases, donor-site morbidity is minimal with an acceptable scar, and both functional and esthetical results were satisfactory. Therefore, Adipofascial flap could be an option for the difficult wounds around the foot and ankle.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.441-446
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• 2011

To investigate aerodynamic performance of high-lift devices, 2D design is the base of the success of high-lift system design for transport aircraft, which can shorten the periods of three-dimensional design and analysis. For the simulation coupled viscous and inviscous euler method (MSES) is used. In this parametric study, Gap and Overlap which can define position of flap is used as design variables and we investigale relation between angle of attack and flap position for lift enhancement.

• 대한두경부종양학회:학술대회논문집
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• 대한두경부종양학회 2006년도 추계학술대회 논문집
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• pp.219-219
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• 2006

• Advances in aircraft and spacecraft science
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• 제2권1호
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• pp.45-56
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• 2015

The attitude aerodynamic control is an important subject in the design of an aerospace plane. Usually, at high altitudes, this control is fulfilled by thrusters so that the implementation of an aerodynamic control of the vehicle has the advantage of reducing the amount of thrusters fuel to be loaded on board. In the present paper, the efficiency of a wing-flap has been evaluated considering a NACA 0010 airfoil with a trailing edge flap of length equal to 35% of the chord. Computational tests have been carried out in hypersonic, rarefied flow by a direct simulation Monte Carlo code at the altitudes of 65 and 85 km, in the range of angle of attack 0-40 deg. and with flap deflection equal to 0, 15 and 30 deg.. Effects of the flap deflection have been quantified by the variations of the aerodynamic force and of the longitudinal moment. The shock wave-boundary layer interaction and the shock wave-shock wave interaction have been also considered. A possible interaction of the leading edge shock wave and of the shock wave arising from the vertex of the convex corner, produced on the lower surface of the airfoil when the flap is deflected, generates a shock wave whose intensity is stronger than those of the two interacting shock waves. This produces a consistent increment of pressure and heat flux on the lower surface of the flap, where a thermal protection system is required.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 춘계학술대회 논문집
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• pp.347-352
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• 2013

Seoul National University Flap (SNUF) blade is a small-scaled rotor blade incorporating a small trailing-edge flap control surface driven by piezoelectric actuators at higher harmonics for vibration attenuation. Initially, the blade was designed using two-dimensional cross-section analysis and a geometrically exact one-dimensional beam analysis, and material configuration was finalized. Flap deflection angle of ${\pm}45^{\circ}$ was established as the criterion for better vibration reduction performance based on an earlier simulation. Flap linkage mechanism design is carried out and static bench tests are conducted to verify the flap actuation mechanism performance. Different versions of test beds are developed and tested with the flap and chosen APA 200M piezoelectric actuators. Through significant improvements, a maximum deflection of ${\pm}3.7^{\circ}$ was achieved. High frequency experiments are conducted to evaluate the performance and transfer function of the test bed is determined experimentally. As the static tests are almost completed, rotor power required for testing the blade in whirl tower (centrifugal environment) is calculated and further preparations are under way.

• Archives of Reconstructive Microsurgery
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• 제11권2호
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• pp.146-152
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• 2002

As the defects of the penis caused by trauma, surgical amputation, or congenital abnormality give the patients both psychological trauma and functional impairment, reconstruction of the penis is mandatory. Radial forearm free flap is reliable one-stage procedure, which can reconstruct both the phallus and the urethra. Chang and Whang's adaptation of the "tube-in-a-tube" concept and its incorporation into a free flap design represented a major advance in microsurgical phallic construction. Biemer described a modification of the radial forearm flap design in which the neourethra was centered over the radial artery, but the phallic shaft was separated into two paraurethral swatches. The authors have performed one-stage penile reconstruction in two patients since 1998, using a radial forearm free flap. Our present design incorporates the original Biemer triple skin island and includes a fourth distal island for neoglans. One case was the amputation of the penis from felonious assault and the other case was the iatrogenic penile amputation from repetitive urologic surgery for congenital hypospadia. All patients showed aesthetically acceptable results and good tactile sensory recovery. Severe complications such as necrosis, fistula, or urethral stricture were not occurred. Biemer's method modified by the authors is reliable one-stage penile reconstruction providing good aesthetic and functional results.

• Archives of Plastic Surgery
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• 제47권2호
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• pp.194-197
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• 2020

Anterior neck burns represent a major reconstructive challenge due to severe sequalae including restriction in movement and poor aesthetic outcomes. Common treatment options include skin grafting with/without dermal matrices, and loco-regional and distant free flap transfers with/without prior tissue expansion. Such variation in technique is largely influenced by the extent of burn injury requiring resurfacing. In order to optimize like-for-like reconstruction of the anterior neck, use of wide, thin and long flaps such as the anterolateral thigh (ALT) perforator flap have been reported with promising results. Of note, some patients have a tendency towards severe scar contractures, which may be contributed by the greater extent of inflammation during wound healing. We report our experience at 4 years' followup after secondary reconstruction of severe, anterior neck burn contractures in two patients by harvesting the ALT flap with a butterfly design. This technique provides adequate wound resurfacing of the burned neck and surrounding areas, and provides good neck extensibility by addressing both anterior and lateral aspects of the scar defect simultaneously. Such a flap design reduces tension on wound edges and thus, the risk of contracture recurrence in what remains a particularly challenging type of burn reconstruction.

• Archives of Plastic Surgery
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• 제33권5호
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• pp.655-658
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• 2006

Purpose: The main goals of correcting syndactyly of the hand are to form normal web appearance and to prevent motor dysfunction. We modified the original three-square-flap to improve interdigital web space and to reduce the wound healing problem due to tension. Methods: From July 2005 to February 2006, three cases of moderate to minor syndactyly were treated using modified three-square-flap. These flaps were made in such as way that the A flap from dorsal side, the B flap from the interdigital surface, and the C flap from the volar side. We modified the design of dorsal A flap as a hourglass shape instead of square shape to make normal hourglass shaped interdigital web and to reduce the tension of closure with other two flaps(B and C flap). The B and C flap were made as square shape. Results: During 4 to 10 months follow-up period, acceptable esthetic results were obtained without any specific complication, using our modification of the three-square-flap. Conclusion: Our method showed more satisfactory web appearance and was safe to use even in the cases of syndactyly secondary to burns and post-traumatic scars because of excellent blood circulation.

• Archives of Plastic Surgery
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• 제34권4호
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• pp.448-454
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• 2007

Purpose: The objective of this study was to evaluate the outcomes of using the free flap in the reconstruction of maxillary defects. Methods: 27 consecutive cases of maxillary reconstruction with free flap were reviewed. All clinical data were analyzed, including ideal selection of flap, time of reconstruction, recurrence of cancer, postoperative complications, flap design, and follow-up results. The main operative functional items, including speech, oral diet, mastication, eye globe position and function, respiration, and aesthetic results were evaluated. Results: Among the 24 patients who underwent maxillary reconstruction with the free flap, 14 patients underwent immediate reconstruction after maxillary cancer ablation, and 10 patients underwent delayed reconstruction. There occurred 1 flap loss. Recurrences of the cancer after the reconstruction happened in 2 cases. Postoperative complications were 3 cases of gravitational ptosis of the flap, 2 cases of the nasal obstruction, and 1 case of fistula formation. Out of 27 free flaps, there were 15 latissimus dorsi myocutaneous flaps, 5 radial forearm, 4 rectus abdominis myocutaneous flaps, 1 scapular flap, 2 fibula osteocutaneous flap, respectively. Flaps were designed such as 1 lobe in 9 cases, 2 lobes in 9 cases, and 3 lobes in 5 cases. Among the 14 patients who had intraoral defect or who had palatal resection surgery, 2 patients complained the inaccuracy of the pronunciation due to the ptosis of the flap. It was corrected by the reconstruction of the maxillary buttress and hung the sling to the upper direction. All of the 14 patients were able to take unrestricted diets. In 6 patients who had reconstruction of inferior orbital wall with rib bone graft, they preserved normal vision. Aesthetically, most of the patients were satisfied with the result. Conclusion: LD free flap is suggested in uni-maxilla defect as the 1st choice, and fibular osteocutaneous flap and calvarial bone graft to cover the larger defect in bi-maxilla defect.