• 한국방재학회:학술대회논문집
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• 한국방재학회 2008년도 정기총회 및 학술발표대회
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• pp.249-252
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• 2008

본 연구에서 북한의 지진자료에 대해 지진파의 이론적인 파형이 파수(wavenumber)와 주파수(frequency)에 대한 적분의 형태로 계산된다. 이 방법은 매질에 대해 많은 층의 입력값을 적용할 수 있기 때문에 실제지진 자료와 비슷한 이론적인 파형을 계산할 수 있다. 반복 작업에 의해 각 층의 두께와 속도, 감쇄상수 등을 고려한 한반도 지각에 가장 잘 적용할 수 있는 모델을 사용해서 북한의 폭파와 지진자료와 비슷한 이론적인 파형을 계산하였다. 본 연구의 결과는 지표의 퇴적층의 두께, 속도, 감쇄 상수가 이론적인 파형 계산에 매우 중요하다는 사실을 말한다. 실제 지진자료와 이론 파형을 비교 시, 초기 주시와 파형의 모양이 아주 잘 맞는 것을 볼 때 결과 모델이 한반도의 실제 지각구조와 매우 비슷하고 북한의 지진자료의 이론 파형 계산이 잘 되었다는 것을 알 수 있다.

• 한국구조물진단유지관리공학회 논문집
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• 제16권1호
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• pp.89-98
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• 2012

일체형 삼각 트러스 형태의 철선을 아연도금 강판에 용접한 철선일체형 데크 플레이트는 슬래브 시공 시 현장시공 최소 및 동바리와 지보공 등 거푸집 공사비 절감을 목적으로 개발되어 이미 많은 현장에 적용되고 있다. 본 연구에서는 180mm 두께 슬래브에 적용 가능한 철선일체형 데크 플레이트 시스템을 개발하기 위해 실험적 연구를 수행하였다. 상부철선, 하부철선, 래티스 철선, 경간, 단부가공방법을 변수로 채택하여 총 14개의 시험체를 실물크기로 제작하여 실험을 수행하였다. 실험결과 시험체의 최종 파괴형태 변화 및 단부가공방법이 시험체의 구조 성능에 영향을 미치지 않는 것으로 나타났으며, 하부철선의 영향보다는 래티스 철선이 시험체의 거동에 큰 영향을 미치는 것으로 나타났다.

• Restorative Dentistry and Endodontics
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• 제19권1호
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• pp.159-168
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• 1994

The purpose of this study was to evaluate the shear bond strength of the porcelain laminate specimens according to the surface roughness of the cut enamel of human anterior teeth. Flat enamel surfaces were prepared in 30 extracted human anterior teeth with diamond disc which were divided into two groups. Group 1 Coarse enamel surface group prepared with LVS-3 bur. Group 2 Fine enamel surface group prepared with superfine diamond bur. 30 teeth specimens of two group were stored in normal saline during 24 hours. 30 disk - type porcelain laminate specimens with diameter 4mm and thickness 1mm were made and sand - blasted on internal surface which were to cemented on enamel surface. Porcelain laminate specimens were cemented on enamel surface with Choice Veneer System (Bisco Dental, U.S.A) according to manufacture's instructions. All teeth specimens of two groups were manipulated with same method and stored In normal saline before testing. An Universal Testing machine (Model No.UTM-4206,Instron, U.S.A) was used to apply shear loads in the vertical directed, and the force required for separation was recorded with a cross head speed of 3mm/min and 500kg in full scale. The results were as follow ; 1. The mean shear bond strength of coarse surface group was 36.30kg and that of fine surface group was 44.39 kg, but there was no significant difference in breaking strength of two groups(p>0.05).

• Archives of Plastic Surgery
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• 제34권1호
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• pp.64-69
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• 2007

Purpose: The key of treatment in syndactyly is to separate the fused digits safely, and to create a normal web space with enough cutaneous coverage. Despite many techniques have described the correction of syndactyly, skin graft still remains the annoying one. We designed the pentagonal flap from hand dorsum to reconstruct the web space reliably and try to minimize the need for skin graft. Methods: Between July 2003 and August 2005, six cases of syndactyly were corrected at UCLA Medical Center and Hallym University Sacred Heart Hospital using dorsal pentagonal flap for web space reconstruction and straight incisions for the sides of digits to minimize the need for skin graft. The proximal edge of the pentagonal flap was designed in V shape to allow for easy closure of the donor site after advancement. The pentagonal flap was advanced volarly with the underlying dermofat tissues to form a digital web. In some cases, skin defects were unavoidable and covered with full thickness skin graft from the inguinal area. Results: Syndactyly were seen in 4 cases of Apert syndrome, 1 postburn scar webbing with PIP joint contracture and 1 recurrence after the incomplete reconstruction. In all Apert syndrome, straight line incision was used along the sides of the fingers and skin graft was needed. But, in 2 cases of incomplete type, we could save the need for skin graft only for the correction of syndactyly. We could get a good looking web space without any complications such as flap or graft loss. Conclusion: As a modification of Sherif's V-Y dorsal metacarpal flap, we believe pentagonal flap could be one of the easiest and safest way to reconstruct the web space of syndactyly in functional and cosmetic standpoint.

• Archives of Plastic Surgery
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• 제38권4호
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• pp.351-358
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• 2011

Purpose: The inflammatory phase is considered an integral part of adult wound healing, but fetal wound healing studies have shown scarless healing results in the absence of the inflammation process. The COX-2 pathway is an essential component of inflammation. The purpose of this study is to identify the effect of a topical selective COX-2 inhibitor on inflammation in rabbit skin wound healing and scarring. Methods: Full-thickness wounds were made on 6 New Zealand rabbits' ears. Topical 5% celecoxib + vehicle (experimental tissue) and vehicle only (controlled tissue) were applied daily for 14d on each side of the ears. Scar samples were harvested at 2 wks, 4 wks, and 8 wks after the wounding. Each sample was stained with hematoxylin and eosin and the Masson's trichrome stain to evaluate inflammation and scar formation. Results: Histological analysis demonstrated a significant reduction of inflammation, neovascularization, and scar elevation in the experimental tissue as compared to the control. Additionally, experimental tissue exhibited faster improvement of collagen organization similar to that of normal tissue. Conclusion: This study suggests that the topical application of a selective COX-2 inhibitor on a rabbit ear wound resulted in decreased inflammation and had a positive effect on the reduction of scar formation.

• Archives of Plastic Surgery
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• 제38권4호
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• pp.451-457
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• 2011

Purpose: As a central feature of the face, the nose has considerable significance in appearance and expression. Reconstruction of full thickness defects of the nasal ala has always been a challenge because of the 3-dimensional structure. For reconstruction of post burn defects of ala, skin graft, local or pedicled flap and composite graft are optionally available. We have reconstructed the ala defects using adiposocutaneous graft and observed the outcome. Methods: From March 2003 to December 2010, 19 cases in 11 patients with scar contracture and defect on ala portion were performed operation using adiposocutaneous graft. As a donor site, we used the inguinal crease and posterior auricular area and the donor site was primarily closed. We made incision through the superior rim of ala and released fully. A graft is applied to recipient site with larger size than recipient volume. Results: The mean age of the patient was 38.6 years (16~51), males are seven patients and females are four patients. The operation was performed bilaterally in 5 patients and unilaterally in 6 patients. Composite grafts were harvested from inguinal area in 13 cases and posterior auricular area in 6 cases. In one case, we did 4 times of operation to get enough volume. All the grafts were well taken. The mean size of the graft was 3.63 $cm^2$. Conclusion: For reconstruction of post burn defects of ala, it's not easy to use local flap or pedicled flap because of hardness and fibrosis of surrounding tissue. So, we choose adiposocutaneous graft for ala deformity reconstruction, got satisfactory outcome in color matching and texture.

• Archives of Plastic Surgery
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• 제38권4호
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• pp.401-407
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• 2011

Purpose: A number of flap for nipple reconstruction have been well described in the literature. However, most of these techniques do not permit the reconstruction of a projecting nipple and all are hampered to some extent by long-term loss of nipple projection. The objective of this study is to evaluate the long-term result and clinical efficacy of nipple reconstruction using skate flap technique after breast reconstruction. Methods: A retrospective chart review was carried out on 23 patients who underwent 25 nipple reconstructions. In those patients with greater than 10 mm nipple projection, reconstruction with skate flap and full-thickness skin graft and/or tattooing was performed. Maintenance of nipple projection was then carefully assessed over one-year follow-up. The following factors were analyzed: type of breast reconstruction, type of areola reconstruction, followup period, decrease in nipple projection, complication, and whether secondary nipple reconstruction was necessary and/or performed. Results: Breast reconstructions were performed in 17 patients with free transverse rectus abdominis musculocutaneous flap, 3 patients with extended latissimus dorsi musculocutaneous flap, and 3 patients with expander and implant. The mean follow-up after nipple reconstruction was 17 months. Mean loss of projection were $17.0{\pm}13.99%$, $25.0{\pm}12.70%$, $30.0{\pm}12.57%$ and $30.8{\pm}12.49%$ at 3, 6, 9 months and over one year, respectively. The greatest decrease in projection was noted in the first 3 months following surgery. Conclusion: These results indicated that nipple reconstruction with skate flap showed about 70 percent of the projection achieved over one year postoperation. Therefore, the skate flap may be a reliable method of nipple reconstruction in those patients with greater than 10 mm nipple projection.

• Archives of Plastic Surgery
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• 제37권6호
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• pp.847-849
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• 2010

Purpose: Traditional radical surgery for vulvar cancer produces severe skin and soft tissue defects in the vulvar and vaginal area. Vulvoperineal V-Y advancement fasciocutaneous flaps have limitations in advancement and tension at the wound margin and vaginal orifice area, causing wound disruption or vaginal wall exposure. Therefore, we designed the "Butterfly flap" using a vulvoperineal V-Y advancement fasciocutaneous flap and an inguinal rotational skin flap for 3-dimensional reconstruction of vagina and vulvar area. Methods: A 27 year-old female was diagnosed with vulvar intraepithelial neoplasia. Radical vulvectomy and full-thickness-skin-graft was performed. We designed a vulvoperineal V-Y advancement fasciocutaneous flap as the greater wing and inguinal rotational skin as the lesser wing. After flap elevation, the inguinal flap was rotated $180^{\circ}$ to reconstruct the labia major and vaginal orifice. The perineum was reconstructed using V-Y advancement flaps. Results: The flap survived completely, without any complications. After 6 months, the patient was able to perform normal sexual activities and after 18 months, the patient was able to give birth to normal child by caesarean section. Conclusion: The traditional vulvoperineal V-Y advancement fasciocutaneous flap is thin, reliable, easily elevated and matches local skin quality. However, the vaginal wall becomes exposed due to limited advancement and tension of the flap. The "Butterfly flap" using a vulvoperineal V-Y advancement fasciocutaneous flap and an inguinal rotational skin flap is useful for the release of vaginal orifice contracture, reconstruction of the labia major, and 3-dimensional reconstruction of vagina and vulvar area.

• Archives of Plastic Surgery
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• 제37권6호
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• pp.763-768
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• 2010

Purpose: Reconstruction of soft tissue defect using tissue expander can provide better flap which is more similar to surrounding tissue in color, skin texture and hair compared to other methods. Many pediatric patients need reconstruction of soft tissue defect because of giant congenital nevi, congenital or acquired malformations and burn scars. Reconstruction using tissue expander is adequate to minimize dysmorphism in these patients. We intended to assess outcomes of using tissue expander in pediatric patients by retrospective study. Methods: Total cases were 168 of pediatric patients who received soft tissue reconstruction using tissue expander by the same surgeon from February, 1982 to May, 2009. All patients who received soft tissue reconstruction were under 10 years old. Mean age was 4.3 years old, the youngest 13 months, the oldest 8 years. Eightynine cases were male and 79 cases were female. Most common cause was giant hairy nevi (67 cases, 39.9%), secondary cause was burn scar/scar contracture (61 cases, 36.3%). Trunk (38 cases, 22.6%) was most common anatomical location. Results: Soft tissue defects were successfully covered using tissue expander in 149 cases (88.7%) without major complications. There was infection on 8 cases (4.7%) and we treated by adequate antibiotics in these cases. There were tissue expander folding or valve displacement on 5 cases (3%). Conclusion: Usage of tissue expander is useful on pediatric patients because tissue expansion is rapid on children and there are less secondary contractures on operation site than full thickness skin graft. Because of psychological stress due to tissue expander, operation should be performed before school age.

• Archives of Plastic Surgery
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• 제36권5호
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• pp.519-524
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• 2009

Purpose: This study was conducted to establish the most effective method of cell therapy by comparing and analyzing the level of wound healing after various cell delivery methods. Methods: Human mesenchymal stem cells were administered using 5 different methods on full thickness skin defects which were deliberately created on the back of 4 - week old mice using a 8 mm punch. Different modes of administration, cell suspension, local injection, collagen GAG matrix seeding, fibrin, and hydrogel mix methods were used. In each experiment group, $4{\times}105$ mesenchymal stem cells were administered according to 5 deferent methods, and were not for the corresponding control group. Results: The wound healing rate was fastest in the local injection group. The wound healing rate was relatively slow in the collagen matrix group, however, the number of blood vessels or VEGF increased most in this group. Conclusion: For rapid wound healing through wound contraction, it is advantageous to administer MSC by the local injection method. For the healing process of a wide area, such as a burn, the seeding of cells to collagen matrix is thought to be effective.