• 한국가구학회지
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• 제21권1호
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• pp.26-39
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• 2010

This is a leading study to replace the structural analysis methodology on the specific traditional joint by a numerical analysis. Tests were carried out to test the compressive methodologies with the numerical results. The Japanese larch was used as a sample. The Orthotropic property of wood was specifically considered for the finite element numerical analysis. Linear numerical analysis and non-linear numerical analysis for the BEAM element and the two SOLID elements of ANSYS were used to analyze the compressive performance. In addition, more finely divided elements were used to raise the accuracy of the numerical result. Finally, the statistically significant differences were tested between that of the analytical and numerical results. It could be concluded that the SOLID 64 element shows the most optimum result when the non-linear analysis with the more finely divided element was used. However, finely dividing of the element is a considerable time consuming process, and it is quite difficult to raise the accuracy of the non-linear numerical analysis. Therefore, if considering the vertical displacement to be of the only interest, the BEAM element is more efficient than the SOLID element because the BEAM element is reflected as a simple line, which is less time consuming and difficult in dividing the elements. But, the BEAM element cannot accurately model the knot as a strength defect factor which is an important property in the orthotropic property of wood. Therefore, the SOLID element should be used to model the strength defect factor, knot, as it can be efficiently applied on the structural size flexure member which could be more strongly effected by the knot. In addition, it is useful at times when the failure types of members are to be more closely investigated, as the SOLID element is able to examine the local stress distribution of the member. The conclusion drawn by this study is of the good concordance between analytical results and numerical results of compressive wood members, but how orthotropic properties should only be considered. The numerical analysis on the specific Korean traditional joints will be based on the current study results.

• 비파괴검사학회지
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• 제31권2호
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• pp.150-156
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• 2011

본 논문에서는 현재 산업 전반에 널리 사용되고 있는 복합재료(탄소섬유강화플라스틱, 유리섬유강화플라스틱)의 비파과검사를 위한 광적외선 열화상기법을 이용한 복합재료 측정 표준기술개발을 위한 결함(인클루젼, 충간결함) 검출 기술을 실험하였다. 결함의 검출률을 높이기 위하여 위상잠금 방법을 활용하였다. 결과는 시험편의 두께에 따라 광원의 조사시간을 늘릴 경우 결함 검출의 확률이 높아진다는 것을 알 수 있다. 하지만 50 mHz 이하의 광원을 가하였을 때에도 결과값이 좋아지지 않는 점은 열확산이 재료 전체에 영향을 미치게 되면 결함 부위가 전체적으로 열평형 상태가 되어 결함 검출이 어려움을 파악할 수 있었다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권5호
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• pp.380-390
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• 2004

Bone healing plays an important role in orthognathic and craniofacial surgery. Bone tissue repair and regeneration are regulated by an array of growth and morphogenetic factors. Bone formation and remodeling require continuous generation of osteoprogenitor cells from bone marrow stromal cells, which generate and respond to a variety of growth factors with putative roles in hematopoiesis and mesenchymal differentiation. In this study, the efficacy of a single application of hepatocyte growth factor to promote bone regeneration in 5-mm experimental calvarial defects of adult male rats was assessed histologically and immunohistochemically. The result of the experimental site were compared with those of the contralateral contral side. None of the control and experimental bone defects demonstrated complete bone closure. Bone regeneration was found close th the margine and central part of the defects. At 1, 2 weeks, there were found much significant cellural mitotic activity and many inflammatory cells and osteoblasts on the experimental site than control site. At 4, 6 weeks, new bone apposition was founded in both site but, more apposition was seen at experimental site. At 8, 12 weeks, also, some differences was found that more apposition of new bone and collagen fiber was seen on experimental site. Our results have some possibility that HGF do a early positive role to repair the bone defect. More study will be needed.

• 한국콘텐츠학회논문지
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• 제9권7호
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• pp.110-120
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• 2009

최근 소프트웨어 품질평가 및 인종에 대한 인식의 제고와 더붙어 소프트웨어 개발 기업에서 품질투자를 통한 고품질 확보의 중요성에 대한 인식이 증대되고 있다. 그러나 실질적으로 어느 정도 수준에서 품질투자가 이루어져야 하는지, 품질투자를 통해 실질적으로 소프트웨어 품질 개선의 검증이 이루어지지 않음으로 해서 품질투자를 통한 품질개선을 원하는 기업들이 정확한 방향을 설정하지 못하고 있는 문제가 발생 하고 있다. 본 연구에서는 국제표준인 ISO/IEC 9126과 소프트웨어 시험에 관한 지침인 ISO/IEC 12119를 기반으로 메트릭을 구축하였으며 소프트웨어 시험사례를 통해 축적된 결함 데이터를 분석, 결과를 도출하고 미들웨어 소프트웨어의 품질 평가 사례를 조사/분석하여 품질수준과 결함 수준을 분석하고 개발 과정 에서 취약한 부분을 도출하여 대처 방안을 검토하였다. 본 연구를 통해 미들웨어 소프트웨어의 품질향상을 유도하고 양적/질적인 수요를 충족할 수 있다고 본다.

• Journal of the Korean Wood Science and Technology
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• 제29권2호
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• pp.91-99
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• 2001

목재산업에서 생산성과 품질 향상을 위해서는 공정의 자동화가 절실히 요구되고 있다. 화상처리시스템의 현장 적용성 개선을 위해 국산 소나무와 상수리나무 및 서어나무를 대상으로 옹이, 할렬, 수피 등과 같은 주요 결함들을 인식해내는 알고리듬을 개발하였다. 목재가공공정에서 컨베이어 위를 이동하고 있는 목재를 가상하여 제재목의 규격과 목제품의 품질에 영향을 주는 표면결함들을 대상으로 그 형태와 크기 및 위치를 인식할 수 있는 화상 처리기술을 개발하였다. 화상처리를 이용하여 결함으로 인식된 각 라벨에 대해 8가지의 특성을 개발, 결함인식의 기준으로 사용하였으며, 8가지 특성을 이용하여 수종별 결함 추출의 제한 조건을 마련한 후 필터링을 실시하여 실제 결함과 결함으로 인정되지 않는 라벨을 구분하였다. 또한 수종별로 가장 효과적인 기준의 적용절차를 밝히므로써 결함 인식의 오차를 줄이는 한편, 처리대상 수종에 대한 유연성을 확보하고자 하였다. 한편, 컨베이어를 이동하고 있는 목재의 규격이나 표면상태에 관련된 모든 자료들이 database의 형태로 작성되도록 하여 이후 실제 산업현장에 대한 적용 가능성을 타진하고자 하였다. 그 결과 소나무와 상수리나무 표변에 존재하는 옹이의 오인률은 1% 이하로 매우 우수하였으며, 상수리나무의 할렬과 서어나무의 수피에 대한 오인률도 13% 이하로 낮출 수 있었다.

• Archives of Plastic Surgery
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• 제35권6호
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• pp.653-658
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• 2008

Purpose: Skin and soft tissue defect is one of the major challenges faced by plastic surgeons. Adipose derived stromal cells, which can be harvested in large quantities with low morbidity, display multilineage mesodermal potential. Therefore, adipose derived stromal cells have been met with a great deal of excitement by the field of tissue engineering. Recently, Adipose derived stromal cells have been isolated and cultured to use soft tissue restoration. In order to apply cultured cells for clinical purpose, however, FDA approved facilities and techniques are required, which may be difficult for a clinician who cultures cells in a laboratory dedicated to research to utilize this treatment for patients. In addition, long culture period is needed. Fortunately, adipose derived stromal cells are easy to obtain in large quantities without cell culture. The purpose of this study is to present a possibility of using uncultured adipose derived stromal cells for wound coverage. Methods: Seven patients who needed skin and soft tissue restoration were included. Five patients had diabetic foot ulcers, 1 patient got thumb amputation, and 1 patient had tissue defect caused by resection of squamous cell carcinoma. The patients' abdominal adipose tissues were obtained by liposuction. The samples were digested with type I collagenase and centrifuged to obtain adipose derived stromal cells. The isolated adipose derived stromal cells were applied over the wounds immediately after the wound debridement. Fibrin was used as adipose derived stromal cells carrier. Occlusive dressing was applied with films and foams and the wounds were kept moist until complete healing. Results: One hundred to one hundred sixty thousand adipose derived stromal cells were isolated per ml aspirated adipose tissue. All patients' wounds were successfully covered with the grafted adipose derived stromal cells in a 17 to 27 day period. No adverse events related to this treatment occurred. Conclusion: The use of uncultured adipose derived stromal cells was found to be safe and effective treatment for wound coverage without donor site morbidity.

• Tuberculosis and Respiratory Diseases
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• 제76권3호
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• pp.136-140
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• 2014

Pulmonary artery sarcoma (PAS) is a rare, poorly differentiated malignancy arising from the intimal layer of the pulmonary artery. Contrast-enhanced chest computed tomography (CT) is a good diagnostic modality that shows a low-attenuation filling defect of the pulmonary artery in PAS patients. An 18-year-old man was referred to our hospital for the evaluation and management of cavitary pulmonary lesions that did not respond to treatment. A contrast-enhanced CT of the chest was performed, which showed a filling defect within the right interlobar pulmonary artery. The patient underwent a curative right pneumonectomy after confirmation of PAS. Although lung parenchymal lesions of PAS are generally nonspecific, it can be presented as cavities indicate pulmonary infarcts. Clinicians must consider the possibility of PAS as well as pulmonary thromboembolism in patients with pulmonary infarcts. So, we report the case with PAS that was diagnosed during the evaluation of cavitary pulmonary lesions and reviewed the literatures.

• Journal of Periodontal and Implant Science
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• 제30권4호
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• pp.803-814
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• 2000

Current acceptable methods of promoting periodontal regeneration are basis of removal of diseased soft tissue, root treatment, guided tissue regeneration, graft materials, biological mediators. Platelet Rich Plasma have been reported as a biological mediator which regulate activities of wound healing progress including cell proliferation, migration, and metabolism. The purpose of this study is to evaluate the possibility of using the Platelet Rich Plasma as a regeneration promoting agent for furcation involvement defect. Five adult beagle dogs were used in this experiment. With intrasulcular and crestal incision, mucoperiosteal flap was elevated. Following decortication with 1/2 high speed round bur, degree II furcation defect was made on mandibular third(P3), forth(P4) and fifth(P5) premolar. 2 month later experimental group were PRP plus bovine bone and bovine bone only. After 4, 8 weeks, the animals were sacrificed by perfusion technique. Tissue block was excised including the tooth and prepared for light microscope with Gomori's trichrome staining. At 4 weeks after surgery, there were rapid osteogenesis phenomenon on the defected area of the Platelet Rich Plasma plus bovine bone group and early trabeculation pattern was made with new osteoid tissue produced by activated osteoblast. Bone formation was almost completed to the fornix of furcation by 4 weeks after surgery. In conclusion, Platelet Rich Plasma can promote rapid osteogenesis during early stage of periodontal tissue regeneration.

• Archives of Plastic Surgery
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• 제34권2호
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• pp.197-202
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• 2007

Purpose: The gluteal artery perforator flaps earned its popularity in buttock reconstruction due to the lower morbidity of the donor site and the flexibility in the design. Speedy and safe reconstruction is important for the success of buttock reconstruction. If a proper design is selected, satisfactory results can be obtained with more simple method of surgery. Methods: Between April 2005 and April 2006, buttock reconstruction by using gluteal artery perforator flaps were performed on sacral sores(6 cases), ischial sores(2 cases) and malignant melanoma on buttock(1 case). Various designs depending on the location and the size of the defect was made. In those designs, perforator was used as an axis for the minimal dissection of the vessel. Donor site from which sufficient amount of soft tissue can be transferred was selected, and also not causing high tension against the recipient site during the donor site closure. In addition, postoperative aesthetics, and the possibility of another design of a second operation which can be necessary in the future, was considered. Results: Patient follow up was for a mean period of 10.8 months. All flaps survived except for one that had undergone partial necrosis. Wound dehiscence was observed in one patient treated by secondary closure. Most patients presented with cosmetically and functionally satisfying results Conclusion: By designing the flap using the perforator as an axis, depending on the defect size and degree, reconstruction can be performed with only a small tension to the donor and the recipient site. And the minimal perforator dissection allowed easier and faster reconstruction. Selection of a proper design is the key procedure which greatly affects operation time and result success.

• 핵의학기술
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• 제13권3호
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• pp.67-75
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• 2009

목적 : Tl-201 심근관류 SPECT의 정량적 평가를 위해 사용되는 다양한 프로그램은 자료의 분석 방법에 있어서 각각 차이가 있는 것으로 보고되고 있다. 따라서 동일한 환자의 자료를 대상으로 정량적 분석을 하여도 프로그램 상호간의 측정치 오차가 발생할 것으로 예상된다. 그 중 심근의 관류결손 정도를 표현할 수 있는 정량적 지표를 이용하여 현재 각 병원에서 가장 일반적으로 사용하고 있는 심근관류분석 프로그램 QPS (Quantitative Perfusion SPECT)와 4DM (4DMSPECT) 그리고 ECT (Emory Cardiac Toolbox)의 분석값을 이용하여 프로그램 상호간의 연관성을 알아보고자 한다. 실험재료 및 방법 : 2008년 12월 1일 부터 2009년 2월 14까지 서울아산병원 핵의학과에서 Tl-201을 이용하여 게이트 심근관류 SPECT를 시행한 환자 145명을 대상으로 하였다. 이들 중 심혈관 질환의 가능성이 비교적 적다고 판단된 정상군 80(남/여=38/42, $65.1{\pm}9.9$세)명과 게이트 심근관류 SPECT의 판독결과를 통해 가역성 관류결손이나 고정 관류결손 등 심혈관 질환의 판정을 받은 비정상군 65(남/여=45/20, $63.0{\pm}8.7$세)명을 선별하였다. QPS와 4DM 그리고 ECT 프로그램을 이용하여 각각의 군에서 분석된 정량적 지표인 LAD, LCX, RCA 영역에서의 관류결손 범위율의 합(Total Defect Extent, TDE)과 부하기 관류점수합(Summed Stress Score, SSS)을 이용하여 상관관계 분석과 차이분석(paired t-test, Bland-Altman)을 이용하여 통계 결과를 비교 분석하였다. 결과 : 연구 대상 145명의 4DM:QPS, QPS:ECT, ECT:4DM 프로그램의 상관 계수는 SSS에서 각각 0.84, 0.86, 0.82이었고, TDE에서 각각 0.87, 0.84, 0.87로 SSS와 TDE 모두 높은 상관관계가 있었다. paired t-test 분석 결과에서는 QPS:ECT만 SSS (p=0.92)와 TDE (p=0.33) 모두 통계적으로 유의한 차이가 없었고, 4DM:QPS, ECT:4DM은 SSS와 TDE 모두 통계적으로 유의한 차이가 있었다(p<0.01). 비정상군 65명의 4DM/QPS, QPS/ECT, ECT/4DM 프로그램의 상관 계수는 SSS에서 각각 0.72, 0.72, 0.70이었고, TDE에서 각각 0.77, 0.70, 0.77로 SSS와 TDE 모두 높은 상관관계가 있었다. 비정상군 역시 paired t-test 분석 결과 QPS:ECT만 SSS (p=0.89)와 TDE (p=0.23) 모두 통계적으로 유의한 차이가 없었고, 4DM : QPS, ECT:4DM은 SSS와 TDE 모두 통계적으로 유의한 차이가 있었다(p<0.01). 정상군 80명의 분석 결과에서도 QPS : ECT만 SSS (p=0.95)와 TDE (p=0.73) 모두 통계적으로 유의한 차이가 없을 뿐, 4DM:QPS, ECT:4DM은 SSS와 TDE 모두 통계적으로 유의한 차이가 있었다(p<0.01). 결론 : 심혈관 질환을 가진 환자뿐 아니라 심혈관 질환의 가능성이 적은 환자에서도 Tl-201 심근 관류 SPECT의 관류 결손을 분석한 결과, 4DM은 QPS와 ECT 프로그램에 비해 SSS와 TDE 모두 낮게 분석되는 경향을 보였지만 프로그램 상호간에는 좋은 상관관계가 있다는 것을 확인 할 수 있었다. 하지만 이와 같이 좋은 상관관계에도 불구하고 Bland-Altman 분석 결과에서 프로그램간의 큰 변이 차이 때문에 임상에서 각각의 프로그램을 이용한 분석값을 서로 호환하여 사용할 수는 없을 것으로 판단된다. 그렇지만 이러한 분석결과는 임상적인 판독을 위한 참고 자료로서 유용하게 이용될 수 있을 것이라 기대된다.