• 한국콘텐츠학회논문지
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• 제11권12호
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• pp.60-70
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• 2011

기존의 콘텐츠관리시스템(CMS: Contents Management System)들은 일반적으로 응용분야에 독립된 도메인을 기반으로 개발되어 콘텐츠의 활용이 해당 CMS 분야로 한정된다. 이러한 특성은 CMS를 통한 정보의 교류와 공유를 효율적으로 지원하지 못하는 단점을 들어낸다. 한편, 메타데이터 표준화는 주로 콘텐츠의 응용분야에 따라 다양하게 이루어지고 있어, 분야별 표준화 방법과 표현방법에 큰 차이를 보이고 있으며, 서로 다른 분야의 콘텐츠에 대한 상호활용은 거의 불가능하다. 본 논문에서는 통합메타데이터 개념으로 진정한 표준화가 이루어질 수 있는 METS 기반 스키마를 제안함으로써 이기종 CMS에서 생성된 콘텐츠들의 중복 사용문제를 해결하였다. 여기서 제안된 새로운 통합메타데이터 프레임워크는 콘텐츠 활용분야의 제한을 받지 않고 콘텐츠의 내용 기반으로 진정한 표준 메타데이터로 활용될 수 있도록 서로 다른 분야에서 생성된 콘텐츠들의 상호운용성을 확보하였다. 또한 메타데이터 수신 기술들의 통합을 통하여 메타데이터 정보를 폭넓게 이용하고, 중복된 콘텐츠를 제거하여 다양한 프로그램과 서비스에서 응용할 수 있는 효율적인 메타데이터 통합 체계를 제안하였다. 제안된 기술에 대한 검증을 실시한 결과, 기존의 10.3% 수준의 중복률을 최저 0.5% 수준으로 감소시키는 효과를 얻었으며, 제안된 기술의 효율성과 안정성을 검증하고 기술개발의 타당성을 검증하기 위한 중복 메타데이터 필터링 능력은 최저 92%에서 최대 96% 수준으로 나타났다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제32권4호
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• pp.324-331
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• 2010

The radial forearm free flap (RFFF) has become a workhorse flap as a means of reconstructing surgical defects in the head and neck region. We have transferred 12 RFFFs with fasciocutaneous type on oral cavity defects in 12 patients after cancer resection and submucous fibrotic lesion ablation from 2005 to 2007 at Department of oral and maxillofacial surgery, Pusan National University Hospital. We reviewed retrospectively patients' charts and followed up the patients. Clinical analysis on the cases with RFFFs focusing on flap morbidity, indications and available vessels was done. The results of study are follows: 1. RFFF could be applied for all kind of defects after resection of tongue, floor of mouth, buccal mucosa, denuded bone of palate, maxilla, and mandible. 2. All free flaps could be used for primary reconstruction. The survival rate of 12 RFFFs was 92%. Partial marginal loss of the flaps was shown as 3 cases among 12 cases. Large size-vessels like superior thyroid artery, facial artery, internal jugular vein were favorable for microvascular anastomosis. 3. Parenteral nutrition instead of nasal L-tube also can be favorable for postoperative a week for better healing of the flap if the patients couldn't be tolerable with nasal tubing. 4. Donor sites with thigh skin graft were repaired with wrist band for 2 weeks. The complications included scarring, abnormal sensation on hand, and reduced grip strength in few patients, but those didn't induce major side effects. 5. Most RFFFs were well healed even if mortality rate of cancer patients was shown as 50% (5/10 persons). The mortality of patients was not correlated with morbidity of the flaps. We could identify the usefulness of RFFF for restoration of oral function, esthetics if the flap design, tissue transfer indications, and well controlled operation are proceeded.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제29권2호
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• pp.102-107
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• 2003

At orthodontic treatment, we have made every effort to get rigid anchorage which is not stirred when teeth move. As a result, the miniscrew that is rigid anchorage was invented recently, and now it is used widely. Concerning the advantage of miniscrew, it is reduced dependence of extraoral anchorage and it shortens treatment time for rapid tooth movement. In contrast, the defect of miniscrew is falling off it resulted from increasing of the mobility. So the purpose of this research is to be of help to prognose clinical use of miniscrew, which is inserted for intraoral anchorage, by investigating and comparing the failure rate of miniscrew for loading time. This study researches the failure rate of miniscrew for teeth movement at the orthodontic treatment. The failure rate of miniscrew in mid course, after inserting 147 miniscrews in 51 patients, is 13%(20/147). It showed no statistically significant differences as compared man with woman, maxilla with mandible, double-head with uni-head miniscrew, and drilling and non-drilling before inserting the miniscrew. In comparison below twenties with over twenties and the times that we give load to miniscrew, it produced that the failure rate of miniscrew is 9.7% higher in the case of below the twenties than over the twenties. Also, the failure rate of loading immediately is 10.8% higher than loading after 7 days. According to using driver for the insertion of miniscrew, the failure rate of miniscrew is higher in the case of using machined driver than in the case of using hand driver when the level of significance is 95%. According to the research, we can suppose that the failure rate has no concern with using miniscrew on man or woman, maxilla or mandible, the shape of head, and drilling or non-drilling before insertion of miniscrew. Therefore, we can choose eclectic miniscrew as demands. In addition, we must notify the patient, below twenties, to be possibility of high failure rate. And It is strongly recommended to give load after $1{\sim}2$ weeks for healing of the insertion area.

• Journal of Periodontal and Implant Science
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• 제39권sup2호
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• pp.213-222
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• 2009

Purpose: Recently, interest in chitosan has increased due to its excellent biological properties such as biocompatibility, antibacterial effect, and rapid healing capacity. On the other hand, hydroxyapatite is used as a bone substitute in the fields of orthopedics and dentistry. The hydroxyapatite-chitosan (HA-CS) complex containing hydroxyapatite nanoparticles was developed for synergy of both biomaterials. The objective of this study was to evaluate the effect of hydroxyapatite (HA)-chitosan (CS) membrane on bone regeneration in the rat calvarial defect. Methods: Eight-millimeter critical-sized calvarial defects were created in 70 male Sprague-Dawley rats. The animals were divided into 7 groups of 10 animals and received either 1) chitosan (CS) 100% membrane, 2) hydroxyapatite (HA) 30%/CS 70% membrane, 3) HA 30%/CS 70%, pressed membrane, 4) HA 40%/CS 60% membrane, 5) HA 50%/CS 50% membrane, 6) HA 50%/CS 50%, pressed membrane, or 7) a sham . surgery control. The amount of newly formed bone from the surface of the rat calvarial defects was measured using histomorphometry, following 2- or 8- week healing intervals. Results: Surgical implantation of the HA - CS membrane resulted in enhanced local bone formation at both 2 and 8 weeks compared to the control group. The HA - CS membrane would be significantly more effective than the chitosan membrane in early bone formation. Conclusions: Concerning the advantages of biomaterials, the HA-CS membrane would be an effective biomaterial for regeneration of periodontal bone. Further studies will be required to improve the mechanical properties to develop a more rigid scaffold for the HA-CS membrane.

• 대한치과보철학회지
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• 제39권6호
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• pp.659-681
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• 2001

Platelet-rich plasma(PRP) has been known to increase the rate and degree of bone formation by virtue of growth factors in concentrated platelets. Although its great healing effect on bone defect or pre-implantation site preparation in conjunction with bone substitute has been reported, the effect associated with implant is unknown. The purpose of this study was to investigate the effect of PRP on rapid osseointegration of endosseous dental implants in the rabbit tibiae. Twenty two adult female New Zealand white rabbits, weighing approximately 2.7-3.3kg, were used for this study. Twelve of the 22 animals were used for histomorphometric analysis and ten of the 22 were for removal torque test. Each animal received two implants in each tibia (two treated with PRP and two as control) and was given fluorochrome intramuscularly. For histomorphometric analysis, rabbits were divided into four groups according to the healing period. At 1 week, 2 weeks, 4 weeks and 8 weeks postoperatively, each three animals were sacrificed serially and the amount and rate of bone formation around dental implant were examined on the undecalcified sections under fluorescent microscope, polarized microscope and light microscope connected to a personal computer equipped with image analysis system. For removal torque test, rabbits were divided into two groups and removal torque tests were performed at 4 weeks, 10 weeks after implant placement. In total, 88 screw shaped, commercially pure titanium implants (Neoplant, Neobiotech, Seoul, Korea) were used in this study. Labeling pattern reflected differences of two groups in bone formation rate at each period. Histomorphometrically, PRP group showed significantly higher bone volume within threads compared to control group at 2 weeks ($70.30{\pm}4.96%$ vs. $50.68{\pm}6.33%$; P < .01) and 4 weeks ($82.59{\pm}5.94%$ vs. $72.94{\pm}4.57%$; P < .05 ). PRP group at 1, 2 and 4 weeks revealed similar degree of bone volume formation comparable to control group at 2, 4 and 8 weeks, respectively. On the other hand, while PRP group showed higher bone-implant contact ($47.37{\pm}8.09%$) than control group ($33.16{\pm}13.47%$) at 2 weeks, there were no significant differences between PRP group and control group for any experimental period. Removal torque values also showed no significant differences between PRP group and control group at any experimental period (P > .05). These findings imply that PRP could induce rapid, more bone formation around implant during early healing period and get faster secondary stability for reducing healing period, though it has not induced bone maturation enough to resist functional loading.

• 대한조선학회논문집
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• 제38권1호
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• pp.99-107
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• 2001

어선 제작시 어선의 고속화 및 어로작업 등에 의한 내구성을 향상시키기 위해 선각재질이 가볍고, 강도, 화재 및 해수의 부식 등에 뛰어난 재료의 사용이 요구되어지고 있다. 이러한 어선으로서는 크게 FRP어선과 Al어선으로 대별할 수 있다. 그러나 FRP어선은 가볍고 강도는 우수하나 인화성이 높아서 열에 매우 약하고 선박 제작 과정에 있어 인체에 해로운 유해성분이 발생할 뿐만 아니라, 폐선의 경우 산업폐기물로써 환경 오염에 큰 영향을 미치고 있다. 그런 반면에, Al어선은 FRP어선의 단점을 보완할 수 있는 재료로써, 고강도 및 경량화의 효과를 낼 수 있고, FRP어선보다 인화성이 낮아서 열에 강하고, 내구성이 높아 해수의 부식방지에 뛰어나므로 Al 어선의 개발이 시급한 실정이다. 그러나, 알루미늄 합금은 용접성이 좋지 않고 용접변형 및 균열이 발생하고, 건조 비용이 비싸다는 단점이 있다. 따라서, 본 연구에서는 Al 합금 접합시의 문제점 해결방안으로 용접이음부의 새로운 형상을 개발하고 개발한 신형상에 대한 역학적 거동을 규명하고자 하였다. 이를 위해, 먼저 평판 이론을 이용하여 구조부재를 단순화하여 평판, 보강판, 신형상에 대하여 해석함으로써 강도를 비교 검토하고, 이러한 결과를 토대로 자체 개발된 용접열전도 및 용접열응력 수치해석 프로그램을 사용하여 평판과 신형상의 온도분포, 용접잔류응력, 인장, 압축시의 강도를 수치시뮬레이션을 통하여 비교, 검토하였다. 또한, 인장 시험편을 제작하여 실험을 통하여 강도를 비교함으로써 신형상에 대한 적용 가능성 및 역학적 우수성을 입증하고자 하였다.

• 한국지능시스템학회논문지
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• 제14권1호
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• pp.9-14
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• 2004

감정은 지능을 지닌 존재의 이성판단에 영향을 준다. 그래서 주변 환경정보에 의해 평가된 기본적이고 보편적인 감정을 로봇에 가미하면 더욱 인간과 가까운 지능 로봇이 될 것이다. 그러나 인간의 감정을 학습하기 위해서는 다양한 감각정보의 학습과 패턴 분류가 선행되어야 하고 이를 위해서 적합한 네트워크 구조가 요구된다. 신경망은 시스템의 특징을 추출하는데 매우 우수한 능력을 발휘하고 있다. 그러나 임시적 혼선현상과 지역 최소치에 수렴하는 단점이 있다. 그래서 복잡한 문제를 단순한 여러 개의 부분적인 문제로 나누어 해결하는 모듈라 설계방법이 관심의 대상이 되고 있다. 본 논문에서는 수많은 감정평가와 학습 데이터 패턴들을 학습하기 위해서 재결합과 재구성에 탁월한 성능을 지닌 Jacobs와 Jordan이 제안한 모듈라 네트워크와 상황의 재 표현이 가능하고 예측값과 모델링에 적합한 특징을 지닌 궤환 신경망을 결합하였다. 구성된 구조는 기존의 모듈라 네트워크의 학습결과와 비교 검토하였다.

• 대한핵의학회지
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• 제37권4호
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• pp.229-234
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• 2003

목적: 홍역 감염 후 속발되는 뇌염은 사망률이 높아 조기진단 및 적극적인 치료가 예후에 중요하다. 저자들은 홍역 후 발생된 뇌염에 대한 Tc-99m ECD 뇌혈류 SPECT와 뇌핵자기공명영상(MRI)의 진단 성능을 비교하였고 뇌혈류 SPECT상 중등도 이상의 심한 뇌혈류 감소가 호발하는 부위를 알아보았다. 대상 및 방법: 홍역으로 진단받은 112명 중에서 의식저하, 경련, 마비 등의 임상증상과 혈청 및 뇌척수액에서 홍역 특이항체가 관찰되어 홍역 후 급성 뇌염으로 진단받고 Tc-99m ECD 뇌혈류 SPECT와 MRI를 시행받은 11명(M : F=4 : 7, 연령 $1.6{\sim}14$세)을 대상으로 하였다. SPECT상 관찰되는 뇌혈류는 0(정상)에서 3(결손)으로 점수화하였고 2점 이상인 경우를 중등도 뇌혈류 감소로 정의하였다. 홍역 후 발생된 뇌염 환아에서 MRI와 SPECT의 두부병소 진단 성능과 중등도 뇌혈류 감소의 호발부위를 알아보았다. 결과: MRI 시행결과 7명(63.6%)에서 T2-강조영상에서 회백질의 고강도 변화가 관찰되었으나, SPECT상 11명(100%) 모두에서 뇌혈류 감소 부위가 관찰되었다. 중등도 뇌혈류 감소는 전두엽(81.8%), 측두엽(72.7%), 후두엽(27.3%), 기저핵(27.3%), 두정엽(9.1%) 순서로 호발하였다. 결론: 홍역 후 발생된 뇌염 환아에서 두부병소를 진단하는데 MRI에 비하여 Tc-99m ECD 뇌혈류 SPECT가 좀더 도움이 될 것으로 사료된다.

• Archives of Plastic Surgery
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• 제34권1호
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• pp.52-59
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• 2007

Purpose: The venous flap is used as an alternative method to the standard free flap for the management of small and thin soft tissue defects. Especially, the venous flap has advantages of being thin, easy harvest and various donor sites, as well as it having lower morbidity. Yet their clinical applications have been limited by their unstable postoperative course and also by their complications such as partial necrosis. The aim of this study is to extend the clinical indications of venous flaps with using various methods. Methods: From May 2005 to March 2006, total of 19 patients(21 cases) underwent various venous flaps for soft tissue defects as a result of trauma(15 cases), facial skin cancer(3 cases), chronic ulcer(1 case) and surgical wound for congenital anomaly(2 cases). The arterialized venous free flap were applied in 18 cases, the pure venous free flap was applied in 1 case and the pure venous pedicled flap were applied in 2 cases. Among them, two flow-through arterialized venous free flaps were applied that used the great saphenous vein to reconstructed major arteries as well as the injured skin and soft tissues in the arm. All the flap were harvested from the volar wrist(11 cases), dorsum of foot(5 cases), thenar(2 cases), and medial thigh(3 cases). Results: The sizes of the flap ranged from $0.75cm^2$ to $264cm^2$(mean size: $40.06cm^2$). The follow-up period ranged from two to twelve months. In the majority of cases, we obtained satisfying results, which was the excellent reconstruction of skin and soft tissue defects and especially in the case of limb salvage, replantation and cancer reconstruction. However, there were 5 cases of partial necrosis and 2 cases of complete failure. The donor sites were closed primarily in 7 cases and wound closure with skin graft were in 14 cases. Conclusion: We conclude that the venous flap will not only be useful for reconstruction of small defect in the hand and foot, but also be useful for various other clinical indications.

• Archives of Plastic Surgery
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• 제37권4호
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• pp.340-345
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• 2010

Purpose: Recently, bioceramics have become popular as a substitute graft material for reconstruction of bony defect after trauma or tumor surgery. Among the bioceramic materials, hydroxyapatite (HA) is favored due to its biocompatibility. HA scaffold is composed of the interconnected reticular framework, macropores and micropores. Macropores play an important role in cell migration, nutrients supply and vascular ingrowth. On the other hand, a number of micropores less than $10{\mu}m$ form an irregular surface on HA scaffolds, which prevents the osteoblast from adhering and proliferating on the surface of HA scaffold. Methods: In this study, three different groups were designed for comparison. In the first group (group A), conventional method was used, in which HA pellet was applied without surface pretreatment. The second group (group B) was given a HA pellet that has been coated with crystalline HA solution prior to application. In the third group (group C), the same method was used as the second group, where the pretreated HA pellet was heated ($1250^{\circ}C$, 1 hour) before application. Osteoblast-like cells ($2{\times}10^4$/mL) were scattered onto every pellet, then they were incubated in 5% $CO_2$ incubator at $37^{\circ}C$ for twelve days. During the first three days, osteoblast cells were counted using the hemocytometer daily. ALP activity was measured on the 3, 6, 9 and 12 culture days using the spectrophotometer. Results: Under SEM, group A showed a surface with numerous micropores, and group B revealed more rough crystal surface. Group C revealed a fused crystal appearance and flattened smooth surface. In proliferation and ALP activity of osteoblast cells, group C showed better results compared to group B. Group A which lacks pretreatment of the surface showed less osteoblast proliferation and ALP activity than group C, but showed better results than group B. Conclusion: We found that crystallized HA with heat treatment method enhances the osteoblasts proliferation and differentiation on the surface of HA pellets.