• 한국정보통신학회논문지
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• 제16권12호
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• pp.2800-2807
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• 2012

애드-혹 네트워크는 기간망에 의존하지 않고, 노드들끼리 자율적으로 데이터 이동 경로를 형성하는 네트워크이다. 일반적으로 애드-혹 네트워크는 다중-홉 통신을 기반으로 하며 네트워크의 규모가 커질수록 경로 설정을 위한 제어 패킷의 양이 급격히 증가하게 되고 노드의 수명이 단축 된다. 이러한 노드들의 특성으로 인해서 네트워크 크기에 따른 보다 에너지 효율성 적용이 가능한 경로 설정 기법에 대한 연구가 요구되고 있다. 본 논문에서는 특히 계층적인 클러스터 구조 기반의 애드-혹 네트워크 환경에서 노드가 동질적 공간-포아송의 조건에서 노드의 분포 밀도와 속성정보를 고려한 클러스터의 계층 깊이 결정 알고리즘인 CACHE-R(Context-Aware Clustering Hierarchy, Efficient and Resilient)를 제안한다. 제안하고자 하는 CACHE-R기법은 최적화된 계층의 깊이와 속성정보를 적용함으로써 에너지 보존적인 경로를 설정하여, 전체 네트워크의 에너지 소비량을 감소시키고 네트워크 수명을 향상되는 특성을 보여주었다.

• 한국지반환경공학회 논문집
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• 제7권6호
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• pp.75-88
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• 2006

본 논문은 지중강판 구조물에 고강도강의 사용 가능성을 평가하였다. AASHTO(2004)와 CHBDC(2000)의 좌굴강도식의 차이점과 제정적인 배경, 주요 설계인자에 대한 매개변수를 연구하였다. 원형 지중강판구조물의 좌굴강도식은 지간, 토피고, 단면조건, 인장강도, 뒷채움 흙의 다양한 설계변수를 고려한 탄소성해석, 기하학적 비선형해석의 수치해석 결과를 토대로 제안하였다. 해석결과 CHBDC의 설계기준이 좌굴강도를 산정하는데 있어 적합하였으며, 고강도강 사용시 좌굴안정성도 확보되고 좌굴강도의 개선효과에 뛰어났다.

• 대한정형도수물리치료학회지
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• 제11권1호
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• pp.65-73
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• 2005

Osteoarthritis has been considered a disease of the elderly because it is uncommon before the age of 40 years and is seen in approximately 80% of United States citizens older than 65 years. general population on kuri city in korea revealed that prevalence of knee osteoarthritis is 10.2%, increasing with age. High level of physical activity in men and age, post-menopause and obesity in women can be risk factor. Osteoarthritis is no evidence that a acquired process initiated much earlier in life through mechanical, metabolic, genetic, or other origins. A high tibial osteotomy alters static lower extremity alignment thereby decreasing medial compartment loading. As well, conservative treatment strategies, such as knee braces and valgus heel wedges, affect lover limb mechanics and attempt to reduce medial compartment loading. It was hypothesized that valgus heel wedges and modified orthoses would shift the center of pressure laterally on the foot during level walking, reducing the moment arm of the adduction moment in the frontal plane, thereby resulting in a decrease in the knee adduction moment. In the 1980s, the effect of wearing a laterally wedged insole on osteoarthritic patients with a varus deformity of the knee was firsted, and since then, kinematic and kinetic analyses concerning this condition have mainly focused on a static standing position. Since the early 1990s, the beneficial effect of wearing a laterally wedged insole to treat osteoarthritis of the knee has also been reported in dynamic conditions, but these studies did not answer the question of the kinematic and kinetic mechanisms that resulted in the reduced symptoms in patents with knee osteoarthritis. therefore, the effect of wearing laterally wedged insole has not been sufficiently studied.

• 한국인구학
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• 제33권3호
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• pp.75-99
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• 2010

이 논문의 목적은 한국사회의 세대갈등을 권력갈등, 이념갈등, 문화갈등으로 구분하여 갈등 형성의 배경과 실태를 분석하고 그 함의를 논의하는 데 있다. 실태 분석을 위하여 관공서의 집합 자료와 경험적 연구결과들이 활용되었다. 우선, 세대간 권력갈등의 핵심은 권력 이양시기를 둘러싼 충돌에 있다. 세대간 권력갈등을 의회 권력에 국한시켜 볼 때, 정권교체기의 이념적 지향의 부침과는 무관하게 젊은 의원들의 비율이 꾸준히 증가하는 저(低) 연령화 추세가 지속되고 있었다. 이러한 세대교체 추세는 당분간 다른 영역에서도 유지될 것으로 보인다. 다음으로, 세대간 이념갈등은 2002년 대선 전 후 극대화되었으나 04년 총선 이래 점차 완화되었다. 그러나 조건의 변화에 따라 일정한 계기가 주어지면 다시 활성화될 수 있을 것이다. 마지막으로, 문화 격차의 견지에서 볼 때 세대균열의 깊은 골은 대략 출생시점 1970년경을 중심으로 형성되었다. 문화갈등의 축을 성장주의 대 소비주의, 집단주의 대 개인주의, 권위주의 대 탈권위주의로 설정하여 갈등의 배경과 실태를 검토했다. 세 유형의 갈등 중 문화갈등의 역기능에 주목해야 한다. 세대간 문화격차 확대는 상호 의사소통을 방해하며 상호 교류와 공동 활동 기피라는 결과를 낳을 수 있기 때문이다. 문화갈등 완화를 위해, 사회 제 부문의 부조리와 비리 척결 그리고 세대 통합 프로그램을 활용하는 방안 등이 제시되었다.

• 한국화재소방학회논문지
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• 제30권5호
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• pp.82-86
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• 2016

건축용 내화강재가 적용된 양단 고정단 보부재의 고온 시 최대 내력과 처짐을 해석적으로 평가하였으며, 이 결과를 일반강재 적용 정정 보부재와의 비교평가를 통하여 안전성을 평가한 결과, 건축용 내화강재 적용 부정정 보부재의 내화성능을 일반 강재 정정 보부재로 평가되는 것은 안전측이었으며, 부재길이가 길어지면 처짐의 증대와 최대 내력의 감소가 유발되는 등 이에 대한 보완책이 요구되는 것으로 나타났다.

• Restorative Dentistry and Endodontics
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• 제16권1호
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• pp.133-150
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• 1991

To study the mechanical behavior depended on the restoration method and alveolar bone height at endodontically treated teeth. a finite element model was made which was applied by four types of restoration methods and alveolar bone height on upper central incisor and then 1 Kg force was applied on each model as follows; 1) $45^{\circ}$ diagonal load on incisal edge. 2) $26^{\circ}$ diagonal load on lingual surface. and 3) horizontal load on labial surface. The author analyzed the displacement and stress of teeth and their supporting tissue by finite element method according to three type of loading conditions. The results were as follows : 1. The displacement by restoration method and the stress in dentin was found greater in restoration without a post than in that with a post. 2. The displacement and stress was found about the same when compared : A) in Resin model and PFM model applied by restoration method without a post and B) in PRC model and CPC model applied by restoration method with a post. 3. The lower alveolar bone height was. the greater was the displacement and stress. 4. The lower alveolar bone height was. the greater slightly was the stress of restoration without a post than in that with a post. 5. The stress in loading condition was the greatest in P1 in dentin and post. and was greatest in P3 in alveolar hone. 6. In the restoration method without a post. stress concentration in labial dentin was distributed to a figure of long belt in adjacent part to periodontal ligament. while in restoration method with a post. it was distributed in adjacent part to post side. And in all types of restoration method stress concentration in alveolar bone was distributed along the compact bone of labial and lingual surface.

• Restorative Dentistry and Endodontics
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• 제12권1호
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• pp.51-64
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• 1986

The purpose of this study is to obtain the data of prestep in cavity preparation by observing changed conditions of laser irradiated dental hard tissues. The forty five extracted caries free human molars were divided into three groups and each group into five subgroups. A $CO_2$ laser irradiation was performed each subgroup of group I for one second with output power of 5 W, 10 Wand 20 W. On group II, laser irradiation was done ten times for 0.1 second duration using same power ratings as group I. On group III, laser irradiation was done 0.1 second, 0.2 second and 0.4 second with output power of 50 W. We investigated mineral contents and crater wall of obtained specimens, i.e., laser irradiated teeth, using computer controlled electron probe microanalyzer and scanning electron microscope. The following results were obtained: 1. Both calcium and phosphorus contents in laser irradiated enamel crater wall were increased, and magnesium content was decreased, but these trends were not statistically significant. 2. In laser irradiated dentin, change of mineral content was more significant. 3. In laser irradiated enamel and dentin, there were no significant differences on mineral content change due to irradiation condition and energy density. 4. In scanning electron microscopic study, enamel rods of the crater wall were fused and clefts were observed in parallel with the direction of enamel rod for all groups. 5. In laser irradiated dentin, irregular fusion and clefts were observed. In irradiated teeth with high power and short duration, the locally formed narrow crater wall was observed.

• Restorative Dentistry and Endodontics
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• 제26권4호
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• pp.341-349
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• 2001

Dental caries is the most common oral disease. There are many factors contributing to its development, but complete understanding and prevention are not fully known. However, it is possible to remineralize the early enamel curious lesion by fluoride containing remineralization solution. Recently the pH-cycling model has been used to examine the effect of fluoride solution on remineralization of artificial caries in vitro as it can closely simulate the conditions encountered in vivo within a carefully controlled environment. The aim of this study was to evaluate the remineralizing effects of supersaturated buffer solutions under pH-cycling model. The specimen with 3mm-diameter was made using mature bovine incisors which has no caries and has sound enamel surface. Early curious lesions were produced by suspending each specimens into demineralization solution at pH 5.0 for 33 hours and the specimen whose surface hardness value ranged from 25 to 45 VHN were used. The pH cycling treatment regimen consisted of 5 min soaks of three treatment solutions four times per days for 15 days and the continuous cycling of demineralization and remineralization were carried out for 15 days. Following the pH-cycling treatment regimen, the specimens' surface microhardness were measured by the Vickers hardness test (VHN) and analyzed by ANOVA and Duncan's multiple-range test. 1. The surface microhardness value of supersaturated solution, Senstime, and Gagline groups were increased after pH cycling, and that of supersaturated solution was significantly Increased compared to saline group(P<0.05). 2. The surface remineralization effect of fluoride containing solutions was accelerated by saliva under pH-cycling mode 3. The pH cycling model was considered appropriate to mimic the intra-oral pH changes when evaluating demineralization and remineralization in vitro. Under the results of above study, salivary remineralization effect can be improved by fluoride containing remineralization solution. The pH-cycling model was considered appropriate to mimic the intra-oral pH changes when evaluating demineralization and remineralization in vitro.

• 대한소아치과학회지
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• 제24권4호
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• pp.795-804
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• 1997

Developmental dental morphological anomalies are fusion, gemination, twinning, concrescence and etc. They may cause many problems in conservative, periodontal and esthetic aspects. Fusion is a condition where two separate tooth buds unite at some stage in their development to form a bifid crown. If tooth contact occurs early, at least before the start of calcification, the two teeth may be completely unites to form a single large tooth. If tooth contact occurs after the time when a portion of the tooth crown has completed its formation, there may be union of the roots only. In fusion the dentin is always confluent. Fusion teeth is more common in the deciduous than in the permanent dentition. Fused teeth are relatively rare, and are mostly mandibular anterior teeth. Fusion of normal and supernumerary teeth or between normal teeth may occurs. The exact etiology factor of fusion is unknown, but genetic and environmental factors seems to be related. A variety of complications and subsequent treatments have been suggested on this teeth. Periodontal conditions may arise due to a groove formed at the line of fusion of the two teeth. Crowding or Protrusion with potential for malocclusion or delayed eruption of adjacent teeth. Fusion teeth appear in the anterior region, they usually cause esthetic problems. Treatments vary depending on the problem, the location, and the extent of fusion. Treatment of fused teeth has been reported from endodontic, orthodontic, periodontic, surgical and multidisciplinary. This report presents the esthetic improvements by separation of two clinical crowns. Bone reduction or endodontic treatments are not required.

• Nuclear Engineering and Technology
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• 제14권3호
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• pp.122-137
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• 1982

고리 1호기 일부 반응도사고에 대한 민감도 분석을 수행하였다. 본 민감도 분석에 고려한 반응도 사고는 비교적 진행속도가 빠른 사고로서 미임계나 저출력 시동조건에서 발생한 제어뱅크 인출사고와 제어봉 일출사고가 이에 속한다. 본 분석작업은 다음과 같이 세단계로 수행하는 바 원자로 평균출력의 변동 계산과 최고점에서의 열전달계산 그리고 DNBR계산 단계로 나눌 수 있다. 계산에 사용된 전산코드들은 본 분석을 위하여 개발하거나 기존 전산코드들을 수정ㆍ보완하여 제작하였으며 신뢰도도 평가하였다. 원자로 설계 및 운전변수들이 사고발생시 원자로의 거동에 미치는 영향을 조사하기 위하여 민감도 분석을 수행하였다. 본 민감도 분석 결과에 근거하여 고리 1호기 반응도사고 분석에 사용된 최종안전분석보고서의 가정과 초기조건이 타당한가를 조사하였고, 또한 계산 결과도 보수적이고 신뢰할 수 있는지 판별하였다. 고리 1호기 반응도사고 분석에 사용된 가정 및 초기조건을 재검토하고 민감도를 분석한 결과 최종안전분석보고서의 해석결과는 보수적이고 신뢰 할 수 있는 것으로 평가되었다.