• Structural Engineering and Mechanics
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• 제78권2호
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• pp.219-230
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• 2021

International seismic codes stipulate that adjacent buildings should be separated by a specified minimum distance, otherwise the pounding effect should be considered in the design. Recent researches proposed an alternative method (Double Difference Combination Rule) to estimate seismic gap between structures, as this method considers the cross relation of adjacent buildings behavior during earthquakes. Four different criteria were used to calculate the minimum separation distance using this method and results are compared to the international codes for five separation cases. These cases used four case study buildings classified by different heights, lateral load resisting systems and fundamental periods of vibrations to assess the consistency in results for the alternative methods. Non-linear analysis was performed to calculate the inelastic displacements of the four buildings, and the results were used to evaluate the relation between elastic and inelastic displacements due to the ductility of structural elements resisting seismic loads. A verification analysis was conducted to guarantee that the separation distance calculated is sufficient to avoid pounding. Results shows that the use of two out of the four studied methods yields separation distances smaller than that calculated by the code specified equations without under-estimating the minimum separation distance required to avoid pounding.

• 대한전자공학회논문지SD
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• 제41권7호
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• pp.13-20
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• 2004

미세 광학 벤치의 설계를 위해서 두 가지 테스트 벤치에 대해 결합효율을 계산하였다. 광섬유로 들어오고 나가게 되는 빛을 볼 렌즈를 통과한 것과 그렇지 않은 것으로 설계하였다. 미세 광학 벤치의 실제 제작 과정에서 발생할 수 있는 광소자들의 위치 에러를 고려하여 시뮬레이션을 하였고, 그것들의 허용오차를 -3 ㏈ 조건으로 정하였다. 볼 렌즈가 없는 fiber-to-fiber에서는 lateral misalignment가 2.7 um 그리고 tilt 에러가 5.8o 이내로 나타났다. 각각의 광섬유 앞단에 광의 집속을 위해 볼 렌즈가 놓여지면 working distance는 60 um로 확장되어지나, 각각의 광소자들이 놓여진 위치 파라미터 사이에 보다 강한 교호작용이 존재하기 때문에 tolerance design을 위해 교호작용을 함께 고려해야 한다.

• Journal of Periodontal and Implant Science
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• 제34권1호
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• pp.19-28
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• 2004

Tooth is the most important element in esthetic consideration on facial area. Tooth alignment which is in harmony with gingiva, lips, and face is also key element. The purpose of this study was to give a clinical discipline for restoration of gingival contour, which contains a ratio of maxillary 6 anterior teeth, research for gingival contour etc., in case of rehabilitation of maxillary anterior teeth. 300 Dankook university dental school students ,who is their twenties and free from periodontitis, participate in this study. The result was from each 70 males and females who had normal occlusion and tooth alignment. Length, width and length/width ratio of maxillary 6 anterior teeth were 0.74-0.81 in male, 0.81-0.84 in female. There was significant difference between male and female. The most deepest position of gingiva in maxillary central incisor and canine was located in distal part of teeth and maxillary lateral incisor was middle portion. In maxillary central incisors, gingival line of the most deepest point appeared significant difference between male and female (p<0.01) whereas there was no difference in lateral incisors and canines. Distance between interdental papilla apex and the most deepest portion appeared significant difference between male and female. Distance of the deepest position of gingiva is statistically significant except maxillary central incisors and lateral incisors. Standard deviation and mean of the width of labio-lingual were measured in cervical area and there was a significant difference both male and female.(p<0.01) From this result, we could get the mean of maxillary anterior gingival line and these results have great value in clinical guidance in studying maxillary anterior teeth.

• Archives of Plastic Surgery
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• 제32권6호
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• pp.710-716
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• 2005

A total of 21 patients were operated. Via a columellar labial incision, the upper lateral cartilages were separated from the septum. A submucous resection of the septal cartilage was carried out. After rasping the convex lateral nasal wall of the unaffected side, a low-to-low lateral nasal osteotomy was conducted. Along the deviated dorsal line at the bony vault passing the submucous tunnel, a paramedian nasal osteotomy was performed. The convex side of the nasal bone flap was contoured by rasping. The convex side of the "T"-shaped dorsal septum was trimmed. A total direct septal extension graft of the septal cartilage was done and the alar cartilages were suspended to it. The postoperative results were evaluated by photogrammetric analysis processed by a "neon glow" filter in Adobe Photoshop. The distance from the nasal midline to the most deflective point at 5 levels was measured, and the proportion indices were obtained in regard to intercanthal distance. The results revealed improvement in all levels (p < 0.05), although not perfect. In summary, this technique can result in a clinically good-looking in spite of a slight deflection that still exists

• 한국지진공학회논문집
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• 제24권5호
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• pp.233-241
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• 2020

This paper is to investigate the retrofitting effect for a non-seismic reinforced concrete frame strengthened by perimeter steel moment frames with indirect integrity, which ameliorates the problems of the direct integrity method. To achieve this, first, full-scale tests were conducted to address the structural behavior of a two-story non-seismic reinforced concrete frame and a strengthened frame. The non-seismic frame showed a maximum strength of 185 kN because the flexural-shear failure at the bottom end of columns on the first floor was governed, and shear cracks were concentrated at the beam-column joints on the second floor. The strengthened frame possessed a maximum strength of 338 kN, which is more than 1.8 times that of the non-seismic specimen. A considerable decrease in the quantity of cracks for the strengthened frame was observed compared with the non-seismic frame, while there was the obvious appearance of the failure pattern due to the shear crack. The lateral-resisting capacity for the non-seismic bare frame and the strengthened frame may be determined per the specified shear strength of the reinforced columns in accordance with the distance to a critical section. The effective depth of the column may be referred to as the longitudinal length from the border between the column and the foundation. The lateral-resisting capacity for the non-seismic bare frame and the strengthened frame may be reasonably determined per the specified shear strength of the reinforced columns in accordance with the distance to a critical section. The effective depth of the column may be referred to as the longitudinal length from the border between the column and the foundation. The proposed method had an error of about 2.2% for the non-seismic details and about 4.4% for the strengthened frame based on the closed results versus the experimental results.

• 한국지반공학회논문집
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• 제26권12호
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• pp.51-60
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• 2010

자중에 의한 토압은 일반적으로 깊이에 따라 선형비례하여 증가되지만, 상재하중에 의해 발생되는 토압은 분포형태와 지반상태 및 경계조건에 따라 다르게 분포한다. 본 연구에서는 변위가 구속된 강성벽체에 연직상재하중에 의한 토압분포를 실험적으로 연구하기 위하여 실내모형토조[30 cm(폭) ${\times}$ 110 cm(길이) ${\times}$ 88 cm(높이)]에 각 2개의 로드셀이 배치된 8개의 토압판으로 구성된 강성벽체를 설치하여 연직상재하중의 크기와 위치(벽체에서 이격거리)를 변화시켜 가면서 토압분포와 토압의 영향범위를 관찰하였다. 실험결과, 연직상재하중에 의해 발생되는 수평토압은 일정위치에서 최대값을 보이고 깊어질수록 감소하여 한계깊이를 초과하면 무시할 만큼 작아졌다. 수평토압이 최대가 되는 깊이와 한계깊이는 연직상재하중의 크기와는 무관하게 벽체와의 이격거리에 따라 다르게 나타났다.

• Archives of Plastic Surgery
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• 제41권6호
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• pp.709-715
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• 2014

Background The distally based sural artery flap is a reliable, local reconstructive option for small soft tissue defects of the distal third of the leg. The purpose of this study is to describe an adipofascial flap based on a single sural nerve branch without sacrificing the entire sural nerve, thereby preserving sensibility of the lateral foot. Methods The posterior aspect of the lower limb was dissected in 15 cadaveric limbs. Four patients with soft tissue defects over the tendo-achilles and ankle underwent reconstruction using the adipofascial flap, which incorporated the distal peroneal perforator, short saphenous vein, and a single branch of the sural nerve. Results From the anatomical study, the distal peroneal perforator was situated at an average of 6.2 cm (2.5-12 cm) from the distal tip of the lateral malleolus. The medial and lateral sural nerve branches ran subfascially and pierced the muscle fascia 16 cm (14-19 cm) proximal to the lateral malleolus to enter the subcutaneous plane. They merged 1-2 cm distal to the subcutaneous entry point to form the common sural nerve at a mean distance of 14.5 cm (11.5-18 cm) proximal to the lateral malleolus. This merging point determined the pivot point of the flap. In the clinical cases, all patients reported near complete recovery of sensation over the lateral foot six months after surgery. All donor sites healed well with a full range of motion over the foot and ankle. Conclusions The distally based sural artery adipofascial flap allowed for minimal sensory loss, a good range of motion, an aesthetically acceptable outcome and can be performed by a single surgeon in under 2 hours.

• 한국방사선학회논문지
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• 제18권4호
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• pp.345-353
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• 2024

본 연구의 목적은 디지털 방사선 장비를 이용하여 요추 측면 검사 시 사용되고 있는 조사야 크기 및 조사야 크기에 영향을 미치는 요인의 상관관계 분석을 통해, 적절한 조사야 크기 및 중심 엑스선 입사지점을 제안하는데 있다. 2023년 1월 1일부터 2023년 12월 31일까지 S병원 영상의학과에서 요추 측면 검사를 시행한 환자 중 본 연구 목적에 적합한 148명의 검사 결과를 분석하였다. 측정 방법은 영상에서 나타난 전체 가로 폭을 검사 시 사용된 조사야 가로폭의 크기(CS)로 설정하고, 영상에 포함된 등쪽 조사야 끝에서부터 제 3요추의 척추 돌기관절까지 수직으로 연결한 거리(AJD), 영상의 조사야 등쪽 끝 부분에서 제 3요추 몸통 중심까지의 거리(BD), 영상의 등쪽 조사야 끝 부분에서 제 3요추의 척추 경 중심까지의 거리(PD)를 측정하였다. 성별, 연령, 신장, 체중, 체질량지수에 따른 종속변수의 평균값의 비교분석을 위해 독립표본 t 검정과 일원배치분산분석을 이용해 평균값을 비교하였으며, 사후분석으로는 duncan을 이용했다. 독립변수와 종속변수 간의 상관성은 pearson 상관분석을 통해 분석하였다. 본 연구에서 통계적 유의성은 p값 0.05 이하를 유의한 것으로 설정하였다. 요추 측면 검사 시 CS의 평균값은 252.45 mm 였으며, AJD는 102.11 mm, BD는 141.17 mm, PD는 119.73 mm로 나타났다. CS 및 AJD, BD, PD는 남성이 여성에 비해 평균값이 크게 나타났으나, 성별에 따른 평균값 차이에 대한 통계적 유의성은 BD에서만 나타났다(p<0.05). 연령에 따른 그룹별 평균값에 약간의 차이는 있었지만 통계적 유의성은 없었다(p>0.05). 신장, 체중, 체질량지수에 따른 CS 및 AJD, BD, PD의 평균값은 독립변수에 따라 차이가 있었으며, 그 차이는 모두 통계적으로 유의한 차이를 보였다(p<0.05). 상관관계 분석 결과, 조사야 크기 및 AJD, BD, PD는 성별, 연령과는 상관성이 없었으며, 신장과는 약한 양의 상관관계를 보였고, 체중과 체질량지수와는 중간 정도 양의 상관관계를 나타냈다. 본 연구의 결과 요추 측면 검사 시 CS는 신장과 체중, BMI와 상관성이 있는 것으로 나타났다. 그리고 임상에서 조사야 크기 조절시 체중과 체질량지수를 고려하여 중심 엑스선의 입사점을 척추 돌기관절로 이동시킨다면, 약 5%의 조사야 크기 감소 효과를 기대할 수 있을 것으로 생각된다.

• 한국도로학회논문집
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• 제13권2호
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• pp.57-65
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• 2011

본 연구에서는 도시부도로의 곡선구간에서 주행차량의 횡방향 이격량을 분석하여 차량 주행에 필요한 최소 소요차로폭을 산정하였으며 본 연구결과와 선행연구에서 제시된 직선구간에서의 최소 소요차로폭을 비교 분석하였다. 이를 바탕으로 도로의 선형과 차종에 따라 곡선구간에서의 최소 소요차로폭을 제시하였다. 조사대상 곡선구간 도로의 차로폭은 2.79m~3.40m이다. 주행차량의 횡방향 이격량의 분포 및 조사대상 차량의 85%를 기준으로 누적분포를 분석하였다. 분석결과 곡선구간에서의 최소 소요차로폭이 소형차량의 경우 2.31m~2.58m, 대형차량의 경우 2.80m~3.27m로 산정되었다. 본 연구결과는 녹색교통 도입을 위한 공간, 도로공사 중, 소형차 전용도로의 건설 등에 활용될 수 있을 것이다. 또한 설계자의 목적에 따라 유연한 차로폭 설계기준의 적용에 필요한 기초적인 연구로 활용될 수 있을 것으로 기대된다.

• The Journal of Advanced Prosthodontics
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• 제9권6호
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• pp.470-475
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• 2017

PURPOSE. The purpose of this study was to identify the complex course of the mandibular canal using 3D reconstruction of microCT images and to provide the diagram for clinicians to help them understand at the interforaminal region in Korean. MATERIALS AND METHODS. Twenty-six hemimandibles obtained from cadavers were examined using microCT, and the images were reconstructed. At both the midpoint of mental foramen and the tip of anterior loop, the bucco-lingual position, the height from the mandibular inferior border, the horizontal distance between two points, and position relative to tooth site on the mandibular canal were measured. The angle that the mental canal diverges from the mandibular canal was measured in posterior-superior and lateral-superior direction. RESULTS. The buccal distance from the mandibular canal was significantly much shorter than lingual distance at both the mental foramen and the tip of anterior loop. The mandibular canal at the tip of anterior loop was significantly located closer to buccal side and higher than at the mental foramen. And the mental canal most commonly diverged from the mandibular canal below the first premolar by approximately $50^{\circ}$ posterior-superior and $41^{\circ}$ lateral-superior direction, which had with a mean length of 5.19 mm in front of the mental foramen, and exited to the mental foramen below the second premolar. CONCLUSION. These results suggest that it could form a hazardous tetrahedron space at the interforaminal region, thus, the clinician need to pay attention to the width of a premolar tooth from the mental foramen during dental implant placement.