• Restorative Dentistry and Endodontics
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• 제2권1호
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• pp.27-31
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• 1976

Eighty mandibular first premolars were injected with china ink, decalcified, cleared and used in an in vitro study to determine the number of root canals, the frequency and location of lateral canals, the location of apical foramens, the frequency of apical deltas, and the curvature of root canals. The results were as follows: 1. Most of the teeth demonstrated single canal, but 22.5% of the teeth were found to have bifurcated or trifurcated canals. 2. Of the 99 canals studied, 37.3% of the canals were found to have lateral canals and these ramifications were usually located in the apical third of the root. 3. 27 apical foramens were located directly on the root apex and 66 foramens laterally. 4. 6 canals showed mesial curvature, 49 canals distal curvature, 11 canals buccal curvature, and 25 canals lingual curvature.

• Restorative Dentistry and Endodontics
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• 제10권1호
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• pp.183-186
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• 1984

Thirty maxillary lateral incisors were injected with china ink, decalcified, cleared and used in an in vitro study to determine the number of root canals, the frequency and location of lateral canals, the location of apical foramens, the frequency of apical deltas, and the curvature of root canals. The results were as follows: 1. Most of the teeth demonstrated single canal, but 6.7% of the teeth were found to have bifurcated canals. 2. Of the 32 canals studied, 37.5% of the canals were found to have lateral canals and these ramifications were usually located in the and apical third of the root. 3. 9 apical foramens were located directly on the root apex and 21 foramens laterally. 4. 3 canals showed mesial curvature, 20 canals distal curvature, 4 canals labial curvature, and 3 canals palatal curvature.

• 대한치과의사협회지
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• 제15권11호
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• pp.753-756
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• 1977

Eighty-two maxillary canine were injected with china ink, decalcified, cleared and used in a study, in vitro, to determine the number of root canals, the frequency and location of lateral canals, the location of apical foramens, and the curvature of root canals. The results were as follows; 1.All of the maxillary canines showed the single canals. 2. Of the 82 canals studied, 20.7% of the canals were found to have lateral canals and most ramification of them were located in the apical third of the root. 3. In the case of the curvature, the mesial curvature of the canals (40.3%) usually showed more than the distal curvature of them (13.4%) 4. 41.2% of the apical foramen were located directly on the root apex and 58.5% of them laterally.

• 대한치과의사협회지
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• 제16권12호통권115호
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• pp.929-933
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• 1978

Sixty six mandibular incisor were injected with China ink, decalcified, cleared and used to study the number of root canals, the frequency and location of lateral canals, the location of apical foramens, the frequency of apical deltas, and the curvature of root canals. The results were as follows: 1. Most of the teeth demonstrated single canal, but 19.7% of the teeth were found to have bifurcated canals. 2. 12% of the teeth were found to have lateral canals and these ramifications were located in the apical third of the root. 3. 25 apical foramens were located directly on the root apex and 41 foramens laterally. 4. 43 canals showed straight, 7 canals distal curvature, 7 labial curvature, 3 mesial curvature.

• Current Optics and Photonics
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• 제1권4호
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• pp.378-388
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• 2017

We present a graphical method for determining a pair of optical materials and powers to design an achromatic and athermal lens system with corrected Petzval curvature. To graphically obtain the solutions, a three-dimensional (3D) glass chart is proposed. Even if a particular material combination is unavailable, we can select an element suitable for a specific lens and continuously change the element powers of an equivalent single lens for aberrations correction. Thus, we can iteratively identify the materials and powers on a 3D glass chart. By designing a fisheye lens using this method, an achromatic and athermal system with flat Petzval curvature is obtained, over the specified waveband and temperature ranges.

• Current Optics and Photonics
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• 제2권4호
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• pp.324-331
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• 2018

This paper describes a symmetric method for determining a combination of element power and optical material to design a catadioptric system with corrected color aberration and flat Petzval curvature. To graphically obtain the solutions, a glass chart containing the Abbe number, the refractive index, and the optical power, which are closely related to these aberrations, is suggested. First, we recompose an optical system as a doublet of the specific lens and an equivalent single lens, and then locate both lenses on lines that are symmetric to each other on a glass chart, through changing the lens parameters effectively. Utilizing this method, an achromatic catadioptric system with flat Petzval curvature is obtained.

• Restorative Dentistry and Endodontics
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• 제4권1호
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• pp.23-27
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• 1978

Fifty two mandibular permanent canines were chosen to study the anatomy of the root canal. The experimental teeth were injected with China ink, decalcified, cleared and observed to investigate the number of root canals, frequency and location of lateral canals, the location of apical foramens, the frequency of apical deltas, and the curvature of root canals. The results were as follows: 1) all of the experimental teeth demonstrated single canal. 2) of the 52 canals, 9.6% of the canals were found to have lateral canals and the locations of the lateral canals were in the apical third of the roots 3) Thirty three apical foramens were located laterally on the root apices and nineteen foramens were located on the centers of the root apices. 4) 37 canals showed straight curvature, 12 canals distal curvature. 3 canals labial curvature.

• 척추신경추나의학회지
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• 제5권2호
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• pp.33-41
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• 2010

Objectives : This study is designed to find out the relationship of scoliotic curve, cervical lordosis, lumbar lordosis and Ferguson's angle. Method : The study was composed of 46 scoliosis patients who had single curvature(Group I) on their lumbar spine(Group I-A) or thoracic spine(Group I-B) and 38 patients who had double curvature(Group II) on their lumbar and thoracic spine. The patients were evaluated with X-ray findings of full spine AP and Lateral views and statistically analyzed. Results : 1. Group II showed a significant increase in scoliotic curve angle as compared with Group I(P<0.05). 2. Scoliotic curve has a negative relationship with cervical lordosis in group II. Conclusion : 1. The patients who has double curvature of spine had higher scoliotic curve angle compared with who has single curvature. 2. The Scoliotic curve and cervical lordosis was statistically concerned on patients who has double curvature of spine.

• 한국잡초학회지
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• 제7권1호
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• pp.84-89
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• 1987

HBR[(22s, 23s)-homobrassinolide]과 auxin류(類)의 생장조절제(生長調節劑) 단독(單獨) 또는 혼용(混用) 처리시(處理時) 무우 자엽병(子葉柄)의 상편생장(上偏生長)(굴절(屈折))에 어떻게 影響(影響)을 마치는가를 구명(究明)하여 얻어진 결과(結果)를 요약(要約)하연 다음과 같다. 1. HBR 단독처리(單獨處理)는 농도(濃度)에 관계(關係)없이 무우 자엽병(子葉柄) 굴절(屈折)에 영향(影響)하지 않았다. 2. 천연식물생장조절제(天然植物生長調節劑) IAA, IBA, NAA의 굴절효과(屆折效果)는 짧았고 IAA는 처리후(處理後) 4(시간(時間)), IBA는 12~24 시간(時間), NAA는 12 시간(時間) 지나면 감소(減少)하였다. 이 가운데 NAA 100ppm 처리구(處理區)에서 가장 높았고 IAA 처리(處理)에서 전반적으로 가장 높았고 IAA 처리(處理)에서 전반적으로 가장 효과(效果)가 낮았다. 3. 합성(合成) auxin 류(類)인 MCP나 2, 4-D의 굴절효과(屈折效果)는 대체로 36시간(時間) 지속(持續)되었으며 고농도(高濃度)인 100 ppm에서 무처리(無處理)에 3배(倍) 이상(以上) 증대(增大)시켰다. 30ppm 이하(以下)의 저농도(低濃度)에서는 효과(效果)도 작고 농도간(濃度間) 차(差)도 작았다. 4. NAA와 HBR의 혼용(混用)은 NAA 100ppm 처리(處理)에서 HBR 100 ppm 단독(單獨)보다 약(約) 3배(倍) 증대(增大)시켰으나 30 ppm 이하(以下)의 농도(濃度)에서는 큰 차이(差異)가 없었다. 5. HBR에 MCP 3ppm의 혼용(混用)은 HBR 단독처리(單獨處理)에 비(比)하여 굴절각(屈折角)을 약(約) 3배(倍) 증대(增大)시켰다. HBR과 2.4-D의 혼용(混用)은 농도(濃度)가 증가(增加)할수록 굴절각(屈折角)의 반응(反應)이 크게 나타났으며 100 ppm 혼용(混用)에서 HBR 단독처리(單獨處理)에 비(比)하여 약(約) 8배(倍) 증가(增加)시켰다.

• Structural Engineering and Mechanics
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• 제78권3호
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• pp.255-267
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• 2021

The analysis of simply supported single-cell skew-curved reinforced concrete (RC) box-girder bridges is carried out using a finite element based CsiBridge software. The behaviour of skew-curved box-girder bridges can not be anticipated simply by superimposing the individual effects of skewness and curvature, so it becomes important to examine the behaviour of such bridges considering the combined effects of skewness and curvature. A comprehensive parametric study is performed wherein the combined influence of the skew and curve angles is considered to determine the maximum bending moment, maximum shear force, maximum torsional moment and maximum vertical deflection of the bridge girders. The skew angle is varied from 0° to 60° at an interval of 10°, and the curve angle is varied from 0° to 60° at an interval of 12°. The scantly available literature on such bridges focuses mainly on the analysis of skew-curved bridges under dead and point loads. But, the effects of actual loadings may be different, thus, it is considered in the present study. It is found that the performance of these bridges having more curvature can be improved by introducing the skewness. Finally, several equations are deduced in the non-dimensional form for estimating the forces and deflection in the girders of simply supported skew-curved RC box-girder bridges, based upon the results of the straight one. The developed equations may be helpful to the designers in proportioning, analysing, and designing such bridges, as the correlation coefficient is about 0.99.