• Journal of Forest and Environmental Science
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• 제34권3호
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• pp.235-241
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• 2018

This study was conducted to find out the growth pattern of Pinus koraiensis plantation over 34 years, focusing on DBH, height, basal area and allometric change. Total increment (TI), mean annual increment (MAI) and correlation coefficient were calculated and compared with stand and dominants. Total increment and mean annual increment of both DBH and height of dominants were bigger than those of stand. The difference was apparently shown bigger in DBH than height. Unlike DBH and height the total increment and mean annual increment of basal area per hectare of dominants were distinctively smaller than those of stand. Furthermore MAI of dominant was increasing until age 42, while MAI of stand increased at early ages and then gradually decreased after culmination like MAIs of DBH and height. MAIs of basal area of dead trees at each measurement tended to increase until early age (18 years in this study), while it reached a peak and gradually decrease after that (21 years in this study). Correlation coefficient between DBH and height tended to decrease as both dominant and stand age and the difference between dominant and stand was not clearly shown over the measurement period. Correlation coefficients between DBH and crown width tended to decrease as the trees age and correlation coefficients of dominant were clearly shown smaller than that of stand. Correlation coefficients of height and crown width also was found to be similar to correlation coefficients between DBH and crown. Meanwhile correlation coefficient of height and crown width dropped more radically than coefficient of DBH and crown width as the trees age.

• Journal of Periodontal and Implant Science
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• 제35권3호
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• pp.761-776
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• 2005

The purpose of the present study was to examine the relationship between the form of the clinical crowns in the maxillary anterior segment and the clinical feature of gingiva such as morphological characteristics and the gingival thickness. Fifty periodontally healthy subjects were clinically examined regarding the probing depth, the thickness of the free gingiva, and the width of the keratinized gingiva. From study models of the maxillary anterior region, the width at cervical third(CW) and the length(CL) of the clinical crown, the papillary height, and the gingival angle of the 6 anterior teeth were measured. Each tooth was classified into 4 groups (longnarrow, NL; narrow, N; wide, W; short-wide, WS) according to CW/CL ratio and all the data were compared between groups NL and WS using independent t-test. Stepwise multiple regression analysis was performed for each tooth region with the gingival thickness at the level of sulcus bottom, the width of keratinized gingiva, and gingival angle as the dependent variables. As the results, the NL group of the upper anterior teeth displayed, higher papilla height, and narrower keratinized gingiva, more acute gingival angle resulting in pronounced "scalloped" contour of the gingival margin, compared to the WS group. There was no significant difference between groups NL and WS with respect to probing depth and the gingival thickness. The regression analyses demonstrated that the gingival thickness in central incisors was significantly associated to the mesio-distal width and bucco-lingual width of the crown, and labial probing depth. The width of keratinized gingiva was significantly associated with labial probing depth in central incisors and with proximal probing depth and gingival angle in lateral incisors, and with labial and proximal probing depth, and gingival angle in canines. The gingival angle was significantly associated with papillary height and CW/CL ratio and additionally with proximal probing depth in central incisors, with the width of keratinized gingiva in lateral incisors, and with labial probing depth and the width of keratinized gingiva in canines. These results indicate that the form of clinical crown in upper anterior region could influence the clinical feature of gingiva and the influencing factors might be different according to the tooth region.

• Journal of Forest and Environmental Science
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• 제18권1호
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• pp.45-52
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• 2001

본 논문은 솔잎혹파리 피해임지에서 수목의 외형적인자(수고, 수관폭, 흉고직경, 지하고)와 shigometer를 이용한 전기 저항치 ($k{\Omega}$)의 관계를 조사하였다. 외형적인자와 저항치간의 관계는 수고, 수관폭, 흉고직경은 높은 상관관계가 있었고, 지하고는 뚜렷한 관계가 나타나지 않았다. 수고, 수관폭, 흉고직경은 큰 수목이 전기저항치가 낮았고(수목의 활력이 높음) 작은 수목이 전기저항치가 높았다(수목의 활력이 낮음). 솔잎혹파리 피해임지의 고사목과 생존목을 비교하면 고사목이 생존목에 비하여 수관폭과 흉고직경의 크기는 작았고, 지하고는 높았다. 전기저항치를 3등급으로 구분 한 결과(< $14{\Omega}$, 생존가능성 양호, $14{\sim}20{\Omega}$, > $20k{\Omega}$고사 가능성 있음), 외형적인자의 크기는 낮은등급(< $14{\Omega}$)에서 수고, 수관폭, 흉고직경이 컸으며, 지하고는 낮았다. 조사한 외형적인자와 수세와의 관계를 직선회귀 방정식으로 산출한 결과 Y=-0.572${\times}$수고-1.163${\times}$수관폭-0.242${\times}$흉고직경+0.757${\times}$지하고+25.765이였으며 이들의 회귀식은 5%의 수준에서 유의성이 인정된다.

• 한국산림과학회지
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• 제97권5호
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• pp.501-507
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• 2008

The data of crown width with 4 directions, DBH, tree height, and coordinate for sample trees were collected from 30 permanent sample plots in secondary fore st of the Maoershan Experimental Forestry Farm, Northeast China. In this paper, the competition of individual trees in stand were discussed for secondary forest by using iterative Hegyi competition index and crown overlap index that represented the competitive and cooperative interactions among neighboring trees. Active competitors of subject tree in the competition zone were selected to calculate the iterative competition index. Using the results of crown classification based on the equal crown projection area, a new distance dependent competition index called crown overlap index (COI) was developed for secondary forest. The COI performed well in describing the crown competition rather than crown competition factor (CCF). The individual-based competition index discussed in this paper will provide more precise for developing individual tree growth models for secondary forest and it can also use to adjust the stand structure for spatial optimal management.

• Restorative Dentistry and Endodontics
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• 제35권5호
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• pp.395-400
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• 2010

치관부 파절편 재부착술식은 접착치의학의 발달과 더불어 치관파절 치료 방법 중 하나로 자리매김하였다. 하지만 치관치근파절된 치아에 있어서 기존의 치관부 파절편 재부착술식으로는 치은연하 영역의 수복 및 생물학적 폭경의 유지가 어려워 부가적인 치관연장술 또는 치아 정출술 등이 요구되게 된다. 하지만 이번 증례보고는 치수노출을 동반한 치관-치근파절을 치료함에 있어서 이러한 부가적인 술식 없이 변형된 치관부 파절편 재부착술식만을 이용하여 처치한 사례이다. 환자는 근관치료 후 post 삽입 및 재부착 술식을 시행 받았으며 이때 치관 파절편의 변형을 통해 생물학적 폭경을 위한 공간 유지 및 적절한 접착을 위한 영역을 확보할 수 있었고 이후 한차례의 재파절이 발생하였지만 재차 재부착 후 2년간의 follow up을 통해 치주부착상실 없이 치관 파절편이 잘 유지되는 것이 관찰되었다.

• 한국측량학회지
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• 제33권6호
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• pp.605-614
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• 2015

Drone imaging, which is more cost-effective and controllable compared to airborne LiDAR, requires a low-cost camera and is used for capturing color images. From the overlapped color images, we produced two high-resolution digital surface models over different test areas. After segmentation, we performed tree identification according to the method proposed by , and computed the tree height and the canopy crown size. Compared with the field measurements, the computed results for the tree height in test area 1 (coniferous trees) were found to be accurate, while the results in test area 2 (deciduous coniferous trees) were found to be underestimated. The RMSE of the tree height was 0.84 m, and the width of the canopy crown was 1.51 m in test area 1. Further, the RMSE of the tree height was 2.45 m, and the width of the canopy crown was 1.53 m in test area 2. The experiment results validated the use of drone images for the extraction of a tree structure.

• 한국산림과학회지
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• 제89권2호
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• pp.256-259
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• 2000

솔잎혹파리 피해 극심지인 강원도 양양군 현남면 인구리의 소나무 임지에서 고사목과 생존목을 대상으로 흉고직경, 수고, 지하고, 수관고, 수관폭, 수관상태 등의 임목 특성을 비교 조사하였으며 판별분석법을 이용하여 솔잎혹파리에 의한 피해위험도를 평가하였다. 고사목과 생존목간에 흉고직경 및 수고는 차이가 없었으나 수관고는 생존목에서 395.88cm로 고사목의 347.25cm 보다 컸으며, 수관상태 역시 단목의 피해위험도에 크게 영향을 미치는 것으로 나타났다. 수관폭은 고사목에서는 평균 121.04cm인데 비해 생존목은 182.44cm로서 생존목이 컸으며, 수관단면적과 수관부피는 생존목이 각각 $2.82m^2$, $4.45m^2$, 고사목은 $1.30m^2$, $1.78m^2$로 생존목이 2배 이상 컸다. 생존목과 고사목의 단목 특성을 이용하여 판별분석을 실시한 결과 수관단면적, 지하고에 대한 수관고 비율, 수관상태, 수관단면적에 대한 수관부피의 비율, 수관폭에 대한 수관고의 비율 등이 중요인자로 나타났으며, 판별분석 모델의 예측효율은 86.7%였다.

• Spatial Information Research
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• 제20권6호
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• pp.45-57
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• 2012

도시지역의 가로수는 보행자와 운전자에게 쾌적한 환경을 제공하며 탄소를 흡수하는 중요한 역할을 수행한다. 따라서 가로수의 위치, 수고, 수관폭 등에 대한 효율적인 획득과 관리가 필요하다. 본 연구는 항공라이다 자료를 이용하여 도시지역 가로수에 대한 개수, 위치, 수고, 수관폭의 수치적인 정보를 추출하는 방법론을 제안하였다. 가로수는 그 형태와 크기가 다를 수 있기 때문에 본 연구에서는 수관폭의 크기를 변화시키면서 가로수를 추출하는 방법을 제안하였다. 또한 가로수는 일반적으로 도로변을 중심으로 식재되기 때문에 이러한 식재위치의 직선적 특성을 이용하여 가로수점들을 선택하였다. 오산시 일부를 대상으로 가로수 추출에 대한 실험을 수행하였으며 결과는 1/1,000 수치지도와 비교하여 제안한 방법론의 적합성을 평가하였다. 실험 결과를 통해서, 가로수의 위치오차는 최소 0.5m, 최대 1.9m, 그리고 평균제곱근오차는 약 ${\pm}0.4m$를 나타냈다.

• 한국정밀공학회지
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• 제19권11호
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• pp.200-210
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• 2002

In twin roll strip casting process, coupled analyses of heat transfer and deformation for the cast roll are carried out by using the finite element program MARC to examine the thermal crown. Shrink fit effect and plastic deformation are considered. The results shows that the thermal crown is greatly influenced by shrink ft and that the thermal crown for POSCO Pilot Caster 2 Copper Roll has “M” shape. The effects of several factors on thermal crown are also investigated. The amount of thermal crown increases as heat flux, casting speed, steeve thickness and casting roll width increase and decreases as the casting roll diameter increases.

• 대한심미치과학회지
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• 제3권1호
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• pp.44-50
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• 1995

Abutment dies which resemble the actual size and shape of crown abutment is essential in most of the research area of fixed prosthodontics like marginal accuracy, crown seating, behavior of luting agent and so on. Seeing the large portion of research is done with round shaped dies in different size and cone angles, the necessity of research on the crown abutment is self-evident. 500 molar abutments were collected randomly through the commercial dental laboratoy, regrdless of their position in the dental arch, sex, and age. The measurements of 22 points of a die were done, and the results were as fogbows : 1. The height of the molar dies was $3.9{\pm}1.2mm$ 2. The bucco-lingual width was $8.9{\pm}1.2mm$ at the base, and $7.4{\pm}1.2mm$ at the occlusal. 3. The desio-sistal width was $8.2{\pm}1.2mm$ at the base, and $7.0{\pm}1.3mm$ at the occlusal.