• 한국산림과학회지
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• 제96권2호
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• pp.189-196
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• 2007

Allometry, basal area equations, and volume equations were developed with various tree measurement variables for the major species, Quercus mongolica and Quercus variabilis, in Korean natural hardwood forests. For allometry models, the relationships between total height-DBH, crown width-DBH, height to the widest portion of the crown-total height, and height to base of crown-total height were investigated. Multiple regression methods were used to relate annual basal area growth to tree variables of initial size (DBH, total height, crown width) and relative size (relative diameter, relative height) as well as competition measures (competition index, crown class, exposed crown area, percent exposed crown area, live crown ratio). For tree volume equations, the combined-variable and Schumacher models were fitted with DBH, total height and crown width for both species.

• Journal of Forest and Environmental Science
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• 제27권1호
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• pp.47-54
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• 2011

Allometry and basal area equations were developed with various tree measurement variables for the major species; Quercus variabilis, Quercus mongolica, Pinus koraiensis and Larix leptolepis in Korea. For allometry models, the relationships between total height-DBH, crown width-DBH, height to the widest portion of the crown-total height, and height to base of crown-total height were investigated. Multiple regression methods were used to relate annual basal area growth to tree variables of initial size (DBH, total height, and crown width), relative size (relative diameter and relative height) as well as competition measures (competition index, crown class, and live crown ratio).

• 대한치과보철학회지
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• 제44권2호
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• pp.165-173
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• 2006

Purpose: With gold electroforming system fir the double crown, the secondary crown is electroformed directly onto the primary crown. An even thick layer of high precision can be acquired. It is thought that the retention of electroformed outer crown is primarily acquired by the adhesive force (surface tension) through the saliva which is interposed between precisely fitted inner and outer crown. The purpose of this study was to investigate the effect of taper and surface area of inner crown on the retentive force of electroformed outer crown according to the presence of saliva. Materials and methods: 32 titanium inner crowns with cervical diameter of 8 mm and cone angles of 0, 2, 4, 6 degrees, which had same surface area by regulated height, were machined on a lathe. Another 32 titanium inner crowns with cone angles of 0, 2, 4, 6 degrees, which had doubled surface area by increased cervical diameter. were fabricated. Eight specimens of each group, for a total of 64 titanium inner crowns, were prepared. The electroformed outer crowns were fabricated directly on the inner crowns by using electroforming machine(GAMMAT free, Gramm Technik, Germany). The tertiary frameworks were waxed-up on the electroformed outer crown and cast using nonprecious alloy($Rexillium^(R)III,\;Jeneric^(R)/Pentronh^(R)$ Inc., USA). The cast metal frameworks were sandblasted with alubimium oxides and cemented using resin cement(Superbond C&B, Sun Medical Co., Japan) over the electroformed copings of each specimen. Then, artificial saliva($Taliva^(R)$, Halim Pharm. Co., Korea) was sprayed between the inner and outer crown, and they were connected under 5 kg force. The retentive force was measured by the universal testing machine(Tinius Olsen 1000, Tinius Olsen, USA) with a cross-head speed of 66.67 mm/sec. The direction of cross-head travel was exactly aligned with the path of removal of the respective specimens. This measurement procedures for retentive force of electroformed outer crown with artificial saliva were repeated in the same way without presence of artificial saliva. Results and Conclusion: The following conclusions were drawn: 1. The retentive force of electroformed outer crown was decreased according to increased taper of inner crown(P<.05). 2. The retentive force of electroformed outer crown showed no significant differences according to surface area and the presence of artificial saliva(P>.05).

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.515-518
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• 2005

LiDAR(Light Detection and Ranging) with digital aerial photograph can be used to measure tree growth factors like total height, height of clear-length, dbh(diameter at breast height) and crown projection area. Delineating crown is an important process for identifying and numbering individual trees. Crown delineation can be done by watershed method to segment basin according to elevation values of DSMmax produced by LiDAR. Digital aerial photograph can be used to validate the crown projection area using LiDAR. And tree height can be acquired by image processing using window filter$(3cell\times3cell\;or\;5cell\times5cell)$ that compares grid elevation values of individual crown segmented by watershed.

• 대한소아치과학회지
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• 제29권3호
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• pp.382-388
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• 2002

전라북도 전주시 유치원 어린이 650명을 대상으로 구강내 검사 실시하여 평균 연령 4.5세 어린이 100명(남아 50명, 여아 50명)의 유치열 석고모형을 계측하여 다음과 같은 결과를 얻었다. 1. 유치의 계측자내 오차는 제1유구치에서 다소 크고, 총평균치는 0.255mm이었다. 2. 유치의 근원심 및 순(협)설측 치관 직경은 전체 유치에서 남아가 여아보다 컸다. 3. 변동계수(coefficient variation)는 남 여아 모두 유전치부위가 유구치부위에 비해 다소 큰 경향을 보였고, 근원심 및 순(협)설측 치관 직경 모두 제2유구치에서 크기변화가 가장 적게 나타났다. 4. 좌, 우측 동명치 사이의 차이를 나타내는 비대칭성에서는 상악 근원심 크기 측정을 제외하고는 근원심 및 협설측 치관 크기 측정 모두에서 제2유구치가 제1유구치보다 보다 덜 비대칭적이었다. 5. Crown index는 상악의 경우 여아보다 남아에서 큰 반면, 하악의 경우에는 유견치를 제외하고는 여아에서 컸다. Crown module은 여아보다 남아에서 컸고, 일반적인 치아크기가 유중절치에서부터 제2유구치까지 점차 증가하였다. Crown area도 여아보다 남아에서 컸으며 하악 유중절치가 가장 적은 면적을 나타냈고, 상악 제2유구치가 가장 큰 면적을 나타냈다.

• 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.

• 한국환경복원기술학회지
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• 제15권3호
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• pp.45-54
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• 2012

This study intended to analyze growth condition of each object by protected tree's ground for 45 places registered to Pyeongtaek protected tree list in locational characteristics, conduct exchange analysis for impediment extent rate in crown area and tree type to the result and suggest the measures to manage artificial impediment which is an effect on protected tree condition. In this study, the tree whose area of impediment for crown area is less than 21% is tree condition of grade 1~2, less than 21~50% is grade 2~3 and more than 50% is grade 3~5. The more impediment is, the more inconvenience causes on growth and development. So, it verified that the area rate must maintain less than 21% for the root system management of protected tree. For the standard of managing artificial impediment which is an effect on the tree condition of protected trees, the below matters intend to be suggested. The first, the impediment in crown area should be less than 21%. But, if there is not artificial impediment out of crown area, the rate of impediment area is considered to increase somewhat. The second, growth space of protected tree should be maintained by crown area at least and impediment should be established out of the crown area. The third, during the national project and land development, surroundings of protected tree must be applied as park, resting place, etc. and the establishment area of impediment (artificial impediment and natural impediment) in crown area must be limited. The forth, publicity for regional people (especially, land owner) is necessary for the protection of natural inheritance and the value of dependence on local government and village which are the subject of management must be announced widely through the internet media, etc, so its importance must be recognized. The fifth, the matters related to protected tree management must be able to limit artificial damage which is for surroundings of protected tree through the mutual connection among the local governments; construction, civil engineering, architecture, water and sewage, agriculture and forest and others. Also, following studies on the effects of kinds, thickness, etc. of impediment around the protected tree on trees should be continued.

• 대한치과의사협회지
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• 제21권5호통권168호
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• pp.415-423
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• 1983

A total of 202 full coverage crowns from 31 patients was investigated to find out the relationships between crown contour and gingival response. Every experimental crown has its contralateral natural tooth for its control group. Gingival Index and buccolingual width of the crowns were measured on both experimental and control group. Following conclusions were obtained from the study. 1. Most of the crown restorations were overcontoured and the increments were servere at cervical and height of contour area. 2. Height of contour and contact point of the restored crown were located near cervical area. Besides, most crowns had narrow embrasure with wide contact area. 3. Gingival Index around crown restorations was significantly larger than that of control group. 4. the interrelationship between Gingival Index and restored material or restored period was not verified at 5% significant level. 5. When grouping the artificial crowns into overcontoured, normal contoured, and undercontoured group by their width increment, the gingival inflammation was the severest in the overcontoured group and the mildest in the undercontoured group.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.676-679
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• 2006

Mangrove crowns were delineated using active sensor LIDAR (LIght Detection And Ranging) data by a crown delineating model developed in this study. LIDAR data were acquired from airborne survey by a helicopter for the estuary of Macouria in the northeast coast of French Guiana. The canopy height image was derived from LIDAR vector data by calculating the difference between ground and non-ground data. The mangrove site in the study area was classified to three sectors by the time of mangrove settlement; Mangrove 1986, 2002 and 2003. The estimated crown of Mangrove 1986 was reliable defined for their size, number and volume because of larger crown size and bigger variation of crown height. The tree crown size of Mangrove 2002 and 2003 by the model was overestimated and the number of trees was much underestimated. The estimated crown was not for single crown but a crown group due to homogenous crown height and spatial resolution of LIDAR data. However the canopy height image derived from LIDAR data provided three-dimensional information of mangroves.

• 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.