• Korean Journal of Environment and Ecology
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• v.21 no.2
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• pp.134-140
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• 2007

The purpose of this study is to investigate the landscape image and visual preference for ridges of the Seongpanak district at Mt. Hallasan. For this, the evaluation of the artificial and natural landscape is compared through the medium of color slides. Data is analyzed through the descriptive statistics and spatial image is analyzed by factor analysis algorithm. Principle component analysis and Varimax Method are applied to extraction and factor rotation respectively. The results of this study can be summarized as follows : General visual imagesthe Seongpanak district at Mt. Hallasan are clean, beautiful and attractive. The degree of visual preference increased commensurately with the lower rate of artificial factors. Landscape Factors covering the spatial image are found to be 'aesthetic value', 'spatial scale', 'natural quality', and 'topography' factor, which account for 57.6% of the total variants. The aesthetic value variable is the most important factor in visual preference and the unnatural factors are found to present negative elements with visual preference.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.4
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• pp.563-575
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• 2003

The purpose of this study was to investigate differences in craniofacial characteristics of professional sportsmen who have practiced since their prepubertal periods. From the standardized lateral and P-A cephalograms of 137 sportsmen, 7 angular, 19 linear, 4 ratio, and 2 index measurements were measured and evaluated by means of statistical methods. The samples were divided into three groups: Group 1; ice hockey(n=17), foot-ball(n=27), basketball(n=16) Group 2; baseball(n=16), gymnastics(n=13), and Group 3; judo(n=18), ssireum(n=10), weight lift(n=20). The results were as follows: It seemed obvious that the cephalic indices of the 3 groups exhibited brachycephalic headform (Group 1; $0.85{\pm}0.04$, Group 2; $0.84{\pm}0.04$, Group 3; $0.83{\pm}0.06$) and there was no statistical difference among the groups (p>0.05). The facial indices of the Group 1 ($0.93{\pm}0.05$) and Group 2 ($0.93{\pm}0.04$) exhibited definite leptoprosopic facial forms while the Group 3 ($0.90{\pm}0.04$) showed more or less euryprosopic facial form, and there appeared significant difference between the Group 1 and 3 (p<0.05), and also between the Group 2 and 3 (p<0.05). There appeared strong relationships between the facial indices and the facial axis angle, mandibular plane angle, total craniofacial height, total facial height, upper anterior dental height, lower anterior dental height, mandibular length, lower anterior facial height ratio, and especially with lower anterior facial height (p<0.001). It seemed that most of the vertical facial measurements of the Group 1 and 2 appeared to be larger than those of the Group 3.

• Journal of the korean academy of Pediatric Dentistry
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• v.42 no.2
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• pp.126-135
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• 2015

The purpose of this study was to evaluate the skeletal and dentoalveolar effects of facemask therapy and to compare the anchorage of a bonded expander in patients with Class III malocclusion and different vertical skeletal patterns. Twenty subjects with Class III malocclusion were included in this study and were treated with a facemask and bonded expander. Based on the FMA, subjects were divided into two groups of 10 patients each: a high vertical group (HV; mean FMA $33.56^{\circ}$) and an average vertical group (AV; mean FMA $24.88^{\circ}$). Lateral cephalograms were taken and evaluated before and after treatment. In both groups, forward movement of the maxilla and backward rotation of the mandible were observed after treatment, with no statistical differences between the groups. Vertical skeletal variables increased in both groups, but the increase of FMA was significantly larger in the HV group than the AV group. Mesial movement of maxillary molars and proclination of maxillary incisors which indicate anchorage loss of bonded expander were observed in both groups, with no significant differences between the groups. In conclusion, facemask therapy resulted in effective maxillary protraction in both HV and AV groups. However, the open bite tendency was increased more in the HV group.

• Journal of Korean Society of Forest Science
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• v.59 no.1
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• pp.37-45
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• 1983

Taxonomic distribution of ecto- and endomycorrhizae among woody species growing in Korea was studied and their distribution was compared with foreign literature, Most of root samples were collected from Central Branch Station of forest Research Institute in Gwangneung, Gyonggido. A total of 32 families, 63 genera, 102 species were examined. Ectomycorrhizae were observed in the following 13 general of Pinaceae (Pinus Larix, Picea, Abies), Salicaceae (Populus, salix), Betulace (Alnus, Betula, Carpinus, Corpylus), Fagaceae(Quercus, Casianea), and Tiliaceae (Tilia), Endomycorrhizae (vesicular-arbuscular) were observed in Populus and the rest of the 49 genera. Rhus was the only genus which did not have either ecto- or endomycorrhizae, while foreign literature listed following genera having both mycorrhizal types: Juniperus, Cupressus, Populus, Salix, Juglans, Alnus, Ulmus, Malus, Pyrus, and Tilia. Juniperus, Ulmus, Pyrus, and Acer which were reported to have facultative ectomycorrhizae were free of ectomycorrhizae, Some morphological characteristics of endomycorrhizae are shown in photogrphs and discussed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.549-557
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• 2013

An flood inundation map is able to convey spatial distribution of inundation to a decision maker for flood risk management. A roughness coefficient with unclear values and a discharge obtained from the stage-discharge rating equation are key sources of uncertainty in flood inundation mapping by using a hydraulic model. Also, the uncertainty analysis needs an observation for the flood inundation, and satellite images is useful to obtain spatial distribution of flood. Accordingly, the objective of this study is to quantify uncertainty arising roughness and discharge in flood inundation mapping by using a hydraulic model and a satellite image. To perform this, flood inundations were simulated by HEC-RAS and terrain analysis, and ISODATA (Iterative Self-Organizing Data Analysis) was used to classify waterbody from Landsat 5TM imagery. The classified waterbody was used as an observation to calculate F-statistic (likelihood measure) in GLUE (Generalized Likelihood Uncertainty Estimation). The results from GLUE show that flood inundation areas are 74.59 $km^2$ for lower 5 % uncertainty bound and 151.95 $km^2$ for upper 95% uncertainty bound, respectively. The quantification of uncertainty in flood inundation mapping will play a significant role in realizing the efficient flood risk management.

• The korean journal of orthodontics
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• v.34 no.5 s.106
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• pp.380-393
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• 2004

The Purpose of this study was to investigate the dentoalveolar compensation according to anteroposterior skeletal discrepancy in normal occlusion and to evaluate cephalometric parameters that quantitatively describe dental compensations. The study consisted of 90 subjects (50 males. 40 females) who were selected among specimens of normal occlusion at Seoul National, University Dental Hospital, Dept. of Orthodontics. Lateral cephalograms in centric occlusion were traced and digitized for each subject. According to the anteroposterior skeletal pattern the sample was divided into three groups. Cephalometric data were analyzed for the three groups using the SPSS program. Independent t-test, correlation analysis and regression analysis were carried out. The results were as fellows: Dentoalveolar compensation was found in upper and lower incisor inclination and occlusal plane inclination. As the mandible located anterior to the maxilla, the maxillary incisors incisors more labially. the mandibular incisors more lingually, and the occlusal plane continued to flatten. The dental parameters most correlated with anteroposterior skeletal discrepancy were L1 to SN and L1 to FH. Among the compensatory dentoalveolar changes, lower incisor inclination was strongly related to the anteroposterior jaw relationship and played au imposrtant role in obtaining a normal incisor relationship U1 to PtGn and L1 to APog were constant irrelevant to anteroposterior skeletal discrepancy.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.649-653
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• 2001

The Chiari malformation is a deformation within the central nervous system which the lower brain stem and the cerebellum migrate into the foramen magnum causing herniation. In 1891, Arnold Chiari classified such symptoms into 3 categories. This case report is of a 8-year-old female with the complaint of a slight facial swelling and pain on the upper right molar during tooth brushing since 10 days before. Clinical examination showed gingival pocket formation on distal of the upper right first molar with pain and mobility of the tooth. Radiographic examination showed generalized low bone density in the upper molar area, and especially no bone support above the upper right and left first molars were noted. With a temporary diagnosis of Early-onset periodontitis, consultations with medical doctors for the possibility of an underlying systemic disease were made during periodontal treatment. 3D CT was taken with after a final diagnosis of Chiari malformation. Generalized thinning and defect of the cranial bone was noted and the foramen magnum was slightly enlarged. The occipital and maxillary bone was low in density, and the alveolar bone of maxillary posterior teeth was especially almost non-existing causing the upper right and left first molar to be floating. For this, the patient went under consultation with the department of neurosurgery and is still under observation. Periodontitis in childreren is very rare. When symptoms of periodontitis appear in a child, due to the possibility of an underlying systemic disease such as leukemia, histiocytosis X, and hypophosphatasia, proper examinations should be carried out so that the primary factor the symptoms can be treated.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.645-650
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• 2004

Calcifying odontogenic cyst(COC) is a rare developmental odontogenic cyst, which shows diverse classification and terminology. Cystic epithelial lining of COC is composed of basal cell layer of columnar cells and overlying layer of stellate reticulum. In the epithelium, ghost cells that might induce adjacent mesenchymal tissue to develop dental organ are shown characteristically. In spite of low rate of recurrence, we have to get a histopathological examination so that odontogenic lesions may recur without fully curettage of lining epithelium. 7-year-old male child came pediatric dentistry in wonkwang university dental hospital in order to check the delayed eruption of left maxillary central incisor. Radiographic examination revealed a well-defined radiopaque mass, overlapping impacted left central and lateral incisor crown. Enucleated mass was tooth-like features and also had epithelium lining. Results of histopathologic procedure, we saw the lots of ghost cell and proliferating hard dental tissues. Also we saw the cystic epithelium cells. It revealed diagnosis of the COC associated complex odontoma. For this reason one should consider of COC when patients present odontoma-like lesion with impacted tooth.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.1414-1419
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• 2015

A method for detecting a skin region on the image is generally used to detect the color information. However, If saturation lowered, skin detection is difficult because hue information of the pixels is lost. So in this paper, we propose a method of correcting color of lower saturation of skin region images by the lighting. Color correction process of this method is saturation image acquisition and low-saturation region classification, segmentation, and the saturation of the split in the low saturation region extraction and color values, the color correction sequence. This method extracts the low saturation regions in the image and extract the color and saturation in the region and the surrounding region to produce a color similar to the original color. Therefore, the method of extracting the low saturation region should be correctly preceding. Because more accurate segmentation in the process of obtaining a low saturation regions, we use a multi-threshold method proposed Otsu in Hue values of the HSV color space, and create a binary image. Our experimental results for 170 portrait images show a possibility that the proposed method could be used efficiently preprocessing of skin color detection method, because the detection result of proposed method is 5.8% higher than not used it.

• Restorative Dentistry and Endodontics
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• v.30 no.6
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• pp.477-485
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• 2005

The aim of this study was to compare the length between the mesio-buccal and mesio-lingual canal of the mandibular molars before and after early coronal flaring at the different measuring time using several electronic apex locators. Fifty mandibular molars with complete apical formation and patent foramens were selected. After establishing the initial working length of the buccal and lingual canal of the mesial root using a surgical microscope (Carl Zeiss Co Germany) at 25X with #15 K-fle tip just visible at the foramen, radiographs were taken for the working length. After measuring the length of mesio-buccal and mesio-lingual canal (control group), the electronic lengths were measured at different times using several electronic apex locators (experimental groups; I-Root ZX, II-Bingo, III-Propex, IV-Diagnostic). After early coronal flaring using the $K^3$ file, the additional electronic lengths were measured using the same manner The results were as follows: One canal has a correct working length for the mesial root of the mandibular molar, it can be used effectively for measuring the electronic working length of another canal when the files are superimposed or encountered at the apex. In addition, the accuracy of the electronic apex locators was increased as the measurement was accomplished after the early coronal flaring of the root canal and the measuring time was repeated.