• Investigative Magnetic Resonance Imaging
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• v.3 no.2
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• pp.179-187
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• 1999

Purpose : This paper introduces a computationally inexpensive context-dependent classification of multi-echo MRI with Bayes compound decision model. In order to produce accurate region segmentation especially in homogeneous area and along boundaries of the regions, we propose a classification method that uses contextual information of local enighborhood system in the image. Material and Methods : The performance of the context free classifier over a statistically heterogeneous image can be improved if the local stationary regions in the image are disassociated from each other through the mechanism of the interaction parameters defined at he local neighborhood level. In order to improve the classification accuracy, we use the contextual information which resolves ambiguities in the class assignment of a pattern based on the labels of the neighboring patterns in classifying the image. Since the data immediately surrounding a given pixel is intimately associated with this given pixel., then if the true nature of the surrounding pixel is known this can be used to extract the true nature of the given pixel. The proposed context-dependent compound decision model uses the compound Bayes decision rule with the contextual information. As for the contextual information in the model, the directional transition probabilities estimated from the local neighborhood system are used for the interaction parameters. Results : The context-dependent classification paradigm with compound Bayesian model for multi-echo MR images is developed. Compared to context free classification which does not consider contextual information, context-dependent classifier show improved classification results especially in homogeneous and along boundaries of regions since contextual information is used during the classification. Conclusion : We introduce a new paradigm to classify multi-echo MRI using clustering analysis and Bayesian compound decision model to improve the classification results.

• Korean Journal of Ecology and Environment
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• v.40 no.2
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• pp.223-233
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• 2007

For this study, we analyzed spatial and temporal patterns of trophic state and water quality over the period of $2002{\sim}2005$, using the water chemistry dataset obtained from the Korea Rural community & Agriculture corporation. Most reservoirs, based on TN, showed eutrophic (about 88% of the total). About 20% of agricultural reservoirs, based on TP, showed eutrophic after the criteria of OECD (1982), while 71% and 3% were Hesotrophic and oligotrophic, respectively. Seasonal variations were evident due to the intense monsoon rain during July${\sim}$August; conductivity, COD, SS, nutrients, and chlorophyll-${\alpha}$ (CBL) increased in the postmonsoon compared to the premonsoon. TP values had positive functional relations with conductivity, COD, and CHL values. COD and SS peaked during the intense monsoon. Mean values of TP and CHL values were two times greater in the intense monsoon than the weak monsoon. The increased TP was probably due to inorganic suspended solids from point and non-point sources during the monsoon. Ratios of TN : TP had strong in- verse relations ($R^2$=0.843, p<0.001, n=34) with TP, but not with TN (p>0.05, n=34). Log10-transformed CHL increased with TP in most P-limited reservoirs $(Log_{10}TP=0.5{\times}Log_{10}CHL+0.086)$. Similarity analysis, based TN, TP, and CHL showed that three groups were separated at 90% similarity level; One group was reservoirs with high salinity nearby the seawater, and the other two groups were reservoirs with a low salinity of the inland, and intermediate salinity, respectively.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.4
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• pp.267-272
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• 2015

'Tight junctions (TJ)' have recently been identified in the granular cell layer of the human epidermis, where they contribute to the normal adhesion between keratinocytes and to the physiologic barrier function of the epidermis. Among the TJ proteins in the epidermis, occludin is an important transmembrane protein, which is considered as a major component. The purpose of this study is to investigate whether regional variation exists in the expression of the tight junction protein occludin in normal human epidermis. Indirect immunofluorescence staining for occludin was performed with specimens taken from different areas of normal skin (4 from each of 7 different anatomical sites, including the scalp, face, posterior neck, upper arm, abdomen, lower back, and inner thigh). The degrees of the expression-intensity in each specimen were estimated with the reciprocals of positive end-point titer of occludin in an indirect immunofluorescence study. The highest degree expression-intensity of the TJ protein occludin among the different areas of normal epidermis was observed on the face and abdomen with a titer of 600 (p=0.001). The lowest intensity of expression of occludin was seen in the epidermis from the upper arm. Skin specimens from the scalp, neck, back, and leg demonstrated intermediate degrees of the expression in intensity. The expression of occludin in the skin samples obtained from different locations of the body showed a statistically significant variation. This suggests that there is a certain degree of regional variation in the expression-intensity of TJ protein 'occludin' in the human epidermis.

• The korean journal of orthodontics
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• v.31 no.6 s.89
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• pp.567-578
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• 2001

To investigate the difference of Texture exhibited on interproximal enamel surface with each different stripping method and the susceptibility of proximal enamel to demineralization after stripping and the application of a topical fluoride go] and sealant, one hundred human premolars, which were Previously extracted for orthodontic reasons were evaluated by means of Scanning electron microscopy and laser fluorescence. The results were as follows : 1. No matter what the initial stripping instrument was the furrows that resulted from all the stripping methods were not completely removed by careful polishing. 2. Among the enamel surfaces that were treated with three different initial abrasive instruments, followed by the same polishing method (Sof-$Lex^{(r)}$ disks), the enamel surfaces that were treated with 700 crosscut carbide bur showed the smoothest surfaces. 3. The stripped teeth, no matter what the initial stripping instrument was, were less resistant to initial demineralization than untreated teeth. But no difference in caries susceptibility according to differently stripped methods was found (p<(0.001). 4. Teeth treated with APF-gel or sealant were mote resistant to demineralization than those treated without other treatment after stripping (p<0.001). 5. Comparing groups treated with APF-gel to groups treated with sealant, the former was more resistant to demineralization than the tatter (p<0.05). In conclusion, enamel surfaces that were stripped jnterproximally were less resistant to demineralization even though various attempts were made to produce smooth, self-cleaning enamel surfaces. Therefore, additional treatment-sealant or calcifying/ fluoridating solution To the stripped enamel surfaces is recommended.

• Journal of KIISE:Databases
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• v.36 no.4
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• pp.263-279
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• 2009

Shape features in a content-based image retrieval (CBIR) system are divided into two classes: contour-based and region-based. Contour-based shape features are simple but they are not as efficient as region-based shape features. Most systems using the region-based shape feature have to extract the region firs t. The prior works on region-based systems still have shortcomings. They are complex to implement, particularly with respect to region extraction, and do not sufficiently use the spatial relationship between regions in the distance model In this paper, a region extraction method that is the combination of an edge-based method and a region growing method is proposed to accurately extract regions inside an object. Edges inside an object are accurately detected based on the Canny edge detector and the Hough transform. And the modified Integrated Region Matching (IRM) scheme which includes the adjacency relationship of regions is also proposed. It is used to compute the distance between images for the similarity search using shape features. The experimental results show the effectiveness of our region extraction method as well as the modified IRM. In comparison with other works, it is shown that the new region extraction method outperforms others.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.4
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• pp.685-693
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• 2007

Class I malocclusion without skeletal problem results from tooth size/arch-size discrepancies, either evidenced by crowding, or spacing problems. Treatment method can be chosen according to dentition, the amount of arch discrepancy, patient compliance, or patient demands. We report of clear aligner and spring aligner that can be applicated in cases of permanent dentition with minimal arch discrepancy in anterior segment. There are some limits of application, but these are very useful appliances in the selective case. When crowding exists, definitive analysis and diagnosis should be made before starting treatment because certain amount of space must be obtained somewhere in the dentition to resolve the crowding. Therefore, appliance should be applied when lacking space is small. Also, in cases with spacing arch circumference is reduced after alignment so no problem in intermaxilla occlusal relationship must be confirmed. In case with crowding, judicious removal of interproximal enamel is indicated.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.2
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• pp.203-214
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• 2018

Root resorption of the permanent maxillary incisors can occur due to ectopic eruption of the permanent canines. Severe root resorption threatens the long-term survival of the affected incisors. The aim of the present study was to identify risk factors for root resorption of the maxillary incisors associated with impacted maxillary canines. In the present study, we retrospectively analyzed the Cone-Beam Computed Tomography (CBCT) scans of 65 children and adolescents with ectopically erupting maxillary canines (total of 88 impacted canines). Root resorption of central incisors was significantly associated with the mesiodistal position and root development of the adjacent canine. Root resorption of lateral incisors was significantly associated with sex, age, and the buccolingual and vertical position of the adjacent canine. However, enlargement of the dental follicle was not significantly associated with root resorption of adjacent incisors. Although incisor resorption is difficult to diagnose and predict, our findings suggest that changes in the dental follicles of the erupting maxillary canines do not cause resorption of the adjacent permanent incisors. CBCT should be utilized to ensure early diagnosis of impacted canines and precise evaluation of incisor root resorption.

• Journal of Cadastre & Land InformatiX
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• v.47 no.2
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• pp.19-37
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• 2017

Visible Infrared Imaging Radiometer Suite Day-Night Band (VIIRS-DNB) data provides a much higher capability for observing and quantifying nighttime light (NTL) brightness in comparison with Defense Meteorological Satellite-Operational Linescan System (DMSP-OLS) data. In South Korea, there is little research on the detection of NTL brightness change using VIIRS-DNB data. This study analyzed the spatial distribution and change of NTL brightness between 2013 and 2016 using VIIRS-DNB data, and detected its spatial relation with possible influencing factors using regression models. The intra-year seasonality of NTL brightness in 2016 was also studied by analyzing the deviation and change clusters, as well as the influencing factors. Results are as follows: 1) The higher value of NTL brightness in 2013 and 2016 is concentrated in Seoul and its surrounding cities, which positively correlated with population density and residential areas, economic land use, and other factors; 2) There is a decreasing trend of NTL brightness from 2013 to 2016, which is obvious in Seoul, with the change of population density and area of industrial buildings as the main influencing factors; 3) Areas in Seoul, and some surrounding areas have high deviation of the intra-year NTL brightness, and 71% of the total areas have their highest NTL brightness in January, February, October, November and December; and 4) Change of NTL brightness between summer and winter demonstrated a significantly positive relation with snow cover area change, and a slightly and significantly negative relation with albedo change.

• Journal of Korean Society of Forest Science
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• v.65 no.1
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• pp.31-42
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• 1984

This study contains the scientific justification of the forest aromatic bath(F.A.B) in the stage of introduction and the general concepts using in the design of the forest aromatic bath ground, especially definition of F.A.B, basic activities and facilities, carrying capacity and criteria deserving much consideration in designing of it. Terpene, the origin of F.A.B appearance, is made clear that it is efficacious in our physical health. The forest (coniferous one) mainly exhales terpene about noon and morning and seasonally spring and summer time. The most influential factor to exhale terpene is the climate one-wind, temperature, sunlight, humidity. Forest canopy and leaves are related to the concentration of terpene in the forest area. The basic activities for F.A.B are mostly static, and so are the facilities. The forest aromatic bath room(F.A.B.R) which a person must be given for F.A.B. is $169m^2$, 59 persons per ha. This $169m^2$ is the carrying capacity of F.A.B. The sites of F.A.B.G. might better be located around the national and provincial park, mountain torrent, hot spring zone and the waterfronts. Meanwhile, forest management in F.A.B.G should be enforce in order to keep on constantly maintaining the exhalation quantity of terpene.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.4
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• pp.85-93
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• 2008

The MAEULSOOP, Korean traditional village groves have been installed and survived since 7th Century to serve local village dwellers as a community forest. The common sense of their reasons for being is related to the surroundings such as hills, waterways and wind-ways. To understand the roles in a local community, spatial characteristics of distribution, locations and shapes were tested at the two-characterized regions, the Southwestern Flat Region and the Eastern Hilly Region. Approximately more than 500 written evidences related to trees and forests were surveyed, for example village names, folk tales and lists of designated trees for protection. Twenty sites in each region were selected and tested for the spatial analysis. Aerial photographs, DEM and the ArcGIS with a modified AML for slope analysis are applied based on the criteria of the KLCIS(Kwon, 2002; 권진오, 2008). The major factors in the role of the MAEULSOOP based on the spatial character of two regions are; the array and locations of hills for encircling or exposure, locations against corridors and waterway or not, locations of the community to serve, the conservation of energy. Although locations and shapes of the MAEULSOOP are slightly different, it seems that one of the prime roles is what makes their everyday life difficult the most in the community.