• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.12
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• pp.194-200
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• 2012

In this paper, we proposed a SPICE model of high-voltage insulated gate bipolar transistor(IGBT). The proposed model consists of two sub-devices, a MOSFET and a BJT. Basic I-V characteristics and their temperature dependency were realized by adjusting various parameters of the MOSFET and the BJT. To model nonlinear parasitic capacitances such as a reverse-transfer capacitance, multiple junction diodes, ideal voltage and current amplifiers, a voltage-controlled resistor, and passive devices were added in the model. The accuracy of the proposed model was verified by comparing the simulation results with the experimental results of a 1200V trench gate IGBT.

• Korean Journal of Remote Sensing
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• v.36 no.5_2
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• pp.949-959
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• 2020

In this paper, as a prior study related to the generation of topographic information using the CAS500-1/2 satellite, we propose a method of extraction DSM for each 1:5000 scaled map in North Korea using KOMPSAT-3A strip images. This technique is designed to set the processing area by receiving shape file, only to generate output for every 1:5000 scaled map. In addition, dense point clouds and the DSM were extracted by applying MDR, a robust stereo image matching technique. Considering that the strip images are input in the units of scenes, we attempted to extract a DSM by processing and merging multiple image pairs in one 1:5000 map area. As a result, it was possible to confirm the generation of an integrated DSM with minimal separation at the junction, and as a result of the accuracy analysis, it was confirmed that the accuracy was within 5m compared to GCP.

• The Korea Journal of Herbology
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• v.31 no.5
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• pp.85-92
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• 2016

Objectives： This study is experimental comparison of brown rice (BR) and germinated brown rice (GBR) on upper gastrointestinal diseases animal models.Methods： The ICR mice were divided randomly into four groups of six animals each (Normal mice, gastritis mice, gastritis mice treated with BR, gastritis mice treated with 48h GBR). Gastritis was induced by administration of 0.5 mL 150 mM HCl-60% ethanol. Six-week-old male Sprague-Dawley (SD) rats were randomly divided into 7 groups after 1 week adaptation. (Normal rat, reflux esophagitis (RE) rat, RE rat treated with BR, RE rat treated with 24,30,36,48h GBR). Reflux esophagitis was induced by ligation with a 2-0 silk thread both the pylorus and the transitional junction between the forestomach and the corpus in SD rats.Results： HCl/ethanol-induced gastric mucosal injury mice were ameliorated mucosal damage upon histological evaluation by treatment of 48h GBR than BR. Optical changes such as hyperemia and multiple erosions were observed in the rats with RE and damage to the normal rats was not apparent. The oral administration of GBR significantly diminished against gross mucosal damage in a germination time-dependent manner. Also, the administration of GBR suppressed the biomarker of oxidative stress, reactive oxygen species (ROS) and produces peroxynitrite (ONOO-) in serum. However, the administration of GBR could not affect to the pH level secreted from stomach when compared with Control group.Conclusions： These findings suggest that GBR could have improving effects on upper gastrointestinal diseases in a germination time-dependent manner.

• Journal of the Korean Society for Railway
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• v.19 no.1
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• pp.46-53
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• 2016

LED light sources have been known to have a long life and good energy efficiency compared to traditional light sources. Recently, headlamps using LED light sources have ensured the forward visibility and safe operation of high-speed rolling stock. However, assessing the lifespan of LED headlamps based on real test data is not easy because it depends on the multiple stress factors such as a fixed driving current, junction temperature, vibration and so on. Generally, LED headlamps have failed before their advertised life span mainly due to temperature. Thus, the performance assessment of a temperature control unit should be done before a life cycle test of LED headlamps. This study attempted to develop a prototype temperature control module for a lifecycle test system using a commercial LED headlight and verified the system through experiments.

• Journal of Periodontal and Implant Science
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• v.43 no.4
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• pp.160-167
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• 2013

Purpose: This study examined the factors that can be associated with the appearance of the interproximal papilla. Methods: One hundred and forty-seven healthy interproximal papillae between the maxillary central incisors were examined. For each subject, a digital photograph and periapical radiograph of the interdental embrasure were taken using a 1-mm grid metal piece. The following parameters were recorded: the amount of recession of the interproximal papilla, contact point-bone crest distance, contact point-cemento-enamel junction (CEJ) distance, CEJ-bone crest distance, inter-radicular distance, tooth shape, embrasure space size, interproximal contact area, gingival biotype, papilla height, and papilla tip form. Results: The amount of recession of the interproximal papilla was associated with the following: 1) increase in contact point-bone crest, contact point-CEJ, and CEJ-bone crest distance; 2) increase in the inter-radicular distance; 3) triangular tooth shape; 4) decrease in the interproximal contact area length; 5) increase in the embrasure space size; and 6) flat papilla tip form. On the other hand, the amount of gingival recession was not associated with the gingival biotype or papilla height. In the triangular tooth shape, the contact point-bone crest distance and inter-radicular distance were longer, the interproximal contact area length was shorter, and the embrasure space size was larger. The papilla tip form became flatter with increasing inter-radicular distance and CEJ-bone crest distance. Conclusions: The relative position of the interproximal papilla in healthy subjects was associated with the multiple factors and each factor was related to the others. A triangular tooth shape carries a higher risk of recession of the interproximal papilla because the proximal contact point is positioned more incisally and the bone crest is positioned more apically. This results in an increase in recession of the interproximal papilla and flat papilla tip form.

• The korean journal of orthodontics
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• v.47 no.3
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• pp.176-185
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• 2017

Objective: To evaluate the relationship of gingival thickness (GT) and the width of keratinized gingiva (WKG) with different malocclusion groups and the level of crowding. Methods: A total of 187 periodontally healthy subjects (121 females and 66 males) who presented at the Faculty of Dentistry in $Y{\ddot{u}}z{\ddot{u}}nc{\ddot{u}}$ Yil University for orthodontic treatment were enrolled in the study. The individuals involved in the study were divided into three groups; Angle Class I malocclusion, Angle Class II malocclusion, and Angle Class III malocclusion. Each group was classified as mild, moderate, or severe according to the level of crowding. WKG was determined as the distance between the mucogingival junction and the free gingival margin. GT was determined by the transgingival probing technique. Factorial variance analysis and the Duncan multiple comparison test were employed to identify the extent to which a difference was apparent between the groups according to these parameters. Results: It was determined that teeth in the mandibular anterior region display the thin gingival biotype. WKG and GT were observed as being higher at the mandibular incisor teeth in the severe crowding group and at the mandibular canine teeth in the mild crowding group. The GT of the mandibular right central and lateral incisors was found to be thinner in the Angle Class III group. Conclusions: Within the limits of this study, the results demonstrate that, there is no significant relationship of WKG and the mean GT in the mandibular anterior region according to the Angle classification.

• Korean Institute of Interior Design Journal
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• v.21 no.3
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• pp.22-30
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• 2012

Nowadays the issue of environmental pollution and ecological destruction is not a simple issue but an important issue to be continuously considered. It is deemed that a study for recycled new materials is immediately required and this study is to analyze features and processing methods of new materials which can be used to interior space. We found the recycled new materials used for space through researching various web sits. And then we analyzed what the base materials are and classified that base materials are whether natural or artificial of the recycled materials. We classified processing methods of the recycled new materials after researching general processing methods. The result of this study would be an important material to the research and development of new finishing materials with consideration of environment and to the research for a guideline of applicable new materials. The results of this study are as follows : First, we could classify widely 2 categories into natural material and artificial material and then 10 subcategories into metal, glass, wood, rubber, stone, plastic, leather or fabric, ceramic, concrete and so on, and analyzed that which material is mostly used and whether it is single material or multiple material. In order to analyze the feature of processing method. Second, we could classify into 4 categories such as junction, surface process, molding, and insert, and found out which processing method is applied based on objects of research. Third, as an analysis result of the recycled new material feature, in order to develop various new materials, it is required to study on combination and application of 2 materials or more rather than single material. Four, as a analysis result of the processing method feature, I would like to suggest that development and application of various processing methods are required. Especially, it is necessary to grope for a way to develop new functional materials for interior space through a systemic research and analysis of processing method of other fields. Furthermore, a way to reuse recycled new materials should be considered in a stage of selection and application of processing method.

• Restorative Dentistry and Endodontics
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• v.42 no.2
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• pp.87-94
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• 2017

Objectives: Chitosan has been widely investigated and used. However, the literature does not refer to the shelf life of this solution. This study evaluated, through the colorimetric titration technique and an analysis of dentin micro-hardness, the shelf life of 0.2% chitosan solution. Materials and Methods: Thirty human canines were sectioned, and specimens were obtained from the second and third slices, from cemento-enamel junction to the apex. A 0.2% chitosan solution was prepared and distributed in 3 identical glass bottles (v1, v2, and v3) and 3 plastic bottles (p1, p2, and p3). At 0, 7, 15, 30, 45, 60, 90, 120, 150, and 180 days, the specimens were immersed in each solution for 5 minutes (n = 3 each). The chelating effect of the solution was assessed by micro-hardness and colorimetric analysis of the dentin specimens. 17% EDTA and distilled water were used as controls. Data were analyzed statistically by two-way and Tukey-Kramer multiple comparison (${\alpha}=0.05$). Results: There was no statistically significant difference among the solutions with respect to the study time (p = 0.113) and micro-hardness/time interaction (p = 0.329). Chitosan solutions and EDTA reduced the micro-hardness in a similar manner and differed significantly from the control group (p < 0.001). Chitosan solutions chelated calcium ions throughout the entire experiment. Conclusions: Regardless of the storage form, chitosan demonstrates a chelating property for a minimum period of 6 months.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1999.10a
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• pp.111-121
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• 1999

From the traffic analyses, and model constructions and verifications for speed prediction on the freeway ramp junctions with 70mph speed limit, the following results obtained: ⅰ) The traffic flow distribution showed a big difference depending on the time periods. Especially, more traffic flows were concentrated on the freeway junctions in the morning peak period when compared with the afternoon peak period. ⅱ) The occupancy distribution was also shown to be varied by a big difference depending on the time periods. Especially, the occupancy in the morning peak period showed over 100% increase when compared with the 24hours average occupancy, and the occupancy in the afternoon peak period over 25% increase when compared with the same occupancy.ⅲ) The speed distribution was not shown to have a big difference depending on the time periods. Especially, the speed in the morning peak period shown 10mph decrease when compared with the 24hours' average speed, but the speed did not show a big difference in the afternoon peak period.ⅳ) The analyses of variance showed a high explanatory power between the speed predictive models(SPM) constructed and the variables used, especially the upstream speed. ⅴ) The analysis of correlation for verifying the speed predictive models(SPM) constructed on the ramp junctions were shown to have a high correlation between observed data and predicted data. Especially, the correlation coefficients showed over 0.95 excluding the unstable condition on the diverge sectionⅵ) Speed predictive models constructed were shown to have the better results than the HCM models, even if the speed limits on the freeway were different between the HCM models and speed predictive models constructed.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.26 no.1
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• pp.37-45
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• 2024

Objective: To review the characteristics of distal middle cerebral artery (MCA) aneurysm treated by microsurgery, the detailed surgical options, and the clinical result. Methods: We retrospectively reviewed cerebral aneurysm in the M2 and M3 segments of the MCA surgically treated between January 2015 and December 2022. The demographic data, aneurysm-related findings, type of surgical approach, surgical technique, and clinical outcomes of the enrolled patients were analyzed. Results: Sixteen distal MCA aneurysms were treated with microneurosurgery (incidence, 1.0%; female, 12; mean age, 58.1 years; ruptured, three). Twelve aneurysms were in the M2 segment (insular segment), two aneurysms at the M2-M3 junction, and two aneurysms in the M3 segment (opercular segment). Twelve aneurysms were saccular (average size, 4.9 mm; multiplicity, 50%; average aneurysms, 3.0; partially thrombosed, 1; sidewall aneurysm, 2). Three aneurysms were fusiform, of which two were ruptured. Of the ruptured aneurysms, one was a ruptured dissecting aneurysm. The trans-sylvian and trans-sulcal approaches were used in fourteen and two patients, respectively. Neck clipping, wrap clipping, and surgical trapping were performed in twelve, one, and one patient, respectively. Proximal occlusion was performed in one patient. Bypass technique was required in two patients (neck clipping and proximal occlusion). The modified Rankin Score was 6 in the two patients with ruptured aneurysms. The remaining patients did not show further neurological deterioration after microneurosurgery. Conclusions: Distal MCA aneurysms had a high incidence of being diagnosed with multiple other aneurysms and were relatively non-saccular.