• Journal of Korean society of Dental Hygiene
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• v.19 no.2
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• pp.317-327
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• 2019

Objectives: This study aimed to evaluate the effects of occlusion patterns using the T-scan $III^{(R)}$ system and oral parafunctional behaviors on temporomandibular joint disorder (TMD) in female college students. Methods: A questionnaire survey assessed TMD symptoms and oral behavioral checklist (OBC) scores in 120 female college students in their early twenties. Occlusion was evaluated using the T-scan $III^{(R)}$ system. Logistic regression analysis was performed to investigate the relationship between occlusion and OBC scores based on patients' symptoms of TMD and to determine whether OBC scores were a predictor of TMD. Results: A total of 101 participants with an average age of 22 (${\pm}2.17$) years were included in the analysis. The reported symptoms of TMD were categorized as moderate (28.8%), slight (27.7%), severe (25.7%), and asymptomatic (17.8%). Occlusion was analyzed using the T-scan $III^{(R)}$ system, and the mean occlusion time was 0.42(${\pm}0.5$) seconds. The results of logistic regression analysis showed that the group that would 'clench or grind teeth' during sleep showed an odds ratio for TMD that was 8.9 times higher than that in the group without this behavior. The group that would 'hold, tighten, or tense muscles without clenching' while awake showed an odds ratio for TMD that was 21.3 times higher than that in the group without this behavior. Conclusions: We confirmed that oral parafunctional behavior affects TMD. Therefore, we would like to continue studying the diagnosis and treatment of TMD by evaluating occlusion patterns and related OBC scores.

• The Transactions of the Korean Institute of Power Electronics
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• v.24 no.6
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• pp.438-444
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• 2019

In this paper, bidirectional LLC resonant DC/DC converters with the primary auxiliary windings in transformers of resonant circuits are proposed. Although the resonant capacitors are used on both the primary and secondary sides, regardless of the direction of power flow, the main feature of the proposed converters exhibits high gain characteristics without any mutual coupling between the resonant capacitors. For one of the proposed converters, an investigation of the operating characteristics in each mode has been carried out. A prototype of a 3.3 kW bidirectional LLC resonant converter for interfacing 750 V DC buses has been built and tested to verify the validity and applicability of the proposed converter.

• Journal of Electrical Engineering and Technology
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• v.12 no.6
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• pp.2247-2255
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• 2017

Because the on-board charger (OBC) is installed in electric vehicles (EVs), high power density is regarded as a key technology. Among components of the OBC, inductors occupy more than 30% of the total volume. Thus, it is important to reduce the volume and the weight of inductors while maintaining thermal stability. Discontinuous conduction mode (DCM) can satisfy these requirements; however, only a few studies have adopted the DCM operation for OBCs because of the large inductor current ripple. In this paper, a design process is proposed for application of the DCM operation to OBCs. In order to analyze the inductor losses accurately, a numerical formula for the inductor current ripple is deduced based on a detailed analysis. Two inductors are fabricated using several ferrite cores and powder cores taking into consideration the inductor size, inductor losses, and temperature rise. In order to verify the analysis and design process, experimental results are presented that show that the designed inductors satisfy the requirements of the OBCs.

• Nutrition Research and Practice
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• v.4 no.2
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• pp.99-105
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• 2010

Obesity is considered a mild inflammatory state, and the secretion of inflammation-related cytokines rises as adipose tissue expands. Inflammatory cytokines, including tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interlukin 6 (IL-6) and monocyte-chemoattractant protein 1 (MCP-1), are modulated by adipose tissue and known to play an important role in insulin resistance which is the common characteristics of obesity related disorders. In this study we analyzed the effects of Sasa borealis leaves extract on inflammatory cytokines and insulin resistance in diet induced obese C57/BL6J mice. The obese state was induced by a high fat diet for 20 weeks and then the mice were divided into two groups; obese control group (OBC, n = 7) and experimental group (OB-SBE, n = 7). The OBC group was fed a high fat diet and the OB-SBE group was fed a high fat diet containing 5% Sasa borealis leaves extract (SBE) for 12 weeks. We also used mice fed a standard diet as a normal control (NC, n = 7). The body weight and adipose tissue weight in the OB group were significantly higher than those in the NC group. The effects of the high fat diet were reduced by SBE treatments, and the body weight and adipose tissue deposition in the OB-SBE group were significantly decreased compared to the OBC group. The OBC group showed higher serum glucose and insulin levels which resulted in a significant increase of incremental area under the curve (IAUC) and HOMA-IR than the NC group. Also, serum leptin, TNF-${\alpha}$, and IL-6 levels were significantly higher in the OBC group than in the NC group. In contrast, the OB-SBE group showed a reversal in the metabolic defects, including a decrease in glucose, insulin, IAUC, HOMA-IR, TNF-${\alpha}$, IL-6 and leptin levels. These results suggest that BSE can suppress increased weight gain and/or fat deposition induced by a high fat diet and theses effects are accompanied by modulation of the inflammatory cytokines, TNF-${\alpha}$ and IL-6 secretion resulting in improved insulin resistance.

• Geophysics and Geophysical Exploration
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• v.11 no.2
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• pp.109-115
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• 2008

It is very important to estimate the physical properties of survey area and delineate the geological basement in marine site survey for the design of offshore structures. For the purpose of providing high quality data by means of engineering site survey, it is necessary to apply several survey techniques and carry out the integrated interpretation to each other. In this study, we applied single channel seismic reflection method and OBC (Ocean Bottom Cable) type seismic refraction method at shallow marine. We used a dual boomer-single channel streamer as a source-receiver in seismic reflection survey and airgun source-the developed OBC type streamer in seismic refraction survey. We made 24 channels OBC type streamer which has 4m channel interval and each channel is composed of single hydrophone and preamplifier. We tested the field applicability of the proposed method and applied the typical seismic data processing methods to the obtained reflection data in order to enhance the data quality and image resolution. In order to estimate the geological velocity distribution from refraction data, seismic refraction tomography technique was applied. Therefore, we could successfully perform time-depth conversion using the velocity information as an integrated interpretation. The proposed method could provide reliable geologic information such as sediment layer thickness and 3D basement depth map.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2006.04a
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• pp.73-92
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• 2006

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.4
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• pp.43-51
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• 2012

• KIPE Magazine
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• v.25 no.4
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• pp.28-34
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• 2020

• KIPE Magazine
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• v.24 no.4
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• pp.43-49
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• 2019

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.196-197
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• 2013

친환경 차량의 필수장치로 사용되는 OBC(On Board Charger) 및 LDC(Low DC-DC Converter)는 시스템 성능은 물론 하드웨어적인 신뢰성과 더불어 차량에서 발생할 수 있는 다양한 Fault로부터 차량과 운전자를 보호할 수 있는 안정성과 신뢰성을 확보하는 것이 요구된다. OBC/LDC 개발에 있어 시제품을 제작하여 성능 검증과 하드웨어 신뢰성을 확보하는 것은 현재의 개발 프로세서로 충분하지만 차량에서 발생하는 다양한 Fault 상황에 대한 강건성 확보는 실차에 탑재하여 검증하지 않고서는 뚜렷한 검증 방법이 없는 실정이다. 이에 따라 본 논문에서는 차량에서 발생될 수 있는 다양한 Fault 상황을 시뮬레이터로 모사하여, 이러한 Fault를 전력변환장치에 인위적으로 주입시킨 뒤 전력변환장치가 정상적으로 동작하는지 분석한다. 이를 통해 실차에 탑재하지 않고 전력변환시스템의 신뢰성을 검증하기 위한 방안을 제시한다.