• Proceedings of the KIPE Conference
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• 2015.11a
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• pp.123-124
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• 2015

Recently interest on DC systems has been grown up extensively for more efficient connection with renewable energy. During the operation, there happens DC_link voltage variations. This paper focuses on the DC voltage stabilization applied in stand-alone DC microgrid to improve the system stability by keeping the voltage within limits. Batteries and a variable speed diesel generator cover the shortage of power after all available renewable energy is consumed. Load shedding or power generation reduction should automatically takes place if the maximum tolerable voltage variation is exceeded. PSIM based simulation results are presented to evaluate the performance of the proposed control measures.

• Annual Conference of KIPS
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• 2012.11a
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• pp.421-423
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• 2012

본 연구에서 개발한 포토앨범/다이어리 어플리케이션은 아기의 성장과정을 사진/음성으로 기록할 수 있는 다이어리 기능을 제공한다. 또한, 아기와 관련된 각종 기념일(생일, 예방접종일 등)에 대한 일정을 관리할 수 있다. 음성녹음도 지원하기 때문에 아기와 부모의 대화, 그리고 부모의 음성일기 등을 빠짐없이 기록할 수 있다. HTML5기반 하이브리드 애플리케이션(Hybrid Application)은 다중 플랫폼을 지원하기 때문에 한번 개발하면 여러 플랫폼에서 사용할 수 있으므로 개발비용을 절약할 수 있을 뿐더러, HTML5 Device API를 사용함으로써 네이티브 앱과 동일하게 디바이스를 제어할 수 있다. 본 연구에서는 포토앨범/다이어리 스마트폰 애플리케이션을 HTML5 개발하여 아이폰 iOS와 안드로이드를 지원하며, 다양한 스마트폰 센서/장치에 접근할 수 있도록 개발되었다.

• Annual Conference of KIPS
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• 2012.04a
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• pp.946-949
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• 2012

일반적으로 낸드플래시는 Matlab이나 간단한 프로그램 언어를 통하여 분석하는 경우가 많았다. 그 이유는 많은 데이터와 공정마다 변하는 데이터 format 그리고 여러 가지 분석방법의 다양성이 그 이유이다. 그 때문에 분석시간과 분석의 정형화가 이루어지지 않았다. 본 논문의 낸드플래시의 분석을 정형화 하였고, DB를 이용하여 많은 양의 테스트데이터를 관리 하였다. 또한 여러 종류의 테스트데이터 format에 대하여 범용 적으로 사용할 수 있도록 제작 하였다. 제작된 분석기는 낸드플래시의 CCI특성 및 EW cycle과 retention에 대한 stress resistance를 분석할 수 있다. 객체지향 으로 설계가 되어 추후 유지 보수를 용이하게 설계하였다.

• Journal of Korea Multimedia Society
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• v.21 no.2
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• pp.271-280
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• 2018

Recently, big data has been growing rapidly due to the development of IT technology. Especially in the medical field, big data is utilized to provide services such as patient-customized medical care, disease management and disease prediction. In Korea, 'National Health Alarm Service' is provided by National Health Insurance Corporation. However, the prediction model has a problem of short-term prediction within 3 days and unreliability of social data used in prediction model. In order to solve these problems, this paper proposes a disease prediction model using medicine prescription data generated from actual patients. This model predicts the total number of patients and the risk of disease in each region and uses the ARIMA model for long-term predictions.

• Journal of Periodontal and Implant Science
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• v.26 no.1
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• pp.133-142
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• 1996

Ten intrabony defects in 10 patients were treated by flap surgery including root surface debridement and placement of an expanded polytetrafluoroethylene(ePTFE) membrane. The membranes were removed after 4-6 weeks. This study was performed to examine the retrived ePTFE membrane by scanning electron microscopy(SEM) for bacterial contamination and adherent connective tissue elements, and to compare it with clinical conditions. The cervical portion of the membrane, which in most cases had become partially exposed to the oral cavity, had a bacterial deposit. Small bacterial colonies and a scatter of single cells in some instances extended into the apical portion of the membrane. Fibroblast-like cells, erythrocytes and fibrous structures were seen in the apical portion of the membrane. Outer surface of membrane tends to more bacterial contamination than inner surface(p<0.01), and upper portions more than lower portions(P<0.01). Comparison of ultrastructural findings and clinical conditions revealed that extent of bacterial contamination of the membrane correlated with gingival inflammation and extent of membrane exposure, but it was not significant statistically. The results suggested that gingival inflammation and membrane exposure affect periodontal regeneration by the use of ePTFE membrane.

• Korean Journal of Medicinal Crop Science
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• v.17 no.3
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• pp.161-164
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• 2009

This study was conducted to investigate the weight of crown part effect on growth and bolting response of Ostericum koreanum Kitagawa. Bolting rate with crown part weight was represented 0%, 0%, 4.1%, 12.9%, 25.1%, 34.9% corresponding to each crown part weight 5 g, 10 g, 20 g, 30 g, 40 g, 50 g. The heavier the crown part weight was the higher the direction rate rose and the flowering time came earlier. The dried root amount was the highest at 30 g and crown part number, the length of root, and crown diameter showed all the highest figures at 30 g. The relation between amount per 10 g and outcrop weight increased on secondary regression formula as weight increased and reached its peak at 29.7 g and then decreased over 29.7 g.

• Journal of Space Technology and Applications
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• v.2 no.3
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• pp.221-229
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• 2022

This paper reports on the design and installation of a thermostat to keep the temperature of the fluxgate magnetometer constant and the data stability evaluation after installation. The thermostat was installed at the Icheon Geomagnetic Observatory operated by the Korean Space Weather Center of National Radio Research Agency. It was designed in consideration of stability of temperature control against safety incident, potential effects on magnetic field measurement, and the temperature control efficiency. After the temperature control device was installed, it was confirmed that the temperature was constantly maintained at the level of 20℃. Delta F and baseline values were used to evaluate geomagnetic data stability, and it was confirmed that delta F and baseline fluctuations were reduced after installation of the thermostat.

• The Korea Journal of Herbology
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• v.27 no.6
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• pp.49-54
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• 2012

Objective : We recently reported that OMC-2010 has an immuno-modulatory effects via inhibiting tumor necrosis factor (TNF)-${\alpha}$ and interleukin (IL)-5. However, we did not find out which constituents play an important role in immuno-modulatory effect of OMC-2010. Thus, this study was performed to estimate the effects of constituents of OMC-2010 on cytokine production in mouse spleen cells, then ultimately reach to find out effective constituents regulating splenic cytokine production. Methods : Mouse spleen cells were pre-treated with water and ethanol extract of constituents of OMC-2010 such as Rehmannia glutinosa (RG), Pinellia ternata (PT), Citrus unshiu Markovich (CUM), Glycyrrhiza uralensis (GU), Platycodon grandiflorum (PG), Schisandra chinensis (SC). After 1 h, the cells were stimulated with lipopolysaccharide (LPS, 1 ${\mu}g/ml$) for 48 h. Then the cells were harvested for real-time reverse transcription polymerase chain reaction to detect cytokine productions. Results : The water extract of RG extract significantly inhibited the LPS-induced inTNF-${\alpha}$ and IL-5 mRNA expressions, but the water extract of PT, CUM, GU, PG, and SC did not. The ethanol extract of RG, PT, and SC significantly inhibited the LPS-induced TNF-${\alpha}$, and IL-5 mRNA expressions, but the ethanol extract of CUM, GU, and PG did not. Conclusions : Theses results could suggest that the water extract of RG and the ethanol extract of RG, PT, and SC inhibited the expression of TNF-${\alpha}$ and IL-5, which means that the possible candidate of OMC-2010 water extract's action might be RG, and ethanol extract's action might be RG, PR, and SC.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.1
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• pp.44-49
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• 2015

Urea has been the most useful N-source, due to lower cost per unit of N. But nitrogen use efficiency of urea may be reduced because of losses from agricultural system by volatilization of ammonia to atmosphere. This study was conducted to evaluate the nitrogen efficiency and growth of hot pepper (Capsicum annuum L.) by mixed treatment with nitrogen and zeolite. They were treated with N $161kg\;ha^{-1}$, N $230kg\;ha^{-1}$, nitrogenzeolite mixture (NZM) $161kg\;ha^{-1}$, NZM $230kg\;ha^{-1}$ and N $0kg\;ha^{-1}$, respectively. In the soil chemical properties after experiment, soil pH decreased but available $P_2O_5$, EC and total nitrogen increased in nitrogen-zeolite mixture treatment. $NO_3-N$ content in the soil showed the highest level in NZM $230kg\;ha^{-1}$. NZM $161kg\;ha^{-1}$ treatment increased growth and yield of hot pepper compared to urea alone. Nitrogen utilization efficiency of hot pepper plant was 47.15% at the treatment of NZM $161kg\;ha^{-1}$, while 36.74% at N $230kg\;ha^{-1}$. These results showed that application of mixture of nitrogen and zeolite had positive influence to improve the efficiency of nitrogen utilization and increase of red pepper yield.

• Journal of Industrial Technology
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• v.21 no.B
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• pp.233-240
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• 2001

This research was conducted with the aim of efficiently managing large scale of rivers such like Songyang-river through predicting water quality change with analyzing the characteristics of the flowing in nutrients and pollutants. The main result will be used as basic data for effectively operating reservoirs through controling water quality and quantity. The relationship between quantity of flow and water quality was analyzed and pollution loading into the basin was estimated. Three areas of Soyang-river upstream and one area of Suip-cheon in Yanggu-gun were selected as research sites. Flow and water quality were measured simultaneously. The relation between quantity of discharge and pollution concentration and between quantity of discharge and pollution loading were analyzed by statistical method, respectively. We provided a rating curve through measuring quantity of discharge(collecting quantity of discharge) and pollutograph and pollution loading curve through water quality data. Also, we analyzed the correlation between quantity of discharge per unit area and pollution loading per unit area in each basin. As resurt of this research, Buk-cheon spot revealed an excellent first grade water quality for the items including $BOD_5$, DO, and SS. The correlation coefficient between Buk-cheon spot's quantity of discharge and pollution loading was 0.896~0.996, showing the validity of analysis applying correlation curve formula of quantity of discharge and pollution loading in the same spot. Also, pollution loading per unit area of the items including $BOD_5$, COD, DO, SS, T-N, T-P increased as the area of basins get increased following the sequence of Buk-cheon, Suip-cheon, Naelin-cheon spots.