• Korean Journal of Organic Agriculture
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• v.20 no.4
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• pp.607-618
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• 2012

The blueberry gall midge, Dasineura oxycoccana (Diptera: Cecidomyiidae), has known as a key pest of blueberries in the southeastern United States, Europe and Canada. It can cause considerable damage to developing flower buds and also injure vegetative growth by distorting and blackening shoot tips on blueberries. In 2010, same damage symptoms were observed on blueberries, Vaccinium spp., in Hwaseong-si, Gyeonggi-do. And, D. oxycoccana was identified from the farms and it was designated as a quarantine pest in Korea. The occurrences of D. oxycoccana and its damages were investigated in the blueberry greenhouse in 2011. Nationwide survey revealed that most of the blueberry greenhouses were infected by D. oxycoccana. An environment-friendly management method for D. oxycoccana was developed by changing soil environment in the blueberry greenhouse.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.3
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• pp.229-236
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• 2003

This study recorded an object using a digital video recorder, and then tried to estimate 3-D positional information and to reconstruct an image. Firstly, the accuracy of measurement results from a video recorder was evaluated and tested for an applicability, then it applied to a real object to construct 3-D digital model. This study assumed that there is no lens distortion in a video recorder, and all bundles should precisely pass through the projection center of a lens. The image size for orientations is determined by the size of CCD chip and the number of pixels. The average squared error from the result by a digital video recorder and that by triangular survey from 1-second theodolite shows 0.0173m error in x,y coordinates. Without knowing the accurate information on the lens distortion and the coordinates of the projection center, this study reasonably produces acceptable results in the reconstruction of 3-D model. In consequence, this study found that the image from a digital video camera can be reconstructed 3-D model only from the information on a camera type.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.11a
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• pp.462-465
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• 2011

최근 우리나라에서는 대형 화재사고가 빈번히 발생함에 따라 그로 인한 재산 및 인명피해가 날로 증가하고 있는 실정이다. 따라서 건축물 내에서 화재가 발생할 경우 인명피해를 최소화하기 위하여 피난유도설비의 설치를 의무화하고 있다. 지금까지 일반적으로 가장 널리 사용되고 있는 피난유도설비로는 유도등이 있으며, 최근 들어 피난유도선의 설치도 다중이용업소를 중심으로 점차 확대되어가고 있는 추세이다. 피난유도설비는 평상시 이용되는 교류 상용전원에 의해서뿐만 아니라 비상시 이용되는 직류 비상전원에 의해서도 정상적으로 작동되어야 하기 때문에, 피난유도설비의 전원장치는 주어진 전원으로부터 주어지는 교류 또는 직류를 발광부에 맞게 일정한 전압과 주파수로 변환시켜주어야 한다. 실제로 LED(발광다이오드) 유도등은 상용전원으로부터 220V의 교류를 받아서 전원장치에서 정류변환을 통해 얻어지는 낮은 전압 24V의 직류를 이용하며, 대부분의 유도등 백라이트로 사용되고 있는 CCFL(냉음극형광램프)에는 상용전원으로부터 220V, 60Hz 교류를 인가받아 전원장치에서 정류 역변환을 통해 만들어진 100kHz의 고주파 교류가 공급된다. 더욱이 유도선의 전원장치에서는 상용전원 220V, 60Hz의 교류를 인가받아 정류 역변환 및 교류변환 과정을 차례로 거쳐 최종적으로 100V, 400Hz의 교류로 전환하여 TFEL(박막전계발광) 소자로 전송하게 된다. 한편, 상용전원이 차단된 상태에서도 전원장치는 마찬가지로 비상전원으로부터 24V의 직류를 공급받아 인버터를 통해 역변환 하여 100kHz의 고주파 교류를 만들어 주거나 추가적인 교류변환을 거쳐 100V, 400Hz의 교류로 변환시켜 내보낸다. 본 연구에서는 상대적으로 복잡한 전력변환 회로들을 포함하고 있는 유도선의 전원장치를 개선하여, 전원장치의 연결가능길이를 기존의 60m에서 최대 100m까지 연장시킴으로써, 터널이나 지하도와 같은 곳에서 특히 경쟁력을 갖게 될 것으로 기대된다.

• Applied Chemistry for Engineering
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• v.17 no.6
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• pp.658-664
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• 2006

$\rho$, $\alpha$-dimethyl benzyl alcohol was resolved by the biphasic dynamic kinetic resolution (DKR). Acidic zeolite was used as a racemization catalyst while immobilized enzyme was employed for kinetic resolution. The effects of the process variables including nature of acyl donor, reaction temperature, substrate concentration, ratio of the two catalysts and stirring rate on the conversion and enantiomeric purity of the product were investigated. In DKR of $\rho$, $\alpha$-dimethyl benzyl alcohol, the product of 99% ee was obtained with a maximum yield of 88%. The high performance of the catalyst system was maintained in the condition of higher TON and under repeated use.

• Journal of Korea Game Society
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• v.12 no.4
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• pp.33-44
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• 2012

With the development of online game industry, the focal structure of game industry is under the expansion from content production to service management. In line with the trend, game service management and user satisfaction to the service as well have gained their weight in the game industry. However, since previous studies have focused on content production, little was discussed on the game service management. The current study investigated the effects of game service on user satisfaction. In addition, we tested the effects of a user's game service satisfaction on the user's loyalty toward the games with consideration of the user's content satisfaction and the gaming period. Results showed that there is a significant association between service satisfaction and user loyalty in the user's continual use of the games. Specifically, light users showed high loyalty with the increase of service satisfaction as they continue playing the games.

• Journal of Korean Society for Geospatial Information Science
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• v.3 no.2 s.6
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• pp.75-82
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• 1995

The calculation of astronomic latitude and longitude have been carried by astrolabe, theodolite. Conventional procedures to determine it require clear weather conditions, time high cost. So we need more effective method to decide them. The objective here is to present method to computate astronomic latitude and longitude by mixing GPS observation result and geodetic height. Also to decide geodetic height we used GPS/leveling, DMA(n=m=180) and OSU91A(n=m=360) methods. Compared to conventional procedures we could obtain astronomic latitude and longitude using GPS by $1{\sim}3'$ difference. If the precise geoid model of Korea will be developed, we can compute astronomic latitude and longitude effectively using GPS observation only.

• Applied Biological Chemistry
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• v.29 no.1
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• pp.78-82
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• 1986

Panax ginseng seedlings were grown in vermiculite with nutrient solution different in nitrogen, phosphorus ana potassium level. Ginsenoside contents of root were investigated by high performance liquid chromatogram. Elimination or increase of one of N.P.K. increased or decreased total saponin content. Nitrogen was most effective (15.5% for-N to 8.9% for 3N) and potassium least. Similar trend was shown in each ginsenoside. According to coefficient of variation in one nutrient treatment or among all nutrient treatments ginsenoside Re was most insensitive to nutrient change and also other environmental factors and Rd most sensitive. Diol content (PD) was more variable than triol (PT) and variation of PT/PD was about half of them. Variation of ginsenoside content by nutrient change had no relation with the ginsenoside content. Similarity of ginsenoside pattern slightly decreased with the difference of saponin content by nutrient change. Root weight was significantly small only in tap water plot.

• Journal of Korea Foundry Society
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• v.31 no.5
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• pp.284-287
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• 2011

Microstructures and tensile properties at ambient and elevated temperatures were studied by substituting RE for Sr in Mg-6%Al-(3-X)%RE-X%Sr alloys (X = 0~3). With increasing Sr content, $Al_4Sr$ phase with lamellar morphology was newly introduced at interdendritic regions, with a gradual extinction of needle-shaped $Al_4RE$. The Mg-6%Al-3%Sr alloy shows dendritic grains and interdendritic eutectic phases containing bulky Mg-Al-Sr and lamellar $Al_4Sr$ with more continuous manner. The substitution of Sr for RE provided higher YS, UTS and creep resistance at $175^{\circ}C$, which indicates that Sr would be more beneficial in tensile properties and creep resistance at elevated temperature than RE for the Mg-Al based casting alloys.

• Journal of the Korean Chemical Society
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• v.55 no.1
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• pp.14-18
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• 2011

Esterification of methacrylic acid with ethylene glycol was carried out over Heteropolyacids [HPA: $H_4SiW_{12}O_{40}$ (STA) and $H_3PW_{12}O_{40}$ (PTA)] supported on ZSM-5. For comparison, the same reaction was carried out over unsupported HPA, $H_2SO_4$, $BF_3$ and PTSA. Among the catalysts studied, HPA showed better activity compared to $H_2SO_4$, $BF_3$ and PTSA. Catalytic activity was compared with HPA supported ZSM-5 catalysts. Typical results indicated that 30 wt% PTA supported on ZSM-5 showed nearly the same activity as that of bulk PTA. It was found that the reaction follows first order kinetics with respect to methacrylic acid. The reaction products were identified by $^1H$-NMR and FT-IR.

• Korean Journal of Food Science and Technology
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• v.36 no.2
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• pp.361-364
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• 2004

EPA and DHA extracted from methyl esterified squid oil were purified by silver exchanged resin, silver nitrate-impregnated silica gel, silver exchanged zeolite, and silica gel column chromatography, among which column chromatography using mixture of silver exchanged resin and silica gel (10% by weight) showed the best result. By this simple purification method, EPA and DHA were concentrated from 12.5 to 27.9% (yield, 86,0%) and from 21.7 to 49.5% (yield, 87.3%), respectively. Silver exchanged resin had additional advantages of outstanding reusability and simple recovery of silver.