• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.7
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• pp.720-728
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• 2011

In this paper, development of the monopulse secondary surveillance radar antenna which can be used for IFF system is presented. This antenna that is passive linear array is comprised of the row-feeder and several array-elements. The row-feeder provides sum, different and SLS(Sidelobe Supression) channels which are optimized the distribution of the power and phase ratio. The azimuthe sidelobe level of the sum channel beam pattern is -20 dBc or less. The SLS channel covers the sidelobe of the sum-chanel in the whole azimuth angle range. And the difference channel is used to perform the mono-pulse function, improves the detection accuracy in the azimuth direction. Meanwhile, the arrayelement makes shaped beam in the elevation angle, in order to eliminate the clutter and multipath effects from the ground. Performance of the antenna developed is verified by the measurement of S-parameters and far-field beam pattern, and satisfies all of the development specifications well.

• Journal of the Korean earth science society
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• v.26 no.3
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• pp.297-304
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• 2005

Serpentinites in Chungnam area are mainly composed of serpentines. Serpentines of olivine origin consist of pseudomorphs of olivines and show mesh textureen closed with magnetites along the boundaries of serpentine crystals. In some serpentinites, serpentinization is occurred in crystal boundaries and/or cracks of olivines and pyroxenes which are relict minerals of dunite and harzburgite. On the process from olivine to serpentine, Mg ions are greatly decreased and Si ions are greatly increased, and $Fe^{2+}\;and\;Fe^{3+}$ ions are a little decreased. But, on the process from pyroxene to serpentine, Si ions are greatly decreased and Mg ions are greatly increased. Magnetites around the serpentine crystals were formed from the iron which had been left out through this serpentinization process of olivine. Serpentinization from the original rocks such as dunite and harzburgite in Chungnam area was occurred by various waters affected after formation of original rock, and particularly by metamorphic water in the metamorphic conditions ranging from green schist facies to granulite facies through amphibolite facies.

• Journal of Intelligence and Information Systems
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• v.14 no.4
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• pp.201-216
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• 2008

Nowadays various new items are available, but limitation of searching effort makes it difficult for customers to search new items which they want to purchase. Therefore new item providers and customers need recommendation systems which recommend right items for right customers. In this research, we focus on the new item recommendation issue, and suggest preference boundary- based procedures which extend traditional content-based algorithm. We introduce the concept of preference boundary in a feature space to recommend new items. To find the preference boundary of a target customer, we suggest heuristic algorithms to find the centroid and the radius of preference boundary. To evaluate the performance of suggested procedures, we have conducted several experiments using real mobile transaction data and analyzed their results. Some discussions about our experimental results are also given with a further research area.

• Tunnel and Underground Space
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• v.19 no.2
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• pp.107-122
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• 2009

Insufficient reinforcement for maximizing payability and benefits in mining cavities causes subsidence problems and it threatens residents' lives and properties. So many reinforcement management methods are developed and now various methods are being applied in the field. Among them, a filling method which sends reinforcement materials in the cavities is used extensively. However, domestic geological condition and coal mining methods are so complicate that make many steep cavities. Because of those problems, it is difficult to apply foreign methods directly, which is valid for horizontal cavities. In this study, the injection volume of quick setting grouting material which is developed for filling cavities in domestic condition and the shape of consolidated bodies are investigated. And a programming method for estimating proper injection amounts of filling materials is proposed. The results are verified by numerical analysis using UDEC.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.286-286
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• 2009

벼 유기재배시 토양양분공급용으로 이용되고 있는 유기자재(금수강산골드)를 대조로 하고 식물성유기 자재(쌀겨팰렛), 동물성유기자재, 식물성과 동물성이 혼합된 유기자재를 질소 성분량(7kg/10a)을 기준으로 하여 이앙 20일전에 전량 기비로 시비하고 경운한 다음 동진1호를 시험품종으로 하여 2년연속 유기 자재와 벼를 재배하면서 일어나는 토양의 이화학적 특성과 벼 생육 및 특성의 변화를 시기별로 조사하였다. 시험 전 토양의 화학성은 전반적으로 유기물은 높고 인산함량은 매우 낮은 조건의 토양이었다. 관행유기자재(금수강산골드)는 20일경에 50% 무기화율을 보였으나, 식물성자재 40~60일경, 동물성자재와 혼합자재(식물성+동물성)는 60~80일경에 47~52% 무기화 정도를 나타내 식물성 자재의 무기화 속도가약 20일정도 빨랐다. 토양 중의 유기물 잔존함량은 식물성자재 > 혼합자재 > 동물성자재 > 관행 순이었으며, 토양 중의 전 질소 잔존함량의 경우 관행유기자재는 처리초기부터 빠르게 감소하는 특성을 보이나, 식물성자재와 혼합 자재는 시비초기와 거의 비슷한 수준을 유지하였고, 동물성 자재는 서서히 감소되는 경향이었다. 토양 물리성은 액상과 공극율 다소 증가되는 경향이었으며 식물성과 혼합유기자재처리구가 컸으며, 토양 유효 입단 형성력에 있어서도 유사한 경향이었다. 벼 수량 특성은 관행유기자재보다 1년차에는 3~9%의 낮았으나, 2년 연속처리를 할 경우 관행유기자재를 처리할 때와 동일한 생산성을 기대할 수 있었다. PME와 $\beta$-Glucosidase의 효소활성은 관행유기자재 < 식물성자재 < 동물성자재 < 혼합유기자재의 순으로 높은 경향을 볼 수 있었다.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.285-285
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• 2009

벼 유기재배에 있어서 녹비작물을 이용하여 화학비료를 대신하고 있으나 녹비를 이용하기 위해서는 월동 전에 파종하고 이듬해 벼 이앙 전에 토양에 환원을 해야 하는 번거로움이 있다. 따라서 벼 재배 직전에 유기자재를 이용하여 화학비료를 대신하고자 했을 경우 유기자재를 전층시비와 표층시비의 차이에 따른 토양중의 이화학적 특성과 벼의 수량특성의 변화를 구명하였다. 벼 유기재배시 토양양분공급용으로 이용되고 있는 유기자재 4종을 공시하여 유기자재의 질소 성분량(7kg/10a)을 기준으로 하여 이앙 20일전에 시비방법별로 전층시비와 표층시비 2처리로 구분하여 전량 기비시비하고 경운한 다음 동진1호를 시험품종으로 하여 2년 연속 시비처리와 벼를 재배하면서 일어나는 토양의 이화학적 특성과 벼 생육 및 특성의 변화를 시기별로 조사하였다. 시험 전 토양의 화학성은 표층시비구의 염류농도, 가리와 석회의 함량이 다소 높아서 염류농도가 전층 시비구 보다 높은 조건의 토양이었다. 유기자재별 무기화 정도는 전층시비보다 표층시비를 할 때 약 20~30일 정도 빨랐다. 토양 중의유기물 잔존함량은 시비방법간의 큰 차이는 없었으나 표층시비를 할 경우 후기로 갈수록 다소 증가되는 경향이었으나, 전질소 잔존함량은 감소되었다. 토양 액상과 공극율은 전층시비>표층시비였으며, 입단 형성력도 같은 경향이었다. 토양 효소활성은 PME의 활성은 유기자재를 전층처리하였을 때 촉진되었으며, $\beta$-Glucosidase의 활성은 전층보다 표층처리시 활성이 높았다. 시비방법에 따른 벼의 수량 특성은 시비방법별로는 표층시비를 할 경우 전층시비보다 4~7%의 높은 특성을 보였으며, 관행대비 1년차에는 3~9%의 낮았으나, 2년 연속처리를 할 경우 대조구와 비슷해 지는 경향이었다.

• Journal of Plant Biotechnology
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• v.29 no.4
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• pp.241-246
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• 2002

Somatic embryos or adventitious buds were formed from the segments of zygotic embryo of Lycium chinense Mill. on Murashige and Skoog (MS) medium supplemented with auxins (2,4-D, NAA, IAA) and / or cytokinins (zeatin, kinetin, BAP). Embryogenic callus formed on MS medium containing 0.5 mg/L 2,4-D and then differentiated into somatic embryos without transfer to hormone free medium. On the other hand, adventitious buds were formed on medium with 0.01 mg/L 2,4-D and 0.5 mg/L zeatin. Among various parts of zygotic embryos, the morphogenic potential was higher in the cotyledonary region, and the most organogenic potential was found in cotyledon followed by radicle, hypocotyl, and whole embryo. Histologically, bipolar structure of the heart-shaped embryos were confirmed and in adventitious buds only shoot apical meristems were found to exist.

• Journal of Preventive Medicine and Public Health
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• v.24 no.4 s.36
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• pp.507-515
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• 1991

One, two, six and ten week old Sprague-Dawley rats were exposed to carbon monoxide at 3,700 ppm for 30 minutes, and carboxyhemoglobin was measured immediateley. 5, 30, 60, 90, 120 minutes after the exposure. In each time after the exposure, the means of the carboxyhemoglobin levels were compared among the week age groups. The regression analysis was done using the natural logarithm of the carboxyhemoglobin concentration as a dependent variable and the time after the exposure as an independent vaiable. From the regression equation, the half lives of the carboxyhemoglobin were calculated. The one week old rats showed significantly higher carboxyhemoglobin level than other week age rats in the entire time after the exposure. The corrected carboxyhemoglobin concentration calculated by subtracting the normal carboxyhemoglobin level from the measured carboxyhemoglobin at each age group, showed no uniform differences.

• Research in Plant Disease
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• v.7 no.3
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• pp.134-139
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• 2001

Effects of tomato-juice and KH$_2$PO$_4$ as exogenous nutrients on the infection of Botrytis cinerea LVF12 and pathogenicity to tomato were investigated. B. cinerea LVF12, which was previously reported as a casual agent of the gray mold rot of perilla, was used for pathogenesis on tomato leaves. No infection was induced, and no lesion developed on tomato leaves by the conidial suspension of LVF12 when the inoculum was prepared in sterilized water. However, when the conidial suspensions of LVF12 added with various concentrations and conditions of tomato-juice were inoculated on whole tomato plants, the disease was induced readily, Among them, 20% tomato juice with 0.1M KH$_2$PO$_4$ appeared to be the most suitable nutrient to promote high disease incidence on tomato. For the pathogenicity test according to the growing stage of tomato, the mature leaves were more susceptible than seedlings. Symptoms on the infected plants were initial small gray spots at the inoculated area. Later the whole leaves, petioles and stems became gray and eventually fell off, Under high humidity conditions, the diseased leaves and stems were covered with gray hyphae and conidia. All symptoms of infected plants were identical to those in the field conditions.

• Korean Journal of Microbiology
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• v.31 no.4
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• pp.274-278
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• 1993

Overproduced proteins in many cases result in forming insoluble inclusion bodies, and their formation might be due to high concentration of protein. To investigate how proteins become insoluble, chloramphenicol acetyltransferase (CAT) and .betha.-lactamase were overproduced, and their solubilities and activities were determined. CAT was accumulated from 9 to 45% of total cellular protein in a fully soluble form without inclusion body formation. CAT specific activity was shown to be proportional to the amount of the protein produced. Moderately produced .betha.-lactamase by the phase T7 expression system at 30.deg.C comprised only mature forms in a soluble form. However, overproduced .betha.-lactamase at 37.deg.C became insoluble. Most precursor forms of .betha.-lactamase in the cytoplasm were insoluble, whereas majority of the mature forms in the periplasm space were soluble. Also, chaperone GroE proteins which assist proper protein folding and translocation did not increase .betha.-lactamase solubility significantly under the experimental condition. It seems that the formation of inclusion bodies in the cell is related to the nature of protein itself rather than just to high concentration of protein.