• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.551-551
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• 2016

북한과의 대표적 공유하천인 임진강 유역은 유역의 2/3를 차지하고 있는 북한지역내에서 신뢰할만한 강우 및 수문관련 정보에 접근할 수 없는 문제점이 존재한다. 또한, 임진강 중류에는 북한에서 운영하는 황강댐의 예고없는 수문운영에 따라 수시로 하류 홍수피해가 발생할 수 있는 상황이며, 이에 대비하여 우리나라에는 군남 홍수조절지를 건설하여 운영하고 있다. 하지만 임진강 상류에 대한 수문정보를 취득하기 어렵기 때문에 가까운 수위관측소의 수위변화와 저류함수 모형 등을 이용하여 댐 운영을 실시하고 있는 것이 현실이다. 본 연구에서는 미계측유역에서의 수문정보를 확보하기 위한 목적으로 레이다강우 등 원격탐사정보와 분포형 강우-유출모형을 이용하여 황강댐 유입량을 산정할 수 있는 수문모형을 구축하였다. 황강댐유역의 수문모형 실매개변수를 보정하기 어렵기 때문에 인근 한탄강댐유역의 매개변수를 지역화를 통하여 전이하여 활용하였다. 산정된 수문곡선은 동시간대 한탄강댐 유입량의 면적비적용, 강수의 공간전이후 산정된 한탄강댐 유입량의 면적비적용등의 다양한 시나리오에서 모의된 수문곡선과의 비교를 수행하여 본 기법의 타당성을 입증하고자 시도하였다. 또한 군남홍수조절지 유입수문곡선과의 비교를 통하여 황강댐과 4월 5일댐의 수문운영현황 및 잔유역유입량을 역추정코자 하였다.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.1
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• pp.13-20
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• 2021

GaN has shown good potential owing to its better chemical stability than other materials and tunable bandgap with materials such as InN and AlN. Tunable bandgap allows GaN to make the maximum utilization of the solar spectrum, thus improves the solar-to-hydrogen (STH) efficiency. In addition, GaN band gap contains the oxidation and reduction level of water, so it can split water without external voltage. However, STH efficiency using GaN itself is low and has been actively studied recently to improve it. In this thesis, we have summarized the studies related to the use of GaN as a photoelectrode for photoelectrochemical water splitting.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.3
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• pp.303-311
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• 1996

The microflora changes of 10 water-controled treatments combined with livestock manures(pig, chicken) and bulking agents(sawdust, paper sludge) were investigated. The B/F values of the P-1 and C-1(65%, $H_2O$) treatments were 3571 and 5400 respectively, but those of the P-4 and C-4(50%, $H_2O$) treatments showed very low values, 667 and 334, respectively. The B/F values tended to increase with higher water content of the treatments. In the composting processes, the successions of microflora, adapting the compost environments, took place via fluctuating temperature. In the high temperature period, the numbers of mesophilic bacteria and fungi decreased, but that of the spore forming bacteria increased. However, the number of mesophilic bacteria inereased during the cold period. The B/F values of compost ranged 25-300, which indicates a decrease in the quantity of bacteria. The time required for the temperature of compost to reach $60^{\circ}C$ showed different patterns. There was no pathogenic microorganism in the treatments which reached a high temperature in a short period of time, but, in the treatments which reached a high temperature over a Long period of time, the pathgenic microorganism was not still alive.

• Korean journal of food and cookery science
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• v.15 no.1
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• pp.16-22
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• 1999

The relation between food intakes and dental caries was investigated with 211 primary school students (83 boys and 128 girls) in Kumsan area. The results were as follows. The rate of dental caries of the subjects was 65.4%. 83.9% of the subjects had a snack, 69.5% of students having a snack and 44.1% of students having not snack was dental caries (p<0.001). For tooth brushing numbers per day, 38.4% of subjects was one time, and 61.6% was more than two times. For tooth brushing time, 31.8% had before meals and 68.2% after meals. The intake frequency rate of main food was cooked rice 33.30%, ramyun 14.81%, bread 9.57%, rice cake 6.16%, nodule 4.88% in good group, and cooked rice 27.04%, rice cake 12.04%, ramyun 8.50%, bread 8.11%, fried rice 5.49% in dental caries group. The intake frequency rate of a side dish was kimchi 13.88%, egg 6.21%, dried laver 5.51%, fish paste 5.51%, fish 5.03%, kongjaban 0.44% in good group, and potato soup 6.86%, cucumber 6.56%, sprout soup 5.78%, bean curd 5.33%, sesame leaf 5.21%, lettuce 1.23% in dental caries group. The intake frequency rate for snack was ice cream 9.85%, biscuit 7.35%, gum 6.17%, chestnut 6.16%, apple 5.81%, milk 5.56%, yogurt 4.86%, gypo 4.39%, candy 4.15%, chocolete 3.91% in good group, and biscuit 10.00%, ice cream 6.75%, candy 5.88%, fruit canned food 5.70%, milk 5.41%, corn 5.00%, banana 5.00%, peanut 4.42%, fritter 4.39% in dental caries group. The rate of cariogenic food, detergent food, protective food in a side dish were 4.0%, 40.8%, 55.1%o in good group, and 11.5%, 43.9%, 44.6% in dental group respectively (p<0.001). The rate of cariogenic food, detergent food, protective food in a snack 67.8%, 10.4%, 21.7% in good caries group, and 75.3%, 8.8%, 15.9% in dental caries group respectively (p＜0.001).

• Journal of Nutrition and Health
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• v.47 no.1
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• pp.51-66
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• 2014

Purpose: The objective of this study was to investigate the differences of sodium intake in the diet according to the kind of meal, food group, and dish group. Methods: A dietary survey was conducted using the 24-hour recall method from April to May, 2009. The study subjects consisted of 701 elementary and 1,184 middle school students in the Jeju area. Mean sodium intake and the percentage contribution of meals and each dish and food group to daily sodium intake were calculated. Results: The daily sodium intake was 2,868.4 mg and 3,032.5 mg in elementary and middle school students. For elementary school students, breakfast, lunch, dinner, and snack provided approximately 18.0%, 35.1%, 32.8%, and 14.1% of total daily sodium intake, and for middle school students, 15.3%, 40.2%, 29.1%, and 15.5%, respectively. Major food groups for sodium intake were spices (1,252.5 mg in elementary, 1158.0 mg in middle school students), vegetables and their products (409.0 mg, 495.6 mg), cereal and grain products (322.4 mg, 647.8 mg), and fish and shellfish (255.3 mg, 336.6 mg). Except cereal and grain products, sodium intake of the food groups mentioned above was greater at lunch and dinner than at breakfast and snack. And, the elementary and middle school students obtained 5.9% and 9.8% of total daily sodium intake from cereal and grain products at snack. Among the 29 dish groups, the highest dish groups contributing to dietary sodium intake were soup and stew and tang/jeongol, consuming 19.8% (elementary school students) and 25.4% (middle school students) of daily sodium intake. The following major dish groups contributing to dietary sodium intake, in order, were kimchi, seasoned vegetables, grilled dish, stir-fried dish, and $\grave{a}$ la carte. By meals, the percentage of sodium intake from soup, kimchi, stew, fried dish, and stir-fried dish at school lunch was high, from noodles, grilled dish, and $\grave{a}$ la carte at dinner, and from bakery/snacks and noodles at snack. Conclusion: Sodium intake from the various side dishes at school lunch was high and noodles and bakery/snacks were popular snack foods in elementary and middle school students in Jeju area. In order to lower the intake of sodium, students need to be educated about eating less soup and choosing better snacks.

• Proceedings of the KWS Conference
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• 2010.05a
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• pp.24-24
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• 2010

마찰교반접합법은 특정한 회전수로 회전하는 용접 툴을 이용하여 접합하고자 하는 피접합재의 맞댄면에 삽입시킨 후 툴을 이동시키거나 혹은 시편을 견고하게 고정시킨 장치(backing plate)가 움직여 고상 상태에서 접합이 이루어진다. 알루미늄, 마그네슘 등 비교적 융점이 낮은 저융점 재료의 재료에 처음 적용이 되어 많은 연구가 활발히 진행되었고 타 용접방법에 비해 우수한 접합특성을 나타내었다. 최근 이러한 마찰교반접합은 이러한 저융점 재료를 넘어서 스틸, 타이타늄, 니켈 등과 같은 고융점 재료 등에 대한 적용이 늘어나고 있다. 마찰교반접합을 이용하여 이러한 고융점 재료의 접합 경우 내마모성 및 내열성 등의 내구성이 갖추어진 툴과 이러한 툴을 냉각시킬 수 있는 냉각 장치 등이 필요로 하나 경제적 측면이나 접합부의 우수한 특성 등을 고려 할 때 그 적용 및 발전 가능성이 매우 높다고 볼 수 있다. 2상 스테인레스 강은 금속 조직적으로 페라이트와 오스테나이트 상이 거의 1:1의 동등한 비율로 매우 미세하게 결합된 구조를 가지고 있다. 또한 이상 스테인레스 강은 각상의 개개의 특성에 기인하여 염소 분위기에서 응력부식 저항성이 우수하고, 공식과 틈부식에 대한 저항성이 매우 뛰어나다. 그리고 이상 스테인레스 강은 비교적 고가인 Ni이 일반 오스테나이트 스테인리스 강의 약 1/2의 수준으로 적게 포함이 되어 경제적인 이점을 지니고 있으며 또한 용접성이 좋아 산업계의 수요는 현재 점차 증가하고 있는 상황이다. 하지만 이러한 이상 스테인리스 강은 용접 후 페라이트 상의 조대화, 그리고 페라이트 상의 분율이 오스테나이트 상의 분율보다 높아지게 되어 용접부에서의 저온 인성 감소 및 내식성 저하 등의 문제가 발생하게 된다. 그리하여 용접 시 이러한 문제점을 해결하기 위해서는 입열량의 조절이 가장 필요로 하는 것으로 알려져 있다. 본 연구에서는 마찰교반용접을 이용하여 두께 3mm의 대표적인 이상 스테인리스 강인 SAF2205 스테인리스 강에 대해 맞대기 마찰교반접합을 실시하였다. 툴 회전속도를 변수로 하여 접합을 실시하였으며 접합 시 툴은 $Si_3N_4$ 툴을 사용하였다. 접합 후 외관상태 점검, 미세조직 관찰, 경도 및 인장강도 측정 등의 실험을 실시하였고, 이러한 결과를 이용하여 미세조직과 기계적 특성과의 관련성을 조사하였다.

• Journal of the Korean Institute of Gas
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• v.15 no.6
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• pp.28-33
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• 2011

The purpose of this paper analyzes and studies to improve the failure cases on the computer that one of electronic control elements for engine in liquified petroleum gas vehicle. The first case, it certified the non-starting phenomenon of engine that it's electronic control unit didn't control the fuel for idle speed actuator because of no given action signal in slow-cut solenoid valve. The second case, it knew the bad condition phenomenon of engine and back-fire by the wire melting of ignition coil and firing of transistor being inside ECU. The third case, it certified the action stoping phenomenon of engine and malfunctioning signal for engine ECU because of leakage of current and an excess current by moisture inflowing inside ECU curcuit plate. Therefore, it is thought that will elevate the durability and reliability of engine computer throughout procure of quality.

• Korean journal of food and cookery science
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• v.13 no.4
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• pp.472-477
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• 1997

Iron was bound to neutral detergent fiber (NDF) obtained from 15 kinds of vegetables commonly consumed in Korea. Iron binding capacity of NDF ranged from 37.83% to 85.51%, and it increased as the pH increased and reached to the maximum at pH 7 in all vegetables. The amount of Fe bound to NDF increased as the Fe concentration increased.

• Journal of the Korean Vacuum Society
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• v.5 no.2
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• pp.139-146
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• 1996

Transparent and conducting Sb-doped $SnO_2$ thin films were prepared by rf magnetron sputtering technology. But it showed a serious damage phenomenon on the surface of as-deposited films. In order to avoid a damage caused in the substrate center and location facing to target erosion, a ring plate of masking glass was installed at 1.5 cm above target surface. The uniformity and electrical characteristic of $SnO_2$ thin films were evaluated by the control of optimal conditions in the magnetron sputtering operation such as rf power, sputtering gas pressure, and substrate temperature. In the experimental results using the operating conditions, the optimum temperature, which produced uniform and damageless films, shifted with the change of gas pressure. The rate was about $100^{\circ}C$/5 mTorr at rf power of 50 W Similarly, the optimum temperature in compensation for an increase of rf power shifted down to a proper rate.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.3
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• pp.171-182
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• 2006

In this study, rainfall-runoff analysis was performed for Yongdam watershed($930km^2$) using KOWACO flood analysis model based on Storage Function Method as lumped hydrologic model and Vflo which was developed for real-time flood prediction by University of Oklahoma. The results shows that, the hydrographs of lumped and distributed model with uncalibrated parameters which estimated from physical or experimental relationship show significant biases from observed hydrographs. However, the hydrograph at Cheoncheon site from the distributed model follows the actual hydrograph to an extent that no more calibration is necessary. It encourages that distributed model can have advantages for application in real-time flood forecasting as physically based distributed hydrologic model which can construct event-independent basin parameter group.