• Title/Summary/Keyword: 평균류

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Study on the Characteristic of the Surface Wind Field around Pusan Area (부산지역의 지표 바람장의 특성에 관한 연구)

  • 김유근;홍정혜
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2000.11a
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    • pp.176-178
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    • 2000
  • 대기경계층내에서의 흐름은 평균류, 난류(Turbulence) 그리고 파동(wave) 3가지로 분류되는데 수평적으로 수 ms$^{-1}$ 연직적으로 수 cms$^{-1}$의 평균류에 의해서 수중기, 운동량, 열, 오염물질의 수송이 일어나며 이것들은 난류에 의해서 연직적 수송이 일어 난다. 그리고 평균류의 시어(shear)나 평균류가 장애물을 만나면서 형성되는 파동에 의해서 운동량, 에너지 등의 수송이 이루어진다(Stull., 1988). (중략)

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The Content of Minerals in Algae (해조류(海藻類)의 무기성분(無機成分))

  • Lee, Jong-Ho;Sung, Nak-Ju
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.9 no.1
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    • pp.51-58
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    • 1980
  • Sixteen species of algae (4 species of green algae, 5 species of brown algae and 7 species of red algae) were collected from the coast of Chungmu, Gyeongnam, from June to October, 1976. The content of minerals in algae were analyzed by Atometic Absorption Spectrophotometer. The results were as followed 1) The content of Iron and Nickel in green algae were abundant, and those of Lead, Nickel and Manganese in brown algae were low. 2) The content of Cadmium were in the range of 0.58-1.04ppm (average: 0.85ppm) in green algae, 0.32-2.10ppm (average: 1.08ppm) in brown algae and 0.54-1.70ppm (average: 1.04ppm) in red algae. The content of Cadmium were in the range of 0.3-0.6ppm in laver, Porphyra tenera, sea mustard, Undaria pinnatifida, and tangle, Laminaria japonica, but its content was lower than those expected. 3) The content of Lead were in the range of 0.67-1.40ppm (average: 1.03ppm) in green algae, 0.60-1.00ppm (average: 0.82ppm) in brown algae, 0.56-2.40ppm (average: 1.28ppm) in red algae and its content in algae were lower than in fish and shellfish. 4) The content of Copper were in the range of 10.8-24.2ppm (average: 18.95ppm) in green algae, 7.4-24.6ppm (average: 18.16ppm) in brown algae, 6.4-31.2ppm (average: 19.94ppm) in red algae and those content were considerably abundant except for some algae. 5) The content of Nickel were in the range of 5.4-16.6ppm (average: 9.1ppm) in green algae, 1.0-4.4ppm (average: 2.32ppm) in brown algae and 0.7-4.6ppm (average: 2.59ppm) in red algae. 6) The content of Iron were in the range of 686.4-1159.0ppm (average: 916.5ppm) in green algae, 131.0-499.2ppm (average: 310.16ppm) in brown algae and 156.0-530.4ppm (average: 248.2ppm) in red algae. Especially, that of Iron in green algae showed higher value than in any other. 7) The content of Manganese were in the range of 48-221ppm (average: 157.25ppm) in green algae, 12-65ppm (average: 41ppm) in brown algae and 72-162ppm (average: 121ppm) in red algae. Especially, that of Manganese in brown algae showed lower value than in any other. 8) The content of Zinc were in the range of 191.3-451.1ppm (average: 290.05ppm) in green algae, 89.9-374.2ppm (average: 202.64ppm) in brown algae and 106.4-281.4ppm (average: 188.93ppm) in red algae. 9) The content of Magnesium were in the range of 0.48-1.83% (average: 1.27%) in green algae, 1.04-1.71% (average: 1.21%) in brown algae and 0.42-1.24% (average: 0.097%) in red algae. 10) The content of Fluorine were in the range of 29.2-92.7ppm (average: 53.03ppm) in green algae, 33.3-43.5ppm (average: 39.18ppm) in brown algae and 32.4-59.0ppm (average: 44.84ppm) in red algae.

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New method of estimating average phase current in accordance with the switching state of the One-shunt inverter (1-shunt 인버터의 스위칭 상태에 따른 새로운 평균 상전류 추정 방법)

  • You, Jae Jun;Ku, Hyun Keun;Yeom, Han Beom;Kim, Jang Mok
    • Proceedings of the KIPE Conference
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    • 2015.07a
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    • pp.501-502
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    • 2015
  • 본 논문에서는 3상 인버터 직류단에 하나의 shunt 저항을 삽입한 1-shunt 인버터의 평균 상전류를 추정하는 새로운 알고리즘을 제안한다. 2개의 영벡터와 6개의 유효전압 벡터의 조합으로 구현되는 SVPWM 방식에서, 각 스위칭 상태에 따른 상전류 기울기를 알 수 있다면, 유효전압 벡터 인가시간을 이용하여 평균 상전류를 추정할 수 있다. 본 논문에서는 각 스위칭 상태에서의 전류기울기와 인가시간을 이용하여 평균 상전류를 추정하고 이를 일반화 한다. 제안된 알고리즘의 정확성은 실험적 결과를 통해 증명한다.

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Contents of Nitrate and Nitrite in Vegetables and fruits (채소류와 과칠류 중의 질산염 및 아질산염의 함량)

  • Shin, Jung-Hye;Kang, Min-Jung;Yang, Seung-Mi;Kim, Hyung-Sik;Sung, Nak-Ju
    • Journal of Food Hygiene and Safety
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    • v.17 no.2
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    • pp.101-105
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    • 2002
  • A total of 53 vegetables and fruits, consisting of 23 leaf vegetables, 4 fruits vegetables, 4 edible roots,7 spice vegetables and 15 fruits were analyzed for contents of nitrate and nitrite by ion chromatography. Nitrite was detected 10 of 23 kinds of leaf vegetables, which was dominant in lettuce by average 349.9 mg/kg. Nitrate contents of leaf vegetables were average 578.3 mg/kg, 415.7 mg/kg, 348.6 mg/kg in wild plant, mustard leaf and chinese vegetable, respectively. Nitrite was not detected in fruits vegetables and rootcrops but the nitrate contents were abundant and the highest in squash(average, 86.2 mg/kg) and radish(average, 297.5 mg/kg), respectively. In spice vegetables, mate contents were from 0 to 29.8 mg/kg, but not detected in garlic. In welsh onion, its nitrite were higher in small type than large type, while nitrate contents were higher 3 times in the latter. Nitrate contents of fruits were lower in apple(average, 0.5 mg/kg) and higher in plum(average, 76.6 mg/kg) than other samples.

Determination of real-time monitoring places in water distribution system using unsteady analysis (상수관망에서 부정류 해석을 이용한 실시간 모니터링지점 선정)

  • Kwon, Hyuk-Jae
    • Proceedings of the Korea Water Resources Association Conference
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    • 2012.05a
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    • pp.472-476
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    • 2012
  • 부정류 해석프로그램을 이용하여 각 절점에서 갑작스런 유량의 변화가 일어났다고 가정하여 부정류 해석을 수행하였다. 각 절점에서 소요유량(demand)이 추가로 발생할 경우에 대해서 부정류 해석을 수행하였다. 추가 소요유량이 발생하였다는 것은 그 절점에서의 누수량으로 간주할 수 있으므로 실제 일어날 수 있는 누수에 대한 민감도 분석을 하여 센서의 설치지점을 선정한다면 보다 더 정확한 모니터링 지점선정이 될 것으로 판단된다. 다음과 같은 두 가지 방법을 통하여 모니터링 최적지점 선정방법을 비교하였다. 첫 번째는 한 절점에서 갑작스런 소요유량의 변화가 발생하면 그로인해 부정류가 발생한다. 이때 각 절점에서의 압력변위와 유량변화가 발생한 절점의 압력비를 합하고 절점의 수로 평균하여 민감도 분석을 수행한다. 특정 절점에서 유량변화로 발생한 압력의 변화가 다른 절점에 얼마나 영향을 미치는지에 대한 기여도를 부정류 해석결과를 이용하여 정량적으로 산정하는 방법이다. 특정 절점에서 유량의 변화가 생겼으므로 부정류해석 결과는 누수가 없을 때 최초 계산하였던 각 절점에서의 압력이 크게 유동하게 된다. 이때의 최고치와 최저치의 차는 압력변위이고 최초압력과의 비를 합산하고 절점의 수로 평균한 값을 비교하였다. 이렇게 계산된 값이 가장 큰 절점이 모니터링 지점으로 우선 선정된다. 두 번째 방법은 유량변화로 발생한 절점의 압력변위와 그 절점의 최초압력의 비를 산정하는 방법이며 부정류해석결과를 이용하였다. 한 절점에서 유량을 변화시키고 부정류로 인해 발생하는 압력변위와 최초압력의 비를 합산하고 절점수로 평균하여 민감도 분석을 수행한 것이다. 어느 절점의 압력변위와 최초압력의 비를 정량적으로 산정하여 민감도를 분석하고 비교하였다.

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Estimation of Geostrophic Current Calculated from Sea Surface Topography in East Sea (동해의 해면지형 계산에 의한 지형류의 흐름 추정)

  • Yun Hong-Sic;Lee Dong-Ha
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.24 no.2
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    • pp.159-165
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    • 2006
  • This paper deals with the estimation of geostrophic current using the sea surface topography calculated from the geoidal height from EGM96 geopotential model and the mean sea surface height from CLS_SHOM mean sea surface model. The CLS_SHOM model was developed using the altimetry data set. The estimation of geostrophic current is available in the characteristic research of ocean in many country, while for East Sea a few studies were done. The goal of this study is basically to provide the characteristics of geostrophic current in East Sea. The results show that the mean sea surface topography (SST) in East Sea is about 0.37 m and the mean geostrophic velocity is -0.028 m/sec. The Pacific water enters into the East Sea through the Korea Strait and after passing the strait, this inflow splits into two branches: one flows northward along the Korean coast and another outflows into Pacific ocean through Tsugaru and Soya strait passing the east-northeastward along the Japanese outer shelf, and outflows into Okhotsk ocean.

Variation of Nitrate Content on Distributed Vegetables in Korea (국내유통 채소류의 질산염 함량변이)

  • Lee Ju-Young;Park Yang-Ho;Jang Byoung-Choon;Kim Seok-Cheol;Kim Pil-Joo;Ryu Su-Noh
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.50 no.spc1
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    • pp.231-238
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    • 2005
  • Nitrate contents of lettuce and chinese cabbage which aye consumed mostly in vegetables in Korea were $403\~6,935$ (mean 3,088), $31\~5,391$ (mean 2,412), and $310\~6,374$ (mean 3,017) mg/kg, respectively. Nitrate contents of root vegetables and fruit vegetables were lower than those of leaf vegetables. There was no different of nitrate content in vegetables by area, but the nitrate contents of summer vegetables were higher than those of winter vegetables. Nitrate contents of Danmugi, Kimchi, and Young radish Kimchi were 346, 1,411, and 3,240 mg/kg, respectively. Nitrate contents of juice of Danmugi, Kimchi, and younger radish Kimchi were 340,979, and 1,383 mg/kg, and there was no different of nitrate content by area.

A Study on the Lava Terraces with Different Elevation in Jeju (해발에 따른 제주도 용암류대지 지형의 세분화에 관한 연구)

  • Hyun, Byung-Keun;Jug, Yeon-Tae;Hyun, Geun-Soo;Moon, Kyung-Hwan;Song, Kwan-Cheol;Sonn, Yeon-Kyu;Zhang, Young-Seon;Park, Chan-Won;Hong, Suk-Young;Kim, Lee-Hyun;Choi, Eun-Young;Jang, Byeong-Chun
    • Korean Journal of Soil Science and Fertilizer
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    • v.42 no.2
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    • pp.88-97
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    • 2009
  • This study was conducted to obtain the basic information to increase the practical use of soil survey data through the subdividing of lava shapes with soil sequences due to different elevations in Jeju. The numbers of soil series of lava topography had occupied many of whole soil series in Jeju. When its topography subdivide, it give more detailed soil information. The obtained results are as follows; The lava topography to subdivide lava topography were studied with 38 soil series according to elevation in Jeju. Division of elevation are less than 50m, 50m to 200m, and 200m to 400m and more than 400m. Name the depending on elevation, less than 50m is called lower part of lava, 50m to 200m is called middle part of lava, and 200m to 400m and more than 400m are called upper part of lava. The characteristics of lava subdivide are as follows; soil family texture of lower part of lava is fine silty to clayey, drainage classes are various, average of available soil depth is 75.3cm, average of gravely contents are 11.6%, average of slopeness is 7.2%, limiting factor are various and soil order are various. soil family texture of middle part of lava is fine silty to coarse silty, drainage classes are well to very well, average of available soil depth is 65.9cm, average of gravely contents are 14.7%, average of slopeness is 11.3%, limiting factor are ashy and soil order are Andisols and Inceptisols. Soil family texture of upper part of lave is fine silty, drainage classes are well, average of available soil depth is 72.8cm, average of gravely contents are 16.0%, average of slopeness is 14.9%, limiting factor are ashy and skeletal, and order are Andisols.

Analysis of Nitrate Contents of Agricultural Products by HPLC-UV (HPLC-UV를 이용한 농산물의 질산염 함량분석)

  • Jo, Sung-Ae;Kim, Eun-Hee;Han, Sung-Hee;Yuk, Dong-Hun;Kim, Jung-Hun;Park, Seog-Gee
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.39 no.9
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    • pp.1335-1339
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    • 2010
  • A total of 550 samples were analysed for nitrate contents using HPLC-UV. Nitrate contents of leaf vegetables were higher than those of root vegetables and fruit vegetables. The average nitrate content of the radish leaves (4875.8 mg/kg) was the highest, followed by marsh mallow (4711.7 mg/kg), crown daisy (4546.9 mg/kg) and vitamins (4239.5 mg/kg). The nitrate content in fruits of strawberry and banana averaged at 24.0 mg/kg and 438.5 mg/kg, respectively. Nitrate was not detected in other fruits. In fruiting vegetables nitrate contents were less than 1000 mg/kg. In onion, lotus root and radish, nitrate contents were 253.7mg/kg, 352.4mg/kg and 2849.0 mg/kg, respectively, with no detection in garlic. Nitrate contents in mushrooms were less than 100 mg/kg.

와전류시험에 의한 조사핵연료봉의 건전성 평가

  • 구대서;박윤규;김은가
    • Proceedings of the Korean Nuclear Society Conference
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    • 1995.05b
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    • pp.651-657
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    • 1995
  • 고리원자력1호기에서 각각 2주기, 4주기동안 연소한 핵연료봉 G33-N2(평균연소도:3464MWD/MTU) 및 G23-14(평균연소도:13917MWD/MTU)에 대하여 와전류시험을 수행한 결과 G33-N2 핵연료봉 하단으로부터 각각 2290mm, 2878mm 위치에 관통결함신호와 내부결함신호를 얻었다. 또한 G23-l4 핵연료봉에서는 ridge 와전류신호를 획득하였다. 비파괴적 와전류시험을 통하여 관통결함 및 내부결함으로 예측된 위치에서 파괴적 금속조직시험을 수행하여 얻은 결과는 와전류시험결과와 잘 일치하였다 G23-l4 핵연료봉에서 획득한 ridge 와전류신호는 직경측정시험결과와 비슷한 경향을 보여 주었다. 따라서 와전류시험을 통하여 핵연료봉에 대한 건전성 평가 도구로서의 그 신뢰성이 양호함을 실증하였으며 핵연료봉의 ridge 정보도 제공할 수 있음을 입증하였다.

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