• 대한금속재료학회지
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• 제46권3호
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• pp.150-158
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• 2008

The temperature distribution of high speed tool steel rod has been studied during high speed hot rolling procedures. The tool steel rod shows severe temperature gradient during rolling procedures and the temperature at the center of rod are much higher than that at the surface of rod. This temperature gradient accumulated after every rolling procedure and the center of rolled rod could be remelt in some procedures to cause inside defects. In this study, the temperature distribution was simulated using finite element method and the processing parameters such as rolling speed, cooling condition, have been discussed to prevent the temperature increases at the center of rod.

• 한국토양비료학회지
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• 제49권5호
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• pp.420-428
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• 2016

For more than 50 years, satellite images have been used to monitor crop growth. Currently, unmanned aerial vehicle (UAV) imagery is being assessed for analyzing within field spatial variability for agricultural precision management, because UAV imagery may be acquired quickly during critical periods of rapid crop growth. This study refers to the derivation of growth estimating equation for highland Kimchi cabbage using UAV derived normalized difference vegetation index (NDVI) and agro-meteorological factors. Anbandeok area in Gangneung, Gangwon-do, Korea is one of main districts producing highland Kimchi cabbage. UAV imagery was taken in the Anbandeok ten times from early June to early September. Meanwhile, three plant growth parameters, plant height (P.H.), leaf length (L.L.) and outer leaf number (L.N.), were measured for about 40 plants (ten plants per plot) for each ground survey. Six agro-meteorological factors include average temperature; maximum temperature; minimum temperature; accumulated temperature; rainfall and irradiation during growth period. The multiple linear regression models were suggested by using stepwise regression in the extraction of independent variables. As a result, $NDVI_{UAV}$ and rainfall in the model explain 93% of the P.H. and L.L. with a root mean square error (RMSE) of 2.22, 1.90 cm. And $NDVI_{UAV}$ and accumulated temperature in the model explain 86% of the L.N. with a RMSE of 4.29. These lead to the result that the characteristics of variations in highland Kimchi cabbage growth according to $NDVI_{UAV}$ and other agro-meteorological factors were well reflected in the model.

• 응용통계연구
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• 제34권3호
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• pp.439-447
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• 2021

범지구적 이상기후의 잦은 출현으로 기상 변화에 대한 관련 연구가 활발히 진행되고 있지만, 장기간 축적된 기상자료를 이용한 경향성 분석 연구는 부족하였다. 본 연구에서는 비모수적 분석방법을 이용해 40년간 종관기상관측장비(ASOS)로 부터 축적된 기온 시계열 자료의 경향성을 분석하였다. 남한지역의 연평균 기온과 계절별 평균기온 시계열 자료에 대한 Mann-Kendall 검정 결과 상승 경향성이 존재하는 것으로 나타났다. 또한 Pettitt 검정을 적용해 탐색된 변동점을 전후로 경향성의 정도를 파악할 수 있는 Sen's slope를 계산한 결과, 변동점 이후의 최근 자료에서 기온의 상승 경향성이 더욱 큰 것을 확인하였다.

• 한국작물학회지
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• 제38권5호
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• pp.458-465
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• 1993

양액재배를 통하여 질소가급도와온도 및 수분부족 조건에 따른 유모기 보리의 질소 흡수 및 동화와 생장의 변화를 조사하였던 바, 그 결과를 요약하면 다음과 같다. 1. 보리의 질소 흡수량은 양액의 질소가급도가 160ppm까지 높아질수록 증가하였으나 흡수된 질소의 동화는 80ppm에서 최고에 달하였고, 이보다 높아졌을 때는 체내에 무기능질소로 축적되었다. 2. 유묘기(3～4엽기)보리의 질소동화 및 건물생산은 엽중 질소농도가 약 3.4%일 때 최고에 달아혔다. 3. 유묘기 보리의 질소 흡수는 -2bar 이하의 수분 포텐셜 조건 또는 5$^{\circ}C$이하의 온도조건에서 현저히 감소하였다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.320-323
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• 2006

Temperature inversion may cause air pollution problems because air pollutants cannot be dissipated through vertical motion of the atmosphere and are accumulated near the surface. The air quality is worsen gradually if an inversion event lasts for a long time. An inversion event is defined as consecutive temperature profiles with occurrence of the temperature inversion condition. In this paper, temperature inversion events over three major cities on Taiwan are analyzed. They are measured by ground-based microwave radiometers installed in Taipei, Taichung, and Kaohsiung from 2002 to 2004 by the Environment Protection Administration (EPA) of Taiwan. Characteristics of temperature inversion events at the three cities are extracted using different classification methods.

• 한국작물학회지
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• 제26권1호
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• pp.90-95
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• 1981

참깨 재배지역 차이에 따른 품종문제를 추적하여 본 결과 다음과 같은 결론을 얻였다. 1. 참깨 재배지역에 따른 품질은 남부지역에서 생산된 것보다 중북부지역에서 생산된 것이 리놀산함량이 많았다. 2. 러놀산함량은 등열기간 중 적산온도와 r =-0.595**의 부상관관계를 일사량과는 r=0.613**의 정상관을 보여서 등열기간의 적산온도가 낮고 일사양이 많으며 강우량도 많은 조건에서 리놀산함량 높았다. 3. 오레인산함량에서는 리놀산의 경우와 달리 남부지방에서 생산된 참깨가 중북부산 참깨보다 오레인산함량이 더 높았다. 4. 오레인산함량은 등숙기간 중 적정평균 온도와 r=0.644**의 정상관관계를 일사량과는 r=-0.456**의 부상관 관계를 보였다. 5. 참깨 지방산중 오레인산과 리놀산함량은 이두 지방산함량이 대부분 차지하고 있음으로 서로 상대적인 함량관계를 가지고 있는 경향이다. 6. 참깨의 유질은 주산지인 남부보다 중북부산 참깨의 품질이 더 우수하다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 1995년도 추계 학술대회지
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• pp.36-37
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• 1995

• 디지털산업정보학회논문지
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• 제11권1호
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• pp.9-18
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• 2015

Numerical analysis of PSC box bridge bearings for high speed KTX train vehicles has been carried out as a virtual simulation for Ubiquitous Technology. Improved numerical models of bridge, vehicle and interaction between bridge and train are considered, where bending and torsional modes are provided, whereas the exist UIC code is applied by the simplified HL loading. Dynamic and static analysed results are compared to get Dynamic Amplification Factors (D. A. F.) for maximum deflections and bending stresses up to running speed of 500 km/h. Equation from the regression analysis for the D. A. F. is presented. Sliding distance of the bearings for various KTX running speeds is compared with maximum and accumulated distances by the dynamic behaviors of PSC box bridge. Dynamic and static simulated sliding distances of the bearings according to the KTX running speed are proved as a major parameter in spite of the specifications of AASHTO and EN1337-2 focused on the distance by temperature variations.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 추계학술대회 논문집
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• pp.318-321
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• 2007

The temperature distribution of high speed tool steel wire/bar during high speed hot rolling procedures has been studied in this study. The tool steels wire/bar show severe temperature gradient during rolling procedures and the temperature of center part much higher than that of the surface. This temperature gradient accumulated after every rolling procedure and the center of rolled wire/bar could be remelt in a certain stage to cause inside defects. In the present study, the temperature distribution was simulated using finite element method and the processing parameters such as rolling speed, cooling condition, has been discussed to prevent the temperature increases of center wire/bar.

• 한국수산과학회지
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• 제41권3호
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• pp.208-214
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• 2008

This study monitored a variety of marine communities during monthly or bimonthly censuses from February 1999 to August 2000. The communities investigated included artificial reefs composed of various substrates, which were placed on an area of sandy bottom at 8, 10, and 13m depths in Muronohana, Ikata, Shikoku, Japan. Economically important shell fishes, such as the turban shell and abalone, appeared on the artificial reefs after 1 month of construction. Shell fishes were recorded at levels of five to 20 individuals per reef. A total of 37 species (4 orders, 19 families) were identified during the experimental period. Apagon semilineatus, Trachurus japonicus, Pteragogus sp., and Pterogobius elapoides accumulated over an average of 100 individuals during the study period. Apagon semilineatus, Pteragogus sp., and P. elapoides accumulated over 1,000 individuals on all artificial reefs in May 1999. Trachurus japonicus reached well over 500 individuals in the artificial iron reef during June and July 2000. Higher monthly variation in fish abundance occurred during periods of high temperature, as compared to periods of low temperature between December 1999 and March 2000. More fish were observed in the artificial iron reef than in the artificial concrete reef, because the former offered a broader inner space and the shadows of the roofs served as a shelter for fish.