• Wind and Structures
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• 제17권4호
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• pp.435-449
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• 2013

The vehicle-induced aerodynamic loads bring vibrations to some of the highway sound barriers, for they are designed in consideration of natural wind loads only. A field experiment is carried out with respect to three important factors: vehicle type, vehicle speed and the vehicle-barrier separation distance. Based on the results, the time-history of pressures is given, showing identical characteristics in all cases. Therefore, the vehicle-induced aerodynamic loads acting on the highway sound barrier are summarized as the combination of "head impact" and "wake impact". The head impact appears to have potential features, while the wake impact is influenced by the rotational flow. Then parameters in the experiment are analyzed, showing that the head impact varies with vehicle speed, vehicle-barrier separation distance, vehicle shape and cross-sectional area, while the wake impact is mainly about vehicle-barrier separation distance and vehicle length.

• 수산해양기술연구
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• 제45권3호
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• pp.144-150
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• 2009

The choice behavior of the octopus in response to the environment-friendly colored sinker for octopus driftline and the sinker's fishing effect were studied under experimental conditions in the water tank and the field. The colors of the sinkers used for the experiment are white, black, yellow and green. Artificial baits are attached to the sinkers in order to attract the octopuses in the experiment. In the water tank experiment, two sinkers of two different colors are placed in a compartmentalized corner of the rectangular tank, and a CCD camera records the choice behaviors of the octopuses to the colored sinkers. In the field experiment, the catch investigation of octopus for each colored sinker was conducted 14 times in total by using 2(A, B) commercial fishing boats at the coast of Gangneung within 30m of depth in 2006. The number of colored sinkers per operation was a total of 24-40 pieces with the same number of sinkers individually for four colors. As a result, it was found that the octopus selected white the most followed by black and yellow in their choice of colored sinkers in the water tank experiment, and green was the lowest in their choice. Even in the field experiment, the sinkers of white and black showed a higher catch of octopus than the sinkers of yellow and green.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.999-1008
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• 1996

The development and improvement of the originally designed direct rice sowing machine were carried out for the specific purpose of saving labor and increasing the efficiency of field operations in rice cultivation in the northern part of Japan. the prototype super wide spreader has a unique mechanism which propels rice seeds by compressed air and spreads them from the pivoting nozzle while the machine is in motion. The effective field capacity of sowing operation is about 6 ha/h. This spreader can also handle granular chemicals such as fertilizers, herbicides, pesticides and insecticides.

• 한국약용작물학회지
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• 제15권4호
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• pp.261-265
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• 2007

인삼재배가 가능한 임간의 기후적 특성과 임간재배지내에서의 병해충 발생상황 및 생육상황을 관행재배지와 비교해본 결과는 다음과 같다. 가. 임간재배지의 온도는 관행재배지보다 $1^{\circ}C$ 정도 낮고 습도는 2% 정도 높았으며 토양온도는 $1.9^{\circ}C$ 낮고 토양수분도 11.8%가 낮았다. 임간재배지의 풍속은 관행재배지보다 3배 정도 늦었으며 결로시간은 3.3시간 긴 것으로 나타났다. 특히 일사량은 현저히 부족하였고 강우량도 약간 부족한 것으로 나타났으나 큰 차이는 없었다. 나. 2003년이 2004년과 2005년보다 병해의 발생이 많았고 임간재배지에서의 병해발생이 관행재배지보다 심하였다. 때문에 8월 중순경에 지상부가 거의 다 고사되었다. 임간재배지의 주요 병해충으로는 탄저병, 점무늬병 및 뿌리썩음병이었고, 관행재배지는 위의 병해와 잿빛곰팡이병의 발생이 주를 이루는 것으로 나타났다. 해충으로는 잎별레와 나방류가 가해하는 것으로 조사되었다. 3년근의 생육상황을 비교한 결과 임간재배지에서 자란 인삼의 생육상황이 전반적으로 50% 이상 불량하였고 특히 근중은 87.2% 정도 가벼운 것으로 나타났다.

• 한국약용작물학회:학술대회논문집
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• 한국약용작물학회 2011년도 추계학술발표회
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• pp.154-155
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• 2011

• 한국연초학회지
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• 제12권2호
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• pp.91-101
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• 1990

A field experiment was conducted to find out the effects of field productivity, variety and nitrogen rate on the yield, quality, chemical constituents and physical properties of burley cured leaf in three field with different productivity(Degree of field productivity: A ; high, B ; medium, C : low) during successive two years(1988~89). The yield and quality were remarkably lowered when nitrogen fertilizer being applied much in low productive field. As compared with Burley 21, KB101 showed high yield, particularly the yield of KB101 in low productive field was relatively high. The effect of nitrogen rate on the yield was somewhat different according to field productivity and production year. When the nitrogen fertilizer being applied above 22.5kg/10a, the added nitrogen had no effect on the yield. Total nitrogen content of cured leaf grown in low productive field was high while total alkaloid was low, therefore total alkaloid/total nitrogen ratio was remarkably low. The lightness, red and yellow color of cured leaf grown in low productive field was remarkably low. As compared with Burley 21, the contents of total alkaloid and total nitrogen and shatter resistance index of cured leaf was somewhat low, while the filling power, lightness, red and yellow color were slightly high. Total nitrogen content of cured leaf was increased remarkably by nitrogen addition, but total alkaloid was not increased though the nitrogen fertilizer being applied above 22.5kg/10a. The filling power and shatter resistance index of cured leaf grown in high nitrogen plot, and the lightness and yellow color were low while the red color was relatively high. It comes into question that the visual quality being increased as well as increment of yield and nitrogenous compounds by nitrogen addition in high productive field. In low productive field, it is considerable that nitrogen addition for high yield should be prohibited because it causes the decrement of yield and quality, on the contrary.

• 한국작물학회지
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• 제45권4호
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• pp.232-236
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• 2000

To obtain a basic information on the development of effective control strategies for weedy rice in direct seeding rice cultivation, occurrence patterns of weedy rice as influenced by different cultural practices such as cultivation method, water management, seeding time, and tillage were investigated in field or pot experiments. High occurrence of weedy rice was observed in a continuous direct seeding paddy field as compared to machine transplanted one. Based on the percent of weedy rice panicle over three years trial, high ridged dry seeding was highest with 36.9%, followed by wet seeding with 30.9%, water seeding with 14.6% and machine transplanting rice with 0.8%, indicating 97.8% reduction in weedy rice occurrence by machine transplanting rice as compared with high ridged dry seeding. Germination of weedy rice was promoted to 83-94 % when rice panicle was flooded from September 30 to October 10 for 6 days and 74-88% for 9 days on October 20. Weedy rice occurrence was also substantially reduced by delayed seeding on June 10 and intensive tillage. The results suggest that machine transplanting rice be more effective cultural practice than flooding treatment, delayed seeding and intensive tillage when weedy rice problem occurs in direct seeded paddy field.

• 방사선산업학회지
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• 제6권1호
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• pp.41-47
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• 2012

A field tracer experiment using a radioisotope was conducted to analyze the transport and dispersion characteristics of pollutants in the coastal area near a Wolsung. A rod float including GPS was released to track the paths of radioisotope. NaI detector was installed to measure the released radioisotope from the boat, and measurements were performed with the real time. The measured tracer data by a field experiment can be used as the basic data for understanding the transport characteristics of pollutants and verifying numerical models near the offshore.

• 한국작물학회지
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• 제29권2호
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• pp.198-202
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• 1984

답리작과 전작 유채재배에서 지방산조성이 개량된 품종을 공시하여 시비량을 달리했을 때의 토양화학적 성질, 종실의 유분함량 및 지방산조성의 변화를 조사한 결과를 요약하면 다음과 같다. 1. 유분함량은 전작재배에서보다 답리작재배에서 높았고 지방산조성에서는 Palmitic. Linoleic. Linolenic acid함량은 답리작재배에서 높았으며 Stearic과 Oleic acid는 전작재배에서 높아지는 경향이었다. 2. 질소시용은 많을수록 함유율이 증가하는 경향이나 15kg/10a 이상에서는 오히려 감소하였으며 인산과 가리는 모두 증가할수록 함유율이 증가하였다. 3.양질 지방산인 Oleic+Linoleic acid의 함량은 답리작보다는 전작재배의 경우 평균 2∼5％ 더 높아서 유질이며 우수하였다. 4. Oleic acid와 Linoleic acid 함량은 질소의 증시에 의해 증가하는 경향이며 인산과 가리에서는 전작인 경우 8kg/10a까지는 증가하나 그 이상에서는 감소하였으며 답리작에서는 인산, 가리의 증시효과가 없었다.

• 한국토양비료학회지
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• 제49권1호
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• pp.12-16
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• 2016

To identify the effects of straw mulching on soil physicochemical properties in reclaimed saline soil, field experiment was conducted for 3 years (2010~2012) in Saemangeum reclaimed land. Soil series of the experimental field was Munpo and soil texture was fine sandy loam. The experiment was conducted at a field with EC of $2.4dS\;m^{-1}$ (field I) and the other field with EC of $5.6dS\;m^{-1}$ (field II). Each experimental field was treated with rye straw incorporation, mulching with rye straw and control. In 2010 rye straw produced from other field was used for the experiment and in 2011~2012 rye straw cultivated at the same experimental field was used. After rye straw application, soybean was cultivated. After 3 years field experiment, by rye straw incorporation, soil salinity decreased from $2.4dS\;m^{-1}$ to $0.6dS\;m^{-1}$ at field I but increased from $5.6dS\;m^{-1}$ to $7.6dS\;m^{-1}$ at field II. By mulching with rye straw soil salinity decreased from $2.4dS\;m^{-1}$ to $0.5dS\;m^{-1}$ at field I and also decreased from $5.6dS\;m^{-1}$ to $0.5dS\;m^{-1}$ at field II. By rye straw incorporation and mulching soil organic matter increased from $2g\;kg^{-1}$ to $4g\;kg^{-1}$. At field I yields of soybean were similar between rye straw incorporation and mulching but at field II yield of soybean increased apparently by mulching with rye straw compared to rye straw incorporation and control.