• 한국토양비료학회지
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• 제44권1호
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• pp.98-103
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• 2011

The System of Rice Intensification (SRI) is a new concept of increasing the yield of rice produced in farming. Therefore, we investigated the impacts of planting density on nutrient uptake as affected by SRI under no-till cropping system. The field was prepared as a randomized complete block design with three treatments: $10{\times}10$ cm, $20{\times}20$ cm and $30{\times}30$ cm planting densities. The root dry mass was significantly increased in the wider planting densities (p<0.05%). The highest grain yield was obtained in $20{\times}20$ cm planting density plot (p<0.05%) due to higher plant density per unit area and spikelets number per panicle. The total uptake amounts by rice plant were significantly higher in $20{\times}$20 cm planting density plot as 94.8 kg $ha^{-1}$ for T-N and 29.9 kg $ha^{-1}$ for P than other planting densities plots, but K and Mg uptake were significantly higher in $10{\times}10$ cm planting density plot (p<0.05%). In this study, our findings suggest that SRI should be considered as a new practice for the rice productivity.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.101-101
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• 2022

In recent years, due to climate change, the livestock industry has become more interested in the production of forage crops. In Korea, more than 74% of forage crops are cultivated in winter rice fields. In particular, Italian ryegrass (IRG) is depends on imports for more than 70% of its seeds. In generally, the IRG rapeseed cultivation method involves sowing from early October to mid-October by drill sowing seeding or spot seedling. However, the sowing period is delayed due to frequent rainfall during. And, same period require a lot of seeds. However, raising seedlings and transplanted IRG will overcome weather conditions and reduce the amount of seeds. This study was intended to be applied to the domestic IRG seed industry in the future through growth and quantity evaluation according to transplant time and planting density for the production of good quality IRG seeds in rice paddy fields. In this study, transplanting time (October 20, October 30, November 10) and planting density (50, 70, and 80) were cultivated at the National Institute of Crop Science in 2021. The amount of fertilizer applied was adjusted to (N-P₂O₅-K₂O) 4.5-12-12 (kg/10a), and then 2.2(kg/10a) of nitrogen was added each year. For the growth survey, leaf area, canopy coverage, plant length, and seed yield were investigated. Along with the transplanting time, the plant length was higher on October 20 than on October 30 and November 10. On the other hand, leaf area index changes differed depending on the transplanting time and planting density, and were particularly high on October 20, 80 density and 70 density, but similar on October 30 and November 10. 1000 seed weight showed no difference with transplanting time and planting density. On the other hand, the seed yield was 215(kg/10a) for 80 density on October 20, 211(kg/10a) for 70 density, 118(kg/10a) for 50 density, and 80 density for October 30 and November 10. and 70 density did not differ. On the other hand, the 50 density on October 30 and November 10 were 164(kg/10a) and 147(kg/10a) respectively. As can be seen from this study, the earlier the transplant, the higher the seed yield. However, the 50 density was reduced in yield compared to the 70 density and 80 density.

• Journal of Ginseng Research
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• 제8권2호
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• pp.178-183
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• 1984

This study was conducted to know the influence of plant age and cultural conditions such as plant population density and light intensity under the shading on the leaf shape of panax ginseng. The result obtained were as follows; 1) Leaf length(L)/maximum width(W) was no difference with different age of over 3-over 3year old plant, but that of 1 or 2-yearold was smaller than those of over 3-year old. The values of L/W showed in the order of 2 or 4,3, 1 or 5 leaflet. 2) Ratios of leaflet area to leaf area were 32.0% in leaflet 3, from 209.% to 27.9% in leaflet 2 or 4, and from 6.5% to 7.1% in leaflet 1 or 5. 3) The coefficients of variability for L/W and ratio of leaflet area to leaf area of leaflet 3 were smallest among leaflets. 4) There were significant differences between largest and smallest leaflet 3, leaf areas and ratio of leaflet 3 area to leaf area in same plant. 5) LW and ratio of leaflet 3 area to leaf area were not affected by plant population density. 6) It showed a tendency that the L/W was increased with increasing the light transmittance rate (LTR). The ratio of leaflet 3 area to leaf area of ginseng grown under 20% LTR was not different comparing to that of plant grown under 5% LTR, but it was significantly increased in plant grown at 100% LTR.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1995년도 추계학술발표회논문집(1)
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• pp.254-259
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• 1995

Large scale display panel(LSDP) is a main component in the next generation main control rooms. LSDP is located at the front of VDU-based operator's workstation and plays an important role in providing operators with overall information of plant status through mimic diagram, text/digit, graph, and so on. A critical matter determined at the first stage of LSDP design is how much information is displayed, because the information density of LSDP affects operator's performance. Many human factors guidelines recommend low information density of displays to avoid degrade of operator's performance, but doesn't provide a useful limit of information density. In this paper, we considered information density as the number of plant parameters and investigated the proper number of plant parameters through a human factors experiment. The experiment with 4 subjects was carried out and response time, error, and heart rate variation as criterion measures were recorded and analyzed. As the results, it is identified that the proper number of parameters in a LSDP is about thirty.

• 화훼연구
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• 제16권1호
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• pp.23-27
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• 2008

이 연구에서 재식밀도, 적심, 그리고 예취가 생육과 수량에 영향을 미쳤다. 재식거리 $90cm{\times}30cm$에서 최고의 생장과 수량을 얻었는데, 이 재식거리에서는 최고초장이 140cm, 식물체당 1차, 2차 및 3차 분지수가 각각 32개, 164개 및 367개로 자랐다. 이 처리에서 건조한 꽃의 무게는 10a당 98kg에 달해 재식거리 $120cm{\times}30cm$에 비해 40% 증수되었다. 경경, 지상부 건물중 및 건조한 꽃 무게는 적심 하였을 때 무적심에 비해 증가되었다. 7월 10일 적심시 건조한 꽃 무게가 10a당 102kg으로 무적심에 비해 57% 증가되었다. 생육과 수량특성은 무예취와 6월 10일 예취 처리간에 비슷하였지만 7월 10일 예취에서는 초장, 경경 및 분지수가 무처리에 비해 유의하게 감소되었다. 누적 지상부 건물중은 모든 처리에서 차이가 없었지만 6월 10일 예취시 건조한 꽃 무게와 꽃수가 10a당 각각 123kg과 2,592개로 가장 많았다.

• 식물병연구
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• 제20권2호
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• pp.107-111
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• 2014

나선선충 접종 밀도가 토마토의 생육에 미치는 영향을 조사하고자, 시판 토마토 6품종을 직경 10-cm 토화분에 심고, 나선선충을 0, 0.02, 0.2, 2마리/g 토양 수준으로 접종하여 60일간 온실에서 재배하였다. 나선선충은 식물체의 무게나 뿌리의 무게에는 영향을 미치지 않았으나 키에는 영향을 주었는데(P < 0.05), 토양 g 당 나선선충 2마리 접종 시 포세이돈 품종은 무처리에 비하여 키가 24% 위축되었다. 나선선충을 접종하였을 때(2마리/g 토양), 가장 나선선충의 선충의 증식이 많았던 토마토 품종은 호용으로 최종 선충 밀도는 7.0마리/g 토양 이었고, 가장 나선선충의 선충의 증식이 적었던 토마토 품종은 미니흑수품종으로 최종 선충 밀도는 2.2마리/g 토양 이었다.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2000년도 추계학술대회 논문집
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• pp.108-112
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• 2000

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2000년도 춘계학술대회 논문집
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• pp.75-80
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• 2000

We revisit the arrested Ekman boundary layer problem, using a fully non-linear numerical model with the subgrid dissipation modeled by the large eddy simulation method (LES). The main objective of this study is to find out whether the dynamic balance of the arrested Ekman boundary layer explained by MacCready and Rhines (1991) is valid for high Reynolds number. The model solution indicates that for high Reynolds number and low Richardson number flows, the density anomaly diffusion by near-wall turbulent action may become intense enough to homogenize completely the density structure within the boundary layer, in the direction perpendicular to the sloping wall. Then the buoyancy effect becomes negligible allowing a near-equilibrium Ekman boundary layer flow to persist for a long period.

• 전기전자학회논문지
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• 제23권2호
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• pp.487-494
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• 2019

본 논문에서는 토양에 침투하는 미세먼지의 영향을 피하여 폐쇄된 공간에서 물과 배양액을 이용하는 IOT(Internet of Things) 기반의 수경재배 식물공장을 제작하고, PLC(Programmable Logic Controller) 제어 방법을 제안한다. 제작된 수경재배 식물공장은 터치스크린과 스마트폰을 통하여 산소의 농도, 양액의 농도, 온도, 습도의 정도를 모니터링 하고, 히터 및 쿨러제어, 환풍기 및 제습장치 제어, LED의 파장 등을 사용하여 식물이 적정한 환경에서 성장할 수 있도록 제어한다.

• The Plant Pathology Journal
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• 제17권5호
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• pp.295-299
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• 2001

The relative density of phytoplasmas in witches'broom (WB)-infected jujube trees was investigated using compatitive polymerase chain reaction (PCR). During dormant and defoliating seasons, the densities of phytoplasmas were about the same in roots and twigs. In early growing season, the density showed the highest rates in roots, then in twigs and in petioles. however, the density was highest in petioles and the lowest in roots during actively growing season. Throughout the year, root samples did not show any serious fluctuation compared with that of t2wigs and petioles. Density was lowest during actively growing season in root samples. In contrast, petiole sample densities varied to a great extent depending on the season, very high during actively growing season, but very low during the early growing season, In twig samples, the densities were very high and almost the same in both defoliating and dormant seasons. Among the parts of the trees, phytoplsma density was the most stable in root samples throughout the year. The highest densities of phytoplasmas were about the same in all tree parts. These results suggest that the phytoplasmas may overwinter not only in roots but also in twigs, and that multiplication rate of phytoplsma becomes very high right after the early growing season.