• 한국측량학회지
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• 제37권6호
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• pp.499-506
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• 2019

정규수치표면모델(NDSM: Normalized Digital Surface Model)은 원격탐사데이터의 상세 분석을 위한 핵심 적인 자료로 사용된다. 지상기준높이인 정규수치표면모델을 생성하기 위한 가장 간단한 방법은 수치표면모델(DSM: Digital Surface Model)에서 수치지형모델(DTM: Digital Terrain Model)을 차분하는 것이지만, 무인항공기 데이터의 경우 높은 해상도의 특성상 식생, 도심 구조물 등 많은 수의 복잡한 지형지물을 포함하고 있어 정확한 수치지형모델을 추출하기 어렵다. 본 연구에서는 무인항공기 데이터의 고해상도 특성을 잘 살리고 비용효율적인 수치지형모델 생성이 가능하도록 RGB 기반 식생 지수인 ExG (Excess Green)를 이용하여 낮은 ExG 값을 갖는 영역 확장법의 초기 시드점을 선정하였다. 이때 국소적으로 낮은 식생지수 값을 갖는 초기 시드점이 잘못 추출되는 문제를 해결하기 위하여 지역적 윈도우 분석을 적용하였다. 이후, 해당 위치의 수치표면모델값을 바탕으로 영역 확장법을 적용하여 이웃하는 지면 화소들을 병합하였다. 영역 확장법 적용을 위해 경사도 파라미터가 사용되었으며 최종적으로 병합된 세그먼트의 크기가 0.25㎡ 초과일 경우 초기 시드점을 지면점으로 결정하였다. 다양한 경사도 파라미터 값을 설정하여 무인항공기 데이터 기반 정규수치표면모델 생성의 최적 경사도 기준값을 도출하고자 하였다. 최종적으로 추출된 지면점들에 대한 정확도 평가를 수행하였으며 지면점들에 보간법을 적용하여 정규수치표면모델을 생성하고 제안 기법을 농업지역에 적용하여 농작물의 지상기준높이 추출 및 농업 모니터링 가능성을 검증하였다.

• Journal of Ecology and Environment
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• 제37권4호
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• pp.165-175
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• 2014

A natural population of Adonis multiflora, a spring ephemeral herb growing in temperate deciduous forests, was studied to determine the seed production characteristics. Plant size, flowering time, and seed number were monitored from February 2009 to May 2011 in main growing season (i.e., from March through May). The biomass rates of the shoot and the root in the A. multiflora population were 22-24% and 76-78%, respectively, and the biomass of the root was proportional to that of the shoot. The flowering rate was 60% in the plants with 1 to 2 g of shoot biomass, and 100% in the plants with >2 g of shoot biomass. In the plants with root biomass between 4 and 6 g, the flowering rate was 43% and, in the plants with the root biomass over 8 g, it was 100%. The shoot biomass was a better predictor of the flower production probability than the root biomass. The number of flowers and seeds was closely correlated to shoot biomass at 1% significance level. The size of the plant that produced seed excessively instead of the shoot biomass in one year typically decreased in the next year and vice versa. The flowering time and its duration were closely related to the number of faithful seeds but not to that of total seeds. The number of faithful seeds was proportionate to flowering duration and inversely proportionate to flowering time (year day, YD). In a plant, the number of faithful seeds noticeably decreased with the inflorescence (i.e., order of flower in a plant), and this difference between the two successive flowers was significant at the 1% level between the first and the third flower in 2009 and 2011 but not between the third and the fourth. However, the number of total seeds was mostly similar in the first through the fourth flower for all three years.

• 한국결정성장학회지
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• 제6권2호
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• pp.129-140
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• 1996

본 연구에서는 수열성장법을 이용해서 알루미늄 수화물로부터 코런덤($\alpha$-Al_{2}O_{3}$) 단결정을 지조하였고, 합성 조건에 관해 조사하였다. 수열 조건에 영향을 미치는 주요인자는 반응온도, 종자결정 및 반응시간이었으며, 특히 종자결정은 코런덤의 입도와 결정형태에 큰 영향을 미쳤다. 영양제로 사용한 일본산 깁사이트에 종자결정을 첨가해서 2시간 동안 수열반응 시킨 결과 $460^{\circ}C$에서 중량평균입경이 $11\;\mu\textrm{m}$인 육방정의 코런덤 결정이 합성되었으며, 또다른 유형의 러시아산 깁사이트로부터는 $420^{\circ}C$에서 중량평균입경이 $6\;\mu\textrm{m}$인 육방정의 코런덤 결정이 합성되었다.

• 한국작물학회지
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• 제48권2호
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• pp.81-88
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• 2003

Soybeans [Glycine max (L.) Merr.] are frequently exposed to unfavorable environments during growing seasons and water is the most important factor limiting for the production system. The purpose of this study was to determine the leaf water potential changes by irrigation, and to evaluate the relationships of leaf water potential, growth and yield in soybeans. Three soybean cultivars, Hwangkeumkong, Shinpaldalkong 2, and Pungsannamulkong, were planted in growth chamber and field with irrigated treatments. Leaf water potential of three soybean cultivars was positively correlated with leaf water content during vegetative and reproductive growth stages in growth chamber and field experiments. Leaf water potentials measured for three soybean cultivars under growth chamber were higher than those of under field conditions. Higher leaf water potential with irrigated plots under field was observed compared to conventional plots during reproductive growth stages. Leaf water potentials of three soybean cultivars were continually decreased during reproductive growth stages under field and there was no significant difference among them. Number of leaves, leaf water content, pod dry weight, number of seeds and seed dry weight with irrigated plots were higher than those of conventional plots. The results of this study suggested that leaf water potential could be used as an important growth indicator during the growing season of soybean plants.

• Mycobiology
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• 제39권3호
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• pp.206-218
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• 2011

The seed-borne mycoflora of sorghum and foxtail millet collected from different growing areas in South Korea were isolated and taxonomically identified using dry inspection, standard blotter and the agar plate method. We investigated the in vitro and in vitro germination rates of disinfected and non-disinfected seeds of sorghum and foxtail millet using sterilized and unsterilized soil. The percent recovery of seed-borne mycoflora from the seed components of sorghum and foxtail millet seeds was determined and an infection experiment using the dominant species was evaluated for seedling emergence and mortality. A higher number of seed-borne fungi was observed in sorghum compared to that of foxtail millet. Eighteen fungal genera with 34 fungal species were identified from the seeds of sorghum and 13 genera with 22 species were identified from the seeds of foxtail millet. Five dominant species such as Alternaria alternata, Aspergillus flavus, Curvularia lunata, Fusarium moniliforme and Phoma sp. were recorded as seed-borne mycoflora in sorghum and 4 dominant species (Alternaria alternata, Aspergillus flavus, Curvularia lunata, Fusarium moniliforme) were observed in foxtail millet. The in vitro and in vitro germination rates were higher using disinfected seeds and sterilized soil. More seed-borne fungi were recovered from the pericarp compared to the endosperm and seed embryo. The percent recovery of seed-borne fungi ranged from 2.22% to 60.0%, and Alternaria alternata, Curvularia lunata and 4 species of Fusarium were isolated from the endosperm and embryo of sorghum and foxtail millet. Inoculation of the dominant seed-borne fungi showed considerable mortality of seedlings. All the transmitted seed-borne fungi might well be a primary source of infection of sorghum and foxtail millet crops.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 춘계학술대회
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• pp.116-118
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• 1997

In hippocampal morphology Abnormalities, including unilateral or bilateral volume loss, are known to occur in epilepsy, Alzheimer's disease, and in certain amnestic syndromes. To detect such abnormalities in hippocampal morphology, we present a method that combines region growing and dynamic contour model to detect hippocampus from MRI brain data. The segmentation process is performed two steps. First region growing with a seed point is performed in the region of hippocampus and the initial contour of dynamic contour model is obtained. Second, the initial contour is modified on the basis of criteria that integrate energy with contour smoothness and the image gradient along the contour. As a result, this method improves fairly sensitivity to the choice of the initial seed point, which is often seen by conventional contour model. The power and practicality of this method have been tested on two brain datasets. Thus, we have developed an effective algorithm to extract hippocampus from MRI brain data.

• 한국작물학회지
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• 제23권2호
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• pp.126-132
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• 1978

To examine the effects of P.E. film and rice straw mulching on fall grown potato(Shimabara cultivar) in the middle region of Korea, sprouted seed tuber pieces were transplanted with six kinds of mulching treatments on 24th July and harvested on 25th October. P.E. film mulching from transplanting resulted the perfect rot of transplanted seed pieces due to the excessive high soil temperature (noon soil temperature of about 4$0^{\circ}C$ continued until the middle of August). P.E. film mulching from 15th September to harvest increased the marketable tuber yields by 35% due to the raising of soil temperature by 1-3$^{\circ}C$ and maintaining of available soil moisture in dry season. Rice straw (whole or cut in 10cm length) mulching lowered the soil temperature in hot season and raised it in cool season and maintained available soil moisture in dry season. Therefore better emergence, growth and yields were induced. Effects of whole straw, whole growing season and thicker mulching were greater than cut straw, half growing season and thinner mulching. 6cm mulching of whole or cut straw during whole growing season resulted the increasing of marketable tuber yields by 56 or 48%.

• 한국자원식물학회지
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• 제9권2호
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• pp.113-119
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• 1996

This study inverstigates growing seedling of onion for 91 farmhouses at Muan, Hampyeong and Sinan which are major areas of production from Jan. to Apr., 1994 to enhance the research effect of onion and then the following results are obtained. Over 60% of the farmhouses have cultured onion continuously over 11years. Early mature variety cultured is over 9 varieties and among them Kinkyu variety is cultured most frequently. Late mature variety is over 13 and Changyongdaego, Bonganwhang and Chunjudaego varieties are cultured most. Most of the farmhouses used seeds less than 6 dl at small area less than $40m^2$ and especially in the case of early variety ,they purchased it at seed stores with 15,000-20,000 won/dl and sowed them with broadcasting method. Amount of fertilizer level of onion seed is ranged from nonfertilizer level to $16.8g/m^ and most of the farmhouses employ molding after seeding with straw and compost and they did not use thinning. Irrigation is performed by 1-4 times before sprouting of onion seed and most of the farmhouses transplant long nursery plant over 46 days hand weeding is used.

• 한국작물학회지
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• 제42권4호
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• pp.424-428
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• 1997

This study was carried out to investigate the effects of sowing dates, Apr. 25, May 15, June 5 and June 25, on sex ratio, growth and seed yield of "Chonnam species", local variety of hemp plant. The results were following as. : In sex ratio according to the different seeding dates, the revealating rate of female and male plants were highest on June 25, and Apr. 25, respectively. The length of stem, the number of branches, nodes, and seed yield were increased on May 15, but these charateristics were rapidly reduced on June 25 because of short growing period. Yield of seeds was increased by 24％ on May 15 comparing with 1.30ton /ha on Apr. 25.

• 한국작물학회지
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• 제65권4호
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• pp.339-345
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• 2020

Recently, abnormal weather conditions, such as extreme high temperatures and droughts, have increased in frequency due to climate change, there has accordingly been growing concern regarding the detrimental effects on field crop, including soybean. Therefore, this study was conducted to examine the effects of increased temperatures on soybean growth and yield using a temperature gradient chamber (TGC). Two major types of soybean cultivar, a medium- seed cultivar such as Daepung-2 and a large-seed cultivar such as Daechan, were used and four temperature treatments, aT+1℃ (ambient temperature+1℃), aT+2℃ (ambient temperature+2℃), aT+3℃ (ambient temperature+3℃) and aT+4℃ (ambient temperature+4℃) were established to examine the growth response and seed yield of each cultivar. Seed yield showed a higher correlation with seed weight (r=0.713***) and an increase in temperature affected seed yield by reducing the single seed weight. In particular, the seed growth rate of the large-seed cultivar (Daechan) increased at high temperature, resulting in a reduction in the number of days for full maturity. Our results accordingly indicate that large-seed cultivar, such as Daechan, is potentially vulnerable to high temperature stress. The results of this study can be used as basic data in the development of cultivation technology to reduce the damage caused by elevated temperatures. Also, further research is required to evaluate the response of each process contributing to seed yield production under high temperatures.