• Korean Journal of Soil Science and Fertilizer
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• v.40 no.5
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• pp.354-363
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• 2007

In order to investigate the optimum rate and interval of silicate fertilizer application for rice cultivation, Chucheong byeo variety, one of commonly cultivated rice cultivar in Korea was planted on two different wetland rice soils located on Hwaseong-si from 2002 to 2005; Jisan series(a member of the fine loamy, mixed, mesic family of Fluvaquentic Endoaquepts), known as "Productive Paddy Soil", without any conspicuous limiting factor, and Seokcheon series (a member of the coarse loamy, mixed, nonacid, mesic family of Fluvaquentic Endoaquetps), known as "Sandy Paddy Soil", sandiness being major limiting factor. There were three rate treatments of silicate fertilizer application; the amount of silicate fertilizers needed to adjust the available soil silicate contents to 130, 200, and $270mg\;kg^{-1}$ was applied, in the first year only. There was an additional plot; applying the amount of silicate fertilizer needed to adjust soil available silicate to 130 ppm every year, which would serve as the base for the evaluation of residual effects of silicate fertilizers in the plots where different rates of silicate fertilizer were applied. From the yield data in first year, it was found that optimum available silica in the soil are $154mg\;kg^{-1$ and $160mg\;kg^{-1}$, in Jisan and Seogcheon soils, respectably. The duration of residual effects of silicate fertilizer was different depending upon the amount of applied silicate fertilizers and the soils. The higher the application rate, the residual effect lasted longer, and the residual effect was lasted longer in Jisan(clay loam) soil than in Seogcheon(sandy loam) soil. During four years, sum of the rate of contribution to increase available soil silica of applied silicate fertilizer in different soils ranged 18.6% and 24.1% in Jisan soil and Seogcheon soil, respectively. This may suggest that much portion of applied silicate would be either lost from the soil or remain in the soil as insoluble form. This deserves further study.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.1
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• pp.134-142
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• 2020

In this study, in order to evaluate the self-healing performance of cement composites the self-healing test method and the analysis method were suggested by applying constant water head permeability test, chloride migration test and repeated bending test. The method of making a cracked specimen and controlling crack width are also proposed. Constant head water permeability test can evaluate the healing performance by using the decreasing rate of water flow passing through the crack zone of a specimen. Furthermore, the equivalent crack width can be used to intuitively investigate the healing effect with healing period. The chloride migration test can evaluate the healing rate by the decreasing rate of the diffusion coefficient obtained by ASTM C 1202. Mechanical healing performance can be evaluated using ISR and IDR estimated from load vs. CMOD relationship graph obtained through the repeated bending test. Finally, the applicability of proposed self-healing evaluation methods was examined by testing mortar specimens with or without self-healing agents.

• Journal of Korea Water Resources Association
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• v.55 no.12
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• pp.1077-1089
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• 2022

With the construction of Seoul National University (SNU), the Mt. Gwanak watershed has undergone some urbanization. As with other campus catchments, data related to the water cycle is extremely limited. Therefore, this study began by collecting hydrological and meteorological data using Atmos-41, a complex meteorological observation instrument. The observation results of Atmos-41 were validated by analyzing the statistical characteristics and confidence intervals based on the monthly variability of data from the Korea Meteorological Administration. Results of the previous research were used to validate the simulated surface runoff and infiltration using the Storm Water Management Model (SWMM). The potential evapotranspiration (PET) simulated by the SWMM was rectified by comparing it to the Atmos-41 observation data. Multiple regression analysis was employed to adjust for the fluctuations in precipitation, relative humidity, and wind speed because the calculated SWMM PET tends to be underestimated during periods of low temperatures. R² increased from 0.54 to 0.80 when compared to the Atmos-41 PET. The rate of change in the water cycle as a consequence of the SNU's construction resulted in a 15.7% increase in surface runoff, a 14.2% decrease in infiltration rate, and a 1.6% decrease in evaporation.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.4
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• pp.635-641
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• 2012

The present study evaluated the effect of chitosan on the changes of soil chemical properties, soil microbial population, and yield of red pepper (Capsicum annuum L.) for eco-friendly agriculture in an upland field. We utilized four treatment groups, control, foliar spray, soil drench, and foliar spray + soil drench with chitosan, and analyzed these variations throughout the seven, fourteen, and twenty one days interval. The pH values, organic matter, and available phosphate in the upland soil at the harvesting stage decreased in the chitosan treatment. The populations of bacteria, actinomyces, and fungi in the upland field were increased in plots treated with chitosan. The chlorophyll content of leaves was no significant differences between the control and the chitosan treatments, while calcium content of leaves was significantly higher in the chitosan treatments than in the control. In addition, the nitrogen content of leaves was no significant differences between the foliar spray and the soil drench. The yield of red pepper was significantly higher in the control ($383kg\;10a^{-1}$) than the chitosan treatments and the yield of soil drench with chitosan reached up to 95% of control.

• Journal of Bio-Environment Control
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• v.16 no.4
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• pp.388-394
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• 2007

To product the edible fresh shoots of Sedum sarmentosum in summer season, 4 local strains were cultivated with cutting propagation under 0, 30, 50, 70, 90% shading. Effect of shading on shoot growth, leaf chroma value, SPAD value, and bitterness were investigated at 35 days after cutting. Plant height, the number of node and leaf stem diameter in $30{\sim}90%$ shading were increased than in the control, and Pohang local strain had little-overgrowth shoot, thicker stem, a few brenches per shoot, and larger leaf compared to the other local strains. Fresh and dry weight under shading were increased than in the control, dry weight of pohang local strain was highest in 50% shading. Hunter L and b values were decreased out of proportion to higher shading rate. SPAD value in $50{\sim}90%$ shading was significantly lower than in the control. The bitterness of fresh shoot was decreased out of proportion to higher shading rate. In Summer season, producing the fresh shoot of S. sarmentosum was excellent in 50% shading, and Pohang local strain among 4 local strains was more stable and good in yield and quality under shading.

• Journal of Bio-Environment Control
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• v.19 no.4
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• pp.305-310
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• 2010

This study was carried out to investigate the effect of air humidity and water content of medium on the growth and physiological disorder of paprika in summer hydroponics. Treatments were composed of air humidity of control (over 90%) and dehumidification (low 90%) and water content of 80% and 50%. Time domain reflectometry (TDR) sensors and dehumidifier were used in a drip irrigation system and control system of air humidity, respectively. The early growth of paprika was not affected by air humidity but increased by high water content (80%) of medium. Mean fruit weight was reduced at high air humidity and low water content (50%) of medium, but the fruit number per plant and yield were increased at low air humidity. The incidence of brown fruit stem increased with increasing air humidity and water content of medium. Rate of blossom end rot increased in the low water content medium compared with the high water content medium. The nitrogen (N) was higher content in brown fruit stem than normal stem, but calcium (Ca) was lower.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2001.04b
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• pp.71-72
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• 2001

최근 수출오이의 재배 면적이 계속증가 추세에 있어 '99년 현재 143ha에 달하고 있다. 그러나 수출오이는 국내 오이와 재배방법이 상당히 달라 국내 오이는 주지착과형이지만 수출오이는 측지착과형으로 측지의 발생여부에 따라 수확량의 차이가 심하다. 따라서 수출오이의 성공여부는 측지발생을 어느정도 시키느냐에 달려 있다고 해도 과언이 아니다. 그런데 수출오이의 재배시기는 우리나라에서 재배환경이 가장 불량한 겨울철(10-2월)로, 저온 및 투광량 부족 등으로 인하여 측지발생율이 매우 저조하다. 따라서 본 시험은 수출오이의 측지 발생율을 높이고자 지중가온기 설치 여부에 따른 효과를 구명하고자 실시하였다. 그 결과, 생육(Table 1)은 접수의 줄기 직경이 지중가온 처리시 10.22mm로, 무가온의 8.64mm보다 굵었고, 엽장과 엽폭에 있어서도 지중가온 처리가 무가온 처리보다 좋았다. 곡과 발생수에 있어서도 지중가온 처리는 주당 0.73개가 발생하였으나, 무가온은 1.26개가 발생되어 지중가온 처리시 무가온에 비해서 생육이 좋아지고, 곡과 발생이 적었다. 주당 측지발생수(Table 2)는 지중가온구가 13.7개였고, 무가온구는 11.7개로 지중가온을 하면 측지발생수가 증가함을 알수 있었다. 또한 상품수확과수에 있어서도 지중가온구는 주당 45개인데 반해 지중무가온구는 38개였으며 따라서 전체적인 수량이 10a당 8,100kg으로, 무가온구의 6,840kg보다 18%의 증수효과가 있었다. 따라서 수출오이재배시 지중가온을 하면, 측지발생수가 증가하고 특히 장측지(Fig. 1)가 다수 발생하여 측지 수확과수가 증가하며, 곡과 등 기형과 발생이 감소하여 상품수량이 증가되므로써 기존 지중 무가온 재배에 비해 14% 소득향상 효과를 기대할 수 있다.시 생장이 둔화되었다. 밀폐시킨 삼각플라스크에서 자라는 Cell은 상태도 좋지 않고 전반적인 증식량도 적었다. Cell은 환기정도에 민감한 것으로 판단되며 삼각플라스크에서 약 35일 정도의 생장 주기를 가지는 것으로 사료된다. 배양 3주까지는 플라스틱 뚜껑으로 밀폐시킨 bottle에서 가장 많은 체세포배를 얻었다. Air filter를 달아 2일 마다 신선한 공기를 넣어 주었을 때는 배의 발달이 많이 늦어져 배양 3주째에 다른 처리보다 배의 수가 훨씬 적었다. 체세포배가 발달하는 동안에는 산소를 많이 요구하지 않으나 성숙하는 동안에는 산소를 많이 요구하는 것으로 생각된다.적인 것으로 나타났다. 다만, 곡선형은 물론 직선형에서도 열교환 튜브의 배치밀도, 튜브 길이 및 두께 등의 변화에 따른 최적화 연구가 수반되어야 할 것으로 판단된다.에서 제공된 API는 객체기반 제작/편집 도구에 응용되어 다양한 멀티미디어 컨텐츠 제작에 사용되었다.x factorization (NMF), generative topographic mapping (GTM)의 구조와 학습 및 추론알고리즘을소개하고 이를 DNA칩 데이터 분석 평가 대회인 CAMDA-2000과 CAMDA-2001에서 사용된cancer diagnosis 문제와 gene-drug dependency analysis 문제에 적용한 결과를 살펴본다.0$\mu$M이 적당하며, 초기배발달을 유기할 때의 효과적인 cysteamine의 농도는 25~50$\mu$M인 것으로 판단된다.N)A(N)/N을 제시하였다(A(N)=N에 대한 A값). 위의 실험식을 사용하여 헝가리산 Zempleni 시료(15%$S_{XRD}$)의 기본입자분포로부터 %$S_{XRD}

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.6
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• pp.387-394
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• 2002

This study was conducted to compare an econamical efficiency of a recommended rate of fertilizer with the criterion of the sustainable agriculture direct income support system(SADISS). Red pepper was cultivated with different fertilizer application levels of the standard amount of fertilizer for red pepper(SAFR), fertilizer recommended by soil testing for red pepper(FRST) and decrement of 20, 40, 60 and 80 percent of fertilizer recommended by soil testing for red pepper(DFRST 20, 40, 60, 80) and that of farmer's habitual practies fertilization (FHPF). The changes by different levels of applied fertilizer was compared with those of SADISS. The results were summirized as follows: No yield difference was found among the FHPF, SAFR, FRST and DFRST20, but yield decrease in FRST40, 60 and 80. T-N, $P_2O_5$ and $K_2O$ in FHPF were 24, 9 and 53 percent respectively, and it were the lowest ones among the treatments. Fertilizer efficiency of red pepper was decreased with application rate of fertilizer. Fertilization ratio of N and P in DFRST(40, 60, 80 percent) was not sufficiency for red pepper. Economical efficiency of FRST and DFRST20 showed sufficiently in comparison with FHPF. Therefore, it could be possible that FRST and DFRST20 were recommended as methods for SADISS in red pepper cultivation.

• Journal of Bio-Environment Control
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• v.5 no.1
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• pp.50-56
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• 1996

This experiment was carried out to investigate the effects of new material, bioceramic powder in the nutrient solution(0.02%) and foliar spray(0.2%) on the growth and fruit quality of aeroponically grown tomato(Lycopersicon esculentum MILL. cv. Seokwang). Plant height was lowered, but root growth was increased both treatment of bioceramic powder into the nutrient solution and foliar spray. Cluster growth of tomato plants increased up to 14% over than that of control in the plot of foliar spray with bioceramic powder. Total plant dry weight also increased when bioceramic powder was treated both into the nutrient solution and foliar spray. T/R ratio was reduced by the treatment of bioceramic powder, but NAR and RGR showed the highest in the plot of foliar spray treated with 0.2% bioceramic powder than that of the other plots. Cumulative fruit fresh and dry weight were reduced when bioceramic powder was treated into nutrient solution but foliar spray produced more cumulative fruit fresh and dry weight than that of control. It was shown that treatment of bioceramic powder into the nutrient solution and foliar spray could be improved sugar degree without reducing fruit yields.

• Horticultural Science & Technology
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• v.32 no.1
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• pp.41-45
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• 2014

This study was conducted to investigate the effects of crown numbers on growth and yield of ever-bearing strawberry (Fragaria ${\times}$ ananassa Duch.) 'Goha' cultivar. Strawberry seedlings were planted with $55{\times}30cm$ distance on April 29, and the randomized block experimental was designed by putting the crown numbers by 1, 3, 5 and crown-unremoved as the control. At the early growth stage, as the numbers of crown decreased, the size of leaf became larger and inflorescence diameter became thicker. Plant height became higher as the number of crown increased at the final harvesting time. Fresh weight of crown-unremoved plants was 118 g, showing 77.2 g higher than that of plants with one crown. Numbers of the developed inflorescence of plants with five crowns and crown-unremoved was 20.1, whereas 6.8 of plants with one crown, resulted in 13.3 more crowns. However, crown number did not significantly affect the fruit quality. As the crown number increased, the average fruit weight was lighter and the marketable fruit rate was shown to decrease significantly. The marketable yield of crown-unremoved plants was $17,372kg{\cdot}ha^{-1}$, showing 68% higher than plants with one crown. Therefore, crown management without thinning crowns was recommended and inflorescence thickness less than 3 mm should be removed for successful production of ever-bearing strawberry 'Goha' cultivar during summer season.