• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.5661-5668
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• 2012

In the era of water scarcity, saving toilet water is one of the most effective ways to save water. In this study, two-phase flow for the development of highly-efficient toilet has been analysed with VOF(Volume Of Fluid) method. Since the whole model requires extensive computing time, part of the whole model has also been adopted to reduce the analysis time. Four different rim models were considered for flow distribution analysis and sizes of rim holes were found to become more important rather than locations or numbers of rim holes in achieving flow distribution effectively. In addition, velocity and pressure of two-phase flow due to siphon phenomenon have been studied through the analysis of whole model. Therefore, this study provides a variety of fundamental data for the development of highly-efficient toilet.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.6
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• pp.946-953
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• 2012

When water shortage has been getting worse recently, toilet water-saving is one of the most effective way to solve the water shortage. Therefore, in this study, toilet flushing performance was investigated with VOF(Volume Of Fluid) model to obtain the basic design data for the development of high-efficiency toilets. The result showed that the shorter trapway, the longer the flushing duration time. However, the shorter trapway is found to have disadvantage in exhausting dirt due to relatively weak siphon and higher curvature. Since the remaining water in a trapway appears to help siphon, it is also an important factor in developing high-efficiency toilets. Although higher water level in the water tank shows better performance in flushing, lower water level is preferred to save water. Too low water level may cause dirt to clog the trapway due to relatively weak siphon.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.100-100
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• 2018

물 고추냉이는 십자화과의 숙근성 다년생 초본식물로서 일본과 대만 등에서 재배되며 세계 여러 나라에서 식품, 가공원료, 향신료, 의약소재 등으로 이용되고 있다. 우리나라에서는 철원과 무주 등에서 재배되고 있으나 재배환경 및 기술의 한계로 규모와 생산량은 매우 저조한 실정이다. 따라서 본 연구는 물 고추냉이 순환 베드시스템 개발을 위한 기초연구로 수행되었다. 마사토의 높이와 고랑의 유무에 따라 3개 베드 (A-마사토 높이 4.0cm, 고랑 있음, B-마사토 높이 5.5cm, 고랑 있음, C-마사토 높이 7.0cm, 고랑 없음)로 시험하였다. 물 고추냉이의 생장량과 식물체 내의 양분 분석(질소, 인산, 칼륨)을 분석하였다. 그 결과 베드 높이가 가장 낮고(4cm) 고랑이 있는 베드에서 생장량이 가장 우수하였고 마사토 높이가 가장 높은(7cm) 처리구보다 생장량이 2배 이상 증가하였다. 전체적으로 엽장보다 엽폭이 길었고 심장형 잎의 특성을 그대로 나타내었다. 식물체 내의 양분 분석 결과 처리구 별로 질소, 인산, 칼륨의 함량 차이가 크게 나타났다. A 베드에서 질소 4,150, 인산 500, 칼륨 1,500ppm 에 비하여 C 베드는 질소 730, 인산 120, 칼륨 700ppm 정도로 낮았다. 대조구의 동일 지역, 동일 기간의 계류지 하우스재배(데이터 미발표)에 비해 순환식 베드 재배가 우수하였고, 특히 A 베드에서 가장 우수하여 절수, 2단 재배 등의 예상되는 효과를 감안할 때 물 고추냉이 순환식 베드 재배의 가능성이 충분하다고 판단된다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.4
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• pp.59-65
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• 1980

An attempt was made to survey soybean cultivars that were nonsensitive to the photoperiod for selection as possible breeding materials for wide area adaptable varieties. Fifty-five cultivars were subjected to different day length conditions. The number of days from sowing until flowering was shortened under short day length conditions, and late varieties tended to be more sensitive to day length than early varieties. The response to day length of the tested cultivars might be divided into three groups; low, intermediate and high degree, by their accelerated rate of flowering. Especially four varieties in the low responding group, Gembokin, Wirth, Wayne and Pi.54613 were identified to be nonsensitive to day lengths, that is, neutral varieties. They also showed little variation in morphological characteristics under different day length conditions.

• Journal of Korean Society of Forest Science
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• v.26 no.1
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• pp.13-18
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• 1975

This study was intended to clarify interrelations among seven characters of bamboo and their influences upon its culm-volume. The analysis of covariance was used to obtain phenotypic correlations, genotypic correlations and environmental correlations among some characters of Phyllostachys bambusoides Sieb. et Zucc., and thereby path-coefficients were calculated based on Dewey's method. The characters considered here included the breast height diameter, culm-height, clear-length, subterranean stem, number of bamboo joints, butt-end diameter and culm-volume of bamboo. Average values, standard errors, variances and standard deviations for the characters mentioned above are shown in Table 1, and phenotypic correlations, genotypic correlations and environmental correlations among seven characters are shown in Table 2, according to the results, there are highly significant relationships among lines but not among some replications. According to Table 4, heritability values in the breast height and butt-end diameters are higher than those in other characters mentioned above. On the other hand, environmental correlations among general characters appear to have lower values than phenotypic and genotypic correlations do. It also appears that the butt-end diameter and breast height diameter are highly correlated with the culm-volume of bamboo. The path-coefficients of individual characters to the culm-volume of bamboo are computed from the correlations (Table 4) and presented in Figure 1 and Table 5, where it could shown the direct and indirect effects on the bamboo culm-volume of each character.