• Proceedings of the Korea Water Resources Association Conference
• /
• 2008.05a
• /
• pp.1174-1177
• /
• 2008

이상기후기간동안 유역의 수문 변화는 강수변화와 기온변화 등 복합적인 상관관계에 의하여 나타난다. 우리나라 지역의 최근 강수변화는 연 강수량의 증가 추세를 보이나 기온 또한 상승하므로 강수효율의 연변화, 월변화 및 지역 변화특성의 분석이 필요하다. 본 연구에서는 강수변화와 기온변화의 상관관계로 나타나는 월강수량을 월 증발량으로 나눈 P-E비 즉 강수효율을 분석하였다. 이상기후기간과 평년에 대한 강수효율 분석 결과 강수량의 영향이 지배적이고 기온이 강수효율에 미치는 영향은 미미하다 하겠다. 일반적으로 연 강수효율은 엘리뇨>평년>라니냐기간 순으로 나타난다. 이러한 일반적 특성과 달리 도시화된 서울과 인천지역의 연강수효율은 기후에 따른 차이를 발견할 수 없으나 연 강수효율과 달리 월 강수효율변화는 매우 큼을 보였다. 고도 200m 이상인 점과 섬이라는 지역 특성으로 인하여 울릉도는 평년>라니냐>엘리뇨라는 타 지역과 상반된 강수효율 분포를 보였다. 남부지역으로 갈수록 엘리뇨해의 강수효율이 높은 것으로 보아 엘리뇨의 영향을 더 많이 받는 지역은 북부지역 보다는 남부지역 이라는 것을 알 수 있다. 엘니뇨해의 7, 8월의 강수효율이 높게 나타났으며 이는 엘니뇨해의 7, 8월의 강수량이 많다는 것을 의미한다. 또한 엘리뇨 기간 9, 10월 강수 효율은 평년에 비하여 낮게 나타났다. 라니냐해의 강수효율 분포를 살펴보면 6, 9월에 강수효율이 높게 나타났으며 11, 12월 강수효율이 평년에 비하여 낮게 나타났다. 서울, 강릉, 울릉, 부산, 광주, 여수, 제주지역의 강수효율이 타 지역에 비해 높게 나타났다. 서울, 부산, 광주 지역은 고도의 도시화로 인해, 강릉, 울릉도, 여수, 제주 지역은 해양과 인접한 지형적 특성 때문이라 판단된다. 강수효율 또한 강수량이 집중되는 5월부터 8월까지 증가하는 것으로 나타났다. 나머지 달은 대부분 감소하는 것으로 분석되었다.

• Journal of the Korea Institute of Building Construction
• /
• v.12 no.3
• /
• pp.284-290
• /
• 2012

Cement Fineness Modulus (CFM) is a method of expressing the distribution of particle sizes of cement in numeric form. If CFM is controlled through crush process of cement without modifying the chemical components or mineral composition of cement, it is judged to be able to produce a cement satisfying various requirements because it is estimated to enable various approaches to cement such as high early strength, moderate heat, low heat cement and so on. Therefore, in this study, as basic research for manufacturing special cement utilizing the controls of CFM, the intention was to review the impacts of CFM on the fundamental properties of concrete. To summarize the result, as mixture characteristics of fresh concrete, ratio of small aggregate and unit quantity were gradually increased, securing greater fluidity, with an increase in CFM, while the amount of AE and SP were reduced gradually. In addition, setting time was delayed as CFM increased. Furthermore, compression strength was relatively high during initial aging as CFM became smaller, but as time passed, compression strength became smaller, and it showed the same level of strength as aging time passed about three years.

• Journal of the Korea Convergence Society
• /
• v.9 no.7
• /
• pp.63-68
• /
• 2018

Research on smart farms centering on greenhouse cultivation is actively under way due to the decrease in agriculture population and aging, but in the case of vegetables such as vegetables, outdoor cultivation is 70%. Therefore, there is a need to improve productivity and prevent soil contamination by automating, cultivating, and intelligentizing the outdoor cultivation of agriculture crops. In this paper, we show the case of establishing a outdoor production system using the Internet of things and define the environmental variables in the outdoor production system. By measuring soil temperature, water content, electrical conductivity and acidity through sensors, LoRa communication module transmits the information to the outdoor production system. The outdoor production system controls the amount of fertilizer and the volume of water based on this sensor data. We have developed a system that manages a wide range of crops using LoRa technology, which is a suitable communication method for cultivating crops, and manages production volume and sales performance.

• Journal of Bio-Environment Control
• /
• v.19 no.4
• /
• pp.372-376
• /
• 2010

In recent years, the bagging cultivation of summer squash (Cucurbita moschata) is applied for surface protection during harvest and extension of storage period. In this study, the effect of plastic bagging cultivation of summer squash on improvement of quality and extension of storage period was investigated. The yield and the length of fruit didn't have no difference between bagging and control treatment but the bagging treatment significantly made more regular size and light weight of fruits, and increased the number of fruits because of the limitation of their growth. The bagging treatment decreased weight loss and fruit softening during the their storage. Therefore it showed effective means for quality improvement and storage extension of summer squash.

• Applied Biological Chemistry
• /
• v.6
• /
• pp.45-50
• /
• 1965

To confirm the increase effect of $MNH_4$ which has been compounded as a result of two years' potted rice experiments, we have established simple experiment areas in the paddy field of Kyung-Puk, Kyung-Nam and Chon-Puk Provinces and have done the completely randomized design experiments with the following results. 1. Comparison of the gross weight of the harvested rice (Straw included) : The $MNH_4$ 1-area has produced 10-28% more harvest than that of control-area. 2. Comparison of the weight of the Unpolished Rice: The $MNH_4$ 1-area has shown 10-23% increase compared with the control-area. 3. In the comparison of the nutrients of the rice from the $MNH_4-area$ with those of the rice from the control area, $MNH_4-area$ showed increase of $N_2$, $P_{2}O_5$ and $SiO_2$ but a slight decrease of $K_2O$.

• Korean journal of applied entomology
• /
• v.17 no.1 s.34
• /
• pp.49-51
• /
• 1978

The 'take-all' disease of wheat was first reported in Korea in 1947. Ophiobolnis graunis was isolated again from wheat and barley in 1976 and 1977. In 1977, perithecia of Ophiobolus were found on stems of rice, wheat and corn. Perithecia were formed on recommend varieties of wheat in the greenhouse as a result of artificial inoculation of mycelia into the soil. During 1977, Take-all of wheat and barley was quite severe. The result of survey made during this showed about 5 percent that the disease was present in Suweon, Daejeon, Yesan and Yongin. The Take-all infection causes remarkable decrease in the average weight of the grain, followed by a reduction in the number of tillers per plant and amount of gram per ear.

• Journal of the Korea Institute of Building Construction
• /
• v.17 no.1
• /
• pp.55-61
• /
• 2017

This paper is to investigate experimentally the effect of substitution of recycled coarse aggregate(RCA) under 13mm on the engineering properties of the concrete using gap graded coarse aggregates. Concretes with 0.4 of water to cement ratio(W/C) were fabricated to achieve 30MPa of design strength with coarse aggregate over 13mm in size with the maximum size of 25mm. RCA was substituted for coarse aggregate over 13mm from 10% to 50% and crushed coarse aggregate under 13mm was also substituted for coarse aggregate over 13mm from 20% to 40%, respectively. Test results indicated that the replacement of RCA up to 20% resulted in an increase of fluidity and strength. It also caused a decrease in the drying shrinkage due to dense packing effect by achieving continuous grading of mixed aggregates. For practical application of RCA, when properly substituted, the use of RCA enabled the concrete to reduce water contents and sand to aggregate ratio in mixing design stage of the concrete. And, it can also enhance the compressive strength of the concrete.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.28 no.2
• /
• pp.252-257
• /
• 1983

This study was conducted to find out the stalk curing methods that can reduce photobleaching, and shorten the curing period in burley to bacco stalk curing. The results obtained summarized as follows. In the ventilation window-plot, the temperature within the curing house was high and the curing period was shortened, too. The rate of photobleached leaves of whole plant stalk curing-plot was higher than those of any other plots. In the ventilation window-plot, the labor of operating the curing house was saved and the yield and visual quality of cured leaves were high, too. For reducing the photobleaching of leaves, following procedures are desirable; to prevent the lower leaves from drying up and overripening at maturing stage, cut the stalk after first or second priming, shorten the curing period as possible when the 80% of leaf bodies changed brown.

• Research in Plant Disease
• /
• v.9 no.1
• /
• pp.52-56
• /
• 2003

It was conducted to investigate the effect of rice downy mildew (RDM) infection to plant growth and yield components in water seeding stage, and to screen of varietal resistance to downy mildew. Being infected by rice downy mildew, chlorotic spot appeared in the leaf and leaf length was shortened. As the infected rice was growing, internode was not elongated properly and was deformed, and then panicle was not arised or mal-formed. Plant height of infected rice was shortened at all growth stage, and while the number of tillers of infected rice was more decreased than that of healthy plant before maximum tillering stage, and that of infected rice was more increased after heading stage. While the number of internode of infected tiller was much increased than that of healthy tiller internode length of infected tiller was shorter. As the rice infected by RDM severely, the number of panicles per square meter and ripening of rice was more decreased and yield of rice was extremely much decreased. As result of the varietal resistance screening with rice seedling, Geyh-wabyeo and Donjinbyeo were resistant varieties to downy mildew.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.21 no.2
• /
• pp.258-268
• /
• 1976

This study was conducted in order to know the ecology and to establish the control method of Potamogeton distinctus A. BENN. The tubers of Bog pond weed was almostly located at soil depth of 10 cm to 20cm, germination rates and number of formed tubers were different according to transplanting depth of soil. Effects of herbicides application on weeds were different according to leaf-stage of pondweed, and the pondweed were withered to death by absorption of Avirosan into the leaves. It was suitable to keep water depth at 3cm level until about a week after Avirosan application.