• 동력기계공학회지
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• 제9권4호
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• pp.24-30
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• 2005

For a reciprocating compressor of household refrigerators, a direct analogy between the pipe flow network and the electric circuit network has been utilized to set up a mathematical model for oil supply system. Individual lubrication elements of the oil supply system, such as propeller- installed oil cap, oil galleries, radial oil feeding holes, spiral oil grooves, and various sliding surfaces have been analogized by equivalent electric elements, and these have been combined together to form an electric circuit corresponding to the whole oil supply system. By solving the closed network equations of the model, oil flow rates at various lubrication elements could be obtained. Total amount of the oil flow rate drawn into the shaft has been measured and compared reasonably well with the prediction of the numerical simulation.

• 한국농공학회논문집
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• 제54권5호
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• pp.17-24
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• 2012

The main purposes of the agricultural reservoir enlargement (ARE) project are to secure water supply reliability (WSR) for agriculture and to release environmental water during dry seasons. In this study, an operational rule that will simultaneously satisfy both the above issues was developed. Initial amount of water storage at the beginning of non-irrigation season (1st October) was divided into 3 stages, and the target level of water storage at the beginning of irrigation seasons (1st April) was set up. Required operational curves and release amounts were estimated based on the stages and target water levels. To evaluate the applicability of this rule, the amount of water released for environmental purposes and WSRs were analyzed for three reservoirs (Unam, Jangchi and Topjeong). The ratio between annual amount of release and additional amount of water storage were 1.6, 1.85, and 4.1 for the Unam, Jangchi, Tapjeong reservoirs, respectively. Also, the WSRs of all reservoirs were found to become higher than when the design standard was applied. Therefore, it is considered that the proposed rule is more suitable for the enlarged agricultural reservoirs operation as it satisfies the WSRs while securing the environmental water release.

• 한국수자원학회논문집
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• 제31권6호
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• pp.821-832
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• 1998

본 논문에서는 상수도시설을 효율적으로 운영하는 데 필요한 1일 급수량 수요를 예측하는 방식에 대하여 인공지능(Artificial Inteligence)이라 불리는 퍼지 뉴론(fuzzy neuron)을 이용하여 연구하였다. 퍼지뉴론이란 퍼지정보(fuzzy information)를 입력으로 받아들이고 처리하는 퍼지 신경망을 일컫는 말이다. 본 연구에서는 소속함수와 퍼지규칙을 신경망으로 학습하는 기능인 적응식 학습방법을 통하여 1일 급수량을 예측하였으며 연구대상 지역으로는 광주광역시를 선정하였다. 또한 1일 급수량 예측에 있어서 필요한 변수 선택을 위해 입력자료를 상관분석, 자기상관, 부분자기상관, 교차상관 분석 등을 하였으며 동정된 입력변수는 급수량, 평균기온, 급수인구이다. 먼저 급수량, 평균기온, 급수인구로 모델을 구성하였고, 한편으론 기상청의 기후예보자료를 신뢰할 수 없는 경우에는 급수량을 예측할 수 있도록 급수량 자료만으로 모델을 구성하여 그 유효성을 검증하였다. 제안된 모형식은 사고 등의 인위적인 조작(단수 등)이 가해지는 시기를 포함하고도 실측치와 모형의 예측치와의 오차율이 최대 18.46%, 평균2.36% 이내로 나타나, 모형의 결과는 상수도 시설의 운용 및 급·배수관망의 실시간 제어에 많은 도움을 주리라 생각된다.

• 플랜트 저널
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• 제15권3호
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• pp.35-41
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• 2019

본 연구는 석탄 연소에서 우드펠릿 전소 보일러로 설비를 개조하여 실제 운영 중인 125 MW급 영동화력 1호기 보일러를 대상으로 2단 연소용 공기의 공급위치와 비율을 조정하여 NOx 및 CO발생에 미치는 영향을 시험하였다. 2단 연소용 공기량이 상대적으로 증가하면, 연료입도가 작아서 낮은 과잉 공기비(1.10)로 연소할 경우 NOx는 약간 감소하고 CO는 급격히 감소하지만, 연료 입도가 커서 높은 과잉공기비(1.33)로 연소할 경우 NOx는 약간 증가하지만 CO는 거의 영향을 받지 않았다. 또한 2단 연소용 공기량이 같아도 공급위치가 주연소기 상부로 편중될수록 NOx 및 CO 발생 농도는 낮게 나타났으며 과잉 공기비가 높은 경우 2단 연소용 공기량에 무관하게 NOx 및 CO의 발생은 매우 낮은 수준을 유지한다는 것을 알 수 있었다.

• 한국화재소방학회논문지
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• 제24권6호
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• pp.20-27
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• 2010

배연설비는 연기를 배출한 만큼 공기가 유입되도록 계획된다. 이때 유입공기의 속도가 배연에 어떠한 영향을 미치는지를 FDS를 통하여 분석하였다. 그 결과 화재의 위치로부터 급기구가 가까이 설치된 경우 화재 플럼으로 유입되는 기류속도가 빨라져 상승하는 화재 플럼을 흩트려 버리는 현상이 일어남을 발견하였다. 그로인해 배연성능이 저하되어 연기층의 강하가 더욱 빠르게 촉진되었으며 흐트러진 화재 플럼은 연기층을 교란시켜 가시거리를 더욱 나쁘게 하였다. 따라서 공기유입구의 위치는 화재의 위치로부터 충분히 이격된 위치에 설치하여 화재 플럼으로의 유입공기속도를 낮추도록 하여야 배연효율이 좋아진다는 것을 확인하였다.

• 한국농공학회지
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• 제8권2호
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• pp.1193-1199
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• 1966

More stable and higher yields in rice paddy depend mainly upon an adequately balanced supply of water for higher yield. Rice paddy is supplied naturally by rainfall but inevitably requires artificial supplenental irrigation for higher yields. Even though it may be true that the water requirement of rice plants is generally higher than those of other crops, the submerged condition is not necessarily required for rice. The moisture requirements of rice vary according to its growing stages and it is possible to increse the irrigation efficiency by means of lessening the loss due to percolation and evapolation in the field. This experiment was conducted on the effect of the various amount of water supply and different irrigation periods for yield and yield components, and was carried out to find out the most suitable irrigation method and to increase the irrigation efficiency for higher yields in rice paddy. Randomized block design with 3 replications was employed where the 3 levels of the amount of irrigation water; (120% moisture contents), unirrigated (90~100%) and more un irrigated candition (80~90% moisture content), and levels of the various irrigation periods; usual, initial, intermediate and final periods, being treated. The results obtained in this experiment are as follows: 1. As for the physical and chemical and soil properfies, and other characteristics, there are no differences among the treatments enough to be effective for the growth of rice plants. 2. Culm length was measured after harvest as shown in table 2. 3. Difference of the amount of irrigation water did not change the culm length and ear length, however it also indicated more apparent increase in final treatment plots thatn that of usual. 3. No difference in the number of ears and number of ears pers per hill was founded treatments both in the difference of water supply and in the various irrigation periods. 4. There is no difference in the maturing rate and 1000 grains weight. 5. The number of panicles and grains and more increased in 80~100% moisture contents soil than those of 120%. and it shows in un irrigated plots, more irrigated plots and control plots in turn. Other wise according to the period\ulcorner of irrigation the trend is appeared in turn initial, usual, final and intermediate treatments.6. Yield as shown in table 7. 8 was more increased in unirrigated plots(90~IOO% moisture content) than the control plots (120% moisture content) by up to 8.2% and also 3. 2% in more unirrigated plots than that of control by periods is shown: usual plots final, initial, inter mediate treatment plots in turn. 7. The above resutts lead to the conclusion that no remarkable, differences in yields and soil properties are made by the unirrigation. However, it is apparent that this treatment has .some advantages in the points that one could spare the amount of water supply for irrigation with more increase in yield. In addition, a higher temperature and a brisk oxygen supply would be possible throug h this treatments. Accordingly, these treatment would be a more reasonable and economical cultivation method of rice for the better harvest.

• 생물환경조절학회지
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• 제18권2호
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• pp.119-123
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• 2009

토마토의 펄라이트 배지경에서 공급했던 일본원시배양액의 폐양액은 EC는 $1.9{\sim}2.4dS/m$, pH는$5.5{\sim}7.1$의 범위였으며 다량 원소의 농도는 $NH_{4}^+$가 감소하였을 뿐 대부분 공급양액과 큰 차이가 없었다. 토마토 폐양액의 1L 관비시 퇴비시비량의 증가에 따라 토마토의 초장, 경경, 엽장, 엽폭 등 일반생육과 잎의 엽록소 함량이 현저히 좋아지는 경향을 보였으나 2L 관비처리에서는 일정한 경향이 없었다. 토마토 잎의 엽록소 함량은 주당 1L, 퇴비량이 4,000kg/10a 처리구에서 가장 높게 나타났다. 토마토 식물체의 생체중과 건물중도 폐양액의 1L 관비시 퇴비시비량의 증가에 따라 증가하는 경향이었으나 2L에서는 일정하지 않았다. 토마토의 수량도 일반생육과 비슷한 경향으로 관비량과 퇴비량 증가에 따라 증가하는 경향을 보여 관비량 1L, 퇴비량 4,000kg/10a 처리구에서 가장 많았다. 당도는 퇴비량과 관비량에 따른 일정한 경향이 없었으며 관비량 2L, 퇴비량 2,000kg/10a 처리구에서 fructose. glucose 및 총 당함량이 가장 높았다. 그러므로 이상의 결과로 볼 때 폐양액을 이용한 친환경적인 관비재배가 가능하며, 또한 관비재배에서 품질도 보장 할 수 있다고 판단된다.

• 한국지반신소재학회논문집
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• 제13권4호
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• pp.1-10
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• 2014

이 논문에서는 현장모형 실험을 통하여 동결온도에 따른 상수도관의 거동변형특성을 다루었다. 동결 온도 조건에 따라 상수도관에 미치는 동상압력과 Marston-Spangler 이론에 의한 동상 압력은 다소 차이를 나타내는 것을 보이며, Marston-Spangler이론만으로 관에 작용하는 하중을 고려하는 것은 안전측을 벗어날 수도 있다는 것을 염두 해야 한다. 또한 현장모형실험을 통한 상수도관의 변형률은 수치해석결과보다 작은 값을 나타내는 것을 확인하였다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제24권2호
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• pp.23-37
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• 2019

To evaluate the available groundwater supply to the agricultural water demand in the future with the climate change scenarios for 40 sub-regions in Jeju Island, groundwater recharge and the available groundwater supply were estimated using water balance analysis method. Groundwater recharge was calculated by subtracting the actual evapotranspiration and direct runoff from the total amount of water resources and available groundwater supply was set at 43.6% from the ratio of the sustainable groundwater capacity to the groundwater recharge. According to the RCP 4.5 scenario, the available groundwater supply to the agricultural water demand is estimated to be insufficient in 2020 and 2025, especially in the western and eastern regions of the island. However, such a water shortage problem is alleviated in 2030. When applying the RCP 8.5 scenario, available groundwater supply can't meet the water demand over the entire decade.

• 대한한약학회:학술대회논문집
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• 대한한약학회 2007년도 Autumn Conference
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• pp.129-144
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• 2007

In order for stable demand-supply and regularity of distribution, "The regulations for management of demand-supply and distribution of medicinal herbs" were established on 1995. Therefore, the medicinal herbs of good quality have been controled to be distributed in the market. However, to be wide of the purpose, the standardized sound distribution system was caused due to the governmental control on demand-supply to protect domestic farmers who produce the material for medicinal herbs, which results in the over distribution of non-standardized or illegally imported medicinal herbs. In addition, because of the distribution of faulty or poor medicinal herbs, there are chances of affecting bad effects on public health. The standardized medicinal herbs cover 514 different kinds in total, of which 69 products are specified to be standardized in the oriental medicine product companies. Also, in order to protect farmers who produce the materials for medicinal herbs, the amount of imported materials are regulated in normal times. The 14 different materials for medicinal herbs, which are allowed to be imported to a certain amount only when the shortage of goods or sudden rise of prices is to happen, are frequently introduced into domestic market as food not as medical usage, and the origin of those illegally changes to home cropped one for the distribution in the market. In addition, the system of distribution are to be disordered and the condition for the distribution of medicinal herbs of good quality can not be made since they illegally changes the usage of the materials for medicinal herbs from their original one and can not be regulated by the domestic laws.