간단(簡單)한 교시용(敎示用) 수리실험장치(水理實驗裝置)에 관(關)한 연구(硏究)

유한열 한국농공학회 1965 韓國農工學會誌 : 전원과 자원 Vol.7 No.2

Some simple devices to demonstrate important hydraulic principles to students are necessitated in fluid mechanics or hydraulics classes. These devices should be easy to make and operate with inexpensive cost. The writer has studied some simple demonstrh-ation apparatus of hydraulic principles which were made with cheap materials. The purpose of this paper is to present the results of the study. In this paper, hydraulic principles that can be demonstrated by using these apparatus are described, the plans of them are presented, and how to make them and what materials to be used are briefly explained. An axial-flow fan is a device with which the flow of air is supplied for several purposes. It consists of a duct, a fan and a guide vane. It may be possible to demonstrate the principles of propeller, drag force, lift, etc.

傾斜度및 傾斜長이 土壤侵蝕에 미치는 影響에 關한 硏究

朴成宇,劉漢烈 서울大學校 農科大學 1977 서울대농학연구지 Vol.2 No.1

When it comes to reclaiming slopy upland, there should be prepared any facilities and agronomical management systems appropriate enough to protect soil erosion phenomena that are accelarated by the reclamation. The controlling factors for soil erosion are considered as agronnomical management and engineering construction. All the phenomena of soil erosion chiefly consisting of soil detachment, transportation, and sedimentation by raindrop and surface runoff, etc. are varied with so indescribably compricating parameters that they are supposedly natural and consequently uncontrolled events for a long time. Through worldwise enormous experiments for nearly a century, they are under mathematical description. The results are so-called Universal Soil Loss Equation. We have not evaluated the feasibility of the Equation. With our facing impending problems concened with the related undergoing project throughout the Republic, however, the Equation is greatly wanted to be modfied for suitable application through evaluation of each parameter. This study is primarily conducted for the purpose: especially concerned with modification of slop-length factor(??) in the Equation. There being difference between the tested plots and the standard plot described in the Equation, the results would not be fit enough to estimate the direct effects of slope-length parameter on soil loss. Some descriptive results are delivered here between variation of slope-length and corresponding soil loss. The observed soil erosion quantity is about three times more than the calculated value using the established Taneta's ??-values. Such the results imply Taneta's ??-valuefuction may have some restriction applying for the ?? value of the Equation in the Republic.

윤환관개방법과 적정시설 연구

유한열 한국농공학회 1971 한국농공학회논문집 Vol.13 No.1

본 실험은 공시품종 농림6호를 택하였다. 이앙일은 6월14일이었으며 착공일은 6월20일이었고 총 관개일수는 110일이었다. 식재밀도는 $21cm{\times}21cm$로서 각 시험구의 크기는 $9.9m^2$(3평)이며 평당 70주를 심었다. 시험포토양은 Loam으로 화하적인 성분은 표-3과 같다. 물은 상류에 있는 서호저수지에서 흘러나오는 것을 양수해서 사용하였으므로 서호의 수질과 같았다. 총 관개일수 110일중 54일에 걸쳐 분산하여 비가 내렸으므로 수도재배의 성적에는 비교적 큰 영향을 미친 것 같다. 수도의 생육기간중 소비수량을 조사하고저 삼투량측정기, 감수심측정기, 라이시미터를 설치하였으며 조사한 결과 삼투량은 평균 14mm/day로 나타났다. 이 실험을 통하여 용수량을 적절한 때에 알맞게 공급함으로써 증수의 효과를 기대하였고 또 용수량의 절약을 꾀하고져 적정한 관개방법을 얻고져 하였다. 실험결과를 요약하면 다음과 같다. 1. 윤환관개구의 수량은 상시담수한 관개구 보다 증수효과를 보았다. 즉 8일 관개구는 보통구의 14.4% 증수되었고 상시 담수관개구(1일관개구)에 비해서는 27%의 효과가 있었다. 그러나 이것은 금년과 같은 호 조건의 강우에 힘입은 것이 아닌가 생각된다. 2. 관개용수에 있어서는 보통구에 대해서 밑다짐 9cm구와 비닐무공구는 약 52%의 용수량절약을 이루었고 8일 관개구와의 비교에서는 약 44%의 용수절약을 얻었다. 상시 담수구는 작물생육에도 악영향을 미쳐서 성장률도 좋지 않았으며 물의 소비량도 많음을 보았다. 3. 보통구에 대한 소비수량을 조사하여 보면 가장 많은 기간이 수잉기, 출수기에 있었고 그 이후는 감소현상을 나타냈다. 4. 계속 관개구(비닐처리구)는 다른 시험구에 비하여 5일 앞서 출수하였다. 5. 윤환관개구는 상시관개구에 비하여 출수가 늦은 현상이 나타났다.年)보다 많었고 또 평균온도(平均溫度)가 다소(多少) 낮었기 때문에 유의성(有意性)은 인정(認定)할 수 없었다. (5) 비닐처리구(處理區)는 용수(用水)의 절약(節約)은 컸으나 기타(其他) 요소(要素)에 있어서는 유의성(有意性)을 인정(認定)하지 못하였다. (6) 관개용수량(灌漑用水量)에 있어서는 전관개일수(全灌漑日數) 102일중(日中) 강우일수(降雨日數) 54일(日)을 제(除)한 나머지 실지(實地)로 관개(灌漑)한 48일(日)에 있어서 밑다짐 9cm 구(區)와 비닐무공구(無孔區)가 243.3mm의 관개용수량(灌漑用水量)으로 족(足)하였으며 67%의 용수절약(用水節約)을 보았고 기타(其他)는 그림 15에서 보는 바와 같은 용수절약(用水節約)을 인정(認定)하였다. (7) 침투량(浸透量)은 $40{\sim}30mm/day$였든 것이 비닐지수벽(止水壁)을 설치(設置)한 구(區)에서는 10mm 정도(程度) 감소(減少)됨을 알 수 있다. (8) 생육상태(生育狀態)가 양호(良好)하며 일반(一般) 상시(常時) 담수구(水區)와 같은 병해(病害)나 도복(倒伏) 현상(現狀)은 발견(發見)되지 않았다. (8) 용배수조직(用排水組織)이 완비(完備)되고 각구(各區)마다 급수관(給水管)이 개별(個別)로 설치(設置)되어야 절수(節水)도 되고 답내(畓內)의 수온(水溫)도 상승(上昇)함을 알았다.rghum식물(植物)의 환경온도(環境溫度)를 달리 하였을 때 NEL가치(價値)는 각각(各各) 4.87MJ($30/25^{\circ}C$), 5.46MJ($25/20^{\circ}C$) 및 5.81MJ/kg($18/8^{\circ}C$)로 변(變)하여 고온(高溫)에서 net energy lactation 축적(蓄積)이 크게 감소(減少)되었다.다. 그러나 기온(氣溫)이 낮은 조건(條件) In this research, Nong-rim No. 6 was adopted as a test variety of rice. Rice seedlings were transplanted on June 14, 1970. Roots were settled into soil on June 20 and a total number of days irrigated of $21cm{\times}21cm$ and an area of $9.9m^2$ for a test plot were accepted, planting 70 stumps of rice in a test plot. The soil in test plots are classified by soil test as oam, and its chemical contents are as shown in Table 3. Irrigation water was secured by pumping from the Sudun stream that originates at the Suho reservoir. Accordingly, the qualities of irrigation. water are considered to be the same as those of water stored in the Suho reservoir. There were 54 days of intermittent rainfalls in total during the whole 110-day period of irrigation. As a result, it is likely that the growth of rice plants was influenced by rainfall at a comparatively great degree. In order to measure the amounts of water consumption, infiltrometers, measuring devices for the decreases of water depths and lycimeters were provided. As a result of measurements, an average daily rate of infiltration was observed to be 14mm/day. It is expected from this research that the effect of increased yield will be secured by supplying optimum amounts of water for irrigation on proper times, and that the amounts of water consumption for irrigation can be saved by applying suitable irrigation methods. The test results obtained are summarized as follows: 1. Yields produced in the test plots of continuous irrigation are lower than those in the test plots of rotational irrigation, i.e., yields produced at the test plots irrigatied once in a period of 8 days are higher by 27% in average than those produced at test plots of continuous irrigation. 2. The amounts of irrigation water for test plots, which have a clay layer of 9cm in thickness and vynil diaphragm without holes, are saved by about 52% in comparison with ordinary test plots. 3. Ears are sprouted 5 days earlier at continuous irrigation plots as compared with other test plots. 4. It seems that there are growing stages of rice plants such as those of forming and sprouting of ears, in which the amounts of irrigation water are consumed more in comparison with the other stages. Therefore, it may be possible to increase of decrease the amount of irrigation water, according to the growing stage of rice plant, so as to save irrigation water.

Diesel engine modeling with multi-model correction of manifold pressure for development of control algorithms

유한열,민경한 한국자동차공학회 2015 한국자동차공학회 학술대회 및 전시회 Vol.2015 No.11

한계귀류력 개념에 의한 안전개수로 설계법

유한열 한국농공학회 1973 한국농공학회논문집 Vol.15 No.3

學校組織管理에 있어서의 人間關係 改善 硏究

유한열 성균관대학교 교육대학원 1987 교육논총 Vol.2 No.-

콩크리-트의 산침식(酸侵蝕)

유한열 한국농공학회 1960 韓國農工學會誌 : 전원과 자원 Vol.3 No.1

경사지(傾斜地) 상전(桑田)에 있어서 토양침식방지법(土壤侵蝕防止法)의 비교시험

유한열 ( Han Yeol Ryu ) 한국농공학회 1968 韓國農工學會誌 : 전원과 자원 Vol.10 No.1

The purpose of this experiment is to measure runoffs and soil losses produced in mulberry test plots so as to determine their differences for different planting densities of mulberry saplings. Test plots were prepared on a 22° slope by applying semi-terrasing method as proposed by the Sericulture Experiment Station of the Office of Rural Development. Two planting densities were selected. One was to plant mulberry rows 1. 8 Meters apart and the other was 2.1 meters apart. 1) The following results were obtained through this experiment in the first year. Total runoffs were 92. 39 tons/10a from the 1.8-m plot and 95. 62 ton/10a from the 2.1-m plot, showing a silte difference. Total soil losses were 1.69 tons/10a from the former and 2.33 ton/10a from the latter, showing some difference. 2) Runoff rates are 23% for the 1.8-m plot and 24% for the 2. 1m plot.

전작물(田作物)의 관개법(灌漑法)에 관(關)한 비교연구(比較硏究)(I)

유한열 ( Han Yeol Ryu ),고재군 ( Chae Koon Koh ) 한국농공학회 1969 韓國農工學會誌 : 전원과 자원 Vol.11 No.1

In this experiment furrow and fixed nozzle methods in irrigating chiness cabbages were compared on the grounds of yields and amounts of irrigation water. A simple electric device was used to measure soil moisture contents. As a result, the following items were derived: 1) A slight significance was observed between the yield produced at the furrow irrigation test plot and that at the sprinkler irrigation plot. 2) The ratio of the amount of irrigation water applied at the furrow irrigation plot to that at the sprinkler irrigation plot was approximately 2.7 : 1.

한계소유력(限界掃流力) 개념(槪念)에 의(依)한 안전개수로(安全開水路) 설계법(設計法)

유한열 ( Han Yeol Ryu ),박승우 ( Seung Woo Park ) 한국농공학회 1973 韓國農工學會誌 : 전원과 자원 Vol.15 No.3