先天性 心疾患의 診療

琴東爀 최신의학사 1976 最新醫學 Vol.19 No.10

태양에너지를 이용한 곡물건조시스템의 시뮬레이션에 관한 연구

금동혁,전용운 ( Dong Hyuk Keum,Yong Woon Jeon ) 한국농업기계학회 1979 바이오시스템공학 Vol.4 No.2

태양열을 이용한 곡물건조에 관한 연구

금동혁,고학균,최재갑 ( Dong Hyeug Kum,Hak Kyun Koh,Jae Kap Choi ) 한국농업기계학회 1978 바이오시스템공학 Vol.3 No.1

小兒期의 胃粘膜脫垂

琴東爀,金英嫄,趙明來,金潗 金原出版 1969 小兒科 Vol.10 No.2

ArcGIS Model Builder를 이용한 토양유실 우선관리 지역 선정 자동화 모형 개발

금동혁,최재완,김익재,공동수,류지철,강현우,임경재,Kum, Dong-Hyuk,Choi, Jae-Wan,Kim, Ik-Jae,Kong, Dong-Soo,Ryu, Ji-Chul,Kang, Hyun-Woo,Lim, Kyoung-Jae 한국농공학회 2011 한국농공학회논문집 Vol.53 No.1

Due to increased human activities and intensive rainfall events in a watershed, soil erosion and sediment transport have been hot issues in many areas of the world. To evaluate soil erosion problems spatially and temporarily, many computer models have been developed and evaluated over the years. However, it would not be reasonable to apply the model to a watershed if topography and environment are different to some degrees. Also, source codes of these models are not always public for modification. The ArcGIS model builder provides ease-of-use interface to develop model by linking several processes and input/output data together. In addition, it would be much easier to modify/enhance the model developed by others. Thus, simple model was developed to decide soil erosion hot spot areas using ArcGIS model builder tool in this study. This tool was applied to a watershed to evaluate model performance. It was found that sediment yield was estimated to be 13.7 ton/ha/yr at the most severe soil erosion hot spot area in the study watershed. As shown in this study, the ArcGIS model builder is an efficient tool to develop simple models without professional programming abilities. The model, developed in this study, is available at http://www.EnvSys.co.kr/~sateec/toolbox for free download. This tool can be easily modified for further enhancement with simple operations within ArcGIS model builder interface. Although very simple soil erosion and sediment yield were developed using model builder and applied to study watershed for soil erosion hot spot area in this study. The approaches shown in this study provides insights for model development and code sharing for the researchers in the related areas.

벼의 常溫通風 乾燥特性

琴東赫 成均館大學校 1980 論文集 Vol.28 No.-

Low-temperature drying systems have been extensively used for drying cereal grains such as shelled corn and wheat. However, little reseach on rough rice drying has been done in this area, especially very little in Korea. In designing a low temperature drying system, quality loss, airflow requirements, fan power and energy requirements should be throughly studied. The factors affecting low temperature drying systems are airflow rate, initial moisture content, the amount of heat to drying air, fan operation methods and the weather conditions. The major objectives of this study were to analyze the effects of the performance factors on drying charactaristics of rough rice, Three hourly observations based on the 9-year weather data in Chuncheon area were used to simulate rough rice drying. The results can be summarized as follows: 1. The moisture differential, top to bed layer of grain, was a minimum when airflow rate was high and the air temperature was low, and was larger for the intermittent fan operation ad compared with continuous fan operation. 2. Equilibrium moisture content was found to be greatly depentent upon the variability of weather, the amount of heat added to drying air, and the fan operation methods, but indepenent upon airflow rate. Time requred to dry bed layer to equilibrium moisture content was constan, approximately 14 to 15 days, regardless of the amount of heat added. fan operation methods, and initial moisture content. 3. Equilbririum moisture content was 13.7 percent wet basis for the continuous fan operation and 12.4 percent we basis for the intermittent fan operation respectively with no heat add, therfore it may be considered that the drying potential of natural air for October was high and the weather conditions was satisfactory for natural air drying of rough rice. 4. Average moisture content when top layer was dried to 15 percent wet basis ranged from 14.1 to 14.4 percent wet basis for the continuous fan operation and from 13.2 to 13.5 percent wet basis for the intermittent fan operation respectively with no heat add. 5. Drymatter loss was the highest in the top layer of grain which dried last. Drymatter loss increased greatly during drying to 16 percent wet basis and then very slowly and was approximately constant after drying to 15 percent wet basis. That means grain deterioration may not occurred below 15 or 16 percent moisture. Therefore, in natural air and low temperature drying stsyem, one of the most important factors was the grain deterioration during drying top layer to 15 or 16 percent wet basis. 6. Doubled airflow rate reduced required drying time by about 33 to 50 percent, heat added (1.1 to 2.8℃)reduced by about 20 to 60 percent, and 2 percent increase in initial moisture content in the range of 18 to 24 moisture increased by about 17 to 30 percent, regardless of the fan operation methods. 7. The intermittent fan operation showed 30 to 40 percent decrease in required drying time as compared with the continuous fan operation. 8. Drymatter loss decrease ranged from 38 to 45 percent approximately each time the airflow rate was doubled, from 15 to 25 percent approximately for the heat added to drying air ranging from 1 to 2.8 degrees, and increase from 50 to 60 percent approximately for each two percent increase in initial moisture content in the range of 18 to 24 percent wet basis. 9. Drying time and drymatter loss may have a two-fold change as a result of weather conditions in different year. These facts was not caused by the air temperature differences, but the relative humidity differences.

원형빈을 이용한 벼의 누적혼합 상온통풍건조에 관한 연구

금동혁,박춘우 성균관대학교 생명과학자원연구소 1997 生命資源科學硏究 Vol.4 No.2

This study was performed to determine natural air drying characteristics of rough rice in a round steel bin of 300 tons capacity. Drying test was conducted at Rice Processing Complex in Jincheon. The bin was filled with rough rice every day and mixing by stirring device. Moisture contents, grain temperatures, grain quality, airflow rate, electrical energy consumpsions, fan power, ambient air temperatures, and relative humidities were measured during experimental period. The results were as follows; 1. Total weight of paddy rice filled the bin was 164 tons during experimental period. Daily maximum amount of input paddy rice was 21 tons, and daily average amount was 7 tons. 2. Initial crack ratio ranged from 4% to 7% for paddy rice above 22% in moisture content, 7% to 18% for below 20% in moisture content. 3. Average ambient air temperature and relative humidity was 10.2℃ and 67% respectively. Equilibrium moisture content for average weather conditions was 14.7% in wet basis. 4. Plenum air temperature was 2.2℃ above ambient air temperature. This temperature rise reduced relative humidity by about 7% point. Equilibrium moisture content for these plenum air conditions was 13.3% in wet basis. 5. Grain temperature was 12.0℃ in unmixed grain layer, 7.1℃ in mixed grain layer. Temperature of grain in unmixed layer was nearly equal to plenum air temperature, and in mixed layer was about 5℃ below plenum air temperature. 6. Moisture content of paddy rice in bottom(unmixed) layer was decreased to below 15% in wet basis 6 days after start of drying and fluctuated between 13% and 16.2% according to weather conditions, and reached 13.9% at the end of drying process. Moisture content in mixing layer was decreased to below 16% in wet basis 10 days after drying and reached 15.2% at the end of drying. 7. Moisture content of grain in unmixed layer was slightly higher value in center and north part of bin, and same level in another part. Standard deviation of moisture content distribution in unmixed grain layer was 0.81% in wet basis. It appeared that grains in mixed layer were mixed and dried uniformly considering 0.5% in standard deviation of moisture content. 8. Drying rate showed maximum value of 0.28 %,w.b./hr early in the drying period and then decreased to 0.023%,w.b./hr with increased grain depth and lowered moisture of input grain. Adsorption occured during the late period of drying, and thus drying rate showed minus value. 9. Crack ratio of rice in unmixed layer after drying was 6.6% that was 1.4% point higher than that of sample in laboratory test, and in mixed layer was 7.9% that was 0.4% lower than that of sample. 10. Total energy required for removing one kilogram water was 2,771 kJ. Energy for operating fan was 92.8% and for stirring device was 7.2% of total energy.

小兒期의 心不全

琴東爀 金原出版 1979 小兒科 Vol.20 No.9

短粒種벼의 吸濕平衡含水率

琴東赫,鄭春植,朴勝濟 成均館大學校 科學技術硏究所 1987 論文集 Vol.38 No.1

Adsorption equilibrium moisture content for short grain rough rice of Akihikari variety were determined at 20, 30, 40 and 50℃ and relative humidities ;ranging from 46.3 to 90.9 percent. A static method of equilibrium was used by suspending 16g of samples in jars with different saturated salt solutions. Triplicated samples were used for all trials. A new quadratic equation was proposed to correlate the EMC data and compared with Henderson, Chung-Pfost, and Day-Nelson equations. The goodness of fit of each equation was evaluated by determining the "Error Mean Square(EMS)". Quadratic equation gave the smallest EMS value followed by the Henderson equation.

시뮬레이션에 의한 循環式 穀物乾燥機의 性態分析

琴東赫,韓宗昊 成均館大學校 科學技術硏究所 1986 論文集 Vol.37 No.1

This study was performed to develop a simulation model for rice circulating dryer and to analyze the effect of the performance factors on the energy consumption, drying rate and crack ratio by using the developed model. The results obtained are summarized as follows. 1. Simulation model for rice circulating dryer was developed and validated by comparison with experimental results. The developed model was found suitable for predicting grain moisture content during drying process. 2. Drying rate was increased by increasing the layer thickness(0.1∼0.5m). Fuel energy was decreased and electric energy was increased as the layer thickness increased. Therefore, the total energy can be reduced by increasing the layer thickness. 3. Drying rate was increased with the increased grain flow rate. The fuel energy and the electric energy were decreased with the increased grain flow rate. Therefore, the energy consumption can be reduced by decreasing the grain flow rate(5㎥/hr) used in the current continuous flow rice dryer. 4. Energy consumption was increased rapidly with the increased airflow rate, but its effect on the drying rate was much less. 5. The effect of the drying air temperature on the energy consumption varied with the ambient air conditions. If rough rice was dried at nighttime of late in September and early in October, the total energy consumption was decreased by increasing the drying air temperature. But in the daytime, the total energy consumption was jncreased by increasing the drying air temperature up to 40℃. 6. When maximum drying rate regarded as 1.5% w. b. /hr, considering rough rice damage, drying air temperature could be increased up to 60℃. Drying process carried at this temperature was the best operating condition in view of energy consumption. 7. About 15% of drying energy consumption could be reduced operating in the daytime rather than in the nighttime in case of the ambient air conditions at Suwon region.