• Journal of Biosystems Engineering
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• v.30 no.3 s.110
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• pp.155-160
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• 2005

The objective of this research was to establish a domestically available cooling storage technique by cold-air in winter, using winter cool air ventilation fur determining rough rice cooling method in the storage and dry bin. The rough rice storage characteristics of two test conditions, winter cool-air ventilation storage and ambient temperature storage, were evaluated from January to July 2001, using a storage and dry bin of 300-ton capacity. Results of this research are as follows: Grain temperature was from $-5.1\~-8.5^{\circ}C$ after winter cool-air ventilation, and grain initial temperature for ambient temperature bin storage was $0.3\~1.9^{\circ}C$. Moisture content of rough rice decreased from $0.28\;to\;0.93\%$ and from $1.53\;to\;1.92\%$ to compare with original moisture contents for winter cool-air ventilation, and for ambient temperature bin storage, respectively. Broken ratio of brown rice from winter cool-air ventilation bin increased from $0.16\;to\; 0.92\%$, and brown rice broken ratio was from $2.24\;to\;2.86\%$ for ambient temperature bin storage to compare with initial broken ratio. Hardness of stored rice increased along storage period increase in alt storage methods, and cooling bin storage increased rice hardness of 0.271kgf: this increasing was lower then the other methods from 0.059 to 2.239kgf. Germination rates were decreased approximately 9.03, 3.14 and $3.20\%$ for upper, middle, and bottom of ventilating winter air bin, respectively, and germination rates of 2.70, 3.47 and $4.14\%$ were approximately decreased for upper, middle, and bottom parts of ambient temperature bin storage, respectively.

• Journal of Biosystems Engineering
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• v.32 no.1 s.120
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• pp.13-19
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• 2007

Storage rough rice in low temperature using the winter cold air avoids rough rice temperature increase which happens from early May, and this is possible by installing a cooling system in the top of a bin, the room between top rice level and bin ceiling. The research objective is to establish low temperature rough rice storage technique, furnishing winter cold air to rough rice, by investigating the cooling system potential of maintaining low rough rice temperature and by analyzing rough rice storage characteristics over a storage period. The rough rice storage characteristics were evaluated from January to August 2003, using a storage and dry bin of 400-ton capacity. Results of this research are as follows: Cooling bin using the cooling system in the top of the bin maintained the rice temperature less than 15$^{\circ}C$ in entire portions in August. Moisture contents and germination rates of rough rice were decreased over the storage period, on the other hand, the rough rice stored in the ambient temperature bin had relatively lower moisture contents and germination rates to compare with the bin using winter cold air. Crack ratio and acid value of brown rice in the ambient temperature bin storage had increased more than the cooling bin storage. The result indicates that the storage bin using winter cold air and the cooling system maintains moisture content and germination of rice, minimizes cracked kernel and acid value, and preserves rice quality as well.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.3
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• pp.165-172
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• 2017

In this study, centrifugal fan blades used to circulate cold air inside a household refrigerator were optimized to achieve high performance and low noise by using the response surface method, which is frequently employed as an optimization algorithm when multiple independent variables affect one dependent variable. The inlet and outlet blade angles, and the inner radius, were selected as the independent variables. First, the fan blades were optimized to achieve the maximum volume flow rate. Based on this result, a prototype fan blade was manufactured using a 3-D printer. The measured P-Q curves confirmed the increased volume flow rate of the proposed fan. Then, the rotation speed of the new fan was decreased to match the P-Q curve of the existing fan. It was found that a noise reduction of 1.7 dBA could be achieved using the new fan at the same volume flow rate.

• Journal of the Korean Society of Radiology
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• v.9 no.3
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• pp.131-137
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• 2015

The purpose of this study is to warm up the conventional X-ray table by inventing and design for X-ray table with an attached heating device using less unloaded X-ray, CNT (carbon nano tube) heating element. Configuration of the product design for adhesive carbon heating element X-ray is composed of a conventional X-ray table, carbon nano tube planar heating element, an electrode line, flame resisting protective film, and the bottom film. Characteristics and advantages of this invented product is to provide gentle feeling, the sense of security, and eliminating anxiety to the patient wearing a patient gown and feel the cool air while receiving the test. Thus we are strongly recommend to use this device in the clinical situation.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1109-1116
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• 2009

To the development of construction techniques and construction of glass-walled structure is generalized. Existing wall to support the role of the vertical load was lose. Features and the beautiful side of the curtain wall job was to be highlighted. Carriage access to the interior of the windows will cause pain in the neck with a cold feeling. And in the windows, drafty windows, under floor heating occurs despite the condensation phenomenon occurs. droplets that occurs around the window (the cause of the mold) in summer and winter, the heat energy and move through the glass is warmer outside. Therefore, to reduce energy efficiency affects absolutely. When you apply heat to the carriage window, the surface of the glass system, the spread of the cold air does not occur. Therefore, energy savings cars and heating of the interior is cold.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.489-496
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• 2004

The effect of airconditioning and heating system when aircurtains installed in subway electrical rolling stock at entrance door. It blocks cold/hot air of outside. It is good for health with its blocking effect against dusts exhaust fumes, odor bugs and smoke from outside. It always maintains clean and pleasant atmosphere inside. It helps you to have health with its ever-equal temperature distribution at inside. It saves lots of maintenance cost for heating/cooling (about 86$\%$) since it cuts the loss of hot air under heating as well as of cold air under air-conditionin. Customers can feel pleasant go in and out (better than before) with the door. It is an indispensable product for the employers to cut the cost. It makes customers feel pleasant near doors, since it isnt influenced by temperature difference of cold/hot air when the door opens/closes. In electrical rolling stock passenger temperature is a lot different from that the door opens/closes. One of the main aims is to create an acceptable thermal environment without draught problem. Temperature, gradients when aircurtains installed in subway electrical rolling stock at entrance door have been studied. And the temperature measured at 0.1, 0.5, 1.3, 1.7m above the floor. It has been found that temperature, with large fluctuations caused more draught influence.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.22 no.1
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• pp.20-25
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• 1977

In order to find out the effect of five kinds of cultural treatments in fall crop production of potatoes the experiments were carried out with Simabara cultivar at Chonan in 1976. Sprouting of dormant seed pieces were induced by soaking in 2ppm GA and 250ppm Ethrel mixed solution for 60 minutes. Seed pieces with longer sprouts at transplanting, and increasing of urea(nitrogen) application from 10 to 30 Kg per 10a resulted better growth, yields, and quality. Application of total nitrogen at one time on 24th July(transplanting date) resulted lower emergence, yields, growth, and quality as compared with divided application on 24th July and 15th August and 5th September. Higher transplanting than 60$\times$20cm or 70$\times$17cm resulted slender growth and lower yields. Deeper mulch with wheat straw (from 4 to 12cm) induced lower maximal earth temperature in summer and higher minimal earth temperature in autumn.

• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.3
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• pp.133-140
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• 2002

Site-specific minimum temperature forecasts are critical in a short-term decision making procedure for preventive measures as well as a long-term strategy such as site selection in fruits industry. Nocturnal cold air pools frequently termed in mountainous areas under anticyclonic systems are very dangerous to the flowering buds in spring over Korea, but the spatial resolution to detect them exceeds the current weather forecast scale. To supplement the insufficient spatial resolution of official forecasts, we developed a GIS - assisted frost risk assesment scheme for using in mountainous areas. Daily minimum temperature data were obtained from 6 sites located in a 2.1 by 2.1 km area with complex topography near the southern edge of Sobaek mountains during radiative cooling nights in spring 2001. A digital elevation model with a 10 m spatial resolution was prepared for the entire study area and the cold air inflow was simulated for each grid cell by counting the number of surrounding cells coming into the processing cell. Primitive temperature surfaces were prepared for the corresponding dates by interpolating the Korea Meteorological Administration's automated observational data with the lapse rate correction. The cell temperature values corresponding to the 6 observation sites were extracted from the primitive temperature surface, and subtracted from the observed values to obtain the estimation error. The errors were regressed to the flow accumulation at the corresponding cells, delineating a statistically significant relationship. When we applied this relationship to the primitive temperature surfaces of frost nights during April 2002, there was a good agreement with the observations, showing a feasibility of site-specific frost warning system development in mountainous areas.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.04a
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• pp.243-246
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• 2010

최근 정보량의 급격한 증가로 데이터센터는 점차 대형화되고 있으며, 통합적으로 관리/운영되기 위해서는 전산실내 적절한 온도와 습도의 유지가 필수적이므로, 전산실내 에너지의 사용 효율을 극대화하기 위한 연구가 꾸준히 이루어지고 있다. 이 연구에서는 국내 공공부문의 대형 전산실을 모델로 선정하여 전산실 내 서버의 위치, 용량 그리고 냉각시스템 등을 고려하여 전산실내 열/유동특성을 수치적으로 규명함으로써, 에너지 효율 극대화를 추구하고 전력을 절감하여 저탄소 녹색성장과 그린IT 환경을 구축 하고자 한다. 이를 위하여 실제 측정한 환경 데이터를 바탕으로 전산유체역학(CFD)을 이용하여 3차원 비압축성, 정상상태의 열/유동특성을 예측한다. 또한 기존 및 개선된 전산실에 대한 비교결과를 바탕으로 새로운 열/유동조건을 도출하며, 이를 통하여 전산실 운영에 필요한 에너지 효율향상 방안을 제안하고자 한다. 연구 결과, 전산실 천장의 냉기유입부분과 열기배출부분으로 나뉘어 냉복도와 온복도를 형성하며, 내부 서버와 기타 각종 장비들의 발열 등으로 부분적인 열섬(Thermal island)현상이 나타났다. 이러한 열섬현상을 줄이고, 전산실내 환경을 최적화하기 위하여 찬공기 유입부분의 속도, 배출구의 유량, 그리고 냉/온 복도의 역할 변경 등 여러 가지 가능한 매개변수에 대한 연구가 필수적이다. 또한, 서버에서 발생한 고온의 공기를 배출하는 것이 전산실 내 적절한 온도구현에 효과적이며, 열섬현상을 방지하기 위해서는 이 부분에 차가운 공기의 유입이 필요하다는 것을 알 수 있었다.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.2
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• pp.76-84
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• 2013

An adequate downscaling of the official forecasts of Korea Meteorological Administration (KMA) is a prerequisite to improving the value and utility of agrometeorological information in rural areas, where complex terrain and small farms constitute major features of the landscape. In this study, we suggest a simple correction scheme for scaling down the KMA temperature forecasts from mesoscale (5 km by 5 km) to the local scale (30 m by 30 m) across a rural catchment, especially under temperature inversion conditions. The study area is a rural catchment of $50km^2$ area with complex terrain and located on a southern slope of Mountain Jiri National Park. Temperature forecasts for 0600 LST on 62 days with temperature inversion were selected from the fall 2011-spring 2012 KMA data archive. A geospatial correction scheme which can simulate both cold air drainage and the so-called 'thermal belt' was used to derive the site-specific temperature deviation across the study area at a 30 m by 30 m resolution from the original 5 km by 5 km forecast grids. The observed temperature data at 12 validation sites within the study area showed a substantial reduction in forecast error: from ${\pm}2^{\circ}C$ to ${\pm}1^{\circ}C$ in the mean error range and from $1.9^{\circ}C$ to $1.6^{\circ}C$ in the root mean square error. Improvement was most remarkable at low lying locations showing frequent cold pooling events. Temperature prediction error was less than $2^{\circ}C$ for more than 80% of the observed inversion cases and less than $1^{\circ}C$ for half of the cases. Temperature forecasts corrected by this scheme may accelerate implementation of the freeze and frost early warning service for major fruits growing regions in Korea.