• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.1
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• pp.52-57
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• 2009

In this study, a simulation program has been developed to predict the performance of energy recovery ventilators fur various indoor and outdoor conditions. In order to get a fundamental data about domestic air condition, the heat recovery ventilator is selected with the product of the wind quantity $250m^3/h$ Japanese M companies which are satisfied at High Efficiency Certification Standards. At the case on which the heat recovery ventilator is established, heating load decreases by 69.1% and cooling load decreases by 59.4% in Seoul, and heating load decreases by 66.4% and cooling load decreases by 59.6% in Pusan. The maximum humidification load of winter or summer time with $0.737{\ell}/h$ or $1.008{\ell}/h$ occurred in March from Kangnung or August from Mokpo respectively. In Southern part region and East Sea of winter time, the condensation or frost on exhaust side dose not occurred on exhaust side, but the area of that outside is occurred. Therefore, the preventive measure from the area except a southern part region and the east coast area must be considered, in order to condense or frost not to occur on exhaustion side in winter.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.356-362
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• 2018

Hot pepper is a kind of seasoning vegetables, which is a major item in the Korean vegetable market. Since the use of hot pepper is processed into pepper powder, which is a powder form of dried hot pepper, improvement of quality and productivity of dried hot pepper is important. Therefore, this experiment was conducted to suggest proper drying method by comparing the changes of hot pepper powder ingredients considering production cost according to the drying method. As a drying method, we used sun drying and heat drying which are widely used in practice. We also compared the productivity and quality of dried hot pepper by applying a dehumidifying drying method using a dehumidifier. Drying rate of hot pepper was highest of 85.1% at heat drying. Accordingly moisture content of hot pepper powder was lowest of 13.5% at heat drying. The American Spice Trade Association (ASTA) color value, which influenced the coloring of red pepper, showed higher in heat drying and dehumidified drying treatment than the sun drying treatment. The content of capsaicinoids was higher at sun drying treatment than that of at both heat drying and dehumidified drying treatments. The content of sugar was higher at heat drying and dehumidified drying treatment where drying time was relatively short than that of sun drying treatment. Also, there was no significant difference in sugar content between the two treatments. The production cost of dried hot pepper with dehumidified drying was 9.9% more efficient than heat drying. Through this study, it was found that heat and dehumidified drying method were effective in increasing sugar content and coloring of hot pepper powder. In order to improve the capsaicinoid content of red pepper, it is considered that appropriate drying temperature and drying time should be added in the process of heat drying and dehumidified drying.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.206-211
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• 2016

Various applications require dry air at low temperature, such automation equipment, semiconductor manufacturing, chemical production lines, and coating processes for the shipbuilding industry. Four evaporators for low temperature (below $0^{\circ}C$) were installed for a dehumidification system. Moist air is cooled sequentially over three evaporators. The first evaporator has an evaporation temperature of $13^{\circ}C$, that of the second evaporator is $5^{\circ}C$, and that of the third evaporator is maintained at $-1.3^{\circ}C$. In the fourth evaporator implantation thereby the moisture contained in the moisture air. A pressure regulator (CPCE 12) is used at this point and is defrosted when the vapor pressure is below a set value. The non-implantation moisture of the air is a heating system that uses the waste heat of a condenser with high temperature. It develops the cooling type's dehumidifier, which is important equipment that prevents the destruction of protein and measures the temperature and humidity at each interval by changing the front air velocity from 1.0 m/s to 4.0 m/s. The cooling capacity was also calculated. The greatest cooling capacity was 1.77 kcal/h for a front air velocity of 2.0 m/s

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.7
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• pp.380-394
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• 2015

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2014. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of heat and mass transfer, cooling and heating, and air-conditioning, the flow inside building rooms, and smoke control on fire. Research issues dealing with duct and pipe were reduced, but flows inside building rooms, and smoke controls were newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for thermal contact resistance measurement of metal interface, a fan coil with an oval-type heat exchanger, fouling characteristics of plate heat exchangers, effect of rib pitch in a two wall divergent channel, semi-empirical analysis in vertical mesoscale tubes, an integrated drying machine, microscale surface wrinkles, brazed plate heat exchangers, numerical analysis in printed circuit heat exchanger. In the area of pool boiling and condensing, non-uniform air flow, PCM applied thermal storage wall system, a new wavy cylindrical shape capsule, and HFC32/HFC152a mixtures on enhanced tubes, were actively studied. In the area of industrial heat exchangers, researches on solar water storage tank, effective design on the inserting part of refrigerator door gasket, impact of different boundary conditions in generating g-function, various construction of SCW type ground heat exchanger and a heat pump for closed cooling water heat recovery were performed. (3) In the field of refrigeration, various studies were carried out in the categories of refrigeration cycle, alternative refrigeration and modelling and controls including energy recoveries from industrial boilers and vehicles, improvement of dehumidification systems, novel defrost systems, fault diagnosis and optimum controls for heat pump systems. It is particularly notable that a substantial number of studies were dedicated for the development of air-conditioning and power recovery systems for electric vehicles in this year. (4) In building mechanical system research fields, seventeen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the evaluation of work noise in tunnel construction and the simulation and development of a light-shelf system. The subjects of building energy were worked on the energy saving of office building applied with window blind and phase change material(PCM), a method of existing building energy simulation using energy audit data, the estimation of thermal consumption unit of apartment building and its case studies, dynamic window performance, a writing method of energy consumption report and energy estimation of apartment building using district heating system. The remained studies were related to the improvement of architectural engineering education system for plant engineering industry, estimating cooling and heating degree days for variable base temperature, a prediction method of underground temperature, the comfort control algorithm of car air conditioner, the smoke control performance evaluation of high-rise building, evaluation of thermal energy systems of bio safety laboratory and a development of measuring device of solar heat gain coefficient of fenestration system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.1
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• pp.94-131
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• 2007

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 2004 and 2005 has been done. Focus has been put on current status of research in the aspect of heating, cooling, air-conditioning, ventilation, sanitation and building environment. The conclusions are as follows. (1) Most of fundamental studies on fluid flow were related with heat transportation of facilities. Drop formation and rivulet flow on solid surfaces were interesting topics related with condensation augmentation. Research on micro environment considering flow, heat, humidity was also interesting for comfortable living environment. It can be extended considering biological aspects. Development of fans and blowers of high performance and low noise were continuing topics. Well developed CFD and flow visualization(PIV, PTV and LDV methods) technologies were widely applied for developing facilities and their systems. (2) The research trends of the previous two yews are surveyed as groups of natural convection, forced convection, electronic cooling, heat transfer enhancement, frosting and defrosting, thermal properties, etc. New research topics introduced include natural convection heat transfer enhancement using nanofluid, supercritical cooling performance or oil miscibility of $CO_2$, enthalpy heat exchanger for heat recovery, heat transfer enhancement in a plate heat exchanger using fluid resonance. (3) The literature for the last two years($2004{\sim}2005$) is reviewed in the areas of heat pump, ice and water storage, cycle analysis and reused energy including geothermal, solar and unused energy). The research on cycle analysis and experiments for $CO_2$ was extensively carried out to replace the Ozone depleting and global warming refrigerants such as HFC and HCFC refrigerants. From the year of 2005, the Gas Engine Heat Pump(GHP) has been paid attention from the viewpoint of the gas cooling application. The heat pipe was focused on the performance improvement by the parametric analysis and the heat recovery applications. The storage systems were studied on the performance enhancement of the storage tank and cost analysis for heating and cooling applications. In the area of unused energy, the hybrid systems were extensively introduced and the life cycle cost analysis(LCCA) for the unused energy systems was also intensively carried out. (4) Recent studies of various refrigeration and air-conditioning systems have focused on the system performance and efficiency enhancement. Heat transfer characteristics during evaporation and condensation are investigated for several tube shapes and of alternative refrigerants including carbon dioxide. Efficiency of various compressors and expansion devices are also dealt with for better modeling and, in particular, performance improvement. Thermoelectric module and cooling systems are analyzed theoretically and experimentally. (5) According to the review of recent studies on ventilation systems, an appropriate ventilation systems including machenical and natural are required to satisfied the level of IAQ. Also, an recent studies on air-conditioning and absorption refrigeration systems, it has mainly focused on distribution and dehumidification of indoor air to improve the performance were carried out. (6) Based on a review of recent studies on indoor environment and building service systems, it is noticed that research issues have mainly focused on optimal thermal comfort, improvement of indoor air Quality and many innovative systems such as air-barrier type perimeter-less system with UFAC, radiant floor heating and cooling system and etc. New approaches are highlighted for improving indoor environmental condition as well as minimizing energy consumption, various activities of building control and operation strategy and energy performance analysis for economic evaluation.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.6
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• pp.987-995
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• 2009

The effects of Kwamaegi on serum lipid profiles and ROS(reactive oxygen spices) generating and scavenging enzyme activities were investigated in rats. The three experimental groups were divided as follows: normal control diet group (NC), 5% naturally prepared and freeze-dried Kwamaegi supplemented diet group (NPK) and 5% chitosan-ascorbate treated and artificially dried (CWDD: Chilly Wind & Dehumidification Drier) Kwamaegi supplemented diets group (CAK). There were no significant differences in weight gain, feed intake, feed efficiency ratio or organs weights per body weight including liver, kidney, heart and spleen among the group. In addition, there were no significant differences in serum triglyceride and total cholesterol contents. The HDL-cholesterol contents of the NC, CAK and NPK groups were 62.00, 36.48 and 78.44 mg/dL while LDL-cholesterol contents were 62.00, 36.48 and 78.44 mg/dL, respectively, which were significantly different. The atherogenic indeces in the experimental groups were 0.62, 1.20 and 0.13, respectively. There were no significant differences in total XOD (xanthine oxidoreductase) activities; however XOD type O activity was higher in the NPK group than un the NC group and in the CAK group XOD type O activity was 21~45% lower compared to NC and NPK groups. SOD (superoxide dismutase) activity was significantly higher in the CAK group than in the NC and NPK groups, while there were no significantly differences in GST (glutathione S-transferrase) activity among the groups. Furthermore, serum ALT activity was higher in the NPK group versus the NC and CAK groups. GSH (glutathione) content was higher and LPO (lipid peroxide) content lower in the CAK group compared to the NC and NPK groups. Forem the above results, we suggest that CA treated and artificially dried Kwamaegi is not only a hygienic product but also has lowering effects on LDL-cholesterol and the atherogenic index together with the lowering of ROS-generating and increasing of ROS-scavenging enzyme activities compared to other natural products.