• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.6
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• pp.293-299
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• 2015

In Korea, it is the law that an apartment building which consists of over 100 households must have a ventilation system installed, either natural or mechanical. The heat recovery ventilator (HRV) is great way to reduce energy consumption. In this research we confirmed that based on site's construction plan and existing diffuser form, performed purpose CFD which simulates operation in temperatures below $-5^{\circ}C$ to circumstances of installation of an HRV in an apartment. As a result of this research we found that when the diffuser's aperture area was adjusted, the distribution of air temperature and residence time of air was more equally distributed and air temperature was higher, compared to when the diffuser has an identical aperture area. We also found that we are able to increase even more air temperature and air distribution of air temperature and residence time of air was even more equally distributed when run in parallel with a splitter damper.

• Journal of the Korean Solar Energy Society
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• v.27 no.2
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• pp.111-119
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• 2007

The annual mean temperature of South Korea has risen by $1.3^{\circ}C$ for last 100 years by urbanization and industrialization. Especially, the frequency of unusual hot weather in summer increases for a long time and the frequency of unusual cold weather in winter clearly decreases. In recently, The considerable portion of curtain wall system is appled to building skin in domestic. As related to this, the Korea Institute of Construction Technology devised the box typed double skin facade(It is occasionally called as FDFS : Functional Double Facade System) as an alternative that reflects the distinctive local climate and saves cooling energy. Two mock-ups($49m^*4.9m$) applied to single skin(curtain wall) and double skin each were monitored under the outdoor condition. Therefore, the characteristics of natural ventilation and cooling energy consumption of each window had been analyzed in real time. The results of this study are summarized as follow, Analysis of the experiment on an air conditioner: the indoor temperature of the chamber with FDFS is lower than that of the chamber with single skin facades by $3{\sim}6$ degrees(C). A temperature variation of about $1{\sim}2$ degrees between the 0.2m and 1.7m height of the mock-up occurs in FDFS, while that of about maximum 7 degrees occurs in single skin facade at noon with abundant intensity of solar accident. Also, 67 percent of energy consumption for air conditioning has been saved.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.3
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• pp.433-442
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• 2013

This study aimed to compare the dynamics of air temperature and velocity under two different ventilation and housing systems during summer and winter in Korea. The $NH_3$ concentration of both housing systems was also investigated in relation to the pig's growth. The ventilation systems used were; negative pressure type for the enclosed pig house (EPH) and natural airflow for the conventional pig house (CPH). Against a highly fluctuating outdoor temperature, the EPH was able to maintain a stable temperature at 24.8 to $29.1^{\circ}C$ during summer and 17.9 to $23.1^{\circ}C$ during winter whilst the CPH had a wider temperature variance during summer at 24.7 to $32.3^{\circ}C$. However, the temperature fluctuation of the CPH during winter was almost the same with that of EPH at 14.5 to $18.2^{\circ}C$. The NH3 levels in the CPH ranged from 9.31 to 16.9 mg/L during summer and 5.1 to 19.7 mg/L during winter whilst that of the EPH pig house was 7.9 to 16.1 mg/L and 3.7 to 9.6 mg/L during summer and winter, respectively. These values were less than the critical ammonia level for pigs with the EPH maintaining a lower level than the CPH in both winter and summer. The air velocity at pig nose level in the EPH during summer was 0.23 m/s, enough to provide comfort because of the unique design of the inlet feature. However, no air movement was observed in almost all the lower portions of the CPH during winter because of the absence of an inlet feature. There was a significant improvement in weight gain and feed intake of pigs reared in the EPH compared to the CPH (p<0.05). These findings proved that despite the difference in the housing systems, a stable indoor temperature was necessary to minimize the impact of an avoidable and highly fluctuating outdoor temperature. The EPH consistently maintained an effective indoor airspeed irrespective of season; however the CPH had defective and stagnant air at pig nose level during winter. Characteristics of airflow direction and pattern were consistent relative to housing system during both summer and winter but not of airspeed. The ideal air velocity measurement favored the EPH and therefore can be appropriate for the Korean environment. Further emphasis on its cost effectiveness will be the subject of future investigations.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.12
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• pp.1234-1268
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• 2004

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 2002 and 2003 has been carried out. Focus has been put on current status of research in the aspect of heating, cooling, air-conditioning, ventilation, sanitation and building environment/design. The conclusions are as follows. (1) Most of fundamental studies on fluid flow were related with heat transportation in diverse facilities. Drop formation and rivulet flow on solid surfaces were interesting topics related with condensation augmentation. Research on micro environment considering flow, heat transfer, humidity was also interesting to promote comfortable living environment. It can be extended considering biological aspects. Development of fans and blowers of high performance and low noise were continuing research topics. Well developed CFD technologies were widely applied for analysis and design of various facilities and their systems. (2) Heat transfer characteristics of enhanced finned tube heat exchangers and heat sinks were extensively investigated. Experimental studies on the boiling heat transfer, vortex generators, fluidized bed heat exchangers, and frosting and defrosting characteristics were also conducted. In addition, the numerical simulations on various heat exchangers were performed and reported to show heat transfer characteristics and performance of the heat exchanger. (3) A review of the recent studies shows that the performance analysis of heat pump have been made by various simulations and experiments. Progresses have been made specifically on the multi-type heat pump systems and other heat pump systems in which exhaust energy is utilized. The performance characteristics of heat pipe have been studied numerically and experimentally, which proves the validity of the developed simulation programs. The effect of various factors on the heat pipe performance has also been examined. Studies of the ice storage system have been focused on the operational characteristics of the system and on the basics of thermal storage materials. Researches into the phase change have been carried out steadily. Several papers deal with the cycle analysis of a few thermodynamic systems which are very useful in the field of air-conditioning and refrigeration. (4) Recent studies on refrigeration and air-conditioning systems have focused on the system performance and efficiency enhancement when new alternative refrigerants are applied. Heat transfer characteristics during evaporation and condensation are investigated for several tube shapes and new alternative refrigerants including natural refrigerants. Efficiency of various compressors and performance of new expansion devices are also dealt with for better design of refrigeration/air conditioning system. In addition to the studies related with thermophysical properties of refrigerant mixtures, studies on new refrigerants are also carried out. It should be noted that the researches on two-phase flow are constantly carried out. (5) A review of the recent studies on absorption refrigeration system indicates that heat and mass transfer enhancement is the key factor in improving the system performance. Various experiments have been carried out and diverse simulation models have been presented. Study on the small scale absorption refrigeration system draws a new attention. Cooling tower was also the research object in the respect of enhancement its efficiency, and performance analysis and optimization was carried out. (6) Based on a review of recent studies on indoor thermal environment and building service systems, it is noticed that research issues have mainly focused on several innovative systems such as personal environmental modules, air-barrier type perimeterless system with UFAC, radiant floor cooling system, etc. New approaches are highlighted for improving indoor environmental conditions and minimizing energy consumption, various activities of building energy management and cost-benefit analysis for economic evaluation.

• The KIPS Transactions:PartB
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• v.9B no.5
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• pp.663-672
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• 2002

In this paper, Using an automatic tracking system, behavior of an aquatic insect, Chironomus sp. (Chironomidae), was observed in semi-natural conditions in response to sub-lethal treament of a carbamate insecticide, carbofuran. The fourth instar larvae were placed in an observation cage $(6cm\times{7cm}\times{2.5cm)}$ at temperature of $18^\circ{C}$ and the light condition of 10 time (light) : 14 time (dark). The tracking system was devised to detect the instant, partial movement of the insect body. Individual movement was traced after the treatment of carbofuran (0.1ppm) for four days 2days : before treatment, 2 days : after treatment). Along with the other irregular behaviors, "ventilation activity", appearing as a shape of "compressed zig-zag", was more frequently observed after the treatment of the insecticide. The activity of the test individuals was also generally depressed after the chemical treatment. In order to detect behavioral changes of the treated specimens, wavelet analysis was implemented to characterize different movement patterns. The extracted parameters based on Discrete Wavelet Transforms (DWT) were subsequently provided to artificial neural networks to be trained to represent different patterns of the movement tracks before and after treatments of the insecticide. This combined model of wavelets and artificial neural networks was able to point out the occurrence of characteristic movement patterns, and could be an alternative tool for automatically detecting presences of toxic chemicals for water quality monitoring. quality monitoring.

• Journal of Bio-Environment Control
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• v.20 no.3
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• pp.176-181
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• 2011

The fan and pad evaporative cooling system is one of the main cooling methods in greenhouses. Its efficiency is very high, but it has some disadvantages as temperature gradient in greenhouse is large. This study was conducted to reduce the internal temperature gradients in the fan and pad cooling greenhouses. Experiments on cooling performance were carried out in a greenhouse equipped with air duct and integrated fan and pad system as an idea of this study. It showed that the cooling efficiency of an integrated fan and pad system was 75.7% in the first stage and 88.6% in the second stage. When this cooling system was operated for an unshaded and a shaded greenhouse, there were cooling effects of $5.7\sim7.6^{\circ}C$ and $7.4\sim9.7^{\circ}C$ to the control greenhouse, respectively. Maximum temperature differences in a cooling greenhouse, with a length of 18m, were $1.6\sim1.7^{\circ}C$ for shaded conditions and $2.3\sim2.7^{\circ}C$ for unshaded conditions. This greenhouse cooling method, with air duct and integrated fan and pad system, can reduce about 40~50% of the internal temperature gradients in the usual fan and pad cooling greenhouses.

• Journal of Environmental Science International
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• v.21 no.8
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• pp.931-938
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• 2012

The effects were investigated of different lengths and numbers of slitwalls in drainless containers on growth and change in soil moisture volumes on the growth of Diffenbachia amoena 'Marianne' and Begonia rex. Drainless containers filled with amended soil, with square shape ($240mm{\times}240mm$) were used, as well as three different sets of slitwalls (2, 4 or 8, respectively) in addition to non-slitwall containers. Two indoor foliage plants were grown in slitwall containers in randomized blocks with 3 replications in greenhouse conditions, from March to September, 2009. Soil moisture volumes per container were measured by weighing containers every 2 hours during the day. The change in soil moisture volumes showed considerable differences among slitwalls tested in comparison to control containers before and after twice-weekly irrigation. Particularly, the differences in the S2 (195mm, slitwall 2) containers were significantly greater than other containers tested. For Diffenbachia amoena 'Marianne', plant height, length of leaf, dry weight and fresh weight were higher with S2 containers than with those grown in other containers tested. The Begonia rex with the best quality in terms of plant height, length of leaf and width of leaf was grown in S8 (360mm, slitwall 8) containers. Particularly, statistical analysis has indicated that shoot fresh weights of Begonia rex grown in S8 were 3-fold higher than those grown in CS8 containers. The different results obtained within the two species led us to hypothesize a species-specific influence on indoor foliage plant performance. However, plants of both species grown in slitwall containers showed good results compared with plants grown in non-slitwall containers.

• Journal of The Korea Institute of Healthcare Architecture
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• v.9 no.1
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• pp.7-15
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• 2003

Contemporary hospital has more and more extension because the growth and change of hospital has to respond the various needs. For expanding, the sky bridge(sky walk) becomes one of the method to interconnect two or more buildings on the air. Sometimes the designers don't know exactly how the sky bridge works after construction. Beyond the role of interconnecting two buildings, the role of sky bridge is transformed the main axis of pedestrian in the whole hospital organization. This scope of analysis is about the sky bridge of Hanyang University hospital. The first method is the investigation of the utilization in this time. The second is the analysis of design drawings got form the designing of the past(1994-1998). From this analysis, the conclusions are followings.；The designer who wants to apply the sky bridge should more consider about, 1) how the sky bridge impacts the whole spatial system such as the pedestrian, patients, physicians, service's facilities etc. 2) what the inside of sky bridge has something such as natural light, ventilation, and the height, depth, width of aisle, the sign for seeking orientation. etc. In future the research relating sky bridge should be studied some hospital as well as one hospital for comparing the characteristics of the concepts and organizations

• Journal of Korean Society of Environmental Engineers
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• v.34 no.5
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• pp.316-325
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• 2012

In this study, we suggested adequate control technology by analyzing emission process and main chemical of VOC/HAPs generated from four paint factories in Busan area. And we estimated whether Kapok fiber, which is a natural material, can be commercially used for an absorbent by testing adsorption ability. As a result of this sturdy, above 60% of VOC/HAPs was volatilized and dispersed inside the working place without conducting control system of facilities during manufacturing paints. Concentration profile of VOC/HAPs, which is volatile naturally outside the factories, is surveyed above 70% at Toluene, Ethylbenzene, and Xylene. And a result of evaluation of odor attribution level about the component whose Odor Threshold is known, it is estimated that major cause material of A, B, C factories is Toluene and that of D factory is m/p-Xylene. And that result presented design arguments such as facilities specifications, activated carbon filling volume, and replace cycle of activated carbon as control technology. Also, that result presented emission process improvement such as adsorption of central-controlled ventilation device, installation of inlet flenge, and potable cleaning process. The rate of pollutant adsorption of Kapok fiber, which is natural material, is indicated about 91.9%, 66.7%. That result validated the possibility as replacement of activated carbon.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.10
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• pp.756-766
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• 2011

In order to investigate the degree of apartment parking lot dust contamination, total 72 samples of parking lot dust (36 from ground parking lots and 36 from the underground parking lots) were collected in Daegu city from the end of March to the early June 2010. The dust samples were sieved below $100{\mu}m$, and analysed by ICP for 14 elements after an acid extraction. Results obtained from the source assessment of trace element using enrichment factor showed that Fe, K, Mg, Mn, Na and V were influenced by natural sources, while Cd, Cr, Cu, Ni, Pb and Zn were influenced by anthropogenic sources in both the ground parking lot and the underground parking lot. And results showed that Ca were influenced by natural sources in the ground parking lot, but influenced by anthropogenic sources in the underground parking lot. The measured values were remarkably higher in components from natural sources than in components from anthropogenic sources. Underground parking lot dust was more affected by anthropogenic sources and contaminated compared with the ground parking lot dust. Pollution index of heavy metals revealed that underground parking lot dust was 5.5 times more contaminated with heavy metal components than the ground parking lot dust. The results of correlation analysis among trace elements indicated that components in the ground parking lot were more correlated than those in the underground parking lot, and especially more correlated with natural sources-natural sources. Analysis for correlations between components and influencing factors in the underground parking lot showed that concentrations of heavy metals were higher with smaller number of parking spaces and no ventilation system, and older apartments in last paint and cleaning had relatively higher contents of heavy metals than those of recently painted and cleaned.