• Journal of Korea Society of Industrial Information Systems
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• v.21 no.6
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• pp.71-80
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• 2016

Along with the increase in the standard of living, the interest and awareness level of the public about environmental issues have also gradually increased. Recently, time spent on indoor activities have increased and the need for awareness and demand on methods in improving the quality of an indoor environment has been recognized. The purpose of this study is to sense the environment information through real-time monitoring of the room environment by using the IoT based technology and to maintain and improve the indoor environment to an appropriate level through the developed interlocking controller device. This provides an automatic control system in improving the indoor environment at home and other small areas like general offices in place of the traditional passive interior environmental improvement actions or large-scale facility control system. A status analysis with the relative reference values of the air quality and CO2, temperature and humidity and illumination and noise was applied through transmitting a control signal to automatic control module in accordance with the nine indoor environment standards set to improve the indoor environment.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.135-140
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• 2005

Installation of ceiling type unit is achieved by one of efforts for agreeable classroom environment embodiment along with economic growth. But research about changing the position of ceiling type unit is lacking in present. Therefore, this thesis is to study the thermal environment of 5 different position cases of ceiling type, namely Case A, B, C, D, E. Here, Case C is the case that has the position of ceiling type center of the classroom and the other 4 alternatives are 0.7 m away from the Case C according to x and z axis. In this thesis temperature distributions, air current distribution, heat amenities such as PMV of occupants are analyzed as the environmental factors. Through these factors, Case C and Case D are the better position alternatives than the alternatives of Case A, Case B and Case E because the latter cases the air current reaches directly to indoor occupants so that occupants feel chilly. This thesis has a conclusion under the condition of only one inlet air temperature and seat arrangement. But afterwards more inlet air condition and seat arrangement must be considered.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.11
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• pp.803-809
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• 2007

To those who spend most time within a room, comfortable indoor environment is a very critical element to job performance and health. The comfort technology, which is for enhancing comfort in human living, relates with various factors to ensure human activities efficient, comfortable, safe and satisfactory. Experiments were performed in environmental chamber. Experimental conditions were combinations from three temperatures of 18, 22 and 26C, and two relative humidity levels of 45 and 60%. Air-flow was controlled to 0.1m/s through the experiment. Four male and four female university students participated in the experiments. They had normal blood pressure and their body temperature was under $37^{\circ}C$. From the experiments for evaluating thermal sensation to the air-heating conditions, relationships among TSV, CSV, $SET^*$, PMV were analyzed. Results can be summarized as followings; Thermal neutrality $SET^*$ of man and female was $24.8^{\circ}C$. In air-heating condition, $SET^*$ values for thermal comfort zone were $23.0{\sim}26.5^{\circ}C$. These values were higher than the values from ASHRAE.

• Journal of Environmental Science International
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• v.30 no.1
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• pp.45-55
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• 2021

In this study, the odor of the parts and the odor of the surrounding environment were classified and verified. In order to increase the reliability of odor quantitative/qualitative analysis, the selection criteria for 5 sensory evaluators were established, and the n-Butanol control solution for each odor intensity was periodically trained to recognize the odor intensity before sensory evaluation. In addition, although various odor thresholds have been used through several studies, verification of whether the odor intensity value obtained through GC/MSD analysis is similar to the degree to which a person directly smells and feels it. It is important to select the odor threshold that has the best correlation with the odor intensity calculated by the person smelling the odor. Finally, sampling and measuring flowing airflow and temporary odors such as odor component analysis was experimentally difficult due to limited collection space and differences in concentration of generated components. In this study, a quantitative analysis was made possible by using the low temperature concentration (cooling) trap method. Through this, it was confirmed that the correlation with the actual odor intensity was not caused by the product itself, but by the environmental factor discharged from the product after creating the odor environment.

• Journal of Environmental Science International
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• v.12 no.2
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• pp.207-215
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• 2003

The purpose of this study is to estimate the air quality of subway stations having underground platforms in Busan Metropolitan City, from September to November 2000, over seven times. The places of the investigation include Yonsan-dong station, Somyon station, Busan station, Nampo-dong station, and Dusil station. Samplings were conducted at three points in each station, i.e. gates, ticket gates, and platforms. CO, NO, $NO_2$, and $O_3$ were the main components of air for this analysis. In order to more fully understand station environments, we also measured an air temperature at each point. The results showed that the $O_3$ average concentration of Yonsan-dong station was higher than others with 38~51 ppb. The average concentration of NO was high at the ticket gate and platform at Somyon station (119 ppb, 122 ppb) and Nampo-dong station (102 ppb, 100 ppb). These results show that the air pollution of stations with underground shopping malls were higher than others. At Somyon station having a junction station, NO and $NO_2$ concentration levels of platform-2 (noncrowded) were higher than platform-1 (crowded). This is most likely due to the accumulation of air pollutants and inadequate ventilation systems. To find the relationship of the indoor (platform) and outdoor (gate), we analyzed the I/O ratio. The averages of CO and $O_3$ were both higher than one: 1.16 and 1.82, respectively. In the correlations between each material and the others, NO vs $NO_2$ was the highest with R=0.63. In the correlations between indoor and outdoor, $O_3$ was the highest with R=0.64.

• Journal of the Korean Institute of Rural Architecture
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• v.19 no.1
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• pp.23-34
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• 2017

The purpose of this paper is to suggest the preliminary data for the improvement of the senior centers' indoor environment and the upcoming progress located in rural areas. In wanju county, 81.8% of seniors were enrolled in senior centers, and used the facility everyday. Also, most of the users tended to use the facilities between 12 a.m. and 6 p.m. The majority of users had lunch at the senior centers. The facilities of most senior centers were in poor condition, and some had their restroom outdoor. Also, most senior centers are exposed to high concentrations of carbon dioxide during winter. During this season, the thermal environment in the restroom was bad. However, the users' level of the facilities' satisfaction was positive. Senior centers have been operating the facilities with difficulties, due to the low financial support from the local autonomous organization. The indoor temperature in most centers, especially, was above $30^{\circ}C$ during summer on account of lack of funding for airconditioning. Therefore, it could be recommended that the local autonomous entity start regular check-ups and repairs for the poor indoor environment and facilities, with more financial support and active supervision of the management.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.1
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• pp.101-110
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• 2022

For this purpose, the authors proposed and proved usefulness of the modified mean skin temperature which is integrated mean radiation temperature and the effect of floor contacted heat conduction. The mean radiation temperature is applied form factor between half cross-legged human body and surrounding wall of indoor. In addition the floor contacted heat conduction is applied heat transfer coefficient of half cross-legged human body. Eight Korean young men were targeted for the experiment. From the experiment the authors excerpted physiological reaction and psychological reaction in Ondol environment which is combined physiccal environmental factor of artificial climate chamber, air and floor temperature. As a result of the experiment it is confirmed that heat conduction has more impact than heat exchange from existing research for the heat exchange between half cross-legged human body and surrounding wall in Ondol thermal environment. Thereby, it is proved the effectiveness of the modified mean skin temperature which is added floor contacted temperature to the Ondol thermal environmental evaluation index.

• Journal of environmental and Sanitary engineering
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• v.18 no.1
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• pp.51-57
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• 2003

Indoor air quality(IAQ) in workplace and residential environments has been concern of people. Recently, Ministry of Environment in Korea has recognized the potential risk on the healthy effect related to indoor air pollution at home. Therefore, the purpose of this study was performed to measure the indoor air pollutants of IAQ at different homes and investigate to compare the perception of IAQ recognition at home from questionnaire survey in Seoul. We estimated the IAQ of selected 6 homes based on site region and housing type. The indoor air pollutants and parameters such as temperature, relative humidity, respirable suspended particulate matter($PM_{10}$), formaldehyde(HCHO), total bacteria counts, carbon monooxide(CO) and carbon dioxide($CO_2$) were monitored for summer and winter. In monitoring results, the respirable suspended particulate matter(($PM_{10}$) and indoor airborne bacteria level of home 5 and 6 were higher than the standard of the public $150{\;}{\mu}g/m^3$ and $500{\;}{\mu}g/m^3$, the level formaldehyde(HCHO) was exceed 0.1 ppm of the standard of Korea at all monitored homes. In statistics analysis, we could find a correlation between the building age and the concentration of CO, TBC were significant at 0.01 level and Relative Humidity was significant at 0.05 level for summer. Finally, the important air pollutants of IAQ in home were HCHO and total bacteria counts(TBC). And we performed a questionnaire survey of 500 people about their awareness for the importance of IAQ in our home during same period. In results, all most response of occupant has recognized the importance of IAQ at home. Therefore, it can be concluded that the IAQ of selected 6 home studied was perceived as acceptable, it is recommended that the government related IAQ was suggested the guideline and control of IAQ problems, and the occupants need to be effort to reduce the exposure of sources to undesirable pollutants.

• Journal of Animal Environmental Science
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• v.18 no.1
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• pp.1-8
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• 2012

The study was conducted to investigate the effects of climate on indoor environment of a swine house with natural. This study was tested in the beef swine stall at Young-in, Kyung-ki do. The test was experimented for the effect of interior environment by the outdoor environment and the interior-pan. The results are as follows. 1. In test 1 ($T_{out}$ : $25.7^{\circ}C$, without fan), an indoor air flow pattern was showed that entered from sidewall winch-curtain to went out of a indoor by the ridge winch-curtain. And the velocity of a section of the center was measured two times as large as the velocity of the floor. It is the acceleration of the velocity by thermal buoyancy. And, the entered air was rapidly dissipated by flow energy. So that in the swain livestock with sidewall winch-curtain is effected by thermal buoyancy. And the air temperature of the indoor was distributed more higher as compared with the outdoor temperature. This result is caused by the sensible heat from swine and the ventilation is restricted. 2. In test 2 (($T_{out}$ : $25.7^{\circ}C$, with fan), the velocity of a section of the center was measured more higher as compared with the test 1. And the variance of air velocity was distributed higher as compared with the test 1. This result is showed dead region of air flow with a fan operation. And, the variance of gas density was distributed lower as compared with the test 1.

• Journal of Environmental Science International
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• v.21 no.5
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• pp.563-572
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• 2012

Unlike water applications, the photocatalytic technique utilizing light-emitting-diodes as an alternative light source to conventional lamp has rarely been applied for low-level indoor air purification. Accordingly, this study investigated the applicability of UV-LED to annular-type photocatalytic reactor for removal of indoor-level benzene and toluene at a low concentration range associated with indoor air quality issues. The characteristics of photocatalyst was determined using an X-ray diffraction meter and a scanning electron microscope. The photocatalyst baked at $350^{\circ}C$ exhibited the highest photocatalytic degradation efficiencies(PDEs) for both benzene and toluene, and the photocatalysts baked at three higher temperatures(450, 550, and $650^{\circ}C$) did similar PDEs for these compounds. The average PDEs over a 3-h period were 81% for benzene and close to 100% for toluene regarding the photocatalyst baked at $350^{\circ}C$, whereas they were 61 and 74% for benzene and toluene, respectively, regarding the photocatalyst baked at $650^{\circ}C$. As the light intensity increased from 2.4 to 3.5 MW $cm^{-1}$, the average PDE increased from 36 to 81% and from 44% to close to 100% for benzene and toluene, respectively. In addition, as the flow rate increased from 0.1 to 0.5 L $min^{-1}$, the average PDE decreased from 81% to close to zero and from close to 100% to 7% for benzene and toluene, respectively. It was found that the annular-type photocatalytic reactor inner-inserted with UV-LEDs can effectively be applied for the decomposition of low-level benzene and toluene under the operational conditions used in this study.