• Particle and aerosol research
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• v.11 no.1
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• pp.1-8
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• 2015

In this study, indoor $PM_{10}$ concentration was measured by different type of real-time instruments in public transport vehicles. Light-scattering method is widely used in measuring the size of particulate matters and there is two types of light-scattering methods; one is the nephelometer type which measures the light-scattering degree by aerosol cloud, the other is the spectrometer type which measures light-scattering degree by individual particle. We observed the variation of $PM_{10}$ in KTX, subway and express bus carriages by 1-minute resolution and found that there is similar tendency in pattern among 4 light-scattering devices but difference in absolute concentrations. By comparing gravimetric result in a subway cabin, the spectrometer type device, C, was chosen as a reference device. The conversion factors of nephelometer device A-1, A-2, and B were 1.666, 1.463 and 2.125 respectively.

• Architectural research
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• v.1 no.1
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• pp.47-53
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• 1999

An interesting of desktop air-conditioning system is the Personal Environmental Module(PEM) System. The PEM system allows the occupant to choose the desired temperature, air volume and direction of the discharged air. In this study, the measurements on the age of air and the air change effectiveness, using the tracer gas method, are carried out to analyze the ventilation performance for provision of fresh air near the breathing zone by the PEM. The relations between the PEM for optimal control and other factors related to indoor air quality, and the ventilation for the PEM are examined. Also, three different supply diffuser types(desktop, floor and ceiling) are compared in view of their ability to distribute supply air to the workstation breathing zone. The desktop diffuser type could deliver air directly to the occupants breathing zone with a high degree of effectiveness. The minimum local age of air was measured in the breathing zone, which is directly supplied with air from the PEM diffusers, and the measured local air change effectiveness of the desktop diffuser in the breathing zone was about 1.13 to 1.23 times greater than that of the ceiling and floor diffusers. When the minimum outside air change rate as specified using ASHRAE Standard 62R is supplied with a desktop diffuser type, the volume of outside air can be reduced 13 to 23%, resulting in a commensurate in ventilation energy use.

• Korean Institute of Interior Design Journal
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• v.16 no.5
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• pp.107-114
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• 2007

Sustainable interior design is defined as interior design in which all systems and materials are designed with an emphasis on integration into a whole for the purpose of minimizing the negative impacts and maximizing the positive impacts on environmental, economic, and social systems over the life cycle of the interior components of a building. To achieve sustainability, it is important to pay attention to the design factors that significantly affect environmental eco-system. The purpose of this study was to describe how interior designers applied sustainable intoner design factors and how important they perceived sustainable interior design factors to be. Internet-based survey of interior design practitioners was conducted to collect data. A random sample was drawn from the American Society of Interior Designers membership list. Findings indicated that although interior designers acknowledge the importance of sustainable design practice, they have not frequently applied it to their projects. The results of this study suggest future educational strategies for students majoring in interior design and continuing education for intoner design professionals.

• Journal of Environmental Health Sciences
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• v.47 no.6
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• pp.540-547
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• 2021

Background: Indoor air pollutants are caused by a number of factors, such as coming in from the outside or being generated by internal activities. Typical indoor air pollutants include nitrogen dioxide and carbon monoxide from household items such as heating appliances and volatile organic compounds from building materials. In addition there is carbon dioxide from human breathing and bacteria from speaking, coughing, and sneezing. Objectives: According to recent research results, most indoor air pollution is known to be greatly affected by internal factors such as burning (biomass for cooking) and various pollutants. These pollutants can have a fatal effect on the human body due to a lack of ventilation facilities. Methods: We fabricated a polydopamine (PDA) layer with Ti substrates as a coating on supported glass fiber fabric to enhance its photo-activity. The PDA layer with TiO₂ was covalently attached to glass fiber fabric using the drop-casting method. The roughness and functional groups of the surface of the Ti substrate/PDA coated glass fiber fabric were verified through infrared imaging microscopy and field emission scanning electron microscopy (FE-SEM). The obtained hybrid Ti substrate/PDA coated glass fiber fabric was investigated for photocatalytic activity by the removal of ammonia and an epidermal Staphylococcus aureus reduction test with lamp (250 nm, 405 nm wavelength) at 24℃. Results: Antibacterial properties were found to reduce epidermal staphylococcus aureus in the Ti substrate/PDA coated glass fiber fabric under 405 nm after three hours. In addition, the Ti substrate/PDA coated glass fiber fabric of VOC reduction rate for ammonia was 50% under 405 nm after 30 min. Conclusions: An electron-hole pair due to photoexcitation is generated in the PDA layer and transferred to the conduction band of TiO₂. This generates a superoxide radical that degrades ammonia and removes epidermal Staphylococcus aureus.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.11
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• pp.2172-2178
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• 2007

In indoor environment, the combination of the two variations, large scale(path loss) and small scale(fading), leads to non-linear variation of RSSI(received signal strength indicator) values as distance varied. This has been one of the difficulties for indoor location estimation. This paper presents new findings on indoor RSSI characterization for more accurate model building. Experiments have been done statistically to find overall trend of RSSI values at different places and times within the same room. From experiments, it has been shown that the variation of RSSI values can be determined by both spatial and temporal factors. These two factors are directly indicated by the two main parameters of path loss model. The results show that all sensor nodes which are located at different places share the same characterization value for the temporal parameter whereas different values for the spatial parameters. The temporal parameter also has a large scale variation effect that is slowly time varying due to environmental changes. Using this relationship, the characterization for location estimation can be more efficient and accurate.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2009.04a
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• pp.193-198
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• 2009

This study focuses on building an effective environmental control system for the ubiquitous housing environment. In order to build an effective environmental control system that will provide a comfortable, pleasant, and convenient environment for residents, information on how people cognize the indoor and outdoor environmental conditions, information on human beings, and information of the space should be studied. Also more studies need to be done in which method would be the best way to integrate these informations that would affect the users in the most positive way. The current environmental control system only carries the information on providing separate information of environmental factors such as light, temperature, humidity, heat, and sound. However, it is difficult to understand the energy efficiency of an architectural element through this system. Therefore, this study proposes an energy monitoring system utilizing spatial information.

• KIPS Transactions on Computer and Communication Systems
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• v.6 no.9
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• pp.369-376
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• 2017

Recently, an RSSI-based fingerprinting localization technology has been widely used in indoor location-based services. In the conventional fingerprinting method, as many APs as possible are used to increase the accuracy of location estimation. In another study, a part of APs having the strongest RSSI signal intensity are selected and used to reduce the time spent for positioning. However, it does not reflect the influence of RSSI occurred from the changes of the surrounding environments such as human movement or moving obstacles in a real environment. The environmental changes may cause the difference between the predicted RSSI signal strength value and the measured value, and thus occur an unpredictable error in the position estimation. Therefore, in order to mitigate the error caused by environmental factors, it is necessary to select APs suitable for indoor positioning estimation considering the changes in the surrounding environments. In this paper, we propose a method to select stable APs considering the influence of surrounding environments and derive a suitable positioning algorithm. In addition, we compare and analyze the performance of the proposed method with that of the existing AP selection methods through experiments.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.5 no.5
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• pp.461-470
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• 2015

There has been a significant increase in the amount of research on reducing the lighting power consumption of buildings and also an increasing demand for technological development. Light shelf has been recognized as one of the most efficient solutions to this issue and related researches have been conducted, which have mostly focused on factors related to simple light shelves and are not suitable as an appropriate basis for the design of light shelves. Thus this study aims to establish the proper design basis for light shelves by evaluating the performance of shelves per reflection rate in indoor areas. Power consumption rate and indoor illumination intensity distribution of a testbed built based on actual living conditions were calculated for the performance evaluation, of which the results are as following: 1) Reduction of reflection rate of ceiling and walls caused average illumination intensity in summer, winter and median seasons, and evenness per reflection rate of indoor areas was found to be different in summer, winter and median seasons, making it a necessary consideration for designing light shelves. 2) Calculation of power consumption from lighting control showed that a high reflection rate of indoor areas may be suitable for power consumption reduction, and that reflection rates higher than 80% for ceilings and higher than 75% for walls in terms of the efficiency of researches on the indoor reflection rate and its application would be appropriate. This study is meaningful as the research focuses on light shelves based on considering indoor environmental factors. More studies will be required that consider a variety of factors.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.10 no.1
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• pp.160-169
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• 2000

Daily indoor and outdoor nitrogen dioxide ($NO_2$) concentration for 30 days were measured in 28 houses with questionnaire of housing characteristics in Brisbane, Australia. Using mass balance equation and regression analysis, penetration factors and source strength factors were calculated. The penetration factors of 27 houses except one house were between zero and 1, though penetration factor should be between zero and 1 by means of mass balance equation. Relationship between indoor and outdoor concentrations in each 27 house was calculated using regression analysis. According to the obtained linear regression equation, the slope means penetration factor and the intercept means source strength factor. Calculated mean and standard deviation of coefficients of determination ($R^2$) in electric and gas range houses were $0.70{\pm}0.13$ and $0.57{\pm}0.21$, respectively. The source strength factors were more than zero in 27 houses. Mean and standard deviation of slopes in electric and gas range houses were $0.65{\pm}0.18$ and $0.56{\pm}0.12$, respectively. Mean and standard deviation of intercepts in electric and gas range houses were $1.49{\pm}1.25$ and $5.77{\pm}3.55$, respectively. Air exchange rate and source strength were calculated from penetration factor and source strength factor, respectively. Geometric mean and standard deviation of calculated air exchange rates in 27 houses were $1.1/hr{\pm}1.5$. Presence of gas range was the most significant factor contributing to indoor $NO_2$ level in house characteristics (p=0.003). In gas range houses, source strengths ranged from 4.1 to $33.1cm^3/hr{\cdot}m^3$ with a mean $12.7cm^3/hr{\cdot}m^3$ and a standard deviation 9.8. The source strengths of gas range houses were significantly different from those of electric range houses by t-test (p<0.001)

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.9
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• pp.863-872
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• 2005

It is important to control indoor environment for influence on health and comfort of occupants in large-sized discount stores. On the other hand large-sized discount stores have a large number of visitors, vestibules, open spaces, high energy consumption and increasing of outside air intake. This study aims to offer the design data of building services system that can save energy and control environment through field measurement selecting two large-sized discount stores. Indoor environment factors such as temperature, relative humidity, air velocity and concentrations of $CO_2$, CO gas and TSP were measured and evaluated. In each case of $CO_2$, and CO gas, its maximum values were 2,800 ppm and 20 ppm. So proper strategy for the indoor air quality is indispensable in this type of building. Dry bulb temperature varies from $18^{\circ}C$ to $28^{\circ}C$ according to a measuring point and time. From this results, it is inferred these buildings had excessive equipment capacity. In terms of economical and environmental points, these data will be utilized to the design of HVAC system of retail facilities.