• Yonsei Medical Journal
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• 제59권9호
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• pp.1123-1130
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• 2018

Purpose: Exposure to indoor radon is associated with lung cancer. This study aimed to estimate the number of lung cancer deaths attributable to indoor radon exposure, its burden of disease, and the effects of radon mitigation in Korea in 2010. Materials and Methods: Lung cancer deaths due to indoor radon exposure were estimated using exposure-response relations reported in previous studies. Years of life lost (YLLs) were calculated to quantify disease burden in relation to premature deaths. Mitigation effects were examined under scenarios in which all homes with indoor radon concentrations above a specified level were remediated below the level. Results: The estimated number of lung cancer deaths attributable to indoor radon exposure ranged from 1946 to 3863, accounting for 12.5-24.7% of 15623 total lung cancer deaths in 2010. YLLs due to premature deaths were estimated at 43140-101855 years (90-212 years per 100000 population). If all homes with radon levels above $148Bq/m^3$ are effectively remediated, 502-732 lung cancer deaths and 10972-18479 YLLs could be prevented. Conclusion: These findings suggest that indoor radon exposure contributes considerably to lung cancer, and that reducing indoor radon concentration would be helpful for decreasing the disease burden from lung cancer deaths.

• 환경위생공학
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• 제14권4호
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• pp.85-92
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• 1999

Indoor air quality tends to be the dominant contributor to personal exposure because most people spend over 90% of their time indoors. For some contaminants, exposure to indoor air poses a potentially greater health threat than outdoor air exposures. Indoor nitrogen dioxide ($NO_2$) levels are mainly affected gas range, flue gas spillage, kerosene heaters, wood-burning appliances and cigarette smoke. In addition, indoor $NO_2$ levels are influenced by such house characterization as surface reaction and air exchange rate. In this study, the measurements of indoor and outdoor $NO_2$ concentrations were taken using identical protocols, and information was collected on housing characteristics using identical questionnaires in 14 houses out of 15 houses for daily 30 daily 30 days in Brisbane, Australia.The usage of gas range was the most contributing factor in indoor $NO_2$ concentration in relation to house characteristics. Average indoor and outdoor ratios of NO2 concentration in electronic and gas cooking houses were $0.6{\pm}0.1$ and $0.9{\pm}0.2$, respectively. The frequency distributions of $NO_2$ concentration in each house were approximately log-normal Geometric mean of indoor $NO_2$ concentrations of electronic and gas cooking houses for daily 30 days ranged from 2.5 ppm to 11.5 ppm with a mean 6.8 and from 4.7 ppm to 28.6 ppm with a mean 15.6 ppm, respectively. The $NO_2$ concentrations between electronic and gas cooking houses were significantly different (p<0.05). Since each house has different life-style and house characteristics, sampling interval to measure the $NO_2$ levels was recommended above 7 days.

• Spatial Information Research
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• 제19권3호
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• pp.53-62
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• 2011

최근 실내 공간 내에서의 위치 정보를 이용한 공간정보 서비스가 실외공간에서 제공되는 서 비스만큼 공간정보시스템의 중요한 응용분야로 자리 잡고 있다. 실외 공간과 달리, 실내 공간의 위치 정보는 좌표기반이 아닌, 방 번호와 같은 기호를 기반으로 표현된다. 따라서 실내공간에서 이동객체의 위치를 추적하기 위해서는 이동객체의 현재 위치를 이용하여 좌표정보를 예측하는 것이 아니라, 기호적 추론이 필요하다. 이에 본 논문에서는 RFID센서를 이용하여 이동객체의 위치를 항상 명시적으로 결정할 수 있는 추적가능 실내 기호공간을 위한 프레임웍을 제안한다. 우선, 실내기호공간과 실내기호공간에서의 위치추적에 대한 개념을 소개하고, 추적 가능한 실내 기호공간을 위한 접근성 그래프를 정의한다. 둘째로, RFID 리더기의 배치방법, 추적 가능한 실내기호공간을 위한 접근성 그래프 생성방법과 이를 이용한 위치 추적방법을 제시한다. 마지막으로, 제시한 방법의 유효성을 보이기 위하여 실험결과를 보인다.

• Spatial Information Research
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• 제16권4호
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• pp.441-453
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• 2008

LBS, GIS 및 유비쿼터스 컴퓨팅의 기술의 빠른 발전과 함께, 우리가 다루는 공간은 더 이상실외공간에 한정되지 않고, 실내공간으로 확장되고 있다. 그런데 실내공간은 실외공간과 다른 특징을 가지고 있으므로 실내의 공간의 통합되고 연속적인 서비스를 제공하기 위하여서는 새로운 이론, 데이터모델 및 시스템을 개발하여야 한다. 이러한 이유로 실내공간인지를 위한 기초이론을 개발하고, 핵심기술 및 시스템을 구축하고, 서비스를 제공하기 위한 프로젝트가 시작되었다. 본 논문에서는 실내공간인지(ISA) 프로젝트의 목표와 연구주제들을 소개한다. 그리고 실내공간데이터베이스 관리시스템의 기초적 데이터타입과 연산자를 위한 프리즘데이터 모델을 소개한다. 또한 T. Kolbe가 제안한 실내공간 모델도 함께 소개한다. 이 모델은 다양한 공간을 통합하는데 기초가 될 것이다.

• Spatial Information Research
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• 제21권5호
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• pp.73-82
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• 2013

최근 국내외적으로 실내공간에 대한 관심이 높아지면서, 실내공간정보 구축 및 서비스에 관한 다양한 연구가 이루어지고 있다. 실내공간 정보를 구축함에 있어서 BIM(Building Information Modeling) 자료는 매우 유용하다. 이에, BIM 자료를 GIS에서 활용하기 위한 다양한 연구가 진행되고 있다. BIM 자료를 GIS에서 활용하기 위해서는 실내공간정보 구축을 위한 변환기술과 자료 가시화 기술이 반드시 필요하다. 기존 연구들이 대부분 실내공간 정보 구축을 위한 변환에 집중되어 있으며, BIM을 기반으로 구축된 공간정보들의 가시화에 관한 연구는 거의 이루어지지 않았다. 이에 본 연구에서는 BIM과 GIS 연계를 위하여 BIM 자료기반으로 실내 공간 자료를 구축했을 때, 실내 시설물 관리 시스템에 적용할 수 있는 실내공간 세밀도(LOD:Level of Detail) 모델을 제시하였다.

• 대한안전경영과학회지
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• 제22권1호
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• pp.33-44
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• 2020

This study analyzed how the installation of a pressure gauge in the indoor fire hydrant of an apartment building affected identifying pressurized water in the pipe, making it easier to conduct internal inspection on the fire suppression system, and ensuring reliability of fire suppression. The following are the study's results: First, identifying pressurized water in the indoor firefighting pipe had a positive effect on the installation of a pressure gauge in the indoor fire hydrant. This implies that a higher level of identification of pressurized water in the indoor firefighting pipe had a positive impact on improving the installation and use of a pressure gauge in the indoor fire hydrant. Second, making it easier for the fire safety officer to inspect the fire suppression system had a positive effect on the installation of a pressure gauge in the indoor fire hydrant. This suggests that if it becomes easier for the apartment building's stakeholder to conduct internal inspection or the firefighting facility manager to carry out inspection on the fire suppression system, it would have a positive effect on the installation of a pressure gauge in the indoor fire hydrant. Finally, ensuring reliability in fire suppression had a positive effect on the installation of a pressure gauge in the indoor fire hydrant. This implies that if it becomes easier to identify pressurized water in the indoor firefighting pipe, for the fire safety officer to conduct internal inspection, or for the firefighting facility manager to carry out inspection in accordance with the fire suppression system's internal inspection requirements, it would increase reliability in fire suppression, making it more necessary to install a pressure gauge in the indoor fire hydrant.

• 대한임베디드공학회논문지
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• 제17권1호
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• pp.9-17
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• 2022

As the COVID-19 pandemic situation worsens, the time spent indoors increases, and the exposure to indoor environmental pollution such as indoor air pollution and noise also increases, causing problems such as deterioration of human health, stress, and discord between neighbors. This paper designs and implements a system that measures and monitors indoor air quality and noise, which are representative evaluation criteria of the indoor environment. The system proposed in this paper consists of a particulate matter measurement subsystem that measures and corrects the concentration of particulate matters to monitor indoor air quality, and a noise measurement subsystem that detects changes in sound and converts it to a sound pressure level. The concentration of indoor particulate matters is measured using a laser-based light scattering method, and an error caused by temperature and humidity is compensated in this paper. For indoor noise measurement, the voltage measured through a microphone is basically measured, Fourier transform is performed to classify it by frequency, and then A-weighting is performed to correct loudness equality. Then, the RMS value is obtained, high-frequency noise is removed by performing time-weighting, and then SPL is obtained. Finally, the equivalent noise level for 1 minute and 5 minutes are calculated to show the indoor noise level. In order to classify noise into direct impact sound and air transmission noise, a piezo vibration sensors is mounted to determine the presence or absence of direct impact transmitted through the wall. For performance evaluation, the error of particulate matter measurement is analyzed through TSI's AM510 instrument. and compare the noise error with CEM's noise measurement system.

• Journal of Korean Society for Atmospheric Environment
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• 제11권E호
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• pp.45-54
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• 1995

Indoor air quality models are useful to predict indoor air pollutant concentrations as a function of several indoor factors. Indoor air quality model was developed to evaluate the pollutant removal efficiency of variable-air-volume/bypass filtration system (VAV/BPFS) compared with the conventional variable-air-volume (VAV) system. This model provides relative pollutant removal effectiveness of VAV/BPFS by concentration ratio between the conventional VAV system and VAV/BPFS. The predictions agree closely, from 5 to 10 percent, with the measured values for each energy load. As a results, we recommend the VAV/BPFS is a promising alternative to conventional VAV system because it is capable of reducing indoor air pollutant concentration and maintaining good indoor air quality.

• 교육시설
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• 제14권4호
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• pp.43-52
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• 2007

People spend more than 90% of their time indoor. Nowadays as they are interested in environment much more than before, indoor air pollution has been regarded as new environmental problems. At present, an air quality check is required prior to the completion of construction. However this study shows that the density level of HCHO and VOCs in a classroom was increased after furnishing the classroom. Thus, to measure the quality of air more effectively and accurately, it should be measured after the indoor space are furnished. Newly-built schools are tested for this study. The building sites were investigated to measure and evaluate the IAQ (Indoor Air Quality) in newly-built schools. The result of this study can be used as a basis to improve the environment air condition of the educational facilities.

• Journal of Electrical Engineering and Technology
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• 제10권1호
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• pp.436-442
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• 2015

In this paper, we develop an indoor localization device which embeds localization information into indoor light-emitting-diodes (LED) lighting systems. The key idea of our device is the use of the newly proposed "bit stuffing method". Through the use of stuff bits, our device is able to measure signal strengths even in transient states, which prohibits interference between lighting signals. The stuff bits also scatter the parts of the signal where the LED is turned on, thus provides quality indoor lighting. Additionally, for the indoor localization system based on RSSI and TDM to be practical, we propose methods for the control of LED lamps and compensation of received signals. The effectiveness of the proposed scheme is validated through experiments with a low-cost implementation including an indoor navigation task.