Personal or population exposure to hazardous air pollutants has often been assessed by time-weighted average model with combining concentrations of indoor environments and time-activity pattern, which were mainly a single measurement. However, daily levels of air pollutants in indoor environments may greatly be changed because of source emission, ventilation, decay rate and so on. Subsequently exposure by a single measurement in indoor environments could not be assessed properly. In this study, we measured the consecutive 21 daily indoor and outdoor measurements of nitrogen dioxide (NO₂) with 37 houses and 19 shops such as restaurants and coffee shops beside street by using of passive samplers. Considering that average concentration during 21 days was true value, paired t-test was conducted. Daily variations of NO₂ in houses with constant or low emission source were different from those in restaurants with irregular or high emission source. These results can be explained that the NO₂ emission of indoor sources could affect the validity of measurement periods.

본 논문에서는 위치기반서비스의 핵심기능을 담당하는 측위기술 중 흔히 사용되고 있는 삼각측량법과 최소자승법을 보정한 방법을 이용하여 객체의 위치를 결정하는 알고리즘의 산포를 감소시키는 방안을 연구하였다. 두 측위 방법에서 사용되는 거리값은 모두 동일한 보정과 필터링 과정을 적용하였으며, 프로그램 구현 후 실내에서 테스트를 실시하였다. 프로그램은 LabView 2010으로 구현하였고, 각각의 알고리즘을 모듈화하여 필터링 적용 전후 및 개선효과를 비교하기 쉽도록 구성하였다. 일반적인 환경에서 실험한 결과 삼각측량이 최소자승법보다 더 좋은 정확도를 보여주었고, 필터링 과정을 거칠수록 정확도가 향상되는 것을 확인하였다.

This study was performed in the 175 selected child-care facilities in the urban area (Seoul, Suwon, Daejeon, and Busan) and the industrial complex area (Sihwa and Yeosu) to measure of the characteristics of VOCs in the indoor air from August, 2007 to April, 2008. All samples were collected at the indoor and outdoor places to the child-care facilities in spring, summer, and winter seasons using the Tenex absorption trap and were analyzed through the GC/MSD. The mean concentration of VOCs in the 175 child-card facilities showed the highest levels of 73.68 ㎍/m³in the toluene and the lowest levels of 0.28 ㎍/m³in the chlorobenzene. In the concentration of the TVOC, it exceeded 2.5 times more as the indoor air quality guideline in Korea. The result of this study was found that the concentration of VOCs in the child-care facilities in Korea may influenced from the some factors such as the constructional period, traffic density, and ventilation rate. These findings may expected to imply that effective risk management strategies should be applied to minimize the public health effects for children in the child-care facilities in Korea.

Location-Based Service(LBS) is a service that provides a variety of convenience in life using location information that can be obtained by mobile communication network or satellite signal. In order to provide LBS precisely and efficiently, we need the location determination technology, platform technology and server technology. In this study, we studied on how we can reduce the error on location determination of objects such people and things. Fingerprint location determination method was applied to this study because it can be used at current wireless communication infrastructure and less influenced by a variety of noisy environment than other location determination methods. We converted the probability value to logarithmic scale value because using the sum of k probability values is not suitable to be applied to weight determination. In order to confirm the performance of suggested method, we developed location determination test program with Visual Basic 6.0 and performed the test. According to indoor and outdoor test results, the suggested stochastic method reduced the distance error by 17%, 18% and 9% respectively at indoor environment and 25%, 11% and 4% at outdoor environment compared with deterministic NN, kNN and kWNN fingerprint methods.

Location-Based Service(LBS) is a service that provides a variety of convenience in life using location information that can be obtained by mobile communication network or satellite signal. In order to provide LBS precisely and efficiently, we have to need technologies such as location determination technology, platform technology and server technology first. In this study, we studied on how we can reduce the error on location determination of objects such people and things. Fingerprint location determination method was applied to this study because it can be used at current wireless communication infrastructure and less influenced by a variety of noisy environment than other location determination methods. We used the time of arrival(ToA) method in fingerprint location determination method. In order to confirm the performance of suggested method, we developed location determination test program with LAbVIEW 2010 and performed the test. According to indoor test results, the suggested method reduced the distance error by 24%, 34% and 19% respectively at indoor environment compared with deterministic kWNN and Rice Gaussian fingerprint methods.

본 연구는 서울시 아파트 200가구의 거주자를 대상으 로 실내식물이 거주자의 행복지수에 미치는 영향을 알아 보기 위한 조사로서, 그 동안 원예치료와 식물의 기능성 연구 등 여러 연구를 통해 나타난 식물의 인간에 대한 긍정적인 역할에 착안하여, 거주자와 가장 가까이 있는 실내식물이 궁극적인 목표인 거주자의 행복에 어떻게 관여하고 있는지를 분석하고자 하였다. 실내식물을 키 우면서 행복감이 가장 컸을 때는 꽃이 피었을 때라고 응 답한 사람이 전체의 57% 로 가장 많았고, 그 뒤를 이어 새싹이 돋았을 때가 33% 를, 분갈이 했을 때와 직접 키 운 식물을 분양했을 때가 각각 2%, 기타가 7% 였다. 식 물과 함께하는 시간이 많을수록 행복지수는 1시간 내 에서 정비례관계를 보였다. 실내식물의 재배관리주체가 누구냐에 따른 행복지수 에서는 본인이 직접 관리하는 경우의 행복지수가 67.90, 가족구성원이 관리하는 경우의 행복지수는 65.09, 기타가 64.79로 분석되었다. 실내식물 선호도와 실내정원의 면 적에 따른 행복지수도 정비례관계를 나타냈으며 실내화분 식물의 개수가 많아지면 행복지수도 증가하였다.

A system has been developed to reduce fluctuation of the indoor temperature in a radiant floor heating system. The system we developed and implemented is called BoilerMan. With the BoilerMan system the hot water circulation pump is controlled by computer software which implements a unique strategy. To minimize the system development time a user-friendly development environment was used. This development environment was useful in the implementation and testing of the efficiency of our strategy. The environment also serves as an easy means for system maintenance. The BoilerMan went through a few test runs against a real apartment house and the result showed significant reductions in the initial temperature overshoots against the target values. It also reduced the operatingtime of the hot water circulation pump. Such positive results were possible due to our unique strategy that exploits heating efficiency information collected from the past run of the very same system. Since the strategy was implemented with embedded software, it makes the BoilerMan flexible, too.

Recent apartment houses tend to expose the problems of unbalanced floor temperatures and real temperature due to changes in thermal performance arising from reinforced insulation and air tightness. In this study, the indoor thermal environment was analyzed against the apartment unit household in the type of individual heating, central heating, and District Heating methods in order to determine the operational status of indoor thermal environments and heating system by Heating supply systems. The temperature of hot water supplied at the time the indoor loads occurs to the maximum by Heating supply systems was found to rise in order to individual heating (70℃) , central heating(47℃) and District Heating (41℃). The hot water supply frequency showed variable changes in the range of 3 to 6 times per day in cases of individual heating while periodical changes was ranging from 3 or 4 times a day in the case of central heating and district heating. The width of variation of floor surface temperatures depending on the temperature of the supply water was found to be in order of Individual Heating, District Heating, and Central Heating. The average floor surface temperature appeared similar to the hot water supply temperature pattern in the order of 26.4 to 30.2℃ for Individual Heating, 28.2 to 28.6℃ for Central Heating, and 24.8 to 29.4℃for District Heating. In the case of non-heating where heating is not implemented, the temperature of the floor surface was 22.8℃ to 26.0℃ showing the same temperature as the indoor temperature. Heating supply appeared to be maintained in a stable manner overall in a sporadic manner ranging from 3 to 6 times a day, which was maintained in a stable manner on the whole regardless of the heating method.

The purpose of this study was to assess an alternative method to characterize indoor environmental factors by multiple indoor and outdoor measurements. Using a mass balance model and regression analysis, penetration factor and source strength factor were calculated using multiple indoor and outdoor measurements. This study was performed in 30 selected apartments in Seoul, Asan, and Daegu area which were constructed within 4 years and over 4 years, to measure the concentration of NO₂ from July, 2004 to September. The results of this study are as follows. The average concentration of NO₂ in Seoul, Asan, and Daegu area in the apartment constructed within 4 years are nitrogen dioxide 48.01㎍/m³ and in the apartment over 4 years are nitrogen dioxide 46.54㎍/m³. Mean ratios of indoor to outdoor NO₂ concentrations are Seoul 0.99, Asan 0.83, Daegu 1.18. The deposition constant and the source strength of NO₂ were 0.97±0.55 hr-1 and 16.33±12.30 ppb/h, respectively. In conclusion, indoor environmental factors were effectively characterized by this method using multiple indoor and outdoor measurements.

This study presents residential indoor and outdoor exposure concentrations distributions of volatile organic compounds (VOCs, benzene, toluene, xylene) and nitrogen dioxide (NO₂) in industrial area (case) and agricultural area (control) during 5 days. Concentrations of VOCs and NO₂ were measured with passive samplers in residential indoor and outdoor. Most of benzene, toluene and NO₂ mean concentrations in case area were higher than those in control area. Considering the indoor and outdoor ratios (I/O) were higher than 1, the residence might be have the sources of indoor air pollutants such as smoking and using of gas range. Residential indoor concentrations of benzene, toluene, and NO₂ with indoor smokers were higher than those and without indoor smokers. In conclusion, it is suggested that personal exposures to air pollutants might be affected by indoor sources as well as outdoor pollutants emitted from industrial complex, and indoor air quality and outdoor air quality should be simultaneously considered to reduce the personal exposure to air pollutants.

연구는 관엽식물 4종을 배지종류, 광도 및 이산화탄소 농도를 달리하여 식물의 광합성 반응을 조사하고, 그 결과에 기초하여 실내환경 조절에 효율적인 식물을 선정하고자 실시하였다. 식물재료로는 싱고니움, 디펜바키아, 쉐프렐라 홍콩, 드라세나를 사용하였으며, 성분과 성질이 다른 두 배지(peatmoss, hydroball)에 각각 재배하였다. 광도는 PPFD 0, 30, 50, 80, 100, 200, 400, 600μmol·m-2·s-1의 수준으로 조절하고, 이산화탄소 농도는 0, 50, 100, 200, 400, 700, 1000, 1500μmolCO2·mol-1의 수준으로 처리하였다. 광도 및 엽육내 CO2 농도변화에 따른 관엽식물의 광합성 반응을 조사한 결과, 약광에서의 광합성 능력을 나타내는 순양자수율은 쉐프렐라 홍콩과 디펜바키아에서 높게 나타났으며, 두 실내식물은 고농도의 이산화탄소 환경에서도 다른 두 식물에 비해 높은 광합성율을 기록했다. 드라세나 와네키는 두 조건 모두에서 가장 낮은 광합성 효율을 보였다. 두 배지 처리에 따라서는 각각의 관엽식물에서 엇갈린 광합성 반응이 관찰되었다. 쉐프렐라 홍콩은 피트모스 배지에서 광과 이산화탄소 증가에 따라 하이드로볼 배지에 비해 높은 광합성 속도를 보였지만, 디펜바키아는 그와는 정반대로 하이드로볼 배지에서 더욱 높은 광합성율을 기록했다. 싱고니움의 경우는 광처리에 의해서는 피트모스 배지에서 높은 광합성율을 보였지만 이산화탄소 처리에서는 배지간 차이가 없었다. 가장 낮은 광합성 효율을 보인 드라세나 와네키는 광에 의한 배지간 차이가 없었으며, 이산화탄소 증가시에는 피트모스에서 다소 높은 광합성율을 보였다. 따라서 실험한 4가지 관엽식물 중 광합성 효율이 가장 높았던 쉐프렐라 홍콩이나 하이드로볼 배지에서 높은 효율을 보인 디펜바키아가 실내 공기정화 및 실내 환경조절에 적합할 것으로 판단된다.

Indoor, outdoor, and personal nitrogen dioxide (NO₂) exposures were studied in a population of housewives. Daily Indoor and outdoor NO₂ concentrations were measured and compared with simultaneously personal exposures of 17 housewives for 7 consecutive days in 17 houses. In this study, indoor and outdoor NO₂ samples at home were collected only while the housewives were at home samples. Time activity patterns and house characteristics were used to determine the effects of these factors on personal exposure. Since housewives spent their times in indoor houses with mean of 78.3%, their NO₂ exposures were associated with indoor houses NO₂ levels (r= 0.89) rather than outdoor NO₂ level (r= 0.85). Contribution of indoor NO₂ concentration on personal exposure was estimated by 70.77% by using of mass balance model. The close association between measured indoor NO₂ concentrations and measured personal exposure and contribution of indoor NO₂ concentration suggests that measuring indoor concentrations of NO₂ in the home is sufficient to estimate personal exposure accurately.

The aim of this study is to estimate and compare indoor air quality(IAQ) at stock rooms in general library and in National Archives and to provide fundamental data in order to enact the law on management of IAQ at stock rooms in general library. The survey of IAQ in stock rooms was performed in Seoul National Archives in August 2009, and the basic data on level of indoor air pollutants in stock rooms at general library was collected from domestic journal. The concentration of NO₂ was 114.1 ppb at audiovisual documentary stock rooms in National Archives. That value exceeded 50 ppb guideline that was legislated by the Korean Ministry of Public Administration and Security. The concentration of PM₁₀ and VOCs were 59±9㎍/m³ and 367±83㎍/m³, respectively at stock rooms in general library. These values were exceeded from the guideline of Korean Ministry of Public Administration and Security that is 50㎍/m³ for PM₁₀ and 400㎍/m³ for VOCs. Also, the exceeded probability from the guideline was 83.7% in PM₁₀ and 35.6% in VOCs. Therefore, we suggest that a national plan for the management of IAQ at stock rooms in general library should be established.

This study investigated the indoor air concentrations and the harmful effects on health by hazardous pollutants in the normal classrooms and special classrooms of 132 elementary, middle, and high schools located in 13 sites in Chungnam from February 2006 to June 2007. The results obtained from this investigation are as follows. As the results of the survey on the indoor air quality, volatile organic compounds were higher in normal classrooms(251.67㎍/m³) than special classrooms (181.59㎍/m³), and formaldehyde was significantly higher in special classrooms (34.22㎍/m³) than normal classrooms (24.61㎍/m³). With regards to the differences of pollutant distribution among elementary, middle, and high schools, volatile organic compounds were the highest in elementary schools (210.79㎍/m³) followed by middle schools (207.79㎍/m³) and high schools (195.96㎍/ m³), and formaldehyde was the highest in high schools (36.03㎍/m³) followed by elementary schools (29.84㎍/ m³) and middle schools (29.16㎍/m³). With regards to the mean concentration of pollutants by school building age, VOCs were the highest in less than 1 year old classrooms (410.93㎍/m³), followed by less than 3 years old classrooms (156.52㎍/m³) and less than 2 years old classrooms (120.18㎍/m³). Formaldehyde was also investigated to be significantly higher in less than 1 year old classrooms (41.37㎍/m³) than 2 or 3 years old classrooms (31.50㎍/m³, 22.21㎍/m³, respectively).

In order to capture the indoor CO₂ gas from public indoor spaces, a commercial zeolite(4A) was modified with alkali metals useful for adsorption. The prepared sorbents showed somewhat improved adsorption capacity. A few isotherm models were reviewed to characterize the adsorption mechanism of test sorbents. Sips model was found the most appropriate for low level indoor CO₂ adsorption, but revealed a significant error in low pressure regimes and required numerical analysis for quantitative evaluation. Thus, a parameter(qm) in the equation was empirically recorrelated with a operation temperature. As a result, the final model equation including a simple linear function presented less errors for evaluation of the potential capacity of adsorption.

The objective of this study was to estimate distribution of hazardous air pollutants and volatile organic compounds at diverse indoor areas in school. The indoor air samples were collected at 19 school in three different areas of southern Korea region from September to October 2009. The concentrations of PM-10 and formaldehyde in all sampling sites were below indoor air quality guideline of the Ministry of Education, Science and Technology. The CO₂ level and TBC (total bacteria count) were higher than the guideline for 4 sites and 12 sites, respectively. The concentration of TVOC for 23 sites exceeded the guideline. Also, TVOC level of metropolitan sampling sites were somewhat higher than small and medium-size city sampling sites. The concentration of indoor air pollutants affected by various conditions such as season, region, and indoor/outdoor environment. This study result shows that concentration of several pollutants such as CO₂, TBC, and TVOC were higher than the guideline for some sampling sites. Therefore, it is necessary to manage indoor air quality and establish effective emission reduction strategies regard for characteristics of each school.

To research indoor air pollution in the training rooms of technical high school, the temperature, air current, humidity, CO₂, CO, O₃ were measured by Indoor Climate System(ICS 500, Casella, UK) at each classroom, scientific laboratory, electricity training room, electronic equipment training room and welding training room. The change of air pollution concentration and its correlation were additionally compared and analyzed. At closed small space such as classroom, scientific laboratory, electronic equipment training room and electricity training room, the CO₂ concentration was obtained to the 2,030ppm(max.), which is higher than notified and recommended standard value(1,000ppm) by Ministry of Health and Welfare and Ministry of Environment, Korea. At welding training room where is larger and more ventilated than general classroom, CO concentration was measured to the 3.6ppm, which is higher than average 1ppm measured at other training rooms. The concentration of O₃ is not yet regulated from the standards of underground air quality, but at welding training room it was measured as 0.11ppm(max.) that is higher than 0.01ppm measured at other training rooms. The higher value of temperature, air current, radiant temperature and CO₂ concentration was shown at scientific laboratory, electricity training room and electronic equipment training room where are closed and same with the scale of classroom. And the higher concentration of CO₂, CO and O₃ was shown at welding training room which was opened larger classroom. The indoor air pollution by CO₂, CO and O₃ may directly affect on the training room where many students work at a small space, and they should be controlled appropriately. Each experimental formulas were made for the estimation of CO₂, CO and O₃ concentration depending on some kinds of variables at each training room. It is found that indirect ventilation system with a filter will be needed for regular and constant ventilation and the ventilation system should be applied to protect and make clean and comfortable environment of training rooms at technical high school.

Indoor air quality can be affected by indoor sources, ventilation, decay and outdoor levels. Although technologies exist to measure these factors, direct measurements are often difficult. Toluene and nitrogen dioxide (NO₂) concentrations of residential indoor and outdoor were simultaneously measured and compared in 16 houses, using passive samplers during every 3 days for 60 days. Concentrations of toluene and NO₂ were analyzed by gas chromatography and spectrophotometer, respectively. Using a mass balance model, penetration factor (ventilation rate divided by sum of ventilation rate and deposition constant) and source generation factor (source generation rate divided by sum of ventilation rate and deposition constant) were calculated by multiple indoor and outdoor measurements. The mean contributions of toluene of indoor and outdoor sources on residential indoor air quality were estimated to be 31.01% and 67.00%, respectively. On the other hand, mean contributions of NO₂ were 58.93% and 41.06%, respectively. These results could be explained that contributions of indoor and outdoor air pollutants sources are different to residential indoor air concentrations. In conclusion, contributions of outdoor air and indoor sources affecting indoor air quality were effectively characterized using multiple indoor and outdoor measurements.