• Physical Therapy Rehabilitation Science
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• 제10권3호
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• pp.356-366
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• 2021

Objective: This study aimed to compare gait ability through gait evaluations in indoor and outdoor environments according to the general characteristics and walking ability of stroke patients. Design: Crossed-sectional study. Methods: The subjects of this study were 57 hospitalized stroke patients.The study subjects were asked to select an indoor environment and an outdoor environment in random order, and the Timed Up and Go Test (TUG), 10-Meter Walk Test (10MWT), Figure-Eight Walk Test (F8WT) and the Functional Gait Assessment (FGA) were used to assess each environment. Results: The TUG, 10MWT, F8WT time and number of steps, and FGA showed a significant decrease in gait ability in the outdoor environment compared to the indoor environment (p<0.05). Although the TUG, 10MWT, and the time required for the F8WT were statistically higher in the outdoor compared to the indoor environment at points 2, 3, and 4, but not 5 of the functional ambulatory category (FAC), significant increases in the number of steps of the F8WT were found in the outdoor compared to the indoor environment for only points 2 and 3 of the FAC (p<0.05). In the FAC 3 and 4, there was a statistically significant decrease in the outdoor compared to the indoor environment only in the FGA (p<0.05). Conclusions: Therefore, it has been shown that the gait ability of stroke patients is reduced in the outdoor environment compared to the gait ability in the indoor environment.

• Journal of the Korean Wood Science and Technology
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• 제45권5호
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• pp.519-524
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• 2017

본 연구는 황벽나무의 물리, 역학적 성질의 특성과 부후성을 조사하였다. 기건밀도는 실내, 외 방치한 목재에서 각각 0.41, $0.43g/cm^3$로 나타났다. 전수축율 시 T/R비는 실내, 외에서 각각 1.40, 1.32로 나타났다. 흡습성은 온도 $40^{\circ}C$ 상대습도 90% 경우 실내, 외에서 각각 16.30, 15.80%로 나타났다. 압축강도는 실내, 외에서 각각 43.81, 40.33 MPa 휨강도는 84.63, 68.80 MPa, 충격강도는 3.43, $4.00J/cm^2$, 경도는 횡단면에서 각각 47.92, 49.20 MPa로 나타났다. 경도는 횡단면에서 각각 47.92, 49.20 MPa로 나타났다. 1년간 실내에 방치한 목재와 실외에 방치한 목재는 부후에 강하고, 또한 T/R비도 낮은 편으로 치수가 안정한 나무로 판단된다.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2003년도 봄 학술발표회 발표논문집
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• pp.155-160
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• 2003

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. The purpose of this study was to develop an alternative method to characterize indoor environmental factors by multiple indoor and outdoor measurements. Daily indoor and outdoor $NO_2$ concentrations were measured for 30 consecutive days in 28 houses in Brisbane, Australia, and for 21 consecutive days in 37 houses in Seoul, Korea. Using a mass balance model and regression analysis, penetration factor (ventilation rate divided by the sum of ventilation rate and deposition constant) and source strength factor (source strength divided by the sum of ventilation rate and deposition constant) were calculated using multiple indoor and outdoor measurements. Subsequently, the ventilation rate and $NO_2$ source strength were estimated. Geometric means of ventilation rate were 1.44 ACH in Brisbane, assuming a residential $NO_2$ deposition constant of 1.05 $hr^{-1}$, and 1.36 ACH in Seoul, with the measured residential $NO_2$ deposition constant of 0.94 $hr^{-1}$. Source strengths of $NO_2$ were 15.8 $\pm$ 18.2 ${\mu}g$/$m^3$.hr and 44.7 $\pm$ 38.1${\mu}g$/$m^3$.hr in Brisbane and Seoul, respectively. In conclusion, indoor environmental factors were effectively characterized by this method using multiple indoor and outdoor measurements.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2004년도 International Conference Current Challenges and Advances in Environmental Health
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• pp.45-50
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• 2004

Indoor air quality can be affected by indoor sources, ventilation, decay and outdoor levels. Alt hough technologies exist to measure these factors, direct measurements are often difficult. The purpose of this study was to develop an alternative method to characterize indoor environmental factors by multiple indoor and outdoor measurements. Daily indoor and outdoor NO2 concentrations were measured for 30 consecutive days in 28 houses in Brisbane, Australia, and for 21 consecutive days in 37 houses in Seoul, Korea. Using a mass balance model and regression analysis, penetration factor (ventilation rate divided by the sum of ventilation rate and deposition constant) and source strength factor (source strength divided by the sum of ventilation rate and deposition constant) were calculated using multiple indoor and outdoor measurements. Subsequently, the ventilation rate and NO2 source strength were estimated. Geometric means of ventilation rate were 1.44 ACH in Brisbane, assuming a residential NO2 deposition constant of 1.05 hr-1, and 1.36 ACH in Seoul, with the measured residential NO2 deposition constant of 0.94 hr-1. Source strengths of N02 were 15.8 ${\pm}$ 18.2 ${\mu}$g/m3${\cdot}$hr and 44.7 ${\pm}$ 38.1 ${\mu}$g/m3${\cdot}$hr in Brisbane and Seoul, respectively. In conclusion, indoor environmental factors were effectively characterized by this method using multiple indoor and outdoor measurements.

• 설비공학논문집
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• 제22권1호
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• pp.20-25
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• 2010

In this study, As a basic research for improving indoor thermal environment at tower type apartment houses, specifications of heat storage and heat emission in the structures of apartment houses were investigated, and the ratio of indoor and outdoor air velocity at tower type apartment house was examined, too. Indoor temperature at night time was higher than outdoor air temperature because heat emission from the structure of wall, ceiling and floor those are constructed by use of reinforced concrete which has large heat capacity. The ratio of indoor and outdoor air velocity was lower than 0.1 and this was caused by the plan of tower type apartment house. PMV was in the range of 0.3~1.9, and was about 1.0 (it means slightly warm) at 10 : 00 p.m.. To improve indoor thermal environment in summer season at tower type apartment houses, it needs more investigation on specifications of heat storage and heat emission in the structure including winter season, and on the improvement of the ratio of indoor and outdoor air velocity.

• KIEAE Journal
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• 제16권2호
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• pp.5-10
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• 2016

Purpose: Recently, many public office buildings which were built by curtain wall increased rapidly, but the results of the investigation of the government, these buildings have been found that the heating and cooling thermal load is high, and showed low energy efficiency. Method: To evaluate the effects by applying outdoor louver and indoor blind, which can control solar radiation in order to reduce the heating and cooling load of public office building which was built by glass curtain wall. The heating and cooling load was calculated via Energyplus, building and outdoor louver, indoor blind were modeled by Google sketchup connected to Energyplus. Result: The results of this study were as follows; the case of applying various outdoor louver, the heating and cooling load all decreased as compared to the case without applying outdoor louver, the case of applying indoor blind, the heating and cooling load decreased as compared to the case without applying indoor blind, but indoor blind showed low energy performance comparing outdoor louver.

• 한국환경과학회지
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• 제4권5호
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• pp.61-61
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• 1995

Volatile organic compounds(VOCs) are of concern for their potential chronic toxicity, their suspected role in the formation of smog, and their suspected role in destruction of stratospheric ozone. Present study evaluated the exposures to selected VOCs in three microenvironments: 2 chlorinated and 5 aromatic VOCs in the indoor and outdoor air, and 5 aromatic VOCs in the breathing zone air of gas-service station attendants. With permissible Quality Assurance and Quality Control performances VOC concentrations were measured 1) to be higher in indoor air than in outdoor air, 2) to be higher in two Taegu residential areas than in a residential area of Hayang, and 3) to be higher in the nighttime than in the daytime. Among five aromatics, Benzene and Toluene were two most highly measured VOCs in breathing zone air of service station attendants. Based on the sum of VOC concentrations, the VOC exposure during refueling was estimated to be about 10% of indoor and outdoor exposures. For Benzene only, the exposure during refueling was estimated to cause about 52% of indoor and outdoor exposure. The time used to calculate the exposures was 2 minutes for refueling and 24 hours for indoor and outdoor exposures.

• 한국환경과학회지
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• 제4권5호
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• pp.447-459
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• 1995

Volatile organic compounds(VOCs) are of concern for their potential chronic toxicity, their suspected role in the formation of smog, and their suspected role in destruction of stratospheric ozone. Present study evaluated the exposures to selected VOCs in three microenvironments: 2 chlorinated and 5 aromatic VOCs in the indoor and outdoor air, and 5 aromatic VOCs in the breathing zone air of gas-service station attendants. With permissible Quality Assurance and Quality Control performances VOC concentrations were measured 1) to be higher in indoor air than in outdoor air, 2) to be higher in two Taegu residential areas than in a residential area of Hayang, and 3) to be higher in the nighttime than in the daytime. Among five aromatics, Benzene and Toluene were two most highly measured VOCs in breathing zone air of service station attendants. Based on the sum of VOC concentrations, the VOC exposure during refueling was estimated to be about 10% of indoor and outdoor exposures. For Benzene only, the exposure during refueling was estimated to cause about 52% of indoor and outdoor exposure. The time used to calculate the exposures was 2 minutes for refueling and 24 hours for indoor and outdoor exposures.

• 대한건축학회논문집:구조계
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• 제36권2호
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• pp.155-163
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• 2020

Indoor airborne particles are consisted of outdoor- and indoor-generated particles, which can be characterized by their compositions, generation features and toxicity. The identification of source contribution of indoor and outdoor origin to indoor particles is important to understand PM_2.5 transport in a building as well as its impact on occupant health. The objective of this study is to investigate seasonal source contribution to indoor PM_2.5 concentration depending on airtightness of apartment units. To evaluate the source contribution, particle transport including penetration, generation, exfiltration in an apartment housing unit was simulated by using CONTAM with particle and airflow simulation parameters obtained from field measurements. The result showed that the outdoor source contribution to indoor air was relatively dominant in the leaky housing unit during spring (77.2%) and winter (73.9%), and the indoor source was dominant in the airtight housing unit during summer (60.3%) and fall (60.7%). These results indicate the seasonal health risk of indoor PM_2.5 can be varied according to airtightness of apartment units.

• 한국지열·수열에너지학회논문집
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• 제7권2호
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• pp.30-36
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• 2011

In this study, energy saving performance of outdoor temperature reset control strategy for central cooling system is researched by experiments. Outdoor temperature reset control is the control method to change indoor air set temperature according to outdoor air temperature change. The range of indoor air set temperature is represented by the comfort temperature range of indoor air temperature offered from ASHRAE and indoor air set temperature is programmed between $22^{\circ}C$ and $27^{\circ}C$ by outdoor air temperature $20^{\circ}C{\sim}32^{\circ}C$ in summer. As a result of applying outdoor temperature reset control to central cooling system, the suggested control method shows better performances of energy savings than the conventional method which indoor temperature maintains constantly.