• International Journal of Air-Conditioning and Refrigeration
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• v.10 no.4
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• pp.177-183
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• 2002

A pulsed tracer gas technique is applied to measure the distributions of local mean age and local mean residual-life-time of air in a half-scale experimental chamber, The airflow patterns in the chamber are visualized by a Helium bubble generator for three different exhaust locations. A supply slot is located at the top of a right wall, and an exhaust slot is at either bottom-left (Case 1), bottom-right (Case 2), or top-left (Case 3) location. Results show that the distributions of local mean age and local mean residual-life-time are different from each other, but both of them are closely related to the airflow pattern in the space. Included are discussions on explaining the variations of overall room ventilation effectiveness depending upon airflow rates for three different supply-exhaust configurations.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.10 no.6
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• pp.658-665
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• 1998

This paper investigates local exhaust effectiveness in a room with a supply and an exhaust slots on the ceiling. The mean age of air is an indicator of supply effectiveness, while the mean residual life time can be used as an indicator of exhaust effectiveness. The distribution of local mean residual life time in a space is calculated by four different numerical procedures. The reverse-flow calculation method has been proved to show quite accurate results while it can save considerable amount of computation time and efforts, compared to the method by its original definition. It is concluded that the diffusion term in the equation of mean residual life time can be neglected. The spatial and temporal diffusion characteristics of the contaminant are also discussed.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.9
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• pp.853-859
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• 2001

A pulsed tracer gas technique is applied to measure distributions of local mean age and residual life time of air in a half-scale experimental chamber. The room airflow patterns are flow-visualized by a Helium bubble generator for three different exhaust locations. A supply slot is located at the top of a right wall, and an exhaust slot is either at bottom-left(Case 1), bottom-right(Case 2), or top-left(Case 3) location. Results show that the distribution of LMA and LMR are different from each other, but both of them are closely related to the airflow pattern in the space. Results on overall room ventilation effectiveness are provided depending upon ventilation airflow rates for three different supply-exhaust configurations.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.405-410
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• 2006

This paper presents a control algorithm of supply and exhaust diffusers by recognizing a contaminant source location. CFD analysis has been conducted to calculate steady state airflow and concentration distributions in a model room, which has two supply and two exhaust openings on the ceiling. Calculations have been performed for five cases out of nine different ventilation modes by combining on/off control of the supply and exhaust openings. Local mean residual life times are obtained and compared at 9 internal points for each ventilation case. Depending on the contaminant source location, the ventilation system is operated at an optimum ventilation mode, which can results in maximum exhaust performance.

• The Journal of Korean Physical Therapy
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• v.17 no.1
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• pp.43-68
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• 2005

The purpose of this study was to report the physical status of adult with cerebral palsy who live in local community areas including Seoul, Busan, Daegu in Republic of Korea at 2004. 202-individuals with cerebral palsy(140 male, 62 female; mean age 31.9 years; range 19 to 64 years) were surveyed. Measures included a 29-item self-reported health status measure focusing on musculoskeletal status and functional performances. Adult cerebral palsy required continuous management for musculoskeletal and ambulatory function through therapeutic approach. This survey is restricted to population who had cared in welfare center for cerebral palsy in local community, so it needs to investigate home-residual adults with cerebral palsy and the population in rural community. The results were as follows: 1. Participants reported that they had a limitation of a daily of life activity due to musculoskeletal pain($43\%$), there was significant differences between a limitation of a daily of life activity and the decreased ambulatory function(p<.05). 2. Thirty six point six percentile of participants had the decreased ADL function, it was significant related with the impaired body location(p<.05) 3. Thirty nine point one percentile of participants who can independently gait had the decreased ambulatory function, it was significant differences with the usage of ambulatory assistive devices(p<.05). 4. There was significant differences ambulatory function both the body region with impairment and a grade of disability(p<.05). 5. Sixteen point three percentile of participants could not ambulate any more, there was significant differences between a age and a point of time for non-ambulation(p<.05). 6. There was significant differences between ambulatory function and physical activity(p<.05).