• 한국소음진동공학회논문집
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• 제17권4호
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• pp.342-349
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• 2007

Following the 2002 World-Cup held in Korea, studies have been actively conducted on plans to utilize all-weather stadiums of fine figures, where large-scale spaces are available for various utilizations. In Japan, dome-type stadiums have been built and are utilizing across the whole nation not only for sports events but also variety of other large-scale events. PTFE(poly tetra fluoro ethylene) is one of the membrane material mainly used for the outer ceiling surface of membrane structures. However, there has not been enough research on the acoustical properties of PTFE membrane material which has been widely used in the multi-purpose stadiums. In this study, air permeability values and sound absorption coefficient of PTFE membrane materials were measured and evaluated in the gymnasium. From the results of measurements of sound absorption coefficient and air permeability of inner membrane materials, it was found that the sound absorption coefficient was good in the air permeability range of $5{\sim}15\;cc/cm^2/s$. Also the relation ship between air permeability and sound absorption coefficient was very high and the sound absorption coefficient was the highest in the range of $6{\sim}9\;cc/cm^2/s$. Secondly, an analysis on the measurements sound absorption characteristics of inner membrane material reveals that the overall sound absorption coefficient was stabilized(higher than 0.5 throughout the whole frequency bands) when the air space behind the membrane material was deeper than 600 mm. When PTFE sound absorptive membrane material was installed in the ceiling of gymnasium, it was confirmed that sound absorptive membrane material can reduce reverberation and increase speech intelligibility in the gymnasium.

• The Journal of Korean Physical Therapy
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• 제27권4호
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• pp.252-257
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• 2015

Purpose: The purpose of this study was to assess psychometric properties of the Korean version of the Stroke Impact Scale 3.0 (K-SIS 3.0) in patients with stroke. Methods: Patients with stroke longer than 3 months were invited to participate in the study at specialized rehabilitation centers in Busan. Information on patients was collected using Mini-Mental State Examination (MMSE), Modified Bathel Index (MBI), Beck Depression Index (BDI), WHODAS 2.0-12 item, and K-SIS. Floor and ceiling effects of each domain of K-SIS were examined. The internal consistency of each domain of the K-SIS was calculated using Cronbach's ${\alpha}$. Correlation between K-SIS and each scale was assessed using Spearman's correlation coefficient. Results: Ninety subjects participated in the study. The K-SIS was found to have excellent internal consistency (Cronbach's ${\alpha}=0.93$). Each domain of the consistency ranged from 0.86 to 0.94, except the emotion (${\alpha}=0.51$). Significant correlations were observed between MMSE and domains of memory and thinking, and communication (r=0.48 and 0.52 respectively). BDI was negatively related to domains of emotion, ADL, mobility, and participation (r=-0.43, -0.49, -0.52 and -0.33 respectively). Specific daily activity (MBI) and general functioning (WHODAS 2.0) were also found to be closely related to the domains of ADL, mobility, and participation (ranging from r=-0.41 to r=-0.59). No ceiling and floor effect was observed. Conclusion: Excellent reliability and validity of K-SIS were obtained in the study and it could be suggested that K-SIS may be used for patients with stroke for collection of information on functioning in the clinical context.

• 한국화재소방학회논문지
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• 제20권4호
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• pp.1-12
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• 2006

경사계단통로의 천장 아래로 확산되는 연기의 냉각 및 일시 차단을 위해 설치된 2개의 스프링클러헤드와 깊이가 0.54m인 제연커텐의 통합작동시 그 제연성능을 조사하기 위해 제연구역의 크기가 $17.92m{\times}4.00m{\times}6.12m$인 단일계단통로의 화재모형에 대해 FDS로 화재모의실험을 수행하였다. 스프링클러헤드 반응시간은 화재크기가 증가할수록 감소하며, 제연커텐이 있는 경우가 없는 경우보다 1.1초 증가하고, 화원에서 경사통로출구까지 연기전파시간은 화재크기가 증가할수록 상당히 감소하며, 연기전파지연효과는 스프링클러의 작동여부와는 관계가 없음을 확인할 수 있었다. 스프링클러와 제연커텐의 통합작동은 연기냉각측면에서는 효과가 큰 반면 연기전파지연측면에서는 작지만 효과가 있는 것을 확인할 수 있었다. 살수냉각효과에 의해 경사통로에는 고온연기층의 복사열유속의 화상위험은 감소되나, 헤드살수의 하향끌림과 연기와 공기의 혼합 난류 현상에 의해 경사통로 입구부 주변에는 짙은 연기층이 형성되어 시계약화 및 연기질식 위험은 증가하여 피난에 어려움이 가중될 것으로 사료된다.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.154-158
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• 2009

The vortex ventilation system (VV) which uses a rotating finned swirler installed coaxially with the exhaust duct is a very effective local ventilator. VV can enhance the capture depth by a factor of 3-5 compared to the conventional exhaust hood, in the absence of any solid walls nearby. In real situations there may exist ceiling, side wall and floor, all of which can affect the flow field and suction performance by way of the no-slip condition on the walls. 3D CFD simulation was performed in order to see the effect of the floor on the capture performance of the VV. The presence of floor reduced suction flow velocity, and increased the critical rotational speed which is the rotational speed required for stable vortex formation. Flow velocity profile along the axis could be well approximated by a universal functional form when the distance from the exhaust inlet is non-dimensionalized by the distance to the floor. Capture depth, define by the distance from the exhaust inlet to a point of velocity decreased to 10% of that at the inlet, is reduced by about 10% when the floor distance is 6 times the exhaust hood diameter.

• 한국건축시공학회지
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• 제8권5호
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• pp.93-99
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• 2008

The environment draws attention in the global community and a growing number of Koreans have interest in improving the quality of life, the importance of house environment has attracted the attention of the public. Against this backdrop, constructors have unveiled environmentally -friendly projects. However, they failed to establish people-oriented environment by being occupied with maximizing profitability through the improvement of brand image and caused sick house syndrome that has recently made controversy. In this regard, the study analyzed the mechanism of discharge of TVOC, one of the sick house syndrome-causing materials, that affects IAQ and its characteristics and examined the effect that granodiorite has on reduction of the discharge of TVOC in order to minimize damage. Experimental sample consisted of interior finishing materials frequently used in ceiling, wall and floor and adhesives used at a time of construction, and the TVOC of building materials was measured through the use of septum bottle unlike In the existing chamber method. Measures to counter the sick house syndrome were suggested by reducing the possible damage from the stage of selection of building material and by figuring out the effect that the granodiorite has on reduction of the discharge of TVOC.

• KIEAE Journal
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• 제7권2호
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• pp.57-62
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• 2007

Recently Among indoor noises plumbing noise from supply and drain water pipe is being pointed out as a annoying noise following to floor impact noise, and it is increasing the rate to point the noise due to the following several reasons: water pressure, vibration by fabricated structures and direct noise propagation from upper floor through ceiling This study aims to analyse the characteristics of toilet stool plumbing noise in apartment bathroom which are generated by crossing plumbings and elbows. And it analyse the effect of noise reduction by soundproofing and insulations which are covered at crossing plumbings. And also analyse the characteristics of noise about a type of elbows, crossing plumbing and result of dB(A). At last it provide a fundamental data for the purpose of reduction of plumbing noise in apartment.

• International Journal of Air-Conditioning and Refrigeration
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• 제15권3호
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• pp.101-107
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• 2007

Indoor air quality becomes of a concern recently in view of human health. This study investigates the air diffusion performance and the air change efficiency of a classroom, when outdoor air is introduced in two different ways in addition to the heating/cooling operation of a ceiling-mounted heat pump. A CFD analysis has been performed to investigate the effect of the discharge angle of the air jets from the heat pump for both parallel and series types of outdoor air system. It is observed that the series type creates more uniform indoor environment compared to the parallel type in general. It can be concluded the discharge angle should not be larger than 40o for the parallel type, in order not to generate thermal stratification in the room.

• 한국실내디자인학회논문집
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• 제3호
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• pp.10-17
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• 1994

Restaurant is a settign for est and social intercousrse fo rpeople in the cities, and is essential to provide its users with pleasant and comfort space. Color is used as a design tool which has most powerful effect to change the nature of a space and atmosphere, As a basic study for desirable environmental color for restaurant, this is studied mainly on the following discussion points. 1) Inportance of environmental color and its role in accordance with space characteristics as restaurant. 2) The psychological effects of color in the clinetes, color conditioning of the dining ares, problem of change in the appearance of color in the selection of materials and color harmony of total environments. 3) Prior to color planning in detail , the nature and characteristics each restaurant contains and their correlation with various locational , physical , social environmental , human variables have been analyzed. And the total atmosphere of the dining area as a place where the clients finally stay has been dealt with various visual , environmental and functional problems of color about fixed elements such as the wall. the floor, the ceiling and semifixed elements such as tables, chairs, etc.

• 설비공학논문집
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• 제6권3호
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• pp.267-281
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• 1994

The Combustion gas behavior induced by fire in a building is numerically investigated. The typical building for this analysis is partially divided by a vertical baffle projecting from the ceiling. The solution procedure includes the low Reynolds number ${\kappa}-{\varepsilon}$ model for the turbulent flow and the discrete ordinates method is used for the calculation of radiative heat transfer equation. The effects of the location and size of fire source and baffle length on velocity and temperature distributions, species mass fraction and flame location are analyzed. As the results of this study, it is found that the case when the fire source is located at the vertical wall is more dangerous than at the bottom wall in view of the combustion products and flame location. It is also found that the radiation effect cannot be neglected in analyzing the building in fire.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.300-303
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• 2004

In this paper, floor impact noise reduction in a cruise ship cabin by using floating floor is studied. A mock-up is built by using 61 steel plate, and two identical cabins are made where 25t panel is used to construct wall and ceiling inside the steel structure. Various floating floor systems are tested for which normalized impact noise is measured according to ISO 140-7 It is shown that effect of VL(Visco-elastic Layer) is negligible when it is used between deck and mineral wool, since most vibration absorption occurs in the wool. In addition, direction of the mineral wool fiber affects impact noise significantly.