• Title/Summary/Keyword: Ventilation Characteristics

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The effect of a risk factor on quantitative risk assessment in railway tunnel (철도터널에서 위험인자가 정량적 위험도 평가에 미치는 영향)

  • Yoo, Ji-Oh;Kim, Jin-Su;Rie, Dong-Ho;Shin, Hyun-Jun
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.17 no.2
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    • pp.117-125
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    • 2015
  • Quantitative risk assessment (QRA) of railway is to create a variety of scenario and to quantify the degree of risk by a result of the product of accident frequency and accident. Quantitative risk Assessment is affected by various factors such as tunnel specifications, characteristics of the fire, and relation of smoke control and evacuation direction. So in this study, it is conducted that how the way of smoke control and the relation of smoke control and evacuation direction affect quantitative risk assessment with variables (the tunnel length (2, 3, 4, 5, 6 km) and the slope (5, 15, 25‰)). As the result, in a train fire at the double track tunnel (Area = $97m^2$), it is most efficient to evacuate to the opposite direction of smoke control regardless of the location of train in train fire. In addition, under the same condition, index risk in mechanical ventilation up to 1/10.

A Study on Temporality of 'Phenomenology of music' in Rem Koolhaas's space (렘 콜하스 공간의 음악현상학적 시간성에 대한 연구)

  • Kang, So-Yeon;Yoon, Sang-Young;Yoon, Jae-Eun
    • Korean Institute of Interior Design Journal
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    • v.22 no.1
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    • pp.115-123
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    • 2013
  • Today, the views on Temporality of space have been changed not only to be based on the concept of time, but also to identify the space with a body adapted to the new circumstances. The study suggests that the actions of performers in space have been important by changes of views and are connected to the music phenomenology mixed with music whose tempo is the phenomenology related with of human consciousness itself, and derives the temporal property by putting them into Rem Koolhaas space with the fluid quality. According to Clifton's Phenomenology of Music, an understanding of music is made in both human body and consciousness as two ways to listen to sounds and enjoy music. Though a correlation between the characteristics of Clifton's Phenomenology of Music and one of resulted from uncertainty and immateriality of modern space Temporality, we could work out four kinds of characters which are the continuity of the fluidity from temporal programs, contrasting changes or synchronicity, the multidimensionality from synesthesia of line and face, ventilation by quality of the material and immaterial circumstances of sound effects, the implication in events resulted from cognition for information and unexpected actions, and the autonomy of the route of a variety of experiences including intimate connection of inter-related events and temporary and diverse external conditions. Hereby Temporality of musical phenomenology in Rem Koolhaas's space can be experienced by systems base oh the importance of host's motion, changes of programs according to the motion as well as uncertainty and immaterial changes. Due to the changes user's emotion and motion is undergone as Temporality that changes automatically.

A Study on the Characteristics of Non-hierachical Arrangement of SANAA's Work by Space Syntax (공간구문론을 이용한 SANAA 작품의 비위계적 공간구성 특성 연구)

  • Lee, Ki-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.8
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    • pp.735-744
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    • 2016
  • This study attempted quantitative analysis by space syntax on the plan of a non-hierarchical arrangement, which selected SANAA's work after Almere Stadt Theater, and analyzed the difference in the quantitative value of the non-hierarchical arrangement in plan that appears externally. The analysis results were as follows. First, SANAA's spaces with a non-hierarchical arrangement plan that appears externally showed a definite quantitative value difference, and had a hierarchical space difference in the plan that does not appear externally. Second, the spaces with a high integration value also had a high connectivity value, which is indicated by increasing the number of space openings using the method of giving hierarchy to the non-hierarchical arrangement plan or adjusting the size of the room or location to grant hidden hierarchy. Third, SANAA used exterior corridor rather than interior corridor in grid-type plan to solve the accessibility problem, and the open coat spaces between rooms provide natural lighting and ventilation and are used as equipment that controls the hidden hierarchy of space at the same time.

An Estimation of Performance Test and Uncertainty of Measurement for a Large Axial-flow Fan Based on ANSI/AMCA 210 Standard (ANSI/AMCA 210 기준에 의한 대형 축류 송풍기의 성능시험 및 측정 불확도 평가)

  • Ko, Hee-Hwan;Chung, Cheol-Young;Kim, Kyung-Yup
    • The KSFM Journal of Fluid Machinery
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    • v.17 no.2
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    • pp.24-29
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    • 2014
  • In general, a large-capacity axial flow fan is used for industrial processes or ventilation in a social overhead capital infrastructure. The main characteristics of the large axial-flow fan need a lot of electrical power consumption and operate 24 hours a day, 365 days a year. Since the large axial flow fan consumes several hundreds to thousands kW per hour, both manufacturer and consumer are struggling to select high efficiency products for saving energy and reducing operation cost. Therefore, the performance testing should be accurately conducted in experimental equipments. The performance estimation and uncertainty of measurement of the axial-flow fan gathered from the result from nozzle shaped testing equipments certified with ANSI/AMCA standard and duct shaped testing equipment under the same experimental condition. The experimental results from both facilities have maximum 17% differences in performance evaluation and uncertainty of measurement. As considering that the differences, it is doubt about the reliability of testing result. The test was repeated with the specific term during 12 months because it is important to fully reflect the real conditions and to decide the repeatability of data. The evaluation of duct type testing facilities was failed to get an uncertainty measure. Testing results were previously published. As a series of previous paper, axial fan (∅1690 mm) and duct type testing facilities were fabricated. The purpose of fabricating testing equipment was testing an uncertainty measurement under the controlled environments.

Respiratory air flow measuring technique without sensing element on the flow stream (호흡경로 상에 감지소자가 없는 새로운 호흡기류 계측기술)

  • Lee, In-Kwang;Park, Jun-Oh;Lee, Su-Ok;Shin, Eun-Young;Kim, Kyung-Chun;Kim, Kyung-Ah;Cha, Eun-Jong
    • Journal of Sensor Science and Technology
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    • v.18 no.4
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    • pp.294-300
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    • 2009
  • Cardiopulmonary resuscitation(CPR) is performed by artificial ventilation and thoracic compression for the patient under emergent situation to maintain at least the minimum level of respiration and blood circulation for life survival. Quality of the pre-hospital CPR not only significantly affects the patient's survival rate but also minimizes side effects caused by CPR. Good quality CPR requires monitoring respiration, however, traditional respiratory air flow transducers cannot be used because the transducer elements are located on the flow axis. The present study developed a new technique with no physical object on the flow stream but enabling the air flow measurement and easily incorporated with the CPR devices. A turbulence chamber was formed in the middle of the respiratory tube by locally enlarging the cross-sectional area where the flow related turbulence was generated inducing energy loss which was in turn converted into pressure difference. The turbulence chamber was simply an empty enlarged air space, thus no physical object was placed on the flow stream, but still the flow rate could be evaluated. Both inspiratory and expiratory flows were obtained with symmetric measurement characteristics. Quadratic curve fitting provided excellent calibration formula with a correlation coefficient>0.999 (P<0.0001) and the mean relative error<1 %. The present results can be usefully applied to accurately monitor the air flow rate during CPR.

Thoracic Trauma in Children (소아에서의 흉부외상)

  • 구본원;김성완
    • Journal of Chest Surgery
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    • v.30 no.1
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    • pp.77-82
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    • 1997
  • Sixty children were admitted to he Department of Thoracic and Cardiovascular Surgery, Kyungpook National University Hospital for the treatment of thoracic injuries for about a 10year period ending in August, 1995. We reviewed the hospital records retrospectively, to see the characteristics of the scope and consequences of childhood chest injuries. Mean age was 9 years and forty-six cases(77%) were male. Fifty children(83%) were victims of a blunt trauma. Among the blunt trauma patients, more than 60% were traffic-related. All victims of penetrating trauma were male. Among the blunt trauma patients, rib fracture was the most frequently found (52%) followed by pneumothorax(42%), although significant intrathoracic injuries occurred without rib fractures in )2% of blunt trauma cases. Associated injuries were present in 42% of children reviewed. Most frequently performed surgical procedure was closed thoracostomy(45% ), and ten children required thoracotomy and fifteen needed assisted ventilation. Modified Injury Severi y Scale(MISS) score was measured in the multiple Injured group. MISS score correlated significantly with the length of stay In the intensive care unit. One child(1.7% ), involved in a traffic accident, died of sepsis.

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Characteristics of Particulate Matter Generated during the Operation of a Small Directly Fired Coffee Roaster (소형 직화식 커피 로스터 이용 시 발생하는 미세먼지 특성 연구)

  • Yu, Da Eun;Kim, Seung Won
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.30 no.2
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    • pp.236-248
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    • 2020
  • Objectives: The purpose of this study was to evaluate the concentrations of particulate matter generated during coffee roasting and to study various factors affecting the concentrations. Methods: Differences in concentration levels were investigated based on various factors to understand the emission rates of particulate matter over time and to compare the mass and number concentrations according to their size. Sampling was performed in closed laboratories without the operation of air conditioning or ventilation. Optical Particle Sizer(OPS) was used as a measuring device. An OPS measures using a light-scattering method. Sampling was performed for sixty minutes at one-minute intervals. The background concentration was measured for about 30 minutes before starting of coffee roasting. The concentrations of particulate matter generated during coffee roasting were monitored until roasted coffee beans were removed from the roaster and cooled down. Several factors affecting the concentrations of particulate matter were investigated, which includes the origins of green beans, the roasting level, and the input amount of green beans. Results: The results of this study may be summarized as follows: 1) There was no difference in particulate matter concentration levels by the origin of the green beans, but a statistically significant difference in concentration levels by roasting level and the input amount of green beans; The higher the roasting level, the higher was the particulate matter concentration. The more green beans we put in the roaster, the higher were the concentrations; 2) The PM10 mass concentrations increased over time. The average concentration after roasting was higher than the average concentration during roasting; 3) In the distribution of mass and number concentration by particle diameter, the majority of particles was below 2.5 ㎛. Conclusions: Persons who work in roastery cafes can be exposed to high concentrations of particulate matter. Therefore, personal exposure and risk assessment should be conducted for roastery cafe workers.

The Characteristics of Persimmon Juice Dyeing Using Padding and UV Irradiation Method (Part I) -Color and Properties of Persimmon Juice Dyed Cotton Fabrics- (패딩과 자외선 조사법을 이용한 감즙 염색 특성(제1보) -감즙 염색 면직물의 염색성과 물성-)

  • 한영숙;이혜자;유혜자
    • Journal of the Korean Society of Clothing and Textiles
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    • v.28 no.6
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    • pp.795-806
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    • 2004
  • Unripe indigenous persimmons which contain rich tannins have been used as natural dye materials traditionally and have been using continuously for dyed clothes named Gal-ot in Jeju. Those persimmons were cheap and easy to use as dyes because of inedible and widely cultured in Korea. Persimmon juice dyes not only make fabrics brown-color but also give functional and hygienic properities such as stiffness, air ventilation of clothes, antibacterial activity, protectivity against ultraviolet light. However there are several serious problems which are ristriction of dyeing periods, longtime irradiation, uneven color and low color fastness etc. in persimmon juice dyeing. This study purpose to improve dye effect and method in order to enlarge useability of persimmon juice dyeing. Cotton fabrics were pad-dyed to 100% pick-up using padding machine after dipping in persimmon juice extracted from unripe persimmons indigenous from Jeju. It was possible and available to control pick-up rate. The color of dyed cotton fabrics by padding method was more even and repeatable than which by traditional hand method. Persimmon juice concentrations were 4 types of 10, 25, 50 and 100%. The more concentration increased, the more color deepened. UV Irradiation instead of sunlight was applied to color developing. Irradiation times were shortened till 1∼8 hrs. Same color values could be taken without water wetting which were required in sunlight irradiation. Tensile strengths of cotton fabrics pad-dyed with low concentration of persimmon juice decreased but recovered at high concentrations. Elongations(%) of cotton fabrics pad-dyed with persimmon juice were increased 1% more than undyed cotton in sunlight irradiation. Drape stiffness increased upto double times as much as.

Development of Tunnel-Environment Monitoring System and Its Installation II -Measurement in Gumjung Tunnel- (터널 환경 측정 시스템 개발 및 측정 II -금정터널 측정결과 분석-)

  • Park, Won-Hee;Cho, Youngmin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.4
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    • pp.758-765
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    • 2016
  • This paper is a follow-up paper to the publication, "Development of Tunnel-Environment Monitoring System and Its Installation I - Monitoring System and Measurement in Subway Tunnel" [1]. An environment monitoring system was installed in the 20.3-km-long Gumjung tunnel, which has the general structure of a high-speed double-track railway tunnel. Data were collected for approximately one year. Monthly and daily data were obtained and analyzed for the temperature and relative humidity in summer and winter months. This paper discusses the environmental characteristics at different positions in the tunnel. The results are expected to be widely used in studies on tunnel ventilation and the improvement of air quality and thermal environments.

A Comparative Experimental Study on Thermal Performance of Box-typed Double Skin and Curtain Wall in Cooling Period (박스형 이중외피와 커튼월의 냉방기 열적성능에 관한 비교실험 연구)

  • Park, Chang-Young;Lee, Keon-Ho;Yoon, Yong-Sang;Choi, Chang-Ho
    • Journal of the Korean Solar Energy Society
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    • v.27 no.2
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    • pp.111-119
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    • 2007
  • The annual mean temperature of South Korea has risen by $1.3^{\circ}C$ for last 100 years by urbanization and industrialization. Especially, the frequency of unusual hot weather in summer increases for a long time and the frequency of unusual cold weather in winter clearly decreases. In recently, The considerable portion of curtain wall system is appled to building skin in domestic. As related to this, the Korea Institute of Construction Technology devised the box typed double skin facade(It is occasionally called as FDFS : Functional Double Facade System) as an alternative that reflects the distinctive local climate and saves cooling energy. Two mock-ups($49m^*4.9m$) applied to single skin(curtain wall) and double skin each were monitored under the outdoor condition. Therefore, the characteristics of natural ventilation and cooling energy consumption of each window had been analyzed in real time. The results of this study are summarized as follow, Analysis of the experiment on an air conditioner: the indoor temperature of the chamber with FDFS is lower than that of the chamber with single skin facades by $3{\sim}6$ degrees(C). A temperature variation of about $1{\sim}2$ degrees between the 0.2m and 1.7m height of the mock-up occurs in FDFS, while that of about maximum 7 degrees occurs in single skin facade at noon with abundant intensity of solar accident. Also, 67 percent of energy consumption for air conditioning has been saved.