• Title/Summary/Keyword: Air ventilation

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The Characteristics and Applications of Han-Ok in the Perception of their Residents and Experts (전문가와 거주자 인식 관점에서 본 한옥의 특성과 적용)

  • Lee, Min-Ah
    • Korean Journal of Human Ecology
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    • v.20 no.2
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    • pp.487-503
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    • 2011
  • The purpose of this study was to investigate residents' perceptions and attitudes towards Han-Ok based on a study of the characteristics and elements of Han-Ok that experts perceived. For the study, in-depth interviews were conducted and the data of 7 experts and 24 Han-Ok residents were analyzed. The results of the study were as follows. First, the characteristics of spatial arrangements are primarily emphasized and provide emotional stability for the residents. Placement on the ground, a suitable scale, appropriate openings and closures, hierarchical spatial system and a spatial relationship provide a feeling of comfort and protection. Second, the spaces and the materials of Han-Ok are considered the representative elements providing functionality and health. The close relationship between the inside and outside area makes the air naturally circulate and natural materials such as wood, soil, and paper have the function as natural ventilation, heat storage, and in the prevention of various illnesses. Third, residents in modern society put more of a value on experiences of natural environments that are usually impossible in the city. The simple and incomplete characteristics in using color, materials, and form, provide a culture of story telling and a leisurely lifestyle. Fourth, the cold and spatial inconvenience of Han-Ok are solved by partially using modernized equipment and material. The functionality of spatial systems in Han-Ok needs to be promoted in order to change the residents' perceptions of cold in Han-Ok.

Thoracoscopic Discectomy of the Herniated Thoracic Discs (흉추 추간판 탈출증에서 흉강경하 흉추간판 절제술)

  • Lee, Sang Ho;Lim, Sang Rak;Lee, Ho Yeon;Jeon, Sang Hyeop;Han, Young Mi;Jung, Byung Joo
    • Journal of Korean Neurosurgical Society
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    • v.29 no.12
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    • pp.1577-1583
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    • 2000
  • Objectives : Among the various types of minimally invasive spine surgeries, thoracoscopic surgery is becoming more widely accepted and increasingly utilized. This report delineates our clinical experience using thoracoscopy to resect herniated thoracic discs in 16 patients who suffered from myelopathy or intolerable radiculopathy. Patients and Methods : Between Mar. 1997 and Sep. 1999, 16 consecutive patients underwent thoracoscopic discectomy for treatment of herniated thoracic discs. There were 12 men and 4 women(mean age 43.5 years ; range 18-61 years). Eleven patients presented with myelopathic signs and symptoms from spinal cord compression and 5 patients had incapacitating thoracic radicular pain without myelopathy. The surgical level was varied between T3 and T12. The pathology of specimen were 11 hard discs and 5 soft discs herniations. Thoracoscopic techniques were performed with long narrow spine instruments and high speed drill through 3 or 4 ports under one lung ventilated general anesthesia. During the operation three patients were converted to open thoracotomy due to intolerable one lung ventilation, excessive bleeding and inadequate operation field. The mean operation time was 264min.(range : 100-420min.), and postoperative mean admission period was 11 days. Results : Clinical and neurological outcomes were good in all patients(mean follow-up period 20 months). Among the eleven myelopathic patients, 8 improved neurologically, and 3 stabilized. Among the five radiculopathic patients, 4 recovered completely and no patient had worsened. Postoperative complications were pleural effusion in one case, intercostal neuralgia in one, delayed hemopneumothorax in one, prolonged air leakage in one and pneumonia in one case. Conclusions : Thoracoscopic discectomy needs a steep learning curve to be familiar to anatomical space and handling of endoscopic instruments. However, it is technically feasible and can be effectively performed with acceptable results.

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Development of control and monitoring board for building energy saving valve (빌딩 에너지 절감 밸브용 제어 및 감시 보드 개발)

  • Oh, Jin-Seok;Kang, Young-Min;Jang, Jae-Hee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.22 no.6
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    • pp.895-902
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    • 2018
  • Energy consumption in buildings is close to 40% of the total national energy consumption in developed countries such as US and Japan, and Korea accounts for 24% of total energy consumption. In buildings, HVAC can't freely control the cooling flow rate according to the required calorie, so energy is not used efficiently. Therefore, by using the energy saving valve, the flow rate can be controlled by the required amount of heat and the energy can be saved. In this paper, we define basic conditions and develop control and monitoring boards for building energy saving valves based on PIC processor with low power and high cost-effectiveness. The designed board displays and transmits in real time information about two temperature values, flow values and calculated calories for temperature difference measurement. The developed board will be useful for real - time monitoring of the state of the valve in the future and development of the valve for the offshore.

Calibration and Performance Test of Hot-wire Anemometers by Using a Calibration Wind Tunnel (풍동장치를 이용한 열선풍소계의 보정 및 실태 평가)

  • Ha, Hyun-Chul;Kim, Tae-Hyeung;Kim, Eun-A;Kim, Jong-Chul;Oh, Jung-Ryng;Jung, Ho-Keun
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.9 no.2
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    • pp.110-122
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    • 1999
  • Hot-wire anemometers are most commonly used in measuring hood capture velocities due to their accuracy and convenience. But it was questionable that the anemometers being used in the field are accurate enough for the purpose of measurements. To answer this ques tion, a calibration wind tunnel was newly devised and tested. Subsequently, 53 hot-wire anemometers being currently used in the field were tested to evaluate the accuracy of anemometers. The average error was 16.93% while the average errors in the low (0.5~5m/s) and high (5~20m/s) velocity range were 17.40% and 16.45%, respectively. Most of anemometers underestimated the true velocities. It might be due to the contamination of hot-wire, resulting in the slow heat transfer between the sensor and air flow. Astonishingly, 16 of 53 anemometers were out of order due to the malfunctioning of zero adjustment control, power supply, display panel and sensor. It is desirable to calibrate periodically and clean the sensor after using in the dirty environment.

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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.

An Experimental Study on the Effect of Hanji Windows on Indoor Air Temperature and Humidity Control (한지창호의 실내 온.습도 조절효과에 관한 실험적 연구)

  • Jang Gil-Soo;Park Sa-Keun;Song Min-Jeong;Shin Hoon
    • Journal of the Korean housing association
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    • v.17 no.2
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    • pp.125-134
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    • 2006
  • The tightness of windows have devoted to the improvement of thermal insulation and energy saving in buildings. But it is known that this tightness causes some side effects such as low ventilation, low capacity to humidity and temperature control and these are not profitable for inhabitants. To act on these side effects, Korean traditional windows which are composed of Han-Ji(Koreand traditional paper) and Chang-Sal(Korean traditional wooden frame) have been studied to get a reasonable solutions for these problems. In this study, to compare the thermal and humidity control performance of current window(12 mm pair) and Korean traditional windows, frames which are made of existing window and Korean traditional windows are adapted to scale model house and then humidity and temperature of in and out of scale model house are measured and analysed. The results of this study are followings ; 1) When Korean traditional window charges 20cm(1/8 of total window area) from total window area, Han-Ji window has higher thermal insulation than that of existing window in daytime. There is the most big thermal difference when double faced with double-ply Han-Ji window is placed to mock-up house. In night-time, the temperature difference is very small so this means that Korean traditional window is good to cover direct sunlight in daytime and reduce the temperature of balcony. One faced with one-ply han-Ji window has the best humidity penetration performance among three type of Korean traditional windows. 2) When Korean window area enlarged to 40cm(1/4 of total window area), the function of 40cm width Han-Ji window is higher than that of 20cm's. This means that enlargement of Han-Ji window cover direct sunlight more and is more efficient in humidity penetration.

The First Case of Novel Influenza A (H1N1) Fatality in Korea

  • Seol, Hee-Yun;Eom, Jung-Seop;Kim, Mi-Hyun;Cho, Woo-Hyun;Kim, Ji-Eun;Kim, Ki-Uk;Jeon, Doo-Soo;Park, Hye-Kyung;Kim, Yun-Seong;Lee, Min-Ki;Park, Soon-Kew
    • Tuberculosis and Respiratory Diseases
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    • v.68 no.6
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    • pp.350-353
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    • 2010
  • Here we report the first fatality caused by H1N1 influenza virus infection with acute respiratory distress syndrome in Korea. A 55-year-old man presented at our emergency department with dyspnea, fever, diffuse myalgia and malaise. Bilateral lung air-space consolidation was detected on his initial chest radiograph combined with severe hypoxemia. He was supported by mechanical ventilation and treated with antibiotics. A nasopharyngeal aspirate was positive for influenza A rapid antigen and oseltamivir was started on day 3 of admission. The nasal swab sample was positive for influenza H1N1 virus by real-time reverse-transcriptase polymerase chain reaction. Despite aggressive treatment, he had refractory hypoxemia and uncontrolled septic shock. On day 5 of admission he went into cardiac arrest and expired.

Evaluation of Heating and Cooling Thermal Output Characteristics of Prefabricated Steel Wall Panel System for Radiant Heating and Cooling (강판 마감형 조립식 벽패널 복사냉난방시스템의 냉난방 방열 특성 평가)

  • Lim, Jae-Han;Koo, Bo-Kyoung;Kim, Sung-Im;Song, Seung-Yeong
    • Journal of the Korean Solar Energy Society
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    • v.33 no.2
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    • pp.70-77
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    • 2013
  • Recently the radiant panel heating and cooling system has been regarded as an alternative of low temperature heating and high temperature cooling by applying the renewable energy sources to the heating and cooling of buildings. Especially this system can be used as HVAC system alternatives in super high-rise buildings for energy saving and thermal comfort. Also it can be possible to reduce the plenum space because the minimum ventilation air will be supplied into the space. This study focused on the evaluation the basic characteristics of thermal output in prefabricated steel wall panel system for radiant heating and cooling. In order to evaluate the thermal output according to both various supply water temperatures and supply water flow rates, three-dimensional dynamic heat transfer analysis was performed. As results, for the heating mode, thermal output increased by 26% with the supply temperature increasing by $5^{\circ}C$. The surface temperature of panels range within $1{\sim}3^{\circ}C$. For the cooling mode, thermal output decreased by 18.2% with the supply temperature increasing by $2^{\circ}C$. The surface temperature of panels range within $0.5{\sim}1^{\circ}C$ and it was shown the even temperature distribution.