• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.7
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• pp.543-551
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• 2002

Gravity ventilators allow the escape of the warm air and air contaminants due to both (either) buoyancy and (or) convection. As a natural ventilation strategy, various gravity ventilators can be installed on the roof. Ventilation efficiency could be affected by various parameters, such as, area of openings, wind velocity and incidence angle, temperature difference between inside and outside, and shape of ventilator. Especially, the shape of roof gravity ventilator might be one of influencing factors for the effective ventilation. The window type gravity ventilators are frequently installed instead of general (standard) gravity ventilator. However, the ventilation efficiencies of them were not proved yet. To compare the ventilation efficiency, general type ventilator and two window type ventilators were numerically tested. Mean age of air, temperature and CO concentration were predicted by using commercial CFD code, AIRPAK (Ver. 2.0) with various conditions. The predicted result showed that general type ventilator is more effective for natural ventilation than window type ventilators.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.1
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• pp.46-51
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• 2014

Objectives: The principal aim of this study was to compare the concentrations of gaseous pollutants emitted in enclosed pig buildings between different rates of general ventilation and determine the variations in the patterns of gaseous pollutants as affected by ventilation rate. Materials and Methods: The experiment was performed in the growing/finishing room($20.0m{\times}12.0m{\times}3.0m$) of a pig confinement building located on the experimental farm of Seoul National University. The conditions of the general ventilation rate for three treatments were 30%($4.12m^3s^{-1}$), 50%($6.87m^3s^{-1}$) and 70%($9.61m^3s^{-1}$). The data presented in the study were collected overa total of 45 days, 15 days for each of the three treatments from March to May 2011. A total of six air samplings were taken at 1.5m above the floor of the pig building. The environmental agents measured in the pig building were ammonia, hydrogen sulfide and odor concentration index for gaseous pollutants with temperature and hydrogen sulfide for thermal factors. Results: There were significant differences in the ammonia and odor concentration index in the pig building among the three general ventilation rate conditions(p<0.05), whereas hydrogen sulfide did not show a significant difference among three conditions of general ventilation rate(p>0.05). As the general ventilation rate applied to the pig building increases, it appears that all the indoor environmental agents measured in this study simultaneously decrease. Conclusions: The gaseous pollutants significantly affected by the general ventilation rate in pig building were ammonia and odor concentration index(p<0.05). However, it was found that hydrogen sulfide and thermal factors, temperature and relative humidity were not influenced significantly by variation in the general ventilation rate.

• KIEAE Journal
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• v.4 no.3
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• pp.187-194
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• 2004

In many other buildings, hospital is very important because of its function and purpose. A proper building service systems including heating, cooling, ventilation and plumbing systems is required in hospial. Besides, a special systems like medical gas, vacuum cleaning systems are required to prevent contamination as well as cure a patient in hospital. Ventilation is very important method to keep the indoor pressure and clean class. There are some specific rooms to consider clean class and indoor pressure in the general hospital. In this article, specific rooms were set to operating room, laboratory, ICU, isolation unit, and sterilizer room. In this case study, design factors of ventilation system, including air changes of OA and TA, indoor pressure, clean class, filter, and material of system, of specific rooms in hospital were proposed through a literature research and a design examples review.

• Korean Journal of Bronchoesophagology
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• v.1 no.1
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• pp.109-115
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• 1995

High frequency Jet ventilation (HFJV) via cricothyroid membrane puncture contols frequency of ventilation as 20-200/min and persuits adequate gas exchange. HFJV was known to have advantages such as improvement of PaO$_2$, lesser barotrauma, stable hemodynamic effects, good operative field and lesser movement of head. The purpose of this study was to clarify the advantages of HFJV in cases of microlaryngeal surgery which operating time was expected even within 30 minutes. Twenty-eight patients were divided two groups : 1)control group : general endotracheal Intubation anesthesia. 2)experimental group : HFJV via cricothyroid membrane puncture with intravenous anesthesia, frequency 40/min, I/E ratio 40%, driving pressure 40 psi. We analyzed blood pressure, arterial blood gas, score of general condition and recovery time after operation. In conclusion, HFJV via cricothyroid membrane puncture had a good score of general condition and rapid recovery of consciousness, although some accumulation of P$CO_2$and elevation of blood pressure.

• Korean Journal of Poultry Science
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• v.21 no.3
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• pp.207-217
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• 1994

This is to provide basic information and technical data, supported by literature search, for use in designing and /or evaluating ventilation systems for broiler shelters. At first, the general design information including weather data, building requirements, ventilation requirements, and supplemental heating and cooling, was presented. Then, environment requirements for broilers, which are for temperature, humidity, air movement, radiant heat, were described and the optimal ventilation systems for broiler were developed.

• KIEAE Journal
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• v.9 no.4
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• pp.17-22
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• 2009

It is common to design the duct branches where to supply the required air flow for individual room in residential apartment house. However it is difficult to adjust the air volume adequately in small air duct branches in residential ventilation system. The purpose of this study is to figure out the performance of Multidrop chamber coupling system for the residential ventilation system. The experiments were designed to simulate apartment of $84m^2$ and established multidrop chamber duct and general duct on the ceiling of the apartment. Distribution performance of air supply rate were evaluated in this experiments. As a result, distribution performance of air supply rate in the general duct is different from designed air supply rate by about 35% ~ 50% and about 10% in the multidrop chamber system. In additional the sound insulation performance of the multidrop chamber system decreased about 20% compared with general duct system. Therefore, the multidrop chamber system is considered to satisfy proper air supply rate of each room and to improve the sound insulation performance in apartment Houses.

• Archives of Craniofacial Surgery
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• v.9 no.2
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• pp.77-80
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• 2008

Purpose: The majority of nasal fractures have been treated by closed reduction. And they were manipulated under local anesthesia or general anesthesia. Under the local anesthesia, patients can feel the pain and fear, so general anesthesia through the endotracheal intubation became popularized recently to treat the nasal fracture. But it has still the drawbacks of postanesthetic complication. Therefore, under the mask ventilation anesthesia using oral airway, we tried to manipulate the nasal fracture. Methods: From July 2007 to November 2007, we worked with fifty patients that were manipulated the nasal fracture. Fifty patients were divided into two groups, general anesthesia with the endotracheal intubation group(n=25) and the mask ventilation using oral airway group(n=25). We checked up the anesthesia time, postanesthetic complication, postoperative aesthetic & functional problem of nose in two groups. Results: In total operation time and sore throat frequency among the postoperative anesthetic complications, there was statistically significant difference between the mask ventilation group and the endotracheal intubation group(p<0.05). But there was no difference statistically in nausea frequency(p>0.05). And no patients complained of postoperative nasal complication such as septal deviation, septal perforation, nasal obstruction and hump nose in two groups. Conclusion: Through the mask ventilation using oral airway, we could reach satisfactory results in the anesthetic time and postanesthetic complication.

• Fashion & Textile Research Journal
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• v.16 no.3
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• pp.485-491
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• 2014

This study verified the effect of summer flight ventilation developed in a previous study based on wearing comfort evaluation. Seven healthy males in their twenties volunteered for this experiment conducted in aclimatic chamber. The experiment consisted of three consecutive periods of rest (20 minutes), running on a treadmill (10 minutes) and recovery (20 minutes). A comparative evaluation was conducted on the general flight suit which had no ventilation holes and summer flight suit that use subjective satisfaction measures and objective measures. The subjective satisfaction was evaluated according to the criteria of temperature sensation, wet sensation, thermal comfort and fatigue sensation. The objective satisfaction was measured by skin temperature, microclimate (temperature and humidity), sweat rate and thermography. The comparative wearing evaluation identified the summer flight suit decreased the temperature between skin and suit by $0.42^{\circ}C$ (upper arm), $0.9^{\circ}C$ (calf) and the skin temperature by $0.3^{\circ}C$ (shoulder), $0.4^{\circ}C$ (upper arm), $0.5^{\circ}C$ (calf) as compared to the general flight suit. The humidity inside the summer flight suit decreased at head (7.73%), shoulder (5.86%), upper arm (5.26%), and calf (8.73%) compared to the one inside the general flight suit. Thermography showed that the air flowed through ventilation holes (neck and armpit). The design of ventilation holes applied to the summer flight suit can be applicable to overall clothing that requires thermal comfort such as dust-free garments, mechanical clothing and combat uniforms.

• Journal of Environmental Science International
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• v.5 no.6
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• pp.683-697
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• 1996

Industrial ventilation is a crucial engineering measure to protect workers from hazardous airborne contaminants. Designing a ventilation system is not an easy task. To solve this problem, many U. S. computer programs and softwares have been developed. In Korea, asoftware, called as VPMC, was developed by Korea Industrial Safety Corporation. But VPMC could not stand alone since it can be used to design not a hood, but a ventilation system. In this research, therefore, a preprocessing software was developed. It can be used to design general ventilation system, canopy hood, open surface tank hood. The program was written in Microsoft Visual Basic. In near future, this software will be incorporated into a total package software which can be used to design a whole ventilation system.

• Land and Housing Review
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• v.10 no.3
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• pp.1-7
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• 2019

Indoor particulate matter(PM) is a carcinogen and needs to be removed and managed. It is generally reduced and removed through ventilation and filtration. Owing to the recent occurrence of high-concentration fine dust and yellow dust in the atmosphere, however, it is difficult to expect the purification of indoor air through the simple introduction of the outside air. For residential buildings, in particular, they are highly dependent on natural ventilation but the lack of natural ventilation is worsening because concerns over the inflow of external pollutants are increasing. Therefore, this study designed and manufactured a window ventilation system that does not require a duct to improve the maintenance and management problems of general ventilation system, and constructed indoor PM concentration change data through performance evaluation.