• The Korean Journal of Emergency Medical Services
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• v.26 no.3
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• pp.37-46
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• 2022

Purpose: TThe experiment was designed to compare the efficiency of ventilation between conventional BVM ventilation and a newly devised A-BVM ventilation method with Tidal volume, total ventilation rate, average Ventilation speed, and average Ventilation volume. Methods: 40 Paramedical students who agreed to participate in the study were analyzed. Values were measured using IMB PASS after 2 minutes of Brayden Pro manikin with BVM and A-BVM ventilation. The difference in general characteristics was assessed by t-test and ANOVA and the difference in ventilation methods was analyzed by IBM SPSS. Results: A significant difference was found between the two ventilation methods in terms of tidal volume (t=-11.203, p<.001), ventilation time (t=-3.834, p<.001), and optimum ventilation probability (t=10.770, p<.001). A-BVM ventilation method, rather than BVM ventilation method, showed a value close to the appropriate amount recommended by Korean Advanced Life Support (500~600mL) in tidal volume, and higher in optimum ventilation probability. Conclusion: We could identify the a better mode of ventilation. Further studies on the efficacy of existing BVM ventilation methods as compared to device augmented BVM ventilation methods should be carried out to ensure that adequate ventilation is available to patients in clinical practice.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.502-507
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• 2009

Trend of mechanical ventilation system applied to apartment house is introduced and feasibility study on installation of the individual room control ventilation as energy-saving method is carried out through field experiment. While initial cost of installation for the individual room control ventilation increases, the running cost is lower than the individual household control ventilation due to automatic flow rate control and reduction of fan power, and the management cost also decreases due to extension of use life of components. As the results of field experiment on $115m^2$-type apartment house, the individual room control ventilation could save the amount of 1,459.5Wh/day when compared with the individual room control ventilation

• Explosives and Blasting
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• v.24 no.2
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• pp.9-22
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• 2006

In general, tunnel construction except for special cases such as very short tunnels must require an artificial ventilation system. Especially, it is efficient for long tunnels to use the combination of a proper ventilation system according to the progress of the excavation. Neung-Dong Tunnel of which length is 4,580m has been originally designed as using ventilation system of blower and exhaust mixture types. Since it has been expected to result in some problems, its design Is analyzed to find the way to improve ventilation system by estimating the amount of required fresh air, considering various ventilation mixture types, ventilation's fluidity analysis and contaminant's distribution by numerical analysis. Economical efficiency for each type is also reviewed to determine the best ventilation system.

• Journal of the Korean Society of Tobacco Science
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• v.28 no.2
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• pp.136-143
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• 2006

This study was conducted to determine the amount of unprotonated nicotine in cigarette mainstream smoke and to investigate its relationship to level of filter ventilation and machine smoking conditions. Unprotonated nicotine from TPM trapped on a Cambridge filter pad(CFP) was adsorbed by Carboxen/PDMS SPME fiber, thermally desorbed and determined by GC/MS. 2R4F reference cigarette, twelve commercial brands from the Korean market and five test cigarette samples, which had the same tobacco blend with different levels of filter ventilation, were analyzed for unprotonated nicotine. In commercial brands, the amount of unprotonated nicotine changed slightly depending on the pH values of smoke, and decreased as the tar level increased. filter ventilation in these commercial cigarettes was $28{\sim}80%$ and the higher filter ventilation increased relative unprotonated nicotine levels, but not significantly. However, in five test cigarettes with different filter ventilation$(0{\sim}70%)$, unprotonated nicotine levels increased almost linearly with the level of filter ventilation. Concentrations of unprotonated nicotine in mainstream smoke generally increased in order $HC\;<\;ISO\;{\leq}\;MDPH$ machine smoking conditions. The ratio of unprotonated nicotine to total nicotine among $cigarettes({\alpha}_{fb})$ increased in order RC < MDPB < ISO conditions. Concentrations of unprotonated nicotine varied with three machine smoking conditions.

• Journal of Distribution Science
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• v.17 no.7
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• pp.65-76
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• 2019

Purpose - The purpose of this study is to investigate economical ventilation effectiveness to reduce hazardous materials exposure and damage of workers by analyzing exposure amount of noxious substances under various ventilation conditions of nail salon for indoor environments. Research design, data, and methodology - This study was carried out with cooperation of Nail shop located in SeongNam city to involve an analysis of the environmental impact indoor air quality, pollutant exposure and economical cost-effectiveness in the nail workplace. The hazardous substances were PM-10(Particulate Matter-10㎛), VOCs(Volatile Organic Compounds) and Formaldehyde, which are the major materials of nail workplace. Results - PM-10 is reduced by about 60% with air cleaner, forced artificial ventilation by 32%, and natural ventilation by about 12%. TVOCs and Formaldehyde showed similar efficiency (80~100%) after natural ventilation and ventilation after 60 minutes. The removal efficiencies of VOCs and formaldehyde were similar to those of natural ventilation and mechanical ventilation system. However, in case of dust, natural ventilation was reduced by artificial ventilation system due to inflow of external dust during natural ventilation. Conclusions - If the pollution degree of outdoor air is not high, air volume is high, and natural ventilation is performed when the air conditioning and heating system is not operated. Even at the end of the work, it keeps operating for 60 minutes to remove the pollutants generated. Results of this analysis demonstrated that the worker environment can be improved by adopting institutional legislation and guidelines for ventilation.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.5
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• pp.482-489
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• 2004

The purpose of this study is to reevaluate the performance of Hanji as a architectural material. Recent studies report that one of the causes of the Sick-HouseㆍSick-Building Syndrome is due to the contaminants from interior materials and the lack of ventilation. In this study, the properties of Hanji are investigated. The major focuses of this research are (1) how efficient the Hanji is for ventilation of the house and (2) whether the usage of Hanji brings required ventilation volume to the house. According to the test results, differential pressure in the air and the amount of ventilation showed linear relationship. Test results differ from various kinds of Hanji. Since houses usually have double window system, Hanji can be used to the windows system, especially for inner part of double window system. It is suggested that the combination of Hanji windows for the inner part and glass windows for outer part is very effective, and offers a solution to improvement of indoor air quality and the lack of ventilation with passive ventilation that has less energy consumption.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.9
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• pp.207-214
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• 2019

Natural ventilation through openings such as windows in school buildings is an efficient resource for natural cooling during the intermediate season of the year. Because the natural ventilation uses the wind outside the building, the amount of ventilation will depend not only on the wind speed and wind direction but also on the window layout and open window ratio. Therefore, in this study, the natural ventilation plans of school classroom windows are divided into 4 types and 8 cases as shown in Table 1. The characteristics of cooling effect by natural ventilation are simulated by applying Energyplus's Airflow Network Model and the comfort of the occupants is evaluated by the number of hours included in the 80% acceptability range of the ASHRAE Standard 55-2010 adaptive comfort model for the weekdays (Monday-Friday) and the class hours (08: 00-19: 00). Based on the analysis results of the above, this study presents basic data related to classroom cooling plan using intermediate season natural ventilation.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.163-167
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• 2008

In this study, the 1/35 reduced-scale model experiment were conducted to investigate designed ventilation effect on the smoke movement at rescue station fire in railway tunnel. A model tunnel with 2 mm thick, 10 m long, 0.19 m high and 0.26 m was made by using Froude number scaling law. The cross-passages installing escape door at the center were connected between incident tunnel and rescue tunnel. The n-heptane pool fires with heat release rate 698.97W were used as fire source. The fire source was located at the center and portal of incident tunnel as worst case. A operating ventilation system extracted smoke amount of 0.015 cms(cubic meters per second). The smoke temperature and CO gas concentration in cross-passage were measured to verify designed ventilation system. The result showed that, at center fire case without ventilation, smoke did not propagate to rescues station. In portal fire case, smoke spreaded to rescues station without ventilation. But smoke did not propagated to rescues station with designed ventilation.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.18 no.2
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• pp.115-121
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• 2008

In winter season, the survey was performed in three commercial office buildings in the metropolitan Seoul, Pusan, and Gwangju city. The purpose of the survey was to evaluate the effectiveness of ventilation for offices in commercial buildings. The data were compared to standard of applicable to the indoor ventilation in office. The results indicated that the most commercial office buildings used the air handing unit and fan coil unit as HVAC system, and the intake amount of fresh outdoor air were very inadequate to compared to the ASHRAE standard value of $0.57\;m^3/min/person$. Also the surveyed all commercial office building used the HVAC system as a meas of controlling temperature for office indoor air. Ultimately, these results presented that there were possibility of evoking indoor air quality problems by the insufficient ventilation.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.1
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• pp.62-62
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• 2001

The cigarette ventilation affects not only the amount of tar and nicotine delivery by a cigarette, but also the composition of the smoke. Therefore, it is important to stabilize of variability in cigarette ventilation that would be affected by changes in cigarette components. This work was conducted to determine the major factors that influence the cigarette ventilation and also to provide fundamental informations for improving the uniformity of cigarette performances. To evaluate the effect of cigarette ventilation as a dependant variable, the three independent factors were the air permeability of plugwrap, tipping paper and the filter pressure drop. We determined the effect of paper permeability on ventilation variability and the optimum condition in combinations of independent factors. The mean of cigarette ventilation was increased as plugwrap permeability increases, particularly at 26,000 CU. However, it was exhibited that standard deviation and coefficient of variation of the cigarette ventilation were decreased with increasing plugwrap permeability. At the 600 CU and 1,200 CU of tipping paper permeability, process capability index (Cp) of the cigarette ventilation increased as plugwrap permeability increases. Following the optimum condition of cigarette ventilation induced by fitted regression equation, one was to optimize 50% ventilation level is by combination with plugwrap permeability of 16,000 CU, tipping paper permeability of 810 CU, filter pressure drop of 319 mm$H_2O$, respectively.