• Journal of Bio-Environment Control
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• v.11 no.4
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• pp.175-180
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• 2002

This study was conducted to examine the effect of row covering materials on the growth and yield of broccoli for early production in the open meld. Materials for plastic tunnel were row-covering (ventilating non-woven fabric), perforated film (2.3％ pore space) and P.E. film. The types of row covers were tunnel and covering period was one months after transplanting. The row cover and perforated film increased daily air and soil temperature by 3~4$^{\circ}C$ and 2~3$^{\circ}C$, respectively as compared to no covering. Also, relative humidities in those treatments were higher than those in P.E. and no covering. The row covering and perforated film enhanced plant growth. Broccoli grew best and abnormal head appeared the least with row covering treatment. Days taken for head formation, however, did not differ between treatments but the weight of curd was over 400 g in the treatment of row covering and perforated film covering. Marketable yield doubled under row covering as compared to no covering. The first harvest time was earlier by two weeks in row-covering. The results of this experiment indicated that covering row-cover film in spring cultivation was effective fer not only yield increase but also quality evaluation in early production of broccoli.

• Journal of Bio-Environment Control
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• v.29 no.3
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• pp.259-264
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• 2020

In this study, the humidity control effect of a counter-flow ventilator was analyzed in a greenhouse with high relative humidity at night in the winter season. A case of the counter-flow ventilator was 0.96 × 0.65× 0.82(W × D × H, m) and there were heat transfer element and two fans for air supply and exhaust in the counter-flow ventilator. Two counter-flow ventilators were used in this study and the setting humidity of the ventilators was 80%. The temperature and relative humidity at night(18:00-8:00) in the greenhouse were measured. In a greenhouse without a counter-flow ventilator, the average temperature and humidity was 14.9℃, 82.8%, respectively. When the counter-flow ventilator was operated, the corresponding averages were 15.1℃, 79.9%. The independent sample t test of monthly temperature and relative humidity showed no difference in temperature, and a significant difference in relative humidity with 1% of the significance level. Therefore, using the counter-flow ventilator helps to control relative humidity in greenhouse and increase yield.. And further research considering the pros and cons of using the counter-flow ventilator is needed.

• The Korean Journal of Emergency Medical Services
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• v.12 no.3
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• pp.17-26
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• 2008

Purpose : This study aimed to make comparison before and after CPR training for health college students (departments of visual optics, occupational therapy, and health welfare administration). The questionnaire consisted of self-efficacy, knowledge, and attitudes toward CPR affect performance ability. Through this study, the researchers tried to provide basic data in developing of cardiopulmonary resuscitation training programs and training methods for health college students. Methods : This study was applied to 83 health college students (departments of visual optics, occupational therapy, and health welfare administration) in G Province. Data were collected from September 22 to October 9, 2008. Analysis was performed by using SPSS WIN 12.0 Version program. Frequency analysis, t-test, ANOVA, and Pearson's correlation coefficients were used. Statistical significance was based on p < .05. Results : 1. There was an increase with(${\rightarrow}$ in) 1.69 point before education and 3.01 after education of artificial ventilation(p < .001). There was an increase in 1.46 point before education and 3.24 after education of airway(p < .001). There was an increase in 1.54 point before education and 2.84 after education of chest compression location(p < .001). There was an increase in 1.97 point before education and 3.13 after education of chest compression(p < .001). 2. The difference between self-efficacy, knowledge, and attitude before and after CPR education, the self-efficacy increased from 2.08 point before education(p < .001 to 3.18 point after education. Knowledge increased from 2.09 point before education(p < .001) to 3.28 point after education. Attitude increased from 1.75 point before education(p < .001 to 3.05 point after education. 3. The correlation between self-efficacy, knowledge, and attitude toward CPR), was not changed before education. After education, knowledge showed quantitative correlation(r = .219, p < .05) with attitude. 4. In regression analysis with the aim of examining influence of self-efficacy, knowledge, and attitude upon performance ability, the effect wasn't given to performance ability before education. After education, the self-efficacy was indicated to have significant effect on performance ability(p < .05).

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.441-447
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• 2021

It were investigated changes in internal and external temperature, relative humidity using tyvek, weedstop, and 35% shading net as covering material to reduce the freezing damage of 'Shiranui' hybrid mandarin grown in open field. It were also evaluated canopy covering effect and LT₅₀ of leaves by covering material when it was cold at -2℃. In tyvek, temperature difference between inside and outside was low at the height of 1.5m and was high at 0.4m. The relative humidity differed greatly between day and night, and was high at 6-8 a.m. At -2℃, Sum of temperature at the height of 1.5m of canopy for 24-hour after covering were at 3.4℃ higher in tyvek than in control. The LT₅₀ of leaves was at 1.51℃ in tyvek, 1.33℃ in withstop, and 1.61℃ in 35% shading net lower than in control. Considering thermal insulation and relative humidity in canopy, tyvek is expected to reduce low temperature damage when covering after making a fine hole for ventilation.

• Science of Emotion and Sensibility
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• v.24 no.4
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• pp.69-78
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• 2021

The development of smart healthcare wearables for health is accelerating. Among them, many wearable products using EMS electrical stimulation, which is one of the active research fields, have been released. However, the EMS wearable, which has been studied or released, is released in a comprehensive full-body suit that does not focus on muscle segmentation or a belt that covers the entire abdomen. Therefore, this study intends to use two breathing methods by applying an EMS pattern that subdivides specific muscles and attach a stretch sensor that can measure breathing to the abdominal pressure belt. The measurement method was conducted by inhaling and exhaling, and the subjects were 10 men in their 20s with healthy bodies. As a result of this study, the sensor's sensitivity was 5 and 3 mm, and the basic sensor in both thoracic and abdominal breathings and the EMS abdominal pressure belt showed improved respiration activation after applying electrical stimulation before and after application. It is concluded that, because of the two patterns produced based on the physical function, the difference in respiration activation effect and sensitivity between sensors could be confirmed with three sensors rather than not applying electrical stimulation suitable for the respiration method. Based on the results of this study, a follow-up study aims to develop breathing smart clothing that can be monitored in real time in clothing-type wearable products that incorporate EMS patterns and stretch sensors.

• Journal of Environmental Health Sciences
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• v.47 no.6
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• pp.540-547
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• 2021

Background: Indoor air pollutants are caused by a number of factors, such as coming in from the outside or being generated by internal activities. Typical indoor air pollutants include nitrogen dioxide and carbon monoxide from household items such as heating appliances and volatile organic compounds from building materials. In addition there is carbon dioxide from human breathing and bacteria from speaking, coughing, and sneezing. Objectives: According to recent research results, most indoor air pollution is known to be greatly affected by internal factors such as burning (biomass for cooking) and various pollutants. These pollutants can have a fatal effect on the human body due to a lack of ventilation facilities. Methods: We fabricated a polydopamine (PDA) layer with Ti substrates as a coating on supported glass fiber fabric to enhance its photo-activity. The PDA layer with TiO₂ was covalently attached to glass fiber fabric using the drop-casting method. The roughness and functional groups of the surface of the Ti substrate/PDA coated glass fiber fabric were verified through infrared imaging microscopy and field emission scanning electron microscopy (FE-SEM). The obtained hybrid Ti substrate/PDA coated glass fiber fabric was investigated for photocatalytic activity by the removal of ammonia and an epidermal Staphylococcus aureus reduction test with lamp (250 nm, 405 nm wavelength) at 24℃. Results: Antibacterial properties were found to reduce epidermal staphylococcus aureus in the Ti substrate/PDA coated glass fiber fabric under 405 nm after three hours. In addition, the Ti substrate/PDA coated glass fiber fabric of VOC reduction rate for ammonia was 50% under 405 nm after 30 min. Conclusions: An electron-hole pair due to photoexcitation is generated in the PDA layer and transferred to the conduction band of TiO₂. This generates a superoxide radical that degrades ammonia and removes epidermal Staphylococcus aureus.

• Journal of Environmental Impact Assessment
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• v.31 no.5
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• pp.286-295
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• 2022

In this study, the concentration distribution of indoor radon in Daejeon Metropolitan City was investigated and the reduction efficiency was evaluated by applying the radon reduction methods. Based on the results of the National Institute of Environmental Research, indoor radon measurements were conducted on 24 selected houses, and the average value of District A was 261 Bq/m3, far exceeding the standard, and even in the same house, indoor radon concentration was affected by measurement point and time. In the case of eight houses that applied the soil venting method to reduce radon, the indoorradon level was significantly lowerthan the standard value, and the average reduction efficiency was also around 55%, indicating a good reduction effect. In addition, the average reduction efficiency was around 90% in the two houses that carried out the shielding method, showing the very excellent effect of the indoorradon reduction. Even if the same reduction method is applied when reducing radon, the reduction efficiency may vary depending on various factors such as the structure of the building, the frequency of ventilation, and the season, so it is necessary to accurately evaluate the effectiveness of the reduction method in the future. Based on this, it is necessary to establish indoor radon management measures in Daejeon Metropolitan City to reduce human harm caused by radon exposure.

• Journal of The Korean Society of Integrative Medicine
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• v.12 no.1
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• pp.27-39
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• 2024

Purpose : Smoking is a major factor in chronic obstructive pulmonary disease (COPD), but the effect of electrical cigarette smoking on COPD development is still uncertain. This study aimed to compare the functions of airways and lungs exposed to combustible cigarettes and electrical cigarettes based on the pulmonary function test (PFT) results from the Korean National Health and Nutrition Examination Survey (NHANES). Methods : This study used data from 8,942 participants with PFT results out of 47,309 total subjects from the 6th to 8th Korean NHANES (2014-2015, 2016-2018, and 2019, respectively). Individuals with diseases such as cancer, ex-smokers, and dual tobacco users were excluded. The PFT results were analyzed according to the COPD diagnostic criteria. After adjusting for confounding variables, a complex sample generalized linear model ANOVA test was performed to investigate the association between PFT results and combustible smoker or electrical cigarette user groups. Results : In an analysis based on the obstructive ventilatory disorders (forced expiratory volume in 1 second[FEV₁]/forced vital capacity[FVC]<.7), combustible cigarette smokers showed a 3.46 times higher risk of COPD compared to non-smokers, while electrical cigarette smokers exhibited no significant difference in terms of COPD-related risks compared to non-smokers. FEV₁ showed a negative relation with combustible cigarette smokers as reported elsewhere (B=-.07, p<.001). FEV₁/FVC was negatively related to both combustible cigarette smokers (B=-.03, p<.001) and electrical cigarette smokers (B=-.02, p<.001). Conclusion : FEV₁/FVC decreases were observed in the long-term exposure to both combustible and electrical cigarettes. The lower FEV₁ in the combustible cigarette group implies the worsening of the severity of COPD, suggesting more damage to the airways and lungs in the short term. Therefore, the temporary electrical cigarettes use for the transition period in order to smoking cessation potentially aids to reduce the harmful effect of combustible cigarettes in COPD development.

• Journal of the Korean Society of School Health
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• v.37 no.1
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• pp.1-11
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• 2024

Purpose: The purpose of the study was to conduct a descriptive survey to examine the knowledge, infection prevention behaviors, and health beliefs regarding COVID-19 and to identify factors that influence infection prevention behaviors in elementary and middle school students based on the Health Belief Model. Methods: The study included 388 elementary and middle school students in Seoul, Gyeonggi, and Jeonbuk provinces. Data were collected from September 1 to September 15, 2023. The questionnaire consisted of 10 questions about COVID-19 knowledge, 13 questions about infection prevention behaviors, and 15 questions about health beliefs. The collected data were subjected to multiple hierarchical regression analyses. The cronbach's α of infection prevention behaviors was 0.83, the KR-20 of COVID-19 related knowledge was 0.68, and the Cronbach's α of COVID-19 related health beliefs was 0. 78. Results: In Model 1, females showed higher levels of infection prevention behaviors than males (β=.14, p=.006) and middle school students showed lower levels of infection prevention behaviors than elementary school students (β=-.10, p=.037). In Model 2, among COVID-19-related health beliefs, barriers had a significant negative effect on infection prevention behaviors (β=-.20, p<.001) and cues to action had a significant positive effect on infection prevention behaviors (β=.14, p=.037), indicating that lower barriers and higher cues to action were associated with higher levels of infection prevention behaviors. Conclusion: The results showed that prevention behaviors were associated with lower barriers and higher cues to action among COVID-19 health beliefs. Elementary and middle school students in Korea spend a lot of time in groups at private academies or school, which are closed spaces with poor ventilation, making them vulnerable to new infectious diseases such as COVID-19. Unlike adults, infectious diseases can have serious impact on their mental and social health. Therefore, it is necessary for schools to provide accurate and timely health education about COVID-19 to increase cues to action for elementary and middle school students in order to improve their infection prevention behaviors.

• Tuberculosis and Respiratory Diseases
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• v.43 no.6
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• pp.987-996
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• 1996

Background : We prospectively evaluated the applicability and effect of noninvasive ventilation (NIV) in acute respiratory failure and tried to find out the parameters that could predict successful application of NIV. Methods : Twenty-six out of 106 patients with either acute ventilatory failure (VF: $PaCO_2$ > 43 mm Hg with pH < 7.35) or oxygenation failure (OF: $PaO_2/AO_2$ < 300 mm Hg with $pH{\geq}7.35$) requiring mechanical ventilation were managed by NIV (CPAP + pressure suppon, or BiPAP) with face mask. Eleven out of 19 cases with VF (57.9%) (M : F=7 : $55.4{\pm}14.6$ yrs) and 15 out of 87 cases with OF (17.2%) (M : F=12 : 3, $50.6{\pm}15.6$ yrs) were s uilable for NIY. Respiratory rates, arterial blood gases and success rate of NIV were analyzed in each group. Results: 81.8% (9/11) of YF and 40% (6/15) of OF were successfully managed on NIV and were weruled from mechanical ventilator without resorting to endotracheal intubation. Complications were noted in 2 cases (nasal skin necrosis 1, gaseous gastric distension 1). In NIV for ventilatory failure, the respiration rate was significantly decreased at 12 hour of NIV ($34{\pm}9$ /min pre-NIV, $26{\pm}6$ /min at 12 hour of NIV, p=0.045), while $PaCO_2$ ($87.3{\pm}20.6$ mm Hg pre-NIV, $81.2{\pm}9.1$ mm Hg at 24 hour of NIV) and pH ($7.26{\pm}0.04$, $7.32{\pm}0.02$, respectively, p <0.05) were both significantly decreased at 24 hour of NIV In NIV for oxygenation failure, $PaCO_2$ were not different between the successful and the failed cases at pre-NIV and till 12 hours after NIV. The $PaO_2/FIO_2$ ratio, however, significantly improved at 0.5 hour of NIV in successful cases and were maintained at around 200 mm Hg (n=6 : at baseline, 0.5h, 6h, 12h : $120.0{\pm}19.6$, $218.9{\pm}98.3$, $191.3{\pm}55.2$, $232.8{\pm}17.6$ mm Hg, respectively, p=0.0211), but it did not rise in the failed cases (n=9 : $127.9{\pm}63.0$, $116.8{\pm}24.4$, $100.6{\pm}34.6$, $129.8{\pm}50.3$ mm Hg, respectively, p=0.5319). Conclusion : From the above results we conclude that NIV is effective for hypercapnic respiratory failure and its success was heralded by reduction of respiration rale before the reduction in $PaCO_2$ level. In hypoxic respiratory failure, NIV is much less effective, and the immediate improvement of $PaO_2/FIO_2$ ratio at 0.5h after application is thought to be a predictor of successful NIV.