• Pediatric Infection and Vaccine
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• v.28 no.2
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• pp.66-81
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• 2021

The coronavirus disease 2019 pandemic has been continuously spreading throughout the world. As of July 15, 2021, there have been more than 188 million confirmed cases and more than 4.06 million deaths. Although the incidence of severe infections is relatively low in children and adolescents compared to adults, a complication called multisystem inflammatory syndrome in children (MIS-C) may occur in some cases at approximately 2-6 weeks after severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. MIS-C can be seen in patients of various ages, from young infants to adolescents, and may present with diverse clinical manifestations. While fever present in a great majority of patients, symptoms suggesting the involvement of the digestive or nervous system and the skin and mucous membranes (Kawasaki disease-like symptoms) also appear in many cases. Cardiac involvement may also be observed, including left ventricular dysfunction, myocarditis, coronary artery dilatation, and coronary aneurysm. In some cases, hypotension or shock can occur, and mechanical ventilation or treatment in the intensive care unit may be necessary. Fortunately, recovery is generally reported after appropriate treatment. MIS-C is a rare but important complication of SARS-CoV-2 infection in children and adolescents. As such, it is important to recognize the clinical symptoms and provide appropriate treatment at an early stage. In this review, the epidemiology, clinical symptoms, suggested pathophysiology, diagnostic approach, and treatment of MIS-C will be discussed.

• Journal of Appropriate Technology
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• v.7 no.1
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• pp.51-58
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• 2021

This study proposes the design and implementation of a low-cost emergency ventilator which can be helpful during the COVID-19 pandemic where the supply of automatic ventilators is not smooth compared with the urgent demand worldwide. Easy implementation and lower price were made possible by using AMBU-bag and off-the-shelf embedded micro-controller board. Moreover, while 3D printing is used by companies and experts around the world to build prototype hardware, materials which are readily available from surrounding environments so that people in countries where it is difficult to access many advanced technologies could manufacture the system. The design features AMBU-bag automation, not use 3D printing, and it can contrl speed. By allowing speed control, ventilation can be performed according to the conditions of the patient being used. A complementary point in the study is that it is difficult to fix the start point of the wiper motor used first. A method for complementing this is a method for replacing the brush DC motor with a position feedback function. Secondly, the AMBU-bag may wear out in the long-term process of compressing the AMBU-bag because the arm and the fixing frame are made of wood. To complement this, the part of fixing frame and arm parts that the AMBU-bag touches need to be wrapped in a material such as silicon to minimize friction.

• Fire Science and Engineering
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• v.15 no.1
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• pp.23-33
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• 2001

The utility tunnels are the important facility as a mainstay of country because of the latest communication developments. However, the utilities tunnel is difficult to deal with in case of a fire accident. When a cable burns, the black smoke containing poisonous gas will be reduced. This black smoke goes into the tunnel, and makes it difficult to extinguish the fire. Therefore, when there was a fire in the utility tunnel, the central nerves of the country had been paralyzed, such as property damage, communication interruption, in addition to inconvenience for people. This paper is based on the fire occurred in the past, and reenacting the fire by making the real utilities tunnel model. The aim of this paper is the scientific analysis of the character image of the fire, and the verification of each fire protection system whether it works well after process of setting up a fire protection system in the utilities tunnel at a constant temperature. The fire experiment was equipped with the linear heat detector, the fire door, the connection water spray system and the ventilation system in the utilities tunnel. Fixed portion of an electric power supply cable was coated with a fire retardant coating, and a heating tube was covered with a fireproof. The result showed that the highest temperature was $932^{\circ}c$ and the linear heat detector was working at the constant temperature, and it pointed at the place of the fire on the receiving board, and Fixed portion of the electric power supply cable coated with the fire retardant coating did not work as the fireproof. The heating tube was covered with the fireproof about 30 minutes.

• Journal of Bio-Environment Control
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• v.22 no.2
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• pp.138-145
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• 2013

In order to develop the efficient control algorithm of the two-fluid fogging system, cooling experiments for the many different types of fogging cycles were conducted in tomato greenhouses. It showed that the cooling effect was 1.2 to $4.0^{\circ}C$ and the cooling efficiency was 8.2 to 32.9% on average. The cooling efficiency with fogging interval was highest in the case of the fogging cycle of 90 seconds. The cooling efficiency showed a tendency to increase as the fogging time increased and the stopping time decreased. As the spray rate of fog in the two-fluid fogging system increased, there was a tendency for the cooling efficiency to improve. However, as the inside air approaches its saturation level, even though the spray rate of fog increases, it does not lead to further evaporation. Thus, it can be inferred that increasing the spray rate of fog before the inside air reaches the saturation level could make higher the cooling efficiency. As cooling efficiency increases, the saturation deficit of inside air decreased and the difference between absolute humidity of inside and outside air increased. The more fog evaporated, the difference between absolute humidity of inside and outside air tended to increase and as the result, the discharge of vapor due to ventilation occurs more easily, which again lead to an increase in the evaporation rate and ultimately increase in the cooling efficiency. Regression analysis result on the saturation deficit of inside air showed that the fogging time needed to change of saturation deficit of $10g{\cdot}kg^{-1}$ was 120 seconds and stopping time was 60 seconds. But in order to decrease the amplitude of temperature and to increase the cooling efficiency, the fluctuation range of saturation deficit was set to $5g{\cdot}kg^{-1}$ and we decided that the fogging-stopping time of 60-30 seconds was more appropriate. Control types of two-fluid fogging systems were classified as computer control or simple control, and their control algorithms were derived. We recommend that if the two-fluid fogging system is controlled by manipulating only the set point of temperature, humidity, and on-off time, it would be best to set up the on-off time at 60-30 seconds in time control, the lower limit of air temperature at 30 to $32^{\circ}C$ and the upper limit of relative humidity at 85 to 90%.

• Journal of Bio-Environment Control
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• v.27 no.3
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• pp.253-259
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• 2018

This study set out to select a system to realize an optimal environment for strawberry cultivation greenhouses based on data about the growth and development of strawberry and its environment and to provide basic data for the research of its improved productivity. For these purposes, the investigator conducted a field survey with greenhouses for strawberry cultivation in western Gyeongnam. The findings show that farmers in their fifties and sixties accounted for the biggest part in the age groups of strawberry farmers. While those who were under 50 were accounted for approximately 67.5%, those who were 60 or older accounted for 32.5%. As for cultivation experiences, the majority of the farmers had ten years of cultivation experiences or less with some having 30 years of cultivation experiences or more. All the farmers built an arch type single span greenhouse. Those who used nutrient solutions were about 75.0%, being more than those who used soil. All of the farmers that used a nutrient solution adopted an elevated hydroponic system. The single span greenhouses were in the range of 7.5~8.5m, 1.3~1.8m and 2.5~3.5m for width, eaves, and ridge height, respectively, regardless of survey areas. The rafters interval was about 0.7~0.8m. In elevated hydroponic cultivation, the width, height, and interval of the beds were about 0.25m, 1.2m and 1.0m, respectively. As for the strawberry varieties, the domestic ones accounted for approximately 97.5% with Seolhyang being the most favorite one at about 65.0%. As for the internal environment factors of greenhouses, 38 farmers measured only temperature and relatively humidity. As for hydroponics, the farmers used a hydroponics control system. Except for the farmers that introduced a smart farm system for temperature and humidity control, approximately 85.0% controlled temperature and humidity only with a control panel for side windows and ventilation fans. As for heating and heat insulation, all of the farmers were using water curtains with many farmers using an oil or electric boiler, radiating lamp or non-woven fabric, as well, when necessary.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.2
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• pp.144-149
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• 2018

The eggs are incubated for 18 days through the generator and incubated in the developing incubator. During the developmental period, the weight loss of the fetus is correlated with the ventricular formation, and the proper ventricular formation is also associated with the healthy embryonic hatching and the egg hatching rate. However, in the incubator period of the domestic hatchery, it is a reality to acquire the resultant side by the Iranian standard weight measurement with the experience of the hatchery and the person concerned and the development period without the apparatus for measuring the present weight. As a result, prevalence of early mortality, hunger and illness during hatching are frequent. Monitoring the reduction of weaning weight is crucial to obtaining chick quality and hatching performance with weight changes within the development machine. Water loss is different depending on the size of eggs, egg shell, and elder group. We can expect to increase the hatching rate by measuring the weight change in real time and optimizing the ventilation change accordingly. There is a need to develop a real-time measurement system that can control 10 to 13% reduction of the total weight during hatching. The system through this study is a way to check the one - time directly when moving the existing egg, and it is impossible to control the measurement of the fetal water evaporation within the development period. Unlike systems that do not affect the hatching rate, four load cells are connected in parallel on the Arduino sketch board and the AT-command command is used to connect the mobile phone and computer in real time. The communication speed of Bluetooth was set to 15200 to match the communication speed of Arduino and Hyper-terminal program. The real - time monitoring system was designed to visually check the change of the weight of the fetus in the artificial incubator. In this way, we aimed to improve the hatching rate and health condition of the hatching eggs.

• Korean Journal of Environmental Agriculture
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• v.37 no.4
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• pp.268-276
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• 2018

BACKGROUND: In the month of January 2018, fine dust alerts and warnings were issued 36 times for $PM_{10}$ and 81 times for PM2.5. Air quality is becoming a serious issue nation-wide. Although interest in air-purifying plants is growing due to the controversy over the risk of chemical substances of regular air-purifying solutions, industrial spread of the plants has been limited due to their efficiency in air-conditioning perspective. METHODS AND RESULTS: This study aims to propose a vegetation-based bio-filter system that can assure total indoor air volume for the efficient application of air-purifying plants. In order to evaluate the quantitative performance of the system, time-series analysis was conducted on air-conditioning performance, indoor air quality, and comfort index improvement effects in a lecture room-style laboratory with 16 persons present in the room. The system provided 4.24 ACH ventilation rate and reduced indoor temperature by $1.6^{\circ}C$ and black bulb temperature by $1.0^{\circ}C$. Relative humidity increased by 24.4% and deteriorated comfort index. However, this seemed to be offset by turbulent flow created from the operation of air blowers. While $PM_{10}$ was reduced by 39.5% to $22.11{\mu}g/m^3$, $CO_2$ increased up to 1,329ppm. It is interpreted that released $CO_2$ could not be processed because light compensation point was not reached. As for the indoor comfort index, PMV was reduced by 83.6 % and PPD was reduced by 47.0% on average, indicating that indoor space in a comfort range could be created by operating vegetation-based bio-filters. CONCLUSION: The study confirmed that the vegetation-based bio-filter system is effective in lowering indoor temperature and $PM_{10}$ and has positive effects on creating comfortable indoor space in terms of PMV and PPD.

• Korean Journal of Poultry Science
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• v.33 no.1
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• pp.57-63
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• 2006

This study was conducted to investigate the effect of ventilating system of environmental controlled broiler house on broiler production. Three hundred eighty four broiler chicks (Hubbard, mean live weight of $44.5{\pm}2.0g/bird$) were reared for 2 wk. The results of the present study were summarized as follows : 1. Ammonia gas production was lower in the second and the third floors of cages compared with first floor of cages 13.5 and 13.5 vs 14.6 ppm, respectively). The observations of ammonia production in the morning and afternoon were similar. The production of carbon dioxide was not different between morning and afternoon, but it was tended to decrease in the forth floor of cages due to a fresh air 2. A wind velocity in the enclosed house was similar across lower, middle and upper section (0.57m/sec, 0.22m/sec and 0.04msec, respectively). In order to maintain an optimal air flow velocity in the cages, the duct entrance was punched, and then the air flow was full-round in the overall space in the cage. 3. Daily liveweight gain, feed intakes, and feed efficiency were not significant differences among treatments during whole experimental period (P>0.05). Therefore, the present results showed that temperature, moisture and atmosphere controlling were desirable, and air flew evenly in the cage.

• Journal of the Korean Institute of Landscape Architecture
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• v.48 no.5
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• pp.80-88
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• 2020

With the issuance of one-week fine dust emergency reduction measures in March 2019, the public's anxiety about fine dust is increasingly growing. In order to assess the application of air purifying plant-based bio-filters to public facilities, this study presented a method for measuring pollutant reduction effects by creating an indoor environment for continuous discharge of particle pollutants and conducted basic studies to verify whether indoor air quality has improved through the system. In this study conducted in a lecture room in spring, the background concentration was created by using mosquito repellent incense as a pollutant one hour before monitoring. Then, according to the schedule, the fine dust reduction capacity was monitored by irrigating for two hours and venting air for one hour. PM₁₀, PM_2.5, and temperature & humidity sensors were installed two meters front of the bio-filters, and velocity probes were installed at the center of the three air vents to conduct time-series monitoring. The average face velocity of three air vents set up in the bio-filter was 0.38±0.16 m/s. Total air-conditioning air volume was calculated at 776.89±320.16㎥/h by applying an air vent area of 0.29m×0.65m after deducing damper area. With the system in operation, average temperature and average relative humidity were maintained at 21.5-22.3℃, and 63.79-73.6%, respectively, which indicates that it satisfies temperature and humidity range of various conditions of preceding studies. When the effects of raising relatively humidity rapidly by operating system's air-conditioning function are used efficiently, it would be possible to reduce indoor fine dust and maintain appropriate relative humidity seasonally. Concentration of fine dust increased the same in all cycles before operating the bio-filter system. After operating the system, in cycle 1 blast section (C-1, β=-3.83, β=-2.45), particulate matters (PM₁₀) were lowered by up to 28.8% or 560.3㎍/㎥ and fine particulate matters (PM_2.5) were reduced by up to 28.0% or 350.0㎍/㎥. Then, the concentration of find dust (PM₁₀, PM_2.5) was reduced by up to 32.6% or 647.0㎍/㎥ and 32.4% or 401.3㎍/㎥ respectively through reduction in cycle 2 blast section (C-2, β=-5.50, β=-3.30) and up to 30.8% or 732.7㎍/㎥ and 31.0% or 459.3㎍/㎥ respectively through reduction in cycle 3 blast section (C-3, β=5.48, β=-3.51). By referring to standards and regulations related to the installation of vegetation bio-filters in public facilities, this study provided plans on how to set up objective performance evaluation environment. By doing so, it was possible to create monitoring infrastructure more objective than a regular lecture room environment and secure relatively reliable data.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.3
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• pp.100-119
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• 2020

During recent years, the heat environment and particulate matter (PM₁₀) have become serious environmental problems, as increases in heat waves due to rising global temperature interact with weakening atmospheric wind speeds. There exist urban heat islands and urban pollution islands with higher temperatures and air pollution concentrations than other areas. However, few studies have examined these issues together because of a lack of micro-scale data, which can be constructed from spatial data. Today, with the help of satellite images and big data collected by private telecommunication companies, detailed spatial distribution analyses are possible. Therefore, this study aimed to examine the spatial distribution patterns of urban heat islands and urban pollution islands within Busan Metropolitan City and to compare the distributions of the two phenomena. In this study, the land surface temperature of Landsat 8 satellite images, air temperature and particulate matter concentration data derived from a private automated meteorological observation system were gridded in 30m × 30m units, and spatial analysis was performed. Analysis showed that simultaneous zones of urban heat islands and urban pollution islands included some vulnerable residential areas and industrial areas. The political migration areas such as Seo-dong and Bansong-dong, representative vulnerable residential areas in Busan, were included in the co-occurring areas. The areas have a high density of buildings and poor ventilation, most of whose residents are vulnerable to heat waves and air pollution; thus, these areas must be considered first when establishing related policies. In the industrial areas included in the co-occurring areas, concrete or asphalt concrete-based impervious surfaces accounted for an absolute majority, and not only was the proportion of vegetation insufficient, there was also considerable vehicular traffic. A hot-spot analysis examining the reliability of the analysis confirmed that more than 99.96% of the regions corresponded to hot-spot areas at a 99% confidence level.