• Journal of the Korea Computer Graphics Society
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• v.27 no.3
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• pp.43-53
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• 2021

This paper presents an interactive wind system that generates artificial winds in a virtual reality (VR) environment according to online user inputs from a steering wheel and an acceleration pedal. Our system is composed of a head-mounted display (HMD) and three electric fans to make the user sense touch from the winds blowing from three different directions in a racing car VR application. To evaluate the effectiveness of the winds for reducing VR cybersickness, we employ the simulator sickness questionnaire (SSQ), which is one of the most common measures for cybersickness. We conducted experiments on 13 subjects for the racing car contents first with the winds and then without them or vice versa. Our results showed that the VR contents with the artificial winds clearly reduce cybersickness while providing a positive user experience.

• Atmosphere
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• v.28 no.4
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• pp.469-477
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• 2018

We performed the comparison of observed $PM_{10}$ and $PM_{2.5}$ at both the Yonsei University and the AIRKOREA site in the same Seodaemun-gu district, Seoul from March to December 2016. Generally, the moderate correlations between two sites were found for both $PM_{10}$ and $PM_{2.5}$, but monthly difference was somewhat occurred, implying that the measurement situation is not equally maintained even in a closely located area. Particularly correlations became weaker in June and July, which seems the impact of rainy conditions. Correlations between two stations were higher for $PM_{10}$ compared to $PM_{2.5}$, probably indicating the spatially larger difference of fine mode particle. Monthly mean variation was similar between two sites showing a maximum in March and minimum in August. Diurnal variation was somewhat different: morning peak at Yonsei University but evening peak at the Seodaemun-gu AIRKOREA site, reflecting the difference of local air condition. We also compared the extent of $PM_{10}$ and $PM_{2.5}$ according to the local wind speed and direction. In general, the level of particulate matter was high when the wind is blowing from the northwestern area with low wind speed, meaning the high accumulation effect of transported air particles. Findings of this study can be usefully considered for the investigation about the discrepancy of aerosol measurement in a local scale.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.3
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• pp.559-572
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• 2019

In the southeast sea of Korea, the cold water is concentrated in every summer, showing in abnormal oceanic conditions. Cold water occurred in the southeast sea is dominantly influenced by wind, which occurs when the south wind is continuously blowing for 3 to 7 days more. In this study, water temperature, wind speed and direction data of KMA, KHOA and KHNP, Chlorophyll-a of COMS/GOCI, GHRSST Level 4 SST of NASA, and red tide alert data of the National Institute of Fisheries Science were used to analyze the correlation between occurrence and change of the cold water and the red tide of Cochlodinium polykrikoides. The upwelling cold water mass showed a characteristic of moving northward along the current and occurrence a high concentration of chlorophyll along the water mass. Also, when the warm current were strong, the characteristic of red tide showed a northward moving.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.1
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• pp.23-31
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• 2021

Purpose : To compare the immediate effects of air stacking maneuver using resuscitator bags and balloons. Methods : Twenty healthy young adults participated in this study. Forced vital capacity (FVC) and peak cough flow (PCF) tests were performed at pre-intervention, and then, the maximum insufflation capacity (MIC), forced expiratory volume in 1 s (FEV1), FEV1/FVC, peak expiratory flow (PEF), and peak cough flow (PCF) were measured using the air stacking maneuver via resuscitator bags and balloons. Interventions were randomly performed, and a 40-min break was provided between interventions. The evaluation process in this study was conducted in accordance with the guidelines of the American Thoracic Society (ATS) 2019. To compare the three outcomes measured at pre-and post-interventions, repeated measures analysis of variance was performed. Results : A significant difference was found in the MIC, FEV1, PEF, and PCF after the air stacking maneuver using resuscitator bags and balloons, whereas no significant difference was observed between resuscitator bags and balloons. Conclusion : No significant difference was found in the immediate effect of the air stacking maneuver using resuscitator bags and balloons in this study. Air stacking maneuver using balloons can increase the success rate of the techniques by providing visual feedback on the amount of air insufflation when performed with balloon blowing exercise. Balloons are cheaper and easier to buy compared to manual resuscitator bags; therefore, education on the air stacking maneuver using balloons will have a positive effect on pulmonary rehabilitation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.10
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• pp.1288-1293
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• 2020

As fears of infection with the Corona 19 virus increase, an untact mood is also blowing in the real estate market. Changes in life style are bringing about changes in the way of life and patterns of consumption. In the real estate marketing market, such changes are inevitable. In particular, marketing using a real estate model house has the characteristics of marketing that is closely related to the denseness that many people visit in an enclosed space. These characteristics include all three features (airtight, dense, close), characteristics mentioned in the COVID-19 prevention rules. Therefore, in this study, we will look at ways to reinforce model house customer marketing in line with the untact (non-face-to-face) trend and to avoid the above three features, characteristics in the model house customer marketing process, and show the implementation results to avoid features. Through this, we propose a safe and expandable real estate marketing strategy through the avoidance of the three features of corona 19.

• Journal of Ocean Engineering and Technology
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• v.35 no.6
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• pp.414-425
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• 2021

Overcrowding of high-rise buildings in urban zones change the airflow pattern in the surrounding areas. This causes building wind, which adversely affects the wind environment. Building wind can generate more serious social damage under extreme weather conditions such as typhoons. In this study, to analyze the wind speed and wind speed ratio quantitatively, we installed five anemometers in Haeundae, where high-rise buildings are dense, and conducted on-site monitoring in the event of typhoon OMAIS to determine the characteristics of wind over skyscraper towers surround the other buildings. At point M-2, where the strongest wind speed was measured, the maximum average wind speed in 1 min was observed to be 28.99 m/s, which was 1.7 times stronger than that at the ocean observatory, of 17.0 m/s, at the same time. Furthermore, when the wind speed at the ocean observatory was 8.2 m/s, a strong wind speed of 24 m/s was blowing at point M-2, and the wind speed ratio compared to that at the ocean observatory was 2.92. It is judged that winds 2-3 times stronger than those at the surrounding areas can be induced under certain conditions due to the building wind effect. To verify the degree of wind speed, we introduced the Beaufort wind scale. The Beaufort numbers of wind speed data for the ocean observatory were mostly distributed from 2 to 6, and the maximum value was 8; however, for the observation point, values from 9 to 11 were observed. Through this study, it was possible to determine the characteristics of the wind environment in the area around high-rise buildings due to the building wind effect.

• Journal of Environmental Impact Assessment
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• v.31 no.5
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• pp.334-342
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• 2022

The stringent air environment conservation act forced to build an indoor dome for coal storage. However, it causes some problems due to accumulation of fly ash and harmful substances inside. To solve this problem, this study analyzed the pattern of internal airflow and the amount of ventilation for an indoor coal yard. Overall, the airflow inside the indoor coal yard tended to move to the southwest facing the mountain. In addition, sea-breeze was blowing from the northern louver window facing the sea, where airflow was flowing in. The total flow rate flowing into the indoor coal yard was 918,691 m³/h, and the number of natural ventilation per hour was 0.6 times. Therefore, it is proposed to install a forced ventilation device at the location where internal air flow is concentrated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.5
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• pp.98-107
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• 2021

During the sea trial test for the aerovane in AOE-II, a malfunction occurred in the wind detector movement around 40 to 90° on the starboard side and around 270 to 320° on the port side. The purpose of this study was to analyze and improve the cause of the above phenomenon. The wind detector was covered with a mast structure and was not affected directly by the blowing wind, and a vortex air current was formed behind the mast structure, causing the motion malfunction. The above problem was solved by moving and installing the wind detector on the newly installed mast yard. After conducting vibration analysis and reviewing the effects of vibration, the wind detector was installed in the new mast yard and verified by a sea trial test. Since the improvement plan was slightly effective, the position of the wind detector moved away from the mast on the new mast yard and was re-verified through a sea trial test. The movement malfunction of the wind detector did not occur, confirming that it is an appropriate improvement plan.

• Journal of Internet of Things and Convergence
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• v.7 no.4
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• pp.1-7
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• 2021

Recently, technological differentiation(sensor, AI) of products using IoT technology to satisfy consumer needs in the mature market for smart home appliances has received a lot of positive responses. However, air conditioner products are in the early stages of convergence technology. Therefore, air conditioner products are fields that require ICT technologies for information production, collection, processing, storage, and service development beyond IoT. In this paper, we collect and store contactless bio-signal using IR-UWB radar technology. The blowing direction of the air conditioning is controlled according to bio-signal and user's sleep is monitored to provide an optimal sleep environment. In addition, we propose a service algorithm that can provide comfort with changes in the optimal conditions of air conditioning and emotional lighting depending on the discomfort index environment. Through this study, we developed an intelligent smart air conditioning service platform with ICT technology of bio-signal, discomfort index, and emotional lighting.

• Journal of the Korea Institute of Building Construction
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• v.22 no.1
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• pp.115-123
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• 2022

Statistics on the occurrence of fires in residential facilities over the past 10 years, show that approximately 40% are fires in apartment buildings. To prevent the spread of fire and support evacuation in apartment housing, the fire resistance performance and performance design of fire doors are becoming more important. This study established a database using 395 quality inspection reports from 2016 to 2020, which passed the fire performance test, and derived the fire door performance-influencing factors through an analysis of the structure (12 elements) of the fire door. As a result, the effect of core material, adhesive, hinge type, blowing agent, etc. was confirmed in 287 pass cases. On the other hand, it was confirmed that the occurrence of flames and crevices in the 108 cases of failure were the major failure factors in the fire door fire resistance test. Fire doors are composed of composite materials to prevent failure of fire resistance performance, and efficient design and quality control are required through standardization of components.