• Journal of the Korean Society of Earth Science Education
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• v.15 no.1
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• pp.91-102
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• 2022

Sinsu Island in Korea National Marine Park is suitable for geological learning and geotourism as various geological structures, geological activities, and fossils can be observed. In this study, eight geosites were developed by analyzing 2015 revision science curriculum. The 3D panoramic geological virtual field trips were developed according to the three-step outdoor learning model. The 3D panoramic geological virtual field trips, which consist of 8 classes, are composed of cooperative learning by group, enabling autonomous inquiry activities. It is designed to realize convergence education that can learn not only geology but also creativity and humanity through nodular Limestones, exfoliation, salt weathering, perforated shell holes, sedimentary structures and environments, dinosaurs habitats, and volcanic activity. Five experts revised and supplemented the Delphi analysis method to verify the validity of the development purpose and direction. The satisfaction with the geological field for Sinsu Island course was 4.52, indicating that the overall satisfaction with the field course was high. By reflecting on the opinions of each student and reinforcing safety education, we completed the 3D panoramic geological virtual field trips for Sinsu Island. The 3D panoramic geological virtual field trips in Sinsu Island in Korea National Marine Park will be a good example of geology learning tourism where you can make memories and enjoy while studying geology.

• Microbiology and Biotechnology Letters
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• v.50 no.2
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• pp.165-192
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• 2022

The microbial metagenome characteristics of bioaerosols and particulate matter (PM) in the outdoor atmospheric environment and the effects of climate and environmental factors on the metagenome were analyzed. The concentrations of bacteria and fungi in bioaerosols and PM were determined by sampling different regions with different environmental properties. A variety of culture-independent methods were used to analyze the microbial metagenome in aerosols and PM samples. In addition, the effects of meteorological and environmental factors on the diversity and metagenomes of bacteria and fungi were investigated. The survival, growth, and dispersal of the microorganisms in the atmosphere were markedly affected by local weather conditions and the air pollutant concentration. The concentration of airborne microorganisms increased as the temperature increased, but their concentration decreased in summer, due to the effects of high temperatures and strong ultraviolet rays. Humidity and microbial concentration were positively correlated, but when the humidity was too high, the dispersion of airborne microorganisms was inhibited. These comprehensive data on the microbial metagenome in bioaerosols and PM may be used to understand the roles and functions of microorganisms in the atmosphere, and to develop strategies and abatement techniques to address the environmental and public health problems caused by these microorganisms.

• Journal of the Korea Society of Computer and Information
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• v.27 no.7
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• pp.49-55
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• 2022

In this paper, we propose an obstacle detection method that can operate robustly even in external environmental factors such as weather. In particular, we propose an obstacle detection system that can accurately inform dangerous situations in AR through DB-based feature matching and RANSAC-based multiplane method. Since the approach to detecting obstacles based on images obtained by RGB cameras relies on images, the feature detection according to lighting is inaccurate, and it becomes difficult to detect obstacles because they are affected by lighting, natural light, or weather. In addition, it causes a large error in detecting obstacles on a number of planes generated due to complex terrain. To alleviate this problem, this paper efficiently and accurately detects obstacles regardless of lighting through DB-based feature matching. In addition, a criterion for classifying feature points is newly calculated by normalizing multiple planes to a single plane through RANSAC. As a result, the proposed method can efficiently detect obstacles regardless of lighting, natural light, and weather, and it is expected that it can be used to secure user safety because it can reliably detect surfaces in high and low or other terrains. In the proposed method, most of the experimental results on mobile devices reliably recognized indoor/outdoor obstacles.

• Journal of Internet Computing and Services
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• v.23 no.3
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• pp.13-20
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• 2022

IEEE 802.11ay Wi-Fi is the next generation wireless technology and operates in mmWave band. It supports the MU-MIMO (Multiple User Multiple Input Multiple Output) transmission in which an AP (Access Point) can transmit multiple data streams simultaneously to multiple STAs (Stations). To this end, the AP should perform MU-MIMO beamforming training with the STAs. For efficient MU-MIMO beamforming training, it is important for the AP to estimate signal strength measured at each STA at which multiple beams are used simultaneously. Therefore, in the paper, we propose a deep learning-based link quality estimation scheme. Our proposed scheme estimates the signal strength with high accuracy by utilizing a deep learning model pre-trained for a certain indoor or outdoor propagation scenario. Specifically, to estimate the signal strength of the multiple concurrent beams, our scheme uses the signal strengths of the respective single beams, which can be obtained without additional signaling overhead, as the input of the deep learning model. For performance evaluation, we utilized a Q-D (Quasi-Deterministic) Channel Realization open source software and extensive channel measurement campaigns were conducted with NIST (National Institute of Standards and Technology) to implement the millimeter wave (mmWave) channel. Our simulation results demonstrate that our proposed scheme outperforms comparison schemes in terms of the accuracy of the signal strength estimation.

• Korean Journal of Remote Sensing
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• v.38 no.6_1
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• pp.1515-1526
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• 2022

Image-based 3D reconstruction is to restore the shape and color of real-world objects, and image sensors mounted on mobile platforms are used for positioning and mapping purposes in indoor and outdoor environments. Due to the increase in accidents in underground space, the location accuracy problem of underground spatial information has been raised. Image-based location estimation studies have been conducted with the advantage of being able to determine the 3D location and simultaneously identify internal damage from image data acquired from the inside of pipeline-type underground facilities. In this study, we studied 3D reconstruction based on the images acquired inside the pipe-type underground facility and reference data. An unmanned mobile system equipped with a stereo camera was used to acquire data and image data within a pipe-type underground facility where reference data were placed at the entrance and exit. Using the acquired image and reference data, the pipe-type underground facility is reconstructed to a geo-referenced 3D shape. The accuracy of the 3D reconstruction result was verified by location and length. It was confirmed that the location was determined with an accuracy of 20 to 60 cm and the length was estimated with an accuracy of about 20 cm. Using the image-based 3D reconstruction method, the position and line-shape of the pipe-type underground facility will be effectively updated.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.6
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• pp.155-163
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• 2022

In order to avoid the spread of Covid-19, outdoor activities are decreasing worldwide and the time spent at home is increasing. As physical activity declines, the number of people who feel bored, restless and immune deficient is increasing. As indoor life becomes more permanent, multiple approaches to home workout are becoming active. This paper examines how the Covid blue (boredom and social anxiety) produced in the no-touch era affects quality of life through the use of home training applications. Questionnaires were collected from Chinese people using a website dedicated to Chinese questionnaires, and finally 383 appropriate data were analyzed using SPSS24.0 and AMOS24.0. The research results showed that the actual experience of using home workout had a positive impact on quality of life. The higher the user's sense of social unease about being late in the untact, It was found that the higher the social anxiety perceived by users about the untact era, the higher the interactivity and exercise satisfaction with the home workout app. Home workout application can improve exercise satisfaction and quality of life, which are more positive effects beyond the result of resolving consumers' boredom. Therefore, it can be used as a channel for digital services.

• Journal of Conservation Science
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• v.36 no.6
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• pp.505-510
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• 2020

In this study, the anti-stain effect of the Traditional Myoung-oil, which has been reproduced through traditional method, the Clean Myoung-oil, which was developed in an eco-friendly method through scientific analysis of Traditional Myoung-oil, and the perilla oil, which is the raw material of Myoung-oil and is currently used as a finishing agent when repairing wooden cultural properties was evaluated. As a result of the evaluation, perilla oil showed almost no anti-stain effect, whereas both types of Myoung-oil showed high anti-stain effect. However, it was confirmed that the anti-stain effect was significantly reduced after 4 weeks of exposure to the strain when Myoung-oil was diluted with terpene oil, a natural solvent. Thus, it was considered that the amount of treatment in the wood affected the anti-stain effect of Myoung-oil. In other words, in constructing wooden buildings, Myoung-o il is more suitable as a finishing agent to suppress mold growth than perilla oil. And, in order to increase the applicability of Myoung-oil, it is suggested that additional research on the optimal treatment amount and treatment method that can inhibit mold growth inhibition in outdoor environments is necessary.

• Journal of People, Plants, and Environment
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• v.24 no.2
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• pp.119-135
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• 2021

Background and objective: This study was conducted to identify the components of kindergartener horticultural education by deriving objective components of horticultural education using the Delphi survey method, and then to provide basic data that can be used when creating horticultural programs in the regular curriculum. Methods: A total of 32 experts including professors of early childhood education, kindergarten directors, horticultural therapy professors, and horticultural therapists were selected as the Delphi panel. Of the 32 selected, only 29 answered all three rounds of the surveys. For the first round of the survey, an open-ended questionnaire, was used, and in the second and third rounds closed-ended questionnaires were used. Results: Results indicated that under the category of the goals of horticultural education, there were 7 items related to the current problems of horticultural education, 16 items related to the need for horticultural education in the smart age, 18 items related to the direction of horticultural education, and 5 items related to the areas most suitable for horticulture education for young children in the Nuri Curriculum. Results in the category of the implementation of horticultural education indicated that 2 items related to horticultural education hours, 3 items related to the venue for horticultural education, 2 items related to the activity types applicable to the Nuri Curriculum, and 4 items related to the objects of horticultural activities were derived. As the current problems of horticultural education, the following items were identified: event-oriented activity (M = 4.24) and lack of kindergarten teachers' opportunities for systematic gardening education (M = 4.21). The results related to the necessity of horticultural education indicated the following items: education on respect for life through caring (M = 4.59), emotional intelligence and stability (M = 4.55), directly experience of the growth process of plants (M = 4.55), and development of the five senses (M = 4.55). Finally, within the direction of horticultural education: nurturing the desire to live with nature (M = 4.50), and learning about life (M = 4.44) was identified, which had higher averages. Within the areas of the Nuri Curriculum, which is most consistent with horticultural education, nature exploration (M = 4.69) and the integration of all areas (M = 4.59) were derived as priorities. Also, regarding the implementation of horticultural education, the following items were derived as the priority from the expert group: 30-40 minutes (M = 4.14) and 40-50 minutes (M = 4.14) for class periods, outdoor garden in a kindergarten(M = 4.66) for the venue of gardening education, outside play (M = 4.59) for the activity type, and vegetable crops (M = 4.55) for the objects of gardening activities. Conclusion: It is significant that the goal and implementation of kindergartner horticultural education were objectively derived through collecting opinions of expert panels. Based on the results of this study, a horticultural education program for kindergarten teachers should be implemented.

• Journal of the Korean Wood Science and Technology
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• v.30 no.4
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• pp.27-32
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• 2002

We investigated the effect of polyethylene glycol(PEG) treatment of preservative treated green japanese cedar(Cryptomeria japonica) round posts on their preservative penetration and check formation during the air drying. The round rods were dip-treated in 10% preservative solution of Basilit CFK for 1 day, followed by application(3, 5, and 10 times) with 50% PEG-400 solution, and then dried for 30 days under natural conditions. The rate of preservative penetration into sapwood was a low by 23.2% without PEG treatment, whereas that was a high by about 51.2~64.5% with PEG treatment. From these results, it was assumed that PEG played an affirmative role in the penetration of preservative components loaded onto the surface of round rods by dipping. During the air drying, the formation of drying checks decreased significantly with increasing application times of PEG. Even though some drying checks in PEG treated rods were developed, the number and size of checks was reduced remarkably by PEG treatment. After 2 months of outdoor exposure, PEG treatment failed to reduce checking in preservative-treated rods whereas finishing of polyurethane resin lacquer after PEG treatment was significantly effective in preventing check development.

• Particle and aerosol research
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• v.18 no.3
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• pp.51-59
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• 2022

In this work, virion concentration and its dose changes by HVAC and air cleaners were estimated in a subway station platform to control airborne infection of SARS-CoV-2. Collection efficiencies with particle size were measured for the air filter equipped in a HVAC in one subway station in Daejeon. Indoor PM_2.5 changes according to outdoor PM_2.5 with time were also measured to estimate air infiltration rate in the subway station platform. When infected persons generate virions by 10⁴, 10⁵, 10⁶, 3 × 10⁶ and 5 × 10⁶ h^-1 in a 2,400 m³ volume platform, the concentration and dose were estimated as 9, 92, 275 and 458 virions/m³ and 4, 43, 130 and 217 virions after 1 hour exposure, respectively. The concentration and dose were reduced by 70%, and 64%, respectively by operations of both HVAC (with a flow rate of 16,000 m³/h, MERV 11) and ten air cleaners(with total CADR 10,740 m³/h) compared to those without operation of both HVAC and air cleaners. However, virion dose in the platform was estimated to be too low at the general conditions due to a large space, a high air infiltration (3 h^-1) and a short residence time (usually < 10 mins) in the platform irrespective of the operations of HVAC or air cleaners. HVAC with filters and air cleaners would be more necessary in the concourse or shopping areas in the subway stations to reduce the infection dose from a few hundred to several tens virions in a hour.