• Korean Journal of Remote Sensing
• /
• v.38 no.5_3
• /
• pp.953-966
• /
• 2022

Since aerosols adversely affect human health, such as deteriorating air quality, quantitative observation of the distribution and characteristics of aerosols is essential. Recently, satellite-based Aerosol Optical Depth (AOD) data is used in various studies as periodic and quantitative information acquisition means on the global scale, but optical sensor-based satellite AOD images are missing in some areas with cloud conditions. In this study, we produced gap-free GeoKompsat 2A (GK-2A) Advanced Meteorological Imager (AMI) AOD hourly images after generating a Random Forest based gap-filling model using grid meteorological and geographic elements as input variables. The accuracy of the model is Mean Bias Error (MBE) of -0.002 and Root Mean Square Error (RMSE) of 0.145, which is higher than the target accuracy of the original data and considering that the target object is an atmospheric variable with Correlation Coefficient (CC) of 0.714, it is a model with sufficient explanatory power. The high temporal resolution of geostationary satellites is suitable for diurnal variation observation and is an important model for other research such as input for atmospheric correction, estimation of ground PM, analysis of small fires or pollutants.

• Journal of the Korean Society of Radiology
• /
• v.16 no.5
• /
• pp.661-672
• /
• 2022

After the outbreak of the SARS-CoV2 virus that causes COVID-19, it spreads around the world with the number of infections and deaths rising rapidly caused a shortage of medical resources. As a way to solve this problem, chest X-ray diagnosis using Artificial Intelligence(AI) received attention as a primary diagnostic method. The purpose of this study is to comprehensively analyze the detection of COVID-19 via AI. To achieve this purpose, 292 studies were collected through a series of Classification methods. Based on these data, performance measurement information including Accuracy, Precision, Area Under Cover(AUC), Sensitivity, Specificity, F1-score, Recall, K-fold, Architecture and Class were analyzed. As a result, the average Accuracy, Precision, AUC, Sensitivity and Specificity were achieved as 95.2%, 94.81%, 94.01%, 93.5%, and 93.92%, respectively. Although the performance measurement information on a year-on-year basis gradually increased, furthermore, we conducted a study on the rate of change according to the number of Class and image data, the ratio of use of Architecture and about the K-fold. Currently, diagnosis of COVID-19 using AI has several problems to be used independently, however, it is expected that it will be sufficient to be used as a doctor's assistant.

• Journal of Christian Education in Korea
• /
• v.66
• /
• pp.273-307
• /
• 2021

The purpose of this study is to explore the inner perceptions and dilemmas of young people about the church. To achieve the purpose of the study, this study sampled the research subjects, and conducted in-depth interviews and FGI. The sample in this study was 21 young adults who met the study criteria. Some of these people are not currently attending church or have thought of moving to another church. In this study, research was conducted based on the analysis procedure of Riessman (1993). Focusing on the procedures of 'telling,' 'recording,' and 'analyzing,' the experience and life situation of the study participants are to be grasped. Through this process, we analyzed the situation and context of why young people leave the church. It consisted of 5 areas and 15 sub-themes. Based on the research results, it was found that young adults need a church and are looking for a church. The church is a mystical space, but from an pedagogical point of view, the church is a space for teaching and learning faith. As experts in theology and education, the minister must create a space so that the church can become a space of transcendence, a space of intimacy, a space of understanding, a space of change, a space of service, and a space of reflection.

• Ecology and Resilient Infrastructure
• /
• v.8 no.2
• /
• pp.112-119
• /
• 2021

In 2012, the National Park Service conducted an ecological health assessment to efficiently preserve and manage the ecosystem. The need for improving pre-existing management indicators was recognized from the revised Natural Park Act because, while the indicators of the existing evaluation system focused on endangered species, ecosystem disturbance, diversity, water quality (BOD, DO), and habitat fragmentation, they did not reflect the lack of indicators for marine ecological assessment, policy changes, and the time demands. The evaluation results comprised a five-point grading system, which made the analysis of immediate changes, difficult. Therefore, the benthic pollution index (BPI) and habitat restoration indicators were added to improve the evaluation system. The National Park was assessed using 10 classifications, however, only four classifications were evaluated. The ratings were divided into five states, and ten classes were presented as pictograms. The assessment results showed a similar trend as the indicators were improved, increasing from level 3 to level 5. However, the results of the Wolaksan National Park after improvement in the indicators were lower than that before the improvement, whereas, for the Juwangsan National Park, it was higher. This study aims at contributing to the scientific and systematic management of the national park ecosystem by improving the ecological health assessment system.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.25 no.4
• /
• pp.63-80
• /
• 2022

As a technology to analyze and predict an issue has been developed by constructing real space into virtual space, it is becoming more important to acquire precise spatial information in complex cities. In this study, images were acquired using an unmanned aerial vehicle for urban area with complex landscapes, and land cover classification was performed object-based image analysis and semantic segmentation techniques, which were image classification technique suitable for high-resolution imagery. In addition, based on the imagery collected at the same time, the replicability of land cover classification of each artificial intelligence (AI) model was examined for areas that AI model did not learn. When the AI models are trained on the training site, the land cover classification accuracy is analyzed to be 89.3% for OBIA-RF, 85.0% for OBIA-DNN, and 95.3% for U-Net. When the AI models are applied to the replicability assessment site to evaluate replicability, the accuracy of OBIA-RF decreased by 7%, OBIA-DNN by 2.1% and U-Net by 2.3%. It is found that U-Net, which considers both morphological and spectroscopic characteristics, performs well in land cover classification accuracy and replicability evaluation. As precise spatial information becomes important, the results of this study are expected to contribute to urban environment research as a basic data generation method.

• Journal of Korea Water Resources Association
• /
• v.55 no.12
• /
• pp.1091-1104
• /
• 2022

Climate change is predicted to increase the frequency and intensity of rainfall worldwide, and the pattern is changing due to inundation damage in urban areas due to rapid urbanization and industrialization. Accordingly, the impact assessment of climate change is mentioned as a very important factor in urban planning, and the World Meteorological Organization (WMO) is emphasizing the need for an impact forecast that considers the social and economic impacts that may arise from meteorological phenomena. In particular, in terms of traffic, the degradation of transport systems due to urban flooding is the most detrimental factor to society and is estimated to be around £100k per hour per major road affected. However, in the case of Korea, even if accurate forecasts and special warnings on the occurrence of meteorological disasters are currently provided, the effects are not properly conveyed. Therefore, in this study, high-resolution analysis and hydrological factors of each area are reflected in order to suggest the depth of flooding of urban floods and to cope with the damage that may affect vehicles, and the degree of flooding caused by rainfall and its effect on vehicle operation are investigated. decided it was necessary. Therefore, the calculation formula of rainfall-immersion depth-vehicle speed is presented using various machine learning techniques rather than simple linear regression. In addition, by applying the climate change scenario to the rainfall-inundation depth-vehicle speed calculation formula, it predicts the flooding of urban rivers during heavy rain, and evaluates possible traffic network disturbances due to road inundation considering the impact of future climate change. We want to develop technology for use in traffic flow planning.

• Journal of Korean Library and Information Science Society
• /
• v.53 no.2
• /
• pp.215-239
• /
• 2022

All public libraries are local public goods and cultural infrastructures whose ideological pillars are publicly operated, free, and open to all. This identity is justified when the public library provides various knowledge information, various programs, and community space to local residents within the service area, and ultimately contributes to the cultural development of the nation and society. To this end, the country and local governments must expand the number of individuals that meet legal standards, deploy competent professionals, and provide facilities and spaces that are easy to access and use. However, if there is a gap in infrastructure and services between regional public libraries, it causes inequality in access and use of residents, which inevitably leads to information gap and cultural welfare gap. Therefore, this study was analyzed the relative gap using the location quotient, key infrastructure indicators and service indicators of public libraries of regional government in Korea and basic local government in the Chungnam region from the viewpoint that the balanced development and capacity building of public libraries must precede the establishment of a public library in Chungnam region as a life-friendly knowledge information service institution, culture enjoyment and lifelong learning space. Based on the results, a method to resolve the gap was suggested by dividing the elements of gaps in public libraries into accessibility, core infrastructure, and services, focusing on vulnerable cities and counties in the Chungnam region.

• Journal of The Korean Association For Science Education
• /
• v.42 no.2
• /
• pp.215-226
• /
• 2022

This study analyzed the trends and causes of the decline in Korean students' positive experiences about science (PES). To do this, 4th to 10th grade students were sampled by grade at general elementary, middle, and high schools in Seoul, and then a questionnaire was administered to ask the students about their PES and the causes for their decline. The results of one-way ANOVA for Test for Indicators of Positive Experiences about Science (TIPES) revealed that there were no statistically significant differences according to grade and school level in the overall mean of TIPES scores. However, the results were slightly different for each sub-component. That is, in 'science academic emotion,' the mean of elementary school students was statistically significantly higher than that of middle school students. In addition, the mean of 4th graders was significantly higher than the mean of middle school 1st graders, middle school 3rd graders, and high school 1st graders, respectively. The mean of high school students was statistically significantly higher than that of middle school students in 'science-related career aspiration.' In the 'science-related self-concept', 'science learning motivation,' and 'science-related attitude,' the differences in scores according to grade and school level were not statistically significant. The main causes of the decline in each sub-components of PES were somewhat different depending on the school level. Based on these results, the ways to improve students' PES were sought according to grade and school level.

• Journal of Internet Computing and Services
• /
• v.23 no.2
• /
• pp.29-35
• /
• 2022

UV rays have beneficial or harmful effects on the human body depending on the degree of exposure. An accurate UV information is required for proper exposure to UV rays per individual. The UV rays' information is provided by the Korea Meteorological Administration as one component of daily weather information in Korea. However, it does not provide an accurate UVI at the user's location based on the region's Ultraviolet index. Some operate measuring instrument to obtain an accurate UVI, but it would be costly and inconvenient. Studies which assumed the UVI through environmental factors such as solar radiation and amount of cloud have been introduced, but those studies also could not provide service to individual. Therefore, this paper proposes a deep learning model to calculate UVI using solar object information and sunlight characteristics to provide an accurate UVI at individual location. After selecting the factors, which were considered as highly correlated with UVI such as location and size and illuminance of sun and which were obtained through the analysis of sky images and solar characteristics data, a data set for DNN model was constructed. A DNN model that calculates the UVI was finally realized by entering the solar object information and sunlight characteristics extracted through Mask R-CNN. In consideration of the domestic UVI recommendation standards, it was possible to accurately calculate UVI within the range of MAE 0.26 compared to the standard equipment in the performance evaluation for days with UVI above and below 8.

• Education of Primary School Mathematics
• /
• v.25 no.2
• /
• pp.143-160
• /
• 2022

This study was conducted to discuss educational implications by analyzing the types of mathematical thinking that appeared in challenge math in 5th and 6th grade math teacher's guidebooks. To this end, mathematical thinking types that can be evaluated and nurtured based on teaching and learning contents were organized, a framework for analyzing mathematical thinking was devised, and mathematical thinking appearing in Challenge Math in the 5th and 6th grade math teachers' guidebooks was analyzed. As a result of the analysis, first, 'challenge mathematics' in the 5th and 6th grades of elementary school in Korea consists of various problems that can guide various mathematical thinking at the stage of planning and implementation. However, it is feared that only the intended mathematical thinking will be expressed due to detailed auxiliary questions, and it is unclear whether it can cause mathematical thinking on its own. Second, it is difficult to induce various mathematical thinking at that stage because the questionnaire of the teacher's guidebooks understanding stage and the questionnaire of the reflection stage are presented very typically. Third, the teacher's guidebooks lacks an explicit explanation of mathematical thinking, and it will be necessary to supplement the explicit explanation of mathematical thinking in the future teacher's guidebooks.