• Journal of Korean Society of Disaster and Security
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• v.15 no.4
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• pp.87-98
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• 2022

In recent years, frequent localized heavy rainfalls, which have a lot of rainfall in a short period of time, have been increasingly causing flooding damages. To prevent damage caused by localized heavy rainfalls, Hydrological Quantitative Precipitation Forecast (HQPF) was developed using the Local ENsemble prediction System (LENS) provided by the Korea Meteorological Administration (KMA) and Machine Learning and Probability Matching (PM) techniques using Digital forecast data. HQPF is produced as information on the impact of heavy rainfall to prepare for flooding damage caused by localized heavy rainfalls, but there is a tendency to overestimate the low rainfall intensity. In this study, we improved HQPF by expanding the period of machine learning data, analyzing ensemble techniques, and changing the process of Probability Matching (PM) techniques to improve predictive accuracy and over-predictive propensity of HQPF. In order to evaluate the predictive performance of the improved HQPF, we performed the predictive performance verification on heavy rainfall cases caused by the Changma front from August 27, 2021 to September 3, 2021. We found that the improved HQPF showed a significantly improved prediction accuracy for rainfall below 10 mm, as well as the over-prediction tendency, such as predicting the likelihood of occurrence and rainfall area similar to observation.

• Applied Chemistry for Engineering
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• v.34 no.3
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• pp.307-312
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• 2023

In this study, a catalytic oxidation-heat recovery system was designed that can remove unreacted with a concentration of about 1% to 6% in the exhaust gas of hydrogen fuel cells and recover heat to ensure safety in the hydrogen economy. The safety system was devised by filling hydrogen oxidation catalysts at room temperature that can remove unreacted hydrogen without any energy source, and an exhaust-heat recovery device was integrated to efficiently recover the heat released from the oxidation reaction. Through CFD analysis, variations in pressure and fluid within the system were shown depending on the filling conditions of the hydrogen oxidation system. In addition, it was found that waste heat could be recovered by optimizing the temperature of the exhaust gas, flow rate, and pressure conditions within the heat recovery system and securing hot water above 40 ℃ by utilizing the exhaust gas oxidation heat source above 300 ℃. Through this study, it was possible to confirm the potential of utilizing hydrogen processes, which are applied in small to medium-sized systems such as hydrogen fuel cells, as a safety system by evaluating them at a pilot scale. Additionally, it could be a safety guideline for responding to unexpected hydrogen safety accidents through further pilot-scale studies.

• Journal of Science Education
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• v.46 no.2
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• pp.195-211
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• 2022

In this study, we explored the meaning of astronomical observation activities of five earth science teachers through in-depth interviews. Semi-structured interviews were conducted after providing a questionnaire based on Seidman's three-step process of interview. By analyzing the interview transcript, the educational implications inherent in astronomical observation activities were extracted. Teachers have constructed systematic basis of observation and astronomy in the observational astronomy and laboratory class during their course in the teacher education institute. After they became in-service teachers, practical know-hows of astronomical observation activities in schools were developed with the help of colleagues. By designing and executing astronomical observation activities for students, teachers notice positive changes in the cognitive domain, affective domain, and career perception of the students. Hence, teachers consider that astronomical observation activities have great educational effects. In addition, astronomical activities appear to be very rewarding and satisfying experiences to teachers, by providing opportunities for having pride as an earth science teacher. However, teachers tend to find difficulties in operating astronomical observation activities in fields, due to both internal and external obstacles. It is found that the removal of internal obstacles is more important for teachers to attempt or to continue astronomical observation activities. In this sense, it is necessary to support teachers by providing timely training courses with related content, as well as opportunities to share their experiences within a peer group such as teachers' research society.

• Journal of The Korean Association For Science Education
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• v.43 no.2
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• pp.125-137
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• 2023

This study analyzed the types of knowledge building discourse and knowledge building processes in small group learning using augmented reality. Eight 8th grade students took classes using augmented reality in solubility, boiling and melting points. These classes were carried out twice and all the classes were videotaped and recorded. Every student participated in a semi-structured interview. In the types of knowledge building discourse, the proportion of knowledge sharing and knowledge construction was similar. Beneath the knowledge sharing, the proportion of introductory level discussion was higher than identifying key elements of augmented reality. Recalling existing knowledge rarely appeared. Under the knowledge construction, the proportion of advanced level discussion was the highest and the proportion of sharing and critiquing ideas at a different level and efforts to rise above current levels of explanation was similar. The introductory level discussion and identifying key elements of augmented reality were developed into efforts to rise above current levels of explanation and sharing and critiquing ideas at a different level. Visualized results of knowledge building processes showed all the students' graph drew an upward curve, though cumulative number of impact value was different by each student. As a result of the study, effective ways of improving small group learning using augmented reality are discussed.

• Journal of the Korean Society of Floral Art and Design
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• no.40
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• pp.97-123
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• 2019

The purpose of this study is to analyze the spatial characteristics of the unit of garden and to classify and symbolize it, to provide the basis for analyzing the works based on the characteristics of the space and to provide the data that can become the logical foundation for garden design. The research method first analyzed the behavioral scene analysis and the grounded theory methodology as the theory about the space type. It controls the subjectivity of the researcher and derives the characteristics of the space for the garden image based on the experiential knowledge of the expert, It is a qualitative analysis method that aims to increase credibility. The actual case target was the author garden which was exhibited at the 2017 Seoul Garden Expo. Through this process, we have simplified the characteristics of the space and the positives and negatives accordingly. We have grasped the relationship between spatial space, sculptural space, architectural space, and environmental space.. Research on qualitative topics such as the characteristics of space can not completely exclude the subjectivity of the researcher in terms of its characteristics, but such research can provide a rationale for interpreting and evaluating the gardens that depend on the individual's taste.. It can also contribute to the development of the field by providing reference materials for garden designs that rely on designer intuition, or by providing a logical basis for design.

• Korea Science and Art Forum
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• v.21
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• pp.437-449
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• 2015

The research aims to verify the effects of preference for science and self-directed learning ability of the science puppet show program that the researcher has developed as a STEAM education model. The results for conducting the survey with the same questionnaire before and after the program targeting the students showed that the science puppet show had effects on increasing the science related assignment performance will of the behavioral will among the three sub-dimensions including emotional respond, value cognition and behavioral will, but there was no effect on overall aspects of science preference. It can be interpreted as reflecting the characteristics of the scientific talents who already have a high level of preference for science. In addition, the three sub-dimensions including the cognitive regulation, motivational regulation and behavioral regulation had effects on the self-directed learning ability. Especially it had great effects on the directed learning ability of cognitive regulation, learning motivation of motivational regulation, tool application of behavioral regulation, and cooperation capacity which were greater for female students than male students. It is judged that the three-staged science puppet show program including the 'content integrating stage' that the students integrate the curriculum contents, 'integrated mission stage' of solving the visualization, auralization and performance missions by themselves, and 'process integration stage' of making the stage piece all together.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.6 no.5
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• pp.367-377
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• 2016

The purpose of the projects for strengthening the Service Business Competitiveness, which had been sponsored by the Ministry of Trade, Industry and Energy, and managed by the NIPA, is to support for combining the whole business process of the SMEs with the business model considering the scientific aspects of the services, to enhance the productivity of them and to add the values of their activities. 5 organizations are selected in 2014, and 4 in 2015 as leading organizations for these projects. This study analyzed the efficiency of these projects using DEA. Throughout the analysis of the prior researches, this study used the amount of government-sponsored money as the input variable, and the number of new customer business, the sales revenue, and the number of new employment as the output variables. And the result of this analysis showed that the decision making unit 12, 15, and 21 was efficient. And from this study, we found out two more performance indicators such as, the number of new employment and the amount of sales revenue, besides the number of new customer businesses.

• Advanced Industrial SCIence
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• v.2 no.2
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• pp.9-15
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• 2023

Since silicone rubber heaters are flexible, they can be directly attached or installed in objects to be heated even in flat, curved or three-dimensional shapes. Since the current heating method heats the entire object to be heated and raises it to a required temperature, ignoring areas or positions where heat is not required, partial intensive heating cannot be performed. When using multi-heating zones, rather than heating the entire object to be heated, only the parts that need heat are intensively heated according to the process, so it is possible to heat quickly by local location by applying different amounts of heat with a small amount of electric capacity to each place that needs heat, and heat energy can reduce. In this study, the temperature and heating time of the partially concentrated region in the multi-heating region structure are measured so that a uniform temperature or temperature difference occurs in the region requiring thermal fusion. In order to determine the optimal power density range and reduce capacitance, the safety of a silicon rubber heater manufactured with a multi-heating zone structure is investigated. If the silicon rubber heater is manufactured in a multi-heating method, the multi-intensive heating technology can be ideally applied to all heating processes.

• Journal of Intelligence and Information Systems
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• v.29 no.2
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• pp.35-56
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• 2023

With the development of information and communication technology, numerous reviews are continuously posted on websites, which causes information overload problems. Therefore, users face difficulty in exploring reviews for their decision-making. To solve such a problem, many studies on review helpfulness prediction have been actively conducted to provide users with helpful and reliable reviews. Existing studies predict review helpfulness mainly based on the features included in the review. However, such studies disable providing the reason why predicted reviews are helpful. Therefore, this study aims to propose a methodology for applying eXplainable Artificial Intelligence (XAI) techniques in review helpfulness prediction to address such a limitation. This study uses restaurant reviews collected from Yelp.com to compare the prediction performance of six models widely used in previous studies. Next, we propose an explainable review helpfulness prediction model by applying the XAI technique to the model with the best prediction performance. Therefore, the methodology proposed in this study can recommend helpful reviews in the user's purchasing decision-making process and provide the interpretation of why such predicted reviews are helpful.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.3
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• pp.131-146
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• 2023

Smart card data is widely used in the public transportation field. Despite the inevitability of various errors occur during the data collection and storage; however, smart card data errors have not been extensively studied. This paper investigates inherent errors in boarding and alighting station information in smart card data. A comparison smart card data and bus boarding and alighting survey data for the same time frame shows that boarding station names differ by 6.2% between the two data sets. This indicates that the error rate of smart card data is 6.2% in terms of boarding station information, given that bus boarding and alighting survey data can be considered as ground truth. This paper propose 6-step algorithm for correcting errors in smart card boarding station information, linking them to corresponding information in Bus Information System(BIS) Data. Comparing BIS data and bus boarding and alighting survey data for the same time frame reveals that boarding station names correspond by 98.3% between the two data sets, indicating that BIS data can be used as reliable reference for ground truth. To evaluate its performance, applying the 6-step algorithm proposed in this paper to smart card data set shows that the error rate of boarding station information is reduced from 6.2% to 1.0%, resulting in a 5.2%p improvement in the accuracy of smart card data. It is expected that the proposed algorithm will enhance the process of adjusting bus routes and making decisions related to public transportation infrastructure investments.