• Journal of Korea Water Resources Association
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• v.46 no.6
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• pp.655-666
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• 2013

Lately, intensity and frequency of natural disasters such as flood are increasing because of abnormal climate. Casualties and property damages due to large-scale floods such as Typhoon Rusa in 2002 and Typhoon Maemi in 2003 rapidly increased, and these show the limits of the existing disaster prevention measures and flood forecasting systems regarding irregular climate changes. In order to efficiently respond to extraordinary flood, it is important to provide effective countermeasures through an inundation model that can accurately simulate flood inundation patterns. However, the existing flood inundation analysis model has problems such as excessive take of analysis time and accuracy of the analyzed results. Therefore, this study conducted a flood inundation analysis by using the Gerris flow solver that uses quadtree grid, targeting the Baeksan Levee in the Nakdong River Basin that collapsed because of a concentrated torrential rainfall in August, 2002. Through comparisons with the FLUMEN model that uses unstructured grid among the existing flood inundation models and the actual flooded areas, it determined the applicability and efficiency of the quadtree grid-based flood inundation model of the Gerris flow solver.

• Journal of The Korean Association For Science Education
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• v.22 no.2
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• pp.336-344
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• 2002

The purpose of this study was to analyse achievement of 'Scientific Inquiry and the Nature of Science' in the Third International Mathematics and Science Study-Repeat (TIMSS-R), which was performed in 1999 with 38 nations participating. Korean 8th grade students' achievement of 'Scientific Inquiry and the Nature of Science' was compared to that of other countries and other content areas in science. Average percent correct of items in each subcategory - Scientific Method, Experimental Design, Scientific Measurements, Describing and Interpreting Data - was also analysed. Although 'Scientific Inquiry and the Nature of Science' topics were not included in intended curriculum in Korea, Korean students' average scale score of 'Scientific Inquiry and the Nature of Science' was significantly higher than international average and, in comparison with other science content areas, achievement of that area was relatively high. The reasons could be that the most students studied topics related to 'Scientific Inquiry and the Nature of Science' through the implemented curriculum and that the Korean teachers recognized the importance of inquiry. According to the results to analyze subcategories, the average percent correct of Korea were higher than 50% except the 'Scientific Measurements' subcategory. However, the international average percent correct were lower than 50%. Especially, the average percent correct of Korea was the highest in 'Describing and Interpreting Data' subcategory despite there were many students who were confused at observation, hypothesis and conclusion.

• Communications of Mathematical Education
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• v.24 no.3
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• pp.563-585
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• 2010

The major goals of this study are to find the factors that enhance self-directed math learning in college math classes and to provide the students with the opportunities to check and develop their self-directed math learning attitude. For these research goals, we prepared the questionnaires that asked about their learning motivations, basic learning ability, self-discipline strategies, and self-directed learning strategies. Another purpose of the questionnaires was to give them the chances to check and improve their attitude toward those learning strategies, motivation and ability. From the research results, we find that the important factors for self-directed learning are internal & external motivations, concentration ability, and the goal-setting and plan-making abilities. In addition, concentration ability, good habit, stress-control, recognition of math value, and self-directing ability are found to be necessary for the desirable learning environment. On the other hand, we find that the ability to perform note-taking, class preparation and review, time-control, and test-control is required for the selection and practice of self-fitting learning strategies. Finally, we provided our own self-directed math learning model. Our model, containing the necessary factors for self-directed math learning, is the revised and modified one of Knowles(1975)'s 5 stage self-directed learning model that comprises diagnosis of learning desire, setting learning goals, grasping human&material resources, selection and practice of proper learning strategies, and evaluation of learning results.

• Science of Emotion and Sensibility
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• v.20 no.4
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• pp.79-88
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• 2017

As the age in which the importance of sensitivity has increased, education for the future generation regarding emotion engineering, affective recognition and cognitive science have taken center stage. We measure human's emotion quantitatively, analyze evaluation and apply them to various services in life, which are based on human technology. Therefore, we need the education which is related to emotion science to cultivate talented people. The goal of this paper is to suggest the possibility of emotion science education and effective methods through development of the STEAM (Science, Technology, Engineering, Arts, Mathematics) program which can teach emotion science to early elementary school students by applying it to pilot classes. For this study, first, we build a program, 'The mind made by figure' for student of early elementary school. The method of STEAM was used in this program, because it is an effective system to educate the emotion science. We recognize the needs and value of this program development through theory and benchmarking of STEAM related to emotion science. And then the contents of class, activities, course book and kit are designed with elementary school textbook of pertinent grade. Secondly, we analyze the result which is applied in two pilot classes of second grade by satisfaction survey and teacher interview. As a result, the average of satisfaction level was very high (4.40/5), Class participation was especially high. Third, we discuss the ability, value and limits of this program based on the result of analysis. The outcome of this research shows that students of early elementary school who have difficulty in understanding science can approach the education program related to emotion science with ease and interest. We hope this education will help students understand emotion science effectively, and to train people to lead the emotion centered era.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.6A
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• pp.97-106
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• 2008

Quality of Protection(QoP) provides a standard that can evaluate networks offering protection. Also, QoP estimates stability of the system by quantifying intensity of the security. Security should be established based on the circumstance which applied to appropriate level, and this should chose a security policy which fit to propose of network because it is not always proportioned that between stability of security mechanism which is used at network and performance which has to be supported by system. With evolving wireless networks, a variety of security services are defined for providing secure wireless network services. In this paper, we propose a new QoP model which makes up for weak points of existing QoP model to choose an appropriate security policy for wireless network. Proposed new QoP model use objectively organized HVM by Flow-based Abnormal Traffic Detection Algorithm for constructing Utility function and relative weight for constructing Total reward function.

• International journal of advanced smart convergence
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• v.12 no.3
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• pp.89-103
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• 2023

Obstructive sleep apnea (OSA) is one of the most prevalent sleep disorders that can lead to serious consequences, including hypertension and/or cardiovascular diseases, if not treated promptly. Continuous positive airway pressure (CPAP) is widely recognized as the most effective treatment for OSA, which needs the proper titration of airway pressure to achieve the most effective treatment results. However, the process of CPAP titration can be time-consuming and cumbersome. There is a growing importance in predicting personalized CPAP pressure before CPAP treatment. The primary objective of this study was to optimize the CPAP titration process for obstructive sleep apnea patients through EEG feature engineering with machine learning techniques. We aimed to identify and utilize the most critical EEG features to forecast key OSA predictive indicators, ultimately facilitating more precise and personalized CPAP treatment strategies. Here, we analyzed 126 OSA patients' PSG datasets before and after the CPAP treatment. We extracted 29 EEG features to predict the features that have high importance on the OSA prediction index which are AHI and SpO2 by applying the Shapley Additive exPlanation (SHAP) method. Through extracted EEG features, we confirmed the six EEG features that had high importance in predicting AHI and SpO2 using XGBoost, Support Vector Machine regression, and Random Forest Regression. By utilizing the predictive capabilities of EEG-derived features for AHI and SpO2, we can better understand and evaluate the condition of patients undergoing CPAP treatment. The ability to predict these key indicators accurately provides more immediate insight into the patient's sleep quality and potential disturbances. This not only ensures the efficiency of the diagnostic process but also provides more tailored and effective treatment approach. Consequently, the integration of EEG analysis into the sleep study protocol has the potential to revolutionize sleep diagnostics, offering a time-saving, and ultimately more effective evaluation for patients with sleep-related disorders.

• The Journal of the Convergence on Culture Technology
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• v.9 no.4
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• pp.95-103
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• 2023

This paper proposes an artificial intelligence convergence education program for teaching the main concept and principle of Support Vector Machines(SVM) at elementary schools. The developed program, based on Jeju's natural environment theme, explains the decision boundary and margin of SVM by vertical and parallel from 4th grade mathematics curriculum. As a result of applying the developed program to 3rd and 5th graders, most students intuitively inferred the location of the decision boundary. The overall performance accuracy and rate of reasonable inference of 5th graders were higher. However, in the self-evaluation of understanding, the average value was higher in the 3rd grade, contrary to the actual understanding. This was due to the fact that junior learners had a greater tendency to feel satisfaction and achievement. On the other hand, senior learners presented more meaningful post-class questions based on their motivation for further exploration. We would like to find effective ways for artificial intelligence convergence education for elementary school students.

• Journal of The Korean Association For Science Education
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• v.26 no.2
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• pp.200-211
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• 2006

The purpose of this study was to analyze Korean middle school student achievement in environmental science based on the TIMSS 2003 (Trends in International Mathematics and Science Study), a student comparison of 46 participating nations. Korea ranked the fourth with a mean score of 554 in environmental science. However, all 3 environment science topics assessed in TIMSS are not included in the Korean science curriculum through 8th grade, even though they are included in most other participating nations' curricula. The average percent correct of items was analyzed according to the main topic, the item type and the cognitive domain. Items that showed differences between the average percent correct of Korea and the international average as well as differences between the average percent correct of boys and girls were further analyzed. Results revealed that Korean students performed better than the international average, especially in 'use and conservation of natural resources', multiple-choice items, and items requiring 'factual knowledge'. Also, male students demonstrated significantly higher achievement than female students. On the other hand, Korean students showed relatively lower achievement in constructed-response items, items that contained content they had not learned in science lessons and items requiring descriptions of the uses and effect of science and technology. Moreover, Korean student lacked understanding about acid rain, global warming, and ozone layer destruction. Korean female students showed relatively lower environmental conceptions and lower performance on items requiring data analysis than Korean male students. On the basis of these results, this study suggested that topics of environmental science be included in the science curriculum and taught in the science classroom to help middle school students more fully comprehend environmental issues.

• Journal of The Korean Association For Science Education
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• v.27 no.4
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• pp.346-353
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• 2007

In order to be efficient in teaching, a teacher should understand the current learner's level through diagnostic evaluation. This study has examined the major issues arising from the noble diagnostic assessment tool based on the theory of knowledge space. The knowledge state analysis method is actualizing the theory of knowledge space for practical use. The knowledge state analysis method is very advantageous when a certain group or individual student's knowledge structure is analyzed especially for strong hierarchical subjects such as mathematics, physics, chemistry, etc. Students' knowledge state helps design an efficient teaching plan by referring their hierarchical knowledge structure. The knowledge state analysis method can be enhanced by computer due to fast data processing. In addition, each student's knowledge can be improved effectively through individualistic feedback depending on individualized knowledge structure. In this study, we have developed a diagnostic assessment test for measuring student's learning outcome which is unattainable from the conventional examination. The diagnostic assessment test was administered to middle school students and analyzed by the knowledge state analysis method. The analyzed results show that students' knowledge structure after learning found to be more structured and well-defined than the knowledge structure before the learning.

• Journal of Science Education
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• v.48 no.1
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• pp.31-46
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• 2024

This study analyzes the academic achievement characteristics of Korean fourth graders on the problem solving and inquiry tasks (PSIs) introduced in TIMSS 2019. TIMSS 2019 conducted a computer-based assessment in addition to the traditional paper-based assessment. The PSIs were included only in the computer-based assessment, so 30 countries participated in the PSIs of the computer-based assessment. PSIs consist of integrating multiple content and cognitive domains, including 10 or fewer items. Most of the items are constructed in an open-ended format rather than multiple-choice. The analysis results showed that there were differences in student achievement across countries depending on the inclusion of PSIs. Korea's average achievement score decreased by 1 point. The analysis of individual items showed that students' achievement was somewhat low, and the correct answer rate for male students was generally higher than that for female students in many items. Furthermore, item-by-item analysis revealed that there were items where countries such as England and Finland had higher correct answer rates than traditional high-achieving countries, i.e. Singapore, Taiwan, and Korea. Considering the recent emphasis on integrated education, it seems necessary to review the use of PSIs in assessments in Korea as well.