• Journal of the Korean Society for Aviation and Aeronautics
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• v.25 no.4
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• pp.124-129
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• 2017

Clouds are an important factor in aircraft flight. In particular, a significant impact on small aircraft flying at low altitude. Therefore, we have verified and characterized the low level cloud prediction data of the Unified Model(UM) - based Local Data Assimilation and Prediction System(LDAPS) operated by KMA in order to develop cloud forecasting service and contents important for safety of low-altitude aircraft flight. As a result of the low level cloud test for seven airports in Korea, a high correlation coefficient of 0.4 ~ 0.7 was obtained for 0-36 leading time. Also, we found that the prediction performance does not decrease as the lead time increases. Based on the results of this study, it is expected that model-based forecasting data for low-altitude aviation meteorology services can be produced.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.2
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• pp.197-206
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• 2000

A hybrid control structure for vision-based soccer robot system is considered. The structure is om-posed of four levels such as the role action behavior and execution levels. The control structure which is a combination of hierarchical and behavioral structures can efficiently meet the behavior and design specifications of a soccer robot system Among the four levels only the design of the action level is proposed in the paper and is experimentally evaluated. Design hypothesis and evaluation method are presented to improve the reliability and accomplishment of the robot system. Due to the essential element of soccer robot system design a systematic design procedure of the action level is proposed With the proposed structure and algorithm of the action level the excellent result was shown at the MiroSot'98 held in France.

• International Journal of Concrete Structures and Materials
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• v.7 no.3
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• pp.175-182
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• 2013

A damage-based approach for the performance-based seismic assessment of reinforced concrete frame structures is proposed. A new methodology for structural damage assessment is developed that utilizes response information at the material level in each section fiber. The concept of the damage evolution is analyzed at the section level and the computed damage is calibrated with observed experimental data. The material level damage parameter is combined at the element, story and structural level through the use of weighting factors. The damage model is used to compare the performance of two typical 12-story frames that have been designed for different seismic requirements. A series of nonlinear time history analyses is carried out to extract demand measures which are then expressed as damage indices using the proposed model. A probabilistic approach is finally used to quantify the expected seismic performance of the building.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.6
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• pp.272-279
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• 2000

This paper describes a controller design and dynamic performance analysis of UPFC based on 3-level inverters. Major attention is focused on the controller design for both shunt and series inverters, including regulator design for the dc link voltage sharing across the dc capacitors. An energy-based approach was investigated for effectively designing the controller. A detailed UPFC model has been developed with EMTP using 24-pulse 3-level inverters to verify this approach. Simulation results about dynamic performance of UPFC confirm effects for increasing transmission capacity and damping low-frequency oscillation. The developed simulation model would be very effective to analyze the dynamic performance of UPFC.

• Journal of Korean Elementary Science Education
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• v.35 no.1
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• pp.39-53
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• 2016

This study aimed to understand students' learning in elementary science classes in terms of participatory perspective. Participatory perspective is based on the participationist views on learning. Based on the participatory perspective, this study used two concepts of participationism: 'the changes of learning on commognition' of Sfard (2007) and 'the identity' of Wenger (1998/2007). Based on these concepts, four episodes of an elementary science class were analyzed. The results showed that students carried out their learning from objective-level learning to meta-level learning. And students defined who they are by identifying and negotiating scientific meaning during the learning. These results showed students become members of science community through their participations in science class.

• Journal of Ocean Engineering and Technology
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• v.11 no.3
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• pp.8-19
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• 1997

In this study an adequate type of offshore structure at the Sakhalin region as cold region is proposed and its structural design results are presented based on the reliability analysis. Structural safety assessment has been carried out for the proposed offshore structure at the Sakhalin area as designed by the reliability method. And a rational design procedure is presented based on the reliability analysis. Followings are drawn through the present study : - Four colum TLP structure is proposed as an adequate offshore structure type at the cold region like the Sakhalin region and the reliability-based structural design results are presented. It is seen that the proposed type is a more adequate and economic than the fixed type. - Safety assessment of the proposed structure applying the extended incremental load method is performed. - Referring the allowable safety level for offshore structures it has been found present TLP structure has sufficient structural safety at the system level as well as at the component level.

• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.6
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• pp.1007-1019
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• 2015

The determination of the required seawall height is usually based on the combination of wind speed (or wave height) and still water level according to a specified return period, e.g., 50-year return period wind speed and 50-year return period still water level. In reality, the two variables are be partially correlated. This may be lead to over-design (costs) of seawall structures. The above-mentioned return period for the design of a seawall depends on economy, society and natural environment in the region. This means a specified risk level of overtopping or damage of a seawall structure is usually allowed. The aim of this paper is to present a conditional risk probability-based seawall height design method which incorporates the correlation of the two variables. For purposes of demonstration, the wind speeds and water levels collected from Jiangsu of China are analyzed. The results show this method can improve seawall height design accuracy.

• East Asian mathematical journal
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• v.35 no.4
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• pp.451-465
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• 2019

Textbooks are official materials so that these are the most frequently used teaching materials in school. The teacher constructs the lesson based on the contents of the textbook to achieve the learning goal. Thus, textbooks play an important role because the quality of the contents in textbooks affects the cognitive level of students. This study investigates the cognitive domain based on Bloom's Taxonomy of Educational Objectives(knowledge, understanding, application, analysis, synthesis and evaluation) of 'Values and Expression' in the mathematics textbook of the first grade of middle school reflecting the 2015 revised mathematics curriculum. We also looked at cognitive levels based on Bloom's Taxonomy of Educational Objectives. As a result, it was found that understanding was dominant in 'Values and Expression'. Also, although the problem of requiring a higher level of cognition is increasing as the unit finishes, there are still a high percentage of low level of problems.

• Journal of Industrial Convergence
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• v.14 no.1
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• pp.1-13
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• 2016

I have done a case study on individual level based-organizational behavior textbooks published in Korea and USA. The objects are 'organizational behavior' by Su Yong Jung and 'organizational behavior' by Im Chang Hee in Korea, and 'organizational behavior' by Schermerhorn, Osborn, Uhl-Bien, & Hunt and 'organizational behavior' by Robbins, & Judge. The goal of this study is to identify the differences of the perspectives on the individual level based-organizational behavior between Korean and American textbooks. This research finding shows that it is valid to classify organizational behavior into such categories as individual differences, attitude, emotion & stress, perception & learning, and motivation in the Korean textbooks for the better future study.

• Journal of Industrial Convergence
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• v.14 no.1
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• pp.27-37
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• 2016

I have done a case study on organization level based-organizational behavior textbooks published in Korea and USA. The objects are 'organizational behavior' by Su Yong Jung and 'organizational behavior' by Im Chang Hee in Korea, and 'organizational behavior' by Schermerhorn, Osborn, Uhl-Bien, & Hunt and 'organizational behavior' by Robbins, & Judge. The goal of this study is to identify the differences of the perspectives on the organization level based-organizational behavior between Korean and American textbooks. This research finding shows that it is valid to classify organizational behavior into such categories as organizational structure, organizational culture, and organizational change in the Korean textbooks for the better future study.