• Journal of The Korean Association For Science Education
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• v.21 no.2
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• pp.255-263
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• 2001

The purpose of this study is to analyse the eighth grade students' performance of open investigations for two kinds of tasks: the qualitative one which involves the descriptive approach through observation, and the quantitative one which involves the quantitative data processing through control of variables. Researcher's observation, interview data as well as students' investigation reports, self-evaluations were analysed. The difficulties of qualitative open investigation lie in detecting and dealing with unexpected observations, of which the acceptance and interpretation were influenced by preconceptions. On the other hand, managing several variables, making reliable and valid measures, and quantitative data processing constituted main difficulties of quantitative open investigation. Some students could recognize the deficiencies of their methods and findings in qualitative one, but few in quantitative one. These results suggest the teaching point for each task of open investigations.

• Journal of Information Management
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• v.42 no.4
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• pp.1-21
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• 2011

The purpose of this study is to suggest a model for increasing international use of Korean scholarly journals. Recently DOI and open access are remarkable from the standpoint of increasing the opportunity of global exposition and citation of domestic scholarly journal papers. The data used in investigation and analysis were from KAMJE, KISTI, DOAJ and SCIMAGO. The model comprising DOI service and open access is obtained through analyzing DOI and open access utilization models and investigation on both.

• Journal of Power Electronics
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• v.9 no.6
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• pp.949-959
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• 2009

This paper presents a systematic investigation of the fault-mode behaviors of matrix converter systems. Knowledge about converter behaviors after fault occurrence is important from the standpoint of reliable system design, protection and fault-tolerant control. Converter behaviors have been, in detail, examined with both qualitative and quantitative approaches for key fault types, such as switch open-circuited faults and switch short-circuited faults. Investigating the fault-mode behaviors of matrix converters reveals that converter operation with switch short-circuited faults leads to overvoltage stresses as well as overcurrent stresses on other healthy switching components. On the other hand, switch open-circuited faults only result in overvoltage to other switching components. This study can be used to predict fault-mode converter behaviors and determine additional stresses on remaining power circuit components under fault-mode operations.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2006.11a
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• pp.448-451
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• 2006

Multi-residential housing in Korea has many problems basically because maintenance, management, and remodelling have been done without considering building elapse and residents' needs. Residential open building has been suggested as one of the solutions. Even though the techniques have been actively developed for residential open building in Japan and the Netherlands, some obstacles are still existing. Especially in Korea, due to the lack of studies for facilitating residential open building, the development and popularization of residential open building are delayed. With the concern that the facilitation of process and systems is as important as technical development, the evaluation of process and systems is needed for promoting residential open building. As result, strong investigation of current situation can offer basic foundation to facilitate residential open building. The purpose of this study is to propose plans to facilitate residential open building in Korea through a comparative study between Korean and Japanese system.

• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.1
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• pp.56-69
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• 2015

This paper presents a numerical study on investigating on hydrodynamic characteristics of a marine propeller in oblique flow. The study is achieved by RANS simulations on an open source platform - OpenFOAM. A sliding grid approach is applied to compute the rotating motion of the propeller. Total force and moment acting on blades, as well as average force distributions in one revolution on propeller disk, are obtained for 70 cases of combinations of advance ratios and oblique angles. The computed results are compared with available experimental data and discussed.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.69
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• pp.633-654
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• 2016

Recently open data has been spread rapidly in the world include Korea. Accordingly in international trade field open data and using it became a key point to get competitiveness. In this study, the author make an attempt to suggest the way for quality improvement of international trade information by looking for some problems with crating and using the information. Thus, the problems of using information are can be point out as follows. Firstly the range of open data is narrow. Secondly the management of the open data is not conducted properly. Thirdly the suppliers of the open data didn't prepare some investigation system for their data's usability for user. Expansion of the organizations who open data is one way to solve quantitative problem. There are four suggestions to solve qualitative problems. Firstly the guidelines should be established and operated in each organizations respectively. Secondly the criterion of expenses for open data should be arranged among the concerned parties. Thirdly the ability of the manpower and organization who charged in the quality improvement of information should be reinforced both quantitatively and qualitatively. Lastly the system for data usability for user should be equipped in early stages. Finally the author emphasize the establishment of total management system for using open data in international trade is not needed only the efforts of the specific parties but also all parties led by Ministry of Industry, Trade and Energy in order to carry out above suggestions successfully.

• The korean journal of orthodontics
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• v.16 no.1
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• pp.35-49
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• 1986

Etiologies and traditional treatment modalities regarding anterior open-bite were discussed to elucidate the advantages and disadvantages. And an emphasis was placed on the understanding of the true nature of anterior open-bite. Most anterior open-bite malocclusions can be treated with a high degree of sucess and stability without surgical intervention with the congnizance of the anatomy, the physiology and the dynamics of orthodontic mechanotherapy. In this regard, a Multiloop Edgewise Arch Wire (MEAW) Technic, which has been developed during the past twenty years by Dr. Kim, was introduced. Three cases with anterior open-bite malocclusion were presented to demonstrate the mechanotherapy.

• The Mathematical Education
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• v.43 no.3
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• pp.275-289
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• 2004

The purpose of the study is to investigate how children and preservice teachers would make a progress in solving the open-problems related to area. In knowledge-based information age, information inquiry, information construction, and problem solving are required. At the level of elementary school mathematics, area is mainly focused on the shape of polygon such as square, rectangle. However, the shape which we need to figure out at some point would not be always polygon-shape. With this perspective, many open-problems are introduced to children as well as preservice teacher. Then their responses are analyzed in terms of their logical thinking and their understanding of area. In order to make students improve their critical thinking and problem solving ability in real situation, the use of open problems could be one of the valuable methods to apply.

• Smart Structures and Systems
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• v.23 no.6
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• pp.553-564
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• 2019

Modeling of magnetorheological (MR) dampers for cable vibration control to facilitate the design of even more effective and economical systems is still a challenging task. In this study, a parameter-adaptive three-element model is first established for a full-scale MR damper based on laboratory tests. The parameters of the model are represented by a set of empirical formulae in terms of displacement amplitude, voltage input, and excitation frequency. The model is then incorporated into the governing equation of cable-damper system for investigation of open-loop vibration control of stay cables in a cable-stayed bridge. The concept of optimal voltage/current input achieving the maximum damping for the system is put forward and verified. Multi-mode suboptimal and Single-mode optimal open-loop control method is then developed. Important conclusions are drawn on application issues and unique characteristics of open-loop cable vibration control using MR dampers.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2005.11a
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• pp.157-162
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• 2005

It is necessary for us to research and analyze of Open Housing in order to change new housing system, because exiting multi family housing is lack of flexibility and easy remodeling. The purpose of this study is to supply and grasp basic planning and design data for flexibility of Open Housings in Korea. This study is based on the literature survey and actual investigation through visiting 17 open housing sites from 1995 to 2005 in Netherlands, Finland and Japan, which are main Open Housing. We analyzed the planning methods and elements for flexibility of open housing block and unit plan, and described the contents of analyses. We found a lot of planning and design methods-supplying option plan and user participation before occupation, various structural system for openness, common piping shaft location, slab-down and applying access flooring system, movable and demountable partition wall system etc. -applied to the open housings, and findings are applicable to the planning and designing works of apartment housings in Korea.