• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.221-224
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• 2003

In the open die forging process, it is difficult to optimize process parameters such as die shape, initial ingot size, feeding pitch, rotation angle and other process parameters in the operational environments. Therefore in this study, 3D finite element analysis has been performed to obtain optimal process condition for open die forging process. FEM analyses at various feeding pitches and rotation angles provide process conditions to make round bar having precise dimensional accuracy.

• Journal of Korean Elementary Science Education
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• v.32 no.3
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• pp.285-297
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• 2013

The purpose of this research is to find the effect of the lesson using open-inquiry report Lubric on open-inquiry standard and science process skill; to find the change of cognition on open-inquiry for elementary school 5th grade students. Two classes (elementary school 5th grade) were selected which located in a small and medium-sized city for this research and they were separated as an experimental group and a comparative group. Open-inquiry lesson was done by referring teaching method which introduced through the curriculum. The procedure was understanding about open-inquiry, making open-inquiry subject, planning, and performing inquiry, mid-term, performing inquiry, making a report, presentation, and evaluation. Open-inquiry report Lubric which developed by Sook-Kyung Kim et al. (2010) was provided to the experimental group. Comparative group was instructed by using open-inquiry report which introduced to the elementary school 5th grade science text book. Interview paper was developed in order to check out the effect of the research by using a test paper of science process skill. The following could be found out through the research. After open-inquiry lesson, 10 open-inquiry reports(5 reports from experimental group, 5 reports from comparative group) have been drawn at random as samples from the total 62 sets (30 reports from experimental group, 32 reports from comparative group) and evaluated by a researcher and two elementary school teachers who have master degree. The reliability of the 3 scorers was 0.923 of mean correlation coefficient. And then the researcher evaluated all open-inquiry reports. The average score of open-inquiry report was 66.78 for experimental group, 54.27 for comparative group, respectively. And there was a significant difference at p<0.05 level as a result of the t-test. The experimental group rated high at p<0.05 level according to the analysis of post-science process skill test. According to the result of survey, both experimental group and comparative group had understood open-inquiry activity. It was especially rated high for experimental group on understanding scientific inquiry process, interest and satisfaction in open-inquiry and re-participation rate. By interviewing experimental group, it is recognized that the students utilized Lubric very well through the overall process. Finally, self-evaluation was done during open-inquiry activity and it was reported that the students gained more knowledge about science and changed to positive about science. As a result, the lesson using open-inquiry report Lubric was effective for students to improve writing skill of an open-inquiry report and science process skill and finally changed the cognition to positive about open-inquiry lesson.

• Journal of Korea Society of Industrial Information Systems
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• v.11 no.3
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• pp.59-68
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• 2006

Recently, introduction of Open Source Software into informatization of the government and public sector has been actively examined, however, Open Source Software is being rarely adopted due to the lack of verified and reliable data with regard to the criteria, process, performance and stability for introduction of Open Source Software. In this paper, the process, method and plan for performance verification for introduction of Open Source Software into mission critical systems of the government and public sector are suggested in order to solve the aforesaid problem Specially, a test system to judge whether or not to adopt Open Source Software in school affairs system of the NEIS(National Education Information System) of the Korean government was set up, and the method and process of performance verification by stage in addition to feasibility study were applied to the test system for verification. Based on the result of performance evaluation in the test system, the application of Linux to school affairs system of the NEIS is being successfully practiced. It is expected that this study will be a guideline to technical review process and performance verification method as necessary to introduce Open Source Software into the mission critical systems of government and public agencies.

• Journal of Korea Technology Innovation Society
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• v.5 no.2
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• pp.212-227
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• 2002

This study reviews the institutional frameworks of Open Source software and develops the stylized facts of Open Source software innovation. Open Source software have to solve two difficult problems for encouraging innovation. First, the source code of Open Source software program should be open and freely distributed and it is very difficult for developers to appropriate the results of their investments. Second, as Open Source software development process is characterized by the participation of communities of developers, it is not easy to coordinate and manipulate the development process. These difficulties of developing Open Source Software have been solved by the particular incentive schemes and coordinating mechanisms. This study reviews the study on the motivation of Open Source software development and the mechanisms which coordinate innovation process of Open Source software with peer review and meritocracy, and how these characteristics promote innovation in Open Source software communities.

• Journal of Korea Technology Innovation Society
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• v.7 no.1
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• pp.1-20
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• 2004

In this paper, we try to explore the nature of open source software development process. The process involves peculiar characteristics which seem to defy the traditional economic reasoning for technology policy. Based upon the comparative case study of open source software development process with the two innovation processes adopted from literature on economic history, we argue that technology policy should strike the balance between provision of innovation incentives and voluntary disclosure of information.

• Journal of Information Technology Services
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• v.5 no.3
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• pp.99-108
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• 2006

Public institutions are considering adoption of open-source software in the process of information projects. However, there doesn't exist reliable information about an adoption process for open-source software. Performance and stability problems of this software also persist, as a result, current open-source software is not widely used. As a software market and industry grows, Benchmark test has been performed more often than before in order to help customers understand and select the most appropriate product among myriad similar ones. It is certain that more objective and trustful data evidence should be obtained by way of utilizing the procedures and methods of Benchmark Test in decision making process for selecting an open-source software. For this research, Benchmark test was applied as a way of demonstrating performance verification of an open-source software in the public institutions. It is certain that more objective and trustful data evidence should be obtained by way of utilizing the procedures and methods of Benchmark Test in decision making process for selecting an open-source software. It also introduces a case study of a information system, which selected and implemented open-source software, in order to confirm the validity of this research. This research will serve as a guideline to adopt open-source software in governments as well as public institutions.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.143-147
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• 2003

Despite of outstanding optical performance of glass lens, glass lens have not been widely used because of poor productivity and high cost due to manufacturing process i.e. grinding, polishing. However, press-forming method of glass lens overcomes this disadvantage because of mass production. When glass lens is produced by press-forming method using closed die, it is needed that the volume of glass lens preform precisely measured in order to prevent incomplete products and to increase in life of die. The present paper shows the shortcoming of forming process with closed die, and performs FEM simulation of forming process with open die in order to overcome this shortcoming. The design parameter of open die is selected in standard of assembly with optical module and maintenance of optical performance. FEM simulation is carried out with selected parameter of open die and two basic preform. According to distribution of effective strain in glass lens, optical property of glass lens formed at each set of die and preform is compared.

• Transactions of Materials Processing
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• v.12 no.4
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• pp.296-301
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• 2003

Though a glass tens has outstanding optical performance, it has not been widely used because manufacturing process shows poor productivity and high cost. However, press-forming method of glass lens overcomes these disadvantages with mass production. When glass lens is produced by press-forming method using closed die, it is needed that the volume of glass lens preform is precisely measured in order to prevent incomplete products and to increase in life of die. The present. paper shows the shortcoming of forming process with closed die, and performs FEM simulation of forming process with open die in order to overcome this shortcoming. The design parameters of open die are selected on the basis of assembly with optical module and maintenance of optical performance. FEM simulation is carried out with selected parameter of open die and two basic preform. According to distribution of effective strain in glass lens, optical property of glass lens formed at each set of die and preform is compared.

• Journal of Environmental Science International
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• v.19 no.9
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• pp.1169-1175
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• 2010

A case study for the design of a wind farm in complex terrain was carried out using the wind farm site analysis software OpenWind, which has an open-source platform and is free to use. The Youngdeok Wind Farm, constructed on mountainous terrain in Korea, was chosen as a model site; the design process reproduced using OpenWind. A comparison of the positions of the wind turbine derived from the OpenWind optimization process and the current positions were in good agreement. The annual energy production predicted by OpenWind compared with the prediction by the micrositing software, WindSim, were also validated to within 1%. Therefore, it was confirmed that OpenWind can be used for a practical wind farm design project. It is also anticipating that this paper will provide a prototype process for the design of a wind farm site and offer a database for the post-evaluation of a constructed wind farm in Korea.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.10a
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• pp.174-177
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• 2001

The automated computer-aided drafting technique is attempted for drawing process pictures of axisymmetric solid forgings which are mainly used in automobile industry. For this study basic concepts to draw the shape of an element are described and applied to the 2-dimensional and 3-dimensional modeling of forged parts. 2-dimensional display of process pictures is developed by using AutoLISP language in AutoCAD software of a drafting technique and 3-dimensional view of process pictures is based on the UG/open API and UG/open GRIP languages of Unigraphics software. Testing the developed program to forging of bolts and ballstuds, it was shown to give good results to be applicable in forging industry.