• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.3
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• pp.102-108
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• 2006

This paper proposes a 36-pulse back-to-back voltage source converter using four sets of 12-pulse bridges with pulse-Interleaving auxiliary circuit. The proposed back-to-back voltage source converter has an independent control capability of active power and reactive power at the at connection point. The principle of increasing the number of pulses was analyzed using theoretical approach. The operational feasibility of proposed system was verified through computer simulations with PSCAD/EMTDC software. The proposed back-to-back converter can be widely used for the HVDC and FACTS devices.

• Korean Institute of Interior Design Journal
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• no.9
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• pp.24-29
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• 1996

The objectives of this study is to create an environment which students could apply effectively through focused on the innovative methods of education and CAD course contents. The facts which were able to figure out from this study were as follows ; 1. After the analysis of the CAD course contents of the american universities, their common contents were in order of introduce to Computer Aided Drafting and design with Auto CAD/ provide fundamental knowledge of the application for use in design/ examine and how this effects 2 D image and model creation/ CAD as a design tool . Over all trend of CAD course contents of interior design program in american university is moving toward utilizing CAD as a design tool. 2. On the other hand, common contents of our local universities were simply introducing CAD. It means that our course contents are more methodological and theoreatical . And american university's program is focused on problem solving solution as a design tool.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.727-730
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• 2005

Cellulose based Electro-Active Papers (EAPap) is very promising material due to its merits in terms of large bending deformation, low actuation voltage, ultra-lightweight, and biodegradability. These advantages make it possible to utilize applications, such as artificial muscles and achieving flapping wings, micro-insect robots and smart wall papers. This paper investigates the in-plane strains of EAPap under electric fields, which are useful for a contractile actuator application The preparation of EAPap samples and the in-plane strain measurement system are explained, and the test results are shown in terms of electric field, frequency and the oriental ions of the samples. The power consumption and the strain energy of EAPap samples are discussed. Although there are still unknown facts in EAPap material, this in-plane strain may be useful for artificial muscle applications.

• The Journal of Society for e-Business Studies
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• v.22 no.1
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• pp.51-64
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• 2017

After Bitcoin was proposed by Satoshi Nakamoto in 2009, studies have been carried out to apply the Block Chain technology in various environment, which was applied as a distributed transaction of Bitcoin. Smart contracts, voting and proof of ownership of digital contents are typical applications of Block Chain. They used the feature that it is impossible to modify or delete once recorded facts. They also applied to prove relevant facts and to provide data integrity. The applied cases are mainly made in an environment where the data should or could be open to the public, and they have been proposed as solutions to solve the problems occurred in relations. This fact has led to the attention that Block Chain can be applied as a good alternative in similar circumstances. In this study, real estate market service was selected to expand the application range of Block Chain. Although there are about 250 applications and web services in total, the satisfaction is not high due to false offerings. Thus we propose a countermeasure against the problem by applying the Block Chain to the real estate market service, and investigate the research direction of the Block Chain in the future market.

• Journal of Korean Elementary Science Education
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• v.33 no.4
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• pp.773-783
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• 2014

In National Curriculum of Science revised in 2007, the Free Inquiry was newly introduced to increase students' interest in science and to foster creativity by having students make their own question and find answer by themselves. The purpose of the study was to analyze characteristics, in cognitive domain, appeared in the processes of performing the Free Inquiry activities applying a brain-based evolutionary science teaching and learning principles. For this study, 106 fifth grade students participated, and they performed individually Free Inquiry activities. In order to characterize of the diversifying, estimating-evaluating-executing, and extending-applying activities in cognitive domain (C-DEF), the Free Inquiry diary constructed by the students, observations by a researcher, and interviews with the students were analyzed both quantitatively and qualitatively. The major results of this study were as follows: First, at C-D step, many students (71.5%) had difficulty in searching the meanings of their results and the contents of interpretations were at the level of simple description of their results. A few students (15.2%) derived interpretations based on causal relationships between specific variable and result. Also, the tendency that the numbers of interpretation about meaning of their results were increased as the scores of science attitude and achievement was appeared. Second, at C-E step, the students showed tendency of considering facts exactly explaining inquiry topic and being appliable to daily life rather than objectivity or accuracy of scientific knowledge. Third, at C-F step, there were three types of extension and application: simple repetition (8.2%), extension (64.0%), and upward application (17.6%) types. Based on these findings, implications for supporting appropriate interpretation, evaluation, and application of inquiry results are discussed.

• Journal of The Korean Association For Science Education
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• v.19 no.4
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• pp.560-569
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• 1999

This study was conducted with two science classes of the 8th grade students in Seoul during 4 weeks. The numbers of students in the classes were 37 and 38, and they were taught for 12 class hours. Questions obtained for 12 class hours from 75 students were analyzed and grouped into patterns. All together 1.108 questions from the students were classified into six categories: 'No Connection' (7%). 'Contradiction' (3%), 'Recall' (23%), 'Reframe' (40%), 'Application' (18%), and 'Extension' (9%). Irrelevant questions to learning and questions of false proposition were classified into 'No Connection' and 'Contradiction', respectively. Questions repeating what were already explained were grouped into 'Recall'. Those requiring other examples and/or additional explanations were grouped into 'Reframe'. Those requiring practical applications and/or explanations for other concrete facts were grouped into 'Application'. Finally. Questions for higher and/or other concepts were grouped into 'Extension'. We also discussed educational implications of the above categorized questions in this study.

• Journal of Advanced Navigation Technology
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• v.18 no.6
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• pp.609-618
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• 2014

Information system audit, by checking overall matters about constructing and managing information system, has to contribute to improvement of information system's quality and improving performance of projects. For this, an auditor has to present objective corroborative facts which back up result of audit and ways of improvement, but in reality, general(especially businessmen's) cognition is that audit is biased by way too subjective opinions. Local experience and theoretical research until now propose that tools of automating audit will be an active means of systematically collecting and proposing these objective evidences of audit. This research not only verified that in the field of audit, phenomenon of technology application can be explained and predicted by applying TAM, but it also contributed in extending theoretical base on information technology and audit by distinguishing several characteristics which appear in the process of the model's application and analysis.

• Korean Journal of Organic Agriculture
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• v.7 no.2
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• pp.125-151
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• 1999

After the release of facts that the high nitrate contents in vegetables by Korean organic farming, organic farmers were recommended by Korean Organic Farmer Association to apply 20t/ha compost while they applied before as much as they could, sometimes even more than 100t/ha. This study was aimed to check the safety of Korean organic product in terms of nitrate content. Current nitrate content in leaf and root vegetables by 3 different farming systems(organic farming, conventional farming, greenhouse farming) were monitored and furthermore it was compared with previously published another data in Korea to find out any changes among the monitored years(1993-1999). Current nitrate content in chinese cabbage, lettuce and kale became less compare to those of the beginning of monitoring, and especially those cultivated organic farming got the lowest value while previous organic vegetables at beginning of 90's showed the higher value than those cultivated in greenhouse. This decrease in organic vegetables was affected by less application rate of organic fertilizer than before at 20t/ha. But the nitrate level by organic farming was still higher compare to those cultivated by conventional farming in open field, since currently monitored organic vegetables were cultivated basically in greenhouse condition. It shows the organic farmer the necessity of transfer their farming site and condition from greenhouse to open field in order to decrease of its high level of nitrate caused long-term application and slow release characteristics of organic fertilizer. It was concluded the adoption of soil nitrate test to recommend a organic farmer the exact application rate for need of crop growth. Additionally the mechanism of lower nitrate accumulation in rice and fruit vegetables were also discussed in the paper.

• Korean Journal of Soil Science and Fertilizer
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• v.7 no.2
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• pp.107-112
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• 1974

In order to establish a rational application method of potash to paddy rice(Oryza sativa L. Jinheung, a Japonica variety) field and pot experiments on split application of two rates (6kg and 12kg $K_2O$ per 10a) of potash at a certain critical growing stage have conducted in 1973 and the results were as follows: 1. At the treatment where a rate of 6kg $K_2O$ per 10a(lower dose) of potash was supplied in two split doses, a half at transplanting time and the other half at young panicle formation stage, the yield of paddy rice appeatred to be low due to less number of panicles per hill. (Field experiment) 2. The treatment where potash supply ceased at transplanting time or at effective tillering stage but supplied at the other two stages (including panicle initiation stage) have failed to increase K content in the flag leaf and have shown low maturity and low thousand grain weight, which resulted in low paddy rice yield. (pot experiment) 3. From above two facts, it is concluded that the application of potash at transplanting time is an important practice for the high yielding of paddy rice. 4. The application of lime seemed to stimulate later growth of paddy depressing the unnecessary increase of poor miserable tillers in early stages of growth.

• Journal of Technology Innovation
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• v.14 no.1
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• pp.67-99
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• 2006

Utilizing the patent application data between 1997 and 2002, this study focuses on analysing the impact of patents on firm value. Especially we attempt to examine the difference of patents between venture firms and general firms. This paper first shows that the number of the patent applications of general firms listed on the securities market is more than that of venture firms listed on KOSDAQ. It is thought that this result is originated from the facts that the size of firms of the securities market is usually bigger than that of the firms of KOSDAQ and that these large firms could manage R&D more efficiently. Second, this paper reports that there is no difference in the ratio of patent maintenance between venture firms and general firms. Both venture firms and non-venture firms would do their best to keep their patents after patent regisration. Third, in the regression of patent index and firm growth, we find that the excellence of patent and the number of patents per employee would have an impact on the growth of firms. Fourth, the regression of patent index and profitability shows that the excellence and the number of patents per employee might have an effect on the profitability of firms.