• Journal of Power Electronics
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• v.13 no.2
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• pp.186-196
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• 2013

This paper presents a low voltage-stress AC-linked charge equalizing system for balancing the energy in a serially connected, valve-regulated lead acid battery string using a modular converter that consists of multiple transformers coupled together. Each converter was coupled through an AC-linked bus to increase the overall energy transfer efficiency of the system and to eliminate the problem of the unbalanced charging of batteries. Previous solutions are based on centralized and modularized topologies. A centralized topology requires a redesign of the hardware and related components. It also faces a high voltage stress when the number of batteries is expanded. Modularized solutions use low-voltage-stress, double-stage, DC-linked topologies which leads to poor energy transfer efficiency. The proposed solution uses a low-voltage stress, AC-linked, modularized topology that makes adding more batteries easier. It also has a better energy transfer efficiency. To ensure that the charge equalization system operates smoothly and safely charges batteries, a small intelligent microcontroller was used in the control section. The efficiency of this charge equalization system is 85%, which is 21% better than other low-voltage-stress DC-linked charging techniques. The validity of this approach was confirmed by experimental results.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.3
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• pp.499-505
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• 2010

This paper analyzed that the coordination of recloser-fuse when a superconducting fault current limiter (SFCL) is installed to a power distribution system linked small scale cogeneration system. As a rule, the recloser to properly protect against both permanent and temporary fault is installed to upstream of fuse. Therefore, in a power distribution system linked small scale cogeneration system, the fault current is increased by adding fault current of small scale Cogeneration system when a permanent fault occurs, and the fuse could melt during the first fast operation of the recloser because of more sufficient heat from the increased current. However, when SFCLs are applied into a power distribution system linked small scale cogeneration system, the coordination of recloser-fuse could be accomplished due to decreased fault current as the effect of the impedance value of the SFCL. Therefore, to solve these problems, we analysed the operation of recloser-fuse coordination in a power distribution system linked small scale cogeneration system with SFCL using PSCAD/EMTDC.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.23 no.2
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• pp.5-25
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• 2012

The purpose of this study is to develop linked data of authority data in national archives of Korea as a cornerstone for linked data cloud of Korea. The study analyzed data structure of authority data as well as a retrieval system. It finally developed linked data based on RDF/OWL, Dublin Core, and SKOS. The study also employed TopBraid ComposerTM as a tool for ontology construction. The visualization of the tool provides users with flexible search and browsing between data as well as access of detail authority data. It complements the search of a current system in terms of flexible linking between records and authority data. The study also suggests future work to publish linked data of archival data set itself and make rich relationships among data in museums, libraries, and other archives.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.562-565
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• 2000

For solving problems of manpower and improving working environment, Robot System have been introduced. In the past, Robot System was adopted mass production, indoor factory condition, but present Robot System is applied to many other fields. This applied field is Robot System was adopted fruit harvest, maintenance, and so on. The developed Multi-Linked Lifter is applied to eminant multi-purpose working. The purpose of this study is to develop control algorithm for this equipment composed of multi-linked manipulator.

• The Journal of Korean Association of Computer Education
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• v.14 no.2
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• pp.47-59
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• 2011

Linked Data is about using the web to link related data that wasn't linked previously. To publish linked data, people should be able to represent, share, and link pieces of data, information, and knowledge by using URIs and RDF. However, building linked data is not easy for the common users who do not know the knowledge or skill about using URIs and RDF. In this paper, we present a system that the common users can create linked data by connecting data originated from different RDFs. They build linked data by adding new links to connect between RDF data saved in their computers or searched from Swoogle. We can apply the proposed system to creating educational contents. For example, teachers can develop various learning contents by building linked data that connects different data suited to the learning level of their students.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.165-170
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• 2001

This paper presents performance analysis of two-linked robot system using ER (electro rheological) valve actuators. An ER fluid consisting of soluble chemical starches (particles) and silicone oil is made and its field-dependent yield stress is experimentally distilled using electro-viscometer. From this result, the design parameters of ER valve are determined. Based on parameter study, an ER valve system is designed and manufactured. Furthermore, the measured pressure drop is compared with predicted one obtained from the Bingham model. Following the evaluation of field-dependent pressure drop of ER valve, a two-linked robot system with two ER valve actuators is then constructed and its governing equation of motion is derived. From this equation, PID controller is established. Consequently, control performances of the proposed two-linked robot system featuring ER valve are evaluated.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.86-87
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• 2013

Construction data is one of the most important resources in a construction project. The construction data is generally stored in the PMIS. However, it has been analyzed that the PMIS revealed limitations in suggesting valuable information by analyzing the data. In order to overcome such limitations, the linked-data methodology used in big data management has been studied. The purpose of this study is to suggest a methodology that improves the system by developing a more effective data collection and management model using the linked-data format.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.67-68
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• 2011

This paper analysed a protective equipment in power distribution system linked distribution power system when a superconducting fault current limiter(SFCL) is installed. This paper focused on a recloser, because the recloser is a general protective equipment. When power distribution system linked distribution power system, a fault current is increased by adding fault current of distribution power system. The increased fault current makes many problems. But SFCLs are limiting fault current and help the protective equipment to operate normal process. We analysed the operation of protective equipment in power distribution system linked distribution power system with SFCLs.

• Journal of Broadcast Engineering
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• v.9 no.2
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• pp.102-109
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• 2004

We have proposed an Object-linked Broadcasting Service that displays various data related to the object onscreen. In thls paper, we describe the structure of the Object-linked Broadcasting System that will enable our proposal to be realized, and report new techniques that we have developed to create the system. We have carried out the experiment to confirm the system performance as well as execution of each technology assembling the system. We have confirmed that the performance of the system we developed satisfies the proposed specification based on user requirements and current technology.

• Journal of Practical Engineering Education
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• v.15 no.1
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• pp.183-192
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• 2023

This study analyzes the performance of flipped learning, an offline class method conducted in a degree-linked work-learning parallel system. Training in the work-study parallel system, which is conducted as part of job competency improvement, has thoroughly adhered to the offline method, but in line with COVID-19, unlike before, it is changing in the direction of using the online method more actively. However, educational methods such as flipped learning are not new because the degree-linked operation is applied to the academic system and education method of universities and is practically the same form as general university education. Therefore, it is necessary to analyze the educational performance and complementary points of flipped learning, which has recently been expanded in the degree-linked work-study parallel system, considering the characteristics of this system, in which classes are held only on weekends. As a result of statistical analysis based on the survey, some of the outcomes of flipped learning have been confirmed, and in order to increase the performances, it is necessary to continuously seek out specific measures to encourage learning and expand communication between instructors and students.