• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.5
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• pp.1073-1077
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• 2011

The breaking capacity of circuit breakers could be no more increased in the electric power system. This is because the fault current increases due to continuous increases in electric power demand and facilities. To solve the problem, it is necessary to come up with an alternative. The superconducting fault current limiter (SFCL) has received an attention among various alternatives. The SFCL effectively reduce a fault current in cooperation with a power circuit breaker. A various types of the SFCL are suggested and a study on them have been progressed. As a result of it, the SFCL can be applyed to the electric power system in the near future. But, a study on recovery behaviors of the SFCL is not enough for applying to the electric power system. If the superconducting elements do not completely recover to the superconducting state after fault operation, it might be a breakdown of the superconducting elements due to heavy power burden and it gives an bad influence on the working of other electric devices. Additionally, the distribution power system has reclosing operation such as open-0.3sec-closed/open-3min-closed/open procedure. So we need to study more about improvement of the recovery behaviors of the SFCL. In this paper, we analyzed the recovery behaviors of a flux-coupling type SFCL according to reclosing operation when a single line-to-ground fault occurred and we compared recovery behaviors of the SFCL with and without a neutral line between secondary reactors and superconducting elements. Also, the flux-coupling type SFCL has advantageous for increases of capacity by controlling the variation in turn ratios between two reactors. Consequently, when the number of turns of the secondary reactors increased, the power burden of the superconducting elements was bigger due to the increase of impedances of the secondary reactors. To distribute the power burden, two superconducting elements connected in series and the balanced quenching of the superconducting elements was induced by connecting a neutral line.

• The Journal of the Korea Contents Association
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• v.11 no.12
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• pp.764-773
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• 2011

Modern police activity is achieved than individual achievement by police officers through member's interaction. It is police's goal which protect citizen's life and body, property and is public order maintenance and to achieve this, suitable police official's selection and public official upgrading the quality and capacity strengthening are important element. But, polices organization has characteristic that do activity by team, and therefore, mutual cooperation of police officers is important first of all for public order preservation. Therefore, this study limited as patrol police officers and investigated realization difference about organizational effectiveness for public order maintenance. Analysis result, realization of organizational effectiveness appeared difference according to sex, age, area, police departments, class, period.

• Journal of the Korean Society for information Management
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• v.37 no.3
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• pp.275-299
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• 2020

This study investigates the factors affecting behavioral intention of professors and students at universities to use academic libraries in a hybrid library environment where a traditional physical library is combined with a digital library that is centered on online information use. The structural relationships among factors were also analyzed in this study by utilizing a combined behavioural model which was based on TPB and TAM. This study identified users' intention to use academic libraries according to changes in the use environment, and the findings of this study bring a valuable meaning to library administrators for setting up the strategic plan for the future of academic libraries. The results of this study imply that academic libraries should strategically setup an effective and efficient operating plan based on awareness, attention and cooperation, in order to survive as well as to accomplish balanced growth in rapidly changing environment.

• Proceedings of the KAIS Fall Conference
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• 2011.05b
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• pp.1052-1056
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• 2011

이 연구는 동위원소실에 근무하는 임상병리사들의 방사선 방어에 대한 지식, 태도 및 행위수준을 조사하여 상관관계를 파악하고 방사선 안전관리에 대한 행위에 영향을 미치는 요인을 분석하기 위해 시행하였다. 설문지는 2010년 10월부터 11월까지 대전 충청권 및 서울 경기권 동위원소실 임상병리사를 연구 대상자로 하여 연구자자 임의로 선정 직접설문, 또는 우편방식으로 조사하였고, 수집된 자료는 SPSS12.0 프로그램을 이용하여 빈도와 백분율, T-검정, ANOVA, 다중회귀분석법을 이용하여 분석하였다. 방사선 안전관리에 대한 지식 점수는 평균은 11.5점이었으며 표준편차는 ${\pm}$1.9 분포를 보였다. 방사선 안전관리에 대한 태도 점수는 평균 69.0점, 표준편차는 ${\pm}$5.4이었다. 방사선 방어에 대한 행위점수는 평균은 57.1점, 표준편차 ${\pm}$3.5이었다. 방사선 안전관리 행위에 있어 이론적으로 알고 있는 내용에 비해 수행이 현저히 떨어진 결과가 나왔으며, 방사선 안전관리에 대한 지식, 태도, 행위와의 상관성은 통계적으로 유의한 상관관계를 보였다(p<0.01). 행위점수에 영향을 미치는 요인으로는 종사자법정교육, RI 면허취득, 지식, 태도로 나타났다. 결론적으로 동위원소실에 근무하는 임상병리사의 방사성동위원소 안전관리 행위는 태도에 비하여 수행이 현저히 떨어진 결과가 나왔고, 안전관리 행위에 영향을 주는 인자로 종사자법정교육, RI 면허취득, 지식점수, 태도점수를 알 수 있었다. 업무 진행에 있어 잘못된 지식의 습득 및 태도를 취할 수 있는 가능성이 충분히 있으며 이를 바로 잡을 수 있도록 안전관리에 대한 지속적인 교육을 실시함과 더불어 RI면허 취득, 방사선 종사자에게 교육의 효과를 더욱 높이기 위한 적절한 교육 자료의 개발이 필요하다고 할 수 있다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.913-916
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• 2001

From 1994 the cooperation between NEU of China and MJU of South Korea for study of ReBaCuO (Re=Rare earth elements) superconductors has been carried out. The progress has been got in following projects. Critical current density ($J_c$) of YBaCuO superconductor prepared by Melting Textured Growth (MTG) was improved. In the preparation of textured YBaCuO, 20 wt.% of YBaCuO 211 phase was added, which would be climactic for the microcracks in the textured YBaCuO. The effects of the 211 phase and Ag content on the superconductivity were studied and discussed in detail. The improved $J_c$ value was reached to 8$\times$10^4 A/cm^2 (77K,0T). Single phase $YbBa_{2}Cu_{3}O_{x}$ superconductor was sintered by the traditional powder metallurgical method, and its reaction process was studied. In recent years, NdBaCuO superconductor is being performed. The behavior of $Nd_{4}Ba_{2}Cu_{2}O_{10}$(Nd422 phase) and the solid solubility, x in the superconductor $Nd_{1+x}Ba_{2-x}Cu_{3}O_{y}$ by the heat treatment in the low oxygen partial pressure (1%) or Ar at $950{\circ}C$ were investigated. The zone-melting process was used to make oriented NdBaCuO superconductor in order to increase the critical current density.

• Tunnel and Underground Space
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• v.14 no.5
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• pp.345-352
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• 2004

In a shotcrete support system, the cooperation of the ground and the shotcrete lining makes it possible to transfer the shear stress to the shotcrete lining, which is dedicated to form a stable structure. In this study, a homogeneous model ground with constant strength was produced by using gypsum and the tunnel was excavated with a top heading method under the definite initial stress. During the excavation, the stress in the ground around the tunnel and the deformation of shotcrete lining were measured, The tensile stress was generated in tangential direction in the ground near the tunnel and in the shotcrete lining due to tunnel excavation. This shows the unified behavior of the ground and shotcrete lining, which is the most typical characteristic of the shotcrete support. As a result, the rates of in-situ stress during the excavation at a top boundary line was 9% and at top arch heading 15%. It was 48% right after excavating the heading and 94% before cutting the bench.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.3
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• pp.49-58
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• 2009

Healthcare organizations need mutual cooperation among various medical professionals in order to carry out the performance of their duties spite of haying a strong job specialization and independence based on license. However, spite of the importance of leadership roles, there have not been enough researches dealt with leadership effect under the complex duties' relationship of a healthcare organization. This study suggested a new model by combining characteristics of leadership style, job satisfaction, and organizational commitment using Structural Equation Model (SEM). The data were self-administered questionnaires collected in 2006 from 437 employees (nurses, medical technicians, and administrative staffs) of 5 hospitals located in Seoul. The items of questionnaire were composed as a method of choosing new leadership style based on the Bass's standardized questionnaire on a Iransactionaljtransformational leadership combining the Leader Behavior Description Questionnaire-XII (LBDQ-XII) of the Ohio State University and Graen and Uhl-Bien's LMK scale through simulation techniques responding to organizational commitment. As a result, the leadership style increasing employees' self-confidence and having continuous response relationship between managers and employees improved their discretion and empowerment as well as worthwhileness and pride. However, the leadership style emphasizing reward and a sense of duty brought about a bed result that was not able to effectively respond to employees' discretion and empowerment and even weakened their worthwhileness and pride. After all, the leadership style based on vision and change had an effect on organizational commitment but the other one based on reward and a sense of duty seemed to be unsuccessful in organizational commitment. Therefore, the desirable leadership in a healthcare organization should be based on employees' self-confidence and continuous response relationship between managers and employees.

• 한국태양에너지학회:학술대회논문집
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• 2008.11a
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• pp.63-68
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• 2008

Efforts tp overcome the current challenge of global warming and abnormal temperature are being taken around the world. According to a report, average temperature of Korea has increased by about $0.8^{\circ}C$ for a century. In particular, temperature has rapidly increased since year 2000. Climate changes have brought remarkable changes in our lives. For example, agricultural field will see changes in crops and production. Energy used to maintain and manage architectures will be changed as well. In order to actively cope with rapidly changing global climate which drives changes from the basic behavior of our lives to subtle changes, international cooperation and researches are performed around the word. For instance, as a part of these global efforts, research on typical meterological data for computer simulation program to evaluate architecture energy performance is in progress in Korea. In order to conduct research on typical meterological data in format of data per time, reference regarding monthly maximum/minimum temperature time is required. Unfortunately, however, reference regarding maximum/minimum temperature time hasn't been defined in Korea. Therefore, this study aims to provide fundamental data essential for various researches by calculating maximum/minimum temperature time of major cities across Korea. According to the study, maximum temperature occurs at 3 p.m and minimum temperature occurs at 5 a.m or 6 a.m. respectively, in overall areas.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2036-2041
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• 2005

The underwater multi-agent technology has many potential for the various activities related to ocean development/conservation in the near future. For example, in such fields as water pollution investigation, aquaculture control, or coral reef research, we feel a growing need for a system that realizes underwater continuous monitoring in the wide rang e. In this case, the target monitoring area will be sliced planar hierarchically toward the depth as monitoring layers, and many AUVs arranged on each layer track the given trajectory and gather various environmental information continuously, with communicating each other in the layer or with other layers. To realize those systems we need to develop AUV multi-agent technologies. So we are now building basic systems for basin experiment for the development of AUV multi-agent behavior. We must experience many situations and problems to be solved for the development of its elemental technologies by using real systems as well as our computer simulations. In this paper we introduce our concept of the experiment in the near future and the hardware/software design of our two types of handy AUVs and ultrasound ranging/communication system for that experiment. One AUV is designed using a 17inches-diameter glass sphere with DOS/V and RT-Linux based subsystems, which is intended to use not only in the basin but also in the calm real sea. The other AUV is designed for the basin experiment using a 7inches-diameter acrylic sphere with low-cost embedded system with SH-2 based subsystems. The basin experiment to verify the basic AUV facilities and ultrasound ranging for position detection was carried out.

• Journal of dental hygiene science
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• v.20 no.2
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• pp.107-117
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• 2020

Background: In this study, we tried to comprehensively explore clinical dental hygienist's experience of a prevention-based incremental oral health care program, which was pilot-operated by dental clinics, define prevention-based incremental oral health care as experienced in the field, and identify factors to be considered. Methods: This study conducted a focus group interview with five dental hygienists who participated in an ongoing oral management pilot project in 2016. The interview was conducted by a researcher, and the co-research team attended as progress assistants and recorded characteristics of the participants, main dictations, and non-verbal characteristics. All interviews were recorded and underwent thematic analysis to examine the questions of the study as the main axis. Results: As a result of the study, 65 meaningful statements were extracted by code, integrated into 24 sub-categories, and structured into 11 categories. Finally, four keywords were drawn: characteristics, facilitating factors, conflicting factors, and improvement measures for prevention-based incremental oral health care. Regarding prevention-based incremental oral health care in dental clinics, dental hygienists were highly aware of the physical and mental burdens of personalized treatment and education for each individual. They were responsible for the patient and for facilitating changes in the behavior of the client, leading to professional satisfaction. The dental team's cooperation and supportive attitude were found essential to continue oral health care in the dental clinic. Conclusion: Through dental team-based treatment philosophy sharing and collaboration, it is possible to provide prevention-based incremental oral health care in dental clinics. In future, it is necessary to develop a system for establishing a sustainable preventative management system for public health promotion.