• Journal of Power System Engineering
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• v.6 no.2
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• pp.5-11
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• 2002

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.4
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• pp.577-583
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• 2013

We have analyzed influence of potential rise in negative bus, which caused by decrease of power feeding line insulation, upon protecting method of DC ground protection device which detecting potential rise between negative bus and ground in order to detect ground fault in the rubber wheel system. For this purpose, we proposed negative potential equation between negative bus and ground and calculated negative potential according to system condition changes by estimating power feeding line insulation changes in steel wheel system and rubber wheel system, and equalizing DC power feeding system when ground fault occurred. Also, in order to estimate negative potential of real system, we modeled the rubber wheel system, and simulated normal status, grounding fault occurrence and power feeding line insulation changes. In normal status, negative potential did not rise significantly regardless of vehicle operation. When ground fault occurred, negative potential rose up over 300V regardless of fault resistance. However, we also observed that negative potential rose when power feeding line insulation dropped down under $1M{\Omega}$. In conclusion, our result shows that in case of rubber wheel system unlike steel wheel system, relay will be prevented maloperation and insulation status observation can be ensured when ground over voltage relay will be set 200V ~ 300V.

• Journal of Korea Society of Industrial Information Systems
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• v.10 no.2
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• pp.21-25
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• 2005

Human performance of system control under excessive mental-workload may differ from stable situation. In this study, design guidelines of secondary control system were introduced to enhance performance of safety control system. Under urgent situation, the first performance criterion is not a reaction time but safe control reaction that prevents system disaster. Therefore it is important to find out the facts that are mainly related system safety. Experimental results show performance of primary task didn't reflect whole system influence within a limited short reaction time. In this situation, the secondary task is more sensitive to system influence that varied with some factors of urgent status. Therefore, when a system proceeds to abnormal and unsafe status, and even more the reaction time is limited within a very short time to control the system, the estimation of human performance is more sensitive using secondary task performance then primary task performance. Those results mean it is required to develop various secondary tasks to design safety control systems preventing disaster, And also require many studies of estimation methods human performances especially when system status varies dangerous and/or unsafe situation.

• The Journal of Information Systems
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• v.24 no.2
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• pp.189-208
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• 2015

Purpose While individuals have unique abilities for planned behavior, they also often act irrationally. In this study, we draw on myopic loss aversion perspective as a meta-theoretical lens to explain why mobile applications users have inertia from updating their applications, ultimately leading them to use current version of applications. Design/methodology/approach Based on a survey of 219 users, this study conducts its research model using partial least square analysis and also demonstrates that both subconscious triggers (habit and anxiety) of system 1 thinking and conscious triggers (sunk cost and transition cost) of system 2 thinking promotes user's inertia, thus leading to the willness to continue use current versions. Findings By grounding the research model in the combination of both status quo bias and dual information processing theory from the behavioral economics, this study provide an alternative theoretical lens to describe why mobile users hesitate to update their applications. The results of this research show that all triggers have significant impacts on inertia. This study also found that the relationship between inertia and willingness to continue to use current version was positively significant.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.39 no.1
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• pp.71-76
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• 2002

Because the driving time is increased under the low speed by rapidly increasing of vehicles, this paper is presented a new ignition control system for improvement the fuel economy, which only some of cylinders are using under the idle status or low speed and preserving the engine rpm. is applicable to effective in fuel economy. An actual hardware was made to prove this new control system. The developed variable cylinder engine concentrated the heat neat the cylinders in idle status or low speed, so there was a problem in re-ignition. It was the reason of a lot of exhaust gas, high fuel consumption and instability of engine revolution. In this paper, in order to solve above problem to show the improvement fuel economy using the new ignition control system and valve opening period at idle status of low speed.

• Journal of Korean Public Health Nursing
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• v.28 no.3
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• pp.536-552
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• 2014

Purpose: The purpose of this study was to explore how homeless shelter worker and public health nurses perceive health status and health care of homeless shelter residents (HSRs). Methods: Data collected through focus group interviews. In Focus group, in-depth discussions were between 150 to 160 minutes. Data analyzed using Krueger (1998) step analysis. Participants were seven experienced clinical social workers, nurses working homeless shelters, and public health center nurses for dosshouse people. Results: The results were 4 themes and 15 sub-themes: Characteristics of HSRs, perception of health and health problem of HSRs (alcohol related disease, hypertension Diabetics, gastro-intestinal disease, dental disease and infectios disease such as Tuberculosis, musculo-skeletal disease, prostate problem), health care status of HSRs(insufficient health care service, discrimination of medical staff, lack of health care management, low satisfaction community health care services), and the health care proposal of HSRs(nurse in homeless shelter, integrated health care system, understanding of homeless) Conclusion: Based on the findings of this study, health care programs focusing on understanding of HSRs and chronic diseases of HSRs increasing steadily although the management system is limited. Therefore, more systemized health care plan and health referral system for homeless people.

• The Journal of Korean Medical History
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• v.29 no.2
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• pp.107-115
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• 2016

Purposes : The Purpose of this study was to review a current status on acupuncture and traditional Chinese medicine in Canada focusing on the rules of regulatory bodies of 5 states including legislation history, development in professional self-regulation, education and evaluation system. Methods : Based on literature review, we studied on 5 legislated states cases, educational accreditation status and licensure system. We also interviewed on a person who is a chair of CTCMA & CARB-TCMPA and more TCM practitioners in British Columbia within educational topics. Results & Conclusions : Acupuncture legislations have been approved by the governments in Canada between 1988 and 2014 within the acceptance of self-regulation. Since then, regulatory bodies in each states have tried to strengthen their duties and rights as a healthcare professionals. Based on firm laws and regulations, occupational competency-based education in acupuncture and TCM has been gradually improved and established quite well in parallel with a development of higher educational system in Canada.

• Journal of the Korea Safety Management & Science
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• v.10 no.4
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• pp.165-171
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• 2008

In the policy management system of the safety&health(same as the environment and the quality), the documentation of the management system is required in various international standards & guides. In case of 3 level classification of the system documents, it generally will be identified such name as the manual, the procedure(or the process) and the job instruction. Each level of the document has the unique role and usage though, the job instructions, especially, would be developed to support the practical job worker. Considering such document level, the job instructions should be reflect the latest know-how of the job-handling methods. And that, it should be used at any times by the related job worker. This paper is prepared for surveying the actual usage status of the job instructions of the domestic enterprises holding ISO certificate and trying to suggest the better way of application of the system documents.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.3
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• pp.332-341
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• 2013

SCADA RTU is a remote control unit equipped in substations for automatic operation of a power system. The RTU monitors and measures the operation status of remote substations to transmits the signals to upper SCADA system and receives control command signals from dispatch center to actuate corresponding apparatus. The RTU receives the standard time from GPS receiver to synchronize the times for all devices and acquires the status event of power apparatus using DIM. Without the time synchronization between GPS and RTU, stable operation of the power system and accurate analysis of the system fault are impossible due to the time error of SOE. In this paper, a test is performed to identify if the operation time of SCADA RTU DIM coincides with the standard time. And we tried to find the reason of error, to minimize the time discrepancy. Through this study, RTU operation time could be synchronized with the standard time within 10[ms] to improve the reliability of SOE data.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.440-444
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• 2015

As domestic construction investment has been gradually reduced, expanding overseas construction is one of the most important issues for Korean construction companies. Among these issues, strategies for overseas CM services have widely been discussed, because the CM services have features of high growth potential and value-added area when compared with other construction sectors. Therefore, recent efforts focus on further development in advanced CM capabilities and expansion to overseas market. However, there has been lack of quantitative research to investigate current status and future direction of CM industry. In this sense, this research investigated what CM has achieved for the past 17years (between 1997 and 2013) and what CM should accomplish for future strategies. The purpose of this research is to statistically analyze total of 2,983 CM service contracts over the past 17 years published in KISCON (Knowledge Information System of Construction Industry) in order to examine current status of CM industry in terms of market type, contract size, commodity type, and owner's type. Based on this research, it is expected to suggest for future strategies and development directions from the CM industry perspective that could provide quantitative analyses, improve current CM statistics systems and strengthen the competitiveness in international CM market.