• Title/Summary/Keyword: 2 order system

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A Study on the Diagnosis and Improvement of Present Superintendent Election and Education Standing Committee System (현행 교육감 선거 및 교육상임위원회제도 진단 및 개선연구)

  • Joo, Chul-An
    • Journal of Fisheries and Marine Sciences Education
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    • v.26 no.1
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    • pp.22-33
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    • 2014
  • This study is to diagnose the present superintendent election and education standing committee system for improvement based upon Constitutional values of local education system. The findings are the followings. To improve the election system of superintendent it is recommended to maintain present election system rather than change it drastically since the present system ensure relatively more autonomy, expertise, and political neutrality of local education system. However, the qualification such as years of educational experiences of superintendent candidates need to be restored. Regarding education standing committee it suggest that all or at least 2/3 members need to be educational representatives rather than general representatives. For superintendent as well as education standing committee election, it needs to elaborate the vote ballet such as change of candidates name order by voting place to reduce its effects to election results. It also needs to strengthen public management of election such as expenses and TV forums among candidates.

Comparison of contacting and non-contacting methods in measuring the surface roughness of texture (섬유의 거칠기 측정에 있어서 비접촉식 방식과 접촉식 방식의 비교)

  • 박연규;강대임;송후근;권영하
    • Science of Emotion and Sensibility
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    • v.2 no.1
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    • pp.105-111
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    • 1999
  • In order to introduce the touch to engineering and industries, it must be preceded to dstablish a quantitative barometer of the feeling. for this purpose, we developed a tactile measuring system to measure physical properties of texture, such as surface roughness, friction coefficient and compliance. The tactile measuring system uses a LASER type displacement sensor, which is a non-contacting system, in measuring the surface roughness. By considering that human tactile system is a contacting mechanism, this non-contacting method needs to be modified. As a precedent research of that, we compared the contacting and non-contacting method in this paper. Surface roughness of ten cloths were measured by using the measuring system, then compared to the test results using the Kawabata evaluation system(KES), which uses a contacting method in measuring the surface roughness.

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An Experimental Study on the System Identification and Anti-Rolling System Design for a Ship with Flaps (선미측에 플랩을 갖는 선박의 동특성 규명과 횡동요 제어계 설계)

  • 김영복;강귀봉;채규훈
    • Journal of Ocean Engineering and Technology
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    • v.18 no.2
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    • pp.39-45
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    • 2004
  • We have investigated the usefulness of an active stabilizing system to reduce ship rolling under disturbances, using varying reaction of the flaps. In the proposed anti-rolling system for a ship, the flaps, as the actuator, are installed on the stern, in order to reject the rolling motion induced by disturbances, such as waves. The action induced by the flaps, which is dependent upon the power of the disturbances, can keep the ship in balance. In this study, we define the system parameters under the given system structure, using spectral analysis and experimental studies. Based on this information, we design the controller to evaluate the usefulness of the proposed system.

An introduction to the MMI system of strip casting Process (박판주조공정의 MMI 시스템 소개)

  • Joo, Moon-G.;Lee, D.S.;Kim, Y.H.;Kang, T.
    • Proceedings of the KIEE Conference
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    • 2000.07d
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    • pp.2778-2780
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    • 2000
  • MMI system for strip caster 2 is described. It has been developed as a PC-based MMI system whose data is collected from the VME-based control system by ETHERNET. MMI elements that mimic the caster and its utilities are designed by using commercial program. In order to implement the UDP/IP communication in MMI, UDP/IP manager program with DDE that is a intercommunication protocol in MS-window is developed and connected with MMI mimics. Operator commands in MMI system are carried out immediately in VME system and the responses are displayed on MMI system. The developed MMI system has been proven to be convenient and stable through the operation of the past 5 years.

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A Study on Battery Charger Reliability Improvement of Nuclear Power Plants DC Distribution System (원자력발전소 직류 전력계통의 충전기 신뢰도 향상방안 연구)

  • Lim, Hyuk-Soon;Kim, Doo-Hyun
    • Journal of the Korean Society of Safety
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    • v.25 no.2
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    • pp.24-28
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    • 2010
  • The nuclear power Plant onsite AC electrical power sources are required to supply power to the engineering safety facility buses if the offsite power source is lost. Typically, Diesel Generators are used as the onsite power source. The 125 VAC buses are part of the onsite Class 1E AC and DC electrical power distribution system. The DC power distribution system ensure the availability of DC electrical power for system required to shutdown the reactor and maintain it in a safety condition after an anticipated operational occurrence or a postulated Design Base Accident. Recently, onsite DC power supply system trip occurs the loss of system function. To obtain the performance such as reliability and availability, we analyzed the cause of battery charger trip and described the improvement of DC power supply system reliability. Finally, we provide reliability performance criteria of charger in order to ensure the probabilistic goals for the safety of the nuclear power plants.

Fuzzy Linguistic Variable Based Approach for Safety Assessment of Human Body in ELF Electromagnetic Field Considering Power System States (계통상태를 고려한 ELF 전자계의 인체안전평가를 위한 퍼지언어변수 접근법)

  • 김상철;김두현;고은영
    • Journal of the Korean Society of Safety
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    • v.12 no.2
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    • pp.70-79
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    • 1997
  • This paper presents a study on the fuzzy linguistic variable based approach for safety assessment of human body in ELF electromagnetic field considering power system states. To cope with the demand in modern industry, the power system becomes larger in scale, higher in voltage. The advent of high voltage system has increased the relative importance of field effects. The analysis of ELF electromagnetic field based on Quasi-Static Method is introduced while the power system is included to model the expected and/or unexpected uncertainty caused by the load fluctuation and parameter changes. In order to analyze the power system, Monte Carlo simulation method and contingency analysis method are adopted in normal state and alert state, respectively. In the safety assessment of human body, the approach based on fuzzy linguistic variable is employed to overcome the shortcomings resulting from a crisp set concept. The suggested scheme is applied to a sample system(modified IEEE 14 bus system) to validate the usefulness.

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A Reliability Enhancement Methodology of the IEC61850 based Substation Automation System (IEC61850 기반 변전소자동화시스템인 신뢰도 향상기법)

  • Lim, Seong-Il
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.9
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    • pp.75-81
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    • 2008
  • The effect of the fault could be propagated to healthy region when the fault on the power system is not cleared in time. In order to enhance reliability of the protective relay, a dual and/or backup system is adopted for the power system protection. The IEC61850 has become an international standard of the substation automation system for interoperability between heterogeneous IEDs from different vendors. This paper introduces a reliability enhancement technique for the substation automation system using characteristics of the IEC61850.

Network System Design for Measurement of Bridges (교량의 계측을 위한 네트워크 시스템 설계기법)

  • Cho, Hyo-Nam;Hong, Seung-Ho;Park, Kyung-Hoon;Kim, Wook-Heon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.3 no.2
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    • pp.221-232
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    • 1999
  • This study investigates the applicability and design scheme of fieldbus network in the measurement system used for precise and safe construction as well as efficient maintenance of bridges. In order to maximize the function and performance of bridge monitoring system, this study introduces the CAN(Controller Area Network), one of the fieldbus protocols, in the measurement system of bridges. This study presents the implementation method of CAN on the monitoring system of bridge, and also proposes a bandwidth allocation scheme for the design of network. The validity of the proposed CAN design method is verified through a simulation experiment. It is shown that the CAN can be readily applicable to the measurement system of bridges.

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A Study on the Output Power Enhancement of GaAs/AlGaAs Solar Cell using Concentration Method (집광에 의한 GaAs/AlGaAs태양전지의 출력 증대 연구)

  • Lee, Dong-Ho;Kim, Young-Hwan;Song, Jin-Dong;Kim, Seong-Il
    • New & Renewable Energy
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    • v.5 no.3
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    • pp.26-31
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    • 2009
  • Using MBE growth method, GaAs/AlGaAs solar cell structure was grown. Deposited electrodes are Au/Ni/Ge for n-type and Au/Pt/Ti for p-type electrodes were deposited by E-beam evaporator. Indoor light concentrators were devised and fabricated in order to concentrate artificial solar rays. Also mirror and prism and Fresnel lens concentration system with solar simulator were devised and fabricated. Results of solar cell characteristics were measured with shutting system which can control the amount of light. Maximum power density was 2.13 W/$cm^2$ and maximum concentration was 124 sun, when mirror with Fresnel lens was used at $7854\;mm^2$ of shutter hole.

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A Study on Evaluating Learning Effects Based on Analysis of Satisfaction in E-learning

  • Kwon, Yeong-ae;Noh, Younghee
    • International Journal of Knowledge Content Development & Technology
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    • v.5 no.2
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    • pp.103-122
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    • 2015
  • This study examined student satisfaction with e-learning experiences in order to determine which factors had the greatest impact on reports of satisfaction among students at Konkuk University. We surveyed 4,889 students enrolled in e-learning courses and analyzed 830 completed questionnaires to identify factors that influence student satisfaction with e-learning. Results showed significant correlations between system factors and satisfaction ($R^2=0.577$; p = 0.000). The system factor with the greatest impact on satisfaction was course attendance rate (0.224; p = 0.000).