• Title/Summary/Keyword: 동형

Search Result 617, Processing Time 0.027 seconds

모타보호 다기능 디지털 계전기의 증가추세

  • 김기욱
    • Electric Engineers Magazine
    • /
    • v.266 no.10
    • /
    • pp.40-44
    • /
    • 2004
  • 모타보호를 위한 다기능디지털전기가 증가추세에 있다. 이번 글에서는 계전기의 일반적인 사항을 비롯하여 특성에 따른 계전기의 종류와 구비조건 및 사용상태, 법적인 EOCR 설치근거에 의한 선정방법, 기술활용방법 및 적용사례, 디지털 계전기와 열동형 계전기의 비교 등을 소개하였다. <중략>

  • PDF

Frequency Shaped Optimal Control of Semi-active Suspension System Using an MR Damper (자기유변유체를 이용한 반능동형 현가장치의 Frequency shaped 최적 제어)

  • 김기덕;이재형;전도영
    • The Korean Journal of Rheology
    • /
    • v.11 no.2
    • /
    • pp.112-121
    • /
    • 1999
  • An MR(Magneto-Rheological) fluids damper is designed and applied to vibration suppression of a 1/4 car model. The damping constant of MR damper changes according to input current which is controlled in a semi-active way. Several control algorithms are compared in simulations and experiments. The advantage of the proposed Frequency shaped LQ control is that passenger comfort is emphasized in the range of 4~8Hz and driving safety is emphasized around the resonance frequency of unsprung mass.

  • PDF

Semi-Active Control of Helicopter Landing Gear using Magneto-Rheological Damper (MR 댐퍼를 이용한 헬기 착륙장치 반능동제어)

  • Hwang, Jae-Up;Hwang, Jae-Hyuk;Bae, Jae-Sung;Hyun, Young-O;Lim, Kyoung-Ho;Kim, Doo-Man;Kim, Tae-Wook
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.36 no.4
    • /
    • pp.346-351
    • /
    • 2008
  • In this paper, the semi-active control of a helicopter landing gear using magneto -rheological(MR) damper is studied. A dynamic model of the MR damper is formulated by incorporating magnetic field-dependent Bingham properties of the MR fluid. The electromagnet of the MR damper is designed and its magnetic field is analyzed using a commercial finite element code. The damping characteristics of MR damper by changing the intensity of the magnetic field are investigated and the dynamic responses of the helicopter landing gear with MR damper are simulated. The semi-active control of the helicopter landing gear is simulated by implementing a sky-kook control algorithm and its performance is evaluated comparing to the passive control.

A Study on the Development of Low Speed Twin-Hull Form for Seabed Organic Sediment Collection (해저 유기퇴적물 수거를 위한 저속 쌍동형 선형개발 연구)

  • Park, Je-woong;Kim, Do-jung;Oh, Woo-jun;Jeong, Uh-cheul
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.22 no.2
    • /
    • pp.246-252
    • /
    • 2016
  • In this study, conceptual design of the fore-body hull form of catamaran type dredging vessel was performed that can effectively remove the contaminated sediments in coastal seabed. The hull form was simpled for the easy hull construction and the resistance performance was investigated to find out the effect of hull form parameters between variation of waterline and angle of entrance, etc. The relation between resistance performance and characteristics of free surface flows according to variation of bow forms was investigated by model testing in the circulating water channel and using Ansys CFX. The improvement of ship resistance performance to the wave resistance decrease due to improved wave pattern has been verified according to move the stem and the volume of the shoulder to the fore part of the vessel.

An Empirical Analysis on the Determinants of VOD Viewing Pattern of Users in IPTV Platform (IPTV에서의 VOD 시청패턴 결정 요인에 관한 실증 분석)

  • Cho, Shin;Kim, Hee Sun
    • The Journal of the Korea Contents Association
    • /
    • v.15 no.4
    • /
    • pp.153-167
    • /
    • 2015
  • This paper empirically analyzes specific characteristics of VOD users and their practical viewing patterns, using socio-demographic data of the current IPTV subscribers in combination with actual data of genre usage and payment. The findings revealed active viewing patterns of male, the unemployed, high earners and early adopters. In terms of preferences, households with large numbers of women prefer time shift contents, whereas households composed of more men or preschoolers prefer non-time shift contents. Likewise, the households that have more women or higher income had relatively a lot of experiences of purchasing time shift contents on one hand, but the households characterized by the larger numbers of family members or unemployed householder or young householder showed much willingness to pay premium contents on the other hand. Given the utilization of correct database, the findings offer useful information conducive to service promotion and marketing strategies to maximize VOD use in the practical dimension.

A Study on the Isomorphism and Standardization of School Development Plan and Specialization Plan (「학교발전계획 및 특성화계획」의 동형성 및 표준화 연구)

  • Ha, Ji-hye;Lim, Heon-Wook
    • Journal of Convergence for Information Technology
    • /
    • v.7 no.3
    • /
    • pp.47-53
    • /
    • 2017
  • The university must open the "School Development Plan and Specialization Plan" at the university allimi. The reason for this is the Special Act on the Disclosure of Information by Educational Institutions, enacted on May 25, 2007, and the Plan for Reform of University Reform announced by the Ministry of Education on Mar 28, 2014. Therefore, we examined the similarity and standardized model of the "School Development Plan and Specialization Plan" published by a total of 137 colleges. As a result of the study, only 17(12.4%) of the college produced information in two ways(school development and specialization), and the rest were not. The school development plan presented quantitative indicators such as world number one, The characterization plan presented qualitative indicators such as human. Based on this, standardized research procedures and conception are presented.