• Title/Summary/Keyword: 공관

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Variable speed drive of a Switched Reluctance Motor by adjusting switching angles (Switched Reluctance Motor의 스위칭각 조정에 의한 가변속 구동특성)

  • Hwang, Jong-Kyu;Kong, Gwan-Sik;Hwang, Young-Moon
    • Proceedings of the KIEE Conference
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    • 1993.07b
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    • pp.1026-1029
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    • 1993
  • Inherent speed-torque performance of Switched Reluctance Motor is similar to that of series wound DC motor. Thus, the speed of the motor is extremely regulated according to load torque. For the purpose of controlling the speed and torque of SRM it is necessary to change the applied DC link voltage or the switch-ON and switch-OFF angles which control the phase current of the motor. This paper describes speed-torque characteristics of an integral horse power Switched Reluctance Motor by adjusting the switch-ON and switch-OFF angles. Speed at rated load torque can be regulated by adjusting the switching angles and the control scheme is applied to 2kW, 3 phase, 6/4 SRM.

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A Study on the Characteristics of a Counter Rotating DC Motor (반전직류전동기(Counter Rotating DC Motor, CRDCM)의 특성 연구)

  • Kim, Hyun-Chel;Kong, Yeong-Kyung;Kong, Gwan-Sik
    • Proceedings of the KIEE Conference
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    • 1994.11a
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    • pp.101-103
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    • 1994
  • This report describes CRDCM(Counter Rotating DC Motor) that we have designed, manufactured and tested. CRDCM have two rotating rotors: one is a outer rotor as field set, another is a inner rotor as armature set. One of the most difficult problem is an elimination of the centrifugal force acting on brush when outer rotor is rotated. We solved a problem for centrifugal force of commutation brush by compensation set of counter mass through trial and error. It was verified the performance of motor at present.

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Analysis of temperature rise in a salient-pole synchronous generator (돌극형 동기발전기의 열전달 해석)

  • Oh, S.G.;Sung, G.D.;Ha, H.S.;Kong, G.S.;Ko, Y.;Hwang, Y.M.
    • Proceedings of the KIEE Conference
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    • 1995.07a
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    • pp.113-115
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    • 1995
  • The calculations of the temperature rise in the armature have long been considered among some of the most important problems in the design of the rotating machine. Despite the many methods of calculation propose, very few have been used in the actual design. In most cases, These methods are inadequate for measuring a wide range of temperature distribution because of the complicated structure of the machine. In this paper, the armature is divided into seven portions, and the thermal equivalent circuit is introduced as a simulation of the armature. The test machine is 1000Kw salient-pole synchronous generator.

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KINITI LIS : Library Information System(I) - System Structure and Operation - (산업기술정보원(産業技術情報院)의 자료관리(資料管理) 시스템(I) -시스템 구성(構成)과 운영-)

  • Choi, Won-Tae
    • Journal of Information Management
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    • v.23 no.2
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    • pp.73-89
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    • 1992
  • KINITI collects a wide variety of information resources such as serials, monographs, reports, microfilms/fiches etc. in the field of science, technology, and industry. This is an overview of KINITI-LIS(Library Information System). KINITI-LIS has been developed using IBM 3090/150 E by KINITI staffs. Subsystems of KINITI-LIS are as follows ; acquisition system, cataloging system, retrieval system, circulation system, serials control system.

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The study of stability exercise using pressure biofeedback unit for low back pain (요통에서의 pressure biofeedback unit(stabilizer)를 사용한 안정화 운동)

  • Kim, Gook-Joo;Kong, Kwan-Woo;Kwon, Sun-Oh;Jang, Yong-Geun;Hwang, Hee-Jun;Park, Jun-Ki
    • Journal of Korean Physical Therapy Science
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    • v.19 no.2
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    • pp.63-71
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    • 2012
  • Purpose : This study aimed to acquire a basic knowledge about lumbar stability and inquire into exercise approach of pressure biofeedback unit for lumbar stability. Methods : This study was composed with reviewed theory of lumbar stability and several books and articles for exercise using pressure biofeedback unit. Results : The stability of lumbar should work symmetrical with passive, active, control subsystem in neutral zone, and local muscles should be using for stability. Especially, selective using of transverse abdominis work for lumbar stability importantly. The control of using pressure biofeedback unit may important not only examination but treatment. Conclusion : The stability of lumbar need co-contraction of specific local muscle and training for timing as well as using pressure biofeedback unit for accurate control may use for examination and therapedic approach.

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A Performance Analysis of FFH/BFSK System Using Diversity Under Rayleigh Fading (레이라이 페이딩하에서 FFH/BFSK 시스템의 diversity를 이용한 성능 분석)

  • 조용진;이두석;공관식;조형래
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 1999.05a
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    • pp.280-285
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    • 1999
  • In this paper, we have analyzed a performance of fast frequency hopping communication systems when a rayleigh fading caused by envelope variations of a signal received in multipath channel is, but it is not considered that intentional or unintentional jamming can be. The multipath fading channel and rayleigh fading are confirmed by theoretical analysis. In fading or non-fading, the performance of this system is studied. When the path diversity is applied to this system, the performance is shown to be superior to non-diversity systems about 20dB. for modulation methods, BFSK was compared with DPSK.

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Analysis of H/V Ratio using Recent Earthquake (국내관측소의 부지 증폭특성 연구)

  • Yoo, Seong-Hwa;Oh, Tae-Seok;Kim, Jun-Kyoung
    • 한국지구물리탐사학회:학술대회논문집
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    • 2006.06a
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    • pp.175-180
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    • 2006
  • The horizontal to vertical ratio technique in spectral domain is a common useful technique to estimate empircal site transfer function. The technique, originally proposed by Nakamura, is porposed to analyse the surface waves in the micortremor records. The purpose of this paper is to estimate spectral ratio using observed data at the seismic stations in Korean Peninsula from the Fukuoka earthquake including many aftershocks. The results show that most of the stations have fairly good amplification factors. However, some of the stations show that very high amplification factors at narrow high frequency band. Those stations which have very high amplification factors seem to do some kind of mechanical consideration for quality observation.

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The Mixing of Forced Plume In the Coastal Waters (연안해역 중력 분류의 혼합 과정)

  • Jang, Seon-Deok;Seo, Jeong-Mun;Lee, Jong-Seop
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.26 no.1
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    • pp.26-33
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    • 1990
  • The behavior and mixing process of the forced plume are studied in the hydraulic laboratory. The dilution rate of discharged waste water from the port in various hydraulic condition was analized. The effect of densimetric Froude number and the discharge type on the dilution rate are discussed: In the vertical discharge, the forced plume of small densimetric Froude number mixes more actively than that of the large one. In the horizontal discharge, forced plume of large densimetric Froude number dilutes more rapidly than that of the small one. The mixing takes place more vigorously in the horizontal discharge than in the vertical one. The multi-port diffuser is more effective for the waste water discharge system than the single port diffuser in the tidal swinging coastal sea.

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A Performance Analysis of FFH/BFSK System Using Diversity Under Rayleigh Fading (레이리 페이딩하에서 diversity를 이용한 FFH/BFSK 시스템의 성능 분석)

  • 조용진;이두석;공관식;정지원;조형래
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.3 no.3
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    • pp.579-586
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    • 1999
  • In this paper, we have analyzed a performance of fast frequency hopping communication systems when a rayleigh fading caused by envelope variations of a signal received in multipath channel is, but it is not considered that intentional or unintentional jamming can be. The multipath fading channel and rayleigh fading are confirmed by theoretical analysis. In fading or non-fading, the performance of this system is studied. When the path diversity is applied to this system, the performance is shown to be superior to non-diversity systems about 20dB. For modulation methods, BFSK was compared with DPSK.

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Sensory Function Research of Ichthyic Lateral Line and Development of Lateral Line Teaching Aid. (어류의 옆줄 감각기능 연구 및 옆줄 교구 개발)

  • Kwoon, Jung Hyeon;Kim, MI Jeong
    • Korean Educational Research Journal
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    • v.39 no.1
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    • pp.15-38
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    • 2018
  • This study aimed to confirm that the lateral lines of fish indicate water temperature, water pressure, water flow, and sound waves by conducting a direct experiment. To confirm the superiority of fish lateral lines to detect material stimuli after the experimental study of the fish lateral line's sensation function, the lateral line's tissue was expanded and the shape of the lateral side of the fish was created using a 3-D printer to realize the lateral stripe parity. The amplification effect was confirmed by measuring the sound waves, which was the material stimulus of the lateral diagonal parabola. This proved that fish lateral lines are biotechnologically superior sensory organs.

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