• Title/Summary/Keyword: ChoiIn-gyu

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Analysis of analog MPPT Algorithms for Low cost Photovoltaic System (저가형 태양광 발전시스템을 위한 아날로그 MPPT 알고리즘의 특성 해석)

  • Kim Han-Goo;Lee Sang-Yong;Choi Moon-Gyu;Kim Hong-Sung;Choe Gyu-Ha
    • Proceedings of the KIPE Conference
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    • 2004.07a
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    • pp.121-124
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    • 2004
  • In this paper, Simple and inexpensive analog maximum power point tracker (MPPT) algorithm for photovoltaic power system and low power system of doesn't use digital signal processor (DSP). The control circuit is composed such that the actual current and voltage are sensed directly from the PV array. These two signals are then multiplied by a single-chip multiplier. The multiplier output go through different time constants genesis pulse width modulated to switch. Finally those were verified through simulation.

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Navigation of a mobile robot with stationary and moving obstacles using fuzzy-neural network (퍼지-뉴럴을 이용한 이동 로봇의 장애물 충돌 회피)

  • Park, Chan-Gyu;Choi, Jeong-Won;Kwon, Soon-Hak;Lee, Suk-Gyu
    • Journal of Institute of Control, Robotics and Systems
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    • v.5 no.8
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    • pp.990-994
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    • 1999
  • This paper proposes a new fuzzy-neural algorithm for navigation of a mobile robot with stationary and moving obstacles environment. The proposed algorithm uses fuzzy algorithm for its speed control and neuralnetwork for effective collision avoidance. Some computer simulation results for a mobile robot equipped with ultrasonic range sensors show that the suggested navigation algorithm is very effective to escape in stationary and moving obstacles environment.

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A Study on the Calculation of S.L.I.M. Equivalent Circuit Parameter by Finite Element Method (유한요소법에 의한 선형 유도전동기의 등가회로 정수 산정에 관한 연구)

  • Im, Dal-Ho;Choi, Chang-Gyu;Kim, Gyu-Tak;Lee, Heon-Soo
    • Proceedings of the KIEE Conference
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    • 1989.07a
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    • pp.37-39
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    • 1989
  • In this paper, the governing equation of each analyzed region of Single-sided Linear Induction Motor was induced from Maxwell's electromagnetic equation. And the linear induction motor was analyzed by finite element method. for calculating inductance, energy perturbation method was applied.

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Experimental Study on Antifungal effects of Sophorae Subprostratae Radix, Aconiti Radix, Hibisci Syriaci Cortex and those mixture, Phellodendri Cortex, Sophorae Radix, Torilis Fructus on various species of the dermatophytes (足部白癬茵의 韓方治療劑 開發을 위한 硏究)

  • Choi, Gyu-dong;Kwon Young kyu, Yeong-Gyu
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.13 no.1
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    • pp.267-279
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    • 2000
  • Minimum inhibitory concentration(MIC) of Sophorae Subprostratae Radix. Aconiti Radix, Hibisci Syriaci Cortex and those mixture. Phellodendri Cortex, Sophorae Radix, Torilis Fructuson on various species of the dermatophytes on Microsporium gypseum, Trichophytone rubrum and Epidermophytone floccosum were determined after 4 weeks of incubation at $25^{\circ}C$ in Sabouraud dextrose broth. The results were summarized as followes : 1. Antifungal effects of Phellodendri $Cortex\;{\cdot}Hibisci$ Syriaci Cortex and mixture of Sophorae Subprostratae Radix, Aconiti Radix, Hibisci Syriaci Cortex on T rubrum which is the most common organism of tinea pedis were more effective than that of the others. 2 These results suggested that herbal medicines such as Phellodendri $Cortex\;{\cdot}Hibisci$ Syriaci Cortex and mixture of Sophorae Subprostratae Radix, Aconiti Radix, Hibisci Syriaci Cortexse can be used to treat tinea pedis and to improve untoward effects associated with the administration of antifugual agents.

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DC-link Shaping Method in Boost Converter-Inverter System for Six-step Torque ripple Reduction (컨버터-인버터 시스템에서 6-스텝 시 토크 리플을 줄이기 위한 가변 직류단 전압 제어 방법)

  • Choi, Hyeon-gyu;Lim, Gyu Cheol;Ha, Jung-Ik
    • Proceedings of the KIPE Conference
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    • 2017.07a
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    • pp.274-275
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    • 2017
  • 부스트-인버터 시스템에서 6-스텝 시 토크 리플을 줄이기 위한 방법을 제시한다. 모델 기반의 전압 방정식을 통해 필요한 직류단 전압의 크기 및 위상을 구하고 전류 전향 보상을 통해 전압을 합성한다. 이를 통해 직류단 캐패시턴스를 수 ${\mu}F$까지 낮출 수 있어 캐패시터의 부피 및 비용을 절감할 수 있다. 이러한 최적 해 운전 시 생기는 입력 파워 리플의 문제점을 해결하기 위한 일정 파워 공급 방법을 제시하며 이를 통해 운전영역에 따른 적절한 운전 방법의 선택을 제시한다.

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Ultrasonic Pulse Velocity of Normal Aggregate Concrete and Lightweight Aggregate Concrete at Early age According to Elapsed Time (초기재령에서 보통골재 및 경량골재 콘크리트의 시간경과에 따른 초음파 속도 변화)

  • Kim, Won Chang;Choi, Hyeong Gil;Nam, Jeong Soo;Kim, Gyu Young;Lee, Tae Gyu
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2021.11a
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    • pp.61-62
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    • 2021
  • Because of the problem of increasing self-weight due to the enlargement and high-rise of buildings using normal aggregate concrete, the need for structural lightweight aggregate concrete increases. However, early strength prediction is required when placing structural lightweight aggregate concrete, but research is insufficient. In this study, the ultrasonic pulse velocity of normal aggregate concrete and lightweight aggregate concrete was measured at early age. As a result, the ultrasonic pulse velocity of lightweight aggregate concrete was lower than normal aggregate concrete according to elapsed time at early age.

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The Integration of Hardware using PLC for Turbine control system (PLC를 적용한 터빈제어시스템의 하드웨어 구성)

  • Choi, In-Gyu;Jeong, Chang-Ki;Ahn, Byung-Ju
    • Proceedings of the KIEE Conference
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    • 2002.07d
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    • pp.2203-2205
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    • 2002
  • In order to have the competitive power in control system economically, development of low price control system must be conducted. In this paper, we are tring to think over the integration of hardware using progammable logic controller for Turbine control system. The detailed contents are system's overview and integration of system and system redundant and power supply.

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Effects of Mixed Bone and Brisket Meat on Physico-Chemical Characteristics of Shank Bone and Rib Extracts from Hanwoo

  • Choi, Hyung-Gyu;Choi, Hyun-Su;Choi, Young-Seok;Jung, Myung-Ok;Choi, Jung-Seok;Choi, Yang-Il
    • Food Science of Animal Resources
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    • v.36 no.1
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    • pp.61-67
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    • 2016
  • This study was conducted to investigate the effects of mixed bone and brisket meat on the quality characteristics and nutritional components of shank bone extract and rib extract from Hanwoo. The pH values were influenced by the raw bones, mixed bone, brisket meat and their interactions (p<0.05). The salinity, sugar content, turbidity, and essential amino acid values increased significantly with addition of mixed bone and brisket meat. All attributes of sensory evaluation score were the highest in T6 (Rib 500 g + Mixed bone 500 g + Brisket meat 400 g) (p<0.05). The mixed bone significantly increased the saturated fatty acids of shank bone extract (p<0.001). Thus, the addition of mixed bone and brisket meat had a positive effect on the quality and nutritional components in shank and rib extracts of Hanwoo cattle.