• Title/Summary/Keyword: Chun-Kwang

Search Result 1,164, Processing Time 0.026 seconds

Servo Drive of Induction Motor Using Space Voltage Vector PWM Current Control Method (공간전압벡터 PWM 전류제어방식에 의한 유도전동기 서보운전)

  • Seo, Young-Soo;Sung, Dae-Yong;Ha, Jung-Wook;Cha, Kwang-Hun;Kim, Young-Chun
    • Proceedings of the KIEE Conference
    • /
    • 1996.07a
    • /
    • pp.467-469
    • /
    • 1996
  • In this paper, the voltage equation of the stationary reference frame was reduced in squirrelcage induction motor using vector control algorithm, and changed that of the d-q synchronously rotating reference frame, so the torque equation was reached, and propose vector control algorithm for speed control. Also the real time control was possibled using DSP(TMS320C31) to experiment system which show high accuracy speed response characteristics by liner current control using space voltage vector PWM method.

  • PDF

The Design and Implementation of TCSC System for KERI Simulator (KERI 시뮬레이터 적용을 위한 TCSC 시스템 설계)

  • Jeon, Jin-Hong;Kim, Kwang-Su;Kim, Ji-Won;Chun, Yeung-Han
    • Proceedings of the KIEE Conference
    • /
    • 2003.10b
    • /
    • pp.220-223
    • /
    • 2003
  • 본 논문에서는 한국전기연구원에서 보유하고 있는 아날로그형 전력계통 시뮬레이터인 KERI 시뮬레이터에 적용하고자 개발 중인 TCSC 시스템 시뮬레이터의 설계 방법과 적용 결과를 제시하고 한다. KERI 시뮬레이터는 전력계통시스템을 모의하기위해 한국전기연구원에서 보유하고 있는 실험장비로 3개의 동기발전기와 345kV 송전선로 모델, 각종 계통 설비의 축소 모형으로 구성되어 있다. 지금까지 UPFC, STATCOM과 같은 FACTS 모의장치의 계통 적용을 검토하기 위한 연구가 이루어져 왔다.

  • PDF

Design of High Performance 5 Phase Step Motor Drive System with Current Control Loop (전류 제어기를 가지는 고성능 5상 스텝 모터 구동 드라이버 설계)

  • Chun, Kwang-Su;Kim, Hak-Jin;Kwon, Yong-Kwan;Kang, Suk-Hee
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.11 no.5
    • /
    • pp.447-453
    • /
    • 2006
  • This paper proposes that 5 phase step motor drive system has high performance utilizing a micro step control with a current controller. Also this paper proposes an analog current controller to minimize size of the 5 phase step motor drive system. It has better advantages of cost and noise and heating than commercial products. As a result, Applying this system to position control robot the validity of suggested analog current controller and driver system is verified.

Analysis of Particle Mobilization and Impact on Filter Performance in Drainage Tunnels (토립자 유동이 터널 배수재의 폐색에 미치는 영향 연구)

  • Park, Kwang-Joon;Lee, In-Mo
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 1999.10a
    • /
    • pp.169-176
    • /
    • 1999
  • 본 논문은 지하수 흐름하에서의 풍화 잔류토의 세립자 유동특성을 파악하기 위한 수치모델을 개발하고, 실내에서 실시한 수리 모형실험을 통하여 수치모델의 적합성을 규명하였다. 한국의 풍화 잔류토는 점토와 모래의 중간 상태의 특성을 보이는 관계로 기존의 토립자 유동모델중 점토 또는 모래에 적합한 모델에 의해서는 정확한 유동특성의 파악에 한계가 있었다. 따라서, 본 연구에서는 한국의 풍화 잔류토에 적합한 세립자 유동모델을 제시함으로써 풍화 잔류토를 대상으로 시공되는 굴토공사, 댐 축조공사, 그리고 터널공사시 지하수 유입에 따른 세립토사의 유실특성을 이론적으로 규명하였고, 현장에서 배수재로 광범위하게 쓰이고 있는 토목섬유인 부직포의 투수 및 배수특성을 검토하였다

  • PDF

A Study on Analysis of Reliability to Korean version Questionaries on Respiratory Symptoms in Korea - For the responese to dental technician Laboratory - (우리나라 호흡기계질환의 역학조사에 사용되는 설문지의 신뢰도 분석 연구 - 일부 치과기공사를 대상으로 -)

  • Ko, Jai-Chun
    • Journal of Technologic Dentistry
    • /
    • v.17 no.1
    • /
    • pp.72-81
    • /
    • 1995
  • The study was performed to compare the raliablity of two Korean version questionaires for respiratory symptoms and ilness being used in Korea. The subjects were 103 dental laboratory technician who divided into two groups as SUN-81-AL and SUN-93. The duration of test-retest was one two month. The differences between two groups interms of average age, height, and weight were negligible. The SUN-93 showed higher agreement compared to SUN-81-AL except items cough and smoking. The Sun-93 deserved to prefer to be used in resporatory epidemiologic study.

  • PDF

Expression and Purification of Recombinant Human Bone Morphogenetic Protein-7 (rhBMP-7) in Bacillus subtilis (고초균을 이용한 재조합 인간 골 형성 단백질-7의 발현과 정제)

  • Kim, Chun-Kwang;Oh, Sung-Duk;Rhee, Jong-Il
    • KSBB Journal
    • /
    • v.25 no.3
    • /
    • pp.257-264
    • /
    • 2010
  • Bone morphogenetic protein-7 (BMP-7) is one of important growth factors for skeletal development and bone growth. In this work, BMP-7 was efficiently expressed in recombinant Bacillus subtilis. The mature BMP-7 protein indicated molecular weight of 15.4 kDa by Western blot assay and was secreted into culture medium with 0.35 ng/mL. The extracellular and intracellular rhBMP-7 proteins were purified by using a FPLC system with an ion exchange column and a gel filtration column. The extracellular and intracellular rhBMP-7 proteins had finally a 57.1% purity and a 36.2% purity, respectively. The purified rhBMP-7 proteins showed an intact biological activity which stimulated alkaline phophatase (ALP) activity in MC3T3-E1 cells.

Fine Needle Aspiration Cytology of Acinic Cell Carcinoma of the Parotid Gland - A case report - (이하선의 선방세포암종의 세침흡인 세포학적 소견 - 1예 보고 -)

  • Lee, Won-Ae;Chun, Yi-Kyeong;Oh, Mee-Hye;Khang, Shin-Kwang
    • The Korean Journal of Cytopathology
    • /
    • v.3 no.2
    • /
    • pp.75-81
    • /
    • 1992
  • Acinic cell carcinoma is a rare salivary gland tumor of low-grade malignancy. It comprises only about 2.5% of all salivary gland tumors. We recently experienced a case of fine needle aspiration cytology of acinic cell carcinoma of the parotid gland. The characteristic cytopathologic features were 1) cellular aspirate consisting of monomorphic cells in large sheets or singly, 2) formation of acini and/or microcysts, 3) abundant granular cytoplasm with sharp cytoplasmic borders, 4) bland nuclei with micronucleoli, and 5) clear background.

  • PDF

Antioxidative Activities of Solvent Extracts from Blueberry (Blueberry 추출물의 항산화 효과)

  • Kim, Tae-Choon;Bae, Kang-Soon;Kim, Il-Kwang;Chun, Hyun-Ja
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.19 no.1
    • /
    • pp.179-183
    • /
    • 2005
  • Recent interest in the possible protective effects of dietary antioxidant compounds against human degenerative disease has prompted investigation of foods such as blueberries, which have a high antioxidant capacity. This study was performed to determine the antioxidative activity of methanol extract and solvent fractions from blueberry. Blueberry was extracted with methanol and then fractionated with n-hexane, EtOAc, BuOH and water to get active fractions. And their antioxidant capacities in each fraction were determined by using the DPPH and FRAP assay, and tyrosinase inhibitor. Ethyl acetate fraction of blueberry exhibited antioxidant capacity.

Pharmacognostical Studies on ‘Manryong’ (만룡(蔓龍)의 생약학적(生藥學的) 연구(硏究))

  • Lee, Seo-Yun
    • Korean Journal of Pharmacognosy
    • /
    • v.6 no.3
    • /
    • pp.125-129
    • /
    • 1975
  • The pharmacognostical and pharmacological studies of 'Manryong' were carried out, which has been widely used in Chun-Ra Province, Korea and the following results were obtained. 1) The original plant of the bulb MANRYONG is Erythronium japonicum DECNE. (Liliaceae). 2) The internal structure consists of mostly parenchyma containing numerous starch grains, vascular bundles and substituted fibers. 3) The external surface occurs as a yellowish white and slightly bented ovoidal shape. 4) 'Manryong; contains 11 kinds of free amino acids, such as asparagin, tryptophan, cystine, glutamic acid, threonine, glycine, leucine, proline, histidine, methionine, and alanine. 5) Hemolytic action of the crude saponin isolated from 'Manryong' is weaker than that of digitonin. 6) Effects of 'Manryong' extracts on ceruloplasmin were studied and an antidotal activity of the extracts was found in liver intoxicated with carbon tetrachloride.

  • PDF