• 제목/요약/키워드: RC Bank

검색결과 19건 처리시간 0.027초

전기철도 급전계통의 고조파 억제용 RC뱅크의 적정 위치에 관한 연구 (Optimal Location of RC bank limiting Harmonics in Electric Railway System)

  • 이한민;오광해;창상훈
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 하계학술대회 논문집 B
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    • pp.1254-1256
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    • 2001
  • This paper composes the Electric Railway System with the common grounding based on the 5-port network model. We compare the magnification ratio of harmonic currents according to locations of RC bank(i.e s/s. sp, and pp). It takes a lot of costs to equip the RC-bank at all location. And it is NOT effective that RC-bank is equipped at S/S. Finally, this paper proposes SP as the optimal site of RC-bank aspect reducing harmonic.

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Fruits Extracts Mediated Synthesis of Zinc Oxide Nanoparticles Using Rubus coreanus and its Catalytic Activity for Degradation of Industrial Dye

  • Rupa, Esrat Jahan;Gokulanathan, Anandapadmanaban;Ahn, Jong-Chan;Mathiyalagan, Ramya;Markus, Josua;Elizabeth, Jimenez Perez Zuly;Soshnikova, Veronika;Kim, Yeon-Ju;Yang, Deok-Chun
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2018년도 춘계학술발표회
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    • pp.93-93
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    • 2018
  • This study disclosed the aqueous fruits extract of Rubus coreanus as a sustainable agent for the synthesis of Rubus coreanus zinc oxide nanoparticle (Rc-ZnO Nps) using as a reducing and capping precursor for co-precipitation method. The development of Rc-ZnO was assured by white precipitated powder and analyzed by spectroscopic and analytical instruments. The UV-visible (UV-Vis) studies indicate the maximum absorbance at 357nm which confirmed the formation of ZnO Nps and the purity, functional group and monodispersity were assured by field emission transmission electron microscopy (FE-TEM), Fourier Transform Infrared (FTIR) Spectroscopy and dynamic light scattering (DLS). The X-ray powder diffraction (XRD) data revealed the Nps is 23.16 nm in size, crystalline in nature and possess hexagonal wurtzite structure. The Rc-ZnO Nps were subjected for catalytic studies. The Malachite Green dye was degraded by Rc- ZnO NPs in both dark and light (100 W tungsten) conditions and it degraded about 90% at 4 hours observation in both cases. The biodegradable, low cost Rc-ZnO NPs can be a better weapon for waste water treatment.

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한국 전기철도 시스템의 RC-Bank의 최적 위치 및 설계 (Optimal Location and Design of RC-Bank on Korean Electric Railway System)

  • 이한민;김길동;오세찬;박성혁
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2005년도 추계학술대회 논문집
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    • pp.754-764
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    • 2005
  • This paper presents the RC-Bank installation by its optimal location and design to reduce harmonics on the Korean high-speed railway system. The system model of the Korean high-speed railway system is based on 8-port representation, which is an extension of 2-port network theory. A new proposed model is for harmonic analysis in $2\times27.5kV$ traction power supply system including feeders, contact lines, rails and autotransformers. The proposed model is developed by combining fundamental element models of the Korean high-speed railway system, and it is verified by comparing simulation results with measurement data regarding the amplification rate of harmonic currents.

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필터뱅크 출력을 이용한 실시간 격리 단어 인식에 관한 연구 (A Study on the Real Time Recognition of Korean Isolated Words with Filter Bank Output)

  • 김계국;이종악;강성진
    • 한국음향학회지
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    • 제10권3호
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    • pp.5-12
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    • 1991
  • 本 硏究에서는 韓國語 10개 도市名을 認識 對象으로 하였다. 各 單語는 男性 話者 10人에 의하여 5번씩 反復 發音한 500單語를 對象으로 하여 필터뱅크 出力을 抽出하여 認識 파라미터로 使用하였다. 필터뱅크는 RC 能動素子를 利用하여 200[Kz]부터 1/3 octave 間隔으로 15채널로 構成하였다. 基準音은 集團化 알고리즘에 의해 設定하였으며 類似度 比較를 위해 DTW 알고리즘을 利用하였다. 距離 計算式에 따른 認識結果를 把握하기 위하여 유크리드 式과 체비셔브 式을 使用하여 距離를 計算하였으며 認識 結果 각각 16.4[%], 15.0[%]의 誤認識率을 얻었다.

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홍삼농축액에서 Saccharomyces cerevisiae와 Saccharomyces carlsbergensis에 의한 Ginsenosides의 bioconversion (Bioconversion of Ginsenosides in Red Ginseng Extract by Saccharomycescerevisiae and Saccharomyces carlsbergensis)

  • 장미;민진우;김주한;김세영;양덕춘
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2010년도 정기총회 및 춘계학술발표회
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    • pp.16-16
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    • 2010
  • Ginseng(Panax ginseng C.A. Meyer) is reported to have many pharmaceutical activities. The minor ginsenosides(Rd, Rg3, Rh2 and compound K) display pharmaceutical properties superior to those of the major ginsenosides. These minor ginsenosides, which contribute a very small percentage, are produced by hydrolysis of the sugar moieties of the major ginsenosides. The pH of red ginseng extracts fermented with S. cerevisiae and S. carlsbergensis decreased rapidly during 3 days of fermentation, with no further significant change thereafter. After 20 days of fermentation, a relatively small difference remained in the acidity of extracts fermented with S. cerevisiae (0.54%) and S. carlsbergensis (0.58%). Reducing sugar in the S. cerevisiae and S. carlsbergensis extracts decreased from 25.86 to 4.54 mg/ml and 4.32 mg/ml glucose equivalents, respectively; and ethanol contents increased from 1.5% at day 0 to 16.0 and 15.0%, respectively, at 20 days. Ginsenosides Rb1, Rb2, Rc, Re, Rf, and Rg1 decreased during the fermentation with S. cerevisiae, but Rd and Rg3 increased by 12 days. Ginsenosides Rb1, Rb2, Rc, Re and Rg1 decreased gradually in the extract with S. carlsbergensis, but Rd and Rg3 were increased at 6 days and 9 days.

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새로운 자동 구증구포방법에 의한 인삼사포닌의 변환 및 이화학적 특성 (Changes of Ginsenosides and Physiochemical Properties in Ginseng by New 9 Repetitive Steaming and Drying Process)

  • 김염;김연주;전지나;왕초;민진우;정선영;양덕춘
    • 한국자원식물학회지
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    • 제25권4호
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    • pp.473-481
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    • 2012
  • 구증구포방법은 기존의 홍삼제조방법에서와 같이 9회 반복 과정으로 새로운 신규사포닌 등 성분변화가 일어나지만 시간이 오래 걸리고 복잡하며 어떤 특수 성분이 얼마나 증가 되는지 보고 되어 있지 않다. 또한 기존의 구증구포방법은 제조공정 중 건조시 보통 $60^{\circ}C$에서 열풍건조를 하기 때문에 건조시 관리의 부족으로 간혹 벤조피렌에 노출되는 경우가 있다. 본 방법은 새로운 자동 구증구포방법으로 제조시간이 약 2배정도 단축되며 특히 건조시 습열냉각건조를 통하기 때문에 벤조피렌함량이 거의 검출되지 않았다. 또한 사포닌 변환 등은 기존 구증구포방법과 같이 사포닌 변화가 일어나 홍삼에서만 나타나는 Rg3와 기타 효능활성물질 등이 분석되었다. 인삼사포닌의 경우에는 증포횟수가 증가함에 따라 흡수가 어려운 major ginsenoside(Rg1, Re, Rb1, Rc, Rb2 및 Rd)의 함량이 점차적으로 감소되고 대신 흡수가 빠르고 항암활성이 강한 minor ginsenoside (Rh1, 20(S)-Rg2, 20(R)-Rg2, 20(S)-Rg3, 20(R)-Rg3, Rk1 및 Rg5)의 함량이 점차적으로 증가하였다. 특히 diol계 사포닌인 ginsenosides Rb1, Rb2, Rc 및 Rd는 Rg3, Rk1 및 Rg5로 전환되었고, triol계 사포닌인 ginsenosides Rg1 및 Re는 Rh1, Rg2로 전환되었다. 수삼에서의 환원당, 산성다당체 및 총 페놀 화합물 함량은 7회까지 유의적으로 증가하였고 8회부터 점차 감소하는 경향을 보였다. DPPH 라디칼 소거활성은 7회까지 점차적으로 감소하여 $IC_{50}$값이 68% 감소되는 것으로 나타났으며 7회부터 9회까지는 큰 유의적 차이가 없었다. 결론적으로 본 자동 구중구포방법은 기존의 방법과 물질생성은 거의 비슷하지만 시간이 단축되고 벤조피렌 함량이 거의 검출되지 않아 앞으로 고부가가치 인삼산업에 많은 도움을 줄 것으로 생각된다.

Versatile UPQC Control System with a Modified Repetitive Controller under Nonlinear and Unbalanced Loads

  • Trinh, Quoc-Nam;Lee, Hong-Hee
    • Journal of Power Electronics
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    • 제15권4호
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    • pp.1093-1104
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    • 2015
  • A standard repetitive controller (RC) is theoretically able to replace a bank of resonant controllers in harmonic signals tracking applications. However, the traditional RC has some drawbacks such as a poor dynamic response and a complex structure to compensate grid frequency deviations for an effective unified power quality conditioner (UPQC) control scheme. In order to solve these problems, an improved RC with an outstanding dynamic response and a simplified grid frequency adaptive scheme is proposed for UPQC control systems in this paper. The control strategy developed for the UPQC has delay time, i.e., one-sixth of a fundamental period (Tp/6), repetitive controllers. As a result, the UPQC system can provide a fast dynamic response along with good compensation performance under both nonlinear and unbalanced loads. Furthermore, to guarantee the excellent performance of the UPQC under grid frequency deviations, a grid frequency adaptive scheme was developed for the RC using a simple first order Padé's approximation. When compared with other approaches, the proposed control method is simpler in structure and requires little computing time. Moreover, the entire control strategy can be easily implemented with a low-cost DSP. The effectiveness of the proposed control method is verified through various experimental tests.

전기철도 시스템의 9~150 kHz 대역에서의 RFI 노이즈 전달 경로 분석 (Analysis on the RFI Noise Path of Electrical Railway System in the Frequency Range of 9 kHz to 150 kHz)

  • 권석태;정연춘
    • 한국전자파학회논문지
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    • 제23권12호
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    • pp.1373-1379
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    • 2012
  • 철도 시스템에서 방사하는 9~150 kHz 대역의 자기장 복사 방출은 철도 시스템 주변의 무선 설비 등에 영향을 주어 통신 성능의 저하나 오동작을 초래할 수 있다. 본 논문에서는 전기 철도 시스템에서 방사하는 9~150 kHz 주파수 대역의 전자파 노이즈에 대한 등가 회로 모델을 소스 및 전달 경로 분석을 통하여 제안하고, 철도차량의 견인 구동 시스템과 변전 시스템에서 발생하는 수 kHz의 스위칭 노이즈가 급전선과 선로의 루프 회로를 통하여 방사됨을 확인하였다. 또한, 실제의 구리-국수 간 중앙선 철도의 RC Bank의 효과를 분석하여 이러한 회로 등가 모델의 유효성을 검증하였고, 급전선과 선로 사이에 적정한 용량의 커패시터를 장하함으로써 효과적으로 설계 대책이 가능함을 보였다.

인삼의 구증구포에 의한 Ginsenoside의 성분변화 및 BACE-1 억제효과 (Conversion of Ginsenosides by 9 Repetitive Steamings and Dryings Process of Korean Ginseng Root and Its Inhibition of BACE-1 Activity)

  • 김도완;김유진;이연진;민진우;김세영;양덕춘
    • 동의생리병리학회지
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    • 제22권6호
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    • pp.1557-1561
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    • 2008
  • Red ginseng possibly has new ingredients converted during steaming and dry process from fresh ginseng. Kujeungkupo method which means 9 repetitive steamings and dryings process was used for the production of red ginseng from 6-year old ginseng roots. Saponin was extracted from each red ginseng produced at the 1st, 3rd, 5th, 7th, and 9th during the steaming and drying treatment, and we analyzed saponin content with TLC. Minor saponins, such as ginsenoside-Rg3, -Rh2, compound K, and F2, increased as the process time of steaming and drying, but major saponins (ginsenoside-Rb1, -Rb2, -Rc, -Rd, -Re, -Rf, -Rg1) were decreased. Major saponins were yet observed almost at the 1st process, then degraded as the increasing time of steaming and drying process. Especially, ginsenoside-Re and -Rg were observed as considerable amount after the 1st treatment, but there were no trace of them after the 9th treatment. Ginsenoside-Rg1, -Rb2, and -Rb1 were also reduced remarkedly by 96.6%, 96%, and 92.3%, respectively. Minor saponins were increased significantly, especially for ginsenoside-Rg3 and ginsenoside-F2. These results suggest that Kujeungkupo method is the very useful method for the production of minor ginsenoside-Rg3 and -Rh2.

Gypenoside V로부터 minor ginsenosides의 생산 (Production of Minor Gisenosides from Gypenoside V)

  • 손나리;민진우;장미;김효연;전지나;양덕춘
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2010년도 정기총회 및 추계학술발표회
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    • pp.20-20
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    • 2010
  • Panax ginseng C.A Meyer is frequently taken orally as a traditional herbal medicine in Asian countries. The major components of ginseng are ginsenoside, which are pharmaceutical activity. The six major ginsenosides, including Rb1, Rb2, Rc, Rd, Re and Rg1 account for 90% of total ginsenosides. Even though the minor ginsenosides, including Rg3, Rh2 and compound K has high pharmacetical activities, the price of minor ginsenosides is too high. Therefore we isolated the gypenoside V and made it converted to minor ginsenosides. In the plant Gynostemma pentaphyllum Makino, gypenosdie V was presented as dominant saponin (content about 2.4%), and was similar to protopanaxadol type ginsenosides such as ginsenoside Rb1. In this study, we confirmed that the coversion of gypenoside V to minor ginsenosides after using the various treatment such as heating, acid treatment, commercial edible enzyme, and lactobacillus. Consequently, we optimizied the transformation of gypenoside V to minor ginsenoside using Thin Layer Chromatography (TLC), High Performance Liquid Chromatography (HPLC), Time-of-flight Mass Spectrometry (LC/TOF/MS).

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