• 제목/요약/키워드: line regulation

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Coordinated Wide-Area Regulation of Transmission System for Voltage Profile Improvement and Power Loss Reduction

  • Asadzadeh, Babak;Golshannavaz, Sajjad
    • Transactions on Electrical and Electronic Materials
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    • 제18권5호
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    • pp.279-286
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    • 2017
  • In this paper, an optimal approach for the wide-area regulation of control devices in a transmission network is proposed. In order to realize an improved voltage profile and reduced power loss, existing devices such as tap-changing transformers, synchronous machines, and capacitor banks should be controlled in a coordinated and on-line manner. It is well-understood that phasor measurement units in transmission substations allow the system operators to access the on-line loading and operation status of the network. Accordingly, this study proposes efficient software applications that can be employed in area operation centers. Thus, the implanted control devices can be regulated in an on-line and wide-area coordinated approach. In this process, efficient objective functions are devised for both voltage profile improvement and power loss reduction. Subsequently, sensitivity analysis is carried out to determine the best weighting factors for these objectives. Extensive numerical studies are conducted on an IEEE 14-bus test system and a real-world system named the Azarbayjan Regional Transmission Network. The obtained results are discussed in detail to highlight the promising improvements.

봉독(蜂毒) 약침액(藥鍼液)이 염증(炎症) 및 통증(痛症) 관련(關聯) 유전자(遺傳子) 발현(發現)에 미치는 영향(影響) (The effects of Honey Bee Venom for Aqua-acupuncture on Expression of Genes Related with Inflammation and Pain)

  • 정혜윤;고형균
    • Journal of Acupuncture Research
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    • 제19권3호
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    • pp.41-50
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    • 2002
  • Objective : To study anti-inflammatory, analgesic effect and molecular biological mechanism of honey bee venom for aqua-acupuncture, human mast cell line(HMC-1) and human glioma cell line(HS683) were treated with bee venom. Methods : Cell viability of bee venom was tested by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) asssay. To explore whether anti-inflammatory, analgesic effects of bee venom are associated with the control of gene expression, quantitative RT-PCR analysis of inflammation and pain related genes was performed. Results : The MTT assay demonstrated that cell viability was not decreased by treatment with 10-9 ug/ml bee venom in comparison with 10-2, 10-3, 10-4, 10-5, 10-6, 10-7, 10-8, 10-9, 10-10 and 10-11 ug/ml. sPLA2 and COX-l were down-regulated by treatment with 10-9 ug/ml bee venom in HS683 Cell line in comparison with control. COX-2 was up-regulated by treatment with 10-9 ug/ml bee venom in HS683 Cell line and HSP-2 was up-regulated by treatment with 10-9 ug/ml bee venom in HMC-1 Cell line in comparison with control. sPLA2, COX-1 and COX-2 showed no significant regulation in HMC-1 Cell line and cPLA2 also showed no significant regulation in both HMC-l and HS683 Cell line between control and bee venom treated group.

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공정변화에 따른 LDO 레귤레이터의 특성 분석 (Characteristic Analysis of LDO Regulator According to Process Variation)

  • 박원경;김지만;허윤석;박용수;송한정
    • 전자공학회논문지 IE
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    • 제48권4호
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    • pp.13-18
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    • 2011
  • 본 논문에서는 LDO 레귤레이터의 공정변화에 따른 특성변화를 1 ${\mu}m$ 20 V 고 전압 CMOS 공정을 사용하여 시뮬레이션 하였다. 공정변화에 따른 3종류의 SPICE 파라미터(문턱전압과 실효채널길이가 평균적인 Typ(typical), 평균 이하인 FF(fast), 평균 이상인 SS(slow) 파라미터)를 LDO 레귤레이터 시뮬레이션에 활용하였다. 시뮬레이션 결과,SS 파라미터 사용의 경우, 라인 레귤레이션이 3.6 mV/V, 부하 레귤레이션이 0.4 mV/mA, 부하전류 변화에 따른 출력전압이 안정화되는 시간이 평균 0.86 ${\mu}s$였다. 그리고 Typ 파라미터 사용의 경우, 라인 레귤레이션이 4.2 mV/V, 부하 레귤레이션이 0.44 mV/mA, 부하전류 변화에 따른 출력전압이 안정화되는 시간이 평균 0.62 ${\mu}s$였다. 마지막으로 FF 파라미터 사용의경우 라인 레귤레이션이 7.0 mV/V, 부하 레귤레이션이 0.56 mV/mA, 부하전류 변화에 따른 출력전압이 안정화되는 시간이 평균 0.27 ${\mu}s$였다. 향후, 이러한 공정변화에 따른 회로 특성의 변화를 고려한 효율적 회로설계가 필요할 것으로 사료된다.

Myogenic Differentiation of p53- and Rb-deficient Immortalized and Transformed Bovine Fibroblasts in Response to MyoD

  • Jin, Xun;Lee, Joong-Seub;Kwak, Sungwook;Jung, Ji-Eun;Kim, Tae-Kyung;Xuo, Chenxiong;Hong, Zhongshan;Li, Zhehu;Kim, Sun-Myoung;Whang, Kwang Youn;Hong, Ki-Chang;You, Seungkwon;Choi, Yun-Jaie;Kim, Hyunggee
    • Molecules and Cells
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    • 제21권2호
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    • pp.206-212
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    • 2006
  • We have established in culture a spontaneously immortalized bovine embryonic fibroblast (BEF) cell line that has lost p53 and $p16^{INK4a}$ functions. MyoD is a muscle-specific regulator capable of inducing myogenesis in a number of cell types. When the BEF cells were transduced with MyoD they differentiated efficiently to desmin-positive myofibers in the presence of 2% horse serum and 1.7 nM insulin. The myogenic differentiation of this cell line was more rapid and obvious than that of C2C12 cells, as judged by morphological changes and expression of various muscle regulatory factors. To confirm that lack of the p53 and $p16^{INK4a}$ pathway does not prevent MyoD-mediated myogenesis, we established a cell line transformed with SV40LT (BEFV) and introduced MyoD into it. In the presence of 2% horse serum and 1.7 nM insulin, the MyoD-transduced BEFV cells differentiated like the MyoD-transduced BEFS cells, and displayed a similar pattern of expression of muscle regulatory proteins. Taken together, our results indicate that MyoD overexpression overcomes the defect in muscle differentiation associated with immortalization and cell transformation caused by the loss of p53 and Rb functions.

경량전철 운전규칙 연구 (Operational Regulation on Light Rail Transit)

  • 황현철;조봉관;조홍식;홍재성;류상환
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2009년도 제40회 하계학술대회
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    • pp.1195_1196
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    • 2009
  • Light rail transit is classified to rubber-tired LRT, lear induction motor LRT, steel wheel LRT, monorail and tramway. LRT except for tramway are usually operated without driver and tramway are driven depending on driver's sight like usual car. LRT, which is one type of urban guided transit, shall be operated according to domestic "Operational Regulation for Urban Guided Transit" but existing regulation does not contain the safety related codes for driverless operation. In this paper, we investigate "IEC 62267 : Railway Application-Safety Requirements for Automated Urban Guided Transit" and compensate for existing operational regulation by referring to international standard and operational rule of commercial line.

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Styrylpyrone Derivative Induces Apoptosis through the Up-Regulation of Bax in the Human Breast Cancer Cell Line MCF-7

  • Chien, Alvin Lee Teck;Pihie, Azimahtol Hawariah Lope
    • BMB Reports
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    • 제36권3호
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    • pp.269-274
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    • 2003
  • In the fight against cancer, novel chemotherapeutic agents are constantly being sought to complement existing drugs. Various studies have presented evidence that the apoptosis that is induced by these anticancer agents is implicated in tumor regression, and Bcl-2 family genes play a part in apoptosis following treatment with various stimuli. Here, we present data that a styrylpyrone derivative (SPD) that is extracted from the plant Goniothalamus sp. showed cytotoxic effects on the human breast cancer cell line MCF-7. SPD significantly increased apoptosis in MCF-7 cells, as visualized by phase contrast microscopy and evaluated by the Tdt-mediated dUTP nick end-labeling assay and nuclear morphology. Western blotting and immunostaining revealed up-regulation of the proapoptotic Bax protein expression. SPD, however, did not affect the expression of the anti-apoptotic protein, Bcl-2. These results, therefore, suggest SPD as a potent cytotoxic agent on MCF-7 cells by inducing apoptosis through the modulation of Bax levels.

ZCS 보조회로를 이용한 ZVT Boost 컨버터에 관한 연구 (A Study on ZVT Boost Converter Using a ZCS Auxiliary Circuit)

  • 류동균;이우석;최태영;서민성;원충연;김영렬
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2001년도 추계학술대회 논문집
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    • pp.129-132
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    • 2001
  • Recently, a ZVT boost converter is embedded in a power factor correction system. The control circuit of the converter assures soft-switching for all the MOSFETs and load regulation. The PFC system contains additional control circuits which assure the input voltage in a sinusoidal form and feed-forward line voltage regulation. In this paper, a soft switching boost converter with zero-voltage transition(ZVT) main switch using zero-current switching(ZCS) auxiliary switch is proposed. Operating intervals of the converter are persented and analyzed. The proposed results show that the main switch maintains UT while auxiliary switch retains ZCS for the complete specified line and load conditions.

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배편계통에 도입되는 분산전원의 운전가능범위 결정에 관한 연구 (A Study for Determining the Permissible Operating Range of Distributed Generation interconnected into Distribution System)

  • 김태응;김재언
    • 대한전기학회논문지:전력기술부문A
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    • 제51권2호
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    • pp.93-101
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    • 2002
  • This paper describes a new method for determining the permissible operating range of DG(Distributed Generation) when DG is introduced into power distribution systems of which the voltage is controlled by LDC(Line Drop Compensator). Much of the DG installed during the next millennium will be accomplished through the reconstruction of the electric power industry. But in that case, it is difficult to properly maintain the terminal voltage of low voltage customers by using only LDC. This paper presents a method for determining the permissible operating range of DG for proper voltage regulation of power distribution systems with LDC. Proposed method has been applied to a 22.9 kV model and practical distribution systems, and its result is almost identical with the simulation result.

Bus 전압 레귤레이션을 위한 쌍방향 Buck-Boost DC-DC컨버터 (Bi-directional Buck-Boost DC-DC Converter for Bus Voltage Regulation)

  • 고태일;김양모
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1994년도 하계학술대회 논문집 A
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    • pp.348-350
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    • 1994
  • In this paper, bi-directional buck-boost DC-DC converter for bus regulation system is presented. This converter which has one buck and one boost topology achieves bi-directional power flow using a common power inductor and alternative power switches. By connecting the battery to bus line, it can be regulated to bus voltage and charged the battery alternatively. And as an application, a mode controller is adopted to the converter.

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Asparagus Racemosus Leaf Extract Inhibits Growth of UOK 146 Renal Cell Carcinoma Cell Line: Simultaneous Oncogenic PRCCTFE3 Fusion Transcript Inhibition and Apoptosis Independent Cell Death

  • Verma, Shiv Prakash;Tripathi, Vikash Chandra;Das, Parimal
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권5호
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    • pp.1937-1941
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    • 2014
  • Aims: To evaluate anti-cancer activity of Asparagus racemosus (AR) leaf extract on UOK146, a renal cell carcinoma cell line, and explore its mechanism of action. Materials and Methods: Dried AR leaves were extracted with chloroform and dissolved in DMSO. This extract was applied to UOK146 and cell death was estimated by MTT assay. In addition PRCC-TFE3 fusion transcripts were detected by real time PCR. Results: Extract was found to be cytotoxic with an $IC_{50}$ of 0.9 mg/ml as estimated by dose response curve. Antitumor activity of the permissible doses of the extract was assessed by the down regulation of PRCC-TFE3 fusion transcript (38%) responsible for oncogenicity of the UOK146 cell line. No increment in the BAX, a proapoptotic marker level was observed. Conclusions: Evidence of antiproliferative effect, PRCC-TFE3 fusion transcript inhibition and static BAX level clearly indicate that AR extract provides or elicits an apoptosis independent anticancer effect on RCC cells by some specific mechanism of regulation.