• Title/Summary/Keyword: Protection function

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최적화 기법이 적용된 전력계통 안정화 시스템 개발 (Development of power system stabilization program using optimization method)

  • 안창한;백영식
    • 전기학회논문지
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    • 제64권3호
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    • pp.370-374
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    • 2015
  • Various protective equiptments are used for the power system control and protection. Numerous facilities are monitored at the same time in real time and introduction of optimization method and analysis of the method are required for generation control and facility management considering the demand fluctuations. However, the existing system analysis programs are difficult to link with the other sw and there are some problems with user convenience. To solve these problems the present conditions of the system are figured out in real time and the equipment insert method was estimated by optimization method, and the system that showed the system analysis program is developed. PSS/E has been used as system anlysis program for stabilizing system development which applied the optimization. method and Python language is applied in order to link the input and output values with the DB automatically. Lastly, DLL of matlab has been made included in C++ for solving the objective function using opmization method.By linking this to DB, power flow was calculated in PSS/E and the result was represented by Intouch screen.

An Important Role of Nrf2-ARE Pathway in the Cellular Defense Mechanism

  • Lee, Jong-Min;Johnson, Jeffrey A.
    • BMB Reports
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    • 제37권2호
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    • pp.139-143
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    • 2004
  • The antioxidant responsive element (ARE) is a cis-acting regulatory element of genes encoding phase II detoxification enzymes and antioxidant proteins, such as NAD(P)H: quinone oxidoreductase 1, glutathione S-transferases, and glutamate-cysteine ligase. Interestingly, it has been reported that Nrf2 (NF-E2-related factor 2) regulates a wide array of ARE-driven genes in various cell types. Nrf2 is a basic leucine zipper transcription factor, which was originally identified as a binding protein of locus control region of ss-globin gene. The DNA binding sequence of Nrf2 and ARE sequence are very similar, and many studies demonstrated that Nrf2 binds to the ARE sites leading to up-regulation of downstream genes. The function of Nrf2 and its downstream target genes suggests that the Nrf2-ARE pathway is important in the cellular antioxidant defense system. In support of this, many studies showed a critical role of Nrf2 in cellular protection and anti-carcinogenicity, implying that the Nrf2-ARE pathway may serve as a therapeutic target for neurodegenerative diseases and cancers, in which oxidative stress is closely implicated.

유한요소법을 이용한 코트 스포츠화의 착지 충격력 평가 (Evaluation of Landing Impact Force of Court Sport Shoes by Finite Element Method)

  • 김성호;류성헌;최주형;조진래
    • 대한기계학회논문집A
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    • 제28권11호
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    • pp.1786-1793
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    • 2004
  • A fundamental function of court sport shoes was considered as the protection of human feet from unexpected injuries. But, recently its role for improving the playing competency has been regarded as of more importance. In connection of this situation, intensive efforts are world-widely forced on the development of court sport shoes proving the excellent playing competency by taking kinesiology and biomechanics into consideration. However, the success of this goal depends definitely on the shoes design based upon the reliable evaluation of shoes functional parts. This paper addresses the application of finite element method to the evaluation of landing impact force of court sport shoes. In order to reflect the coupling effect between leg and shoes accurately and effectively, we construct a fully coupled shoes-leg FEM model which does not rely on the independent experimental data any more. Through the numerical experiments, we assess the reliability of the coupled FEM model by comparing with the experimental results and investigate the landing impact characteristics of court sport shoes.

GBCK25, fermented ginseng, attenuates cardiac dysfunction in high fat diet-induced obese mice

  • Sharmila, Judith;Aravinthan, Adithan;Shin, Dong Gue;Seo, Jeong Hun;Kim, Bumseok;Kim, Nam Soo;Kang, Chang-Won;Kim, Jong-Hoon
    • Journal of Ginseng Research
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    • 제42권3호
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    • pp.356-360
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    • 2018
  • The fermentation of medicinal herbs facilitated by microbes is assumed to exert promising therapeutic efficacy on the absorption, bioavailability, and pharmacological effects by speeding up the making or conversion of active constituents into their metabolites. We examined the cardioprotective potential of fermented ginseng, GBCK25, against high-fat diet (HFD)-induced metabolic and functional illnesses as following the essential analysis such as electrocardiographic parameters, alterations of body and organ weights, and echocardiographic studies. The results exhibited that body weights were significantly reduced and the gain of different organ weights were partly eased by GBCK25 treatment. Echocardiography results proposed the amelioration of heart function through normalized levels of left ventricle systolic pressure, ejection fraction, and fractional shortening. These outcomes deliver straight confirmation that GBCK25 could be a potential nutraceutical source for the relief of HFD-induced obesity mediated cardiac dysfunctions.

The Beneficial Effect of Trolox on Sepsis-Induced Hepatic Drug Metabolizing Dysfunction

  • Park, Sang-Won;Lee, Sun-Mee
    • Archives of Pharmacal Research
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    • 제27권2호
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    • pp.232-238
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    • 2004
  • Trolox is a hydrophilic analogue of vitamin E. The aim of this study was to investigate its effects on hepatic injury, especially alteration in cytochrome P450 (CYP)-dependent drug metabolism during polymicrobial sepsis. Rats were subjected to polymicrobial sepsis by cecal ligation and puncture (CLP). The rats were treated intravenously with Trolox (2.5 mg/kg) or vehicle, immediately after CLP. Serum aminotransferases and lipid peroxidation levels were markedly increased 24 h after CLP. This increase was attenuated by Trolox. Total CYP content and NADPH-P450 reductase activity decreased significantly 24 h after CLP. This decrease in CYP content was attenuated by Trolox. At 24 h after CLP, there was a significant decrease in the activity of these CYP isozymes: CYP1A1, 1A2, 2B1, and 2E1. However, Trolox differentially inhibited the decrease in CYP isozyme activity. Trolox had little effect on the decrease in CYP1A1 activity but Trolox significantly attenuated decreases in CYP1A2 and 2E1 activities. In fact, Trolox restored CYP2B1 activity to the level of activity found in control rats. Our findings suggest that Trolox reduces hepatocellular damage as indicated by abnormalities in hepatic drug-metabolizing function during sepsis. Our data also indicates that this protection is, in part, caused by decreased lipid peroxidation.

단독운전 방지를 위한 능동적 주파수 변환 기법의 검출 성능 및 THD 분석 (Detection Performance and THD Analysis of Active Frequency Drift for Anti-Islanding)

  • 조영민;최주엽;송승호;최익;이영권
    • 한국태양에너지학회 논문집
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    • 제35권2호
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    • pp.11-19
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    • 2015
  • Islanding is a phenomenon that EPS(Electric Power System) is continuously energized by PV PCS(Photovoltaic Power Conditioning System) even when EPS is isolated from the grid. Unintentional islanding will result in safety hazard, power quality degradation and many other issues. So, islanding protection of grid-connected PV PCS is a key function for standards compliance. Nowadays, many anti-islanding schemes are researched. But existing anti-islanding schemes used in PV PCS have power quality degradation and non-detection zone issues. This paper analyses not only detection performance of existed anti-islanding schemes using active frequency drift but also THD of PCS output current according to each value disturbance for anti-islanding. In addition, the lowest value of disturbance in each scheme was tabulated under guarantee of anti-islanding condition.

기능성 나노복합 무기질 활성탄계 표면 처리제를 적용한 콘크리트의 내구성능 평가에 관한 실험적 연구 (An experimental study on the durability evaluation of concrete applied functional nano composite inorganic activated carbon based coatings)

  • 양기영;장석재;백종명
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2006년도 추계학술대회 논문집
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    • pp.1385-1390
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    • 2006
  • Concrete structure can be deteriorated by ingress of moisture and aggressive agents. To maintain the sound performance of concrete structure during the service life, it needs to protect concrete from ingress of moisture and aggressive agents before arising deterioration of concrete. Protection of concrete is possible by surface treatment. In this study, durability of the functional nano composite inorganic activated carbon based coatings which can provide a barrier against the ingress of moisture or aggressive ions to concrete is discussed. For the durability evaluation of the coatings, fine void structure evaluation test, chloride penetration acceleration test, accelerated carbonation test, freezing and thawing test, and the accelerated test of chemical erosion are conducted. As the result of this study, the functional nano composite inorganic activated carbon based coatings which became one formed complex compound with adsorption and porosity on concrete surface, had an effect on the function of far infrared radiation, antimicrobial action, air cleaning, airing assurance, and the interception of moisture of deterioration factor, chloride ion, carbon dioxide, sulfate, and so on.

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단계별 환경교감형식에 의한 도심형저층집합주택의 유형별 분류와 자연에너지를 이용하는 냉난방 기법의 사례연구 -일본의 도심형 집합 주거를 중심으로- (A case study on the method of heating and cooling system by types classification and utilization of natural resources in urban centered low-rise collective housing through the Environment communion -Focusing on the urban town house in Japan-)

  • 심재명;김강수
    • KIEAE Journal
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    • 제10권5호
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    • pp.23-30
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    • 2010
  • The residence means a given place. It is repeated that process of overcome, protection, assimilation and adaptation has applied to environmental condition. Architecture is part of environment and various. Thus there are lots of types. We need the place with uniqueness, and it is suitable for biological and humanistic environment. The living space turned to be meaningful place with design, and people start to live with nature together. Therefore design restructures whole environment and makes people to be closed with nature. We have to understand nature of environment to connect one place with the other place, and people start to put down roots certain place. Coping with social needs, we have to develop the architectural alternative which can be applied to natural condition. This study suggest sound high-density urban residential model as it function social mix.

Heme oxygenase-1 유도를 통한 화학 암예방 및 세포보호와 그 분자생물학적 기전 (Chemoprevention and Chemoprotection Through Heme Oxygenase-1 Induction and Underlying Molecular Mechanisms)

  • 김은희;김성환;나혜경;서영준
    • 한국환경성돌연변이발암원학회지
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    • 제26권4호
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    • pp.97-112
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    • 2006
  • Heme oxygenase(HO)-1 is an important antioxidant enzyme that plays a pivotal role in cellular adaptation and protection in response to a wide array of noxious stimuli. Thus, HO-1 induction has been associated with prevention or mitigation of pathogenesis of various diseases, including acute inflammation, atherosclerosis, degenerative diseases, and carcinogenesis. Recent progress in our understanding of the function of molecules in the cellular signaling network as key modulators of gene transcription sheds light on the molecular mechanisms underlyuing HO-1 gene expression. A panel of redox-sensitive transcription factors such as activator protein-1, nuclear factor-kB, and nuclear factor E2-related factor-2, and some of the upstream kinases have been identified as prime regulators of HO-1 gene induction. This review summarizes molecular mechanisms underlying HO-1 expression and the significance of targeted induction of HO-1 as a potential chemopreventive or chemoprotective strategy.

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Improved Photo Degradation of Rhodamine B Dye using Iron Oxide/Carbon Nanocomposite by Photo-Fenton Reaction

  • Kim, Min-Il;Im, Ji-Sun;In, Se-Jin;Kim, Hyuk;Kim, Jong-Gyu;Lee, Young-Seak
    • Carbon letters
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    • 제9권3호
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    • pp.195-199
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    • 2008
  • A nanocomposite consisting of $Fe_3O_4$ and MWCNT was produced via sol-gel technique using $FeCl_3$ along with MWCNT by calcination at $300^{\circ}C$. The degradation effect of rhodamine B dye has been investigated under UV illumination in a darkroom. The degradation reaction was studied by monitoring the discoloration of dye as a function of irradiation time using UV-visible spectrophotometeric technique. The $Fe_3O_4$-MWCNT samples have continuous degradation ability under the UV illumination with the first order kinetics and the dye removal was better than in the pristine $Fe_3O_4$. The resultant composite catalyst was found to be efficient for the photo-Fenton reaction of the dye.