• 제목/요약/키워드: DAMP

검색결과 357건 처리시간 0.023초

HVDC 연계 시스템의 전력계통 안정화 장치의 적정 파라메터 선정에 관한 연구 (A Study on the Optimal Parameter Selection of a Power System Stabilizer for HVDC Linked System)

  • 김경철;최홍규;최병숙;강태은;고영곤
    • 조명전기설비학회논문지
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    • 제15권5호
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    • pp.81-89
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    • 2001
  • 전력 계통 안정화 장치는 전력시스템에 외란이 발생했을 때 저주파수 동요현상을 효과적으로 저감하는 역할을 한다. 본 논문은 제주-해난 HVDC로 연계된 전력시스템에 설치된 PSS의 적정 파라메커 선정이론을 다루었다. 사용한 알고리즘은 위상지연을 적절한 극좌표 이동법으로 보상하고 설정된 댐핑계수가 되도록 이득계수를 구하는 방법이다. PSS 효과를 검증하기 위해 동태 및 과도안정도를 PSS 설치 전과 후로 비교하였다. MATLAB을 근거로 한 PST 프로그램을 사용하여 사례연구 시스템에 적용한 시뮬레이션 결과는 PSS를 설치하므로써 전력시스템이 안정화되어 만족할 만큼의 댐핑효과를 보았다.

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댐붕괴 문제의 해석에 관한 TVD-McCormack기법의 적용 (Application of TVD-McCormack Scheme to Analysis of Dam-Break Problems)

  • 이정규;김태관
    • 한국수자원학회논문집
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    • 제36권3호
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    • pp.365-374
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    • 2003
  • 본 연구에서는 1차원 댐 붕괴 문제의 계산을 위해 TVD-McCormack 기법을 사용하였다. TVD 기법은 진동을 감쇠 시킬 뿐 아니라 수정인자를 가진 항을 포함하지 않는다. 더구나, TVD-McCormack 기법은 source항의 처리에 있어 어려움을 발생시키지 않으며 시간과 공간에 대해 2차 정확도를 유지한다. 제한자의 적당한 적용에 의해 TVD의 특성을 발전시키고, 불연속구간에서의 수치 진동을 줄일 수 있었다. 또한, 본 수치기법에서 예측자(predictor)-보정자(corrector)단계가 충격파의 전파 방향과 같을 때 더 작은 수치오차를 갖는다는 것을 알 수 있었다.

인삼양위탕에 대한 형상의학적 고찰 (Review on Insamyangwi-tang in Hyungsang Medicine)

  • 강경화;이용태
    • 동의생리병리학회지
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    • 제18권6호
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    • pp.1569-1574
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    • 2004
  • A general review is made on Insamyangwi-tang(인삼양위탕). Following conclusions are drawn from the clinical cases of Insamyangwi-tang in Hyungsang medicine. Insamyangwi-tang is composed of four different prescriptions of Huisaeng-san, Sakoonja-tang, Eajin-tang and Pyungwi-san. Huisaeng-tang is usually prescribed for the intestinal convulsion. Sakoonja-tang for the deficiency of Ki. Eajintang for retention of phlegm, Insamyangwi-tang is effective in strengthening the spleen, drying the dampness, warming the middle-warmer to stop vomiting, regulating the flow of Ki, and eliminating phlegm. Insamyangwi-tang is applicable to malaria caused by cold, intestinal convulsion, abdominal mass, edema, tympanites, Yin syndrome of exogenous febrile disease, distension, lack of appetite, stomachache, and diarrhea. Persons with the following characteristic in Hyungsang are more susceptible to Insamyangwi-tang ; Jung type, Hyul type, fish type, Taium meridian type, white fat damp constitution, person with big mouth, and woman rather than man.

용담사간탕을 투여한 화농성 슬관절염 환자의 치검 1례 (The Effect of Youndamsagan-tang on a Case of Septic Knee: A Case Report)

  • 강대희;김영달;김창년;민지연
    • 동의생리병리학회지
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    • 제17권6호
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    • pp.1547-1551
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    • 2003
  • This study was carried out to characterized the effect of Youndamsagan-tang on a Case of Septic Knee. After we gave Youndamsagan-tang to a patient of septic knee, we examined not only symptom of patient but also the thickness and circumference of knee, the change of WBC, ESR, body temperature, VAS. As admission time passes, the pain, flare, swelling and movement of left-side knee joint were improved. The thickness and circumference of knee joint were decreased, and the count of WBC, ESR were decreased. And patient's pain by VAS was subsided. From the above result, administration of Youndamsagan-tang reduces the progressing of pain, flare, swelling and movement in knee joint.

국내산 오리나무속 식물로부터 Diarylheptanoid계열 화합물의 함량분석 (Quantitative Determination of Diarylheptanoid Compounds from Korean Alnus)

  • 임현우;김민기;김현정;심재걸;김광호;최형균;이민원
    • 생약학회지
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    • 제35권4호통권139호
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    • pp.384-387
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    • 2004
  • Genus Alnus are deciduous board-leaved trees or shrubs found in the damp place and mountain and more than 17 species are growing in Korea. The bark of Alnus japonica has been used for the treatment of fever, hemorrhage and diarrehea in oriental traditional medicine. Quantitative analysis of diarylheptanoids which were characteristic components of Alnus species (A. japonica, A. hirsuta, and A. hirsuta var. sibirica), has been conducted by HPLC. The results showed that these plants were rich source of diarylheptanoids and the amount of oregonin and hirsutanonol which were major diarylheptanoids showed seasonal variation.

중의체질의학과 치미병(治未病)센터에 대한 보고 (A Report on Traditional Chinese Medicine (TCM) Constitution Theory and Chinese Health Administration Center)

  • 김상혁;주종천;황동욱;이시우
    • 사상체질면역의학회지
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    • 제22권3호
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    • pp.59-66
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    • 2010
  • 1. Objectives: The objectives of this paper are to report Traditional Chinese Medicine (TCM) Constitution Theory and the present state of Chinese Health Administration Center. 2. Methods: We visited China for "China Technology Survey" in 2009. Our purposes were to research for the study of constitutional medicine in China and to search for the Development Plan of Constitutional Medicine Through the Research of Chinese Constitutional Medicine. This paper is the report of the "China Technology Survey". 3. Results & Conclusions: In China, the concept and diagnosis of TCM constitutions is nine(Balanced Constitution, Qi-deficient Constitution, Yang-deficient Constitution, Yin-deficient Constitution, Phlegm-dampness Constitution, Damp-heat Constitution, Stagnant blood Constitution, Stagnant qi Constitution, Inherited specific Constitution). And Chinese government established the Classification and Diagnosis Standards for the Constitutions of TCM in 2009. TCM Constitution Theory is being widely applied at Health Administration Center that treats 'predisease' patients. Theses Chinese clinical implications of constitutional medicine are a good example for "Sasang Constituional Medicine" Care Service.

어혈(瘀血)로 변증된 피부갑착(皮膚甲錯) 환자에 혈부축어탕(血府逐瘀湯)을 사용한 치험1례 보고 (A Case Report of Skin Scale Treated with Hyulbuchukeotang)

  • 윤현덕;신오철;박치상;이소연
    • 대한한방내과학회지
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    • 제26권3호
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    • pp.720-724
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    • 2005
  • Objective : Skin scale(皮膚甲錯) refers to an excessive dryness of skin which can be found under such conditions as blood deficiency(血虛), blood heat(血熱), damp heat(濕熱), the weakness of stomach(脾胃虛) and blood stasis(瘀血). Method : A sensitive and nervous patient showed symptoms of insomnia and chest discomfort as well as skin scale. He had great anxiety over his illness. He, therefore, was diagnosed as blood stasis caused by outburst of emotions and was prescribed Hyulbuchukeotang(血府逐瘀湯) to remove blood stasis in chest. Result and Conclusion : After taking Hyulbuchukeotang, insomnia, chest discomfort and skin scale eased off. Since not only blood stasis but also other factors may cause skin scale, more research on such cases must be done to determine the efficacy of Hyulbuchukeotang for skin scale.

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거풍제습탕이 뇌허혈이 유발된 백서의 뇌혈류 변화에 미치는 영향 (Effects of Geopungjeseub-tang(Gufengchushi-tang) on the Changes of Cerebral Blood Flow in Rats)

  • 홍석;전상윤
    • 대한한방내과학회지
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    • 제26권3호
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    • pp.596-604
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    • 2005
  • Objectives : Geopungjeseub-tang(Gufengchushi-tang) has been used in oriental medicine for many centuries as a therapeutic agent for hemiplegia caused by deficiency of qi(氣虛) and damp phlegm(濕痰). This study was performed to evaluate effects of Geopungjeseub-tang extract(GJT) on hemodynamics[regional cerebral blood flow(rCBF), pial arterial diameter(PAD), mean arterial blood pressure(MABP), heart rate(HR)] in normal rats and in rats with cerebral ischemia by middle cerebral artery(MCA) occlusion. Also, effects of adrenergic ${\beta}-receptor$, cyclooxygenase on response to GJT were evaluated. Methods : Laser-doppler flowmetry(LDF) measured changes of rCBF, MABP and HR. Video microscope and width analyzer measured changes in PAD. Results : rCBF and PAD increased after treatment with GJT(10mg/kg, i.v.) during the period of cerebral reperfusion, and pretreatment with indomethacin raised rCBF and PAD increased after treatment with GJT during the same period as above. Pretreatment with propranolol decreased rCBF, but increased after GJT treatment, but raised PAD increased after GJT treatment during this period of reperfusion. Conclusion : CR caused diverse responses were observed in rCBF and PAD after treatment with GJT. ACF action is mediated by adrenergic ${\beta}-receptor$ and cyclooxygenase. Result suggest that GJT has an anti-ischemic effect through the improvement of cerebral hemodynamics and has theraputic potential for cerebral apoplexy.

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DCCA 와 Polar Ordination 에 依한 無等山의 森林 群落 分析 (Detrended canonical correspondence analysis and polar ordination analysis on the forest communities of mudungsan.)

  • Kim, Chang-Hwan;Kil, Bong-Seop
    • The Korean Journal of Ecology
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    • 제15권2호
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    • pp.117-125
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    • 1992
  • TWINSPAN(two-way indicator species analysis), DCCA(detrended canonical correspondence analysis) and polar ordination method wee used so as to analyze the the relation between forest vegetation and hibitat of mudungsan(1, 187m) located in kwangju area. Vegetationsurvey consulted 1:25, 000 topographical map, set up 41 quadrats and analyzed from April, 1990 to August, 1991. Forest vegetation of mudungsan was classifild to quercus acutissima community, fraxinus mandshurica community, quercus mongolica community, quercus serrata community, quercus dentata community, quercus variabilis community, and pinus densiflora community by TWINSPANmethod, and this almost coincide with the result of plar ordination. according to DCCA analysis, P. densiflora community was formed in xeric and low altitude region which soil nutrient was poor, compared with other communities. q. variabilis and q. acutissima community wee distributed in the region that low altitude and organic matter content was comparatively low, but q. acutissima community was formed in a damp region while q. variabilis community in a xeric region. q. mongolica and f. mandshurica formed the communities in a high altitude region, especially f. mandshurica cmmunity was distributed in a high humidity region. According to polar ordination analysis, the forest vegetation was classified to 7 communities by means of environmental gradient such as humidity, organic matter, ph, temperature, c.e.c and P2O5.

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HVDC 연계 시스템의 전력계통 안정화 장치와 전력변환기 적정 파라미터 선정에 관한 연구 (A Study on the Optimal Parameter Selection of a Power System Stabilizer and Power Converters for HVDC Linked System)

  • 조의상;김경철;최홍규
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2001년도 학술대회논문집
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    • pp.65-72
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    • 2001
  • Power system stabilizer act efficiently to damp the electromechanical oscillations in interconnected power systems. This paper presents an algorithm for the optimal parameter selection of a power system stabilizer in two-area power systems with a series HVDC link. This method is one of the classical techniques by allocating properly pole-zero positions to fit as closely as desired the ideal phase lead between the voltage reference and the generator electrical power and by changing the gain to produce a necessary damping torque over the matched frequency range. Control of HVDC converter and inverter are used a constant current loop. Proper parameters of PI controllers are obtain based on the Root-locus technique in other to have sufficient speed and stability margin to cope with charging reference values and disturbance. The small signal stability arid transient stability studies using the PSS parameters obtained from this method show that a natural oscillation frequency of the studycase system is adequately damped. Also the simulation results using the HVDC converter and inverter parameters obtained from this proposed method show proper current control characteristics. The simulation used in the paper was performed by the Power System Toolbox software program based on MATLAB.

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