• Title/Summary/Keyword: LFC

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A Study on the Load Frequency Control of Power System Using an Optimal Modulation Controller (최적 변조제어기를 이용한 전력시스템의 부하주파수 제어에 관한 연구)

  • 정형환;허동렬;정문규;주석민;이준탁
    • Journal of Advanced Marine Engineering and Technology
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    • v.26 no.3
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    • pp.299-306
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    • 2002
  • The load frequency control(LFC) of power system is one of important subjects in view of system operation and control. That is, even though the rapid load disturbances are applied to the given power system, the stable and reliable power should be supplied to the users, converging unconditionally and rapidly the frequency deviations and the tie-line power flow ones of each area into allowable boundary limits. Nonetheless of such needs, if the internal parameter perturbation and the sudden load variation are given, the unstable phenomena of power systems can be often brought out because of the large frequency deviation and the unsuppressible power line one. So, an optimal modulation controller for UC of multi-area power system is designed by a recursive algorithm that determines the state weighting matrix Q of a linear quadratic performance criterion. The optimal modulation controller is based on optimal control and can obtain the exact dynamic response of the UC of multi-area power system in the time domain. The performances of the resultant optimal modulation control, that is, the steady-state deviations of frequency and tie-line power flow and the related dynamics, were investigated and analyzed in detail by being applied to the UC of multi-area power system in the perturbations of predetermined internal parameters. Through the simulation results tried variously in this paper for disturbance of stepwise load changes, the superiorities of the proposed optimal modulation controller in robustness and stability were proved.

A Study on the Effects of Sopunghwalhyeoltang-gamibang on the Inhibition of Arthritis Induced by Collagen on the Mouse (소풍활혈탕가미방이 Collagen으로 수발된 생쥐의 관절염 억제에 관한 연구)

  • Gwak Jung Mun;Oh Min Suck;Park Jong Ho;Kim Dong Hee
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.16 no.4
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    • pp.810-817
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    • 2002
  • This study was carried out to know the effects of sopunghwalhyeoltang-gamibang(hereinafter referred to SPHHT) on the inhibition of arthritis induced by collagen on the mouse. Various experimental were performed in vivo (in DBA/1 J mice which are experimental model of arthritis induced by collagen) to analyse the immunomodulatory effects of SPHHT. The results were obtained as follows: 1. The cytotoxicity against mLFC was not measured in all concentration. 2. The arthritis index, incidence, hind paw edema, delayed-type hypersensitivity reaction, spleen weight were reduced in SPHHT treated group. 3. The expression of CD3 ε +/CD4+, CD3 ε +/CD8+ and CD19+ in peripheral blood mononuclear were reduced in SPHHT treated group. 4. The production of pro-inflammatory cytokines such as IL-6 and TNF-α were significantly reduced in SPHHT treated group. 5. The formation of new bones and synivium were stimulated in SPHHT treated group. Comparison of the results for this study showed that Sopung-hwalhyeoltang-gamibang had immunomodulatory effects. So we expect that Sopunghwalhyeoltang-gamibang should be used as a effective drugs for not only rheumatoid arthritis but also another auto-immune disease. Therefore we have to survey continuously in looking for the effective substance and mechanism in the future.

Performance of Suckling Rabbits Fed a Low Fibre Concentrate

  • Piccolo, Giovanni;Bovera, Fulvia;Meo, Carmelo Di;Gazaneo, Maria Pia;Nizza, Antonino
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.10
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    • pp.1421-1424
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    • 2005
  • The aim of this study was to evaluate the effect of two diets different in crude fibre content and ingredients on performance and on caecal characteristics of rabbits around weaning. Thirty litters from thirty New Zealand White does were divided at Day 18 in two groups fed, respectively, a low fibre concentrate (LFC, consisting mainly of soybean meal, delactated whey, barley) from Day 18-28 followed by a creep feed (CF, consisting mainly in alfalfa meal, barley and wheat bran) from Day 29-32, and a CF from Day 18-32. After weaning (32 days) both groups were fed the CF ad libitum for two weeks. During the pre-weaning period, mortality, milk intake and solid feed intake (from Day 20) were recorded daily, while the live weight of kits was recorded twice, at 18 and 32 days. At day 28, one rabbit/litter was slaughtered in order to obtain data on caecal content characteristics. After weaning, the rabbits were located in collective cages, feeding ad libitum CF; feed intake, live weight and mortality were recorded weekly for two weeks. During the preweaning period, there were no differences between the groups in milk and solid feed intake and, by consequence, in live weight at weaning; instead, the mortality was higher (12.5 vs 4.5%) for the group (A) that changed diet at 28 days. Group A showed also a higher caecal pH (6.12 vs. 5.72), propionate to butyrate ratio (0.73 vs. 0.46), ammonia content (9.3 vs. 7.1 mmol/l), but a lower total volatile fatty acid content (66.8 vs. 82.1 mmol/l) than B Group, probably due to the dried milk whey in the concentrate. After weaning, there were no significant differences between the two groups. The authors concluded that the use of a low fibre concentrate for suckling rabbits is not recommended.

The Effect of Forage Level and Oil Supplement on Butyrivibrio fibrisolvens and Anaerovibrio lipolytica in Continuous Culture Fermenters

  • Gudla, P.;Ishlak, A.;Abughazaleh, A.A.
    • Asian-Australasian Journal of Animal Sciences
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    • v.25 no.2
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    • pp.234-239
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    • 2012
  • The objective of this study was to evaluate the effects of forage level and oil supplement on selected strains of rumen bacteria believed to be involved in biohydrogenation (BH). A continuous culture system consisting of four fermenters was used in a $4{\times}4$ Latin square design with a factorial arrangement of treatments, with four 10 d consecutive periods. Treatment diets were: i) high forage diet (70:30 forage to concentrate (dry matter basis); HFC), ii) high forage plus oil supplement (HFO), iii) low forage diet (30:70 forage to concentrate; LFC), and iv) low forage plus oil supplement (LFO). The oil supplement was a blend of fish oil and soybean oil added at 1 and 2 g/100 g dry matter, respectively. Treatment diets were fed for 10 days and samples were collected from each fermenter on the last day of each period 3 h post morning feeding. The concentrations of vaccenic acid (t11C18:1; VA) and c9t11 conjugated linoleic acid (CLA) were greater with the high forage diet while the concentrations of t10 C18:1 and t10c12 CLA were greater with the low forage diet and addition of oil supplement increased their concentrations at both forage levels. The DNA abundance of Anaerovibrio lipolytica, and Butyrivibrio fibrisolvens vaccenic acid subgroup (Butyrivibrio VA) were lower with the low forage diets but not affected by oil supplement. The DNA abundance of Butyrivibrio fibrisolvens stearic acid producer subgroup (Butyrivibrio SA) was not affected by forage level or oil supplement. In conclusion, oil supplement had no effects on the tested rumen bacteria and forage level affected Anaerovibrio lipolytica and Butyrivibrio VA.

The Experimental Study on Anti-thrombotic and Anti-inflammatory Effect of BokbangHongdeungPaejangSan (BHPS) (복방홍등패장산(復方紅藤敗醬散)의 항혈전(抗血栓) 및 항염작용(抗炎作用)에 대한 실험적(實驗的) 연구(硏究))

  • Lim, Dong-Ug;Yoo, Dong-Youl
    • The Journal of Korean Obstetrics and Gynecology
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    • v.19 no.3
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    • pp.151-173
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    • 2006
  • Purpose : This study was performed to evaluate anti-thrombotic and anti-inflammatory effects of BokbangHongdeungPaejangSan water extract (BHPS). Methods : BHPS was investigated using cultured cells and a murine models. As for the parameters of inflammation, levels of several inflammatory cytokines and chemical mediators which are known to be related to inflammation were determined in mouse lung fibroblast cells (mLFC) and RAW 264.7 cells. Results : In experiment of anti-thrombotic effect, BHPS inhibited the platelet aggregation induced by ADP and epinephrine, and inhibited pulmonary embolism induced by collagen and epinephrine. BHPS increased Platelet number and fibrinogen amount, and shortened PT and APTT in thrombus model induced by dextran. In experiment of anti-inflammatory effect, BHPS inhibited IL-1${\beta}$, IL-6, TNF-${\alpha}$, COX-2 and NOS-II mRNA expression in a concentration-dependent manner in RAW 264.7 cell line, and inhibited significantly NO production at 50, 100 ${\mu}g/ml$, and also inhibited ROS production in a concentration-dependent manner. BHPS inhibited IL-1${\beta}$, IL-6 and TNF-${\alpha}$ production significantly in serum of acute inflammation-induced Balb/c mice, and decreased IL-1${\beta}$, IL-6 and TNF-${\alpha}$ production in spleen tissue, but increased IL-1${\beta}$, IL-6 and TNF-${\alpha}$ production in liver tissue. BHPS increased survival rate at the 3th day in ICR mice with lethal endotoxemia induced by LPS. Conclusion : These results suggest that BHPS can be used for treating diverse female diseases caused by thrombosis and inflammation such as endometriosis, pelvic pain, cervicitis, pelvic inflammatory disease and pelvic tuberculosis and so forth.

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Effects of GP extract on oxidative stress and contact dermatitis in NC/Nga Mice induced by DNCB (가감평위산(加減平胃散)이 산화적 손상과 접촉성 피부염에서의 면역 조절작용에 미치는 영향)

  • Park, Eung-Ho;Yun, Mi-Young;Kim, Seon-Bin;Kim, Dong-Hee
    • Journal of Haehwa Medicine
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    • v.16 no.2
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    • pp.131-145
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    • 2007
  • To evaluate the effects of GP on contact dermatitis, we examined the composition of immune cells from drain lymph node in DNCB-induced contact dermatitis murine model NC/Nga mice. And the amount of pathologic cytokines of spleen and antioxidant activity were investigated. The results were summarized as followers; 1. GP did not show cytotoxic effect on mLFC in vitro. 2. GP did not have hepatotoxicity in vivo in the level of ALT, AST. 3. GP decreased the production of DPPH and in a dose-dependent. 4. GP significantly decreased total cell number of DLN in DNCB-induced NC/Nga mice compared to the untreated control group. 5. GP significantly decreased the number of CD3+, CD19+, CD4+, CD8+, CD3+/CD69+ and CD4+/CD45+ in DLN of DNCB-induced NC/Nga mice compared to the untreated control group. 6. GP significantly reduced the level of IL-4 and IFN-$\gamma$ in splenocytes of DNCB-induced NC/Nga mice compared to the untreated control group. Taken together above results, GP have therapeutic effects on contact dermatitis by regulating T cell activation. This study warranted further investigations of molecular mechanisms of GP on contact dermatitis.

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The Experimental Study on Anti-thrombotic and Anti-inflammatory Effect of NeungaSoJeokTang(NSJT) (능아소적탕(稜莪消積湯)의 항혈전(抗血栓) 및 항염작용(抗炎作用)에 대한 실험적(實驗的) 연구(硏究))

  • Je, Jong-Min;Yoo, Dong-Youl
    • The Journal of Korean Obstetrics and Gynecology
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    • v.20 no.3
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    • pp.45-64
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    • 2007
  • Purpose: This study was performed to evaluate anti-thrombotic and anti-inflammatory effects of NeungaSoJeokTang water extract (NSJT). Methods: In the study of anti-inflammatory effects, NSJT was investigated using cultured cells and murine models. As for the parameters of inflammation, levels of several inflammatory cytokines and chemical mediators which are known to be related to inflammation were determined in mouse lung fibroblast cells(mLFC) and RAW 264.7 cells. Results: Prior to the experiment, we evaluated sGOT, sGPT, BUN and creatine after the treatment. As a result, NSJT was innoxious on liver and kidney. In experiment of anti-thrombotic effect, NSJT inhibited the platelet aggregation induced by ADP and epinephrine, and inhibited pulmonary embolism induced by collagen and epinephrine. NSJT did not affect significantly the blood flow rate both in vitro and in vivo. NSJT increased platelet number and fibrinogen amount, and NSJT shortened PT and APTT in thrombus model induced by dextran. In experiment of anti-inflammatory effect, NSJT inhibited $IL-1{\beta}$, IL-6, $TNF-{\alpha}$, COX-2 and NOS-II mRNA expression in a concentration-dependent manner in RAW 264.7 cell line, and inhibited significantly NO production at 50, 100 ${\mu}g/ml$, and also inhibited ROS production in a concentration-dependent manner. NSJT inhibited $IL-1{\beta}$, IL-6 and $TNF-{\alpha}$ production significantly in serum of acute inflammation-induced Balb/c mice, and decreased $IL-1{\beta}$, IL-6 and $TNF-{\alpha}$ production in spleen tissue, but increased $IL-1{\beta}$, IL-6 and $TNF-{\alpha}$ production in liver tissue. NSJT increased survival rate at the 3th day in ICR mice with lethal endotoxemia induced by LPS. Conclusion: These results suggest that NSJT can be used for treating diverse female diseases caused by thrombosis and inflammation such as pelvic pain, pelvic inflammatory disease as well as vulvar pain due to vulvitis, vulvar vestibulitis and so on.

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Effect of Various Combinations of Sugars, Amino Acids, and Fatty Acids on Volatile Compounds of Low-fat Sausages to have Similar Characteristics to Those of Regular-fat Sausages (기존의 유화형 소시지와 유사한 향미를 갖는 저지방 소시지 제조를 위한 당, 아미노산 및 지방산의 조합)

  • Kook, Sung-Ho;Park, Sung-Yong;Chin, Koo-Bok
    • Food Science of Animal Resources
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    • v.29 no.4
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    • pp.487-493
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    • 2009
  • This study was conducted to investigate the effect of various combinations of sugars, amino acids, and fatty acids (oleic/linoleic aicds) on volatile compounds of low-fat sausages (LFSs) to have similar characteristics to those with regular-fat counterparts (RFC). The addition of glucose or fructose alone in LFC increased the concentrations of myristicine, pentadecanal and octadecanal, as compared to RFC. In addition, LFSs containing lysine alone had higher concentration of myristicine, as compared to those with RFC. Without the addition of both oleic and linoleic acids, LFS containing glucose in combination with various amino acids, such as alanine, aspartic acid, cysteine, and lysine, had higher concentration of myristicine, as compared to RFC. Furthermore, myristicine content (ppm) of LFSs was different from those of RFC, regardless of the concentration of lysine in combined with glucose or fructose. LFSs containing oleic and linoleic acids with the combination of glucose/glycine or glucose/alanine had the most similar volatile compounds to those of RFC. These results indicated that volatile compounds isolated from smoked LFSs containing sodium caseinate as a fat replacer and the multiple combinations of sugar, amino acids, and fatty acids had the most similar volatile compounds to those of RFC.

The Effects of BGG on Various Immunological Factors Related to Pathogenesis of Allergic Dermatitis in NC/Nga Mice Induced by Der-f (보음거풍지양탕(補陰祛風止痒湯)이 아토피 피부염을 유발(誘發)한 NC/Nga 생쥐의 면역(免疫) 조절작용(調節作用)에 미치는 영향(影響))

  • Bang, Chan-Kuk;Choi, Jeong-Jun;Eom, Dong-Myung;Kim, Dong-Hee
    • Journal of Haehwa Medicine
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    • v.16 no.2
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    • pp.147-169
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    • 2007
  • To evaluate the therapeutic effects of BGG on atopic dermatitis, we investigated the composition of immune cells of lymph node, PBMC and skin of Dermatophagoides farinae-induced NC/Nga mice. The levels of immunoglobulins in serum were analyzed at the protein level and the amount of pathologic cytokines were investigated using CD3/CD28 stimulated splenocytes. The results are summarized below; 1. BGG showed no cytotoxic effect up to $200\;{\mu}g/m{\ell}$ on mLFC in vitro. 2. BGG showed no hepatotoxicity in vivo based on the levels of ALT and AST. 3. Atopic dermatitis was improved through naked eye examination. BGG reduced the skin clinical index from 2.9 to 1.3 (p<0.01). 4. H&E and toluidine blue staining of tissue biopsies revealed that BGG inhibited the infiltration of lymphocytes and mast cells to skin. 5. BGG reduced the number of CD19 positive B cells in PBMCs by 16% (p<0.01), whereas cells were increased by 26% (p<0.05) in lymph nodes. 6. BGG reduced the numbers of B220+/CD23+ cells by 15% (p<0.01) and 33% in PBMCs and lymph node, respectively. 7. BGG reduced the numbers of B220+/IgE+ cells in PBMCs and lymph node by 21% and 33% (p<0.01), respectively. 8. BGG suppressed the levels of IgE (13%, p<0.001) as well as IgM (34%, p<0.001), IgG2a (40%, p<0.001) and IgG2b (26%, p<0.05). 9. BGG reduced the levels of IL-4 and IFN-$\gamma$ by 7% (p<0.05) and 13% (p<0.001) in anti-CD3 and anti-CD28-activated splenocytes, respectively. 10. BGG considerably inhibited the production of TNF-$\alpha$ and IL-6 by 42% (p<0.01) and 15% in the serum, respectively. Based on the results above, we concluded that BGG has therapeutic effects on atopic dermatitis by regulating the differentiation of B cells and isotype switching of IgE. Further investigations on the molecular mechanisms of BGG on atopic dermatitis are anticipated.

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