• Title/Summary/Keyword: modulation index

Search Result 390, Processing Time 0.022 seconds

Design of Digital PWM Controller for Voltage Source Inverter (전압형 인버터를 위한 디지털 PWM 제어기 설계)

  • 이성백;이종규;정구철
    • The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.7 no.3
    • /
    • pp.27-33
    • /
    • 1993
  • This paper presents the &tal controller for driving high frequency voltage fed PWM inverter that carrier frequency is over 2OkHz.We analyzed the conventional PWM to select a proper PWM pattern. as the result, obtained PWM pattern of the controller in which asynchronus staircase sinusoidal waveform is used as reference signal, and variable carrier ratio method was used for PWM control. The PWM controller is designed by fully digital method. Especially, Thk proposed controller is consisted of 8 bit one-chip microprocessor and digital logic. the former is for arithmetic and data processing, and the latter is for PWM pattern synthesis. Therefore, The responsibility and controllability is improved. Also, Data processing capability is improved using proper program to output modulation index with 9 bits. Circuits configuration of digital controller are made up of one chip 8051 and EPLD, and its controllability is tested by operating voltage fed inverter. Harmonics and current waveform is evaluated and analyzed for the voltage fed inverter system.

  • PDF

A Study on the Immune Modulation of Chunghwatang(CHT) in Atopic Dermatitis Animal Models (아토피피부염 동물 병태 모델에서 청화탕(淸華湯)의 면역조절작용에 관한 연구)

  • Yoo, Heon-Sook;Gim, Seon-Bin;Song, Hyang-Hee;Ji, Joong-Gu;Bak, Ji Won;Kim, Dong-Hee
    • Journal of Haehwa Medicine
    • /
    • v.21 no.1
    • /
    • pp.53-63
    • /
    • 2012
  • Objectives : The aim of this study was to investigate the effect of Chunghwatang (CHT) for atopic dermatitis. Methods : CHT, a verified anti-oxidant and anti-inflammatory effect, was treated in atopic dermatitis animal model to investigate cytokine levels and immunoglobulin production. Results : Clinical skin index was 47.1%, suggesting significant efficacy of CHT in atopic dermatitis treatment. Serum IL-4, IL-6, IL-13, TNF-${\alpha}$ and histamine productions were significantly decreased to 52.3%, 61.8%, 68.0%, 37.4%, and 46.6%, respectively. The production of IL-5 was decreased to 33.3%. The increase of Immunoglobulin IgG1 production along with IgE through the interaction of IgE and IL-4 induced by IL-4 and IL-13 were measured as 20.7% and 23.4%, respectively. Conclusions : The results above, along with the in vitro test results, strongly supports the CHT samples as effective immunomodulator in AD treatments, suggesting its use in clinical practice and basic information for EBM.

Rerformance Analysis of 16 QAM System in a Composite Electromagnetic Interference Environment (복합 전자파 간섭 환경에서 16 QAM 시스템의 성능 분석)

  • 조광윤;조성언;노재성;강희조;조성준
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.12 no.2
    • /
    • pp.285-292
    • /
    • 2001
  • In this paper, the analysis model of a composite electromagnetic interference environment is proposed, and the composite interference consists of three types, i.e., impulse, sinusoidal, and rectangular type. Also, we have derived the p.d.f of the amplitude of the composite interference. And using a derived p.d.f, we have evaluated the performance of 16QAM (Quadrature Amplitude Modulation) system in a composite electromagnetic interference environment. From the results, it is known that when impulse type interference is weaker than the others, the shape of p.d.f is dominantly governed by the power component ratio of sinusoidal and rectangular type interference. On the other hand, when impulse type interference is stronger, the effect of the other two interference becomes insignificant. Also, It is shown that the smaller both impulsive index (A) and the mean power component ratio ($\Gamma$') in impulse type interference are, the worse the performance of 16QAM system is.

  • PDF

The effects of HYT on various immunological factors related to pathogenesis of allergic dermatitis in NC/Nga mice induced by Biostir AD (아토피피부염 동물 병태모델에서의 형개연교탕(荊芥連翹湯)의 면역조절작용)

  • Kang, Ran-Yi;Park, Bo-Kyoung;Gim, Seon-Bin;Choi, Hak-Joo;Kim, Dong-Hee
    • Journal of Haehwa Medicine
    • /
    • v.18 no.2
    • /
    • pp.47-62
    • /
    • 2009
  • Atopic dermatitis induced NC/Nga mice were used to investigate the efficacy of HYT on the recovery of dermatitic symptoms by how HYT influenced the immune related factors. The results are as below: 1. Compared to the control, HYT treated group showed recovery of atopic dermatitis by the naked eye observation, and significant reduction of dermatits index was observed after 14 weeks. 2. HYT treated group showed significant decrease of the ratio of CCR3+, B220+/IgE+, and Gr-1+/CD11b+ immune cells in dorsal skin by 40.5%, 34.2%, and 48.1%, respectively. 3. HYT treated group showed increase in the ratio of CD19+ immune cells within PBMC by 10.8%, as well as decrease in CD3+, CD3+/CD69+, NKT+ ratios by 5.3%, 35.2%, and 44.9%, respectively. 4. HYT treated group showed increase in the expression of IFN-$\gamma$ in serum by 589.3%, whereas the expression of IL-4, IL-5, IL-6, IL-13, TNF-$\alpha$, MCP-1 and RANTES were decreased by 31.4%, 82.1%, 97.1%, 39.5%, 83.7%, 26.1%, 48.6%, respectively. A 47.2% decrease in IgE expression was also observed. The results above strongly supported the improvement of atopic dermatitis by HYT treatment through immune modulation. Further studies on the synergistic effect of each ingredients of HYT and therapeutic effects according to the dosage of each ingredient should be followed for clinical applications. This work was (partly) supported by the RIC program of MKE(Ministry of Knowledge Economy) in Daejeon University.

  • PDF

Anti-oxidative and anti-inflammatory effect of Do-Ki-Tang methanol extract in mouse macrophage cells (마우스 대식세포에서 도기탕 (導氣湯) 메탄올 추출물의 항산화 및 항염증 효과)

  • Kim, Dong-Wan;Yun, Hyun-Jeong;Heo, Jun-Young;Kim, Tae-Hoon;Cho, Hyun-Jin;Park, Sun-Dong
    • The Korea Journal of Herbology
    • /
    • v.25 no.4
    • /
    • pp.103-112
    • /
    • 2010
  • Objective : The aim of this study was to determine whether methanol extract of Do-Ki-Tang (DKT) inhibit free radical generation and production of nitrite an index of NO, $PGE_2$, iNOS, COX-2 and pro-inflammatory cytokines such as TNF-${\alpha}$, IL-$1{\beta}$, IL-6 and MCP-1 in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Methods : Cytotoxic activity of extract on RAW 264.7 cells was measured using 5-(3-caroboxymeth-oxyphenyl)-2H-tetra-zolium inner salt (MTS) assay. The expression level of inflammatory response-related proteins was confirmed by western blot. The production of proinflammatory cytokines was measured by ELISA. Results : Our results indicated that DKT scavenged DPPH radical and nitric oxide in vitro. Moreover, DKT significantly inhibited the LPS-induced NO, $PGE_2$ production and iNOS, COX-2 expression accompanied by an attenuation of TNF-${\alpha}$, IL-$1{\beta}$, IL-6 and MCP-1 formation in macrophages. Furthermore, DKT treatment also blocked LPS-induced intracellular ROS production and the activation of NF-${\kappa}B$ and MAPKs. Conclusion : Our data suggest that the anti-inflammatory effect of DKT is mediated through down-modulation of pro-inflammatory mediators and cytokines by blocking the signaling pathways of NF-${\kappa}B$ and MAPKs. These inhibitory effects by DKT represent a potential therapeutic approach to the treatment of inflammatory diseases.

Cytoprotective action of Rubi Fructus by modulation of Reactive Oxygen Species, peroxynitrite and $Ca^{2+}$ (복분자(覆盆子)의 세포내 ROS, $ONOO^-$ 생성 및 $Ca^{2+}$ 증가 억제에 의한 혈관내피세포 보호작용)

  • Lee, Cheol-Woong;Jeong, Ji-Cheon
    • The Journal of Internal Korean Medicine
    • /
    • v.26 no.3
    • /
    • pp.615-625
    • /
    • 2005
  • Objectives : Poststroke depression is a frequent and specific entity that impaires the rehabilliation and functional recovery of patients with hemiplegia. The author evaluated the effect of Banhahubak-tang(Banxiahoupotang) in patients with poststroke depression. Methods : 38 patients suffering from poststroke depression(determined by Diagnostic and Statistical Manual of Mental Disorders, revised. 3rd edition. and Beck Depression Inventory[BDI] cutoff $point{\geqq}10$) in Kyunghee Oriental hospital were randomized into two groups; treatment group(n=19) and control group(n=19). The treatment group was prescribed with Banhahubak-tang(Banxiahoupotang) three times a day fur a week. Control troop was prescribed with other herbal medicines used for stroke Patients three times a day for a week. Patients were evaluated by use of BDI scale, Modified Barthel Index, Depression of Ki score, Yin syndrome score, and Yang syndrome score. Among 38 patients, 24 patients got BDI scores above 21, which is the cut-off score for depression in Korean. The same procedures and assessments described above were applied. Results : Treatment group did not significantly improve compared with control group. Results yielded only slight significance (P=0.086). Especially. patients with poststroke depression as yin syndrome improved more significantly on BDI than those classified as yang syndrome. When BDI cutoff point for depression was defined as being ${\geq}\;21$, treatment group did not significantly improve compared with control group(P=0.114). However, patients with poststroke depression classified as yin syndrome were also significantly improved on BDI than those classified as yang syndrome. Conclusions : This study suggests that Banhahubak-tang(Banxiahoupotang) is significantly effective in patients with poststroke depression classified as yin syndrome.

  • PDF

Can oliceridine (TRV130), an ideal novel µ receptor G protein pathway selective (µ-GPS) modulator, provide analgesia without opioid-related adverse reactions?

  • Ok, Hwoe Gyeong;Kim, Su Young;Lee, Su Jung;Kim, Tae Kyun;Huh, Billy K;Kim, Kyung Hoon
    • The Korean Journal of Pain
    • /
    • v.31 no.2
    • /
    • pp.73-79
    • /
    • 2018
  • All drugs have both favorable therapeutic and untoward adverse effects. Conventional opioid analgesics possess both analgesia and adverse reactions, such as nausea, vomiting, and respiratory depression. The opioid ligand binds to ${\mu}$ opioid receptor and non-selectively activates two intracellular signaling pathways: the G protein pathway induce analgesia, while the ${\beta}$-arrestin pathway is responsible for the opioid-related adverse reactions. An ideal opioid should activate the G protein pathway while deactivating the ${\beta}$-arrestin pathway. Oliceridine (TRV130) has a novel characteristic mechanism on the action of the ${\mu}$ receptor G protein pathway selective (${\mu}$-GPS) modulation. Even though adverse reactions (ADRs) are significantly attenuated, while the analgesic effect is augmented, the some residual ADRs persist. Consequently, a G protein biased ${\mu}$ opioid ligand, oliceridine, improves the therapeutic index owing to increased analgesia with decreased adverse events. This review article provides a brief history, mechanism of action, pharmacokinetics, pharmacodynamics, and ADRs of oliceridine.

Development of a Reading Training Software offering Visual-Auditory Cue for Patients with Motor Speech Disorder (말운동장애인을 위한 시-청각 단서 제공 읽기 훈련 프로그램 개발)

  • Bang, D.H.;Jeon, Y.Y.;Yang, D.G.;Kil, S.K.;Kwon, M.S.;Lee, S.M.
    • Journal of Biomedical Engineering Research
    • /
    • v.29 no.4
    • /
    • pp.307-315
    • /
    • 2008
  • In this paper, we developed a visual-auditory cue software for reading training of motor speech disorder patients. Motor speech disorder patients can use the visual and/or auditory cues for reading training and improving their symptom. The software provides some sentences with visual-auditory cues. Our sentences used for reading training are adequately comprised on modulation training according to a professional advice in speech therapy field. To ameliorate reading skills we developed two algorithms, first one is automatically searching the starting time of speech spoken by patients and the other one is removing auditory-cue from the recorded speech that recorded at the same time. The searching of speech starting time was experimented by 10 sentences per 6 subjects in four kinds of noisy environments thus the results is that $7.042{\pm}8.99[ms]$ error was detected. The experiment of the cancellation algorithm of auditory-cue was executed from 6 subjects with 1 syllable speech. The result takes improved the speech recognition rate $25{\pm}9.547[%]$ between before and after cancellation of auditory-cue in speech. User satisfaction index of the developed program was estimated as good.

The influence of obesity on the effects of spirulina supplementation in the human metabolic response of Korean elderly

  • Park, Hee-Jung;Lee, Hyun-Sook
    • Nutrition Research and Practice
    • /
    • v.10 no.4
    • /
    • pp.418-423
    • /
    • 2016
  • BACKGROUND/OBJECTIVES: Spirulina, a blue-green alga, is widely produced and commercialized as a dietary supplement with bio- and immune-modulatory functions. We have previously shown that spirulina had favorable effects on lipid profiles, immune functions, and antioxidant capacity in healthy Korean elderly. Despite favorable effect of spirulina supplementation, some sub-populations have shown a poor response to supplementation. Obesity is a factor related to poor-response. Therefore, the purpose of this study was to determine the immuno-modulation, antioxidant capacity, and lipid-lowering effect of spirulina in obese and non-obese Korean elderly. SUBJECTS/METHODS: The subjects were 78 elderly aged 60-87 years. In a randomized double blind, placebo-controlled study, subjects were fed either placebo or spirulina daily, at 8 g for 12 weeks. Subjects were divided into the non-obese group and the obese group based on body mass index (BMI) criteria for Asians suggested by the International Obesity Task Force: $BMI<25kg/m^2$ (non-obese) and $BMI{\geq}25kg/m^2$ (obese). RESULTS: In the non-obese group, spirulina supplementation showed a significant lowering effect on plasma concentration of total cholesterol and LDL-cholesterol, a significant increase in interleukin (IL)-2 concentration (P < 0.01) and a significant increment (P < 0.05) in IL-2/IL-6 ratio, and a significant increase in total antioxidant status level and a significant decrease in thiobarbituric acid reactive substances level. However, these effects were not observed in the obese group. CONCLUSION: These results demonstrated that blood lipid lowering and immune and antioxidant improving response for spirulina supplement was affected by obesity in Korean elderly.

Lamotrigine Decreased Hippocampal Damage and Improved Vascular Risk Markers in a Rat Model of Pentylenetetrazole Induced Kindling Seizure

  • Haggag, Basma S.;Hasanin, Amany H.;Raafat, Mona H.;Kawy, Hala S. Abdel
    • The Korean Journal of Physiology and Pharmacology
    • /
    • v.18 no.3
    • /
    • pp.269-278
    • /
    • 2014
  • Various antiepileptic drugs (AEDs) especially enzyme-inducing AEDs might be associated with increased vascular risk, through impairment of the endogenous antioxidative ability which may trigger oxygen-dependent tissue injury. Lamotrigine (LTG) a non-enzyme-inducing AED has scarce information regarding its effects on oxidative stress. The present study aimed to study the possible modulation of vascular risk factors of epileptogenesis by LTG, in a rat model of kindling seizure induced by pentylenetetrazole (PTZ). Four groups of male Wister rats were used; vehicle control group, PTZ group (alternate day PTZ, 30 mg/kg, i.p), LTG/PTZ group (LTG 20 mg/kg/day p.o and alternate day PTZ) and LTG group. The study period was 5 weeks. Lipoproteins and total homocysteine (tHcy), malondialdehyde (MDA) and reduced glutathione (GSH) were measured. Aortic endothelial function study and histopathological examination of the rats' brains, aortas and coronaries were conducted. Serum total cholesterol (TC), triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C), tHcy, MDA, GSH levels were significantly higher in epileptic rats than normal controls rats. A decrease in HDL-cholesterol with high atherosclerotic index was also demonstrated. The administration of LTG improved the PTZ-kindled seizures. It produced a significant decrease in TC, TG and LDL-cholesterol, MDA, aortic GSH and increase in HDL-cholesterol with no significant effect on serum GSH and tHcy levels. LTG improved endothelium-dependent relaxation, decreased hippocampal neurodegenerative changes and atherosclerotic changes of aortas and coronaries. LTG decreased seizures severity, hippocampal damage and improved vascular risk markers in this rat model of kindling seizures.