• 제목/요약/키워드: Il Woo Lee

검색결과 2,898건 처리시간 0.037초

10KW급 지게차량용 스위치드 릴럭턴스 전동기의 형상 설계 (Shape Design of Switched Reluctance Motor for 10kW type Pallect Truck)

  • 이진우;우경일;김홍석;권병일
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.55-57
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    • 2002
  • In industry, A pallet truck is drived mainly by d.c motor, because it use to battery for input power. However, d.c motor has a brush, this is the disadvantage of the d.c motor for a pallet truck. Though a brushless d.c motor has a permanent magnet, it is for low torque. Switched reluctance motors(SRM) have the advantage a high torque/weight ratio, as the large reluctance torque is made by salient poles of both start and rotor, and a high reliability, this paper design the shape of the switched reluctance motor that will replace a d.c motor for A pallet truck. First of all, designed parameter of SRM, outer diameter, diameter of rotor and stock length, from the outputr equation considering electric loading and magnetic loading. Next, design diameter of stator and rotor, depth of slot pole width, air gap as inner size of motor. The design of SRM certify the torque, the efficiency and the output power by a simulation.

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저전압 고전류용 스위치드 릴럭턴스 전동기의 토오크 성능 향상 (The Improvement on the Torque Performance for Low Voltage and High Currant Type of Switched Reluctance Motor)

  • 이진우;권병일;김홍석;우경일
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.64-66
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    • 2002
  • Recently. switched reluctance motor is noticed because it is simple in structure and mechanically strong. SRM has great competitive power, and the study is developed about improving the characteristics of SRM. The current density of winding becomes larger in designing SRM that has the characteristics of the low voltage and high current. Hence the current density of SRM of a vehicle is high. And in order that we drive SRM in variable speed and protect the switching device. the current of SRM is limited by chopping. So it is impossible to obtain object value of output characteristics by limited current. In this paper, the author design the shape of SRM from Miller's output equation, and verify the design of SRM by using FEM. The waveform of chopping current is predicted by simulation and concur with experimental result. And the torque is improved by applying overlap current.

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SRM의 토크리플을 고려한 극호형상의 최적설계 (Optimum Design of Pole arc shape Considering Torque Ripple of SRM)

  • 이진우;우경일;김홍석;권병일
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.30-32
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    • 2001
  • Switched reluctance motors have the advantage a high torque/weight ratio, as the large reluctance torque is made by salient poles of both start and rotor, and a high reliability. On the other hand, the switched reluctance motors have the disadvantage of a large ripple torque which is made by salient poles. So the application for the industrial fields have been limited to special cases. Geometric significant parameters are ${\beta}_r$ and ${\beta}_s$ respectively the rotor and stator pole arc while the significant electric parameters are the angles where the drive switches are turned on and off. It can be simulated that ${\beta}_r$ and ${\beta}_s$ must be chosen in a particular region of the plane (${\beta}_r,\;{\beta}_s$) called the feasible triangle. The aim of this paper is to simulate the minimum of the torque ripple by using finite element method and to determine the best choice of the rotor and stator pole arc.

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오미자(五味子)가 함유된 고제(膏劑)의 제조방법에 따른 기호도와 기능성 비교 (Comparisons of Preferences and Functional Properties of Soft Extracts from Schisandrae Fructus Depending on the Manufacturing Process)

  • 김홍준;김영식;최고야;이금산;박경범;이승호;최영규;정승일;주영승
    • 대한한의학방제학회지
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    • 제19권1호
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    • pp.243-251
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    • 2011
  • Objectives : To further enhance the business value of domestic Schisandrae Fructus, new products composed of modified Gyeongok-go were developed. Their preferences and antioxidant behaviors were compared under different manufacturing processes. Methods : Sensory evaluation was carried out on a 7-point scale by a taste panel. Additionally, the antioxidant activities were investigated in vitro against ABTS[2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)] and DPPH(2,2-diphenyl-1-picrylhydrazyl). Results : The differences among each sample were not statistically significant in sensory evaluation. In contrast, the antioxidant properties of each sample can have up to twice effect distinction at a final concentration of 2.5 mg/ml. Conclusions : Manufacturing methods, while having smaller effect on sensory evaluation, greatly affected the antioxidant properties. As a consequence, the optimum manufacture conditions need to be established using different manufacture conditions and activity search methods.

가미사군자탕(加味四君子湯)이 OVA로 유발된 천식 마우스에 미치는 영향 (Effects of Gamisagunja-tang in an Ovalbumin(OVA)-Induced Allergic Asthma in Mice)

  • 손지우;신조형;이시형
    • 대한한방내과학회지
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    • 제29권2호
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    • pp.456-468
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    • 2008
  • Objective : The purpose of this study was to investigate the effects of Gamisagunja-tang(GS) on the airway hyper-reactivity (AHR), cytokine production and T cell activation during the ovalbumin (OVA)-induced allergic asthma in mice. Materials and Methods : BALB/c mice were sensitized and challenged with 100 mg of OVA and 1 mg of aluminum potassium sulfate intraperitoneally on days 1 and 7. On day 14, mice were challenged on 3 consecutive days with 5% OVA. AHR and bronchoalveolar fluid (BALF), total inflammatory cell count and the production of cytokines were measured. Results : GS significantly suppressed the infiltration of inflammatory cells in the lung tissue and AHR. GS significantly down regulated the production of IL-4, IL-5 and increases of $INF-{\gamma}$ in BALF. GS reduced the population of eosinophils from lung and spleen in OVA-induced allergic asthma. GS reduced the population of $CD4^{+}$ $CD69^{+}$ $CD25^{-}$ T cells in OVA-induced allergic asthma Conclusion : These results suggest that GS may inhibit the production of IL-4, IL-5 and infiltration of eosinophils and be beneficial oriental medicine for allergic asthma.

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Anti-inflammatory effects of porcine placenta in forced swimming tested fatigue mice and RAW264.7 cells

  • Nam, Sun-Young;Kang, Sang Woo;Kim, Jongbae;Lee, Won Kyung
    • 셀메드
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    • 제7권4호
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    • pp.20.1-20.6
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    • 2017
  • Inflammation has been linked to various diseases. Especially, fatigue is a frequent symptom in several inflammatory disorders. Therefore, blocking inflammatory process is effective in fatigue. We investigated whether Denmark porcine placenta (DPP) alleviates fatigue by inhibiting inflammatory reaction using forced swimming test (FST) animal model and RAW264.7 cells. In FST-induced fatigue animal model, the mice which received the DPP for 21 days showed decreases of interleukin $(IL)-1{\beta}$ and IL-6 serum levels. Furthermore, our data revealed that lipopolysaccharide (LPS)-induced $IL-1{\beta}$, IL-6, and tumor necrosis $factor-{\alpha}$ secretion were markedly inhibited by DPP in RAW264.7 cells without inducing cytotoxicity. LPS-enhanced nitric oxide secretion and inducible nitric oxide synthase expression were inhibited by DPP. The present study also figured out that these effects of DPP were mediated by blockade of caspase-1 and nuclear $factor-{\kappa}B$ activation. Taken together, our results indicated that DPP could be alleviating fatigue as candidate of anti-inflammatory agent.

Identification of IY81149 and Its Metabolites in the Rat Plasma Using the On-Line HPLC/ESI Mass Spectrometry

  • Myung, Seung-Woon;Min, Hye-Ki;Jin, Chang-Bae;Kim, Myung-Soo;Lee, Seung-Mok;Chung, Gi-Ju;Park, Seong-Jun;Kim, Dong-Yeon;Cho, Hyun-Woo
    • Archives of Pharmacal Research
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    • 제22권2호
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    • pp.189-193
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    • 1999
  • Reversed-phase high-performance liquid chromatography/mass spectrometry (HPLC/MS) with an eletcrospray ionization (ESI) interface was applied to the identification of metabolites of IY81149 in the rat plasma. Fragments obtained using collision-induced dissociation (CID) in both positive and negative modes were utilized to elucidate the structure of metabolites. The eluent from the conventional HPLC column was split and directly introduced into an ESI-mass spectrometer for the identification of the structures. the CID technique allowed the sensitive identification of sulfonyl-IY81149 and hydroxy-IY81149 from the rat plasma.

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In Vitro Anti-Inflammatory and Skin Protective Effects of Codium fragile Extract on Macrophages and Human Keratinocytes in Atopic Dermatitis

  • A-yeong Jang;JeongUn Choi;Weerawan Rod-in;Ki Young Choi;Dae-Hee Lee;Woo Jung Park
    • Journal of Microbiology and Biotechnology
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    • 제34권4호
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    • pp.940-948
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    • 2024
  • Codium fragile has been traditionally used in oriental medicine to treat enterobiasis, dropsy, and dysuria, and it has been shown to possess many biological properties. Atopic dermatitis (AD) is one of the types of skin inflammation and barrier disruption, which leads to chronic inflammatory skin diseases. In the current investigation, the protective effects of C. fragile extract (CFE) on anti-inflammation and skin barrier improvement were investigated. In LPS-stimulated RAW 264.7 cells, nitric oxide generation and the expression levels of interleukin (IL)-1β, IL-4, IL-6, iNOS, COX-2, and tumor necrosis factor-alpha (TNF)-α were reduced by CFE. CFE also inhibited the phosphorylation of NF-κB-p65, ERK, p-38, and JNK. Additionally, CFE showed inhibitory activity on TSLP and IL-4 expression in HaCaT cells stimulated with TNF-α/interferon- gamma (IFN-γ). Enhanced expression of factors related to skin barrier function, FLG, IVL, and LOR, was confirmed. These findings implied that CFE may be used as a therapeutic agent against AD due to its skin barrier-strengthening and anti-inflammatory activities, which are derived from natural marine products.

Temporal Expression of Interleukin-1${\beta}$ in the Dorsal Root Ganglion in a Rat Model of Lumbar Disc Herniation

  • Kim, Su-Jeong;Gu, Hee-Jin;Cho, Yun-Woo;Park, Hea-Woon;Lee, Joon-Ha;Hwang, Se-Jin;Ahn, Sang-Ho
    • The Journal of Korean Physical Therapy
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    • 제22권3호
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    • pp.93-98
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    • 2010
  • Purpose: To investigate temporal changes in IL-1${\beta}$ mRNA expression in spinal dorsal horn (DH) and dorsal root ganglion (DRG) in a rat lumbar disc herniation (LDH) model. Methods: Autologous nucleus pulposus, harvested from the tail disc between the second and third coccygeal vertebrae (Co2-3), was implanted next to the left L5 nerve root just proximal to the DRG after partial laminectomy. IL-1${\beta}$ mRNA expression was investigated in DRG and DH in our LDH model. Real-time PCR assays were done using a 7500 Real Time PCR system (Applied Biosystems, USA). Results: Expression of IL-1${\beta}$ in DRG and DH was observed for 30 days postoperatively. Expression of IL-1${\beta}$ mRNA in the ipsilateral DRG of the LDH group gradually increased from 5 to 30 days after surgery. The amount of IL-1${\beta}$ in the contralateral DRG peaked 10 days after surgery and then gradually decreased. However, there was no difference in IL-1${\beta}$ mRNA expression in spinal DH between the LDH group and the sham-operated group. Conclusion: Long-term expression of IL-1${\beta}$ in the LDH model may worsen the chronic pain state. Future studies on inhibition of IL-1${\beta}$ expression in the LDH model will be needed to develop selective treatment strategies for patients with LDH.

만병초와 구상나무 추출물의 RBL-2H3 세포 탈과립, 싸이토카인 유전자 발현에 미치는 영향 (Inhibitory Effect of Extracts from Rhododendron Brachycarpum and Abies Koreana E.H. Wilson on Degranulation and Cytokine Expression in RBL-2H3 Cells)

  • 정의만;김재우;박미진;이성숙;최돈하;이정복;정의배
    • Journal of the Korean Wood Science and Technology
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    • 제41권6호
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    • pp.551-558
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    • 2013
  • 본 연구는 만병초와 구상나무 추출물의 항알러지 효과에 대해 조사하였다. 비만세포 RBL-2H3에 concanavalin A (Con A)를 처리하여 면역반응을 유도한 후 만병초와 구상나무 추출물을 농도별로 처리하여 real-time PCR을 이용하여 IL-4, IL-13의 mRNA 발현량을 확인하였다. 또한 ${\beta}$-hexosaminidase 분비를 측정하여 탈과립 유도효과를 평가하였다. IL-4의 발현은 만병초 $10^{-7}$, $10^{-5}$, $10^{-3}%$ 농도와 구상나무의 모든 농도에서 유의성 있게 감소하였으며, IL-13의 발현은 만병초와 구상나무 모든 농도에서 유의성 있게 감소되었다. 만병초 추출물과 구상나무 추출물의 $10^{-5}$, $10^{-3}%$ 농도에서는 ${\beta}$-hexosaminidase 분비가 유의성 있게 감소하였다. 이러한 결과를 통해 만병초와 구상나무 추출물이 면역반응 표적유전자의 발현을 감소시키고 면역반응에 의해 유도되는 탈과립유도 효과도 감소시킴을 확인할 수 있었다. 이는 만병초와 구상나무 추출물이 항알러지 효과가 있음을 제시하는 결과이다.