• Title/Summary/Keyword: SM Model

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Design of Closed-Loop Feedback-based SM-MF Controller for Power System Stabilizer : Part 1 (전력계통안정기를 위한 폐-루우프 피이드백에 기준한 SM-MF 제어기 설계 : Part 1)

  • Lee, Sang-Seung;Park, Jong-Keun
    • Proceedings of the KIEE Conference
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    • 1997.07c
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    • pp.1162-1164
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    • 1997
  • This paper presents a power system stabilizer(PSS) using sliding mode-model following(SM-MF) including closed-loop f:edback(CLF) and compares the SM-MF PSS without CLF with that including CLF. The aim of this SM-MF PSS including CLF is to damp the low-frequency oscillation by using CLF and then is to obtain asymptotic tracking error between the reference model state and the plant state.

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Design of Discrete-Mode CLF-based SM-MF Controller for Power System Stabilizer : Part 2 (전력계통안정기를 위한 이산-모드 폐루우프 피이드백에 기준한 SM-MF 제어기 설계 : Part2)

  • Lee, Sang-Seung;Park, Jong-Keun
    • Proceedings of the KIEE Conference
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    • 1997.07c
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    • pp.1165-1167
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    • 1997
  • In this paper, the continuous sliding mode-model following(SM-MF) power system stabilizer(PSS) including closed-loop feedback(CLF) is extended to discrete-time sliding mode-model following(DSM-MF) PSS including CLF.

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Design of Full-Order Observer-based SM-MF Controller including CLF for Power System Stabilizer : Part 4 (전력계통안정기를 위한 폐-루우프 피이드백을 가진 전-차수 관측기에 기준한 SM-MF 제어기 설계 : Part4)

  • Lee, Sang-Seung;Park, Jong-Keun
    • Proceedings of the KIEE Conference
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    • 1997.07c
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    • pp.1171-1173
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    • 1997
  • This paper presents the sliding mode observer-model following(SMO-MF) power system stabilizer(PSS) for unmeasurable plant state variables. This SMO-MF PSS can be obtained by combining the sliding mode-model following(SM-MF) including closed-loop feedback(CLF) with the linear foil-order observer(LFOO).

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Inhibitory Effects of Dansam and Dansam-eum on Reflux Esophagitis and Migration of Cancer Cells (단삼과 단삼음의 역류성 식도염 억제 효과 및 암세포 이주 억제 효과)

  • Jung-yeon Kwon;Sang-hyun An;Kyung-hwan Kong
    • The Journal of Internal Korean Medicine
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    • v.43 no.6
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    • pp.1162-1185
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    • 2022
  • Purpose: We examined the effects of Dansam (Salvia miltiorrhiza Bunge, SM) and Dansam-eum (DSE) on gastroesophageal reflux disease (GERD) and reflux esophagitis by comparing the inhibitory effects of SM and DSE with the representative treatment of PPI Omeprazole to determine if the effects of the prescription DSE based on Korean medicine are better than those of a single-use of SM. Methods: We performed experiments using both animal models and cancer cells. Results: Comparison of SM and DSE with PPI in the animal model tests revealed that the effects were superior for SM and DSE than for PPI in all categories (8-OHdG, p-IκB, PAR2, COX-1, cathelicidin, p-JNK, Caspase 3, ATP6V1B1, GRPR, serotonin, and NPY). In three categories (COX-1, serotonin, and NPY), SM and DSE showed superior results over the Controls. In the animal model tests, DSE was superior to SM in all categories except for serotonin. The anti-cancer effects observed in cancer cell tests revealed that SM and DSE had meaningful results in terms of cytotoxicity and cell movement rate, as well as in cancer cell apoptosis. Conclusions: We confirmed that SM and DSE can have effects on reflux esophagitis through the regulation of oxidative stress, inflammation, mucosal protection, apoptosis, proton pumping, and the enteroendocrine system in the stomach and esophagus. We also confirmed that SM and DSE have superior effects to those of PPI on all aspects, especially gastric mucosa protection and enteroendocrine system control. We also confirmed that SM and DSE have anti-cancer effects. Above all, we confirmed that DSE has superior effects on almost all aspects compared to using SM alone.

Finite element analysis for surface hardening of SM45C round bar by diode laser (다이오드 레이저를 이용한 SM45C 환봉 표면경화 열처리의 유한요소해석)

  • Cho, Hae-Yong;Kim, Kwan-Woo;Lee, Jae-Hoon;Suh, Jeong;Kim, Jong-Do
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.683-688
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    • 2007
  • Surface heat treatment of SM45C round bar by diode laser was simulated to find it's condition by using commercial finite element code MARC. Due to axisymmetric geometry, a quarter of model for SM45C round bar was considered and user subroutines were applied to boundary condition for the heat transfer. Material properties such as conductivity, specific heat and mass density were given as a function of temperature. Rotation speed of round bar and feed rate of beam were considered to design heat source model. Shape parameter values of heat source were determined by beam profile. As results, Three dimensional heat source model for diode laser beam conditions of surface hardening has been designed by the comparison between the finite element analysis results and experimental data on SM45C round bar. Diode laser surface hardening for SM45C round bar was successfully simulated and it should be useful to determine optimal heat treatment condition.

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Electrochemical Impedance Spectroscopy and Cyclic Voltammetry Methods for Monitoring SmCl3 Concentration in Molten Eutectic LiCl-KCl

  • Shaltry, Michael R.;Allahar, Kerry N.;Butt, Darryl P.;Simpson, Michael F.;Phongikaroon, Supathorn
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.18 no.1
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    • pp.1-18
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    • 2020
  • Molten salt solutions consisting of eutectic LiCl-KCl and concentrations of samarium chloride (0.5 to 3.0 wt%) at 500℃ were analyzed using both cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The CV technique gave the average diffusion coefficient for Sm3+ over the concentration range. Equipped with Sm3+ diffusion coefficient, the Randles-Sevcik equation predicted Sm3+ concentration values that agree with the given experimental values. From CV measurements; the anodic, cathodic, and half-peak potentials were identified and subsequently used as a parameter to acquire EIS spectra. A six-element Voigt model was used to model the EIS data in terms of resistance-time constant pairs. The lowest resistances were observed at the half-peak potential with the associated resistance-time constant pairs characterizing the reversible reaction between Sm3+ and Sm2+. By extrapolation, the Voigt model estimated the polarization resistance and established a polarization resistance-concentration relationship.

The Grain Growth Mechanism of Sm123 Superconductor in Melt-Textured Growth Method (용융-응고법으로 제조된 Sm123 초전도체의 결정성장 기구)

  • 한상철;성태현;한영희;이준성;김상준
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 2001.02a
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    • pp.9-12
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    • 2001
  • The microstructure evolution and the peritectic solidification of Sm$Ba_{2}$$Cu_{3}$ $O_{7-\delta}$ superconducting materials during the isothermal annealing were studied over the temperature range 1030-$1060^{\circ}C$ The faceted growth of the peritectic phase and its dependence upon Sm-diffusion in the liquid phase are discussed. A growth model is proposed to explain the growth shape of Sm123 crystals.

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Formulation of Dynamic Cyclic Plasticity Model for SM490 and Its Application to 3-Dimensional Elastic-Plastic Finite Element Analysis (SM490강재의 동적반복소성모델의 정식화 및 3차원 탄소성 유한요소해석의 적용)

  • Chang, Kyong Ho;Jang, Gab Chul
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.3A
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    • pp.465-471
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    • 2006
  • To describe hysteretic behavior of steel structures under dynamic loading such as earthquake, the dynamic cyclic plasticity model considering stress-strain relationship and characteristics of used steel materials under static-dynamic deforming is required. In this paper, mechanical characteristics and stress-strain relationship of SM490 was clarified by carrying out static-dynamic monotonic and cyclic loading test. A dynamic cyclic plasticity model of SM490 was proposed based on the test results and applied 3-dimensional finite element analysis using finite deformation theory. An analytical method developed by the authors was verified validity and accuracy by comparing both analysis and test results. The comparison result shows that the analytical method developed by the authors can predict static-dynamic hysteretic behavior of steel structures with accuracy.

Magnetic hysteresis loops of the polycrystalline superconductor ${SmBa_2}{Cu_3}{O_x}$ (다결정 초전도체 ${SmBa_2}{Cu_3}{O_x}$의 자기 이력곡선)

  • Lee J. H;Jung M. S;Lee B. Y;Kim G. C;Kim Y. C;Jeong D. Y
    • Progress in Superconductivity
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    • v.6 no.1
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    • pp.84-88
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    • 2004
  • The polycrystalline superconductor $SmBa_2$$Cu_3$$O_{x}$ is fabricated, and intergranular magnetic properties are investigated using the critical state model, from which some useful parameters such as the critical current density and the intergranular volume fraction are obtained. The curve fitting for M-H hysteresis loop shows that the intergranular critical current density of $SmBa_2$$Cu_3$$O_{x}$ / decreases in the form of ($1-T/T_{c}$ )$^{1.5}$ . The intergranular volume fraction is influenced by granular morphology. From SEM image, the grains of $SmBa_2$$Cu_3$$O_{x}$ are found to be randomly shaped. This mean:; that the intergranular volume fraction of $SmBa_2$$Cu_3$$O_{x}$ / should be smaller than those of superconductors, of which grains are plate-shaped such as Tl-based superconductor.

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Effect of Powder Size on the Rheological Characteristics of Sm-Co Type Compound for Powder Injection Molding (사출성형용 컴파운드의 유연학적 특성에 미치는 SH-CO 계 분말의 입도 영향)

  • 정우상;김윤배;정원용
    • Journal of the Korean Magnetics Society
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    • v.11 no.4
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    • pp.157-162
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    • 2001
  • Rheological characteristics of Sm-Co type plastic magnet compound for powder injection molding process were investigated with the variation of the magnetic powder size, their relative contents and volume fraction using the mixture of fine and coarse powder. Shear viscosity of Sm-Co type compound was decreased with increasing the size of coarse powder due to the increase of powder packing density. However, the smaller the average size of fine powder resulted in the higher viscosity of compound due to the increase of agglomeration force. In case of mechanically milled Sm-Co type powder, the viscosity of compound with the mixture of coarse powder of 125∼75 ㎛ and fine powder of average size of 4.9 ㎛ greatly depends on their relative contents and shows a minimum value at the 60 % coarse powder fraction. This means that the compound shows a maximum packing density at the 60% coarse powder fraction. Compound viscosities satisfied well the rheological model with the volume fraction of magnetic powder, and maximum volume fraction of magnetic powder in Sm-Co type compound for powder injection molding was about 66%.

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