• Title/Summary/Keyword: IHN

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A Verification of the Numerical Energy Conservation Property of the FD-TD(Finite Difference-Time Domain) Method by Using a Plane Wave Analysis (평면파 해석을 이용한 시간영역-유한차분법의 수치적 에너지 보존성질의 증명)

  • Ihn-Seok Kim
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.7 no.4
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    • pp.320-327
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    • 1996
  • This paper presents that the lossy or amplification property of the Finite Difference-Time Domain(FD-TD) method based on the leap-frog scheme is theoretically verified by using a plane wave analysis. The basic algorithm of the FD-TD method is introduced in order to help understanding the analysis procedure. Since our analysis is formulated by the Von Neumann's approach, the stability inequality is also produced as an another outcome.

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Pharmacological Activities of Leaves of Hedera rhombea Bean (상춘등잎의 약리작용)

  • Lee, Ihn-Rhan;Kim, Jung-Sun;Lee, Sun-Hee
    • Korean Journal of Pharmacognosy
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    • v.23 no.1
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    • pp.34-42
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    • 1992
  • The analgesic, anticonvulsant and anti-inflammatory actives of leaves of Hedera rhombea Bean were evaluated. The methanol and butanol fractions showed considerable analgesic activity, but no anticonvulsant activities. Anti-inflammatory activity was found in the methanol, butanol and ether fractions by carrageenin induced edema test.

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Effect of Extracts from the Codonopsis pilosulae Radix on P388 Lymphocytic Leukemia in vivo (만삼(蔓蔘)엑기스가 임파성백혈병 P388에 미치는 영향)

  • Lee, Ihn-Rhan
    • Korean Journal of Pharmacognosy
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    • v.11 no.2
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    • pp.104-107
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    • 1980
  • Mansam, the root of Codonopsis pilosula (Campanulaceae) has a action on blood metabolism. It has been known to possess anti leukemic effect by increasing of red blood cell, at same time, by decreasing white blood cell, with this connection, present study is aimed to clarify such potential anti leukenic effect by testing ethanol extract and chloroform extract against murine tumor model, lymphocytic leukemia P388. The data indicated that these extracts appeared to be inactive against this tumor line.

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Sterols and Steryl glycosides from the Root of Codonopsis pilosula (만삼의 Sterol 및 Steryl glycoside에 관한연구)

  • Lee, Ihn-Rhan;Kim, Young-Hee;Park, Sung-Bae
    • Korean Journal of Pharmacognosy
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    • v.13 no.3
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    • pp.129-131
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    • 1982
  • From the roots of Codonopsis pilosula (Franch.) Nannfeldt (Campanulaceae), ${\alpha}$-spinasterol, mp $165{\sim}7^{\circ}$ and alpha-spinasteryl D-glucoside, mp $283{\sim}5^{\circ}$, were isolated and identified on the basis of chemical and spectral data. Spectral data showed that $\Delta^7-stigmasterol$ and its glucoside were contained as minor components.

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Saturation Compensation of a DC Motor System Using Neural Networks

  • Jang, Jun-Oh;Ahn, Ihn-Seok
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.5 no.2
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    • pp.169-174
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    • 2005
  • A neural networks (NN) saturation compensation scheme for DC motor systems is presented. The scheme that leads to stability, command following and disturbance rejection is rigorously proved. On-line weights tuning law, the overall closed loop performance and the boundness of the NN weights are derived and guaranteed based on Lyapunov approach. The simulation and experimental results show that the proposed scheme effectively compensate for saturation nonlinearity in the presence of system uncertainty.