• Title/Summary/Keyword: ${\pi}$-type

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Studies on HG Type of Heterodera glycines in Korea (국내 콩 씨스트선충의 HG type 분석)

  • Kim, Donggeun;Choi, Insoo;Han, Wonyoung;Ryu, Younghyun;Kim, Myungsik;Bae, Changhwan
    • Research in Plant Disease
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    • v.19 no.1
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    • pp.31-35
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    • 2013
  • Thirteen soybean cyst nematode (SCN) (Heterodera glycines) populations collected in Korea were examined in their HG type by their reproductivity on 7 Plant Introduction indicators for the identification of HG type. Six HG types were identified, HG type 0, 2, 5, 2.5, 1.2.7, and 2.5.7. HG type 2.5 was the most frequent (4 samples, 30.8%), followed by HG type 2.5.7 (3 samples, 23.0%). About 76.9% of SCN populations were reproduced on PI 88788, followed by PI 209332 (61.5%), PI 548316 ('Cloud') (30.8%), and PI 548402 ('Peking') (7.7%). No population could reproduce on PI 90763, PI 437654, thus, they could be used for resistant source for developing SCN resistant soybean in Korea.

A Comparison of DC-DC Buck Converter Controller (DC-DC 벅 컨버터 제어기 비교)

  • Kang, Min Gu
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.7
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    • pp.281-285
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    • 2013
  • Transfer function of Buk DC-DC converter is derived using Laplace transformed LC filter. Using root locus and simulation waveform, this paper shows that Type2 controller proposed in reference has poor performance. Using root locus PI controller has designed. Using operational amp, PI controller is realized. Properly operated Type2 controller is proposed and proved using simulation result.

Fuzzy Precompensated PI Controller for Inverter-type Air-Conditioner (인버터형 에어컨의 온도 제어를 위한 퍼지 전단 보상된 PI 제어기)

  • 장보인;이선우;정문종;유장현;김상권;박윤서
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1997.10a
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    • pp.185-188
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    • 1997
  • In this paper, a fuzzy precompensated PI controller for inverter-type air-conditioner is presented. The presented control scheme is composed of a fuzzy logic precompensator and PI controller, in which two control schemes are serially connected. The rules of the fuzzy precompensator is designed to improve the performance by considering the nonlinear characteristics of a temperature dynamics. The experimental results show the effectiveness of the proposed controller.

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PSO-Based Nonlinear PI-type Controller Design for Boost Converter

  • Seo, Sang-Wha;Kim, Yong;Choi, Han Ho
    • Journal of Electrical Engineering and Technology
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    • v.13 no.1
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    • pp.211-219
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    • 2018
  • This paper designs a nonlinear PI-type controller for the robust control of a boost DC-DC converter using a particle swarm optimization (PSO) algorithm. Based on the common knowledge that the transient responses can be improved if the P and I gains increase when the transient error is big, a nonlinear PI-type control design method is developed. A design procedure to autotune the nonlinear P and I gains is given based on a PSO algorithm. The proposed nonlinear PI-type controller is implemented in real time on a Texas Instruments TMS320F28335 floating-point DSP. Simulation and experimental results are given to demonstrate the effectiveness and practicality of the proposed method.

NEW BROWDER AND WEYL TYPE THEOREMS

  • Berkani, Mohammed;Kachad, Mohammed
    • Bulletin of the Korean Mathematical Society
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    • v.52 no.2
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    • pp.439-452
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    • 2015
  • In this paper we introduce and study the new properties ($W_{\Pi}$), ($UW_{{\Pi}_a}$), ($UW_E$) and ($UW_{\Pi}$). The main goal of this paper is to study relationship between these new properties and other Weyl type theorems. Moreover, we reconsider several earlier results obtained respectively in [11], [18], [14], [1] and [13] for which we give stronger versions.

The Design of a Sliding Mode Controller with Fuzzy PI-type Reaching Law (퍼지 PI 형 도달법칙을 가지는 가변 구조 제어기의 설계)

  • 이재호;조기원;채창현;이상재
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 2001.06a
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    • pp.105-108
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    • 2001
  • In this paper, we proposed a variable structure controller with fuzzy PI-쇼pe reaching law. we fuzzified as inputs to fuzzy system Rf(representative point's orthogonal distance(rd) to switching surface and RP's distance(r) to the origin of the 2-dimensional space whose coordinates are the error and the error rate. The increments of the coefficients $k_{p}$ and $k_{i}$, of the reaching law are calculated appropriate by the simplified Mamdanl inference. The proposed fuzzy PI-type reaching law makes it reduce the chattering and has no need to tune the PI parameters of reaching law. The effectiveness of the proposed fuzzy PI-type reaching law is shown by the simulation results of the control of a Ball-balance System.

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EO Characteristic in the Advanced Vertical Alignment (VA)- π Cell a Homeotropic Blended Polymer (수직 복합폴리머 표면을 이용한 Advanced VA-π cell의 전기 광학 특성)

  • 황정연;이경준;조용민;서대식
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.9
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    • pp.826-832
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    • 2003
  • Blending effects for generating a pretilt angle in nematic liquid crystal (NLC) with negative dielectric anisotropy on the blended polyimide (PI) of homeotropic and homogeneous alignment surface were studied. Also, we investigated the EO performances for the advanced VA- $\pi$ cell using this homeotropic blended PI surface. A many decrease of tilt angle on the polymer surface to blend homeotropic PI and homogeneous PI with side chain type was measured, and the tilt angle decreased as blended ratio and rubbing strength increase. However, a small decrease of tilt angle on the polymer surface to blend homeotropic PI and homogeneous PI with main chain type was measured. The blended effects for generating a pretilt angle were clearly observed, and the many decrease of tilt angle can be achieved by using the blended PI surface. The electro-optical (EO) characteristics using the advanced VA- $\pi$ cell using the homeotropic blended PI surface than that of conventional VA cell can be improved. We suggest that the developed advanced VA-$\pi$ cell on a homeotropic blended PI surface is a promising technique for the achievement of a fast response time, and a high contrast ratio.

Role of p53-dependent PI3K in Radioresistance of Colon Cancer Cells (대장암 세포의 방사선저항성에 대한 p53의존성 PI3K의 역할)

  • Lee, Heui-Kwan;Kim, Jong-Suk;Kwon, Hyoung-Cheol
    • Journal of Food Hygiene and Safety
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    • v.25 no.3
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    • pp.258-262
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    • 2010
  • Radiotherapy is one of the major therapies for cancer treatment. p53 acts as a central mediator of the cellular response to stressful stimuli, such as radiation. Recently it has been known that activation of the phosphatidylinositol-3-kinase (PI3K) pathway is associated with radioresistance. In this study, we investigated whether X-irradiation up-regulates PI3K in a p53-dependent manner in human colon cancer cells. In order to study this phenomenon, we have treated p53-wild type and p53-mutant type HCT116 cells with X-ray. Treatment of wild type HCT116 cells with 8 Gy resulted in a marked increase in PI3K (p85), which paralleled an increase in PTEN, a counterpart of PI3K. However, these effects of X-rays in the p53-mutant cells were not observed. These results suggest that the X-irradiation-induced up-regulation of PI3K/PTEN pathway is p53-dependent.

Liquid Crystal Alignment Effect of Flexible Liquid Crystal Display with Low Temperature Alignment Layer (저온배향막을 이용한 Flexible 액정디스플레이의 액정 배향 효과)

  • Hwang, Jeoung-Yeon;Nam, Ki-Hyung;Kim, Jong-Hwan;Kim, Kang-Woo;Seo, Dae-Shik;Suh, Dong-Hack
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07a
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    • pp.199-202
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    • 2003
  • We have investigated the generation of pretilt angle for a nematic liquid crystal (NLC) alignment with rubbing alignment method on two kinds of polyimide (PI) surfaces using thin plastic substrates. The generated NLC pretilt angles on the pre-imidized type PI are about $3.8^{\circ}$ by the rubbing alignment method with thin plastic substrates, However, the pretilt angle measured at about $2.8^{\circ}$ lower on the polyamic acid type PI than by pre-imidized type PI surface with thin polymer film. The tilt angle increases as increasing curring temperature for making polyimide layer using polyamic acid type PI. It was concluded that pretilt angle in the polyimide surface is attributable to the increasing of imide rato.

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The Effect of ${\pi}$ Bonds on the Calculated Dipole Moments for Tetrahedral and Square Planar [M(Ⅱ)$O_2S_2$] Type Complexes [M(II) = Co(II), Ni(II), Cu(II) and Zn(II)] (사면체 및 사각형 [M(II)$O_2S_2$]형태 착물의 쌍극자 모멘트에 대한 ${\pi}$결합의 영향 [M(II) = Co(II), Ni(II), Cu(II) 및 Zn])

  • Sangwoon Ahn;Jin Ha Park;Chang Jin Choi
    • Journal of the Korean Chemical Society
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    • v.26 no.5
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    • pp.265-273
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    • 1982
  • The effect of ${\pi}$ bonds on the calculated dipole moments for square planar and tetrahedral [M(II)$O_2S_2$]] type complexes has been investigated by two different approaches. One is the approximate molecular orbital method based on the assumption that the mixing coefficient CM of the valence basis sets for the central metal ion and the appropriate ligand orbitals is equal for all ${\sigma}$ and ${\pi}$ bonding molecular orbitals. The other is the more refined calculation based on the semiempirical LCAO-MO method. If ${\sigma}$ bonds only are assumed to be formed, the calculated dipole moments for square planar and tetrahedral complexes are lower than those of the experimental values. If the contribution of ${\pi}$ bonds to the calculated dipole moments are fully considered, the calculated dipole moments for both square planar and tetrahedral [M(II)$O_2S_2$]] type complexes are higher than the experimental values. However if ${\pi}$ bonds are assumed to be delocalzed, the calculated dipole moments for tetrahedral [M(II$O_2S_2$]] type complexes fall in the range of the experimental values, but those for square planar complexes deviate from the experimental values. These results suggest that [M(II)$O_2S_2$]] type complexes may have the tetrahedral structure in inert solvent solution. This structure is in agreement with the experimental one. The calculated dipole moments for tetrahedral [M(II)$O_2S_2$]] type complexes indicate that the contribution of ${\pi}$ bonds to the calculated dipole moments may not be neglected.

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