• Title/Summary/Keyword: Resonance stabilization

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Theoretical Studies of Diels-Alder Reaction (Part Ⅰ). Correlation between the Stabilization Energies of the Transition States and the Resonance Energies of the Isolated Systems (Diels-Alder 反應에 對한 理論的 硏究 (第1報) 遷移狀態의 安定化 에너지와 孤立分子의 共鳴 에너지間의 相關關係)

  • Hong, Yeong-Suek;Byung Kak Park
    • Journal of the Korean Chemical Society
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    • v.16 no.1
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    • pp.33-39
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    • 1972
  • The stabilization energies by interconjugations at the transition states in various Diels-Alder reactions were calculated. It has been found that the stabilization energies are inversely proportional to resonance energies of isolated molecules of polyene and heterocyclic system before reactions. It has been noted that the resonance energies of dienes are smaller than those of dienophiles in two different molecules. Therefore, the possibility of charge-transfer from dienes to dienophiles is hinted.

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A Study on the Stabilization Scheme of Optical Source for Precision Measurement (정밀측정을 위한 안정된 광원에 관한 연구)

  • 김지대;서호성;이동주
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2003.04a
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    • pp.265-271
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    • 2003
  • This study is for the stable optical source in order to get the precision measurement, which contributes to help the laser frequency and the output to be settled. The laser optical frequency is changed by the length of resonance cavity. The length variation of the laser resonance amplitude is affected by the thermal expansion of that system. So, we try not only to adjust the temperature of the laser tube using the heater for fine length of resonance cavity, but also to maintain the fixed temperature of the resonance cavity for outputting the safe laser optical frequency. Therefore, we must take materials with the thermal expansion of the supporting system, which is closer to it of the laser resonance cavity. Using the materials, we can promote to stabilize the temperature of it. In advance, we also plan to get the settlement of the laser frequency and the output in the long km, optimizing and stabilizing the system.

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An Adaptive Digital Notch Filter for Stabilization of Single-Phase Grid-Connected Inverters With LCL Filter (LCL 필터가 결합된 단상 계통연계형 인버터의 안정화를 위한 적응형 디지털 노치 필터)

  • Heo, Jin-Yong;Kim, Hak-Soo;Nho, Eui-Cheol
    • The Transactions of the Korean Institute of Power Electronics
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    • v.26 no.5
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    • pp.307-314
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    • 2021
  • Even though the LCL filters have superior harmonic attenuation ability to L filters, stability has always been an issue. The system could be unstable because of the resonance phenomenon, especially when digital controller is used. Adding a notch filter to the compensator is one approach to solve the problem. Resonance phenomenon can be inhibited by aligning notch frequency to system resonance frequency. However, resonance frequency variation can be obtained because the actual system has a nonstationary characteristic. Therefore, the system could be unstable, where the system parameters are changed when the conventional notch filter is used. An adaptive digital notch filter that stabilizes the system even system parameters are changed. Simulation and experiment results are provided to verify the validity of the proposed adaptive filter.

Vibration suppression control based on model reference approach for LOS stabilization gimbal (모델 참조 제어 방법에 의한 시선 안정화 짐발의 공진 제어)

  • Ma, Jin-Suk;Kang, Myong-Sook;Kwon, Woo-Hyen
    • Journal of Institute of Control, Robotics and Systems
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    • v.5 no.5
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    • pp.540-549
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    • 1999
  • In this paper, the vibration suppression scheme based on a model referece approach is proposed. The vibration results from the coupling of the system and its frequency are given by the mechanical factors. In the proposed scheme, a low frequency vibration mode is transferred to high one. And also its damping ratio can be increased without any mechanical redesign. Therefore, bandwidth and open loop gain of the plant are increased and the performance of the system can be improved. This paper analyzes the proposed vibration suppression scheme, which is compared with the conventional control scheme for mechanical resonance suppression. For proving the realistic validity, we apply the proposed scheme to a LOS(Line Of Sight) stabilization system which has vibration effect. Finally, the proposed scheme is verified through simulations and experiments.

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Biophysical effect of lipid modification at palmitoylation site on the structure of Caveolin 3

  • Ma, Yu-Bin;Kang, Dong-Hoon;Kim, Myeongkyu;Kim, Ji-Hun
    • Journal of the Korean Magnetic Resonance Society
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    • v.23 no.3
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    • pp.67-72
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    • 2019
  • Caveolae are small plasma membrane invaginations that play many roles in signal transduction, endocytosis, mechanoprotection, lipid metabolism. The most important protein in caveolae is the integral membrane protein, caveolin, which is divided into three families such as caveolin 1, caveolin 2, and caveolin 3. Caveolin 1 and 3 are known to incorporate palmitate through linkage to three cysteine residues. Regulation of the protein palmitoylation cycle is important for the cellular processes such as intracellular localization of the target protein, membrane association, conformation, protein-protein interaction, and activity. However, the detailed aspect of individual palmitoylation has not been studied. In the present work, the role of each lipid modification at three cysteines was studied by NMR. Our results suggest that each lipid modification at the natively palmitoylation site has its own roles. For example, lipidations to C106 and C129 are play a role in structural stabilization, however, interestingly, lipid modification to C116 interrupts the structural stabilization.

Swing-Up Control of a Two-Link Pendulum with One Actuator (단일 구동부를 갖는 2축 회전형 진자의 스윙업 제어)

  • Yang, Dong-Hoon;Yoo, Ki-Jeong;Hong, Suk-Kyo
    • Proceedings of the KIEE Conference
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    • 2001.07d
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    • pp.2467-2469
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    • 2001
  • A strategy for the swing-up and stabilization control method for a two-links rotational pendulum according to states of each link of the rotational pendulum is proposed. The proposed controller consists of two modes of control such as divergence mode and stabilization mode. When the controller is in divergence mode, control input is generated using sinusoidal function, which is developed based on resonance period of the pendulum in linear region, to make the second link (pendulum) reach top position. After the controller finishes operation in divergence mode, stabilization control is initiated to keep the pendulum around the top position using pole placement control method. Experimental results are given to show the effectiveness of the proposed method.

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Improvement of Dynamic Characteristics of an Optical Image Stabilizer in a Compact Camera (초소형 카메라 흔들림 보정장치의 동특성 개선)

  • Song, Myeong-Gyu;Son, Dong-Hun;Park, No-Cheol;Park, Kyoung-Su;Park, Young-Pil
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.21 no.2
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    • pp.178-185
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    • 2011
  • Optical image stabilization is a device to compensate the camera movement in the exposure time. The compensation is implemented by movable lens or image sensor that adjusts the optical path to the camera movement. Generally, the camera is moved by a handshake, thus the handshake is considered as an external disturbance. However, there are many other vibrations such as car and train vibration. In this paper, the optical image stabilization system in high frequency region is presented. Notch filter and lead compensator are designed and applied to improve the stability without changing the actuator. To verify the performance of the optical image stabilization system in high frequency region, the experiment equipment with moving object is established. It is confirmed that the opticalimage stabilization system does not diverge at the resonance frequency.