• Title/Summary/Keyword: Anti-shock

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Analysis for Anti-shock Characteristics of Underwater Acoustic Transducers to the Explosive Shock (수중폭발충격에 대한 수중음향 트랜스듀서의 내충격 특성 해석)

  • Goh, Byeong-Jun;Seo, Hee-Seon
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.16 no.11 s.116
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    • pp.1108-1114
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    • 2006
  • Underwater acoustic transducers can be exposed to a underwater explosive shock caused by various types of underwater weapon. So, a robust anti-shock design is required for transducers to endure the underwater explosive shock. To check the anti-shock characteristics of a transducer, underwater explosive shock test is needed. The conditions of underwater explosive shock test are set up referring to various oversea explosive shock test specifications, and the explosive shock pressure values are calculated according to those conditions. Transient analyses art: carried out for two kinds of underwater acoustic transducer model to verify the anti-shock characteristics. The applied model has robust anti-shock characteristics enough to endure the explosive shock up to 2300 psi. In the future, the transducer design should be certified through the fields test, and modified if needed.

Anti-shock Controller Design for Optical Disk Drive Systems with Nonlinear Controller (광디스크 드라이브 시스템을 위한 비선형 제어기를 이용한 Anti-Shock 제어기 설계)

  • Baek, Jong-Shik;Chung, Chung-Choo
    • Proceedings of the KIEE Conference
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    • 2004.11c
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    • pp.675-677
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    • 2004
  • This paper presents a nonlinear controller design for optical disk drive systems to improve anti-shock performance. The nonlinear anti-shock controller is added parallel to the original linear servo control loop. In the previous work, dead-zone nonlinear element is used for nonlinear controller and PID control method is used for linear controller. Although this strategy improves anti-shock performance, it has a narrow stability bound. In this paper, we propose dead-zone with saturation nonlinear element for the nonlinear controller. Since this nonlinear element improves stability margin, we can use higher gain of dead-zone than the controller with dead-zone only. In the linear controller design, we show that lead-lag control has improved stability margin over PID control. Numerical simulation results show that the proposed method can get better performance to the external shock than previously proposed method.

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Anti-shock Controller Design for Optical Disk Drive Systems with a Nonlinear Controller (광디스크 드라이브 시스템을 위한 비선형 Anti-shock 제어기 설계)

  • Baek Jong-Shik;Chung Chung Choo
    • Journal of Institute of Control, Robotics and Systems
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    • v.11 no.9
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    • pp.741-749
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    • 2005
  • This paper presents a nonlinear controller design for optical disk drive systems to improve anti-shock performance. The nonlinear anti-shock controller is added parallel to the original linear servo control loop. In the previous work, a dead-zone nonlinear element is used for the nonlinear controller and a PID control method is used for the linear controller. Although this parallel structure of the controller improves anti-shock performance, it has a narrow stability bound. In this paper, the dead-zone with saturation nonlinear element is proposed for the nonlinear controller. Since this nonlinear element improves stability margin, we can use higher slope gain of dead-zone than that of nonlinear controller using dead-zone only. In the linear controller design, it is shown that the lead-lag control has an improved stability margin over PID control. Numerical simulation results and experimental results show that the proposed method can get better performance to the external shock than previously proposed methods.

Effects of heat and ethanol shock on the membrane proteins of Vibrio vulnificus (열 및 에탄을 shock이 Vibrio vulnificus의 막단백질에 미치는 영향)

  • Heo, Moon-Soo;Jung, Cho-Rok
    • Journal of fish pathology
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    • v.12 no.2
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    • pp.89-99
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    • 1999
  • New sixteen heat shock proteins (Hsps) and ten ethanol shock proteins were appeared on the analysis with SDS-PAGE when cultivation temperature for the Vibrio vulnifrcus ATCC 27562 strain was shifted-up to $42^{\circ}C$ from $30^{\circ}C$ for 20 mins and treated with of 6% ethanol for 10 mins, respectively. Even the induction of thermotolerance in V. vulnificus was coincided with the induction of Hsps if the pre-shock was adjusted to thermal temperature. Outer membrane proteins (OMPs) that were purified from the membrane of cells after heat shock showed more immunodominant pattern to the immunized rabbit anti-V. vulnificus O serum in enzyme-linked immunosorbent assay (ELISA). On the western immunoblot analysis it was confirmed that both 62 kDa IMP and 69 kDa OMP in the Hsps and 48 kDa IMP a major OMP in the ethanol shock proteins were reacted with rabbit anti-V. vulnificus O sera. Agglutination titer of the heat shocked V. vulnificus with rabbit anti-V. vulnificus O serum was higher than that of the untreated bacteria.

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Anti-vibration and Shock-resistant Design for Personal Navigation Device (PND 의 내진특성 개선)

  • Hwang, Hyo-Kune;Ha, Sang-Woo;Yoo, Seung-Hun;Choi, In-Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.04a
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    • pp.861-862
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    • 2008
  • One of trend of portable devices is convergence with other devices, especially with navigation system. This converged system is generally called PND (Personal Navigation Device). This detachable device is developed for personal entertainment in everyday life and navigation system when deriving, so it should meet the specification of vehicle thermal environment, anti-vibration as well as the anti-shock by sudden drop. In this paper, the way to design the hard disk drive damper with CAE, is introduced to get a reliable system from the beginning of the design step.

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Study on The Anti-Shock Performance Evaluation of TFT-LCD module for Mobile IT Devices (이동형 정보통신 기기용 화면표시 장치의 내충격 평가 방법 연구)

  • Kim Byung-Sun;Kim Jung-Woo;Lee Dock-Jin;Choi Jae-Boong;Kim Young-Jin;Baik Seung-Hyun;Chu Young-Bee;Koo Ja-Choon
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.7 s.184
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    • pp.130-137
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    • 2006
  • TFT-LCD(Thin Film Transistor Liquid Crystal Display) module is representative commercial product of FPD(Flat Panel Display). Thickness of TFT-LCD module is very thin. It is adopted for major display unit for IT devices such as Cellular Phone, Camcorder, Digital camera and etc. Due to the harsh user environment of mobile IT devices, it requires complicated structure and tight assembly. And user requirements for the mechanical functionalities of TFT-LCD module become more strict. However, TFT-LCD module is normally weak to high level transient mechanical shock. Since it uses thin crystallized panel. Therefore, anti-shock performance is classified as one of the most important design specifications. Traditionally, the product reliability against mechanical shock is confirmed by empirical method in the design-prototype-drop/impact test-redesign paradigm. The method is time-consuming and expensive process. It lacks scientific insight and quantitative evaluation. In this article, a systematic design evaluation of TFT-LCD module for mobile IT devices is presented with combinations of FEA and testing to support the optimal shock proof display design procedure.

Design and Analysis of MEMS Vibrating Ring Gyroscope Considering High-g shock reliability (고내충격용 MEMS 진동형 링 자이로스코프 설계 및 분석)

  • Yoon, Sung-Jin;Park, U-Sung
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.10
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    • pp.1440-1447
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    • 2015
  • This paper describes a study for anti high-shock design of MEMS vibrating ring gyroscope. Structure models was made by MEMS technology processing. MEMS Vibrating Ring Gyroscope mechanical structure were not only anti-high shock simulated with the LS Dyna Ver 971 software but also with mathematical analysis and the finite element method in order to confirm the shock reliability. Shock test result of a MEMS vibrating gyroscope being developed to have gun-hardened survivability while maintaining tactical grade navigation performance for application to various guided projectiles.

Anti-histamic Effect and IL-4 and GM-CSF mRNA Expression on Sungmagalkun-tang (升麻葛根湯의 항히스타민 효과 및 IL-4와 GM-CSF 발현에 미치는 영향)

  • Kim, Hong-Bae;Kim, Own-Il;Lee, Seung-Yeon
    • The Journal of Pediatrics of Korean Medicine
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    • v.20 no.1
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    • pp.69-83
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    • 2006
  • We investigated the effect of Sungmagalkun-tang (SGT) on the allergy. We conformed compound 48/80-induced active systemic anaphylatic shock, anti-dinitrophenyl IgE-mediated passive cutaneous anaphylaxis and ovalbumin-induced anaphylatic shock. Also observed IL-4 and GM-CSF mRNA expression in ovalbumin-induced allergic lung tissue and RBL-2H3. Histamine release is measured in RBL-2H3. SGT inhibited active systemic anaphylatic shock, passive cutaneous anaphylaxis and ovalbumin-induced anaphylatic shock by oral administration. We observed that SGT was concentration-dependently reduced IL-4 and GM-CSF mRNA expression in ovalbumin-induced allergic lung tissue and RBL-2H3 by SGT. In addition, SGT reduced histamine release in RBL-2H3. These results indicate that SGT has anti-histamic effect and controls IL-4 and GM-CSF mRNA expression on allergy.

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