• Title/Summary/Keyword: Fragile

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Poly(3-hydroxybutyrate) Extrusion by Cells of Recombinant Escherichia coli

  • Lee, Sang-Yup
    • Journal of Microbiology and Biotechnology
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    • v.6 no.2
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    • pp.147-149
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    • 1996
  • Poly(3-hydroxybutyrate) (PHB) was synthesized and accumulated intracellularly to a high concentration (7 g/l) by cultivating recombinant Escherichia coli XL1-Blue (pSYLl05) in a complex medium containing 20 g/l glucose. The morphology of PHB granules was examined by transmission electron microscopy. The PHB granules synthesized in recombinant E. coli were much larger than reported values for wild type microorganisms, and were often irregularly shaped. Some cells were apparently extruding PHB into the medium, which suggests that PHB granules maintain some fluidity and cells become fragile due to PHB accumulation.

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Non-fragile controller design for discrete-time descriptor systems (이산시간 특이시스템의 비약성 제어기 설계)

  • Kim, Jong-Hae
    • Proceedings of the KIEE Conference
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    • 2008.04a
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    • pp.209-210
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    • 2008
  • 본 논문에서는 제어기에 승산형 섭동을 가지는 제어기와 이산시간 특이시스템을 안정화시키는 비약성 제어기 설계방법을 제시한다. 강인 비약성 제어기가 존재할 조건과 제어기 설계방법을 블록최적화가 가능한 선형 행렬부등식 접근방법으로 제안한다. 또한, 제어기의 약성 성도를 표시하는 비약성 척도를 동시에 계산함으로 승산형 섭동의 제어기 최대 변동정도를 제시한다. 제안한 비약성 제어기는 제어기의 이득 변동에도 불구하고 이산 시간 특이시스템의 강인 안정성을 보장한다.

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A Study of Distorted Document Image Restoration using Structured Light (Structured Light를 이용한 왜곡된 문서 영상 복원에 관한 연구)

  • 곽규섭;채옥삼
    • Proceedings of the IEEK Conference
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    • 2000.11d
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    • pp.235-238
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    • 2000
  • This paper describes the implementation of document image restoration system for the geometric distortion using structured light. To get accurate document images, the bounded book must be flattened by pushing down the book with a class plate. However, most of ancient documents are too fragile to be pushed. The proposed system restores the distorted character image due to geometric distortion.

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The construction of a crowned surface (크라운 곡면 형성)

  • Kim, Hoi-Sub
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.10 no.2
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    • pp.49-52
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    • 2006
  • Theses days, the thickness of Brown tube becomes thinner since the display products are rapidly replaced by PDP, LCD etc. Accordingly, the shadow mask part also become flat. We propose the method of designing the surface with crown since the flat surface is fragile to vibration and shock.

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Cutting Process Monitoring Using Tool Dynamometer in End-Milling Process (엔드밀 공정에서 공구 동력계를 이용한 절삭상태 감시)

  • 김홍겸;양호석;이건복
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2001.10a
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    • pp.14-18
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    • 2001
  • Rise in cutting force causes tool damage and worsens product quality resulting in machining accuracy deterioration. Especially, fragile material cutting brings about breakage of material and worsens product surface quality. In this study, we trace the locus of cutting force and examine the machined surface corresponding to the cutting force loci. and build up a monitoring system for deciding normal operation or not of cutting process.

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DCI Based Watermarking for Image Verification and Authentication (인증과 무결성을 위한 DCT 기반 워터마킹)

  • 이혜란;박지환
    • Proceedings of the Korea Multimedia Society Conference
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    • 2001.06a
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    • pp.506-509
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    • 2001
  • 본 논문에서는 디지털 영상의 변조를 확인함과 동시에 변조의 위치를 확인하는 DCT 기반의 fragile watermarking을 제안한다. 디지털 영상의 인증과 무결성을 위해 기존의 Wong이 사용한 해쉬 함수와 비대칭키 암호 알고리즘을 사용하며, 영상에 DCT 변환을 함으로서 영상의 모든 픽셀에 워터마크를 삽입하지 않고서도 변조의 유무를 확인하는 것이 가능하다. 본 논문에서는 DCT 계수 중 일부 저주파 계수의 하위 비트에 워터마크를 삽입하여 워터마크의 비가시성과 연성을 만족하며 변조의 유무와 위치를 확인한 수 있게 된다.

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Speed control of induction motor using Fuzzy PI controller (퍼지 PI 제어기를 이용한 유도전동기 속도제어)

  • 조정민;함년근;이상집;이승환;이훈구;김용주;한경희
    • Proceedings of the KIPE Conference
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    • 1998.07a
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    • pp.230-233
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    • 1998
  • The conventional PI controller are fragile in parameter variation and load-variation. Therefore, in this paper, a speed control algorithm based on the Fuzzy PI controller is proposed for the high performance speed control of a voltage-source inverter to drive 3-phase induction motors. The computer simulation results show that the proposed controller are more excellent control characteristics than conventional PI controller in transient-state and steady-state response.

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The Prepaid Trust and Corporate Turnaround: A Study on the Corporate Turnaround via System Dynamics Approach (공여된 신뢰와 기업회생 : 시스템 다이내믹스 기업회생 모형 연구)

  • 박헌준;김상준
    • Korean System Dynamics Review
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    • v.3 no.1
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    • pp.131-163
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    • 2002
  • This study examines the effect that the prepaid trust has in saving the troubled business. Developing a formal system dynamics model, building on case studies of corporate turnaround, we developed a mathematical model on the relationship between the prepaid trust and corporate turnaround. The Model shows how the prepaid trust can shift an organizational system from fragile condition to resilient condition of a firm. This study elaborartes a new set of conditions under which organizations may turn around via prepaid trust of stakeholders.

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Relativistic Hydrodynamics and Quasiperiodic Oscillations

  • MATHEWS GRANT J.;FRAGILE P. CHRIS;WILSON JANES R.
    • Journal of The Korean Astronomical Society
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    • v.34 no.4
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    • pp.265-269
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    • 2001
  • We present preliminary numerical simulations of tilted-disk accretion around a rotating black hole. Our goal is to explore whether hydrodynamic instabilities near the Bardeen-Petterson radius could be responsible for generating moderate-frequency quasi-periodic oscillations in X-ray binaries. We review the relevant general relativistic hydrodynamic equations, and discuss preliminary results on the structure and dynamics of a thin, Keplerian disk.

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