• Title/Summary/Keyword: Stable region

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Production and Partial Characterization of Lacticin JW3, a Bacteriocin Produced by Lactococcus lactis JW3 Isolated from Commercial Swiss Cheese Products

  • Jeong, Min-Yong;Baek, Hyeon-Dong
    • 한국생물공학회:학술대회논문집
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    • 2000.04a
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    • pp.554-557
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    • 2000
  • Strain JV3 was isolated from commercial Swiss cheese products and identified as a bacteriocin producer, which has bactericidal activity against Leuconostoc mesenteroides KCCM 11324. Strain JW3 was identified tentatively as Lactococcus lactis by the API test. The activity of lacticin JW3, named tentatively as the bacteriocin produced by Lactococcus lactis JW3, was detected during the mid-log growth phase, and reached a maximum during the early stationary phase, and decreased after the late stationary phase. Its antimicrobial activity on sensitive indicator cells was completely disappeared by protease IV. The inhibitory activities of lacticin JW3 were detected during treatments of up to $121\'^{circ}C$ for 15 min. Lacticin JW3 was very stable over a pH range of 2.0 to 9.0 The apparent molecular mass of lacticin JW3 was estimated to be in the region of 3-3.5kDa, which was determined by the direct detection of bactericidal activity after SDS-PAGE.

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Stability Limit Properties of a Control System on the Space of Adjustable Parameters (조정파라미터 공간에서의 제어계 안정한계 특성)

  • 최순만
    • Journal of Advanced Marine Engineering and Technology
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    • v.25 no.2
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    • pp.351-356
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    • 2001
  • In this paper, a general one-loop control system was assumed as a model system which has a time-delay element connected with a first order-lag element in series. After the corresponding parameter set causing stability limit condition for the model system was obtained by mathematical procedures, their loci on the parameter space was taken according of frequency change,. The parameter set loci of stability limit showed a specific pattern, and particularly the curves on the Kp-Ti parameter space were able to generalized in the form of an exponential formula. These properties were also compared with the results taken from experimental procedures by Nyquist response method and Ziegler & Nichols method on the time domain, and both results were confirmed to be nearly same.

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Fuzzy Controller for Nonlinear Systems Using Intelligent Digital Redesign (지능형 디지털 재설계기법을 이용한 비선형 시스템의 제어기 설계)

  • 이상준;이남수;주영훈;박진배
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2000.11a
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    • pp.176-179
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    • 2000
  • This paper addresses a fuzzy controller for nonlinear systems control using a pole placement in a specified disk and fuzzy controller is redesign for Intelligent digital redesign method. for nonlinear system, we obtain continuous time state feedback gain that guarantee stability of globally TS fuzzy system. The feedback gain is satified pole placement in a specified disk region so that the closed loop system is stable, For digital control redesgin of continuous time TS fuzzy model, we does state matching and obtain feedback gain of digital controller. Finally, it is shown that the proposed method is feasible through a computer simulation.

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Study for the Structural walls with Interlocking Spirals on the boundary (단부에 Interlocking Spiral을 가진 전단벽의 거동에 관한 연구)

  • 홍성걸;김록배;정하선;구광현
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.05a
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    • pp.865-870
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    • 2001
  • This paper propose a new seismic detail for ductility enhancement by interlocking spiral reinforcement in the potential yield regions of a wall. Through the theoretical consideration and experiment program, confinement with interlocking spirals lead the structural walls to ductile behavior. All specimens show stable hysteretic behavior and good energy dissipation capacity. Also the increase of shear strength mainly induces a flexural failure mode. As interlocking spiral are used in lapped splice region, they increase the bond strength and prevent a early tensile failure caused by the loss of bond stresses. Consequently, the confinement with interlocking spirals may result in a lower value of force reductions factor, newly proposed detail will be provide more economical design.

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The Effect of Acetic Acid in Synthesizing PbSe Quantum Dots by Hot Solution Chemical Process (고온 열분해 반응법을 이용한 PbSe 나노입자의 Acetic Acid 첨가에 대한 영향)

  • Baek, In-Chan;Seok, Sang-Il;Chung, Yong-Chae
    • Journal of the Korean Ceramic Society
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    • v.44 no.2 s.297
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    • pp.89-92
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    • 2007
  • PbSe, with a band gap in the mid-infrared and a samll effective mass, is an interesting material for optical and electrical applications in infrared region. Various colloidal synthetic routes for synthesizing PbSe quantum dot nanoparticles have been developed in the last couple of years. In this work, stable colloidal solutions containing crystalline PbSe particles in the order of 5-15 nm were synthesized using different amount of acetic acid in high boiling coordinating solvents. The size and shape of PbSe nanoparticles was greatly influenced by coexistence of acetic acid in synthetic medium. It was observed by TEM that the shape of PbSe nanoparticles with different amount of acetic acid was changed from spherical to cube or star types.

THE STUDY FOR THE PROFILES OF MIXED DENTITION (한국인 아동의 측모에 관한 연구)

  • Park T. W.
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.8 no.1
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    • pp.17-21
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    • 1978
  • The study was to analyze on the hard and soft tissue profiles in mixed dentition. The subject consisted of 100 males and 100 females from 9 to 12 years of age and with a normal occlusion and acceptable profiles. On the basis of SnH line and SnV line, the author traced all the cephalograms and calculated the mean value and standard deviation in each measuring category and evaluated the sexual difference, the proper limit of development. The obtained results were as follows; 1. Individual variations of the lower facial part were larger the upper facial part in depth and height. 2. Sexual difference of lower facial part was significant in depth and height. 3. All the measured values to the SnH and SnV line were larger in male than in female but revealed resemblance in the profilogram. 4. The measured values of the region of nose, upper lip and point A showed stable tendency.

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InGaAsP/InP Buried-Ridge Waveguide Laser with Improved Lateral Single-Mode Property

  • Oh, Su-Hwan;Kim, Ki-Soo;Kwon, Oh-Kee;Oh, Kwang-Ryong
    • ETRI Journal
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    • v.30 no.3
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    • pp.480-482
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    • 2008
  • A novel InGaAsP/InP buried-ridge waveguide laser diode structure is proposed and demonstrated for use as a single-mode laser. The lateral mode of the proposed device can be controlled by adjusting the composition and thickness of the InGaAsP layer grown over the active region. Stable single-mode operation without kinks or beam-steering is achieved successfully with lateral and transverse in the junction plane even for the device with the ridge width of 9 ${\mu}m$ up to an injection current of 500 mA.

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Performance Evaluation of Local Descriptors for Affine Invariant Region Detector (어파인 변환에 불변하는 지역 검출기에 대한 특징 기술자의 성능 평가)

  • Lee, Man Hee;Park, In Kyu
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2014.06a
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    • pp.181-182
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    • 2014
  • 본 논문에서는 어파인(affine) 변환에 불변하는 지역 검출기에 대하여 다양한 기술자의 성능을 비교하였다. 지난 수 년간 다양한 특징 기술자들이 연구되어 왔고, 이러한 특징 기술자들은 각각의 목적에 따라 상이한 특성을 갖고 있기 때문에 동일한 조건에서 다양한 기술자들의 성능을 비교하는 연구가 필요하다. 그러나 어파인 변환에 불변하는 지역 검출기에 대해 최적의 특징 기술자를 찾는 연구는 미흡한 실정이다. 따라서 본 논문에서는 지역적인 패치 기반의 특징 기술자뿐만 아니라 바이너리 기술자와 최근에 제안된 기술자들의 성능을 비교하였다. 제안하는 실험에서는 MSER (maximally stable extremal regions) 검출기를 이용하여 어파인 변환에 불변하는 지역을 검출하였고, 영상 확대 및 축소, 회전, 시점 변환 및 변형 가능한 물체에 대하여 각각 기술자의 성능을 비교하였다.

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Performance of the PEMFC for the mobile devices according to cathode (Cathode에 따른 휴대용 PEM 연료전지의 성능 변화)

  • Lee, Se-Won;Lee, Kang-In;Park, Min-Soo;Chu, Chong-Nam
    • 한국신재생에너지학회:학술대회논문집
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    • 2008.05a
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    • pp.550-553
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    • 2008
  • In this paper, experiments of air-breathing proton exchange membrane fuel cell (PEMFC) for mobile devices were carried out according to the cathode conditions. These conditions are defined by the cathode flow field plate type (the channel type, the open type) and the cathode surface direction. Single cell and 6-cell stack were used in this experiments. The experimental results showed that the open type cathode flow field plate gave better performance for small size PEMFCs because the open type cathode plate allowed better air convection than the channel type cathode plate. In the experiments related to the direction of the slits on the cathode flow field plate, the horizontal slit cell was better than the vertical slit cell. With respect to the cathode surface direction, when the cathode surface is placed in the direction normal to the ground, PEMFC generated more stable power in the mass transport loss region.

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Feature of the Change of the Arsenic Ionic State and Prediction of Toxicity in Aqueous Environment depending on Temperature Condition (온도 조건에 따른 비소 이온의 수중 상태 변화 특성 및 독성 예측)

  • Won, Yu-Ra;Kim, Dong-Su
    • Journal of Korean Society on Water Environment
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    • v.29 no.2
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    • pp.176-183
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    • 2013
  • The variation of the stable region of arsenic compounds in aqueous environment with temperature has been investigated by constructing the Pourbaix diagram of arsenic at different temperatures. The standard potential corresponding to the boundary between arsenic compounds with different charge valence was estimated to be decreased with temperature, which means the stability of arsenic compound with +5 charge valence increases. The distribution diagram of the most highly oxidized arsenic compound showed that arsenic acid is formed at higher pH and arsenate is generated at lower pH as temperature rises. The aquatic toxicity due to arsenic compounds was considered to be decreased with temperature in the neutral pH condition based on the $LD_T$ value defined in this study.