• Title/Summary/Keyword: sensitivity enhancement

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Two Approaches in LCDs With Fast Electro-optic Response: PSV-mode FLCDs and FM-TN-LCDs

  • Kobayashi, Shunsuke
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.911-914
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    • 2004
  • This paper discusses on new two LCD technologies featured by the fast electro-optic response:one is polymer-stabilized FLCDs that exhibit V-shaped electro-optic (EO) switching called PSV-mode FLCDs with response time of 400 ${\mu}$ s; and the other is TN-mode LCDs that exhibit a frequency modulation response (called PM-TN LCDs)and a peculiar sensitivity to the high frequency component of driving voltage waveforms resulting in a short decay time constant of 5ms and an enhancement in the over-driving that yields short response time of 1ms between two gray levels.

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Synthesis and Sensing Properties of Pd Nanoparticle-Functionalized SnO2 Nanowires

  • Akash, Katoch;Choi, Sun-Woo;Kim, Eun-Kyeong;Kim, Sang-Sub
    • Journal of Sensor Science and Technology
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    • v.20 no.5
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    • pp.289-293
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    • 2011
  • Networked $SnO_2$ nanowires were uniformly functionalized with Pd nanoparticles via ${\gamma}$-ray radiolysis. The Networked $SnO_2$ nanowires were fabricated through a selective growth method. The sensing properties of the Pd-functionalized $SnO_2$ nanowires were analyzed in terms of their response to $NO_2$ and CO gases. The response time and sensitivity of the sensors were significantly improved for $NO_2$ at lower temperatures by the Pd functionalization. The enhancement in the sensing properties is likely to be due to the spillover effect of the Pd nanoparticles.

Development of Nanostructured Plasmonic Substrates for Enhanced Optical Biosensing

  • Byun, Kyung-Min
    • Journal of the Optical Society of Korea
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    • v.14 no.2
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    • pp.65-76
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    • 2010
  • Plasmonic-based biosensing technologies have been successfully commercialized and applied for monitoring various biomolecular interactions occurring at a sensor surface. In particular, the recent advances in nanofabrication methods and nanoparticle syntheses provide a new route to overcome the limitations of a conventional surface plasmon resonance biosensor, such as detection limit, sensitivity, selectivity, and throughput. In this paper, optical and physical properties of plasmonic nanostructures and their contributions to a realization of enhanced optical detection platforms are reviewed. Following vast surveys of the exploitation of metallic nanostructures supporting localized field enhancement, we will propose an outlook for future directions associated with a development of new types of plasmonic sensing substrates

Enhancement of Roll Stability by Speed-Adaptive Robust Control (속도감은 강건제어에 의한 롤 운동 특성개선)

  • Kim, Hyo-Jun;Park, Yeong-Pil
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.4
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    • pp.167-175
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    • 2001
  • This paper presents design of active roll controller of a vehicle and experimental study using the electric actuating roll control system. Firstly, parameter sensitivity analysis is performed based on 3DOF linear vehicle model. The controller is designed in the frame work of gain-scheduled H$\infty$ control scheme considering the varying parameters induced by laden and running vehicle condition. In order to investigate a feasibility of an active control system, experimental work is performed using hardware-in-the -loop setup which has been constructed by the devised electric actuating system and the full vehicle model with tire characteristics. The performance is evaluated by experiment using hardware-in-the -loop simulation under the conditions of some steer maneuvers and parameter variations.

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Constitutive Model for a Confined Concrete Cylinder with an Unbonded External Steel Jacket

  • Roh, Young-Sook
    • Architectural research
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    • v.17 no.1
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    • pp.41-48
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    • 2015
  • Early investigations focused mainly on manipulating the confinement effect to develop a reinforced concrete column with lateral hoops. Based on this legacy model, Li's model incorporated the additional confinement effect of a steel jacket. However, recent experiments on plain concrete cylinders with steel jackets revealed relatively large discrepancies in the estimates of strength enhancement and the post-peak behavior. Here, we describe a modified constitutive law for confined concrete with an unbonded external steel jacket in terms of three regions for the loading stage. We used a two-phase heterogeneous concrete model to simulate the uniaxial compression test of a $150mm{\times}300mm$ concrete cylinder with three thicknesses of steel jackets: 1.0 mm, 1.5 mm, and 2.0 mm. The proposed constitutive model was verified by a series of finite element analyses using a finite element program. The damaged plasticity model and extended Drucker-Prager model were applied and compared in terms of the level of pressure sensitivity for confinement in 3D. The proposed model yielded results that were in close agreement with the experimental results.

Development of Localization Sensor System for Intelligent Robots (지능로봇용 위치인식 시스템 개발)

  • You, Ki-Sung;Choi, Chin-Tae
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.2
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    • pp.116-124
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    • 2011
  • A service robot can identify its own position relative to landmarks, the locations of which are known in advance. The main contribution of this research is that it gives various ways of making the self-localizing error smaller by referring to special landmarks which are developed as high gain reflection material and coded array associations. In this paper, the authors propose a set of indices to evaluate the accuracy of self-localizing methods using the selective reflection landmark and infrared projector, and the indices are derived from the sensitivity enhancement using 3D distortion calibration of camera. And then, the accurarcy of self-localizing a mobile robot with landmarks based on the indices is evaluated, and a rational way to minimize to reduce the computational cost of selecting the best self-localizing method. The simulation results show a high accuracy and a good performance.

The implementation of a Gd-pMOSFET thermal neutron detector and the enhancement of its sensitivity (Gd-pMOSFET 열중성자 측정기 구현 및 감도개선)

  • Lee, Nam-Ho;Kim, Seung-Ho
    • Proceedings of the KIEE Conference
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    • 2005.10b
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    • pp.430-432
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    • 2005
  • 저에너지 중성자가 가톨리늄(Gd) 막에 입사되면 중성자 포획과정에서 전환전자가 생성된다. 이 전환전자에 의해 pMOSFET $SiO_2$ 산화층에서 발생된 전자-전공쌍이 발생되고, 이 가운데 정공은 산화층 내부에 쉽게 붙잡혀(Trap) 양전하 센터로 작용하게 된다. 이 축적된 전하는 pMOSFET의 문턱전압(Threshold voltage)을 변화시킨다. 본 연구에서는 이러한 간접측정 원리를 이용하여 열중성자를 실기간 탐지할 수 있는 반도체형 탐지소자를 개발하고 하나로(HANARO) 방사선장에서의 시험을 통해 성능을 검증하였다. 그리고 감도관련 변수의 최적화를 통하여 작업자가 사용 가능한 범위의 고감도 열중성자 선량계로 개선 제작하였다. 개발된 선량계는 소형으로 실시간 열중성자 측정이 가능하며 감마방사선으로부터 독립적으로 열중성자를 측정할 수 있는 장점도 지니고 있다.

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DSP Architecture for Weak Signal Acquisition in Assisted GPS

  • Cho, Deuk-Jae;Choi, Il-Heung;Moon, Sung-Wook;Lee, Sang-Jeong;Park, Sang-Hyun
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.33.6-33
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    • 2002
  • For RF sensitivity enhancement, the previous assisted GPS acquisition architecture adopts not only the coherent integration technique but also the non-coherent integration technique since the long coherent integration time increases the number of the frequency search cells. But the non-coherent integration technique induces the squaring loss, which is the dominant factor among the acquisition losses of assisted GPS dealing with weak GPS signals. This paper proposes an efficient architecture for weak signal acquisition in assisted GPS. In this paper, it is explained that the proposed architecture reduces the squaring loss using a modified non-coherent integration technique. Furthermore, it is..

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Enhancement in the Viability and Biosensing activity of Freeze-Dried Recombinant Bioluminescent Bacteria

  • Park, Sue-Hyung;Gu, Man-Bock
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.5 no.3
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    • pp.202-206
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    • 2000
  • The genetically-engineered Escherichia coli strain, DPD2540, which contains a fabA:::luxCDAbefusion gene, gives a bioluminescent output when membrane fatty acid synthesis is needed. For more pactical application of this strain in the filed as biosensor, freezedrying was adopted. A 12% surcrose solution with Luria-Bertani (LB) broth, as determined by the viability after freeze-drying, was found to be most most effective composition for lyophilization solution among various compositions testitons tested. Rapid freezing with liquid nitrogen also gave the best viability after freeze-drying as compared to samples frozen at-7$0^{\circ}C$ and -2$0^{\circ}C$. The biosensing activities of the cells showed a greater sensitivity when the cells from the expontial phase were freeze-dried. Finally, the optimum temperature for use of the freeze-dried cells in the biodencor field was determined.

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Enhancement of Computational Efficiency of Reliability Optimization Method by Approximate Evaluation of Sub-Optimization Problem (부 최적화 문제의 근사적인 계산을 통한 신뢰도 최적설계 방범의 효율개선)

  • Jeong, Do-Hyeon;Lee, Byeong-Chae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.10
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    • pp.1597-1604
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    • 2001
  • Alternative computational scheme is presented fur reliability based optimal design using a modified advanced first order second moment (AFOSH) method. Both design variables and design parameters are considered as random variables about their nominal values. Each probability constraint is transformed into a sub -optimization problem and then is resolved with the modified Hasofer- Lind-Rackwitz-Fiessler (HL-RF) method for computational efficiency and convergence. A method of design sensitivity analysis for probability constraint is presented and tested through simple examples. The suggested method is examined by solving several examples and the results are compared with those of other methods.