• 제목/요약/키워드: RA scheme

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Mobile Robot Driving using Moving Window

  • Choi, Sung-Yug;Kang, Jin-Gu;Hur, Hwa-Ra;Ju, Jin-Hwa
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.758-761
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    • 2003
  • This paper introduces a method that can detect obstacles and corridor environments from the images captured by a CCD camera in an automobile or mobile robot is proposed. Processing the input dynamic images in real time requires high performance hardware as well as efficient software. In order to relieve these requirements for detecting the useful information from the images in real time, a "Moving Window" scheme is proposed. Therefore, detecting the useful information, it becomes possible to search the obstacles within the driving corridor of an automobile or mobile robot. The feasibility of the proposed algorithm is demonstrated through the simulated experiments of the corridor driving.

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A Novel Range Estimator for Surface to Air Missile with Closing Velocity Measurements

  • Ra, W.S.;Whang, I.H.;Lee, J.I.
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.1822-1825
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    • 2003
  • A practical range estimator based on the robust Kalman filter is proposed to solve the range estimation problem for surface to air missile(SAM) homing guidance. Apart from the previous works based on the extended Kalman filter(EKF) with bearing only measurement, the proposed scheme makes use of line-of-sight(LOS) rate to ensure the fast convergency at long-range. In this reason, the robust Kalman filter is considered to deal with LOS rate measurement error. The recursive linear structure of proposed filter is easy to implement and make it possible to reduce computational burdens. Moreover, it shows good estimation performance without specific guidance law such as oscillation proportional navigation guidance(OPNG).

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A Modified Weighted Least Squares Range Estimator for ASM (Anti-Ship Missile) Application

  • Whang Ick-Ho;Ra Won-Sang;Ahn Jo-Young
    • International Journal of Control, Automation, and Systems
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    • v.3 no.3
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    • pp.486-492
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    • 2005
  • A practical recursive WLS (weighted least squares) algorithm is proposed to estimate relative range using LOS (line-of-sight) information for ASM (anti-ship missile) application. Apart from the previous approaches based on the EKF (extended Kalman filter), to ensure good convergence properties in long range engagement situations, the proposed scheme utilizes LOS rate measurements instead of conventionally used LOS angle measurements. The estimation error property for the proposed filter is investigated and a simple error compensator is devised to enhance its estimation error performances. Simulation results indicate that the proposed filter produces very accurate range estimates with extremely small computations.

Performance of DQPSK-OFDM Based T-DMB Additional Data Transmission Scheme (DQPSK-OFDM 기반의 T-DMB 부가 정보 전송기법의 성능 분석)

  • Cha, Jae-Sang;Rho, Jung-Kyu;Kim, Gun;Park, So-Ra;Lee, Yong-Tae;Bae, Jung-Nam;Kim, Jin-Young
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.10 no.5
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    • pp.127-131
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    • 2010
  • In this paper, we propose the novel additional data transmission technology for DQPSK-OFDM based T-DMB system using watermarking technique. The proposed algorithms which is possible that it can transmit data in indoor or shadow region and improve transmission efficiency. We certified availability of our proposed technology by using various simulation. The results of the paper can be applied to wireless multimedia digital broadcasting systems.

Performance Improvement Scheme of T-DMB Watermarking Technique Using Convolutional Codes (길쌈 부호화기를 이용한 T-DMB 워터마킹 기법의 성능개선 기법)

  • Cha, Jae-Sang;Rho, Jung-Kyu;Kang, Jang-Mook;Kim, Gun;Park, So-Ra;Lee, Yong-Tae;Bae, Jung-Nam;Kim, Jin-Young
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.10 no.5
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    • pp.121-125
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    • 2010
  • In this paper, we propose the performance improvement technique using convolutional codes for T-DMB watermarking system. By applying the channel coding, the error performance is improved and the capacity of additional data is increased. We certified availability of our proposed technology by using various simulation.

Optical Application of Diamond Turning Process (광학 응용을 위한 다이아몬드 터닝 가공)

  • 이봉주;김대중;정상화;박순섭;김상석;김정호;유영문;김주하
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1881-1884
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    • 2003
  • Diamond turning machines have, been used for the processing of surface like a mirror with the control scheme of minimizing shape error, Ultra-precision diamond fuming is applied to produce highly precision optical components required not only a high machining accuracy but also a good surface roughness. Al-6061 is widely used as optical parts such as laser reflector's mirror or multimedia instrument. In this study, thermal-imaged Al flat mirrors are fabricated by SPDT. The surface roughness 3.472 nm Ra, power 2 fringe(at 632.8 nm) and irregularity 1 fringe(at 632.8 nm) for form waviness of thermal-imaged Al flat mirror are very satisfied to the required specification in industry.

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A New Inverse Scattering Technique Using the Moment Method in the Spectral Domain , II : Numerical Simulation (파수영역에서 모멘트 방법을 이용한 새로운 역산란 방법 , II : 수치계산)

  • Lee, Jae-Min;Kim, Se-Yun;Ra, Jung-Woong
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.25 no.10
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    • pp.1150-1157
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    • 1988
  • In this paper, the reconstruction of complex permittivity distribution on a rectangular cross section of inhomogeneous dielectric cylinders is performed by employing the spectral inverse scattering scheme presented in the part I of these companion papers. Numerical simulations provide the superresolution to the permitivity profiles nearly regardless of the measurement locations of the scattered field and the permittivity distributions on the cross section.

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Hydrodynamics Embedded Navigation Filter Design for Underwater Autonomous Systems (수중 자율이동시스템의 수력학 모델 내장형 항법필터 설계)

  • Kim, Eun-Chong;Lee, Yun-Ha;Jung, Young-Kwang;Ra, Won-Sang
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.1383-1384
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    • 2015
  • In this paper, a dynamics model embedded navigation filter is newly suggested for underwater autonomous systems without position or attitude aid. In order to ensure the observability on the INS errors, the hydrodynamics of the underwater vehicle is incorporated with the INS attitude error. This approach allows us to estimate and compensate the INS errors in spite of using external velocity sensor. Through the simulation, the performance and effectiveness of the proposed scheme are demonstrated.

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LEARNING-BASED SUPER-RESOLUTION USING A MULTI-RESOLUTION WAVELET APPROACH

  • Kim, Chang-Hyun;Choi, Kyu-Ha;Hwang, Kyu-Young;Ra, Jong-Beom
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2009.01a
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    • pp.254-257
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    • 2009
  • In this paper, we propose a learning-based super-resolution algorithm. In the proposed algorithm, a multi-resolution wavelet approach is adopted to perform the synthesis of local high-frequency features. To obtain a high-resolution image, wavelet coefficients of two dominant LH- and HL-bands are estimated based on wavelet frames. In order to prepare more efficient training sets, the proposed algorithm utilizes the LH-band and transposed HL-band. The training sets are then used for the estimation of wavelet coefficients for both LH- and HL-bands. Using the estimated high frequency bands, a high resolution image is reconstructed via the wavelet transform. Experimental results demonstrate that the proposed scheme can synthesize high-quality images.

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A Design of People-Centric Distress Broadcast Scheme Using Context-Aware Technology in Pervasive Systems (Pervasive System에서 Context-Aware 기술을 이용한 People-Centric Distress Broadcast 기법 설계)

  • Dofitas Jr., Cyreneo S.;Ra, In-Ho
    • Proceedings of the Korea Contents Association Conference
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    • 2013.05a
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    • pp.51-52
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    • 2013
  • Recent advances in WSN and the wide use of social sensing technologies have been changing our daily lives. In the process of creating intertwining connections and interconnections greatly influencing on the way we communicate with other people, WSN and social communication media have a number of important capabilities that support their utilization in distress broadcast during emergency situations. This paper proposes a system model that makes better utilization of WSN and social sensing capabilities in sending out distress messages to the intended recipients more efficiently and effectively.

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