• Title/Summary/Keyword: interpolation error

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Multi-view Video Coding using View Interpolation (영상 보간을 이용한 다시점 비디오 부호화 방법)

  • Lee, Cheon;Oh, Kwan-Jung;Ho, Yo-Sung
    • Journal of Broadcast Engineering
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    • v.12 no.2
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    • pp.128-136
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    • 2007
  • Since the multi-view video is a set of video sequences captured by multiple array cameras for the same three-dimensional scene, it can provide multiple viewpoint images using geometrical manipulation and intermediate view generation. Although multi-view video allows us to experience more realistic feeling with a wide range of images, the amount of data to be processed increases in proportion to the number of cameras. Therefore, we need to develop efficient coding methods. One of the possible approaches to multi-view video coding is to generate an intermediate image using view interpolation method and to use the interpolated image as an additional reference frame. The previous view interpolation method for multi-view video coding employs fixed size block matching over the pre-determined disparity search range. However, if the disparity search range is not proper, disparity error may occur. In this paper, we propose an efficient view interpolation method using initial disparity estimation, variable block-based estimation, and pixel-level estimation using adjusted search ranges. In addition, we propose a multi-view video coding method based on H.264/AVC to exploit the intermediate image. Intermediate images have been improved about $1{\sim}4dB$ using the proposed method compared to the previous view interpolation method, and the coding efficiency have been improved about 0.5 dB compared to the reference model.

Regeneration of the Retarded Time Vector for Enhancing the Precision of Acoustic Pyrometry (온도장 측정 정밀도 향상을 위한 시간 지연 벡터의 재형성)

  • Kim, Tae-Kyoon;Ih, Jeong-Guon
    • The Journal of the Acoustical Society of Korea
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    • v.33 no.2
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    • pp.118-125
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    • 2014
  • An approximation of speed of sound in the measurement plane is essential for the inverse estimation of temperature. To this end, an inverse problem relating the measured retarded time data in between set of sensors and actuators array located on the wall is formulated. The involved transfer matrix and its coefficient vectors approximate speed of sound of the measurement plane by using the radial basis function with finite number of interpolation points deployed inside the target field. Then, the temperature field can be reconstructed by using spatial interpolation technique, which can achieve high spatial resolution with proper number of interpolation points. A large number of retarded time data of acoustic paths in between sensors and arrays are needed to obtain accurate reconstruction result. However, the shortage of interpolation points due to practical limitations can cause the decrease of spatial resolution and deterioration of the reconstruction result. In this works, a regeneration for obtaining the additional retarded time data for an arbitrary acoustic path is suggested to overcome the shortage of interpolation points. By applying the regeneration technique, many interpolation points can be deployed inside the field by increasing the number of retarded time data. As a simulation example, two rectangular duct sections having arbitrary temperature distribution are reconstructed by two different data set: measured data only, combination of measured and regenerated data. The result shows a decrease in reconstruction error by 15 % by combining the original and regenerated retarded time data.

HRTF Interpolation Using a Spherical Head Model (원형 머리 모델을 이용한 머리 전달 함수의 보간)

  • Lee, Ki-Seung;Lee, Seok-Pil
    • The Journal of the Acoustical Society of Korea
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    • v.27 no.7
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    • pp.333-341
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    • 2008
  • In this paper, a new interpolation model for the head related transfer function (HRTF) was proposed. In the method herein, we assume that the impulse response of the HRTF for each azimuth angle is given by linear interpolation of the time-delayed neighboring impulse responses of HRTFs. The time delay of the HRTF for each azimuth angle is given by sum of the sound wave propagation time from the ears to the sound source, which can be estimated by using azimuth angle, the physical shape of the underlying head and the distance between the head and sound source, and the refinement time yielding the minimum mean square error. Moreover, in the proposed model, the interpolation intervals were not fixed but varied, which were determined by minimizing the total number of HRTFs while the synthesized signals have no perceptual difference from the original signals in terms of sound location. To validate the usefulness of the proposed interpolation model, the proposed model was applied to the several HRTFs that were obtained from one dummy-head and three human heads. We used the HRTFs that have 5 degree azimuth angle resolution at 0 degree elevation (horizontal plane). The experimental results showed that using only $30\sim40%$ of the original HRTFs were sufficient for producing the signals that have no audible differences from the original ones in terms of sound location.

Isolated Words Recognition using Correlation VQ-HMM (상관성있는 VQ-HMM을 이용한 고립 단어 인식)

  • 이진수
    • Proceedings of the Acoustical Society of Korea Conference
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    • 1993.06a
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    • pp.109-112
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    • 1993
  • In this paper, we propose the modified VQ, applied correlation between codewords in order to reduce the error rate due to personal and speakers' temporal variation. Such a modified VQ is used in the stage of preprocessing of HMM and the temporal variation is absorbed by nonlinear Decimation and Interpolation of vowel part that we obtain higher recognition rate than not so case. The objects of experiment are Korea 142 DDD regional names and we show that the proposed method increase the recognition rate.

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A Channel Estimation Method for MIMO-OFDM Systems (MIMO-OFDM 시스템에서의 채널 추정 기법)

  • Kim, Gyeong-Seok;Ahn, Do-Rang;Lee, Dong-Wook
    • Proceedings of the KIEE Conference
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    • 2004.11c
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    • pp.277-279
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    • 2004
  • In this paper, we propose an channel estimation method for Multi-Input Multi-Output-Orthogonal frequency Division Multiplexing (MIMO-OFDM). The proposed method estimates uniquely all channel frequency responses needed in space-frequency block coded OFDM systems using "comb-type" pilot symbols. To reduce the computational complexity of the proposed method, least square(LS) and linear minimum mean square error(LMMSE) are used in the frequency-domain. The performance of the proposed approach is evaluated by computer simulation for rayleigh fading channel.

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A Motion-Adaptive De-interlacing Method using Motion Compensated Interpolation (움직임 보상을 통한 움직임 기반의 De-interlacing 기법)

  • 이성규;강석규;이동호
    • Proceedings of the IEEK Conference
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    • 2001.09a
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    • pp.371-374
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    • 2001
  • 본 논문에서는 움직임 보상을 이용한 Motion-Adaptive De-interlacing Method를 제안 한다. 정확한 움직임 추정을 위해서 Pre-filter로서 EBMF(Edge Based Median Filter)를 사용하며 새로운 Block Matching Method를 제안한다. Temporal Filter로서 Motion Missing Error를 제거하기 위해 입력 영상의 움직임 영역에 따라 각각 다른 임계 값을 적용하는 AMPDF(Adaptive Minimum Pixel Difference Filter)를 적용하였으며 MMD(Maximum Motion Detection)와 SAD(Sum of Difference)를 이용하여 빠른 움직임 영역에서 화질을 향상시켰다. 최종적으로 잘못된 움직임 보상에 기인하는 화질의 열화를 방지하기 위한 Motion Correction Filter를 제안한다.

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ON APPROXIMATIONS BY IRRATIONAL SPLINES

  • LEVIN, MIKHAIL P.
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.5 no.1
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    • pp.47-53
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    • 2001
  • A problem of approximation by irrational splines is considered. These splines have a constant curvature between interpolation nodes and need only one additional boundary condition for derivatives, which should be set only at one of two boundary nodes, that is impossible for usual polynomial splines required boundary conditions at both boundary nodal points. Some estimations for numerical differentiation and rounding error analysis are presented.

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A study of distillation column control by using a neural controller (신경제어기를 이용한 증류탑의 제어에 관한 연구)

  • 이문용;박선원
    • 제어로봇시스템학회:학술대회논문집
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    • 1990.10a
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    • pp.234-239
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    • 1990
  • A neural controller for process control was proposed that combines a simple feedback controller with a neural network. This control was applied to distillation control. The feedback error learning technique was used for on-line learning. Important characteristics on neural controller were analyzed. The proposed neural controller can cope well with strong interactions, significant time delays, sudden changes in process dynamics without any prior knowledge of the process. It was shown that the neural controller has good features such as fault tolerance, interpolation effect and random learning capability

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Development of two axis contouring control system based on stepping motor (스텝핑 모우터를 이용한 2축 윤곽제어 장치 개발에 관한 연구)

  • 김교형;이기설
    • 제어로봇시스템학회:학술대회논문집
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    • 1987.10b
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    • pp.228-231
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    • 1987
  • Microprocessor-based software DDA interpolator is developed and applied to two axis contouring control of X-Y table. Developed assembly program is composed of feedrate, linear and circular DDA interpolation routines. Reference-pulse type of open-loop stepping motor control system in which the micro-computer produces a sequence of reference pulses for each axis of motion is adopted. To test performance of the developed program, X-Y table drive system based on stepping motor and shaft encoder is designed. Contouring error of the system in linear and circular path is within .+-.0.2 mm.

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PROBE FEEDING SIMULATION USING OVERLAPPING-GRID TECHNIQUE FOR FDTD

  • Min, Kyeong-Sik;Vu, Manh-Dat
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2005.06a
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    • pp.442-447
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    • 2005
  • This paper presents an application of overlapping-grid technique for probe feeding simulation. The overlapping grid technique is used to solve contour path problem. In this technique, field interpolation is very important to make communication between two coordinates. By applying overlapping-grid technique, error of contour path in probe feeding simulation is reduced.

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