• Title/Summary/Keyword: matrix correction

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Color Correction with Optimized Hardware Implementation of CIE1931 Color Coordinate System Transformation (CIE1931 색좌표계 변환의 최적화된 하드웨어 구현을 통한 색상 보정)

  • Kim, Dae-Woon;Kang, Bong-Soon
    • Journal of IKEEE
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    • v.25 no.1
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    • pp.10-14
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    • 2021
  • This paper presents a hardware that improves the complexity of the CIE1931 color coordinate algorithm operation. The conventional algorithm has disadvantage of growing hardware due to 4-Split Multiply operations used to calculate large bits in the computation process. But the proposed algorithm pre-calculates the defined R2X, X2R Matrix operations of the conventional algorithm and makes them a matrix. By applying the matrix to the images and improving the color, it is possible to reduce the amount of computation and hardware size. By comparing the results of Xilinx synthesis of hardware designed with Verilog, we can check the performance for real-time processing in 4K environments with reduced hardware resources. Furthermore, this paper validates the hardware mount behavior by presenting the execution results of the FPGA board.

The Lens Aberration Correction Method for Laser Precision Machining in Machine Vision System (머신비전 시스템에서 레이저 정밀 가공을 위한 렌즈 수차 보정 방법)

  • Park, Yang-Jae
    • Journal of Digital Convergence
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    • v.10 no.10
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    • pp.301-306
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    • 2012
  • We propose a method for accurate image acquisition in a machine vision system in the present study. The most important feature is required by the various lenses to implement real and of the same high quality image-forming optical role. The input of the machine vision system, however, is generated due to the aberration of the lens distortion. Transformation defines the relationship between the real-world coordinate system and the image coordinate system to solve these problems, a mapping function that matrix operations by calculating the distance between two coordinates to specify the exact location. Tolerance Focus Lens caused by the lens aberration correction processing to Galvanometer laser precision machining operations can be improved. Aberration of the aspheric lens has a two-dimensional shape of the curve, but the existing lens correction to linear time-consuming calibration methods by examining a large number of points the problem. How to apply the Bilinear interpolation is proposed in order to reduce the machining error that occurs due to the aberration of the lens processing equipment.

DGNSS-CP Performance Comparison of Each Observation Matrix Calculation Method (관측 행렬 산출 기법 별 DGNSS-CP 성능 비교)

  • Shin, Dong-hyun;Lim, Cheol-soon;Seok, Hyo-jeong;Yoon, Dong-hwan;Park, Byungwoon
    • Journal of Advanced Navigation Technology
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    • v.20 no.5
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    • pp.433-439
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    • 2016
  • Several low-cost global navigation satellite system (GNSS) receivers do not support general range-domain correction, and DGNSS-CP (differential GNSS) method had been suggested to solve this problem. It improves its position accuracy by projecting range-domain corrections to the position-domain and then differentiating the stand-alone position by the projected correction. To project the range-domain correction, line-of-sight vectors from the receiver to each satellite should be calculated. The line-of-sight vectors can be obtained from GNSS broadcast ephemeris data or satellite direction information, and this paper shows positioning performance for the two methods. Stand-alone positioning result provided from Septentrio PolaRx4 Pro receiver was used to show the difference. The satellite direction information can reduce the computing load for the DGNSS-CP by 1/15, even though its root mean square(RMS) of position error is bigger than that of ephemeris data by 0.1m.

A New Illumination Compensation Method based on Color Optimization Function for Generating 3D Volumetric Model (3차원 체적 모델의 생성을 위한 색상 최적화 함수 기반의 조명 보상 기법)

  • Park, Byung-Seo;Kim, Kyung-Jin;Kim, Dong-Wook;Seo, Young-Ho
    • Journal of Broadcast Engineering
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    • v.25 no.4
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    • pp.598-608
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    • 2020
  • In this paper, we propose a color correction technique for images acquired through a multi-view camera system for acquiring a 3D model. It is assumed that the 3D volume is captured indoors, and the position and intensity of the light is constant over time. 8 multi-view cameras are used, and converging toward the center of the space, so even if the lighting is constant, the intensity and angle of light entering each camera may be different. Therefore, a color optimization function is applied to a color correction chart taken from all cameras, and a color conversion matrix defining a relationship between the obtained 8 images is calculated. Using this, the images of all cameras are corrected based on the standard color correction chart. This paper proposed a color correction method to minimize the color difference between cameras when acquiring an image using 8 cameras of 3D objects, and experimentally proved that the color difference between images is reduced when it is restored to a 3D image.

Low Density Parity Check (LDPC) Coded OFDM System Using Unitary Matrix Modulation (UMM) (UMM(Unitary Matrix Modulation)을 이용한 LDPC(Low Density Parity Check) 코디드 OFDM 시스템)

  • Kim Nam Soo;Kang Hwan Min;Cho Sung Ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.5A
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    • pp.436-444
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    • 2005
  • Unitary matrix modulation (UMM) is investigated in multiple antennas system that is called unitary space-time modulation (USTM). In an OFDM, the diagonal components of UMM with splitting over the coherence bandwidth (UMM-S/OFDM) have been proposed. Recently LDPC code is strongly attended and studied due to simple decoding property with good error correction property. In this paper, we propose LDPC coded UMM-S/OFDM for increasing the system performance. Our proposed system can obtain frequency diversity using UMM-S/OFDM like USTM/OFDM, and large coding gain using LDPC code. The superior characteristics of the proposed UMM-S/OFDM are demonstrated by extensive computer simulations in multi-path Rayleigh fading channel.

Determination of Arsenic, Lead and Selenium in Rice Flour by Graphite Furnace Atomic Absorption Spectrometry (흑연로원자흡수분광법에 의한 쌀분말시료중의 비소, 납, 셀레늄의 정량)

  • Cho, Kyung-Haeng;Suh, Jung-Ki
    • Analytical Science and Technology
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    • v.12 no.2
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    • pp.130-135
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    • 1999
  • A graphite furnace atomic absorption spectrometry (GFAAS) with matrix modification has been used to determine trace amounts of arsenic, lead and selenium in rice flour samples. A mixed solution of palladium and magnesium nitrate was used as a matrix modifier to convert the analyte elements into a phase of higher thermostability and to increase the volatility of concomitants in graphite furnace. Matrix modification effects by the mixed solution were investigated for several elements (As, Cd, Cu, Pb, Se, Zn). It has been found that the matrix modifier substantially increase the pyrolysis and atomization temperature, and absorbance for As, Pb and Se. The concentration of As, Pb and Se in rice flour samples were determined by standard addition method with Zeeman background correction after microwave acid digestion. In this method the characteristic concentrations of As, Pb and Se are 26 ng/g, 18 ng/g, 24 ng/g on the basis of dry sample respectively.

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An Efficient QCLS Positioning Method Using Weight Estimation for TDOA Measurements (TDOA 측정치를 이용한 가중치 추정방식의 QCLS 측위 방법)

  • Kim, Dong-Hyouk;Song, Seung-Hun,;Park, Kyoung-Soon;Sung, Tae-Kyung
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.44 no.4 s.316
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    • pp.1-7
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    • 2007
  • When the sensor geometry is poor, the user position estimate obtained by of GN (Gauss-Newton) method is often diverged in radio navigation. In other to avoid divergence problem QCLS (Quadratic Correction Least Square) method using TDOA (Time Difference of Arrival) measurements is introduced, but the estimation error is somewhat large. This paper presents the modified QCLS method using weighted least square. Since the weighting matrix is influenced by the unknown user position, two-step approach is employed in the proposed method. The weighting matrix is estimated in the first step using least square, and then find user position is obtained using weighted least square. Simulation results show that the performance of the proposed method is superior to the conventional QCLS all over the workspace.

Two-dimensional OCDMA Encoder/Decoder Composed of Double Ring Add/Drop Filters and All-pass Delay Filters (이중 링 Add/Drop 필터와 All-pass 지연 필터로 구성된 이차원 OCDMA 인코더/디코더)

  • Chung, Youngchul
    • Korean Journal of Optics and Photonics
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    • v.33 no.3
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    • pp.106-112
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    • 2022
  • A two-dimensional optical code division multiple access (OCDMA) encoder/decoder, which is composed of add/drop filters and all-pass filters for delay operation, is proposed. An example design is presented, and its feasibility is illustrated through numerical simulations. The chip area of the proposed OCDMA encoder/decoder could be about one-third that of a previous OCDMA device employing delay waveguides. Its performance is numerically investigated using the transfer-matrix method combined with the fast Fourier transform. The autocorrelation peak level over the maximum cross-correlation level for incorrect wavelength hopping and spectral phase code combinations is greater than 3 at the center of the correctly decoded pulse, which assures a bit error rate lower than 10-3, corresponding to the forward error-correction limit.

Matrix type CRC and XOR/XNOR for high-speed operation in DDR4 and GDDR5 (DDR4/GDDR5에서 고속동작을 위한 matrix형 CRC 및 XOR/XNOR)

  • Lee, JoongHo
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.8
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    • pp.136-142
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    • 2013
  • CRC features have been added to increase the reliability of the data in memory products for high-speed operation, such as DDR4. High-speed memory products in a shortage of internal timing margin increases for the CRC calculation. Because the existing CRC requires many additional circuit area and delay time. In this paper, we show that the matrix-type CRC and a new XOR/XNOR gate could be improved the circuit area and delay time. Proposed matrix-type CRC can detect all odd-bit errors and can detect even number of bit errors, except for multiples of four bits. In addition, a single error in the error correction can reduce the burden of re-transmission of data between memory products and systems due to CRC errors. In addition, the additional circuit area, compared to existing methods can be improved by 57%. The proposed XOR gate which is consists of six transistors, it can reduce the area overhead of 35% compared to the existing CRC, 50% of the gate delay can be reduced.

Meteor-Statistical Analysis for Establishment of Jejudo Wind Resource Database (제주도 풍력자원 데이터베이스 구축을 위한 기상통계분석)

  • Kim, Hyun-Goo;Jang, Moon-Seok;Lee, Eon-Jeong
    • Journal of Environmental Science International
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    • v.17 no.6
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    • pp.591-599
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    • 2008
  • In order to support the development of wind farms in Jejudo, a wind resource database for Jejudo has been established using a meteor-statistical analysis of KIER(Korea Institute of Energy Research) met-mast measurements and KMA(Korea Meteorological Administration) weather data. The analysis included wind statistics, tower shading, an exposure category classification using satellite images, the effect of atmospheric stability on the wind profile exponent, and a correlation matrix of wind speed to gain an understanding of the meteorological correlation between long-term weather observation stations and short-term met-mast measurements. The wind resource database for Jejudo, is to be provided as an add-on to Google $Earth^{TM}$, which is expected to be utilized as a guideline for the selection of an appropriate reference site for long-term correction in the next wind farm development project.