• 제목/요약/키워드: error correction algorithm

검색결과 468건 처리시간 0.03초

고밀도 디스크 드라이브의 서보트랙 기록오차 보정 알고리즘 (A New Correction Algorithm of Servo Track Writing Error in High-Density Disk Drives)

  • 강창익;김창환
    • 제어로봇시스템학회논문지
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    • 제9권4호
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    • pp.284-295
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    • 2003
  • The servo tracks of disk drives are constructed at the time of manufacture with the equipment of servo track writer. Because of the imperfection of servo track writer, disk vibrations and head fluctuations during servo track writing process, the constructed servo tracks might deviate from perfect circles and take eccentric shapes. The servo track writing error should be corrected because it might cause interference with adjacent tracks and irrecoverable operation error of disk drives. The servo track writing error is repeated every disk rotation and so is periodic time function. In this paper, we propose a new correction algorithm of servo track writing error based on iterative teaming approach. Our correction algorithm can learn iteratively the servo track writing error as accurately as is desired. Furthermore, our algorithm is robust to system model errors, is computationally simple, and has fast convergence rate. In order to demonstrate the generality and practical use of our work, we present the convergence analysis of our correction algorithm and some simulation results.

CNC 공작기계 선형피치오차의 최적 보정알고리즘을 구현하는 자동 측정 및 보정 시스템의 개발 (Development of Computer Aided Measurement and Compensation System for Linear Pitch Error Correction in CNC Machine Tools Implementing a New Optimal Correction Algorithm)

  • 이석원;박희재;주종남
    • 한국정밀공학회지
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    • 제15권1호
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    • pp.69-77
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    • 1998
  • Linear displacement accuracy is one of the most important factors that determine machine tool accuracy The laser interferometer has been usually recommended for the measurement of linear displacement accuracy. In this paper, microcomputer aided measurement and compensation system has been developed for the pitch error in a CNC machine tool. For accurate pitch error calculation. the analysis code for the pitch error has been also implemented according to the international standards (ISO). The PC based automatic compensation system for the pitch error is also implemented. A new algorithm for calculating optimum value for pitch error compensation is proposed, minimizing the deviation at each target points. The development system has been applied to a practical CNC maching center and the performance has been demonstrated.

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에러 보정 코드를 이용한 비동기용 대용량 메모리 모듈의 성능 향상 (Performance Improvement of Asynchronous Mass Memory Module Using Error Correction Code)

  • 안재현;양오;연준상
    • 반도체디스플레이기술학회지
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    • 제19권3호
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    • pp.112-117
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    • 2020
  • NAND flash memory is a non-volatile memory that retains stored data even without power supply. Internal memory used as a data storage device and solid-state drive (SSD) is used in portable devices such as smartphones and digital cameras. However, NAND flash memory carries the risk of electric shock, which can cause errors during read/write operations, so use error correction codes to ensure reliability. It efficiently recovers bad block information, which is a defect in NAND flash memory. BBT (Bad Block Table) is configured to manage data to increase stability, and as a result of experimenting with the error correction code algorithm, the bit error rate per page unit of 4Mbytes memory was on average 0ppm, and 100ppm without error correction code. Through the error correction code algorithm, data stability and reliability can be improved.

음절 복원 알고리즘을 이용한 핵심어 오류 보정 시스템 (Key-word Error Correction System using Syllable Restoration Algorithm)

  • 안찬식;오상엽
    • 한국컴퓨터정보학회논문지
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    • 제15권10호
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    • pp.165-172
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    • 2010
  • 어휘 인식 시스템의 오류 보정방법으로는 오류 패턴매칭 기반 방법과 어휘의미 패턴 기반방법이있으며, 이들 방법에서는 오류 보정을 위해 핵심어를 의미적으로 분석하지 못하는 문제점을 가지고 있다. 이를 개선하기 위해 본 논문에서는 음절 복원 알고리즘을 이용한 핵심어 오류 보정 시스템을 제안한다. 인식된 음소 열을 의미 분석 과정을 거쳐 음소가 갖는 의미를 파악하고 음절 복원 알고리즘을 통해 음운 변동이 적용되기 이전의 문자열로 복원하므로 핵심어를 명확히 분석하고 오인식을 줄일 수 있다. 시스템 분석을 위해 음소 유사율과 신뢰도를 이용하여 오류 보정율을 구하였으며, 어휘 인식 과정에서 오류로 판명된 어휘에 대하여 오류 보정을 수행하였다. 에러 패턴 학습을 이용한 방법과 오류 패턴 매칭 기반 방법, 어휘 의미 패턴 기반 방법의 성능 평가 결과 3.0%의 인식 향상율을 보였다.

오차수정법을 도입한 비압축성 유체유동 해석을 위한 수치적 방법 (Numerical algorithm with the concept of defect correction for incompressible fluid flow analysis)

  • 권오붕
    • 대한기계학회논문집B
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    • 제21권3호
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    • pp.341-349
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    • 1997
  • The characteristics of defect correction method are discussed in a sample heat conduction problem showing the numerical solution of the error correction equation can predict the error of the numerical solution of the original governing equation. A way of using defect correction method combined with the existing algorithm for the incompressible fluid flow, is proposed and subsequently tested for the driven square cavity problem. The error correction equations for the continuity equation and the momentum equations are considered to estimate the errors of the numerical solutions of the original governing equations. With this new approach, better velocity and pressure fields can be obtained by correcting the original numerical solutions using the estimated errors. These calculated errors also can be used to estimate the orders of magnitude of the errors of the original numerical solutions.

The Design of Error Detection Auto Correction for Conversion of Graphics to DTV Signal

  • Ryoo-Dongwan;Lee, Jeonwoo
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 ITC-CSCC -1
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    • pp.106-109
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    • 2002
  • In the integrated systems, that is integrated digital TV(DTV) internet and home automation, like home server, is needed integration of digital TV video signal and computer graphic signal. The graphic signal is operating at the high speed and has time-divide-stream. So the re-request of data is not easy at the time of error detection. therefore EDAC algorithm is efficient. This paper presents the efficiency error detection auto correction(EDAC) for conversion of graphics signal to DTV video signal. A presented EDAC algorithms use the modified Hamming code for enhancing video quality and reliability. A EDAC algorithm of this paper can detect single error, double error, triple error and more error for preventing from incorrect correction. And it is not necessary an additional memory. In this paper The comparison between digital TV video signal and graphic signal, a EBAC algorithm and a design of conversion graphic signal to DTV signal with EDAC function is described.

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광학식 디스크에 적합한 RS 부호의 새로운 복호 기법 (New Decoding Techniques of RS Codes for Optical Disks)

  • 엄흥열;김재문;이만영
    • 전자공학회논문지A
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    • 제30A권3호
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    • pp.16-33
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    • 1993
  • New decoding algorithm of double-error-correction Reed-Solmon codes over GF(2$^{8}$) for optical compact disks is proposed and decoding algorithm of RS codes with triple-error-correcting capability is presented in this paper. First of all. efficient algorithms for estimating the number of errors in the received code words are presented. The most complex circuits in the RS decoder are parts for soving the error-location numbers from error-location polynomial, so the complexity of those circuits has a great influence on overall decoder complexity. One of the most known algorithm for searching the error-location number is Chien's method, in which all the elements of GF(2$^{m}$) are substituted into the error-location polynomial and the error-location number can be found as the elements satisfying the error-location polynomial. But Chien's scheme needs another 1 frame delay in the decoder, which reduces decoding speed as well as require more stroage circuits for the received ocode symbols. The ther is Polkinghorn method, in which the roots can be resolved directly by solving the error-location polynomial. Bur this method needs additional ROM (readonly memory) for storing tthe roots of the all possible coefficients of error-location polynomial or much more complex cicuit. Simple, efficient, and high speed method for solving the error-location number and decoding algorithm of double-error correction RS codes which reudce considerably the complexity of decoder are proposed by using Hilbert theorems in this paper. And the performance of the proposed decoding algorithm is compared with that of conventional decoding algorithms. As a result of comparison, the proposed decoding algorithm is superior to the conventional decoding algorithm with respect to decoding delay and decoder complexity. And decoding algorithm of RS codes with triple-error-correcting capability is presented, which is suitable for error-correction in digital audio tape, also.

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Blind QR Code Steganographic Approach Based upon Error Correction Capability

  • Chiang, Yin-Jen;Lin, Pei-Yu;Wang, Ran-Zan;Chen, Yi-Hui
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제7권10호
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    • pp.2527-2543
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    • 2013
  • A novel steganographic QR code algorithm, which not only coveys the secret into the widely-used QR barcode but also preserves the readability of QR content and the capability of error correction, is presented in this article. Different from the conventional applications for QR barcode, the designed algorithm conceals the secret into the QR modules directly by exploiting the error correction capability. General browsers can read the QR content from the QR code via barcode readers; however, only the authorized receiver can further reveal the secret from the QR code directly. The new mechanism can convey a larger secret payload along with adjustment of the QR version and error correction level. Moreover, the blind property allows the receiver to reveal the secret without the knowledge of the embedded position of modules. Experimental results demonstrate that the new algorithm is secure, efficient and feasible for the low-power QR readers and mobile devices.

Considerations on Ionospheric Correction and Integrity Algorithm for Korean SBAS

  • Bang, Eugene;Lee, Jiyun
    • Journal of Positioning, Navigation, and Timing
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    • 제3권1호
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    • pp.17-23
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    • 2014
  • Satellite Based Augmentation Systems (SBAS) provide ionospheric corrections at geographically five degree-spaced Ionospheric Grid Points (IGPs) and confidence bounds, called Grid Ionospheric Vertical Errors (GIVEs), on the error of those corrections. Since the ionosphere is one of the largest error sources which may threaten the safety of a single frequency Global Navigation Satellite System (GNSS) user, the ionospheric correction and integrity bound algorithm is essential for the development of SBAS. The current single frequency based SBAS, already deployed or being developed, implement the ionospheric correction and error bounding algorithm of the Wide Area Augmentation System (WAAS) developed for use in the United States. However, the ionospheric condition is different for each region and it could greatly degrade the performance of SBAS if its regional characteristics are not properly treated. Therefore, this paper discusses key factors that should be taken into consideration in the development of the ionospheric correction and integrity bound algorithm optimized for the Korean SBAS. The main elements of the conventional GIVE monitor algorithm are firstly reviewed. Then, this paper suggests several areas which should be investigated to improve the availability of the Korean SBAS by decreasing the GIVE value.

V.F. 모델링을 이용한 주행차량의 진동에 대한 도로영상의 계측오차 보정 알고리듬 (A Measurement Error Correction Algorithm of Road Image for Traveling Vehicle's Fluctuation Using V.F. Modeling)

  • 김태효;서경호
    • 제어로봇시스템학회논문지
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    • 제12권8호
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    • pp.824-833
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    • 2006
  • In this paper, the image modelling of road's lane markings is established using view frustum(VF) model. From this model, a measurement system of lane markings and obstacles is proposed. The system also involve the real time processing of the 3D position coordinate and the distance data from the camera to the points on the 3D world coordinate by virtue of the camera calibration. In order to reduce their measurement error, an useful algorithm for which analyze the geometric variations due to traveling vehicle's fluctuation using VF model is proposed. In experiments, without correction, for instance, the $0.4^{\circ}$ of pitching rotation gives the error of $0.4{\sim}0.6m$ at the distance of 10m, but the more far distance cause exponentially the more error. We con finned that this algorithm can be reduced less than 0.1m of error at the same condition.