• Title, Summary, Keyword: error correction algorithm

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

  • 강창익;김창환
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.4
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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.

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

  • 이석원;박희재;주종남
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.1
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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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Performance Improvement of Asynchronous Mass Memory Module Using Error Correction Code (에러 보정 코드를 이용한 비동기용 대용량 메모리 모듈의 성능 향상)

  • Ahn, Jae Hyun;Yang, Oh;Yeon, Jun Sang
    • Journal of the Semiconductor & Display Technology
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    • v.19 no.3
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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.

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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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    • v.7 no.10
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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.

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

  • Ahn, Chan-Shik;Oh, Sang-Yeob
    • Journal of the Korea Society of Computer and Information
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    • v.15 no.10
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    • pp.165-172
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    • 2010
  • There are two method of error correction in vocabulary recognition system. one error pattern matting base on method other vocabulary mean pattern base on method. They are a failure while semantic of key-word problem for error correction. In improving, in this paper is propose system of key-word error correction using algorithm of syllable restoration. System of key-word error correction by processing of semantic parse through recognized phoneme meaning. It's performed restore by algorithm of syllable restoration phoneme apply fluctuation before word. It's definitely parse of key-word and reduced of unrecognized. Find out error correction rate using phoneme likelihood and confidence for system parse. When vocabulary recognition perform error correction for error proved vocabulary. system performance comparison as a result of recognition improve represent 2.3% by method using error pattern learning and error pattern matting, vocabulary mean pattern base on method.

Electrostatic Coupling Intra-Body Communication Based on Frequency Shift Keying and Error Correction (FSK 통신 및 에러 정정을 통한 Intra-Body Communication)

  • Cho, Seongho;Park, Daejin
    • IEMEK Journal of Embedded Systems and Applications
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    • v.15 no.4
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    • pp.159-166
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    • 2020
  • The IBC (Intra-Body Communication) benefits from a wireless communication system for exchanging various kinds of digital information through wearable electronic devices and sensors. The IBC using the human body as the transmission channel allows wireless communication without the transmitting radio frequency waves to the air. This paper discusses the results of experiments on electrostatic coupling IBC based on FSK (Frequency Shift Keying) and 1 bit error correction. We implemented FSK communication and 1 bit error correction algorithm using the MCU boards and aluminum tape electrodes. The transmitter modulates digital data using 50% duty square wave as carrier signal and transmits data through human body. The receiver performs ADC (Analog to Digital Conversion) on carrier signal from human body. In order to figure out the frequency of carrier signal from ADC results, we applied zero-crossing algorithm which is used to detect the edge characteristic in computer vision. Experiment results shows that digital data modulated as square wave can be successfully transmitted through human body by applying the proposed architecture of a 1ch GPIO as a transmitter and 1ch ADC for as a receiver. Also, this paper proposes 1 bit error correction technique for reliable IBC. This technique performs error correction by utilizing the feature that carrier signal has 50% duty ratio. When 1 bit error correction technique is applied, the byte error rate at receiver side is improved around 3.5% compared to that not applied.

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

  • Gwon, O-Bung
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.3
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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
    • Proceedings of the IEEK Conference
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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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New Decoding Techniques of RS Codes for Optical Disks (광학식 디스크에 적합한 RS 부호의 새로운 복호 기법)

  • 엄흥열;김재문;이만영
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.30A no.3
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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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Considerations on Ionospheric Correction and Integrity Algorithm for Korean SBAS

  • Bang, Eugene;Lee, Jiyun
    • Journal of Positioning, Navigation, and Timing
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    • v.3 no.1
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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.