• Title/Summary/Keyword: Error correction

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Packet-Level Scheduling for Implant Communications Using Forward Error Correction in an Erasure Correction Mode for Reliable U-Healthcare Service

  • Lee, Ki-Dong;Kim, Sang-G.;Yi, Byung-K.
    • Journal of Communications and Networks
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    • v.13 no.2
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    • pp.160-166
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    • 2011
  • In u-healthcare services based on wireless body sensor networks, reliable connection is very important as many types of information, including vital signals, are transmitted through the networks. The transmit power requirements are very stringent in the case of in-body networks for implant communication. Furthermore, the wireless link in an in-body environment has a high degree of path loss (e.g., the path loss exponent is around 6.2 for deep tissue). Because of such inherently bad settings of the communication nodes, a multi-hop network topology is preferred in order to meet the transmit power requirements and to increase the battery lifetime of sensor nodes. This will ensure that the live body of a patient receiving the healthcare service has a reduced level of specific absorption ratio (SAR) when exposed to long-lasting radiation. We propose an efficientmethod for delivering delay-intolerant data packets over multiple hops. We consider forward error correction (FEC) in an erasure correction mode and develop a mathematical formulation for packet-level scheduling of delay-intolerant FEC packets over multiple hops. The proposed method can be used as a simple guideline for applications to setting up a topology for a medical body sensor network of each individual patient, which is connected to a remote server for u-healthcare service applications.

Scattering Bar Optical Proximity Correction to Suppress Overlap Error and Side-lobe in Semiconductor Lithography Process (Overlap Margin 확보 및 Side-lobe 억제를 위한 Scattering Bar Optical Proximity Correction)

  • 이흥주
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.4 no.1
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    • pp.22-26
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    • 2003
  • Overlap Errors and side-lobes have been simultaneously solved by the rule-based correction using the rules extracted from test patterns. Lithography process parameters affecting attPSM lithography process have been determined by the fitting method to the real process data. The correction using scattering bars has been compared to the Cr shield method. The optimal insertion rule of the scattering bal's has made it possible to suppress the side-lobes and to enhance DOF at the same time. Therefore, in this paper, the solution to both side-lobe and overlap Error has been proposed using rule-based confection. Compared to the existing Cr shield method, the proposed rule-based correction with scattering bars can reduce the process complexity and time for mask production.

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Quality Monitoring Method Analysis for GNSS Ground Station Monitoring and Control Subsystem (위성항법 지상국 감시제어시스템 품질 감시 기법 분석)

  • Jeong, Seong-Kyun;Lee, Sang-Uk
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.18 no.1
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    • pp.11-18
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    • 2010
  • GNSS(Global Navigation Satellite System) Ground Station performs GNSS signal acquisition and processing. This system generates error correction information and distributes them to GNSS users. GNSS Ground Station consists of sensor station which contains receiver and meteorological sensor, monitoring and control subsystem which monitors and controls sensor station, control center which generates error correction information, and uplink station which transmits correction information to navigation satellites. Monitoring and control subsystem acquires and processes navigation data from sensor station. The processed data is transmitted to GNSS control center. Monitoring and control subsystem consists of data acquisition module, data formatting and archiving module, data error correction module, navigation determination module, independent quality monitoring module, and system maintenance and management module. The independent quality monitoring module inspects navigation signal, data, and measurement. This paper introduces independent quality monitoring and performs the analysis using measurement data.

Correction of the Approximation Error in the Time-Stepping Finite Element Method

  • Kim, Byung-Taek;Yu, Byoung-Hun;Choit, Myoung-Hyun;Kim, Ho-Hyun
    • Journal of Electrical Engineering and Technology
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    • v.4 no.2
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    • pp.229-233
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    • 2009
  • This paper proposes a correction method for the error inherently created by time-step approximation in finite element analysis (FEA). For a simple RL and RLC linear circuit, the error in time-step analysis is analytically investigated, and a correction method is proposed for a non-linear system as well as a linear one. Then, for a practical inductor model, linear and non-linear time-step analyses are performed and the calculation results are corrected by the proposed methods. The accuracy of the corrected results is confirmed by comparing the electric input and output powers.

Implementation and Performance Analysis of DGPS & RTK Error Correction Data Real-Time Transmission System for Long-Distance in Mobile Environments

  • Cho, Ik-Sung;Ha, Chang-Seung;Yim, Jae-Hong
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.291-291
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    • 2002
  • DGPS(Differential Global Positioning System) and RTK(RealTime Kinematic) is in one of today's most widely used surveying techniques. But It's use is restricted by the distance between reference station and rover station and it is difficult to process data in realtime by it's own orgnizational limitation in precise measurement of positioning. To meet these new demands, In This paper, new DGPS and RTK correction data services through Internet and PSTN(Public Switched Telephony Network) have been proposed. For this purpose, we implemented performance a DGPS and RTK error correction data transmission system for long-distance using the internet and PSTN network which allows a mobile user to increase the distance at which the rover receiver is located from the reference in realtime. and we analyzed and compared DGPS and RTK performance by experiments through the Internet and PSTN network with the distance and the time.

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Recursive Error-Component Correcting Method for 3D Shape Reconstruction (3차원 형상 복원을 위한 재귀적 오차 성분 보정 방법)

  • Koh, Sung-shik
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.10
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    • pp.1923-1928
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    • 2017
  • This paper is a study on error correction for three-dimensional shape reconstruction based on factorization method. The existing error correction method based on factorization has a limitation of correction because it is optimized globally. Thus in this paper, we propose our new method which can find and correct the only major error influence factor toward three-dimensional reconstructed shape instead of global approach. We define the error-influenced factor in two-dimensional re-projection deviation space and directly control the error components. In addition, it is possible to improve the error correcting performance by recursively applying the above process. This approach has an advantage under noise because it controls the major error components without depending on any geometric information. The performance evaluation of the proposed algorithm is verified by simulation with synthetic and real image sequence to demonstrate noise robustness.

The Utilization of Local Document Information to Improve Statistical Context-Sensitive Spelling Error Correction (통계적 문맥의존 철자오류 교정 기법의 향상을 위한 지역적 문서 정보의 활용)

  • Lee, Jung-Hun;Kim, Minho;Kwon, Hyuk-Chul
    • KIISE Transactions on Computing Practices
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    • v.23 no.7
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    • pp.446-451
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    • 2017
  • The statistical context-sensitive spelling correction technique in this thesis is based upon Shannon's noisy channel model. The interpolation method is used for the improvement of the correction method proposed in the paper, and the general interpolation method is to fill the middle value of the probability by (N-1)-gram and (N-2)-gram. This method is based upon the same statistical corpus. In the proposed method, interpolation is performed using the frequency information between the statistical corpus and the correction document. The advantages of using frequency of correction documents are twofold. First, the probability of the coined word existing only in the correction document can be obtained. Second, even if there are two correction candidates with ambiguous probability values, the ambiguity is solved by correcting them by referring to the correction document. The method proposed in this thesis showed better precision and recall than the existing correction model.

Error Correction Methode Improve System using Out-of Vocabulary Rejection (미등록어 거절을 이용한 오류 보정 방법 개선 시스템)

  • Ahn, Chan-Shik;Oh, Sang-Yeob
    • Journal of Digital Convergence
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    • v.10 no.8
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    • pp.173-178
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    • 2012
  • In the generated model for the recognition vocabulary, tri-phones which is not make preparations are produced. Therefore this model does not generate an initial estimate of parameter words, and the system can not configure the model appear as disadvantages. As a result, the sophistication of the Gaussian model is fall will degrade recognition. In this system, we propose the error correction system using out-of vocabulary rejection algorithm. When the systems are creating a vocabulary recognition model, recognition rates are improved to refuse the vocabulary which is not registered. In addition, this system is seized the lexical analysis and meaning using probability distributions, and this system deactivates the string before phoneme change was applied. System analysis determine the rate of error correction using phoneme similarity rate and reliability, system performance comparison as a result of error correction rate improve represent 2.8% by method using error patterns, fault patterns, meaning patterns.

Rule-based Speech Recognition Error Correction for Mobile Environment (모바일 환경을 고려한 규칙기반 음성인식 오류교정)

  • Kim, Jin-Hyung;Park, So-Young
    • Journal of the Korea Society of Computer and Information
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    • v.17 no.10
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    • pp.25-33
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    • 2012
  • In this paper, we propose a rule-based model to correct errors in a speech recognition result in the mobile device environment. The proposed model considers the mobile device environment with limited resources such as processing time and memory, as follows. In order to minimize the error correction processing time, the proposed model removes some processing steps such as morphological analysis and the composition and decomposition of syllable. Also, the proposed model utilizes the longest match rule selection method to generate one error correction candidate per point, assumed that an error occurs. For the purpose of deploying memory resource, the proposed model uses neither the Eojeol dictionary nor the morphological analyzer, and stores a combined rule list without any classification. Considering the modification and maintenance of the proposed model, the error correction rules are automatically extracted from a training corpus. Experimental results show that the proposed model improves 5.27% on the precision and 5.60% on the recall based on Eojoel unit for the speech recognition result.

GPS Anomaly Analysis and Pseudorange Accuracy Improvement by Anomalous Satellite Elimination

  • Yoo, Yun-Ja;Cho, Deuk-Jae;Park, Sang-Hyun
    • Journal of Navigation and Port Research
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    • v.34 no.7
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    • pp.511-516
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    • 2010
  • GPS anomaly has increased according to the degradation of satellite performance, and many GPS users could be exposed to any kinds of error-included signals without any previous notice when unscheduled error occurred. RSIM (Reference Station Integrity Monitors) is a typical monitoring method to broadcast PRC (Pseudo Range Correction) for users. However, there were some cases that the receiver detected the anomalous satellite's signal even though it was unhealthy set, consequently it occurred a large range error. Then it is important to monitor the integrity of GPS signal and it is needed to devise the correction method of pseudorange by eliminating error-occurred PRN for notification to GPS users when it is monitored that the anomaly occurred. This paper proposes the basic concept of how to correct the pseudorange. The paper also shows the analysis results of PRN10 GPS anomaly occurred on day 39 in 2007 with corrected results by eliminating anomaly satellite (PRN10). The proposed correction method shows decreased pseudorange error range compared to the case when the anomaly satellite were used.