• 제목/요약/키워드: Parity

검색결과 1,098건 처리시간 0.028초

패리티 공간기법을 이용한 위치 서보계의 고장검출 (A PARITY SPACE APPROACH TO FAULT DETECTION FOR A POSITION SERVO SYSTEM)

  • 최경영;박태건;이기상
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 1997년도 하계학술대회 논문집 B
    • /
    • pp.746-748
    • /
    • 1997
  • The parity relation approach for the fault detection and isolation (FDI) of a large diesel engine actuator position servo system is presented. Main purpose of the FDI system is to detect and isolate two important faults, actuator fault and sensor fault, that, if not detected and compensated, degrade the overall system performance. Simulation results are given to show the practical applicability of the FDI scheme.

  • PDF

Automatic detection of the lung orientation in digital PA chest radiographs

  • Nahm, Kie-B.
    • Journal of the Optical Society of Korea
    • /
    • 제1권1호
    • /
    • pp.60-64
    • /
    • 1997
  • An image processing algorithm is presented that can identify the orientation as well as the left/right side (parity) of the digitized radiographs. The orientation was found by computing the mean square deviation between the sampled gray values along the center and their best-fit linear regression relations. The parity was determined by comparing the area difference between two thresholded images of the left and the right side around the heart, which is assumed to be around the center of the image. This method was tested with 86 images with their orientations intentionally rotated. The rotation was limited to multiples of 90 degrees, as this was the way the rotation is most likely to happen in the clinical environment. We obtained positive responses for 85 out of 86 images subject to the screening.

분산형 PLC 시스템에서의 고장 허용 제어 (A Fault Tolerant Control for Distributed Programmable Logic Controller System)

  • 정석권;정영미
    • 동력기계공학회지
    • /
    • 제8권1호
    • /
    • pp.62-68
    • /
    • 2004
  • This paper describes a fault tolerant control in distributed PLC(Programmable Logic Controller) system to ensure reliability of controllers which have some faults simultaneously. First, the behavior of PLC is modeled as discrete expressions using Galois field. Then, we design the control laws for additional spare controllers to generate parity code with two dimensions. Finally, the algorithm for estimating normal output instead of abnormal output from the controllers with fault is suggested. Comparing to the traditional duplication method, the suggested method can reduce the number of spare controllers significantly to ensure control reliability. This method will be applied to an automatic system in order to increase reliability. Also, it can improve cost performance of the system.

  • PDF

중풍 환자의 배뇨장애에 대한 가미대지황탕가감 치료 증례보고 (Case Report of Post-CVA Voiding Dysfunction Treated with Gamidaejihwang-tangaggam)

  • 홍상훈;박상은
    • 대한한의학방제학회지
    • /
    • 제23권2호
    • /
    • pp.261-269
    • /
    • 2015
  • Objectives : The purpose of this case reports is to report the possibility of Post-CVA voiding dysfunction treated with Gamidaejihwang-tangaggam(加味大地黃湯加減). Methods : Three patients with Post-CVA voiding dysfunction were treated by Gamidaejihwang-tanggagam. Effect of treatment is assessed as Bladder Function Parity. Results and conclusions : Bladder function parity score improved, in three case. Additional research is needed on the effects of Gamidaejihwang-tanggagam for a Post-CVA Voiding disfunction.

SDIO에서 RAID 레벨 5의 효율적인 구현 (Efficient Implementation of RAID Level 5 on Single Disk I/O)

  • 김호진;황인철;맹승렬;윤현수
    • 한국정보과학회:학술대회논문집
    • /
    • 한국정보과학회 2004년도 봄 학술발표논문집 Vol.31 No.1 (A)
    • /
    • pp.64-66
    • /
    • 2004
  • 단일 입출력 디스크(SDIO)는 클러스터 환경에서 빠르고 신뢰성 있는 분산 저장장치를 제공한다. 단일 입출력 디스크는 주로 RAID 레벨 0이나 레벨 1을 사용하는데, RAID 레벨 5를 사용함으로써 좋은 성능과 좋은 신뢰도 그리고 높은 디스크 용량 사용률을 얻을 수 있다. 그러나 RAID 레벨 5를 사용함으로써 네트웍 오버헤드 문제, 작은 데이터의 기록 성능 문제, 동시 기록 문제가 발생한다. 위의 새 가지 문제를 해결하거나 최소화하기 위하여 본 논문에서는 Parity Cumulating이라는 접근방법을 제시한다. Parity Cumulating은 패리티의 계산을 두 개의 노드로 분산시킴으로써 네트웍 오버헤드를 줄이고, 패리티를 버퍼에 저장하고 디스크에 작업이 없을 때 처리함으로써 작은 데이터의 기록 성능을 높이며 동시 기록시 일관성을 지킨다.

  • PDF

VDSL 시스템에서의 LDPC 코드 연구 (Analysis a LDPC code in the VDSL system)

  • 조경현;강희훈;이상회;나극환
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 2006년도 하계종합학술대회
    • /
    • pp.999-1000
    • /
    • 2006
  • The LDPC Code is focusing a powerful FEC(Forward Error Correction) codes for 4G Mobile Communication system. LDPC codes are used minimizing channel errors by modeling AWGN Channel as VDSL system. The performance of LDPC code is better than that of turbo code in long code word on iterative decoding algorithm. LDPC code are encoded by sparse parity check matrix. there are decoding algorithms for a LDPC code, Bit Flipping, Message passing, Sum-Product. Because LDPC Codes use low density parity bit, mathematical complexity is low and relating processing time becomes shorten.

  • PDF

화소영역 분산비디오 부호화기법에서 효과적인 화질 예측방법 (An Effective Quality Estimation in Pixel-domain Distributed Video Coding)

  • 김진수
    • 한국정보통신학회:학술대회논문집
    • /
    • 한국정보통신학회 2013년도 추계학술대회
    • /
    • pp.1024-1026
    • /
    • 2013
  • 분산비디오기법은 초경량의 비디오 부호화기를 구현 가능한 이론을 제공한다. 기존의 방법은 패리티비트 요구량을 수신측에서 결정한 다음에 부호화기측으로 요구하는 방법이 널리 연구되어 왔다. 비트율 제어 측면에서 매우 효과적이지만 화질의 측면에서는 어떠한 정보도 제공되고 있지 않고 있다. 본 논문에서는 화소영역에서 수신되는 패리티비트에 의해 보정되는 가상채널 잡음의 양에 따라 복원된 프레임의 품질을 예측하는 방법을 제안한다. 모의실험을 통하여 제안한 방법은 기존의 비트율 제어방법에 따라 화질이 적응적으로 제어될 수 있음을 보인다.

  • PDF

Cycles in Conditional Faulty Enhanced Hypercube Networks

  • Liu, Min;Liu, Hongmei
    • Journal of Communications and Networks
    • /
    • 제14권2호
    • /
    • pp.213-221
    • /
    • 2012
  • The architecture of an interconnection network is usually represented by a graph, and a graph G is bipancyclic if it contains a cycle for every even length from 4 to ${\mid}V(G){\mid}$. In this article, we analyze the conditional edge-fault-tolerant properties of an enhanced hypercube, which is an attractive variant of a hypercube that can be obtained by adding some complementary edges. For any n-dimensional enhanced hypercube with at most (2n-3) faulty edges in which each vertex is incident with at least two fault-free edges, we showed that there exists a fault-free cycle for every even length from 4 to $2^n$ when n($n{\geq}3$) and k have the same parity. We also show that a fault-free cycle for every odd length exists from n-k+2 to $2^n-1$ when n($n{\geq}2$) and k have the different parity.

병렬 어레이 프로세싱을 위한 반집합 대수 LDPC 부호의 구성 (Construction of Semi-Algebra Low Density Parity Check Codes for Parallel Array Processing)

  • 이광재;이문호;이동민
    • 한국통신학회논문지
    • /
    • 제30권1C호
    • /
    • pp.1-8
    • /
    • 2005
  • 본 논문에서는 이중 대각 부행렬에 근거한 결정적 LDPC 부호의 일종인 반집합 대수 LDPC 행렬이라는 새로운 LDPC 부호의 구성을 제시한다. 이러한 구성 방법에 의해 일종의 high rate LDPC 부호를 얻게 되며, 이 부류의 부호들은 큰 girth와 양호한 최소거리 특성을 갖는다. 또한, 순환 시프트 레지스터를 이용한 단순한 병렬 어레이 구조로 구현할 수 있으며, 반복 복호에 의해 용이하게 처리될 수 있다.

An Improvement of UMP-BP Decoding Algorithm Using the Minimum Mean Square Error Linear Estimator

  • Kim, Nam-Shik;Kim, Jae-Bum;Park, Hyun-Cheol;Suh, Seung-Bum
    • ETRI Journal
    • /
    • 제26권5호
    • /
    • pp.432-436
    • /
    • 2004
  • In this paper, we propose the modified uniformly most powerful (UMP) belief-propagation (BP)-based decoding algorithm which utilizes multiplicative and additive factors to diminish the errors introduced by the approximation of the soft values given by a previously proposed UMP BP-based algorithm. This modified UMP BP-based algorithm shows better performance than that of the normalized UMP BP-based algorithm, i.e., it has an error performance closer to BP than that of the normalized UMP BP-based algorithm on the additive white Gaussian noise channel for low density parity check codes. Also, this algorithm has the same complexity in its implementation as the normalized UMP BP-based algorithm.

  • PDF