• 제목/요약/키워드: sequential pattern analysis

검색결과 113건 처리시간 0.026초

부분방전 해석 방법으로 PSA(Pulse Sequence Analysis)의 문제점에 대한 고찰 (Some Considerations on the Problems of PSA(Pulse Sequence Analysis) as a Partial Discharge Analysis Method)

  • 김정태;이호근
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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    • pp.327-330
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    • 2004
  • Because of its effectiveness for the PD(partial discharge) pattern recognition, PSA(Pulse Sequence Analysis) has been considered as a new analytic method instead of conventional PRPDA(Phase Resolved Partial Discharge Analysis). However, PSA has a big problem that can misanalyze patterns in case of data missing resulting from poor sensitivity because it analyses the correlation between sequential pulses, which leads to hesitate to apply it to on-site. Therefore, in this paper, the problems of PSA such as data missing and noise adding cases were investigated. For the purpose, PD data obtained from various defects including noise adding data were used and analysed, The result showed that both cases can cause fatal errors in recognizing PD patterns. In case of the data missing, the error depends on the kinds of defect and the degree of degradation. Also, it could be noticed that the error due to adding noises was larger than that due to some data missing.

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부분방전 해석 방법으로 PSA(Pulse Sequence Analysis)의 현장 적용성에 대한 고찰 (Some Considerations on the On-site Applicability of PSA(Pulse Sequence Analysis) as a Partial Discharge Analysis Method)

  • 김정태;이호근
    • 한국전기전자재료학회논문지
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    • 제18권5호
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    • pp.484-489
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    • 2005
  • Because of its effectiveness for the PD(Partial Discharge) pattern recognition, PSA(Pulse Sequence Analysis) has been considered as a new analytic method instead of conventional PRPDA(Phase Resolved Partial Discharge Analysis). However, it is generally thought that PSA has some possibility to misjudge patterns in case of data-missing resulting from poor sensitivity because it analyses the correlation between sequential pulses, which leads to hesitate to apply it to on-site. Therefore, in this paper, the problems of PSA such as data-missing and noise-adding cases were investigated. for the purpose, PD data obtained from various defects including noise-adding data were used and analyzed. As a result, it was shown that both cases could cause fatal errors in recognizing PD patterns. In case of the data missing, the error was dependant on the kinds of defect and the degree of degradation Also, it could be noticed that the error due to adding noises was larger than that due to some data missing.

기하학과 비선형 공간 형태의 상관성에 관한 기초 연구 (A Study on the Interrelationship between Geometry and Nonlinear Figure of Space)

  • 이철재
    • 한국실내디자인학회논문집
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    • 제14권1호
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    • pp.160-167
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    • 2005
  • The paper raises a question in argument about the method of creating space depending on accidental creation by computer as the method of describing movement pattern, and emphasizes the role of the mathematics which may change the shape into the image or reflection, that is, data which human may understand and expect. If the mathematics could be the method of describing movement pattern, it may play a important role on the analysis of architectural space based on the idea of post-constructionism, which is likely to consider the modern architectural space recognized as the sequential frames containing movement, as the suspended state of the moving object. And then, this infinite series, 'the sum' of the suspended state, is not studied mathematically and scientifically, but is able to be shaped by reviewing the validity in mathematics about the nonlinear space. This is, therefore, the fundamental research in order to define the role of the mathematics in formation of space of contemporary architecture.

위성탑재장비 장착패턴을 고려한 제작 오차 분석

  • 김경원;김진희;김성훈;이주훈;황도순
    • 항공우주기술
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    • 제3권2호
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    • pp.20-24
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    • 2004
  • 본 논문에서는 위성용 전자 장비 장착을 위한 인서트의 형태/위치 공차 해석법에 대해 기술한다. 위치 공차를 구하기 위해 순차적 이차 계획법이 사용되었으며, 예제로 다목적 실용위성 2호기 STM(Structure and Thermal Model)의 RDU(Remote Drive Unit)와 OBC(On-Board Computer)의 장착 경우를 해석하였다.

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회전근개 파열의 수술적 치료 후 회전근개 초음파 소견 (Postoperative Ultrasound Findings of the Rotator Cuff Tendon after Arthroscopic Repair of a Rotator Cuff Tear)

  • 권동락
    • Clinical Pain
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    • 제19권2호
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    • pp.64-69
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    • 2020
  • Ultrasound (US) imaging is an efficient, easy to use, rapid, dynamic, noninvasive, with rare side-effects and inexpensive tool allowing for facilitated diagnosis and management of the painful shoulder. It also has advantages over other imaging modalities in the evaluation of the postoperative shoulder for rotator cuff integrity and correct anchor and suture placement, as well as rotator cuff analysis following repair surgery. Early postoperative tendons frequently had a hypo- echoic echo texture and the absence of a fibrillar pattern, which might be misinterpreted as recurrent tears. however, these features often normalized into tendons with an increased echo texture and the reappearance of a fibrillar pattern at 6 months. Based on these sequential findings, the US findings within 3 months after surgery should be interpreted with caution to accurately understand and monitor the repaired tendon status.

구매의도 생성 순서와 구매실현 순서의 역전 현상을 감안한 확장된 순차분석 방법론 (An Investigation on Expanding Traditional Sequential Analysis Method by Considering the Reversion of Purchase Realization Order)

  • 김민석;김남규
    • 한국정보시스템학회지:정보시스템연구
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    • 제22권3호
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    • pp.25-42
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    • 2013
  • Recently various kinds of Information Technology services are created and the quantities of the data flow are increase rapidly. Not only that, but the data patterns that we deal with also slowly becoming diversity. As a result, the demand of discover the meaningful knowledge/information through the various mining analysis such as linkage analysis, sequencing analysis, classification and prediction, has been steadily increasing. However, solving the business problems using data mining analysis does not always concerning, one of the major causes of these limitations is there are some analyzed data can't accurately reflect the real world phenomenon. For example, although the time gap of purchasing the two products is very short, by using the traditional sequencing analysis, the precedence relationship of the two products is clearly reflected. But in the real world, with the very short time interval, the precedence relationship of the two purchases might not be defined. What was worse, the sequence of the purchase intention and the sequence of the purchase realization of the two products might be mutually be reversed. Therefore, in this study, an expanded sequencing analysis methodology has been proposed in order to reflect this situation. In this proposed methodology, the purchases that being made in a very short time interval among the purchase order which might not important will be notice, and the analysis which included the original sequence and reversed sequence will be used to extend the analysis of the data. Also, to some extent a very short time interval can be defined as the time interval, so an experiment were carried out to determine the varying based on the time interval for the actual data.

생물학적 데이터 서열들에서 빈번한 최대길이 연속 서열 마이닝 (Mining Maximal Frequent Contiguous Sequences in Biological Data Sequences)

  • 강태호;유재수
    • 정보처리학회논문지D
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    • 제15D권2호
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    • pp.155-162
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    • 2008
  • DNA 염기 서열이나 단백질 아미노산 서열과 같은 생물학적 서열 데이터들은 일반적으로 많은 수의 항목들을 가지고 있다. 생물학적 데이터 서열들에는 보통 빈번하게 발생하는 수 백개의 항목으로 이루어진 연속된 서열들이 존재한다. 이들 서열들에서 빈번하게 발생하는 연속 서열을 검색하는 것은 생물학적 서열 분석에서 중요한 부분을 차지하고 있다. 이전에는 순차 패턴을 효과적으로 발견하고자 하는 많은 연구들이 수행되었으며 대부분의 기존 순차패턴 마이닝 기법들은 Apriori 알고리즘을 기반으로 한다. PrefixSpan 알고리즘은 Apriori 기반의 가장 효율적인 순차패턴 마이닝 기법이다. 하지만 이 알고리즘은 길이-1인 빈발 패턴들로 부터 서열 패턴을 확장해나가는 방식이다. 따라서 길이가 긴 연속 서열을 포함하는 생물학적 데이터서열들에 대한 검색방법으로는 적합하지 않다. 최근에는 기존의 PrefixSpan방식을 이용하면서도 반복적인 처리과정을 줄인 MacosVSpan이 제안되었다. 하지만 이 알고리즘 또한 길이가 긴 생물학적 데이터 서열들로부터 빈번하게 발생하는 연속 서열들을 검색하기에는 효율적이지 않다. 본 논문에서는 많은 양의 생물학적 데이터 서열들로부터 빈번한 연속서열을 고정길이 확장 트리를 이용하여 효과적으로 찾아내는 방법을 제안한다. 그리고 다양한 환경에서 실험을 통해 제안하는 방식이 MacosVSpan알고리즘에 비해 검색성능이 보다 우수함을 보인다.

와전류 브레이크를 위한 영구자석 배열의 최적설계 (Optimal Design of Permanent Magnet Arrays for Eddy Current Brakes)

  • 최재석;유정훈
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.609-611
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    • 2008
  • Eddy current is usually generated in material with high conductivity by time-varying source such as AC current and also is induced in the moving source with relative velocity. The contactless magnetic brakes make use of the braking force from the eddy current generated by moving source and currently used for the secondary brakes of heavy trucks, buses and rail vehicles. This study aims to design the magnetization pattern of a permanent magnet type eddy current brake system to maximize the braking force. The analysis of the brake system is based on the two-dimensional finite element analysis. We use the sequential linear programming as the optimizer and the adjoint variable method for the sensitivity analysis.

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와전류 브레이크의 영구자석배열 최적설계 (Optimal Array Design of the Permanent Magnet in an Eddy Current Brake)

  • 최재석;유정훈
    • 대한기계학회논문집A
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    • 제33권7호
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    • pp.658-663
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    • 2009
  • Eddy current is usually generated in the material with high conductivity by time-varying source such as AC current and also is induced by the moving source with relative velocity. The contactless magnetic brake makes use of the braking force from the eddy current generated by the moving source and currently used for the secondary brakes of heavy trucks, buses and rail vehicles. This study aims to design the magnetization pattern of the eddy current brake system of a permanent magnet type where the design aim is to maximize the braking force. The analysis of brake systems is based on the two-dimensional finite element analysis. We use the sequential linear programming as the optimizer and the adjoint variable method is applied for the sensitivity analysis.

사용자 로그 분석과 클러스터 내의 문서 유사도를 이용한 동적 추천 시스템 (A Dynamic Recommendation System Using User Log Analysis and Document Similarity in Clusters)

  • 김진수;김태용;최준혁;임기욱;이정현
    • 한국정보과학회논문지:소프트웨어및응용
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    • 제31권5호
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    • pp.586-594
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    • 2004
  • 웹 문서들은 빠른 생성과 소멸의 특징 때문에, 사용자는 찾고자하는 웹 문서를 신속하고 정확하게 추천해 줄 시스템을 요구하고 있다. 정제되지 않은 웹 데이타에는 사용자들의 축적된 경험들을 포함하는 유용한 정보들을 포함하고 있다. 현재, 이러한 유용한 정보를 마이닝 기법이나 통계학적 측정 방법 등을 가지고 정제하여 추천 시스템을 통해 사용자에게 제공하려는 노력이 시도되고 있다. 기존의 정보 필터링 방식은 사용자들의 프로파일을 반드시 이용해야 하는 문제점을 갖고 있으며, 협력적 필터링 방식은 First Rater 문제와 Sparsity 문제가 있다. 또한 사용자 브라우징 패턴을 이용하는 동적 추천 시스템은 연관성이 없는 웹 문서들을 결과로서 제공한다는 문제점이 있다. 본 논문에서는 웹 문서 형식에 따라 웹 문서 사이의 유사도를 이용하여 웹 문서를 분류하고, 웹 서버에 기록된 로그 파일을 이용하여 사용자 브라우징 순차 패턴 DB를 생성한다. 이렇게 생성된 정보들과 사용자들의 세션 정보를 이용하여, 사용자가 웹 문서에 접근했을 때 현재 웹 문서와 유사도가 높은 상위 N개의 연관 웹 문서 집합을 제공하고, 순차적인 특성을 갖는 웹 문서를 추천 문서로 제공하는 시스템을 제안한다.