• Title/Summary/Keyword: sequential pattern analysis

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

  • Kim, Jeong-Tae;Lee, Ho-Keun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.11a
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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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Some Considerations on the On-site Applicability of PSA(Pulse Sequence Analysis) as a Partial Discharge Analysis Method (부분방전 해석 방법으로 PSA(Pulse Sequence Analysis)의 현장 적용성에 대한 고찰)

  • Kim, Jeong-Tae;Lee, Ho-Keun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.18 no.5
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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.

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

  • Lee Chul-Jae
    • Korean Institute of Interior Design Journal
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    • v.14 no.1
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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

  • Kim, Kyung-Won;Kim, Jin-Hee;Kim, Sung-Hoon;Lee, Ju-Hun;Hwang, Do-Soon
    • Aerospace Engineering and Technology
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    • v.3 no.2
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    • pp.20-24
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    • 2004
  • In this paper, a pattern/position tolerance analysis is visited on the insert to mount spacecraft electronic equipment. SQP(Sequential Quadratic Programming) is used to obtain the position tolerance. For examples, the cases of RDU(Remote Drive Unit) and OBC(On Board Computer) in the KOMPSAT-2 STM(Structure and Thermal Model) are analyzed.

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

  • Kwon, Dong Rak
    • Clinical Pain
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    • v.19 no.2
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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.

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

  • Kim, Minseok;Kim, Namgyu
    • The Journal of Information Systems
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    • v.22 no.3
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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.

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

  • Kang, Tae-Ho;Yoo, Jae-Soo
    • The KIPS Transactions:PartD
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    • v.15D no.2
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    • pp.155-162
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    • 2008
  • Biological sequences such as DNA sequences and amino acid sequences typically contain a large number of items. They have contiguous sequences that ordinarily consist of hundreds of frequent items. In biological sequences analysis(BSA), a frequent contiguous sequence search is one of the most important operations. Many studies have been done for mining sequential patterns efficiently. Most of the existing methods for mining sequential patterns are based on the Apriori algorithm. In particular, the prefixSpan algorithm is one of the most efficient sequential pattern mining schemes based on the Apriori algorithm. However, since the algorithm expands the sequential patterns from frequent patterns with length-1, it is not suitable for biological dataset with long frequent contiguous sequences. In recent years, the MacosVSpan algorithm was proposed based on the idea of the prefixSpan algorithm to significantly reduce its recursive process. However, the algorithm is still inefficient for mining frequent contiguous sequences from long biological data sequences. In this paper, we propose an efficient method to mine maximal frequent contiguous sequences in large biological data sequences by constructing the spanning tree with the fixed length. To verify the superiority of the proposed method, we perform experiments in various environments. As the result, the experiments show that the proposed method is much more efficient than MacosVSpan in terms of retrieval performance.

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

  • Choi, Jae-Seok;Yoo, Jeong-Hoon
    • Proceedings of the KSME Conference
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    • 2008.11a
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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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Optimal Array Design of the Permanent Magnet in an Eddy Current Brake (와전류 브레이크의 영구자석배열 최적설계)

  • Choi, Jae-Seok;Yoo, Jeong-Hoon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.33 no.7
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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.

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

  • 김진수;김태용;최준혁;임기욱;이정현
    • Journal of KIISE:Software and Applications
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    • v.31 no.5
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    • pp.586-594
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    • 2004
  • Because web documents become creation and disappearance rapidly, users require the recommend system that offers users to browse the web document conveniently and correctly. One largely untapped source of knowledge about large data collections is contained in the cumulative experiences of individuals finding useful information in the collection. Recommendation systems attempt to extract such useful information by capturing and mining one or more measures of the usefulness of the data. The existing Information Filtering system has the shortcoming that it must have user's profile. And Collaborative Filtering system has the shortcoming that users have to rate each web document first and in high-quantity, low-quality environments, users may cover only a tiny percentage of documents available. And dynamic recommendation system using the user browsing pattern also provides users with unrelated web documents. This paper classifies these web documents using the similarity between the web documents under the web document type and extracts the user browsing sequential pattern DB using the users' session information based on the web server log file. When user approaches the web document, the proposed Dynamic recommendation system recommends Top N-associated web documents set that has high similarity between current web document and other web documents and recommends set that has sequential specificity using the extracted informations and users' session information.