• Title/Summary/Keyword: Material feature

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A Study on Signal Feature Extraction of Partial Discharge Types Using Discrete Wavelet Transform Technique (이산웨이블렛 변환기법을 이용한 부분방전종류의 신호특징추출에 관한연구)

  • Park, Jae-Jun;Jeon, Byung-Hoon;Kim, Jin-Seong;Jeon, Hyun-Gu;Baek, Kwan-Hyun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.05c
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    • pp.170-176
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    • 2002
  • In this papers, we proposed the feature extraction method due to partial discharge type of transformers. For wavelet transform, Daubechie's filter is used, we can obtain wavelet coefficients which is used to extract feature of statistical parameters (maximum value, average value, dispersion, skewness, kurtosis) about acoustic emission signal generated from each partial discharge type. The defects which could occur in a transformer were simulated by using needle-plane electrode, IEC electrode and Void electrode. Also, these coefficients are used to identify signal of partial discharge type electrode fault in transformer. As a result, from compare of acoustic emission amplitude and acoustic average value, we are obtained results of IEC electrode> Void electrode> Needle-Plane electrode. otherwise, In case of skewness and kurtosis, we are obtained results of Needle-Plane electrode electrode> Void electrode> IEC electrode.

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Evaluation of Chaotic evaluation of degradation signals of AISI 304 steel using the Attractor Analysis (어트랙터 해석을 이용한 AISI 304강 열화 신호의 카오스의 평가)

  • 오상균
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.9 no.2
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    • pp.45-51
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    • 2000
  • This study proposes that analysis and evaluation method of time series ultrasonic signal using the chaotic feature extrac-tion for degradation extent. Features extracted from time series data using the chaotic time series signal analyze quantitatively material degradation extent. For this purpose analysis objective in this study if fractal dimension lyapunov exponent and strange attractor on hyperspace. The lyapunov exponent is a measure of the rate at which nearby trajectories in phase space diverge. Chaotic trajectories have at least one positive lyapunov exponent. The fractal dimension appears as a metric space such as the phase space trajectory of a dynamical syste, In experiment fractal(correlation) dimensions and lyapunov experiments showed values of mean 3.837-4.211 and 0.054-0.078 in case of degradation material The proposed chaotic feature extraction in this study can enhances ultrasonic pattern recognition results from degrada-tion signals.

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A Development of the Tolerance Modeler for Feature-based CAPP (특징형상에 기반한 공정설계를 위한 공차 모델러 개발)

  • 김재관;노형민;이수홍
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.267-271
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    • 2000
  • A part definition must not only provide shape information of a nominal part but also contain non-shape information such as tolerances, surface roughness and material attributes. Although machining features are useful for suitable shape information for process reasoning in the CAPP, they need to be integrated with tolerance information for effective process planning. We develop the tolerance modeler that efficiently integrates machining features with tolerance information for feature-based CAPP It is based on the association of machining features, tolerance features. and tolerances Tolerance features, where tolerances are assigned, are classified into two types; one is the face that is a topological entity on a solid model and the other is the functional geometry that is not referenced to topological entities. The functional geometry is represented by using machining features All the data for representing tolerance information with machining features are stored completely and unambiguously in the independent tolerance structure. The developed tolerance modeler is implemented as a module of a comprehensive feature-based CAPP system.

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Feature Extraction of Simulated fault Signals in Stator Windings of a High Voltage Motor and Classification of Faulty Signals

  • Park, Jae-Jun;Jang, In-Bum
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.18 no.10
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    • pp.965-975
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    • 2005
  • In the case of the fault in stator windings of a high voltage motor. it facilitates certain destructive characteristics in insulations. This will result in a decreased reliability in power supplies and will prevent the generation of electricity, which will result in huge economic losses. This study simulates motor windings using normal windings and four faulty windings for an actual fault in stator winding of a high voltage motor. The partial discharge signals produced in each faulty winding were measured using an 80 PF epoxy/mica coupler sensor. In order to quantified signal waves its a way of feature extraction for each faulty signal, the signal wave of winding was quantified to measure the degree of skewness shape and kurtosis, which are both types of statistical parameters, using a discrete wavelet transformation method for each faulty type. Wave types present different types lot each faulty type, and the skewness and kurtosis also present different quantified values. The result of feature extraction was used as a preprocessing stage to identify a certain fault in stater windings. It is evident that the type of faulty signals can be classified from the test results using faulty signals that were randomly selected from the signal, which was not applied in the training after the training and learning period, by applying it to a back-propagation algorithm due to the supervising and learning method in a neural network in order to classify the faulty type. This becomes an important basis for studying diagnosis methods using the classification of faulty signals with a feature extraction algorithm, which can diagnose the fault of stator windings in the future.

Transformable Design in Contemporary Fashion (현대패션에 나타난 트랜스포머블 디자인)

  • Lim, Byung-Soo;Yim, Eun-Hyuk
    • Journal of the Korea Fashion and Costume Design Association
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    • v.17 no.3
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    • pp.29-43
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    • 2015
  • This study investigates transformable designs in contemporary fashion. In contemporary society, designs are accompanied by various changes such as transformation of shapes or variation of material beyond the certain form of dress. As a result of having interest in transformable designs with the various attempts on the overall design, transformable design is being suggested as an attempt as the new manner, radical concept, or alternative of multi-purpose lifestyle. With the constant research and collection presentation by the designers of empirical disposition, transformable dress has been evolving gradually. The feature of transformable design appeared in dress is considered as 'variability' which changes in the flow of time. Furthermore, the morphological variability and variability of material have been examined as visual stimuli and conversion of material. By analyzing and assorting diverse transformable dresses comprehensively, it could be divided into technique-oriented transformable design and transformable design with a wearer's intervention. The technique-oriented transformable design is subdivided into the conversion of material and the conversion of form; the transformable design with a wearer's intervention into the conversion of functional frame and the conversion of aesthetic feature.

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A Study on the Formative Feature Characteristics of Korean Jeans Fashion (한국 진즈 패션의 조형성에 관한 연구)

  • Choi, Hae-Joo
    • Journal of the Korea Fashion and Costume Design Association
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    • v.8 no.3
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    • pp.101-111
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    • 2006
  • Jeans fashion in contemporary fashion has various meanings and values, and the importance of it increases. The purpose of this study is to analyze the formative feature characteristics and the aesthetic values of Korean jeans fashion. Fashion photograghs from leading monthly fashion magazines from 2000 to 2005 were analyzed. The types of styles and the formative feature characteristics and the aesthetic values of Korean jeans fashion were studied. The major conclusions of the study are as follows 1. The types of Korean jeans fashion styles were western style, punk style, neo classic style and ethnic style. 2. The characteristics of Korean jeans fashion designs were the varieties in material, color, technique of expression and application. 3. The formative feature characteristics were traditionalism, sexualism, extraordinarily and exhibitionism. Korean jeans fashion has developed creative and decorative designs through various designs and styles. As the activities of the people can be increased in the future, the function and the design of jeans fashion can be developed diversely.

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Construction of Attractor System by Integrity Evaluation of Polyethylene Piping Materials (폴리에틸렌 배관재의 건전성 평가를 위한 어트랙터 시스템의 구축)

  • Taik, Hwang-Yeong;Kyu, Oh-Seung;Won, Yi
    • Proceedings of the KSME Conference
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    • 2001.06a
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    • pp.609-615
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    • 2001
  • This study proposes analysis and evaluation method of time series ultrasonic signal using attractor analysis for fusion joint part of polyethylene piping. Quantitatively characteristics of fusion joint part is analysed features extracted from time series. Trajectory changes in the attractor indicated a substantial difference in fractal characteristics. These differences in characteristics of fusion joint part enables the evaluation of unique characteristics of fusion joint part. In quantitative fractal feature extraction, feature values of 4.291 in the case of debonding and 3.694 in the case of bonding were proposed on the basis of fractal dimensions. In quantitative quadrant feature extraction, 1,306 point in the case of bonding(one quadrant) and 1,209 point(one quadrant) in the case of debonding were proposed on the basis of fractal dimensions. Proposed attractor feature extraction can be used for integrity evaluation of polyethylene piping material which is in case of bonding or debonding.

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차세대 리소그래피 기술에 대한 전자빔 리소그래피의 응용

  • 김성찬;신동훈;이진구
    • Electrical & Electronic Materials
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    • v.17 no.6
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    • pp.3-10
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    • 2004
  • 1970년대 초반 이후 반도체 산업의 비약적 발전은 다양한 응용으로 적용되어 여러 분야의 산업들의 성장을 촉진시키고, 번영시켰다. 이런 성장의 중심에서, 반도체 소자의 feature size의 감소는 초소형, 저전력, 고기능 특성을 갖는 소자의 생산을 가능하게 하였으며 이를 기반으로 소자의 재현성, 생산성 증가로 이어져 반도체 산업을 성공시킨 필수적인 요건이 되어 왔다. 실질적으로, 반도체 소자의 feature size는 매 3년마다 약 70%씩 감소해 왔다. 최근에는 반도체 기술 발전의 고속화가 이루어지고 있어 그 속도가 2년 주기로 단축되었다. 이런 현상은 Rayleigh equation으로 도출되었으며, 이것은 유명한 무어의 법칙(Moore's law)의 기본 원리이기도 하다. 이런 반도체 소자의 feature size 감소는 특정 패턴의 선폭에 대한 미세화가 필수적인 요건이며, 미세한 선폭을 형성시키기 위한 노광기술은 feature size 감소의 핵심 기술로 대두되고 있다.(중략)

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특징형상을 이용한 선각설계

  • 이경식;최영;강원수
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.04a
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    • pp.559-564
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    • 1995
  • Feature based design approach is widely studied for the application of mechanical part design and process planning. Mechanical parts are associated with volumetric form features in nature. Therfore, one of the important characteristics that reside in the form feature research until now is that features have been studied in connection with CAPP for material removal. We studied the application of feature based design for ship structure design. Ship structure has interesting nature that tis distinct from mechanical parts. Among these are multiple cell structure, non-volumetric part and production by welding or assembling. An idea of applying feature based design paradigm for design, process planning, cost analysis and engineering calculation was shown. Non-manifold geometric modeler ACIS was adopted to fully benefit from the non-manifold nature of ship structure.

A Study on Costume Feature of Italian Masque Commedia Dell'arte and Korean Masque (이태리 가면희극 코메디아 델라르테(commedia dell'arte)와 한국 가면극의 복식특성 연구)

  • Kim, Hee-Jung
    • Journal of the Korean Home Economics Association
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    • v.47 no.2
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    • pp.15-26
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    • 2009
  • The purpose of this study is to research development process of commedia dell'arte and Korean masque that have similar figure, grasp similarity and difference and find the meaning of masque and costume in both theatrical arts. Italian commedia dell'arte and Korean masque are performed by wearing standardized mask and costume depending on the role. As common points, first, the characters have unique names and possess unique features of character, costumes, masks and playing styles. Through the feature, the audiences can understand role of actor and the actors can devote themselves to their role by wearing masks and costumes. Second, although background plays an important role in commedia dell'arte, the role of costume is more important. Because masque speaks for poverties of general people indirectly, the costumes of general people were used as they are. As different point, first, most of Korean masks cover entire face, restricting speech of actor but masks of commedia dell'arte cover only upper part of face and expos mouth and chin of actor, enabling actors to express various emotions depending on the character. Second, priority is given to personality of actor and origin area and current silhouette, material and color that changed by century is reflected in the costume of commedia dell'arte but silhouette, material and color of the Age of Joseon Dynasty were adopted in Korean masque.