• 제목/요약/키워드: transformation method

검색결과 3,357건 처리시간 0.027초

Bottle Label Segmentation Based on Multiple Gradient Information

  • Chen, Yanjuan;Park, Sang-Cheol;Na, In-Seop;Kim, Soo-Hyung;Lee, Myung-Eun
    • International Journal of Contents
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    • 제7권4호
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    • pp.24-29
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    • 2011
  • In this paper, we propose a method to segment the bottle label in images taken by mobile phones using multi-gradient approaches. In order to segment the label region of interest-object, the saliency map method and Hough Transformation method are first applied to the original images to obtain the candidate region. The saliency map is used to detect the most salient area based on three kinds of features (color, orientation and illumination features). The Hough Transformation is a technique to isolated features of a particular shape within an image. Therefore, we utilize it to find the left and right border of the bottle. Next, we segment the label based on the gradient information obtained from the structure tensor method and edge method. The experimental results have shown that the proposed method is able to accurately segment the labels as the first step of product label recognition system.

미분변환법을 이용한 회전외팔보의 자유진동해석 (Free Vibration Analysis of a Rotating Cantilever Beam by Using Differential Transformation Method)

  • 신영재;지영철;윤종학;유영찬
    • 대한기계학회논문집A
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    • 제31권3호
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    • pp.331-337
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    • 2007
  • Rotating cantilever beams can be found in several practical engineering applications such as turbine blades and helicopter rotor blades. For reliable and economic design, it is necessary to estimate the dynamic characteristics of those structures accurately and efficiently since significant variation of dynamic characteristics resulted from rotational motion of the structures. Recently, Differential Transformation Method(DTM) was proposed by Zhou. This method has been applied to fluid dynamics and vibration problems, and has shown accuracy, efficiency and convenience in solving differential equations. The purpose of this study, the free vibration analysis of a rotating cantilever beam, is to seek for the reliable property of DTM and confidence in the results obtained by this method by comparing the results with that of finite element method applied to linear partial differential equations. In particular, this study is worked by supposing optional T-function values because the equations governing chordwise motion are based on two differential equations coupled with each other. This study also shows mode shapes of rotating cantilever beams for various rotating speeds.

$\delta$-LQG/LTR보상기에 의한 디지털 자동조종장치 설계 (Digital Autopilot Design Using $\delta$-LQG/LTR Compensators)

  • 이명의;김승환;권오규
    • 대한전기학회논문지
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    • 제40권9호
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    • pp.920-928
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    • 1991
  • This paper proposes a design procedure based on the LQG/LTR (Linear Quadratic Gaussian/ Loop Transfer Recovery) method for a launch vehicle. Continuous-discrete type LQG/LTR compensators are designed using the e-transformation to overcome numerical problems occurring in the process of discretization. The e-LQG/LTR compensator using the e-transformation is compared width the z-LQG/LTR compensator using the z-transformation. The performance of the overall system controlled by the compensator is evaluated via simulations, which show that the discretization error problem is resolved and the control performances are satisfactory in the proposed compensator.

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알콕사이드로부터 Seed가 첨가된 알루미나의 제조(I): 분말특성 (The Preparation of Seeded Alumina from Alkoxide (I): Powders)

  • 김창은;임광일;이해욱
    • 한국세라믹학회지
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    • 제29권5호
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    • pp.367-376
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    • 1992
  • The powder characteristics of seeded alumina prepared from alkoxide by sol-gel method were studied. When ${\alpha}$-Al2O3 seeded powders used, these ${\alpha}$ phase transformation temperatures decreased than those of unseeded powders by 110$^{\circ}C$ and fine powders under 0.1 $\mu\textrm{m}$ could be obtained. When Fe-nitrate added powders used, fast transformation rate resulted from ionic effects of Fe3+, but hard aggregated morphology exhibited. When ${\alpha}$-Al2O3 and Fe nitrate simultaneously added, these powders represented lower transformation temperature but resulted in microstructure with aggregated particles.

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NUMERICAL EVALUATION OF CAUCHY PRINCIPAL VALUE INTEGRALS USING A PARAMETRIC RATIONAL TRANSFORMATION

  • Beong In Yun
    • 한국수학교육학회지시리즈B:순수및응용수학
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    • 제30권4호
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    • pp.347-355
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    • 2023
  • For numerical evaluation of Cauchy principal value integrals, we present a simple rational function with a parameter satisfying some reasonable conditions. The proposed rational function is employed in coordinate transformation for accelerating the accuracy of the Gauss quadrature rule. The efficiency of the proposed rational transformation method is demonstrated by the numerical result of a selected test example.

아키텍처 기반 소프트웨어 개발에서 소프트웨어 아키텍처 변형을 지원하기 위한 방법 (An Approach to Support Software Architecture Transformation in Architecture-Based Software Development)

  • 최희석;염근혁
    • 한국정보과학회논문지:소프트웨어및응용
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    • 제32권1호
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    • pp.10-21
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    • 2005
  • 소프트웨어 아키텍처는 복잡 다양한 소프트웨어 시스템을 개발하는 데 있어서 개발될 소프트웨어의 품질 달성에 중요한 영향을 미치는 핵심 설계로서 인식되고 있다. 따라서 아키텍처 기반의 소프트웨어 개발에서 고품질 소프트웨어 개발을 위하여 소프트웨어 아키텍처에 대한 변형이 필수적으로 요구된다. 그러나 아키텍처 변형 시 적용 가능한 설계 대안들의 다양성과 그것들이 아키텍처에 미치는 결과에 대한 예측의 어려움으로 인하여, 소프트웨어 아키텍처 변형을 적용하는 것이 쉽지 않다. 그러므로 다양한 설계 대안들이 아키텍처에 미치는 결과를 이해하고 분석하는 것을 통하여 소프트웨어 아키텍처 변형을 지원하기 위한 방법이 필요하다. 본 논문에서는 소프트웨어 아키텍처 변형을 체계적으로 지원하기 위한 방법을 제안한다. 제안하는 방법에서는 소프트웨어 아키텍처에 포함된 아키텍처 설계 결정들과 그것들에 대한 제약조건들을 바탕으로 결정 제약조건 그래프를 정의한다. 결정 제약조건 그래프를 이용하여 소프트웨어 아키텍처의 주요 설계 결정들간의 의존 관계를 명시적으로 나타냄으로써, 소프트웨어 아키텍처 변형 과정에서 특정 설계 결정에 대한 설계 변형이 아키텍처에 미치는 영향을 체계적으로 분석 가능하게 한다. 본 논문에서 제시하는 소프트웨어 아키텍처 변형 방법은 아키텍처 변형에 대한 전반적인 이해를 용이하게 함과 동시에, 궁극적으로는 고품질 소프트웨어 개발을 위한 새로운 버전의 아키텍처 재생성을 돕는다

고온 변형 곡선을 이용한 동적 재결정 해석과 동적 상변태의 조기 예측 (Precise Flow Stress Analysis for the Occurrence of Dynamic Ferritic Transformation and Dynamic Recrystallization of Austenite in Low Carbon Steel)

  • 박노근
    • 대한금속재료학회지
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    • 제56권11호
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    • pp.779-786
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    • 2018
  • There have been previous attempts to observe the occurrence of dynamic ferritic transformation at temperatures even above $Ae_3$ in a low-carbon steel, and not only in steels, but recently also in titanium alloys. In this study, a new approach is proposed that involves treating true stress-true strain curves in uniaxial compression tests at various temperatures, and different strain rates in 0.1C-6Ni steel, which is a model alloy used to decelerate the kinetics of ferrite transformation from austenite. The initial flow stress up to peak stress was used to analyze the change in dynamic softening phenomena, such as dynamic recovery, dynamic recrystallization, and dynamic transformation. It is worth mentioning that for predicting the occurrence of dynamic transformation, flow stress before reaching peak stress is much more sensitive to the change in the dynamic softening rate due to dynamic transformation, compared to peak stress. It was found that the occurrence of dynamic ferritic transformation could be successfully obtained even at temperatures above $Ae_3$ once the deformation condition was satisfied. This deformation condition is a function of both the strain rate and the deformation temperature, which can be described as the Zener - Hollomon parameter. In addition, the driving force of dynamic ferritic transformation might be much less than that of the dynamic recrystallization of austenite at a given deformation condition. By applying this technique, it is possible to predict the occurrence of dynamic transformation more sensitively compared with the previous analysis method using peak stress during deformation.

위상면궤적을 이용한 전력계통의 고장판별에 관한 연구 (A Study on the Classification of Arcing Faults in Power Systems using Phase Plane Trajectory Method)

  • 박남옥;신영철;안상필;여상민;김철환
    • 대한전기학회논문지:전력기술부문A
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    • 제51권5호
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    • pp.209-216
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    • 2002
  • Recently, there is greater demand for stable supply of electric power as higher level of our living. It becomes the important problem that the cause of fault in power system is found out in early stage, if once it occurs. In this respect, accurate classification of arcing faults in power systems is vitally important. This paper presents a new classification method for arcing faults in power system. To obtain data of various faults including high impedance fault(HIF) and low impedance fault(LIF), HIF model with the ZnO arrester is adopted and implemented within the overall transmission system model based on the electromagnetic transients program(EMTP). Results of phase plane trajectory if Clarke modal transformation using postfault current and voltage are utilized to classify types of arcing faults. The performance of the proposed method is tested on a typical 154 kV korean transmission system under various fault conditions. As can be seen from results, phase plane trajectory of postfault current should be combined with that of o component from Clarke modal transformation to give reliability of clear fault classification. Thus the proposed method can classify arcing faults including LIFs and HIFs accurately in power systems.

모바일 장치를 위한 MPEG-4 콘텐츠의 객체 및 장면 트리 변환 (Transforming Objects and a Scene Tree of MPEG-4 Contents for Mobile Devices)

  • 김상욱;김경덕;이숙영
    • 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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    • 제11권2호
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    • pp.124-132
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    • 2005
  • 본 논문에서는 모바일 장치를 위한 MPEG-4 콘텐츠 저작을 위하여 객체 및 장면 트리 변환을 이용한 방법을 제안한다. 제안하는 방법은 저작시 MPEG-4 콘텐츠의 객체와 장면 트리를 변환하여 모바일 장치에서 재생할 수 있도록 콘텐츠를 재구성한다. 이 방법은 모바일 장치의 작은 인터페이스에서 재생을 효율적으로 할 수 있도록 장면에 표현되는 각 객체를 기하 객체로 변환하고 그 외형을 축소하여 초기 로딩 시간을 감소시키며, 원 객체의 재생은 사용자가 재생 장면에서 해당 기하 객체를 선택할 때 재생된다. 그리고 제안한 방법을 기존 저작 도구에 적용하여, 모바일 장치의 재생기에서 효율적으로 MPEG-4 콘텐츠를 재생시킬 수 있음을 보였다.