• 제목/요약/키워드: Level set methods

검색결과 1,033건 처리시간 0.039초

Equivalence in Alpha-Level Linear Regression

  • Yoon, Jin-Hee;Jung, Hye-Young;Choi, Seung-Hoe
    • Communications for Statistical Applications and Methods
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    • 제17권4호
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    • pp.611-624
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    • 2010
  • Several methods were suggested for constructing a fuzzy relationship between fuzzy independent and dependent variables. This paper reviews the use of the method by minimizing the square of the difference between an observed and a predicted fuzzy number in an ${\alpha}$-level linear regression model. We introduce a new distance between fuzzy numbers on the basis of a mode, a core point and a radius of an ${\alpha}$-level set of a fuzzy number an construct the fuzzy regression model using the proposed fuzzy distance. We also investigate sufficient condition for an equivalence in the ${\alpha}$-level regression model.

클래스 수준 뮤테이션 분석을 위한 동등 뮤턴트 검출 기법 (An Equivalent Mutation Detection Method for Class-Level Mutation Analysis)

  • 장원호;마유승;권용래
    • 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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    • 제16권5호
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    • pp.571-575
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    • 2010
  • 클래스 수준 뮤테이션 분석(class-level mutation analysis)의 경우, 동등 뮤턴트(equivalent mutant)는 전체 뮤턴트들의 개수에서 많은 비중을 차지하기 때문에 동등 뮤턴트의 검출은 뮤테이션 수행 비용 절감에 매우 중요하다. 하지만 현재까지 클래스 수준 뮤테이션을 대상으로 동등 뮤턴트를 검출하는 연구는 미미한 실정이다. 본 논문에서는 클래스 수준 뮤테이션을 대상으로 의존성 그래프(dependency graph)를 이용하여 동등 뮤턴트를 검출하기 위한 기법을 제안한다. 제안한 기법은 인트라-클래스(intra-class) 수준에서 정적분석을 수행함으로써 인트라-메소드(intra-method) 수준의 분석 방법을 사용하는 기존의 연구들이 검출할 수 없었던 클래스 수준 동등 뮤턴트를 검출할 수 있었다.

교복 재활용 필요성과 교복 재활용 교육을 위한 교과과정 분석 (An Analysis of the Curriculum for School Uniform Recycling Education and the Need for School Uniform Recycling)

  • 서승연;신은미
    • 한국환경교육학회지:환경교육
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    • 제24권2호
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    • pp.54-69
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    • 2011
  • The objectives of this study were to investigate the need for school uniform recycling and to review the school uniform recycling-related education. 231 female high school students were asked to answer regarding the wearing state of school uniform and their satisfaction level. 10 subjects in middle school technology/home economy were evaluated. As the result, the students wore 1~2 pieces of school uniform, which showed that it was hard to keep them clean by washing them often. The satisfaction level of school uniform was not high, The lowest item was the price. Therefore, to increase the satisfaction level of the school uniforms and also to increase the sanitary level of the school uniforms, it was advisable to purchase a recycled school uniform at cheaper prices to have an extra set. For a vitalization of the recycled school uniforms, the middle school technology/home economy subjects were reviewed. In the topic of "clothing acquisition plan and purchase", the themes of planned purchase, overconsumption of clothing and environmental pollution were discussed and included preferable behaviors for disposal. The topic of "clothing manufacturing and recycling" listed recycling the clothes that are not worn or exchanging them with neighbors as well as suggesting methods to illicit environment-friendly behaviors and carrying them out. However, some textbooks only briefly explained the methods of recycling and more detailed and practical methods need to be suggested in the curriculum. In addition, the contents regarding the environment in the clothing topic need to be supplemented more and more changes, such as related education plans or data development, are required. The objectives of this study were to investigate the need for school uniform recycling and to review the school uniform recycling-related education. 231 female high school students were asked to answer regarding the wearing state of school uniform and their satisfaction level. 10 subjects in middle school technology/home economy were evaluated. As the result, the students wore 1~2 pieces of school uniform, which showed that it was hard to keep them clean by washing them often. The satisfaction level of school uniform was not high, The lowest item was the price. Therefore, to increase the satisfaction level of the school uniforms and also to increase the sanitary level of the school uniforms, it was advisable to purchase a recycled school uniform at cheaper prices to have an extra set. For a vitalization of the recycled school uniforms, the middle school technology/home economy subjects were reviewed. In the topic of "clothing acquisition plan and purchase", the themes of planned purchase, overconsumption of clothing and environmental pollution were discussed and included preferable behaviors for disposal. The topic of "clothing manufacturing and recycling" listed recycling the clothes that are not worn or exchanging them with neighbors as well as suggesting methods to illicit environment-friendly behaviors and carrying them out. However, some textbooks only briefly explained the methods of recycling and more detailed and practical methods need to be suggested in the curriculum. In addition, the contents regarding the environment in the clothing topic need to be supplemented more and more changes, such as related education plans or data development, are required.

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시가지 발파에서 공저 전색물이 발파진동에 미치는 영향 (The Effect of Bottom-Hole Stemming Materials on Vibration Level at Urban Area Blasting)

  • 강추원
    • 터널과지하공간
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    • 제7권1호
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    • pp.51-57
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    • 1997
  • This study provides the results of two different blasting methods applied at the H Telcon construction site in Yeon-dong, Cheju Island. One is the traditional blasting method without bottom-hole stemming and the other with bottom-hole stemming using the materials such as sand, polystyrene and sawdust in 5~10 cm lengths. The effect of these materials on vibration level was studied. Assuming that safety criterion of vibration level be 0.5cm/set, 95% confidence limit line of measured data shows that maximum charge weight per delay could be increased in the following order; traditional methed, polystyrene stemming, sand stemming, sawdust stemming.

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CAD Scheme To Detect Brain Tumour In MR Images using Active Contour Models and Tree Classifiers

  • Helen, R.;Kamaraj, N.
    • Journal of Electrical Engineering and Technology
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    • 제10권2호
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    • pp.670-675
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    • 2015
  • Medical imaging is one of the most powerful tools for gaining information about internal organs and tissues. It is a challenging task to develop sophisticated image analysis methods in order to improve the accuracy of diagnosis. The objective of this paper is to develop a Computer Aided Diagnostics (CAD) scheme for Brain Tumour detection from Magnetic Resonance Image (MRI) using active contour models and to investigate with several approaches for improving CAD performances. The problem in clinical medicine is the automatic detection of brain Tumours with maximum accuracy and in less time. This work involves the following steps: i) Segmentation performed by Fuzzy Clustering with Level Set Method (FCMLSM) and performance is compared with snake models based on Balloon force and Gradient Vector Force (GVF), Distance Regularized Level Set Method (DRLSE). ii) Feature extraction done by Shape and Texture based features. iii) Brain Tumour detection performed by various tree classifiers. Based on investigation FCMLSM is well suited segmentation method and Random Forest is the most optimum classifier for this problem. This method gives accuracy of 97% and with minimum classification error. The time taken to detect Tumour is approximately 2 mins for an examination (30 slices).

레밸 세트 모텔을 이용한 형태 추출과 3차원 영상의 표면 정합 볼륨 렌더링에 관한 연구 (A Study on Shape Registration Using Level-Set Model and Surface Registration Volume Rendering of 3-D Images)

  • 김태형;염동훈;주동현;김두영
    • 융합신호처리학회논문지
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    • 제3권4호
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    • pp.29-34
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    • 2002
  • 본 논문에서는 전처리 과정에서 원영상에 있는 잡음을 제거하기 위해 비등방성 필터를 적용하여 물체의 경계와 모양을 추출하기 위해 Osher와 Sethian이 제안한 레벨셋에 기초한 새로운 기하활성 모델을 제시한다. 처리과정에서 처리시간을 최소화하기 위하여 전체 영상에서가 아닌 경계 근처 이웃 픽셀에서만 계산을 수행하는 협대역 방법을 사용한다. 각 슬라이스들은 비등방 필터링을 통해 잡음을 제거하고 형태 추출된 결과영상을 3차원 데이터 셋으로 구성하여 볼륨 렌더링을 통해 2차원 평면에 잡음이 제거된 깨끗한 영상결과물을 얻을 수 있었다.

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20대 여성의 유방 부피 계측치에 따른 브래지어 컵의 분류 (A Study on the Classification of Brassiere Cups by Breast Volume Measurement Values on Women in their Twenties)

  • 박유신;김선미;김은란
    • 대한인간공학회지
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    • 제23권2호
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    • pp.93-104
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    • 2004
  • The research subjects of this study were 30 unmarried Korean women from 20 to 29 who had never had an operation on their breast. Measurement method using plaster breast mold was used for measuring their volume of breast. The correlation between their breast volume and the methods to set up brassiere cups with the existing method and with their circumference of breast was analyzed using KendalI's Coefficient. which was to figure out a method which had a bigger correlation with the volume of breast between the method to set up brassiere cups using the existing method and the method using the circumference of breast. The results analyzed showed that the coefficient of correlation between the existing method and the volume of breast was .12 and the significance level was .45. They didn't have any correlation. On the other hand. the coefficient of correlation between the circumference of breast and the volume of breast was .82. which was very high values and the significance level was very high .0001. Therefore. it turned out that it was difficult to set up brassiere cups by using the existing method and it was easier and more reliable to set up the cups by using the circumference of breast.

볼륨영상 분할을 위한 새로운 레벨 셋 방법과 기존 방법의 성능비교 (Performance Comparison Between New Level Set Method and Previous Methods for Volume Images Segmentation)

  • 이명은;조완현;김선월;진연연;김수형
    • 정보처리학회논문지B
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    • 제18B권3호
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    • pp.131-138
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    • 2011
  • 본 논문에서는 볼륨 의료영상 분할에 대한 기존의 레벨 셋 기법과 제안하는 방법의 성능을 비교하고자 한다. 기존의 방법들은 영역의 정보만을 이용하여 분할을 시행하므로, 영상의 종류에 따라서 정확한 분할을 못한 경우가 있다. 따라서 새롭게 제안하는 방법은 정확한 분할 결과를 위하여 영상의 객체가 가지고 있는 에지 정보와 영역 정보를 함께 이용한다. 에지 정보는 레벨 셋의 곡면이 객체의 표면에 잘 도달할 수 있도록 해주는 기울기 벡터장을 이용하고, 영역 정보는 각 영역에서 픽셀의 밝기 값을 가우시안 분포를 이용하여 통계적 모델로 적합시킴으로써 영상의 분할에 적용하였다. 또한, 곡면 주변 잡음의 영향을 최소화 시켜주는 정규화 항을 사용한다. 기존의 레벨 셋 기반의 방법들과 제안한 방법의 성능 평가를 위하여 실제 볼륨 의료영상에 대하여 다양한 실험을 실시하고, 분할된 결과의 비교를 통하여 제안된 방법의 우수성을 입증한다.

Stable Model for Active Contour based Region Tracking using Level Set PDE

  • Lee, Suk-Ho
    • Journal of information and communication convergence engineering
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    • 제9권6호
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    • pp.666-670
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    • 2011
  • In this paper, we propose a stable active contour based tracking method which utilizes the bimodal segmentation technique to obtain a background color diminished image frame. The proposed method overcomes the drawback of the Mansouri model which is liable to fall into a local minimum state when colors appear in the background that are similar to the target colors. The Mansouri model has been a foundation for active contour based tracking methods, since it is derived from a probability based interpretation. By stabilizing the model with the proposed speed function, the proposed model opens the way to extend probability based active contour tracking for practical applications.

Development of Free-surface Decomposition Method and Its ApplicationDevelopment of Free-surface Decomposition Method and Its Application

  • Park, Sunho
    • Journal of Advanced Research in Ocean Engineering
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    • 제3권2호
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    • pp.75-82
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    • 2017
  • With the development of computational fluid dynamics (CFD), studies on shipbuilding and maritime issues including free-surface wave flow have been conducted. Although the volume of fluid (VOF) and level-set methods are widely used to study the free-surface wave flow, disadvantages exist. In particular, it takes a long time to obtain solutions. In this study, a free-surface capturing code is developed for ship and offshore structures. The developed code focuses on accuracy and computation time. Open source CFD libraries, termed OpenFOAM, are used to develop the code. The results obtained using the developed code are compared with those obtained using interFoam. The results show that the developed code could be used to capture the free-surface wave flow without numerical diffusion; moreover, the accuracy of the developed code is largely the same as that of interFoam.