• 대한기계학회논문집A
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• 제38권10호
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• pp.1139-1145
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• 2014

인체 골격의 모델생성과 형상변동을 파악하는 것은 생체역학의 응용분야에서 중요한 부분을 차지한다. 본 논문에서는 3 차원 대퇴골 모델의 데이터베이스로부터 대퇴골의 형상변동을 통계적으로 분석하고, 추출된 주요 파라미터를 사용하여 대퇴골의 형상을 직관적으로 모델링 할 수 있는 방법을 제안한다. 이를 위해서 먼저 통계적 기법 중에 하나인 주성분 분석(PCA)을 이용하여 대퇴골의 형상변동을 파악하였다. 주성분 분석을 수행하기 위해서는 3 차원 대퇴골 모델 간에 토폴로지(Topology)의 일치가 필요하다. 따라서 대퇴골의 형상에 해부학적 기준점(Landmark)을 정의하여 템플릿 모델이 대상 대퇴골 모델로 변형되기 위한 방향을 결정한 후 곡면 피팅(Surface fitting)을 수행하였다. 다음으로 주성분 분석을 통해 도출된 주성분과 대퇴골의 형상을 대표할 수 있는 해부학적 파라미터와의 상관관계를 정의하였다. 마지막으로 해부학적 파라미터로 대퇴골 모델의 생성 및 형상변동을 가시화 할 수 있는 프로그램을 개발하였다.

• 인터넷정보학회논문지
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• 제10권5호
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• pp.183-194
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• 2009

본 논문에서는 인터넷상에 업로드되는 음란 영상물을 차단하기 위해 활동적 형태 모델(active shape model)을 이용한 유해 영상 탐지 방법을 제안한다. 본 논문에서는 활동적 형태 모델을 이용하여 가슴선의 형태를 주성분 분석(Principle Component Analysis)과 정렬을 통해서 학습하고, 각 제어점에 대응하는 화소값 분포를 학습한다. 그리고 학습된 형태와 화소값 분포를 이용하여 가슴선을 찾는다. 본 논문에서는 형태 모델의 초기 위치를 정확하게 선택하기 위해 스케일, 회전, 이동에 관한 파라미터를 추출한다. 이 정보를 획득하기 위해서 본 논문에서는 유두 부분의 위치를 찾고, 유두 위치로부터 모든 방향으로 방사하여 후보 가슴선을 찾는다. 이와 같이 검출한 가슴선 정보를 이용하여 스케일과 회전 값을 찾아 평균 형태(mean shape)를 위치시키고, 활동적 형태 모델을 반복적으로 탐색한다. 최종적으로 수렴한 형태의 제어점(landmark)과 후보 가슴선과의 거리 평균을 계산하여 유해영상의 유무를 판단한다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 신호처리소사이어티 추계학술대회 논문집
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• pp.445-448
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• 2003

In this paper, we present a hierarchical approach of an enhanced active shape model for video tracking. Kalman filter is used. To estimate a dynamic shape in video object tracking. The experimental results show that the proposed hierarchical active shape model using Kalman filter is efficient.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집A
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• pp.345-350
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• 2000

In this paper, we introduce a new artificial material model for topology optimization. The present material model, named S-shape material model, accelerates topology optimization process especially in mathematical programming. We overcome the instability and the flatness in heuristic optimization process. Numerical examples show the superiority of the proposed material.

• 반도체디스플레이기술학회지
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• 제15권2호
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• pp.61-65
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• 2016

Facial feature detection is a fundamental function in the field of computer vision such as security, bio-metrics, 3D modeling, and face recognition. There are many algorithms for the function, active shape model is one of the most popular local texture models. This paper addresses issues related to face detection, and implements an efficient extraction algorithm for extracting the facial feature points to use on iOS platform. In this paper, we extend the original ASM algorithm to improve its performance by four modifications. First, to detect a face and to initialize the shape model, we apply a face detection API provided from iOS CoreImage framework. Second, we construct a weighted local structure model for landmarks to utilize the edge points of the face contour. Third, we build a modified model definition and fitting more landmarks than the classical ASM. And last, we extend and build two-dimensional profile model for detecting faces within input images. The proposed algorithm is evaluated on experimental test set containing over 500 face images, and found to successfully extract facial feature points, clearly outperforming the original ASM.

• 한국정보과학회논문지:소프트웨어및응용
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• 제30권5_6호
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• pp.454-460
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• 2003

이 논문은 입술의 형태를 효과적으로 인식하는 방법을 제안하였다. 입술은 PDM(Point Distribution Model)을 기반으로 점들의 집합으로 표현하였다. 주성분 분석법을 적용하여 입술 모델을 구하고 모델에서 사용하는 형태계수의 분포를 GMM(Gaussian Mixture Model)을 이용하여 구하였다. 이 과정에서 계수를 정하기 위하여 EM(Expectation Maximization) 알고리듬을 사용하였다. 입술 경계선 모델은 입술을 구성하는 각 점과 주변 영역에서의 화소간 변화를 이용하여 구성하였으며 입술 탐색시 사용되었다. 여러 영상을 대상으로 실험한 결과 좋은 결과를 얻었다.

• 패션비즈니스
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• 제8권4호
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• pp.94-103
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• 2004

The purpose of this study was to make activated electronic business transaction of clothes. The subject used for this study was 19 - 24 aged 149 college women who most likely buying products through internet. By compare the 149 women's body shape with 3D model, 149 women could be judged their body shape objectively. We showed the average 3D model by the measurement of 19 - 24aged women's body shape. 19 - 24aged women are big customer of internet shopping mall. By understanding of the difference between real somatotype and perceptual somatotype, we can reduce the disadvantage such as returning clothes. Also, imaginary fitting model can be used for internet shopping mall, animation work, fashion show, and advertisement work. Therefore, we can expect the worth of this study to do.

• 한국전산유체공학회지
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• 제4권1호
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• pp.34-40
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• 1999

Drag reduction on vehicles are the main concern for the body shape designers in order to lower the fuel consumption rate and to aid the driving stability. The drag of bluff bodies like transportation vehicles is mostly pressure drag due to the flow separation, which can be minimized by controlling the location and size of the separation bubble. In the present study, the TURBO-3D code is incorporated with optimal algorithm based on analytical approximation method to obtain an optimal afterbody shape of the MIRA Model corresponding to the lowest drag coefficient. For this purpose three mutually independent afterbody angles are chosen as design variables, while the drag coefficient is chosen as an objective function. It is demonstrated in the present study that an optimal body shape having the lowest drag coefficient which is about 6% lower than that of the original shape has been successfully obtained within number of iterations of tile optimal design loop.

• 대한기계학회논문집B
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• 제31권8호
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• pp.711-717
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• 2007

Shape optimization of a staggered herringbone groove micromixer using three-dimensional Navier-Stokes analysis has been carried using Kriging model. The analysis of the degree of mixing is performed by the calculation of spatial data statistics. The calculation of the variance of the mass fraction at various nodes on a plane in the channel is used to quantify mixing. A numerical optimization technique with Kriging model is applied to optimize the shape of the grooves on a single wall of the channel. Three design variables, namely, the ratio of groove width to groove pitch, the ratio of the groove depth to channel height ratio and the angle of the groove, are selected for optimization. A mixing index is used as the objective function. The results of the optimization show that the mixing is very sensitive to the shape of the groove which can be used in controlling mixing in microdevices.

• Journal of Information Technology Applications and Management
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• 제24권2호
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• pp.71-80
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• 2017

Software reliability is one of the most elementary and important problems in software development In order to find the software failure occurrence, the instantaneous failure rate function in the Poisson process can have a constant, incremental or decreasing tendency independently of the failure time. In this study, we compared the reliability performance of the software reliability model using the parameters of Pareto life distribution with the intensity decreasing pattern and the shape parameter of Erlang life distribution with the intensity increasing and decreasing pattern in the software product testing. In order to identify the software failure environment, the parametric estimation was applied to the maximum likelihood estimation method. Therefore, in this paper, we compare and evaluate software reliability by applying software failure time data. The reliability of the Erlang and Pareto life models is shown to be higher than that of the Pareto lifetime distribution model when the shape parameter is higher and the Erlang model is more reliable when the shape parameter is higher. Through this study, the software design department will be able to help the software design by applying various life distribution and shape parameters, and providing basic knowledge using software failure analysis.