• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.617-622
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• 2002

This paper presents that the Wavelet Transform can be used to detect the various local defects in a gearbos. Two types of defects which are broken tooth and localized wear, are experimented and the signals are collected by accerometer and analyzed. Because of the complecity of the signals acquired from sensor, it is needed to identify the interesting signal. The natural frequencies of shafts and the gear mesh frequency(GMF) is calculated theretically. DWT, CWT and the aplication are used to extract a gear-localized defect feature from the vibration signal of the gearbox with the defective gear. The results shows the transform is more effective to detect the failures than the Fourier Transform.

• 방송공학회논문지
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• 제7권3호
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• pp.262-270
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• 2002

대부분의 영상색인 기법에서는 영상의 전역 특징값을 이용한다. 그러나 이러한 방법은 영상의 지역적인 변화들을 담아내지 못하기 때문에 만족할 만한 격과를 제공하지 못한다. 본 논문에서는 이러한 문제점을 해결하기 위한 방법으로 영상의 특징점(salient point)과 영상분할을 이용하여 중요영역(important region)을 추출하는 새로운 영역기반 영상검색 시스템을 제안한다. 본 논문에서 제안하는 특징점 추출 기법은 기존의 방법과 비교하여 빠르고 정확한 추출 결과를 보여준다. 선택된 영역에서 추출된 칼라와 질감 정보를 이용하여 검색한 결과는 칼라나 질감 정보의 전력 특징값을 이용한 검색 방법의 결과보다 크게 향상됨을 알 수 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권7호
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• pp.1690-1704
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• 2013

An affine invariant descriptor is proposed, which is able to well represent the affine covariant regions. Estimating main orientation is still problematic in many existing method, such as SIFT (scale invariant feature transform) and SURF (speeded up robust features). Instead of aligning the estimated main orientation, in this paper ellipse orientation is directly used. According to ellipse orientation, affine covariant regions are firstly divided into 4 sub-regions with equal angles. Since affine covariant regions are divided from the ellipse orientation, the divided sub-regions are rotation invariant regardless the rotation, if any, of ellipse. Meanwhile, the affine covariant regions are normalized into a circular region. In the end, the gradients of pixels in the circular region are calculated and the partition-based descriptor is created by using the gradients. Compared with the existing descriptors including MROGH, SIFT, GLOH, PCA-SIFT and spin images, the proposed descriptor demonstrates superior performance according to extensive experiments.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2013년도 하계학술대회
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• pp.66-67
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• 2013

본 논문에서는 지역적인 그래프를 이용하여 면 외 회전에 강인한 특징 기술 및 정합 방법에 대하여 제안한다. 특징 기반의 지역적인 그래프의 경우 SURF 등을 이용하여 찾아진 특징 정보에 대하여 특징 사이의 상관관계를 이용하여 지역적인 그래프를 생성함으로써 특징 기술의 적용 범위를 확장할 수 있고 이러한 지역적인 그래프의 정합을 위하여 새로운 비용 함수와 정합 방법을 제안한다. 또한 특징 정합 시 이를 활용하여 정합 후보를 결정함으로써 면 외 회전이 존재하는 영상에 대해 좀 더 강인한 특징 정합 결과를 얻을 수 있고 실험 결과 기존의 특징 정합 방법에 비하여 찾아지는 후보의 개수가 증가하고 찾아진 정합 결과의 정확도가 증가하는 것을 확인할 수 있다.

• 한국멀티미디어학회논문지
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• 제17권1호
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• pp.15-25
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• 2014

본 논문에서는 지능형 감시 시스템을 위해 공간적 확률 분포와 방향 서술자를 이용하여 다양한 배회행위를 검출하는 방법을 제안한다. 적응적 배경 모델링 기법을 이용하여 움직이는 객체를 검출하고, 검출된 객체로부터 움직임의 정보를 추출한다. 추출된 객체의 움직임 정보는 이동 궤적과 방향에 대해 특징벡터를 생성한다. 생성된 특징벡터는 k-Nearest Neighbor를 통해 최종적으로 배회행위를 검출하게 된다. 제안한 방법을 실내외 다양한 환경에서 테스트하여 배회 행위를 검출하는 결과를 나타내었으며 이는 실시간으로 검출되는 것을 확인하였다.

• 한국농촌건축학회논문집
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• 제14권1호
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• pp.115-124
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• 2012

The purpose of this study is to derive and to apply green factors focusing on the existing old settlements, Topdong 'Yangdalmal' in Cheongju City. This study is conducted through literatures and GBCC (Green Building Certification Criteria) review. Literatures cover the traditional characteristics of farming village and the modern characteristics of urban space today. The results are following as; first, Land Use, Environment, Resource and Energy are the most important green factors by literatures and GBCC. Second, traditional elements and natural elements such as history and culture, natural resource use and passive planning are added. Finally information communication is added as the green factor showed feature of modern society.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2010-2014
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• 2005

Object detection and parameter estimation in point cloud data is a relevant subject to robotics, reverse engineering, computer vision, and sport mechanics. In this paper a software is presented for fully-automatic object detection and parameter estimation in unordered, incomplete and error-contaminated point cloud with a large number of data points. The software consists of three algorithmic modules each for object identification, point segmentation, and model fitting. The newly developed algorithms for orthogonal distance fitting (ODF) play a fundamental role in each of the three modules. The ODF algorithms estimate the model parameters by minimizing the square sum of the shortest distances between the model feature and the measurement points. Curvature analysis of the local quadric surfaces fitted to small patches of point cloud provides the necessary seed information for automatic model selection, point segmentation, and model fitting. The performance of the software on a variety of point cloud data will be demonstrated live.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.219-222
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• 2003

Substantial experimental and theoretical work exists on the bond characteristics of FRP-concrete adhesive joints. Experimental studies show that the bond strength cannot always increase with an increase in the bond length, and that the ultimate strength is strongly influenced by the concrete strength. To solve this feature, analytic solutions based on fracture mechanics are widely used, and the local shear stress-slip curve with a softening branch is known as more rational model. The analytic solution, however, cannot describe various shapes of model curve. In this study, numerical method using interface element is introduced to express various shapes of model curve. Characteristics of adhesive joint is investigated for the shapes of the model curve and their parameters. And the numerical solutions are compared with the test results of CFRP sheet adhesive joints.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.717-718
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• 2008

Fisher Linear Discriminant(FLD) is a sample and intuitive linear feature extraction method in pattern recognition. But in some special cases, such as un-separable case, one class data dispersed into several clustering case, FLD doesn't work well. In this paper, a new discriminant named K-means Fisher Linear Discriminant, which combines FLD with K-means clustering is proposed. It could deal with this case efficiently, not only possess FLD's global-view merit, but also K-means' local-view property. Finally, the simulation results also demonstrate its advantage against K-means and FLD individually.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.135-135
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• 2001

In recent years there have been increasing interests in real-time object tracking with image information. Since image information is affected by illumination, this paper presents the real-time object tracking method based on neural networks that have robust characteristics under various illuminations. This paper proposes three steps to track the object and the fast tracking method. In the first step the object color is extracted using neural networks. In the second step we detect the object feature information based on invariant moment. Finally the object is tracked through a shape recognition using neural networks. To achieve the fast tracking performance, we have a global search for entire image and then have tracking the object through local search when the object is recognized.