• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.812-819
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• 2015

This paper presents a new approach for simulating the internal faults of synchronous machines using distributed computing and Large Change Sensitivity (LCS) analysis. LCS analysis caters for a parallel solution of 3-phase model of a faulted machine within the symmetrical component-based model of interconnected network. The proposed method considers dynamic behavior of the faulty machine and connected system and tries to accurately solve the synchronous machine’s internal fault conditions in the system. The proposed method is implemented in stand-alone FORTRAN-based phasor software and the results have been compared with available recordings from real networks and precisely simulated faults by use of the ATP/EMTP as a time domain software package. An encouraging correlation between the simulation results using proposed method, ATP simulation and measurements was observed and reported. The simplified approach also enables engineers to quickly investigate their particular cases with a reasonable precision.

• International Journal of Contents
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• v.8 no.4
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• pp.95-102
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• 2012

In this paper, we present a technique to extract the title areas from book cover images. A typical book cover image may contain text, pictures, diagrams as well as complex and irregular background. In addition, the high variability of character features such as thickness, font, position, background and tilt of the text also makes the text extraction task more complicated. Therefore, we propose a two steps efficient method that uses Histogram of Oriented Gradients and color information to find the title areas. Firstly, text localization is carried out to find the title candidates. Finally, refinement process is performed to find the sufficient components of title areas. To obtain the best result, we also use other constraints about the size, ratio between the length and width of the title. We achieve encouraging results of extracted title regions from book cover images which prove the advantages and efficiency of the proposed method.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.11a
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• pp.213-216
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• 2005

본 연구에서는 모바일 단말기를 활용할 수 있는 얼굴 영역을 추출 하는 시스템을 구현을 제안한다. 임베디드 프로세서에 커넥티드 콤포넌트 라베링을 이용하여 PDA와 핸드폰, 스마트폰에서 얼굴 영역 추출이 가능한 시스템을 설계 하였다. 얼굴 영역을 추출한 결과 빠른 처리 속도와 높은 추출율을 보였다.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06c
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• pp.565-568
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• 2008

본 논문은 RGB 24bit 컬러 영상으로 전달되는 카메라 원영상에 대해 사람의 얼굴을 안정적으로 감지할 수 있는 알고리즘을 제시한다. RGB 입력영상을 HSI 기반의 컬러모델로 변환하여 피부 색상을 추출하고 그리드 영상을 기반으로 CCL (Connected-Component Labeling) 알고리즘을 적용하여 피부 블럽을 검출한 뒤, 아다부스트 알고리즘을 이용하여 얼굴 영역과 얼굴이 아닌 다른 피부 영역을 구분한다. 제안방법은 일반적으로 얼굴 감지를 위하여 폭넓게 사용되고 있는 아다부스트 알고리즘만을 적용하였을 때보다 얼굴감지 오류를 줄일 수 있다.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.9
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• pp.94-102
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• 2010

The spindle is the main component in machine tools. To develop high speed machine tools, a lot of studies have been carried out for high speed spindle. Bearing is very important part in spindle. The bearing clearance is influenced by shrink fit and thermal expansion during operation. The designer must take into account the reduction of shrink fits. The aims of this study are to grasp the shrink fits and behavior of a bearing which is a deeply connected with fatigue life of bearing and performance of spindle through FEM(Finite Element Method). This paper proposed optimum value of shrink fit considering deformation of spindle and stress of fitting area using design of experiments. Thus, the proposed formula can be used to obtain bearing internal clearance.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.12
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• pp.948-953
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• 2014

Many studies using the assumed mode method have been found for the free vibration analysis of stiffened plate with known elastic boundary conditions. However many local structures such as tank edges and equipment foundations consist of connected structures and it is very difficult to find suitable elastic boundary conditions. In this study combined polynomials which satisfy simply and fixedly supported boundary conditions are proposed. The proposed method has been applied to tanks which bounded by bulkhead and a deck. The results of this study shows good agreements with these obtain by the FEA S/W(Patran/Nastran).

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1997.11a
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• pp.71-74
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• 1997

본 논문은 일반적으로 제약 없는 형식 문서 즉, 논-맨하탄(non-manhattan) 형식의 이진문서영상을 분석하는 기법으로서, 연결요소기법에 기반한 특징추출과 이를 이용한 영역분리 및 분류에 관한 새로운 방법을 제안한다. 제안한 방식은 바텀-업(bottom-up)방식으로서 먼저 처리속도의 고속화와 축소시 특징 영역보존을 위해 임계치 축소기법을 사용하고, 축소된 이진 문서영상내의 각 연결된 검은 화소의 집합을 개체화하고 개체의 특성에 따라 텍스트, 신성분, 해프톤, 도형 그리고 표 등으로 분류한다. 영역분류는 두단계로 이루어지는데, 1차분류에서는 우선, B/W 비, 면적, 외각 테두리의 높이와 너비 비, 테두리선유무 등의 특징을 이용하여 해프톤, 수평 수직선, 테두리(표 및 도형)영역을 분리한다. 이후 2차 분류에서는 문자성분의 수평결합을 통한 텍스트행 성분을 추출한다. 마지막 후처리 과정으로 표분석 알고리듬을 통하여 테두리 영역중 표와 도형을 정확히 구분하고, 또한 도형에 관련한 문서성분을 해당 도형 개체에 연결하는 작업을 수행함으로써 완벽한 영역분류를 한다. 다양한 문서영상을 이용한 시뮬레이션을 통해 제안한 알고리듬의 성능을 입증한다.

• Journal of Microbiology
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• v.35 no.1
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• pp.47-52
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• 1997

To examine whether the xylene component of BTX (benzene, toluene, xylene) mixture is cometabolized and residues are produced in soil, $\^$14/C-labeled-0-xylene was added to sandy loam in combination with unlabeled benzene and toluene. After 4 weeks of incubation in a sealed system connected to an oxygen reservoir, 55.1% of the radiocarbon was converted to $\^$14/CO$\sub$2/, 3.0% was to 95.8% radiocarbon recovery. Biomass incorporation of o-xylene radiocarbon which was detected by fumigation/extraction was usually low (5.6%), but 32.1% radiocarbon became associated with soil humus. Most of the numus-bound radiocarbon was found in humin fraction. In addition to o-xylene, p-xylene and toluene also showed similar results. The evidence shows that some of their reactive methylcatechol biodegradation intermediates attach to the humic metrix in soil in preference to mineralization and biomass incorporation.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1078-1079
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• 2006

The paper presents the possibilities of obtaining new composite materials based on sintered porous ceramics with particles and fibre of $Al_2O_3$ infiltrated by aluminum alloy. The EN AC - AlSi12 alloy features the matrix material, whereas the RF50AX-301 preform, of Saffil Automotive, was used as the reinforcement. Examinations of ceramics preforms permeability were made. Metallographic examination of composite materials made on light microscope and in scanning electron microscope show that aluminum alloys fill micropores in the matrix. New composite materials show twice higher value of hardness in comparison with matrix. Results indicate that it is possible to infiltrate porous ceramic with liquid aluminum alloy to obtain new composite materials were advantageous properties of each component are connected.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1420-1423
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• 2002

The classification and recognition of two-dimensional trademark patterns independently of their position, orientation, size and scale by proposing two feature vectors has been discussed. The paper presents experimentation on two feature vectors showing size- invariance and scale-invariance respectively. Both feature vectors are equally invariant to rotation as well. The feature extraction is based on local as well as global statistics of the image. These feature vectors have appealing mathematical simplicity and are versatile. The results so far have shown the best performance of the developed system based on these unique sets of feature. The goal has been achieved by segmenting the image using connected-component (nearest neighbours) algorithm. Second part of this work considers the possibility of using back propagation neural networks (BPN) for the learning and matching tasks, by simply feeding the feature vectosr. The effectiveness of the proposed feature vectors is tested with various trademarks, not used in learning phase.