• 한국자동차공학회논문집
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• 제5권6호
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• pp.13-27
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• 1997

In the modern design technology, a component should be designed to fit into the overall system performance. A design methodology is developed to expedite the mechan- ical design of complex mechanical systems, The relation between the system design and component design is defined by a top-down approach and the results from the system design are utilized in the component design process. As a design example, an automobile exhaust system is selected for the system design and a bellows is chosen for a component design. Design methodology based on the top-down approach consists of five steps; (1) Analysis of service load, (2) Development of a lumped parameter, (3) Completion of the system design, (4) Selection of the component topology, (5) Completion of the component design, A method using a equivalent matrix is developed in order to determine unknown external forces in linear structural analyses. The bellows is also analyzed by the finite element method using a conical frustum shell element. Various experiments are performed to verify the developed theories. The top-down desi- gn approach is demonstrated by a design case using structural and shape optimization technology. Since the method is relatively simple and easy compared to other methods, it can be applied to the general design where system and component designs are involves simultaneously.

• 응용통계연구
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• 제34권2호
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• pp.127-139
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• 2021

독립성분분석은 혼합 데이터로부터 독립된 신호들을 분리해내는 대표적인 통계적 방법론이며, 그룹 독립성분분석은 독립성분분석을 여러 개체에 적용할 수 있도록 확장한 방법론이다. 그룹 독립성분분석은 기능적 자기 공명 영상 데이터에 활용되어 의학적으로 유의미한 결과를 줌이 알려져있다. 그러나 자기 공명 영상 스캔에서 흔히 일어나는 이상치가 포함되어 있는 경우, 기존의 그룹 독립성분분석은 그 효과가 떨어짐이 알려져있다. 본 연구에서는 ROBPCA 기반의 로버스트한 그룹 독립성분분석 방법론을 제안하였다. 시뮬레이션과 실제 자료 분석을 통해 제안한 방법과 기존 방법을 비교하였고, 그 결과 제안한 방법론의 로버스트성을 입증했다.

• 대한지리학회지
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• 제46권2호
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• pp.212-232
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• 2011

이 연구의 목적은 이지역 코호트 요인법에 의한 인구 추계 방법론을 정립하고, 그것을 부산광역시의 장래 인구 추계에 적용하는 것이다. 우선 시도와 같은 지역 인구의 추계에 있어 우리나라의 공식적인 방법인 순이동 코호트-요인법이 갖는 한계를 예증하였다. 대안으로 지역간 코호트-요인법 중 전체 지역을 두 지역으로 구분한 후 지역 간의 전입과 전출을 분리하여 추계하는 이지역 코호트-요인법을 정립하였다. 이를 바탕으로 부산광역시의 2005~2030년에 대한 인구 추계를 3가지 시나리오 하에서 실행하였다. 순이동 방식을 취한 인구 추계와 이지역 방식을 취한 인구 추계 간에는 상당한 차이가 나타났는데, 전출 초과 지역인 부산의 경우 순이동 방식에서 더 빠른 인구 감소가 나타났다. 이지역 방식에 의한 부산 및 전국추계의 인구 변화 추세를 검토한 결과 추계가 상당히 합리적으로 이루어짐을 확인할 수 있었다. 결론적으로 본 연구에서 제시된 이지역 코호트-요인법은 순이동 코호트-요인법에 비해 논리적으로 더 정연하면서도 실제 추계에 있어서도 높은 유용성을 보여 주었다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2004년도 봄 학술발표회 논문집
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• pp.243-250
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• 2004

This paper reports on the evaluation of the initial stiffness of steel joints using component method as well as experimental tests. The so-called component method corresponds precisely to a simplified mechanical model composed of extensional springs and rigid links, whereby the joint is simulated by an appropriate choice of rigid and flexible components. An application to a cantilever beam-to-column steel joint is presented and compared to the experimental results obtained under cyclic loading condition. Comparison between numerical and experimental results allows to conclude that the numerical model is able to simulate, with a good level of accuracy for initial stiffness, the behaviour of beam-to-column joints.

• 제어로봇시스템학회논문지
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• 제16권8호
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• pp.786-793
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• 2010

This paper proposes a new method called the path-history coverage to generate a test suite to test the state transition behavior of the robot SW component. The proposed method generate a test suite which includes abnormal state transitions based on FSM of target component. Especially the proposed method covers the disadvantage of the mutation test method that the size of the test suite is explosively increasing. Examples including OPRoS Component[1] show the validity of the proposed method.

• Journal of the Korean Data and Information Science Society
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• 제8권2호
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• pp.127-134
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• 1997

A method is proposed for the choice of the number of principal components in principal component regression based on the predicted error sum of squares. To do this, we approximately evaluate that statistic using a linear approximation based on the perturbation expansion. In this paper, we apply the proposed method to various data sets and discuss some properties in choosing the number of principal components in principal component regression.

• 소음진동
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• 제9권2호
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• pp.401-408
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• 1999

A method is presented for the vibration analysis of steam turbine-generator rotor system based on the component mode synthesis method. The motion of each component of the system is described by superposing constraint mode associated with boundary coordinates and constrained normal modes associated with internal coordinates. This method using real fixed-interface modes allows for significant reduction in system model size while retaining the essential dynamic characteristics of the lower modes. The capability of this method is demonstrated in the natural frequency and unbalance response analysis of the steam turbine-generator rotor system in which the dynamics of the pedestal is considered. The results by the present method are compared with finite element method and trnasfer matrix method in terms of the accuracy and computing time.

• 한국IT서비스학회지
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• 제1권1호
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• pp.141-148
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• 2002

As an optimun alternatives for the solution of recent software crisis, we have to develop component technologies so as to develop and propagate business components for various domains to industries. For the sake of development of business components, a conceptual architecture which defines a model for component assembly should be prescribed first, and a systematic specification method based on this model be defined, so we can build a system environments for making specifications and development of each component by the consistent scheme. In this study, we propose a domain architecture model for implementing the pUblic component bank as a project supported by the ministry of information and communication, discuss the conceptual model of specification for developing components of storing component bank, specification steps, specification approach for application of business domains and the development results of them.

• 제어로봇시스템학회논문지
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• 제16권11호
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• pp.1089-1095
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• 2010

We propose an image segmentation method for auto-teaching system of PCB (Printed Circuit Board) assembly inspection machines. The inspection machine acquires images of all components in PCB, and then compares each image with its standard image to find the assembly errors such as misalignment, inverse polarity, and tombstone. The component window that is the area of component to be acquired by camera, is one of the teaching data for operating the inspection machines. To reduce the teaching time of the machine, we newly develop the image processing method to extract the component window automatically from the image of PCB. The proposed method segments the component window by excluding the soldering parts as well as board background. We binarize the input image by use of HSI color model because it is difficult to discriminate the RGB colors between components and backgrounds. The linear combination of the binarized images then enhances the component window from the background. By use of the horizontal and vertical projection of histogram, we finally obtain the component widow. The experimental results are presented to verify the usefulness of the proposed method.

• 전기학회논문지
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• 제61권3호
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• pp.472-478
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• 2012

The inspection machine in PCB (printed circuit board) assembly line checks assembly errors by inspecting the images inside of the component inspection region. The component inspection region consists of region of component package and region of soldering. It is necessary to extract the regions automatically for auto-teaching system of the inspection machine. We propose an image segmentation method to extract the component inspection regions automatically from images of PCB. The acquired image is transformed to HSI color model, and then segmented by several regions by clustering method. We develop a modified K-means algorithm to increase the accuracy of extraction. The heuristics generating the initial clusters and merging the final clusters are newly proposed. The vertical and horizontal projection is also developed to distinguish the region of component package and region of soldering. The experimental results are presented to verify the usefulness of the proposed method.