• 한국소프트웨어감정평가학회 논문지
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• 제17권2호
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• pp.151-159
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• 2021

도표로 작성된 양식 문서에서 도표의 레이아웃 해석에 필요한 그리드 라인을 추출하기 위해 다양한 필터링 또는 모폴로지 등의 방법을 사용하여 직선 성분을 선명하게 개선시키기 위한 연구들이 많이 진행되고 있다. 도표의 직선 성분을 선명화하더라도 직선 내부에 절단 점들이 존재하거나 기울어진 경우에는 직선 추출이 어렵고 도표 셀들의 레이아웃을 논리적으로 표현하는데 여전히 어려움을 겪을 수 있다. 본 연구에서는 직선에 절단점들이 존재하거나 기울어져도 직선을 검출할 수 있는 라인 추적 알고리즘을 제안하였다. 이를 이용하여 그리드 라인을 추출하고 라인들의 교차점 및 셀 정보들을 찾아 도표의 구조를 분석할 수 있는 알고리즘을 마련하였다. 제안한 알고리즘을 실제 양식 문서 영상을 대상으로 실험한 결과 평균 0.41초 처리시간에 96.4%의 도표 구조를 분석할 수 있음을 확인하였다.

• 한국정보과학회논문지:소프트웨어및응용
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• 제34권5호
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• pp.419-430
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• 2007

소프트웨어 개발시 요구사항이 시스템에 제대로 반영되어 개발되고 있는지를 추적하는 일은 아주 중요하다. 이에, 본 연구에서는 추적테이블을 이용하여 요구사항을 추적하는 방법을 연구하였다. 본 연구에서 제시한 추적테이블에서는 제안요청서, 제안서 등의 내용을 명확히 명세하게 함으로써 요구사항의 발생근거를 명확히 하고, 산출물마다 요구사항 식별코드를 매핑하게 하여 산출물간의 일관성 및 완전성 검증하는데 용이하게 하였다. 아울러, 본 연구를 진행하면서 마르미-III v.4.0 방법론의 요구획득단계 산출물중에 추가하거나 보완이 필요한 요소를 발견하게 되었기에 개선된 추적테이블과 함께 부가적인 연구결과로 제시하고자 한다. 본 연구에서 제시한 개선된 추적테이블을 이용하여 산출물을 검증함으로써 소프트웨어 개발시 요구사항 관리 부족으로 일어나는 각종 위험 및 문제요소를 줄일 수 있을 것이다. 또한 마르미-III v.4.0 방법론의 요구획득 단계 산출물을 본 연구의 추적테이블 작성방법에 따라 추가.보완하게 함으로써 마르미-Ⅲ 방법론의 활용을 높이고자 한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.581-586
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• 2003

This paper presents control designs using neural networks (NN) for a XY positioning table. The proposed neurocontroller is composed of an outer PD tracking loop for stabilization of the fast flexible-mode dynamics and an NN inner loop used to compensate for the system nonlinearities. A tuning algorithm is given for the NN weights, so that the NN compensation scheme becomes adaptive, guaranteeing small tracking errors and bounded weight estimates. Formal nonlinear stability proofs are given to show that the tracking error is small. The proposed neuro-controller is implemented and tested on an IBM PC-based XY positioning table, and is applicable to many precision XY tables. The algorithm, simulation, and experimental results are described. The experimental results are shown to be superior to those of conventional control.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.642-645
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• 1991

This paper presents the results of research on hardware and software of the landmark tracking system to the positions of moving robot in real time. The landmark tracking system is composed of CCD camera, landmark, strobo system and image processing board. The algorithm calculates the position and direction by using the coordinate transformation fomula after calculating the centroid and rotation angle of landmark at fixed position using the image data. The experiment is performed with landmark tracking system is loaded on xyz-table. XYZ-table is used for identifying the true position in our experiment. The results shows that this system has high performance with maxima error of .+-.1 pixels.

• Smart Structures and Systems
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• 제14권6호
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• pp.1055-1079
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• 2014

Substructure shake table testing is a class of real-time hybrid simulation (RTHS). It combines shake table tests of substructures with real-time computational simulation of the remaining part of the structure to assess dynamic response of the entire structure. Unlike in the conventional hybrid simulation, substructure shake table testing imposes acceleration compatibilities at substructure boundaries. However, acceleration tracking of shake tables is extremely challenging, and it is not possible to produce perfect acceleration tracking without time delay. If responses of the experimental substructure have high correlation with ground accelerations, response errors are inevitably induced by the erroneous input acceleration. Feeding the erroneous responses into the RTHS procedure will deteriorate the simulation results. This study presents a set of techniques to enable reliable substructure shake table testing. The developed techniques include compensation techniques for errors induced by imperfect input acceleration of shake tables, model-based actuator delay compensation with state observer, and force correction to eliminate process and measurement noises. These techniques are experimentally investigated through RTHS using a uni-axial shake table and three-story steel frame structure at the Johns Hopkins University. The simulation results showed that substructure shake table testing with the developed compensation techniques provides an accurate and reliable means to simulate the dynamic responses of the entire structure under earthquake excitations.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.761-765
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• 1997

Our study of rider's postulator stability and tracking control on a unicycle began form the observation of a human riding. The system including unicycle and human operationg his unicycle is a fuzzy intelligent biomechanical model on basis of instinct and intuition search mechanisms. We proposed a robotic unicycle with one wheel and one body as a basic mode and derived equation of motion to this model. Our works is in making out fuzzy look-up table to control robotic unicycle. Fuzzy look-up table were determined for staight line and curve under reasonable inference emulating human's instinct and intuition riding a unicyale. Simulation results show that postulator stability and tracking control on both straight line and curve were successful by using proposed each fuzzy look-up table.

• 한국지능시스템학회논문지
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• 제14권3호
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• pp.375-382
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• 2004

신경회로망을 이용한 XY 테이블의 비선형 보상기법을 제안한다. 제안된 신경망 제어기는 시스템의 비선형 성분에 의한 성능저하를 보상하는 신경회로망과 시스템의 안정화를 위한 비례미분(PD) 제어기로 구성된다. 신경망 보상 구조가 적응적이고 추적오차와 파라미터 추정치가 유계가 되는 신경망 파라미터 동조알고리듬과 안정도 증명을 제시한다. 신경망 제어기를 위치 테이블에 실험함으로써 비선형 성분에 의한 성능저하를 줄이는 효과를 보여준다.

• Journal of Welding and Joining
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• 제14권4호
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• pp.79-88
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• 1996

For improvement in productivity and weld quality, weld seam tracking and welding parameter control are very essential in the welding of a structure which can not be cxactly fit-up due to mismatch, discontinous gap, deflection, etc.. In this study, an automatic weld seam tracking system is developed for I-butt joint structure, and the system consists of XYZ working table, vision sensor and user interface program. In the developed vision sensor system, an image projection algorithm for weld-line detection and an adaptive current control algorithm for gap variation were implemented. The user interface program developed in this study by basing on the objct oriented concept could provide very convenient way to utilize the tracking system with the pull-down menu driven structure. The developed system showed a good seam tracking and weld quality control capability corresponding to deflected weld lines and gap variations.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 춘계학술대회 논문집
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• pp.680-684
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• 1996

Welding systems cannot adapt to changes in the joint geometry which may occur due to a variety of reason. Automatic seam tracking technigue is essential to adjust the welding torch position in real time as it moves along the seam. Automatic tracking system must keep the welding speed constant unrelation to the change of the welding path. Therefore, the information from the laser displacement sensor must be converted into the input to operate the X-Y table and to rotate the desired torch position by proposed algorithm. In this research, laser displacement sensor is used as a seam finder in the automatic tracking system. X-Y moving table manipulated by ac servo motor controls the position and velocity of the torch-and-sensor part. DC motor controls the position and velocity of the torch. X-Y table controls the position of sensor and relative position of torch is controlled by dc motor which is mounted at sensor-and-torch part. Sensor is always ahead of torch to preview the weld line. From the experimental results, we could see the possiblity that the laser displacement sensor can be used as a seam finder in welding process and that the seam tracking system controlled by proposed algorithm is well done.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.729-733
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• 1997

Due to the variety of disturbance, it is not ease to accomplish the in-process detection of weld line with non-contact sensor. To get around this difficulties problem develop an automatic seam tracking weld system, the reliable signal processing algorithm has been recommanded. In this research, laser displacement sensor is applied as a seam finder in the automatic tracking system. The sensor is controlled by a dc servo motor which is mounted at X-Y moving table. X-Y moving table manipulated by an ac servo motor controls the position and velocity of the welding torch. First, X-Y table moves to Y-axis to search the welding joint feature before starting the welding, and welding joint is from the scanning data and weighting factor for each other. Second, weld line is determined using proposed signal processing algorithm during welding process. Form the experimental results, we could see the possibility that laser displacement sensor with procesed algorithm can be used as a seam finder in welding process under the severe noise (spatter,arc light etc.) condition