• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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• pp.109-113
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• 2006

This paper presents an in-flight alignment method for strapdown inertial navigation systems based on the line-of-sight information. Unlike the existing methods, the proposed method utilizes only the 2-axis angle measurements of the onboard image sensor and does not require any explicit range measurements between the vehicle and landmarks. To improve the accuracy of all the position, velocity, and attitude estimates through the in-flight alignment, an error model of the image-sensor-aided SDINS is derived. A simulation study demonstrates that the accuracy of SDINS can be improved by the line-of-sight information only.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.867-870
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• 2007

In order to solve image sticking phenomena, the gas-phase and liquid-phase interfacial reactions of photosensitive polyimide can annihilate photoreactive carbon-carbon double bonds, which remain after photo-alignment process. The annihilation processes dramatically affect residual DC and photochemical reorientation of photoactive functional groups.

• Spatial Information Research
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• 제10권3호
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• pp.469-480
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• 2002

현행 노선선정시 1:5,000 축척의 수치지도를 이용하여 계획, 검토하고 있으나, 수치 지도는 수정, 갱신주기가 원활치 못하여 급속한 개발에 따른 지형·지물의 변화 등이 반영되지 않아 실제와 상이한 부분들이 존재한다. 이에 대한 대안으로서, 본 연구에서는 기존 노선계획 방법에 의해 수치지도를 기본자료로 사용하여 노선선정을 한 후, 이를 IKONOS 위성영상과 중첩하여 지형·지물의 사실적 표현을 통한 문제점을 파악하고, 이에 따른 노선변경을 하였다. 이로써 기본설계의 질적 내실화와 지형에 맞는 합리적인 도로의 선형을 도출할 수 있었으며, 차후 실시설계 단계에서의 노선변경을 미리 예방함으로써 경제성을 도모할 수 있었다. 한편, IKONOS 영상의 기하학적 보정에 있어서 지상기준점 수가 충분할 경우에는 TPS(Thin Plate Spline)변환을 효과적으로 활용할 수 있음을 알 수 있었다.

• 한국광학회지
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• 제22권1호
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• pp.30-34
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• 2011

본 연구에서는 현재 대부분 작업자에 의해 수동으로 이루어지고 있는 단색화장치 내 광학 요소간 광학정렬을 높은 반복도와 고속으로 수행할 수 있는 자동화 방안에 대해 논의하고자 한다. 단색 분광기의 시준거울 자동정렬을 위해 CCD센서를 이용한 위상이미지 상관기법을 핵심기술로 사용하였다. 실험결과 약 10초 내에 시준거울을 정밀하게 자동정렬 할 수 있다.

• 산업기술연구
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• 제22권A호
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• pp.67-72
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• 2002

A technique for alignment to true north is presented, based on synchronized measurements of vision image by a camera and output voltage of wind direction sensor. The true wind direction is evaluated by means of image processing techniques with least square sense, and then evaluated true value is compared with measured output voltage of the sensor. The proposed technique is applied to real meteorological tower m Daekwanryung test site. In addition, some uncertainty analysis of this method is presented.

• 한국멀티미디어학회논문지
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• 제20권11호
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• pp.1720-1728
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• 2017

Active shape model is widely used in the field of image processing especially on arbitrary meaningful shape extraction from single gray level image. Cootes et. al. showed efficient detection of variable shape from image by using covariance and mean shape from learning. There are two stages of learning and testing. Hahn applied enhanced shape alignment method rather than using Cootes's rotation and scale scheme. Hahn did not modified the profile itself. In this paper, the method using directional one dimensional profile is proposed to enhance Cootes's one dimensional profile and the shape alignment algorithm of Hahn is combined. The performance of the proposed method was superior to Cootes's and Hahn's. Average landmark estimation error for each image was 27.72 pixels and 39.46 for Cootes's and 33.73 for Hahn's each.

• 한국정보기술응용학회:학술대회논문집
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• 한국정보기술응용학회 2005년도 6th 2005 International Conference on Computers, Communications and System
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• pp.229-232
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• 2005

In this paper, an image-based "approach-align -grasp" visual servo control design is proposed for the problem of object grasping, which is based on the binocular stand-alone system. The basic idea consists of considering a vision system as a specific sensor dedicated a task and included in a control servo loop, and we perform automatic grasping follows the classical approach of splitting the task into preparation and execution stages. During the execution stage, once the image-based control modeling is established, the control task can be performed automatically. The proposed visual servoing control scheme ensures the convergence of the image-features to desired trajectories by using the Jacobian matrix, which is proved by the Lyapunov stability theory. And we also stress the importance of projective invariant object/gripper alignment. The alignment between two solids in 3-D projective space can be represented with view-invariant, more precisely; it can be easily mapped into an image set-point without any knowledge about the camera parameters. The main feature of this method is that the accuracy associated with the task to be performed is not affected by discrepancies between the Euclidean setups at preparation and at task execution stages. Then according to the projective alignment, the set point can be computed. The robot gripper will move to the desired position with the image-based control law. In this paper we adopt a constant Jacobian online. Such method describe herein integrate vision system, robotics and automatic control to achieve its goal, it overcomes disadvantages of discrepancies between the different Euclidean setups and proposes control law in binocular-stand vision case. The experimental simulation shows that such image-based approach is effective in performing the precise alignment between the robot end-effector and the object.

• 제어로봇시스템학회논문지
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• 제11권2호
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• pp.122-126
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• 2005

A technique for alignment to true north is presented based on synchronized measurements of vision image by a camera and output voltage of wind direction sensor. The true wind direction is evaluated by means of image processing techniques with least square sense, and then evaluated true value is compared with measured output voltage of the sensor. The uncertainty analysis about the component error for the proposed method in practical situation is performed. The proposed technique is applied to real meteorological tower (wind measuring tower) at the Daekwanryung test site. In addition, some uncertainty analysis of this method is presented.

• 제어로봇시스템학회논문지
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• 제16권12호
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• pp.1233-1240
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• 2010

In the flat panel display and semiconductor industries, the visual alignment system is considered as a core technology which determines the productivity of a manufacturing line. It consists of the vision system to extract the centroids of alignment marks and the stage control system to compensate the alignment error. In this paper, we develop a Kalman filter algorithm to estimate the alignment mark postures and propose a coarse-fine alignment control method which utilizes both original fine images and reduced coarse ones in the visual feedback. The error compensation trajectory for the distributed joint servos of the alignment stage is generated in terms of the inverse kinematic solution for the misalignment in task space. In constructing the estimation algorithm, the equation of motion for the alignment marks is given by using the forward kinematics of alignment stage. Secondly, the measurements for the alignment mark centroids are obtained from the reduced images by applying the geometric template matching. As a result, the proposed Kalman filter based coarse-fine alignment control method enables a considerable reduction of alignment time.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2006년도 춘계학술발표회 논문집
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• pp.265-269
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• 2006

In this study, horizontal alignment of railroad obtained by digital photogrammetry method. The two-dimensional horizontal alignment was reappeared by camera calibration and digital image data. This method's result showed more satisfactory value than existing survey method in horizontal alignment of railroad. Hereafter, this method would be a appropriate method lot the decision of railroad facility' position in small rural area and construction of DB for the design of alignment.