• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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• pp.109-114
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• 2000

A new method for the determination of camera system rotation and translation from in 3-D space using recursive least square method is presented in this paper. With this method, the calculation of the equation is found by a linear algorithm. Where the equation are either given or be obtained by solving five or more point correspondences. Good results can be obtained in the presence if more than the eight point. A main advantage of this new method is that it decouple rotation and translation, and then reduces computation. With respect to error in the solution point number in the input image data, adding one more feature correspondence to required minimum number improves the solution accuracy drastically. However, further increase in the number of feature correspondence improve the solution accuracy only slowly. The algorithm proposed by this paper is used to make camera system rotation and translation easy to recognize even when camera system attached at end effecter of six degrees of freedom industrial robot manipulator are applied industrial field.

• 한국통신학회논문지
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• 제29권2C호
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• pp.272-282
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• 2004

본 논문에서는 정규화 혼합 norm을 이용한 다중 채널 영상 복원 기법을 제안한다. 채널 영상 간 및 채널 영상내의 결정론적 정보를 이용한 다중 채널 영상 복원에 관한 문제를 고려한다. 제안 방식에서는 각 채널 영상에 대해 LMS (Least Mean Square) 및 LMF (Least Mean Fourth) 및 완화 함수를 결합시킨 부가 함수가 제안된다. 더불어, LMS 및 LMF의 상대적 기여도를 제한하기 위한 혼합 norm 매개 변수 및 완화 함수의 중요성을 제어하는 정규화 매개 변수는 반복 영상으로부터 예측된 각 채널의 노이즈 분포에 의해 결정되어 진다. 제안된 방식은 각 채널 영상의 첨부 노이즈 형태에 대한 사전 정보 없이 복원 과정이 가능하다는 점과 두 매개 변수를 반복 과정에서 부분적으로 복원된 영상으로부터 조절할 수 있는 특성을 갖고 있다.

• Journal of information and communication convergence engineering
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• 제16권1호
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• pp.17-22
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• 2018

In massive multiple-input multiple-output (MIMO) systems, linear channel estimation algorithms are widely applied owing to their simple structures. However, they may cause pilot contamination, which affects the subsequent data detection performance. Therefore, herein, for an uplink multicell massive multiuser MIMO system, we consider using an alternating projection (AP) for channel estimation to eliminate the effect of pilot contamination and improve the performance of data detection in terms of the bit error rates as well. Even though the AP is nonlinear, it iteratively searches the best solution in only one dimension, and the computational complexity is thus modest. We have analyzed the mean square error with respect to the signal-to-interference ratios for both the cooperative and non-cooperative multicell scenarios. From the simulation results, we observed that the channel estimation results via the AP benefit the following signal detection more than that via the least squares for both the cooperative and non-cooperative multicell scenarios.

• 대한기계학회논문집A
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• 제30권12호
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• pp.1626-1633
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• 2006

In the present paper, in the context of the meshless interpolation of a moving least squares (MLS) type, a novel method which uses primary and secondary nodes in the domain and on the global boundary is introduced, in order to improve the accuracy of solution. The secondary nodes can be placed at any location where one needs to obtain a better resolution. The support domains for the shape functions in the MLS approximation are defined from the primary nodes, and the secondary nodes use the same support domains. The shape functions based on the MLS approximation, in an integration domain, have a single type of a rational function, which reduces the difficulty of numerical integration to evaluate the weak form. The present method is very useful in an adaptive calculation, because the secondary nodes can be easily added and moved without an additional mesh. Several numerical examples are presented to illustrate the effectiveness of the present method.

• 한국컴퓨터정보학회논문지
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• 제21권12호
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• pp.125-130
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• 2016

Automatic quality inspection by computer vision can be applied and give a solution to the pharmaceutical industry field. Pharmaceutical capsule can be easily affected by flaws like dents, cracks, holes, etc. In order to solve the quality inspection problem, it is required computationally efficient image processing technique like thresholding, boundary edge detection and segmentation and some automated systems are available but they are very expensive to use. In this paper, we have developed a dented capsule image processing technique using edge-based image segmentation, TLS(Total Least Squares) curve fitting technique and adopted low cost camera module for capsule image capturing. We have tested and evaluated the accuracy, training and testing time of the classification recognition algorithms like PCA(Principal Component Analysis), ICA(Independent Component Analysis) and SVM(Support Vector Machine) to show the performance. With the result, PCA, ICA has low accuracy, but SVM has good accuracy to use for classifying the dented capsule.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 D
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• pp.2088-2090
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• 2003

A practical recursive weighted least square(WLS) solution is proposed to solve the passive ranging problem. Apart from the previous works based on the extended Kalman filter(EKF), to ensure the convergency at long-range, the proposed scheme makes use of line-of-sight(LOS) rate instead of bearing information. The influence of LOS rate measurement errors is investigated and it is asserted that the WLS estimates contain bias and scale factor errors. Together with simple compensation algorithm, the estimation errors of proposed filter can be reduced dramatically.

• 한국측량학회지
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• 제32권6호
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• pp.563-570
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• 2014

This paper purposes on stimulating the dynamic behavior of a floating structure model with the image processing and the close-range photogrammetry, instead of the contact sensors. Previously, the movement of structures was presented by the exterior orientation estimation from a single camera following the space resection. The inverse resection yields to 6 orientation parameters of the floating structure, with respect to the camera coordinates system. The single camera solution of interest in applications is characterized by the restriction in terms of costs, unfavorable observation conditions, or synchronization demands when using multiple cameras. This paper discusses the theoretical determinations of camera exterior orientation by using the least squares adjustment, applied of the values from the DLT (Direct Linear Transformation) and the photogrammetric resection. This proposed method is applied to monitor motions of a floating model. The results of 6DOF (Six Degrees of Freedom) from the inverse resection were signified that applying appropriate initial values from DLT in the least square adjustment is effective in obtaining precise exterior orientation parameters. Therefore, the proposed method can be concluded as an efficient solution to simulate movements of the floating structure.

• 정보보호학회논문지
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• 제16권2호
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• pp.13-24
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• 2006

여러 개체가 각자의 정보를 제공하여 이를 바탕으로 정보 제공자의 프라이버시를 보존하면서 공통의 유익한 정보를 얻고자 하는 다자간 협력 계산 프로토콜에 대해서 논한다. 금융, 제조업, 통신 분야 등에서 널리 응용되는 선형계(linear system)의 일반해(general solution)와 최소제곱해(least-square solution)를 구하는 문제에서 프라이버시를 보존하는 실용적인 다자간(multi-party) 협력 계산 프로토콜을 제안한다. 본 논문에 제안된 프로토콜은 기존의 양자간(two-party) 협력 계산 방식을 확장한 새로운 것으로 효율성 측면에서 우수한 실용적인 다자간 계산 프로토콜이다.

• 응용통계연구
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• 제20권2호
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• pp.373-385
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• 2007

선형모형에서 최소자승법에 의한 정규방정식의 해는 유일하지 않은 경우도 있는데 문헌에 따르면 일반화 역행렬을 정의하여, 그 해를 SAS IML로 취급하고 있다. 본 논문에서는 이것에 대한 이론을 보다 체계화하여 교육 및 연구에 도움을 주고자 하는데 그 목적이 있다.

• 전기학회논문지
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• 제58권3호
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• pp.639-644
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• 2009

This paper presents a modified CFS (Closed-Form Solution) for FLAOA (Forward Link AOA) measurements. During when the pseudo-measurement equation for FLAOA is derived, the angle measurement noise is treated more carefully in approximation. As the covariance matrix of the pseudo-measurement noise is influenced by unknown user positions and azimuth, a two-step estimation technique is used in the proposed CFS. The performance of the proposed CFS for FLAOA is compared to that of the conventional CFS for FLAOA and RLAOA (Reverse Link AOA) in a computer simulation. Simulation results show that the proposed method is potentially suitable for applications involving the localization and guidance of indoor mobile robots.