• 한국태양에너지학회 논문집
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• 제40권1호
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• pp.15-24
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• 2020

Building energy consumption generally depends on living patterns of residents and outdoor air temperature changes. Although outdoor air temperature changes effect on building energy consumption, there is no calibration method for the comparison before and after Green Remodeling or BEMS installation etc., Big data of building energy consumption are collected and managed by 『National Integrated Management System of Building Energy』 in Korea, and they are utilized for the development of a calibration method for individual buildings as shown as the calibration method for small-area building stocks in the previous research. This study aims to develope a calibration method using big data of building energy consumption of individual buildings and outdoor air temperature changes, and to propose application of appropriate calibration methods for individual buildings or small-area building stocks according to the calibration purpose and conditions.

• 한국생산제조학회지
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• 제21권1호
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• pp.76-84
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• 2012

This paper presents the measurement system of arrow's point of impact using laser scan camera and describes the image calibration method. The calibration process of distorted image is primarily divided into explicit and implicit method. Explicit method focuses on direct optical property using physical camera and its parameter adjustment functionality, while implicit method relies on a calibration plate which assumed relations between image pixels and target positions. To find the relations of image and target position in implicit method, we proposed the performance criteria based polynomial theorem model that overcome some limitations of conventional image calibration model such as over-fitting problem. The proposed method can be verified with 2D position of arrow that were taken by SICK Ranger-D50 laser scan camera.

• 한국정밀공학회지
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• 제16권2호통권95호
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• pp.164-175
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• 1999

If the camera plane is nearly parallel to the calibration board on which objects are defined, most of existing calibration approaches such as Tsai's radial-alignment-constraint method cannot be applied. Recently, for such an ill-conditioned case, Zhuang & Wu suggested the linear two-stage calibration algorithm assuming that the exact values of focal length and scale factor are known a priori. In this paper, we developed an iterative two-stage algorithm starts with initial guess fo the two parameters to determine the value of the others using Zhuang & Wu's method. In the second stage, the two parameters are locally optimized. This process is repeated until any improvement cannot be expected any more. The performance comparison between Zhuang & Wu's method and our algorithm shows the superiority of ours. Also included are the computational results for the effects of the distribution and the number of calibration points on the calibration performance.

• 대한기계학회논문집
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• 제18권4호
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• pp.977-985
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• 1994

New computer-aided calibration methods for the hot-wire and split film probes are presented. The proposed modified king's law takes into account instantaneous flow angle as well as the variation of calibration coefficients due to the total velocity magnitude change. It is found that the look-up table method has many advantages with respect to the accuracy on data and reducing run time for calibration over other conventional methods. In order to investigate the local sensitivity of the static calibration, a dynamic calibration procedure is also carried out.

• 한국정밀공학회지
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• 제16권7호
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• pp.119-124
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• 1999

A method to find the line of sight ray in space which corresponds to a point in an image plane is presented. The line of sight ray is defined by two points which are the intersections between the two calibration planes and the sight ray. The intersection point is found by the oblique coordinate mapping between the image plane and the calibration plane in the space. The proposed oblique coordinate mapping method has advantages over the transformation matrix method in the required memory space and computation time.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집B
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• pp.48-52
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• 2001

In this paper presents an accurate AFM used that is free from the Z-directional distortion of a servo actuator is described. Two mathematical correction methods by the in-situ self-calibrationare employed in this AFM. One is the method by the integration, and the other is the method by inverse function of the calibration curve. The in situ self-calibration method by the integration, the derivative of the calibration curve function of the PZT actuator is calculated from the profile measurement data sets which are obtained by repeating measurements after a small Z-directional shift. Input displacement at each sampling point is approximately estimated first by using a straight calibration line. The derivative is integrated with reference to the approximate input to obtain the approximate calibration curve. Then the approximation of the input value of each sampling point is improved using the obtained calibration curve. Next the integral of the derivative is improved using the newly estimated input values. As a result of repeating these improving process, the calibration curve converges to the correct one, and the distortion of the AFM image can be corrected. In the in situ self-calibration through evaluating the inverse function of the calibration curve, the profile measurement data sets were used during the data processing technique. Principles and experimental results of the two methods are presented.

• 전기전자학회논문지
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• 제27권4호
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• pp.636-643
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• 2023

본 논문에서는 원전계 환경에서 위상배열안테나를 고속 보정하는 방법이 제안되었다. 원전계에서 수신된 전력만을 통해 각 안테나 요소를 보정하는 기존 rotating-element electric-field vector (REV) 방법을 간소화 한 최대값 보정 방법과, 각 안테나 요소가 아닌 부배열 단위로 묶어서 보정하는 방법이 제안되었다. PPO 알고리즘을 이용하여 위상배열안테나의 분포에 최적화된 파티셔닝을 찾고, 그에 따른 부배열 단위로 보정하여 기존 방법 대비 더 빠른 보정이 가능한 적응형 최대값 보정 방법이 제안 및 시뮬레이션 검증되었다. 보정이 이루어지는 동안 위상배열안테나의 이득이 더 높을 뿐 아니라, 형성되는 빔 패턴이 기존 방법보다 이상적인 빔 패턴에 더 가깝다.

• 제어로봇시스템학회논문지
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• 제13권3호
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• pp.224-229
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• 2007

This paper presents a camera calibration method using several images for three dimensional measurement applications such as stereo systems, mobile robots, and visual inspection systems in factories. Conventional calibration methods that use single image suffer from errors related to reference point extraction in image, lens distortion, and numerical analysis of nonlinear optimization. The camera parameter values obtained from images of same camera is not same even though we use same calibration method. The camera parameters that are obtained from several images of different view for a calibration target is usaully not same with large error values and we can not assume a special probabilistic distribution when we estimate the parameter values. In this paper, the median value of camera parameters from several images is used to improve estimation of the camera values in an iterative step with nonlinear optimization. The proposed method is proved by experiments using real images.

• 대한기계학회논문집B
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• 제21권11호
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• pp.1437-1448
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• 1997

Pressures of a five-hole probe were measured for a full range of yaw and pitch angles and complete pressure coefficient maps were obtained. Based on these maps, various features of five-hole probe pressures were revealed and new five-hole probe calibration coefficients were devised. The new calibration coefficients show non-diverging characteristics for any flow direction and one-to-one correspondence for a wide range of flow angles. These calibration coefficients expand the valid flow angle range of five-hole probe calibration by .+-.10 degrees and complement a critical defect of five-hole probe zone-division calibration method which has not been known yet. Moreover new non-diverging calibration coefficients have advantages in nulling methods, too.

• 한국지능시스템학회논문지
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• 제11권5호
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• pp.413-418
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• 2001

본 논문에서는 기존에 사용한 물리적 카메라 모델 대신 퍼지 모델을 사용한 새로운 카메라 보정 방식을 제안한다. 카메라 보정은 카메라의 영상 좌표계와 실제 환경이 가지는 좌표계와의 관계를 규정하는 것으로, 퍼지 모델을 이용하는 방법은 기존의 방법에서 이용했던 물리적 변수들을 설정할 수는 없지만 카메라 보정의 목적인 카메라 좌표계와 실제 환경 좌표계와의 관계를 별다른 제약없이 규정할 수 있으므로 매우 간단하고 효율적인 카메라 보정 방법이다. 실제 실험을 통해 얻은 실공간상의 하나의 보정면 좌표에 대해 퍼지 모델링 방법을 이용하여 3차원 실 공간 좌표 및 2차원 영상좌표 예측을 통해 제안한 방법의 유효성을 보인다.