• 한국지능시스템학회논문지
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• 제13권5호
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• pp.571-575
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• 2003

In this paper, we describe a method for fuzzy polynomial regression analysis for fuzzy input--output data using shape preserving operations for least-squares fitting. Shape preserving operations simplifies the computation of fuzzy arithmetic operations. We derive the solution using mixed nonlinear program.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제11권2호
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• pp.103-115
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• 2004

A computational algorithm is developed for fitting given data in the plane or in 3-space by implicitly defined quadrics. Implicity implies that the type of the quadric is part of the model and need not be known in advance. Starting with some estimate for the coefficients of the quadric the method will alternatively determine the shortest distances from the given points onto the quadric and adapt the coefficients such as to reduce the sum of those squared distances. Numerical examples are given.

• Current Optics and Photonics
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• 제8권2호
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• pp.151-155
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• 2024

Optical systems often suffer from optical aberrations caused by imperfect hardware, which places significant constraints on their utility and performance. To reduce these undesirable effects, a comprehensive understanding of the aberrations inherent to optical systems is needed. This article presents an effective method for aberration detection using Zernike polynomials. The process involves scanning the object plane to identify the optimal focus and subsequently fitting the acquired focus data to Zernike polynomials. This fitting procedure facilitates the analysis of various aberrations in the optical system.

• 한국의류학회지
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• 제30권1호
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• pp.157-166
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• 2006

The human body, which is composed of concave and convex curvatures, makes it difficult to transfer into 2D patterns directly from 3D data. In previous studies. Jeong, et al.(2004) suggested the block method was fester and easier when dealing with the triangular patches of male's upper dress form. Although the block method is useful to make a pattern, the information(area, length, etc.) from a 2D pattern would be different depending on the direction of the block method. As a result horizontal and diagonal block methods were suggested as optimal methods for 2D tight-fitting patterns. These block methods were closer to the original area of the 3D scan data than the vertical block method. The total area of the 2D pattern obtained by the horizontal and diagonal block methods showed little differences. In case of the horizontal and diagonal block methods, the total error of the 2D pattern area ranged from $0.01\%\~0.25\%$. In comparing the length of the 2D pattern with that of the 3D scan data, the obtained 2D pattern was $0.1\~0.2cm$ shorter than the 3D scan data, which was within the acceptable range of errors in making clothes. 3D space distribution images between the body surface and the experimental clothing were also measured and $3\%$ enlargement of the original pattern was verified as the adequate adjustment.

• 한국생활과학회지
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• 제8권1호
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• pp.211-217
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• 1999

To investigate the fitting and its problems related in clothing fit and to get basic data to develop fitted ready-to-wear garment, total 238 subjects were surveyed during the period of May, 1997 in Taejon. The major results were as follows; 1. The results showed that most subjects had purchased ready-to-wear garments in a department store. 2. The fit of ready-to-wear garments is more suitable in the upper wear such as T-shirts and blouse than in lower wear such as skirts and pants. 3. Fitting problems in ready-to-wear garments were identified, including sleeve length, shoulder area. 4. A variety of fitting problems in ready-to-wear garments were showed waistline, thigh girth, sleeve length. 5. There were significant differences between the demographic variables, i.e. marital status and occupation and clothing problems.

• 전기학회논문지
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• 제56권6호
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• pp.1087-1091
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• 2007

Exact impedance modeling of the electrode/electrolyte interface is important in bio-signal sensing electrode development. Therefore, the investigation of the equivalent circuit models for the interface has been pursued for a long time by several researchers. Previous circuit models fit the experimental results in limited conditions such as frequency range, type of electrode, or electrolyte. This paper describes a new electrical circuit model and its capability of fitting the experimental results. The proposed model consists of three resistors and two constant phase elements. Electrochemical impedance spectroscopy was used to characterize the interface for Au, Pt, and stainless steel electrode in 0.9% NaCl solution. Both the proposed model and the previous model were applied to fit the measured impedance results for comparison. The proposed model fits the experimental data more accurately than other models especially at the low frequency range, and it enables us to predict the impedance at very low frequency range, including DC, using the proposed model.

• 전기학회논문지
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• 제57권11호
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• pp.2095-2101
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• 2008

In this paper, we consider a performance improvement of neural network for predicting defect size of steam generator tube using early stopping. Usually, neural network is trained until MSE becomes less than a prescribed error goal. The smaller the error goal, the greater the prediction performance for the trained data. However, as the error goal is decreased, an over fitting is likely to start during supervised training of a neural network, which usually deteriorates the generalization performance. We propose that, for the prediction of an axisymmetric defect size, early stopping can be used to avoid the over-fitting. Through various experiments on the axisymmetric defect samples, we found that the difference bet ween the prediction error of neural network based on early stopping and that of ideal neural network is reasonably small. This indicates that the error goal used for neural network training for the prediction of defect size can be efficiently selected by early stopping.

• 한국농공학회지
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• 제45권5호
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• pp.117-125
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• 2003

Since the recorded information used for operation of a catchment modelling system contain errors that influence the calibration of catchment modelling system control parameter values, the accurate estimation of these parameters is difficult. Despite these influences, existing traditional calibration approaches focus only on achieving the best "curve fitting" between simulated and recorded data, and not on generic evaluation of control parameter values. This paper introduces an Early Stopping Technique which is aimed at avoiding the procedure of curve-fitting through monitoring improvements in the objective function used for assessing the optimal parameter set. Application of this approach to the calibration of SWMM (Storm Water Management Model) on the Centennial Park catchment in Sydney, Australia is outlined. outlined.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.14-15
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• 2006

A saturation of magnetic flux in the core may occur when a large primary current flows when the iron-cored current transformer is used. This saturation makes the distorted secondary current of the CT. the distorted secondary current may cause the mal-operation or operation time delay of protective relays. CT compensation algorithm using The LSQ(Least Square) fitting method has a problem. It needs to acquire enough data for executing this algorithm without an error. In this paper, an enhanced algorithm using interpolation based LSQ(Least Square) Fitting Method is proposed. The Lagrange Interpolation Method is used for the interpolation and CT is simulated by EMTP. The results show that the proposed algorithm can accurately compensate a distorted secondary current more than existing Algorithm when the saturation severely occurs.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1986년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 17-18 Oct. 1986
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• pp.119-122
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• 1986

An algorithm is proposed to find a stable rational function, which is frequently used in the linear system theory, by curve-fitting a given data. This problem is essentially a nonolinear optimization problem. In order to converge faster to the solution, the following method is used. First, the coefficients of the denominator polynomial are fixed and only the coefficients of the numerator polynomial are adjusted by its linear relationships. Then the coefficients of the numerator are fixed and the coefficients of the denominator polynomial are adjusted by nonlinear programming. This whole process is repeated until a convergent solution is found. The solution obtained by this method converges better than by other algorithms and its versatility is demonstrated by applying it to the design of a feedback control system and a low pass filter.