• Journal of Korean Society for Geospatial Information Science
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• v.10 no.5 s.23
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• pp.75-80
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• 2002

Depending upon geographical features and surrounding errors in the survey field, inaccurate positioning is inevitable in a kinematic DGPs survey. Therefore, a data inaccuracy detection algorithm and an interpolation algorithm are essential to meet the requirement of a digital map. In this study, GPS characteristics are taken into account to develop the data inaccuracy detection algorithm. Then, the data interpolation algothim is obtained, based on the feature type of the survey. A digital map for 20km of a rural highway is produced by the kinematic DGPS survey and the features of interests are lines associated with the road. Since the vertical variation of GPS data is relatively higher, the trimmed mean of vertical variation is used as criteria of the inaccuracy detection. Four cases of 0.5%, 1%, 2.5% and 5% trimmings have been experimented. Criteria of four cases are 69cm, 65cm, 61cm and 42cm, respectively. For the feature of a curved line, cublic spine interpolation is used to correct the inaccurate data. When the feature is more or less a straight line, the interpolation has been done by a linear polynomial. Difference between the actual distance and the interpolated distance are few centimeters in RMS.

• Journal of Korean Society for Geospatial Information Science
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• v.14 no.4 s.38
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• pp.27-36
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• 2006

Conventionally, in order to get accurate geolocation of satellite images we need a set of ground control points with respect to individual scenes. In this paper, we tested the possibilities of modeling satellite orbits from individual scenes by establishing a sensor model for one scene and by applying the model, which was derived from the same orbital segment, to other scenes that has been acquired from the same orbital segment. We investigated orbit-attitude models with several interpolation methods and with various parameter sets to be adjusted. We used 7 satellite images of SPOT-3 with a length of 420km and ground control points acquired from GPS surveying. Results of the conventional individual scene modeling hardly introduced differences among different interpolation methods and different adjustment parameter sets. As the results of orbit modeling, the best model was the one with Lagrange interpolation for position/velocity and linear interpolation for attitude and with position/angle bias as parameter sets. The best model showed that it is possible to model orbital segments of 420km with ground control points measured within one scene (60km).

• The Journal of the Korea Contents Association
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• v.5 no.6
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• pp.97-108
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• 2005

In this paper a method of reconstructing a desired image through the geometrical transformation and the interpolation techniques is presented by comparing different interpolation schemes. Several different interpolation schemes are compared with respect to the amount of error that is the difference between the original and the reverse-projective transformed images. Higher ordered B-spline interpolation turned to be superior to other techniques in reconstructing the image which is desired to be close to the unskewed image as much as possible. In the results, this paper demonstrates that the reverse projection using the higher ordered B-spline interpolation is superior to those conventional interpolation methods, linear, cubic spline for reconstructing image. In experiments, the error decreases as the order of B-spline increases. The proposed technique is useful for various practical and theoretical applications in the area of satellite, medical, and commercial image processing.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.3
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• pp.562-568
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• 2010

In this paper, a low cost magnetic position sensor for linear position detection is proposed. The proposed magnetic sensor can be applied to the linear motor which has stator with periodical teeth, such as transverse flux linear motor(TFLM). Sine and cosine waves can be generated from the unit sensor module as the linear motor moves, and the outputs can be converted to the position data by interpolation IC. To reduce the speed ripple caused by the position error, the Luenberg observer is introduced. The validity of the proposed magnetic position sensor is verified by experiment with a 750N three-phase TFLM.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.691-694
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• 1999

This paper presents a performance improvement technique of 2-D towed array shape estimation using Kalman filters. The proposed algorithm by linear model approximation corrects the position errors caused by the Kalman filter results. However, since the assumed linear model makes errors at bending parts, the spline interpolation algorithm based on curve is proposed to reduce the errors.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.228-231
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• 1987

Microprocessor-based software DDA interpolator is developed and applied to two axis contouring control of X-Y table. Developed assembly program is composed of feedrate, linear and circular DDA interpolation routines. Reference-pulse type of open-loop stepping motor control system in which the micro-computer produces a sequence of reference pulses for each axis of motion is adopted. To test performance of the developed program, X-Y table drive system based on stepping motor and shaft encoder is designed. Contouring error of the system in linear and circular path is within .+-.0.2 mm.

• Journal of computational fluids engineering
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• v.3 no.2
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• pp.1-8
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• 1998

We make use of cubic B-spline interpolation function in two cases: heat conduction and fluid flow problems. Cubic B-spline test function is employed because it is superior to approximation of linear and non-linear problems. We investigated the accuracy of the numerical formulation and focused on the position of the breakpoints within the computational domain. When the domain is divided by partitions of equal space, the results show poor accuracy. For the case of a heat conduction problem this partition can not reflect the temperature gradient which is rapidly changed near the wall. To correct the problem, we have more grid points near the wall or the region which has a rapid change of variables. When we applied the unequally spaced breakpoints, the results show high accuracy. Based on the comparison of the linear problem, we extended to the highly non-linear fluid flow problems.

• Journal of Broadcast Engineering
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• v.17 no.5
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• pp.756-764
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• 2012

In current HEVC, prediction pixels are finally calculated by linear-function interpolation on two reference pixels. It is hard to expect good performance on the case of occurring large difference between two reference pixels. This paper decides more accurate prediction pixel values than current HEVC using linear function. While existing prediction process only uses two reference pixels, proposed method uses DCT-IF. DCT-IF analyses frequency characteristics of more than two reference pixels in frequency domain. And proposed method calculates prediction value adaptively by using linear-function, DCT-IF and cubic-function to decide more accurate interpolation value than to only use linear function. Cubic-function has a steep slope than linear-function. So, using cubic-function is utilized on edge in prediction unit. The complexity of encoder and decoder in HM6.0 has increased 3% and 1%, respectively. BD-rate has decreased 0.4% in luma signal Y, 0.3% in chroma signal U and 0.3% in chroma signal V in average. Through this experiment, proposed adaptive intra prediction method using DCT-IF and cubic-function shows increased performance than HM6.0.

• 전자공학회논문지 IE
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• v.45 no.3
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• pp.13-19
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• 2008

In this paper, we propose a new IPC(Interlace to Progressive Conversion) method based on ELA(EDge Line based Average) interpolation using detecting the reliable edge direction. Existing ELA algorithms execute linear interpolation using edge direction without considering noises. In noisy images, these algorithms degrade quality because if interpolation based on the wrong edge direction. Out scheme is able to solve the problem of existing ELA algorithms in noisy images. First, filter a noisy pixel and estimate sizes of the noiseless orginal pixed and the noise, repectively. Then, considering the size of the noise, calculate weights of ELA and vertical interpolation. If noises exist after IPC, these could be eliminated by post filtering. The experimental results show that our proposed algorithm has about $1{\sim}2$ dB better performance than those of existing ELA algorithms.

• Journal of Digital Convergence
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• v.13 no.9
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• pp.209-218
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• 2015

Computer simulation plays an important role for a theoretical foundation in convergence technology and the interpolation is to know the unknown values from known values on grid points. Therefore it is an important problem to select an interpolation method for digital simulation. The aim of this paper is to compare analysis of interpolation methods for digital simulation. we test six different interpolation methods namely: Quartic-Lagrangian, Cubic Spline, Fourier, Hermit, PWENO and SL-WENO. Through digital simulation of a linear advection equation, we analyse pros and cons for each method. In order to compare performance, we introduce accuracy computing and Error functions. The accuracy computing is used well-known $L^1-norm$ and the Error functions are dispersion function, dissipation function and total error function. High-order methods well apply to computer simulation, unfortunately, side-effects (Oscillation) happen.