• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.423-431
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• 2003

This study presents on generation coefficients of the RFM using GEO-level stereo images of the IKONOS satellite. 3-D positioning and DEM generation of this model on the test field. In result, the maximum error of image coordinates acquired by the upward transform of the RFM did nat exceed 8 pixels. DEM was generated with kriging interpolation extracted three dimensional ground coordinate to rational quadratic function form, me compared it to reference digital elevation model made from 1:5,000 digital map and 1:1,000 digital map, and so, could generate digital elevation model in the accuracy as average RMSE of elevation was ${\pm}$ 3∼5 m in RFM.

• Proceedings of the KOSOMBE Conference
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• v.1991 no.05
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• pp.13-17
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• 1991

3차원 데이타로부터 물체 표면의 입체 도시를 위한 semi-transparent volume rendering 방법은 다른 입체 도시 방법들보다 화질면에서 뛰어나다고 알려져 있다. 본 논문에서는 이러한 semi-transparent volume rendering 방법의 장점을 가지면서 더욱 성능을 향상시킨 입체 데이타 표면의 3차원 도시를 실현시켜 보았다. Aniosotrophic resolution의 3차원 데이타는 directional interpolation을 사용하여 artifact의 발생을 줄였으며 전처리 과정에서 물체 표면까지의 깊이 정보를 구함으로써 계산시간을 줄일 수 있었고 또한 물체의 불투명도 값에 의해 결정되는 표본 간격을 사용함으로써 quantization error를 줄일 수 있었다.

• ETRI Journal
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• v.32 no.6
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• pp.921-931
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• 2010

It has been shown that the principal subspace-based multichannel Wiener filter (MWF) provides better performance than the conventional MWF for suppressing interference in the case of a single target source. It can efficiently estimate the target speech component in the principal subspace which estimates the acoustic transfer function up to a scaling factor. However, as the input signal-to-interference ratio (SIR) becomes lower, larger errors are incurred in the estimation of the acoustic transfer function by the principal subspace method, degrading the performance in interference suppression. In order to alleviate this problem, a principal subspace modification method was proposed in previous work. The principal subspace modification reduces the estimation error of the acoustic transfer function vector at low SIRs. In this work, a frequency-band dependent interpolation technique is further employed for the principal subspace modification. The speech recognition test is also conducted using the Sphinx-4 system and demonstrates the practical usefulness of the proposed method as a front processing for the speech recognizer in a distant-talking and interferer-present environment.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.4 s.175
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• pp.937-945
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• 2000

The assessment of machined surface is difficult because the freeform surface must be evaluated by surface fairness as well as dimensional accuracy. In this study, the machined freeform surface is modeled by interpolating the data measured on the machine tool into the mathematical continuous surface, and then the surface model is improved with the parameterization to minimize surface fairness. The accuracy reliability of the measured data is confirmed through compensation of volumetric errors of the machine tool and of probing errors. Non-uniform B-spline surface interpolation method is adopted to guarantee the continuity of surface model. Surface fairness is evaluated with the consideration of normal curvature on the interpolated surface. The validity and usefulness of the proposed method is examined through computer simulation and experiment on the machine tool.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.763-766
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• 1991

The moving of each axis in the robot manipulator can be represented with the motion of cartesian space. This paper shows the robot manipulator of the straight line trajectory planning algorithms in the cartesian space. The relation formulas between cartesian space and joint space are induced to accomplish a desired trajectory in the cartesian space and the velocity vector of sampling time in the cartesian space is transformed into the velocity vector of joint by the interpolation method. The error of trajectory in moving is removed by obtaining the real position for the present joint position and the desired distance is made by comparing the real position and the next position. Through the simple tests for suggested algorithms are confirmed the validity of algorithms.

• 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.

• Journal of Power System Engineering
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• v.4 no.3
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• pp.72-80
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• 2000

In order to design a stable robust controller, nominal model, and the upper bound about the uncertainty which is the error of the model are needed. The problem to estimate the nominal model of controlled system and the upper bound of uncertainty at the same time is called robust identification. When the nominal model of controlled system and the upper bound of uncertainty in relation to robust identification are given, the evaluation of the validity of the model and the upper bound makes it possible to distinguish whether there is a model which explains observation data including disturbance among the model set. This paper suggests a method to identity the uncertainty which removes disturbance and expounds observation data by giving a probable postulation and plural data set to disturbance. It also examines the suggested method through a numerical computation simulation and validates its effectiveness.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.6
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• pp.16-20
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• 2010

This study proposes a structural design method for the upper control arm installed at the rear side of a SUV. The weight of control arm can be reduced by applying the design. In this research, the former includes optimization technology, and the latter the technologies for selecting aluminum as a steel-substitute material. Strength assessment is the most important design criterion in the structural design of a control arm. At the proto design stage of a new control arm, FE (finite element) analysis is often utilized to predict its strength. In this study, the kriging interpolation method is adopted to obtain the minimum weight satisfying the strength constraint and durability criteria. The optimum results determined from the in-house program are compared with those of ANSYS WORKBENCH. The durability assessment is obtained by a index of fatigue durability and trial & error method, MSC. Fatigue program.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.3
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• pp.16-22
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• 2005

It is difficult to separate those of NC controller from the error of machine tools because the conventional testing methods to inspect the performance are including the errors of moving system, therefore it has been used as the methods that compare the other controllers. Also, it is hard to predict the machine itself errors with the methods assembling the NC controller and moving system on machine because of the variable load conditions. In this study, the performance inspecting system was developed by analyse the $axis\_rotating$ properties of servo system finally outputting from NC controller. The axis torque was controlled by motor dynamometer and the rotating position accuracy was measured by this developed system.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.11
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• pp.144-153
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• 2007

In order to generate the input data for rapid prototyping, a new approach which is based on the implicit surface interpolation method is presented. In the method a surface is reconstructed by creating smooth implicit surface from unorganized cloud of points through which the surface should pass. In the method an implicit surface is defined by the adaptive local shape functions including quadratic polynomial function, cubic polynomial function and RBF(Radial Basis Function). By the reconstruction of a surface, various types of error in raw STL file including degenerated triangles, undesirable holes with complex shapes and overlaps between triangles can be eliminated automatically. In order to get the slicing data for rapid prototyping an efficient intersection algorithm between implicit surface and plane is developed. For the direct usage for rapid prototyping, a robust transformation algorithm for the generation of complete STL data of solid type is also suggested.