• Publications of The Korean Astronomical Society
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• v.20 no.1 s.24
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• pp.73-83
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• 2005

On-The-Fly (OTF) observation method is developed for the efficient use of 6 M radio telescope at Seoul Radio Astronomy Observatory (SRAO). This technique, in which data and information of antenna position are recorded synchronously while driving a telescope regularly and rapidly across a field, provides more efficient use of telescope time and better calibration of the acquired data than the traditional point-to-point observation method does. For the realization of the method, we (1) added RT-Linux modules to the existing operating system, (2) replaced digital voltmeter with voltage-to-frequency converter, and (3) modified many SRAO observation programs. By observing Moon and G78.2+2.7 using this method and comparing them with previous observations, we verify the successful operation and efficiency of the OTF observation mode.

• Journal of KIBIM
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• v.11 no.4
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• pp.1-9
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• 2021

Comparing to general scanning data, the 3D digital map for large construction sites and complex buildings consists of millions of points. The large construction site needs to be scanned multiple times by drone photogrammetry or terrestrial laser scanner (TLS) survey. The scanned point cloud data are required to be registrated with high resolution and high point density. Unlike the registration of 2D data, the matrix of translation and rotation are used for registration of 3D point cloud data. Archiving high accuracy with 3D point cloud data is not easy due to 3D Cartesian coordinate system. Therefore, in this study, iterative closest point (ICP) registration method for improve accuracy of 3D digital map was employed by different overlap ratio on 3D digital maps. This study conducted the accuracy test using different overlap ratios of two digital maps from 10% to 100%. The results of the accuracy test presented the optimal overlap ratios for an ICP registration method on digital maps.

• Korean Journal of Mathematics
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• v.31 no.1
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• pp.121-122
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• 2023

• Industrial Engineering and Management Systems
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• v.11 no.1
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• pp.87-93
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• 2012

This paper discusses a new weighting method for text analyzing from the view point of supervised learning. The term frequency and inverse term frequency measure (tf-idf measure) is famous weighting method for information retrieval, and this method can be used for text analyzing either. However, it is an experimental weighting method for information retrieval whose effectiveness is not clarified from the theoretical viewpoints. Therefore, other effective weighting measure may be obtained for document classification problems. In this study, we propose the optimal weighting method for document classification problems from the view point of supervised learning. The proposed measure is more suitable for the text classification problem as used training data than the tf-idf measure. The effectiveness of our proposal is clarified by simulation experiments for the text classification problems of newspaper article and the customer review which is posted on the web site.

• IEMEK Journal of Embedded Systems and Applications
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• v.15 no.1
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• pp.1-8
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• 2020

A derivation method for a quantized gradient for machine learning on an embedded system is proposed, in this paper. The proposed differentiation method induces the quantized gradient vector to an objective function and provides that the validation of the directional derivation. Moreover, mathematical analysis shows that the sequence yielded by the learning equation based on the proposed quantization converges to the optimal point of the quantized objective function when the quantized parameter is sufficiently large. The simulation result shows that the optimization solver based on the proposed quantized method represents sufficient performance in comparison to the conventional method based on the floating-point system.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.3
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• pp.310-318
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• 1983

Four methods of vegetation analysis were compared to determine the most suitable method to use in transplanted rice. The highest number of weed species, 14 was obtained with the list quadrat method while the least number, 8 was obtained with the line intercept method. The clip quadrat method tended to overestimate weed species with a low moisture content such as Sagittaria trifolia L. and Ludwigia prostrata Roxb while for the list quadrat method, weed species with a high moisture content such as Sagittaria pygmaea Miq. and Monochoria vaginalis (Burm. f) Pres 1 were overestimated. With the line intercept method, weed species having conspicuous leaf blades such as S. trifolia and Potamogeton distinctus Benn. were dominant. Of the methods tested, the line intercept method was the least desirable because it accounted for the least number of weed species. Any of the others could be use for vegetation analysis without any significant problems arising. However, preference was given to the point quadrat method because of the ease of measurement. It was also less tedious and less time consuming than the other methods.

• Journal of the Korea Institute of Military Science and Technology
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• v.1 no.1
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• pp.145-153
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• 1998

In the direct numerical optimization method, the aerodynamic coefficients of the airfoil designed by one-point design can be deteriorated at other operating points. Therefore, the capacity of the multi-point design is indispensable for actual airfoil design. In this paper, the two-point design of transonic airfoils is studied based on the Navier-Stokes equations flow solver and the feasible direction optimization algorithm, and the effects of weighting parameter were analyzed and compared. The results show that the airfoils designed by two-point design satisfy the performances at the peripheral regions of two operating points concurrently and have the favorable aerodynamic characteristics at the point which has larger weighting parameter than the other point.

• Journal of the Korean Home Economics Association
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• v.47 no.4
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• pp.61-72
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• 2009

The purpose of this research is to suggest a new way to approach measuring the waist line of slacks. The pattern formulated enables a construction method that optimizes motion. The method is based on the measurement on the length change of the body surface line. The research reveals: 1. The analysis of expansion and contraction by area showed that G8 markedly shrunk, whilst G15 maximally stretched during M4 motion. 2. The areas that stretched during M2 motion were, in order of size: G10, G17, G16, and G8. Conversely, the areas that shrunk are, in order, G9, G11, and G18. The areas that stretched during M3 motion were G10, G17, G16, G12, and G15; the areas that shrunk were G9, G11, G18, and G8. 3. In constructing the slacks pattern to allow for appropriate movement, we calculated the length between the knee and back of the waist, point (y), using Pythagoras’theorem and trigonometry. The equation was y = 1.005x. 4. In the two pattern N method and L method, y is equal or less than x, but for our research pattern, y was larger than x

• Korean Journal of Mathematics
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• v.18 no.1
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• pp.87-96
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• 2010

We consider the semilinear biharmonic equation with Dirichlet boundary condition. We give a theorem that there exist at least three nontrivial solutions for the semilinear biharmonic boundary value problem. We show this result by using the critical point theory, the finite dimensional reduction method and the shape of the graph of the corresponding functional on the finite reduction subspace.

• The Journal of Natural Sciences
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• v.16 no.1
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• pp.49-54
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• 2005

When teaching on the computing of eigenvalues of a matrix, we introduced the inverse power method. We compared the algorithm which is good for theoretical point of view that is useful for computational point of view.