• Korean Journal of Geomatics
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• v.4 no.1
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• pp.31-37
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• 2004

The aim of this research is comparing the existing approximation models (e.g. Affine Transformation and Direct Linear Transformation) with Rational Function Model as a substitute of rigorous sensor model of linear array scanner, especially push-broom sensor. To do so, this research investigates the mathematical model of each approximation method. This is followed by the assessments of accuracy of transformation from object space to image space by using simulated data generated by collinearity equations which incorporate or depict the physical aspects of linear array sensor.

• Aerospace Engineering and Technology
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• v.7 no.2
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• pp.187-195
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• 2008

Generation of accurate ground coordinates from high resolution satellite image are becoming increasingly of interest. The primary focus of this paper is to compute satellite direct sensor model (DSM) and rational function model (RFM) for accurate generation of ground coordinates from high resolution satellite images. Being based on this we presented an algorithm to be able to efficiently ground coordinates about large area with introducing RFM(rational function model) method applied to rigorous sensor modeling standing on basis of satellite orbit dynamics and collinearity equation, and sensor modeling of high-resolution satellite data like IKONOS, QuickBird, KOMPSAT-2 and others. The general high resolution satellite measures the position, velocity and attitude data of satellite using star, gyro, and GPS sensors.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.417-422
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• 2003

The KOMPSAT-2 MSC(Multi-Spectral Camera), with high spatial resolution, is currently under development and will be launched in the end of 2004. A sensor model relates a 3-D ground position to the corresponding 2-D image position and describes the imaging geometry that is necessary to reconstruct the physical imaging process. The Rational Function Model (RFM) has been considered as a generic sensor model. form. The RFM is technically applicable to all types of sensors such as frame, pushbroom, whiskbroom and SAR etc. With the increasing availability of the new generation imaging sensors, accurate and fast rectification of digital imagery using a generic sensor model becomes of great interest to the user community. This paper describes the procedure to generation of the RPC (Rational Polynomial Coefficients) for KOMPSAT-2 MSC.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.707-714
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• 2001

This paper presents the fundamental study on rational manu(acture of Very High Strength(VHS) concrete using industrial by-products as like silica fume, slag and fly ash. In this study, we had tested various mixing cases to manufacture the VHS concrete(target compressive strength : over 1,000 kgf/$cm^{2}$) which is easily workable (target slump flow : 60$\pm$l0cm), The main variables studied are; 1) test variables to find the optimum replacement ratio of mineral admixture, 2) test variables to find a rational water-binder ratio, a proper binder content, 3) test variables to find the method for reduction of slump loss, 4) test variables to know the influence of air entrainment on frost resistance. From the test results, it is concluded that the rational mix design can be made by using 40% slag, 10% silica fume, and water reducing agent(slump loss reduction type). We found that it is unnecessary to entrain air for freeze-thawing resistance.

• Structural Engineering and Mechanics
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• v.28 no.2
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• pp.239-257
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• 2008

Double-sided punched metal plate timber fasteners present projections on both sides, which offer improved joint fire resistance and better joint aesthetics. In this paper, 3-D nonlinear finite element models were developed to simulate double-sided nail plate fastener timber joints. The models, incorporating orthotropic elasticity, Hill's yield criterion and elasto-plasticity and contact algorithms, are capable of simulating complex contact between the tooth and the timber and between the base plate and the timber in a fastener. Using validated models, parametric studies of the double-sided nail plate joints was undertaken to cover the tooth length and the tooth width. Optimal configuration was assumed to have been attained when increase in nail plate tooth width did not result in a raise in joint capacity, in conjunction with the optimum tooth length. This paper presents the first attempt to model and optimise tooth profile of double-sided nail plate fastener timber joints, which offers rational designs of such fasteners.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.8 no.1
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• pp.1-5
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• 2009

In this paper, we propose a method that applies Vector Fitting (VF) technique to the equivalent circuit model for RF passive components. These days wireless communication system is getting smaller and smaller. So EMI/EMC is an issue in RF. We can solve PI/SI (Power Integrity/Signal Integrity) that one of EMI/EMC problem apply IFFT for 3D EM simulation multiple with input signal. That is time consuming task. Therefore equivalent circuit model using RF passive component is important. VF schemes are implemented to obtain the rational functions. S parameters of the equivalent circuit model is compared to those of EM simulation in case of the microstrip line structure.

• Journal of the Korean Mathematical Society
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• v.51 no.5
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• pp.897-918
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• 2014

This paper addresses multi-window Gabor frames with rational time-frequency product. Such issue was considered by Zibulski and Zeevi (Appl. Comput. Harmonic Anal. 4 (1997), 188-221) in terms of Zak transform matrix (so-called Zibuski-Zeevi matrix), and by many others. In this paper, we introduce of a new Zak transform matrix. It is different from Zibulski-Zeevi matrix, but more direct and convenient for our purpose. Using such Zak transform matrix we characterize rational time-frequency multi-window Gabor frames (Riesz bases and orthonormal bases), and Gabor duals for a Gabor frame. Some examples are also provided, which show that our Zak transform matrix method is efficient.

• Journal of Mechanical Science and Technology
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• v.15 no.2
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• pp.192-198
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• 2001

We consider an interpolation problem with nonuniform rational B-spline curves given ordered data points. The existing approaches assume that weight for each point is available. But, it is not the case in practical applications. Schneider suggested a method which interpolates data points by automatically determining the weight of each control point. However, a drawback of Schneiders approach is that there is no guarantee of avoiding undesired poles; avoiding negative weights. Based on a quadratic programming technique, we use the weights of the control points for interpolating additional data. The weights are restricted to appropriate intervals; this guarantees the regularity of the interpolating curve. In a addition, a knot placement is proposed for pleasing interpolation. In comparison with integral B-spline interpolation, the proposed scheme leads to B-spline curves with fewer control points.

• Journal of the Korea institute for structural maintenance and inspection
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• v.5 no.3
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• pp.153-162
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• 2001

This paper presents the fundamental study on rational manufacture of Ultra High Strength(VHS) concrete using industrial by-products as like silica fume, slag and fly ash. In this study, we had tested various mixing cases to manufacture the UHS concrete(target compressive strength : over $1,000kgf/cm^2$) which is easily workable (target slump flow : $60{\pm}10cm$). The main variables are studied: 1) to find the optimum replacement ratio of mineral admixture. 2) to find a rational water-binder ratio and a proper binder content. 3) to find the method for reduction of slump loss. From the test results, it is concluded that the rational mix design can be made by using 40% slag, 10% silica fume. We found that compressive strength of UHS concrete increases according to decreasing W/B ratio but in W/B ratio 18~20%, the difference is vague and the compressive strength does not necessarily increase according to increasing binder content over 700kg.

• Hwankyungkyoyuk
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• v.14 no.2
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• pp.116-132
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• 2001

The goal of the environmental education in High School is to make students survey and work out the issues on environment and to help them continue and improve the work. It is important that we should educate students the rational ability of decision-making. The more they can make decisions rationally, the more they participate actively in that. The purpose of this study is to develope the model of a new teaching-learning method coinciding with the goal of the environmental education of Social studies in High School. This study is backed up by the following developing processes. To begin with, the contents related to environmental problems in Social Studies Curriculum are being investigated. To urge the importance of STS(Science, Technology and Society), 1 will present the righteous understanding of Science in societal contexts, the development of rational decision-making abilities, and the cognitive connections between society and science. For this, 1'm representing a new model of learning-teaching method, backed up by Constructivism, especially Vygotsky's ZPD theory, giving 4 steps from everyday concepts to natural lingistic thought. Based on the above hypothesis, at last I will represent a STS whose topic is a problem of beach preservation because I intend to show the possibility of STS on the environmental education of Social Studies through this study. This study will help us lay a foundation stone of introducing STS in environmental education of Social Studies.