• Journal of Korean Medical classics
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• v.37 no.1
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• pp.41-56
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• 2024

Objectives : The purpose of this paper is to model each Xíng(行) of the Yīnyáng Wǔxíng(陰陽五行) theory as a vector, to interpret the Xiāngshēng Xiāngkè(相生相剋) theory as a vector sum, and argue the objectivity and universal applicability of the Xiāngshēng Xiāngkè(相生相剋) theory. Methods : The five xíngs of the Wǔxíng were modeled and expressed as vectors, and the Xiāngshēng Xiāngkè theories were quantitatively explained by vector summation. Results : We calculated the Wǔxíng vectors using the vector sum formula, and found that the Xíng vectors that received mutual support increased in size by about 62%, and the Xíng vectors that received opposition decreased in size by about 38%. Conclusions : This result could be considered as quantitative interpretation of the contents of the Xiāngshēng Xiāngkè(相生相剋) theory which has mostly been explained qualitatively. The results of this study could hopefully provide ideas to quantify various theories based on the Yinyangwuxing theory such as Korean Medicine and other traditional fields in East Asian culture.

• Journal for History of Mathematics
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• v.23 no.2
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• pp.89-99
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• 2010

Today linear algebra is one of compulsory courses for university mathematics by virtue of its theoretical fundamentals and fruitful applications. Vector theory and matrix theory constitute of main topics in linear algebra. In the present paper we consider the question which of the two topics is prior in teaching of linear algebra. We suggest that vector theory should be prior to matrix theory contrary to the historical order of them.

• Bulletin of the Korean Mathematical Society
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• v.47 no.1
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• pp.121-129
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• 2010

Using a degree theory for countably condensing multivalued maps, we show that under certain conditions an invariance of domain theorem holds for countably condensing or countably k-contractive multivalued vector fields.

• Research in Mathematical Education
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• v.7 no.1
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• pp.59-67
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• 2003

In linear algebra course, the theory of vector space is usually presented in a very formal setting, which causes severe difficulties to many students. In this study, the effect of teaching the theory of vector space in linear algebra from the geometrical point of view on students' learning was investigated. It was found that the teaching of the theory of vector space in linear algebra from the geometrical point of view increases the meaningful loaming since it increases the visualization.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.2
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• pp.185-191
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• 2004

This study describes the scheme of vector drive system without speed sensor for AC servo motor using theory of a flux observer and based on the field oriented vector control. The new method of speed estimation is presented from operate with the position and magnitude of the secondary flux which obtain from the voltage reference and detected current. As the estimated speed is settled by the flux and the machine-specific parameters. this method don't need to adjust the gain of the parameter. Based on the derived theory for vector control. the scheme for sensorless vector drive of AC servo motor is designed and realized. And the experiment verifies it passable to realize the sensorless vector drive based on a field-oriented type.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.4
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• pp.310-317
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• 2007

In this paper, the system equation for the balanced two-phase induction motor is derived and the characteristics for speed control is also analyzed in the region of constant torque and constant power. The modified vector control theory is applied to two-phase motor drive system. The speed of two-phase motor drive can be controlled precisely by the modified indirect vector control theory. The modified vector control theory is simpler comparing to the conventional vector control because of the simpler axis transformation. The computer simulations and the experimental results presented to confirm the vector control for two-phase inverter fed two phase induction motor system.

• Kyungpook Mathematical Journal
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• v.45 no.2
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• pp.167-169
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• 2005

Here we introduce and study vector bundles, E, on a smooth projective curve X having many "spread" sections and for which $E^{*}\;{\otimes}{\omega}X$ has many "spread" sections. We show that no such bundle exists on X if the gonality of X is too low.

• Industrial Engineering and Management Systems
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• v.12 no.1
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• pp.16-22
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• 2013

This paper proposes a new concept of comonotonicity of uncertain vector based on the uncertainty theory. In order to understand the comonotonicity of uncertain vector, some equivalent definitions are presented. Following the proposed concept, some basic properties of comonotonic uncertain vector are investigated. In addition, the operational law is given for calculating the uncertainty distributions of monotone functions of comonotonic uncertain variables. With the help of operational law, the comonotonic uncertain vector is applied to the premium pricing problems. At last, some numerical examples are given to illustrate the application.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.8 no.3
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• pp.196-201
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• 2008

Statistical learning theory has three analytical tools which are support vector machine, support vector regression, and support vector clustering for classification, regression, and clustering respectively. In general, their performances are good because they are constructed by convex optimization. But, there are some problems in the methods. One of the problems is the subjective determination of the parameters for kernel function and regularization by the arts of researchers. Also, the results of the learning machines are depended on the selected parameters. In this paper, we propose an efficient method for objective determination of the parameters of support vector clustering which is the clustering method of statistical learning theory. Using evolutionary algorithm and bootstrap method, we select the parameters of kernel function and regularization constant objectively. To verify improved performances of proposed research, we compare our method with established learning algorithms using the data sets form ucr machine learning repository and synthetic data.

• International Journal of Precision Engineering and Manufacturing
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• v.6 no.3
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• pp.13-18
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• 2005

This paper presents an effective cutting force model that enables us to predict the instantaneous cutting force in face milling from knowledge of the work material properties and the cutting conditions. The development of the model is based on the orthogonal machining theory with the effective rake angle, which is defined in the plane containing the cutting velocity vector and the chip flow vector. Face milling tests are performed at different feeds and, a fairly good agreement is shown between the predicted cutting forces and the test results.