• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.82-85
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• 1987

The objective of this paper is to develop computer programs to aid in the design and analysis of control systems in which nonlinear characteristics exist. Control systems are dynamic systems, which can be described using various mathematical models. A convenient model for digital computer simulation is the state model in which described using a set of linear and non linear first order differential equations. The digital simulation was performed on a IBM PC/XT personal computer, and the computer language was BASIC. There are four possible configurations from which a user may choose. When running a program, the user is asked to enter the system parameters according to a specified control system configurations are; 1. A control system with a nonlinear element followed by a plant in a feedback configurations(NLSVF1). 2. A control system with a nonlinear device situated between two plants in a feedback configurations(NLSVF2). 3. A control system with a nonlinear element followed by a plant, followed by a the dealy in feedback configurations(TLAG). 4. A motor and load with a backlash nonlinearity between dynamic portions of the motor/load configurations (BACKLASH). The matrix from state equations are integrated using combination the trapezoidal method and fixed point iteration. Several cases which have nonlinearity were implemented on the computer and the results were discussed.

• Journal of Electrical Engineering and information Science
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• v.2 no.6
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• pp.95-105
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• 1997

In this paper, we have studied about design and fabrication of the actively shielded superconducting MRI magnet. Nonlinear optimization methods are usually used to find optimum coil configurations. However the selection of initial coil configurations is very difficult. In case bad initial data are used, it is even impossible to find optimum coil configurations which satisfy predefined constraints. We have developed computer optimization program which consists of two steps. Initial coil configurations are easily selected through linear optimization in the first step and optimum coil configurations are found through nonlinear optimization in the second step. We have also studied about superconducting shim coils to cancel error fields caused by coil fabrication errors. Many researchers published design concepts of shim coil. However all these studies are for shim coil design using filamentary coils with single turn, Shim coils with multi-turns should be used to produce enough field strength to cancel error fields. We have developed computer program for the design of shim coils which have proper thickness and length. An actively shielded superconducting MRI magnet with a small warm bore was fabricated and four sets of superconducting shim coils were equipped. The magnetic field distributions were measured and field correction was carried out using shim coils.

• Steel and Composite Structures
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• v.17 no.1
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• pp.83-103
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• 2014

The objective of this research is to study the ultimate moment capacity of the connections between steel I-beams and concrete-filled steel tube columns using different stiffener configurations. The main parameters considered are column cross section shape, square or circular, and filling the column with concrete. This analytical study includes finite element models using ANSYS program taking geometric and material nonlinearities into consideration. These models are verified against the experimental results obtained from previous researches and current design guides. The results show that using proper stiffener configuration affects the stress distribution through the connection and increases the ultimate moment capacity of the connections. Also, circular column is advantageous than the square column for all stiffener configurations and dimensions.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1485-1487
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• 2000

A variety of target configurations in sputtering process have been proposed to deposit various structures of thin film alloys and compound films. In this study, we presented the comparative experimental results regarding to the characterization of properties of Cu-Ni thin films deposited by using a magnetron co-sputtering method, as a function of target configurations; one is using a single target with varying the area of Ni chips attached on the Cu target and another is using a dual-type target with two targets of Ni and Cu separated each other. Structural(d-spacing, crystal orientation, crystallite size, cross-sectional morphology) and electrical(resistivity) properties of deposited films are characterized and compared as a function of target configurations as well as deposition conditions.

• Journal of the Korean Solar Energy Society
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• v.29 no.2
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• pp.8-13
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• 2009

In this paper, two configurations of PV array are analyzed and tested under shading condition, where two configurations are series-parallel and total-crass-tied configuration. Each photovoltaic module is emulated by two 5 inch po1y-crystalline cells in series and an array is constructed by connecting 24 of the modules to compare a generated maximum power of the two configurations. Pspice and Sun simulator. PASAN IIIb, are used for simulation and experiment to test the array under various partial shading conditions. Test results show the total-cross-tied configuration generates 7.63% higher maximum power than the series-parallel configuration, and it is well matched to the analysis and simulations of the two configurations.

• Journal of the Chungcheong Mathematical Society
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• v.26 no.2
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• pp.403-409
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• 2013

In [20] and [22], the author proved that the union of two linear star-configurations in $\mathbb{P}^2$ of type $t{\times}s$ with $3{\leq}t{\leq}10$ and $t{\leq}s$ has generic Hilbert function. In this paper, we prove that the union of two linear star-configurations in $\mathbb{P}^2$ of type $t{\times}s$ with $3{\leq}t$ and $({a\atop2})-1{\leq}s$ has also generic Hilbert function.

• Journal of the Chungcheong Mathematical Society
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• v.30 no.4
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• pp.435-443
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• 2017

We find a graded minimal free resolution of the union of two star configurations ${\mathbb{X}}$ and ${\mathbb{Y}}$ (not necessarily linear star configurations) in ${\mathbb{P}}^n$ of type s and t for s, $t{\geq}2$, and $n{\geq}3$. As an application, we prove that an Artinian ring $R/(I_{\mathbb{X}}+I_{\mathbb{Y}})$ of two linear star configurations ${\mathbb{X}}$ and ${\mathbb{Y}}$ in ${\mathbb{P}}^3$ of type s and t has the weak Lefschetz property for $s{\geq}{\lfloor}\frac{1}{2}(^t_2){\rfloor}$ and $t{\geq}2$.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.435-440
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• 2005

This study describes a new method of constructing Reconfigurable machine tools configurations from a set of modules or components. This proposed method defines combinability vector for each module and mutual combinability coefficient matrix for adjacent two modules. All of machine configurations possible to be generated from any two adjacent modules can be determined by quadratic form of two associated combinability vectors. Furthermore, all of possible RMT configurations generating from a series of multiple modules also can be obtained by multiplying quadratic form of two adjacent conbinability vectors recursively. Our proposed RMT configuration generating method can be successfully applied to determining all of possible machine configurations from several modules or components at conceptual- or preliminary- design stage.

• Proceedings of the Korean Statistical Society Conference
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• 2003.05a
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• pp.163-165
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• 2003

Some multivariate analyses provide configurations for variables or objects in low dimensional space because we can see easily their relation. In particular, in simple correspondence analysis(SCA), we can obtain the various configurations which are called SCA Maps based on the algebraic algorithms. Moreover, it often occur the variability among them. Therefore, in this study, we will give a comparison of variability of SCA maps using the procrustes analysis which is a technique of comparing configurations in multidimensional scaling.

• Transactions on Electrical and Electronic Materials
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• v.17 no.5
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• pp.257-260
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• 2016

In this paper, two configurations (T-type and Y-type) of dual band Wilkinson Power Divider based upon Hilbert curves are presented. Formerly, the concept of Hilbert Curves was implemented in only designing microstrip antennas. In power dividers, this is the very first attempt of incorporating them for size reduction. In addition to this, an effect of inculcation of high-dielectric constant layer (Hafnium-oxide, HfO₂, ε_r= 25) between a substrate and top metallization in both configurations was investigated. The proposed configurations are designed on a high resistive silicon substrate (HRS) for L and S bands with resonating frequencies of 1.575 and 3.4 GHz. Both configurations have return loss that is better than 20 dB and an insertion loss of around 6 dB; isolation better than 30 dB was achieved for both models.