• Journal of applied mathematics & informatics
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• v.5 no.2
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• pp.507-516
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• 1998

In this study we are concerned with the problem of ap-proximating a locally unique solution of an equation on a Banach space. A semilocal convergence theorem is given for the Super-Halley method in Banach spaces. Earlier results have shown that the order of convergence is four for a certain class of operators [4] [5] [8] These results were not given in affine invariant form and made use of a real quadratic majorizing polynomial. Here we provide our re-sults in affine invariant form showing that the order of convergence is at least four. In cases that it is exactly four the rate of convergence is improved. We achieve these results by using a cubic majorizing polynomial. Some numerical examples are given to show that our error bounds are better than earlier ones.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2003.06a
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• pp.188-192
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• 2003

Pole placement method is widely used in controller design. For the stability of the closed loop system, user-specified desired locations including extra pole locations in the s-plane is chosen and by some procedure, feedback gain is obtained. In this paper, only desired pole location is used, and the calculation process is done for attaining linear quadratic stability. Similarly transformation is used for this. By computer simulations using MATLAB, the effectiveness is shown.

• Communications of the Korean Mathematical Society
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• v.22 no.1
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• pp.53-64
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• 2007

In this paper, we apply the generalized quasilinearization technique to a forced Duffing equation with three-point mixed nonlinear nonlocal boundary conditions and obtain sequences of upper and lower solutions converging monotonically and quadratically to the unique solution of the problem.

• Journal of the Korean Magnetic Resonance Society
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• v.23 no.2
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• pp.46-50
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• 2019

Spin orbit torque would be applied as the next generation of MRAM, so many researchers are interested in related field. To make a more efficient device, electric current should convert into spin current with high efficiency. Moreover, it becomes important to measure efficiency of spin orbit torque accurately. We measured spin torque FMR of W/CoFeB hetero structure system with direct current. The efficiencies of the damping like torque and field like torque were measured by using the linewidth and on-resonance field proportional to direct current. In addition, we analyzed that a quadratic shift of the on-response field was caused by the Joule heating.

• Journal of the Korean Society of Clothing and Textiles
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• v.46 no.5
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• pp.772-788
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• 2022

This study investigates whether the image of the casual Hanbok brand is being communicated to consumers successfully. We conducted a semantic network analysis to identify ways of revitalizing communication between casual Hanbok brands and consumers; in addition, we quantitatively evaluated the effectiveness of communication marketing through Quadratic Assignment Procedure (QAP) analysis. Unstructured data from 2014-2021 were collected through portal sites and then refined and networked. Our analysis showed that casual Hanbok brands generally target younger people and that different brands employ similar methods to promote and popularize the casual Hanbok style. Consumers tended to recognize and show interest in casual Hanbok, suggesting the potential to expand the market to Blue Ocean. However, some of our findings revealed the potential factors of style coordination risk and prejudice against existing Hanbok, which could potentially hinder casual Hanbok's uptake and adoption. We conclude that increasing the demand for casual Hanbok depends not only on delivering an accurate brand image to consumers but also on balancing fashion with traditional images when planning products and providing styling information.

• ETRI Journal
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• v.39 no.4
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• pp.467-479
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• 2017

This study examines how the characteristics of cooperative research and development (R&D) projects in the public domain impact information and communication technology (ICT) convergence. Based on the analysis of 416 cooperative R&D projects under the ICT-based industry convergence R&D program in Korea, the study finds that the characteristics of cooperative R&D projects significantly impact ICT convergence. Moreover, the participation of public research institutes and universities is critical for ICT convergence compared with that of firms. However, in firm-to-firm cooperation, the participation of small and medium enterprises contributes to cross-sectional convergence, while the participation of large firms leads to overall and longitudinal convergence. R&D inputs such as the number of partners and government subsidies exhibit an inverted U-shaped relationship (negative quadratic effect) with technology convergence. Project duration and homogeneous partners are also critical factors for ICT convergence. The results indicate several implications and guidelines on how to effectively organize cooperative R&D projects to facilitate technology convergence.

• Journal of Electrical Engineering and Technology
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• v.6 no.4
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• pp.493-504
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• 2011

The present paper presents a genetic algorithm (GA) to maximize social welfare and perform congestion management by optimally placing and sizing one Thyristor-Controlled Series Capacitor (TCSC) device in a double-sided auction market. Simulation results, with line flow constraints before and after the compensation, are compared through the Sequential Quadratic Programming SQP method, and are used to analyze the effect of TCSC on the congestion levels of modified IEEE 14-bus and 30-bus test systems. Quadratic, smooth and nonsmooth (with sine components due to valve point loading effect) generator cost curves, and quadratic smooth consumer benefit functions are considered. The main aims of the present study are the inclusion of customer benefit in the social welfare maximization and congestion management objective function, the consideration of nonsmooth generator characteristics, and the optimal locating and sizing of the TCSC using real code-based GA to guarantee fast convergence to the best solution.

• Journal of Drive and Control
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• v.14 no.4
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• pp.45-50
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• 2017

The gas spring is a hydropneumatic adjusting element, consisting of a pressure tube, a piston rod, a piston and a connection fitting. The gas spring is filled with compressed nitrogen within the cylinder. The filling pressure acts on both sides of the piston and because of area difference it produces an extension force. Therefore, a gas spring is similar in function compare to mechanical coil spring. Conversely, optimization is a process of finding the best set of parameters to reach a goal while not violating certain constraints. The AMESim software provides NLPQL (Nonlinear Programming by Quadratic Lagrangian) and GA (genetic algorithm) for optimization. The NLPQL method builds a quadratic approximation to the Lagrange function and linear approximations to all output constraints at each iteration, starting with the identity matrix for the Hessian of the Lagrangian, and gradually updating it using the BFGS method. On each iteration, a quadratic programming problem is solved to find an improved design until the final convergence to the optimum design. In this study, we conducted optimization design of the gas spring reaction force with NLPQL.

• Journal of applied mathematics & informatics
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• v.28 no.5_6
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• pp.1467-1476
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• 2010

The aim of this paper is to propose a cubic convergent regula falsi iterative method for solving the nonlinear equation f(x) = 0, where f : [a,b] $\subset$ R $\rightarrow$ R is a continuously differentiable. In [3,6] a quadratically convergent regula falsi iterative methods for solving this nonlinear equations is proposed. It is shown there that both the sequences of diameters and iterative points sequence converge to zero simultaneously. So The aim of this paper is to accelerate further the convergence of these methods from quadratic to cubic. This is done by replacing the parameter p in the iteration of [3,5,6] by a function p(x) defined suitably. The convergence analysis is carried out for the method. The method is tested on number of numerical examples and results obtained shows that our methods are better and more effective and comparable to well-known methods.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.9
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• pp.62-66
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• 2009

Three inputs of given three magnetic fluxes of an induction motor are calculated. Then, the calculation of magnetic flux for minimum input is repeated using quadratic interpolation method until the convergence criteria are satisfied. The maximum efficiency control is fulfilled with the final magnetic flux for minimum input. Simulation results verify the effectiveness of the proposed method.