• Journal of the Korean Statistical Society
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• v.25 no.4
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• pp.471-487
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• 1996

In this paper we propose an efficient scoring type one-step GM-estimator, which has a bounded influence function and a high break-down point. The main point of the estimator is in the weighting scheme of the GM-estimator. The weight function we used depends on both leverage points and residuals So we construct an estimator which does not downweight good leverage points Unider some regularity conditions, we compute the finite-sample breakdown point and prove asymptotic normality Some simulation results are also presented.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.1C
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• pp.50-58
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• 2004

An image enhancement method using modified anisotropic diffusion filter is proposed in this paper. It employs sensor noise estimation and scale space methods based on the minimum reliable scale. Then the anisotropic diffusion filter is modified by the calculated critical value function and local gradient. Through simulation, it is verified that the proposed algorithm has the capability of little or no noise amplification in homogenous region as well as superior edge enhancement.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.5
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• pp.882-889
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• 2010

This paper presents a method of finding the optimal operating point minimizing a given objective function with 3 phase power flow equations and operational constraints, called 3 phase optimal power flow (3POPF). 3 phase optimal power flow can provide operation and control strategies for the distribution systems with distributed generation assets, which might be frequently in unbalanced conditions assuming that high penetration rate of renewable energy sources in the systems. As the solution technique for 3POPF, this paper adopts a simulation-based method of particle swarm optimization (PSO). In the PSO based 3POPF, a utility function needs to be defined for evaluation of the degree in operational improvement of each particle's current position. To evaluate the utility function, in this paper, NR-based 3 phase power flow algorithm was developed which can deal with looped distributed generation systems. In this paper, illustrative examples with a 5-bus and a modified IEEE 37-bus test systems are given.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.118.1-118
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• 2001

In this paper, we suggest a new distribution model for a single phase transformer which is different from the existing model which was modeled for only primary parts, but new distribution model is modeled for primary and secondary parts. Using this model, we simulate various faults of the transformer to know how the transfer function vary from the normal one, i.e., the trend of the variation of transfer function. As an another approach, we measure the voltage and current of a three phase transformer while various faults are made at the transformer. From the simulation of the model and experiment, we fine some trends of the variation of transfer function.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.718-721
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• 2005

The purpose of the study is to evaluate the usage of microtremor in estimation of subsurface structure and ground response to ground motion. Ground motion amplification based on site condition of an area is an important parameter for dynamic design. Microtremor cover the characteristics in a low frequency range, while forced vibrations cover them in a high-frequency range. Microtremor consider ground characteristics and offer transfer function in area. To determine the dominant frequency, the passive microtremor measurement is performed and to determine the transfer function of test site, active microtremor measurement is performed. Microtremor measurement in the site is compared with theoretical transfer function calculated from the known structures.

• Communications for Statistical Applications and Methods
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• v.1 no.1
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• pp.27-32
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• 1994

We propose a robust regression estimator which has both a high breakdown point and a bounded influence function. The main contribution of this article is to present a weight function in the generalized M (GM)-estimator. The weighting schemes which control leverage points only without considering residuals cannot be efficient, since control leverage points only without considering residuals cannot be efficient, since these schemes inevitably downweight some good leverage points. In this paper we propose a weight function which depends both on design points and residuals, so as not to downweight good leverage points. Some motivating illustrations are also given.

• International Journal of Advanced Culture Technology
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• v.6 no.3
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• pp.22-26
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• 2018

The goal of this study was to find out whether early maladaptive schemas (EMS) can be differentiated between the gifted adolescents and delinquent adolescents. Two groups of adolescents were recruited as participants to be surveyed. 144 gifted adolescents were taken from a gifted science and math education center, and 115 delinquent adolescents who had committed crime were taken from 4 police stations in the area of Gyungnam province in Korea. The Korean version of the Schema Inventory for Children was used to measure the level of the early maladaptive schemas (EMS). Stepwise discriminant function analysis yielded a function containing 5 maladaptive schemas (failure, unrelenting standards, vulnerability to harm and illness, loneness/mistrust/abuse, and subjugation), classifying 75.29 accurately into either gifted adolescents or delinquent adolescents. These results suggested that the types of adolescents (gifted adolescents, and delinquent adolescents) can be predicted based on early maladaptive schemas. The findings are discussed from the perspective of Schema Therapy and school counseling.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.18 no.4
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• pp.283-294
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• 2014

In this paper we study consumption-labor supply decision of an agent who prepares for retirement at a known time in the future. The agent is assumed to have a preference which is represented by the von Neumann-Morgenstern utility function in which the felicity function has constant relative risk aversion over the composite of consumption and leisure. The composite is obtained by the Cobb-Douglas function. A general problem has been studied by Bodie et al. (2004). We contribute to the literature by deriving the Slutsky equations and conducting comparative statics. In particular, we show that wealth effect can exhibit an interesting property depending upon the time until retirement, as the interest rate increases.

• Fire Science and Engineering
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• v.30 no.1
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• pp.81-85
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• 2016

Reasonable disaster prevention signs play an important role in guiding evacuation. Through the field investigation on disaster prevention signs in shelters and surrounding areas in Beijing, some problems were found in the using of sign system. Based on the principle of integrated design, evacuation and rescue requirements, it is necesssary to make further study on aspects such as, design of function, systematic consideration, humanization design, as well as the internationalization using. This paper presents an evaluation index system for disaster prevention signs. Such a system is very important for strengthening the independent guiding function of sign systems and improving evacuation efficiency. An effective connection could be realized between the internal environment of buildings, evacuation routes, and emergencey shelters.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.87-90
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• 1988

This paper reports a simple posteriori error estimate method for adaptive finite element mesh generation using quadratic shape function especially for the magnetic field problems. The elements of quadratic shape function have more precise solution than those of linear shape function. Therefore, the difference of two solutions gives error quantity. The method uses the magnetic flux density error as a basis for refinement. This estimator is tested on two dimensional problem which has singular points. The estimated error is always under estimated but in same order as exact error, and this method is much simpler and more convenient than other methods. The result shows that the adaptive mesh gives even better rate of convergence in global error than the uniform mesh.