• 대한기계학회논문집A
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• 제27권11호
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• pp.1809-1814
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• 2003

Differential evolution (DE) algorithm is presented and applied to global optimization in this research. DE suggested initially fur the solution to Chebychev polynomial fitting problem is similar to genetic algorithm(GA) including crossover, mutation and selection process. However, differential evolution algorithm is simpler than GA because it uses a vector concept in populating process. And DE turns out to be converged faster than CA, since it employs the difference information as pseudo-sensitivity In this paper, a trial vector and its control parameters of DE are examined and unconstrained optimization problems of highly nonlinear multimodal functions are demonstrated. To illustrate the efficiency of DE, convergence rates and robustness of global optimization algorithms are compared with those of simple GA.

• Journal of the Korean Data and Information Science Society
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• 제16권3호
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• pp.705-712
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• 2005

Entropy is the basic concept of information theory. It is well defined for random varibles with known probability density function(pdf). For given data with unknown pdf, entropy should be estimated. Usually, estimation of entropy is based on the approximations. In this paper, we consider a kernel based approximation and compare it to the cumulant approximation method for several distributions. Monte carlo simulation for various sample size is conducted.

• 대한수학회보
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• 제43권2호
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• pp.253-263
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• 2006

In this paper we introduce a new concept, a 'periodicizing' function for the linear differential equation with the periodic forcing function. Moreover, we construct this function, which is closely related with the solution of a difference equation and an indefinite sum. Using this function, we can obtain a representation of solutions from which we see immediately the asymptotic behavior of the solutions.

• 전자공학회논문지A
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• 제29A권7호
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• pp.82-88
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• 1992

This paper presents one of the first comprehensive studies of how hot electron degradation impacts the input offset voltage of a CMOS differential amplifiers. This study utilizes the concept of a virtual source-coupled MOSFET pair in order to evaluate offset voltaged egradation directly from individual device measurement. Next, analytical models are developed to describe the offset voltage degradation. These models are used to examine how hot electron induced offset voltage is affected with the device parameters.

• Journal of Applied and Pure Mathematics
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• 제4권1_2호
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• pp.71-77
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• 2022

This work considers the existence and uniqueness of fuzzy solutions for impulsive abstract partial neutral functional differential systems. To establish the existence and uniqueness, we apply the concept of impulse, semi group theory and suitable fixed point theorem.

• Journal of applied mathematics & informatics
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• 제41권4호
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• pp.883-892
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• 2023

In this research, under some specific situations, we precisely derive new coupled fixed point theorems in a complete b-metric space endowed with the graph. We also use the concept of coupled fixed points to ensure the solution of differential equations for the system of impulse effects.

• 디자인학연구
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• 제17권2호
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• pp.335-350
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• 2004

디자인은 아직 존재하지 않는 가상의 것을 조형적인 실체로 구체화하는 것이다. 그 기본개념의 규명을 통해서만이, 합리적 가치를 수반한 차별화 된 디자인 개념의 가치 창출이 가능하리라고 생각한다. 디자인의 특질이 주어진 조건과 환경에 따라 문제의 성격과 그에 대한 결과가 달라지게 되기 때문에 모든 디자인은 상황적이다. 본 연구에서는 디자인의 기본 과정인 문제의 분석 종합평가의 단계에서, 가장 적절하고 합리적인 차별화 된 디자인개념(Differential Design Concept)을 찾기 위함이다. 선행적으로 시대적 추구가치 및 제품디자인의 가치관 변화를 고찰해 보았다. 이러한 시대적 추구 가치가 실제의 제품에 어떻게 구현되었는가를 조사 분석하였다. 현대디자인의 대표적 트랜드인 3-2. 기능 중심적 디자인 3-3. 감성중심적 디자인 3-4. 은유를 통한 이미지 전달의 디자인 3-5. 환경친화적 디자인의 차별화 된 디자인개념의 제품디자인 구현 사례를 분석하였다. 사례분석을 근거로 미래 사회 트랜드로 다가온 지속가능한 발전의 사회 속에서 어떻게 차별화 된 디자인 개념을 적용시킬 수 있는가를 규명해 보았다. 사례 분석을 통해 나타난 내용은 \circled1 시대정신의 가치가 제품의 메시지(Design Image)로 부각되어야 한다. \circled2 환경적합성을 우선적 고려 요인으로 하여야 한다. \circled3 차별화 된 소비자 욕구 충족의 가치를 실현하여야 한다. \circled4 상품의 라이프싸이클(Life-Cycle)이 길도록 유도한다. \circled5 기업의 지속적 성장을 촉진한다. \circled5 사용자 중심의 제품가치 고려가 선결되어야 한다는 것이다. \circled7 문화적, 언어적 장벽을 극복하고 사람들이 익숙하게 기억할 메타포의 투영을 필요로 하며, \circled8 시대적 가치관과 관습적 가치관의 공통분모 적 인간 본연의 가치관의 적용이 선결되어야 하며, \circled9 물질적 만족의 욕구 충족이 아닌 마음의 만족을 충족시키고 적용시키는 차별화 된 디자인개념이 요구되어 진다. 이에 더하여 제품의 저변에 굿ㆍ디자인(Good-Design)요소가 가미된 독창적이고 차별화 된 디자인개념이 소비자와의 감성적 교감을 이룰 수 있다고 생각된다. 즉 모든 디자인의 가치는, $\ulcorner$인간이 만물의 척도$\lrcorner$ 라는 인본주의 사상에 근거하여 평가되어야 한다.

• Journal of applied mathematics & informatics
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• 제32권5_6호
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• pp.791-805
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• 2014

In this article, we investigate third order three-point fuzzy boundary value problem to using a generalized differentiability concept. We present the new concept of solution of third order three-point fuzzy boundary value problem. Some illustrative examples are provided.

• 대한간호학회지
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• 제23권1호
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• pp.90-106
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• 1993

This study attempted to analyze the psychological impact of mentally retarded children on their normal siblings in the family. The data were collected from siblings of 130 mentally retarded children using a questionnaire with a semantic differential scale. ANOVA and simple correlation coefficient tests were employed to examine the relationship between the siblings’ self-concept and psychological frustration. The major results of the study are as following. 1. Female siblings showed a lower degree of self-concept than male siblings. 2. No significant relationship was found between self-concept and frustration stimuli. 3. Parent related frustration stimuli was no significantly different in sex age, siblings, religion, and retardation level of mentally retarded children. 4. Siblings related frustration stimuli was significantly related to only one item in sex. 5. Their peers related frustration stimuli while sex as well as religion was significantly related to only one item.

• 아동학회지
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• 제26권1호
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• pp.169-182
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• 2005

Influence of parenting, peer relationship, and teacher's support on the development of children's self-concept was assessed in Korean and Korean-Chinese elementary school students. Subjects were 280 Korean children in Korea and 210 Korean-Chinese children in Shenyang, China. The Self-Perception Profile for Adolescents(Harter, 1988), Parenting Practice(Cho et al., 2001), and 4 items from Social Support(Koo, 2000) were used to measure self-concept, parenting, and peer relationships, respectively. Data were analyzed by Pearson's correlation, factor analysis, and multiple regression. Results revealed differential influences between the two cultures : Korean children's self-concepts were significantly influenced by his/her peer relationships and teacher's support while Korean-Chinese children's self-concepts were influenced by teacher's support and parenting.