• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제3권2호
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• pp.81-97
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• 1999

This paper deals with the time optimal control problem for the retarded semilinear system by using the construction of fundamental solution in case where the principal operators are unbounded operators.

• 대한수학회보
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• 제52권1호
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• pp.159-172
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• 2015

This paper presents a new sufficient condition for the oscillation of all solutions of difference equations with several deviating arguments and oscillating coefficients. Corresponding difference equations of both retarded and advanced type are studied. Examples illustrating the results are also given.

• 대한수학회지
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• 제36권2호
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• pp.317-332
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• 1999

In this paper we deal with the optimal control problem for the semilinear functional differential equations with unbounded delays. We will also establish the regularity for solutions of the given system. By using the penalty function method we derive the optimal conditions for optimality of an admissible state-control pairs.

• 대한수학회지
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• 제50권3호
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• pp.627-639
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• 2013

The goal of this paper is to obtain the regularity and the existence of solutions of a retarded semilinear differential equation with nonlocal condition by applying Schauder's fixed point theorem. We construct the fundamental solution, establish the H$\ddot{o}$lder continuity results concerning the fundamental solution of its corresponding retarded linear equation, and prove the uniqueness of solutions of the given equation.

• 대한수학회논문집
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• 제28권3호
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• pp.559-569
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• 2013

The purpose of this paper is to establish existence, uniqueness and a variation of constant formula of solutions for semilinear partial functional differential equations with unbounded delays and nonlinear part involving integro differetial terms.

• East Asian mathematical journal
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• 제19권1호
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• pp.133-150
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• 2003

This paper will show that the relation (1.1) $$L^1({\Omega}){\subset}C_0(\bar{\Omega}){\subset}H_{p,q}$$ if 1/p'-1/n(1-2/q')<0 where p'=p/(p-1) and q'=q/(q-1) where $H_{p.q}=(W^{1,p}_0,W^{-1,p})_{1/q,q}$. We also intend to investigate the control problems for the retarded systems with $L^1(\Omega)$-valued controller in $H_{p,q}$.

• Journal of applied mathematics & informatics
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• 제9권1호
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• pp.213-230
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• 2002

We deal with the approximate controllability for semilinear systems with time delay in a Hilbert space. First, we show the existence and uniqueness of solutions of the given systems with the mere general Lipschitz continuity of nonlinear operator f from $R\;\times\;V$ to H. Thereafter, it is shown that the equivalence between the reachable set of the semilinear system and that of its corresponding linear system. Finally, we make a practical application of the conditions to the system with only discrete delay.

• 한국세라믹학회지
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• 제37권7호
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• pp.681-685
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• 2000

The influence of ZnCl2 in portland cement hydration was studied. The hydration reaction was progressed with ZnCl2 solution to observe the adiabatic hydration exothermic and hydration products. To compare with cement hydration, Ca(OH)2 solution reacted with ZnCl2 was carried out. The addition of ZnCl2 solution to the portland cement was retarded hydration quantitatively. Because ZnO which was produced in certain pH adsorbed with unhydrated cement made retarded the hydration reaction.

• 한국정보교육학회:학술대회논문집
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• 한국정보교육학회 2010년도 하계학술대회
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• pp.143-149
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• 2010

최근 정신지체아들을 위한 음악교육의 중요성이 크게 부각되고 있으나 그들의 인지적 정의적 결함으로 인해 종래의 일반적인 음악수업 방식만으로는 음악 인지를 발달시키는 학습을 기대하기 어렵다. 이에 본 연구에서는 MMCP (Manhattanville Music Curriculum Program)이론에 근거한 정신지체아의 음악인지능력 (음악 동일성, 음악 유목화, 음악 서열화)을 향상시키기 위한 컨텐츠를 설계하였다. MMCP 이론은 음악의 본질을 이해시키며 특징음악 (18~19C의 음악) 만을 취급하는 음악이 아닌 모든 민족의 음악문화를 이해하고 포함하는 보다 포괄적인 음악교육이다. 본 시스템으로 기대할 수 있는 효과로는 첫째, 정신지체장애인의 음악적 인지 발달 뿐 아니라 인지적, 신체적, 사회적, 정서적 발달을 고양시킬 수 있다. 둘째, 정신지체장애인을 위한 개별화 음악교육이 가능하다. 셋째, 능동적이고 상호작용적인 음악교육이 가능하다.

• 한국치위생학회지
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• 제1권1호
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• pp.19-37
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• 2001

The purpose of this study was to develop effective oral health education programs for mentally retarded children and promote their oral health, by offering oral health education for 45 mentally retarded children between age 6 to 20, tracking the change of their knowledge depending on the frequency of education, and examining the educational effect before and after oral health education. The children with mental retardation attended a special school for idiots in Gweonseon-gu, Suwon, Kyonggi Province, being able to take training(IQ 25-49). The education program was designed to be suitable for their cognitive power after consultation with a special school teacher. A teacher provided the same education seven times, once a week, and an interview was held with each of them to assess their correct answer rate. The findings of this study were as below: 1. The repeated oral health education served to have the children with mental retardation acquire better knowledge about harmful food for the teeth, what had to be done after eating cookies or candies between meals, the right time for toothbrushing, the concept of dental caries, and how to cope with dental caries(p<0.01). But after that education was offered four times, the frequency of that education made no difference. 2. The repeated oral health education increased, their knowledge on the role of the teeth and the right choice of toothbrush(p<0.01), yet there was no significant difference in their knowledge about oral health behavior, because they had already been familiar with that. 3. As a result of investigating the change of their oral health know-ledge before and after oral health education according to the type of handicap, the type of handicap made no significant difference to the change of their oral health knowledge. 4. The oral health education for the children with menial retardation had a significantly different effect on their knowledge about harmful food for the teeth, what had to be done after eating between meals, the right time for toothbrushing, the role of the teeth. the right choice and use of toothbrush, how to do toothbrushing, and fluorine(p<0.01).