• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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• pp.473-476
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• 1998

No Abstract. See Full-text.

• Bulletin of the Korean Chemical Society
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• 제30권7호
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• pp.1481-1484
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• 2009

When isolated phenol or a small phenol-solvent cluster is excited to the $S_1\;state\;of\;{\pi}{\pi}^*$ character, the hydrogen atom of the hydroxyl group dissociates via a ${\pi}{\sigma}^*$ state that is repulsive along the O-H bond. We computationally investigated the substitution effects of an amino group on the excited state hydrogen transfer reaction of phenol. The time-dependent density functional theory (TDDFT) with B3LYP functional was employed to calculate the potential energy profiles of the ${\pi}{\pi}^*$ and the ${\pi}{\sigma}^*$ excited states along the O-H coordinate, together with the orbital shape at each point, as the position of the substituent was varied. It was found that the amino substitution has an effect of lowering the ${\pi}{\sigma}^*$ state and enhancing the excited state hydrogen transfer reaction.

• Bulletin of the Korean Chemical Society
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• 제33권12호
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• pp.4204-4206
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• 2012

• 대한기계학회논문집A
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• 제26권10호
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• pp.2060-2066
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• 2002

The closed-loop state and input observer is a pole-placement type observer and estimates unknown state and input variables simultaneously. Pole-placement type observers may have poor transient performance with respect to ill-conditioning factors such as unknown initial estimates, round-off error, etc. For the robust transient performance, the effects of these ill-conditioning factors must be minimized in designing observers. In this paper, the transient performance of the closed-loop state and input observer is investigated quantitatively by considering the error bounds due to ill-conditioning factors. The performance indices are selected from these error bounds and are related to the observer robustness with respect to the ill -conditioning factors. The closed-loop state and input observer with small performance indices is considered as a well-conditioned observer from the transient perspective.

• 대한수학회지
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• 제49권4호
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• pp.715-731
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• 2012

This paper considers the stability of positive steady-state solutions bifurcating from the trivial solution in a delayed Lotka-Volterra two-species predator-prey diffusion system with a discrete delay and subject to the homogeneous Dirichlet boundary conditions on a general bounded open spatial domain with smooth boundary. The existence, uniqueness and asymptotic expressions of small positive steady-sate solutions bifurcating from the trivial solution are given by using the implicit function theorem. By regarding the time delay as the bifurcation parameter and analyzing in detail the eigenvalue problems of system at the positive steady-state solutions, the asymptotic stability of bifurcating steady-state solutions is studied. It is demonstrated that the bifurcating steady-state solutions are asymptotically stable when the delay is less than a certain critical value and is unstable when the delay is greater than this critical value and the system under consideration can undergo a Hopf bifurcation at the bifurcating steady-state solutions when the delay crosses through a sequence of critical values.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2003년도 추계 학술발표회논문집
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• pp.66-73
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• 2003

The technique for the seismic reliability evaluation of the electric power network is presented. In the previous study, the state of the substations was represented by the bi-state which is classified as failure or survival. However, the hi-state model can result in oversimplified analysis, because substations are worked by the parallel operating system. In this paper, Considering the characteristics of the parallel operating system, the damage of the substation is expressed by the multi-state for the more realistic seismic reliability evaluation. Using Monte-Carlo simulation method, the seismic reliability for Korean 345㎸ electric power network is evaluated. Analysis results show that reliability levels of the network by the multi-state analysis is higher than that by the hi-state analysis and the electric power network in southeastern area of the Korean Peninsular may be vulnerable to earthquakes.

• 대한화학회지
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• 제67권3호
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• pp.165-174
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• 2023

The development of all-solid-state batteries (ASSBs) has been gaining attention in recent years due to their potential to offer higher energy densities, improved safety, and longer cycle life compared to conventional lithium-ion batteries. However, several challenges must be addressed to achieve the practical application of ASSBs, such as the development of high-performance solid-state electrolytes, stable electrode-electrolyte interfaces, and cost-effective manufacturing processes. In this review paper, we present an overview of the current state of ASSB research, including recent progress in solid-state electrolyte and cathode/anode materials, and cell architecture. We also summarize the recent advancements and highlight the remaining challenges in ASSB research, with an outlook on the future of this promising technology.

• 한국터널지하공간학회 논문집
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• 제3권4호
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• pp.35-55
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• 2001

최근 터널 구조물이 점차 노후화됨에 따라 터널의 안전성을 평가하기 위한 점검 및 진단이 많이 수행되고 있다. 그러나 터널구조물의 상태 및 안전성 평가에 대한 명확한 기준이 없어 조사자의 주관적인 판단에 의존할 수 밖에 없는 실정으로 이에 대한 체계적인 기준정립이 요구되고 있다. 또한 기존방법은 터널라이닝에 대한 평가에 많은 비중을 주고 있어 지반구조물로서의 터널특성을 제대로 반영하지 못하고 있으며, 상태평가요소과 터널등급산정과정이 체계적이지 못하여 이에 대한 보완이 필요하다 할 수 있다. 따라서 본 연구에서는 터널 상태 및 안전성 평가방법의 문제점을 개선하기 위한 새로운 터널구조물상태평가기준을 제시하였다. 본 기준은 국내외의 터널기준을 분석하여 상태평가요소를 선정하고 이를 점수화하였으며, 대표등급산정방법을 정량화하므로서 터널상태를 객관적으로 평가할 수 있도록 하였다. 본 기준과 방법은 터널구조물에 대한 상태평가에 객관성과 신뢰성을 확보하여 보다 효율적인 안전점검 및 진단업무에 활용될 수 있다.

• 여성건강간호학회지
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• 제11권3호
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• pp.218-224
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• 2005

Purpose: The Purpose of this study was to investigate the relationship between state anxiety and maternal fetal attachment of unmarried mothers in a welfare center. Methods: The subjects were 25 unmarried mothers in a welfare center. The data was collected through personal interviews using a questionnaire. The instruments used for this study were the modified Spielberger's state anxiety inventory and Cranley's Maternal-Fetal Attachment Scale. Data was analyzed descriptive statistics, mean, standard deviation, t-test and the pearson correlation coefficient with the SPSS computer program. Results: The age of the subjects ranged from 15 to 25, and their average age was 20.0. The mean score of state anxiety was 58.2. There was significant difference in the degree of maternal state anxiety between the group whose pregnancy was known by their family and the group whose pregnancy was hidden. The group whose pregnancy was known showed a low state anxiety score. There was a significant difference in the degree of maternal state anxiety by the gestational period. The group who were in the second and third gestational trimester showed lower state anxiety score than in the first trimester. The mean score of maternal-fetal attachment(MFA) was 64.9. There were significant differences in the degree of maternal fetal attachment, by an ultrasound scan experience. The most frequently practiced attachment item was "I think the fetus is able to feel(mean 3.8)". Unmarried mothers degree of state anxiety showed a negative correlation with the degree of maternal fetal attachment(r=-.25), but there was no significant difference between the two variables. Conclusions: The unmarried mothers made an effort in striving to reduce their high state anxiety and to enhance maternal fetal attachment. They also realize how to take care of their state anxiety.

• 한국사회복지학
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• 제40권
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• pp.191-225
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• 2000

The purpose of this study is to formulate the way of the feminist strategy in Germany which is to change in the process of the globalization in the economic relations. The radical feminism which is the main streaming of german feminism shows a little interest in the role of the german welfare state (social state) to improve the quality of life of women. The german welfare state is, as the feminism says, only a instrument of patriarchy to perpetuate the domination of men over women. The german welfare state has played, but, an important role for the individualization of the relation of women's life which is the first condition for the emancipation of women from the patriarchal domination. That is a result of the interaction between the german welfare state and feminism. The role of the german welfare state for the interest of women is now challenged by the globalization of the economic relations which tries to reduce the standard of social services. The greatest victim of this process is women. Therefore it is necessary for the german feminism to think over the way of his strategy in relation to the german welfare state. The content of this study is as follows: First, the historical background of the german feminism explains how the radical feminism has become the mainstreaming of the german feminism. Seconds, the feminist strategy which rejects the role of the german welfare state for the interest of women has its own limits. Third, the german welfare state has not only developed the ideology of breadwinner but also contributed to the beginning of independent life of woman who were under the control of man. Fourth, the german welfare state is challenged by the economic globalization and being changed by the economic globalization. Fifth, therefore, the feminism has to concentrate to develop a strategy which accepts the limit and the possibility of german welfare state.