• 반도체디스플레이기술학회지
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• 제6권4호
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• pp.59-63
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• 2007

The CNTs are the most extensively studied material which are characterized by the complete property of matter, structure, and the large thermal conductivity (thermal conductivity of CNTs ~>2000W/mK vs. thermal conductivity of Aluminum ~> 204W/mK). Thus, they are successfully applied to the various fields. However, due to the strong agglomeration caused by the van der waal's force, their applications are limited. In the present study, a new method for CNTs dispersion was developed by using the mechanical dispersion, acid treatment, and then Cu was coated. This process produces CNTs/Cu nanocomposite powders, whereby the CNTs are homogeneously located within the Cu powders. The electrical properties of the CNTs/Cu nanocomposite were investigated.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2005년도 하계학술연구발표회 논문개요집
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• pp.94-95
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• 2005

• 한국산학기술학회논문지
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• 제21권2호
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• pp.601-610
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• 2020

최근, 세계적인 기후변화로 인하여 여름철마다 가뭄으로 인한 피해는 점점 심각해지는 상태이다. 이러한 문제를 해결하기 위하여, 산간오지에는 고정(콘크리트)보가 아닌 수위조절이 가능한 가동보가 설치되고 있다. 기존의 가동보 구동방식은 시설관리 및 인력소모로 인해 고가의 운용비용이 발생하여 운용상 어려움을 겪고 있다. 또한, 가동보는 대부분 전력계통과 연계하여 사용하고 있으므로 오지에 설치되는 경우, 전력계통 연계비용에 대한 부담이 증가하고 운용비용도 상승하는 문제점이 발생되고 있다. 따라서, 본 논문에서는 상기의 문제점들을 해결하기 위하여, 가동보(공압식)에 공급되는 기존의 전원을 태양광모듈과 리튬이온전지를 이용한 자연에너지 전원공급시스템으로 대체하는 최적 운용알고리즘과 리튬이온전지의 SOC(state of charge) 평가 알고리즘을 제시한다. 또한, 전력계통의 상용해석 프로그램인 PSCAD/EMTDC를 이용하여 50kW 전원공급시스템의 모델링을 수행하여, 독립운전모드와 계통연계운전모드에서 안정적으로 운용되고 있음을 확인하고, 투자비용에 대한 편익을 분석하여 상용화 가능성을 제시한다.

• 충청수학회지
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• 제31권3호
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• pp.281-285
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• 2018

Let $S_k(N)$ be the space of cusp forms of weight k for ${\Gamma}_0(N)$. We show that $S_k(N)$ is the direct sum of subspaces $S_k^+(N)$ and $S_k^-(N)$. Where $S_k^+(N)$ is the vector space of cusp forms of weight k for the group ${\Gamma}_0^+(N)$ generated by ${\Gamma}_0(N)$ and $W_N$ and $S_k^-(N)$ is the subspace consisting of elements f in $S_k(N)$ satisfying $f{\mid}_kW_N=-f$. We find generators spanning the space $S_k^-(N)$ from $Poincar{\acute{e}}$ series and give all linear relations among such generators.

• Kyungpook Mathematical Journal
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• 제62권1호
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• pp.193-204
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• 2022

A subset S of V(G), where G is a simple undirected graph, is a hop dominating set if for each v ∈ V(G)＼S, there exists w ∈ S such that d_G(v, w) = 2 and it is a locating-hop set if N_G(v, 2) ∩ S ≠ N_G(v, 2) ∩ S for any two distinct vertices u, v ∈ V(G)＼S. A set S ⊆ V(G) is a locating-hop dominating set if it is both a locating-hop and a hop dominating set of G. The minimum cardinality of a locating-hop dominating set of G, denoted by 𝛄_lh(G), is called the locating-hop domination number of G. In this paper, we investigate some properties of this newly defined parameter. In particular, we characterize the locating-hop dominating sets in graphs under some binary operations.

• 대한수학회지
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• 제49권1호
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• pp.139-151
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• 2012

In the previous paper, we gave a characterization of backward shift invariant subspaces of the Hardy space over the bidisk on which [${S_z}^n$, $S_w^*$] = 0 for a positive integer n ${\geq}$ 2. In this case, it holds that ${S_z}^n=cI$ for some $c{\in}\mathbb{C}$. In this paper, it is proved that if [$S_{\varphi}$, $S_w^*$] = 0 and ${\varphi}{\in}H^{\infty}({\Gamma}_z)$, then $S_{\varphi}=cI$ for some $c{\in}\mathbb{C}$.

• 대한수학회보
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• 제33권2호
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• pp.277-287
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• 1996

The theory of integration of functions with values in a Banach space has long been a fruitful area of study. In the eight years from 1933 to 1940, seminal papers in this area were written by Bochner, Gelfand, Pettis, Birhoff and Phillips. Out of this flourish of activity, two integrals have proved to be of lasting: the Bochner integral of strongly measurable function. Through the forty years since 1940, the Bochner integral has a thriving prosperous history. But unfortunately nearly forty years had passed until 1976 without a significant improvement after B. J. Pettis's original paper in 1938 [cf. 11].

• 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 $H_{p,q}$.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제16권4호
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• pp.245-263
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• 2012

The Korean mathematical curriculum has been changed three times during the resent five years. It led to changes in textbook system. In the 2007 revised mathematics curriculum, workbook was developed focusing on student's self-oriented learning, effective practice in differentiated classroom, and mathematics problem solving considering individual difference. This paper examines the characteristics of the tasks and the way the tasks are organized in the textbooks and the workbook in accordance with the 2007 revised mathematics curriculum; comparing with the function section before and after the amendment. Researchers examine whether the textbook and workbook were accomplished the purpose with "cognitive expectation", "level of cognitive demand", "and "response types". Researchers revised framework of [Son, J. W. & Senk, S. (2010). How reform curricula in the USA and Korea present multiplication and division of fraction. Educ. Stud. Math 74(2), 117-142] to make them suitable for the function section at the seventh grade.

• 한국재난정보학회 논문집
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• 제6권1호
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• pp.46-59
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• 2010

In this study, the safety training of comparative analysis of the realities of Korea's safety training and international experience and practical training for the safety experience of a virtual reality simulator, the development of safe conduct as a controlled motion simulator system, image H / W and the control system works, sound effects H / W and the control system works, 4D special effects (smoke, heat, wind, vibration) and a control system integration, mission control system for the selection and evaluation of the proposal, and safety training on Game S / W of development as we have never experienced an earthquake action plan and evacuate to escape the power of experience and the experience of an earthquake (vibration + video), Also the collapse and a fire escape on the experience of following second disaster, the building collapsed during an escape experience in the field, in case of fire According to the initial fire suppression and fire extinguisher usage experience - experience of smoke and heat to escape in, Moreover, the Daegu subway fire in public places such as subway and evacuated to escape the experience, considering the suggested Simulator.