• 응용통계연구
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• 제30권1호
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• pp.159-167
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• 2017

일반적으로 잠재적 이상치군은 검정과정을 통해 최종적으로 이상치 여부를 판단하지만 검정절차를 생략하거나 모의실험에 의해 계산된 유의값을 기반으로 검정을 수행하는 이상치 탐지법들도 있다. 본 논문에서는 가면화나 수렁화현상을 피하기 위하여 이상치후보군에 속한 개별 관찰치를 검정하지 않고 이상치후보군의 부분집합들을 검정하는 절차를 제안한다. 제안된 방법의 활용을 보여주는 예제와 다른 방법과의 검정력 비교를 위한 모의실험 결과가 제시된다.

• Kyungpook Mathematical Journal
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• 제49권2호
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• pp.255-263
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• 2009

For an endomorphism ${\alpha}$ of R, in [1], a module $M_R$ is called ${\alpha}$-compatible if, for any $m{\in}M$ and $a{\in}R$, ma = 0 iff $m{\alpha}(a)$ = 0, which are a generalization of ${\alpha}$-reduced modules. We study on the relationship between the quasi-Baerness and p.q.-Baer property of a module MR and those of the polynomial extensions (including formal skew power series, skew Laurent polynomials and skew Laurent series). As a consequence we obtain a generalization of [2] and some results in [9]. In particular, we show: for an ${\alpha}$-compatible module $M_R$ (1) $M_R$ is p.q.-Baer module iff $M[x;{\alpha}]_{R[x;{\alpha}]}$ is p.q.-Baer module. (2) for an automorphism ${\alpha}$ of R, $M_R$ is p.q.-Baer module iff $M[x,x^{-1};{\alpha}]_{R[x,x^{-1};{\alpha}]}$ is p.q.-Baer module.

• 대한수학회보
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• 제49권1호
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• pp.127-133
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• 2012

It is well known that if the ${\beta}$-expansion of any nonnegative integer is finite, then ${\beta}$ is a Pisot or Salem number. We prove here that $\mathbb{F}_q((x^{-1}))$, the ${\beta}$-expansion of the polynomial part of ${\beta}$ is finite if and only if ${\beta}$ is a Pisot series. Consequently we give an other proof of Scheiche theorem about finiteness property in $\mathbb{F}_q((x^{-1}))$. Finally we show that if the base ${\beta}$ is a Pisot series, then there is a bound of the length of the fractional part of ${\beta}$-expansion of any polynomial P in $\mathbb{F}_q[x]$.

• 대한수학회지
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• 제56권2호
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• pp.289-309
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• 2019

This paper is intended as a discussion of some generalizations of the notion of a reversible ring, which may be obtained by the restriction of the zero commutative property from the whole ring to some of its subsets. By the INCZ property we will mean the commutativity of idempotent elements of a ring with its nilpotent elements at zero, and by ICZ property we will mean the commutativity of idempotent elements of a ring at zero. We will prove that the INCZ property is equivalent to the abelianity even for nonunital rings. Thus the INCZ property implies the ICZ property. Under the assumption on the existence of unit, also the ICZ property implies the INCZ property. As we will see, in the case of nonunital rings, there are a few classes of rings separating the class of INCZ rings from the class of ICZ rings. We will prove that the classes of rings, that will be discussed in this note, are closed under extending to the rings of polynomials and formal power series.

• 로봇학회논문지
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• 제14권3호
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• pp.186-190
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• 2019

When problems occurred in the unstable and/or extreme terrain environment, formal field-driving robots were unable to provide any other options such as the transformation of the wheel and body structure, and so on. For such reason, this paper proposed a novel type of integrated wheel mechanism that can be operated as a conventional driving wheel mode and hybrid wheel-leg mode in order to be negotiated in an unstable terrain environment. The mechanical effect of the proposed variable wheel mechanism was analyzed considering the geometric constraint and power requirement of the actuator for the transformation. In addition, we designed and manufactured the prototype of field-driving robot, which reliably control the variable wheel shape. Finally, the effectiveness of the variable wheel mechanism was verified by preliminary experimental approach.

• 수산경영론집
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• 제36권2호
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• pp.53-69
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• 2005

The recent emergence of electronic commerce could provide different opportunities to small firms in overcoming part of their technological, environmental, organizational, and managerial inadequacies. However, recent research provided a gloomy picture about electronic commerce uptake and use in small firms. Until now few small flrms adopted electronic commerce. This phenomenon gives us several implications. One of the implications is a need to generate more research to small firms' uptake and use of electronic commerce. So, this research aims at what is determinants in small firms' adoption of electronic commerce, especially business - to - business(B2B). Several previous studies were identified various influential variables in adoption of small firms' electronic commerce. To some extent, by industries these variables may be different in influencing B2B adoption of small firms. This study selected fishery industry's wholesale firms as survey domain. Then, It selected some variables from previous studios and group them in several factors for consistently comparing variable's influential power. Through hierarchical influencing model of B2B adoption, managers who worked for fishery wholesale firms were surveyed. Among the first level's factors of the model, business factor was identified as the statistically most influential factor in B2B adoption. Technological factor and environmental factor at the frist level were identified as relatively less influential factors. Among the second level's factors of the model, it was statistically significant only that technological usefulness factor was more influential than technological burden factor in B2B adoption. And among the third level's factors of the model, it was identified that formal plan and task team for B2B, top management support, and mutual beliefs of inter - firms were statistically more influential than related variables in B2B adoption. These results give us some implications. First, fishery wholesale firms recognized B2B as a new business paradigm, and technological problems as not obstacles in adopting B2B. Thus it would be possible to activate the fishery B2B if they were guided to getting B2B benefits and B2B's relative advantages. Second, they considered the power of influential factors might be different by B2B stages. That is, top management support was more important in the B2B introduction stage, and formal plan and task team for B2B and mutual beliefs of inter - firms were more important in the B2B operation stage.

• 한국경제지리학회지
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• 제16권3호
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• pp.423-444
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• 2013

베트남 특히 메콩델타지역은 1990년대 이후 지속적으로 관광객 수가 증가해 왔으며, 특히 터이선 섬은 이 지역의 대표적 농촌관광지 중 하나로 주목받아 왔다. 이 연구는 농촌지역에서 관광개발이 이루어질 때, 관광 자본의 성격(역외/역내)에 따라 공급자들이 어떻게 네트워크를 형성하는지를 밝히고자 하였다. 분석 결과, 터이선 섬의 주요 관광공급자는 크게, 호치민시의 여행사, 지방 여행사, 지역 주민 및 행정기관으로 나타났으며, 이 중, 호치민시의 여행사와 지방 여행사는 관광객(관광 수요)와 지역 주민(관광 공급)을 이어주는 중심적 연결자로서 기능하고 있다는 것이 밝혀졌다. 또한, 호치민시의 여행사와 지방 여행사간의 네트워킹은 서류상 계약(공적 네트워킹)이 지배적인 반면, 지방 여행사와 지역 주민간의 네트워킹은 서류상 계약(공식 네트워킹)과 구두상 계약(비공식 네트워킹)이 동시에 존재하였다. 한편, 지역 주민간의 네트워킹에서는 가족, 친구, 근린관계에 기반한 비공식 네트워킹이 지배적으로 나타났다. 한편, 지방 여행사간 또는 터이선 관광의 최종 목적지이며 지역 주민들에 의해 운영되는 과수 농원(tourist sites) 간에는 어떠한 협조적 네트워킹도 나타나고 있지 않다는 것이 밝혀졌다. 이러한 공급자 간의 네트워킹의 일차적 동기는 가격 경쟁이며, 그 결과 터이선 섬 관광 수입의 대부분이 호치민시의 여행사로 누출되며, 지역내 공급자에게는 일부분만이 돌아가는 수입 분배의 불균형이 나타났다. 즉, 지역내 공급자간의 치열한 경쟁이 호치민시의 여행사와 관광 업무 체결시 교섭력을 발휘할 수 없게 하고 있었다. 최근 지역내 관광 공급자들의 연합조직으로 관광협회가 설립되었지만, 주요 공급자가 아직 가입하고 있지 않으며, 지역내 공급자들의 교섭력을 높이는데는 역부족인 것으로 보여진다.

• 과학교육연구지
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• 제37권2호
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• pp.294-309
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• 2013

이 연구에서는 초등 예비교사들의 과학과 관련된 사회적 문제에 대한 인식을 알아보았다. 연구를 위해 SSI와 관련된 구체적인 이슈로 후쿠시마 원전 사고를 이용하였다. 연구에는 교원양성대학에 재학중인 대학교 2학년생 12명이 참여하였으며, 연구 참여자 모두는 초등학교 과학 교육과정에 대한 내용으로 구성되어 있는 초등 과학교육론을 수강하고 있는 학생들이었다. 연구결과 초등 예비교사들은 모두 후쿠시마 원전 사고에 대해 인지하고 있었으며, 원전 사고에 대해 다양한 매체를 통해 접하고 있음을 알 수 있었다. 특히 인터넷을 많이 사용하는 대학생이어서인지 다른 매체에 비해 인터넷을 통해 원전 사고에 대한 내용을 많이 접하고 있었으며, 또한 인터넷을 통해 추가적인 정보를 얻기도 하였다. 그러나 초등 예비교사는 원전 사고에 대해 인지하고 있는 것과는 달리 많은 정보를 갖고 있지는 않았으며, 원전 사고와 같은 SSI에 대해 평소 관심을 갖고 있거나 교육을 받은 경험을 미비했다. 원전 사고와 같은 SSI에 대해 관심은 없으나 원전 사고와 같은 과학적인 문제들이 사회에 밀접한 영향을 미친다는 것은 인식하고 있는 것으로 나타났다. 아울러 현행 교육과정에 SSI 교육이 적용되어야 한다는 점에서도 모두 공감하고 있었으며, 적용되지 않고 있다는 점에 대해서도 문제인식을 같이 하였다. 이상의 연구 결과를 보면, 과학교육의 목표 중에 하나인 과학의 본성을 이해시키는 측면과 과학 교과에 대한 흥미 제고를 위해서라도 SSI 교육에 더욱 활발한 연구뿐만 아니라 정규 교육과정에의 적용은 매우 중요하며 시급하다고 할 수 있다.

• 한국안전학회지
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• 제20권2호
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• pp.56-60
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• 2005

We studied fire properties of MOF(Metering Out Fit) insulation cover and field condition of 22.9kV power receiving system. $49.5\%$ of formal equipments were installed indoors, whereas $40.8\%$ of informal equipments were installed as H-type. Insulation treatment was not done at a $22.4\%$ ratio of main line($27.7\%$ of transformer, $70.2\%$ of COS, $10.4\%$ of MOF). Fire pattern analysis showed that the fire started at the secondary part of OC wire. In the result of DTA(Differential Thermal Analysis), normal cover showed exothermic reactions at $310^{\circ}C,\;399^{\circ}C\;and\;510^{\circ}C$ (endothermic reactions at $382^{\circ}C$). Whereas damaged cover showed exothermic reactions at $412^{\circ}C$(endothermic reactions at $389^{\circ}C$). In the result of TGA(Thermo Gravimetric Analysis), the thermal weight change of normal cover was similar compared to damaged cover. In the result of FT-IR analysis, normal cover showed absorption peaks at $3,024cm^{-l},\;2,921cm^{-l},\;1,600cm^{-1},\;1,492cm^{-1},\;1,451cm^{-1},\;1,154cm^{-l},\;1,027cm^{-1},\;906cm^{-1}$. Whereas, in case of tracked cover, the absorption peaks that were shown in normal cover disappeared and different absorption peak was shown at $966cm^{-1}$.

• Kyungpook Mathematical Journal
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• 제62권3호
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• pp.437-453
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• 2022

Unlike for polynomial rings, the notion of multiplication for the near-ring of polynomials is the substitution operation. This leads to somewhat surprising results. Let S be an abelian left near-ring with identity. The relation ~ on S defined by letting a ~ b if and only if ann_S(a) = ann_S(b), is an equivalence relation. The compressed zero-divisor graph 𝚪_E(S) of S is the undirected graph whose vertices are the equivalence classes induced by ~ on S other than [0]_S and [1]_S, in which two distinct vertices [a]_S and [b]_S are adjacent if and only if ab = 0 or ba = 0. In this paper, we are interested in studying the compressed zero-divisor graphs of the zero-symmetric near-ring of polynomials R₀[x] and the near-ring of the power series R₀[[x]] over a commutative ring R. Also, we give a complete characterization of the diameter of these two graphs. It is natural to try to find the relationship between diam(𝚪_E(R₀[x])) and diam(𝚪_E(R₀[[x]])). As a corollary, it is shown that for a reduced ring R, diam(𝚪_E(R)) ≤ diam(𝚪_E(R₀[x])) ≤ diam(𝚪_E(R₀[[x]])).