• 대한수학회보
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• 제50권2호
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• pp.389-398
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• 2013

Let R be a ring and $\mathcal{Q}$ be a quiver. In this paper we give another definition of purity in the category of quiver representations. Under such definition we prove that the class of all pure injective representations of $\mathcal{Q}$ by R-modules is preenveloping. In case $\mathcal{Q}$ is a left rooted semi-co-barren quiver and R is left Noetherian, we show that every cotorsion flat representation of $\mathcal{Q}$ is pure injective. If, furthermore, R is $n$-perfect and $\mathcal{F}$ is a flat representation $\mathcal{Q}$, then the pure injective dimension of $\mathcal{F}$ is at most $n$.

• Journal of the Korean Data and Information Science Society
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• 제19권4호
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• pp.1141-1151
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• 2008

Data mining is the process of sorting through large amounts of data and picking out useful information. One of the well-studied problems in data mining is the exploration of association rules. An association rule technique finds the relation among each items in massive volume database. Some interestingness measures have been developed in association rule mining. Interestingness measures are useful in that it shows the causes for pruning uninteresting rules statistically or logically. This paper propose a conditional pure confidence to evaluate association rules and then describe some properties for a proposed measure. The comparative studies with confidence and pure confidence are shown by numerical example. The results show that the conditional pure confidence is better than confidence or pure confidence.

• 대한수학회보
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• 제61권1호
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• pp.83-92
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• 2024

Let R be a commutative ring with nonzero identity and M be an R-module. In this paper, we first introduce the concept of S-idempotent element of R. Then we give a relation between S-idempotents of R and clopen sets of S-Zariski topology. After that we define S-pure ideal which is a generalization of the notion of pure ideal. In fact, every pure ideal is S-pure but the converse may not be true. Afterwards, we show that there is a relation between S-pure ideals of R and closed sets of S-Zariski topology that are stable under generalization.

• 한국자동차공학회논문집
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• 제6권1호
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• pp.222-233
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• 1998

A 4-point pure bending res machine is developed the evaluate the pure vending moment-rotation properties of the thin-walled tubes without imposing shear and tensile forces. The moment-rotation properties of the thin-walled tubes are measured up to and beyond collapse with the pure bending test machine. The test results are compared with those of finite element analyses and existing analytical solution.

• 대한수학회보
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• 제49권6호
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• pp.1251-1254
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• 2012

Pure-strategy Nash Equilibrium (NE) is one of the most important concepts in game theory. Tae-Hwan Yoon and O-Hun Kwon gave a "sufficient condition" for the existence of pure-strategy NEs in matrix games [5]. They also claimed that the condition was necessary for the existence of pure-strategy NEs in undominated matrix games. In this short note, we show that these claims are not true by giving two examples.

• 대한수학회보
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• 제59권5호
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• pp.1237-1246
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• 2022

In this paper, we introduce the concept of N-pure ideal as a generalization of pure ideal. Using this concept, a new and interesting type of rings is presented, we call it a mid ring. Also, we provide new characterizations for von Neumann regular and zero-dimensional rings. Moreover, some results about mp-ring are given. Finally, a characterization for mid rings is provided. Then it is shown that the class of mid rings is strictly between the class of reduced mp-rings (p.f. rings) and the class of mp-rings.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제25권2호
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• pp.127-133
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• 2018

We look at Toeplitz arrays on ${\mathbb{Z}}^d$ and study a characterizing property for pure discrete spectrum in terms of the periodic structures of the Toeplitz arrays.

• Journal of the Korean Data and Information Science Society
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• 제22권2호
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• pp.179-188
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• 2011

연관성 규칙은 방대한 데이터베이스에서 항목간의 관계를 명확히 수치화 함으로써 그들간의 관련성을 표시해주는 기법으로 데이터 마이닝 기법들 중에서 가장 많이 활용되고 있다. 어느 항목이 발생하면 다른 항목도 발생한다는 규칙을 발견하기 위한 기법이 연관성 규칙이라면 음의 연관성 규칙 마이닝은 어느 항목이 발생하면 다른 항목도 발생하지 않는다는 규칙을 찾아내는 기법이다. 기존의 연관성 규칙에 음의 연관성 규칙을 추가하게 되면 어떤 제품을 판매하기 위해서는 그 제품만 마케팅 하는 것 뿐 만 아니라 더 나아가 그 제품이 아닌 어느 제품을 마케팅 하는 것이 필요한지를 판단할 수 있다. 본 논문에서는 음의 연관성 규칙의 단점을 보완할 수 있는 음의 순수 연관성 규칙의 측도들을 제시하고 흥미도 측도가 가져야 할 조건들을 조사하였으며, 예제 데이터를 활용하여 음의 순수 연관성 규칙의 유용성에 대해 살펴보았다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2000년도 추계학술대회 논문집
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• pp.21-24
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• 2000

Ultra-fine grains were produced in pure Al using an Accumulative Rolling-Bonding (ARB) process. After several cycles of the ARB process, pure Al sheets were filled with the ultra-fine grains whose diameters were several hundred nano-meters. With ARB cycles, the nature of grain boundaries of the ultra-fine grains changed from diffusive sub-boundaries to well-defined high angle boundaries. After 7 cycles, ultra-fine polycrystals with large misorientations between neighboring grains were obtained. Sliding wear tests using a pin-on-disk type wear tester were co ducted on the ultra-fine grained pure Al. Wear rates of pure Al increased with the increase of ARB cycle numbers in spite of the increase in hardness. Worn surfaces and cross-sections were examined with optical microscopy (OM) and scanning electron microscopy (SEM) In investigate the wear mechanism of the ultra-fine grained pure Al.

• 전자통신동향분석
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• 제26권4호
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• pp.175-181
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• 2011

이동망 착신독점력 규제를 위해 각국 규제당국은 이동망 착신접속료(Mobile Termination Rate: MTR)를 원가기준으로 규제하고 있다. 원가기준으로는 과거 FDC 방식이 채택되어 왔으나 2002년 영국이 "LRIC+" 방식으로 MTR을 결정한 이래 "LRIC+" 방식이 EU를 비롯한 OECD 주요국의 MTR 산정방식으로 보편화되어 왔다. 그러나 2009년 EU에서 순수증분비용(Pure Long Run Incremental Cost) 방식으로 착신접속료 규제방식 변경을 권고하는 권고안을 채택함으로써 EU 가맹국은 Pure LRIC 방식으로 MTR을 변경하여야 한다. 본 고에서는 Pure LRIC 방식 채택을 권하는 EU 권고안 채택 배경, Pure LRIC 산정 방법론, EU 권고안에 대한 각국의 이행계획을 살펴보며, Pure LRIC 채택이 가져올 영향을 살펴보고자 한다.