• 대한수학회보
• /
• 제53권3호
• /
• pp.925-942
• /
• 2016

We study the structure of rings whose principal right ideals contain a sort of two-sided ideals, introducing right ${\pi}$-duo as a generalization of (weakly) right duo rings. Abelian ${\pi}$-regular rings are ${\pi}$-duo, which is compared with the fact that Abelian regular rings are duo. For a right ${\pi}$-duo ring R, it is shown that every prime ideal of R is maximal if and only if R is a (strongly) ${\pi}$-regular ring with $J(R)=N_*(R)$. This result may be helpful to develop several well-known results related to pm rings (i.e., rings whose prime ideals are maximal). We also extend the right ${\pi}$-duo property to several kinds of ring which have roles in ring theory.

• 대한수학회지
• /
• 제47권4호
• /
• pp.719-733
• /
• 2010

We observe a structure on the products of coefficients of nilpotent polynomials, introducing the concept of n-semi-Armendariz that is a generalization of Armendariz rings. We first obtain a classification of reduced rings, proving that a ring R is reduced if and only if the n by n upper triangular matrix ring over R is n-semi-Armendariz. It is shown that n-semi-Armendariz rings need not be (n+1)-semi-Armendariz and vice versa. We prove that a ring R is n-semi-Armendariz if and only if so is the polynomial ring over R. We next study interesting properties and useful examples of n-semi-Armendariz rings, constructing various kinds of counterexamples in the process.

• 대한수학회논문집
• /
• 제33권3호
• /
• pp.741-750
• /
• 2018

Antoine showed that the properties of Armendariz and NI are independent of each other. The study of Armendariz and NI rings has been doing important roles in the research of zero-divisors in noncommutative ring theory. In this article we concern a new class of rings which generalizes both Armendariz and NI rings. The structure of such sort of ring is investigated in relation with near concepts and ordinary ring extensions. Necessary examples are examined in the procedure.

• 대한수학회논문집
• /
• 제32권4호
• /
• pp.811-826
• /
• 2017

The reversible property of rings was initially introduced by Habeb and plays a role in noncommutative ring theory. In this note we study the reversible ring property on nilpotent elements, introducing the concept of commutativity of nilpotent elements at zero (simply, a CNZ ring) as a generalization of reversible rings. We first find the CNZ property of 2 by 2 full matrix rings over fields, which provides a basis for studying the structure of CNZ rings. We next observe various kinds of CNZ rings including ordinary ring extensions.

• 한국가구학회지
• /
• 제23권4호
• /
• pp.479-484
• /
• 2012

Tree-ring dating can be used to date scientifically prehistoric timbers, historical buildings or woodcrafts. It gives a calendar year to each tree ring and produces the felling dates of logs or wood panels. In this study, we applied tree-ring dating to a medicine cabinet in Seoul Museum of History. We obtained tree-ring data from radial or cross section by taking photographs with a digital camera. The cabinet were dated A.D. 1821 to the last ring. It was about 50 year older than the previous medicine cabinets. Tree-ring patterns indicated that the origin of woods for the cabinet would be near Sorak mountains.

• 한국전산구조공학회논문집
• /
• 제24권3호
• /
• pp.267-274
• /
• 2011

본 연구에서는 K형 관이음부의 내부에 단일 및 이중 환보강재를 설치할 경우에 발생하는 보강효과를 수치적으로 평가하였다. 지부재에 축하중을 받는 비보강 이음부와 환보강 이음부의 국부적 최대응력을 평가하기 위해 유한요소해석을 수행하였다. 작용하중과 내부 환보강재의 기하학적 형상이 이음부 거동에 미치는 영향을 평가하고 보강효과를 산정하였다. 또한 단일 환보강재와 이중 환보강재를 비교 평가하여 배치에 따른 응력분포 변화 및 응력의 분산효과를 산정하였다. 수치해석 결과로부터 이음부의 보강설계 자료에 활용 가능한 환보강재의 경제적 규격을 제시하였다.

• 한국가시화정보학회지
• /
• 제15권2호
• /
• pp.16-20
• /
• 2017

A coffee-ring effect is from capillary flow by different evaporation rate across the droplet. The capillary flow tends particles to accumulate at the edges of the droplet and makes the ring-shaped stain pattern. These coffee-ring formation and suppression of coffee-ring have been a critical role in printing and coating technologies. In this study, we present the experimental study on coffee-ring effect of silver nanowire inside the evaporating sessile droplet. Size and concentration effect of nanowires at coffee-ring effect has been investigated. From the coffee-ring, we observed the regimes of connected rings and disconnected ones and measure the resistivity of single ring pattern with different nanowire length.

• 대한수학회논문집
• /
• 제33권2호
• /
• pp.371-378
• /
• 2018

This article concerns a ring property which is seated between IFP and IPFP rings. We study the insertion property of nonzero powers at zero products, introducing the concept of strongly IPFP ring. The structure of strongly IPFP rings is investigated in relation with nearly seated ring properties and ring extensions.

• 대한수학회보
• /
• 제38권3호
• /
• pp.543-549
• /
• 2001

We show that R[X] is a Krull (Resp. factorial) ring if and only if R is a normal Krull (resp, factorial) ring with a finite number of minimal prime ideals if and only if R is a Krull (resp. factorial) ring with a finite number of minimal prime ideals and R(sub)M is an integral domain for every maximal ideal M of R. As a corollary, we have that if R[X] is a Krull (resp. factorial) ring and if D is a Krull (resp. factorial) overring of R, then D[X] is a Krull (resp. factorial) ring.

• 대한수학회보
• /
• 제53권6호
• /
• pp.1613-1615
• /
• 2016

It is proved that $k[X_1,{\ldots},X_v ]$ localized at the ideal ($X_1,{\ldots},X_v$ ), where k is a field and $X_1,{\ldots},X_v$ indeterminates, is not weakly quasi-complete for $v{\geq}2$, thus proving a conjecture of D. D. Anderson and solving a problem from "Open Problems in Commutative Ring Theory" by Cahen, Fontana, Frisch, and Glaz.