• Title/Summary/Keyword: J-ring

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SKEW POLYNOMIAL RINGS OVER SEMIPRIME RINGS

  • Hong, Chan-Yong;Kim, Nam-Kyun;Lee, Yang
    • Journal of the Korean Mathematical Society
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    • v.47 no.5
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    • pp.879-897
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    • 2010
  • Y. Hirano introduced the concept of a quasi-Armendariz ring which extends both Armendariz rings and semiprime rings. A ring R is called quasi-Armendariz if $a_iRb_j$ = 0 for each i, j whenever polynomials $f(x)\;=\;\sum_{i=0}^ma_ix^i$, $g(x)\;=\;\sum_{j=0}^mb_jx^j\;{\in}\;R[x]$ satisfy f(x)R[x]g(x) = 0. In this paper, we first extend the quasi-Armendariz property of semiprime rings to the skew polynomial rings, that is, we show that if R is a semiprime ring with an epimorphism $\sigma$, then f(x)R[x; $\sigma$]g(x) = 0 implies $a_iR{\sigma}^{i+k}(b_j)=0$ for any integer k $\geq$ 0 and i, j, where $f(x)\;=\;\sum_{i=0}^ma_ix^i$, $g(x)\;=\;\sum_{j=0}^mb_jx^j\;{\in}\;R[x,\;{\sigma}]$. Moreover, we extend this property to the skew monoid rings, the Ore extensions of several types, and skew power series ring, etc. Next we define $\sigma$-skew quasi-Armendariz rings for an endomorphism $\sigma$ of a ring R. Then we study several extensions of $\sigma$-skew quasi-Armendariz rings which extend known results for quasi-Armendariz rings and $\sigma$-skew Armendariz rings.

ON JACOBSON AND NIL RADICALS RELATED TO POLYNOMIAL RINGS

  • Kwak, Tai Keun;Lee, Yang;Ozcan, A. Cigdem
    • Journal of the Korean Mathematical Society
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    • v.53 no.2
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    • pp.415-431
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    • 2016
  • This note is concerned with examining nilradicals and Jacobson radicals of polynomial rings when related factor rings are Armendariz. Especially we elaborate upon a well-known structural property of Armendariz rings, bringing into focus the Armendariz property of factor rings by Jacobson radicals. We show that J(R[x]) = J(R)[x] if and only if J(R) is nil when a given ring R is Armendariz, where J(A) means the Jacobson radical of a ring A. A ring will be called feckly Armendariz if the factor ring by the Jacobson radical is an Armendariz ring. It is shown that the polynomial ring over an Armendariz ring is feckly Armendariz, in spite of Armendariz rings being not feckly Armendariz in general. It is also shown that the feckly Armendariz property does not go up to polynomial rings.

A Stress Analysis of Wall-Thinned Feedwater Ring in Nuclear Power Plant (원전 증기발생기 감육 급수링 응력해석)

  • Min Ki Cho;Ki Hyun Cho
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.17 no.1
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    • pp.56-63
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    • 2021
  • The feedwater ring is an assembly in steam generator internal piping, which distributes feedwater into the secondary side of the steam generator. It consists of an assembly of carbon steel piping, pipe fittings and J-nozzles which are inserted into the top of the feedwater ring and welded to the diameter of the ring. The feedwater ring at the attachment region of the J-nozzle may be susceptible to flow accelerated corrosion (FAC) due to flow turbulence which increases local fluid velocities. If a J-nozzle becomes a loose part, it can cause damage to tubing near the tube sheet. In this paper, the structural stress analysis for a wall thinned feedwater ring and integrity evaluations under assumed loading conditions are carried out in compliance with ASME B&PV SecIII, NB-3200.

Segregation Evaluation Method using J-Ring of High Strength High Fluidity Concrete (고강도 분체계 고유동 콘크리트의 J-Ring을 이용한 재료분리 판정 분석)

  • Lee, Hyuk-Ju;Lee, Young-Jun;Hyun, Seong-Yong;Han, Dong-Yeop;Han, In-Duck;Han, Min-Choel
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2018.11a
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    • pp.157-158
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    • 2018
  • In this study, the current tendency to replace a large amount of material admixture, which is fly ash (FA) and blast furnace slag (BS), into concrete is that high-grade cheese high admixture of high fluidity concrete In consideration of the substitution rate, we considered J-Ring to investigate the influence on the segregation resistance and the method of evaluating the classical segregation. In addition to the admixture replacement rate in the study results, the EIS using J-Ring became lower and the percentage of vehicles with segregation increased. Such a tendency is considered to be positive when J-Ring is used when segregation is judged if segregation degree is similar to EIS using J-Ring.

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Profile Ring Rolling Manufacturing Technology of Alloy 718 (초내열합금 링제품의 형상링 압연 제조 기술)

  • Kim, T.O.;Kim, K.J.;Kim, N.Y.;Lee, J.M.;Yeom, J.T.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2009.10a
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    • pp.425-428
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    • 2009
  • Aerospace engine application needs to stand high temperature and pressure. Because of its mechanical properties such as high strength at high temperature, Alloy 718 is used aerospace engine application about 80%. But alloy 718's mechanical properties cause some problem to manufacturing profile ring like damage of material and mold. In this study, alloy 718's mechanical properties investigated for knowing its formability and using FE-Simulation for designing profile ring roll process and mold shape. Profile ring rolling processing is designed with "Initial material$\rightarrow$Blank$\rightarrow$Linear Ring$\rightarrow$Profilering". Blank's heating temperature is setting $1100^{\circ}C$ for manufacturing a trial profile ring on the basis of FE-Simulation. As a result of manufacturing alloy 718 profile ring, it is possible to make near target profile shape ring with all of the processing condition which gives in this study.

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SYMMETRIC PROPERTY OF RINGS WITH RESPECT TO THE JACOBSON RADICAL

  • Calci, Tugce Pekacar;Halicioglu, Sait;Harmanci, Abdullah
    • Communications of the Korean Mathematical Society
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    • v.34 no.1
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    • pp.43-54
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    • 2019
  • Let R be a ring with identity and J(R) denote the Jacobson radical of R, i.e., the intersection of all maximal left ideals of R. A ring R is called J-symmetric if for any $a,b,c{\in}R$, abc = 0 implies $bac{\in}J(R)$. We prove that some results of symmetric rings can be extended to the J-symmetric rings for this general setting. We give many characterizations of such rings. We show that the class of J-symmetric rings lies strictly between the class of symmetric rings and the class of directly finite rings.

WHEN IS C(X) AN EM-RING?

  • Abuosba, Emad;Atassi, Isaaf
    • Communications of the Korean Mathematical Society
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    • v.37 no.1
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    • pp.17-29
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    • 2022
  • A commutative ring with unity R is called an EM-ring if for any finitely generated ideal I there exist a in R and a finitely generated ideal J with Ann(J) = 0 and I = aJ. In this article it is proved that C(X) is an EM-ring if and only if for each U ∈ Coz (X), and each g ∈ C* (U) there is V ∈ Coz (X) such that U ⊆ V, ${\bar{V}}=X$, and g is continuously extendable on V. Such a space is called an EM-space. It is shown that EM-spaces include a large class of spaces as F-spaces and cozero complemented spaces. It is proved among other results that X is an EM-space if and only if the Stone-Čech compactification of X is.

RINGS CLOSE TO SEMIREGULAR

  • Aydogdu, Pinar;Lee, Yang;Ozcan, A. Cigdem
    • Journal of the Korean Mathematical Society
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    • v.49 no.3
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    • pp.605-622
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    • 2012
  • A ring $R$ is called semiregular if $R/J$ is regular and idem-potents lift modulo $J$, where $J$ denotes the Jacobson radical of $R$. We give some characterizations of rings $R$ such that idempotents lift modulo $J$, and $R/J$ satisfies one of the following conditions: (one-sided) unit-regular, strongly regular, (unit, strongly, weakly) ${\pi}$-regular.

THE ZERO-DIVISOR GRAPH UNDER A GROUP ACTION IN A COMMUTATIVE RING

  • Han, Jun-Cheol
    • Journal of the Korean Mathematical Society
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    • v.47 no.5
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    • pp.1097-1106
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    • 2010
  • Let R be a commutative ring with identity, X the set of all nonzero, nonunits of R and G the group of all units of R. We will investigate some ring theoretic properties of R by considering $\Gamma$(R), the zero-divisor graph of R, under the regular action on X by G as follows: (1) If R is a ring such that X is a union of a finite number of orbits under the regular action on X by G, then there is a vertex of $\Gamma$(R) which is adjacent to every other vertex in $\Gamma$(R) if and only if R is a local ring or $R\;{\simeq}\;\mathbb{Z}_2\;{\times}\;F$ where F is a field; (2) If R is a local ring such that X is a union of n distinct orbits under the regular action of G on X, then all ideals of R consist of {{0}, J, $J^2$, $\ldots$, $J^n$, R} where J is the Jacobson radical of R; (3) If R is a ring such that X is a union of a finite number of orbits under the regular action on X by G, then the number of all ideals is finite and is greater than equal to the number of orbits.