• 제목/요약/키워드: w-finite type

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Front Fillet Welds에서의 탄성응력(彈性應力)의 거동(擧動)에 관(關)한 연구(硏究) (A Study on the Behavior of Elastic Stress Distribution in Front Fillet Welds by Finite Element Method)

  • 엄동석
    • 대한조선학회지
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    • 제12권2호
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    • pp.35-42
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    • 1975
  • This paper investigates the distribution of stress and its behavior at the Root Toe in fillet welding joint. Furthermore, the stress components and principal stresses in the fillet welds are calculated by the finite element method. The distribution of stresses obtained numerically by means of the finite element method is also compared with the experimental results of two dimensional photoelasticity. A Cover plate type and Center block type of fillet welds are used as models for the numerical calculations covering the variations of 2 W/M(thickness of main plate/thickness of cover plate)=1 through 2W/M=4. The results obtained in these studies are summarized as follows; 1) When W2/M values become small, the stress concentration factors of the Root are larger than of the Toe in a C-type. Its critical value is 2W/M=3.00. However, no critical value exists in a T-type. 2) For 2W/M Values being avove 3.5 in a C-type and above 4.0 in a T-type, $K_R$ and $K_{\tau}$ become 1. 3) According to the differences of 2W/M values, the differences in stress become increasing in the Root but become decreasing in the Toe. These differences, however, disappear as the free boundary surface is approached. 4) The stress concentration factors of both the Root and Toe obtained by means of the finite element method have somewhat lower values than obtained by the photoelasiticity. But their principal stress directions coincide in either method. 5) It proves beneficial to employ the finite element method for two-dimensional plane stress analysis in front fillet welding joint.

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w-INJECTIVE MODULES AND w-SEMI-HEREDITARY RINGS

  • Wang, Fanggui;Kim, Hwankoo
    • 대한수학회지
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    • 제51권3호
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    • pp.509-525
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    • 2014
  • Let R be a commutative ring with identity. An R-module M is said to be w-projective if $Ext\frac{1}{R}$(M,N) is GV-torsion for any torsion-free w-module N. In this paper, we define a ring R to be w-semi-hereditary if every finite type ideal of R is w-projective. To characterize w-semi-hereditary rings, we introduce the concept of w-injective modules and study some basic properties of w-injective modules. Using these concepts, we show that R is w-semi-hereditary if and only if the total quotient ring T(R) of R is a von Neumann regular ring and $R_m$ is a valuation domain for any maximal w-ideal m of R. It is also shown that a connected ring R is w-semi-hereditary if and only if R is a Pr$\ddot{u}$fer v-multiplication domain.

On *w-Finiteness Conditions

  • Jung Wook Lim
    • Kyungpook Mathematical Journal
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    • 제63권4호
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    • pp.571-575
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    • 2023
  • Let D be an integral domain and let * be a star-operation on D. In this article, we give new characterizations of *w-Noetherian domains and *w-principal ideal domains. More precisely, we show that D is a *w-Noetherian domain (resp., *w-principal ideal domain) if and only if every *w-countable type ideal of D is of *w-finite type (resp., principal).

A NOTE ON w-NOETHERIAN RINGS

  • Xing, Shiqi;Wang, Fanggui
    • 대한수학회보
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    • 제52권2호
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    • pp.541-548
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    • 2015
  • Let R be a commutative ring. An R-module M is called a w-Noetherian module if every submodule of M is of w-finite type. R is called a w-Noetherian ring if R as an R-module is a w-Noetherian module. In this paper, we present an exact version of the Eakin-Nagata Theorem on w-Noetherian rings. To do this, we prove the Formanek Theorem for w-Noetherian rings. Further, we point out by an example that the condition (${\dag}$) in the Chung-Ha-Kim version of the Eakin-Nagata Theorem on SM domains is essential.

최적정규기저를 갖는 유한체위에서의 저 복잡도 비트-병렬 곱셈기 (A Low Complexity Bit-Parallel Multiplier over Finite Fields with ONBs)

  • 김용태
    • 한국전자통신학회논문지
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    • 제9권4호
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    • pp.409-416
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    • 2014
  • 유한체의 H/W 구현에는 정규기저를 사용하는 것이 효과적이며, 특히 최적 정규기저를 갖는 유한체의 H/W 구현이 가장 효율적이다. 타입 I 최적 정규기저를 갖는 유한체 $GF(2^m)$은 m 이 짝수이기 때문에 어떤 암호계에는 응용되지 못하는 단점이 있다. 그러나 타입 II 최적 정규기저를 갖는 유한체의 경우는 NIST에서 제안한 ECDSA 의 권장 커브가 주어진 $GF(2^{233})$이 타입 II 최적 정규 기저를 갖는 등 여러 응용분야에 적용 되므로, 이에 대한 효율적인 구현에 관한 연구가 활발하게 진행되고 있다. 본 논문에서는 타입 II 최적 정규기저를 갖는 유한체 $GF(2^m)$의 연산을 정규기저를 이용하여 표현하여 확대체 $GF(2^{2m})$의 원소로 표현하여 연산을 하는 새로운 비트-병렬 곱셈기를 제안하였으며, 기존의 가장 효율적인 곱셈기들보다 블록 구성방법이 용이하며, XOR gate 수가 적은 저 복잡도 곱셈기이다.

ON PIECEWISE NOETHERIAN DOMAINS

  • Chang, Gyu Whan;Kim, Hwankoo;Wang, Fanggui
    • 대한수학회지
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    • 제53권3호
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    • pp.623-643
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    • 2016
  • In this paper, we study piecewise Noetherian (resp., piecewise w-Noetherian) properties in several settings including flat (resp., t-flat) overrings, Nagata rings, integral domains of finite character (resp., w-finite character), pullbacks of a certain type, polynomial rings, and D + XK[X] constructions.

NON-FINITELY BASED FINITE INVOLUTION SEMIGROUPS WITH FINITELY BASED SEMIGROUP REDUCTS

  • Lee, Edmond W.H.
    • Korean Journal of Mathematics
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    • 제27권1호
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    • pp.53-62
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    • 2019
  • Recently, an infinite class of finitely based finite involution semigroups with non-finitely based semigroup reducts have been found. In contrast, only one example of the opposite type-non-finitely based finite involution semigroups with finitely based semigroup reducts-has so far been published. In the present article, a sufficient condition is established under which an involution semigroup is non-finitely based. This result is then applied to exhibit several examples of the desired opposite type.

COMBINATORIAL AUSLANDER-REITEN QUIVERS AND REDUCED EXPRESSIONS

  • Oh, Se-jin;Suh, Uhi Rinn
    • 대한수학회지
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    • 제56권2호
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    • pp.353-385
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    • 2019
  • In this paper, we introduce the notion of combinatorial Auslander-Reiten (AR) quivers for commutation classes [${\tilde{w}}]$ of w in a finite Weyl group. This combinatorial object is the Hasse diagram of the convex partial order ${\prec}_{[{\tilde{w}}]}$ on the subset ${\Phi}(w)$ of positive roots. By analyzing properties of the combinatorial AR-quivers with labelings and reflection functors, we can apply their properties to the representation theory of KLR algebras and dual PBW-basis associated to any commutation class [${\tilde{w}}_0$] of the longest element $w_0$ of any finite type.