• Title/Summary/Keyword: integral extension

Search Result 136, Processing Time 0.022 seconds

GENERALIZED NORMALITY IN RING EXTENSIONS INVOLVING AMALGAMATED ALGEBRAS

  • Kwon, Tae In;Kim, Hwankoo
    • Korean Journal of Mathematics
    • /
    • v.26 no.4
    • /
    • pp.701-708
    • /
    • 2018
  • In this paper, seminormality and t-closedness in ring extensions involving amalgamated algebras are studied. Let $R{\subseteq}T$ be a ring extension with ideals $I{\subseteq}J$, respectively such that J is contained in the conductor of R in T. Assume that T is integral over R. Then it is shown that ($R{\bowtie}I$, $T{\bowtie}J$) is a seminormal (resp., t-closed) pair if and only if (R, T) is a seminormal (resp., t-closed) pair.

ASYMPTOTIC FOR THE NUMBER OF STAR OPERATIONS ON ONE-DIMENSIONAL NOETHERIAN DOMAINS

  • Spirito, Dario
    • Journal of the Korean Mathematical Society
    • /
    • v.58 no.5
    • /
    • pp.1239-1260
    • /
    • 2021
  • We study the set of star operations on local Noetherian domains D of dimension 1 such that the conductor (D : T) (where T is the integral closure of D) is equal to the maximal ideal of D. We reduce this problem to the study of a class of closure operations (more precisely, multiplicative operations) in a finite extension k ⊆ B, where k is a field, and then we study how the cardinality of this set of closures vary as the size of k varies while the structure of B remains fixed.

REDUCTION OF ABELIAN VARIETIES AND CURVES

  • Moshe Jarden;Aharon Razon
    • Journal of the Korean Mathematical Society
    • /
    • v.61 no.3
    • /
    • pp.515-545
    • /
    • 2024
  • Consider a Noetherian domain R0 with quotient field K0. Let K be a finitely generated regular transcendental field extension of K0. We construct a Noetherian domain R with Quot(R) = K that contains R0 and embed Spec(R0) into Spec(R). Then, we prove that key properties of abelian varieties and smooth geometrically integral projective curves over K are preserved under reduction modulo p for "almost all" p ∈ Spec(R0).

FACTORIZATION PROPERTIES ON THE COMPOSITE HURWITZ RINGS

  • Dong Yeol Oh
    • Korean Journal of Mathematics
    • /
    • v.32 no.1
    • /
    • pp.97-107
    • /
    • 2024
  • Let A ⊆ B be an extension of integral domains with characteristic zero. Let H(A, B) and h(A, B) be rings of composite Hurwitz series and composite Hurwitz polynomials, respectively. We simply call H(A, B) and h(A, B) composite Hurwitz rings of A and B. In this paper, we study when H(A, B) and h(A, B) are unique factorization domains (resp., GCD-domains, finite factorization domains, bounded factorization domains).

A NOTE ON MIXED POLYNOMIALS AND NUMBERS

  • Mohd Ghayasuddin;Nabiullah Khan
    • Honam Mathematical Journal
    • /
    • v.46 no.2
    • /
    • pp.168-180
    • /
    • 2024
  • The main object of this article is to propose a unified extension of Bernoulli, Euler and Genocchi polynomials by means of a new family of mixed polynomials whose generating function is given in terms of generalized Bessel function. We also discuss here some fundamental properties of our introduced mixed polynomials by making use of the series arrangement technique. Furthermore, some conclusions of our present study are also pointed out in the last section.

Analysis of Patched Cylindrical Shells with Circumferential Through-Wall Cracks (원주방향 관통균열을 갖는 원통형 쉘 구조의 패치보강 해석)

  • Ahn, Jae-Seok;Kim, Young-Wook;Woo, Kwang-Sung
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.32 no.6A
    • /
    • pp.411-418
    • /
    • 2012
  • In this study, behavior of unpatched and patched cylindrical shells with through-wall cracks has been estimated using numerical experiments, and patching effect of them has been investigated according to various patching parameters. To show credibility of numerical models considered, two ways such as h- and p-methods have been adopted. Also, domain integral method and virtual crack extension method have been considered to calculate energy release rates based on linear elastic fracture mechanics. For examples, the unpatched cylindrical shells with circumferential cracks under remote tension have firstly been analyzed to show the validity of finite element modeling with h-method or p-method, and then the results have been compared with literature values published. Next, the sensitive analysis of patch repaired problems in terms of thickness of patch and adhesive, shear modulus of adhesive, composite material type of patch, crack length, etc. has been carried out.

Internal Aerodynamic Noise from Quick Opening Throttle Valve (쓰로틀 밸브의 빠른 열림 동작에 의한 내부공력소음)

  • 정철웅;김성태;김재헌;이수갑
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.14 no.4
    • /
    • pp.310-318
    • /
    • 2004
  • For many industrial problems originating from aerodynamic noise, noise prediction techniques, reliable and easy to apply, would be of great value to engineers and manufacturers. General algorithm is presented for the prediction of internal flow-induced noise from quick opening throttle valve in an automotive engine. This algorithm is based on the integral formula derived by using the General Green Function, Lighthill's acoustic analogy and Curle's extension of Lighthill's. Novel approach of this algorithm is that the integral formula is so arranged as to predict frequency-domain acoustic signal at any location in a duct by using unsteady flow data in space and time, which can be provided by the Computational Fluid Dynamics Techniques. This semi-analytic model is applied to the prediction of internal aerodynamic noise from a throttle valve in an automotive engine. The predicted noise levels from the throttle valve show good agreement with actual measurements. The results show that the dipole noise is dominant in this phenomena and the origin of noise sources is attributed to the anti-vortex lines formed in the down-stream from a throttle valve. This illustrative computation shows that the current method permits generalized predictions of flow noise generated by bluff bodies and turbulence in flow ducts.

Prediction of Cut Propagation Direction of Wrinkled Thin Membrane (얇은 막재에서 컷의 진전방향에 주름이 미치는 영향)

  • Kim, Young-Ah;Woo, Kyeong-Sik
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.40 no.5
    • /
    • pp.423-430
    • /
    • 2012
  • In this paper, the effect of wrinkling on the cut propagation direction of thin membrane was studied using geometrically nonlinear shell element post-buckling analysis. In the analysis, rectangular tensile membrane configuration with a slanted center cut was considered. The cut propagation direction was predicted by maximum energy release rate method, $K_{II}$-zero method, and maximum tangential stress method. The cut propagation angle and the $J$-integral values were calculated for the wrinkled and unwrinkled cases and the results were compared. Various initial cut orientation angles were considered and the effect on the propagation direction was studied. The cut propagation paths were also predicted by virtual cut extension approach.

Development of Hybrid Method for the Prediction of Internal Flow-induced Noise and Its Application to Throttle Valve Noise in an Automotive Engine

  • Cheong, Cheol-Ung;Kim, Sung-Tae;Kim, Jae-Heon;Lee, Soo-Gab
    • The Journal of the Acoustical Society of Korea
    • /
    • v.22 no.4E
    • /
    • pp.183-196
    • /
    • 2003
  • General algorithm is developed for the prediction of internal flow-induced noise. This algorithm is based on the integral formula derived by using the General Green Function, Lighthill's acoustic analogy and Curl's extension of Lighthill's. Novel approach of this algorithm is that the integral formula is so arranged as to predict frequency-domain acoustic signal at any location in a duct by using unsteady flow data in space and time, which can be provided by the Computational Fluid Dynamics Techniques. This semi-analytic model is applied to the prediction of internal aerodynamic noise from a throttle valve in an automotive engine. The predicted noise levels from the throttle valve are compared with actual measurements. This illustrative computation shows that the current method penn its generalized predictions of flow noise generated by bluff bodies and turbulence in flow ducts.