• Title/Summary/Keyword: G-flat modules

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ON GI-FLAT MODULES AND DIMENSIONS

  • Gao, Zenghui
    • Journal of the Korean Mathematical Society
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    • v.50 no.1
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    • pp.203-218
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    • 2013
  • Let R be a ring. A right R-module M is called GI-flat if $Tor^R_1(M,G)=0$ for every Gorenstein injective left R-module G. It is shown that GI-flat modules lie strictly between flat modules and copure flat modules. Suppose R is an $n$-FC ring, we prove that a finitely presented right R-module M is GI-flat if and only if M is a cokernel of a Gorenstein flat preenvelope K ${\rightarrow}$ F of a right R-module K with F flat. Then we study GI-flat dimensions of modules and rings. Various results in [6] are developed, some new characterizations of von Neumann regular rings are given.

COPURE PROJECTIVE MODULES OVER FGV-DOMAINS AND GORENSTEIN PRÜFER DOMAINS

  • Shiqi Xing
    • Bulletin of the Korean Mathematical Society
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    • v.60 no.4
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    • pp.971-983
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    • 2023
  • In this paper, we prove that a domain R is an FGV-domain if every finitely generated torsion-free R-module is strongly copure projective, and a coherent domain is an FGV-domain if and only if every finitely generated torsion-free R-module is strongly copure projective. To do this, we characterize G-Prüfer domains by G-flat modules, and we prove that a domain is G-Prüfer if and only if every submodule of a projective module is G-flat. Also, we study the D + M construction of G-Prüfer domains. It is seen that there exists a non-integrally closed G-Prüfer domain that is neither Noetherian nor divisorial.

GORENSTEIN-INJECTORS, GORENSTEIN-FLATORS

  • Gu, Qinqin;Zhu, Xiaosheng;Zhou, Wenping
    • Journal of the Korean Mathematical Society
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    • v.47 no.4
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    • pp.691-704
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    • 2010
  • Over a ring R, let $P_R$ be a finitely generated projective right R-module. Then we define the G-injector (G-projector) if $P_R$ preservers Gorenstein injective modules (Gorenstein projective modules), the Gflator if $P_R$ preservers Gorenstein flat modules. G-injector (G-flator) and G-injector are characterized focus primarily on the cases where R is a Gorenstein ring, and under this condition we also study the relations between the injector (projector, flator) and the G-injector (G-projector, G-flator). Over any ring we also give the characteristics of G-injector (G-flator) by the Gorenstein injective (Gorenstein flat) dimensions of modules.

(𝓕, 𝓐)-GORENSTEIN FLAT HOMOLOGICAL DIMENSIONS

  • Becerril, Victor
    • Journal of the Korean Mathematical Society
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    • v.59 no.6
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    • pp.1203-1227
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    • 2022
  • In this paper we develop the homological properties of the Gorenstein (𝓛, 𝓐)-flat R-modules 𝓖𝓕(𝓕(R),𝓐) proposed by Gillespie, where the class 𝓐 ⊆ Mod(Rop) sometimes corresponds to a duality pair (𝓛, 𝓐). We study the weak global and finitistic dimensions that come with the class 𝓖𝓕(𝓕(R),𝓐) and show that over a (𝓛, 𝓐)-Gorenstein ring, the functor - ⊗R - is left balanced over Mod(Rop) × Mod(R) by the classes 𝓖𝓕(𝓕(Rop),𝓐) × 𝓖𝓕(𝓕(R),𝓐). When the duality pair is (𝓕(R), 𝓕𝓟Inj(Rop)) we recover the G. Yang's result over a Ding-Chen ring, and we see that is new for (Lev(R), AC(Rop)) among others.

Seperate Driving System For Large Area X-ray Detector In Radiology (대면적 X-ray 검출기를 위한 분할 구동 시스템)

  • Lee, D.G.;Park, J.K.;Kim, D.H.;Nam, S.H.;Ahn, S.H.;Park, H.D.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.11a
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    • pp.388-391
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    • 2003
  • The properties of these detectors can be controlled by electronics and exposure conditions. Flat-panel detectors for digital diagnostic imaging convert incident x-ray images to charge images. Flat panel detectors gain more interest real time medical x-ray imaging. Active area of flat panel detector is $14{\times}17$ inch. Detector is based on a $2560{\times}3072$ away of photoconductor and TFT pixels. X-ray conversion layer is deposited upper TFT array flat panel with a 500m by thermal deposition technology. Thickness uniformity of this layer is made of thickness control technology(5%) of thermal deposition system. Each $139m{\times}139m$ pixel is made of thin film transistor technology, a storage capacitor and charge collection electrode having geometrical fill factor of 86%. Using the separate driving system of two dimensional mosaic modules for large area, that is able to 4.2 second per frame. Imaging performance is suited for digital radiography imaging substitute by conventional radiography film system..

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