• Title/Summary/Keyword: metrics

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CONHARMONIC TRANSFORMATION AND CRITICAL RIEMANNIAN METRICS

  • Byung Hak Kim;In Bae Kim;Sun Mi Lee
    • Communications of the Korean Mathematical Society
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    • v.12 no.2
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    • pp.347-354
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    • 1997
  • The conharmonic transforamtion is a conformal transformation which satisfies a specified differential equation. Such a transformation was defined by Y. Ishi and we generalize his results. In particular, we obtain a necessary and sufficient condition for the invariance of critical Riemannian metrics under the conharmonic transformation.

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LOCALLY PRODUCT INDEFINITE KAEHLERIAN METRICS WITH VANISHING CONFORMAL CURVATURE TENSOR FIELD

  • Kwon, Jung-Hwan;Sohn, Won-Ho
    • Bulletin of the Korean Mathematical Society
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    • v.29 no.1
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    • pp.25-29
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    • 1992
  • The purpose of this paper is to study indefinite Kaehlerian metrics with vanishing conformal curvature tensor field. In the first section, a brief summary of the complex version of indefinite Kaehlerian manifolds is recalled and we introduce the conformal curvature tensor field on an indefinite Kaehlerian manifold. In section 2, we obtain the theorem for indefinite Kaehlerian metrics with vanishing conformal curvature tensor field.

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HIGHER ORDER ASYMPTOTIC BEHAVIOR OF CERTAIN KÄHLER METRICS AND UNIFORMIZATION FOR STRONGLY PSEUDOCONVEX DOMAINS

  • Joo, Jae-Cheon;Seo, Aeryeong
    • Journal of the Korean Mathematical Society
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    • v.52 no.1
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    • pp.113-124
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    • 2015
  • We provide some relations between CR invariants of boundaries of strongly pseudoconvex domains and higher order asymptotic behavior of certain complete K$\ddot{a}$hler metrics of given domains. As a consequence, we prove a rigidity theorem of strongly pseudoconvex domains by asymptotic curvature behavior of metrics.

ON GENERAL (α, β)-METRICS WITH ISOTROPIC E-CURVATURE

  • Gabrani, Mehran;Rezaei, Bahman
    • Journal of the Korean Mathematical Society
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    • v.55 no.2
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    • pp.415-424
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    • 2018
  • General (${\alpha},\;{\beta}$)-metrics form a rich and important class of Finsler metrics. In this paper, we obtain a differential equation which characterizes a general (${\alpha},\;{\beta}$)-metric with isotropic E-curvature, under a certain condition. We also solve the equation in a particular case.

A NEW CLASS OF RIEMANNIAN METRICS ON TANGENT BUNDLE OF A RIEMANNIAN MANIFOLD

  • Baghban, Amir;Sababe, Saeed Hashemi
    • Communications of the Korean Mathematical Society
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    • v.35 no.4
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    • pp.1255-1267
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    • 2020
  • The class of isotropic almost complex structures, J𝛿,𝜎, define a class of Riemannian metrics, g𝛿,𝜎, on the tangent bundle of a Riemannian manifold which are a generalization of the Sasaki metric. This paper characterizes the metrics g𝛿,0 using the geometry of tangent bundle. As a by-product, some integrability results will be reported for J𝛿,𝜎.

An effective metrics program for software process improvement (소프트웨어 프로세스 개선을 위한 측정지표(Metrics) 활용방안)

  • 이장훈;김영균;최영길;신광식
    • Proceedings of the Korean Information Science Society Conference
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    • 2003.10b
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    • pp.241-243
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    • 2003
  • 소프트웨어 프로젝트가 더욱 다양화되고 복잡화 되면서 성공적인 프로젝트 수행을 위해서는 프로세스 개선활동이 필수적이라는 인식이 급속히 확산되고 있다. 성공적인 프로세스 개선을 위해서는 프로세스 개선활동을 지원하기 위한 측정활동이 병행되어야 한다. 그러나 실무에서는 측정지표(Metrics)를 활용하는 것에 많은 어려움을 갖고 있는 것이 현실이다. 따라서 본 논문에서는 정량적인 프로세스 및 프로젝트 관리를 위한 효과적인 측정지표 및 활용방안을 수립함으로써 측정활동 체계를 확립하고 실무에 적용할 수 있도록 가이드 하였다.

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SOME REMARKS ON THURSTON METRIC AND HYPERBOLIC METRIC

  • Sun, Zongliang
    • Bulletin of the Korean Mathematical Society
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    • v.53 no.2
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    • pp.399-410
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    • 2016
  • In this paper, we study the relations between the Thurston metric and the hyperbolic metric on a closed surface of genus $g{\geq}2$. We show a rigidity result which says if there is an inequality between the marked length spectra of these two metrics, then they are isotopic. We obtain some inequalities on length comparisons between these metrics. Besides, we show certain distance distortions under conformal graftings, with respect to the $Teichm{\ddot{u}}ller$ metric, the length spectrum metric and Thurston's asymmetric metrics.

SOME RIGIDITY CHARACTERIZATIONS OF EINSTEIN METRICS AS CRITICAL POINTS FOR QUADRATIC CURVATURE FUNCTIONALS

  • Huang, Guangyue;Ma, Bingqing;Yang, Jie
    • Bulletin of the Korean Mathematical Society
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    • v.57 no.6
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    • pp.1367-1382
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    • 2020
  • We study rigidity results for the Einstein metrics as the critical points of a family of known quadratic curvature functionals involving the scalar curvature, the Ricci curvature and the Riemannian curvature tensor, characterized by some pointwise inequalities involving the Weyl curvature and the traceless Ricci curvature. Moreover, we also provide a few rigidity results for locally conformally flat critical metrics.

On Semi C-Reducibility of General (α, β) Finsler Metrics

  • Tiwari, Bankteshwar;Gangopadhyay, Ranadip;Prajapati, Ghanashyam Kr.
    • Kyungpook Mathematical Journal
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    • v.59 no.2
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    • pp.353-362
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    • 2019
  • In this paper, we study general (${\alpha}$, ${\beta}$) Finsler metrics and prove that every general (${\alpha}$, ${\beta}$)-metric is semi C-reducible but not C2-like. As a consequence of this result we prove that every general (${\alpha}$, ${\beta}$)-metric satisfying the Ricci flow equation is Einstein.

Understanding Channel-diversity Oriented Routing Metrics for Multicast in Wireless Mesh Networks

  • Gao, Hui;Nam, Ji-seung
    • Proceedings of the Korea Information Processing Society Conference
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    • 2013.05a
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    • pp.418-420
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    • 2013
  • Issues on design of routing scheme and routing metric for multicast in multi-channel multi-radio (MCMR) wireless mesh networks (WMNs) are discussed. Emphasis is placed on channel-diversity oriented routing metrics. From case study the conclusion to be drawn is that the key for design of channel-diversity oriented routing metrics is how to construct an optimization function to quantify interdependence between channel assignment and multicast routing throughput.