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Papers

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3

An algorithm for image removals and decompositions without inverse matrices

이덕균 | JCAM (2009)

Partial Differential Equation(PDE) based methods in image processing have been actively studied in the past few years. One of the effective methods is the method based on a total variation introduced by Rudin, Oshera and Fatemi (ROF) \cite{ROF}. This method is a well known edge preserving model and an useful tool for image removals and decompositions..........?

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2

On Elliptic Analogue of the Hardy Sums

김대열 | Bulletin of the Korean Mathematical Society v.46no.1 (2009)

Main Purpose of this paper is to define an elliptic analogue of the Hardy sums. Some results, which are related to elliptic analogue of the Hardy sums, are given

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1

Role of Angular Momentum and Cosmic Censorship in the (2+1)-Dimensional Rotating Shell Collapse

오정근,오정근 | PHYS REV D 79 (2009)

We study the gravitational collapse problem of rotating shells in three-dimensional Einstein gravity with and without a cosmological constant. Taking the exterior and interior metrics to be those of stationary metrics with asymptotically constant curvature, we solve the equations of motion for the shells from the Darmois-Israel junction conditions in the co-rotating frame. We study various collapse scenarios with arbitrary angular momentum for a variety of geometric configurations, including anti-de Sitter, de Sitter, and flat spaces. We find that the collapsing shells can form a BTZ black hole, a three-dimensional Kerr-dS spacetime, and an horizonless geometry of point masses under certain initial conditions. For pressureless dust shells, the curvature singularity is not formed due to the angular momentum barrier near the origin. However when the shell pressure is nonvanishing, we find that for all types of shells with polytropic-type equations of state (including the perfect fluid and the generalized Chaplygin gas), collapse to a naked singularity is possible under generic initial conditions. We conclude that in three dimensions angular momentum does not in general guard against violation of cosmic censorship.

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