• 제목/요약/키워드: O-minimal

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SPACELIKE MAXIMAL SURFACES, TIMELIKE MINIMAL SURFACES, AND BJÖRLING REPRESENTATION FORMULAE

  • Kim, Young-Wook;Koh, Sung-Eun;Shin, Hea-Yong;Yang, Seong-Deog
    • Journal of the Korean Mathematical Society
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    • v.48 no.5
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    • pp.1083-1100
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    • 2011
  • We show that some class of spacelike maximal surfaces and timelike minimal surfaces match smoothly across the singular curve of the surfaces. Singular Bj$\"{o}$rling representation formulae for generalized spacelike maximal surfaces and for generalized timelike minimal surfaces play important roles in the explanation of this phenomenon.

A THEOREM OF G-INVARIANT MINIMAL HYPERSURFACES WITH CONSTANT SCALAR CURVATURES IN Sn+1

  • So, Jae-Up
    • Honam Mathematical Journal
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    • v.31 no.3
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    • pp.381-398
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    • 2009
  • Let $G\;=\;O(k){\times}O(k){\times}O(q)$ and let $M^n$ be a closed G-invariant minimal hypersurface with constant scalar curvature in $S^{n+1}$. Then we obtain a theorem: If $M^n$ has 2 distinct principal curvatures at some point p, then the square norm of the second fundamental form of $M^n$, S = n.

ON G-INVARIANT MINIMAL HYPERSURFACES WITH CONSTANT SCALAR CURVATURE IN S5

  • So, Jae-Up
    • Communications of the Korean Mathematical Society
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    • v.17 no.2
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    • pp.261-278
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    • 2002
  • Let G = O(2) $\times$ O(2) $\times$O(2) and let M$^4$be closed G-invariant minimal hypersurface with constant scalar curvature in S$^{5}$ . If M$^4$has 2 distinct principal curvatures at some point, then S = 4. Moreover, if S > 4, then M$^4$does not have simple principal curvatures everywhere.

AN ALGORITHM FOR GENERATING MINIMAL CUTSETS OF UNDIRECTED GRAPHS

  • Shin, Yong-Yeonp;Koh, Jai-Sang
    • Journal of applied mathematics & informatics
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    • v.5 no.3
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    • pp.771-784
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    • 1998
  • In this paper we propose an algorithm for generating minimal cutsets of undirected graphs. The algorithm is based on a blocking mechanism for generating every minimal cutest ex-actly once. The algorithm has an advantage of not requiring any preliminary steps to find minimal cutsets. The algorithm generates minimal cutsets at O(e.n) {where e,n = number of (edges, vertices) in the graph} computational effort per cutset. Formal proofs of the algorithm are presented.

HEWITT REALCOMPACTIFICATIONS OF MINIMAL QUASI-F COVERS

  • Kim, Chang Il;Jung, Kap Hun
    • Korean Journal of Mathematics
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    • v.10 no.1
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    • pp.45-51
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    • 2002
  • Observing that a realcompactification Y of a space X is Wallman if and only if for any non-empty zero-set Z in Y, $Z{\cap}Y{\neq}{\emptyset}$, we will show that for any pseudo-Lindel$\ddot{o}$f space X, the minimal quasi-F $QF({\upsilon}X)$ of ${\upsilon}X$ is Wallman and that if X is weakly Lindel$\ddot{o}$, then $QF({\upsilon}X)={\upsilon}QF(X)$.

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Fast Training of Structured SVM Using Fixed-Threshold Sequential Minimal Optimization

  • Lee, Chang-Ki;Jang, Myung-Gil
    • ETRI Journal
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    • v.31 no.2
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    • pp.121-128
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    • 2009
  • In this paper, we describe a fixed-threshold sequential minimal optimization (FSMO) for structured SVM problems. FSMO is conceptually simple, easy to implement, and faster than the standard support vector machine (SVM) training algorithms for structured SVM problems. Because FSMO uses the fact that the formulation of structured SVM has no bias (that is, the threshold b is fixed at zero), FSMO breaks down the quadratic programming (QP) problems of structured SVM into a series of smallest QP problems, each involving only one variable. By involving only one variable, FSMO is advantageous in that each QP sub-problem does not need subset selection. For the various test sets, FSMO is as accurate as an existing structured SVM implementation (SVM-Struct) but is much faster on large data sets. The training time of FSMO empirically scales between O(n) and O($n^{1.2}$), while SVM-Struct scales between O($n^{1.5}$) and O($n^{1.8}$).

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SOCLE ELEMENTS OF NON-LEVEL ARTINIAN ALGEBRAS

  • SHIN YONG SU
    • Journal of applied mathematics & informatics
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    • v.17 no.1_2_3
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    • pp.605-614
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    • 2005
  • We show that an Artinian O-sequence $h_0,h_1,{\cdots},h_{d-1},h_d\;=\;h_{d-1},h_{d+l}\;>\;h_d$ of codimension 3 is not level when $h_{d-1}\;=\;h_d\;=\;d + i\;and\;h{d+1}\;=\;d+(i+1)\;for\;i\;=\;1,\;2,\;and\;3$, which is a partial answer to the question in [9]. We also introduce an algorithm for finding noncancelable Betti numbers of minimal free resolutions of all possible Artinian O-sequences based on the theorem of Froberg and Laksov in [2].