• 제목/요약/키워드: Seifert curves

검색결과 4건 처리시간 0.021초

PRIMITIVE/SEIFERT KNOTS WHICH ARE NOT TWISTED TORUS KNOT POSITION

  • Kang, Sungmo
    • 호남수학학술지
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    • 제35권4호
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    • pp.775-791
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    • 2013
  • The twisted torus knots and the primitive/Seifert knots both lie on a genus 2 Heegaard surface of $S^3$. In [5], J. Dean used the twisted torus knots to provide an abundance of examples of primitive/Seifert knots. Also he showed that not all twisted torus knots are primitive/Seifert knots. In this paper, we study the other inclusion. In other words, it shows that not all primitive/Seifert knots are twisted torus knot position. In fact, we give infinitely many primitive/Seifert knots that are not twisted torus knot position.

TWISTED TORUS KNOTS WITH GRAPH MANIFOLD DEHN SURGERIES

  • Kang, Sungmo
    • 대한수학회보
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    • 제53권1호
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    • pp.273-301
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    • 2016
  • In this paper, we classify all twisted torus knots which are doubly middle Seifert-fibered. Also we show that all of these knots possibly except a few admit Dehn surgery producing a non-Seifert-fibered graph manifold which consists of two Seifert-fibered spaces over the disk with two exceptional fibers, glued together along their boundaries. This provides another infinite family of knots in $S^3$ admitting Dehn surgery yielding such manifolds as done in [5].

KNOTS IN S3 ADMITTING GRAPH MANIFOLD DEHN SURGERIES

  • Kang, Sungmo
    • 대한수학회지
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    • 제51권6호
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    • pp.1221-1250
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    • 2014
  • In this paper, we construct infinite families of knots in $S^3$ which admit Dehn surgery producing a graph manifold which consists of two Seifert-fibered spaces over the disk with two exceptional fibers, glued together along their boundaries. In particular, we show that for any natural numbers a, b, c, and d with $a{\geq}3$ and $b,c,d{\geq}2$, there are knots in $S^3$ admitting a graph manifold Dehn surgery consisting of two Seifert-fibered spaces over the disk with two exceptional fibers of indexes a, b, and c, d, respectively.

On Adaptation to Sparse Design in Bivariate Local Linear Regression

  • Hall, Peter;Seifert, Burkhardt;Turlach, Berwin A.
    • Journal of the Korean Statistical Society
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    • 제30권2호
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    • pp.231-246
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    • 2001
  • Local linear smoothing enjoys several excellent theoretical and numerical properties, an in a range of applications is the method most frequently chosen for fitting curves to noisy data. Nevertheless, it suffers numerical problems in places where the distribution of design points(often called predictors, or explanatory variables) is spares. In the case of univariate design, several remedies have been proposed for overcoming this problem, of which one involves adding additional ″pseudo″ design points in places where the orignal design points were too widely separated. This approach is particularly well suited to treating sparse bivariate design problem, and in fact attractive, elegant geometric analogues of unvariate imputation and interpolation rules are appropriate for that case. In the present paper we introduce and develop pseudo dta rules for bivariate design, and apply them to real data.

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