• Title/Summary/Keyword: convexity

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BANACH SPACE WITH PROPERTY (β) WHICH CANNOT BE RENORMED TO BE B-CONVEX

  • Cho, Kyugeun;Lee, Chongsung
    • Korean Journal of Mathematics
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    • v.14 no.2
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    • pp.161-168
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    • 2006
  • In this paper, we study property (${\beta}$) and B-convexity in reflexive Banach spaces. It is shown that k-uniform convexity implies B-convexity and property (${\beta}$). We also show that there is a Banach space with property (${\beta}$) which cannot be equivalently renormed to be B-convex.

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THE CONBITION OF $\zeta$-CONVEXITY

  • Mok, Jin-Sik
    • Journal of applied mathematics & informatics
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    • v.9 no.2
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    • pp.787-791
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    • 2002
  • The aim of this paper is to study the condition of $\zeta$-convexity. We will give examples of $\zeta$-functions in filbert spaces and in non-UMD-spaces.

A LOWER BOUND FOR THE CONVEXITY NUMBER OF SOME GRAPHS

  • Kim, Byung-Kee
    • Journal of applied mathematics & informatics
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    • v.14 no.1_2
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    • pp.185-191
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    • 2004
  • Given a connected graph G, we say that a set EC\;{\subseteq}\;V(G)$ is convex in G if, for every pair of vertices x, $y\;{\in}\;C$, the vertex set of every x - y geodesic in G is contained in C. The convexity number of G is the cardinality of a maximal proper convex set in G. In this paper, we show that every pair k, n of integers with $2\;{\leq}k\;{\leq}\;n\;-\;1$ is realizable as the convexity number and order, respectively, of some connected triangle-free graph, and give a lower bound for the convexity number of k-regular graphs of order n with n > k+1.

A Cerebral Convexity Arachnoid Cyst Associated with a Separate Middle Fossa Arachnoid Cyst-Misdiagnosed as Subdural Hygroma as a Consequence of Rupture of an Arachnoid Cyst - Case Report - (경막하 수종으로 오인된 중두개와 지주막 낭종을 동반한 대뇌궁륭부 지주막 낭종 - 증 례 보 고 -)

  • Kim, Seong-Rim;Park, Hae Kwan;Park, Sung Chan;Rha, Hyung Kyun;Kang, Joon Ki;Choi, Chang Rak
    • Journal of Korean Neurosurgical Society
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    • v.30 no.sup2
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    • pp.340-343
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    • 2001
  • Arachnoid cysts are defined as duplicated arachnoids and their splitting with congenital, intra-arachnoid, and leptomeningeal malformations. They are most commonly located in the middle cranial fossa followed by suprasellar and quadrigeminal cisterns, posterior fossa, and very rare in cerebral convexities. They are often ruptured by trauma or spontaneously and cause subdural hygroma or subdural hematoma. Authors report a case of a 32-year-old woman with a convexity arachnoid cyst mimicking subdural hygroma associated with a separate middle fossa arachnoid cyst. Preoperatively, the convexity arachnoid cyst was misinterpreted as subdural hygroma resulted from a ruptured middle fossa cyst. The patient underwent craniotomy and cyst fenestration into the basal cistern. Two separate arachnoid cysts were found in the cerebral convexity and middle cranial fossa during the operation. Finally, cysts were resolved and she was discharged without any complication.

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Bounding Methods for Markov Processes Based on Stochastic Monotonicity and Convexity (확률적 단조성과 콘벡스성을 이용한 마코프 프로세스에서의 범위한정 기법)

  • Yoon, Bok-Sik
    • Journal of Korean Institute of Industrial Engineers
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    • v.17 no.1
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    • pp.117-126
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    • 1991
  • When {X(t), t ${\geq}$ 0} is a Markov process representing time-varying system states, we develop efficient bounding methods for some time-dependent performance measures. We use the discretization technique for stochastically monotone Markov processes and a combination of discretization and uniformization for Markov processes with the stochastic convexity(concavity) property. Sufficient conditions for stochastic monotonocity and stochastic convexity of a Markov process are also mentioned. A simple example is given to demonstrate the validity of the bounding methods.

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HARDY SPACE OF LOMMEL FUNCTIONS

  • Yagmur, Nihat
    • Bulletin of the Korean Mathematical Society
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    • v.52 no.3
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    • pp.1035-1046
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    • 2015
  • In this work we present some geometric properties (like star-likeness and convexity of order ${\alpha}$ and also close-to-convexity of order ($1+{\alpha}$)/2) for normalized of Lommel functions of the first kind. In order to prove our main results, we use the technique of differential subordinations and some inequalities. Furthermore, we present some applications of convexity involving Lommel functions associated with the Hardy space of analytic functions, i.e., we obtain conditions for the function $h_{{\mu},{\upsilon}}(z)$ to belong to the Hardy space $H^p$.

β-PRECONVEX SETS ON PRECONVEXITY SPACES

  • Min, Won-Keun
    • Communications of the Korean Mathematical Society
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    • v.25 no.1
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    • pp.105-110
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    • 2010
  • In this paper, we introduce the concept of $\beta$-preconvex sets on preconvexity spaces. We study some properties for $\beta$-preconvex sets by using the co-convexity hull and the convexity hull. Also we introduce and study the concepts of ${\beta}c$-convex function and $\beta^*c$-convex function.

INEQUALITIES OF EXTENDED (p, q)-BETA AND CONFLUENT HYPERGEOMETRIC FUNCTIONS

  • Mubeen, Shahid;Nisar, Kottakkaran Sooppy;Rahman, Gauhar;Arshad, Muhammad
    • Honam Mathematical Journal
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    • v.41 no.4
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    • pp.745-756
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    • 2019
  • In this paper, we establish the log convexity and Turán type inequalities of extended (p, q)-beta functions. Likewise, we present the log-convexity, the monotonicity and Turán type inequalities for extended (p, q)-confluent hypergeometric function by utilizing the inequalities of extended (p, q)-beta functions.