• 제목/요약/키워드: Semi-closed

검색결과 308건 처리시간 0.028초

S-closed 공간(空間)과 RC 수렴(收斂)에 관하여 (A Note on S-closed Space and RC-convergence.)

  • 한천호
    • 산업기술연구
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    • 제5권
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    • pp.47-49
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    • 1985
  • Semi-open을 기초로 하여 만들어진 S-closed 공간의 일반적인 성질을 살펴보고 S-closed 공간과 (maximum) filterbase와의 관계를 조사하였다. 이를 바탕으로 regular closed된 cover C, regular open set인 족(族) C, rc-accumulation, (maximum) filterbase에서의 관계(關係)를 살펴 보았다. Mapping theory에서 almost-open almost-continuous map f가 almost continuous되는 것을 보였다.

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ON SUBMODULES INDUCING PRIME IDEALS OF ENDOMORPHISM RINGS

  • Bae, Soon-Sook
    • East Asian mathematical journal
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    • 제16권1호
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    • pp.33-48
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    • 2000
  • In this paper, for any ring R with an identity, in order to study prime ideals of the endomorphism ring $End_R$(M) of left R-module $_RM$, meet-prime submodules, prime radical, sum-prime submodules and the prime socle of a module are defined. Some relations of the prime radical, the prime socle of a module and the prime radical of the endomorphism ring of a module are investigated. It is revealed that meet-prime(or sum-prime) modules and semi-meet-prime(or semi-sum-prime) modules have their prime, semi-prime endomorphism rings, respectively.

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LOCAL SPECTRAL PROPERTIES OF SEMI-SHIFTS

  • Yoo, Jong-Kwang;Kim, Yong-Il
    • Journal of applied mathematics & informatics
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    • 제28권1_2호
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    • pp.499-507
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    • 2010
  • In this note, we study the local spectral properties of semi-shifts. If $T\;{\in}\;L(X)$ is a semi-shift on a complex Banach space X, then T is admissible. We also prove that if $T\;{\in}\;L(X)$ is subadmissible, then $X_T(F)\;=\;E_T(F)$ for all closed $F\;{\subseteq}\;\mathbb{C}$. In particular, every subscalar operator on a Banach space is admissible.

ON SURROGATE DUALITY FOR ROBUST SEMI-INFINITE OPTIMIZATION PROBLEM

  • Lee, Gue Myung;Lee, Jae Hyoung
    • 충청수학회지
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    • 제27권3호
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    • pp.433-438
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    • 2014
  • A semi-infinite optimization problem involving a quasi-convex objective function and infinitely many convex constraint functions with data uncertainty is considered. A surrogate duality theorem for the semi-infinite optimization problem is given under a closed and convex cone constraint qualification.

이산화탄소 배출을 최소화하는 용융탄산염 연료전지 하이브리드 시스템들의 성능 비교 (Performance Comparison of Molten Carbonate Fuel Cell Hybrid Systems Minimizing Carbon Dioxide Emissions)

  • 안지호;윤석영;김동섭
    • 한국수소및신에너지학회논문집
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    • 제28권1호
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    • pp.30-39
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    • 2017
  • Interests in fuel cell based power generation systems are on the steady rise owing to various advantages such as high efficiency, ultra low emission, and potential to achieve a very high efficiency by a synergistic combination with conventional heat engines. In this study, the performance of a hybrid system which combined a molten carbonate fuel cell (MCFC) and an indirectly fired micro gas turbine adopting carbon dioxide capture technologies was predicted. Commercialized 2.5 MW class MCFC system was used as the based system so that the result of this study could reflect practicality. Three types of ambient pressure hybrid systems were devised: one adopting post-combustion capture and two adopting oxy-combustion capture. One of the oxy-combustion based system is configured as a semi-closed type, while the other is an open cycle type. The post-combustion based system exhibited higher net power output and efficiency than the oxy-combustion based systems. However, the semi-closed system using oxy-combustion has the advantage of capturing almost all carbon dioxide.

원심펌프의 성능개선과 캐비테이션 억제에 관한 연구 (Improvement of Pump Performance and Suppression of Cavitation in a Centrifugal Pump)

  • 최영도;쿠로카와준이치
    • 한국유체기계학회 논문집
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    • 제11권1호
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    • pp.18-25
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    • 2008
  • Recent trends of a centrifugal pump are high speed in rotation and high pressure in head with high efficiency to meet the demands of industries. However, the newly developed pumps make trouble of pressure pulsation in the pumping system by performance instability of the pump. Moreover, cavitation, which is a main obstacle of high rotational speed in the pump, occurring in an impeller gives serious damages to the impeller and casing wall. The purpose of present study is not only to develop a simple method to improve pump performance but also to suppress the occurrence of cavitation in the centrifugal pump by use of J-Groove. J-Groove is a shallow groove installed on the casing wall in the meridional direction. The application of J-Groove to a centrifugal pump with a new type impeller of "semi-closed impeller" has proved its effectiveness as a useful countermeasure of the unstable pump performance and cavitation. The results show that the combination of semi-closed impeller and J-Groove can be applied successfully and improves both the pump performance and suction performance.

ON $P-\mathcal{I}$-OPEN SETS

  • Kang, Jeong-Gi;Kim, Chang-Su
    • 호남수학학술지
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    • 제31권3호
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    • pp.293-314
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    • 2009
  • The notions of pre-local function, semi-local functions and ${\alpha}$-local functions with respect to a topology and an ideal are introduced, and several properties are investigated. Also, the concept of $P-\mathcal{I}$-open sets and $P-\mathcal{I}$-closed sets in ideal topological spaces are discussed. Relations between $\mathcal{I}$-open sets and $P-\mathcal{I}$-open sets are provided, and several properties related to $P-\mathcal{I}$-open sets, pre-local functions, semi-local functions and ${\alpha}$-local functions with respect to a topology and an ideal are investigated.

Corrigendum to "On Soft Topological Space via Semi-open and Semi-closed Soft Sets, Kyungpook Mathematical Journal, 54(2014), 221-236"

  • Al-shami, Tareq Mohammed
    • Kyungpook Mathematical Journal
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    • 제58권3호
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    • pp.583-588
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    • 2018
  • In this manuscript, we show that the equality relations of the two assertions (ix) and (x) of [Theorem 2.11, p.p.224] in [3] do not hold in general, by giving a concrete example. Also, we illustrate that Example 6.3, Example 6.7, Example 6.11, Example 6.15 and Example 6.20 do not satisfy a soft semi $T_0$-space, a soft semi $T_1$-space, a soft semi $T_2$-space, a soft semi $T_3$-space and a soft semi $T_4$-space, respectively. Moreover, we point out that the three results obtained in [3] which related to soft subspaces are false, by presenting two examples. Finally, we construct an example to illuminate that Theorem 6.18 and Remark 6.21 made in [3] are not valid in general.

Continuity of Higher Derivations on Some Semiprime Banach Algebras

  • Lee, Young-Whan
    • 충청수학회지
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    • 제2권1호
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    • pp.37-44
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    • 1989
  • In this paper, it is shown that automatic continuity of derivations on some semi prime Banach algebras can be extended to higher derivations. In particular, we show that if every prime ideal is closed in a commutative semi prime Banach algebra then every higher derivation on it is continuous.

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ON THE SEMI CONTINUOUS FUNCTIONS WITH THE OPEN PROPERTY

  • Kim, Seungwook
    • Korean Journal of Mathematics
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    • 제13권2호
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    • pp.241-248
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    • 2005
  • Some of the generalized continuous functions and their basic properties are introduced in concern with the cover theory. The open property of a function is a crucial tool for the survey of this area.

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