• Title/Summary/Keyword: NEAR

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ON STRONG FORM OF REDUCEDNESS

  • Cho, Yong-Uk
    • Honam Mathematical Journal
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    • v.30 no.1
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    • pp.1-7
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    • 2008
  • A near-ring N is said to be strongly reduced if, for a ${\in}$ N, $a^2{\in}N_c$ implies $a{\in}N_c$, where $N_c$ denotes the constant part of N. We investigate some properties of strongly reduced near-rings and apply those to the study of left strongly regular near-rings. Finally we classify all reduced and strongly reduced near-rings of order ${\leq}$ 7 using the description given in J. R. Clay [1].

A STUDY ON STRONGLY REDUCED AND REGULAR NEAR-RINGS

  • Cho, Yong-Uk
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2008.04a
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    • pp.125-126
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    • 2008
  • A near-ring N is called strongly reduced if, for a ${\epsilon}$ N, $a^2\;{\epsilon}\;N_c$ implies a ${\epsilon}\;N_c$, where $N_c$ denotes the constant part of N. We investigate some properties of strongly reduced near-rings and apply those to the study of left strongly regular near-rings. Finally we classify some reduced, and strongly reduced near-rings.

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Observations on the Near-Nozzle Behavior of an Unsteady Fuel Spray (노즐부근에서의 비정상분무 거동)

  • 구자예;정흥철
    • Transactions of the Korean Society of Automotive Engineers
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    • v.2 no.4
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    • pp.100-111
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    • 1994
  • Observations on the near-nozzle behavior of an unsteady fuel spray through single cylindrical hole nozzle were made by phase Doopler anemometer and microphotographs. At the edge of the spray, droplet velocity peaked during needle opening and closing. Droplet sizes tended to be small on the edge of spray. The near-nozzle spray angle taken from the microphotographs was time-dependent, even though it increased with gas-to-liquid density ratio as expected. The near-nozzle spray angle was the greatest on the initial stage and decreased to a relatively constant value after about one third of the total injection duration regardless of the ambient gas conditions, even in the near-vaccum condition. The wider near-nozzle spray angle in the early stage is due to the flow characteristics inside the nozzle rather than aerodynamic interactions. However, once the spray was established, aerodynamic interactions are essential in the near-nozzle atomization.

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Seismic response of nuclear containment structures due to recorded and simulated near-fault ground motions

  • Kurtulus Soyluk;Hamid Sadegh-Azar;Dersu Yilmaz
    • Structural Engineering and Mechanics
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    • v.87 no.5
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    • pp.431-450
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    • 2023
  • In this study, it is intended to perform nonlinear time-history analyses of nuclear power plant structures (NPP) under near-fault earthquakes showing directivity pulse and fling-step characteristics. Simulation procedures based on cycloidal pulse and far-fault ground motions are also used to simulate near-fault motions showing forward-directivity and fling-step characteristics and the structural responses are compared with those of the recorded near-fault ground motions. Because it is aimed to determine specifically the pulse type characteristics of near-fault ground motions on NPPs, all the ground motions are normalized to have a PGA of 0.3 g. Depending on the obtained results it can be underlined that although near-fault ground motion has the potential to cause damage mostly on structural systems having larger periods, it may also have noticeable effects on the responses of rigid structures, like NPP containment buildings. On the other hand, simulated near-fault motions can help us to get an insight into the near-fault mechanism as well as an approximate visualization of the structural responses under near-fault earthquakes.

The Understanding of Determination of Horizontal Centration Point of Single-vision Reading Glasses (단초점 근용 안경의 수평방향 설계점 결정에 대한 이해)

  • Kim, Min Ho;Kim, Hyun-Il
    • Journal of Korean Ophthalmic Optics Society
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    • v.14 no.2
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    • pp.1-8
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    • 2009
  • Purpose: The purpose of this study is to compare degrees of asthenopia in after wearing of dispensed reading glasses with different criterion of P.D. Methods: The person who has minus near correction power (distance correction value (-)) is compared to the degree of asthenopia by wearing of dispensed reading glasses with near P.D(-B) and distance P.D. The person who has plus near correction power is compared to degree of asthenopia by wearing of dispensed reading glasses with near P.D-B, distance P.D, near P.D-A. The "Near-P.D-A" means reduced optical centre distance of reading glasses of positive correction value at which the same effect of prism B.O through near visual point in distance glasses exist at near visual point in reading glasses. Results: When near correction value is (-), dispensed reading glasses with distance P.D have caused less asthenopia than dispensed glasses with near P.D-B. When the near correction value is (+), we cannot confirm that which P.D is more useful for reading glasses. As a result of this study, dispensed reading glasses with near P.D-A have caused less asthenopia than another criterion of P.D. Conclusion: The effect of prism B.I through a near visual point in distance glasses ((-) correction value) reduce convergence demand. Therefore (-) correction value-reading glasses support convergence in near vision, because the effect of prism B.I of reading glasses is smaller than that of distance glasses. When the near correction value is (+), centration points can be determined by one of near P.D-A, near P.D-B, distance P.D.

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A STUDY ON BAER AND P.P. NEAR-RINGS

  • Cho, Yong-Uk
    • East Asian mathematical journal
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    • v.16 no.1
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    • pp.105-110
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    • 2000
  • Baer rings were introduced by Kaplansky [3] to abstract various properties of rings of operators on a Hilbert spaces. On the other hand, p.p. rings were introduced by A. Hattori [2] to study the torsion theory. In this paper we introduce Baer near-rings and p.p. near-rings and study some properties and give some examples.

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A STUDY ON WEAK BI-IDEALS OF NEAR-RINGS

  • Cho, Yong-Uk
    • East Asian mathematical journal
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    • v.24 no.2
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    • pp.145-149
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    • 2008
  • From the notion of bi-ideals in near-rings, various generalizations of regularity conditions have been studied. In this paper, we generalize further the notion of bi-ideals and introduce the notion of weak bi-ideals in near-rings and obtain some characterizations using this concept in left self distributive near-rings.

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A KUROSH-AMITSUR LEFT JACOBSON RADICAL FOR RIGHT NEAR-RINGS

  • Rao, Ravi Srinivasa;Prasad, K.Siva
    • Bulletin of the Korean Mathematical Society
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    • v.45 no.3
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    • pp.457-466
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    • 2008
  • Let R be a right near-ring. An R-group of type-5/2 which is a natural generalization of an irreducible (ring) module is introduced in near-rings. An R-group of type-5/2 is an R-group of type-2 and an R-group of type-3 is an R-group of type-5/2. Using it $J_{5/2}$, the Jacobson radical of type-5/2, is introduced in near-rings and it is observed that $J_2(R){\subseteq}J_{5/2}(R){\subseteq}J_3(R)$. It is shown that $J_{5/2}$ is an ideal-hereditary Kurosh-Amitsur radical (KA-radical) in the class of all zero-symmetric near-rings. But $J_{5/2}$ is not a KA-radical in the class of all near-rings. By introducing an R-group of type-(5/2)(0) it is shown that $J_{(5/2)(0)}$, the corresponding Jacobson radical of type-(5/2)(0), is a KA-radical in the class of all near-rings which extends the radical $J_{5/2}$ of zero-symmetric near-rings to the class of all near-rings.

ON NEAR-RINGS WITH STRONG REGULARITY

  • Cho, Yong-Uk
    • The Pure and Applied Mathematics
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    • v.17 no.2
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    • pp.131-136
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    • 2010
  • Throught this paper, we will investigate some properties of left regular and strongly reduced near-rings. Mason introduced the notion of left regularity and he characterized left regular zero-symmetric unital near-rings. Also, this concept have been studied by several authors. The purpose of this paper is to find some characterizations of the strong reducibility in near-rings, and the strong regularity in near-rings which are closely related with strongly reduced near-rings.