• Nuclear Engineering and Technology
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• v.28 no.3
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• pp.320-330
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• 1996

The streaming rays(SR) method is improved and extended to multigroup, anisotropic scattering, and three-dimensional angular space(x-y-z(infinite))problems. This method is applied to the shielding problems in which the ray effect occurs seriously. For verification, the results of MORSE-CG code are used as reference solution and the results of TWODANT code are compared. The results show that solutions of the SR method are much better than those of the TWODANT code and are in good agreement with those of the MORSE-CG code. Also, to reduce computing time, two acceleration algorithms are implemented in the SR method : the standard coarse-mesh rebalance and a new angular two-grid acceleration.

• Kyungpook Mathematical Journal
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• v.49 no.2
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• pp.255-263
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• 2009

For an endomorphism ${\alpha}$ of R, in [1], a module $M_R$ is called ${\alpha}$-compatible if, for any $m{\in}M$ and $a{\in}R$, ma = 0 iff $m{\alpha}(a)$ = 0, which are a generalization of ${\alpha}$-reduced modules. We study on the relationship between the quasi-Baerness and p.q.-Baer property of a module MR and those of the polynomial extensions (including formal skew power series, skew Laurent polynomials and skew Laurent series). As a consequence we obtain a generalization of [2] and some results in [9]. In particular, we show: for an ${\alpha}$-compatible module $M_R$ (1) $M_R$ is p.q.-Baer module iff $M[x;{\alpha}]_{R[x;{\alpha}]}$ is p.q.-Baer module. (2) for an automorphism ${\alpha}$ of R, $M_R$ is p.q.-Baer module iff $M[x,x^{-1};{\alpha}]_{R[x,x^{-1};{\alpha}]}$ is p.q.-Baer module.

• Kyungpook Mathematical Journal
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• v.60 no.1
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• pp.53-69
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• 2020

Let (A, M) ⊂ (B, N) be commutative quasi-local rings. We consider the property that there exists a ring D such that A ⊆ D ⊂ B and the extension D ⊂ B is inert. Examples show that the number of such D may be any non-negative integer or infinite. The existence of such D does not imply M ⊆ N. Suppose henceforth that M ⊆ N. If the field extension A/M ⊆ B/N is algebraic, the existence of such D does not imply that B is integral over A (except when B has Krull dimension 0). If A/M ⊆ B/N is a minimal field extension, there exists a unique such D, necessarily given by D = A + N (but it need not be the case that N = MB). The converse fails, even if M = N and B/M is a finite field.

• The Pure and Applied Mathematics
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• v.10 no.3
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• pp.177-183
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• 2003

In this paper, we initiate the study of some annihilator conditions on polynomials which were used by Kaplansky [Rings of operators. W. A. Benjamin, Inc., New York, 1968] to abstract the algebra of bounded linear operators on a Hilbert spaces with Baer condition. On the other hand, p.p.-rings were introduced by Hattori [A foundation of torsion theory for modules over general rings. Nagoya Math. J. 17 (1960) 147-158] to study the torsion theory. The purpose of this paper is to introduce the near-rings with Baer condition and near-rings with p.p. condition which are somewhat different from ring case, and to extend a results of Armendariz [A note on extensions of Baer and P.P.-rings. J. Austral. Math. Soc. 18 (1974), 470-473] and Jøndrup [p.p. rings and finitely generated flat ideals. Proc. Amer. Math. Soc. 28 (1971) 431-435].

• The Pure and Applied Mathematics
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• v.15 no.4
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• pp.387-392
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• 2008

In this note, an alternative proof and extensions are provided for the following conclusions in [6, Theorem 1 and Theorem 3]: The functions $\frac1{x^2}-\frac{e^{-x}}{(1-e^{-x})^2}\;and\;\frac1{t}-\frac1{e^t-1}$ are decreasing in (0, ${\infty}$) and the function $\frac{t}{e^{at}-e^{(a-1)t}}$ for a $a{\in}\mathbb{R}\;and\;t\;{\in}\;(0,\;{\infty})$ is logarithmically concave.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.11-18
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• 1997

Fire safety systems in large buildings are likely to be complex and may be designed independently of other systems. This means that the interactions and interfaces between the fire safety systems and between the environmental control systems and the fire safety systems may not be carried out properly. Many large, recent buildings have many technological component systems that are used for the control of the environment within the building. Because of the "special" nature of the fire safety systems there is little consideration is given to the possibility systems with a dual function. However, many of the functions of fire safety systems are extensions of systems that provide the day to day control over the internal environment. The present world-wide trend towards the establishment of performance codes, and regulations, will enable the functional design of all systems and thereby allow closer integration of the "ordinary" and "special" systems. Some aspects of the functional and performance characteristics of systems in buildings are introduced and discussed. Special reference is made to the contributions of the systems to the minimisation of fire damage.e minimisation of fire damage.

• Journal of Institute of Convergence Technology
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• v.4 no.1
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• pp.37-41
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• 2014

For the analysis of lifting surface at high angle of attack, a Nonlinear Vortex Lattice Method(NLVLM) was used. The NLVLM is intented to compute the interactions between lifting surfaces and separated vertical flow. The lifting surfaces are represented by a lattice of discrete vortex rings. And wakes are represented by families of non-lintersecting, semi-infinite vortex line segments. The image method also used to analyze the ground effect. It is found that vortex lines separated from lifting surfaces represent the separated flows successfully. Although the present method is applied for the rectangular wing and delta wing, extensions can be possible for the arbitrary lifting surfaces. The Present results show good agreement with experimental data.

• Journal of the Korean Mathematical Society
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• v.46 no.5
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• pp.1027-1040
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• 2009

A ring R is called IFP, due to Bell, if ab = 0 implies aRb = 0 for a, b $\in$ R. Huh et al. showed that the IFP condition is not preserved by polynomial ring extensions. In this note we concentrate on a generalized condition of the IFPness that can be lifted up to polynomial rings, introducing the concept of quasi-IFP rings. The structure of quasi-IFP rings will be studied, characterizing quasi-IFP rings via minimal strongly prime ideals. The connections between quasi-IFP rings and related concepts are also observed in various situations, constructing necessary examples in the process. The structure of minimal noncommutative (quasi-)IFP rings is also observed.

• Journal of the Korean Mathematical Society
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• v.53 no.6
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• pp.1211-1223
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• 2016

Let M be an n-dimensional $K{\ddot{a}}hler$ manifold with positive holomorphic bisectional curvature and let ${\Omega}{\Subset}M$ be a pseudoconvex domain of order $n-q$, $1{\leq}q{\leq}n$, with $C^2$ smooth boundary. Then, we study the (weighted) $\bar{\partial}$-equation with support conditions in ${\Omega}$ and the closed range property of ${\bar{\partial}}$ on ${\Omega}$. Applications to the ${\bar{\partial}}$-closed extensions from the boundary are given. In particular, for q = 1, we prove that there exists a number ${\ell}_0$ > 0 such that the ${\bar{\partial}}$-Neumann problem and the Bergman projection are regular in the Sobolev space $W^{\ell}({\Omega})$ for ${\ell}$ < ${\ell}_0$.

• Annual Conference of KIPS
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• 2019.10a
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• pp.461-464
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• 2019

2017년에 대표적인 프로세서 취약점인 Meltdown과 Spectre가 발표됨에 따라 Intel의 CPU에서 다양한 취약점이 노출되었다. 이 취약점은 하드웨어 기반으로 신뢰 할 수 있는 환경을 보장해주는 TEE(Trusted Execution Environment) 기술을 사용하는 Intel의 SGX(Software Guard Extensions)에서도 유효하다. 따라서 이러한 취약점을 이용하여 신뢰 할 수 있는 환경에서 데이터의 무결성 및 기밀성을 훼손하는 다양한 공격 연구가 활발히 이루어지고 있다. 본 논문에서는 Intel SGX의 다양한 공격 연구에 대한 최신 동향을 살펴보며, 이에 따른 향후 연구 전망을 제시하고자 한다.