• 대한수학회보
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• 제53권5호
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• pp.1341-1352
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• 2016

Let R be a commutative Noetherian ring, ${\Phi}$ a system of ideals of R and $I{\in}{\Phi}$. In this paper among other things we prove that if M is finitely generated and $t{\in}\mathbb{N}$ such that the R-module $H^i_{\Phi}(M)$ is $FD_{{\leq}1}$ (or weakly Laskerian) for all i < t, then $H^i_{\Phi}(M)$ is ${\Phi}$-cofinite for all i < t and for any $FD_{{\leq}0}$ (or minimax) submodule N of $H^t_{\Phi}(M)$, the R-modules $Hom_R(R/I,H^t_{\Phi}(M)/N)$ and $Ext^1_R(R/I,H^t_{\Phi}(M)/N)$ are finitely generated. Also it is shown that if cd I = 1 or $dimM/IM{\leq}1$ (e.g., $dim\;R/I{\leq}1$) for all $I{\in}{\Phi}$, then the local cohomology module $H^i_{\Phi}(M)$ is ${\Phi}$-cofinite for all $i{\geq}0$. These generalize the main results of Aghapournahr and Bahmanpour [2], Bahmanpour and Naghipour [6, 7]. Also we study cominimaxness and weakly cofiniteness of local cohomology modules with respect to a system of ideals.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.184-187
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• 2000

In this paper, a ring-type ultrasonic motor divided into 12 sectors was modeled by Atila program using finite element method(FEM). The stator consists of a piezoelectric ceramic poled alternately in opposite directions and elastic material. And the stator dimension was $\Phi$40 (outer diameter), $\Phi$ 30(inner diameter), 0.5mm(ceramic thickness) and 3mm(elastic material thickness). As a simulation result, 6$\lambda$ displacement occurred at approximately 52kHz, and this resonance frequency is similar to calculated result 57kHz. The position of maximum displacement was at the edge of stator.

• 대한수학회보
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• 제40권1호
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• pp.91-99
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• 2003

In this paper, we show that if the ring of a Merits context (A, B, M, N, ${\psi},\;{\phi}$) with zero pairings is a strongly $\pi$-regular ring of bounded index if and only if so are A and B. Furthermore, we extend this result to the ring of a Merits context over quasi-duo strongly $\pi$-regular rings.

• 시멘트 심포지엄
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• 1호
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• pp.64-68
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• 1973

One of the most difficult problems in cement rotary kiln operation must be ring and coating formation. In the Dopol kiln with the capacity of 1,500 t/d($4.4m\phi\times70mL$, meal rings have been accreted on transit zone and end of the kiln and

• 대한수학회지
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• 제54권4호
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• pp.1099-1108
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• 2017

Let R be a commutative ring with non-zero identity and M be a unitary R-module. Let S(M) be the set of all submodules of M and ${\phi}:S(M){\rightarrow}S(M){\cup}\{{\emptyset}\}$ be a function. We say that a proper submodule P of M is a ${\phi}$-semiprime submodule if $r{\in}R$ and $x{\in}M$ with $r^2x{\in}P{\setminus}{\phi}(P)$ implies that $rx{\in}P$. In this paper, we investigate some properties of this class of sub-modules. Also, some characterizations of ${\phi}$-semiprime submodules are given.

• 대한수학회보
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• 제44권2호
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• pp.225-231
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• 2007

Given an injective envelope E of a left R-module M, there is an associative Galois group Gal$({\phi})$. Let R be a left noetherian ring and E be an injective envelope of M, then there is an injective envelope $E[x^{-1}]$ of an inverse polynomial module $M[x^{-1}]$ as a left R[x]-module and we can define an associative Galois group Gal$({\phi}[x^{-1}])$. In this paper we describe the relations between Gal$({\phi})$ and Gal$({\phi}[x^{-1}])$. Then we extend the Galois group of inverse polynomial module and can get Gal$({\phi}[x^{-s}])$, where S is a submonoid of $\mathbb{N}$ (the set of all natural numbers).

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.241-245
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• 1998

This paper gives the novel design of compensated ring anode-short for power GTO thyristor. By means of this design the power GTO of $\Phi$63.5mm 2500A/4500V reaches more uniform turn-off compared with conventional ring short GTO, resulting in higher turn-off ability and low tail current/tail time.

• 환경생물
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• 제26권2호
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• pp.66-75
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• 2008

한국꿩 (Korean ring-necked Pheasant, Phasianus colchicus karpowi)과 외국 아종의 유전적 유연관계를 파악하기 위해 야생 한국꿩, 사육 한국꿩, 사육 한국꿩과 외국꿩간의 잡종꿩, 외국꿩 4아종(중국 링넥, 흑 뮤탄트, 백 뮤탄트, 녹치)을 대상으로 ISSR 표지자 분석과 AMOVA 분석을 수행하였다. 야생 한국꿩의 전체 유전 다양성중 94.08%가 서식지 내 개체간 유전적 차이에 기인하고, 5.9% ($\Phi$st=0.059)가 서식지간 차이에 기인하였다. 사육 한국꿩이 유전적으로 야생 한국꿩 보다는 외국꿩 4아종과 가깝게 나타났다. AMOVA분석과 cluster분석에서 사육 한국꿩이 야생 한국꿩은 물론 외국꿩 4아종과도 유전적 차이를 보이는 것으로 미루어 볼 때 사육되고 있는 한국꿩은 한국꿩과 외국 아종간의 다양한 교잡에 의해 생겨난 잡종일 가능성이 높다. 외국꿩 4아종(중국 링넥, 흑 뮤탄트, 백 뮤탄트, 녹치)의 전체 유전 다양성중 96.63%가 아종내 개체간 차이에 기인하고. 3.4% ($\Phi$st=0.034)로 아종간 차이에 기인하여 외국꿩 4아종의 아종간 유전적 차이가 야생 한국꿩의 서식지간 차이보다도 낮은 것으로 나타났다. 이는 본 분석에 사용된 외국꿩 4아종이 형태적으로는 다른 아종으로 분류되지만 유전적으로는 매우 가까운 위치에 있음을 의미한다. 7서식지의 야생 한국정과 외국꿩 4아종을 각각 야생 한국꿩 그룹과 외국꿩 그룹으로 분류하여 두 그룹의 유전적 다양성을 분석한 결과, 전체 유전변이 중 그룹간 차이의 비율은 17% 이상(그룹 내 서식지/아종간 차이는 약 4%)으로 야생 한국꿩이 아종 관계인 외국꿩 4아종과 상당한 유전적 차이를 보이는 것으로 나타났다. 유전적 유연관계 분석결과에서 중국 링넥. 흑 뮤탄트, 백 뮤탄트의 외국꿩 3 아종은 유전적으로 외국 아종에 가까운 사육한국꿩, 잡종꿩과 함께 하나의 분지군을 형성하면서 야생 한국꿩 그룹으로부터 98% 신뢰수준에서 뚜렷하게 구별되었다.

• 대한수학회보
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• 제31권1호
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• pp.93-97
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• 1994

Previously T.Porter [3] has given a relative Chinese Remainder Theorem under the hypothesis that given ring R has at least one .tau.-closed maximal ideal (by his notation Ma $x_{\tau}$(R).neq..phi.). In this short paper we drop his overall hypothesis that Ma $x_{\tau}$(R).neq..phi. and give the proof and some related results with this Theorem. In this paper R will always denote a commutative ring with identity element and all modules will be unitary left R-modules unless otherwise specified. Let .tau. be a given hereditarty torsion theory for left R-module category R-Mod. The class of all .tau.-torsion left R-modules, dented by J is closed under homomorphic images, submodules, direct sums and extensions. And the class of all .tau.-torsionfree left R-modules, denoted by F, is closed under taking submodules, injective hulls, direct products, and isomorphic copies ([2], Proposition 1.7 and 1.10).

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.423-426
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• 2000

The 3-D $31.5$\times$31.5$\times$2.5mm$^3$model of contour vibration mode piezoelectric transformer with Pb($Ni_{1/2}$$W_{1/2}$)$O_3$-Pb(Zr,Ti)$O_3$ ceramics was simulated by ANSYS according to the dot size 17, 18, 19, 20, 21 $mm\phi$ and analyzed the results. The mechanical quality factor of the 3-D model was decreased with the dot size and increased as 2605 at 20 $mm\phi$ and after then decreased again. The output voltage of that sample was 74123 [V] and the maximum stress of the dot electrode at that sample was 288[$10^7$N/$m^2$] and the maximum displacement of the ring electrode at that sample was 128 [$\mu\textrm{m}$].