• 한국항해항만학회지
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• 제40권6호
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• pp.441-450
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• 2016

연안오염퇴적물에 함유된 유기물질과 PAHs의 현장정화를 위한 생물활성촉진제의 효능을 파일럿 규모의 현장실험을 통하여 1년간 평가하였다. 실험 해역의 수온은 계절적인 요인으로 인해 $16.5^{\circ}C$에서 $21^{\circ}C$까지 변화가 있었으나, 파일럿 반응조의 오염퇴적물의 pH는 8.4-8.5로서 비교적 일정하였다. 파일럿 실험종료 후 바탕시험구와 초산, 황산이온, 질산이온을 함유한 생물활성촉진제를 주입한 오염퇴적물의 화학적 산소요구량은 각각 39% 및 79%까지 감소하였으며, 휘발성고형물은 초기 약 15 g/kg에서 7 g/kg 및 2.5 g/kg까지 각각 감소하였다. PAHs는 2- ,3- ,4- ,5-ring 과 6-ring 16PAHs를 평가하였으며, 생물활성촉진제를 주입한 오염퇴적물에서 2-ring 화합물인 나프탈렌은 실험시작 2개월 후 100%(바탕시험구의 감소율 55.6%)까지 감소되어 가장 빨랐고, 12개월 후 3-ring 및 4-ring PAHs의 감소율은 모두 100%(바탕시험구의 감소율 46%-100%)에 달하였다. 5-ring과 6-ring PAHs의 12개월 후의 감소율은 바탕시험구와 생물활성촉진제를 투여한 오염퇴적물에서 각각 26%-87% 및 77%-100%로 평가되었다. 연안오염퇴적물에 투입한 생물활성촉진제는 유기물질 및 난분해물질인 PAHs의 제거속도를 향상시킬 수 있는 것으로 평가되었다.

• 한국임상수의학회지
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• 제16권1호
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• pp.1-7
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• 1999

The purpose of the present study was to evaluate the easiness of suture and fixation of modified total ring prostheses (m-TRP). Twelve healthy dogs (B.W.2-10 kg) were randomly assigned to three groups. In group A (3 dogs), total ring prostheses was fixed by penetrating a suture material through tracheal mucosa. In group B (3 dogs), TRP was fixed by suturing on tracheal cartilage and muscular layer not penetrating through tracheal mucosa. m-TRP was applied to the cervical portions (group M-C,3 dogs), and thoracic portions (group M-T,3 dogs). Operating time of group M-C (37.33$\pm$6.80 min.) was shorter than those of groups B (83.33$\pm$8.50 min.) and A (63.33$\pm$11.06 min.) (p＜0.01). Clinical complications were minimal and limited to mild, short-term hematoma, vomiting, edema, and inflammation. Coughing remarkably decreased in group B rather than group A. Dyspnea was not showed in group A, B, and M-C, but group M-T had a mild dyspnea. Gross postmortem findings were similar in all groups. Mild adhesions were present between prostheses and adjacent structures, but tracheal lumen was clean. Severe adhesions were present where m-TRP had been applied in the thoracic portions. Histopathologic abnormalities included mild to moderate adventitial and periprosthetic fibrosis and mild adventitial inflammation. The present study indicated that m-TRP were easier in suture and fixation than TRP and had no differences in support for trachea and side effects.

• 대한수학회보
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• 제52권4호
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• pp.1353-1363
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• 2015

Let D be a division ring and w($x_1,\;x_2,\;{\ldots},\;x_m$) be a generalized group monomial over $D^*$. In this paper, we investigate subnormal subgroups and maximal subgroups of $D^*$ which satisfy the identity $w(x_1,\;x_2,\;{\ldots},\;x_m)=1$.

• East Asian mathematical journal
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• 제22권2호
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• pp.239-248
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• 2006

Let G be a group acting on a ring R. We will define the group action of G on an intuitionsitic fuzzy set of R. We will introduce intuitionistic fuzzy G-prime ideals of a ring and we will prove that every intuitionistic fuzzy G-prime ideal is the largest G-invariant intuitionistic fuzzy ideal of R contained in the intuitionistic fuzzy prime ideal which is uniquely determined up to G-orbits.

• 호남수학학술지
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• 제45권4호
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• pp.678-681
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• 2023

Let G be a cyclic group of prime power order p^k, and let I be the augmentation ideal of the integral group ring ℤ[G]. We define a derivation on ℤ/p^kℤ[G], and show that for 2 ≤ n ≤ p, an element α ∈ I is in Iⁿ if and only if the i-th derivative of the image of α in ℤ/p^kℤ[G] vanishes for 1 ≤ i ≤ (n - 1).

• 대한수학회보
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• 제31권1호
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• pp.99-104
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• 1994

Let R be a left Artinian ring with identity 1 and let G be the group of units of R. It is shown that if G is finite, then R is finite. It is also shown that if 2.1 is a unit in R, then G is abelian if and only if R is commutative.

• 대한수학회지
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• 제36권6호
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• pp.1021-1031
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• 1999

In this paper we introduce matrix representations of polygroups over hyperrings and show such representations induce representations of the fundamental group over the corresponding fundamental ring. We also introduce the notion of a polygroup hyperring generalizing the notion of a group ring. We establish homo-morphisms among various polygroup hyperrings.

• 대한수학회논문집
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• 제35권4호
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• pp.1087-1093
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• 2020

The aim of this paper is to show that every Engel quasinormal subgroups of the unit group of a division ring with uncountable center is central.

• 약학회지
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• 제47권6호
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• pp.417-421
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• 2003

This paper describes a synthetic route to novel 2'-methyl and 4'-hydroxy carbocyclic nucleosides. The methyl group was successfully installed by carbonyl addition reaction of isopropenyl magnesium bromide followed by ring-closing metathesis and the hydroxy group was directly introduced from carbohydrate chiral template "D-lactose".ose".uot;.

• 대한수학회보
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• 제58권1호
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• pp.47-58
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• 2021

In this article, we completely determine the rings for which every element is a sum of a nilpotent and three tripotents that commute with one another. We discuss this property for some extensions of rings, including group rings.