• Kyungpook Mathematical Journal
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• 제28권1호
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• pp.39-44
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• 1988

In 1940, B. H. Neumann, working with a system more general than a near-field, proved that the additive group of such a system (and of a near-field) is commutative. The algebraic structure he used is known as a Neumann system (N-system). Here, the prime N-systems are classified and for each possible characteristic, examples of N-systems which are neither near-fields nor rings are given. It is also shown that a necessary condition for the set of all odd polynomials over GF(p) to be an N-system is that p is a Fermat prime.

• 대한수학회논문집
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• 제28권4호
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• pp.697-707
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• 2013

In this paper, we introduce the notion of permuting $n$-derivations in near-ring N and investigate commutativity of addition and multiplication of N. Further, under certain constrants on a $n!$-torsion free prime near-ring N, it is shown that a permuting $n$-additive mapping D on N is zero if the trace $d$ of D is zero. Finally, some more related results are also obtained.

• Bulletin of the Korean Chemical Society
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• 제6권2호
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• pp.91-95
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• 1985

The dynamic properties near (and at) a stable steady state are discussed, when a chemical system relaxes from the unstable steady state. The time-dependent correlation length for the fluctuating variable near a stable steady state is explicitly obtained by introducing the probability average for the variable satisfying the rate equation. The study is carried out about the effect of nonlinearity on the correlation length near (and at) a stable steady state.

• Journal of applied mathematics & informatics
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• 제37권1_2호
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• pp.85-95
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• 2019

In this paper, we define near-minimal shadow and study the existence problem of extremal Type I binary self-dual codes with near-minimal shadow. We prove that there is no such codes of length n = 24m + 2($m{\geq}0$), n = 24m + 4($m{\geq}9$), n = 24m + 6($m{\geq}21$), and n = 24m + 10($m{\geq}87$).

• 대한수학회논문집
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• 제34권1호
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• pp.17-26
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• 2019

In this paper, we investigate commutativity of 3-prime near-rings ${\mathcal{N}}$ in which (1, ${\alpha}$)-derivations satisfy certain algebraic identities. Some well-known results characterizing commutativity of 3-prime near-rings have been generalized. Furthermore, we give some examples show that the restriction imposed on the hypothesis is not superfluous.

• Korean Journal of Mathematics
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• 제26권4호
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• pp.729-740
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• 2018

In this paper, we define near-minimal shadow and study the existence problem of extremal Type I additive self-dual codes over GF(4) with near-minimal shadow. We prove that there is no such codes if the code length n = 6m+1($m{\geq}0$), $n=6m+5(m{\geq}1)$.

• 한국안광학회지
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• 제16권3호
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• pp.327-331
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• 2011

목적: 본 연구는 근거리 주시 시 눈의 조절로 인한 난시의 변화를 파악하여 근용 안경사용 시 조절성 난시 발생의 문제점을 제시하는 것을 목적으로 실시되었다. 방법: 근거리 주시 기회가 많은 20세에서 40세까지 154명을 대상으로 포롭터를 사용하여 원거리 교정 굴절력을 측정한 다음 점군시표를 40 cm 거리에 두고 양안시 상태를 유지하기 위하여 두 눈을 동시에 뜨게 하고 한쪽 눈을 운무 시키고 다른 눈에는 크로스실린더 렌즈를 사용하여 근거리 난시축, 난시량을 측정하여 원거리 난시와 비교하였다. 결과: 근거리 주시 시 난시량이 감소 또는 변화가 없는 사람보다 증가한 사람이 많았고, 시력에 영향을 미칠 수 있는 0.75D이상 증가한 눈이 총 30안으로 전체 대상자의 9.7%로 나타났다. 근거리 주시 시 직난시와 사난시가 증가 하였고 난시 축방향은 좌안, 우안, 모두 내회선 하였으며 ${\pm}$5$^{\circ}$ 이상 회전된 눈은 조사대상자의 66.9%인 것으로 조사되었다. 난시의 축방향 회전으로 인하여 잔류난시의 발생이 예상되어 눈에 나쁜 영향을 미칠 것으로 생각된다. 결론: 근거리 주시 시 난시량의 증가와 축방향 회전으로 교정이 안된 안경을 장용하고 근거리를 주시하면 새로운 잔류난시가 발생하여 눈의 안정피로가 증가할 수 있어 근용 굴절검사에서 근거리주시에 의한 난시 변화를 고려되어야 할 것으로 생각된다.

• 대한두경부종양학회지
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• 제8권1호
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• pp.14-20
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• 1992

To clarify the safety of both total and near-total thyroidectomy, and to guide a selectionof an adequate type of surgical treatment of thyroid diseases, 192 consecutive total or near-total thyroidectomy cases were reviewed. They were divided into two groups: ont, the total thyroidectomy group(Group T,N=111) and the other, the near-total thyroidectomy group (Group NT, N=81). In both groups, complication rates, associations of complication rates with extents of surgery and stage of lesion were observed. Complication rate was significantly higher in Group T (53.6% vs 12.3%, p<0.05). But the rate of permanent complications such as permanent hypoparathyroidism and recurrent laryngeal nerve injury was remarkably low(4.5% in Group T, 6.0% in Group NT) and shows no significant difference in both groups. There was no permanent complication in cases where any type of neck dissection had not been performed regardless of the type thyroidectomy. But among whom underwent central compartmental neck dissection(CCND) and functional neck dissection(FND), 4(4.4%) and 4(6.4%) cases showed permanent complications. There was no statistical significance in differences between Group I and NT. In cases who underwent concomittant classical radical neck dissection(RND), 3(25.5%) showed permament complications. In this subgroups, complications were significantly higher in Group T(p<0.005). Complications were also directly related to the stage of the lesion. Only one patient showed permanent complication in 74 intracapsular lesions but 9 permanent complications were observed in 118 advanced lesions. We could clarify both total and near-total thyroidectomy were safe operations and the complications were related to accompanying neck dissections and the disease status rather than total or near-total thyroidectomy itself. Thus, we think that for the cases where higher complication rates are expected, such as locally advanced thryoid cancers or the cases which required wider neck dissection, the near-total thyroidectomy would be a preferrable method.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2004년도 춘계학술대회 논문집
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• pp.233-239
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• 2004

Microbial activity of biofilm formed on the surface of gravels from intertidal zone was estimated using an aerobic respirometer system, and compared with that of suspended marine microorganisms contained in a near shore water. The maximum oxygen uptake rate of the suspended marine microorganisms was 0.15mg O$_2$／L／hr, indicating the potential of purification of polluted near shore water. For the gravels from the intertidal zone, the maximum uptake rate of oxygen was affected by the vertical positions, but their gross value was 0.77mg O$_2$／L／hr, which was around 5.1 times higher than the purification potential of polluted near shore water by the microorganisms contained in the near shore water. The nitrogen removed by the gravels from the intertidal zone and the marine microorganisms was about 1／20-1／39 times of the total consumption of oxygen, which was similar to that of the phosphate. The gravel intertidal zone contained lots of particulate organics, over than that in the near shore water, and this was confirmed from the large difference between total oxygen consumption and the removed soluble COD in the microbial activity test. This indicates that the gravel intertidal zone plays an important role in controlling the non-point source pollutants from land, as well as self-purification of polluted near shore water by trapping and degrading the particulate organics.

• 한국항해항만학회지
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• 제28권2호
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• pp.155-159
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• 2004

Microbial activity of biofilm formed on the surface of gravels from intertidal zone was estimated using an aerobic respirometer system, and compared with that of suspended marine microorganisms contained in a near shore water, The maximum oxygen uptake rate of the suspended marine microorganisms was 0.15mg$O_2$/L/hr, indicating the potential of purification of polluted near shore water. For the gravels from the intertidal zone, the maximum uptake rate of oxygen was affected by the vertical positions, but their gross value was 0.77mg $O_2$/L/hr, which was around 5.1 times higher than the purification potential of polluted near shore water by the microorganisms contained in the near shore water. The nitrogen removed by the gravels from the intertidal zone and the marine microorganisms was about 1/20-1/39 times of the total consumption of oxygen, which was similar to that of the phosphate. The gravel intertidal zone contained lots of particulate organics, over than that in the near shore water, and this was confirmed from the large difference between total oxygen consumption and the removed soluble COD in the microbial activity test. This indicates that the gravel intertidal zone plays an important role in controlling the non-point source pollutants from land, as well as self-purification of polluted near shore water by trapping and degrading the particulate organics.