• 대한수학회지
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• 제54권6호
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• pp.1817-1828
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• 2017

We give a simple and direct proof of the characterization of positivity preserving semi-flows for ordinary differential systems. The same method provides an abstract result on a class of evolution systems containing reaction-diffusion systems in a bounded domain of ${\mathbb{R}}^n$ with either Neumann or Dirichlet homogeneous boundary conditions. The conditions are exactly the same with or without diffusion. A similar approach gives the optimal result for invariant rectangles in the case of Neumann conditions.

• 기록학연구
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• 제31호
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• pp.139-161
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• 2012

Donald K. Sebera 모델은 다른 열화인자의 영향을 고려하지 않고 오직 온도와 습도만의 변화를 이용하여 두 개 이상의 서고환경에 대한 보존성 평가지수를 계산함으로서 기록물의 보존환경을 정량적으로 비교 평가하는데 활용될 수 있다. 본 연구에서는 Donald K. Sebera 모델을 이용하여 기록물관리법에서 제시하고 있는 온 습도 범위에서 종이기록물 보존조건 중 가장 우수한 조건과 가장 열악한 조건에서의 보존성을 비교 분석하였다. 그 결과 기록물관리법에서 허용하고 있는 온 습도 범위 내에서 보존조건이 가장 우수한 조건에서의 종이기록물 보존성 평가지수가 가장 열악한 조건에서 보다 2.47배 더 큰 것으로 나타났다. 또 가수분해반응 활성화에너지가 작을수록 종이기록물의 보존성은 온도보다는 습도에 의한 영향력이 크게 작용하였다. 따라서 보존성 평가지수는 서고의 온 습도 조건이 기록물 보존환경에 적합한지를 쉽게 판단할 수 있기 때문에 온 습도 변화에 대해 보존성 확보가 가능한 도구로 유용하게 활용될 수 있다.

• Journal of applied mathematics & informatics
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• 제27권5_6호
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• pp.1049-1059
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• 2009

Continuous t-norm based shape preserving additions of LR-fuzzy intervals with unbounded support is studied. The case for bounded support, which was a conjecture suggested by Mesiar in 1997, was proved by the author in 2002 and 2008. In this paper, we give a necessary and sufficient conditions for a continuous t-norm T that induces DR-shape preserving addition of LR-fuzzy intervals with unbounded support. Some of the results can be deduced from the results given in the paper of Mesiar in 1997. But, we give direct proofs of the results.

• Journal of applied mathematics & informatics
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• 제6권1호
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• pp.303-307
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• 1999

Let A and B be two strictly dense Banach Algebras on X and Y respectively where X and Y are Banach space. We give some conditions under which full spectrum preserving linear mappings from A into B Jordan morphisms and X is homomorphic to Y.

• Journal of applied mathematics & informatics
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• 제27권3_4호
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• pp.757-762
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• 2009

In allelic model $X\;=\;(x_1,\;x_2,\;{\cdots},\;x_d)$, $$M_f(t)\;=\;f(p(t))\;-\;{\int}^t_0\;Lf(p(t))ds$$ is a P-martingale for diffusion operator L under the certain conditions. We can also obtain a new diffusion operator $L^*$ for diffusion coefficient and we prove that unique solution for $L^*$-martingale problem exists. In this note, we define new symmetric preserving transformation. Uniqueness for martingale problem and symmetric property will be proved.

• 대한수학회보
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• 제51권4호
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• pp.1055-1062
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• 2014

Let $O_n$ and $PO_n$ denote the order-preserving transformation and the partial order-preserving transformation semigroups on the set $X_n=\{1,{\ldots},n\}$, respectively. Then the strictly partial order-preserving transformation semigroup $SPO_n$ on the set $X_n$, under its natural order, is defined by $SPO_n=PO_n{\setminus}O_n$. In this paper we find necessary and sufficient conditions for any subset of SPO(n, r) to be a (minimal) generating set of SPO(n, r) for $2{\leq}r{\leq}n-1$.

• 대한수학회논문집
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• 제28권2호
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• pp.361-369
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• 2013

We introduce a Nielsen type number of a fibre preserving map, and show that it is a lower bound for the number of $n$-orbits in the homotopy class. Under suitable conditions we show that it is equal to the Nielsen type relative essential $n$-orbit number. We also give necessary and sufficient conditions for it and the essential $n$-orbit number to coincide.

• 대한수학회논문집
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• 제30권4호
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• pp.349-361
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• 2015

A fence is an ordered set that the order forms a path with alternating orientation. Let F = (F;${\leq}$) be a fence and let OT(F) be the semigroup of all order-preserving self-mappings of F. We prove that OT(F) is coregular if and only if ${\mid}F{\mid}{\leq}2$. We characterize all coregular elements in OT(F) when F is finite. For any subfence S of F, we show that the set COTS(F) of all order-preserving self-mappings in OT(F) having S as their range forms a coregular subsemigroup of OT(F). Under some conditions, we show that a union of COTS(F)'s forms a coregular subsemigroup of OT(F).

• International Journal of Computer Science & Network Security
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• 제23권6호
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• pp.99-106
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• 2023

Now a days, large volumes of data is accumulating in every field due to increase in capacity of storage devices. These large volumes of data can be applied with data mining for finding useful patterns which can be used for business growth, improving services, improving health conditions etc. Data from different sources can be combined before applying data mining. The data thus gathered can be misused for identity theft, fake credit/debit card transactions, etc. To overcome this, data mining techniques which provide privacy are required. There are several privacy preserving data mining techniques available in literature like randomization, perturbation, anonymization etc. This paper proposes an Enhanced Hybrid Privacy Preserving Data Mining(EHPPDM) technique. The proposed technique provides more privacy of data than existing techniques while providing better classification accuracy. The experimental results show that classification accuracies have increased using EHPPDM technique.

• 대한수학회지
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• 제46권4호
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• pp.813-826
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• 2009

In this paper, we generalize the notions of preserving and strongly preserving maps to arbitrary set based topological categories. Further, we obtain characterizations of each of these concepts as well as interprete analogues and generalizations of theorems of Gerlits at al [20] in the categories of filter and local filter convergence spaces.