• Communications of the Korean Mathematical Society
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• v.28 no.2
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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.

• Communications of the Korean Mathematical Society
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• v.15 no.2
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• pp.357-370
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• 2000

In [6], Cheng-Ye You gave a condition equivalent to the Nielsen number product formula for fiber maps. And Jerzy Jezierski also gave a similar condition for coincidences of fiber maps. The main purpose of this paper is to find the condition for which holds the product formula for Nielsen root numbers N(f;a) = N(f;a) N(fb;a).

• Bulletin of the Korean Mathematical Society
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• v.20 no.1
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• pp.55-63
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• 1983

• Communications of the Korean Mathematical Society
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• v.12 no.3
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• pp.701-707
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• 1997

In [8], we introduce the relative root Nielsen number N(f;X, A, c) for maps of pairs of spaces $f : (X, A) \to (Y, B)$. From it, we obtain some immediate consequences of the definition and illustrate it by some examples. We consider the question whether there exists a map $g : (X, A) \to (Y, B)$ homotopic to a given map $f : (X, A) \to (Y, B)$ which has precisely N(f;X, A, c) roots, that is, the minimum theorem for N(f;X, A, c).

• Journal of the Chungcheong Mathematical Society
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• v.28 no.2
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• pp.243-249
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• 2015

Let X be a closed surface for which the Euler characteristic $_{\mathcal{X}}(X)$ is negative, and let $f:X{\rightarrow}X$ be a self-map that is not surjective. In this short paper, we prove that we can compute the Nielsen number of f, N(f), under some algebraic conditions.

• Journal of the Korean Mathematical Society
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• v.31 no.1
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• pp.69-79
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• 1994

• The Journal of Natural Sciences
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• v.17 no.1
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• pp.1-12
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• 2006

The main results in this paper concern the set of natural numbers correrponding to the least period of periodic orbits of a map on the Klein bottle K.

• Journal of Plant Biotechnology
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• v.42 no.3
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• pp.235-238
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• 2015

Adventitious buds were obtained from isolated cotyledons cultured on MS medium with various concentrations of 6-benzylamino purine (BA) and thidiazuron (TDZ). The highest numbers of adventitious buds were obtained on MS medium supplemented with 0.2 mg/L BA. Experimental culturing with half the petiole portion and half with the terminal segments were grown on MS medium contained with 0.2 mg/L BA. Frequency of the adventitious bud induction was variable accordingly to the type of cultured explants. Explants with the half petiole showed the highest adventitious bud induction rate (80%) compared to explants of half with terminal segment (20%). An elongated shoot from the buds and growth of advent roots were both possible on the 1/2 MS medium without a plant growth regulator. These results offer an effective way in which clonal propagation can be accomplished.

• Industrial Engineering and Management Systems
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• v.15 no.1
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• pp.110-121
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• 2016

With the growing interest in skincare and maintenance, there are increasing numbers of studies on the classification of skin type and the factors influencing each type. This study presents a novel methodology by using data mining, for the determination of the relationships between skin type, lifestyle, and patterns of cosmetic utilization. Eight skin-specific factors, which are moisture, sebum in U-zone (both cheeks), sebum in T-zone (forehead, nose, and chin), pore, melanin, wrinkle, acne, hemoglobin, were measured in 1,246 subjects living in South Korea, in conjunction with a questionnaire survey analyzing their lifestyles and pattern of cosmetic utilization. Using various multivariate statistical methods and data mining techniques, we classified the skin types based on the skin-specific values, determined the relationship between skin type and lifestyle, and accordingly sorted the subjects into clusters. Logistic regression analysis revealed gender-related differences in the skin; therefore, separate analyses were performed for males and females. Using the Gaussian Mixture Modeling (GMM) technique, we classified the subjects based on skin type (two male and four female). Using the ANOVA and decision tree techniques, we attempted to characterize the relationship between each skin type and the lifestyles of the subjects. Menstruation, eating habits, stress, and smoking were identified as the major factors affecting the skin.