• Honam Mathematical Journal
• /
• v.41 no.4
• /
• pp.863-870
• /
• 2019

In this paper, we obtain the enumeration results on the number of linear extensions of diamond posets. We find the recurrence relations and exponential generating functions for the number of linear extensions of diamond posets. We also get some results for the volume of graph polytope associated with bipartite graphs which are underlying graphs of diamond posets.

• Bulletin of the Korean Mathematical Society
• /
• v.42 no.3
• /
• pp.555-561
• /
• 2005

In this note we give characterizations for certain HNN extensions with central associated subgroups to be residually finite. We then apply our results to HNN extensions of polycyclic-by-finite groups.

• Journal of the Chungcheong Mathematical Society
• /
• v.29 no.4
• /
• pp.599-611
• /
• 2016

Let $k={\mathbb{F}}_q(t)$ be a rational function field over the finite field ${\mathbb{F}}_q$. In this paper we obtain formulas of average values of L-functions of some family of Artin-Schreier extensions over k.

• Korean Journal of Mathematics
• /
• v.24 no.4
• /
• pp.601-612
• /
• 2016

In this paper we obtain average of class numbers of some family of Artin-Schreier extensions of rational function field ${\mathbb{F}}_q(t)$, where q is a power of 3.

• Korean Journal of Mathematics
• /
• v.30 no.4
• /
• pp.615-628
• /
• 2022

In this paper, we will prove some extensions of the Eneström-Kakeya theorem to quaternionic polynomials which were already valid for the classical Eneström-Kakeya theorem to complex polynomials. Our kind of extensions have considerably improved the bounds by relaxing and weakening the hypothesis in some cases.

• Honam Mathematical Journal
• /
• v.43 no.4
• /
• pp.741-749
• /
• 2021

A variant of up-down posets described below and the number of their linear extensions were studied. We obtained the exponential generating functions which showed that how they are related to the Euler's up-down numbers.

• Kyungpook Mathematical Journal
• /
• v.57 no.3
• /
• pp.401-417
• /
• 2017

Ever since their introduction, skew PBW ($Poincar{\acute{e}}$-Birkhoff-Witt) extensions of rings have kept growing in importance, as researchers characterized their properties (such as primeness, Krull and Goldie dimension, homological properties, etc.) in terms of intrinsic properties of the base ring, and studied their relations with other fields of mathematics, as for example quantum mechanics theory. Many rings and algebras arising in quantum mechanics can be interpreted as skew PBW extensions. Our aim in this paper is to study skew PBW extensions of Baer, quasi-Baer, principally projective and principally quasi-Baer rings, in the case when the base ring R is not assumed to be reduced. We just impose some mild compatibleness over the base ring R, and prove that these properties are stable over this kind of extensions.

• The Research Journal of the Costume Culture
• /
• v.10 no.2
• /
• pp.146-159
• /
• 2002

This study examines the textile pattern design of Italian fashion brands and their brand extensions by comparing their images. Five Italian fashion brands are chosen and the textile pattern design of their brand extensions, which were presented during the eight collection. Then their design style is compared with the design style of their main brands. The five main brands and their brand extensions are as fellows: Anna Molinari-Blumarine, Dolce & Gabbana-D&G, Girogio Armani-Emporio Armani, Gian Franco Ferre'-GFF, and Prada-MiuMiu. Their color, motive type, motive layout, motive expression, and pattern drawing technique are examined and compared. Results suggest that most brand extensions generally use color, motive type motive layout. and motive expression similar to their main brands. In particular, their pattern drawing technique is a painting style white their main brands use a graphic style. This result suggests that to create and develop new brand extensions, Italian fashion (main brand) firms in general employ color, motive type, motive layout, and motive expression technique similar to main brands, but different drawing technique to differentiate from their main brands. The results of this study suggest that textile pattern design plays an important role in developing new brand extensions and thus should be considered as a crucial part of the product.

• Journal of Global Scholars of Marketing Science
• /
• v.15 no.3
• /
• pp.67-92
• /
• 2005

This study investigates the influence of the mother brand's product types on the consumers' brand evaluations on consistent and inconsistent brand extensions. The study shows that brand extensions consistent with the mother brand's product type have better brand evaluations than inconsistent brand extensions. The study also shows that brand extensions consistent with utilitarian mother products are much more important than consistent brand extensions with hedonic mother brands. Furthermore, results show that the types of consumer involvement influence the consumers' brand evaluations by interacting with types of mother brands and consistency of brand extensions.

• Communications of the Korean Mathematical Society
• /
• v.6 no.1
• /
• pp.89-92
• /
• 1991