• Kyungpook Mathematical Journal
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• v.52 no.2
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• pp.201-208
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• 2012

By the works of Kondo and Sakai, it is known that Alexander polynomials of knots which are transformed into the trivial knot by a single crossing change are characterized. In this note, we will characterize Alexander polynomials of knots which are transformed into the trefoil knot (and into the figure-eight knot) by a single crossing change.

• Kyungpook Mathematical Journal
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• v.56 no.2
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• pp.639-645
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• 2016

In [3] the main theorem was erroneously stated. We needed to assume that the irrationality measure of 1/r is finite to prove the theorem.

• Journal of the Korean Mathematical Society
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• v.48 no.2
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• pp.367-382
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• 2011

We establish a necessary and sufficient condition for a heptagonal knot to be figure-8 knot. The condition is described by a set of Radon partitions formed by vertices of the heptagon. In addition we relate this result to the number of nontrivial heptagonal knots in linear embeddings of the complete graph $K_7$ into $\mathbb{R}^3$.

• Journal of electromagnetic engineering and science
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• v.8 no.1
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• pp.28-33
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• 2008

We have proposed a novel DVB-H(Digital Video Broadcast for Handheld) antenna for folder-type mobile handheld terminal by using a coupling element, a stub, and an L-type matching circuit. The L-type matching circuit consisting of two chip inductors is used for achieving an improved impedance matching over the DVB-H frequency band ($470{\sim}702\;MHz$). Simulated results showed the stub worked to more knot the lower and upper frequency ends of the input impedance curve. The antenna exhibits a flat gain characteristic from 2 to 2.8 dBi over the DVB-H frequency band. The radiation patterns are a stable Figure-of-eight radiation pattern in the frequency range.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.33 no.3
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• pp.58-65
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• 2015

Compared to pavement of Chinese palace gardens, those of private gardens in south part of the Yangtze River(長江) in China shows variety of patterns. In order to figure out what causes the difference in paving pattern, this article focuses on the traditional Chinese ideologies during the all time. An analysis on 'Classical Gardens of Suzhou', which has been designated as UNESCO World Heritage, was used to determine how ideologies have influence on paving pattern of Classical Gardens. As a result, various Chinese ideologies such as Nature worship, Totemism, Confucianism, Taoism, Buddhism, and Folk Culture were found in paving patterns of the private gardens. Pattern of sun in the Retreat & Reflection Garden(Toisawon) is an example of Nature worship among primitive beliefs of ancient China. Phoenix pattern of the Couple's Retreat Garden(Ouyuan, Liuyuan) reflects Totemistic beliefs. Confucianism is the underlying philosophy of Eight Square pattern, Six Square pattern, and Cross Square pattern. These patterns were mainly used to pave large area and easily found in many gardens. Patterns reflect Taoism are "Wufu holding life" pattern(the Five blessing holding life, 五福捧壽), Flat peach pattern, and Alluding Eight Immortals pattern. Paving patterns related to Buddhism are patterns of 'Eight treasures' and Endless knot pattern appears most frequently since it expresses concept of reincarnation well. Paving patterns shows folk culture and beliefs of the time in China are bat, butterfly, dragonfly, frog, carp, and coin(ingot).