• Title/Summary/Keyword: k-type digital fundamental group

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Computer Topology and Its Applications

  • Han, Sang-Eon
    • Honam Mathematical Journal
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    • v.25 no.1
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    • pp.153-162
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    • 2003
  • Recently, the generalized digital $(k_{0},\;k_{1})$-continuity and its properties are investigated. Furthermore, the k-type digital fundamental group for digital image has been studies with the generalized k-adjacencies. The main goal of this paper is to find some properties of the k-type digital fundamental group of Boxer and to investigate some properties of minimal simple closed k-curves with relation to their embedding into some spaces in ${\mathbb{Z}}^n(2{\leq}n{\leq}3)$.

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DIGITAL COVERING THEORY AND ITS APPLICATIONS

  • Kim, In-Soo;Han, Sang-Eon
    • Honam Mathematical Journal
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    • v.30 no.4
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    • pp.589-602
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    • 2008
  • As a survey-type article, the paper reviews various digital topological utilities from digital covering theory. Digital covering theory has strongly contributed to the calculation of the digital k-fundamental group of both a digital space(a set with k-adjacency or digital k-graph) and a digital product. Furthermore, it has been used in classifying digital spaces, establishing almost Van Kampen theory which is the digital version of van Kampen theorem in algebrate topology, developing the generalized universal covering property, and so forth. Finally, we remark on the digital k-surface structure of a Cartesian product of two simple closed $k_i$-curves in ${\mathbf{Z}}^n$, $i{\in}{1,2}$.

REMARKS ON SIMPLY k-CONNECTIVITY AND k-DEFORMATION RETRACT IN DIGITAL TOPOLOGY

  • Han, Sang-Eon
    • Honam Mathematical Journal
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    • v.36 no.3
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    • pp.519-530
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    • 2014
  • To study a deformation of a digital space from the viewpoint of digital homotopy theory, we have often used the notions of a weak k-deformation retract [20] and a strong k-deformation retract [10, 12, 13]. Thus the papers [10, 12, 13, 16] firstly developed the notion of a strong k-deformation retract which can play an important role in studying a homotopic thinning of a digital space. Besides, the paper [3] deals with a k-deformation retract and its homotopic property related to a digital fundamental group. Thus, as a survey article, comparing among a k-deformation retract in [3], a strong k-deformation retract in [10, 12, 13], a weak deformation k-retract in [20] and a digital k-homotopy equivalence [5, 24], we observe some relationships among them from the viewpoint of digital homotopy theory. Furthermore, the present paper deals with some parts of the preprint [10] which were not published in a journal (see Proposition 3.1). Finally, the present paper corrects Boxer's paper [3] as follows: even though the paper [3] referred to the notion of a digital homotopy equivalence (or a same k-homotopy type) which is a special kind of a k-deformation retract, we need to point out that the notion was already developed in [5] instead of [3] and further corrects the proof of Theorem 4.5 of Boxer's paper [3] (see the proof of Theorem 4.1 in the present paper). While the paper [4] refers some properties of a deck transformation group (or an automorphism group) of digital covering space without any citation, the study was early done by Han in his paper (see the paper [14]).

Visual Evaluation Factors of Pork Loin and Korean Consumer's Preference Choice (돈육 등심의 육안적 평가조건과 한국소비자들의 기호도 성향 분석)

  • Cho, S.H.;Park, B.Y.;Byun, J.S.;Kim, J.H.;Ahn, J.N.;Yun, S.G.
    • Journal of Animal Science and Technology
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    • v.46 no.3
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    • pp.415-426
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    • 2004
  • Digital photographs of 16 pork chops were taken and modified images to give 16 treatments: two levels of each of fat cover, color, marbling and drip. Consumers(n = 1,014) were randomly selected and a questionnaire asking for socio-demographic information was completed. Each consumer was asked to select preferred type from 16 treatments and this selection was repeated eight times. There were significant differences in pork selection among age, sex and occupation groups only except income levels. Pork preference choices were different in meat color, fat cover and drip depending on age group. Student consumers aging from 18 to 24 years preferred pork chop having darker color, thinner fat cover and more drip when compared to the other groups(p < 0.05). Male preferred pork having darker and more drip than female(p < 0.05). Marital status had a effect on the preference in meat color and drip. The consumers had different choice in color, fat cover and drip depending on occupation(p < 0.05). This results can provide a fundamental information for industries or processors to develop or produce pork that satisfy each target consumer group in the future.