• Title/Summary/Keyword: contractibility

Search Result 18, Processing Time 0.036 seconds

DIGITAL TOPOLOGICAL PROPERTY OF THE DIGITAL 8-PSEUDOTORI

  • LEE, SIK;KIM, SAM-TAE;HAN, SANG-EON
    • Honam Mathematical Journal
    • /
    • v.26 no.4
    • /
    • pp.411-421
    • /
    • 2004
  • A digital $(k_0,\;k_1)$-homotopy is induced from digital $(k_0,\;k_1)$-continuity with the n kinds of $k_i$-adjacency relations in ${\mathbb{Z}}^n$, $i{\in}\{0,\;1\}$. The k-fundamental group, ${\pi}^k_1(X,\;x_0)$, is derived from the pointed digital k-homotopy, $k{\in}\{3^n-1(n{\geq}2),\;3^n-{\sum}^{r-2}_{k=0}C^n_k2^{n-k}-1(2{\leq}r{\leq}n-1(n{\geq}3)),\;2n(n{\geq}1)\}$. In this paper two kinds of digital 8-pseudotori stemmed from the minimal simple closed 4-curve and the minimal simple closed 8-curve with 8-contractibility or without 8-contractibility, e.g., $DT_8$ and $DT^{\prime}_8$, are introduced and their digital topological properties are studied by the calculation of the k-fundamental groups, $k{\in}\{8,\;32,\;64,\;80\}$.

  • PDF

The Effects of Backrest Angle on Lower Extremity Muscle Strength in Adult

  • Lee, Hae-Hyun;Bang, Hyun-Soo
    • Journal of Korean Physical Therapy Science
    • /
    • v.24 no.3
    • /
    • pp.12-17
    • /
    • 2017
  • Purpose: The purpose of this study was to investigate the effects of backrest angle on lower extremity muscle strength in adult. Method: This research results are based on 10 healthy adults. 10 degree difference in pelvic angle does not effect the cross-connection of the Hamstring muscles, and created 3 types of rest with 20 degree differences each at 95, 115, and 135 degree angles. Result: significantly difference in contractibility muscle strength in accordance to the 3 rake angle. Conclusion: After putting together all these results, since both the expansibility muscle strength and contractibility muscle strength of the knee showed to be effected as the backrest angle changed during isokinetic muscle strength assessment, further research should be conducted if similar research results as this study can be acquired at various angles.

$R^i$-SETS AND CONTRACTIVILITY

  • Baik, Bong-Sin;Hur, Kul;Rhee, Choon-Jai
    • Journal of the Korean Mathematical Society
    • /
    • v.34 no.2
    • /
    • pp.309-319
    • /
    • 1997
  • We introduce $R^i$-sets and give various relations between $R^i$-sets and prove that the hyperspace of a metric continuum containing any one of the $R^i$-set also contains $R^i$ and hence is not contractible.

  • PDF

COMMUTATIVE MONOID OF THE SET OF k-ISOMORPHISM CLASSES OF SIMPLE CLOSED k-SURFACES IN Z3

  • Han, Sang-Eon
    • Honam Mathematical Journal
    • /
    • v.32 no.1
    • /
    • pp.141-155
    • /
    • 2010
  • In this paper we prove that with some hypothesis the set of k-isomorphism classes of simple closed k-surfaces in ${\mathbf{Z}}^3$ forms a commutative monoid with an operation derived from a digital connected sum, k ${\in}$ {18,26}. Besides, with some hypothesis the set of k-homotopy equivalence classes of closed k-surfaces in ${\mathbf{Z}}^3$ is also proved to be a commutative monoid with the above operation, k ${\in}$ {18,26}.

Fabrication of PDMS micro-pads for vibration absorber in MEMS packaging (MEMS packaging을 위한 Micro PDMS pad 제작)

  • Kim, Han-Hyoung;Sim, Se-Hwan;Kim, Sung-Gi;Yang, Seung-Kook;O, Beom-Hoan;Lee, Seung-Gol;Lee, El-Hang;Park, Se-Geun;Lee, Jong-Geun
    • Proceedings of the IEEK Conference
    • /
    • 2008.06a
    • /
    • pp.511-512
    • /
    • 2008
  • Micro-pads made of PDMS(polydimethylsiloane) can be mechanical shock or vibration absorber because of its contractibility. Fabrication of micro-pads and techniques of separation from substrate and attachment to new substrate are developed. Three micron thick PDMS pads were fabricated by imprinting lithography.

  • PDF

The Effect of Luteolin on the Modulation of Vascular Contractility via ROCK and CPI-17 Inactivation

  • Hyuk-Jun, Yoon;Dae Hong, Kang;Fanxue, Jin;Joon Seok, Bang;Uy Dong, Sohn;Hyun Dong, Je
    • Biomolecules & Therapeutics
    • /
    • v.31 no.2
    • /
    • pp.193-199
    • /
    • 2023
  • In this investigation, we made a study of the efficacy of luteolin (a flavonoid found in plants such as vegetables, herbs and fruits) on vascular contractibility and to elucidate the mechanism underlying the relaxation. Isometric contractions of denuded muscles were stored and combined with western blot analysis which was conducted to assess the phosphorylation of myosin phosphatase targeting subunit 1 (MYPT1) and phosphorylation-dependent inhibitory protein for myosin phosphatase (CPI-17) and to examine the effect of luteolin on the RhoA/ROCK/CPI-17 pathway. Luteolin significantly alleviated phorbol ester-, fluoride- and thromboxane mimetic-elicited contractions regardless of endothelial nitric oxide synthesis, implying its direct effect on smooth muscle. It also significantly alleviated the fluoride-elicited elevation in pCPI-17 and pMYPT1 levels and phorbol 12,13-dibutyrate-elicited increase in pERK1/2 level, suggesting depression of ROCK and PKC/MEK activity and ensuing phosphorylation of MYPT1, CPI-17 and ERK1/2. Taken together, these results suggest that luteolin-elicited relaxation includes myosin phosphatase reactivation and calcium desensitization, which seems to be arbitrated by CPI-17 dephosphorylation via ROCK/PKC inhibition.

SUGGESTING IMPROVEMENT METHODS OF FORM WORK FOR COST REDUCTION IN THE MID-RISE APARTMENT HOUSING

  • Jeongseok Lee;Seunghee Kang;Gunhee Cho;Jeongrak Sohn;Jongdae Bang
    • International conference on construction engineering and project management
    • /
    • 2009.05a
    • /
    • pp.1608-1614
    • /
    • 2009
  • In recent days, the study of urban regeneration has been conducting with purposeful and sincere intent starting out with the residential environment improvement works. Within the range of urban regeneration, the low-cost housing technology means development of totally-integrated housing technology that may be applied to the regeneration project, especially for the rundown areas where infrastructure facilities in the urban zone have been degraded and obsoleted. In line with this, among many and varied methods in order for realization of the low-cost housing as a part of urban regeneration project, this study should like to propose an improvement methods of the key technologies in relation to the construction works by type of work with which construction costs (directing cost) would be reduced. And, in order to elicit the method for element technology that has been developed and improved in the most optimal manner centering on the selected construction work by the type of work, the researcher conducted comparative review of summary of element technologies related to the construction works concerned, characteristics, and construction method thereof. In particular, the researcher investigated the expenses (construction cost and labor cost), constructions (contractibility and productivity), safety, quality of works, and the technical status in environmental aspects, and the researcher also conducted analyses and evaluations thereof.

  • PDF