• Title/Summary/Keyword: Knot

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Effects of some Insecticides on Growth of 2 year old Ginseng Panax ginseeng, C.A. Meyer, and Control of Root-knot nematode (몇가지 살충제의 조합이 인삼의 생육 및 근류선충 방제 효과에 미치는 영향)

  • Ahn Y.J.;Choi S.Y.;Han S.C.;Kim Y.T.
    • Korean journal of applied entomology
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    • v.20 no.4 s.49
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    • pp.223-227
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    • 1981
  • These experiments were conducted to investigate the nematicidal effects of the insecticides, Mocap(O-Ethyl-S, S-dipropyl phosphorodithioate), Carbofuran(2,3-Dihydro-2,2-dimethyl benzofuranyl ethyl carbamate), Terbufos (S-tert-buthylthio methyl O,O-diethyl phosphordithioate) and their mixtures (Mocap+carbofuran, Mocap+Terbufos, Carbofuran+Terbufos) on growth of 2year-old ginseng, Panax ginseng C.A. Meyer, and the control of root-knot nematodes. There was no evidence of plant injury from insecticide treatment of ginseng, although the rate of emergence of the treated ginseng was slightly inhibited. The insecticide treatments showed no of-flavor of ginseng plant. Terbufos and Mocap provided heifer confrol of the root-knot nematodes than carbofuran alone and their mixtures. Mixtures of the insecticides showed antagonisitic effect to the root-knot nematodes.

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Finite Type Invariants and the Kauffman Bracket Polynomials of Virtual Knots

  • Jeong, Myeong-Ju;Park, Chan-Young;Yeo, Soon Tae
    • Kyungpook Mathematical Journal
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    • v.54 no.4
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    • pp.639-653
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    • 2014
  • In [9], Kauffman introduced virtual knot theory and generalized many classical knot invariants to virtual ones. For example, he extended the Jones polynomials $V_K(t)$ of classical links to the f-polynomials $f_K(A)$ of virtual links by using bracket polynomials. In [4], M. Goussarov, M. Polyak and O. Viro introduced finite type invariants of virtual knots. In this paper, we give a necessary condition for a virtual knot invariant to be of finite type by using $t(a_1,{\cdots},a_m)$-sequences of virtual knots. Then we show that the higher derivatives $f_K^{(n)}(a)$ of the f-polynomial $f_K(A)$ of a virtual knot K at any point a are not of finite type unless $n{\leq}1$ and a = 1.

Quantization of the Crossing Number of a Knot Diagram

  • KAWAUCHI, AKIO;SHIMIZU, AYAKA
    • Kyungpook Mathematical Journal
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    • v.55 no.3
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    • pp.741-752
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    • 2015
  • We introduce the warping crossing polynomial of an oriented knot diagram by using the warping degrees of crossing points of the diagram. Given a closed transversely intersected plane curve, we consider oriented knot diagrams obtained from the plane curve as states to take the sum of the warping crossing polynomials for all the states for the plane curve. As an application, we show that every closed transversely intersected plane curve with even crossing points has two independent canonical orientations and every based closed transversely intersected plane curve with odd crossing points has two independent canonical orientations.

A Study of Geometric Modeling for Ship Hull Forms Using Open Uniform B-spline Surface (Open 균일 B-spline 곡면을 이용한 선체 곡면 표현에 관한 연구)

  • H.K. Shin;K.W. Park
    • Journal of the Society of Naval Architects of Korea
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    • v.28 no.2
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    • pp.21-27
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    • 1991
  • This paper outlines the method of formulating the bi-cubic B-spline surface of ship hull, employing the open uniform knot vector as well as the periodic uniform knot vector. An appropriate set of B-spline control vertices to generate the B-spline surface is determined by obtaining the pseudoinverse matrix of basis functions. The comparison between the given offsets and the resulting coordinates from the generated ship hull surface shows a good agreement. To check the fairness of the surface Gaussian curvature is calculated on many small subpatches and displayed on the black-and-white plot of the isoparametric net of the surface.

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Control Effect on Root-knot Nematodes by Hot Water Dipping Treatment in Kiwifruit

  • Ma, K.;Cho, Y.;Jeong, B.;Choi, D.
    • Korean Journal of Organic Agriculture
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    • v.19 no.spc
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    • pp.255-258
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    • 2011
  • When kiwifruit root system infected with nematodes was treated by hot water dipping treatment, the maximum temperature for this treatment was suggested as $50^{\circ}C$. The lowest killing temperature of internal root-knot in the root tissue was $48^{\circ}C$. Consequently, root-knot nematodes could be killed without damaging root tissues by the hot water dipping treatment at $48^{\circ}C$ for 10 minutes. This could be useful for organic production and distribution of kiwifruit seedlings by avoiding the synthetic nematicides which are not easily decomposed in soil once applied.

Model test on the net mouth shape of a gape net according to current speeds in Jindo area, Korea (전남 진도지역 낭장망의 유속에 따른 망구형상 변화에 관한 모형실험)

  • Kim, Seonghun;Lee, Donggil;Lim, Jihyun;Park, Seongwook
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.51 no.1
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    • pp.146-153
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    • 2015
  • A model net experiment of the gape net for anchovy in Jindo, Jeollanam-do was carried out to investigate the net shape and hydrodynamic resistance using circulating water channel. The model net was made 1/33 down scale by Tauti's similarity method and the range of experimental current speed was from 0.5 knot to 3.5 knot (increasing 0.5 knot interval). The net mouth height in 0.5 knot of the minimum experiment current speed was shown 26.0 cm (full-scale conversion value 8.58 m). The net mouth height and mouth area in 1.5 knot of the same current speed with a gape net fishing ground were shown 20.0 cm (full-scale conversion value : 6.60 m) and about $507.9cm^2$ (full-scale conversion value : $55.31m^2$). The net mouth height and area were decreased with increase the experimental current speed. The hydrodynamic resistance of the model net in 1.5 knot current speed was shown 1.11 kgf and the value of full-scale conversion by Tauti's method was shown 3.996 ton.

Molecular Biological Diagnosis of Meloidogyne Species Occurring in Korea

  • Oh, Hyung-Keun;Bae, Chang-Hwan;Kim, Man-Il;Wan, Xinlong;Oh, Seung-Han;Han, Yeon-Soo;Lee, Hyang-Burm;Kim, Ik-Soo
    • The Plant Pathology Journal
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    • v.25 no.3
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    • pp.247-255
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    • 2009
  • Root-knot nematode species, such as Meloidogyne hapla, M. incognita, M. arenaria, and M. javanica are the most economically notorious nematode pests, causing serious damage to a variety of crops throughout the world. In this study, DNA sequence analyses were performed on the D3 expansion segment of the 28S gene in the ribosomal DNA in an effort to characterize genetic variations in the three Meloidogyne species obtained from Korea and four species from the United States. Further, PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism), SCAR (Sequence Characterized Amplified Region) PCR and RAPD (Randomly Amplified Polymorphic DNA) were also utilized to develop methods for the accurate and rapid species identification of the root-knot nematode species. In the sequence analysis of the D3 expansion segment, only a few nucleotide sequence variations were detected among M. incognita, M. arenaria, and M, javanica, but not M. hapla. As a result of our haplotype analysis, haplotype 5 was shown to be common in M. arenaria, M. incognita, M. javanica, but not in the facultatively parthenogenetic species, M. hapla. PCR-RFLP analysis involving the amplification of the mitochondrial COII and large ribosomal RNA (lrRNA) regions yielded one distinct amplicon for M. hapla at 500 bp, thereby enabling us to distinguish M. hapla from M. incognita, M. arenaria, and M. javanica reproduced via obligate mitotic parthenogenesis. SCAR markers were used to successfully identify the four tested root-knot nematode species. Furthermore, newly attempted RAPD primers for some available root-knot nematodes also provided some species-specific amplification patterns that could also be used to distinguish among root-knot nematode species for quarantine purposes.