• Title/Summary/Keyword: Knot

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RNA FOLDINGS AND STUCK KNOTS

  • Jose Ceniceros;Mohamed Elhamdadi;Josef Komissar;Hitakshi Lahrani
    • Communications of the Korean Mathematical Society
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    • v.39 no.1
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    • pp.223-245
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    • 2024
  • We study RNA foldings and investigate their topology using a combination of knot theory and embedded rigid vertex graphs. Knot theory has been helpful in modeling biomolecules, but classical knots emphasize a biomolecule's entanglement while ignoring their intrachain interactions. We remedy this by using stuck knots and links, which provide a way to emphasize both their entanglement and intrachain interactions. We first give a generating set of the oriented stuck Reidemeister moves for oriented stuck links. We then introduce an algebraic structure to axiomatize the oriented stuck Reidemeister moves. Using this algebraic structure, we define a coloring counting invariant of stuck links and provide explicit computations of the invariant. Lastly, we compute the counting invariant for arc diagrams of RNA foldings through the use of stuck link diagrams.

2n-Moves and the Γ-Polynomial for Knots

  • Hideo Takioka
    • Kyungpook Mathematical Journal
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    • v.64 no.3
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    • pp.511-518
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    • 2024
  • A 2n-move is a local change for knots and links which changes 2n-half twists to 0-half twists or vice versa for a natural number n. In 1979, Yasutaka Nakanishi conjectured that the 4-move is an unknotting operation. This is still an open problem. It is known that the Γ-polynomial is an invariant for oriented links which is the common zeroth coefficient polynomial of the HOMFLYPT and Kauffman polynomials. In this paper, we show that the 4k-move is not an unknotting operation for any integer k(≥ 2) by using the Γ-polynomial, and if Γ(K; -1) ≡ 9 (mod 16) then the knot K cannot be deformed into the unknot by a single 4-move. Moreover, we give a one-to-one correspondence between the value Γ(K; -1) (mod 16) and the pair (a2(K), a4(K)) (mod 2) of the second and fourth coefficients of the Alexander-Conway polynomial for a knot K.

Knot Tying & Pushing

  • Yu, Jae-Cheol
    • The Academic Congress of Korean Shoulder and Elbow Society
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    • 2005.11a
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    • pp.214-217
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    • 2005
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Resistance of Commercial Pepper Cultivars to Root-knot Nematodes (시판 고추품종에 대한 뿌리혹선충 저항성 검정)

  • Kim, Donggeun;Kwon, Taeyoung;Ryu, Younghyun;Yeon, Ilkwon;Huh, Changseok
    • Research in Plant Disease
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    • v.18 no.4
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    • pp.370-375
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    • 2012
  • Ninety two pepper (Capsicum annuum L.) cultivars were screened for resistance to two common species of root-knot nematodes, Meloidogyne incognita and M. arenaria. All 92 pepper cultivars were resistant to M. arenaria (0-3 eggmass/plant) but were susceptible to M. incognita (76-678 eggmass/plant). Susceptibility to M. incognita were slightly differed; 'Geomok' and 'Shintaepung' had relatively less eggmass (<100 eggmass/plant) when compared to those 29 very susceptible culivars such as 'Bulggotcheoreum' (>300 eggmass/plant). Therefore, pepper is highly recommended as a high-valued rotation crop to only those greenhouses infested with M. arenaria, but should restrict for M. incognita.

Effects of Soil Textures on Infectivity of Root-Knot Nematodes on Carrot

  • Kim, Eunji;Seo, Yunhee;Kim, Yong Su;Park, Yong;Kim, Young Ho
    • The Plant Pathology Journal
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    • v.33 no.1
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    • pp.66-74
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    • 2017
  • This study was conducted to examine infectivity (penetration and gall and egg-mass formations) of the root-knot nematodes, Meloidogyne incognita and M. hapla, on carrots grown in soil conditions of 5 different soil textures consisting of bed-soil (b) and sand (s) mixtures (b-s mixtures) at the ratios of 10:0, 7:3, 5:5, 3:7, and 0:10. For M. incognita, the nematode penetration rates in b-s of 0:10 (100% sand) were significantly higher than in the other b-s mixtures, more greatly at 2 and 5 days after inoculation than at 10 DAI, while no significant differences in the penetration rates were mostly shown for M. hapla at the above DAI. However, for both nematodes, gall and egg-mass formations were remarkably increased in the b-s mixture of 0:10, compared to the other b-s mixtures, which is coincided with the general aspects of severe nematode infestations in sandy soils. This suggests the increased gall and egg-mass formations of M. incognita should be derived from the increased penetration rates in the sandy soil conditions, which provide a sufficient aeration due to coarse soil nature for the nematodes, leading to their mobility increased for the enhanced root penetration. For M. hapla, it is suggested that the sandy soil conditions affect positively on the healthy plant growth with little accumulation of the inhibitory materials and sufficient aeration, enhancing the nematode growth and feeding activities. All of these aspects provide information reliable for the development screening techniques efficient for the evaluation of the nematode resistance in the breeding programs.

Field Application of Egg and Larval Parasitic Fungi and Chemicals for Controlling Root-knot Nematodes on Some Medicinal Herb (몇종의 선충천적 진균과 화학약제를 이용한 약용작물 뿌리혹선충 방제효과 검토)

  • 박소득;추연대;정기채;심용구;최영연
    • Korean journal of applied entomology
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    • v.32 no.1
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    • pp.105-114
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    • 1993
  • Series of studies were conducted to establish biological and chemical control method for Meloidogyne spp to medical herbs by applied of nematophagous fungi, Arthrobotrys spp, Fusarium spp, and egg parastic fungi, Paecilomyces lilacinus were applied for root-knot nematodes on medicinal herbs, Paeonia albiflora, Codonopsis lanceolata, Cnidium officinale. The results are as follow. In pot experiments, The no. of root gall and egg mass and larvae of Cnidium officinale. The results are as follow. In pot experiments. The no. of root gall and egg mass and larvae of Cnidium officinale, Codonopsis lanceolata, Paeonia japonica lowered in P. Lilacinus treated plots compare to untreated control plots. But A. thaumasia F. oxysporum treated plots were less effective. Effect of egg parasitic fungi and chemical treatment at divided root of Paeonia japonica after sterilized in pot were increased in the fresh weight, root weight, control effect in P. lilacinus treated plots as chemical, Carbo G treated plots compare to untreted control plots. I field experiment, the number of root gall, egg mass and nematode density of Paeonia were also suppressed in P. lilacinus treated plots. It was very effective continuous 2 years and transplanting time on Paeonia japonica infested soil with the M. hapla in field in both region, Chillgok and Euisung treated P. lilacinus as chemical treated plots. Soaking effect of insecticide for Paeonia japonica at diving shoot before transplating in pot were effective for 12hours immersion into 1,000 ppm of Benlate T + Mep Ec, Benlate T + Fenthion EC in pot and field Experiment. In the Examination of fungi activily on P.japonica field 1 year after soil treatment, Number of spore of P. lilacinus were 1,000~1,300 in 3 region except Euisung.

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A Review of the Restoration of Braid Belt, Gwangdahoe by Goryeojo Weaving Method in Joseon Dynasty (고려조 기법의 조선시대 광다회 복원 고찰)

  • Lim, Keum-Hee;Cho, Woo-Hyun
    • Journal of the Korean Society of Costume
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    • v.59 no.6
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    • pp.140-155
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    • 2009
  • This study tries to find out the special twine technique of flat string and refers to historical documents, records, artifacts of excavated articles, and real materials. In Japan weaved cloth is called Jomul or Jonue and these methods were brought to Japan from Korea during Aska Period(645${\sim}$710) and Nara Period(710${\sim}$794). Among those knot methods, the 1/1 knot was written as a Shillajo on a documentary record at Heian Period, Engisik, and Samdaesillok which is a historic document from King Saiya to King Gowooko(858${\sim}$887). Also 2/2 knot weaving was recorded as Goryeojo that the technique originated for a long time in Japan. During the Joseon Dynasty, Gunmok was written as Dahoi, and Gwangdahoe, which means wide and flat Gunmok, was the name of Dae(Belt). The frame for the twine Gwangdahoe is no longer in Korea, but only can be found in Japan as a Goraiwoochi loom for Shillajo and Goryeojo from Korea. There are currently artifacts by the techniques of Shillajo and Goryeojo that were excavated in 15${\sim}$17C in Korea. Therefore this study was looked into the artifacts from 6${\sim}$8C in $Sh{\"{O}}so$-in, and the features of Dae (Belt) weaved by Shillajo and Goryeojo case method. Gwangdahoe excavated artifacts in the mid Jeosun Dynasty was restored by the process of Goryeojo weaving method.

The study on the possibility of performance analysis for the compressive member using the numerical method (수치해석법을 활용한 압축부재 성능 해석의 가능성에 대한 연구)

  • Kim, Gwang-Chul
    • Journal of the Korea Furniture Society
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    • v.21 no.1
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    • pp.26-39
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    • 2010
  • This is a leading study to replace the structural analysis methodology on the specific traditional joint by a numerical analysis. Tests were carried out to test the compressive methodologies with the numerical results. The Japanese larch was used as a sample. The Orthotropic property of wood was specifically considered for the finite element numerical analysis. Linear numerical analysis and non-linear numerical analysis for the BEAM element and the two SOLID elements of ANSYS were used to analyze the compressive performance. In addition, more finely divided elements were used to raise the accuracy of the numerical result. Finally, the statistically significant differences were tested between that of the analytical and numerical results. It could be concluded that the SOLID 64 element shows the most optimum result when the non-linear analysis with the more finely divided element was used. However, finely dividing of the element is a considerable time consuming process, and it is quite difficult to raise the accuracy of the non-linear numerical analysis. Therefore, if considering the vertical displacement to be of the only interest, the BEAM element is more efficient than the SOLID element because the BEAM element is reflected as a simple line, which is less time consuming and difficult in dividing the elements. But, the BEAM element cannot accurately model the knot as a strength defect factor which is an important property in the orthotropic property of wood. Therefore, the SOLID element should be used to model the strength defect factor, knot, as it can be efficiently applied on the structural size flexure member which could be more strongly effected by the knot. In addition, it is useful at times when the failure types of members are to be more closely investigated, as the SOLID element is able to examine the local stress distribution of the member. The conclusion drawn by this study is of the good concordance between analytical results and numerical results of compressive wood members, but how orthotropic properties should only be considered. The numerical analysis on the specific Korean traditional joints will be based on the current study results.

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