• Title/Summary/Keyword: entanglement

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Concurrence of Rank-two Multipartite Quantum States (2-계수 양자상태의 양자얽힘 분석)

  • Bae, Joonwoo
    • Korean Journal of Optics and Photonics
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    • v.29 no.2
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    • pp.64-69
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    • 2018
  • In this work, we derive a general lower bound to concurrence of an arbitrary mixture of two pure states, that is, rank-two multipartite quantum states. We show that the lower bound can tightly detect entanglement of rank-two states, and also can be implemented experimentally with present-day technologies, i.e. single-copy level measurement and classical post-processing.

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.

Investigation of entanglement dynamics of flexible polymer chains via comparison of dielectric and viscoelastic properties: a review of recent findings

  • Watanabe, H.
    • Korea-Australia Rheology Journal
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    • v.13 no.4
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    • pp.205-217
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    • 2001
  • This review article summarizes results of recent viscoelastic and dielectric studies for entangled cis-polyisoprene (PI) chains. The PI chains have the so-called type-A dipoles parallel along the chain backbone, and their slow viscoelastic and dielectric relaxation processes reflect the same global chain motion. However, this motion is differently averaged in the viscoelastic and dielectric properties, the former representing the isochronal orientational anisotropy of individual entanglement segments while the latter detecting the orientational correlation of the segments at two separate times (0 and t). On the basis of this difference, the viscoelastic and dielectric data of the entangled PI chains were compared to elucidate detailed features of the chain dynamics. Specifically, the molecular picture of dynamic tube dilation (DTD) incorporated in recent models was tested for linear and star PI chain. The comparison revealed that the DTD picture was valid for linear PI chains but failed for the star PI chains in the dominant part of the terminal relaxation. The failure for the star chains was related to the pre-requisite for the DTD process, rapid equilibration of successive entanglement segments through their constraint release (CR) motion: For the star chains, the dilated tube diameter expected in the terminal regime was considerably large because of a broad distribution of motional modes of the chains, so that the CR-equilibration required for DTD could not occur in time. The terminal relaxation of the star chain appeared to occur through the CR process before the expected DTD process was completed. The situation was different for the linear chain exhibiting narrowly distributed motional modes. The dilated tube expected for the linear chain was rather thin and the required CR-equilibration occurred in time, resulting in the success of the DTD picture. These detailed features of the chain dynamics was revealed only when the viscoelastic and dielectric properties were compared, demonstrating the importance of this comparison.

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Kyeryong Mountain as a Contested Place (경합(競合) 장소(場所)로서의 계룡산(鷄龍山))

  • Ryu Je-Hun
    • Journal of the Korean Geographical Society
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    • v.40 no.5 s.110
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    • pp.553-570
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    • 2005
  • On Kyeryong Mountain, different religious(or ideological) groups have endowed space and place with amalgams of different meanings, uses and values. In addition to Buddhism and Confucianism, Shamanism and other popular beliefs have practiced their own ideologies(or powers) to create and maintain their own territories and identities. The geographies of resistance, involving Shamanism, have been scattered all over the mountain, discontinuous in the territorialization. These geographies of resistance could be identified the best around the most sacred sites, such as Sambulbong, Amyongch'u and Sutyongch'u. The entanglement of Shamanism with Buddhism, in various patterns through space and time, has indeed contributed to the survival of Shamanism as a subordinate power.

Development of a Single Tangle Net for the Brown Shrimp by Observation of Entanglement Behaviour

  • Kim Yong-Hae
    • Fisheries and Aquatic Sciences
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    • v.6 no.1
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    • pp.34-40
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    • 2003
  • Three panel trammel nets were made illegal for the brown shrimp (Penaeus japonicus) or fishes by Korean fisheries law while trammel nets for fleshy prawn in the West sea remained legal. In this study a single panel tangle net with vertical loop lines rigged between the float line and sinker line was specially designed to catch brown shrimp. This net was developed for the first time after observation of the brown shrimp behaviour when reacting to a net in an observation tank. In field experiments these single tangle nets were compared with the traditional trammel nets in the coastal waters of the Keoje area. The mean number of the brown shrimp for 53 fishing operations was 1.13 per unit panel of the single tangle nets when fitted with the vertical loop lines. This was $84\%$ of the mean catch of 1.36 achieved with the trammel nets. These results of fishing experiments using single tangle nets in the field revealed a high fishing efficiency for the brown shrimp and showed little difference from trammel nets. The size of the brown shrimp or number of by-catch was not different between single tangle nets and trammel nets.