20,055 research outputs found

    The Impacts of Animal Disease Crises on the Korean Meat Market

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    Employing the error correction method and historical decomposition with direct acyclic graphs, we quantify the impacts of domestic and oversea animal disease crises on the Korean meat markets. We find that (a) the market partially recovered 16 months after the foot-and-mouth outbreak in 2000, and 13 months after the avian influenza and the U.S. BSE incidents in 2003; (b) animal disease outbreaks have differentiate impacts by disease type and supply chain level. Retailers likely to have windfall profits as the retail price margin increased relative to the farm and wholesale levels; and (c) disease outbreaks affect dynamic price interdependence.Animal disease outbreak, Error correction model, Direct acyclic graphs, Korean meat market, Historical Decomposition, Price margins, Livestock Production/Industries, C32, Q11, L11,

    Does three-tangle properly quantify the three-party entanglement for Greenberger-Horne-Zeilinger-type states?

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    Some mixed states composed of only GHZ states can be expressed in terms of only W-states. This fact implies that such states have vanishing three-tangle. One of such rank-3 states, ΠGHZ\Pi_{GHZ}, is explicitly presented in this paper. These results are used to compute analytically the three-tangle of a rank-4 mixed state σ\sigma composed of four GHZ states. This analysis with considering Bloch sphere S16S^{16} of d=4d=4 qudit system allows us to derive the hyper-polyhedron. It is shown that the states in this hyper-polyhedron have vanishing three-tangle. Computing the one-tangles for ΠGHZ\Pi_{GHZ} and σ\sigma, we prove the monogamy inequality explicitly. Making use of the fact that the three-tangle of ΠGHZ\Pi_{GHZ} is zero, we try to explain why the W-class in the whole mixed states is not of measure zero contrary to the case of pure states.Comment: 10 pages, no figure V2: new calculational results are included. 11 pages: V3 accepted in the Rapid Communication of PRA, 4 pages (two column

    Infodemiološka studija o upotrebi maski za lice tijekom pandemije COVID-19: usporedba SAD-a i Južne Koreje

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    In the midst of the COVID-19 pandemic, there have been varied responses to public health officials\u27 recommendations about wearing face masks as a means to slow the spread of the virus. This study, by using Twitter data, aims to explore the role of digital technology in facilitating public conversations and formulating public perception regarding face masks during the COVID-19 pandemic in two contrasting contexts: the U.S. and South Korea. From January 1, 2020 to April 14, 2020, a total of 22,928 users generated 27,501 tweets regarding face masks in the U.S. network, whereas 17,267 users produced 18,686 tweets in that of South Korea. The results of the semantic network analysis shed light on Americans\u27 initial resistance to wearing masks as well as Koreans\u27 willingness to comply. Details of the results are discussed further in the paper. With real-time data aggregation, this study gives insight into the rising controversy regarding wearing face masks during COVID-19 while providing implications for health officials designing strategic communication messages.Usred pandemije COVID-19, dobivamo različite odgovore na preporuke službenika javnoga zdravstva o nošenju maski za lice kao mjere koja usporava širenje virusa. Ova se studija koristi podacima s Twittera kako bi istražila ulogu digitalne tehnologije u olakšavanju javne komunikacije i formuliranju percepcije javnosti o nošenju maski tijekom pandemije COVID-19 u dva konteksta: SAD-u i Južnoj Koreji. Od 1. siječnja do 14. travnja 2020. u mreži SAD-a ukupno je 22 928 korisnika generiralo 27 501 tweet na temu maski za lice, dok ih je u Južnoj Koreji 17 267 korisnika proizvelo 18 686. Rezultati analize semantičke mreže otkrivaju početni otpor Amerikanaca prema nošenju maski, kao i spremnost Korejaca da se mjera pridržavaju. Pojedinosti rezultata iznesene su u radu. Uz agregaciju podataka u stvarnom vremenu, ova studija daje uvid u sve veći prijepor povezan s nošenjem maski za lice tijekom pandemije COVID-19, dajući u isti mah informacije zdravstvenim djelatnicima koji oblikuju strateške komunikacijske poruke

    Three-way electrical gating characteristics of metallic Y-junction carbon nanotubes

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    Y-junction based carbon nanotube (CNT) transistors exhibit interesting switching behaviors, and have the structural advantage that the electrical gate for current modulation can be formed by any of the three constituent branches. In this letter, we report on the gating characteristics of metallic Y-CNT morphologies. By measuring the output conductance and transconductance we conclude that the efficiency and gain depend on the branch diameter and is electric field controlled. Based on these principles, we propose a design for a Y-junction based CNT switching device, with tunable electrical properties

    Skyrmion Lattice in Two-Dimensional Chiral Magnet

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    We develop a theory of the magnetic field-induced formation of Skyrmion crystal state in chiral magnets in two spatial dimensions, motivated by the recent discovery of the Skyrmionic phase of magnetization in thin film of Fe0.5_{0.5}Co0.5_{0.5}Si and in the A-phase of MnSi. Ginzburg-Landau functional of the chiral magnet re-written in the CP1^1 representation is shown to be a convenient framework for the analysis of the Skyrmion states. Phase diagram of the model at zero temperature gives a sequence of ground states, helical spin \rightarrow Skyrme crystal \rightarrow ferromagnet, as the external field BB increases, in good accord with the thin-film experiment. In close analogy with Abrikosov's derivation of the vortex lattice solution in type-II superconductor, the CP1^1 mean-field equation is solved and shown to reproduce the Skyrmion crystal state.Comment: 10 pages, 7 figure

    Comparative Assessment of Performance Differentials for Male-and-Female-Owned Small Accounting Firms at the Beginning and End of a Ten Year Period

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     The objective of this study was to determine whether the performance gap over a period of ten years between male- and female-owned small accounting firms has converged utilizing a resource-based framework to assess performance. The relevant assets for these firms included human, organizational, and entrepreneurial capital. An analysis of covariance (ANCOVA) was used to determine whether the gender productivity gap converged over this period of time. The response rates were 30 percent and 23 percent respectively for the 1993 and 2003 investigations. An analysis of the data indicates several important findings that (1) a performance gap exists when measured by gross revenues between male- and female-owned small accounting firms, (2) this performance gap has converged after ten years, and (3) the performance gap as measured by the ratio of net profit to sales indicates that female-owned small accounting firms do better than male owned accounting firms
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