14,910 research outputs found

    Simple examples of distinct Liouville-type symplectic structures

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    We discuss some examples of open manifolds which admit non-isomorphic symplectic structures of Liouville type.Comment: v2: one remark added, minor change

    Covariation Among Vowel Height Effects on Acoustic Measures

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    Covariation among vowel height effects on vowel intrinsic fundamental frequency (IF0), voice onset time (VOT), and voiceless interval duration (VID) is analyzed to assess the plausibility of a common physiological mechanism underlying variation in these measures. Phrases spoken by 20 young adults, containing words composed of initial voiceless stops or /s/ and high or low vowels, were produced in habitual and voluntarily increased F0 conditions. High vowels were associated with increased IF0 and longer VIDs. VOT and VID exhibited significant covariation with IF0 only for males at habitua

    A new type of solution of the Schr\"odinger equation on a self-similar fractal potential

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    Scattering a quantum particle by a self-similar fractal potential on a Cantor set is investigated. We present a new type of solution of the functional equation for the transfer matrix of this potential, which was derived earlier from the Schr\"odinger equation.Comment: Latex, 4 pages, 7 eps-figures; the old figures are renewed and new ones are adde

    High-field phase diagram of the Haldane-gap antiferromagnet Ni(C5H14N2)2N3(PF6)Ni (C_5 H_{14} N_2)_2 N_3 (PF_6)

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    We have determined the magnetic phase diagram of the quasi-one-dimensional S=S= 1 Heisenberg antiferromagnet Ni(C5H14N2)2N3(PF6)Ni (C_5 H_{14} N_2)_2 N_3 (PF_6) by specific heat measurements to 150 mK in temperature and 32 T in magnetic field. When field is applied along the spin-chain direction, a new phase appears at Hc2≈14H_{c2}\approx 14 T. For the previously known phases of field-induced order, accurate determination is made of the power-law exponents of the ordering temperature near the zero-temperature critical field HcH_c, owing to the four-fold improvement of the minimum temperature over the previous work. The results are compared with the predictions based on the Bose-Einstein condensation of triplet excitations. Substituting deuterium for hydrogen is found to slightly reduce the interchain exchange.Comment: 6 pages, 6 figure

    Effects of age, sex, context, and lexicality on hyperarticulation of Korean fricatives

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    Seoul Korean is known for a rare three-way laryngeal contrast among lenis, fortis, and aspirated voiceless stops, which has recently undergone a change in phonetic implementation: whereas older speakers rely more on voice onset time (VOT) to distinguish lenis and aspirated stops, younger speakers rely more on onset fundamental frequency (f 0) in the following vowel. This production difference is reflected in disparate strategies for enhancing the contrast in clear speech, supporting the view that younger and older speakers represent the three laryngeal categories differently in terms of VOT and f 0 targets (Kang & Guion, 2008). In the current study, we used the clear speech paradigm to test for change in the representation of the two-way contrast between fortis (/s*/) and non-fortis (/s/) fricatives. Native Seoul Korean speakers (n = 32), representing two generations and both sexes, were recorded producing the coronal stops and fricatives in different vowel contexts, item types (real vs. nonce words), and speech registers (plain citation vs. clear). We report acoustic data on how the above factors influence production of the fricative contrast and discuss implications for the phonological categorization of non-fortis /s/ as lenis, aspirated, or a hybrid lenis-aspirated category.https://drive.google.com/open?id=0B1_NoAiLQlnkZ2RtdEtuYTlaMkkOthe

    Control in the π-calculus

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    This paper presents a type-preserving translation from the call-by-value -calculus ( v-calculus) into a typed -calculus, and shows full abstraction up to maximally consistent observational congruences in both calculi. The -calculus has a particularly simple representation as typed mobile processes where a unique stateless replicated input is associated to each name. The corresponding -calculus is a proper subset of the linear -calculus, the latter being able to embed the simplytyped -calculus fully abstractly. Strong normalisability of the v-calculus is an immediate consequence of this correspondence and the strong normalisability of the linear -calculus, using the standard argument based on simulation between the v-calculus and its translation. Full abstraction, our main result, is proved via an inverse transformation from the typed -terms which inhabit the encoded v-types into the v-calculus (the so-called de nability argument), using proof techniques from games semantics and process calculi. A tight operational correspondence assisted by the de nability result opens a possibility to use typed -calculi as a tool to investigate and analyse behaviours of various control operators and associated calculi in a uniform setting, possibly integrated with other language primitives and operational structures
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