423 research outputs found

    Path description for qq-characters of fundamental modules in type CC

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    In this paper, we investigate the behavior of monomials in the qq-characters of the fundamental modules over a quantum affine algebra of untwisted type C. As a result, we give simple closed formulae for the qq-characters of the fundamental modules in terms of sequences of vertices in R2\mathbb{R}^2, so-called paths, with an admissible condition. This may be viewed as a type C analog of the path description of qq-characters in types A and B due to Mukhin--Young.Comment: v4: minor revision; v3: 23 pages, revised introduction and abstract, reference added, comments added on Remark 2.1, 3.1, 3.2, 4.5, 4.9, 4.10, added Section 4.2 to explain connected components, added Examples 2.4, 4.4, added Lemma 4.6, revised proof of Theorem 4.7, and several typos corrected; v2: 15 pages, typos corrected, reference correcte

    Bivariate Beta-LSTM

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    Long Short-Term Memory (LSTM) infers the long term dependency through a cell state maintained by the input and the forget gate structures, which models a gate output as a value in [0,1] through a sigmoid function. However, due to the graduality of the sigmoid function, the sigmoid gate is not flexible in representing multi-modality or skewness. Besides, the previous models lack modeling on the correlation between the gates, which would be a new method to adopt inductive bias for a relationship between previous and current input. This paper proposes a new gate structure with the bivariate Beta distribution. The proposed gate structure enables probabilistic modeling on the gates within the LSTM cell so that the modelers can customize the cell state flow with priors and distributions. Moreover, we theoretically show the higher upper bound of the gradient compared to the sigmoid function, and we empirically observed that the bivariate Beta distribution gate structure provides higher gradient values in training. We demonstrate the effectiveness of bivariate Beta gate structure on the sentence classification, image classification, polyphonic music modeling, and image caption generation.Comment: AAAI 202

    Crystal base of the negative half of the quantum superalgebra Uq(gl(m∣n))U_q(\mathfrak{gl}(m|n))

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    We construct a crystal base of Uq(gl(m∣n))βˆ’U_q(\mathfrak{gl}(m|n))^-, the negative half of the quantum superalgebra Uq(gl(m∣n))U_q(\mathfrak{gl}(m|n)). We give a combinatorial description of the associated crystal Bm∣n(∞)\mathscr{B}_{m|n}(\infty), which is equal to the limit of the crystals of the (qq-deformed) Kac modules K(Ξ»)K(\lambda). We also construct a crystal base of a parabolic Verma module X(Ξ»)X(\lambda) associated with the subalgebra Uq(gl0∣n)U_q(\mathfrak{gl}_{0|n}), and show that it is compatible with the crystal base of Uq(gl(m∣n))βˆ’U_q(\mathfrak{gl}(m|n))^- and the Kac module K(Ξ»)K(\lambda) under the canonical embedding and projection of X(Ξ»)X(\lambda) to Uq(gl(m∣n))βˆ’U_q(\mathfrak{gl}(m|n))^- and K(Ξ»)K(\lambda), respectively.Comment: 43 page

    Tensile Behavior and Cracking Pattern of an Ultra-High Performance Mortar Reinforced by Polyethylene Fiber

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    This paper presents an experimental study of the compressive strength, tensile behavior (including the tensile strength, tensile strain capacity, and toughness), and cracking patterns of an ultra-high performance mortar (UHPM) reinforced by polyethylene (PE) fiber as well as a discussion of the different tensile behaviors of the UHPM according to the types and contents of fibers used. The UHPM reinforced by microsteel fiber of 1.5 vol% and the UHPM reinforced by PE fibers with three different fiber contents were designed and prepared. A series of experiments was undertaken to assess the effect of PE fiber on the properties of the UHPM. The results found a lower strength level, higher tensile strain capacity and toughness, and a larger crack width in the PE fiber-reinforced UHPM compared to microsteel fiber-reinforced UHPM. It was also demonstrated that tensile strain capacity and toughness of 4.05% and 0.454 MPa m/m, respectively, can be attained when using the proposed polyethylene-fiber-reinforced UHPM

    Quantization of virtual Grothendieck rings and their structure including quantum cluster algebras

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    The quantum Grothendieck ring of a certain category of finite-dimensional modules over a quantum loop algebra associated with a complex finite-dimensional simple Lie algebra g\mathfrak{g} has a quantum cluster algebra structure of skew-symmetric type. Partly motivated by a search of a ring corresponding to a quantum cluster algebra of {\em skew-symmetrizable} type, the quantum {\em virtual} Grothendieck ring, denoted by Kq(g)\mathfrak{K}_q(\mathfrak{g}), is recently introduced by Kashiwara--Oh \cite{KO23} as a subring of the quantum torus based on the (q,t)(q,t)-Cartan matrix specialized at q=1q=1. In this paper, we prove that Kq(g)\mathfrak{K}_q(\mathfrak{g}) indeed has a quantum cluster algebra structure of skew-symmetrizable type. This task essentially involves constructing distinguished bases of Kq(g)\mathfrak{K}_q(\mathfrak{g}) that will be used to make cluster variables and generalizing the quantum TT-system associated with Kirillov--Reshetikhin modules to establish a quantum exchange relation of cluster variables. Furthermore, these distinguished bases naturally fit into the paradigm of Kazhdan--Lusztig theory and our study of these bases leads to some conjectures on quantum positivity and qq-commutativity

    The Light and Period Variations of the Eclipsing Binary AA Ursae Majoris

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    We present new multiband CCD photometry for AA UMa made on 8 nights between January and March 2009; the RR light curves are the first ever compiled. Historical light curves, as well as ours, display partial eclipses and inverse O'Connell effects with Max I fainter than Max II. Among possible spot models, a cool spot on either of the component stars and its variability with time permit good light-curve representations for the system. A total of 194 eclipse timings over 81 yrs, including our five timings, were used for ephemeris computations. We found that the orbital period of the system has varied due to a periodic oscillation overlaid on an upward parabolic variation. The continuous period increase at a fractional rate of ++1.3Γ—\times10βˆ’10^{-10} is consistent with that calculated from the W-D code and can be interpreted as a thermal mass transfer from the less to the more massive secondary star at a rate of 6.6Γ—\times10βˆ’8^{-8} MβŠ™_\odot yrβˆ’1^{-1}. The periodic component is in satisfactory accord with a light-time effect due to an unseen companion with a period of 28.2 yrs, a semi-amplitude of 0.007 d, and a minimum mass of M3sin⁑i3M_3 \sin i_3=0.25 MβŠ™M_\odot but this period variation could also arise from magnetic activity.Comment: 23 pages, including 5 figures and 8 tables, accepted for publication in PAS
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