1,143 research outputs found

    Fermi Surface Reconstruction without Breakdown of Kondo Screening at Quantum Critical Point

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    Motivated by recent Hall-effect experiment in YbRh2_2Si2_2, we study ground state properties of a Kondo lattice model in a two-dimensional square lattice using variational Monte Carlo method. We show that there are two types of phase transition, antiferromagnetic transition and topological one (Fermi surface reconstruction). In a wide region of parameters, these two transitions occur simultaneously without the breakdown of Kondo screening, accompanied by a discontinuous change of the Hall coefficient. This result is consistent with the experiment and gives a novel theoretical picture for the quantum critical point in heavy fermion systems.Comment: 4 pages, 3 figures, submitted to Physical Review Letter

    Relict minerals and their assemblages in Yamato-691 (EH3)

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    Four relict minerals; olivine, pyroxene, a silica mineral and metallic (Fe, Ni) were found in the chondrules and as the mineral fragments of Yamato-691 (EH3). Two mineral assemblages of the relict minerals were found; (a) olivine+pyroxene+metallic (Fe, Ni), and (b) pyroxene+silica mineral. The relict pyroxene in assemblage (a) was formed from the reaction of olivine and silica-rich phase (gas or liquid). These two assemblages cannot coexist under an equilibrium condition. The compositional difference of pyroxene between assemblages (a) and (b) suggests the fractionation which occurred before the chondrule formation

    Uber die epitheloiden Histiozyten nach Hamazaki. : I. Abteilung. Zur Histologie der Zerebrospinalmeningen.

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    The phonological system of a sign language comprises meaningless sub-lexical units that define the structure of a sign. A number of studies have examined how learners of a sign language as a first language (L1) acquire these components. However, little is understood about the mechanism by which hearing adults develop visual phonological categories when learning a sign language as a second language (L2). Developmental studies have shown that sign complexity and iconicity, the clear mapping between the form of a sign and its referent, shape in different ways the order of emergence of a visual phonology. The aim of the present dissertation was to investigate how these two factors affect the development of a visual phonology in hearing adults learning a sign language as L2. The empirical data gathered in this dissertation confirms that sign structure and iconicity are important factors that determine L2 phonological development. Non-signers perform better at discriminating the contrastive features of phonologically simple signs than signs with multiple elements. Handshape was the parameter most difficult to learn, followed by movement, then orientation and finally location which is the same order of acquisition reported in L1 sign acquisition. In addition, the ability to access the iconic properties of signs had a detrimental effect in phonological development because iconic signs were consistently articulated less accurately than arbitrary signs. Participants tended to retain the iconic elements of signs but disregarded their exact phonetic structure. Further, non-signers appeared to process iconic signs as iconic gestures at least at the early stages of sign language acquisition. The empirical data presented in this dissertation suggest that non-signers exploit their gestural system as scaffolding of the new manual linguistic system and that sign L2 phonological development is strongly influenced by the structural complexity of a sign and its degree of iconicity

    Weakly nonlinear analysis of dispersive waves in mixtures of liquid and gas bubbles based on a two-fluid model

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    One-dimensional nonlinear dispersive waves in liquids containing a number of microbubbles are theoretically studied based on two-fluid averaged equations derived by the present authors. The set of equations consists of the conservation laws of mass and momentum for gas and liquid phases, and the equation of motion of the bubble wall. The compressibility of liquid is taken into account, and this leads to the wave attenuation due to bubble oscillations. By using the method of multiple scales, two types of equations for nonlinear wave propagation in long ranges are derived. In a moderately low frequency band, the behavior of weakly nonlinear waves is described by the Korteweg de Vries Burgers equation. On the other hand, in a moderately high frequency band, the nonlinear modulation of quasimonochromatic wave train is described by the nonlinear Schr¨odinger equation with an attenuation term.http://deepblue.lib.umich.edu/bitstream/2027.42/84247/1/CAV2009-final7.pd

    ESPnet-ONNX: Bridging a Gap Between Research and Production

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    In the field of deep learning, researchers often focus on inventing novel neural network models and improving benchmarks. In contrast, application developers are interested in making models suitable for actual products, which involves optimizing a model for faster inference and adapting a model to various platforms (e.g., C++ and Python). In this work, to fill the gap between the two, we establish an effective procedure for optimizing a PyTorch-based research-oriented model for deployment, taking ESPnet, a widely used toolkit for speech processing, as an instance. We introduce different techniques to ESPnet, including converting a model into an ONNX format, fusing nodes in a graph, and quantizing parameters, which lead to approximately 1.3-2×\times speedup in various tasks (i.e., ASR, TTS, speech translation, and spoken language understanding) while keeping its performance without any additional training. Our ESPnet-ONNX will be publicly available at https://github.com/espnet/espnet_onnxComment: Accepted to APSIPA ASC 202

    Major Schools of Marxist Economics in Japan: History and Contemporary Development

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    Marxist economics was introduced into Japan in the 1920s and diverged into several schools. These Marxist schools developed and evolved along with the socio-economic conditions of Japanese society. Japanese Marxism made significant achievements, even though it is facing various difficulties at present. This article offers an account of the formation, development and current quandary of Japanese Marxist economics, so that a comprehensive understanding and overview of Japanese Marxist economics can be obtained
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