117 research outputs found

    The Influence of Network Topology on Sound Propagation in Granular Materials

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    Granular materials, whose features range from the particle scale to the force-chain scale to the bulk scale, are usually modeled as either particulate or continuum materials. In contrast with either of these approaches, network representations are natural for the simultaneous examination of microscopic, mesoscopic, and macroscopic features. In this paper, we treat granular materials as spatially-embedded networks in which the nodes (particles) are connected by weighted edges obtained from contact forces. We test a variety of network measures for their utility in helping to describe sound propagation in granular networks and find that network diagnostics can be used to probe particle-, curve-, domain-, and system-scale structures in granular media. In particular, diagnostics of meso-scale network structure are reproducible across experiments, are correlated with sound propagation in this medium, and can be used to identify potentially interesting size scales. We also demonstrate that the sensitivity of network diagnostics depends on the phase of sound propagation. In the injection phase, the signal propagates systemically, as indicated by correlations with the network diagnostic of global efficiency. In the scattering phase, however, the signal is better predicted by meso-scale community structure, suggesting that the acoustic signal scatters over local geographic neighborhoods. Collectively, our results demonstrate how the force network of a granular system is imprinted on transmitted waves.Comment: 19 pages, 9 figures, and 3 table

    DAC-less and DSP-free PAM-4 transmitter at 112 Gb/s with two parallel GeSi electro-absorption modulators

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    Figure S5. The MAP of the reprogramming process in the WT model. The MAP (white curve) starting from the ME differentiated state (the blue point) to the pluripotent state (the green point) is different from that of differentiation process (Fig. 3A). The green dotted line is the ODE trajectory to compare with the MAP. (PDF 3338 kb

    100 Gbit/s serial transmission using a silicon-organic hybrid (SOH) modulator and a duobinary driver IC

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    100 Gbit/s three-level (50 Gbit/s 00K) signals are generated using a silicon-organic hybrid modulator and a BiCMOS duobinary driver IC at a BER of 8.5x10(-5)(<10(-12)). We demonstrate dispersion-compensated transmission over 5 km

    A Critical Perspective on Moral Neuroscience

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    In this paper, we highlight several historical developments in the neuroscience of ethics as well as recent advances that forecast the experimental research to come. We argue, in particular, that our understanding of the moral brain will benefit from the further use of a formal, mathematical approach to the construction and testing of alternative theories, such as that found in the field of neuroeconomics. The use of economic modeling to understand the psychological processes underlying distributional preferences and charitable giving is reviewed to illustrate this potential. We also consider some obstacles to such an approach, notably the challenge of capturing substantive moral values within a mathematical model
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