372 research outputs found

    Ignorance in Plato’s Protagoras

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    Author Name Disambiguation via Heterogeneous Network Embedding from Structural and Semantic Perspectives

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    Name ambiguity is common in academic digital libraries, such as multiple authors having the same name. This creates challenges for academic data management and analysis, thus name disambiguation becomes necessary. The procedure of name disambiguation is to divide publications with the same name into different groups, each group belonging to a unique author. A large amount of attribute information in publications makes traditional methods fall into the quagmire of feature selection. These methods always select attributes artificially and equally, which usually causes a negative impact on accuracy. The proposed method is mainly based on representation learning for heterogeneous networks and clustering and exploits the self-attention technology to solve the problem. The presentation of publications is a synthesis of structural and semantic representations. The structural representation is obtained by meta-path-based sampling and a skip-gram-based embedding method, and meta-path level attention is introduced to automatically learn the weight of each feature. The semantic representation is generated using NLP tools. Our proposal performs better in terms of name disambiguation accuracy compared with baselines and the ablation experiments demonstrate the improvement by feature selection and the meta-path level attention in our method. The experimental results show the superiority of our new method for capturing the most attributes from publications and reducing the impact of redundant information

    A CRY-BIC negative-feedback circuitry regulating blue light sensitivity of Arabidopsis.

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    Cryptochromes are blue light receptors that regulate various light responses in plants. Arabidopsis cryptochrome 1 (CRY1) and cryptochrome 2 (CRY2) mediate blue light inhibition of hypocotyl elongation and long-day (LD) promotion of floral initiation. It has been reported recently that two negative regulators of Arabidopsis cryptochromes, Blue light Inhibitors of Cryptochromes 1 and 2 (BIC1 and BIC2), inhibit cryptochrome function by blocking blue light-dependent cryptochrome dimerization. However, it remained unclear how cryptochromes regulate the BIC gene activity. Here we show that cryptochromes mediate light activation of transcription of the BIC genes, by suppressing the activity of CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1), resulting in activation of the transcription activator ELONGATED HYPOCOTYL 5 (HY5) that is associated with chromatins of the BIC promoters. These results demonstrate a CRY-BIC negative-feedback circuitry that regulates the activity of each other. Surprisingly, phytochromes also mediate light activation of BIC transcription, suggesting a novel photoreceptor co-action mechanism to sustain blue light sensitivity of plants under the broad spectra of solar radiation in nature

    Learning to Compute Ergodic Rate for Multi-cell Scheduling in Massive MIMO

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    Design of Lattice Structures with Graded Density Fabricated by Additive Manufacturing

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    Lattice structures fabricated by Additive Manufacturing (AM) processes are promising for many applications, such as lightweight structures and energy absorbers. However, predicting and controlling of their mechanical behaviors is challenging due to the complexity of modeling and the uncertainties exist in the manufacturing process. In this paper, we explore the possibilities enabled by controlling the local densities. A set of lattice structures with different density gradients are designed using an implicit isosurface equation, and they are manufactured by Selective Laser Melting (SLM) process with 304L stainless steel. Finite element analysis and compression test are used to evaluate their mechanical properties. The results demonstrate the strong correlations between the structural gradient and the mechanical behavior. Introducing the density gradient provides more possibilities in the design phase, which can be used to further customize the design both structurally and functionally

    Direct contact membrane distillation of refining waste stream from precious metal recovery:Chemistry of silica and chromium (III) in membrane scaling

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    Precious metals, such as platinum group metals (PGMs) with distinct catalytic activity, are widely used as active components in various industrial catalysts. It is, therefore, highly desirable to recover these valuable components from the end-of-life products. We explored treatment of refining wastewater from precious metals recovery using direct contact membrane distillation (DCMD). The role of various initial pH of refining wastewater on DCMD performance was assessed. Results suggested that hydrochloride acid (HCl) and high-quality water can be reclaimed from the real refining wastewater by adjusting initial pH. Furthermore, DCMD water flux decline was mainly caused by silica and chromium (III) scaling, which was dependent on initial pH of refining wastewater. Silica scaling was responsible for the decrease of DCMD performance when the initial pH of refining wastewater increased from original 0.03 to 5 and 7. Silica oligomers in the concentrated feed with various initial pH were identified using mass spectra. Dichlorotetraaquochromiun was identified by X-ray photoelectron spectroscopy and ultraviolet and visible absorbance spectra as the main species contributing to the green colour and scaling on the PTFE membrane surface. Our results suggest that DCMD can be used as a promising and feasible solution for resource recovery from acidic refining waste stream.</p

    Beam Squint-Aware Integrated Sensing and Communications for Hybrid Massive MIMO LEO Satellite Systems

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    The space-air-ground-sea integrated network (SAGSIN) plays an important role in offering global coverage. To improve the efficient utilization of spectral and hardware resources in the SAGSIN, integrated sensing and communications (ISAC) has drawn extensive attention. Most existing ISAC works focus on terrestrial networks and can not be straightforwardly applied in satellite systems due to the significantly different electromagnetic wave propagation properties. In this work, we investigate the application of ISAC in massive multiple-input multiple-output (MIMO) low earth orbit (LEO) satellite systems. We first characterize the statistical wave propagation properties by considering beam squint effects. Based on this analysis, we propose a beam squint-aware ISAC technique for hybrid analog/digital massive MIMO LEO satellite systems exploiting statistical channel state information. Simulation results demonstrate that the proposed scheme can operate both the wireless communications and the target sensing simultaneously with satisfactory performance, and the beam-squint effects can be efficiently mitigated with the proposed method in typical LEO satellite systems.Comment: to appear in IEEE Journal on Selected Areas in Communication

    Widespread subsonic turbulence in Ophiuchus North 1

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    Supersonic motions are common in molecular clouds. (Sub)sonic turbulence is usually detected toward dense cores and filaments. However, it remains unknown whether (sub)sonic motions at larger scales (≳\gtrsim1~pc) can be present in different environments or not. Located at a distance of about 110 pc, Ophiuchus North 1 (Oph N1) is one of the nearest molecular clouds that allows in-depth investigation of its turbulence properties by large-scale mapping observations of single-dish telescopes. We carried out the 12^{12}CO (J=1−0J=1-0) and C18^{18}O (J=1−0J=1-0) imaging observations toward Oph N1 with the Purple Mountain Observatory 13.7 m telescope. The observations have an angular resolution of ∼\sim55\arcsec (i.e., 0.03~pc). Most of the whole C18^{18}O emitting regions have Mach numbers of ≲\lesssim1, demonstrating the large-scale (sub)sonic turbulence across Oph N1. Based on the polarization measurements, we estimate the magnetic field strength of the plane-of-sky component to be ≳\gtrsim9~μ\muG. We infer that Oph N1 is globally sub-Alfv{\'e}nic, and is supported against gravity mainly by the magnetic field. The steep velocity structure function can be caused by the expansion of the Sh~2-27 H{\scriptsize II} region or the dissipative range of incompressible turbulence. Our observations reveal a surprising case of clouds characterised by widespread subsonic turbulence and steep size-linewidth relationship. This cloud is magnetized where ion-neutral friction should play an important role.Comment: 16 pages, 12 figures, accepted for publication in A&
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