298 research outputs found

    Synchrotron resonant radiation from nonlinear self-accelerating pulses

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    Solitons and nonlinear waves emit resonant radiation in the presence of perturbations. This effect is relevant for nonlinear fiber optics, supercontinuum generation, rogue waves, and complex nonlinear dynamics. However, resonant radiation is narrowband, and the challenge is finding novel ways to generate and tailor broadband spectra. We theoretically predict that nonlinear self-accelerated pulses emit a novel form of synchrotron radiation that is extremely broadband and controllable. We develop an analytic theory and confirm the results by numerical analysis. This new form of supercontinuum generation can be highly engineered by shaping the trajectory of the nonlinear self-accelerated pulses. Our results may find applications in novel highly efficient classical and quantum sources for spectroscopy, biophysics, security, and metrology

    Multi-lingual Common Semantic Space Construction via Cluster-consistent Word Embedding

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    We construct a multilingual common semantic space based on distributional semantics, where words from multiple languages are projected into a shared space to enable knowledge and resource transfer across languages. Beyond word alignment, we introduce multiple cluster-level alignments and enforce the word clusters to be consistently distributed across multiple languages. We exploit three signals for clustering: (1) neighbor words in the monolingual word embedding space; (2) character-level information; and (3) linguistic properties (e.g., apposition, locative suffix) derived from linguistic structure knowledge bases available for thousands of languages. We introduce a new cluster-consistent correlational neural network to construct the common semantic space by aligning words as well as clusters. Intrinsic evaluation on monolingual and multilingual QVEC tasks shows our approach achieves significantly higher correlation with linguistic features than state-of-the-art multi-lingual embedding learning methods do. Using low-resource language name tagging as a case study for extrinsic evaluation, our approach achieves up to 24.5\% absolute F-score gain over the state of the art.Comment: 10 page

    Electromechanical-Mode Coupling Model and Failure Prediction of CFRP under Three-Point Bending

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    Carbon fiber reinforced polymer materials (CFRP) cause CFRP to bend or fail when subjected to external loads or impacts. In the case of static three-point bending, using the conductive properties of the carbon fiber inside the CFRP, the overall damage detection and failure prediction can be carried out by electromagnetic methods. The eddy current coil is used to realize real-time monitoring of damage, and the measured voltage value can be mapped to obtain the load of the sample. This paper conducts theoretical analysis and experimental verification, and obtains the relationship between CFRP stress damage and spatial conductivity change, and proposes a CFRP electromechanical coupling model under quasistatic three-point bending. Combined with the theory of electrically ineffective length, the CFRP three-point bending electromechanical coupling model was revised. Experimental results prove that the revised model can describe the load-conductivity change trend of three-dimensional braided CFRP more accurately, which provides a theoretical basis for monitoring the structural health of CFRP through electromagnetic methods

    THE BRANDING OF ETHICS: A Multidisciplinary Investigation into the Ethical Branding Phenomenon in the UK

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    Ethical considerations are a potentially powerful influence on consumer purchasing decisions. Marketers have begun to recognize the need to incorporate business ethics into their marketing activities. The practice of 'ethical branding' is a relatively new phenomenon and previous studies have been mainly focusing on how consumers make sense of it, rather than how and why marketers position their products as ethical brands. This study aims to explore the motives behind ethical branding decisions and the ways in which ethical brands function, by adopting a multidisciplinary approach combining perspectives from marketing and cultural studies. The review of the marketing literature describes the changing nature of marketing, entry barriers, consumer pressure, and business performance as key determinants in marketers' decision-making process with regard to ethical branding. The focus of this study lies in the contribution of cultural studies to the ongoing debate. It highlights the significance of identity, power, and meaning in understanding ethical brands and provides an analysis of various advertisements and marketing campaigns, using cultural studies research methods, in order to explain how products can be marketed as ethically conscious commodities

    Decelerating Airy pulse propagation in highly non-instantaneous cubic media

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    The propagation of decelerating Airy pulses in non-instantaneous cubic medium is investigated both theoretically and numerically. In a Debye model, at variance with the case of accelerating Airy and Gaussian pulses, a decelerating Airy pulse evolves into a single soliton for weak and general non- instantaneous response. Airy pulses can hence be used to control soliton generation by temporal shaping. The effect is critically dependent on the response time, and could be used as a way to measure the Debye type response function. For highly non- instantaneous response, we theoretically find a decelerating Airy pulse is still transformed into Airy wave packet with deceleration. The theoretical predictions are confirmed by numerical simulations
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