Abstractive news summarization based on event semantic link network

This paper studies the abstractive multi-document summarization for event-oriented news texts through event information extraction and abstract representation. Fine-grained event mentions and semantic relations between them are extracted to build a unified and connected event semantic link network, an abstract representation of source texts. A network reduction algorithm is proposed to summarize the most salient and coherent event information. New sentences with good linguistic quality are automatically generated and selected through sentences over-generation and greedy-selection processes. Experimental results on DUC2006 and DUC2007 datasets show that our system significantly outperforms the state-of-the-art extractive and abstractive baselines under both pyramid and ROUGE evaluation metrics

Exploring differential topic models for comparative summarization of scientific papers

This paper investigates differential topic models (dTM) for summarizing the differences among document groups. Starting from a simple probabilistic generative model, we propose dTM-SAGE that explicitly models the deviations on group-specific word distributions to indicate how words are used differentially across different document groups from a background word distribution. It is more effective to capture unique characteristics for comparing document groups. To generate dTM-based comparative summaries, we propose two sentence scoring methods for measuring the sentence discriminative capacity. Experimental results on scientific papers dataset show that our dTM-based comparative summarization methods significantly outperform the generic baselines and the state-of-the-art comparative summarization methods under ROUGE metrics

4,4′-Dimethyl-2,2′-[1,2-phenyl­enebis(nitrilo­methyl­idyne)]diphenol

In the title Schiff base, C22H20N2O2, the benzene ring forms dihedral angles of 53.92 (1) and 3.62 (1)° with the two salicylaldimine groups. There are two strong O—H⋯N intra­molecular hydrogen bonds. The crystal packing is stabilized by weak inter­molecular C—H⋯O hydrogen bonds and π–π stacking inter­actions (average distance 3.39 Å)

Microwave Assisted Reconstruction of Optical Interferograms for Distributed Fiber Optic Sensing

This paper reports a distributed fiber optic sensing technique through microwave assisted separation and reconstruction of optical interferograms in spectrum domain. The approach involves sending a microwave-modulated optical signal through cascaded fiber optic interferometers. The microwave signal was used to resolve the position and reflectivity of each sensor along the optical fiber. By sweeping the optical wavelength and detecting the modulation signal, the optical spectrum of each sensor can be reconstructed. Three cascaded fiber optic extrinsic Fabry-Perot interferometric sensors were used to prove the concept. Their microwave-reconstructed interferogram matched well with those recorded individually using an optical spectrum analyzer. The application in distributed strain measurement has also been demonstrated

Investigation on dynamic effects of frame with specially shaped columns subjected to column failure

Dynamic effects caused by sudden failure of the vertical load-bearing component are an important factor affecting the progressive collapse of building. In order to study the influence of dynamic effects on structure, a collapse experiment of a 1/3-scale, 2×3-bay and 2-story reinforced concrete frame with specially shaped columns with sudden column removal were carried out. The displacement response, reinforcement and concrete strains during the collapse of the frame were studied to reveal the dynamic response of structure such as deformation and internal force redistribution. Experimental results show that the influence of dynamic effects on structure at the moment of component failure was not significant. The structure was still in the elastic stage and collapse did not occur, indicating that reinforced concrete frame designed according to Chinese codes has a good behavior against progressive collapse caused by sudden loss of a first floor column. A progressive collapse dynamic analysis model was established using the alternate path method based on the test frame, and the relationship between the dynamic amplification factors and failure time were derived. Transient time history analysis was carried out on the finite element model of experimental frame using OpenSees to obtain the variation of dynamic amplification factor with the failure time

Spectral analysis for preconditioning of multi-dimensional Riesz fractional diffusion equations

In this paper, we analyze the spectra of the preconditioned matrices arising from discretized multi-dimensional Riesz spatial fractional diffusion equations. The finite difference method is employed to approximate the multi-dimensional Riesz fractional derivatives, which will generate symmetric positive definite ill-conditioned multi-level Toeplitz matrices. The preconditioned conjugate gradient method with a preconditioner based on the sine transform is employed to solve the resulting linear system. Theoretically, we prove that the spectra of the preconditioned matrices are uniformly bounded in the open interval (1/2,3/2) and thus the preconditioned conjugate gradient method converges linearly. The proposed method can be extended to multi-level Toeplitz matrices generated by functions with zeros of fractional order. Our theoretical results fill in a vacancy in the literature. Numerical examples are presented to demonstrate our new theoretical results in the literature and show the convergence performance of the proposed preconditioner that is better than other existing preconditioners