No abstract

No abstract

Words in Chinese text are not naturally separated by delimiters, which poses a challenge to standard machine translation (MT) systems. In MT, the widely used approach is to apply a Chinese word segmenter trained from manually annotated data, using a fixed lexicon. Such word segmentation is not necessarily optimal for translation. We propose a Bayesian semi-supervised Chinese word segmentation model which uses both monolingual and bilingual information to derive a segmentation suitable for MT. Experiments show that our method improves a state-ofthe-art MT system in a small and a large data environment.

This work contributes to develop a new methodology to identify empirical-data-driven causal structure of a domain knowledge. We propose an algorithm as a two-stage procedure by first drawing relevant prior partial relationships between variables and using them as structure constraints in a structure learning task of Bayesian networks (BNs). The latter is then based on a model averaging approach to obtain a statistically sound BN. The empirical study focuses on modeling commuters' travel mode choice. We present experimental results on testing the design of prior restrictions, the effect of resampling size and learning algorithms, and the effect of random draw on fitted BN structure. The results show that the proposed method can capture more sophisticated relationships between the variables that are missing in both decision tree models and random utility models.

Abstract-A new circularly-polarized metasurfaced dipole antenna (MSDA) with wide axial-ratio (AR) beamwidth and radar cross section (RCS) reduction properties is proposed and studied in this paper. This antenna is a quite simple half-wavelength linear dipole right above a metasurface which consists of 9 double-head arrow-shaped unit cells arranged in a 3×3 layout. By cautiously choosing the geometrical parameters of the metasurface and tuning the distance between the dipole and the metasurface, the whole structure turns out to be a circularly-polarized antenna with RCS reduction feature. Simulation results show that the MSDA in circular polarization achieves an operating bandwidth of 410 MHz and a wide AR beamwidth of 123 • and 90 • in ϕ = 0 • and ϕ = 90 • planes respectively, together with a maximum RCS reduction of 10.4 dB in the whole operating band.