Effects of Study-Abroad Experiences on the Second Language and Cultural Awareness of Chinese EFL Learners

  This article explores how social interactions and culture affect Chinese EFL learners during study abroad (SA).The participants, native Chinese speakers learning English as a foreign language spent varying durations in English-speaking countries. A comparative analysis was conducted, differentiating between participants engaged in a two-semester SA and those in a two-academic-year SA, revealing nuanced variations in the findings. Surprisingly, these variations were more strongly associated with Willingness to Communicate (WTC) than the duration of the SA. Furthermore, examining the duration since participants’ return to China hinted individual differences in the perceived effects of their SA and subsequent acculturation. Notably, individuals who spent more time back in their home country after SA tended to develop a stronger sense of identification with their native culture. Intriguingly, these individuals also exhibited a heightened sensitivity to cultural shocks during their SA. The study also explored the correlation between cultural adaptability, strength of ethnic consciousness, and learners’ English proficiency, positing that this dynamic is unstable. The cultural and linguistic effects revealed by these findings provide valuable insights for learners contemplating studying abroad. Additionally, they bear significant pedagogical implications for EFL classroom teaching, both domestically and internationally.

WRHT: Efficient All-reduce for Distributed DNN Training in Optical Interconnect System

Communication efficiency plays an important role in accelerating the distributed training of Deep Neural Networks (DNN). All-reduce is the key communication primitive to reduce model parameters in distributed DNN training. Most existing all-reduce algorithms are designed for traditional electrical interconnect systems, which cannot meet the communication requirements for distributed training of large DNNs. One of the promising alternatives for electrical interconnect is optical interconnect, which can provide high bandwidth, low transmission delay, and low power cost. We propose an efficient scheme called WRHT (Wavelength Reused Hierarchical Tree) for implementing all-reduce operation in optical interconnect system, which can take advantage of WDM (Wavelength Division Multiplexing) to reduce the communication time of distributed data-parallel DNN training. We further derive the minimum number of communication steps and communication time to realize the all-reduce using WRHT. Simulation results show that the communication time of WRHT is reduced by 75.59%, 49.25%, and 70.1% respectively compared with three traditional all-reduce algorithms simulated in optical interconnect system. Simulation results also show that WRHT can reduce the communication time for all-reduce operation by 86.69% and 84.71% in comparison with two existing all-reduce algorithms in electrical interconnect system.Comment: This paper is under the submission of GLOBECOM 202

Separate DOD and DOA Estimation for Bistatic MIMO Radar

A novel MUSIC-type algorithm is derived in this paper for the direction of departure (DOD) and direction of arrival (DOA) estimation in a bistatic MIMO radar. Through rearranging the received signal matrix, we illustrate that the DOD and the DOA can be separately estimated. Compared with conventional MUSIC-type algorithms, the proposed separate MUSIC algorithm can avoid the interference between DOD and DOA estimations effectively. Therefore, it is expected to give a better angle estimation performance and have a much lower computational complexity. Meanwhile, we demonstrate that our method is also effective for coherent targets in MIMO radar. Simulation results verify the efficiency of the proposed method, particularly when the signal-to-noise ratio (SNR) is low and/or the number of snapshots is small

Self-organized Voids Revisited: Experimental Verification of the Formation Mechanism*

In this paper, several experiments were conducted to further clarify the formation mechanism of self organized void array induced by a single laser beam, including energy-related experiments, refractive-index-contrast-related experiments, depth-related experiments and effective-numerical-aperture experiment. These experiments indicate that the interface spherical aberration is indeed responsible for the formation of void arrays