Computer Assisted Language Learning （CALL） has been in use as a learner centered method since 1960. In this paper an attempt is made to evolve a Remedial Grammar （RG） which enables the teacher to develop a reperto...Computer Assisted Language Learning （CALL） has been in use as a learner centered method since 1960. In this paper an attempt is made to evolve a Remedial Grammar （RG） which enables the teacher to develop a repertoire of remedial activities based on the errors identified following Error Analysis （EA） for repeated presentation. The error types are considered as teaching/learning points. The present paper argues that CALL is the right model for effective remedial learning. Remedial Gmaster （RGm）, an authoring package is introduced. This is an exclusive mode of error correction in which interlingual, intralingual, developmental, and global errors are dealt with. The syntactical problems due to the subtle difference between simple past and perfect tenses in English language use are discussed and CALL authoring package presented.展开更多
The intersubcarrier interference(ICI) degrades the performance of the pilot-aided channel estimation in fast time-varying orthogonal frequency division multiplexing(OFDM) systems.To solve the error propagation in join...The intersubcarrier interference(ICI) degrades the performance of the pilot-aided channel estimation in fast time-varying orthogonal frequency division multiplexing(OFDM) systems.To solve the error propagation in joint channel estimation and data detection due to this ICI,a scheme of error propagation determined iterative estimation is proposed,where in the first iteration,Kalman filter based on signal to interference and noise is designed with ICI transformed to be part of the noise,and for the later iterations,a determined iterative estimation algorithm obtains an optimal output from all iterations using the iterative updating strategy.Simulation results present the significant improvement in the performance of the proposed scheme in high-mobility situation in comparison with the existing ones.展开更多
文摘Computer Assisted Language Learning （CALL） has been in use as a learner centered method since 1960. In this paper an attempt is made to evolve a Remedial Grammar （RG） which enables the teacher to develop a repertoire of remedial activities based on the errors identified following Error Analysis （EA） for repeated presentation. The error types are considered as teaching/learning points. The present paper argues that CALL is the right model for effective remedial learning. Remedial Gmaster （RGm）, an authoring package is introduced. This is an exclusive mode of error correction in which interlingual, intralingual, developmental, and global errors are dealt with. The syntactical problems due to the subtle difference between simple past and perfect tenses in English language use are discussed and CALL authoring package presented.
基金Supported by the National Natural Science Foundation of China(No.61372089,61101113,61072088,61201198)the Beijing NaturalScience Foundation(No.4132019)
文摘The intersubcarrier interference(ICI) degrades the performance of the pilot-aided channel estimation in fast time-varying orthogonal frequency division multiplexing(OFDM) systems.To solve the error propagation in joint channel estimation and data detection due to this ICI,a scheme of error propagation determined iterative estimation is proposed,where in the first iteration,Kalman filter based on signal to interference and noise is designed with ICI transformed to be part of the noise,and for the later iterations,a determined iterative estimation algorithm obtains an optimal output from all iterations using the iterative updating strategy.Simulation results present the significant improvement in the performance of the proposed scheme in high-mobility situation in comparison with the existing ones.
