On lossy transmission of correlated sources over a multiple access channel

We study lossy communication of correlated sources over a multiple access channel. In particular, we provide a joint source-channel coding scheme for transmitting correlated sources with decoder side information, and study the conditions under which separate source and channel coding is optimal. For the latter, the encoders and/or the decoder have access to a common observation conditioned on which the two sources are independent. By establishing necessary and sufficient conditions, we show the optimality of separation when the encoders and the decoder both have access to the common observation. We also demonstrate that separation is optimal when only the encoders have access to the common observation whose lossless recovery is required at the decoder. As a special case, we study separation for sources with a common part. Our results indicate that side information can have significant impact on the optimality of source-channel separation in lossy transmission

The predictive effect of teachers’ perception of school principals’ motivating language on teachers’ self-efficacy via a cultural context

The aim of the study is to investigate the relationship between teachers' perception of school principals' motivating language and teachers' self-efficacy mediated by the cultural context. School principals' linguistic communication skills are critical to sustain the motivation of teachers and their self-efficacy. Motivating language theory (MLT), on which this study is based, provides a model that helps us understand how the language, more precisely, the speech acts, used by school principals have an impact on teachers' self-efficacy. A survey method was employed with 252 teachers through convenience sampling. The teachers' mean age was 34.87 (SD = 9.22) years, and the average length of service was 11.72 (SD = 9.42) years. The results showed that school principals' use of motivating language was significantly and positively associated with teachers' self-efficacy (b = 0.10, p < 0.000). The low-context culture was found to have a full mediating effect in this relationship (b = 0.04, t = 3.1771, p < 0.000). The findings contribute to leader communication theory by highlighting a particular emphasis on the language school principals use to motivate teachers