No abstract

There is increasing interest in clarifying how different face emotion expressions are perceived by people from different cultures, of different ages and sex. However, scant availability of well-controlled emotional face stimuli from non-Western populations limit the evaluation of cultural differences in face emotion perception and how this might be modulated by age and sex differences. We present a database of East Asian face expression stimuli, enacted by young and older, male and female, Taiwanese using the Facial Action Coding System (FACS). Combined with a prior database, this present database consists of 90 identities with happy, sad, angry, fearful, disgusted, surprised and neutral expressions amounting to 628 photographs. Twenty young and 24 older East Asian raters scored the photographs for intensities of multiple-dimensions of emotions and induced affect. Multivariate analyses characterized the dimensionality of perceived emotions and quantified effects of age and sex. We also applied commercial software to extract computer-based metrics of emotions in photographs. Taiwanese raters perceived happy faces as one category, sad, angry, and disgusted expressions as one category, and fearful and surprised expressions as one category. Younger females were more sensitive to face emotions than younger males. Whereas, older males showed reduced face emotion sensitivity, older female sensitivity was similar or accentuated relative to young females. Commercial software dissociated six emotions according to the FACS demonstrating that defining visual features were present. Our findings show that East Asians perceive a different dimensionality of emotions than Western-based definitions in face recognition software, regardless of age and sex. Critically, stimuli with detailed cultural norms are indispensable in interpreting neural and behavioral responses involving human facial expression processing. To this end, we add to the tools, which are available upon request, for conducting such research.

Surface traps on GaN-based HEMTs (high-electron-mobility transistors) usually result in the increase of channel on-resistance. It becomes worsen when short pulses are applied during high-frequency and high voltage switching. Here we present a dual-gate transistor structure to suppress the dynamic on-resistance increase. The auxiliary gate under a proper fixed voltage is able to induce additional electrons to compensate the channel carrier loss during main gate switching, leading to a lower dynamic on-resistance. In this work, we benchmarked the fundamental electrical properties of both single-gate and dual-gate HEMTs. We further extracted the dynamic electrical properties by stressing the devices with short pulses. The results suggest a significant mitigation of current collapse of a dual-gate HEMT under a proper bias applied on the auxiliary gate electrode. The physical mechanism based on the charge distribution in the channel is employed to explain the observations.

No abstract

No abstract