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Desmond C. Ong

Publications and source records attributed to Desmond C. Ong.

38 records · Page 3Linked to original sources

A Multimodal LSTM for Predicting Listener Empathic Responses Over Time

People naturally understand the emotions of-and often also empathize with-those around them. In this paper, we predict the emotional valence of an empathic listener over time as they listen to a speaker narrating a life story. We use the dataset provided by the OMG-Empathy Prediction Challenge, a workshop held in conjunction with IEEE FG 2019. We present a multimodal LSTM model with feature-level fusion and local attention that predicts empathic responses from audio, text, and visual features. Our best-performing model, which used only the audio and text features, achieved a concordance correlation coefficient (CCC) of 0.29 and 0.32 on the Validation set for the Generalized and Personalized track respectively, and achieved a CCC of 0.14 and 0.14 on the held-out Test set. We discuss the difficulties faced and the lessons learnt tackling this challenge.

cs.CL↗

Glassy Dislocation Dynamics in 2-D Colloidal Dimer Crystals

Although glassy relaxation is typically associated with disorder, here we report on a new type of glassy dynamics relating to dislocations within 2-D crystals of colloidal dimers. Previous studies have demonstrated that dislocation motion in dimer crystals is restricted by certain particle orientations. Here, we drag an optically trapped particle through such dimer crystals, creating dislocations. We find a two-stage relaxation response where initially dislocations glide until encountering particles that cage their motion. Subsequent relaxation occurs logarithmically slowly through a second process where dislocations hop between caged configurations. Finally, in simulations of sheared dimer crystals, the dislocation mean squared displacement displays a caging plateau typical of glassy dynamics. Together, these results reveal a novel glassy system within a colloidal crystal.

cond-mat.soft↗