Propagation of instability in dielectric elastomers

AbstractWhen an electric voltage is applied across the thickness of a thin layer of an dielectric elastomer, the layer reduces its thickness and expands its area. This electrically induced deformation can be rapid and large, and is potentially useful as soft actuators in diverse technologies. Recent experimental and theoretical studies have shown that, when the voltage exceeds some critical value, the homogenous deformation of the layer becomes unstable, and the layer deforms into a mixture of thin and thick regions. Subsequently, as more electric charge is applied, the thin regions enlarge at the expense of the thick regions. On the basis of a recently formulated nonlinear field theory, this paper develops a meshfree method to simulate numerically this instability

Task-Agnostic Structured Pruning of Speech Representation Models

Self-supervised pre-trained models such as Wav2vec2, Hubert, and WavLM have been shown to significantly improve many speech tasks. However, their large memory and strong computational requirements hinder their industrial applicability. Structured pruning is a hardware-friendly model compression technique but usually results in a larger loss of accuracy. In this paper, we propose a fine-grained attention head pruning method to compensate for the performance degradation. In addition, we also introduce the straight through estimator into the L0 regularization to further accelerate the pruned model. Experiments on the SUPERB benchmark show that our model can achieve comparable performance to the dense model in multiple tasks and outperforms the Wav2vec 2.0 base model on average, with 72% fewer parameters and 2 times faster inference speed.Comment: Accepted by INTERSPEECH 202

A Capacitive Humidity Sensor Based on Multi-Wall Carbon Nanotubes (MWCNTs)

A new type of capacitive humidity sensor is introduced in this paper. The sensor consists of two plate electrodes coated with MWCNT films and four pieces of isolating medium at the four corners of the sensor. According to capillary condensation, the capacitance signal of the sensor is sensitive to relative humidity (RH), which could be transformed to voltage signal by a capacitance to voltage converter circuit. The sensor is tested using different saturated saline solutions at the ambient temperature of 25 °C, which yielded approximately 11% to 97% RH, respectively. The function of the MWCNT films, the effect of electrode distance, the temperature character and the repeatability of the sensor are discussed in this paper

Submodule configuration of HVDC-DC auto transformer considering DC fault

This paper studies the submodule configuration of MMC based non-isolated HVDC-DC autotransformer (HVDC-AT) with DC fault blocking capability, including two-terminal and multi-terminal topologies. The operation principle of the HVDC-AT is described. Considering the arm current differences, the total number of required semiconductors for the HVDC-AT is derived and is compared with the MMC based isolated front-to-front (F2F) DC transformer. A full operation process for the multi-terminal HVDC-AT considering DC fault is then presented, including normal operation, fault isolation and continuous operation of healthy converters after fault. The submodule configuration and fault recovery of the multi-terminal HVDC-AT are validated by simulations using PSCAD/EMTDC