A Study of Dropout-Induced Modality Bias on Robustness to Missing Video Frames for Audio-Visual Speech Recognition

Advanced Audio-Visual Speech Recognition (AVSR) systems have been observed to be sensitive to missing video frames, performing even worse than single-modality models. While applying the dropout technique to the video modality enhances robustness to missing frames, it simultaneously results in a performance loss when dealing with complete data input. In this paper, we investigate this contrasting phenomenon from the perspective of modality bias and reveal that an excessive modality bias on the audio caused by dropout is the underlying reason. Moreover, we present the Modality Bias Hypothesis (MBH) to systematically describe the relationship between modality bias and robustness against missing modality in multimodal systems. Building on these findings, we propose a novel Multimodal Distribution Approximation with Knowledge Distillation (MDA-KD) framework to reduce over-reliance on the audio modality and to maintain performance and robustness simultaneously. Finally, to address an entirely missing modality, we adopt adapters to dynamically switch decision strategies. The effectiveness of our proposed approach is evaluated and validated through a series of comprehensive experiments using the MISP2021 and MISP2022 datasets. Our code is available at https://github.com/dalision/ModalBiasAVSRComment: the paper is accepted by CVPR202

Analysis of Flavor Characteristics and Characteristic Components of White Tea Made from Oolong Tea Cultivars

In order to investigate the differences in flavor quality between white tea made from Oolong tea cultivars and traditional white tea, white teas made from eight Oolong tea cultivars such as Zimeigui and Fuding Dahao white tea as a control were analyzed by sensory evaluation, biochemical assays and multivariate statistical analysis. The results showed that the appearance and infusion color of Oolong white tea were darker, while the taste and aroma were better than those of traditional white tea. The biochemical analysis revealed that the differences in conductivity, pH, and the contents of soluble sugars, free amino acids, gallocatechin gallate (GCG) and epigallocatechin gallate (EGCG) were important factors causing the differences in taste between traditional white tea and white tea made from Oolong tea cultivars. Volatile composition analysis showed that trans-2-nonenal, cis-3-nonen-1-ol, methyl palmitate, linalool, methyl linoleate, cedrol, geranyl formate, phenethyl alcohol, nerolidol, methyl salicylate, dibutyl phthalate and phytone were the key differential aroma components contributing to the difference in aroma between Oolong and traditional white tea. Findings from this study will provide a theoretical reference for flavor diversification of white tea

Study on the Method of Charge Accumulation Suppression of Electrostatic Suspended Accelerometer

Electrostatic suspended accelerometers (ESAs) are widely used in high accuracy acceleration measurement. However, there exist accumulated charges on the isolated mass which damage the accuracy and the stability of ESAs. In this paper, we propose to apply actuation voltage with a combined waveform to suppress the acceleration noise due to deposited charge. A model of the electrostatic force on the mass is established and the deviation voltage is found to be the dominant source of charge noise. Based on the analysis of disturbance electrostatic force under DC and AC signals, actuation combined with DC and AC voltage is designed and the disturbance force due to charge can be suppressed through adjustment towards the duty cycle of different compositions. Simulations and experiments are carried out and the results indicate that the disturbance due to charge can be suppressed up to 40%, which validates the efficiency of the scheme

Study on the Method of Charge Accumulation Suppression of Electrostatic Suspended Accelerometer

Electrostatic suspended accelerometers (ESAs) are widely used in high accuracy acceleration measurement. However, there exist accumulated charges on the isolated mass which damage the accuracy and the stability of ESAs. In this paper, we propose to apply actuation voltage with a combined waveform to suppress the acceleration noise due to deposited charge. A model of the electrostatic force on the mass is established and the deviation voltage is found to be the dominant source of charge noise. Based on the analysis of disturbance electrostatic force under DC and AC signals, actuation combined with DC and AC voltage is designed and the disturbance force due to charge can be suppressed through adjustment towards the duty cycle of different compositions. Simulations and experiments are carried out and the results indicate that the disturbance due to charge can be suppressed up to 40%, which validates the efficiency of the scheme

A new coupling structure and position detection method for segmented control dynamic wireless power transfer systems

In this letter, a new coupling structure for dynamic wireless power transfer (DWPT) systems is proposed. Bipolar coils are symmetrically placed on the transmitter unipolar coils, resulting in natural decoupling between the bipolar coils and the unipolar coils. This special structure can mitigate the self-couplings between the adjacent unipolar transmitter coils and hence facilitate the design of the compensation circuit. Another remarkable advantage of this design is that it can lead to a stable mutual coupling between the transmitter array and the receiver when the receiver moves along the transmitter, making it a natural fit for DWPT applications. Furthermore, to reduce the electromagnetic interference and power loss, an automatic segmented control scheme is implemented, and a position detection method by monitoring the primary current is developed. The feasibility of the proposed coupling structure and the position detection method are verified on a laboratory prototype with 72-V output voltage. The experimental results show that the power fluctuation is within ±2.5%, and system efficiency is around 90%. (This letter is accompanied by a video demonstrating the experimental test). © 2020 IEEE

Analysis and design of a cost-effective single-input and regulatable multioutput WPT system

In this letter, a single-input and regulatable multioutput wireless power transfer system is presented. In particular, the system uses positive and negative half-wave rectifiers and a synchronous rectifier to realize multiple output channels. Each output channel is controllable, providing a flexible wireless charger to meet various charging requirements. Moreover, this system utilizes the inherent half-wave-rectifier channels (#B and #C) to detect synchronous signals for the rectifiers rather than using additional synchronous detection circuits, thereby leading to a cost-effective system. Finally, a 300 W laboratory prototype is contrasted with three voltage levels, i.e., 48, 30, and 24 V. With the help of the control logic, this system shows excellent robustness against different occasions, such as load variations, input disturbance, and misalignment. The overall efficiency ranges from 86.7% to 90.6%. © 1986-2012 IEEE

Advanced magnetic coupler design with multi-directional anti-misalignment capabilities for wireless charging unmanned aerial vehicles

This brief introduces a design of the magnetic coupler tailored for unmanned aerial vehicles (UAVs), distinguished by its robust capability to counteract misalignments, ensuring consistent and reliable charging. This resilience extends beyond mere angular misalignment, also encompassing x - and y - deviations, a testament to the efficacy of the presented magnetic coupling design. The transmitter (TX) incorporates eight solenoid coils, establishing a magnetic field that spans from the core to the periphery. To capitalize on this magnetic field, two rectangular coils have been strategically mounted on the landing gears, aligning with the inherent geometry and space constraints of standard commercial UAV landing apparatus. The employment of air-core receivers also serves to mitigate on-board weight. This meticulously crafted coupling mechanism empowers the system with an impressive capacity to accommodate a full 360° of angular misalignments, in addition to a considerable horizontal offset range of (-50 mm,-50 mm

A Simultaneous power and data transfer method for dynamic wireless charging electric vehicles

This paper proposes a new method for simultaneous dynamic wireless power and data transfer (SDWPDT). When the receiver is moving, both power and data transfer channels are dynamically switched ON/OFF according to the receiver's position. In essence, data is transmitted through the high-frequency electric field (EF) generated by the parasitic capacitances of the coupling coils and the metal shield plates, while power is transmitted through the relatively low-frequency magnetic field (MF) generated by coupling coils. By doing this, mutual interference between two transfer channels (i.e., power and data transfer channels) is relatively small. Firstly, the interference from power to data can be greatly reduced due to the absence of a direct electrical wire-based connection. Secondly, the power loss caused by the data transfer channel in the power link is very small so it can be ignored. In addition, the implementation of real-time communication facilitates the establishment of a closed-loop control within the system. This mechanism guarantees consistent power output during dynamic movement, even in the presence of fluctuations in load or input voltage. Laboratory prototype-based experimental findings substantiate the feasibility of the proposed approach

A dual-coupled double-lcc system with the capability of misalignment tolerance improvement for wireless charging substation inspection robots

This article presents a wireless power transfer system for substation inspection robots. Employing a dual-coupled double inductor-capacitor-capacitor (LCC-LCC) compensation topology, the system aims to address the prevalent challenge of misalignment tolerance improvements. It reveals that the system's output is predominantly influenced by the denominator parameter (i.e.