Improving peak picking using multiple time-step loss functions

The majority of state-of-the-art methods for music infor-mation retrieval (MIR) tasks now utilise deep learningmethods reliant on minimisation of loss functions such ascross entropy. For tasks that include framewise binaryclassification (e.g., onset detection, music transcription)classes are derived from output activation functions byidentifying points of local maxima, or peaks. However, theoperating principles behind peak picking are different tothat of the cross entropy loss function, which minimises theabsolute difference between the output and target valuesfor a single frame. To generate activation functions moresuited to peak-picking, we propose two versions of a newloss function that incorporates information from multipletime-steps: 1)multi-individual, which uses multiple indi-vidual time-step cross entropies; and 2)multi-difference,which directly compares the difference between sequentialtime-step outputs. We evaluate the newly proposed lossfunctions alongside standard cross entropy in the popularMIR tasks of onset detection and automatic drum tran-scription. The results highlight the effectiveness of theseloss functions in the improvement of overall system ac-curacies for both MIR tasks. Additionally, directly com-paring the output from sequential time-steps in the multi-difference approach achieves the highest performance

Fast synchronization 3R burst-mode receivers for passive optical networks

This paper gives a tutorial overview on high speed burst-mode receiver (BM-RX) requirements, specific for time division multiplexing passive optical networks, and design issues of such BM-RXs as well as their advanced design techniques. It focuses on how to design BM-RXs with short burst overhead for fast synchronization. We present design principles and circuit architectures of various types of burst-mode transimpedance amplifiers, burst-mode limiting amplifiers and burst-mode clock and data recovery circuits. The recent development of 10 Gb/s BM-RXs is highlighted also including dual-rate operation for coexistence with deployed PONs and on-chip auto reset generation to eliminate external timing-critical control signals provided by a PON medium access control. Finally sub-system integration and state-of-the-art system performance for 10 Gb/s PONs are reviewed

Broadband quadrature-squeezed vacuum and nonclassical photon number correlations from a nanophotonic device

We report the first demonstrations of both quadrature squeezed vacuum and photon number difference squeezing generated in an integrated nanophotonic device. Squeezed light is generated via strongly driven spontaneous four-wave mixing below threshold in silicon nitride microring resonators. The generated light is characterized with both homodyne detection and direct measurements of photon statistics using photon number-resolving transition edge sensors. We measure $1.0(1)$~dB of broadband quadrature squeezing (${\sim}4$~dB inferred on-chip) and $1.5(3)$~dB of photon number difference squeezing (${\sim}7$~dB inferred on-chip). Nearly-single temporal mode operation is achieved, with raw unheralded second-order correlations $g^{(2)}$ as high as $1.87(1)$ measured (${\sim}1.9$~when corrected for noise). Multi-photon events of over 10 photons are directly detected with rates exceeding any previous quantum optical demonstration using integrated nanophotonics. These results will have an enabling impact on scaling continuous variable quantum technology.Comment: Significant improvements and updates to photon number squeezing results and discussions, including results on single temporal mode operatio