Cascaded encoders for fine-tuning ASR models on overlapped speech

Multi-talker speech recognition (MT-ASR) has been shown to improve ASR performance on speech containing overlapping utterances from more than one speaker. Multi-talker models have typically been trained from scratch using simulated or actual overlapping speech datasets. On the other hand, the trend in ASR has been to train foundation models using massive datasets collected from a wide variety of task domains. Given the scale of these models and their ability to generalize well across a variety of domains, it makes sense to consider scenarios where a foundation model is augmented with multi-talker capability. This paper presents an MT-ASR model formed by combining a well-trained foundation model with a multi-talker mask model in a cascaded RNN-T encoder configuration. Experimental results show that the cascade configuration provides improved WER on overlapping speech utterances with respect to a baseline multi-talker model without sacrificing performance achievable by the foundation model on non-overlapping utterances

Linear Amplifier Breakdown and Concentration Properties of a Gaussian Field Given that its L2\bm{L^2}-Norm is Large

In the context of linear amplification for systems driven by the square of a Gaussian noise, we investigate the realizations of a Gaussian field in the limit where its $L^2$-norm is large. Concentration onto the eigenspace associated with the largest eigenvalue of the covariance of the field is proved. When the covariance is trace class, the concentration is in probability for the $L^2$-norm. A stronger concentration, in mean for the sup-norm, is proved for a smaller class of Gaussian fields, and an example of a field belonging to that class is given. A possible connection with Bose-Einstein condensation is briefly discussed.Comment: REVTeX file, 11 pages, 1 added paragraph in the introduction, 2 added references, minor modifications in the text and abstract, submitted to J. Stat. Phy

Calcification Parameters in Aged Laying Hens

A previous report (A.S. Series 77-26) suggested a role for calcium binding protein (CaBP) and carbonic anhydrase (CA) on egg shell quality in aging birds. The results of an additional study related to this possibility are reported here

Effect of a Physical Phase Plate on Contrast Transfer in an Aberration-Corrected Transmission Electron Microscope

In this theoretical study we analyze contrast transfer of weak-phase objects in a transmission electron microscope, which is equipped with an aberration corrector (Cs-corrector) in the imaging lens system and a physical phase plate in the back focal plane of the objective lens. For a phase shift of pi/2 between scattered and unscattered electrons induced by a physical phase plate, the sine-type phase contrast transfer function is converted into a cosine-type function. Optimal imaging conditions could theoretically be achieved if the phase shifts caused by the objective lens defocus and lens aberrations would be equal zero. In reality this situation is difficult to realize because of residual aberrations and varying, non-zero local defocus values, which in general result from an uneven sample surface topography. We explore the conditions - i.e. range of Cs-values and defocus - for most favourable contrast transfer as a function of the information limit, which is only limited by the effect of partial coherence of the electron wave in Cs-corrected transmission electron microscopes. Under high-resolution operation conditions we find that a physical phase plate improves strongly low- and medium-resolution object contrast, while improving tolerance to defocus and Cs-variations, compared to a microscope without a phase plate

Urban data: harnessing subjective sociocultural data from local newspapers

As data-based governance becomes mainstream, social and cultural interactions that characterise urban life are at risk of being ignored in decision-making practices if only supposedly objective, quantifiable data are used. In this context, this article conceptualises subjective sociocultural data as a data form that considers a city’s intangible and unquantifiable social and cultural aspects. A methodology is proposed for collecting and using subjective sociocultural data by highlighting local press articles as a potential data source. A pilot application conducted in Hamburg, Germany, demonstrates a potential integration of subjective sociocultural data into urban planning processes by analysing over 2500 local newspaper articles. The findings reveal that local journalism can be a data source for understanding diverse social and cultural interactions between citizens and urban places. This street-level information from local newspaper articles can (1) provide urban planners with an overview of newspaper mentions of any specific urban areas, (2) support the identification of local debates, and (3) aid in the observation of emerging places of sociocultural interactions. This approach can support the diverse government and non-government stakeholders engaged in data-based governance to better account for intangible sociocultural aspects of urban life. Practice relevance This research supports governance actors in dealing with the epistemological limitations of purposely gathered and/or objective data by conceptualising a new—currently untapped—data type: subjective sociocultural data sourced from local journalism. By using geographical text analysis on local newspaper articles, urban planners and decision-makers gain access to a wealth of street-level information, local debates and temporal dynamics of urban issues. This approach provides a comprehensive understanding of intangible and unquantifiable aspects of urban life, allowing for more informed and context-sensitive decision-making. The practical benefits include identifying diverse uses of urban spaces, capturing local public debates, and tracking the emergence and disappearance of places in the public sphere, possibly leading to more effective and inclusive urban planning practices

Mitigating cryogenic microcracking in carbon-fibre reinforced polymer composites using negative thermal-expansion nanoparticles functionalized by a polydopamine coating

Herein, we report a new method of mitigating cryogenic microcracking in carbon-fibre reinforced-plastics (CFRPs) using a negative thermal-expansion nanomaterial, zirconium tungstate (ZrW2O8), to simultaneously reduce the thermal residual stresses and enhance the fracture energy of the epoxy matrix of CFRPs. The results show that 1 wt% of added ZrW2O8 nanoparticles functionalized by polydopamine can increase the fracture energy of the matrix material by 140%, reduce the coefficient of thermal expansion by 20% and, more importantly, enhance the interlaminar fracture energy of the resulting CFRP by about 100% at −196 °C. The ZrW2O8-modified matrix has been demonstrated to successfully prevent microcracking at −196 °C in a blocked cross-ply CFRP laminate with a [04/908/04] fibre architecture

On theories of random variables

We study theories of spaces of random variables: first, we consider random variables with values in the interval $[0,1]$, then with values in an arbitrary metric structure, generalising Keisler's randomisation of classical structures. We prove preservation and non-preservation results for model theoretic properties under this construction: i) The randomisation of a stable structure is stable. ii) The randomisation of a simple unstable structure is not simple. We also prove that in the randomised structure, every type is a Lascar type