52 research outputs found

    How does end-to-end speech recognition training impact speech enhancement artifacts?

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    Jointly training a speech enhancement (SE) front-end and an automatic speech recognition (ASR) back-end has been investigated as a way to mitigate the influence of \emph{processing distortion} generated by single-channel SE on ASR. In this paper, we investigate the effect of such joint training on the signal-level characteristics of the enhanced signals from the viewpoint of the decomposed noise and artifact errors. The experimental analyses provide two novel findings: 1) ASR-level training of the SE front-end reduces the artifact errors while increasing the noise errors, and 2) simply interpolating the enhanced and observed signals, which achieves a similar effect of reducing artifacts and increasing noise, improves ASR performance without jointly modifying the SE and ASR modules, even for a strong ASR back-end using a WavLM feature extractor. Our findings provide a better understanding of the effect of joint training and a novel insight for designing an ASR agnostic SE front-end.Comment: 5 pages, 1 figure, 1 tabl

    A Report on Hydrographic Activities Following the Great East Japan Earthquake

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    The Great East Japan Earthquake (Mw9.0) on 11 March 2011 accompanied with a huge tsunami of more than 10 meters in height devastated many cities and ports along the Pacific coast of northeastern Japan, and claimed nearly 20,000 lives with many of them still missing. This report reviews actions taken by the Japan Hydrographic and Oceanographic Department (JHOD) after this unprecedented disaster. Immediately after the earthquake, the JHOD carried out hydrographic surveys for the urgent need to help clear the passage in ports due to sunken debris swept away by the tsunami. These surveys have enabled the vessels with relief supplies on board for the affected areas to enter the ports. The JHOD revisited the affected ports for the next stage of hydrographic surveys. These surveys will contribute to revised nautical charts based on new data collected after the earthquake, and includes the ongoing restoration and reconstruction work of quays and port facilities. This stage includes the re-determination of the datum level of the affected ports, which is necessary because of large subsidence being reported in the areas. All of these efforts by the JHOD clearly demonstrate the significance of the hydrographic activities in case of the post-quake emergency situation, not only for the safety of navigation but also for economic recovery

    Lack of impact of the ALDH2 rs671 variant on breast cancer development in Japanese BRCA1/2‐mutation carriers

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    The aldehyde degrading function of the ALDH2 enzyme is impaired by Glu504Lys polymorphisms (rs671, termed A allele), which causes alcohol flushing in east Asians, and elevates the risk of esophageal cancer among habitual drinkers. Recent studies suggested that the ALDH2 variant may lead to higher levels of DNA damage caused by endogenously generated aldehydes. This can be a threat to genome stability and/or cell viability in a synthetic manner in DNA repair-defective settings such as Fanconi anemia (FA). FA is an inherited bone marrow failure syndrome caused by defects in any one of so far identified 22 FANC genes including hereditary breast and ovarian cancer (HBOC) genes BRCA1 and BRCA2. We have previously reported that the progression of FA phenotypes is accelerated with the ALDH2 rs671 genotype. Individuals with HBOC are heterozygously mutated in either BRCA1 or BRCA2, and the cancer-initiating cells in these patients usually undergo loss of the wild-type BRCA1/2 allele, leading to homologous recombination defects. Therefore, we hypothesized that the ALDH2 genotypes may impact breast cancer development in BRCA1/2 mutant carriers. We genotyped ALDH2 in 103 HBOC patients recruited from multiple cancer centers in Japan. However, we were not able to detect any significant differences in clinical stages, histopathological classification, or age at clinical diagnosis across the ALDH2 genotypes. Unlike the effects in hematopoietic cells of FA, our current data suggest that there is no impact of the loss of ALDH2 function in cancer initiation and development in breast epithelium of HBOC patients

    Prototype-Based Minimum Classification Error / Generalized Probabilistic Descent Training for Various Speech Units

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    In previous work we reported high classification rates for Learning Vector Quantization (LVQ) networks trained to classify phoneme tokens shifted in time. It has since been shown that the framework of Minimum Classification Error (MCE) and Generalized Probabilistic Descent (GPD) can treat LVQ as a special case of a general method for gradient descent on a rigorously defined classification loss measure that closely reflects the misclassification rate. This framework allows us to extend LVQ into a prototype-based minimum error classifier (PBMEC) appropriate for the classification of various speech units which the original LVQ was unable to treat. Speech categories are represented using a prototype-based multi-state architecture incorporating a Dynamic Time Warping procedure. We present results for the difficult E-set task, as well as for isolated word recognition for a vocabulary of 5240 words, that reveal clear gains in performance as a result of using PBMEC. In addition, we discuss the..
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