597 research outputs found
Prosody-Based Measures for Automatic Severity Assessment of Dysarthric Speech
No full textOne of the first cues for many neurological disorders are impairments in speech. The traditional method of diagnosing speech disorders such as dysarthria involves a perceptual evaluation from a trained speech therapist. However, this approach is known to be difficult to use for assessing speech impairments due to the subjective nature of the task. As prosodic impairments are one of the earliest cues of dysarthria, the current study presents an automatic method of assessing dysarthria in a range of severity levels using prosody-based measures. We extract prosodic measures related to pitch, speech rate, and rhythm from speakers with dysarthria and healthy controls in English and Korean datasets, despite the fact that these two languages differ in terms of prosodic characteristics. These prosody-based measures are then used as inputs to random forest, support vector machine and neural network classifiers to automatically assess different severity levels of dysarthria. Compared to baseline MFCC features, 18.13% and 11.22% relative accuracy improvement are achieved for English and Korean datasets, respectively, when including prosody-based features. Furthermore, most improvements are obtained with a better classification of mild dysarthric utterances: a recall improvement from 42.42% to 83.34% for English speakers with mild dysarthria and a recall improvement from 36.73% to 80.00% for Korean speakers with mild dysarthria
A Joint Model for Pronunciation Assessment and Mispronunciation Detection and Diagnosis with Multi-task Learning
No full textEmpirical studies report a strong correlation between pronunciation proficiency scores and phonetic errors in non-native speech assessments of human evaluators. However, the existing system of computer-assisted pronunciation training (CAPT) regards automatic pronunciation assessment (APA) and mispronunciation detection and diagnosis (MDD) as independent and focuses on individual performance improvement. Motivated by the correlation between two tasks, we propose a novel architecture that jointly tackles APA and MDD using CTC and cross-entropy criteria with a multi-task learning scheme to benefit both tasks. To leverage additional knowledge transfer, Wav2Vec2-robust finetuned on TIMIT is used for the joint optimization. The integrated model significantly outperforms single-task learning, with a mean of 0.057 PCC increase for APA and 0.004 F1 increase for MDD on Speechocean762, which reveals that proficiency scores and phonetic errors are correlated for both human and model assessments.N
Developing a Multilingual Spontaneous L2 Speech Corpus for Automated Proficiency Assessment
No full textCurrently, most accessible multilingual L2 spontaneous speech corpora primarily include L2 English from speakers of various L1 backgrounds, with few and often small-scale corpora available for non-English L2s. Annotated assessment data from expert raters is especially rare. This study addresses this gap by constructing a large-scale dataset of spontaneous L2 speech in seven languages (Chinese, Japanese, English, French, German, Spanish, and Russian) from Korean L1 speakers, accompanied by detailed assessments using a carefully designed rubric. The dataset includes extensive metadata analysis and validation processes to ensure the reliability of subjective assessments. To our knowledge, this is the first large-scale, comprehensive corpus of its kind, featuring diverse L2 spontaneous speech from Korean speakers with expert-annotated assessments.N
Increasing Photocurrent in Lead Sulfide Quantum Dots Solar Cells via Overpassing Active Layer Thickness Limitation
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Thermally Stable and Efficient Planar Perovskite Solar Cells through a Facile Surface Passivation Using a Novel IDTT-Based Small Molecule Additive
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초음파 세포자극기
No full textAn apparatus for stimulating cell includes a cell culture chamber, a control device, and first and second exciters. The cell culture chamber includes cell and culture medium. The control device receives first and second exciting signals, and controls magnitudes and phases of the received first and second exciting signals so that a sound pressure level in a focused zone is higher than a sound pressure level in a zone other than the focused zone, and outputs first and second controlled exciting signals. The first and second exciters receive the first and second controlled exciting signals and excite the cell culture chamber
Spatial localization of charged molecules by salt ions in oil-confined water microdroplets
Full text link© 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. Cells contain more than 100 mM salt ions that are typically confined to dimensions of 5 to 10 micrometers by a hydrophobic cellular membrane. We found that in aqueous microdroplets having the same size as cells and that are confined in hydrocarbon oil, negatively charged molecules were distributed rather uniformly over the interior of the microdroplet, whereas positively charged molecules were localized at and near the surface. However, the addition of salt (NaCl) to the microdroplet caused all charged molecules to be localized near the oil-water interface. This salt-induced relocalization required less salt concentration in microdroplets compared to bulk water. Moreover, the localization became more prominent as the size of the microdroplet was reduced. The relocatization also critically depended on the type of oil. Our results imply that salt ions and different hydrophobic interfaces together may govern the local distribution of charged biomolecules in confined intracellular environments11Nsciescopu
An Analysis of Pastor Sunhee Gwark’s Sermons by Using Hermeneutic Methods of Practical Theology for Improving Sermon Paradigm
No full textThe purpose of this project is to analyze the sermons of Sunhee Gwark, the former senior pastor of So-Mang church, into hermeneutic methods of practical theology for improving sermon paradigm. The relationship between the world of Scripture and the world of audience was investigated and the world of audience was valued equally with the world of Scripture in sermon. In order to analyze Gwark\u27s sermons, the standards of evaluating sermon were provided. An improved sermon paradigm was suggested and the author wants this study to contribute to refreshing sermons to be balanced between the world of Scripture and that of audience
Orientation control over bent-core smectic liquid crystal phases
No full textBent-core smectic liquid crystal (LC) phases (B phases) have been widely studied since their unusual polar and chiral properties were discovered in the 1990s. Relatively few studies have examined the mechanisms by which the orientation of the B phase may be controlled to produce the type of macroscopic domain that is essential for organic semiconductor, optical device and patterning applications. This review is intended to cover recent progress towards controlling the B phases upon layering, including anisotropic treatment methods and topographical confinement methods. Finally, this review closes with a discussion of B smectic phases that have been fabricated for use in certain applications
Mussel-Inspired Polydopamine-Treated Reinforced Composite Membranes with Self-Supported CeOx Radical Scavengers for Highly Stable PEM Fuel Cells
No full textThe physical and chemical degradations of a state-of-the-art proton exchange membrane (PEM) composed of a perfluorinated sulfonic acid (PFSA) ionomer and polytetrafluoroethylene (PTFE) reinforcement are induced through the repeated expansion/shrinkage of the ionomer and free radical attacks. Such degradations essentially originate from the loose structure of the materials and the low interactive binding force among the PEM constituents. In this study, the need for simplified design principles of adhesives led to the use of mussel-inspired polydopamine (PD) as an interfacial modifier for the fabrication of highly durable PEM. Indeed, a self-polymerized dopamine layer acts as an interfacial glue, and enables efficient impregnation of a hydrophilic PFSA ionomer into porous hydrophobic PTFE with high packing density, resulting in strong adhesion between the PTFE and the PFSA polymers in the membrane. In addition, the redox property of the PD end groups spontaneously reduces the partial Ce salts in the ionomer solution and anchors them to the PD@PTFE substrate as defective cerium oxide (CeOx) nanoparticles, reducing the dissolution and subsequent migration under cell operations. Finally, a CePD@PTFE membrane shows outstanding durability in fuel cells under an accelerated humidity cycling test with a reduction in the degree of physical and chemical failures.
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