1,721,025 research outputs found
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
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
Fatigue life assessment of thermite welded rails based on laboratory tests and field measurement data
No full textThis in-depth study assesses the fatigue life of thermite-welded 60E1 rails by combining fatigue experimental tests with field measurement data. Material characterization, conducted using X-ray Diffraction (XRD), X-ray Fluorescence (XRF), and Scanning Electron Microscopy (SEM), aimed to understand the fatigue behavior of these materials. The research was particularly focused on highspeed rail lines in South Korea, targeting areas with influence of track condition to collect strain data. By combining dynamic modulus calculations from high-speed tensile tests with the rain flow counting method for determining wheel loads, and employing the Linear Cumulative Damage method for estimating rail fatigue life, this study provides novel insights into the maintenance and durability of thermite welded rails. The integration of detailed laboratory experiments with field stress data offers a significant contribution to the predictive maintenance and lifecycle management of high-speed railway infrastructure.
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
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
An Exploration of the Critical Realism Approach for Institutional Change: A Comparison with Historical Institutionalism
No full text저자의 박사학위 논문(정책변화의 제도적 조건과 메커니즘 분석: 의료보험 규제정책을 중심으로, 2009년 2월, 고려대 행정학과)의 일부를 수정하여 발전시킨 것임제도변화는 행정학 및 정책학 분야에서 지속적으로 논의되는 핵심 연구주제 중 하나이다. 본 연구에서는 제도변화를 설명하는 역사적 제도주의 설명방힉이 가지고 있는 근본적인 한계를 지적하고, 그 대안으로 비판적 실제론(critical realism)을 통해 재구성의 가능성을 탐색하고자 한다. 이를 위해 본 연구는 제도변화와 관련해 역사적 제도주의가 ① 변화와 연속에서 원인과 결과간 관계설정과 관련된 조건과 기제의 문제인 인과성(causality), ② 거시적 구조와 미시적 행위자간 관계설정의 문제인 발현성(emergence), ③ 시간의 흐름과 공간적 맥락간 관계 설정 문제인 역사성(historicity), ④ 연속과 변화의 통합설명이라는 차원에서 한계가 있음을 지적한다. 역사적 제도주의에서 제도의 변화와 연속을 설명하기 위한 새로운 모형을 구성하기 위해서는 이러한 쟁점들에 대한 근본적 재검토가 요구되는데, 본 연구에서는 비판적 실재론이 이에 대한 이론적 대안을 제시하고 있음을 살펴보았다. Institutional change is a theoretical concept which has gained intensive attention in public administration and policy science. This study aims to discuss the fundamental limits of historical institutionalism in explaining institutional change and to suggest a new altemative explanatory model based on critical realism. This research suggests four problems with how historical institutionalism explains institutional change. The first is casuality which, is related with conditions and mechanisms in the course of setting cause and effect. The second is emergence, the matter of setting the relationship between macro-structure and micro-actor. The third is historiaty which determines the relationship between temporal flows and contextual space. This study shows that critical realism will provide a theoretical alternative to historical institutionalism's explanation for institutional change
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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