• Proceedings of the KSPS conference
• /
• 2007.05a
• /
• pp.167-169
• /
• 2007

This study analyzes Korean students' pronunciation errors in stop-nasal sequences in English. For the study, 23 English words of stop-nasal sequences were pronounced by 4 natives and 21 Korean students. The results showed two kinds of pronunciation errors: the insertion of a vowel and the nasal assimilation between stops and nasals. A teaching material was designed based on the errors. After a 60-minute class with the material they were asked to pronounce the same words in another session. There was a substantial improvement in the error correction.

• Phonetics and Speech Sciences
• /
• v.10 no.4
• /
• pp.11-17
• /
• 2018

This study reports on a production experiment designed to investigate how Korean speaking learners of English produce English forms ending in stops. In a repetition experiment, Korean participants listened to English nonce words ending in a stop and repeated what they heard. English speakers were recruited for the same task as a control group. The experimental result indicated that the transcriptions of the Korean productions by English native speakers showed vowel insertion in only 3% of productions although the pronunciation of English final stops showed that noise intervals after the closure of final stops were significantly longer for Korean speakers than for English speakers. This finding is inconsistent with the loanword data where 49% of words showed vowel insertion. It is also not compatible with the perceptual similarity approach, which predicts that because Korean speakers accurately perceive an English final stop as a final consonant, they will insert a vowel to make the English sound more similar to the Korean sound.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.11 no.1
• /
• pp.104-112
• /
• 2000

An evaluation of voice disorder has two methods. One is a perceptual analysis and the other is an acoustic analysis. All of these methods are just focused on sustained vowel. The analysis of conversational speech levels in voice disorder has not been achieved enough. The purpose of the present study is to compare two syllable words and sustained vowel in the vocal polyp patients and normal male speakers and to be applied on the vocal assessment and the voice therapy as a basic data. fifteen male patients with vocal polyp were the subject group. Fifteen healthy male were the control group for this study. The voices of the subject and control group, saved in MDVP of CSL were analyzed by its own analysis program. As a results, in subject group, the voice qualities between the vowel following lenis stop and the sustained vowel had no differences, and the voice qualities were different significantly between the vowel following heavily aspirated stop and the sustained vowel. In the control group the vowel fllowing stops and sustained vowel had also many differences in their voice quality, especially significant between the vowel following glottal stop and e sustained vowel.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.18 no.3
• /
• pp.591-609
• /
• 2024

In this study, preprocessings with all combinations were examined in terms of the effects on decreasing word number, shortening the duration of the process and the classification success in balanced and imbalanced datasets which were unbalanced in different ratios. The decreases in the word number and the processing time provided by preprocessings were interrelated. It was seen that more successful classifications were made with Turkish datasets and English datasets were affected more from the situation of whether the dataset is balanced or not. It was found out that the incorrect classifications, which are in the classes having few documents in highly imbalanced datasets, were made by assigning to the class close to the related class in terms of topic in Turkish datasets and to the class which have many documents in English datasets. In terms of average scores, the highest classification was obtained in Turkish datasets as follows: with not applying lowercase, applying stemming and removing stop words, and in English datasets as follows: with applying lowercase and stemming, removing stop words. Applying stemming was the most important preprocessing method which increases the success in Turkish datasets, whereas removing stop words in English datasets. The maximum scores revealed that feature selection, feature size and classifier are more effective than preprocessing in classification success. It was concluded that preprocessing is necessary for text classification because it shortens the processing time and can achieve high classification success, a preprocessing method does not have the same effect in all languages, and different preprocessing methods are more successful for different languages.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.9 no.7
• /
• pp.2633-2648
• /
• 2015

The problem of visual words' synonymy and ambiguity always exist in the conventional bag of visual words (BoVW) model based object category methods. Besides, the noisy visual words, so-called "visual stop-words" will degrade the semantic resolution of visual dictionary. In view of this, a novel bag of visual words method based on PLSA and chi-square model for object category is proposed. Firstly, Probabilistic Latent Semantic Analysis (PLSA) is used to analyze the semantic co-occurrence probability of visual words, infer the latent semantic topics in images, and get the latent topic distributions induced by the words. Secondly, the KL divergence is adopt to measure the semantic distance between visual words, which can get semantically related homoionym. Then, adaptive soft-assignment strategy is combined to realize the soft mapping between SIFT features and some homoionym. Finally, the chi-square model is introduced to eliminate the "visual stop-words" and reconstruct the visual vocabulary histograms. Moreover, SVM (Support Vector Machine) is applied to accomplish object classification. Experimental results indicated that the synonymy and ambiguity problems of visual words can be overcome effectively. The distinguish ability of visual semantic resolution as well as the object classification performance are substantially boosted compared with the traditional methods.

• Phonetics and Speech Sciences
• /
• v.7 no.1
• /
• pp.57-65
• /
• 2015

This study aimed to identify the development pattern of final stop consonant perception using the gating task. Sixty-four subjects participated in the study: 16 children aged 4 years, 16 children aged 5 years, 17 children aged 6 years, and 15 adults. One-syllable words with consonant-vowel-consonant(CVC) structure, mokㄱ-motㄱ and papㄱ-patㄱ were used as stimuli in order to remove the redundancy of acoustic cues in stimulus words, 40ms-length (-40ms) and 60ms-length (-60ms) from the entire duration of the final consonant were deleted. Three conditions (the whole word segment, -40ms, -60ms) were used for this speech perception experiment. 48 tokens (4 stimuli ${\times}3$ conditions ${\times}4$ trials) in total were provided for participants. The results indicated that 5 and 6 year olds showed final consonant perception similar to adults in stimuli, papㄱ-patㄱ and only the 6-year-old children showed perception similar to adults in stimuli, 'mokㄱ-motㄱ. The results suggested that younger typically developing children require more acoustic information to accurately perceive final consonants than older children and adults. Final consonant perception ability may become adult-like around 6 years old. The study provides fundamental data on the development pattern of speech perception in normal developing children, which can be used to compare to those of children with communication disorders.

• Proceedings of the KSPS conference
• /
• 2006.05a
• /
• pp.55-58
• /
• 2006

The aim of this paper is to investigate the effects of postvocalic consonant cluster (Contrasting nasal-stops consonant with stops) on vowel duration. In particular we focused on the rate of vowel duration in their words. (Experimental I ) and the tendency of unreleased voiceless stops at the end of the words.(Experimental II). The result of experimental I showed that the rate of vowel duration which is preceding single voiceless stops are significantly longer than those preceding nasal-stops counterparts and the percentage of English native speakers was longer than those of Korean leaners of English Experiment II indicated that the tendency of unreleased stop consonants occurred more frequently on single voiceless stops than nasal-stop clusters and Korean learners of English were more frequently produced the unreleased stops than English natives.

• Phonetics and Speech Sciences
• /
• v.13 no.2
• /
• pp.37-44
• /
• 2021

Preliminary findings are reported from five experiments testing the perceived naturalness of word tokens whose vowel durations are altered. The stimuli were minimal pairs of English words ending in a voiced/voiceless plosive. Results show an asymmetric effect of shortening and lengthening of the vowel on the perceived naturalness of the word. Incremental shortening of vowel duration initially shows a stable degree of perceived naturalness but rapidly deteriorates beyond a certain point. On the contrary, only a small degree of lengthening of the vowel made the perceived naturalness of the word quickly decay, but there was a floor effect such that the perceived degree of naturalness does not lower beyond a certain level. Further, the tokens with the original vowel duration were not always scored higher than the stimuli with a small degree of shortening. Future studies should address the issue of speaking rate and the ratio between the vowel and the stop closure duration to better understand the phenomenon. The issue investigated here has implications on the role of prototypical exemplars in the perception of phonotactic naturalness.

• Phonetics and Speech Sciences
• /
• v.15 no.1
• /
• pp.35-45
• /
• 2023

Tohoku Japanese is known to have voiced stops without pre-voicing in word-initial position, whereas traditional or conservative Japanese has voiced stops with pre-voicing in the same position. One problem with this devoicing of voiced stops is that it affects the distinction between voiced and voiceless stops because their voice onset time (VOT) values overlap. Previous studies have confirmed that Tohoku speakers use post-stop fundamental frequency (F0) as an acoustic cue along with VOT to avoid overlap. However, the role of post-stop F0 as a perceptual cue in this region has barely been investigated. Therefore, this study explored the role of post-stop F0 in stop voicing perception along with VOT. Several perception tests were conducted using resynthesized stimuli, which were manipulated along a VOT continuum orthogonal to an F0 continuum. The results showed no significant regional difference (Tohoku vs. Chubu) for nonsense words (/ta-da/). However, for meaningful words (/pari/ 'Paris' vs. /bari/ 'Bali,' /piza/ 'pizza' vs. /biza/ 'visa'), a significant word effect was found, and it was confirmed that some listeners utilized the post-stop F0 more consistently and steadily than others. Based on these results, we discuss innovative listeners who may lead the change in the perception of stop voicing.

• Structural Monitoring and Maintenance
• /
• v.6 no.4
• /
• pp.291-315
• /
• 2019

Fatigue cracks are inevitable in circumstances in which the cyclic loading exists. Therefore, many of mechanical components are in a risk of being in exposure to fatigue cracks. On the other hand, renewing the facilities or infrastructures is not always possible. Therefore, retrofitting the structures by means of the available methods, such as crack arrest methods is logical and in some cases inevitable. In this regard, this paper considers three popular crack arrest methods (e.g., drilling stop-hole, steel welded patch, and carbon fiber reinforced (CFRP) patch), which have been compared by using extended finite element method (XFEM). In addition, effects in terms of the width and thickness of patches and the configuration of drilling stop holes have been evaluated. Test results indicated that among the considered methods, CFRP patches were the most effective means for arresting cracks. Besides, in the case of arresting by means of drilling stop holes, drilling two holes next to the crack-tip was more effective than blunting the crack-tip by drilling one hole. In other words, the results indicated that the use of symmetric welded metal patches could lead to a 21% increase in fatigue life, as compared to symmetric stop holes. Symmetric CFRP patches enhanced the fatigue life of cracked specimen up to 77%, as compared to drilling symmetric stop holes. In addition, in all cases, symmetric configurations were far better than asymmetric ones.