• Speech Sciences
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• v.11 no.4
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• pp.223-232
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• 2004

This study investigated and compared the acoustic characteristics of the Korean stop sound [k'] in three different phonological environments: the tensified lenis stop [k'] as observed in /prek+kaci/, the fortis stop /k'/ as in /pre+k'aci/, and the fortis stop /k'/ following an obstruent as in /prek+k'aci/. The specific research question was whether or not the tensified lenis stop shares all the acoustic features with the other two kinds of fortis stops. The acoustic measures adopted in this study were H1*-H2*, VOT, length of stop closure, and $F_0$. The major findings were that the three stops showed no significant difference in all the acoustic measures except the length of stop closure. The fortis stop /k'/ following an obstruent showed significantly longer duration of stop closure than the other two stops, both of which showed no significant difference. Based on these phonetic results, this study argued that, for the proper phonological description of post-obstruent tensification, the phonological feature [slack vocal folds] of a lenis stop should be changed into [stiff vocal folds, constricted glottis] that the fortis stops should have.

• The Journal of Korean Physical Therapy
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• v.23 no.1
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• pp.37-43
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• 2011

Purpose: We studied the changes in motor response time and stop signal response time following visuomotor skill learning of a stop signal task in young healthy subjects. This study also was designed to determine what an effective practice is for different stop signals in the stop signal task (SST). Methods: Forty-five right-handed normal volunteers without a history of neurological dysfunction were recruited. They all gave written informed consent. In all subjects, motor reaction time (RT) and stop signal reaction time (SSRT) were measured for the stop signal task. Tasks were classified into three categories: predictable-stop signal task (P-SST) practice group random-stop signal task (R-SST) practice group control group. Results: Motor reaction time in the P-SST was significantly reduced when comparing pre- and post-tests (p<0.05). Stop signal reaction times in the P-SST and the R-SST were significantly reduced following motor skill learning (p<0.05). Also, the reaction time of the R-SST was shorter than that of the P-SST. Conclusion: These findings indicate that practice of an SST improves motor performance and stop function for some stop signals in the SST. P-SST practice was effective in the stop function of regular movement because of faster of the motor prediction and preparation but the R-SST was effective in the stop function of movements because of faster motor selection.

• The Journal of Korean Physical Therapy
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• v.32 no.2
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• pp.70-74
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• 2020

Purpose: This study examined whether 1) the motor inhibition response as cognitive-behavioral component is learning though a stop signal task using stop-signal paradigm, and 2) whether there is a difference in the learning degree according to imagery training and actual practice training. Methods: Twenty young adults (males: 9, females: 11) volunteered to participate in this study, and were divided randomly into motor imagery training (IT, n=10) and practice training (PT, n=10) groups. The PT group performed an actual practice stop-signal task, while the IT group performed imagery training, which showed a stop-signal task on a monitor of a personal computer. The non-signal reaction time and stop-signal reaction time of both groups were assessed during the stop-signal task. Results: In the non-signal reaction time, there were no significant intra-group and inter-group differences between pre- and post-intervention in both groups (p>0.05). The stop-signal reaction time showed a significant difference in the PT group in the intra-group analysis (p<0.05). On the other hand, there was no significant intra-group difference in the IT group and inter-group difference between pre- and post-intervention (p>0.05). Conclusion: These results showed that the motor inhibition response could be learned through a stop-signal task. Moreover, these findings suggest that actual practice is a more effective method for learning the motor inhibition response.

• Speech Sciences
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• v.10 no.4
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• pp.57-62
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• 2003

Using EPG, the stop and fricative portions of the Korean and English afficates were examined to find out whether the stop and fricative portions of Korean affricates are the same as those of English ones in articulation, as generally assumed in the literature. The English affricate in the word 'choose' is classified as alveopalatal just like the Korean affricate in the word 'cam'. The results of the EPG data showed that Korean affricates were not articulated the same as those in English, especially in the stop portion. In English, the stop portion of 'choose' was quite similar to /t/ as 'tooth', but in Korean, the stop portion of 'cam' was somewhat different from /t/ in 'tam'. More specifically, the stop portion of /t/ in 'tam' was articulated with the contact at the upper teeth and the alveolar ridge, but the stop portion of /t/ in 'cam' was articulated with the contact in the alveopalatal region. This shifting in the place of articulation of the stop portions of the Korean affricate (from dental and alveolar to alveopalatal) can be explained. Unlike English affricates, the stop portions of Korean affricates and the fricative portions of Korean affricates are co-articulated at the same place of articulation.

• Phonetics and Speech Sciences
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• v.6 no.4
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• pp.195-203
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• 2014

The aim of this study was to investigate the effects of phonation types ([+/- aspirated], [+/- fortis]) on aerodynamic measures with Korean bilabial stops. Sixty-three healthy young adults (30 males, 33 females) participated to evaluate the VOEF (Voicing Efficiency) tasks with bilabial stop consonants /$p^h$/, /p/, /p'/ using Phonatory Aerodynamic System (PAS) Model 6600 (Kay PENTAX Corp, Lincoln Park, NJ). All VOEF measures were significantly influenced by phonation types except RANP(pitch range)(p <.01). For sound pressure, maximum SPL, mean SPL, and Mean SPL during Voicing have been shown to be significantly greatest in fortis stop /p'/ than aspirated /$p^h$/ and lenis stop /p/ (p<.001). On the other hand, mean pitch after lenis stop was significantly lower than after aspirated and fortis stops (p<.001). Peak expiratory airflow, Target airflow, and FVC (Expiratory volume) were significantly lowest in fortis stop /p'/ which might be associated with higher aerodynamic resistance while peak air pressure and mean peak air pressure during closure were significantly lower in lenis stop /p/. Additionally, AEFF (Aerodynamic efficiency) was significantly higher in fortis stop /p'/ than lenis stop /p/ as well as aspirated stop /$p^h$/ (p<.001). Thus, sound pressure, airflow parameters, and aerodynamic resistance made crucial roles in distinguishing fortis /p'/ from lenis stop /p/ and aspirated. Additionally, pitch and subglottal air pressure parameters were important aerodynamic characteristics in distinguishing lenis /p/ from fortis /p'/ and aspirated /$p^h$/. Therefore, accurate aspirated /p/ stop consonant should be elicited when collecting the airflow, intraoral pressure related data with patients with voice disorders in order to enhance the reliability and relevance or validity of aerodynamic measures using PAS.

• Journal of Society of Preventive Korean Medicine
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• v.20 no.2
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• pp.39-51
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• 2016

Objectives : This study was to identify the stop-out experiences of Korean Medicine Students(K.M.S.). The stop-out is defined as a withdrawal temporarily from enrollment at a university. Methods : Data was collected through in-depth individual interviews from 2013 to 2016 and analyzed with Colaizzi's phenomenological methodology. The participants were interviewed once or twice, for 30minutes to 50minutes per interview. Results : Ten theme-clusters were identified from 21 themes. These theme-clusters were divided to 4 divisions as when they made the decision for the stop-out, during their stop-out period, when they went back to school and the meaning of their stop-out. 'A difficult situation to continue the study', 'Uncertainty about their decision and anxiety of the future' are 2 theme-clusters for when they made the decision for the stop-out, 'Conflict and anxiety', 'Novel and free time', 'Improving family relationship and finding new relationship' are 3 theme-clusters for during their stop-out period, 'Anxiety for the returning to school', 'New relationship and sense of relief' are 2 theme-clusters for when they went back to school, and 'Making a present for me', 'An opportunity for the emotional growth', 'Recovery of learning will' are 3 theme-clusters for the meaning of their stop-out that they gave to it. Conclusions : The stop - out of K.M.S. began at the hope that they want to take the lead for their lives. And they would find themselves more mature after the experience of their stop-out. This result could be a basic reference for the counselling of the faculty working with K.M.S.

• MALSORI
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• no.46
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• pp.13-24
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• 2003

This experimental study shows that, in reading of the English isolated words that are enumerated, the releasing of the word-final stop is employed for signaling enumeration in company with the well-known intonational pattern for it. Furthermore, this study tries to find the aspects of the releasing of the stops in the word-final positions, focusing on the association of the stop releasing/nonreleasing with i) the POA (Place of Articulation) distinction of the word-final stop, ii) the various qualities of the vowel before the final stop, and iii) the voice distinction of the stop in the word-final position.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.4
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• pp.266-269
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• 2012

The most recently IGBT (insulated gate bipolar mode transistor) devices are in the most current conduction capable devices and designed to the big switching power device. Use this number of the devices are need to high voltage and low on-state voltage drop. And then in this paper design of field stop IGBT is insert N buffer layer structure in NPT planar IGBT and optimization design of field stop IGBT and trench field stop IGBT, both devices have a comparative analysis and reflection of the electrical characteristics. As a simulation result, trench field stop IGBT is electrical characteristics better than field stop IGBT.

• Speech Sciences
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• v.13 no.1
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• pp.43-54
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• 2006

The purpose of this study is to examine temporal structures of English words beginning with an /s/ plus stop sequence through production experiments with native speakers of Korean learning English and native speakers of English. According to the results of our production experiment, both a beginner and an advanced group of Korean English learners produced /s/ shorter than a following stop, while the opposite pattern was observed in English native speakers' production. An advanced group of Korean English learners were good at producing a stop after /s/ as unaspirated, but their production of a stop following /s/ was different from English native speakers' production in that the closure duration of the stop was much longer.

• MALSORI
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• no.45
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• pp.1-14
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• 2003

This paper criticizes S. Kim (1992), claiming that the perception of place cues in the reduced stop consonant clusters ('reducing' means 'cutting off' the acoustic silence in stop clusters) largely depends on the acoustic characteristics such as formant transition and noise frequency distribution of stop burst, rather than the closure duration time as advocated by S. Kim (1992). The claim is based on the perception test conducted upon 111 stimuli over 10 subjects. The finding is that, when the closure duration is cut off up to the point where only one stop is perceived, place of the second stop, not the first one, in the cluster is in most cases perceived regardless of the places of the first and second stops. It is likely that the place cues of the stop in the prevocalic position mask those in the postvocalic position.