• Phonetics and Speech Sciences
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• v.11 no.4
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• pp.97-108
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• 2019

An automated Praat script was implemented to measure optimal formant frequencies for adults. Optimal formant analysis could be interpreted to show that the deviation of formant frequency that resulted from the two variously combined setting parameters (maximum formant and number of formants) was minimal. To increase the reliability of formant analysis, LPC order should be set differently, based on the gender or vowel type. Praat recommends 5,000 Hz and 5,500 Hz as maximum formant settings and, at the same time, recommends 5 as the number of formants for males and females. However, verification is needed to determine whether these recommended settings are valid for Korean vowels. Statistical analysis showed that formant frequencies significantly varied across the adapted scripts, especially with respect to the data on females. Formant plots and statistical results showed that linear_script and qtone_script are much more reliable in formant measurements. Among four kinds of scripts, the linear and qtone_scripts proved to be more stable and reliable. While the linear_script was designed to have a linearly increased formant step in for-loop, the increment of formant step in the qtone_script was arranged by quarter tone scale (base frequency×common ratio ($\sqrt[24]{2}$)). When looking at the tendency of the formant setting drawn by the two referred algorithms in the context of front vowel [i, e], the maximum formant was set higher; and the number of formants set at a lower value than recommended by Praat. The back vowel [o, u], on the contrary, has a lower maximum formant and a higher number of formants than the standard setting.

• Phonetics and Speech Sciences
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• v.12 no.3
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• pp.1-14
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• 2020

Previous studies have confirmed that /o/ and /u/ in Seoul Korean are undergoing a merger in the F1/F2 space, especially for female speakers. As a substitute parameter for formants, it is reported that female speakers use phonation (H1-H2) differences to distinguish /o/ from /u/. This study aimed to explore whether H1-H2 values are being used as perceptual cues for /o/-/u/. A perception test was conducted with 35 college students using /o/ and /u/ spoken by 41 females, which overlap considerably in the vowel space. An acoustic analysis of 182 stimuli was also conducted to see if there is any correspondence between production and perception. The identification rate was 89% on average, 86% for /o/, and 91% for /u/. The results confirmed that when /o/ and /u/ cannot be distinguished in the F1/F2 space because they are too close, H1-H2 differences contribute significantly to the separation of the two vowels. However, in perception, this was not the case. H1-H2 values were not significantly involved in the identification process, and the formants (especially F2) were still dominant cues. The study also showed that even though H1-H2 differences are apparent in females' production, males do not use H1-H2 in their production, and both females and males do not use H1-H2 in their perception. It is presumed that H1-H2 has not yet been developed as a perceptual cue for /o/ and /u/.

• Journal of KIISE:Software and Applications
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• v.37 no.10
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• pp.788-801
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• 2010

Advancing of mobile device is remarkable, so the research on mobile input device is getting more important issue. There are lots of input devices such as keypad, QWERTY keypad, touch and speech recognizer, but they are not as convenient as typical keyboard-based desktop input devices so input strings usually contain many typing errors. These input errors are not trouble with communication among person, but it has very critical problem with searching in database, such as dictionary and address book, we can not obtain correct results. Especially, Hangeul has more than 10,000 different characters because one Hangeul character is made by combination of consonants and vowels, frequency of error is higher than English. Generally, suffix tree is the most widely used data structure to deal with errors of query, but it is not enough for variety errors. In this paper, we propose fast approximate Korean word searching system, which allows variety typing errors. This system includes several algorithms for applying general approximate string searching to Hangeul. And we present profanity filters by using proposed system. This system filters over than 90% of coined profanities.

• The Journal of the Korea Contents Association
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• v.18 no.4
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• pp.268-278
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• 2018

The purpose of this study is to compare and analyze phonetic items such as the phonemic system, phonological rules, and pronunciation descriptions and notations incorporated in the textbooks. Based on our analysis results, we point out the problems related to pronunciation education, and suggest directions for improvement. First, the presentation order of consonants and vowels in the phonological systems sections of each textbook was different. We recommend that a standard for consonant and vowel presentation order should be prepared, but that this standard should take into consideration the specific purpose of the textbook; the learning strategies and goals, as well as the possibility of teaching and learning. Second, similar to phonemic systems, the presentation order of phonological rules was different for each textbook. To create a standard order for phonological rules, we have to standardize the order of presentation of rules and determine which rules should be presented. Furthermore, when describing phonological rules, the content should be described in common and essential terms as much as possible without the use of jargon. Third, in other matters of pronunciation, there were problems such as examples for pronunciation and lack of exercises. Regarding this, we propose to provide sentences or dialogues as examples for pronunciation, and to link these to various activities and other language functions for pronunciation practice.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.30 no.2
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• pp.95-100
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• 2019

Background and Objectives For patients with polyps and cysts, glottal gaps resulting from their lesions have negative respiratory effects when they vocalize. Phonatory Aerodynamic System is clinically used, but is often limited in the measurement of vowels. So the researchers attempted to verify the usefulness of Phonatory Aerodynamic System by comparing differences in respiratory characteristics and patterns which can be measured by the level of connected speech. Materials and Method Among the subjects who were diagnosed through a stroboscopy, there were 33 patients with polyps and 23 patients with cysts. Then, 36 subjects who were found to have no specific findings through a stroboscopy and perceptual test were selected to the normal group. We compared respiratory characteristics and patterns. And compared vocal polyps and cysts before and after laryngeal micro surgery (LMS). Results First, difference in respiratory patterns between the normal group and the patients with polyps and cysts were examined to show that breath groups, breath group syllables, and expiratory·inspiratory volume were significantly higher in the polyp/cyst group than those in the normal group, indicating that precision was lowered during the conversation, due to reduction in speech intelligibility and interruption of communication. Second, there were significant differences in maximum phonation time, mean flow rate, and subglottal pressure among respiratory characteristics, breath groups, breath group syllables, and inspiratory volume before and after LMS, which appeared to be similar to the normal group. Conclusion The understanding of respiratory characteristics and patterns produced by patients in connected speech which is most similar to natural speech was found to be the objective and useful method for examining characteristics of the subjects.

• Korean Journal of Cognitive Science
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• v.28 no.1
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• pp.65-90
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• 2017

Rewards or penalties become informative only when contingent on an immediately preceding response. Our goal was to determine if the brain responds differently to motivational events depending on whether they provide feedback with the contingencies effective for learning. Event-related fMRI data were obtained from 22 volunteers performing a visuomotor categorical task. In learning-condition trials, participants learned by trial and error to make left or right responses to letter cues (16 consonants). Monetary rewards (+500) or penalties (-500) were given as feedback (learning feedback). In random-condition trials, cues (4 vowels) appeared right or left of the display center, and participants were instructed to respond with the appropriate hand. However, rewards or penalties (random feedback) were given randomly (50/50%) regardless of the correctness of response. Feedback-associated BOLD responses were analyzed with ANOVA [trial type (learning vs. random) x feedback type (reward vs. penalty)] using SPM8 (voxel-wise FWE p < .001). The right caudate nucleus and right cerebellum showed activation, whereas the left parahippocampus and other regions as the default mode network showed deactivation, both greater for learning trials than random trials. Activations associated with reward feedback did not differ between the two trial types for any brain region. For penalty, both learning-penalty and random-penalty enhanced activity in the left insular cortex, but not the right. The left insula, however, as well as the left dorsolateral prefrontal cortex and dorsomedial prefrontal cortex/dorsal anterior cingulate cortex, showed much greater responses for learning-penalty than for random-penalty. These findings suggest that learning-penalty plays a critical role in learning, unlike rewards or random-penalty, probably not only due to its evoking of aversive emotional responses, but also because of error-detection processing, either of which might lead to changes in planning or strategy.

• Korean Journal of Cognitive Science
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• v.34 no.1
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• pp.21-38
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• 2023

The present study was designed to investigate the effect of the difficulty level of retrieval practice and the association strength of categories and stimuli within categories on memory inhibition. Most of the studies have investigated whether inhibition was occurred by manipulating the degree of association strength, emotion value or physical characteristics of non-retrieval practice words within the retrieval practice category. Therefore, it was necessary to study how inhibition occurs according to the degree of difficulty of retrieval stimuli during retrieval practice. The difficulty of retrieval was manipulated into three levels: difficult condition, normal condition, and easy condition through the degree of presentation of consonants and vowels of words during retrieval learning. Additionally, the strength of association between categories and words within categories was manipulated. In previous studies, retrieval-induced forgetting occurred under conditions where the association strength between categories and words within the categories was strong. On the other hand, retrieval-induced forgetting did not occur under conditions where the association strength between categories and words within the categories was weak. The present study, if the inhibition process differs according to the difficulty of retrieval, the possibility of different results from previous studies was explored according to the difference in the strength of association with the category. As a result of the study, in the condition of strong association strength, retrieval-induced forgetting was observed under normal and difficult retrieval difficulty conditions. Whereas retrieval-induced forgetting was not observed under conditions of easy retrieval difficulty condition. In the condition of weak association strength, retrieval-induced forgetting tended to occur under difficult retrieval difficulty conditions. Whereas retrieval-induced forgetting was not observed under conditions of normal and easy retrieval difficulty condition. These results suggest that memory inhibition may appear differently depending on the difficulty of retrieval.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.9
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• pp.4036-4044
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• 2012

This study is aimed to investigate the association between web-based visual stress and MBTI personality types. The stressor deriving visual stress is built by 14 vowels out of Korean alphabet as a content and parallel striples as a background on the screen, which is given to each subject during 5min. The dependent variable indicating how much human takes visual stress is the reduction rate of flicker fusion frequency, which is evaluated with visual flicker fusion frequency tester. The independent variables are gender and 8 MBTI personality types(E-I, S-N, T-F, and J-P), and hypotheses are based on human information processing model and previous studies. The results address that the reduction rate is not significantly affected by gender, S-N, and J-P, but E-I and T-F have significant influences on it. The reduction rate in I-type is almost 2 times as much as that in E-type and T-type has the rate 2.2 times more than F-type. This study can be applicable to determine the adequate personnel for jobs requiring less sensibility to visual stressors in areas that human error may lead to critical damages to an overall system.

• MALSORI
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• no.27_28
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• pp.27-56
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• 1994

Processes involving the change of vowel height are natural enough to be found in many languages. It is essential to have a better feature specification for vowel height to grasp these processes properly, Standard Phonology adopts the binary feature system, and vowel height is represented by the two features, i.e., [\pm high] and [\pm low]. This has its own merits. But it is defective because it is misleading when we count the number of features used in a rule to compare the naturalness of rules. This feature system also cannot represent more than three degrees of height, We wi31 discard the binary features for vowel height. We consider to adopt the multivalued feature [n high] for the property of height. However, this feature cannot avoid the arbitrariness resulting from the number values denoting vowel height. It is not easy to expect whether the number in question is the largest or not It also is impossible to decide whether a larger number denotes a higher vowel or a lower vowel. Furthermore this feature specification requires an ad hoc condition such as n > 3 or n \geq 2, whenever we want to refer to a natural class including more than one degree of height The altelnative might be Particle Phonology, or Dependency Phonology. These might be apt for multivalued vowel height systems, as their supporters argue. However, the feature specification of Particle Phonology will be discarded because it does not observe strictly the assumption that the number of the particle a is decisive in representing the height. One a in a representation can denote variant degrees of height such as [e], [I], [a], [a ] and [e ]. This also means that we cannot represent natural classes in terms of the number of the particle a, Dependency Phonology also has problems in specifying a degree of vowel height by the dependency relations between the elements. There is no unique element to represent vowel height since every property has to be defined in terms of the dependency relations between two or more elements, As a result it is difficult to formulate a rule for vowel height change, especially when the phenomenon involves a chain of vowel shifts. Therefore, we suggest a new feature specification for vowel height (see Chapter 3). This specification resorts to a single feature H and a few >'s which refer exclusively to the degree of the tongue height when a vowel is pronounced. It can cope with more than three degrees of height because it is fundamentally a multivalued scalar feature. This feature also obviates the ad hoc condition for a natural class while the [n high] type of multivalued feature suffers from it. Also this feature specification conforms to our expection that the notation should become simpler as the generality of the class increases, in that the fewer angled brackets are used, the more vowels are included, Incidentally, it has also to be noted that, by adopting a single feature for vowel height, it is possible to formulate a simpler version of rules involving the changes of vowel height especially when they involve vowel shifts found in many languages.

• Proceedings of the KSPS conference
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• 1996.10a
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• pp.109-116
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• 1996

In this paper, I would like to explore the possibility that the nature of place assimilation can be captured in terms of the OCP within the Optimality Theory (Mccarthy & Prince 1999. 1995; Prince & Smolensky 1993). In derivational models, each assimilatory process would be expressed through a different autosegmental rule. However, what any such model misses is a clear generalization that all of those processes have the effect of avoiding a configuration in which two consonantal place nodes are adjacent across a syllable boundary, as illustrated in (1):(equation omitted) In a derivational model, it is a coincidence that across languages there are changes that have the result of modifying a structure of the form (1a) into the other structure that does not have adjacent consonantal place nodes (1b). OT allows us to express this effect through a constraint given in (2) that forbids adjacent place nodes: (2) OCP(PL): Adjacent place nodes are prohibited. At this point, then, a question arises as to how consonantal and vocalic place nodes are formally distinguished in the output for the purpose of applying the OCP(PL). Besides, the OCP(PL) would affect equally complex onsets and codas as well as coda-onset clusters in languages that have them such as English. To remedy this problem, following Mccarthy (1994), I assume that the canonical markedness constraint is a prohibition defined over no more than two segments, $\alpha$ and $\beta$: that is, $^{*}\{{\alpha, {\;}{\beta{\}$ with appropriate conditions imposed on $\alpha$ and $\beta$. I propose the OCP(PL) again in the following format (3) OCP(PL) (table omitted) $\alpha$ and $\beta$ are the target and the trigger of place assimilation, respectively. The '*' is a reminder that, in this format, constraints specify negative targets or prohibited configurations. Any structure matching the specifications is in violation of this constraint. Now, in correspondence terms, the meaning of the OCP(PL) is this: the constraint is violated if a consonantal place $\alpha$ is immediately followed by a consonantal place $\bebt$ in surface. One advantage of this format is that the OCP(PL) would also be invoked in dealing with place assimilation within complex coda (e.g., sink [si(equation omitted)k]): we can make the constraint scan the consonantal clusters only, excluding any intervening vowels. Finally, the onset clusters typically do not undergo place assimilation. I propose that the onsets be protected by certain constraint which ensures that the coda, not the onset loses the place feature.