• Knowledge Management Research
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• v.17 no.2
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• pp.131-163
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• 2016

The purpose of this study is to empirically analyze how social comparative learning of forum participants affects learning effects with an emphasis on participants' characteristics. As today's society is changing at a fast pace, the desire for new knowledge and information has grown accordingly. To quench this thirst for knowledge and information, seminars, symposiums, conferences, forums, conventions, exhibitions, and more are taking place as part of knowledge sharing events across the world. Also, the increased need for knowledge and information exchange has led the development and growth of the convention industry and Meetings, Incentives, Conferences, and Events (Exhibitions)(MICE) industry. Especially, forum is a type of event which invites professionals and specialists to discuss diverse topics and share their knowledge and experience with the audience. The participants utilize it as an opportunity to get close to information providers and enjoy the pleasure of knowledge exchange. However, there have been few empirical analyses on who the participants are, why they attend forum, how they pick up and learn new information and knowledge, and what kinds of learning effects they achieve after the event. This paper is to analyze how social comparative learning of the forum's participants influences learning effects based on Albert Bandura's Social Learning Theory (1977, 1997, 1982. 2001) and Leon Festinger's Social Comparative Theory (1950, 1954). By dividing the participants into two groups, one with high level of self-efficacy and the other with low level of self-efficacy, we have examined the differences in learning effects between the two groups using them as moderating variables. This study was conducted in 'MBN Y Forum 2016,' which is one of the most representative knowledge exchange forums of South Korea. An online survey was distributed out and, 1,307(39.2%) out of the total participants of 3,338 have completed the survey. The survey included questions about whether the participants have gained positive or negative motivations by comparing themselves to the speakers (upward comparison learning) and other participants (lateral comparison learning). The results have shown the quality of messages that the speakers are presenting as knowledge providers is the most significant factor that acts on learning effects. Particularly, the participants had higher levels of self-efficacy and self-esteem than average people. They had a clear goal to learn from the speakers (upward comparison) and received positive motivations from them. In other words, no negative learning effects had been found. This presents a managerial implication that having a qualified speaker is necessary for a forum to be successful. On the other hand, the results from the comparison with the other participants (lateral comparison) were different. The participants were likely to compare themselves to the other participants through observational learning. They could compare listening attitudes, language skills, or capabilities to ask a question. The results have showed the participants received positive motivations from the lateral group but at the same time were jealous of abilities of the others. When the quality of a question by a participant is not good enough, it can have a negative influence on the participants' learning effects. The first group with high levels of self-efficacy and self-esteem had no correlation to negative learning effects from the speakers. They rather had a strong desire to learn from the speakers. On the contrary, the participants perceived the lateral group as a learning subset and competitor. The second group with low levels of self-efficacy and self-esteem saw the quasi-group as a rival. This presents that the individual learning effects can be different depending on the participants' characteristics.

• Phonetics and Speech Sciences
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• v.4 no.3
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• pp.85-92
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• 2012

It is a well-known phenomenon that vowel duration in English is generally longer before a voiced stop than a voiceless one. Past research has postulated that the closure duration of the voiceless stop is generally longer than that of the voiced stop and that the duration of a preceding vowel is determined complementarily by the closure duration of the stop. To shed further light on the phenomenon, this study examined fourteen native speakers of American English who read the monosyllabic words [bVC] (V = [i, ɪ, eɪ, ɛ, æ, ʌ, ɑ], C = [t, d]). First, we found that mean vowel duration was 38 ms longer before the voiced stop than the voiceless (mean duration ratio = 1.24). Second, mean closure duration of the voiced stop was only shorter by 5 ms compared to the voiceless stop (mean duration ratio = 0.97). Therefore, for our subjects, vowel duration was not determined complementarily by the closure duration of the following stop. Third, vowels with longer inherent durations (viz., tense, diphthong, and low vowels) tended to show larger duration ratios in the voiced and voiceless contexts than the vowels with shorter durations (viz., lax vowels). This indicates that the lengthening of inherently shorter vowels before a voiced stop is limited in order to avoid overlapping with longer vowels in the duration range. Fourth, there was no significant gender difference in vowel duration ratios in the contexts of voiced and voiceless stops. Finally, considerable individual differences were found in the vowel and consonant duration ratios.

• Speech Sciences
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• v.14 no.1
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• pp.73-89
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• 2007

This study explored the perception of transplanted English prosody by thirty American and Korean, male and female listeners. The English utterances of various sentence types produced by Korean and American male speakers were employed to transplant the American prosody contours to Korean English utterances. Then, the thirty subjects were instructed to rate the transplanted prosodic components. Results showed that the interactions between the three factors (e.g., rater groups & transplantation types; transplantation types & sentence types; rater groups & transplantation types & sentence types) turned out to be meaningful. Both Americans and Koreans perceived the effectiveness of the combined effect of transplanted duration and pitch or duration and pitch and intensity. However, when perceiving individual prosodic components, Americans and Koreans showed different perceptual ratings. As for the overall prosody change, Americans perceived the change of intensity in a significant way but Koreans did not because intensity is not a crucial semantic factor in Korean. Americans rated the transplantation of duration alone as ineffective while Koreans rated otherwise. This was explained by the difference between English and Korean. The difference of perspective was also significant with different sentence types, especially with the three sentence types that had speech rates slower than other sentence types. A slower speech rate intensified the mismatch between the transplanted duration and the original pitch causing a negative impression on American listeners whereas this did not affect Korean listeners. Pedagogical implications of the findings are discussed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.7
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• pp.2785-2799
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• 2020

We propose a novel speaker adaptation method using acoustic model clustering. The similarity of different speakers is defined by the cosine distance between their i-vectors (intermediate vectors), and various efficient clustering algorithms are applied to obtain a number of speaker subsets with different characteristics. The speaker-independent model is then retrained with the training data of the individual speaker subsets grouped by the clustering results, and an unknown speech is recognized by the retrained model of the closest cluster. The proposed method is applied to a large-scale speech recognition system implemented by a hybrid hidden Markov model and deep neural network framework. An experiment was conducted to evaluate the word error rates using Resource Management database. When the proposed speaker adaptation method using i-vector based clustering was applied, the performance, as compared to that of the conventional speaker-independent speech recognition model, was improved relatively by as much as 12.2% for the conventional fully neural network, and by as much as 10.5% for the bidirectional long short-term memory.

• English Language & Literature Teaching
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• v.15 no.4
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• pp.37-54
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• 2009

This study investigated vocabulary learning strategies used by EFL middle school learners in Korea and examined the relationship between the middle school learners' vocabulary learning strategy (VLS) use and their vocabulary proficiency level. One hundred and forty-one students in a public middle school participated in the study and the data for this study were collected from a vocabulary learning strategy questionnaire and a vocabulary proficiency test. Based on the result of the vocabulary proficiency test, the participants were divided into three proficiency groups: high-, mid- and low- level proficiency groups. The overall findings of the study revealed that the participants used cognitive strategies most frequently and social strategies least frequently. The most frequently used individual strategies were 'using a bilingual dictionary,' 'studying the sound of a word' and 'practicing words through verbal repetition.' The least frequently used ones were 'interacting with native speakers' and 'studying or practicing the meaning of a word in a group.' The research results also showed that the vocabulary proficiency level has a significant influence on the vocabulary strategy use. The more proficient learners used vocabulary learning strategies more actively. More specifically, the high proficiency level group used metacognitive strategies the most. The middle and low proficiency groups used cognitive strategies the most. It is suggested that language teachers should facilitate the vocabulary learning process by helping learners develop appropriate strategies.

• Phonetics and Speech Sciences
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• v.6 no.2
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• pp.163-174
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• 2014

Korean L2 speakers have many problems learning the pronunciation of English words. One of these problems is vowel epenthesis. Vowel epenthesis is the insertion of vowels into or between words, and Korean learners of English typically do this between successive consonants, either within clusters, or across syllables, word boundaries or following final coda consonants. The aim of this study was to investigate whether individual differences in vowel epenthesis are more closely related to the perception and production of segments (vowels and consonants) and prosody or if they are relatively independent from these processes. Subjects completed a battery of production and perception tasks. They read sentences, identified vowels and consonants, read target words likely to have epenthetic vowels (e.g., abduction) and demonstrated stress recognition and epenthetic vowel perception. The results revealed that Korean second-language learners (L2) have problems with vowel epenthesis in production and perception, but production and perception abilities were not correlated with one another. Vowel epenthesis was strongly related to vowel production and perception, suggesting that problems with segments may be combined with L1 phonotactics to produce epenthesis.

• Journal of Korean language education
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• v.29 no.3
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• pp.255-292
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• 2018

Most grading scales of Korean language proficiency tests are based on existing grading scales that are not empirically verified. The purpose of this study is to develop an empirically verified scale descriptor. The 'Performance data-driven approach' that is suggested by Fulcher (1987) was used to develop the detailed description of characteristics for each level of performance. This study is focused on the functional phase of speech samples analysis (coding data) to create explanatory categories of discourse skills into which individual observations of speech phenomena can be scored. The speech samples that were collected through this study demonstrated stages of speech that can be a foundation of a grading scale. The data used in the study was collected from 23 native speakers of Korean. Speech samples were recorded from simulated speaking tests using the 'REFUSAL' task, and transcribed for analysis. The transcript was analyzed using discourse analysis. The result showed that the 'REFUSAL' task needs to go through four functional phases in actual communication. Furthermore, this study found specific and detailed explanatory categories of discourse competence based on the actual native speaker's speech data. Such findings are expected to contribute to the development of more valid and reliable speaking assessment.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.7
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• pp.303-314
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• 2023

Voice conversion, a technology that allows an individual's speech data to be regenerated with the acoustic properties(tone, cadence, gender) of another, has countless applications in education, communication, and entertainment. This paper proposes an approach based on the StarGAN-VC model that generates realistic-sounding speech without requiring parallel utterances. To overcome the constraints of the existing StarGAN-VC model that utilizes one-hot vectors of original and target speaker information, this paper extracts feature vectors of target speakers using a pre-trained version of Rawnet3. This results in a latent space where voice conversion can be performed without direct speaker-to-speaker mappings, enabling an any-to-any structure. In addition to the loss terms used in the original StarGAN-VC model, Wasserstein distance is used as a loss term to ensure that generated voice segments match the acoustic properties of the target voice. Two Time-Scale Update Rule (TTUR) is also used to facilitate stable training. Experimental results show that the proposed method outperforms previous methods, including the StarGAN-VC network on which it was based.

• Phonetics and Speech Sciences
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• v.10 no.1
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• pp.23-31
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• 2018

In this study, we examined how the upper and lower lips articulate to produce labial /p/. Using electromagnetic midsagittal articulography, we collected flesh-point tracking movement data from eight native speakers of Seoul Korean (five females and three males). Individual articulatory movements in /p/ were examined in terms of minimum vertical upper lip position, maximum vertical lower lip position, and corresponding vertical upper lip position aligned with maximum vertical lower lip position. Using linear mixed-effect models, we tested two factors (word boundary [across-word vs. within-word] and speech rate [comfortable vs. fast]) and their interaction, considering subjects as random effects. The results are summarized as follows. First, maximum lower lip position varied with different word boundaries and speech rates, but no interaction was detected. In particular, maximum lower lip position was lower (e.g., less constricted or more reduced) in fast rate condition and across-word boundary condition. Second, minimum lower lip position, as well as lower lip position, measured at the time of maximum lower lip position only varied with different word boundaries, showing that they were consistently lower in across-word condition. We provide further empirical evidence of lower lip movement sensitive to both different word boundaries (e.g., linguistic factor) and speech rates (e.g., paralinguistic factor); this supports the traditional idea that the lower lip is an actively moving articulator. The sensitivity of upper lip movement is also observed with different word boundaries; this counters the traditional idea that the upper lip is the target area, which presupposes immobility. Taken together, the lip aperture gesture is a good indicator that takes into account upper and lower lip vertical movements, compared to the traditional approach that distinguishes a movable articulator from target place. Respective of different speech rates, the results of the present study patterned with cross-linguistic lenition-related allophonic variation, which is known to be more sensitive to fast rate.

• Speech Sciences
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• v.10 no.4
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• pp.117-124
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• 2003

Speaker recognition is the technology that confirms the identification of speaker by using the characteristic of speech. Such technique is classified into speaker identification and speaker verification: The first method discriminates the speaker from the preregistered group and recognize the word, the second verifies the speaker who claims the identification. This method that extracts the information of speaker from the speech and confirms the individual identification becomes one of the most efficient technology as the service via telephone network is popularized. Some problems, however, must be solved for the real application as follows; The first thing is concerning that the safe method is necessary to reject the imposter because the recognition is not performed for the only preregistered customer. The second thing is about the fact that the characteristic of speech is changed as time goes by, So this fact causes the severe degradation of recognition rate and the inconvenience of users as the number of times to utter the text increases. The last thing is relating to the fact that the common characteristic among speakers causes the wrong recognition result. The silence parts being included the center of speech cause that identification rate is decreased. In this paper, to make improvement, We proposed identification rate can be improved by removing silence part before processing identification algorithm. The methods detecting speech area are zero crossing rate, energy of signal detect end point and starting point of the speech and process DTW algorithm by using two methods in this paper. As a result, the proposed method is obtained about 3% of improved recognition rate compare with the conventional methods.