• The Journal of the Convergence on Culture Technology
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• v.7 no.4
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• pp.675-681
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• 2021

With the recent growth of the AI speaker market, the demand for speech synthesis technology that enables natural conversation with users is increasing. Therefore, there is a need for a multi-speaker speech synthesis system that can generate voices of various tones. In order to synthesize natural speech, it is required to train with a large-capacity. high-quality speech DB. However, it is very difficult in terms of recording time and cost to collect a high-quality, large-capacity speech database uttered by many speakers. Therefore, it is necessary to train the speech synthesis system using the speech DB of a very large number of speakers with a small amount of training data for each speaker, and a technique for naturally expressing the tone and rhyme of multiple speakers is required. In this paper, we propose a technology for constructing a speaker encoder by applying the deep learning-based x-vector technique used in speaker recognition technology, and synthesizing a new speaker's tone with a small amount of data through the speaker encoder. In the multi-speaker speech synthesis system, the module for synthesizing mel-spectrogram from input text is composed of Tacotron2, and the vocoder generating synthesized speech consists of WaveNet with mixture of logistic distributions applied. The x-vector extracted from the trained speaker embedding neural networks is added to Tacotron2 as an input to express the desired speaker's tone.

• The Journal of the Acoustical Society of Korea
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• v.41 no.3
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• pp.287-301
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• 2022

The present study aims to investigate the difference of soundscape evaluation results from on-site field test and laboratory test which are commonly used for soundscape surveys. In order to do this, both field and lab tests were carried out at four different areas in Cheongju city. On-site questionnaire surveys were undertaken to 65 people at 13 points. Laboratory listening tests were carried out to 48 adults using recorded sounds and video. Laboratory tests were undertaken to two different groups who had experience of field survey or not. Also, two different sound reproduction tools, headphones and speakers, were used in laboratory tests. As a result, it was found that there is a very close correlation between sound loudness and annoyance in both field and laboratory tests. However, it was concluded that there must be a difference in recognizing the figure sounds between field and laboratory tests since it is hard to apprehend on-site situation only using visual and aural information provided in laboratory tests. In laboratory tests, it was shown that there is a some difference in perceived most loud figure sounds in two groups using headphones and speakers. Also, it was analyzed that there is a tendency that field experienced people recognize the figure sounds using their experienced memory while non-experienced people can not perceive the figure sounds.

• Journal of Korean Elementary Science Education
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• v.41 no.3
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• pp.569-591
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• 2022

This study aims to investigate the educational effects of the visualization of heat conduction using a thermal imaging camera on elementary school students through small group activities. It endeavors to explain the reason for why metal feels cold. The scholars conducted in-depth interviews before and after learning the unit "Temperature and Heat" for four students in fifth grade in Seoul. Recorded video and audio materials of the activities, their outputs, and journals of scholars were collected, reviewed, and analyzed. The result demonstrated that visualizing heat conduction using the thermal imaging camera aroused curiosity and provided an opportunity for sophisticated observation and integrated thinking. In addition, the visualization of the heat conduction phenomenon was used as the basis for interpretation and rebuttal for active communication during the small group activities of the students. Consequently, the students changed their non-scientific beliefs, refined their knowledge, and developed their mental models through a small group discussion based on a thermal image video.

• Journal of The Korean Association For Science Education
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• v.43 no.4
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• pp.351-368
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• 2023

The scientist-led Research and Education (R&E) program aims to strengthen gifted science students' research capabilities under the guidance of scientists. Students' actual research experiences in scientist-led R&E activities range from understanding how scientists conduct research to actively participating in research. To develop R&E that promotes student agency, i.e., student participation, this study aimed to identify the pedagogical characteristics that supported gifted science students' agentic participation in the scientist-led R&E program. We conducted interviews with learners and scientists in three teams undertaking R&E activities every three months. The interview covered their perceptions of R&E activities, student participation, and scientists' support for the activities. The recordings and transcripts of the interviews were used as primary data sources for the analysis. The trajectory of each team's activities, as well as the learners' and scientists' dynamic positioning were identified. Based on this analysis, we inductively identified the pedagogical characteristics that emerged from classes in which the scientists supported the students' learning and engagement in research. Regarding agency, three types of student participation were identified: 1) the sustained exercise of agency, 2) the initial exercise and subsequent discouragement of agency, and 3) the continuous non-exercise of agency. Two pedagogical characteristics that supported the learners' agentic participation were identified: 1) opportunities for students to take part in research management and 2) scientist-student interactions encouraging learners to present expert-level ideas. This study contributes to developing pedagogies that foster gifted science students' agentic participation in scientist-led R&E activities.

• Journal of the Korean Chemical Society
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• v.67 no.4
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• pp.281-295
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• 2023

The purpose of this study was to investigate the effects of role assignment in a group on collaboration in a mid- dle school science class to which Collaborative Problem Solving for Character Competency (CoProC) model was applied. For this purpose, 4 classes in the second year of a middle school located in a small and medium-sized city were selected, two classes among these were assigned roles, and the other classes were not. The science class with 4 topics using CoProC model was carried out. As a result of the study, in middle school science class to which CoProC was applied, it was effective in increasing the collaboration. As a result of analyzing the discussion process using the analysis framework for collaboration developed in this study, the group without role assignment was statistically significantly higher than the group with role assignment in the total score and the four sub-factors, especially in 'partnership building' and 'consensus building' which is a high level of collaboration.

• Journal of Science Education
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• v.47 no.2
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• pp.127-138
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• 2023

In this study, the implementation of science classes by pre-service elementary teachers were explored to foster the digital literacy of elementary students. To this end, interviews were conducted with four university students in their 4th year of study at 'G' Education University in Gwangju, also their teaching plans and class implementation videos were analyzed. Interview questions were divided into the science class planning stage, the science class implementation stage, and the post-science class implementation stage, and the interview contents were transcribed and categorized after recording. The results of the study are as follows. First, in the science class planning stage, pre-service elementary teachers considered the degree of elementary students' familiarity when choosing digital teaching and learning tools to foster digital literacy. While writing the teaching plan, it was difficult to set standards related to fostering digital literacy. Second, while pre-service elementary teachers had positive experiences such as improving students' participation in classes and increasing student-specific guidance through real-time data sharing, class time was exceeded due to poor use of digital teaching and learning tools. Third, after teaching their science classes, pre-service teachers presented reflections and requirements for the class. Based on these results, the necessity of developing digital literacy for pre-service elementary teachers and the need to improve the curriculum of education university were proposed.

• Smart Media Journal
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• v.11 no.11
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• pp.17-24
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• 2022

With the spread of smart speakers based on voice recognition technology and deep learning technology, not only non-disabled people, but also the blind or physically handicapped can easily control home appliances such as lights and TVs through voice by linking home network services. This has greatly improved the quality of life. However, in the case of speech-impaired people, it is impossible to use the useful services of the smart speaker because they have inaccurate pronunciation due to articulation or speech disorders. In this paper, we propose a personalized voice classification technique for the speech-impaired to use for some of the functions provided by the smart speaker. The goal of this paper is to increase the recognition rate and accuracy of sentences spoken by speech-impaired people even with a small amount of data and a short learning time so that the service provided by the smart speaker can be actually used. In this paper, data augmentation and one cycle learning rate optimization technique were applied while fine-tuning ResNet18 model. Through an experiment, after recording 10 times for each 30 smart speaker commands, and learning within 3 minutes, the speech classification recognition rate was about 95.2%.

• Phonetics and Speech Sciences
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• v.14 no.4
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• pp.25-33
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• 2022

This study investigates the relationships between rhythm and fluency indices and listeners' ratings of the rhythm and fluency of Korean college students' English paragraph reading. 17 university students read and recorded a passage from "The North Wind and the Sun" twice before and after three months of English pronunciation instruction. Seven in-service and pre-service English teachers in graduate school assessed the rhythm and fluency of the utterances. In addition, the values of 14 indices of rhythm and fluency were extracted from each speech and the relationships between the indices and the listeners' ratings were analyzed. The rhythm indices of the speakers in this study did not differ significantly from those of native English speakers presented in previous studies in %V, VarcoV, and nPVIV, but were higher in ΔV, ΔC, and VarcoC and lower in speech rate. The level of rhythm and fluency demonstrated by Korean college students was comparable, at least in terms of objective values for certain indices. The fluency indices, such as percentage of pauses, articulation rate, and speech rate, significantly contributed more to predicting both rhythm and fluency ratings than the rhythm indices.

• Journal of The Korean Association For Science Education
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• v.43 no.2
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• pp.181-190
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• 2023

In this study, we compared discourse by environments for using tools in terms of participation types, discourse types, and knowledge building processes. 24 first-year high school students were divided into six groups. They were assigned to the sharing tools environment, which used one marker and one smart device, or the individual tools environment, which used markers and smart devices individually. Students participated in small group learning using AR application based on the concept of chemical bonding. All classes were video- and audio-taped. Semi-structured interviews were conducted with six students who voluntarily agreed. The results of the study revealed that the sharing tools environment had a high proportion of one-student dominating type, while the individual tools environment had a high proportion of partly participating type and most students participating type. In the individual tools environment, the ratio of knowledge sharing and knowledge construction discourse was similar compared to the tool sharing environment, and the sub-discourse types were also diverse. In the sharing tools environment, only some students had a meaningful knowledge building process. On the other hand, in the individual tools environment, most of the group members constructed knowledge about the target concept, and had a meaningful knowledge building process. In addition, the misconceptions that appeared to some group members were corrected through small group discussions.

• Journal of The Korean Association For Science Education
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• v.43 no.2
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• pp.125-137
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• 2023

This study analyzed the types of knowledge building discourse and knowledge building processes in small group learning using augmented reality. Eight 8th grade students took classes using augmented reality in solubility, boiling and melting points. These classes were carried out twice and all the classes were videotaped and recorded. Every student participated in a semi-structured interview. In the types of knowledge building discourse, the proportion of knowledge sharing and knowledge construction was similar. Beneath the knowledge sharing, the proportion of introductory level discussion was higher than identifying key elements of augmented reality. Recalling existing knowledge rarely appeared. Under the knowledge construction, the proportion of advanced level discussion was the highest and the proportion of sharing and critiquing ideas at a different level and efforts to rise above current levels of explanation was similar. The introductory level discussion and identifying key elements of augmented reality were developed into efforts to rise above current levels of explanation and sharing and critiquing ideas at a different level. Visualized results of knowledge building processes showed all the students' graph drew an upward curve, though cumulative number of impact value was different by each student. As a result of the study, effective ways of improving small group learning using augmented reality are discussed.