• The Journal of the Acoustical Society of Korea
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• v.37 no.3
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• pp.147-155
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• 2018

In this paper, we tried to find out sound quality metrics to express discomfort of overload excavator noise and to develop sound quality indexes through multiple regression analysis by using them. For this purpose, the interior noise of cabin under overload condition was recorded for six excavator models with different noise properties and Jury test was carried out by PCM (Paired Comparison Method) and MEM (Magnitude Estimation Method). Jury test result with low consistency was classified into two groups with different preference tendencies by cluster analysis and multiple regression analysis was conducted in order to find out which sound quality metrics have significant effects on discomfort(low preference). As a result, we figured out that the sound quality metrics to express the discomfort were the partial loudness (= $PN_{10Bark}$) between 0 and 10 Bark in case of group1 and the difference between engine noise(= $dB_{EG}$) and hydraulic system noise ($dB_1$) in case of group2. Using the results of preference ranking and tendency analysis of PCM followed by the correlation analysis between PCM and MEM, the more reliable results were adopted by excluding the data with low consistency obtained from Jury test via MEM.

• Journal of the Korean Chemical Society
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• v.61 no.6
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• pp.388-401
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• 2017

In this study, we investigated the characteristics of curriculum design of pre-service chemistry teachers who participated in educational program for teaching in science museum. Three pre-service chemistry teachers at a college of education in Seoul participated. The educational program was composed of workshop, lesson planning and practice, and critique. After the workshop, we conducted semi-structured interviews based on pre-visit, during-visit, post-visit activities planned by the pre-service teachers. We observed and recorded their teaching practices in Gwacheon National Science Museum and following critique by their classmates. We also conducted final interviews. We used a framework for museum practice to analyze their curriculum design. The analyses of the results revealed that all planned their lessons in accordance with the National Science Curriculum, and considered geographical and psychological aspects in their pre-visit activities. They encouraged students to make joint products through small group activities, and gave students autonomy in choosing exhibits to facilitate spontaneous participation. However, they did not consider continuous aspects of pre-visit, during-visit, and post-visit activities. They did not effectively induce students to engage during-visit activities cognitively. They did not make post-visit activities connect students' experiences in science museum to personal experiences.

• Journal of Convergence for Information Technology
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• v.10 no.1
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• pp.219-234
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• 2020

As the Korean society ages, the number of women who specialize in community health care is expected to increase. Therefore, the purpose of this study is to identify and structure the nature of suffering due to job stress among female community health care professionals, and to provide basic data supporting the performance of female health care professionals. To use Parse's theory of human becoming, nine female health care professionals were selected in the community. After forming the "you and me" relationship, the researcher recorded the participants' distress through honest conversations. It was converted to the structure of human becoming through the extraction-synthesis and discovery interpretation process. Through conceptual interpretation, the structure of the experience was developed. At the results, the female health care professionals were the process of overcoming difficulty due to poor working conditions and conflict in roles between work and family through their skills and communication reinforcements in hopes for change. The stable national welfare policies must be established to sustain jobs with female community health care experts through improved working conditions.

• Journal of Korean Association for Spatial Structures
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• v.8 no.3
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• pp.65-73
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• 2008

The present work deals with subjective assessments to propose the objective parameter related to the subjective attribute of reverberation in the coupled room varied the aperture opening size. A 1/10 scale model was built and used for the measurements and subjective assessments. For the subjective tests, binaural impulse responses(BIRs) were measured using a dummy head and the measured BIRs were convolved with anechoic recorded music for the presentation over the headphones. The results showed that the perceived reverberation was the largest in the aperture opening size 12.5%(1.97% of mail) room surface area)and decreased with increasing the aperture opening size over 25% (3.94% of main room surface area) in the main room coupled with the secondary reverberant room. In the main room coupled with the secondary absorptive room, there was no changes in the perceived reverberation up to the aperture opening size 6.25%(0.99% of main room surface area) and it gradually decreased with increasing the aperture opening site over 12.5%. The objective parameter, T30/T15, showed a very low correlation with the perceived reverberation in the coupled room varied the aperture opening size but showed a high correlation with a new objective parameter, T30/Tbp, proposed by the authors. Because the late part decay energy more rapidly increases with increasing the aperture opening site than the early and middle part decay energy, the LDT/EDT or T3/T1 is a better quantifier to measure double slopes in the coupled room than the T30/T15.

• Journal of Science and Technology Studies
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• v.1 no.2 s.2
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• pp.423-438
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• 2001

The purpose of this study is to understand how a teacher's teaching can be changed while he or she teaches the same contents in different classes. The qualitative research method was used in this study. Data were collected from classroom observations, several in-depth interviews, and stimulated-recall interviews after each class. All the data were transcribed and analyzed interpretively, and then, the results of the analysis were checked by each participating teacher. The results are as follows: First, changes appeared in each class in terms of the teaching items, tools, sequence, and time, even though the same teacher taught the same contents. It showed that the teacher's teaching practice changed immediately and intuitively in class. Second, teachers tried to implement "exploratory teaching" or "move-testing teaching" to address the emerging problems during their teaching. They then reflected on and modified their own teaching. This type of change, which happened during the teaching practice, can be an example of "Reflection-in-practice." Thus, the results of this study can provide helpful insights into how teachers might adapt and reflect in their teaching. It suggests that teachers need to recognize their subconscious teaching changes and learn "Reflection-in-practice."

• Journal of The Korean Association For Science Education
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• v.35 no.1
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• pp.95-107
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• 2015

In this case study, we investigated the characteristics of pre-service secondary science teachers' curriculum design for teaching in science museums. Three pre-service secondary science teachers at a college of education in Seoul participated in this study. We have observed and recorded their teaching practices in science museums, collected all of their teaching materials, and conducted semi-structured interviews before and after teaching. All the data collected were analyzed by using the constant comparative method. The analyses of results revealed that the pre-service teachers structured their teaching in a series of pre-visit, during-visit, and post-visit as continuous activities. They attempted to reinforce students' learning experiences during the visit by providing post-visit activities, and also properly considered the principle that activity should be personally meaningful or relevant to students. However, they lacked the perceptions as well as the practical knowledge of reducing student's novelty of the science museum by providing activities prior to the visit, encouraging to engage in joint productive activities, promoting diverse social interactions, and providing students with choices and controls on their learning. On the bases of these results, we made some suggestions in pre-service teacher education for the professional development of teaching in science museum.

• Journal of The Korean Association For Science Education
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• v.32 no.7
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• pp.1109-1123
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• 2012

The purpose of this study is to examine the effects of small group discussion on elementary students' science writing. In this study, four 6th grade students were chosen from an elementary school in Seoul. Students were involved in eight science writing classes and the contents of a small group discussion and interactions were recorded and observed. Students' science works were collected and analysed based on three domains: scientific thinking, logic and originality. The result of this study showed that the contents of a small group discussion greatly affected the scientific thinking domain. A low-achieving student received lots of help from a high-achieving student. It was easy to improve in the logic domain through the science writing classes. Average students got good grades in an originality domain when the subject was related to their real life. A small group discussion would have an effect on science writing ability positively if the students acquired proper guidance on the procedure and manner of discussion. The science writing lesson would be more effective if the learning group was organized homogeneously in the aspects of intelligence achievement and interpersonal relationships.

• Journal of The Korean Association For Science Education
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• v.30 no.1
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• pp.107-123
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• 2010

This study investigated the content and the effect of peer discussion about classroom practices on their science teaching. Participants included three science teachers with chemistry backgrounds in middle and high schools. Each of them had their classes videotaped and observed the footage as well as discussed the lessons together. The teachers had six meetings on 15 recorded lessons including one meeting beforehand. Teachers' discussions were also audio-taped and the data was transcribed. Teachers extensively discussed their lessons not only in terms of instructional strategies and scientific concepts but also the curriculum organization and teaching goals. Analysis of video-recorded lessons showed that instructional strategies were changed partially, but the aspects of curriculum organization in relation to teaching goals were not changed. Analysis of the recorded data revealed that teachers recognized the problems in their science teaching and considered the practical alternative ideas suggested by peers, but teachers proposed the necessity of experience to practice in their class. The study shows that observing and discussing each other's classes is one possible way to improve the class. Implications about teaching improvement for other teachers were discussed.

• Journal of The Korean Association For Science Education
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• v.37 no.4
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• pp.587-597
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• 2017

If we, as educators, want to put students at the center of learning in science classroom, we must let students express their voices and exercise authority. To do this, we developed a classroom activity about 'Making a pet poster', and then we explored how elementary school students perceived their roles and expressed their authority during this activity. Fourth grade students from an elementary school in the city of Seoul participated in the activity, which was videotaped and recorded. We found that students expressed their epistemic authority differently in small group activities and in whole group discussions. In small group activities, they desired to show their authority as "pet experts" by using and selecting various resources from their everyday lives and transforming those resources into suitable forms in public spaces. Meanwhile, in whole group discussions, participants were classified as either presenters or audience members to verify their authority in regard to the pet poster activity; presenters desired to achieve recognition as "pet experts," and audience members assessed the presenters as "testers." In addition, they expressed authority as teachers by leading the whole group discussions. Based on these findings, this paper suggests the implications for new educational strategies to foster a student-centered learning environment.

• Journal of The Korean Association For Science Education
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• v.37 no.4
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• pp.553-564
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• 2017

This study investigated the change of pre-service elementary teachers' professional visions through video-based reflection on science teaching with focus on their attention and pedagogical reasoning about student learning. Specifically, we compared two reflection cycles before and after pre-service elementary teachers went through the collaborative video-based reflection process in a professional learning community. The primary data were collected from eight pre-service elementary teachers and included their science lesson plans, videotaped lessons, video-reflection papers, and transcripts from the interviews. Pre-service elementary teachers' attention was categorized in five aspects: classroom management & control, teacher's instruction, students' thinking & learning, subject knowledge, and assessment. The level of their pedagogical reasoning about student thinking and learning was determined with six levels based on the number of evidence, evidence area, and evidence type. The findings revealed that 1) individual reflection is not enough - collaborative reflection is essential to change their attention toward students learning and thinking 2) pedagogical reasoning levels increase gradually throughout the individual and collaborative video-based reflection processes. The participants not only attributed student learning solely to the characteristics of students but also connected it with their own instruction or science content knowledge and used different types of evidences as they went through two reflection cycles. Implications for using video in the teacher education program were discussed.