• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.54-57
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• 2003

A new non linear, mean value, instantaneous following control technique to design half bridge converter is proposed in witch control principle uses characteristic that reset time of analog integrator is inverse proportion In input voltage. It is Important characteristic that compensation and follow-up control time are same with switching frequency. Is completed in one cycle that base control frequency. Have excellence characteristic that follow in order instruction value exactly stationary state as well as transient state. Half bridge converter that apply this control principle can know that have stabilize and excellence characteristic. This technique is verified through an experiment, and know that experiment result and theory agree well.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.8
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• pp.713-718
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• 2002

Motion controllers are essential components for operating industrial equipments. Compared with general industrial controllers, motion controllers allow motion control requiring greater speed and precision. This paper presents a method for controlling multi-axes motors via industrial networks. To achieve a line or arc interpolation, the master system delivers instructions to slave systems connected to the network. The network instruction transmitted from the master controller is re-interpolated by the individual slaves through sub-interpolators. The re-interpolated feedrate information is transmitted to the motion control loop in which the current position and the reference position are then calculated. In this way, the interpolation driving between control units is achieved via industrial networks.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.301-306
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• 2006

The important field of research on ship operation is related to the high efficiency of transportation, the convenience of maneuvering ships and the safety of navigation. As a way of practical application for a smart ship based on network system, this paper proposes the intelligent support system for ship steering control system based on TCP/IP and desires to testify the validity of the proposal by applying the fuzzy control model to the steering control system. As the specific study methods, the fuzzy inference was adopted to build the maneuvering models of steersman, and then the network system was implemented using the TCP/IP socket-based programming. Lastly, the miniature model steering control system combined with LIBL (Linguistic Instruction-based Learning) was designed to testify for its effectiveness.

• Science of Emotion and Sensibility
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• v.20 no.3
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• pp.49-60
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• 2017

Previous research found that merely touching an object can create psychological ownership and the endowment effect. It was also found that just imagining touching an object without actually touching the object can make the same effect on psychological ownership. Prior research on haptic imagery examined the effect of haptic imagery induced by direct instruction of imaging on psychological ownership. We investigate a new method which can induce the haptic imagery in a more natural way than direct instruction of imaging. We manipulated imagery conditions such as visual-haptic congruence multimodal cue, visual-haptic incongruent multimodal cue, direct instruction condition and control condition, and examined the effects on imagery vividness, feeling of physical control, perceived ownership, and purchase intention. We conducted the experiment on 140 undergraduate students and our results showed that visual-haptic congruence multimodal cue condition is more effective than direct instruction of haptic imagery while visual-haptic incongruence multimodal cue condition is not effective. Our study extends prior haptic imagery research by making important marketing implications for online retailing.

• Journal of Science Education
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• v.35 no.2
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• pp.295-306
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• 2011

Self-directed learning ability is more important than before. It is well-known that traditional teacher-directed lecture class, seminar-like oral presentation class, and even discussion/debate class have not been enough to enforce self-directed learning ability for students. To resolve the problem, a new dynamic complex instruction model (DCIM) was developed for undergraduate and graduate students and a basic frame of DCIM was published by Oh (2010). Here, it is examined if the application of DCIM to a biology class of graduate school can cause improvement of self-directed learning ability. For this, the self-directed learning readiness scale (West & Bentley, 1990) translated by Ryu (1997) and motivation scale (Hayamizu. 1997) translated by Oh (2001) were employed, and then measurements performed with the translated scales were done in the beginning and the last of two DCIM-adapted graduate biology classes at K university, Daegu, South Korea in the first semester of the year 2010. The results show that self-directed learning ability could be significantly improved through the DCIM-adapted class, compared to the result of a teacher-directed lecture class as a control group. With respect to the motivation, there was not found any statistically significant difference between control and experiment groups of graduate students. The present study seems to be meaningful in that it is the first work proving the effect of improvement of self-directed learning ability of graduate students through the DCIM-adapted classes.

• The Journal of the Korea Contents Association
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• v.20 no.8
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• pp.101-113
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• 2020

This study aimed to explore how effective explicit form-focused instruction (FFI) is in teaching the schwa vowel /ə/ to EFL students in a classroom setting. The participants were 25 female high school students, who were divided into the experimental group (n=13) and the control group (n=12). One female American also participated in the study for a speech sample as a reference. The treatment, which involves shadowing model pronunciation by the researcher and a free text-to-speech software and the researcher's feedback in a private session, was given to the control group over a month and a half. The speech samples, for which the participants read the 14 polysyllabic stimulus words followed by the sentences containing the words, were collected before and after the treatment. The paired-samples t test and non-parametric Wilcoxon signed-rank test were used for analysis. The results showed that the participants of the experimental group in the post-test reduced the duration of the schwa by around 40 percent compared to the pre-test. However, little effect was found in approximating the participants' distribution patterns of /ə/ measured by the F1/F2 formant frequencies to the reference point, which was 539 Hz (F1) by 1797 Hz (F2). The findings of this study suggest that explicit FFI with multiple repetitions and corrective feedback is partly effective in teaching pronunciation.

• Journal of The Korean Association For Science Education
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• v.19 no.3
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• pp.400-408
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• 1999

This study investigated the effect of the grouping method in cooperative learning applied to chemistry concept learning. Two grouping methods used were the HML (High-Medium-Low) and the HL/MM (High-Low/Medium-Medium) ability grouping. Three classes (N = 136) at a high school in Seoul were randomly assigned to the control and the treatment groups. Before instruction. the test of attitude toward science instruction, the perception questionnaire of learning environment consisting of three subtests (participation, conflict, and competition), and the questionnaire of self-esteem were administered, and a mid-term examination score was obtained. These scores were used as covariates. After instruction, the three tests administered before instruction and the conceptions test were administered. Two-way ANCOVA results revealed that there was a significant interaction between the treatment and the level of previous achievement. The low-level students in the HL/MM cooperative group performed better than those in the other groups. The cooperative groups, regardless of the grouping methods, exhibited more positive perception than the control group at participation subtest of the perception questionnaire of learning environment.

• The Korean Journal of Emergency Medical Services
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• v.13 no.2
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• pp.87-98
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• 2009

Purpose : This study set out to compare the educational effects of a video self-instruction program for child CPR education on childcare teachers by applying the 2006 KACPR Guideline. By adopting the nonequivalent control group posttest quasi-experimental design, the study examined the educational effects on a group that did not receive instructions from the instructor, another group that received his instructions, and the other group that received an extra three-minute practice training session in addition to instructions. Methods : Data were gathered from August 6 to 18, 2008. As for research tools, the Knowledge Instrument of CPR by Connolly (2006) was used along with the National Practice Test Protocol for C1ass 1 Emergency Medical Technicians (2007) and Common Protocol for CPR (2006) to examine the performance of child CPR. By shooting the guide screen of $Resusci^{(R)}$ Junior CPR Manikin of Leardal with a video camera and using the Skill Guide Checklist of the Common Protocol for CPR (2006), the subjects' technical accuracy of chi1d CPR was evaluated. There were three subject groups: 29 childcare teachers randomly assigned to received the video self-instruction program training for chi1d CPR and no instructions from the instructor made up the control group; 22 childcare teachers randomly assigned to received the program training and instructions from the instructor made up experiment group I; 23 childcare teachers randomly assigned to received an extra three-minute practice training session in addition to the program training and the instructions made up experiment group II. The gathered data were analyzed with SPSS/PC+ (Version 14.0) in frequency, percentage, $X^2$-test, ANOVA, Scheffe test. Results : 1) There were no statistically significant differences (F=1.030, p=.362) among the groups in terms of knowledge scores after the child CPR education. 2) There were statistically significant differences (F=13.625, p=.000) among the groups in terms of performance abilities after the child CPR education. 3) There were no statistically significant differences (F=1.610, p=.207) among the groups in terms of technical accuracy of mouth-to-mouth resuscitation after the child CPR education 4) There were no statistically significant differences (F=1.484, p=.234) among the groups in terms of technical accuracy of chest compression after the child CPR education. Conclusion : The results indicate that childcare teachers can improve their performance abilities in child CPR when the instructors are active with their instructions and extra practice hours are secured through a VSI program. It's also needed to provide education with increasing concentration ratio about the items of lower knowledge points in order to help the teachers learn the accurate theory of child CPR. And there should be VSI programs of diverse conditions to increase the effects of child CPR training among childcare teachers.

• Journal of The Korean Association For Science Education
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• v.29 no.1
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• pp.116-136
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• 2009

Since there are differences in the content, structure and functions of interpersonal communication during the practice of school science classes, it needs to articulate the difference of the modality of pedagogical practice in order to understand science teaching in detail. These characteristics of science teaching can be investigated by further insightful analysis on language in the science classroom. In this study, classroom discourse language codes using Bernstein's code theory were analyzed in the case of a middle school science class on the unit of minerals. The discourse language code was identified by the value of classification, which revealed power relations to the contexts of discourse and participants of discourse. It was also identified by the value of framing, which showed hierarchical relation between teacher and students as discourse subjects, and discursive control on the initiative of discourse. The results addressed that six types of discourse language codes were constructed and that those language codes reflected diverse modalities of science teaching from student-centered instruction to teacher-centered instruction in relation to classroom discourse. The modality of science teaching according to the transition tendencies of discourse language code showed dynamic variations of 'controlled student-centeredness inducing teaching' - 'positional student-centeredness permissive teaching' - 'controlled students' participation permissive teaching' - 'controlled student-centeredness facilitative teaching' - 'student-centeredness enhancing teaching'. In addition, results released that discursively and hierarchically weak control of discourse is necessary for enhancing student-centeredness of science teaching. Moreover, teaching practice enhancing student-centeredness can be accomplished by the harmony of a teacher's perception of discourse language code and his/her orientation to constructivist teaching and student-centered teaching.

• Journal of Korean society of Dental Hygiene
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• v.10 no.1
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• pp.127-140
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• 2010

Objectives : The purpose of this study was to apply team-based learning to dental hygiene students in theoretical oral prophylaxis class, one of required courses geared toward acquiring professional knowledge on preventive public health, as oral prophylaxis was counted among major duties of dental hygienists. It's ultimately meant to compare the effects of team- based learning and expository instruction on the learning motivation and self-directed learning capabilities of learners in order to discuss the effects of team-based learning in dental hygiene education. Methods : The subjects in this study were 60 dental hygiene students at C college. Out of them, 32 students who were freshmen as of 2007 were grouped into an experimental group, and 28 students who were freshmen as of 2006 were selected as a control group. The experimental group was engaged in team-based learning from August 30 to December 6, 2007, and the control group took expository lessons from August 28 to December 8, 2006. Their learning motivation and self-directed learning capabilities were evaluated by using t-test, paired t-test and GLM analysis. Results : The findings of the study were as follows: 1. The experimental group scored better in learning motivation than the control group after they were engaged in team-based learning (p<.001). According to GLM analysis, there was a significant intergroup gap in learning motivation, and the two groups were statistically significantly different in its subfactors involving attention, relevance and confidence(p<.05). 2. The experimental group excelled the control group at self-directed learning capabilities(p<.05), and the team-based learning had a better effect on self-directed learning capabilities than the expository instruction. Conclusions : Given the findings of the study, the team-based learning was more effective than the expository instruction at boosting the learning motivation and self-directed learning capabilities of the students. Therefore revised teaching methods should be prepared in consideration of the characteristics of dental hygiene courses, and the development of new instructional models and educational programs is required as well.