• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.692-697
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• 1997

This paper presents a method of grinding and polishing automation of precision die after CNC machining. The method employs a robot system equipped with a pneumatic spindle and a special abrasive film pad. The robote program is automatically generated off-line from a PC and downloaded to robot controller. Position and orientation data for the program is supplied from cutter contact (CC) data of NC machining process. This eliminates separate robot teaching process. This paper aims at practical automation of die finishing process which is very time consuming and suffering from shortage of workpeople. Time loss for changeover from one product to next is eliminated by off-line programming exploiting appropriate NC machining data. Dextrous 6-axis robot with rigid wrist and simple tooling enables the process applicable to larger, rather complex 3 dimensional free surfaces

• Journal of Industrial Technology
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• v.19
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• pp.173-178
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• 1999

In many areas of technology there are machines and systems controllable in up to six degrees of freedom. Helicopters and underwater vehicles, industrial robots are among the first representatives of this category. They need six degrees of freedom in order to move and orient within their workspace. An even broader and more explosively growing area is 3D computer graphics and virtual environment. In this work, functions of 3D input device are described and two types of commercial 3D input device are presented. Then, a preliminary experiment of a low cost 6 axis force/moment sensor is presented that can also be sued as a 3D input device. A low cost force/moment sensor and its application in robot teaching experiment is described. It computes the direction of 3 components of the force and 3 components of the moment applied by human holding the sensor by hand. The concept is shown by an experiment where the tool position and orientation of a robot in 3 dimensional space is controlled by the proposed sensor.

• Journal of the Korean Chemical Society
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• v.62 no.2
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• pp.99-105
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• 2018

In this paper, we present fortified instructional methods that contributed in improving students' interest toward the expository organic chemistry laboratory course. Reformed TA (Teaching assistant) training and allocation method, a thorough course orientation session, text-light/graphics-heavy results PPT reports, and journal article templated-term papers have improved students' satisfaction in the organic chemistry laboratory course. These methods could be implemented while maintaining the traditional organic chemistry laboratory instruction styles and hence could be broadly applicable.

• 한국기계연구소 소보
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• s.19
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• pp.81-92
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• 1989

This paper presents a simple identification method of the actual kinematic parameters for the robot with parallel joints. It is known that Denavit-Hartenberg's coordinate system is not useful for nearly parallel joints. In this paper, the coordinate frames are reassigned to model the kinematic parameter between nearly parallel joints by four parameters. The proposed identification method uses a straight ruler about 1m long. A robot hand is placed by using a teaching pendant at the prescribed points on the ruler, and corresponding error function is defined. The identified kinematic parameters which make the error function zero are obtained by iterative least square error method based on the singular value decomposition. In the compensation of joint angles, only the position is considered because the usual applications of robot do not require a precise orientation control.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.3 s.96
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• pp.9-17
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• 1999

This paper presents a method of grinding and polishing automation of precision die after CNC machining. The method employs a robot system equipped with a pneumatic spindle and a special abrasive film pad. The robot program is automatically generated off-line program form a PC and downloaded to robot controller. Position and orientation data for the program is supplied form cutter contact (CC) data of NC machining process. This eliminates separate robot teaching process. This paper aims at practical automation of die finishing process which is very time consuming and suffering from shortage of workpeople. Time loss due to changeover from one product to another is eliminated by PC off-line programming exploiting appropriate NC machining data. Dextrous 6-axis robot with rigid wrist and simple tooling enables the process applicable to larger, rather complex 3 dimensional free surfaces.

• International Journal of Computer Science & Network Security
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• v.21 no.12
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• pp.117-122
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• 2021

The article considers the position of scientists on the concept of "pedagogical technology", identifies the signs of pedagogical technology and existing classifications, considers non-traditional (innovative) learning technologies, as well as their practical forms of application in the educational process, summarizes the results, makes recommendations for the practical application of the studied material. The article considered the basic concepts of pedagogical technology, as well as some types of non-traditional (innovative) teaching technologies. Also, examples of the use of some elements of innovative technologies in practical educational activities are given. The choice of specific non-traditional pedagogical technologies is determined by the target orientation, content specificity, individualization of training, technical equipment of the educational institution, etc.

• Journal of Christian Education in Korea
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• v.69
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• pp.139-162
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• 2022

This study verified the effect of learning motivation on immersion by non-face-to-face class method. For this purpose, 101 college students majoring in early childhood education were selected as research subjects. The average age of the study subjects was 22.6 years old, and 51 students took non-real-time non-face-to-face classes, and 50 students took real-time non-face-to-face classes. The study measured the level of immersion and the type of learning motivation after the non-face-to-face class was finished. The measured data were analyzed using descriptive statistical analysis and multiple regression analysis. As a result, in the results for all students, the performance approach goal had the most influence on immersion, and the mastery goal orientation had the next effect. Performance avoidance orientation had no effect. For students in non-face-to-face classes, performance approach goal orientation had an effect on immersion, and for students in real-time non-face-to-face classes, mastery goal orientation had an effect. The implications that can be obtained from the results of this study are as follows. First, non-real-time non-face-to-face classes should cover basic knowledge and skills so that there are no mistakes and failures. Second, non-real-time non-face-to-face classes should allow tasks with appropriate difficulty to be performed with a deadline. Third, real-time non-face-to-face classes should lower the fear of mistakes and failures.

• Journal of The Korean Association For Science Education
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• v.26 no.4
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• pp.518-526
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• 2006

Science career education is for every student as well as for students who want to become scientists. In this study, we developed and applied science career education materials using TV programs which showed successful application of science in industry and business. The effects of the programs were surveyed mainly by questionnaire on 'Science Career Orientation', which have four categories.Video materials using TV programs were effective in changing science career orientation (p<0.05) of junior high school students, but only when the teacher added some cognitive explanation on the scientific concept involved. Providing only video materials were not enough to make meaningful change on science career orientation. The results implied science career education should be linked with science teaching and learning. It also showed the possibility and the way of using informal education like TV program in science career education.

• Journal of The Korean Association For Science Education
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• v.40 no.5
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• pp.543-563
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• 2020

This study explores how the teaching practices of two teachers changed during scientific modeling classes. It also aims to understand these changes in terms of the teachers' modeling pedagogical content knowledge (PCK) development. The study participants were two elementary school teachers and their fifth-grade students. The teachers taught eight lessons of scientific modeling classes about the human body. The data analysis was conducted for lessons 1-2 and 7-8, which best showed the change in teaching practice. The two teachers' teaching practices were analyzed in terms of feedback frequency, feedback content, and the time allocated for each stage of model generation, evaluation, and modification. Teacher A led the evaluation and modification stages in a teacher-driven way throughout the classes. In terms of feedback, teacher A mainly used answer evaluation feedback in lesson 1-2; however, in lesson 7-8, the feedback content changed to thought-provoking feedback. Meanwhile, teacher B mostly led a teacher-driven model evaluation and modification in lesson 1-2; however, in lesson 7-8, she let her students lead the model evaluation and modification stages and helped them develop models through various feedbacks. The analysis shows that these teaching changes were related to the development of modeling PCK components. Furthermore, the two teachers' modeling PCK differed in teaching orientation, in understanding the modeling stages, and in recognizing the value of modeling, suggesting the importance of these in modeling teaching practice. This study can help improve the understanding of modeling classes by revealing the relationship between teaching practices and modeling PCK.

• Journal of The Korean Association For Science Education
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• v.31 no.2
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• pp.198-209
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• 2011

In this study, pre-service science teachers' reflective thinking in their journal writing was investigated. To do this, the authors used pre-service science teachers' journal writing abilities, wherein they not only reported data and result formally, but also wrote their feelings and reflections about an inquiry-based physics experiment they performed. Pre-service science teachers' writings were decomposed into sentences and each sentence was analyzed into a framework with 4 dimensions: knowledge, procedure, orientation and attitude. Reflective thinking in knowledge dimension included reflection on what they know before the experiment, what they still do not know and what they learned from the experiment. Reflective thinking in procedure dimension included recalls of experiences about general experimental procedures and specific experimental skill. Reflective thinking in orientation dimension included their views about the nature of science and science teaching and learning, and reflective thinking in attitude dimension consisted of interests, motives and values about the experiment they performed. While there were some variations in frequency distribution of reflective thinking by the topic of experiments, pre-service science teachers' reflective thinking in journal writings revealed their metacognition on their knowledge and learning, epistemological belief about science and science learning, and affective domain related to experiment. This study can infer that such kind of writing with 'their own language' in an informal way followed by formal 'scientific' reports in a scientific experiment has a significance not only as a mediator representing reflective thinking but also as an instructional activity to facilitate reflective thinking in science learning and teaching.