• Journal of Educational Research in Mathematics
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• v.19 no.2
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• pp.185-206
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• 2009

In the study, I conducted the teaching experiment designed to instruct proof to four 7th grade students by utilizing the analysis method. As the results of this study I could identified that it is effective to teach and learn to find proof methods using the analysis. The results of the study showed that four 7th grade students succeeded in finding the proof methods by utilizing the analysis and representing the proof after 15 hours of the teaching experiment. In addition to the difficulties that students faced in learning proof utilizing the analysis were related to the search for the light conditions for triangles to be congruent, symbolic representation of the proof methods, reinterpretation of drawings given in the proof problems.

• Journal of The Korean Association For Science Education
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• v.25 no.6
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• pp.698-709
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• 2005

When modeling students' conceptual understanding, there are several different frameworks, among which are the alternative conception framework and the mental model framework, which converge to suggest a form of knowledge representation. However, little research has explained how they are different from each other and from memory. The purpose of this study was to develop a new mental model theory that integrates the different terminologies and their background theories, which refer to students' ideas not only in science education, but also in other research areas. For this purpose, at first, we compared different terminologies including alternative conception, p-prim, and mental models, and the underlying theories used for representing students' ideas in learning science. Through such comparison, we tried to find the relationship among them. We reviewed related literature and synthesized the results from both cognitive science (related research areas) and science education approaches, especially, Vosniadou's mental model theory. Based on reviewing previous studies, we have developed a preliminary mental model theory 'an integrated theoretical structure of mental models'. We applied the new mental model theory to interpret data on students' ideas about circular motion from our previous research. We expect our new mental model theory will help us understand how students form their own ideas in science from an integrated perspective.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.2
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• pp.89-97
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• 2006

Interior permanent magnet synchronous motor(IPMSM) has become a popular choice in electric vehicle applications, due to their excellent power to weight ratio. The paper is proposed maximum torque control of IPMSM drive using learning mechanism-fuzzy neural network(LM-FNN) controller and artificial neural network(ANN). The control method is applicable over the entire speed range and considered the limits of the inverter's current and voltage rated value. For each control mode, a condition that determines the optimal d-axis current $i_{d}$ for maximum torque operation is derived. This paper considers the design and implementation of novel technique of high performance speed control for IPMSM using LM-FNN controller and ANN controller. The hybrid combination of neural network and fuzzy control will produce a powerful representation flexibility and numerical processing capability. Also, this paper is proposed speed control of IPMSM using LM-FNN and estimation of speed using ANN controller. The back propagation neural network technique is used to provide a real time adaptive estimation of the motor speed. The proposed control algorithm is applied to IPMSM drive system controlled LM-FNN and ANN controller, the operating characteristics controlled by maximum torque control are examined in detail. Also, this paper is proposed the analysis results to verify the effectiveness of the LM-FNN and ANN controller.

• Journal of radiological science and technology
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• v.42 no.6
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• pp.491-496
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• 2019

The purpose of this study was to apply a concept map to the first-year students of radiologic science and report its effects. The concept map is a visual representation of a major concept and related linking statements. Concept maps are useful tools for students to construct and organize content they have learned. The subjects of this study were first-year grade and at one university in Chungbuk, Korea. They were divided into active and passive participant groups in the class. And they were evaluated the educational effects such as satisfaction, fidelity, learning achievement, and interest before and after using the concept map. As a result, the passive participant group significantly increased the educational effect except for satisfaction, and the active participant group significantly increased the educational effect in all variables (p<0.05). These results showed that concept mapping, which induces first-year grade students to participate in class, could be helpful in radiologic education. It is expected to be used as basic data in various radiologic educational methodology studies in the future.

• Journal of Korean Elementary Science Education
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• v.27 no.2
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• pp.158-169
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• 2008

The purpose of this study was to analyze the uses of the external representations in the $3{\sim}6th$ grade science textbooks developed under the 7th National Curriculum on the basis of the theories and the research results on learning with the multiple representations. The results showed that the frequencies of the macroscopic external representations were higher than those of the symbolic external representations. The external representations with drawing and/or writing, especially writing, were used more frequently than those without drawing and/or writing. However, the most of the external representations were rarely used according to the principles and/or the theories (e.g., personalization principle, dual coding theory, cognitive load theory, and social constructivism theory) for effective uses of the multiple external representations in the science textbooks. The present study provides the guideline to establish the effective uses of the external representations in the science textbooks that not only meet learners but also teachers.

• PNF and Movement
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• v.7 no.1
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• pp.33-46
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• 2009

Purpose : N.A.P.(Neuromuscular Skeletal Plasticity) an integrative neuro-orthopedic concept to facilitate motor strategies in daily life. The primary thesis is, that treatment of body functions and structural impairments should be integrated within goal-oriented activities. The purpose of this article is to demonstrate that the functional activity itself, determines the structure. Material and Methods : A case report of a dentist with brachial plexus lesion after a motor vehicle accident is presented. The necessity for training body functions within relevant tasks is undermined by references which emphasize the importance of training realistic activities to enhance long-term changes in neural representation. Results : The treatment methods presented in this case show significant effects for the patient's ability to participate in his profession within less than a year's time after his motor vehicle accident. Conclusions : Current evidence supports the treatment methods of this concept. The inability to flex his elbow and supinate his forearm placed a considerable doubt to his ability to ever be able to participate in his profession again. Structural reorganization is possible and depends on functional demands, which need to be trained task-specifically. Single case reports may serve as the basis for further randomized controlled studies to support the efficacy of the treatment methods within the N.A.P. concept.

• Journal of The Korean Association For Science Education
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• v.30 no.7
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• pp.920-932
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• 2010

Many topics in science, especially, abstract concepts, relationships, properties, entities in invisible ranges, are described in mathematical representations such as formula, numbers, symbols, and graphs. Although the mathematical representation is an essential tool to better understand scientific phenomena, the mathematical element is pointed out as a reason for learning difficulty and losing interests in science. In order to further investigate the relationship between mathematics knowledge and science understanding, the current study examined 793 high school students' understanding of the pH value. As a measure of the molar concentration of hydrogen ions in the solution, the pH value is an appropriate example to explore what a student mathematical structure of logarithm is and how they interpret the proportional relationship of numbers for scientific explanation. To the end, students were asked to write their responses on a questionnaire that is composed of nine content domain questions and four affective domain questions. Data analysis of this study provides information for the relationship between student understanding of the pH value and related mathematics knowledge.

• Research in Mathematical Education
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• v.23 no.1
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• pp.23-45
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• 2020

Many researches proposed different models and concepts for the PCK. It is important to understand its composition. Most studies investigated the development of PCK and its influence on students' learning from the teachers' perspectives. We developed an instrument for assessing middle school students' perceptions of mathematics teachers' PCK (SPOMTPCK) to investigate the nature of PCK. Theoretical claims and empirical research in PCK were used to design questions and sub-scales for the SPOMTPCK. The face validity of the instrument was established by the expert mathematics teachers and students. A questionnaire consisting of 38 items on a five-point Likert-type scale was used for data collection from 799 middle school students. The exploratory factor analyses resulted in the development of a three-factor scale of 17 items that was proved valid and reliable, that is, pedagogical representation, understanding students and curriculum, and encouraging students' engagement. The Cronbach α coefficients of the scale was 0.935, and the Cronbach α coefficient of three factors were ranged from 0.721 to 0.912. The confirmatory factor analysis showed that the questionnaire has good construct validity and the fit indexes are good. MANOVA analysis of variance revealed that the differences in mathematics teachers' PCK identified by students of different school types and grades were statistically significant. It is a validate measurement to evaluate the perceived mathematics teachers' PCK for middle school students.

• Journal of the military operations research society of Korea
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• v.34 no.1
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• pp.1-11
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• 2008

A methodology for the improvement of simulation based training system for the artillery is proposed in this paper. The complex nonlinear relationship inherent among parameters in artillery firing is difficult to model and analyze. By introducing neural network based simulation, accurate representation of artillery firing is made possible. The artillery training system can greatly benefit from the improved prediction. Neural networks learning is conducted using the conjugate gradient algorithm. The evaluation of the proposed methodology is performed through simulation. Prediction errors of both regression analysis model and neural networks model are analyzed. Implementation of neural networks to training system enables more realistic training, improved combat power and reduced budget.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.22 no.4
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• pp.42-55
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• 2014

The purpose of this research was to identify expertise in ait traffic control by using cognitive skill analysis for novices and experts in routine and non-routine situations. The result of study was to understand expertise in air traffic control tasks in terms of what cognitive processes are responsible for the expert's high performance levels. The problem solving task was difficult for novices, but performed relatively automatically by experts in a routine situation. The difficulty could indicate the presence of controlled processing. Rather than rules and strategies, novices focused more on environmental factors, which merely increase cognitive load. In a non-routine situation, novices showed that they did not categorize the information consistently and alternative resources were not available for them. Experts, however, performed automatically a task by arranging and organizing information related to problem solving components in contexts without regard to a routine and non-routine situation. Especially experts developed a stable representation and directed alternative resources for air traffic flow and efficiency. Based on the results, cognitive processes of experts could be useful to understand expert performance and analyze the learning process, which imply the necessity of developing expertise systematically.