• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1060-1065
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• 2005

An Independent Administrative Corporation Japan Agency for Marine-Earth Science and Technology (JAMSTEC) is developing light-and-small Autonomous Underwater Vehicles (AUV)$^{1)}$, named 'MR-X1' (Marine Robot Experimental 1), which can cruise, investigate and observe by itself without human's help. In this paper, we consider the motion control problem of 'MR-X1' and derive a controller. Since the dynamic property of 'MR-X1' is changed by the influence of the speed, the mathematical model of 'MR-X1' becomes the nonlinear model. In order to design a controller for 'MR-X1', we generally apply nonlinear control theories or linear control theories with some constant speed situation. If we design a controller by applying Linear Quadratic (LQ) optimal control theory, the obtained controller only compensates t e optimality at the designed speed situation, and does not compensate the stability at another speed situations. This paper proposes a controller design method using Linear Matrix Inequalities (LMIs)$^{2),3),4)}$, which can adapt the speed variation of 'MR-X1'. And examples of numerical analysis using our designed controller are shown.

• Journal of Korean Elementary Science Education
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• v.42 no.4
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• pp.538-559
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• 2023

In this study, the interplay between models and theories was explored through a series of focus group discussions (FGDs) involving five experts in science education. The FGDs were held seven times, beginning with the question of what is modeling in relation to models, which is a current area of research in science education. Throughout the discussion, several key issues regarding models and modeling were addressed, with a particular emphasis on their relationship to theory. A notable finding from this study is that the participants' discussions did not converge into a single viewpoint regarding the relationship between theory and models; instead, multiple related issues emerged, leading to attempts to reframe existing concepts and seek new understanding. The study findings relate to three main areas of inquiry: What is the meaning of models or modeling? What is the nature of the relationship between models and theories?, and Is modeling possible without a foundation in theory? Particularly, the relationship between models and theories was discussed in reference to the following points: 1) Is a model to be understood as derived from theory, and is modeling the application of theory to phenomena? 2) Can a model be inferred from theory? 3) Does modeling originate from a specific, structured foundational theory (a framework of empirical knowledge), or is it to be understood through the integration of various resources without explicit reference to a foundational theory? Based on the study outcomes, implications are presented for philosophy of science and for researchers and educators working in the realm of science education.

• Journal of Korean Elementary Science Education
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• v.26 no.1
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• pp.117-130
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• 2007

This study investigated the university proffssors', pre-service teachers' and in-service teachers' perceptions of the specialized science education courses in the 11 national universities of education in Korea, analyzed their perception differences, and made suggestions the future directions for the specialized courses. For this study, 46 university professors, 402 in-service teachers, and 336 pre-service teachers were participated nationwide. The results show that there were significant differences in their perceptions between the three groups. For university professors, for example, the acquisition of science content knowledge appeared to be the most important objective of the courses, whereas the other groups preferred the acquisition of more practical knowledge and skills that they could easily use and apply in their classroom teaching later. The university professors tended to think that the science specialized courses would be very useful to the teachers' teaching and contribute to developing their professionality. On the contrary, the in-service and pre-service teachers tended to think that the courses would be not so useful because science theories construct the courses rather than practical knowledge. The implications of these findings are discussed in relation to the future science teacher education.

• Proceedings of the Korea Society of Design Studies Conference
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• 2005.10a
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• pp.216-217
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• 2005

• Journal of the Korean Chemical Society
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• v.15 no.4
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• pp.171-175
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• 1971

Significant structure theory has been applied to the viscosities of supercooled liquids with success. In the supercooled region, the effect of free volume decrease is so significant that the thermal effects on the solid-like volume must be considered properly. In addition, the two state theories proposed by Jhon and Eyring for water and Litovitz et al. for boron trioxide have been successfully applied to the structure change in the liquid state. Considered liquids are benzene, carbon tetrachloride, p-xylene, water and boron trioxide.

• Journal of the Korean Society for Library and Information Science
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• v.18
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• pp.213-276
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• 1990

To revise and develop a 'Model' Curriculum for training the middle standing professionals equipped with professional technology and theories at the spot of the library, such process were executed as research on bibliographic material and literature, utilization of examination of various questionnaires, interviews with middle standing librarians at the spot of the library, a review on the operational state of the Professor's Association of Library Science of Junior Colleges, some consultation with the Research & Deliberation Committee on Curriculums, etc., and to review the present department of library science at the two-year course's short-term colleges or institutes in foreign countries, Germany which is thought to be similar to our nation's situations and its level of economy and Singapore which is considered to be a newly emerging nation were looked into typically. In particular, since studies on the curriculums of the Library Science Dept. of colleges had already preceded, thereby the framework of the 'Model' curriculum was already achieved, however to review how well such framework is applied to the spot of education and give some improvement on that, some unrelistic findings of different subjects in consideration with reality, while comparing those curriculum schedules of each Library Science Dept. with the 'Model' curriculum schedule, were supplemented or revised to be fit to reality. For some supplementing or revising proposals on the pre studied 'Model' curriculum, some tentative plans which focussed on each field respectively and some tentative plans which focussed on cultural subjects, required major subjects and elective subjects were suggested in duality to be referred to. On such a process of forming a harmony of educational theories and practice, it was planned to revise and develop curriculum in a sense emphasizing on practical exercise, and tried not to neglect on each of the fields of the curriculum centered on the areas of materials organization, linguistics, information resource, information science, library organization, & administration, etc. The study on curriculums should be performed flexible to be applied to the accelerating transition of sciences, and be good examples in instruction.

• Journal of the Korea Institute of Military Science and Technology
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• v.18 no.2
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• pp.146-153
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• 2015

An unmanned aerial photography method by using an unmanned helicopter is useful method for measuring of the water-entry traces of small falling objects into the sea. Pixel sizes on the aerial photograph may be too large due to a limit of camcorder resolution and a wide shooting area. If the pixel size is too large, identification of water-entry trace is impossible. Thus an accurate prediction of water-entry trace size is required. The traces of water-entry could be classified into three types such as splash, water column, and bubble. Diameters of each trace are predicted by water-entry impact pressure theories, cavity theories, and trial test results. The results are verified by drop tests using an unmanned helicopter at two water-entry speeds. As a result, prediction and test results showed sufficient similarity to evaluate the identifiability of water-entry trace.

• Korean Journal of Cognitive Science
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• v.30 no.4
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• pp.239-268
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• 2019

Since last several decades, iconic memory has been accepted theoretically valid for its role of the first storage mechanism in visual memory process. However, there have been relatively less interests in iconic memory among researchers than their interests in visual short- and long-term memory. Such little interests seem to arise from a lack of detailed understandings of theories and methodologies about iconic memory and visual persistence. This study aimed to achieve the understandings by reviewing theories and empirical studies of iconic memory and visual persistence. The study further discussed future direction of iconic memory research according to the essential aspects of phenomenological and ecological criticisms against the validity of iconic memory.

• Asian Journal of Innovation and Policy
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• v.6 no.3
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• pp.245-261
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• 2017

As of the end of August 2017, there were 392 academic articles for $4^{th}$ Industrial Revolution in Korea. Is the vigorous discussion on the 4th Industrial Revolution in Korea normal? We checked the main theories on this topic by existing theories and responses of major countries and industries. The findings are that there are technologies called a Technological Revolution, and the industrial application of some technologies is in the starting stage. If comes, the Industrial Revolution is expected with the structure as follows: excellence science, core technologies, base technologies, application and infrastructure, and institutions. Nonetheless, the brisk studies are from three branches such as the Industry 4.0, social connection and artificial intelligence. The Industry 4.0, the digital transformation of manufacturing is the on-going issue in the industry, and artificial intelligence brings the biggest discourse. The 392 literature are mostly from introduction and preparation for future; technology 15.8%, industry 26.3%, society 24.5%, education 19.1%, policy 10.7%. The labor and employment is only 3.6%.

• Journal of electromagnetic engineering and science
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• v.11 no.3
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• pp.143-151
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• 2011

This paper presents a survey of recent wireless power transfer systems. The issue of wireless power transfer is to achieve a highly efficient system with small positioning errors of the facilities setting. Several theories have been presented to obtain precise system design. This paper presents a summary of design theory for short range power transfer systems and detailed formulations based on a circuit model and an array of infinitesimal dipoles. In addition to these theories, this paper introduces a coil array scheme for improving the efficiency for off axis coils. In the microwave range, tightly coupled resonators provide a highly efficient power transfer system. This paper present san-overlay resonator array consisting of half wavelength microstrip line resonators on the substrate with electromagnetically coupled parasitic elements placed above the bottom resonators. The tight couplings between the waveguide and the load resonator give strong power transmission and achieve a highly efficient system, and enables a contact-less power transfer railroad. Its basic theory and a demonstration of a toy vehicle operating with this system are presented. In the last topic of this paper, harmonic suppression from the rectenna is discussed with respect to acircular microstrip antenna with slits and stubs.