• Radiation Oncology Journal
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• v.16 no.4
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• pp.505-515
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• 1998

Purpose : This study is intended to understand the sensitometric characteristics and the emulsion properties of the commercially available CEA TVS film in comparison with the Kodak X-Omat V film. Materials and Methods : For this purpose, we have formulated an analytic expression of the characteristic curves for x-ray film exposed to mixed radiation of electrons, photons, and visible light. This mathematical expression was developed based on reaction-rate and target-hit theories. Unlike previous expressions. it relates optical density to emulsion properties such as grain size and silver bromide content We have also developed a quantity which characterizes the film response to visible light relative to that to photons and electrons. This quantity could be expressed as a function of grain area. Thus, we have developed mathematical expressions and quantities with which the emulsion properties of the films can be revealed based on the sensitometric characteristics. Demonstrating the use of this analytical study, we exposed CEA and Kodak verification films to the mixed radiation of electrons, photons, and visible light, and interpreted the experimental results accordingly. Results : We have demonstrated that: (1) the saturation density increases as the silver bromide content increases, (2) the time required to reach the threshold dose (to which the film begins to respond) when films are exposed to visible light decreases as the grain size increases, and (3) the CEA film contains more silver bromide. whereas the Kodak film contains larger grains. These findings were supported by the data provided by the manufacturers afterward. Conclusion : This study presented an analytical and experimental basis for understanding the response of X-ray film with respect to the emulsion properties.

• Journal of The Korean Association For Science Education
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• v.34 no.7
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• pp.693-701
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• 2014

Based on social cognitive theory, self-efficacy in the context of learning has been steadily emphasized as an indicator of students' motivation and performance. The premise for developing such an instrument was that a specific measure of Physics self-efficacy was deemed to be an important predictor of the change processes necessary to improve students' physics understanding. In this study we described the process of developing and validating an instrument to measure students' beliefs in their abilities to perform essential tasks in physics and then investigated high school students' self-efficacy about physics learning and performance. Validity and reliability of PSEI were tested using various statistical techniques including the Cronbach alpha coefficient, exploratory factor analysis. The result of factor analysis supported the contention that the Physics Self-Efficacy Inventory (PSEI) was a multidimensional construct consisting of at least four dimensions: understanding and application of Physics concepts, achievement motivation, confidence for physics laboratory, confidence for Mathematics. The result showed that Kroean high schools students have low Physics self-efficacy for the all four dimensions. Therefore, researchers should focus on development of students' Physics self-efficacy. In addition, the instrument may lead to further understanding of student behavior, which in turn can facilitate the development of strategies that may increase students' aspiration to understand and study Physics. More specifically, by using the PSEI as a pre- and post-test indicator, instructors can gain insight into whether students' confidence levels increase as they engage in learning Physics, and, in addition, what type of teaching strategies are most effective in building deeper understanding of Physics concepts.where they freely exchanged opinions and feedback for constructing better collective ideas.

• Journal of The Korean Association For Science Education
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• v.33 no.4
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• pp.708-717
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• 2013

The new paradigm of the 21st Century science education explores a wide range of possibilities that can foster students' interest toward science and creative convergence thinking. In this study, through the analysis of programs that were developed in 'STEAM leader school' and 'STEAM teacher association for research' supported by the 'Ministry of Education, Science, and Technology,' we analyzed the linking frequency with each of STEAM education's fields and teachers' perception for the convergence strategy of technology and engineering. The results of this study show that linking frequency of technology and engineering is lower than the field of arts and mathematics in elementary school, but higher in middle and high school. 'Introduction technology contents in lives' in technology and 'crafts activity' in engineering are the most used teaching and learning strategy in STEAM education. But, although 'crafts activity' is engineering's major way of learning, many teachers understand and use it as a technological teaching learning strategy. It is important to understand that each of STEAM education's field has a unique nature and educational implications, for the effective settlement of STEAM education, we need to consider teaching and learning strategy in various way.

• Cartoon and Animation Studies
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• s.30
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• pp.201-219
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• 2013

Development of digital media in education field at America, UK, Japan etc bring big progress on digital device if education. Japan bring huge progress on digital education by nationally. UK use huge a national budget at digital education development and Sweden which is advanced country of education and a welfare state. Especially UK and Sweden's digital education markets are full now aspect more high quality design. Korea which is advanced country of IT adopted digital text book 2007 with mathematics, through science and English digital text book through the state. Korea's digital text book is in a transition period. that needs case study of advanced country of education for setting design guide and educational effect to digital education media and device plan. All researches are based on LG europe design center at London. Analysis by using KJ method, survey of questionnaire, heuristic method at 4 schools in UK and Sweden. Through analytical researches want to more reality simulation at digital education, and high quality contents with digital socialization. co-work with analog, can get any where, anytime user want without any difficulty. Also interactive GUI design of digital education device to easy to access for user. When plan Digital text book content and design needs methodical design guide for target who students and environment an in-depth study of the appraisal and method. The results of the research are introduce the design plan as a basic research and giving useful design plan to make digital educational media in Korea industrial aspect.

• Journal of Korean Elementary Science Education
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• v.41 no.4
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• pp.658-672
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• 2022

The unique teaching and learning difficulties of speed-related units in elementary school science are mainly due to the student's lack of mathematical thinking ability and procedural knowledge on speed measurement, and curriculums and textbooks must be constructed with these in mind. To identify the implications of composing a new science curriculum and relevant textbooks, this study reviewed the structure and contents of the speed-related units of three curriculums from the 2007 revised curriculum to the 2015 revised curriculum and the resulting textbooks and examined their relevance in light of the literature. Results showed that the current content carries the risk of making students calculate only the speed of an object through a mechanical algorithm by memorization rather than grasp the multifaceted relation between traveled distance, duration time, and speed. Findings also highlighted the need to reorganize the curriculum and textbooks to offer students the opportunity to learn the meaning of speed step-by-step by visualizing materials such as double number lines and dealing with simple numbers that are easy to calculate and understand intuitively. In addition, this paper discussed the urgency of improving inquiry performance such as process skills by observing and measuring an actual object's movement, displaying it as a graph, and interpreting it rather than conducting data interpretation through investigation. Lastly, although the current curriculum and textbooks emphasize the connection with daily life in their application aspects, they also deal with dynamics-related content somewhat differently from kinematics, which is the main learning content of the unit. Hence, it is necessary to reorganize the contents focusing on cases related to speed so that students can grasp the concept of speed and use it in their everyday lives. With regard to the new curriculum and textbooks, this study proposes that students be provided the opportunity to systematically and deeply study core topics rather than exclude content that is difficult to learn and challenging to teach so that students realize the value of science and enjoy learning it.

• Journal of Biosystems Engineering
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• v.16 no.4
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• pp.384-398
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• 1991

A computer program was developed to select the optimum size of farm machine and analyze its operation costs according to various farming conditions. It was written in FORTRAN 77 and BASIC languages and can be run on any personal computer having Korean Standard Complete Type and Korean Language Code. The program was developed as a user-friendly type so that users can carry out easily the costs analysis for the whole farm work or respective operation in rice production, and for plowing, rotarying and pest controlling in upland. The program can analyze simultaneously three different machines in plowing & rotarying and two machines in transplanting, pest controlling and harvesting operations. The input data are the sizes of arable lands, possible working days and number of laborers during the opimum working period, and custom rates varying depending on regions and individual farming conditions. We can find out the results such as the selected optimum combination farm machines, the overs and shorts of working days relative to the planned working period, capacities of the machines, break-even points by custom rate, fixed costs for a month, and utilization costs in a hectare.

• Journal of Radiation Protection and Research
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• v.32 no.1
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• pp.1-8
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• 2007

A model for radiological dose assessment in an urban environment, METRO-K has been developed. Characteristics of the model are as follows ; 1) mathematical structures are simple (i.e. simplified input parameters) and easy to understand due to get the results by analytical methods using experimental and empirical data, 2) complex urban environment can easily be made up using only 5 types of basic surfaces, 3) various remediation measures can be applied to different surfaces by evaluating the exposure doses contributing from each contamination surface. Exposure doses contributing from each contamination surface at a particular location of a receptor were evaluated using the data library of kerma values as a function of gamma energy and contamination surface. A kerma data library was prepared fur 7 representative types of Korean urban buildings by extending those data given for 4 representative types of European urban buildings. Initial input data are daily radionuclide concentration in air and precipitation, and fraction of chemical type. Final outputs are absorbed dose rate in air contributing from the basic surfaces as a function of time following a radionuclide deposition, and exposure dose rate contributing from various surfaces constituting the urban environment at a particular location of a receptor. As the result of a contaminative scenario for an apartment built-up area, exposure dose rates show a distinct difference for surrounding environment as well as locations of a receptor.

• Journal of the Korean Society of Radiology
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• v.14 no.2
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• pp.121-127
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• 2020

The era of the Fourth Industrial Revolution is increasingly demanding mathematical competencies for virtual reality (VR), artificial intelligence (AI) and the like. In this context, this study intended to identify the basic mathematical competency levels of university freshman students in radiology department and to provide basic data thereon. For this, the diagnostic assessment of basic learning competencies for the domain of mathematics was conducted from June 17, 2019 to June 28, 2019 among 78 freshman students of radiology department at S university and D university. As a result, the university students' overall basic mathematical competency levels were diagnosed to be excellent. However, their levels in the sectors of the geometry and vector and the probability and statistics were diagnosed to be moderate, with the mean scores of 2.61 points and 2.64 points, respectively, which were found to be lower than those of the other sections. As for basic mathematical competency levels according to genders, the levels of male students and female students were diagnosed to be excellent, with the mean scores of 17.48 points and 16.29 points, respectively, showing no statistically significant difference (p>0.05). Given the small number of subjects and regional restriction, there might be some limitations in the generalization of the findings of the present study to all university freshman students and all departments. The above results suggest that it is necessary to implement various programs such as student level-based special lectures for enhancing basic mathematical competencies relating to major in order to improve the basic mathematical competencies of freshman students in radiology department, and that it is necessary to increase the students' mathematical competencies by offering major math courses in the curriculum and applying teaching-learning methods matching students' levels.

• Journal of Internet Computing and Services
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• v.17 no.3
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• pp.87-93
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• 2016

In the current information-based society, information and communication technology(ICT) is very important for an individual, a society, and a nation. Especially, for a nation, ICT-related industries are forming an important part of a nation's economy. Also, unlike other industries, ICT-related industries do not require various infrastructures, and have an advantage of being developed with a few talented persons in a short period of time. In this sense, identification and education of gifted children in IT become an essential task of a nation's future. In the past, selection of the gifted children was based on paper tests. However, paper tests incurred various side effects such as private education. Since 2013, observation-recommendation system instead of paper tests has been fully adopted. The purpose of this paper is to analyze the validity of observation-recommendation admission system of the gifted children in IT. For this research purpose, the gifted children in gifted science education center attached in a university at Seoul become the focus of the samples. Their entrance score ranking and graduation record raking are compared for analysis of validity of admission system. After statistical analysis, there is a meaningful correlation between entrance score ranking and graduation record ranking for the gifted children in IT. It means that the higher entrance score ranking, the higher graduation record ranking. The analysis results are expected to be valuable baseline data for deciding usefulness of observation-recommendation admission system.

• 한국지구물리탐사학회:학술대회논문집
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• 2005.09a
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• pp.21-36
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• 2005

Although the main geology of Korea consists of granite and gneiss, it Is not uncommon to encounter anisotropy Phenomena in crosshole radar tomography even when the basement is crystalline rock. To solve the anisotropy Problem, we have developed and continuously upgraded an anisotropic inversion algorithm assuming a heterogeneous elliptic anisotropy to reconstruct three kinds of tomograms: tomograms of maximum and minimum velocities, and of the direction of the symmetry axis. In this paper, we discuss the developed algorithm and introduce some case histories on the application of anisotropic radar tomography in Korea. The first two case histories were conducted for the construction of infrastructure, and their main objective was to locate cavities in limestone. The last two were performed In a granite and gneiss area. The anisotropy in the granite area was caused by fine fissures aligned in the same direction, while that in the gneiss and limestone area by the alignment of the constituent minerals. Through these case histories we showed that the anisotropic characteristic itself gives us additional important information for understanding the internal status of basement rock. In particular, the anisotropy ratio defined by the normalized difference between maximum and minimum velocities as well as the direction of maximum velocity are helpful to interpret the borehole radar tomogram.