• Journal of Digital Convergence
• /
• v.15 no.10
• /
• pp.455-465
• /
• 2017

This study focuses on design development and verification through virtual simulation based on 3D model data in the cloud platform as a method of utilization of engineering technology of design in the fourth industrial revolution era. The goal of research is to develop and examine a design for the needs of the target that has never been met before through virtual simulations that can be conducted in practice. As a research method, we analyzed secondary data to identify the needs of the target, and did literature research for the ergonomic data and target body development stages. In addition, the design development process of this study was shown meaningful result in design, structure, safety, material, durability through loop test of 7 virtual simulations. This study can be applied to the automated process system based on 3D model data in the 4th industrial revolution era and can be used as an element of the cyber physics system for the additional research.

• Journal of The Korean Association For Science Education
• /
• v.8 no.1
• /
• pp.1-22
• /
• 1988

The educational policy of a nation should be based on the results of nation-wide studies and their analyses. This study is the third one in a series of research on "development of improvement plan and monitoring system for secondary school science", focusing on the three major areas, such as students' achievements, science instruction and conditions for science education in vocational high schools. In general, the results showed that science achievements in vocational high schools were significantly lower than those of general high schools. While the achievement level in physics was lower by one percent, the achievement levels in chemistry and biology were significantly lower by more than 5 percents. In the case of scientific inquiry, the results showed much lower scores compared to those of general high schools. Concerning the inquiry abilities, most of the students did not possess the formal operational thinking skills such as controlling variables and combinatorial thinking. The ability of experimental skills seemed to be closely related to the students' majors. Students in industrial arts schools could measure electric resistance very well, while students in agricultural high school students failed completely. In the area of students' attitude toward science, the greater part of the students had the experiences of using scientific equipments (68.6 %), experimentation (54.3 %), and extracurricular science activities (56.9 %). They also showed positive attitude towards the nature of science (59.8%). The results of the survey on science instruction and school conditions for science education showed the needs for improvement In general, the priority of science education in vocational high schools was very low compared to their major subjects. The teachers as well as students thought science text books nor to be difficult These responses and the low achievement levels seemed to be contradictory to each other. The facilities for science experiments were better equipped and installed to general high schools. However. the lack of budget was a major problem for performing experiments uning the facilities. Therefore. science education in vocational high school have many things to be improved For the improvement of science education in vocational high schools, financial support as well as the intention for the improvement must be the essential factors.

• Journal of The Korean Association For Science Education
• /
• v.35 no.6
• /
• pp.1039-1048
• /
• 2015

The purpose of this study is to examine implications of pre-service science teacher training by analyzing science field integration and connection between learning content presented in 'Integrated Science' for high school students based on the 2015 revised science curriculum, and in pre-service science learning materials (textbooks) of the college of education. For this study, the 2015 revised 'Integrated Science' curriculum and 11 types of pre-service science teachers' learning materials related to physics, chemistry, biological science, and earth science were selected. The results were as follows. Most of the learning content presented in the 2015 revised 'Integrated Science' curriculum had integrated two or more science fields. Also, almost all learning content presented in the 2015 revised 'Integrated Science' curriculum were included in pre-service science teachers' education content, with educational content for chemistry introduced at the highest rate. The textbooks for pre-service science teachers had the most learning contents of 'Energy and Environment' domain of 'Integrated Science' for high school students. Accordingly, these results suggest that 'integrated science materials' should be developed for proper the curriculum implementation. Also, training courses for science teachers responsible for 'Integrated Science' are required. Furthermore, a revised curriculum for the college of education and a method to link with certification examinations for secondary school teachers are needed.

• Journal of the Korean Magnetics Society
• /
• v.19 no.3
• /
• pp.113-119
• /
• 2009

$^{57}Fe_xCu_{1-x}O$(x = 0.0, 0.02) powders were prepared by sol-gel method and their crystallographic and magnetic hyperfine properties have been studied using X-ray diffraction and $M{\ddot{o}}ssbauer$ spectroscopy (MS). The crystal structure of the samples is found to be monoclinic without any secondary phases and their lattice parameters increase with increasing annealing temperature ($T_A$), which is attributed to an increase in oxygen-vacancy content. MS measurements at room temperature indicate that $Fe^{3+}$ ions substitute $Cu^{2+}$ sites and ferromagnetic phase grow with increasing $T_A$. Magnetic hyperfine and quadrupole interactions of $^{57}Fe_{0.02}Cu_{0.98}O$ ($T_A=500^{\circ}C$) in the antiferromagnetic state at 17 K have been studied, yielding the following results: $H_{hf}=426.94\;kOe$, ${\Delta}E_Q=-3.67\;mm/s$, I.S.=0.32 mm/s, ${\theta}=65^{\circ}$, ${\phi}=0^{\circ}$, and ${\eta}=0.6$.

• Journal of The Korean Association For Science Education
• /
• v.35 no.1
• /
• pp.15-25
• /
• 2015

This study examined pre-service secondary physics teachers' epistemological beliefs about scientific knowledge, science learning, and science teaching in two different science content topics, Lamarckism and the impetus theory. Two sets of open-ended questionnaires, for each of the topics respectively, were developed in the same format. The pre-service teachers completed the questionnaires at one month intervals. The beliefs were analyzed in two dimensions, knowledge justification and knowledge change for each belief area. The findings show that the majority of pre-service teachers held sophisticated epistemological beliefs about scientific knowledge regardless of content topics. On the other hand, more pre-service teachers exhibited sophisticated beliefs about science learning in the context impetus theory than Lamarckism. In the area of science teaching, the majority of pre-service teachers demonstrated a sophisticated view in knowledge justification but a naive view in knowledge change. When consistency across science topics and belief areas were examined, few pre-service teachers held consistent epistemological beliefs across all topics and areas. The difference in the levels of sophistication in belief areas showed that the pre-service teachers did not connect their epistemological beliefs about science knowledge to their ideas about science teaching and learning. This disconnection seems to make the consistency across topics and areas complicated. The difference in epistemological beliefs about science learning and teaching between two science topics need further inquiry. Implications for teacher education are offered.

• Journal of the Korean Vacuum Society
• /
• v.17 no.4
• /
• pp.311-316
• /
• 2008

Since the presence of the chemical impurities and defect at surfaces and interfaces greatly influence the properties of various semiconductor devices, an unambiguous chemical characterization of the metal and semiconductor surfaces become more important in the view of the miniaturization of the devices toward nano scale. Among the various conventional surface characterization tools, Electron-induced Auger Electron Spectroscopy (EAES), X-ray Photoelectron Spectroscopy (XPS) and Secondary Electron Ion Mass Spectroscopy (SIMS) are being used for the identification of the surface chemical impurities. Recently, a novel surface characterizaion technique, Positron-annihilation induced Auger Electron Spectroscopy (PAES) is introduced to provide a unique method for the analysis of the elemental composition of the top-most atomic layer. In PAES, monoenergetic positron of a few eV are implanted to the surface under study and these positrons become thermalized near the surface. A fraction of the thermalized positron trapped at the surface state annihilate with the neighboring core-level electrons, creating core-hole excitations, which initiate the Auger process with the emission of Auger electrons almost simultaneously with the emission of annihilating gamma-rays. The energy of electrons is generally determined by employing ExB energy selector, which shows a poor resolution of $6{\sim}10eV$. In this paper, time-of-flight system is employed to measure the electrons energy with an enhanced energy resolution. The experimental result is compared with simulation results in the case of both linear (with retarding tube) and reflected TOF systems.

• Journal of the Korean Chemical Society
• /
• v.65 no.2
• /
• pp.133-144
• /
• 2021

Science teachers in elementary schools and secondary schools recognize the necessity of character education, feeling difficulties such as evaluation methods, mood of competition, extra work and lack of time according to previous research, which were based on answers from science teachers not experiencing character education. As a rare study of teacher experiencing, previous researches didn't fully address the problems and suggestions about adopting character education in science classrooms. This study is about teacher practice of character education on site with the CoProC (Collaborative Problem-Solving for Character Competence) program in science classes with which other previous studies shed new light. Five teachers, adapting the CoProC program in their science classes, participated in two interviews, sharing their student achievement in character education. Results showed that student achievement was high when their teacher had experienced the training program, development, and classes of CoProC rather than their normal teaching career. Teacher recognition on the aims of CoProC influenced difficulties, evaluation, and feedback.

• Journal of The Korean Association For Science Education
• /
• v.42 no.2
• /
• pp.289-309
• /
• 2022

In recent years, astronomy has been snowballing: including Higgs particle discovery, black hole imaging, extraterrestrial exploration, and deep space observation. Students are also largely interested in astronomy. The purpose of this study is to discover what needs to be improved in the current astronomy curriculum in light of recent scientists' researches and discoveries. We collected keywords from all papers published from 2011 to 2020 in four selected journals-ApJ, ApJL, A&A, and MNRAS- by R package to examine research trends. The curriculum contents were extracted by synthesizing the in-service teachers' coding results in the 2015 revised curriculum document of six subjects (Science, Integrated Science, Earth Science I, Earth Science II, Physics II, Convergence Science). The research results are as follows: first, keywords that appear steadily in astronomy are 'galaxies: formation, galaxy: active, star: formation, accretion, method: numerical.' Second, astronomy curriculum includes all areas except the 'High Energy Astrophysical Phenomena' area within the common science curriculum learned by all students. Third, it is necessary to review the placement of content elements by subject and grade and to consider introducing new concepts based on astronomy research keywords. This is an exploratory study to compare curriculum and the field of scientific research that forms the basis of the subject. We expect to provide implications for a future revision of the astronomy curriculum as a primary ground investigation.

• Progress in Medical Physics
• /
• v.20 no.4
• /
• pp.317-323
• /
• 2009

The standard dosimetry systems based on an absorbed dose to water recommend to use a planeparallel chamber for the calibration of such a low-megavoltage electron beam as a nominal energy of 6 MeV. For this energy ranges of an electron beam a cylindrical chamber should not be used for the routinely regular beam calibration, but the feasibility of the temporary use of a cylindrical chamber was studied to give temporary solutions for special situations users meet. The PTW30013 chambers and the electron beam quality of $R_{50}=2.25\;g/cm^2$ were selected for this study. 10 PTW30013 chambers, a cylindrical type of chamber, were calibrated in KFDA, the secondary standards dosimetry laboratories, and given the absorbed dose-to-water calibration factors, respectively. A "temporary" $k_{Q,Q_0}$ for each chamber were calculated using the absorbed dose determined by a cross-calibrated planeparallel chamber, with the result of an average 0.9352 for 10 chambers. This value for PTW30013 chamber was used to determine an absorbed dose to water at the reference depth. The absorbed doses determined by PTW30013 chambers were in an agreement within 2% with that by ROOS chamber. In a certain situation where a cylindrical chamber be used instead of a planeparellel chamber, the value of 0.9352 might be useful to determine an absorbed dose to water in the same beam quality of electron beam as this study.

• Progress in Medical Physics
• /
• v.20 no.1
• /
• pp.21-29
• /
• 2009

Breast cancer is the most common form of cancer among korean woman. Therefore, the early detection activities of breast cancer such as breast self-examinations, clinical breast examinations, mammography are important. A yearly mammography examination has been recommended for women aged 40 and older for the early detection of breast cancer in asymptomatic periods. However, the glandular tissue of breast is the most radiation-sensitive tissue, and the determination of average glandular dose (AGD) forms an important part of the quality control of the mammographic systems. Because of the difficulty of estimating AGD directly, it is often estimated from the measurements of the incident air kerma and by applying the appropriate conversion factors. The primary objective of this study was to standardize the method of measuring AGD. The secondary objective was to evaluate the relationships between AGD per various composition and thickness of the breast using Monte Carlo simulations. As a result, we standardized the method of measuring AGD according to International Atomic Energy Agency (IAEA) guidelines (CoP: an international code of practice). Overall, AGD for mammographic practice in Korea was less than 3.0 mGy recommended by the Korea Food and Drug Adminstration (KFDA) protocol, and Korean Institute for Accreditation of Medical Image (KIAMI). The measured and simulated AGD for a given condition were calculated as 1.7 and 1.6 mGy, respectively. For the AGDs obtained, there was no significant difference between them. The simulated AGD was dependent on the fraction of glandular tissue of the breast. The AGD increases with increasing of the breast glandularity due to increasing absorption of low energy photons. The AGD also increases as a function of breast thickness. In conclusion, the results of this study could be used as a baseline to establish a reference level of radiation dose in mammography.