• Journal of The Korean Astronomical Society
• /
• v.39 no.2
• /
• pp.51-56
• /
• 2006

We report the development of a semi-VLBI observation system operating at 21 cm and present the measurement of visibility function toward the sun using this system. The system consists of two 2.3 meter antennas with a maximum separation of 35 meter, a conventional high speed data acquisition system, and a set of programs for software correlation. Since two local oscillators of receiver modules are independent, data had to be fringe-fitted to yield the visibility amplitude. It is found that the visibility amplitude decreases and then bounces back as baseline increases. We confirm that solar disk with brighter limb best explains the measured visibility amplitude.

• The Bulletin of The Korean Astronomical Society
• /
• v.45 no.1
• /
• pp.66.4-67
• /
• 2020

Gyeonggi science high school for the gifted (GSHS) installed 60cm telescope, which is waiting for student observers. It is essential to understand the characteristics of the photometric system, consisting of telescope, filter, and CCD, to get reliable data. CCD images of SA98 Landolt standard field and M67 were obtained on 19th March 2020. The images of each field were combined by filters, i.e., we ignored the monochromatic atmospheric extinction since the photometric objects themselves are standard stars. 24 standard stars in SA98 field and 12 standard stars in M67 were used to derive the tentative transformation equation between our bv photometric system and Johnson BV photometric system. In this poster, we present the preliminary standardization result for Johnson BV photometric system in GSHS 60cm telescope. The reproductivity is discussed by comparing color coefficients of two fields. We plan to extend this process to Johnsons-Cousins BVRI photometric system and narrow-band filters for flux calibration.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.02a
• /
• pp.432-432
• /
• 2011

Dry adhesion caused by Nanoscale contact comes up to important scientific issue. Herein, we introduce bendable nanohairy locking fastener system with high shear strength and mechanically flexible backing. The polymeric patches like velcro are composed of an array of straight nanohairs with 100 nm diameter and $1{\mu}m$ height. To fabricate high aspect vertical nanohairs, we used UV molding method with appropriately flexible and rigid polyurethane acrylate material on PET substrate. Two identical nanohairy patches are easily merged and locked each other induced by van der Waals force. Because nanohairs can be arrayed with high density ${\sim}4{\times}10^8/cm^2$, we can obtain high shear adhesion force on flat surface (~22 N/$cm^2$). Furthermore, we can obtian nanohairy locking system with maximum shear adhesion ~48 N/$cm^2$ of curved surface due to flexibility of PET substrate. We confirm the tendency that shear adhesion force increases, as radius of curvature increases.

• Journal of The Korean Association For Science Education
• /
• v.6 no.2
• /
• pp.35-42
• /
• 1986

Recent studies on the learning of the science concepts indicate that most students have misconceptions of the science concepts. The misconceptions have their roots in the various aspects of teaching and learning situations. The textbooks used in schools have been substantiated as one of the sources of the misconceptions. Genetics has been recognized as one of the most difficult areas for high school students to learn. Therefore, this study had its objective to identify the misconceptions of genetics held by high school students and analyze the high school biology textbook as the source of the misconceptions. In order to indentify the misconceptions of the genetic concepts, the volunteer students were interviewed and genetic content and its sequence in the high school biology textbooks were analyzed. The misconceptions identified in this study are as follow: gamete formation, mitosis, trait expression, and allele and gene behavior in meiosis. This study found that the high school biology textbooks might be the source of those misconceptions. Based on the misconceptions identified, this study proposed direction for efficient instruction of genetics in high schools.

• Journal of the Korean earth science society
• /
• v.25 no.3
• /
• pp.185-193
• /
• 2004

The purpose of this study is to explore high school students' environmental literacy and from its result, to suggest ways to reform environmental education. 1047 students from Seoul and Kyeongki province participated in the survey. The questionnaire consisted of four criteria of environmental literacy including knowledge, skill, attitude and behavior. The result was analyzed and the factors which affect high school students environmental literacy were explored. From this result, we made suggestions to improve environmental education as follows. First, environmental education in school should focus on knowledge criterion. Though school environmental education has been helpful for students to build environmental literacy in attitude and behavior criteria, its effect has not been good enough in knowledge criterion. Second, science education can enhance students' environmental literacy. Students who like science best and students who belong to science major classes were reported to possess better understanding in knowledge criterion. Also, students who like life science appeared to have a more positive attitude in environmental literacy. Third, informal education must be considered to form students' environmental literacy. In particular, the effect of mass media is inarguable. Thus, we should find a way to link formal education and informal education to improve environmental education. Fourth, high school students' interest in the environment must be encouraged since it is evident that higher interest would result in better outcome in environmental education.

• Journal of Engineering Education Research
• /
• v.13 no.5
• /
• pp.15-19
• /
• 2010

Upon request from the Tokushima Prefectural Senior High School of Science and Technology, two faculty staff members and eight students of The University of Tokushima visited the high school and set up a chemistry laboratory class for 59 students. Since the participating senior high school students were freshmen, four simple, safe and visual experiments were selected: 1) Water purification, 2) Surface modification, 3) Briggs-Rauscher reaction, and 4) Polymer synthesis and characterization. All experiments received a favorable reception as a follow-up questionnaire verified. Since the high school students enjoyed the experiments it is hoped that the results will strengthen the students' interest in chemistry. It was good opportunity for the observers; they recognized the difficulty of teaching students.

• Journal of Engineering Education Research
• /
• v.24 no.5
• /
• pp.28-37
• /
• 2021

The purpose of this study was to develop and apply of career education program in science and engineering fields for science gifted high school students. To do this, the career education program was developed and applied to science gifted high school students 129 in H-science gifted high school with K-institute. The results are followings. First, after participating in the career education program, the career decision making self-efficacy of students were increased significantly. Second, it has been increased that external factor of career outcome expectation and continuation effort of grit. In this study, it has showed educational effects of the career education programs that related to career recognition in science and engineering fields for science gifted high school students by developing and applying of program. Based on these results, it is necessary to recognize the importance of customized career education programs for science gifted high school students.

• Korean Journal of Mathematics
• /
• v.17 no.1
• /
• pp.25-36
• /
• 2009

We compute spectrums of left regular isometries and weighted left regular isometries of a strongly perforated semigroup $P=\{0,2,3,4,{\cdots}\}$.

• Journal of applied mathematics & informatics
• /
• v.36 no.1_2
• /
• pp.93-105
• /
• 2018

There are many metric functions in the plane. In this paper we are to classify the metric functions on the plane using two ways such as using sum of distances between some points when start point and end point is fixed, and using area of transferred triangle consisted of distances between 3 points.

• East Asian mathematical journal
• /
• v.23 no.3
• /
• pp.371-380
• /
• 2007

It is well known that the solutions of the Diophantine equation $x^2+xy-y^2=1$ is related to the Fibonacci sequence. In this study, we generalize the above fact to the tribonacci sequence and its generalized from using the group structure of solutions of some Diophantine equations.