• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.2
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• pp.195-202
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• 2015

Hundreds of Steller sea lions, Eumetopias jubatus, migrate from Sakhalin and the northern Kuril Islands to Hokkaido in Japan every winter. During this migration, they may use their roaring sounds to navigate and to maintain their groups. We recorded the roars of wild Steller sea lions that had landed on reefs on the west coast of Hokkaido, and those of captive sea lions, while making video recordings. The fundamental frequency ($F_0$), Formant frequency ($F_1$), pulse repetition rate (PRR), and duration of syllables (T) were analyzed using a sonagraph. $F_0$, $F_1$, and PRR of the roars emitted by captive sea lions increased in the order male, female. By contrast, the $F_1$ of wild males was lower than that of females, while the $F_0$ and PRR of wild males and females did not differ statistically. These results suggest regional differences between the five groups showed that.

• Journal of Engineering Education Research
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• v.20 no.4
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• pp.67-72
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• 2017

It was only 2010 when start-up education spread to undergraduate education in South Korea. Start-up education was conducted so late that there are insufficient studies of evaluation and feedback on the effectiveness of start-up education. Education is a complex concept of teaching people in a desirable direction and developing their inherent abilities. Based on this, start-up education can be defined as cultivating students' entrepreneurial spirit internally and making them exhibit start-up competence externally by teaching them the knowledge, skills and attitudes necessary for business start-up and developing abilities such as creativity, challenge spirit and problem-solving skills. This study conducted pre and post survey to check if the education camp for the technology start-up, which is a practice-oriented start-up education, has an effect on the change of the participating students' perceptions about the business start-up. This study would analyze various factors of college students' business start-up through a factorial analysis so that the quantitative accumulation of start-up education can lead to a qualitative change and propose measures for the management of the quality of the education.

• Spatial Information Research
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• v.22 no.2
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• pp.19-29
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• 2014

As Geoweb is continuously developing, today it is possible for the public to utilize geospatial information technology, whereas only a few experts could apply this technology in the past. The examples that utilize the geospatial information technology creatively in the field of education have been increasing. Google, USGS and NASA, etc. presented various strategies to attract participation from people as they construct the related web-sites and suggest practical examples so that the existing spatial data in public institutions can be utilized in the field of education. In this study, we presented the strategies that converged education and exploratory learning can be vitalized on the primary, middle and high schools by using geospatial information technology. We took a literature review of researches that geospatial information technology had applied in the field of education according to the changes of schools' environments, analyzed internal and foreign web-sites which applied geospatial information technology to the field of education, and finally presented the strategies for application of geospatial information technology in the field of education. The strategies we presented are divided into four parts: 1) construction of course modules, 2) construction of educational database based on geospatial information technology, 3) construction of authoring environments for course modules, and 4) provision of supporting services for vitalizing the education based on geospatial information technology.

• Bulletin of the Korean Chemical Society
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• v.31 no.12
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• pp.3579-3582
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• 2010

We studied the reaction of tri-methylaluminum (TMA) on hydroxyl (OH)-terminated Si (001) surfaces for the initial growth of aluminum oxide thin-films using density functional theory. TMA was adsorbed on the oxygen atom of OH due to the oxygen atom’s lone pair electrons. The adsorbed TMA reacted with the hydrogen atom of OH to produce a di-methylaluminum group (DMA) and methane with an energy barrier of 0.50 eV. Low energy barriers in the range of 0 - 0.11 eV were required for DMA migration to the inter-dimer, intra-dimer, and inter-row sites on the surface. A unimethylaluminum group (UMA) was generated at each site with low energy barriers in the range of 0.21 - 0.25 eV. Among the three sites, the inter-dimer site was the most probable for UMA formation.

• Journal of Information Processing Systems
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• v.15 no.3
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• pp.694-706
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• 2019

In this study, we applied the long short-term memory (LSTM) model to classify the cryptocurrency price time series. We collected historic cryptocurrency price time series data and preprocessed them in order to make them clean for use as train and target data. After such preprocessing, the price time series data were systematically encoded into the three-dimensional price tensor representing the past price changes of cryptocurrencies. We also presented our LSTM model structure as well as how to use such price tensor as input data of the LSTM model. In particular, a grid search-based k-fold cross-validation technique was applied to find the most suitable LSTM model parameters. Lastly, through the comparison of the f1-score values, our study showed that the LSTM model outperforms the gradient boosting model, a general machine learning model known to have relatively good prediction performance, for the time series classification of the cryptocurrency price trend. With the LSTM model, we got a performance improvement of about 7% compared to using the GB model.

• Journal of the Semiconductor & Display Technology
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• v.15 no.1
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• pp.65-69
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• 2016

We have investigated the possibility of recycling of an organic material that is wasted during thermal evaporation. To this end, we have collected a wasted organic material (N,N'-diphenly-N,N'-bis(1,1'-biphenyl)-4,4'-diamine(NPB)) from a vacuum chamber, purified it by recrystallization, and fabricated bilayer organic light-emitting diodes (OLEDs) with the recycled NPB. It is found that the surface roughness of thin films coated with the purified NPB is much enhanced. OLEDs fabricated by thermal evaporation of the purified NPB show lower device efficiency than OLEDs with the original NPB. However, the power efficiency of OLED fabricated by spin coating of the purified NPB is comparable with that of OLED with the original NPB. Therefore, such a recycling method by recrystallization would be more suitable for solution-processed OLEDs.

• Journal of Engineering Education Research
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• v.23 no.6
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• pp.3-16
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• 2020

This study aims to introduce the ENACT model, which is a systematic teaching-learning model for cultivating social responsibility of science and engineering college students, and to discuss its educational implications. For the development of the ENACT model, we conducted extensive literature reviews on RRI, STEM education, and science and technology studies (STS). In addition, we examined exemplary overseas education programs emphasizing social responsibility of scientists/engineers and citizens. The ENACT model consists of five steps; 1) Engage in SSIs, 2) Navigate SSIs, 3) Anticipate consequences, 4) Conduct scientific and engineering practice, and 5) Take action. This model links Socioscientific Issues (SSI) education with engineering education, dividing the major elements of social responsibility education for scientists and engineers into the dimensions of epistemology and praxis, and reflected them in the model. This effort enables science and engineering college students to pursue more responsible and sustainable development by carrying out the responsible problem-solving process based on an understanding of the nature of science and technology. We plan to implement ENACT model based programs for science and engineering college students and to examine the effects.

• Journal of the Semiconductor & Display Technology
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• v.13 no.3
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• pp.27-33
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• 2014

To develop high efficiency crystalline solar cells, the $SiN_x$ film for surface passivation and anti-reflection coating is very important and it is generally deposited by PECVD. In this paper, the $SiN_x$ film deposited by Hot-Wire chemical vapor deposition(HWCVD) that has no plasma damage was studied. First, to optimize the $SiN_x$ film deposition process, $SiH_4$ gas rate and substrate temperature were varied and then refractive index and thickness were measured. When $SiH_4$ gas rate was 22sccm and substrate temperature was $100^{\circ}C$, refractive index was 1.94 and higher than that of other process conditions. Second, the lifetime was measured by varying the annealing temperature and time. The annealing process was made from 5 to 30 minutes at $300{\sim}500^{\circ}C$. When the annealing temperature was $100^{\circ}C$ and time was 10minute, the lifetime was the highest. The lifetime of annealed samples was also measured after the firing process at $975^{\circ}C$. Although the lifetime of all samples was decreased by firing process, the lifetime of annealed samples before the firing process was higher than that of fired samples only. Finally, the characteristics of solar cells with HWCVD $SiN_x$ film were measured.

• 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.

• International Journal of Computer Science & Network Security
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• v.23 no.11
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• pp.32-42
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• 2023

The paper describes the new approaches to the automated analysis of curricula according to the higher education standard. The analysis process is proposed to carry out in two ways: (a) the analysis of completeness and sufficiency of curricula according to the standard of higher education; (b) the comparison of curricula of the same qualification and specialty. The problem of improving the quality of university students' training launches the process of monitoring and analyzing educational curricula and their correspondence to the higher education standard. We developed the rules and methods to compare curricula. In addition, we implemented the automated system of curricula comparison. The paper reveals the use of these methods based on the analysis of the curriculum bachelor level of higher education "Informatics", specialty "Computer science", at the Faculty of Computer Science and Cybernetics of the Taras Shevchenko National University of Kyiv. The findings put towards the idea that the implementation of developed methods as well as the automated system of curricula analysis will improve the educational services by higher education institutions.