• Journal of the Semiconductor & Display Technology
• /
• v.6 no.3
• /
• pp.61-64
• /
• 2007

V-groove device was fabricated for precision coupling of planar optical splitter and optical fibers. V-groove was made through select wet etching of Si wafer by using KOH solution. Etching rate and surface roughness were checked, changing KOH composition(10, 20, 30, 33, 40 wt.%) and etching temperature (50, 60, 70, $80^{\circ}C$) to fabricate V-groove device effectively. Etching rate was the fastest as $1.84\;{\mu}m/min$ in case of etching by 20 wt.% KOH on $80^{\circ}C$, surface roughness was the best in case of etching by 33 wt. % KOH on $80^{\circ}C$.

• Journal of the Semiconductor & Display Technology
• /
• v.15 no.1
• /
• pp.12-16
• /
• 2016

Toluene-free pressure sensitive adhesives were synthesized by using butyl acrylate (BA), 2-hydroxy ethyl acrylate, methyl methacrylate, acrylic acid (AA) as monomers and ethyl acetate as a solvent. The polymerization recipes were designed by changing 1, 3, 5 part per hundreds monomer (phm) of AA content on the basis of 100 BA parts. Two crosslinking agents, ethyl glycol diglycidyl ether (EDGE) and isophorone diisocyanate (IPDI) were added to the synthesized polymers to increase adhesion due to crosslinking. In the measurement of properties, holding power, peel strength, and initial tackiness increased with AA content due to crosslinking between carboxyl group in AA and epoxy group in EDGE and isocyanate group in IPDI. In the comparison of two crosslinking agents, EDGE showed better in the three properties than IPDI by better reaction of epoxy group of EDGE to carboxyl group of AA.

• International Journal of Advanced Culture Technology
• /
• v.12 no.1
• /
• pp.276-280
• /
• 2024

Recently, many policies and fairs have been made in relation to start-ups. In addition, various start-up education for prospective start-ups is being conducted in various ways. Therefore, these days, the number of prospective start-ups who receive such information and start-up education is increasing. Nevertheless, more and more start-ups are still unsuccessful and close their businesses within months or years. In particular, start-ups who continue to maintain their start-ups also see the unfortunate reality of start-ups that find other jobs in various support systems and related policies and relationships that they cannot quit even if they want to. In this study, based on previous studies, factors for satisfaction with entrepreneurship education will be set and a questionnaire will be conducted for prospective entrepreneurs who have completed education at a startup education center in Seoul. The survey results are intended to verify their reliability and validity through empirical analysis. The SPSS statistical package will be used for analysis, and a total of 200 copies of the questionnaire will be distributed and collected. In this study, it was confirmed that the higher the satisfaction with entrepreneurship education, the better the successful entrepreneurship. In addition, I think that further developing various policies or detailed curriculums for entrepreneurship education will be of great help to prospective entrepreneurs taking entrepreneurship education.

• Journal of Engineering Education Research
• /
• v.13 no.1
• /
• pp.17-22
• /
• 2010

This paper examines major activities of Thomas Edison as an example to liberal education for engineers using researches in the history of technology. Edison, as a system builder, developed almost everything necessary to use electric light in the aspects of technology and management. On the contrary, Edison took a conservative stance to new alternating current technology in the case of current war. Edison developed phonograph and motion pictures but didn't understand the meaning of mass culture grown up based on his inventions. This study not only provides an illustrative content to the liberal education for engineers, but also helps to grope for the dynamic character of technological innovation and the desirable features of engineers.

• Journal of information and communication convergence engineering
• /
• v.15 no.4
• /
• pp.217-226
• /
• 2017

Korea has the tenth largest film industry in the world; however, detailed analyses using the factors contributing to successful film commercialization have not been approached. Using big data, this paper analyzed both internal and external factors (including genre, release date, rating, and number of screenings) that contributed to the commercial success of Korea's top 10 ranking films in 2011-2015. The authors developed a WebCrawler to collect text data about each movie, implemented a Hadoop system for data storage, and classified the data using Map Reduce method. The results showed that the characteristic of "release date," followed closely by "rating" and "genre" were the most influential factors of success in the Korean film industry. The analysis in this study is considered groundwork for the development of software that can predict box-office performance.

• Nuclear Engineering and Technology
• /
• v.56 no.8
• /
• pp.3330-3334
• /
• 2024

Void drift between subchannels in a rod bundle is a crucial phenomenon affecting the calculation accuracy of thermal-hydraulic parameters in SMRs. It holds significant importance in enhancing the precision of safety analysis for SMRs. Existing research on experiment and model of void drift between rod bundle subchannels is relatively rare, and the accuracy of model calculations requires improvement. In this study, experiments on gas-liquid two-phase non-equilibrium flow were conducted to measure the redistribution of two-phase flow induced by void drift in a 1 × 2 rod bundle. The experiment results indicated that in bubby flow regime with void fraction less than 0.3, the void diffusion coefficient showed little variation with changes in void fraction. However, in slug flow and annular flow regimes with void fraction exceeding 0.3, the void diffusion coefficient significantly increased with an increase in void fraction. Furthermore, a new void drift model was developed and validated based on a subchannel code. The overall predicted uncertainty for the outlet void fraction in the rod bundle benchmark was less than 13%.

• Journal of the Semiconductor & Display Technology
• /
• v.6 no.4
• /
• pp.65-68
• /
• 2007

An epitaxial NiSi structure on Si (001) substrate was studied by using density functional theory (DFT). Orhorhombic and B2-NiSi structures were compared first. B2 structure was further considered as it has same crystal structure as Si and the lattice mismatch between B2 and Si is small, compared to orthorhombic-NiSi. The lattice parameters of x- and y-direction in B2-NiSi structure were modified to match with those in Si (001). The size reduction of the lattice parameter of B2-NiSi to match with that of Si increased the lattice parameter of z-direction by 10.5%. Therefore, we propose that an optimum structure of NiSi for epitaxial growth on Si (001) is a tetragonal structure.

• Journal of Advanced Navigation Technology
• /
• v.12 no.1
• /
• pp.68-73
• /
• 2008

Recently, remote observation and control technology has grown gradually. According to use home network system and expand super-highway information network, digital video technology observation system gradually has increased. In order that the user conveniently use better than to use web browser observation system, it uses existing digital observation system, personal digital assistant and control module in the place of internet.

• Journal of the Semiconductor & Display Technology
• /
• v.19 no.3
• /
• pp.130-135
• /
• 2020

This paper describes the results of a study on the unmanned cleaning robot that performs the cleaning of the floating photovoltaic panels. The robot uses two SSC (Sliding Suction Cup) adsorptive devices to move up and down the slope. First, the forces generated when the robot moves up the slope are mechanically analyzed. The robot was designed and manufactured to operate stably by using the presented results. Next, the robot motion was tested on the inclined panel. It has been proven that robots are well designed and built to clean sloped panels.

• Journal of the Korean Institute of Gas
• /
• v.14 no.5
• /
• pp.26-31
• /
• 2010

This paper aims to analyze the effect of the introduction of new technology and education for gas safety on the prevention of gas accidents. For the purpose of a study, inspections, safety tests and training programs conducted by KGS were examined and the gas accident data, installation rate of safety devices and training, inspection data for last 20 years were also collected and then Multiple regression analyses were performed by using SPSS. The results showed that in both of City Gas and LPG system, the installation rate of fusecocks and training programs were statistically meaningful for reducing the gas accident rate.