• Proceedings of the Korean Magnestics Society Conference
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• 2009.12a
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• pp.217-219
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• 2009

A GMI magnetic field sensor working based on time-coded principle has been investigated and designed. The laboratory model has been constructed and tested carefully, demonstrating the sensitivity of $3\;{\mu}s/{\mu}T$ in the field range of ${\pm}100\;{\mu}T$. An amorphous thin wire, $100\;{\mu}m$ in diameter ${\times}50\;mm$ in length, was chosen to be sensing element which was fit into a small field modulation coil of 60 mm in length. The sensor is working based on a time-coded principle that, with the magnetic field modulation was chosen in range of hundreds of Hz, the change in time interval of two adjacent GMI peaks relating to external DC magnetic field is proportional to the intensity of the external field to be measured. This mechanism has made a great improvement to the linearity of the sensor.

• Culinary science and hospitality research
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• v.12 no.3 s.30
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• pp.75-90
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• 2006

The purpose of this study is to understand how to activate field training internships through former researches related to training internships. The concept of field training is the same as education of work experience. Students have experienced the skills of practical jobs in the tourism industry and could enhance acquisition of professional theories. According to domestic former researches, students who participated in hotel field practice hardly satisfied with internships due to unreasonable duties, burdens and circumstances regardless of efficiency of school curriculum. Also, they showed dissatisfaction with compensation. However, foreign studies have only focused on communication between hotels and schools. Finally, in order to activate industrial field training internships, schools and hotels have more delicate harmonization to address training internship problems. In addition, promoting field training internships must include proper incentives and must be supported by school. And also the hotel management must offer incentives to the students who are under field training internships in the hotel. From internship programs, students could get much more benefits in hotel job application.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.13-17
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• 2003

In this paper, the design parameters for the magnetic field source at extremely low frequency are proposed. This facility can be used for in vivo experiments with small animals to investigate biological response to the driving magnetic fields. In case that the exposed animals are motionless, the animals may be affected by the directivity of driving field. To avoid this effect, a 2-axis ELF magnetic field driving apparatus was designed, The optimum location and number of turns of each coil were obtained by numerical analysis. Applying these data to the MATLAB code (for computation), the magnetic field distribution was obtained. The calculation result for a well-designed facility showed that the space in which the amplitude of the magnetic field lies within the 95% of the magnetic field distribution was more than 60% of each axis length.

• Journal of Korea Foundry Society
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• v.20 no.2
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• pp.129-140
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• 2000

This study aims at the phase-field modeling of the phase transformation in graphitization of the cast iron. As the first step, we constructed a phase-field model including the phases with negligible solubility. Under the dilute regular solution approximation, a simplified version of the phase-field model was obtained, which can be used for the phase transformation related with the stoichiometric phases. The results from the numerical calculation of the phase-field model was in good agreement with the exact analytic solution. The compositional shift due to Gibbs-Thomson effect can be reproduced within 0.5% error in the numerical calculation. The interface velocity, whereas, in numerical calculation of phase-field model appeared to be 15% larger than that from the analytic solution. This error is due to the shift of the interface position in phase-field model from the position with ${\phi}=0.5$.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.43.3-43.3
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• 2019

Magnetic fields play an important role in supporting molecular clouds against gravitational collapse. The measured magnetic field strengths in molecular clods enable us to see the effect of magnetic fields in star-forming regions. People have used the Chandrasekhar and Fermi (CF) method to estimate magnetic field strength from observational quantities of molecular cloud density, turbulent velocity and polarization angle dispersion. However, previous studies obtained just one magnetic field strength over the quite large region of a molecular cloud by using the CF method. We here suggest a way to estimate magnetic field strength distribution in Orion A region. We used 450 and 850-micron polarization data of James Clerk Maxwell Telescope (JCMT). Magnetic field strengths were estimated in two wavelengths with 4 pixel resolutions of 16, 20, 24 and 28". Through statistical analysis, we proved the difference of magnetic field strengths between two wavelengths were caused by the difference of their beam sizes. Additionally, we calculated the radii of curvature of polarization segments to select a best pixel resolution for estimating the magnetic field distribution. The pixel resolution should be larger than a radius of curvature. We selected that 20 or 24" pixel resolutions are good choices towards Orion A region.

• Journal of Korea Spatial Information System Society
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• v.12 no.1
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• pp.76-84
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• 2010

Many pedestrian simulation models for micro-scale spaces as building indoor areas have been proposed for the last decade and two models - social force model and floor field model - are getting attention. Among these, CA-based floor field model is viewed more favourable for computer simulations than computationally complex social force model. However, Kirchner's floor field model has limitations in capturing the differences in dynamic values of different agents and this study proposes an enhanced algorithm. This study improved the floor field model in order for an agent to be able to exclude the influences of its own dynamic values by changing the data structure, and, also modified the initial dynamic value problem in order to fit more realistic environment. In the simulations, real 3D building data stored in a spatial DBMS were used considering future integration with indoor localization sensors and real time applications.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.3
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• pp.51-56
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• 2001

In this paper, the effect of magnetic field on corona discharge phenomena was experimentally investigated in the needle-plate electrode geometry. Needle-plate geometry discharge system with magnetic field at a right angle to the electric field was made. The corona discharge characteristics with magnetic field were investigated and compared with the corona characteristics without magnetic field in atmospheric pressure. As a result, in case of positive DC corona discharge with magnetic field, corona discharge zone was significantly wider, corona current was lower, and breakdown voltage was higher than those without magnetic field. However, in case of negative DC corona discharge with magnetic field, corona current was slightly higher and breakdown voltage was lower than those without magnetic field. It is thought that this result is due to cyclotron motion of charged particles such as electron and ion by magnetic field.

• International Journal of Knowledge Content Development & Technology
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• v.12 no.3
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• pp.51-77
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• 2022

This study attempted to grasp the current status of field training in the Department of Library and Information Science and the training institutions of the students of the Department of Library and Information Science and to propose a development plan based on this. To this end, a questionnaire survey and survey were conducted on the status of field practice in the Department of Library and Information Science at 4-year and 2-year colleges. As a result of the study, first, it was analyzed that field training has an effect on the employment competitive- ness and employment competency of students, and the field training environment has an effect on career decisions of students in the Department of Library and Information Science. Second, it was found that the library with the most field training was found to be a public library, and it was investigated that in order to allow students to experience various institutions and choose their career path, it was necessary to jointly discover and use field training institutes. Third, the evaluation contents or evaluators of the field training did not show a big difference by school, and it was found that most universities are evaluating the field practice using various scales. Lastly, in order to maintain the level of on-the-job training to some extent, it is necessary to develop a training manual and distribute it to each university.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.31 no.4
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• pp.90-104
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• 2023

This study analyzes the perceptions of college students majoring in aviation services according to the field learning program conducted during their major studies in order to reflect the educational value and academic awareness of the experience of the experiential field learning program. A survey is conducted targeting college students who experience a field learning program conducted by the Aviation Service Department of J University, a four-year university in the Chungcheong region. ANOVA (one-way analysis of variance) is conducted to analyze differences in perceptions of field learning properties, learning satisfaction, academic self-efficacy, and intention to continue studying. Additionally, text mining is conducted using 'Voyant Tools' to analyze students' field trip logs regarding field trip learning program activities. I hope that the results will be used as evidence to build an efficient and systematic learning strategy for operating field learning programs.

• Journal of Korean Elementary Science Education
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• v.21 no.2
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• pp.241-252
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• 2002

Field learning have not well performed in elementary school for various reasons, in spite of the benefits of field study. Absence of suitable geological field courses for elementary science education is one of several reasons The purpose of this study is to develop learning materials for the field geology in Hampyeong region and apply them to the geological related units for elementary science education. The 5 observation sites for the field geology learning in study area include various rocks and geological structure such as granite, gneiss, conglomerate, sandstone, mudstone, plant fossil, fold, fault and weathering phenomenon changing rocks to soil. This study area is suitable place for the field geology learning of elementary science education in Kwangju and Chonnam province because of convenience access, fresh outcrops and distribution of various geological learning materials as rocks and structure.