• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.903-904
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• 2013

• Korean Journal of Crystallography
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• v.4 no.1
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• pp.49-51
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• 1993

The knowledge on the number of necessary and collectable reflections for the crystal structure analysis is greatly helpful in choosing the conditions for X-ray intensity data collection using automatic four circle diffractometer. In this paper, we represent a method to calculate the total unmber of collectable intensity date in an asymmetric unit.

• Journal of applied mathematics & informatics
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• v.28 no.1_2
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• pp.373-381
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• 2010

In this paper we determine all elements in the root lattice of symmetrizable generalized Kac-Moody algebras whose reflections preserve the root systems. Also we discuss elements in the root lattices whose reflection preserve the root lattices.

• Archives of Plastic Surgery
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• v.45 no.4
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• pp.390-392
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• 2018

• Proceedings of the Korea Society of Design Studies Conference
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• 2001.10a
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• pp.23.2-23
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• 2001

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.7
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• pp.1159-1164
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• 2006

Broadband antennas have late-time ringing by multi-reflections between feed points and 0pen ends of the antennas, which indicates the narrowband nature of the antenna. The resistive loading has been used to reduce the late time ringing that is important for ground penetrating radar and resonance detection systems in order to prevent masking of target. In this paper, we design an ultra wide band antenna with resistive loading technique to reduce the internal reflections within the antenna.. The designed antenna is implemented and tested to show inIproved characteristics.

• The Journal of the Korea Contents Association
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• v.5 no.4
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• pp.71-77
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• 2005

On contraction of the muscles, marked changes in X-ray reflections are observed, suggesting that conformational changes of contractile molecules and the movement of myosin heads during muscle contraction. It was found that the successive twitches decreased not only the time needed to the peak tension after the onset of stimulation but also the time needed to the maximum change of the X-ray intensity. However, the difference of the time between the peak tension and the maximum intensity change$(T_i-I_i)$ is nearly the same at any twitch.

• English Language & Literature Teaching
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• v.16 no.1
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• pp.19-40
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• 2009

Teacher written feedback on student compositions has received tremendous attention in second language (L2) writing research. Notwithstanding the importance of understanding both teachers' and students' perspectives on the feedback process, much of the feedback research has only looked into one-side of the story - adopting either the teacher's or the student's perspective. The current study is an attempt to look into both sides of the story by examining the types of written feedback that students prefer, the extent to which students' preferences and teachers' actual feedback practice overlap, and the extent to which student perceptions of teacher feedback coordinate teacher self-reflections on their feedback practice. Three English composition classes (3 teachers and 46 students) at a university participated in this study. It analyzed student and teacher data from questionnaires and teacher written feedback on student compositions. The results showed that students' preference for feedback on global and local issues varied across the three composition classes. This is partly a consequence of how students perceived the type of feedback that their teachers practiced. Teacher self-reflection on and student perception of teacher written-feedback generally coordinated. These findings are discussed in light of how contextual factors affect learner perception of teacher written feedback and underscore the need for examining students' reactions to feedback and teacher self-reflection.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1509_1510
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• 2009

This paper presents the design and simulation results of ohmic contact RF MEMS silicon switch with a high isolation at high frequencies along with the position of a contact part, initial off-state and intermediate off-state including the state where a contact part is placed right over a signal line of coplanar waveguide (CPW). The ohmic contact part is connected with comb drives made of high resistivity single crystalline silicon. The released contact part is $30{\mu}m$ apart from the edge of signal line on the glass substrate along the lateral direction (x-direction) at initial off-state. The electrostatic force of the comb electrode creates the x-directional movement thus initial state is converted to the intermediate off-state. The initial off-state of the switch results in isolations of -31 dB, -24 dB and reflections of -0.45 dB, -0.67 dB at 50 GHz and 110 GHz, respectively. It shows the isolation degradation when the contact part moves right over the signal line of CPW like an initial off-state of a conventional MEMS switch. The isolations and reflections are -31 dB, -24 dB and -0.50 dB, -1.31 dB at 50 GHz and 110 GHz, respectively at the intermediate off-state.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.2
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• pp.291-297
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• 1997

A 2.5 Gbp$\times$8 channel WDM signal was transmitted using read-deployed 123 km optical cable around Daejon area. An error free transmission was achieved with $10^{-10}$ criterion, but the receiver sensitivity varied depending on channel, and some channel showed BER floor. The reans was forud to be in reflection points, and the effects of multiple reflections on the ultra high bit transmission was found to be inreflection points, and the effects of multiple reflections on the ultra high bit transmission was analyzed in this paper.