• Korean Journal of Optics and Photonics
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• v.6 no.4
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• pp.352-358
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• 1995

Measurements of the Faraday rotation and magnetization of terbium-doped Hoya FR5 glass and cerium-doped Hoya FR4 glass have been made as a function of temperature T in the range 4.2 K -10 K and of magnetic field H of up to 80 kG at the $Ar^+$ laser wavelength of 514.5nm. The saturations of magnetization and Faraday rotation above H/T> $5kG.K^{-1}$ can be analyzed by the quantum theory of paramagnetism. Calculated parameters show that the large Verdet constant of $Ce^{3+}$ glass is due to the effective $4f\rightarrow5d$ electric dipole transition effect and that of $Tb^{3+}$ glass is due to the magnetization effect.effect.

• Journal of the Korean earth science society
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• v.31 no.1
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• pp.95-105
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• 2010

The purpose of this study lies in applying generalizability theory depending on the aim of the usage of GALT to analyze the sources of error of single-facet considering item and person only and to analyze the sources of error of multi-facet considering item, person and domain. The study was conducted with 1016 students of local elementary, middle, and high schools. The 21 items of a full version were answered for 40 minute and then the 12 items of short version were sampled to analyze reliability using generalizability theory. Both the full version and the short version of the items were analyzed using Cronbach's alpha for data analysis, and we applied generalizability theory and separate $p{\times}i$ design and $p{\times}(i:h)$ design, G study and D study were performed. Results of analysis are as follows: First, the result of D study after $p{\times}I$ design both on the full version and the short version showed that in the case of the full version, the generalizability coefficient was 0.87 exceeding a normal level of 0.80, and the normal level of generalizability coefficient was achieved in 13 items as well. In case of short version, when 12 items were evaluated, generalizability coefficient was 0.77 not reaching the normal level, and the normal level was achieved in case of more than 15 items. Second, the result of D study after $p{\times}(I:H)$ design on the short version showed that once one domain consists of 2 items in 6 domains, generalizability coefficient was 0.71 which is lower than the normal level of 0.80, the normal level was achieved in more than 5 item cases.

• YAKHAK HOEJI
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• v.39 no.1
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• pp.78-84
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• 1995

Based on Computer graphics molecular modeling method, quinolone derivatives as DNA-gyrase inhibitors formed stable DNA-intercalation complex with deoxycytidilyl-3',5'-deoxy guanosine[d($C_{p}G)_{2}$] dinucleotide. When d($C_{p}G)_{2}$ and d($A_{p}T)_{2}$, were compared in order to find out which DNA could form more stable DNA-Drug complex based on interaction energy($\Delta$E) and DNA-Drug complex energy, d($C_{p}G)_{2}$ resulted in lower energy than d($A_{p}T)_{2}$.

• Nuclear Engineering and Technology
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• v.22 no.2
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• pp.108-115
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• 1990

The measurements of X-ray production cross-sections for 0.5~1.2-MeV proton beam are carried out on Cu and Au. For this experiment, the proton tram generated from the SNU 1.5-MV Tandem Van do Graaff accelerator is Incident on the target. The X-rays and the backscattered protons from the irradiated target are detected simultaneously by the Si(Li) X-ray detector and the SSB (Silicone Surface Barrier) charged particle detector The measured values of X-ray production cross-sections are compared with other experimental values and theoretical values such as the PWBA (Plane Wave Born Approximation) and the ECPSSR(Perturbed Stationary State corrected Energy loss, Coulomb deflection, Relativistic effects) values. For measured cross-sections near 1.0- MeV proton energy, the ECPSSR (D.D. Cohenet al., 1985) shows better agreement than the PWBA. Particularly, that of Au for 1.2 MeV proton beam is 9.69$\pm$ 0.39 barns which deviates from the ECPSSR by less than 5%. and the experimental data for 0.5~1.2- MeV proton agree with most of other experimental values within 30%.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.299-303
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• 2004

In this paper, it is presented a level sensor for measuring a level of the contents of cargo tank using frequency modulated continuous wave(FMCW). The frequency range is 10∼11 GHz, the radar cross section(RCS) of target is 0.8 ㎡ of metal plate. the experiment is performed in laboratory and open ground, the sweep time of the signal is 100 ms, the pyramidal horn antenna of about 20 dBi gain is used, and input power of antenna is about 5 dBm. the beat frequency according to the target moving to 40 m is measured. There is a good agreement between measured and calculated results. But the resolution of the FMCW radar is measured about 10 cm due to nonlinear of voltage controlled oscillator(VCO).

• Korean Journal of Optics and Photonics
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• v.18 no.3
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• pp.196-201
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• 2007

A theoretical study of Brillouin optical time domain analysis (BOTDA) using two pulse lasers is performed. Even though a point detection is made for a pump pulse period, the dynamic range of BOTDA using two pulse lasers is approximately 5 dB more than that of a pulse and a CW laser when the fiber length is 140 km and the Stokes power is 1 mW.

• Journal of Advanced Navigation Technology
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• v.14 no.6
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• pp.817-823
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• 2010

Design of IPI feeding structure affecting the antenna gain improvement of mobile phone was investigated. IPI feeder which based on the T matching theory increase line current for internal antenna such as IFA. So IPI feeder makes higher radiation resistance, and also increases the gain with increasing radiation efficiency. To verify IPI feeding effect, feeder is applied to conventional CDMA/DCS dual band IFA. Measurement shows that IPI-IFA has 0.5 ~ 1.4[dBi] higher gain than conventional IFA at CDMA/DCS band. Resonant frequency did not change.

• Water for future
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• v.19 no.2
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• pp.131-138
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• 1986

Both hydraulic and dynamic characteristics of a single perforated wall are studied theoretically and experimentally. Theoretically, the effect of evanescent modes on wave force acting on a single perated wall is studied by use of the Horiguchi theory. The wave force on the perforated wall is presented to be insensitive to evanescent modes. According to experimental study, The larger perforation ratio(${\gamma}$) grows, the weaker the wave force on the wall becomes sensitively. And in the small value of l/D (ratio of wall thickness(l) to hole diameter(D)) where the holes on the wall are regarded as orifice, the wave force on the wall is insensitive to the variation of l/D. Energy loss coefficient f is estimated at 1.0 in this small value of l/D by use of Horiguchi theory. But in the large value of l/D where the holes are regarded as pipe, the wave force on the wall is relatively sensitive to the variation of l/D and f is estimated at 1.5 by use of Horiguchi theory.

• Journal of the Korea Concrete Institute
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• v.25 no.6
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• pp.683-691
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• 2013

Failure behaviour of deep beams is largely depend on shear span to effective depth ratio(a/d). For deep beams with $a/d{\leq}1.0$, the diagonal splitting of the web and local crushing of concrete near applied loads or supports is the most common failure mode. If the beam contains sufficient web reinforcement, area of local crushing will be increased while area of diagonal splitting is decreased. When web reinforcement above purpose, web should be reinforced both in the horizontal and vertical directions or be reinforced in perpendicular direction to diagonal cracks. For deep beams with 1.0${\leq}2.5$, the increment of shear strength by the horizontal web reinforcement are hardly expected unless amount of main bars very small that the main bars should be reached yielding state when shear failure occurs. In contrast, the vertical web reinforcement prevent the beam from being transferred to tied arch mechanism, and as a result th shear strength of beam increase. In this study, formulas based on upper bound theorem of plastic theory are proposed to predict the shear strength of reinforced concrete deep beams with $a/d{\leq}1.0$. Comparisons with other experiment results are performed, and good agreement between measured and predicted value by proposed formulas is obtained.

• Journal of The Korean Association For Science Education
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• v.27 no.5
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• pp.447-455
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• 2007

The Research works published in the field of Korean science education in relation to the theories of 'J. Piaget', 'D. P. Bruner' or 'J. S. Ausubel' have been analyzed and their general pattern of study were determined. Specifically, based on science education related articles published in several Korean journals, the pattern of research about the three scholars' theory is identified with the classification of the specific kind of journal, year of publication, key word, field of study, field of research, and grade of school. The journals subjected to the present study include 'Journal of the Korean Physical Society', 'Journal of the Korean Chemical Society', 'Journal of the Korean Biology Society', 'Journal of the Korean Earth Science Society', 'Journal of the Korean Association for Research in Science Education', and 'Journal of the Korean Society of Elementary Science Education'. It is determined from the present study as follows: First, the total number of related articles published in said journals is 97, and 'Journal of the Korean Association for Research in Science Education' ranks first in numbers. In terms of time period, it is found that most of the researches has been carried out during the mid 90s, and is still popular today. In addition, our key word search revealed that the 'cognitive development' by Piaget is most widely studied in the articles and biology is the area that has been most frequently studied. As to the field of research, teaching study was the one that has been most widely studied. Further, many articles have focused their studies on middle school. In conclusion, it is found that the Korean research works so far made for the theory of 'J. Piaget', 'D. P. Bruner' or 'J. S. Ausubel' are rather limited to a certain area and field, etc.