• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.12 no.2
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• pp.55-68
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• 2008

One of well known and much studied nonlinear matrix equations is the matrix polynomial which has the form $P(X)=A_0X^m+A_1X^{m-1}+{\cdots}+A_m$, where $A_0$, $A_1$, ${\cdots}$, $A_m$ and X are $n{\times}n$ complex matrices. Newton's method was introduced a useful tool for solving the equation P(X)=0. Here, we suggest an improved approach to solve each Newton step and consider how to incorporate line searches into Newton's method for solving the matrix polynomial. Finally, we give some numerical experiment to show that line searches reduce the number of iterations for convergence.

• Journal of Gynecologic Oncology
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• v.29 no.6
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• pp.89.1-89.8
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• 2018

Objective: Highly effective chemotherapy for patients with low-risk gestational trophoblastic neoplasia (GTN) is associated with almost a 100% cure rate. However, 20%-30% of patients treated with chemotherapy need to change their regimens due to severe adverse events (SAEs) or drug resistance. We examined the treatment outcomes of second-line chemotherapy for patients with low-risk GTN. Methods: Between 1980 and 2015, 281 patients with low-risk GTN were treated. Of these 281 patients, 178 patients were primarily treated with 5-day intramuscular methotrexate (MTX; n=114) or 5-day drip infusion etoposide (ETP; n=64). We examined the remission rates, the drug change rates, and the outcomes of second-line chemotherapy. Results: The primary remission rates and drug resistant rates of 5-day ETP were significantly higher (p<0.001) and significantly lower (p=0.002) than those of 5-day MTX, respectively. Forty-seven patients (26.4%) required a change in their chemotherapy regimen due to the SAEs (n=16) and drug resistance (n=31), respectively. Of these 47 patients failed the first-line regimen, 39 patients (39/47, 82.9%) were re-treated with single-agent chemotherapy, and 35 patients (35/39, 89.7%) achieved remission. Four patients failed second-line, single-agent chemotherapy and eight patients (17.0%) who failed first-line regimens were treated with combined or multi-agent chemotherapy and achieved remission. Conclusions: Patients with low-risk GTN were usually treated with single-agent chemotherapy, while 20%-30% patients had to change their chemotherapy regimen due to SAEs or drug resistance. The second-line regimens of single-agent chemotherapy were effective; however, there were several patients who needed multiple agents and combined chemotherapy to achieve remission.

• East Asian mathematical journal
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• v.26 no.2
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• pp.267-280
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• 2010

In this paper we study construction methods of $n^{th}$ line in triangle. Russian Mathematician Zetel suggested some construction methods of $n^{th}$ line in triangle 80 years ago. We find Zetel's papers, in detail explain the Zetel's construction methods, and suggest two elementary construction methods. Our results are received in the process of Research and Education program in science high school.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1993.11a
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• pp.60-63
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• 1993

We have prepared n-CdS/p-InP hetero- junction solar cells by thermal evaporation. The efficiency under the optium conditions without the grid line contact was 7.3%, and the solar cell having glid line contact with SiO AR coating was the open circuit voltage of 0.71V, the short circuit voltage current density of 15mA/cm$^2$, the fill factor of 0.73, and the efficiency of 11.5%. As result of photoresponse in 400-1000nm wavelength the cutoff of n-CdS/p-InP solar at 500nm results from absorption by the CdS \"window\" and the cutoff at 930 nm result from absorption by the InP.

• Journal of Welding and Joining
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• v.19 no.4
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• pp.429-436
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• 2001

The effect of welding condition on the microstructures of the weld metal in A7N01 welded by $CO_2$ laser was investigated. The number of ripples was increased with decreasing power and increasing welding speed. In the bead without ripple lines, the subgrain microstructures distribution from the fusion line toward the center of the bead were in the order of cellular, dendritic and equiaxed dendrite. However, in the bead with ripple lines, cellular and dendritic were formed between the fusion boundary and the ripple line. Inaddition, those structures were also observed between the ripple line. Equiaxed dendrites were formed only at the center line region. Cellular and dendritics formed near the ripple line were larger than those formed near the fusion boundary. The cooling rates estimated by the dendrite arm spacing were in the range of 200 to 1150oC/s. Cooling rate was increased with decreasing the power and increasing the welding speed. Mg and Zn segregated at the boundaries of cellulars and dendritics, Mg was segregated more than Zn. The segregation of Mg and Zn decreased with increasing cooling rate. Hardness of the weld metal was lower than that of the base metal in all welding conditions and increased as the cooling rate increased.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.3
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• pp.57-69
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• 2011

This study examined the relationship between Phragmites australis' growth and sediment properties at mud tidal flat of Donggum-ri, Gilsang-myeon, Gangwha-gun, Incheon city. Field survey was carried out from May, 2010 to October, 2010. Water content, soil texture, electric conductivity and water table depth for sediment, density, height, dry weight and flowering for P. australis were examined at several plots from the starting point (the coastal embankment) to the end point of the two populations. The result was as follows. Firstly, the water table increased along distance from the embankment at one line (N-line) but was similar at the other line (S-line) in a P. asustralis population. Water tables were higher out of than within a P. australis population at two populations. Secondary, in N-line, the height and dry weight of P. australis decreased along the distance from embankment but, in S-line, those were similar in its population. P. australis' growth was dependent on electric conductivity at lower layer (water table level) rather than upper one (the surface). Thirdly, density of P. australis changed during growing season and was similar in a population, except for the end point of patch. In summary, the growth and distribution of P. australis were dependent on salt content of tidal flat's sediment (water table level) and this was affected by fresh water of the inland.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.483-484
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• 2012

• Journal of applied mathematics & informatics
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• v.7 no.2
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• pp.629-640
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• 2000

this paper present an efficient line-drawing algorithm that reduces the amount of space required, Because of its efficiency , this line-drawing algorithm is faster than the Bresenham algorithm or the recursive bisection method. this efficiency was achieved through a new data structure; namely , the modified segment tree (MST). Using the modified segment tree and the distribution rule suggested in this paper, we dra lines without generating the recursive calls used in [3] and without creating the binary operation used in [4]. we also show that line accuracy improves in proportion to the display resolution . In practice, we can significantly improve the algorithm's performance with respect to time and space, This improvement offer an increase in speed, specially with lines at or near horizontal, diagonal. or vertical ; that is, this algorithm requires the time complexity of (n) and the space complexity O(2k+1), where n is the number of pixels and k is a level of the modified segment tree.

• Journal of Magnetics
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• v.17 no.1
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• pp.13-18
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• 2012

Starting with Kubo's formula and using the projection operator technique introduced by Kawabata, EPR lineprofile function for a $Mn^{2+}$-doped wurtzite structure GaN semiconductor was derived as a function of temperature at a frequency of 9.49 GHz (X-band) in the presence of external electromagnetic field. The line-width is barely affected in the low-temperature region because there is no correlation between the resonance fields and the distribution function. At higher temperature the line-width increases with increasing temperature due to the interaction of electrons with acoustic phonons. Thus, the present technique is considered to be more convenient to explain the resonant system as in the case of other optical transition systems.

• Journal of The Korean Astronomical Society
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• v.35 no.4
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• pp.175-185
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• 2002

Almost half of primeval galaxies show P-Cygni type profiles in the Ly$\alpha$ emission line. The main underlying mechanism for the profile formation in these systems is thought to be the frequency re-distribution of the line photons in expanding scattering media surrounding the emission source. A Monte Carlo code is developed to investigate the Ly$\alpha$ line transfer in an optically thick and moving medium with a careful consideration of the scattering in the damping wings. Typical column densities and expansion velocities of neutral hydrogen investigated in this study are $N_{H1}{\~}10^{17-20}\;cm^{-2}$ and ${\Delta}V{\~} 100 km\;s^{-1}$. We investigate the dependence of the emergent profiles on the kinematics and on the column density. Our numerical results are applied to show that the damped Ly$\alpha$ absorbers may possess an expanding H I supershell with bulk flow of ${\~}200 km\;s^{-l}$ and H I column density $N_{H1}{\~}10^{19}\;cm^{-2}$. We briefly discuss the observational implications.