• Journal of the Korean Crystal Growth and Crystal Technology
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• v.19 no.3
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• pp.130-134
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• 2009

A new long persistent phosphors of $CaZrO_3$ was synthesized at high temperature with weak reduction atmosphere by a traditional solid state reaction method. Photoluminescence spectra analysis showed that the $CaZrO_3$ doped with $Tb^{3+}$ emitted green-yellow emission caused by the energy level transition from the $^5D_3$ and $^5D_4$ to $^7F_1{\sim}^7F_6$. The main emission spectra of 542 nm peak by the $^5D_4{\rightarrow}^7F_5$ transition was revealed through synthesizing at high temperature in $N_2$ gas atmosphere. The afterglow emission spectra of $CaZrO_3:Tb^{3+}$ long persistent phosphores arise at 546 nm peak of narrow range. After the 254 nm ultraviolet light excitation source was switched off, the green-yellow long persistent phosphor can be observed which could last for 8 h in the limit of light perception of dark-adapted human eyes ($0.32\;mcd/m^2$).

• Journal of Korean Society of Forest Science
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• v.73 no.1
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• pp.9-13
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• 1986

Karyotypes are described for Juniperus rigida Sieb. et zucc, in two provenances of Gyeong-nam and Choong-puk. Chromosome numbers of two provenances, are 2n=22. The most common feature of mitotic chromosomes was shown at the chromosome 7, which has secondary constriction on the short arm. And the most differential chromosome was shown at chromosome 9 from Gyeong-nam and chromosome 5 from Choong-puk provenance which bore secondary constriction. The karyotype formulae are as follows; Gyeong-nam, Jinyang provenance race is $$K(2n)=22=2A^m+2B^m+2C^m+2D^{sm}+2E^{st}+2F^m+2^{sc}G^m+2H^m+2^{sc}I^t+2J^{st}+2K^m$$ Choong-puk, Jechun provenance race is $$K(2n)=22=2A^m+2B^m+2C^m+2D^{st}+2^{sc}E^{sm}+2F^m+2^{sc}G^m+2H^m+2I^m+2J^{st}+2K^{sm}$$.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1285-1286
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• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.551-552
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• 2007

• Corrosion Science and Technology
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• v.16 no.1
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• pp.48-48
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• 2017

• 대한핵의학회:학술대회논문집
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• 1989.06a
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• pp.141.1-141.1
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• 1989

• Bulletin of the Korean Mathematical Society
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• v.36 no.1
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• pp.25-31
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• 1999

Let $\nu$ be a positive Borel measure on a space of homogeneous type (X, d, $\mu$), satisfying the doubling property. A condition on a weight $\omega$ for whixh a maximal operator $M\nu f$(x) defined by M$mu$f(x)=supr>0{{{{ { 1} over {ν(B(x,r)) } INT _{ B(x,r)} │f(y)│d mu (y)}}}}, is of weak type (p,p) with respect to (ν, $omega$), is that there exists a constant C such that C $omega$(y) for a.e. y$\in$B(x, r) if p=1, and {{{{( { 1} over { upsilon (B(x,r) } INT _{ B(x,r)}omega(y) ^ (-1/p-1) d mu (y))^(p-1)}}}} C, if 1$infty$.

• The Journal of the Korean dental association
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• v.17 no.2 s.117
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• pp.141-145
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• 1979

The author, through oral examination, had surveyed the caries experienced teeth in 250 Korean mental Disorders(153 males and 97 fameles) who took it a rule consume a Vegetable diet and had litte chance to Consume refimed Corbohydrates, unlike the Common populars. DMF rate DMFT rate index DT rate MT rate and FT rate had been calculated and Compared with Common Popular's in same ages group. Following are the obtained results 1. In the mental Disorders, Caries experience rate was 52.19% 2. D.M.F. rate and index were lower in the females than in the males 3. The Caries experience rate in the mental Disorders was lower than in the Common Populars 4. In the mental Disorders the F.T. rate was higher in females than in males D.T. rate higher in males than in females and MT rate, lower in males than in females 5. In generally D.T. rate in the mental Disorders was lower than in Controls, M.T. rate resembled as Controls and F.T. rate higher

• Textile Coloration and Finishing
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• v.31 no.4
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• pp.332-340
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• 2019

Due to the change in lifestyle, new sensible materials for sportswear and outdoor are needed. This study is conducted in order to obtain the data for sensible materials through nylon twist process. 1-step nylon twisting machine was used to set the optimum twist process. DSC measurements of twisted nylon yarn showed crystallization temperatures around 170℃ and melting temperatures around 220℃. Nylon 40D/13F DTY and Nylon 50D/48F DTY showed optimal results at 160℃, 1,500 T/M(Turns per meter), and Nylon 70D/68F DTY at 160℃, 1,200 T/M(Turns per meter) after 1-step twist process. Also, Nylon 40D/13F DTY was confirmed to have inter-layer property deviation of ±5 percent.

• Journal of Korean Society on Water Environment
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• v.21 no.5
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• pp.500-504
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• 2005

Water samples were collected at 7 sites located along the River Nakdong on 30 occasions. Water qualities, size and fractal dimension ($d_F$) of suspended particles were measured. Laser light scattering method was used to obtain the size and $d_F$ of suspended particles. The average size of particles in this river ranged from $89{\mu}m$ and $169{\mu}m$, which appears to be relatively coarse compared with other rivers worldwide. The average $d_F$ of suspended particles in this study ranged from 1.8 to 1.9. The correlation analysis showed that DO, TN, $NO_3$ and chlorophyll-${\alpha}$ had significant positive relationships with particles size, whereas flow rates and TSS had negative relationships. Interestingly, the factors of which had positive relationships with particles size showed negative relationship with the fractal dimension ($d_F$) of suspended particles. Generally, as the size of particles increased, the fractal dimension of particles decreased which was indicating the shape of the larger particles became more irregular.