• Journal of the Korean Crystal Growth and Crystal Technology
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• v.12 no.6
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• pp.317-322
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• 2002

We have studied the sawing sach as the round brilliant cut, cushion barion cut and marquise cut. Through this study, we could examined the rate of waste from the grinding work, and find a solution for many problems which could be derived from the grinding work. We could reduce the rate of waste by this study about sawing technique; 2.5 % for round brilliant cut, 2.5 % for cushion barion cut and 5.5 % for marquise cut.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.23 no.4
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• pp.173-179
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• 2013

Even though a rough diamond shape is irregular and rugged, it is easy to be processed to make gem, shaped facets (table, crown, pavilion and girdle) were precisely treated because they influence on the evaluation of diamond grading. Those specifications suitable for the standard round brilliant cut diamond polishing were investigated and in 95 % statistical confidence interval, standard deviation, mean and acceptable tolerance were examined. According to these variables (size, angle, depth, and thickness) distribution, the frequency analysis of ratings and proportions were compared with each other. The correlation between each variables and the evidence of influence represented in proportion were determined by the regression analysis applying LSM (Least Square Method). In this research, it was recognized that table sizes of the diamond jewels and pavilion depth (in %) influence the rating decision and in particular, the depth of pavilion acting as the main factor of proportions, also plays an important role in optical phenomena.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.1
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• pp.82-91
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• 2009

Research was initiated to investigate vegetation characteristics of native ('Pureundle' and 'Sewon') and introduced ('Brilliant' and 'Midnight') Kentucky bluegrass (KB, Poa pratensis L.) varieties by soil-seed applying system on a cut-slope in May 17, 2008. There were no statistic differences observed in soil hardness and soil moisture content while significant differences were observed in surface coverage rate, height and disease occurrence in native and introduced KB varieties. The introduced 'Brilliant' KB was highest in the surface coverage rate from the early period of seeding to August 11, 2008. The surface coverage rate of introduced varieties were high when compared to native varieties in their early growth stage. But native varieties reached to equal surface coverage rate with the introduced varieties when three months after seeding. The height of 'Pureundle' and 'Brilliant' KBs were high compared with Midnight and Sewon KBs. 'Pureundle' and 'Brilliant' KBs were damaged by disease whereas there were no disease occurrence in 'Midnight' and 'Sewon' KBs. Probably, the disease occurrence was close related with the height of KBs not with native and introduced KB varieties. These results indicate that the growth of KB on a cut-slope are statistically affected by varieties in early growth stage of this experiment but reach equal rate between native and introduced KB varieties in three months after seeding. This growth characteristics implies the huge potential of native KB varieties seeding for cut-slope vegetation. Considering that native KB varieties are adapted to a environment and have no risk of causing disturbance to the ecosystem compared to the introduced KB varieties, the use of them as native varieties for a cut-slope vegetation can be increased.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.1
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• pp.127-132
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• 2006

The present study deals with polishing machining of diamond for jewelry using developed automatic polishing machine that can cut diamond to have 58 facets in a brilliant cutting which has been hardly achieved by a conventional manually operating polishing machine. Upon the 3-dimensional Sarin M/C test and analysis on the machined diamond by the developed automatic polishing machine its proportion and finishing turned out to be better than the machined diamond by the conventional manually operating polishing machine.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.313-318
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• 2005

The present study deals design and manufacture of automatic polishing machine that can cut diamond to have 58 facets in a brilliant cutting which has been hardly achieved by a conventional manually operating polishing machine. Upon the 3-dimensional Sarin M/C test and analysis on the diamond processed by the automatic polishing machine developed in this study its proportion and finishing turned out to be better than the diamond processed by the conventional method, by being rated as 'very good'.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.13 no.5
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• pp.205-210
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• 2003

Alexandrite-like cubic zirconia single crystals were grown by skull melting method. The R.F. generator (output power is 35 ㎾) used for skull melting was operated at 2 MHz. The grown crystals were doped with up to 1 or 1.5 wt% and 0.5 or 1 wt% of rare earth metal ion (Pr, Nd) on$ ZrO_2-Y_2O_3$ (12 mol%). The grown crystals were cut for slice (0.25 mm) and round brilliant (12 mm in diameter). The cut stones were heat treated in air and nitrogen at $1000^{\circ}C$ for 2 hours and their optical absorption spectra ($\lambda$ = 400∼700 nm) data were obtained.

• Korean Journal of Breeding Science
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• v.40 no.4
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• pp.499-502
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• 2008

A new gerbera variety 'Yellow Wing' was released by the National Horticultural Research Institute (NHRI) in 2007. A cross was made between 'Gold Finger' with yellow and single and 'Yellow Springs' with yellow and spider in 2004. After investigation of the characteristics for 4 years (from 2004 to 2007), it was selected specially for the use of cut-flower. 'Yellow Wing' is a vigorous cultivar with yellow (RHS YO14B), green center and spider type. The flower diameter is 10.6cm. And inner ray floret and disc diameter is 2.83cm and 2.03cm, respectively. It produces a large yield with continuous supply of flowers and has adequate peduncle height and brilliant color. We believe that 'Yellow Wing' has a great potential for expanding cultivated area of domestic gerbera cultivar and increasing farmers-income.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.17 no.1
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• pp.35-40
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• 2007

Cobalt ($Co^{2+}$) doped yttria stabilized cubic zirconia (YSZ, $Y_2O_3\;:\;25{\sim}50wt%$) single crystals grown by a skull melting method were heat-treated in $N_2\;at\;1000^{\circ}C$ for 5 hrs. The reddish brown single crystals were changed into either violet or blue color, respectively. Before and after heat treatment, the Co-doped YSZ crystals cut for wafers (${\phi}6.5{\times}t\;2mm$) and round brilliant (${\phi}10mm$). The optical and structural properties were examined by UV-VIS spectrophotometer and XRD. These results are analyzed absorption by $Co^{2+}\;(^4A_2(^4F)\to{^4P})\;and\;Co^{3+}$, change of energy gap and lattice parameter.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.21 no.3
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• pp.105-109
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• 2011

Critical angle of quartz (R.I. ${\fallingdotseq}$ 1.553) and diamond (R.I. = 2.417) are $40.09^{\circ}$ and $24.26^{\circ}$ that calculated by $sin{\theta}=r_2/r_1$ (r = refractive index, $r_1$ > $r_2$). Brilliance of quartz and diamond are 20.33% and 55.07%. The brilliance data are result of study on the incident light internal round brilliant cut quartz and diamond by the critical angle. Cause of bow-tie phenomenon can be studied by application of critical angle theory and light path inside fancy shape brilliant cut. When refractormetry with typical gem refractometer, critical angle of quartz and corundum are $59.1^{\circ}$ and $77.9^{\circ}$.

• Korean Journal of Breeding Science
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• v.43 no.3
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• pp.206-209
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• 2011

A new gerbera cultivar 'Noble Pink' was released by the National Institute of Horticultural & Herbal Science (NIHHS) in 2009. A cross was made between 'Himalaya' with white and semi-double and 'Vital' with pastel cream and single in 2006. After investigation of the characteristics for four years (from 2006 to 2009), it was selected specially for the use of cut flower. 'Noble Pink' is a vigorous cultivar with pastel pink flower color (RHS R48B), brilliant green disc floret and semi-double. The average flower diameter is 11.8 cm, large flower. And inner ray floret and disc diameter are 4.77 cm and 2.17 cm, respectively. It produces a large yield with continuous supply of cut flowers and has adequate peduncle height. We believe that 'Noble Pink' has a great potential for expanding cultivated area of domestic gerbera cultivars and increasing farmers-income.