• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.2
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• pp.68-71
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• 2008

AlN crystals were grown by the sublimation process. As grown AlN crystals were the polycrystalline boule in the form of the agglomerate of small AlN single crystalline AlN. As-grown AlN boule has a length about 2${\sim}$3 mm long and a diameter of 1 inch. The carbon impurities were observed on the surface and inside of the grown AlN crystals and the growth behavior was investigated by optical microscopy and SEM observation.

• 대한생식의학회:학술대회논문집
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• 2007.11a
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• pp.133-134
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• 2007

• Journal of Korean Neurosurgical Society
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• v.66 no.4
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• pp.409-417
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• 2023

Objective : The association between boule (BOLL) and endothelin receptor type A (EDNRA) loci and intracranial aneurysm (IA) formation has been reported via genome-wide association studies. We sought to identify genome-wide interactions involving BOLL and EDNRA loci for IA in a Korean adult cohort. Methods : Genome-wide pairwise interaction analyses of BOLL and EDNRA involving 250 patients with IA and 296 controls were performed using the additive effect model after adjusting for confounding factors. Results : Among 512575 single-nucleotide polymorphisms (SNPs), 23 and 11 common SNPs suggested a genome-wide interaction threshold (p<1.25×10^-8) involving rs700651 (BOLL) and rs6841581 (EDNRA). Rather than singe SNP effect of BOLL or EDNRA on IA development, they showed a synergistic effect on IA formation via multifactorial pair-wise interactions. The rs1105980 of PTCH1 gene showed the most significant interaction with rs700651 (natural log-transformed odds ratio [lnOR], 1.53; p=6.41×10^-11). The rs74585958 of RYK gene interacted strongly with rs6841581 (lnOR, -19.91; p=1.64×10^-9). Although, there was no direct interaction between BOLL and EDNRA variants, two EDNRA-interacting gene variants of TNIK (rs11925024 and rs1231) and FTO (rs9302654), and one BOLL-interacting METTL4 gene variant (rs549315) exhibited marginal interaction with BOLL gene. Conclusion : BOLL or EDNRA may have a synergistic effect on IA formation via multifactorial pair-wise interactions.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.258-262
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• 2004

This study has been focused on the development of automatic bottle air rinser. It is designed to rinse clean empty bottles prior to filling. The bottles are automatically indexed beneath an air nozzle that has both a clean airjet and vacuum source. The bottle is first given a burst of clean air to loosen any particles from the wall of the bottle. A vacuum sequence follows which removes all particulates into a self contained filter unit. In order to the provide the desired function, analysis is carried out by FEM simulation using FLUENT and CATIA software. The final results of analysis are applied to the design of automatic bottle rinser and the machine is successfully developed.

• Proceedings of the Optical Society of Korea Conference
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• 1997.08a
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• pp.85-85
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• 1997

Czochralski 방법에 의해 육성된 Nd:YAG 단결정으로부터 CW mode의 1064nm laser를 발진시켰다. 육성된 단결정은 직경 50mm, 길이 120mm 이었으며, Nd 이온 농도는 O.2~0.9at% 이었다. 육성된 단결정 boule로 부터 결정학적 결함부위인 core 및 facet가 없는 양질의 단결정 부위를 Twyman-Green interferometer로 선빌하였다. 추출핀 부위는 절단, 가공, 연마공정 및 코팅 공정을 통해 직경 6.35mm, 길이 lOOmm의 laser rod를 제작하였다. 절단은 core drill, 또는 원통 연삭기를 사용하여 rod 형태로 가공하였으며, 상$\cdot$하면 polishing은 평행도 10", 직각도 5', 평활도 $\lambda$/10 수준까지 실험실에서 자체 가공하여 일반적인 laser 발진용 rod의 spec.을 만족시킬 수 있었다.

• Korean Journal of Optics and Photonics
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• v.9 no.3
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• pp.175-180
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• 1998

Nd:YAG single crystal widely used as solid state laser was grown by Czochralski method. <111> single crystal with 0.9at% of $Nd^{3+}$ was grown from the Czochralski furnace with a automatic diameter control system. The vertical temperature gradient in the liquid was the major factor that influence the crystal quality, and the crystal diameter was controlled by the home made computer program. The crystal boule with $\phi$50mm$\times$ι100mm effective size was cut, polished, and antireflection coated. The optical evaluation such as absorption spectrum, fluorescence spectrum coincide with typical features of Nd:YAG single crystal. The laser rod was assembled into the CW laser generator with a Kr lamp. The maximum CW laser output was 70 W and the threshold power and efficiency was 1.3kW and 1.64% respectively.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1996.06b
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• pp.239-257
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• 1996

$\beta$-BaB2O4는 고출력 가시광선 및 적외선을 발진시키는데 유용한, 비선형 특성을 가진 물질이다. $\alpha$-$\beta$ 상전이 온도가 녹는점보다 18$0^{\circ}C$ 낮기 때문에 보통 flux법으로 단결정을 성장시킨다. 수년전 Itoh등은 $\beta$-BaB2O4단결정을 congruent조성의 용액으로부터 Czochralski법으로 metastable한 상태에서 직접 성장시켰다. 그렇지만 그 공정은 잘 이해되지 않고 있으며 재현하기가 매우 어렵다. 저자들은 $\beta$-BaB2O4단결정을 용액표면온도도 1034$^{\circ}$-1085$^{\circ}C$, pulling rate 3mm/h, 10-30 rpm의 범위에서 성장시켰으며 융액표면의 온도구배는 $\beta$-상으로 성장시키는데 매우 중요한 인자로 여겨진다. Seed로는 직경 1-2mm의 c축방향 $\beta$-BaB2O4단결정 봉이 상용되어 성장방향을 조절하고 열응력을 최소화시켰다. 성장된 $\beta$-상의 단결정들은 6-fold모양을 하며 표면에 작은 비늘같은 것들이 붙어있고 중심부에 core가 있는 것을 알았다. Flux법으로 성장시킨 $\beta$-BaB2O4단결정을 사용한 seeds는 단결정 성장 및 냉각 중에 cracks이 자주 발생하였으며, boule의 cracks은 afterheater를 사용할 경우 다소 줄일 수 있었다. 성장된 단결정의 광학특성이 측정되었다.

• Food Science and Preservation
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• v.5 no.2
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• pp.167-171
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• 1998

Bulkogi(roast beef) seasoning stored without cap at 5$^{\circ}C$ and 23$^{\circ}C$ and within capped boule at 5$^{\circ}C$, 23$^{\circ}C$, 38$^{\circ}C$, 48$^{\circ}C$ and heat cycling(38$^{\circ}C$-1 week and 5$^{\circ}C$-1 week) and investigated sensory quality, pH, VBN, amino-N, surface color, and viable cell counts during 6 month storage. Nonpackaged Bulkogi seasoning was deteriorated by molds after 2 weeks at 23$^{\circ}C$ but did not showed any significant quality changes at 5$^{\circ}C$ for 1 month. Sensory scores of packaged sample rapidly declined with the temperature increase but chemical criteria was not significantly changed depending on temperature and storage time. Correlations between sensory scores and chemical parameters was not found, but sensory scores on color was correlated with lightness(L. value) of surface color(r=0.899). Heat cycle storage resulted in similar changes in quality to 38$^{\circ}C$ storage. Ql0 values calculated by sensory evaluation results as a quality index was 6, and the shelf-life of packaged Bulkogi seasoning was predicted 88 months at 23$^{\circ}C$.

• Journal of Biomedical Engineering Research
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• v.17 no.4
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• pp.499-506
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• 1996

Blood flow velocimeter is an essential device to measure the blood flow in skin tissue. In this study, we developed a high-speed LDV(laser Doppler Velocimeter) that has real time processing capability using a DSP(digital signal processing) chip and is able to continuously measure information about blood-flow based on a noninvasive method using self-mixing type laser diode. This LDV system has a simpler structure than any other typical blood flow velocimeter and is composed of new self-mixing probe, stabilizer circuits DSP board, and interf'ace boule We measured velocity of speaker-unit by operational frequencies to identify Doppler effect of this system, performed clinical experiment on bare finger tip and compared it with a commercial euipment BPM403A(USA).

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.4 no.1
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• pp.76-82
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• 1994

Single crystals of Potassium Titanyl Phosphate (KTP) were grown from the flux of $K_6P_4O_13(K_6)$ using a high temperatures solution growth method. To grow the large KTP crystal without inclusion, the temperature gradient in furnace, crystal rotation, orientation of seed crystal, and the cooling rate were controled. The KTP crystals are up to $10(a){\times}28(b){\times}33(c)mm^3$ in size. We investigated the optical inhomogeneity in this KTP crystal by the SHG power measurement and TEM analysis.