• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2013.05a
• /
• pp.913-914
• /
• 2013

• Proceedings of the Optical Society of Korea Conference
• /
• 2006.02a
• /
• pp.167-168
• /
• 2006

• Proceedings of the Optical Society of Korea Conference
• /
• 2006.07a
• /
• pp.501-502
• /
• 2006

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2008.10a
• /
• pp.126-128
• /
• 2008

본 연구에서는 포도송이를 절개하지 않고 광학적인 방법으로 당도를 측정하였다. 광원으로는 $615{\sim}635nm$ 파장 대역의 LED를 사용하였다. 포도의 당도는 안토시아닌의 분포량에 의해 결정되는데 적포도의 경우 적색이 강할수록 안토시아닌이 많이 분포되어있다. 측정 결과 적색을 많이 띠는 적포도의 경우 광 강도가 낮은 것을 확인하였다. 또한 광학적인 방법으로 측정된 광 강도와 당도계로 얻어진 당도를 비교 분석하였다. 그 결과 포도송이의 당도에 따른 상대적 광 강도를 확인하였다.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.10 no.4
• /
• pp.302-308
• /
• 2000

Stable amorphous calcium carbonate were synthesized from the serial work for the synthetic conditions such as concentration of solution, reaction temperature, aging time and pH of mother liquor. By using this as a precusor, calcite, aragonite and vaterite crystal particles were obtained in the water from adequate crystallization conditions. Furthermore, characterization for flourescence were performed by using crystals which were crystallized from the Sn dopped amorphous calcium carbonate. Calcite showed the most intensive emission and the center of emission wavelength was 464 nm with pure blue color. Calcite is expected to be used as phosphor for flourescent lamp because the maximum emission intensity was obtained from the excitation with 255 nm wavelength.

• Restorative Dentistry and Endodontics
• /
• v.35 no.5
• /
• pp.368-373
• /
• 2010

Objectives: This study investigated the effect of infection control barrier thickness on power density, wavelength, and light diffusion of light curing units. Materials and Methods: Infection control barrier (Cleanwrap) in one-fold, two-fold, four-fold, and eightfold, and a halogen light curing unit (Optilux 360) and a light emitting diode (LED) light curing unit (Elipar FreeLight 2) were used in this study. Power density of light curing units with infection control barriers covering the fiberoptic bundle was measured with a hand held dental radiometer (Cure Rite). Wavelength of light curing units fixed on a custom made optical breadboard was measured with a portable spectroradiometer (CS-1000). Light diffusion of light curing units was photographed with DSLR (Nikon D70s) as above. Results: Power density decreased significantly as the layer thickness of the infection control barrier increased, except the one-fold and two-fold in halogen light curing unit. Especially, when the barrier was four-fold and more in the halogen light curing unit, the decrease of power density was more prominent. The wavelength of light curing units was not affected by the barriers and almost no change was detected in the peak wavelength. Light diffusion of LED light curing unit was not affected by barriers, however, halogen light curing unit showed decrease in light diffusion angle when the barrier was four-fold and statistically different decrease when the barrier was eight-fold (p < 0.05). Conclusions: It could be assumed that the infection control barriers should be used as two-fold rather than one-fold to prevent tearing of the barriers and subsequent cross contamination between the patients.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.38 no.12
• /
• pp.1-7
• /
• 2001

Single-layer polymer green electroluminescent devices were fabricated with novel material synthesis by using moleculely-dispersed TTA and NIDI into the polymer PC(B79) emitter layer doped with C6 fluorescent dye which has low operating voltage and high quantum efficiency. A EL cell structure of glass substrate/indium-tin-oxide/PC:TTA:NIDI:C6/Ca/Al was employed and compared with various low work function cathode electrodes Ca and Mg metals. By adjusting the concentration of the fluorescent dye C6, low turn-on voltage of 2.4V was obtained, maximum quantum efficiency of 0.52% at 0.08mole% has been improved by about a factor of ~50 times in comparison with the undoped cell. The PL and EL colors can't be turned by changing the concentration of the C6 dopant. PL emission peaking was obtained at 495nm and EL emission peaking at 520nm with FWHM ~70nm

• Applied Chemistry for Engineering
• /
• v.28 no.5
• /
• pp.571-575
• /
• 2017

In this study, cadmium telluride (CdTe) quantum dots were synthesized by using ultrasonic irradiation method. Optical properties and structural characteristics of the CdTe quantum dots were analyzed by two main variables; the ratio of the precursor and the synthesis time. As the synthesis time increased, the band gap reduction was observed with the growth of CdTe quantum dots. As for the luminescence properties, the red shift appeared at 510~610 nm wavelength range. Also, it was confirmed that the red shift occurs rapidly as the ratio of Te increases. According to PL peak intensity, the highest intensity was shown at 180 to 240 min. Structural characteristics of CdTe quantum dots were investigated through XRD and TEM, and the cubic zinc blend structure was observed. The size of quantum dots was about 2.5 nm and uniformly dispersed when the synthesis time took 210 min. In addition, the apparent crystallinity was discovered in FFT image.

• Applied Biological Chemistry
• /
• v.29 no.2
• /
• pp.159-163
• /
• 1986

The optical properties of monocationic zeolite suspension adsorbed with each of $Na^+$, $NH_4^+$, $Ca^{2+}$, and $Al^{3+}$ were studied in the wavelength range $200{\sim}800nm$. The results were as follows. 1. The optical density of zeolite suspension seemed to be affected by the light absorption of zeolite particles at the wavelength range of $200{\sim}300nm$ and by the light scattering of zeolite particles at wavelength of $300{\sim}800nm$. 2. At the wavelength range of $380{\sim}800nm$, the optical densities of monocationic zeoliteg differed mutually according to adsorbed cations and increased in the order of $Al-\;>\;Ca-\;>\;NH_4->\;Na-zeolite$ suspension. 3. It was convenient that at the wavelength range of $380{\sim}800nm$, the diluted suspension of zeolite was measured in the short wavelength and the concentrated suspension of zeolite was measured in the long wavelength. 4. Zeolite particles in zeolite suspension were aggregated and the size of aggregation size was larger in the order of $Al-\;>\;Ca-\;>\;Na-\;>\;NH_4-zeolite$.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39C no.4
• /
• pp.370-379
• /
• 2014

Recently, the interest in optical network with multifiber link is continuing to rise since the network traffic has been growing exponentially. However, growing traffic in network leads to increasing the energy consumption of the network equipment. In this paper, we propose a dynamic routing and wavelength assignment (RWA) algorithm based on V-like cost function and layered graph to improve energy efficiency in IP over WDM network with multifiber link. The V-like cost function is used to decide the fiber cost according to the number of used wavelengths. The layered graph with multifiber link is used to select the energy efficient route and wavelength. The proposed RWA algorithm is compared and analyzed with conventional algorithm in view of average power consumption and blocking probability through OPNET modeler.