• Title/Summary/Keyword: TM4

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A study on the fabrication of the polarization-insensitive semiconductor optical amplifier (저 편광의존성을 가지는 반도체 광증폭기의 제작에 관한 연구)

  • 황상구;김정호;김운섭;김동욱;박윤호;홍창의
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.4 no.5
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    • pp.1135-1142
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    • 2000
  • In this study, we fabricated a 1.55um polarization-insensitive semiconductor optical amplifier(SOA) with rectangular buried heterostructure using a InGaAsP/InP double heterostructure wafer. Measured characteristics of the fabricated SOA are that 3dR bandwidth is 35nm and 3dB saturation output power is 4dBm. Maximum gain under the 150mA CW driving condition is 19.4dB. We measured the ASE(amplified spontanouse emission) Power spectrum or n and TM mode in the fabricated SOA using ASE measurement system and knew that distributions of the TE and TM mode about the maxinum region are nearly coincident. this shows the fabricated SOA is a polarization-insensitive.

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Photoluminescence properties of $Gd_{1-x}Ln_xCa_3(GaO)_3(BO_3)_4$ (Ln=Eu, Tb, Tm) under UV excitation

  • Kyung, Hyun-Ai;Jung, Ha-Kyun;Seong, Tae-Yeon
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08b
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    • pp.1565-1568
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    • 2007
  • A borate compound was adopted as new host material for $Eu^{3+}$, $Tb^{3+}$ and $Tm^{3+}$ activators. The phosphor samples, $Gd_{1-x}Eu_xCa_3(GaO)_3(BO_3)_4$, $Gd_{1-x}Tb_xCa_3(GaO)_3(BO3)_4$ and $Gd_{1-x}Tm_xCa_3(GaO)_3(BO_3)_4$ have been synthesized by conventional solid-state reaction. The crystalline phase for the resulting powders was identified using an X-ray diffraction $system^1$. Their photoluminescence properties under the excitation of UV ray were investigated. The Eu, Tb or Tm-doped $GdCa_3(GaO)_3(BO_3)_4$ emits efficient red, green or blue light, respectively. It was observed that the optimum concentration of Eu or Tb activator for the borate host was much higher than other $Eu^{3+}$ or $Tb^{3+}-doped$ phosphors.

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The Compensation of the Energy Dependence of TLD (열형광선량계(熱螢光線量計)의 에너지의존성(依存性) 보상(補償))

  • Park, Myeong-Hwan;Lee, Joon-Il;Kwon, Duk-Moon
    • Journal of radiological science and technology
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    • v.16 no.2
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    • pp.51-60
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    • 1993
  • The $CaSO_4$ : Tm-PTFE TLDs have been prepared and their energy dependences of TL intensity to X-rays have been investigated. The dose dependence of the prepared $CaSO_4$ : Tm-PTFE TLDs is linear within the range of $100{\mu}Gy-10Gy$ for X-rays and gamma rays. The spectral peaks of TL emission spectrum are at about 350nm and 475nm. The fading rate of the main peak has been found to be about 2% for 30days when $CaSO_4$ : Tm-PTFE TLDs stored in the dark room at room temperature. The energy dependence of $CaSO_4$ : Tm-PTFE TLD has been compensated by combining the TL responses of one bare TLD and five TLDs filtered with 1.0mm Al, 0.2mm Cu, 0.5mm Cu, 1.5mm Cu, 2.0mm Pb respectively. The determined correction coefficients for filter combination are $a_0=0.078,\;a_1=-0.009,\;a_2=-0.235,\;a_3=0.588,\;a_4=0.568\;and\;a_5=0.180$ respectively. From the results of these studies, the prepared TLD badge of six dosimeter combination may be useful as a radiation dosimeter for personal and environmental monitoring.

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COMPARISON OF COMPRESSIVE STRENGTH AND SURFACE MICROHARDNESS BETWEEN FLOWABLE COMPOSITE RESIN AND GIOMER (유동성 자이오머와 복합 레진의 압축 강도 및 표면 미세 경도 비교)

  • Kim, Jong-Soo
    • Journal of the korean academy of Pediatric Dentistry
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    • v.39 no.4
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    • pp.383-388
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    • 2012
  • The aim of this study was to compare the compressive strength and the surface microhardness of Beautifil flow (Shofu, Kyoto, Japan) with $Filtek^{TM}$ Z350, Z350XT (3M ESPE, USA). Fifteen specimens from each material were fabricated for testing. Compressive strength was measured by using a universal testing machine at a crosshead speed of 1 mm/min. Surface microhardness values were measured by using Vickers hardness tester under 4.9 N load and 10 seconds dwelling time. The compressive strength of Group 2 $Filtek^{TM}$ Z350XT shows the highest value as $218.7{\pm}18.4$ MPa and Group 1 $Filtek^{TM}$ Z350 was $205.5{\pm}27.1$ MPa. Group 3 Beautifil flow F00 was $176.5{\pm}30.3$ MPa, and Group 4 Beautifil flow F10 was $173.4{\pm}26.2$ MPa. The compressive strength of Group 2 is higher than Group 3 and 4 (p < 0.05). The surface microhardness of Group 2 $Filtek^{TM}$ Z350XT shows the highest value as $39.1{\pm}2.1$ and Group 4 Beautifil flow F10 was $27.9{\pm}1.8$. And Group 3 Beautifil flow F00 was $23.1{\pm}1.1$, Group 1 $Filtek^{TM}$ Z350 was $20.4{\pm}0.9$. There was a statistical significant difference in surface microhardness between all groups (p < 0.05). In conclusion, the compressive strength of giomer was below the level of flowable composite resin. However, the surface microhardness of giomer is comparable to that of flowable composite resin. Giomer would be the good alternative to composite resin, if there is improvement of the compressive strength of giomer.

Study on Cell Growth Characteristics with Culture Medium Components by Using MABOOMSTM (마이크로플레이트 기반 생물반응기 시스템(MABOOMSTM)을 이용한 발효배지 성분의 미생물 성장 특성 연구)

  • Sohn, Ok-Jae;Rhee, Jong Il
    • KSBB Journal
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    • v.28 no.1
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    • pp.31-35
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    • 2013
  • In this work a $MABOOMS^{TM}$ has been employed to cultivate microorganisms and investigated the effects of culture medium components on cell growth. A 24-well microplate coated with 4-divided fluorescent sensing membranes was used to monitor the dissolved oxygen, pH and cell concentration during cultivations. Fluorescence intensity for dissolved oxygen or solution pH and reflectance for cell concentration was online monitored by using the $MABOOMS^{TM}$. The online monitoring results showed the effects of culture medium components on cell growth in cultivation processes very well.

퇴적물의 분류를 위한 Landsat TM자료와 Hyperspectral reflectance 자료 적용

  • 유영철;송무영;안충현
    • Proceedings of the KSRS Conference
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    • 2000.04a
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    • pp.178-182
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    • 2000
  • 본 연구의 목적은 실험실에서 퇴적물의 다분광반사 특성과 물성을 측정하고 이를 위성 영상에 적용하여 영상에서 나타나는 퇴적물의 분광차이의 원인을 해석하고, 위성영상에서의 퇴적물의 분류 가능성을 연구하는데 있다. 연구에서는 Landsat TM위성 영상과 350~2500nm 파장대역에 대한 퇴적물 시료의 분광측정 자료를 사용하였으며, 기존의 조사 자료를 토대로 TM 영상에서 퇴적물을 분류한 후, 현장에서 시료를 채취하여 입도 분류를 실시하였다. 퇴적물의 입도와 함수비에 따른 분광특성변화를 검증하였으며, 입도와 함수비에 대한 회귀식을 구하여 이를 영상에 적용 분류하였다. 분석 결과 다분광자료 측정시 퇴적물입도에 따른 분광차이는 미약하였으며 이를 TM 자료로 재구성하였을 때는 분광특성을 구분할 수 없었다. 퇴적물의 분류는 TM Band 4, 5, 7을 이용한 회귀식을 적용할 때 비교적 정확하게 나타났으나, 영상에서 퇴적물의 분광 차이는 입도 크기가 직접적인 요인이 아니라 입도에 의한 함수비 및 유기물 함량의 차이에 기인한 것으로 해석된다.

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THE EFFECT OF IRRADIATION MODES ON POLYMERIZATION AND MICROLEAKAGE OF COMPOSITE RESIN (광조사 방식이 복합레진의 중합과 누출에 미치는 영향)

  • Park, Jong-Jin;Park, Jeong-Won;Park, Sung-Ho;Park, Ju-Myong;Kwon, Tae-Kyung;Kim, Sung-Kyo
    • Restorative Dentistry and Endodontics
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    • v.27 no.2
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    • pp.158-174
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    • 2002
  • The aim of this study was to investigate the effect of light irradiation modes on polymerization shrinkage, degree of cure and microleakage of a composite resin. VIP$^{TM}$ (Bisco Dental Products, Schaumburg, IL, USA) and Optilux 501$^{TM}$ (Demetron/Kerr, Danbury, CT, USA) were used for curing Filtek$^{TM}$ Z-250 (3M Dental Products, St. Paul., MN, USA) composite resin using following irradiation modes: VIP$^{TM}$ (Bisco) 200mW/$\textrm{cm}^2$ (V2), 400mW/$\textrm{cm}^2$ (V4), 600mW/$\textrm{cm}^2$ (V6), Pulse-delay (200 mW/$\textrm{cm}^2$ 3 seconds, 5 minutes wait, 600mW/$\textrm{cm}^2$ 30seconds, VPD) and Optilux 501$^{TM}$ (Demetron/Kerr) C-mode (OC), R-mode (OR). Linear polymerization shrinkage of the composite specimens were measured using Linometer (R&B, Daejeon, Korea) for 90 seconds for V2, V4, V6, OC, OR groups and for up to 363 seconds for VPD group (n=10, each). Degree of conversion was measured using FTIR spectrometer (IFS 120 HR, Bruker Karlsruhe, Germany) at the bottom surface of 2 mm thick composite specimens V2, Y4, V6, OC groups were measured separately at five irradiation times (5, 10, 20, 40, 60 seconds) and OR, VPD groups were measured in the above mentioned irradiation modes (n=5 each). Microhardness was measured using Digital microhardness tester (FM7, Future-Tech Co., Tokyo, Japan) at the top and bottom surfaces of 2mm thick composite specimens after exposure to the same irradiation modes as the test of degree of conversion(n=3, each). For the microleakage test, class V cavities were prepared on the distal surface of the ninety extracted human third molars. The cavities were restored with one of the following irradiation modes : V2/60 seconds, V4/40 seconds, V6/30 seconds, VPD , OC and OR. Microleakage was assessed by dye penetration along enamel and dentin margins of cavities. Mean polymerization shrinkage, mean degree of conversion and mean microhardness values for all groups at each time were analyzed using one-way ANOVA and Duncan's multiple range test, and using chi-square test far microleakage values. The results were as follows : . Polymerization shrinkage was increased with higher light intensity in groups using VIP$^{TM}$ (Bisco) : the highest with 600mW/$\textrm{cm}^2$, followed by Pulse-delay, 400mW/$\textrm{cm}^2$ and 200mW/$\textrm{cm}^2$ groups, The degree of polymerization shrinkage was higher with Continuous mode than with Ramp mode in groups using Optilux 501$^{TM}$ (Demetron/Kerr). . Degree of conversion and microhardness values were higher with higher light intensity. The final degree of conversion was in the range of 44.7 to 54.98% and the final microhardness value in the range of 34.10 to 56.30. . Microleakage was greater in dentin margin than in enamel margin. Higher light intensity showed more microleakage in dentin margin in groups using VIP$^{TM}$ (Bisco). The microleakage was the lowest with Continuous mode in enamel margin and with Ramp mode in dentin margin when Optilux 501$^{TM}$ (Demetron/Kerr) was used.

Studies on the Comparative Analysis Between GE Prodigy and $FRAX^{TM}$ Tool in Absolute Fracture Risk Assessment Tool (골절의 절대위험도 평가방법에서 GE Prodigy와 FRAX Tool의 비교분석에 관한 고찰)

  • Lee, Hwa-Jin;Lee, Hyo-Yeong;Yun, Jong-Jun;Lee, Mu-Seok;Song, Hyeon-Seok;Park, Se-Yun;Jeong, Ji-Uk
    • The Korean Journal of Nuclear Medicine Technology
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    • v.13 no.3
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    • pp.137-142
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    • 2009
  • Purpose: World Health Organization (WHO) have suggested that an individual's 10-year absolute fracture risk is more reliable than Bone Mineral Density (BMD) measurement as the predictor of osteoporotic fracture. In 2008, Fracture Risk Assessment Tool ($FRAX^{TM}$) was developed by WHO to evaluate fracture risk of patients based on individual's clinical risk factors. The purpose of this study is to offer the comparative analysis of the existing GE prodigy and $FRAX^{TM}$ Tool in Absolute Fracture Risk Assessment Tool. Materials and Methods: 201 women ($55{\pm}3.5$ years) underwent femoral neck BMD measurement using GE Prodigy. The 10-year probability (%) of hip fracture (or a major osteoporosis-related fracture) was estimated using T-scores of GE prodigy and $FRAX^{TM}$. We made a comparative analysis of these data using SPSS (Ver.12). Results: There was a significant difference statistically between T-score ($-0.52{\pm}0.97$) of GE prodigy and T-score ($-1.45{\pm}0.81$) of $FRAX^{TM}$ (r=0.977, p=0.000). Also, there was a significant difference statistically between a major osteoporosis- related fracture ($9.15{\pm}3.71$) of GE prodigy and a major osteoporosis-related fracture ($4.87{\pm}1.51$) of $FRAX^{TM}$ (r=0.909, p=0.000). Moreover, a statistically significant difference was found in the 10-year probability of hip fracture of GE prodigy ($1.56{\pm}1.48$) and of hip fracture ($0.53{\pm}0.61$) of $FRAX^{TM}$ (r=0.905, p=0.000). Conclusions: There was a significant difference statistically between GE prodigy and $FRAX^{TM}$ Tool in Absolute Fracture Risk Assessment Tool. Especially, T-score, a major osteoporosis-related fracture and the 10-year probability of hip fracture that were estimated using GE prodigy tended to show the higher results than one evaluated by $FRAX^{TM}$ Tool. In conclusion, $FRAX^{TM}$ Tool may provide a better tool. The application of $FRAX^{TM}$ Tool as a fracture predictor remains to be clarified.

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