• Title/Summary/Keyword: PL characteristics

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PL characteristics of silicon-nanocrystals as a function of temperature (온도에 따른 실리콘 나노결정 PL 특성)

  • Kim, Kwang-Hee;Kim, Kwang-Il;Kwon, Young-Kyu;Lee, Yong-Hyun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.08a
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    • pp.93-93
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    • 2003
  • Photoluminescence(PL) properties of Silicon nanocrystals (nc-Si) as a function of temperature is reported to consider the mechanism of PL. Nc-Si has been made by $Si^+$ ion-implantation into thermal $SiO_2$ and subsequent annealing. And after gold had been diffused at the same samples above, the resultant PL spectra has been compared to the PL spectra from the non-gold doped nc-Si. PL peak energy variation from nc-Si is same with the variation of energy bandgap of bulk silicon as temperature changes from 6 K to room temperature. This result may mean nc-Si is still indirect transition material like bulk silicon. Gold doped nc-Si reveals short peak wavelength of PL spectrum than gold undoped one. PL peak shift through gold doing process shows clearly the PL mechanism is not from defect or interface states. PL intensity increases from 6K to a certain temperature and then decrease to room temperature. This characteristic with temperature shows that phonon have a role for the luminescence as theory explains that electron and hole can be recombined radiatively by phonon's assist in nc-Si, which is almost impossible in bulk silicon. Therefore luminescence is observed in nc-Si constructed less than a few of unit cell and the peak energy of luminescence can be higher than the bulk bandgap energy by the bandgap widening effect occurs in nanostructure.

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Luminescence Characteristics and Crystal Structure of CaWO4-Li2WO4-Eu2O3 Phosphors (CaWO4-Li2WO4-Eu2O3계 형광체의 PL 특성과 결정구조)

  • Kim, Jeong-Seog;Choi, Jin-Ho;Jeong, Bong-Man;Kang, Hyun-Ju
    • Journal of the Korean Ceramic Society
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    • v.43 no.1 s.284
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    • pp.10-15
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    • 2006
  • Photoluminescence (PL) and crystal structures of the $(l-x)CaWO_4-xLi_2WO_4$ binary system added with $Eu_2O_3$ activator have been characterized. The $CaWO_4\;and\;Li_2WO_4$ have the scheelite and phenakite structures respectively. The $CaWO_4-Li_2WO_4-Eu_2O_3$ phosphors show the red luminescence of 613 nm peak wavelength. The wavelength range of excitation spectral band is $380\~470$ nm with the peak wavelength of 397 nm. The $0.88(0.5CaWO_4-0.5Li_2WO_4)-0.12Eu_2O_3$ showed the most superior luminescence characteristics. The effect of co-doping elements such as $Al_2O_3$ and rare-earth oxides on PL has been characterized. The co-doping elements deteriorated the luminescence intensity except the $Al_2O_3$ and $Gd_2O_3$. The PL characteristics of $CaWO_4-Li_2WO_4-Eu_2O_3$ phosphors have been compared to those of the alkali europium double molybdates (tungstates) of scheelite-related structure such as $LiEu(MoO_4)_2$ and $CsEu(MoO_4)_2$. The crystal structures of $(l-y)[(l-x)CaWO_4-xLi_2WO_4]-yEu_2O_3$ phosphors have been characterized using XRD data and rietveld refinement.

A Study on the Current Situation Analysis of Korean Logistics Industry and the Characteristics of Logistics Firms (국내 물류시장의 현황과 물류기업의 특성에 관한 연구 -내부거래비중을 중심으로-)

  • Kim, Jong-Chill;Park, Dong-Gi
    • Journal of Korea Port Economic Association
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    • v.30 no.3
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    • pp.209-230
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    • 2014
  • The purpose of this study is to have a main change of korea logistics industry analysis and take in the whole situation and the characteristics about a logistics firms. In korean logistics industry, The rate of a carriage is among the low-level as compared with the increasingly high prices for diesel. besides, a national logistics cost and the sales in the transportation industry has increased steadily. On the other hand, the number of trucks and transfer companies has decreased steadily. This change is attributed to expansion of logistics firm size through the limit on a raise in the number of trucks and introduction of a direct consignment system. But medium and small logistics firm size is dwindling in numbers. In the meantime, 2PL since early 2000s has rapidly rose as powerful players in logistics industry by a strong Support of the parent companies. Government and academia have long noted the limit and problems of 2PL system and emphasize on the necessity of activating the 3PL system. So this study divided broadly into two groups that the primary characteristics of korea logistics industry are 2PL and 3PL. Through the results of this study, the management and financial perspectives mean that there is a considerable difference between 2PL and 3PL.

Effect of Root Medium Formulations on Growth and Nutrient Uptake of Hot Pepper Plug Seedlings (혼합상토의 조성이 고추 플러그 묘의 생육 및 무기원소 흡수에 미치는 영향)

  • Choi, Jong-Myung;Ahn, Joo-Won;Ku, Ja-Hyeong
    • Journal of Bio-Environment Control
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    • v.15 no.4
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    • pp.369-376
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    • 2006
  • This research was conducted to evaluate the effect of root medium formulations on growth and nutrient uptake of hot pepper 'Knockgwang' in 72-cell plug trays. To achieve this, the nine root media were formulated by adjusting blending rate of perlite (PL) to coir (CO), peatmoss (PM) or coir+peatmoss (5:5, v/v, COPM). Then, the growth characteristics and tissue nutrient contents were determined at 35 and 70 days after sowing. The elevated blending rate of PL to CO increased fresh and dry weight of hot pepper at 35 days after sowing. The treatments of 20% in blending rate of PL to PM or that of 0% to COPM produced the highest fresh and dry weight among perlite treatments of PM or COPM. The results of crop growth at 70 days after sowing also showed similar trends to those of 35 days after sowing. The elevated blending rate of PL to CO or PM decreased tissue $P_2O_5$ and K contents and increased Ca and Mg contents at 35 days after sowing, With the equal blending rate of perlite, the plant tissue grown in CO had higher K contents and lower N, Ca and Mg contents than those in PM and COPM. The elevated blending rate of perlite in three organic matter also decreased tissue $P_2O_5$ and K contents at 70 days after sowing, but Ca and Mg contents were the highest in the treatment of 20% PL in CO, 40% PL in PM and 40% PL in COPM among perlite treatments in each organic matter.

Selection Criteria of Manufacturers toward Third-Party Logistics Services with Reference to China SuZhou Industrial Park (중국 제조업체의 제3자 물류 선택요인과 성과에 관한 연구 : 중국 소주 공업원구를 중심으로)

  • Koh, Yong-Ki;Jin, Yu-Pyeong;Shin, Jeong-Yong
    • International Commerce and Information Review
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    • v.11 no.3
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    • pp.75-100
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    • 2009
  • With the change of various business environments, needs for the third party logistics(3PL) service are strategically considered for securing core competitiveness of manufacturers in China. Thus, manufacturers not only have worked with 3PL service providers for cutting costs of logistics, but also they are willing to have Win-Win relationship with the 3PL service provider. In this paper, comparing situation and characteristics of both China and developed-countries, especially in the particularity of manufacturing companies in China. The most important thing is that 3PL service providers must be able to manage supply chain of manufacturers with logistic planning abilities and to operate logistics services with logistic infrastructures and IT systems. In the view of long-term development, incubating logistics specialists is also the influencing fact that makes 3PL service providers more competitive with high quality logistics service and infrastructures.

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PL Characteristics of ZnO thin film on PES substrate by PLD (PES기판 상에 PLD법으로 제작된 ZnO박막의 발광 특성)

  • Choi, Young-Jin;Lee, Cheon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.211-211
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    • 2010
  • 본 논문에서는 ZnO 박막을 휘어지기 쉬운 PES(polyethersulfone) 기판위에 PLD(pusled laser deposition)법을 사용하여 다양한 조건에서 성장시켰다. 성장된 ZnO 박막의 표면 형상과 광특성을 SEM과 PL을 사용하여 측정하였고, 레이저 밀도 0.3 J/$cm^2$, 기판 온도 $200^{\circ}C$에서 가장 좋은 광특성을 보였다.

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A Study on the Effectiveness of 3PL Logistics Information System : A Focus on the Role of Supply Chain Performance in Shipper and Long-term Relationship intention (3PL 물류정보시스템의 효과성에 관한 실증적 연구 : 화주기업의 공급사슬성과와 장기지향적관계성의 역할을 중심으로)

  • Cho, Jae-yong
    • Journal of Venture Innovation
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    • v.3 no.2
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    • pp.111-128
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    • 2020
  • Recently, in the process of globalization of companies, the use of third party logistics providers (3PL) has been strengthened. Therefore, the purpose of this study is to test the effectiveness of the logistics information system provided by 3PL companies. This study is to test the relationship between the effect of the characteristics of the 3PL logistics information system on the shipper's supply chain performance, that is, logistics performance, customer performance, and organizational performance, and the shipper's loyalty to the 3PL company, that is, 3PL corporate performance. In addition, long-term relationship orientation is to test whether there is a moderating effect between the shipper company and the 3PL company. Through this, this study aims to provide strategic implications for improving the competitiveness of 3PL companies. In this study, a total 205 data were collected and used for analysis of shippers companies for hypothesis testing, and analyzed using SPSS 21.0 and AMOS 21.0 statistical programs. The results of the study are summarized as follows. First, it was found that the accuracy, timeliness, and usefulness of the 3PL logistics information system all had a significant positive (+) effect on the performance of the shipper's supply chain. Second, it was found that the accuracy, timeliness, and usefulness of the 3PL logistics information system all had a significant positive (+) effect on 3PL corporate performance. Third, it was found that the performance of the supply chain of the shipper company had a significant positive (+) effect on the performance of the 3PL company. Finally, it was found that long-term relationship orientation had a moderating effect on the relationship between the performance of the shipper company's supply chain and the performance of the 3PL company. The purpose of this study is to provide academic and practical implications for securing competitive advantage through the logistics information system of 3PL logistics companies.

Role of Crystallographic Tilt Angle of GaAs Substrate Surface on Elastic Characteristics and Crystal Quality of InGaP Epilayers (GaAs 기판표면의 Tilt각도가 InGaP 에피막의 탄성특성 및 결정질에 미치는 영향)

  • 이종원;이철로;김창수;오명석;임성욱
    • Journal of the Microelectronics and Packaging Society
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    • v.6 no.1
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    • pp.1-10
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    • 1999
  • InGaP epilayers were grown on the flat, $2^{\circ}$off, $6^{\circ}$ off, and $10^{\circ}$off GaAs substrates by organo-metallic vapor phase epitaxy, and influences of crystallographic misorientation of the substrate on the structural and optical properties such as lattice mismatch, elastic strain, lattice curvature, misfit stress, and PL intensity /line-width were investigated in this study. Material characterizations were carried out by TXRD( tripple-axis x-ray diffractometer) and low temperature (11K) PL (photoluminescence). With increase of the substrate misorientation angle (S.M.A.), the relative incorporation of Ga atoms on the substrate surface was found to be enhanced. Also, with increase of the S. M. A., the x-ray line-width of the InGaP epilayer was reduced, indicating that the crystal quality of the epilayer could be improved tilth a misoriented substrate. It was also found that the elastic accommodation of the strain-free lattice misfit was more remarkable in a misoriented sample. PL intensity increased, and PL line-width and emission wavelength decreased with the increase of S. M. A. The results conclude that the elastic characteristics and the crystal quality of the InGaP epilayer could be remarkably enhanced when the misoriented substrates were employed.

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Optical Characteristics of Multi-Stacked InAs/InAlGaAs Quantum Dots (다층 성장한 InAs/InAlGaAs 양자점의 광학적 특성)

  • Oh, Jae-Won;Kwon, Se-Ra;Ryu, Mee-Yi;Jo, Byoung-Gu;Kim, Jin-Soo
    • Journal of the Korean Vacuum Society
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    • v.20 no.6
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    • pp.442-448
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    • 2011
  • Self-assembled InAs/InAlGaAs quantum dots (QDs) grown on an InP (001) substrate have been investigated by using photoluminescence (PL) and time-resolved PL measurements. The single layer (QD1) and seven stacks (QD2) of InAs/InAlGaAs QDs grown by the conventional S-K growth mode were used. The PL peak at 10 K was 1,320 nm for both QD1 and QD2. As the temperature increases from 10 to 300 K, the PL peaks for QD1 and QD2 were red-shifted in the amount of 178 and 264 nm, respectively. For QD1, the PL decay increased with increasing emission wavelength from 1,216 to 1,320 nm, reaching a maximum decay time of 1.49 ns at 1,320 nm, and then decreased as the emission wavelength was increased further. However, the PL decay time for QD2 decreased continuously from 1.83 to 1.22 ns as the emission wavelength was increased from 1,130 to 1,600 nm, respectively. These PL and TRPL results for QD2 can be explained by the large variation in the QD size with stacking number caused by the phase separation of InAlGaAs.

Vegetational Structure of Orchardgrass Sward Ⅰ. Changes of dry matter production by the times of year and its relation both morphological and structual characteristics (Orchardrass의 植生構造 Ⅰ. 乾物生産性의 經年的 變化와 形態的, 構造的 形質과의 關係)

  • Lee, Joo-Sam
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.8 no.2
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    • pp.77-84
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    • 1988
  • This experiment was conducted to investigate the morphological and structual characters and the dry weight of plant (DW/pl.) concerned vegetational structure of orchardgrass pastures by the times of year, from 1 year to 7 year previous, 1986 through 1980, alternately. this experiment was carried out on the experimental fields of Yonsei University. The results are summarized as follows: 1. Population density (PD) was extremely decreased by the times of year. 2. Pasture productivity was highest at 3 year old pasture, was lowest at 5 year old pasture and was recovered at 7 year old pasture. 3. Recovery of pasture productivity was followed the increase of dry weight of plant (DW/pl.) and number of tillers per plant (NT/pl.) 4. The population density of 7 year old pasture was 14 plants per square meter. 5. The number of tillers per plant (NT/pl.), dry weight of plant (DW/pl.) plant length (PL), and plant size (PS) was frequently showed the highest values by the times of established year. 6. The stubble diameter (DIA), stubble area (SB), plant size (PS), distance between neibour plant (DIS) and leaf area index (LAI) was increased according to the times of year. 7. The dry weight of plant (DW/pl.) was positively significant correlations with the number of tillers per plant (NT/pl.) all of the established pastures, but the dry weight of a tiller (WT) was tended to increase of correlations with the dry weight of plant (DW/pl.) by the times of year. 8. Differences between morphological and structual characters was recognized according to the times of year.

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