• Title/Summary/Keyword: Light stability

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A study on the Molding Stability of Hydro-mechanical High Speed Injection Molding for Thin-Walled(0.3mm) LGP (초박형(0.3t) 도광판 적용을 위한 유압식 고속사출성형의 성형 안정성 연구)

  • Kim, J.S.;Oh, J.G.;Jeong, C.;An, H.J.;Hwang, C.J.;Kim, J.D.;Yoon, K.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2008.10a
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    • pp.422-425
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    • 2008
  • Recently, electronic products and related parts are required to have thin thickness because of small form factor. To go with the trend, LGP(light guide plate) of LCD BLU(Liquid Crystal Display Back light unit: It is one of kernel parts of LCD) for cell phone has the thickness of 0.3 mm and the battery case of cell phone has 0.25 mm. Accordingly, high speed injection molding is required to make products which have thin thickness. High speed injection molding means that the resin is injected into the cavity at higher than normal speed avoiding short shot. In the case of hydro-mechanical high speed injection machine, it requires the design for hydraulic unit to make high injection speed and the design for control unit to control hydraulic unit. In the present paper, we concentrated on the molding stability of hydro-mechanical high speed injection machine to make an LGP of 0.3 mm thickness.

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Stability and Sedimentation Properties of TiO2 Nanoparticles (TiO2 나노 분말의 분산 안정성 및 침강 특성)

  • Woo S.H.;Lee M.K.;Rhee C.K.
    • Journal of Powder Materials
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    • v.13 no.4 s.57
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    • pp.263-268
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    • 2006
  • In this study, the colloidal stability and sedimentation behavior of crystalline $TiO_2$ particles (300nm) in various organic solvents have been investigated by means of a backscattered light flux profile (Turbiscan). The backscattered light flux profiles revealed that the $TiO_2$ nanoparticles were readily sedimented in water, methyl alcohol, and ethyl alcohol due to a flocculation-induced particle growth, while a particle coalescence and a sedimentation of the $TiO_2$ nanoparticles were hardly observed in isopropyl alcohol. The migration velocities of the $TiO_2$ particle were measured as around 6.15/min, 12.53 m/min, 6.51m/min, and 0.18m/min for water, methyl alcohol, ethyl alcohol, and isopropyl alcohol, respectively, showing a remarkably slow migration of the $TiO_2$ particles in isopropyl alcohol.

A Study of Functionality and Stability of LDPE-Nano TiO2 Composite Film (LDPE-나노 TiO2 복합 필름의 기능성 및 재질안정성 평가)

  • Lee, Wooseok;Ko, Seonghyuk
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.23 no.2
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    • pp.67-74
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    • 2017
  • In this work, the effects of nano $TiO_2$ on functionality and stability of low density polyethylene (LDPE) composite films were investigated for food packaging application. LDPE-nano $TiO_2$ composite films were prepared with various $TiO_2$ contents (0, 0.5, 1.0, 3.0 and 5.0wt%) by melt-extrusion and their basic properties such as crystallinity, chemical bonds and surface morphology were examined by XRD, FTIR and SEM. Ultraviolet (UV) light barrier property of as-prepared LDPE-nano $TiO_2$ composite films was also studied and the presence of nano $TiO_2$ resulted in significant improvement of UV light barrier compared to the pure LDPE film. To evaluate influence of nano $TiO_2$ on LDPE properties required as packaging material, thermal, mechanical, gas barrier and optical properties of LDPE-nano $TiO_2$ composite films were characterized with various analytical techniques including TGA, UTM, OTR, WVTR and UV-vis spectroscopy. As a result, except optical property of LDPE, no significant effects were found in other properties. Opacity of pure LDPE was greatly increased with increasing concentration of nano $TiO_2$.

Study on Stability of Ceramides in Liquid Crystalline Emulsions at High Temperature (세라마이드의 액정에멀젼 내 고온 제형 안정성 연구)

  • Hong, Sung Yun;Chang, Yujin;Lee, Jun Bae;Park, Chun Ho;Park, Myung Sam
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.45 no.1
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    • pp.1-7
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    • 2019
  • We introduce to prepare liquid crystalline emulsion composed of cetearyl alcohol, cetyl palmitate, sorbitan palmitate, sorbitan olivate, ceramide and so on which can enforce interface between oil-based particle and water phase. In terms of structural analysis, the stability of the liquid crystalline emulsion including ceramide, which is immisible ingredient, at high temperature was proved by polarized microscope, cryo-SEM, small-angle x-ray scattering, in addition to viscometer and static light scattering by physical analysis.

Memory Propagation-based Target-aware Segmentation Tracker with Adaptive Mask-attention Decision Network

  • Huanlong Zhang;Weiqiang Fu;Bin Zhou;Keyan Zhou;Xiangbo Yang;Shanfeng Liu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.18 no.9
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    • pp.2605-2625
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    • 2024
  • Siamese-based segmentation and tracking algorithms improve accuracy and stability for video object segmentation and tracking tasks simultaneously. Although effective, variability in target appearance and background clutter can still affect segmentation accuracy and further influence the performance of tracking. In this paper, we present a memory propagation-based target-aware and mask-attention decision network for robust object segmentation and tracking. Firstly, a mask propagation-based attention module (MPAM) is constructed to explore the inherent correlation among image frames, which can mine mask information of the historical frames. By retrieving a memory bank (MB) that stores features and binary masks of historical frames, target attention maps are generated to highlight the target region on backbone features, thus suppressing the adverse effects of background clutter. Secondly, an attention refinement pathway (ARP) is designed to further refine the segmentation profile in the process of mask generation. A lightweight attention mechanism is introduced to calculate the weight of low-level features, paying more attention to low-level features sensitive to edge detail so as to obtain segmentation results. Finally, a mask fusion mechanism (MFM) is proposed to enhance the accuracy of the mask. By utilizing a mask quality assessment decision network, the corresponding quality scores of the "initial mask" and the "previous mask" can be obtained adaptively, thus achieving the assignment of weights and the fusion of masks. Therefore, the final mask enjoys higher accuracy and stability. Experimental results on multiple benchmarks demonstrate that our algorithm performs outstanding performance in a variety of challenging tracking tasks.

Experimental studies of homogeneity and stability honeybee venom using ultra-high performance liquid chromatography (주사제 사용을 위한 봉독의 균질성 및 안정성 평가)

  • Han, Sang Mi;Kim, Se Gun;Hong, In Phyo;Woo, Soon Ok;Jang, Hye Ri;Lee, Kyung Woo
    • Korean Journal of Veterinary Service
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    • v.39 no.2
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    • pp.81-86
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    • 2016
  • Honeybee venom (BV) from Apis mellifera L. has been used as natural antimicrobial compounds in pigs, cows, dairy cattle and chicken farms in Korea. The purpose of this study was conducted to confirm homogeneity and stability of BV dissolved with distilled water or saline solution. Melittin was analyzed with ultra-high performance liquid chromatography (UPLC) for BV to secure the validation of analysis. BV at concentration of 1 mg/mL was dissolved with distilled water or saline solution at room temperature. Homogeneity of BV dissolved with distilled water or saline solution at upper, milddle, and lower layers all satisfied the accuracy and precision criteria. Stability of BV dissolved with distilled water or saline solution for 7 days all satisfied the criterion both light and dark storage condition. BV has satisfied with homogeneity and stability in distilled water or saline solution at room temperature under light or dark condition. The results of this study suggest that BV has a possibility as the substitute of natural antimicrobial agents for the animal drugs and feed additives.

Stability of Henna Natural Hair Dye Cream Formulation According to Cetyl Alcohol Contents (Cetyl alcohol 함량에 따른 크림 제형 Henna 천연 염모제의 안정성)

  • Kang, Eyoung;Lee, Seunghee;Kim, Woonjung;Jung, Jongjin
    • Journal of the Korean Applied Science and Technology
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    • v.38 no.4
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    • pp.1176-1182
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    • 2021
  • In this study, the emulsion stability of henna, a natural hair dye, according to the content of cetyl alcohol, one of the emulsification stabilizers, was analyzed, and the content of cetyl alcohol showing the most stable emulsification was confirmed. To analyze the emulsion stability, differences in particle size, particle shape, viscosity, and color after dyeing were compared according to the content of cetyl alcohol. As a result of dynamic light scattering (DLS) zeta analysis, cetyl alcohol 3% showed the highest zeta potential value of 115.9 mV, and the particle size distribution was henna in which a cream-type hair dye containing 3% cetyl alcohol was dispersed in distilled water. The width of the particle size distribution was narrow compared to. As a result of viscometer analysis, the viscosity increased as the content of cetyl alcohol increased. As a result of measuring the henna pH of the cream formulation, it was measured in a pH range suitable for the scalp. As a result, emulsion stability increases as the content of cetyl alcohol increases in henna cream formulations for hair dye.

Analysis of Quenching Resistor Effect to Improve Stability of TIA Circuit for APD (APD용 TIA 회로의 안정성 개선을 위한 Quenching 저항 영향 분석)

  • Ki, Dong-Han;Jin, Yu-Rin;Kim, Sung-Mi;Cho, Seong-Ik
    • Journal of IKEEE
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    • v.26 no.3
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    • pp.373-379
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    • 2022
  • In this paper, since the APD(Avalanche Photo Diode) for LTV(Light to Voltage) conversion uses a high voltage in the operating range unlike other PD(Photo Diode)s, the quenching resistor must be connected in series to prevent overcurrent when using the TIA(Transimpedance Amplifier). In such a case, quenching resistance may affect the transfer function of the TIA circuit, resulting in serious stability. Therefore, in this paper, by analyzing the effect of APD quenching resistance on the voltage and current loop transfer function of TIA, we propose a loop analysis and a method for determining the quenching resistance value to improve stability. TIA circuit with quenching resistance was designed by the proposed method and the stability of operation was verified through simulation and chip fabrication.

A Study on the Stability of the Ca-Bentonite Colloids Using a Dynamic Light Scattering Method (동적광산란 방법을 이용한 칼슘벤토나이트 콜로이드의 안정성에 대한 연구)

  • Baik Min-Hoon;Park Jong-Hoon;Cho Won-Jin
    • Journal of Soil and Groundwater Environment
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    • v.11 no.3
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    • pp.12-19
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    • 2006
  • In this study, the stability of Ca-bentonite colloids from Gyeongju area was studied by investigating the changes in the size of the bentonite colloids using a dynamic light scattering method depending on the geochemical conditions such as pH and ionic strength. Kinetic and equilibrium coagulation behavior of the bentonite colloids was investigated by changing the pH and ionic strength of the bentonite suspensions. The results showed that the stability of the bentonite colloids strongly depended upon contact time, pH, and ionic strength. It was also shown that the bentonite colloids were unstable at higher ionic strength greater than 0.01 M $NaClO_4$ at whole pH values considered. In addition, the stability ratio Wand the critical coagulation concentration (CCC) were also calculated using the data from the kinetic coagulation experiments. The stability ratio W was decreased as the ionic strength increased and varied with pH depending on the ionic strength. The CCC of the Ca-bentonite colloids was about 0.05 M $NaClO_4$ around pH 7.

Research Method of Driving Driver to improve Stability and Reliability of AC LED (AC LED의 안정성과 신뢰성 향상을 위한 구동용 DRIVER 연구방안)

  • Yoon, Yongho
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.20 no.1
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    • pp.205-210
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    • 2020
  • Thanks to the shift in awareness of environmentally friendly energy and government initiatives, practical light-emitting diode(LED) lighting fixtures have emerged and are being distributed, resulting in very large energy savings. However, in actual use of LED lighting, it is possible to use it as an individual, but when using a large street light or a whole home lighting, the whole lighting system is realized due to various problems such as efficiency, stability, and reliability. Doing so has several problems. Although AC-LED has been developed recently to solve safety problems such as heat generation phenomenon of the conventional DC-LED, it also has various problems such as quality safety and reliability, which are difficult to use as outdoor lighting using existing AC Power. This happens. Accordingly, the appropriate power for AC-LED should be developed and applied, and the emergence of such LED lighting will play a role as a tool that can overcome the limitations of existing LED lighting and implement sustainable energy saving.