• Title, Summary, Keyword: physical media dependent

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Physical Media Dependent Prototype for 10-Gigabit-Capable PON OLT

  • Kim, Jongdeog;Lee, Jong Jin;Lee, Seihyoung;Kim, Young-Sun
    • ETRI Journal
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    • v.35 no.2
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    • pp.245-252
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    • 2013
  • In this work, we study the physical layer solutions for 10-gigabit-capable passive optical networks (PONs), particularly for an optical link terminal (OLT) including a 10-Gbit/s electroabsorption modulated laser (EML) and a 2.5-Gbit/s burst mode receiver (BM-Rx) in a novel bidirectional optical subassembly (BOSA). As unique features, a bidirectional mini-flat package and a 9-pin TO package are developed for a 10-gigabit-capable PON OLT BOSA composed of a 1,577-nm EML and a 1,270-nm avalanche photodiode BM-Rx, including a single-chip burst mode integrated circuit that is integrated with a transimpedance and limiting amplifier. In the developed prototype, the 10-Gbit/s transmitter and 2.5-Gbit/s receiver characteristics are evaluated and compared with the physical media dependent (PMD) specifications in ITU-T G.987.2 for XG-PON1. By conducting the 10-Gbit/s downstream and 2.5-Gbit/s upstream transmission experiments, we verify that the developed 10-gigabitcapable PON PMD prototype can operate for extended network coverage of up to a 40-km fiber reach.

Role of Crossflow Module Media in Gas-liquid-solid Separation and Biomass Retention in Hybrid Anaerobic Filter (교차흐름식 모듈 충전 hybrid 혐기성여상의 기·액·고 분리능 및 슬러지보유능)

  • Chang, Duk;Chae, Hee-Wang;Bae, Hyung-Suk;Chung, In;Han, Sang-Bae;Hur, Joon-Moo;Hong, Ki-Ho
    • Journal of Korean Society of Water and Wastewater
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    • v.23 no.6
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    • pp.769-778
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    • 2009
  • Performances and internal behaviors of the upflow hybrid anaerobic filters treating a dairy wastewater were analyzed to identify the functions and roles of the modular crossflow media and sludge bed layer and to discover their interrelationship in the filter. The media could perform independent biological and physical separation role without buildup of sludge bed, while the role of sludge bed was dependent on the function of the media. The filter packed with the crossflow media did not necessarily require the formation of sludge bed when treating a dairy wastewater. Biological contribution of the media was controlled by that of biologically active sludge bed complementing mutually each other. The gas-liquid-solid separation capability of the media was indispensible to ensure the active biological role of sludge bed, since sludge bed buildup without the media had no independently effective biological function. It was believed that the filter in itself could also function as a selector for physical gas-liquid-solid separation resulting in selectively concentrating particles with superior settleability in sludge bed. The sludge bed in the filter played a key role in the physical solids capture from influent as well as biological organics removal.

High-pressure synchrotron X-ray diffraction study of tremolite and actinolite in various fluids

  • Kong, Mihye;Vogt, Thomas;Lee, Yongjae
    • Current Applied Physics
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    • v.18 no.11
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    • pp.1218-1224
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    • 2018
  • Pressure-dependent structural and morphological changes of two amphibole minerals, tremolite and actinolite, were investigated up to 7.0 GPa using synchrotron X-ray powder diffraction underthree different pressure transmission media (PTM): water (W), $CO_2$ and silicone oil (SI). The elastic response of tremolite and actinolite are found to be dependent on the PTM used. When using water (W) as PTM, tremolite and actinolite show normal volume contractions with bulk moduli of 74(1) and 78(1) GPa, respectively. When using $CO_2$ as PTM, we observe the formation of calcite from tremolite above 3.8(1) GPa, whereas actinolite did not show any carbonation reaction. Under silicone oil PTM, we observe modulated volume contraction behaviors in both samples, compared to water and $CO_2$ PTM, with bulk moduli in the order of 90(1) and 94(4) GPa for tremolite and actinolite, respectively.

Characteristics of Electronic, Magnetic Transformation for Environment Change in Magnetic Recording Media (자기기록매체에 있어서 환경변화에 따른 자기 및 전자 변환 특성)

  • Yoon, Man-Youn;Shin, Jong-Soon
    • Journal of the Korean Printing Society
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    • v.22 no.2
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    • pp.13-22
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    • 2004
  • Selected chemical, physical, mechanical, and magnetic properties of magnetite, Co-${\gamma}-Fe_2O_3$, $CrO_2$ recording tapes were studied, under three sets of temperature and humidity conditions, to accelerate the tapes' aging. The results. obtained indicated that changes in temperature, huminity and magnetic properties were dependent. Changes in the magnetic properties can be used to predict the life expentancy of the information stored in the media. Together, all of these properties can be used to assess the overall storage characteristics of magnetitie, Co-${\gamma}-Fe_2O_3$, $CrO_2$ recording tapes.

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Geomechanical and thermal reservoir simulation during steam flooding

  • Taghizadeh, Roohollah;Goshtasbi, Kamran;Manshad, Abbas Khaksar;Ahangari, Kaveh
    • Structural Engineering and Mechanics
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    • v.66 no.4
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    • pp.505-513
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    • 2018
  • Steam flooding is widely used in heavy oil reservoir with coupling effects among the formation temperature change, fluid flow and solid deformation. The effective stress, porosity and permeability in this process can be affected by the multi-physical coupling of thermal, hydraulic and mechanical processes (THM), resulting in a complex interaction of geomechanical effects and multiphase flow in the porous media. Quantification of the state of deformation and stress in the reservoir is therefore essential for the correct prediction of reservoir efficiency and productivity. This paper presents a coupled fluid flow, thermal and geomechanical model employing a program (MATLAB interface code), which was developed to couple conventional reservoir (ECLIPSE) and geomechanical (ABAQUS) simulators for coupled THM processes in multiphase reservoir modeling. In each simulation cycle, time dependent reservoir pressure and temperature fields obtained from three dimensional compositional reservoir models were transferred into finite element reservoir geomechanical models in ABAQUS as multi-phase flow in deforming reservoirs cannot be performed within ABAQUS and new porosity and permeability are obtained using volumetric strains for the next analysis step. Finally, the proposed approach is illustrated on a complex coupled problem related to steam flooding in an oil reservoir. The reservoir coupled study showed that permeability and porosity increase during the injection scenario and increasing rate around injection wells exceed those of other similar comparable cases. Also, during injection, the uplift occurred very fast just above the injection wells resulting in plastic deformation.

Chirality in Non-Hermitian Photonics

  • Yu, Sunkyu;Piao, Xianji;Park, Namkyoo
    • Current Optics and Photonics
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    • v.3 no.4
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    • pp.275-284
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    • 2019
  • Chirality is ubiquitous in physics and biology from microscopic to macroscopic phenomena, such as fermionic interactions and DNA duplication. In photonics, chirality has traditionally represented differentiated optical responses for right and left circular polarizations. This definition of optical chirality in the polarization domain includes handedness-dependent phase velocities or optical absorption inside chiral media, which enable polarimetry for measuring the material concentration and circular dichroism spectroscopy for sensing biological or chemical enantiomers. Recently, the emerging field of non-Hermitian photonics, which explores exotic phenomena in gain or loss media, has provided a new viewpoint on chirality in photonics that is not restricted to the traditional polarization domain but is extended to other physical quantities such as the orbital angular momentum, propagation direction, and system parameter space. Here, we introduce recent milestones in chiral light-matter interactions in non-Hermitian photonics and show an enhanced degree of design freedom in photonic devices for spin and orbital angular momenta, directionality, and asymmetric modal conversion.

The Moderating Effect of Perceived Control over Appearance in the Social Comparison Process with Advertisement Models (광고모델과의 사회적 비교과정에서 외모통제력 지각이 갖는 조정효과)

  • Lee Yoon-Jung
    • Journal of the Korean Society of Clothing and Textiles
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    • v.30 no.4
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    • pp.633-643
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    • 2006
  • When women are exposed to images of other attractive women such as media models, it is known that many go through a social comparison process and a contrast effect occurs which results in unfavorable perception and attitudes toward the self. This paper suggests women's perception of control over their appearance as one of the factors that may moderate the contrast effect of a social comparison with attractive media models. An experiment with 211 women was conducted to examine the differential effect of viewing attractive models versus non-human images on the responses of women with high/low perceived control over appearance. A two(Stimuli Type: attractive-model image vs. non-human image) by two(Perceived Control over Appearance: High vs. Low) MANCOVA model was tested with physical appearance anxiety, self-esteem, and body satisfaction as dependent variables and appearance orientation, body mass index, age, years of schooling, ethnicity, and marital status as covariates. A significant Perceived Control main effect on Physical Appearance Anxiety and Self-Esteem and a significant Stimuli Type by Perceived Control interaction effect on Physical Appearance Anxiety and Self-Esteem were found. Those who perceived high control over their appearance were more likely to have higher self-esteem and lower appearance anxiety. However, among those who saw attractive model's images, women perceived low appearance control showed less anxiety and higher body satisfaction than those perceived high appearance control.

Effect of the Shape and Size of Quorum-Quenching Media on Biofouling Control in Membrane Bioreactors for Wastewater TreatmentS

  • Lee, Seonki;Lee, Sang Hyun;Lee, Kibaek;Kwon, Hyeokpil;Nahm, Chang Hyun;Lee, Chung-Hak;Park, Pyung-Kyu;Choo, Kwang-Ho;Lee, Jung-Kee;Oh, Hyun-Suk
    • Journal of Microbiology and Biotechnology
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    • v.26 no.10
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    • pp.1746-1754
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    • 2016
  • Recently, spherical beads entrapping quorum quenching (QQ) bacteria have been reported as effective moving QQ-media for biofouling control in MBRs for wastewater treatment owing to their combined effects of biological (i.e., quorum quenching) and physical washing. Taking into account both the mass transfer of signal molecules through the QQ-medium and collision efficiencies of the QQ-medium against the filtration membranes in a bioreactor, a cylindrical medium (QQ-cylinder) was developed as a new shape of moving QQ-medium. The QQ-cylinders were compared with previous QQ-beads in terms of the QQ activity and the physical washing effect under identical loading volumes of each medium in batch tests. It was found that the QQ activity of a QQ-medium was highly dependent on its specific surface area, regardless of the shape of the medium. In contrast, the physical washing effect of a QQ-medium was greatly affected by its geometric structure. The enhanced anti-biofouling property of the QQ-cylinders relative to QQ-beads was confirmed in a continuous laboratory-scale MBR with a flat-sheet membrane module.

Vibration analysis of double-bonded micro sandwich cylindrical shells under multi-physical loadings

  • Yazdani, Raziye;Mohammadimehr, Mehdi;Zenkour, Ashraf M.
    • Steel and Composite Structures
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    • v.33 no.1
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    • pp.93-109
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    • 2019
  • In the present study, vibration analysis of double bonded micro sandwich cylindrical shells with saturated porous core and carbon/boron nitride nanotubes (CNT/BNNT) reinforced composite face sheets under multi-physical loadings based on Cooper-Naghdi theory is investigated. The material properties of the micro structure are assumed to be temperature dependent, and each of the micro-tubes is placed on the Pasternak elastic foundations, and mechanical, moisture, thermal, electrical, and magnetic forces are effective on the structural behavior. The distributions of porous materials in three distributions such as non-linear non-symmetric, nonlinear-symmetric, and uniform are considered. The relationship including electro-magneto-hydro-thermo-mechanical loadings based on modified couple stress theory is obtained and moreover the governing equations of motion using the energy method and the Hamilton's principle are derived. Also, Navier's type solution is also used to solve the governing equations of motion. The effects of various parameters such as material length scale parameter, temperature change, various distributions of nanotube, volume fraction of nanotubes, porosity and Skempton coefficients, and geometric parameters on the natural frequency of double bonded micro sandwich cylindrical shells are investigated. Increasing the porosity and the Skempton coefficients of the core in micro sandwich cylindrical shell lead to increase the natural frequency of the structure. Cylindrical shells and porous materials in the industry of filters and separators, heat exchangers and coolers are widely used and are generally accepted today.

Antimicrobial Effect of Medical Adhesive Composed of Aldehyded Dextran and ${\varepsilon}$-Poly(L-Lysine)

  • Lee, Jeong-Hyun;Kim, Hye-Lee;Lee, Mi-Hee;Taguchi, Hideaki;Hyon, Suong-Hyu;Park, Jong-Chul
    • Journal of Microbiology and Biotechnology
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    • v.21 no.11
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    • pp.1199-1202
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    • 2011
  • Infection of surgical wounds is a severe problem. Conventional tissue reattachment methods have limits of incomplete sealing and high susceptibility to infection. Medical adhesives have several advantages over traditional tissue reattachment techniques, but still have drawbacks, such as the probability of infection, low adhesive strength, and high cytotoxicity. Recently, a new medical adhesive (new-adhesive) with high adhesive strength and low cytotoxicity, composed of aldehyded dextran and ${\varepsilon}$-poly(L-lysine), was developed. The antimicrobial activity of the new-adhesive was assayed using agar media and porcine skin. In the agar diffusion method, inoculated microorganisms that contacted the new-adhesive were inactivated, but this was not dependent on the amount of new-adhesive. Similar to the agar media results, the topical antimicrobial effect of new-adhesive was confirmed using a porcine skin antimicrobial assay, and the effect was not due to physical blocking based on comparison with the group whose wounds were wrapped.