• Title/Summary/Keyword: density of media

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Barium Ferrite Media for Extremely High Density Recording Applications

  • Yang-Ki Hong;Hong-Sik Jung
    • Journal of Magnetics
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    • v.3 no.3
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    • pp.96-98
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    • 1998
  • In this paper a structurally coupled and magnetically decoupled Ba-ferrite thin film medium is proposed to evade the superparamagnetic limit and reduce media noise. The proposed medium consists of ferrimagnetic Ba-ferrite nano-grains (< 10 nm) and a non-magnetic grain boundary material. Magnetic grains are crystallographically matched with the grain boundary material. Spherical or cubic shaped Ba-ferrite particle is also proposed for above 100 Kfci particulate recording application.

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Parallel Writing and Detection for Two Dimensional Magnetic Recording Channel

  • Zhang, Yong;Lee, Jaejin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37A no.10
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    • pp.821-826
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    • 2012
  • Two-dimensional magnetic recording (TDMR) is treated as the next generation magnetic recording method, but because of its high channel bit error rate, it is difficult to use in practices. In this paper, we introduce a new writing method that can decrease the nonlinear media error effectively, and it can also achieve 10 Tb/$in^2$ of user bit density on a magnetic recording medium with 20 Teragrains/$in^2$.

A Case Study of The Participant Network of Community Media in Seoul: Mapo FM Community Media (공동체 미디어의 참여자 네트워크 특성과 의미 분석: 마포FM 사례를 중심으로)

  • Jang, Si-Yeon;Chae, Young-Gil
    • The Journal of the Korea Contents Association
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    • v.16 no.5
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    • pp.720-731
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    • 2016
  • This study aims to understand characteristics and roles of community media in Seoul to discuss the meanings of the media. Community media is constructed based upon the networks of relations of community participants, whose characteristic relations of participants within the network determines the roles and meanings of the media for the community. Research have shown that community media's unique open, participatory, and horizontal communicative structures enable to realize such objects. For this study, we chose Mapo FM to conduct case study based upon network analysis of 'participant network' of the media. In particular, we tried to measure the density and centrality of the network, which can explain the relational characteristics of the networks of the media. In addition, we also conducted in-depth interviews of participants to better understand the problems and meanings of the community media. The findings suggest that unlike the conceptual and theoretical assumptions, the community media under the study lacks of open, participatory, and horizontal ways of participation in the media.

A Study on Calculation of Capacitance Parameter for Interconnection Line in Multilayer Dielectric Media (다층 유전체 매질에서의 Interconnection Line에 대한 Capacitance Parameter 계산에 관한 연구)

  • 김한구;곽계달
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.26 no.8
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    • pp.1187-1196
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    • 1989
  • In this paper, a method for computing the capacitance parameter for a multi-interconnection line in a multilayered dielectric region is presented. The number of interconnection lines and the number of dielectric layers are arbitrary, and the interconnection lines are finite cross section or infinite cross section. The surface of lines and dielectric interface are divided into subsection. The surface charge density of each subsection is a constant step-pulse function for each subsection. After the solution of surface charge density is effected by the method of moments, capacitance parameter is calculated.

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Repeatable calibration of Hounsfield units to mineral density and effect of scanning medium

  • Crookshank, Meghan;Ploeg, Heidi-Lynn;Ellis, Randy;MacIntyre, Norma J.
    • Advances in biomechanics and applications
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    • v.1 no.1
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    • pp.15-22
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    • 2014
  • Computed tomography (CT) is being utilized in orthopaedics and related research to estimate bone strength. These applications benefit from calibration of Hounsfield units to mineral density typical of long bone, up to $1750mg/cm^3$. This study describes a method for establishing repeatable calibration of Hounsfield units to density, and determines the effects of imaging medium on calibration accuracy. Four hydroxyapatite standards were imaged in air on 7 occasions over 19 weeks using a helical multi-slice CT scanner. Each standard was scanned 5 times in different media: porcine soft tissue, water, and air. Calibrated densities were highly repeatable (CV<3.5%). No difference in density was observed between water and soft tissue conditions (p>0.08). This work provides a model for determining repeatable scanner-specific density calibration, demonstrates that the linear relationship between Hounsfield units and density extends to values typical of cortical bone, and supports the practice of imaging calibration standards in an environment similar to that of the target bone.

Effect of Ceramics Mixing on Mushrooms Mycelial Growth and Density (세라믹스(Ceramics) 배지첨가에 의한 버섯 균사생육의 영향)

  • Chang, Hyun-You;Byun, Jae-Myun;Nho, Moon-Gee;Kim, Ki-Taek
    • Journal of Agricultural Extension & Community Development
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    • v.7 no.1
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    • pp.175-180
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    • 2000
  • This experiment was conducts to find out the effects of ceramics mixing on mushrooms mycelial growth and density. It is better ceramics in $800^{\circ}C$ than $1000^{\circ}C$ to mycelial growth and density of Pleurotus astreatus, Flamulina velutepes, Lentinus edodes and Inonotus obliqua . Mycelial growth according to ceramics mixing contents with mushrooms media is good till 0.16% ceramics mixing, but if mycelial growth and density take into consideration, 0.12% ceramics mixing contents is best.

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Regulation of Star Formation in Turbulent, Multiphase Interstellar Media

  • Kim, Chang-Goo;Kim, Woong-Tae;Ostriker, Eve C.
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.66.1-66.1
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    • 2010
  • Using two-dimensional numerical hydrodynamic simulations, we investigate the star formation rate (SFR) in turbulent, multiphase, galactic gaseous disks. Our simulation domain is axisymmetric, and local in the radial direction and global in the vertical direction. Our models include galactic rotation, vertical density stratification, self-gravity, radiative heating and cooling, and thermal conduction, but do not include spiral-arm features. Turbulence in our models is driven by momentum feedback from supernova explosion events occurring in localized dense regions formed by thermal and gravitational instabilities. Self-consistent radiative heating, representing enhanced/reduced FUV photons from the star formation, is also taken into account. By controlling three parameters (the gas surface density, the stellar disk density, and the angular rotation rate) that characterize local galactic disks, we explore how the SFR depends on the background environmental state. We also discuss the relation between the SFR and the gas surface density found in our numerical models in comparison with observations.

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Applicability of Spent Mushroom Media as Horticultural Nursery Media (버섯재배 후 탈병배지의 원예용 상토재료 이용성 검토)

  • Lee, Chan-Jung;Cheong, Jong-Chun;Jhune, Chang-Sung;Kim, Seung-Hwan
    • Korean Journal of Soil Science and Fertilizer
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    • v.42 no.2
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    • pp.117-122
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    • 2009
  • This study was carried out to investigate applicability of Spent Mushroom Media(SMM) as horticultural nursery media. After the mushroom has been harvested, the SMM contains a lot of organic material, different microorganism and high density of mushroom hypha. The pH, phosphate and exchangeable cation concentrations of SMM of Flammulina velutipes were higher than those of any other treatment. The CEC and $NH_4-N$ were the highest in SMM of bottle-cultivated oyster mushroom (Pleurotus ostreatus). Bacteria and fungi showed the highest density in SMM of Flammulina velutipes. Most dominant bacteria were Microbacterium sp., Rhodococcus sp. and Agrobacterium sp. in SMM of Flammulina velutipes and Bacillus sp., Pseudomonas sp., Curtobacterium sp. and Microbacterium sp. in that of Pleurotus eryngii. The SMM contained high density of mushroom hypha that inhibited germination of seed and growth of young seedlings. Therefore, composting process of the SMM is indispensible to decline of vitality of mushroom hypha. The SMM of Flammulina velutipes with 0~30% vermiculite showed high germination rate in red pepper and chinese cabbage seeds. SMM of Pleurotus eryngii with 20% vermiculite showed 100% germination rate in red pepper seeds, but chinese cabbage seeds nearly failed to germinate with 30% vermiculite. The growth of red pepper was increased according to increasing mixture ratio of vermiculite. Accordingly, we concluded that SMM of Flammulina velutipes contained 0~30% of vermiculite can be used to horticultural growth bed for red pepper.

Effect of Inoculation Time and Population Density of Pseudomonas agarici and P. tolaasii on the Mycelial Growth and the Fruit body Formation in Flammulina velutipes (Pseudomonas agarici와 P. toluaasii의 접종시기 및 접종농도가 팽이버섯의 균사생장과 자실체형성에 미치는 영향)

  • Lee, Hyun-Uk;Moon, Byung-Ju;Lee, Heung-Su;Cha, Heung-Oh;Cho, Dong-Jin;Shin, Won-Kyo
    • The Korean Journal of Mycology
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    • v.26 no.1 s.84
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    • pp.60-68
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    • 1998
  • The effect of P. agarici and P. tolaasii causing the bacterial disease of mushrooms on the mycelial growth and fruitbody formation of F. velutipes was evaluated in laboratory. When the pathogenic bacteria was inoculated simultaneously with F. velutipes or 5 days after inoculation of F. velutipes, they significantly deterred both mycelial growth and fruitbody formation of F. velutipes in sawdust culture and showed strong inhibition under high population density. They appeared to be tender or milky in exhibiting symptom on F. velutipes by inoculating the concentration of $10^2{\sim}10^6$ of unit/g media, and their growth seemed to be stopped under $10^8\;cfu/g$ media. On $10^2\;cfu/g$ media of P. agarici and $10^4\;cfu/g$ media of P. tolaasii, there was no effect on the fruitbody yield of F. velutipes. P. tolaasii was more suppressive in the mycelial growth of F. velutipes than P. agarici, while on fruitbodies formation of F. velutipes, P. agarici showed slightly higher inhibition than that of P. tolaasii. When the bacteria was inoculated 10 days after inoculation of F. velutipes, both mycelial growth and fruit body formation were not affected nearly.

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