• Title/Summary/Keyword: diffusion pattern

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Numerical Modeling of a Rectangular Type Inductively Coupled Plasma System (사각형 유도 결합 플라즈마 시스템의 수치 모델링)

  • Joo, Jung-Hoon
    • Journal of Surface Science and Engineering
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    • v.45 no.4
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    • pp.174-180
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    • 2012
  • Low pressure inductively coupled plasma characteristics of argon and oxygen are numerically simulated for a 400 mm rectangular type system with a plasma fluid model. The results showed lower power absorption profile at the corner than a circular one in a 13.56 MHz driven 1.5 turn antenna system with a drift-diffusion and quasi-neutrality assumption. Ions controlled by electric field are more non-uniform than metastables and the power absorption profile of oxygen plasma is affected by horizontal gas flow pattern to show 25% lower power absorption at the pumping flange side. Oxygen negative ions which are generated in electron collisional dissociation of oxygen molecules was calculated as 0.1% of oxygen atoms with similar spatial profile.

Disposal Characteristics of Dredged Material from the Hopper Dredger (호퍼준설선의 투기특성)

  • Jeong, D.D.;Lee, J.W.
    • Journal of Korean Port Research
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    • v.11 no.2
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    • pp.203-214
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    • 1997
  • Hydraulic dredgers(Hopper dredger) are the most important piece of equipment in the entire harbor engineering field, and most suitable for the removal of sand and weakly consloidated sediment such as silt. In maintenance dredging, specially confined harbor or congested passage area, Hopper dredger is user most popularly because less obstruction and danger to navigation than other mostly stationary dredgers. Investigation of the physical behave of dredged material disposal in coastal water from the Hopper dredger includes estimations of pattern as well as thickness of material on the bottom. Calculation based on vertical settling and horizontal advection of single particles ignore the effects of bulk properties of the disposed marterial, vertical and horizontal diffusion. and material dilution due to the entrainment of ambient water during descent. This paper focuses on the analysis of dredging and dumping characteristics and the spatial and temporal changes in the dumping fields for the water column and bottom at a hypothetically confined coastal water. This model accounts the behavior of material after release from the hopper dredger. It is shown that the model describes the qualitative feature of prototype dumping process and its response.

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Transcallosal Ipsilateral Motor Pathway from the Unaffected Hemisphere in a Patient with Traumatic Brain Injury

  • Jang, Woo-Hyuk;Lee, Mi-Young;Kwon, Yong-Hyun;Jang, Sung-Ho
    • The Journal of Korean Physical Therapy
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    • v.26 no.3
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    • pp.216-219
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    • 2014
  • Purpose: We presented with a patient with traumatic brain injury who showed a transcallosal ipsilateral motor pathway from unaffected motor cortex to affected extremities, as evaluated by diffusion tensor tractography (DTT). Methods: One patient and six age-matched normal subjects were enrolled. A 42-year-old left hemiparetic male who suffered from brain injury by motor vehicle accident 9 years ago showed a leukomalactic lesion in the right corona radiata and parieto-temporal lobe. His left extremities were completely paralyzed initially, but recovered slowly over 2 years. At the time of the evaluation, he was able to grasp and release an object, and to walk with spastic gait pattern. DTT was performed using 1.5 T with a Synergy-L Sensitivity Encoding head coil. DTT was obtained with termination criteria of FA <0.2 and an angle change > $45^{\circ}c$. Results: The motor tracts of the unaffected (left) hemisphere of the patient and control subjects originated from the motor cortex and descended along the known corticospinal tract without any transcallosal tract. By contrast, the tract of the affected (right) hemisphere originated from the left premotor cortex, descended through the left corona radiata, and then crossed the mid-portion of the corpus callosum. The tract then descended through the known corticospinal tract pathway to the right medulla. Conclusion: We conclude that the transcallosal ipsilateral motor pathway from the unaffected hemisphere appeared to contribute to the motor recovery in this patient.

A Study on the Influence of Substituting Cu Eine Particle for CuO on NiCuZn Ferrite (CuO 대신 Cu 미분말 치환이 NiCuZn Ferrite에 미치는 영향에 관한 연구)

  • Kim, Jae-Sik;Koh, Jae-Gui
    • Journal of the Korean Magnetics Society
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    • v.13 no.1
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    • pp.15-20
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    • 2003
  • Diffusion speed of Cu metal fine particle is fast better than CuO, so it will promote grain growth in sintering. In this paper, the influence on substituting Cu fine particle for CuO of NiCuZn ferrite with basic composition (N $i_{0.204}$C $u_{0.204}$Z $n_{0.612}$ $O_{1.02}$)F $e_{1.98}$ $O_{2.98}$ has been investigated with varying Cu/CuO ratio. The perfect spinel structure of sintered specimen at 90$0^{\circ}C$ was confirmed by the analysis of XRD patterns. The best condition was obtained when the ratio of Cu/CuO was 60%, and the permeability was 1100 and Ms was 87 emu/g in this condition. Cu has influenced on grain growth in sintering, substituting Cu fine particle for CuO could lower sintering temperature over the 3$0^{\circ}C$. After sintering, substituting Cu performed as good as CuO.s CuO.s CuO.

Improved Vector Error Diffusion for Reduction of Smear Artifact in the Boundary Regions (경계 영역에서의 색번짐 현상을 줄이기 위한 향상된 벡터 오차 확산법)

  • 이순창;조양호;김윤태;이철희;하영호
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.3
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    • pp.111-120
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    • 2004
  • This paper proposes a vector error diffusion method for smear artifact reduction in the boundary region. This artifact mainly results from a large accumulation of quantization errors. In particular, color bands with a smear artifact, the width of a few pixels appear along the edges. Accordingly, to reduce this artifact, the proposed halftoning process excludes the large accumulated Quantization error by comparing the vector norms and vector angles between the error-corrected vector and eight primary color patches. When the vector norm of the error corrected vector is larger than those of eight primary color patches, the quantization error vector is excluded from the quantization error distribution process. In addition, the quantization error is also excluded when the angle between eight primary color patches and error corrected vector is large. As a result, the proposed method enables a visually pleasing halftone pattern to be generated by all three color separations into account in a device- independent color space and reduces smear artifact in the boundary regions.

Analysis of Artificial Intelligence's Technology Innovation and Diffusion Pattern: Focusing on USPTO Patent Data (인공지능의 기술 혁신 및 확산 패턴 분석: USPTO 특허 데이터를 중심으로)

  • Baek, Seoin;Lee, Hyunjin;Kim, Heetae
    • The Journal of the Korea Contents Association
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    • v.20 no.4
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    • pp.86-98
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    • 2020
  • The artificial intelligence (AI) is a technology that will lead the future connective and intelligent era by combining with almost all industries in manufacturing and service industry. Although Korea is one of the world's leading artificial intelligence group with the United States, Japan, and Germany, but its competitiveness in terms of artificial intelligence patent is relatively low compared to others. Therefore, it is necessary to carry out quantitative analysis of artificial intelligence patents in various aspects in order to examine national competitiveness, major industries and future development directions in artificial intelligence technology. In this study, we use the IPC technology classification code to estimate the overall life cycle and the speed of development of the artificial intelligence technology. We collected patents related to artificial intelligence from 2008 to 2018, and analyze patent trends through one-dimensional statistical analysis, two-dimensional statistical analysis and network analysis. We expect that the technological trends of the artificial intelligence industry discovered from this study will be exploited to the strategies of the artificial intelligence technology and the policy making of the government.

A Study on the Change of Competition Factors According to Diffusion Stage - Focusing on the Case of Tablet and Notebook PCs (확산단계에 따른 경쟁요인 변화 연구:Tablet과 노트북 사례를 중심으로)

  • Seo, Young-Il;Jang, Joon-Kyu;Lee, Zoon-Ky
    • The Journal of the Korea Contents Association
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    • v.15 no.7
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    • pp.128-137
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    • 2015
  • Going through rapid changes, the field of information technology (IT) has launched many innovative products. Some of those products have spread, forming a stable market, whereas others have disappeared. The purpose of the study is to purpose a theoretical model to show changes in the importance of competition factors over the three stages. Our study applied the innovation adoption stage model of the Innovation Diffusion Theory (IDT) to the industry life cycle of the Industry Life Cycle (ILC) Theory resulting in three stage of introduction, growth, and maturity, and defined a model of market characteristics according to time. By using the model, we analyzed the case of notebook computers and tablet and checked the fitness of the model. Results show that five competition factors worked differently according to time. In the introduction stage, relative functionality and relative playfulness are important competition factors. In the growth stage, compatibility is added to those two factors. In the last maturity stage, compatibility, complexity, and cost level are important competition factors.

Charaterization of Nisin Production and Resistance of Lactococcus lactis ssp. lactis $ML_8$ (Lactococcus lactis ssp. lactis $ML_8$의 Nisin 생산 및 저항 특성)

  • 김등양;이형주
    • Microbiology and Biotechnology Letters
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    • v.19 no.6
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    • pp.619-623
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    • 1991
  • To investigate nisin production and resistance of Lactococcus lactis ssp. tactis ML (L. lactis $ML_8$, effects of medium, pH of culture broth, and cell growth on the nisin activity, and effect of nisin with or without $Ca^[2+}$ ion on the growth of L. lactzs were analyzed. In the bio-assay of nisin by the agar diffusion method, inhibition-zone diameter of Micrococcus Javus was propotional to the logarithm of nisin concentration ranged 0.5~20 unitlml (12.5~500 ng/mf). Nisin activity of the pasteurized culture filtrates of L. lactis MLs was high at pH 2!3 but was inactivated completely at pH over 6.0. Nisin production of the L. lactis $ML_8$ cultured on LTB broth increased at late logarithmic phase and reached 10.5 unitlml after 16 hr. The cell growth of L. lactis LM 0230, a plasmid free and nisin sensitive strain, was inhibited on agar medium containing 7 unitlrnl of nisin, while L. lactis $ML_8$ showed high survival ability at 20 unitld of nisin. When 40 mM $Ca^[2+}$ ion was added to Elliker broth with 8 unitlml of nisin, the growth pattern of L. lactis $ML_8$ was similiar to that on control medium which did not contain nisin and $Ca^[2+}$ ion, and this suggested that $Ca^[2+}$ increased the nisin resistance of the L. lactis.

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Measurement-based Face Rendering reflecting Positional Scattering Properties (위치별 산란특성을 반영한 측정기반 얼굴 렌더링)

  • Park, Sun-Yong;Oh, Kyoung-Su
    • Journal of Korea Game Society
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    • v.9 no.5
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    • pp.137-144
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    • 2009
  • This paper predicts 6 facial regions that may have sharply different scattering properties, rendering the face more realistically based on their diffusion profiles. The scattering properties are acquired in the form of high dynamic range by photographing the pattern formed around an unit ray incident on facial skin. The acquired data are fitted to a 'linear combination of Gaussian functions', which well approximates the original diffusion profile of skin and has good characteristics as the filter. During the process, to prevent its solutions from converging into local minima, we take advantage of the genetic algorithm to set up the initial value. Each Gaussian term is applied to the irradiance map as a filter, expressing subsurface scattering effect. In this paper, to efficiently handle the maximum 12 Gaussian filterings, we make use of the parallel capacity of CUDA.

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Influence of corrosive phenomena on bearing capacity of RC and PC beams

  • Malerba, Pier Giorgio;Sgambi, Luca;Ielmini, Diego;Gotti, Giordano
    • Advances in concrete construction
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    • v.5 no.2
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    • pp.117-143
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    • 2017
  • The attack of environmental aggressive agents progressively reduces the structural reliability of buildings and infrastructures and, in the worst exposition conditions, may even lead to their collapse in the long period. A change in the material and sectional characteristics of a structural element, due to the environmental damaging effects, changes its mechanical behaviour and varies both the internal stress redistribution and the kinematics through which it reaches its ultimate state. To identify such a behaviour, the evolution of both the damaging process and its mechanical consequences have to be taken into account. This paper presents a computational approach for the analysis of reinforced and prestressed concrete elements under sustained loading conditions and subjected to given damaging scenarios. The effects of the diffusion of aggressive agents, of the onset and development of the corrosion state in the reinforcement and the corresponding mechanical response are studied. As known, the corrosion on the reinforcing bars influences the damaging rate in the cracking pattern evolution; hence, the damage development and the mechanical behaviours are considered as coupled phenomena. The reliability of such an approach is validated in modelling the diffusion of the aggressive agents and the changes in the mechanical response of simple structural elements whose experimental behaviour is reported in Literature. A second set of analyses studies the effects of the corrosion of the tendons of a P.C. beam and explores potentially unexpected structural responses caused by corrosion under different aggressive exposition. The role of the different types and of the different positions of the damaging agents is discussed. In particular, it is shown how the collapse mode of the beam may switch from flexural to shear type, in case corrosion is caused by a localized chloride attack in the shear span.