• 제목/요약/키워드: reflected diffusion

검색결과 46건 처리시간 0.024초

REFLECTED DIFFUSION WITH JUMP AND OBLIQUE REFLECTION

  • Kwon, Young-Mee
    • 대한수학회보
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    • 제35권2호
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    • pp.269-278
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    • 1998
  • Let ($G,\;{\upsilon}$) be a bounded smooth domain and reflection vector field on $\partial$G, which points uniformly into G. Under the condition that locally for some coordinate system, ${\mid}{\upsilon^i}{\mid}\;i\;=\;1,{\cdot},{\cdot}$,d - 1, where is constant depending on the Lipschitz constant of G, we have tightness for reflected diffusion with jump on G with reflection $\upsilon$ depending only on c. From this, we obtain some properties of L-harmonic function where L is a sum of Laplacian and integro one.

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ON REFLECTED DIFFUSION WITH DISCONTINUOUS COEFFICIENT

  • Kwon, Young-Mee
    • 대한수학회논문집
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    • 제12권2호
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    • pp.419-425
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    • 1997
  • Consider a d-dimensional domain D that has finite Lebesque measure and a Dirichlet form which has discontinuous coefficient. Then the stationary Markov process corresponding to the given Dirichlet form is a semimartingale under suitable condition for D and the coefficient.

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광 항적경로 모델을 이용한 피하조직에서의 광 특성에 관한 연구 (A Study on Optical Properties in Biological Tissue Using A Photon Path Diffusion Model)

  • 임현수
    • 대한의용생체공학회:의공학회지
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    • 제15권3호
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    • pp.265-274
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    • 1994
  • This paper proposes a method of noninvasive reflectance light to measure the blood fractional volume (Vb) and oxygen saturation ($SO_2$) of biological tissue. We chose the red light of 660nm and infrared light of 880nm. In Vivo reflectance data were obtained by the physiological changes front the surface of the skin over the calf in human subject. The reflected light intensity from different layers within a biological tissue was measured by specially designed reflectometer to apply photon path diffusion model. The collected data represent the changes of blood (ractional volume and oxygen saturation at each reflected light wavelengths. The data evaluation was assessed by examining the slopes of the plotted indices for the changes in oxygen saturation and blood (ractional volume. The results presented in this paper claim that light reflectance can separately discriminate the change of blood volume and that of oxygenation in muscle and also in skin.

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우리나라 기술확산정책의 현황과 전개방안 (Technology Diffusion Policies of Korea : Current Situation and Policy Directions)

  • 이공래
    • 기술경영경제학회:학술대회논문집
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    • 기술경영경제학회 1998년도 제13회 하계학술발표회 논문집
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    • pp.226-249
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    • 1998
  • Technology diffusion policy can be defined as the role of government in linking knowledge production with usage. It has an importance due to the fact that linking knowledge between the producing agent and using agent does not automatically occur. If knowledge produced by an R&D agent is not used by somebody else, the knowledge may deteriorate to a social loss since knowledge production consumes a considerable degree of social resources. Explicit technology diffusion policies are not found in Korea. There we, however, a number of implicit policies to promote technology diffusion, mainly by promoting cooperation among universities, industries and research institutes. Government R&D programs have provided incentives for cooperative research projects, and many government sponsored institutes have been assigned the role of technology assistance for small and medium sized firms. Nevertheless, diffusion policies remain weak in comparison to other innovation and technology policies. This is reflected in the relatively small scale of government support for technology diffusion programs. In addition, there is no systematic approach between the different ministries for enhancing diffusion across technologies, institutions, sectors and regions. A comprehensive evaluation of government diffusion programs, which is necessary for improving policy and program design, is lacking. Enhancing the diffusion of technology in Korea will require the strengthening of policies at different levels, including; 1) increasing the orientation of science and technology policies towards diffusion; 2) increasing the scale of existing diffusion programs; 3) developing new diffusion programs, in particular sector-specific or manpower training programs; 4) developing policies to encourage a culture of cooperation that can facilitate technology diffusion; and 5) carrying out substantial policy research to develop diffusion policies.

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Propagation of plane waves in an orthotropic magneto-thermodiffusive rotating half-space

  • Sheokand, Suresh Kumar;Kumar, Rajeshm;Kalkal, Kapil Kumar;Deswal, Sunita
    • Structural Engineering and Mechanics
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    • 제72권4호
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    • pp.455-468
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    • 2019
  • The present article is aimed at studying the reflection phenomena of plane waves in a homogeneous, orthotropic, initially stressed magneto-thermoelastic rotating medium with diffusion. The enuciation is applied to generalized thermoelasticity based on Lord-Shulman theory. There exist four coupled waves, namely, quasi-longitudinal P-wave (qP), quasi-longitudinal thermal wave (qT), quasi-longitudinal mass diffusive wave (qMD) and quasi-transverse wave (qSV) in the medium. The amplitude and energy ratios for these reflected waves are derived and the numerical computations have been carried out with the help of MATLAB programming. The effects of rotation, initial stress, magnetic and diffusion parameters on the amplitude ratios are depicted graphically. The expressions of energy ratios have also been obtained in explicit form and are shown graphically as functions of angle of incidence. It has been verified that during reflection phenomena, the sum of energy ratios is equal to unity at each angle of incidence. Effect of anisotropy is also depicted on velocities of various reflected waves.

Twisted product representation of reflected brownian motion in a cone

  • Kwon, Young-Mee
    • 대한수학회논문집
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    • 제11권2호
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    • pp.471-480
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    • 1996
  • Consider a strong Markov process $X^0$ that has continuous sample paths in the closed cone $\bar{G}$ in $R^d(d \geq 3)$ such that the process behaves like a ordinary Brownian motion in the interior of the cone, reflects instantaneously from the boundary of the cone and is absorbed at the vertex of the cone. It is shown that $X^0(t)$ has a representation $R(t) \ominus (t)$ where $R(t) \in [0, \infty)$ and $\ominus(t) \in S^{d-1}$, the surface of the unit ball.

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산전 지역의 거점 확산형 주거환경개선사업에 대한 주민의견 조사 (The Survey on Residents' Opinion of the Stronghold Diffusion Residential Environment Improvement Plan in San-Jun)

  • 김선중;장희진
    • 한국주거학회:학술대회논문집
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    • 한국주거학회 2009년 춘계학술발표대회 논문집
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    • pp.332-337
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    • 2009
  • The stronghold diffusion style method is resident participation style residential environment improvement plan that first of all, the general public constructs base facilities which the temporary occupancy public housings, commonness use facilities, roads, etc. And then with using the public housing of the stronghold sector, the resident oneself improves the house with independence or commonness. As a result induction of the voluntary participation of economic situation and the resident where the improvement will is reflected and introduction of versatile maintenance method through stronghold development with participation of the general public, this study tries to present the residential improvement method of diffusion style. San-Jun was selected in the subject of investigation area in stronghold diffusion style residential environmental improvement plan area. Investigation contents population register quality and quality of present house, the degree which is a house environmental improvement plan, about residential improvement the fact etc. Because unsatisfactorily in compliance with the deterioration and spatial narrow of the house, The above of half is an improvement intention. Hereafter residential improvement, According to the condition which is economic, residential improvement will change. The plan will be able to augment the economic enemy capability of the resident should grope and the residents oneself creates the environment will be able to improve the house. Also with creating, activating a resident organization, through autonomous decision-making process, the residential improvement could be advanced continuously.

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복잡한 지형상에서 실시간 피폭해석 시스템 검증 (Validation of a Real-Time Dose Assessment System over Complex Terrain)

  • 서경석;김은한;황원태;최영길;한문희;정성태
    • Journal of Radiation Protection and Research
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    • 제24권1호
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    • pp.31-38
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    • 1999
  • 원자력시설의 사고시 신속한 방재대책 결정지원 체계를 수립하기 위하여 실시간 방사선 피폭해석 시스템(FADAS : Following Accident Dose Assessment System)을 개발하였다. 개발된 시스템의 정확도 향상 및 국내 부지 특성자료의 모수화를 위하여 복잡한 지형상에 위치한 영광 원자력발전소 주변에서 야외 확산실험이 수행되었다. 확산실험을 통하여 얻어진 바람의 평균 및 난류장 성분은 부지 특성별 변수로 실시간 방사선 피폭해석 시스템에 반영되었다. 확산모형의 계산결과와 실험을 통하여 관측된 추적자 가스의 농도분포를 상호 비교한 바 어느 정도 일치하고 있었다. 개발된 시스템은 현재 구축중인 국가 규모의 비상대응지원체제에 기본 모듈로서 활용 중에 있으며 지속적인 확산실험을 통하여 부지 특성 변수들이 반영된 확산모형을 개선할 예정이다.

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라그랑지 입자 모델을 이용한 k-ε Algebraic Stress Model과 Mellor-Yamada Model의 비교 연구 (A Comparative Study of k-ε Algebraic Stress Model and Mellor-Yamada Model Applied to Atmospheric Dispersion Simulation Using Lagrangian Particle Dispersion Model)

  • 김상백;오성남
    • 한국대기환경학회지
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    • 제20권1호
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    • pp.47-58
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    • 2004
  • The $textsc{k}$-$\varepsilon$ algebraic stress model (KEASM) was applied to atmospheric dispersion simulation using the Lagrangian particle dispersion model and was compared with the most popular turbulence closure model in the field of atmospheric simulation, the Mellor-Yamada (MY) model. KEASM has been rarely applied to atmospheric simulation, but it includes the pressure redistribution effect of buoyancy due to heat and momentum fluxes. On the other hand, such effect is excluded from MY model. In the simulation study, the difference in the two turbulence models was reflected to both the turbulent velocity and the Lagrangian time scale. There was little difference in the vertical diffusion coefficient $\sigma$$_{z}$. However, the horizontal diffusion coefficient or calculated by KEASM was larger than that by MY model, coincided with the Pasquill-Gifford (PG) chart. The applicability of KEASM to atmospheric simulations was demonstrated by the simulations.s.

양모의 저온 염색 소개 - Sirolan LTD Process from ICI (Low Temperature Dyeing Process by Intercellular diffusion through Cell Membrane Complex Modification of Wool. - Technology based on CSIRO and ICI)

  • 윤일남
    • 한국염색가공학회:학술대회논문집
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    • 한국염색가공학회 2001년도 추계학술발표회 논문집
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    • pp.3-11
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    • 2001
  • Fundamental studies at the CSIRO division of Wool technology and ICI on the diffusion of dyes into wool〔1,2〕have let to development of a new approach to wool dyeing. In this method, the cell membrane complex of wool is modified before dyeing by treatment under mildly alkaline conditions with a special chemicals. Wool pretreated with ethoxylated quaternary ammonium salt has an increased rate of dyebath exhaustion and dye penetration early in the dyeing cycle. This enables the treated material to be dyed below the boil for a similar time to the conventional cycle. This technique can be used on untreated and shrinkresist-treated wool and wool/nylon blends. In addition to good macro-levelness and excellent coverage of tippiness, the low temperature dyeing process give higher exhaustion levels of dyestuffs and insect-resist agent and hence cleaner effluent liquors, compared with conventional dyeing process. Low Temperature Dyeing process cause significantly less fiber damage than conventional way. The reduction in damage is reflected in improved processing performance of the dyed wool.

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