• Title/Summary/Keyword: Cross diffusion

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Drift Velocities for Electrons in $SF_6$-Ar Mixtures Gas by Simulation (시뮬레이션에 의한 $SF_6$-Ar혼합기체(混合氣體)의 전자(電子) 이동속도(移動速度))

  • Kim, Sang-Nam
    • Proceedings of the KIEE Conference
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    • 2006.07c
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    • pp.1566-1567
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    • 2006
  • Energy distribution function for electrons in $SF_6$-Ar mixtures gas used by MCS-BEq algorithm has been analysed over the E/N range $30{\sim}300$[Td] by a two term Boltzmann equation and by a Monte Carlo Simulation using a set of electron cross sections determined by other authors, experimentally the electron swarm parameters for 0.2[%] and 0.5[%] $SF_6$-Ar mixtures were measured by time-of-flight (TOF) method. The results show that the deduced electron drift velocities, the electron ionization or attachment coefficients, longitudinal and transverse diffusion coefficients and mean energy agree reasonably well with theoretical for a rang of E/N values.

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A Simulation of the ionization coefficients in mixtures of $SF_6$ and Ar (시뮬레이션을 이용한 $SF_6-Ar$의 전리계수)

  • Kim, Sang-Nam
    • Proceedings of the KIEE Conference
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    • 2005.07c
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    • pp.2202-2204
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    • 2005
  • In this dissertation the results of the combined experimental and theoretical studies designed to understand and predict the spatial growth and transport coefficients for electrons in $SF_6$ and $SF_6-Ar$ mixtures have described. The transport coefficients for electrons in (0.1[%]) $SF_6-Ar$, (0.5[%])$SF_6-Ar$,(1.0[%])$SF_6-Ar$,(3.0[%])$SF_6-Ar$ and(5.0[%]) $SF_6-Ar$ mixtures were measured by time-of- flight method, and the electron energy distribution function and the parameters of the velocity and the diffusion were determined by the variation of the collision cross-sections with energy.

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Drift Velocities for Electrons in $SF_6$-Ar Mixtures Gas by Simulation (시뮬레이션을 이용한 $SF_6$-Ar혼합기체의 전자 이동속도)

  • Hwang, Cheong-Ho;Kim, Sang-Nam
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.451-452
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    • 2007
  • Drift velocities for electrons in $SF_6$-Ar mixtures gas by simulation has been analysed over the EIN range 30~300[Td] by a two term Boltzmann equation and by a Monte Carlo Simulation using a set of electron cross sections determined by other authors, experimentally the electron swarm parameters for 0.2[%] and 0.5[%] $SF_6$-Ar mixtures were measured by time-of-flight (TOF) method. The results show that the deduced electron drift velocities, the electron ionization or attachment coefficients. longitudinal and transverse diffusion coefficients and mean energy agree reasonably well with theoretical for a rang of E/N values.

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A Simulation of the ionization coefficients in mixtures of $SF_6$ and Ar (시뮬레이션을 이용한 $SF_6$-Ar혼합기체의 전리계수)

  • Kim, Sang-Nam
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.1494-1495
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    • 2007
  • In this dissertation the results of the combined experimental and theoretical studies designed to understand and predict the spatial growth and transport coefficients for electrons in $SF_6$ and $SF_6$-Ar mixtures have described. The transport coefficients for electrons in (0.1[%])$SF_6$-Ar, (0.5[%])$SF_6$-Ar, (1.0[%])$SF_6$-Ar, (3.0[%])$SF_6$-Ar and (5.0[%])$SF_6$-Ar mixtures were measured by time-of-flight method, and the electron energy distribution function and the parameters of the velocity and the diffusion were determined by the variation of the collision cross-sections with energy.

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Energy Distribution Function for Electrons in SF6+Ar Mixtures Gas used by MCS-BEQ Algorithm (SF6+Ar혼합기체의 MCS-BEq에 의한 전자분포함수)

  • Kim, Sang-Nam
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.51 no.1
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    • pp.28-32
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    • 2002
  • Energy distribution function for electrons in $SF_6+Ar$ mixtures gas used by MCS-BEq algorithm bas been analysed over the E/N range 30-300[Td] by a two term Boltzmann equation and by a Monte Carlo Simulation using a set of electron cross sections determined by other authors, experimentally the electron swarm parameters for 0.2[%] and 0.5[%] $SF_6+Ar$ mixtures were measured by time-of-flight(TOF) method. The results show that the deduced electron drift velocities, the electron ionization or attachment coefficients, longitudinal and transverse diffusion coefficients and mean energy agree reasonably well with theoretical for a rang of E/N values.

Measurement of the Thermal Behavior of a Nd:YAG Laser Rod by Analyzing Interference Fringe from a He-Ne Probe Beam (He-Ne 레이저 탐사광의 간섭효과를 이용한 Nd:YAG 레이저봉의 온도측정)

  • 김광석;공홍진;김덕현;김철중
    • Korean Journal of Optics and Photonics
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    • v.1 no.2
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    • pp.204-209
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    • 1990
  • The temperature variation at a laser rod center induced by high repetetion rate pumping was measured by counting the number of inteference frigne shift and found to be consistent with the theoretical value obtained from heat diffusion equation. The spatial homogeneity and energy transfer rate of flashlamp pumping by the single elliptical reflector plated with gold were evaluated by measuring interference fringes oever the cross section of a Nd:YAG laser rod.

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A Study on the Dipole Chaff RCS for Aircraft (항공기용 다이폴 채프의 RCS에 관한 연구)

  • Lim, Joong-Soo;Kim, Min-Nyun;Chae, Gyoo-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.3
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    • pp.690-694
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    • 2008
  • In this paper, the computation of electromagnetic wave scattering is presented for chaff clouds which is widely used to protect an aircraft. The RCS depends on the wind, the aircraft velocity, and the atmospheric diffusion. It is assumed that the RF chaff is a thin dipole antenna and the RCS is calculated based on the scattering wave theory. The theoretical estimation and the simulation results are compared and shown a good agreement.

Microstructures and Cyclic Oxidation Resistance of Aluminide Coatings for Inconel 600 (Inconel 600에 있어서 Al抗散浸透 被覆層의 微細組織과 耐反復酸化性)

  • Chung, In-Sang;Byun, Chang-Suk
    • Journal of the Korean institute of surface engineering
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    • v.20 no.2
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    • pp.60-73
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    • 1987
  • For the purpose of improving the cyclic oxidation resistance of Ni-base superalloy, Inconel 600, aluminide coating methods are studied. The formation rate of aluminide coating layers is measured as a function of time and pack composition to find out the optimum coating condition. The evaluation of cyclic oxidation is established by the change in weight, the microphotography and EPMA of cross sectional area during $200^{\circ}C\;{\leftrightarrow}\;950^{\circ}C\;and\;200^{\circ}C\;{\leftrightarrow}\;1100^{\circ}C$, respectively. The thickness of coating layer and weight gains are parabolic behavior in propotion to time and Al contents. In pack of low aluminum contents, 2 wt%, however, weight gain is decreased when activator, $NH_4Cl$ is higher than 2 wt%. The cyclic oxidation resistance of the coating carried out at 1100$^{\circ}C$ are superior to those of the coating diffusion-treated after pack cementation at 800$^{\circ}C$. Aluminide oxide, which is formed in external scale, is barrier to the cyclic oxidation.

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Innovation Performance of Social Enterprises: An Empirical Study in India

  • Tirumalsety, Revendranath;Gurtoo, Anjula
    • Asian Journal of Innovation and Policy
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    • v.8 no.2
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    • pp.238-273
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    • 2019
  • Social enterprises pursue innovation to create socio-economic impact for the marginalized communities. The founders of social enterprises drive goal-oriented innovation, whereas, interactions with ecosystem is crucial to create and diffuse innovation. However, studies are scant on creation as well as diffusion of innovation emerging from social enterprises. This paper attempts to understand innovation emerging from social enterprises through an exploration of innovation focus, interactions with ecosystem, and measurement of innovation performance. A cross-sectional study is performed to understand the relationship between founders' orientation and innovation performance, and the mediating role of innovation focus and ecosystem interactions. A cluster sampling across four states in India - Karnataka, Telangana, Maharastra and Tamil Nadu - resulted in participation from 207 social enterprises. The results of partial least squared structural equation modeling (PLS-SEM) demonstrate the positive complementary mediating role of innovation focus in the relationship between founders' orientation and innovation performance. Moreover, this paper illustrates that founders' persistent focus on innovation creates positive results for social enterprises as well as beneficiaries.

A Study on Industries's Leading at the Stock Market in Korea - Gradual Diffusion of Information and Cross-Asset Return Predictability- (산업의 주식시장 선행성에 관한 실증분석 - 자산간 수익률 예측 가능성 -)

  • Kim Jong-Kwon
    • Proceedings of the Safety Management and Science Conference
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    • 2004.11a
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    • pp.355-380
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    • 2004
  • I test the hypothesis that the gradual diffusion of information across asset markets leads to cross-asset return predictability in Korea. Using thirty-six industry portfolios and the broad market index as our test assets, I establish several key results. First, a number of industries such as semiconductor, electronics, metal, and petroleum lead the stock market by up to one month. In contrast, the market, which is widely followed, only leads a few industries. Importantly, an industry's ability to lead the market is correlated with its propensity to forecast various indicators of economic activity such as industrial production growth. Consistent with our hypothesis, these findings indicate that the market reacts with a delay to information in industry returns about its fundamentals because information diffuses only gradually across asset markets. Traditional theories of asset pricing assume that investors have unlimited information-processing capacity. However, this assumption does not hold for many traders, even the most sophisticated ones. Many economists recognize that investors are better characterized as being only boundedly rational(see Shiller(2000), Sims(2201)). Even from casual observation, few traders can pay attention to all sources of information much less understand their impact on the prices of assets that they trade. Indeed, a large literature in psychology documents the extent to which even attention is a precious cognitive resource(see, eg., Kahneman(1973), Nisbett and Ross(1980), Fiske and Taylor(1991)). A number of papers have explored the implications of limited information- processing capacity for asset prices. I will review this literature in Section II. For instance, Merton(1987) develops a static model of multiple stocks in which investors only have information about a limited number of stocks and only trade those that they have information about. Related models of limited market participation include brennan(1975) and Allen and Gale(1994). As a result, stocks that are less recognized by investors have a smaller investor base(neglected stocks) and trade at a greater discount because of limited risk sharing. More recently, Hong and Stein(1999) develop a dynamic model of a single asset in which information gradually diffuses across the investment public and investors are unable to perform the rational expectations trick of extracting information from prices. Hong and Stein(1999). My hypothesis is that the gradual diffusion of information across asset markets leads to cross-asset return predictability. This hypothesis relies on two key assumptions. The first is that valuable information that originates in one asset reaches investors in other markets only with a lag, i.e. news travels slowly across markets. The second assumption is that because of limited information-processing capacity, many (though not necessarily all) investors may not pay attention or be able to extract the information from the asset prices of markets that they do not participate in. These two assumptions taken together leads to cross-asset return predictability. My hypothesis would appear to be a very plausible one for a few reasons. To begin with, as pointed out by Merton(1987) and the subsequent literature on segmented markets and limited market participation, few investors trade all assets. Put another way, limited participation is a pervasive feature of financial markets. Indeed, even among equity money managers, there is specialization along industries such as sector or market timing funds. Some reasons for this limited market participation include tax, regulatory or liquidity constraints. More plausibly, investors have to specialize because they have their hands full trying to understand the markets that they do participate in

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