• Title/Summary/Keyword: Absorption model

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Optical Properties of Admolecules near a Phase -Conjugate Mirror (위상 공액 거울에 흡착된 분자의 광학적 성질)

  • 김영식
    • Journal of the Korean Vacuum Society
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    • v.5 no.1
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    • pp.33-38
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    • 1996
  • The induced linewidth, frequency shift and absorption spectrum for a molecular dipole in the vicinity of a phase -conjugate mirror have been investgated within a classical phenomenological model, with particularreference to the technique of optical phase conjugation by a surface. While the shifts and the widths show similar characteristics as those obtained recently by Bochove who considered the problem within the context of four-wave mixing, the results obtained in the present model can be defined uniquely with the possibility of an infinite lifetime for the excited admolecule . Furthermore, the absorption lineshape obtained here some interesting features which depend on both the magnitude and the phase of the complex reflectivity of the mirror.

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Development of an Accurate Numerical Model for Density-Dependent Groundwater Flow and Solute Transport (밀도가 변하는 지하수흐름과 용질의 수송을 위한 정확한 수치모델의 개발)

  • Park, Nam-Sik
    • Journal of Korea Water Resources Association
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    • v.30 no.6
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    • pp.753-759
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    • 1997
  • A new numerical model was doveloped to simulate density-dependent ground water flow and solute transport. Accuracy of a numerical model depends upon how well it simulates advection dominant situations because numerical oscillations can spoil solutions for these situations. Nonlinear oscillation-absorption finite element method. based on the variational principle, was employed. Unlike previous numerical models, this model can easily be expanded for more complex situations. Accuracy of the model is evaluated by comparing with analytical solutions and results of other numerical model.

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An Investigation on the Acoustic Impedances and Estimation Models of Multiple Layer Perforated Plate Systems (다중 다공판 시스템의 음향임피던스와 계산모델에 관한 고찰)

  • 이동훈;허성춘;허성욱;김민배
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.05a
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    • pp.1238-1243
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    • 2002
  • In this study, the validity of the acoustic impedance model and the estimation model by electro-acoustic analogy suggested by Maa for predicting the absorptive performance of multiple layer perforated plate systems is investigated. From the comparison between the experiment and calculation for the absorption performance of double layer perforated plate system, the calculated results of using Rao and Munjal's impedance model and transfer matrix method are closer to the experimental values than those of using Maa's impedance model and electro-acoustic analogy. Therefore, in order to apply the acoustic impedance model and the estimation model by electro-acoustic analogy suggested by Maa to the multiple layer perforated plate systems, it is necessary that the suggested acoustic impedance and estimation models should be re-examined.

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Does Inward Foreign Direct Investments Affect Export Performance of Micro Small and Medium Enterprises in India? An Empirical Analysis

  • SINGHA, Seema;KUMAR, Brajesh;CHOUDHURY, Soma Roy Dey
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.9
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    • pp.143-156
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    • 2022
  • This article examines the effect of inward foreign direct investments (FDI) on the export performance of micro, small & medium enterprises (MSMEs) in India, and investigates the spillover impact and absorption capacity of the MSMEs sector. For the first time, the researchers applied the intersectoral linkage approach to investigate the matter and used a panel dataset between 2006 and 2017. The coefficients of forward and backward linkages are estimated by using the Rasmussen method, the study employs a basic linear panel data model, followed by various diagnostic tests to identify the problem of heteroscedasticity, autocorrelation / serial correlation, cross-sectional dependencies, multicollinearity, time-individual specific tests, and unobserved effects. The PCSE model was applied for robust standard error and the Hausman-Taylor IV model to check the robustness of the result generated in the linear panel data model. Despite the high prevalence of forward and backward intersectoral connections and the Lack of absorption capacity of local firms, the results show that FDI has little of an impact on the export performance of micro, small, and medium-sized businesses in India. This study adds to the existing literature on determining local firms' spillover effect and absorption capacity in response to inward FDI.

Inference of Chromospheric Plasma Parameters on the Sun from Strong Absorption Lines

  • Chae, Jongchul;Madjarska, Maria S.;Kwak, Hannah;Cho, Kyuhyoun
    • The Bulletin of The Korean Astronomical Society
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    • v.45 no.1
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    • pp.44.4-45
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    • 2020
  • The solar chromosphere can be observed well through strong absorption lines. We infer the physical parameters of chromospheric plasmas from these lines using a multilayer spectral inversion. This is a new technique of spectral inversion. We assume that the atmosphere consists of a finite number of layers. In each layer the absorption profile is constant and the source function is allowed to vary with optical depth. Specifically, we consider a three-layer model of radiative transfer where the lowest layer is identified with the photosphere and the two upper layers are identified with the chromosphere. This three-layer model is fully specified by 13 parameters. Four parameters can be fixed to prescribed values, and one parameter can be determined from the analysis of a satellite photospheric line. The remaining eight parameters are determined from a constrained least-squares fitting. We applied the multilayer spectral inversion to the spectral data of the Hα and the Ca II 854.21 nm lines taken in a quiet region by the Fast Imaging Solar Spectrograph (FISS) of the Goode Solar Telescope (GST). We find that our model successfully fits most of the observed profiles and produces regular maps of the model parameters. We conclude that our multilayer inversion is useful to infer chromospheric plasma parameters on the Sun.

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A Mediation Analysis of Absorption Capacity by Bootstrapping Technique in Multiple Mediator Model (다중매개모델에서 bootstrapping기법을 이용한 흡수능력의 매개효과 분석)

  • Kim, Hyun-Woo;Lee, Hong-Bae;Shin, Yong-Ho
    • Journal of the Korea Society for Simulation
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    • v.24 no.4
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    • pp.89-96
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    • 2015
  • The mediation methods suggested by Baron and Kenny, Sobel, Aroian and Goodman, have widely used to test the mediating effect. However, as there are many problems in statistical test power, as well as statistical accuracy, a bootstrapping technique has been suggested as an alternative. In this paper, we adopt the phantom variables based on the bootstrapping technique to test the mediating effect in multiple mediator model consisting of three or more mediating variables. In particular, we formulate the multiple mediator model for analyzing the relations among organizational resources, the absorption capacity as mediating variables and technology commercialization capabilities. And using the bootstrapping approach, we analyzed the mediating effect of the absorption capacity by setting of phantom variables and calculated total indirect effect size and the statistical significance. The empirical results are as follows. First, we confirmed that the bootstrapping approach and the phantom variable is the very efficient and systematic mediation method. Second, we recognized that there is a difference in the mediating characteristics of the absorption capacity depending on the resource characteristics of human resources and material resources obviously.

Study on Normal and Random incidence Absorption Coefficient (수직 및 랜덤입사 흡음률에 관한 연구)

  • Kang Hyun-Ju;Kim Bong-Ki;Kim Sang-Ryul
    • Proceedings of the Acoustical Society of Korea Conference
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    • spring
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    • pp.283-286
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    • 2000
  • Comparison for various empirical models of normal incident absorption was made, along with experiments. Comparative result indicates that Voronina model which is function of fiber diameter and porosity is more suitable than the other models. An investigation for correlation between normal and random incident absorption was carried out by experiment and analysis. It appears that at the low frequencies, the random incident absorption is higher than the normal one, whileas at the high frequencies, the random incident absorption is decreased due to the effect of grazing incident components.

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A study on The Application of a Vertical Absorption System Cooled by Air (공냉형 수직 흡수식 시스템의 적용에 관한 연구)

  • 김정국;조금남
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 2003.05a
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    • pp.351-357
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    • 2003
  • In absorption system, the performance of the absorber is critical the overall system performance, size, and first-cost. The objective of this paper is to provide a comprehensive review of the significant effects that researchers have made to numerically analysis model the coupled heat and mass transfer process that occur during falling-film absorption and experimental researches. This study includes experimental work in the enhancement of absorption performance, the effect of the geometry of a vertical absorber, and the effect of configuration of absorption system. This paper is used to highlight key areas which need attention such as film ans vapor hydrodynamics, especially the non-periodicity, instability, and recirculatory motion of waves in the vertical absorber case.

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Coupled Heat and Mass Transfer in Absorption of Water Vapor into LiBr-$H_2O$ Solution Flowing on Finned Inclined Surfaces

  • Seo, Taebeom;Cho, Eunjun
    • Journal of Mechanical Science and Technology
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    • v.18 no.7
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    • pp.1140-1149
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    • 2004
  • The absorption characteristics of water vapor into a LiBr-H$_2$O solution flowing down on finned inclined surfaces are numerically investigated in order to study the absorbing performances of different surface shapes of finned tubes as an absorber element. A three-dimensional numerical model is developed. The momentum, energy, and diffusion equations are solved simultaneously using a finite difference method. In order to obtain the temperature and concentration distributions, the Runge-Kutta and the Successive over relaxation methods are used. The flat, circular, elliptic, and parabolic shapes of the tube surfaces are considered in order to find the optimal surface shapes for absorption. In addition, the effects of the fin intervals and Reynolds numbers are studied. The results show that the absorption mainly happens near the fin tip due to the temperature and concentration gradient, and the absorbing performance of the parabolic surface is better than those of the other surfaces.