• Journal of Soil and Groundwater Environment
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• v.11 no.6
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• pp.28-34
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• 2006

Laboratory column tests using $Cl^-$ tracer were conducted to study the correlation of soil particle distribution and hydrodynamic dispersion mechanism with three kinds of ununiformed soil samples, in which the ratio of gravel and sand versus silt and clay is 24.5 for S-1 soil, 4.48 for S-2 soil, and 0.4 for S-3 soil. Chloride breakthrough curves with time were fitted with gaussian functions. The relative concentrations of chloride were converged to 1.0 after 0.7 hours for S-1, 6.3 hours for S-2, and 389 hours for S-3. Average linear velocity, longitudinal dispersion coefficient, and longitudinal dispersivity were calculated by chloride breakthrough curves. Longitudinal dispersion coefficients were $1.20{\times}10^{-4}\;m^2/sec$ for S-1, $8.87{\times}10^{-7}\;m^2/sec$ for S-2, and $1.94{\times}10^{-9}\;m^2/sec$ for S-3. Peclet numbers calculated by the molecular diffusion coefficient of chloride and the mean grain diameters of soils were $2.59{\times}10^2$ for S-1, $6.27{\times}10^0$ for S-2, and $1.35{\times}10^{-4}$ for S-3. Mechanical dispersion was dominant for the hydrodynamic dispersion mechanism of S-1. Both mechanical dispersion and molecular diffusion were dominant for the hydrodynamic dispersion mechanism of S-2, but mechanical dispersion was ascendant over molecular diffusion. Hydrodynamic dispersion in S-3 was occurred mainly by molecular diffusion. When plotting three soils on the graph of $D_L/D_m$ versus Peclet number produced by Bijeljic and Blunt (2006), the values of $D_L/D_m$ for S-1 and S-2 were more than 2.0 order compared to their graph. S-3 was not plotted on their graph because the Peclet number was as small as $1.35{\times}10^{-4}$.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09a
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• pp.520-521
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• 2005

• The Journal of the Korea Contents Association
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• v.16 no.11
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• pp.358-368
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• 2016

The kimchi industry is a high value-added industry, boosts the self-esteem of the people as a measure of a country's culture industry, and is one of the strategic industries to be fostered. However, the kimchi industry is struggling due to the lack of national consensus on the importance and value of the kimchi industry. Therefore, the purpose of this study was to analyze how much the kimchi industry contributes to the national economy by measuring economic effects of the kimchi industry on national economy. To achieve this purpose, the study used the kimchi industry Input-Output Table of year 2013 of korea. The results shows that kimchi industry induce 510,013 billion won of national production, especially the retail trade distribution industry shows that production inducement coefficient is 1.8418(row), 1.1760(column), Index of the power of dispersion is 0.9611, index of the sensitivity of dispersion is 0.6136, income inducement coefficient is 0.1820, tax inducement coefficient is 0.0084 and employment inducement coefficient is 0.003. With the help of information technology.

• Journal of the Optical Society of Korea
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• v.20 no.5
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• pp.567-574
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• 2016

We propose a highly birefringent and dispersion compensating photonic crystal fiber based on a double line defect core. Using a finite element method (FEM) with a perfectly matched layer (PML), it is demonstrated that it is possible to obtain broadband large negative dispersion of about -400 to -427 ps/(nm.km) covering all optical communication bands (from O to U band) and to achieve the dispersion coefficient of -425 ps/(nm.km) at 1.55μm. In addition, the highest birefringence of the proposed PCF at 1.55 μm is 1.92 × 10^-2 and the value of birefringence from the wavelength of 1.26 to 1.8 μm (covering O to U bands) is about 1.8 × 10^-2 to 1.92 × 10^-2. It is confirmed that from the simulation results, the confinement loss of the proposed PCF is always less than 10^-3 dB/km at 1.55 μm with seven fiber rings of air holes in the cladding.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.8 no.1
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• pp.1-13
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• 1972

Yellow croacker, Tseudociaena manchurica Jordan et Thompson in the Yellow Sea and East China Sea are subjected to be caught by trawl nets throughout the year. First indices of population size in every period 8re calculated. Considering present status of the yellow croacker fishery and ecology of the fish, mathematical models must have been established in order to determine catchability coefficient, natural m ortali ty, fishing mortality, recrui ting coefficient of the fish ing ground, and dispersion coefficienl from the fishing ground. The results an, summmarized as follows: Catchabil i ty coefficient $(C) = 2. 2628 {\times} 10^{-5}$ Natural mortality (M)=0.3293 Population for lhe first half season(July 1st to the following January 3lst) Initial population = 14, 621 $/\frac{M}{T}$ Recruitment =45, 597 $/\frac{M}{T}$ Natural mortality = 8, 660 $/\frac{M}{T}$ Final population =42, 970 $/\frac{M}{T}$ Population for the latter 1131f scason(February 1st to June 30th) Initial population = 69, 170 $/\frac{M}{T}$ Dispersion =51, 688 $/\frac{M}{T}$ Natural mortality = 6, 082 $/\frac{M}{T}$ Final population = 1, 802 $/\frac{M}{T}$.

• Spatial Information Research
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• v.20 no.6
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• pp.69-76
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• 2012

In this study, we derived the characteristics of the geo-spatial information industry by using input-output analysis. For this analysis, we classified the geo-spatial information industry and reorganized the input-output table. And we derived the production inducement coefficient, index of the power of dispersion and index of the sensitivity of dispersion in the geo-spatial information industry. We confirmed that geo-spatial information industry has a small production inducement coefficient and a great forward linkage effect. Based on these facts, we suggested the strategy direction as follows: 1) building the industrial eco-system, 2) managing both advance and applicability enhancement, 3) Establishing from a long-term point of view.

• Journal of Korean Ophthalmic Optics Society
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• v.10 no.4
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• pp.267-272
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• 2005

We deposited thin films of organic light-emitting-material $Alq_3$(alumina quinoline) on silicon and slide-glass substrates using thermal evaporation method, and measured spectra of ellipsometry angles ${\Delta}$ and ${\Psi}$ in the photon-energy range of 1.5~5.0 eV using a variable angle spectroscopic ellipsometer. The optical constants, refractive index and extinction coefficient, of $Alq_3$ were determined via the dispersion parameters extracted from the curve-fitting process based on Jellison-Modine dispersion function. The reliability of determined optical constants were verified through the comparison of measured and simulated transmittance curves and the good agreement between simulated absorption-coefficient curves and absorbance spectra measured using a spectrophotometer.

• Journal of Korea Water Resources Association
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• v.54 no.11
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• pp.863-873
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• 2021

The mechanical dispersion which dominates solute transport in porous media is caused by the difference in flow velocity within pores. Longitudinal dispersion coefficient and longitudinal dispersivity that are hydro-dispersive parameters of advection-dispersion equation can only be obtained by experiment. Hydraulic mean radius that represents the amount and intensity of flowing water within pores can be obtained by the formula using the factors for physical properties. A slug injection test was conducted and a power type empirical formula for obtaining a longitudinal dispersivity using a hydraulic mean radius in rockfill porous media was derived. It is possible to obtain the longitudinal dispersivity depending on transport distance because it contains a formula for a scale constant, and expected to be applicable to waterways filled with homogeneous gravel and small flow rate.

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.289-293
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• 2008

In this study, in order to find out the movement of polluted substance that is flown into the river and the characteristics of dispersion, the experiment that used the RI (Radio Isotope) tracer in the river was undertaken, and by using the experiment result, the figure modelling was undertaken to analyze the general type of pollutant dispersion. In addition, in order to calculate more accurate dispersion range and moving time, the experiment was done in about 2km from the measuring points of Namdaecheon around the Yongdam Dam of the upper Geum River to the lower stream, and modeling was undertaken for the 20km zone from the measuring points to the lower stream. In order to find out the flow of river and dispersion of polluted substance, RMA (Resource Modeling Associates)-2 and RMA-4 program are used in study. The site experiment using the RI was implemented for the experiment in the applied area and the same area, and the distance between each zone was set for 1㎞ with the slight difference for site situation and measured the density date of one second distance through the NaI apparatus to measure the density data of one second interval. On the basis of this measured data, it is compared and analyzed with the result of figure copy of RMA-2 and RMA-4 models to make the comparison and analysis of density distribution following the change in expansion coefficient that makes great influence on expansion range and dispersion in natural rivers. The influence of expansion coefficient on river can be researched and the measured density data, the maximum and minimum density time, and the basic data to calculate the expansion coefficient was prepared in this study.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.258-259
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• 2009

Pipe wall thinning is one of severe problems on structural safety in nuclear power plants. A guided wave can be a proper tool for the fast evaluation or monitoring. As for gradual wall thinnings, however, low sensitivity caused by the low reflection coefficient limits the use of the guided wave. In this work, instead of the guided wave reflection at the wall thinning, the variation of dispersion characteristics is concerned. SH waves were employed due to several advantages and the magnetostrictive patch transducers were used for the excitation and sensing of the SH waves. The proposed method were verified with some experiments and showed the feasibility as an effective tool for the inspection of gradual wall thinning.