• Environmental Engineering Research
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• v.11 no.5
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• pp.241-249
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• 2006

A mathematical model is described for the prediction of convective upward transport of an organic solvent driven by evaporation at the surface, which is known as the major transport mechanism in the in-situ photolysis of a soil contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD). A finite-element model was proposed to incorporate the effects of multiphase flow on the distribution of each fluid, gravity as a driving force, and the use of hysteretic models for more accurate description of k-S-p relations. Extensive numerical calculations were performed to study fluid flow through three types of soils under different water table conditions. Predictions of relative permeability-saturation-pressure (k-S-p) relations and fluids distribution for an illustrative soil indicate that hysteresis effects may be quite substantial. This result emphasizes the need to use hysteretic models in performing flow simulations including reversals of flow paths. Results of additional calculations accounting for hysteresis on the one-dimensional unsaturated soil columns show that gravity affects significantly on the flow of each fluid during gravity drainage, solvent injection, and evaporation, especially for highly permeable soils. The rate and duration of solvent injection also have a profound influence on the fluid saturation profile and the amount of evaporated solvent. Key factors influencing water drainage and solvent evaporation in soils also include hydraulic conductivity and water table configuration.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.45-46
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• 2015

Recently, the large amount of sulfur is globally generated by the development of the petroleum refining industry every year. In this study, without the use of the sulfur with a high melting point used in the previous studies, the modified sulfur mortar with addition of a melting point of about 65℃ were tested to determine their distribution and strength properties according to the mixing method and curing conditions. This study is a test to find out the Density, Absorption and Table Flow of the modified sulfur and general sulfur. As result, general industrial sulfur flow was lower, showed a high absorption rate.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.470-472
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• 1996

POSCO has a plan for facility expansion in plate mill by building No.3 Plate Mill. By No.3 Plate Mill's coming on line, POSCO' current plate production of 2.3 million tons will increase by over 1 million tons to 3.36 million tons (Currently, annual domestic demand for plates is 4.42 million tons). With the plan of facility expansion, POSCO also has the plan of integrating the Plate Warehouse. But, we came to have a question whether the roller table from the mill to the warehouse could carry extended products. Engineers working in the mill wanted to install transfer facility to reduce the load of the roller table, but the engineers in facility purchasing team didn't want to buy the new facility. So, We needed to analyzed the material flow by simulation. The simulation was done on the VAX system by SLAM II. And this project was done by two engineers for 2 months. In the end, we concluded that two transfer facilities are needed for material flow with no bottle neck point.

• Journal of the Korea Society of Computer and Information
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• v.6 no.1
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• pp.74-81
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• 2001

In this paper. the architecture of a high-speed ATM router using ATM switch is studied and the performance of the high-speed ATM router is analyzed through simulation. The high-speed ATM router using ATM switch is able to reduce the load of router and the processing time of a packet in the router. The size of router buffers has been studied through simulation processes for the analysis of performance capacity in due course of making changes in routing time(RT), which is the performance capacity parameters of high-speed ATM routers, flow table size(FS), flow live time(FT) and input circuit efficiencies. The result of this study can be used as the source material for analyzing the suitability of equipment in upgrading networks and applying high-speed ATM routers by using ATM switches.

• Journal of Yeungnam Medical Science
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• v.6 no.2
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• pp.47-55
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• 1989

High frequency ventilation (HFV) is a new ventilatory technique that uses very small tidal volume(less than the anatomic dead space) and high frequency, and classified 4 distinct types according to frequency and mode of gas delivery. The mechanism of gas transport of high frequency oscillation ventilation(HFOV) is somewhat different to other types of HFV. To evaluate the determinants of $PaCO_2$ in HFOV, a study was done with a HFOV on 9 cats, and the results are : 1) $PaCO_2$ was not correlated with frequency at the constant stroke volume(6 voltage) and bias flow (6L/minutes). 2) $PaCO_2$ was correlated with stroke volume but not with bias flow under the constant frequency(15Hz/min) and bias flow(3 to 6L/min). From above results, the main determinant of $PaCO_2$ on artificial ventilation with HFOV was stroke volume, but further study between flow, the site of delivery to the airway and humidification of bias flow and $CO_2$ elimination is required in future research.

• Journal of the Korea Furniture Society
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• v.24 no.1
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• pp.15-23
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• 2013

The form of the furniture developed variously according to the flow of the time. The Soban used in the modern living space is used as a decoration. but the furniture has to be used according to the form of the modern life and residential space. The furniture is the medium interacting with the surrounding environment in the residential space. I reconstruct the splendid fanciness of the pattern of the Haejuban and nature of structure and apply to the table design. The table gave the change of the form in order to be suitable for the residential space. and it raised the efficiency of the convenient of the custody and space utilization.

• Geomechanics and Engineering
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• v.4 no.2
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• pp.91-103
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• 2012

Focusing on the effect of excess pore pressure dissipation on liquefaction-induced ground deformation, a series of 1-g shaking table tests were conducted in a rigid soil container by use of saturated Toyoura sand, the relative density of which was 20-60%. These tests were subjected to the sinusoidal base shaking with step increased accelerations: 100, 200, 300 and 400 Gals for 2-4 seconds. Shaking table tests were done using either water or polymer fluid with more viscous than water, thus varying the sand permeability of model tests. Excess pore pressures, accelerations, settlements and lateral deformations were measured in each test. Test results are presented in this paper and the effect of sand permeability on liquefaction and liquefaction-induced ground deformation was discussed in detail.

• Journal of Korean Tunnelling and Underground Space Association
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• v.18 no.6
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• pp.581-591
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• 2016

Several attempts to construct multi-purpose tunnel for both road and waterway have been made. The multi-purpose tunnel is mainly used as a road tunnel, however it is transferred to waterway to control flood during rainy season. The planning of the multi-purpose tunnel is recognized as cost-effective way of infrastructure construction. In case of the multi-purpose tunnel constructed beneath groundwater table, seasonal fluctuation of groundwater table and repeated flow in the tunnel may cause long-term deterioration of the tunnel system. In this study, the behavior of multi-purpose tunnel in view of groundwater table or flow in the tunnel is investigated using model test and numerical modeling method. The results have shown that rising of groundwater table caused buoyant force to the tunnel and the fluctuation of rainwater in the tunnel generated loosening of surrounding ground. It is recommended to evaluate the effect of the long-term water pressure variation in the design of a multi-purpose tunnel.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.11
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• pp.939-945
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• 2002

The rise throughput and the stability in the device fabrication can be obtained by applying chemical mechanical polishing (CMP) process in 0.18 $\mu\textrm{m}$ semiconductor device. However, it still has various problems due to the CMP equipment. Especially, among the CMP components, process variables are very important parameters in determining the removal rate and non-uniformity. In this paper, we studied the DOE (design of experiment) method in order to get the optimized CMP equipment variables. Various process parameters, such as table and head speed, slurry flow rate and down force, have investigated in the viewpoint of removal rate and non-uniformity. Through the above DOE results, we could set-up the optimal CMP process parameters.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.28-29
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• 2017

Recently, the tendency of the insulation of buildings to be important is making the buildings airtight. However, in order to get closer to the technology, it is necessary to improve the performance of walls and panels of buildings, but it is a problem due to the increase of the unit price. We will review the basic data on the density and table flow characteristics of high thermal insulation materials.