• Korean Journal of Oriental Medicine
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• v.4 no.1 s.4
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• pp.47-62
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• 1998

We explicate the forming mechanism of Sasang constitution as the principle of energy distribution which is based on the evolutionary hypothesis. The result was obtained as follows: 1. The principle of form-image (形象) in oriental medicine can be explained with the relation between structure and function that a life acquires through the adaptation and evolution. 2. The Sung-jung (性情) in Sasang constitutional medicine can be explained as the strategy for survival or the pattern of adaptation by which an individual or a species lives in this world. 3. The forming mechanism of Sasang constitutional organic phase (臟局) can be explained as the principle of energy distribution which includes three hypothesis (hypothesis of limited resources, hypothesis of preference and hypothesis of effectiveness). 4. It is postulated that the local hemodynamics is one of the most important factors that determine the difference of Sasang constitutional organic function. 5. The relation of metabolic rate, local hemodynamics and thermo-metabolism is inseparable and it is the important point of forming mechanism of Sasang constitution and the diagnosis of pulse.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.10
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• pp.654-661
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• 2008

Our government will make a plan regulating the cooling limit temperature of the summer season to 26 degree and the heating limit temperature of the winter season to 20 degree for energy saving. Where, the key point of this politic pursuit can be the charge system on heating and cooling cost. Currently, the heating and cooling cost are charged as much as the volume or heat flow rate regardless of the high and low room temperature. However, we have suggested new cost estimating methodology as a worth method in the precedent study, and preformed the worth evaluation and cost allocation of electricity and heat on various cogenerations. In this study, we applied the suggested worth method to four kind of warm air, and preformed the worth evaluation and cost allocation of each warm air. As a result, the more energy a customer saved, the more heating unit cost decreased, and the more energy a customer consumed, the more heating unit cost increased. From this analysis, we hope that the suggested worth methodology can offer a theoretical basis to the politic pursuit of government, and induce the spontaneous energy saving of consumers.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.2
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• pp.134-143
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• 2001

This paper presents the characteristics of flank and tip seal leakage in a scroll compressor for air-conditioners with R-22 under actual operating conditions. It is well known that the leakage has significant effect on the performance of the scroll compressor. Experiments were performed by using indirect method for measuring mass flow rate passing through flank and tip seal under actual operating conditions, In addition, an analytical model for tip seal leakage was developed to investigate tangential and radial leakage observed at grooves and contact points of tip seals. For low oil concentration, theoretical results were compared with experimental data to verify the analytical model. As a result, leakages through flank and tip seal parts were evaluated as afunction of pressure ratio, orbiting angle, discharge pressure, tip clearance, and leakage point. It was also found that the tip seal leakage was considerable even though the tip seal provided adequate sealing effect.

• Nuclear Engineering and Technology
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• v.53 no.7
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• pp.2221-2228
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• 2021

One-dimensional oxygen transport relation is indispensable to study the oxygen distribution in the LBE-cooled system with an oxygen control device. In this paper, a numerical research is carried out to study the oxygen transport characteristics in a gas-phase oxygen control device, including the static case and dynamic case. The model of static oxygen control is based on the two-phase VOF model and the results agree well with the theoretical expectation. The model of dynamic oxygen control is simplified and the gas-liquid interface is treated as a free surface boundary with a constant oxygen concentration. The influences of the inlet and interface oxygen concentration, mass flow rate, temperature, and the inlet pipe location on the mass transfer characteristics are discussed. Based on the results, an oxygen mass transport relation considering the temperature dependence and velocity dependence separately is obtained. The relation can be used in a one-dimensional system analysis code to predict the oxygen provided by the oxygen control device, which is an important part of the integral oxygen mass transfer models.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.216-221
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• 1998

A study on induction plasma deposition with ceramic materials, yttria-stabilized-zirconia ZrO$_2$-Y$_2$O$_3$ (m.p 264O $^{\circ}C$), was conducted with a view developing a new method for nuclear fuel fabrication Before making dense pellets more than 96％TD., the spraying condition was optimized through the process parameters, such as chamber pressure, plasma plate power powder spraying distance, sheath gas composition, probe position, particle size and powders different morphology. The results with a 5mm thick deposit on rectangular planar graphite substrates showed a 97.11％ theoretical density when the sheath gas flow rate was Ar/H$_2$120/20 l/min, probe position 8cm, particle size -75 ${\mu}{\textrm}{m}$ and spraying distance 22cm by AMDRY146 powder. The degree of influence of the main effects on density were powder morphology. particle size, sheath gas composition, plate power and spraying distance, in that order. Among the two parameter interactions, the sheath gas composition and chamber pressure affects density greatly. By using the multi-pellets mold wheel type, the pellet density did not exceed 94%T.D., owing to the spraying angle.

• The KSFM Journal of Fluid Machinery
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• v.16 no.5
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• pp.5-10
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• 2013

The regenerative pump is a kind of turbomachine which is capable of developing high pressure rise at relatively lower flow rates compared to the centrifugal and axial pumps. Although the efficiency of regenerative pumps is much lower than other turbomachines, still they have been widely used in many industrial applications for working at low specific speeds. There are some theoretical models to analysis the pump performance, however, the effect of the blade angle on the pump performance has not been covered in any model to date. In the present study, experimental study on the regenerative pump performance according to the impeller blade angle and its shape has been carried out. The straight radial blades with forward, backward and chevron blades which have inclined angles of $15^{\circ}$, $30^{\circ}$ and $45^{\circ}$ were tested. The pump performance characteristics as the pressure head, efficiency were obtained depending on the flow rate for every impeller, and their results, expressed in appropriate non-dimensional coefficients, were compared and analysed in detail. From the experimental results, it was found that the pressure head and the efficiency depend strongly on the blade angles as well as the blade type. These experimental data has made it possible to better understand the effects of the blade angle on the pump performance, and widen the applicability of the current performance analysis and design models with including the effect of blade angles.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.5
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• pp.541-548
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• 2017

A theoretical study on gas-liquid two-phase flow flushing systemnitrogen gas to the oil used for existing flushing equipment was conducted on the basis of ISO code so as to improve performance of existing high-temperature oil flushing equipment used in ocean plant facility drying field. For study, we analyzed process simulation results mixed fluid mixing ratio, temperature, Reynolds number and liquid hold up affectcleaning performance after designing oil-nitrogen gas mixture flushing system process. As a result, as the volume flow rate of mixed fluid increases with the tube diameter the volume fraction of the gas phase constant, the liquid fraction difference value at the inlet and outlet of horizontal hydraulic piping increases. It was found that the phase distribution between oil and nitrogen gas bubbles varies depending on the position the pipe lengthdirection. This change in phase distribution is expected to have a significant impact on the clean performance of an oil-nitrogen gas mixture flushing system.

• Korean Chemical Engineering Research
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• v.48 no.1
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• pp.88-92
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• 2010

DNA structure studies attract many interests in pharmaceutical, biochemical and medical disciplines. Among them, base pairs play a vital role in biological information transfer. Therefore, they need to be analyzed in various ways and the pair of guaninine and cytosine is the present analytical object. Separation of guanine and cytosine was researched by Aspen chromatography simulator and HPLC(High Performance Liquid Chromatography) experiments. Aspen chromatography simulation resulted in various chromatograms with changes of sample concentration, eluent flow rate and number of plate. The resolutions and yields of guanine and cytosine were calculated to obtain a best separation condition. $C_{18}$ HPLC column and water/methanol/acetic acid mixture(90/10/0.2) were used for separation of guanine and cytosine. HPLC parameters(resolution and number of theoretical plate) were calculated under different flow rates and sample concentrations. Aspen chromatography simulation and HPLC experimental results were compared with fair agreement.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.6 no.3
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• pp.237-246
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• 1994

Experimental data are reported for charging and collection of NaCl aerosols in the 0.03- to $0.2{\mu}m$-geometric-mean-diameter range in 2-stage parallel-plate electrostatic precipitators. The NaCl aerosols are generated with geometric standard deviation of about 1.74 and particle generation rate of about 10^9 particles/see by the constant output atomizer and injected into the air flow in the clean wind-tunnel. The 2-stage parallel-plate electrostatic precipitator installed in the test section of the wind-tunnel is operated with a positive corona discharge. The NaCl aerosols in the channel flow are sampled and transported to the aerosol particle number concentration measurement system by using the isoaxial sampling and transport system constructed based on the Okazaki and Willeke design. The aerosol particle number concentration measurement system measures the size distribution of submicrometer aerosols by an electrical mobility detection technique. It is confirmed from comparing the measured collection efficiencies in this study and the predicted ones by our previous theoretical analysis that the predicted collection efficiencies agree well with the experimental ones. It is also found from the comparison that below about $0.02{\mu}m$ all particles are not charged and the uncharged particles are not collected, and consequently 2-stage parallel-plate electrostatic precipitators are not suitable for that particle size range.

• Journal of the Korean Geotechnical Society
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• v.19 no.4
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• pp.55-64
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• 2003

Desiccation of a soil is basically the removal of water by evaporation, which is controlled by evaporativity and evaporability. Surface evaporation improves the trafficability which is essential for the access of construction equipment in the area reclaimed with soft clay. The existing traditional methods for evaluating evaporation can not account for the deformation of reclaimed soft soils during evaporation. Therefore, a theoretical model for predicting the rate of evaporation from the surface of a deformable material is proposed. The model is based on a system of equations for coupled heat and mass transfer in unsaturated soils. The modified pressure plate extractor test and glass desiccator test were carried out to obtain the soil-water characteristic curve for a deformable soil. The column drying test was conducted to investigate one dimensional water flow, heat flow and evaporation in the surface. A finite difference program was developed to solve the coupled nonlinear partial differential equations, which permit the study of water, vapor and heat flows in the deformable soil. Comparison between measured and simulated values shows a reasonably good matching between the two.