• Journal of the Korean Society of Clothing and Textiles
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• v.19 no.1
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• pp.36-50
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• 1995

The purpose of this study was 1) to estimate the improvement of thermal storage/release and moisture transport properties of PEG-treated acrylic athletic socks and suggest the optimum add-on for PEG treatment, 2) to investigate wear performance of untreated cocks and two kinds of socks treated with PEG of minimum and optimum add-on respectively, and 3) to consider the effect of thermal storage/release and moisture transport properties of PEG- treated socks on the wear performance and the subjective comfort zone. Thermal activities of specimens treated by PDC were evaluated on a DSC by measuring the heat of fusion on heating and the heat of crystallization on cooling. Moisture regain, absorption speed, wickability, water retenti on value, and water-vapor permeability were measured. In the wear trials that the subjects performed a subsequent exercise protocol wearing three differently treated socks in a conditioned environment ($14\pm2^{\circ}C$, 65$\pm$2% R.H.), microclimate temperature and humidity, and subjective wear sensations including thermal sensation, wettedness, softness, fit, and overall comfort were obtained. PEC-treated specimens with more than 20% add-on showed thermal storage on heating and thermal release on cooling by a DSC and the heat contents of treated ones were generally proportional to the add-ons. Moisture transport properties were highly improved after PEG treatment and increased rapidly with increasing add-on. The tendencies were, however, relaxed above 50% add-on and the treated knits were much stiffer above that add-on. In the wear trials of untreated, PEG add-on 20%, and 50% acrylic socks, the changes of microclimate temperature of 50% socks were significantly less than that of 20% socks. PEG add-on 50% socks showed significantly less changes of microclimate humidity than other two kinds of socks. Three kinds of socks showed significant differences in overall comfort and add-on 50% socks were accepted more comfortable than other two kinds of socks. Comfort zone of foot was extended after PEG treatment on socks and it implied that the subjects wearing PEG- treated socks felt comfortable in wider ranges of microclimate temperature and humidity.

• Journal of Korea Water Resources Association
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• v.37 no.4
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• pp.257-271
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• 2004

To evaluate behavior in representing solute transport in natural streams, the storage zone model of the axially periodic transient storage zones is developed. The periodic transient storage zone model and continuous storage zone model are verified using the parameters and the tracer concentration vs. time curves observed in laboratory channels. The periodic storage zone model best fit the measured concentration vs. time curves, while the continuous storage model fails to describe some fluctuations and the plateau region of the tail occurring in a discontinuous transient storage system. Dispersion data from Shingobee River, Minnesota, U. S. A. show that the concentration curves simulated by the proposed model fit the observed concentration curves well.

• Nuclear Engineering and Technology
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• v.54 no.9
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• pp.3347-3352
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• 2022

In 2013, the International Atomic Energy Agency (IAEA) changed the recommended maximum range of the Emergency Planning Zone (EPZ) to 30 km, and the Kori Nuclear Power Plant in Republic of Korea has also expanded the EPZ to 30 km, following the recommendation. As a result, metropolitan cities with a high population density are contained within the EPZ, and evacuating millions of people should be considered if the 30 km range of evacuation is to take place. This study proposes an evacuation plan using buses (public transportation) to transport people outside of the EPZ, quickly and efficiently. To verify the appropriate mode share ratio of buses that can guarantee the right of vulnerable road users and reduce traffic congestion, a model was built simulating the Kori Nuclear Power Plant in Ulsan Metropolitan City. The scenarios were established by changing the mode share ratio of buses and passenger cars by 10%. Considering a large-scale network analysis at the city level, a cell transmission model was applied to calculate the evacuation time in each scenario. The result shows that the optimal mode share ratio of buses is 40%, with a total evacuation time of 132 min, considering feasible bus fleets in Ulsan Metropolitan City.

• Ecology and Resilient Infrastructure
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• v.11 no.2
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• pp.23-34
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• 2024

Sediment, aquifer materials, surface water, and groundwater from brackish Songji lake affected by salinity of seawater, were collected and a pilot scale column experiment was conducted to simulate the nitrogen transport through the hyporheic zone. Upstream experiments of groundwater displayed that groundwater containing a small amount of salt percolated into aquifers and sediments, maintaining low dissolved oxygen concentrations. In addition, partial denitrification occurred in the aquifer due to salinity and low dissolved oxygen, resulting in the accumulation of NO₂^-. In sediments,nitrogenous compounds were reduced due to adsorption by long residence times or microbial-mediated oxidation/reduction reactions. Downstream experiments of surface water displayed that surface water from the brackish lake, containing high concentrations of dissolved oxygen and salts, infiltrated into the sediments and aquifer, supplying high dissolved oxygen concentrations. This resulted in biological nitrification in the sediments and aquifer, which reduced nitrogen-based pollutants despite the high salt concentration in the surface water. Whereas partial denitrification at low dissolved oxygen concentrations in the upwelling mixing zone was observed by salinity and accumulated NO₂^-, nitrification at high dissolved oxygen concentrations in the downwelling mixing zone was not significantly affected by salinity. These results confirm that salinity in the brackish water lake has some influence on the nitrogen behavior of the hyporheic mixing zone, although nitrogen behavior is a complex combination of factors such as DO, pH, substrate concentration, and organic matter concentration.

• Water Engineering Research
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• v.4 no.2
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• pp.69-85
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• 2003

Previously developed empirical equations used to calculate the parameters of the transient storage model are analyzed in depth in order to evaluate their behavior in representing solute transport in the natural streams with storage zone. A comparative analysis of the existing theoretical and experimental equations used to predict parameters of the transient storage (TS) model is reported. New simplified equations for predicting 4 key parameters of the TS model using hydraulic data sets that are easily obtained in the natural streams are also developed. The weighted one-step Huber method, which is one of the nonlinear multi-regression methods, is applied to derive new parameters equation. These equations are proven to be superior in explaining mixing characteristics of natural streams with the transient storage zone more precisely than the other existing equations.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.653-655
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• 1992

Longitudinal and transverse normal zone propagation in the superconducting coil are analyzed and propagation velocity is derived from the heat balance equations in the propagating boundary region. Transverse velocity is nearly $10^{-2}$ order of longitudinal velocity. Propagation velocity ie linearly proportional to the transport current. Increasing lamp current speeds up longitudinal velocity by 0.279 m/s under the applied field of 2T. Transient heat transfer has a significant effect on normal zone propagation velocity and it decreases longitudinal velocity by 4.2 m/s under the applied field of 2T as being compared to steady-state heat transfer.

• Water Engineering Research
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• v.1 no.3
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• pp.171-185
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• 2000

A mathematical model to adequately predict complex mixing characteristics of sorptive polluants in natural streams with pools-and-riffes has been developed. In this model, sorption of pollutants onto the bed sediment as well as mass storage and exchange in the storage zones were incorporated into one-dimensional mass balance equatins. The geometric and hydraulic characteristics of the pool-riffle sequences were properly conceptualized. Simulations with parameters of pool-and-riffle streams better fit the measured data in overall shape and peak concentration than simulations with parameters for uniform channels. The analyses on the characteristics of the storage zone model parameters reveal that a linear relationship between the logrithm of the storage zone volume ratio and a function of the friction factor exists. A linear relatiohship might also be tenatively assumed between the logarithm of the dimensionless mass exchange coefficient and the logarithm of the aspect ratio of the storage zone if some of the high values of the dimensionless mass exchange coefficient collected on the successive bed forms are excluded.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.7
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• pp.1041-1049
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• 1994

Longitudimal and transverse normal zone propagations in the superconducting coil are analyzed and propagation velocity is derived from the heat balance equations in the propagating boundary region. The results of applying to the specific superconducting wire show that propagation velocity is linearly proportional to the transport current and increasing ramp current speeds up the longitudinal velocity by 1.22[m/s] under the applied field of 2T. Transient heat transfer has a significant effect on the normal zone propagation velocity and it decreases longitudinal velocity by 5.2[m/s] under the applied field of 2T as being compared to the steady-state heat transfer. Increasing ramp current speeds up the Z-axis transverse propagation velocity by 0.042[m/s] and transverse velocity of R and Z axis is costant regardless of the current flows.

• 한국ITS학회:학술대회논문집
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• 2008.11a
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• pp.611-616
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• 2008

• 한국ITS학회:학술대회논문집
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• 2003.11a
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• pp.182-187
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• 2003