• Preventive Nutrition and Food Science
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• v.3 no.3
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• pp.295-301
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• 1998

Potential applications of irradiation technology inpostharvest handling of agricultural products have been documented over the past five decades. The biological effects of ionizing radiation on food were demonstrated to have the potential both of reducing the storage losses by controlling spoilage microoraganisms, insects, to have the potential both of reducing the storge losses by controlling spoiliage microorganisms, insects, sprouting and ripening, and of improving the hygienic quality of raw and processed products. Food irradiation is recognized as a physical and cold process using gamma-rays from radioisotope sources and electron-beam from the accelerator. As one of the technologies or techniques for preserving and improving the safety of food, irradiated technology has been approved in some 40 countries for more than 200 individeual items of foods and of these about 30 countries including Korea are commerically utilizing this technology. Although limited quantities of irradiated foods are available in the market now, the proper uses of this renewed technology will offer great possibilities not only for increasing the availability of postharvest agricultural products, thereby contributing to price stabilization in the off-season, but also for reducing reliance on chemicals used for sanitary and quarantine requirements. This paper deals with biological actions of ionizing radiation and its potential applications in the agri-food industry from the international point of view.

• International Journal of Automotive Technology
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• v.8 no.6
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• pp.781-790
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• 2007

Hybrid electric vehicles(HEV) combined with more than one power sources have great potential to improve fuel economy and reduce pollutant emissions. The Integrated Starter Generator(ISG) HEV researched in this paper is a two energy sources vehicle, with a conventional internal combustion engine(ICE) and an energy storage system(batteries). In order to investigate the potential of diesel engine hybrid electric vehicles in fuel economy improvement and emissions reduction, a Dynamic Programming(DP) based supervisory controller is developed to allocate the power requirement between ICE and batteries with the objective of minimizing a weighted cost function over given drive cycles. A fuel-economy-only case and a fuel & emissions case can be achieved by changing specific weighting factors. The simulation results of the fuel-economy-only case show that there is a 45.1% fuel saving potential for this ISG HEV compared to a conventional transit bus. The test results present a 39.6% improvement in fuel economy which validates the simulation results. Compared to the fuel-economy-only case, the fuel & emissions case further reduces the pollutant emissions at a cost of 3.2% and 4.5% of fuel consumption with respect to the simulation and test result respectively.

• International Journal of Naval Architecture and Ocean Engineering
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• v.5 no.4
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• pp.513-528
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• 2013

A floating Oscillating Water Column (OWC) wave energy converter, a Backward Bent Duct Buoy (BBDB), was simulated using a state-of-the-art, two-dimensional, fully-nonlinear Numerical Wave Tank (NWT) technique. The hydrodynamic performance of the floating OWC device was evaluated in the time domain. The acceleration potential method, with a full-updated kernel matrix calculation associated with a mode decomposition scheme, was implemented to obtain accurate estimates of the hydrodynamic force and displacement of a freely floating BBDB. The developed NWT was based on the potential theory and the boundary element method with constant panels on the boundaries. The mixed Eulerian-Lagrangian (MEL) approach was employed to capture the nonlinear free surfaces inside the chamber that interacted with a pneumatic pressure, induced by the time-varying airflow velocity at the air duct. A special viscous damping was applied to the chamber free surface to represent the viscous energy loss due to the BBDB's shape and motions. The viscous damping coefficient was properly selected using a comparison of the experimental data. The calculated surface elevation, inside and outside the chamber, with a tuned viscous damping correlated reasonably well with the experimental data for various incident wave conditions. The conservation of the total wave energy in the computational domain was confirmed over the entire range of wave frequencies.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.395-400
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• 2005

The ship hull part is always exposed to severe corrosive environments. Therefore, it should be protected in appropriate ways to reduce corrosion problems. So there are two effective methods in order to protect the corrosion of ship hull. One is the paint coating as a barrier between steel and electrolyte (seawater) and the other is the cathodic protection(CP) supplying protection current. In the conventional design process of the cathodic protection system the required current densities of protected materials have been used. However, the anode position of field or laboratory experiment for obtaining the required current density for CP is significantly different from anode position for real structures. Therefore, the recent CP design must consider the optimum anode position for potential distribution equally over the ship hull. The CP design companies in the advanced countries can obtain the potential distribution results on the cathodic materials by using the computer analysis module. This study would show how to approach the potential analysis in the field of corrosion engineering. The computer program can predict the under protection area on the structure when the boundary condition and analysis procedure are reasonable. In this analysis the polarization curve is converted to the boundary condition in material data.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.3
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• pp.41-53
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• 2013

The study for the estimation potential natural vegetation was estimated the occurrence probability distribution using geographic information system(GIS) in Bukhansan National Park. Correlation and factor analysis were analyzed to estimate probability distribution. Coefficients were calculated by logistic regression analysis. Correlation coefficients were significantly at the 0.01 level. Commonality of elevation, annual mean temperature, warmth index and potential evapotranspiration were high value, but topographic index was low value. Communities of over the 0.3 points distribution probability, Quercus mogolica communities were the largest area, 76,940,900 $m^2$, Pinus densiflora communities area was 860,800 $m^2$, Quercus acutissima communities area was 500,100 $m^2$ and Quercus variabilis communities area was 1,000 $m^2$, but Q. aliena, Q. serrata, Carpinus laxiflora and Zelcova serrata communities was not appeared. Therefore, potential national vegetation of Bukhansan national park was likely to be Q. mongolica community, P. densiflora community, Q. acutissima community and Q. variabilis community.

• Geotechnical Engineering
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• v.6 no.3
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• pp.41-52
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• 1990

To investigate the liquefaction potential of sands, a series of untrained cyclic triaxial compression tests is carried out on the samples of Ottawa, Joomoonjin, Hn river and Hongseung sands. The constitutive equations of sands are derived to explain the mechanical behavior of sands under cyclic stresses, and are applicable to liquefaction analysis. The following results are obtainded in this study. 1. Sands with the lower confining pressure or relative density are to be easily liquefied, and when the amplitude of cyclic stress are large, liquefaction takes places over only a few cycles. 2. Stress ratio, porewater pressure ratio and cyclic shear strains are to be good criteria to evaluate liquefaction potential of sands. 3. Hongseung sands which contains some silty clay shows higher dynamic properties than other sands. 4. The dynamic behaviors of undisturbed Hongseung sand are about same as those of dense sands. It is noted that undisturbed Hongseung sand shows higher liquefaction potential than the samples made by pluviation under same relative density, 5. The constitutive equations of soils under cyclic loads are developed based on the theory of elasto-plasticity, logarithmic stress-strain rela'tionship, non-associated flow rule and the concept of the boundary surface. The derived equations is applicable to predict the behavior of sands under cyclic loads and liquefaction potential with a higher accuracy. 6. Based on results of the study it may be concluded that cracks of the foundations and dislocation of the structures at Hongseung earthquakes(Oct. 7, 1978, Richter scald 5.2) are not brought by the liquefaction process.

• The Research Journal of the Costume Culture
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• v.26 no.2
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• pp.157-171
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• 2018

As the next generation of smartphone and tablet computers, wearable devices are currently being developed and available in market in various forms. Smart clothing is a wearable device that holds the greatest potential for future development but low in market penetration. This study was designed to identify factors that influence adoption and diffusion of smart clothing. In-depth interviews with potential consumers who were knowledgeable about and interested in smart clothing were conducted. A semantic network analysis method was used. The results showed that consumers perceived smart clothing as a garment rather than as a type of wearable device and had a positive perception of smart apparel as more convenient and advanced than functional apparel. At the same time, however, consumers had a negative perception of smart clothing as unnecessary, ugly, and injurious to health. Consumers also worried that wearing smart apparel over long periods of time would negatively impact their health. Factors affecting resistance to smart apparel included low utility, perceived risk, and lack of aesthetic completeness. Usefulness and convenience were factors that affected the acceptance of smart clothing. The innovativeness of the product was more influential than consumer innovativeness in the process of adoption and diffusion of smart clothing.

• Journal of Microbiology and Biotechnology
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• v.6 no.1
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• pp.30-35
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• 1996

Distillery wastewater was used in a thermophilic laboratory-scale two stage anaerobic digester to test the effects of the redox potential of the first acidogenic reactor on the performance of the system. The digester consisted of first a acidogenic reactor and the an upflow anaerobic sludge blanket (UASB) reactor. The digestor was operated at a hydraulic retention time (HRT) of 48 h. Under these conditions, about 90% of the chemical oxygen demand as measured by the chromate method ($COD_{cr}$) was removed with a gas production yield of 0.4 l/g-COD removed. The redox potential of the acidogenic reactor was increased when the reactor was purged with nitrogen gas or agitation speed was increased. The increase in reduction potential was accompanied by an increase in acetate production and a decrease in butyrate formation. A similar trend was observed when a small amount of air was introduced into the acidogenic reactor. It is believed that the hydrogen partial pressure in the acidogenic reactor was decreased by the above mentioned treatments. The possible failure of anaerobic digestion processes due to over-loading could be avoided by the above mentioned treatments.

• Journal of the Korean Solar Energy Society
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• v.38 no.4
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• pp.43-54
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• 2018

In this study, we assessed dependency of small hydropower potentials on the two different runoff such as the estimated runoff based on the rainfall amounts and measured runoff. The hydpropower potentials were evaluated using actural power generations taken from Deoksong, Hanseok, and Socheon small hydropower plants over Han and Nakdong river basins, respectively. As a result of comparing the actual power generation amount with the potential amount based on the rainfall amount and the estimated amount based on the observed flow amount by each small hydroelectric power plant, the degree of latent small hydro energy by the observed flow was confirmed to be high. It is confirmed that the potential hydroelectric power generation rate is estimated to be about average 30%Point higher than the actual generation amount as a result of the measured flow rate rather than using the rainfall amount. Based on this, a method for improving the degree of the actual generation amount is proposed.

• Korean Journal of Metals and Materials
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• v.47 no.10
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• pp.644-651
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• 2009

The passivation (or deactivation) of a metal surface during oxide film formation has been quantitatively explored for a ferritic stainless steel by using dynamic electrochemical impedance spectroscopy (DEIS). For this purpose, the electrochemical impedance spectra were carefully examined as a function of applied potential in the active nose region of the potentiodynamic polarization curve, to separate the charge transfer resistance and oxide film resistance. From the discrepancy in the potential dependence between the experimental charge transfer resistance and the semi-empirically expected one, the degree of passivation could be quantitatively estimated. The sensitivity of passivation of the steel surface to anodic potential, which might be the measure of the quality of the oxide film formed under unit driving force or over-potential, decreased by 31% when 3.5 wt% NaCl was added to a 5 wt% $H_2SO_4$ solution.