• Atmosphere
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• v.26 no.4
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• pp.635-647
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• 2016

The effects of sea surface temperature (SST) gradient induced by the previous typhoon on the following typhoon motion over East Asia have been investigated using Weather Research and Forecasting (WRF) model for the previous Typhoon Bolaven (1215) and following Typhoon Tembin (1214). It was observed that Typhoon Bolaven remarkably reduced SST by about $7^{\circ}C$ at Yellow Sea buoy (YSbuoy). Using the WRF experiments for the imposed cold wake over West of Tembin (WT) and over East of Tembin (ET), this study demonstrates that the effects of eastward SST gradient including cold wake over WT is much significant rather than that over ET in relation to unexpected Tembin's eastward deflection. This difference between two experiments is attributed to the fact that cold wake over WT increases the magnitude of SST gradient under the eastward SST gradient around East Asia and the resultant asymmetric flow deflects Typhoon Tembin eastward, which is mainly due to the different atmospheric response to the SST forcing between ET and WT. Therefore, it implies that the enhanced eastward SST gradient over East Asia results in larger typhoon deflection toward the region of warmer SST according to the location of the cold wake effect. This result can contribute to the improvement of track prediction for typhoons influencing the Korean Peninsula

• BMB Reports
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• v.38 no.4
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• pp.468-473
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• 2005

The energetics of nitrate uptake by intact cells of the halotolerant cyanobacterium Aphanothece halophytica were investigated. Nitrate uptake was inhibited by various protonophores suggesting the coupling of nitrate uptake to the proton motive force. An artificially-generated pH gradient across the membrane (${\Delta}pH$) caused an increase of nitrate uptake. In contrast, the suppression of ${\Delta}pH$ resulted in a decrease of nitrate uptake. The increase of external pH also resulted in an enhancement of nitrate uptake. The generation of the electrical potential across the membrane ($\Delta\psi$) resulted in no elevation of the rate of nitrate uptake. On the other hand, the valinomycin-mediated dissipation of $\Delta\psi$ caused no depression of the rate of nitrate uptake. Thus, it is unlikely that $\Delta\psi$ participated in the energization of the uptake of nitrate. However, $Na^+$-gradient across the membrane was suggested to play a role in nitrate uptake since monensin which collapses $Na^+$-gradient strongly inhibited nitrate uptake. Exogenously added glucose and lactate stimulated nitrate uptake in the starved cells. N, N'-dicyclohexylcarbodiimide, an inhibitor of ATPase, could also inhibit nitrate uptake suggesting that ATP hydrolysis was required for nitrate uptake. All these results indicate that nitrate uptake in A. halophytica is ATP-dependent, driven by ${\Delta}pH$ and $Na^+$-gradient.

• Korean Journal of Food Science and Technology
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• v.52 no.3
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• pp.296-303
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• 2020

Hop-resistant lactic acid bacteria (LAB) are well-known, major beer-spoilage bacteria. The hop-gradient agar containing ethanol (c-HGA+E) method has been used to examine hop-resistance of beer-spoilage LAB. However, the selection of beer-spoilage bacteria by the c-HGA+E method is either too selective or too inclusive. Furthermore, it is accompanied by a complicated experimental procedure, high-cost and time. To overcome these disadvantages, the modified hop-gradient agar with ethanol (m-HGA+E) method was developed. The most remarkable modifications were the shape of the petri dish and the inoculation method for bacteria. The efficiency and validation of the m-HGA+E approach were proven by the formation of colonies at different hop concentrations in the bottom layer, co-culture with the bacteriocin producer and by PCR detection of hop-resistant genes. This study demonstrated that m-HGA+E is a rapid, economical, and easy method to monitor potential hop-resistant beer-spoilage LAB during the beer brewing process.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.265-270
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• 2007

The potential and step voltage distribution around low voltage joint-box cover were simulated with the variation of resistivity of water, depth of submerged water and point of leakage current. The potential distribution is very high gradient around low voltage joint-box, this condition is very dangerous states.

• Geophysics and Geophysical Exploration
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• v.7 no.1
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• pp.41-44
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• 2004

Measurements of streaming potential can provide a means for the detection and quantification of contaminants in groundwater prior to remediation. However, laboratory determinations of specific electrolyte properties are required for an adequate analysis of the hydraulic gradient in complex situations. Data obtained for the King River in Tasmania confirm a linear relationship linking streaming potential data and hydraulic gradients. Laboratory samples at low concentration (0.001M KCl) indicate values in the range 20-80 mV/cm of water pressure, while for higher concentrations (0.01M KCl) values are less than 25 mV/cm. Similar ion concentrations are observed in the King River, consistent with field correlations indicating values for streaming potential close to 15 mV/cm. In-situ fluid samples are required for more detailed analysis of local anomalies that may be associated with variations in recharge and migration of contaminants.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.3 no.2
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• pp.146-155
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• 2002

Surface complexation models employ mass law equations to describe the reaction of surface functional groups with ions in the solution and also Gouy-Chapman theory to consider the electrostatic effects in the surface reactions. In current surface complexation models, however, the coulombic factors used are not wholly consistent with the Gouy-Chapman model of the surface. This study was to provide the derivation of the coulombic term usually employed and then a revised coulombic term completely consistent with Gouy-Chapman Theory. The electrical potential energy. zF${\psi}$, in current surface complexation models is not consistent with the Gouy-Chapman theory with the potential gradient close to the charged surface but with the Donnan model with the uniform potential. Even though the new coulombic factor yielded lower surface potential, it provided worse fits for acid-base titration data of the goethite suspensions.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.1017-1021
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• 1991

This paper is to explore the potential use of the modeling capacity of neural networks for control applications. The tasks are carried out by two neural networks which act as a plant identifier and a system controller, respectively. Using information stored in the identification network control action has been developed. Without supervising control signals are generated by a gradient type iterative algorithm.

• Journal of Internet Computing and Services
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• v.15 no.3
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• pp.71-77
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• 2014

The equalization algorithm based on the cross-information potential concept and Dirac-delta functions (CIPD) has outstanding ISI elimination performance even under impulsive noise environments. The main drawback of the CIPD algorithm is a heavy computational burden caused by the use of a block processing method for its weight update process. In this paper, for the purpose of reducing the computational complexity, a new method of the gradient calculation is proposed that can replace the double summation with a single summation for the weight update of the CIPD algorithm. In the simulation results, the proposed method produces the same gradient learning curves as the CIPD algorithm. Even under strong impulsive noise, the proposed method yields the same results while having significantly reduced computational complexity regardless of the number of block data, to which that of the e conventional algorithm is proportional.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1360-1361
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• 2008

This paper presents the surface potential rise distribution near grounding electrodes produced by ground fault currents. The small-scale model with the foundation pedestal in hemispherical tank was used to simulate the ground fault condition of the electrical installations for street lamps. When entering the fault current through the test ground electrode, surface potential rise, potential gradient, touch and step voltages for different grounding electrode shapes were measured, and the results obtained were discussed.

• Ocean and Polar Research
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• v.27 no.3
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• pp.277-288
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• 2005

Spatial distribution and vertical structures of water masses around the Antarctic continental margin are described using synthesized hydrographic data. Antarctic Surface Water (AASW) over the shelf regime is distinguished from underlying other water masses by the cut-off salinity, varying from approximately 34.35 to 34.45 around Antarctica. Shelf water, characterized by salinity greater than the cut-off salinity and potential temperature less than $-17^{\circ}C$, is observed on the Ross Sea, off George V Land, off Wilkes Land, the Amery Basin, and the Weddell Sea, but in some shelves AASW occupies the entire shelf. Lower Circumpolar Deep Water is present everywhere around the Antarctic oceanic regime and in some places it mixes with Shelf Water, producing Antarctic Slope Front Water (ASFW). ASFW, characterized by potential temperature less than about $0^{\circ}C$ and greater than $-17^{\circ}C$, and salinity greater than the cut-off salinity, is found everywhere around Antarctica except in the Bellingshausen-Amundsen sector. The presence of different water masses over the Antarctic shelves and shelf edges produces mainly three types of water mass stratifications: no significant meridional property gradient in the Bellingshausen and Amundsen Seas, single property gradient where ASFW presents, and a V-shaped front where Shelf Water exists.