• 한국지진공학회논문집
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• 제27권3호
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• pp.157-162
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• 2023

As a result of active geological investigation of faults in Korea, many Quaternary faults have been identified and some of them were judged to have potential to generate earthquakes. Those faults need to be considered as additional seismic sources in the seismic hazard analysis. When a fault is introduced as a new source, the earthquakes generated by the fault should be removed from the area sources that include any part of the fault, to avoid double counting. In practice, however, double counting cannot completely be avoided as the complete separation of the fault-generated earthquakes from the area sources is impossible due to uncertainties related to the earthquake location, subsurface structures of faults, etc. When a new fault source is introduced, the only constraint is the invariance of earthquake frequency. The maximum earthquake and the Richter-b value should also be subject to change, but there are no competent approaches to estimate the change due to incomplete separation of earthquakes. To gain insight into the effect of a new fault source, an example calculation of the seismic hazard were carried out. The example calculation shows that addition of a new fault source centers seismic hazard around the fault source.

• Journal of information and communication convergence engineering
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• 제9권6호
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• pp.738-742
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• 2011

This paper has studied drain induced barrier lowering(DIBL) for Double Gate MOSFET(DGMOSFET) using analytical potential model. Two dimensional analytical potential model has been presented for symmetrical DGMOSFETs with process parameters. DIBL is very important short channel effects(SCEs) for nano structures since drain voltage has influenced on source potential distribution due to reduction of channel length. DIBL has to be small with decrease of channel length, but it increases with decrease of channel length due to SCEs. This potential model is used to obtain the change of DIBL for DGMOSFET correlated to channel doping profiles. Also device parameters including channel length, channel thickness, gate oxide thickness and doping intensity have been used to analyze DIBL.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2000년도 추계 학술대회논문집
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• pp.9-14
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• 2000

Computational methods can be classified roughly into two parts: one is the methods based on a potential flow theory, and the other is numerical solvers(CFD) based on Navier-Stockes equation. Methods based on a potential theory are more effective than CFD when the free surface effect is considered. Especially Rankine source method seems to become widespread for simulations of wave making problems. For computations of viscous flow problems, CFD techniques have rapidly been developed and have shown many successful results in the viscous flow calculation. Present paper introduces a computational system 'WAVIS' which includes a pre-processor, potential ant viscous flow solvers and a post-processor. To validate the system, the calculated results for modem commercial hull forms are compared with measurements. It is found that the results from the system are in good agreement with the experimental data, illustrating the accuracy of the numerical methods employed for WAVIS.

• 대한수학회논문집
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• 제15권1호
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• pp.155-172
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• 2000

Mode interactions at Unstable fluid interfaces induced by a shock wave (Richtmyer-Meshkov Instability) are studied both analytically and numerically. The analytical approach is based on a potential flow model with source singularities in incompressible fluids of infinite density ratio. The potential flow model shows that a single bubble has a decaying growth rates at late time and an asymptotic constant radius. Bubble interactions, bubbles of different radii propagates with different velocities and the leading bubbles grow in size at the expense of their neighboring bubbles, are predicted by the potential flow model. This phenomenon is validated by full numerical simulations of the Richtmyer-Meshkov instability in compressible fluids for initial multi-frequency perturbations on the unstable interface.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 International Symposium
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• pp.58-69
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• 2003

Soil contamination in the United States is managed using a risk-based decision making process. In other words, we don't ask, 'how much soil contamination can be cleaned up\ulcorner' Instead we ask, 'how much contamination can be safely left in place\ulcorner' The determination of 'safe' levels of contamination is based upon the potential for exposure and the toxicity of the contaminants of concern in soil. Potential for exposure is determined by evaluating potential exposure pathways from source to receptor given current or reasonably anticipated land use. Soil cleanup goals are then calculated for any complete exposure pathways based upon toxicity and the route of exposure. In some cases, institutional or engineering controls are also used to limit the potential for exposure. In order to prevent a continuous degradation of environmental quality, risk-based cleanup approaches must be combined with strong contamination prevention programs. In addition, alternative risk management approaches should be incorporated into an overall risk reduction strategy.erall risk reduction strategy.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.743-747
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• 1996

A Potential Field Method is applied to the proposed algorithm for the planning of collision-free paths of redundant manipulators. The planning is carried out on the base of kinematic configuration. To make repulsive potentials, sources are distributed on the boundaries of obstacles. To escape from local minimum of the main potential and to attack other difficulties of the planning, various potentials are defined simultaneously, Inverse Kinematics Problems of the redundant manipulators are solved by unconstrained optimization method. Computer simulation result of the path planning is presented.

• 정보저장시스템학회:학술대회논문집
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• 정보저장시스템학회 2005년도 추계학술대회 논문집
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• pp.53-55
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• 2005

The surface potential variations are measured, according to the enhanced measuring speed and voltage sensitivity, using an active device, such as a field effect transistor $(FET)^{1-3}$. In this study, the surface potential was mapped in the patterned $SiO_2$ medium at room temperature. An improved FET-tip cantilever, which has a source, a drain, and an n- channel, was used in this study. The potential images were analyzed both in the contact mode and the non-contact mode, using only a pre-amplifier system instead of a lock-in the amplifier.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.465-465
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• 2010

Cut off probe, the efficient method, can measure the plasma parameters like the plasma electron density and the electron temperature. Plasma potential is also one of the important parameters in plasma processing but cannot be measured by cut off probe yet. Thus we developed method to measure plasma potential by focusing on relation between bias on a tip and sheath around tip. The system consist of a ICP(Inductive Coupled Plasma) source, a Network analyzer and a bias tee that can be bridge apply DC voltage on the cut off probe tip. Plasma potential is identified by using this system. The results corresponded well with the measured results by single langmuir probe(SLP).

• 한국식품영양학회지
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• 제22권3호
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• pp.449-455
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• 2009

The principal objective of this study was to determine the quality and potential of DHEA formation after the addition of diosgenin of yam(Dioscorea spp.) during the fermentation of soybean paste. All samples were divided into three groups based on the variety of yam. In sample A, the soy source was not separated from soybean paste and in sample B, the soybean source was separated from soybean paste. The range in salt concentration in the samples was as follows : sample A: 10.5~11.8%, samples B: 7.9~8.8%. However, no substantial differences between the two samples, in terms of salt content, were observed. The crude protein and crude lipid content were found to decrease with the fermentation time of soybean paste(passage of 30 days: 26.4~32.3% and 4.45~5.90%, passage of 60 days: 24.5~28.5% and 3.95~4.90%, respectively). As the fermentation time of soybean paste increased, the nitrogen from amino compounds increased(passage of 30 days: 531.9~687.7 mg%, passage of 60 days: 551.3~706.8 mg%). In regards to color and preference, sample B, where the soy source was separated from soybean paste, was better than sample A, where the two components were not separated. After a soybean paste fermentation time of 60 days, the diosgenin of yam, which was added to the soybean paste, was not detected in tested samples, and the contents of DHEA formation in soybean paste were as follows: sample A: $488.0\pm42.5{\sim}719.3\pm44.8{\mu}g/g$, sample B: $287.3\pm20.6{\sim}482.7{\pm}36.5{\mu}g/g$.

• Journal of Power Electronics
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• 제18권1호
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• pp.70-80
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• 2018

A novel strategy based on a zero common mode voltage pulse-width modulation (ZCMV-PWM) technique and zero-sequence circulating current (ZSCC) feedback control is proposed in this study to eliminate ZSCCs between three-level neutral point clamped (NPC) voltage source inverters, with common AC and DC buses, that are operating in parallel. First, an equivalent model of ZSCC in a three-phase three-level NPC inverter paralleled system is developed. Second, on the basis of the analysis of the excitation source of ZSCCs, i.e., the difference in common mode voltages (CMVs) between paralleled inverters, the ZCMV-PWM method is presented to reduce CMVs, and a simple electric circuit is adopted to control ZSCCs and neutral point potential. Finally, simulation and experiment are conducted to illustrate effectiveness of the proposed strategy. Results show that ZSCCs between paralleled inverters can be eliminated effectively under steady and dynamic states. Moreover, the proposed strategy exhibits the advantage of not requiring carrier synchronization. It can be utilized in inverters with different types of filter.