• Proceedings of the Membrane Society of Korea Conference
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• 2004.05a
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• pp.132-135
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• 2004

It has been known that transport characteristics of ions are very complicated in CEDI system due to the inter-relations between ion exchange media and solution. Thus, this study sought to determine the ionic mobility of cobalt ion through cation exchange textile under electroregeneration and consequently verify the transport mechanisms of cobalt ion in a CEDI system.(omitted)

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2005.09a
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• pp.134-138
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• 2005

The design of ion channel targeted library is a valuable methodology that can aid in the selection and prioritization of potential ion channel-likeness for ion-channel-targeted bio-screening from large commercial available chemical pool. The differences of property profiling between the 93 ion-channel active compounds from MDDR and CMC database and the ACDSC compounds were classified by suitable descriptors calculated with preADME software. Through the PCA, clustering, and similarity analysis, the compounds capable of ion channel activity were defined in ACDSC compounds pool. The designed library showed a tendency to follow the property profile of ion-channel active compounds and can be implemented with great time and economical efficiencies of ligand-based drug design or virtual high throughput screening from an enormous small molecule space.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.877-881
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• 2006

We obtained sputtering yields for the MgO, $MgAl_2O_4$ and $MgAl_2O_4/MgO$ films using the FIB system. $MgAl_2O_4/MgO$ protective layers have been found to have less $24^{\sim}^30%$ sputtering yield values from 0.24 atoms/ion up to 0.36 atoms/ion than MgO layers with the values from 0.36 atoms/ion up to 0.45 atoms/ion for irradiated $Ga^+$ ion beam whose energies ranged from 10 keV to 14 keV. And $MgAl_2O_4$ layers have been found to have lowest sputtering yield values from 0.88 up to 0.11. It is also found that $MgAl_2O_4/MgO$ and MgO have secondary electron emission $coefficient({\gamma})$ values from 0.09 up to 0.12 for $Ne^+$ ion whose energies ranged from 50 eV to 200 eV.

• JSTS:Journal of Semiconductor Technology and Science
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• v.8 no.3
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• pp.251-263
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• 2008

In this paper, we report an analytical modeling and 2-D Synopsys Sentaurus TCAD simulation of ion implanted silicon carbide MESFETs. The model has been developed to obtain the threshold voltage, drain-source current, intrinsic parameters such as, gate capacitance, drain-source resistance and transconductance considering different fabrication parameters such as ion dose, ion energy, ion range and annealing effect parameters. The model is useful in determining the ion implantation fabrication parameters from the optimization of the active implanted channel thickness for different ion doses resulting in the desired pinch off voltage needed for high drain current and high breakdown voltage. The drain current of approximately 10 A obtained from the analytical model agrees well with that of the Synopsys Sentaurus TCAD simulation and the breakdown voltage approximately 85 V obtained from the TCAD simulation agrees well with published experimental results. The gate-to-source capacitance and gate-to-drain capacitance, drain-source resistance and trans-conductance were studied to understand the device frequency response. Cut off and maximum frequencies of approximately 10 GHz and 29 GHz respectively were obtained from Sentaurus TCAD and verified by the Smith's chart.

• Journal of Electrical Engineering and Technology
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• v.13 no.3
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• pp.1173-1184
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• 2018

The lifetime of a lithium-ion battery is one of the most important issues of the energy storage system (ESS) because of its stable and reliable operation. In this paper, the lifetime management method of the lithium-ion battery for energy storage system is proposed. The lifetime of the lithium-ion battery varies, depending on the power usage, operation condition, and, especially the selected depth of discharge (DOD). The proposed method estimates the total lifetime of the lithium-ion battery by calculating the total transferable energy corresponding to the selected DOD and achievable cycle (ACC) data. It is also demonstrated that the battery model can obtain state of charge (SOC) corresponding to the ESS operation simultaneously. The simulation results are presented performing the proposed lifetime management method. Also, the total revenue and entire lifetime prediction of a lithium-ion battery of ESS are presented considering the DOD, operation and various condition for the nations of USA and Korea using the proposed method.

• Journal of Electrical Engineering and Technology
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• v.13 no.6
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• pp.2561-2567
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• 2018

The extension of DC battery backup time in the DC power supply system of nuclear power plants (NPPs) remains a challenge. The lead-acid battery is the most popular at present. And it is generally the most popular energy storage device. However, extension of backup time requires too much space. The lithium-ion battery has high energy density and advanced gravimetric and volumetric properties. The aim of this paper is development of the sizing formula of stationary lithium-ion batteries. The ongoing research activities and related industrial standards for stationary lithium-ion batteries are reviewed. Then, the lithium-ion battery sizing calculation formular is proposed for the establishment of industrial design standard which is essential for the design of stationary batteries of nuclear power plants. An example of calculating the lithium-ion battery capacity for a medium voltage UPS is presented.

• Mass Spectrometry Letters
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• v.6 no.4
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• pp.91-98
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• 2015

The Brownian motion or Wiener process, as the physical model of the stochastic procedure, is observed as an indexed collection random variables. Stochastic procedure are quite influential on the confinement potential fluctuation in the quadrupole ion trap (QIT). Such effect is investigated for a high fractional mass resolution Δm/m spectrometry. A stochastic procedure like the Wiener or Brownian processes are potentially used in quadrupole ion traps (QIT). Issue examined are the stability diagrams for noise coefficient, η=0.07;0.14;0.28 as well as ion trajectories in real time for noise coefficient, η=0.14. The simulated results have been obtained with a high precision for the resolution of trapped ions. Furthermore, in the lower mass range, the impulse voltage including the stochastic potential can be considered quite suitable for the quadrupole ion trap with a higher mass resolution.

• Journal of Surface Science and Engineering
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• v.48 no.4
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• pp.179-184
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• 2015

Quadrupole Mass Spectrometers (QMS) is a very useful tool in vacuum process diagnosis. Tungsten filament based ion sources are vulnerable to contamination from process gas monitoring. Common symptoms of quadrupole mass spectrometer malfunction is appearance of unwanted contaminant mass peaks or no detection of any ion peaks. We disassembled used quadrupole mass spectrometer and found out black insulating deposits on inside of ion source parts. Five steps of cleaning procedure were applied and almost full restoration of functions were confirmed in two types of closed ion source quadrupole mass spectrometer. By using a numerical modeling (CFD-ACE+) technique, the electric potential profile of ion source with/without insulating deposit was calculated and showed the possibility of quadrupole mass spectrometer malfunction by the deterioration of designed potential profile inside the ion source.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1609-1611
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• 1994

In ECR and helicon reactors for plasma processing, a high density plasma is generated in a source region which is connected to a diffusion region where the processing takes place. Large density and potential gradients can develop at the orifice of the source which drive ion currents into the diffusion region. The average ion velocity may become the order of the sound velocity. Measurements of the ion saturation current to a Langmuir probe are used as a standard method of determining the plasma density in laboratory discharges. However, the analysis becomes difficult in a steaming plasma. We have used the HAMLET plasma simulator to simulate the ion flow to a large langmuir probe in an ECR plasma. The collection surface was aligned with the Held upstream, normal to the field, and downstream. ion trajectories through the electric and magnetic fields were calculated including ion-neutral collisions. We examines the ratio of ion current density to plasma density as a function of magnetic field and pressure.

• Journal of Mechanical Science and Technology
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• v.20 no.10
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• pp.1670-1679
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• 2006

The development of the oxidation, wear and corrosion resistant materials that could be used in severe environmental conditions is needed. The elementary technologies for surface modification include ion implantation and/or thin film coating. Furthermore, in order to develop ion implantation technique to the specimens with three-dimensional shapes, plasma-based ion implantation (PBII) techniques were investigated. As a result, it was found that the ion implantation and/or thin film coating used in this study were/was effective for improving the properties of materials, which include implantations of various kinds of ions into TiAl alloy, TiN films formed on surface of base material and coatings in high-temperature steam. The techniques proposed in this study provide useful information for all of the material systems required to use at elevated temperature. For the practical applications, several results will be presented along with laboratory test results.