• Nuclear Engineering and Technology
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• v.53 no.4
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• pp.1323-1330
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• 2021

This work reported the radiation shielding characteristic of the bismuth titanium vanadium sodium tellurite glass system. The density of the specially-developed glass samples was increased from 2.21 to 4.01 g/cm³ with the addition of Bi₂O₃, despite the fact the molar volume is decease within 85.43-54.79 cm³/mol. The WinXcom program was used to approximate the effect of Bi₂O₃ on the gamma radiation shielding parameters of bismuth titanium vanadium sodium tellurite glasses. The ㎛ values decrease with the increase of Bi₂O₃ concentration. The computed data shows that the glass sample with 20 mol.% of Bi₂O₃ content has the greatest radiation attenuation performance in comparison to other selected glasses. The Bi₂O₃-TiO₂-V₂O₅-Na₂O-TeO₂ glass system shows excellent neutron shielding material with high long-term light transmittance and discharge resistance and could be potentially used as transparent radiation-resistant shielding glass applications.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.10
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• pp.834-839
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• 2000

The structural properties that SEM photograph of ZnO varistors surface studied by fractal mathematics program were investigated to verify the relations of electrical characteristics. The SEM photograph of ZnO varistors surface were changed by binary code and the grain shape of that were analyzed by fractal dimension. The void of ZnO varistors surface was found by fractal program. The relation between grain density and electrical properties depend on fractal dimension. The grain size in ZnO varistors surface was decreased by increasing of Sb$_2$O$_3$ addition. The spinel structure was formed by Sb$_2$O$_3$addition and it was depressed the ZnO grain formation. The grain size of ZnO by Sb$_2$O$_3$addition were from 5 to 10[${\mu}{\textrm}{m}$]. Among of ZnO varistors, fractal dimension of ZnO4 was very high as a 1.764. The density of grain boundary in ZnO2 and ZnO3 varistors surface was 15[%] by formed spinal structure. The breakdown electric field of ZnO2 that fractal dimension has 1.752 was very high to be 8.5[kV/cm]. When the fractal dimensin was high, the grain shape of ZnO varistors was complex and the serial layers of ZnO grain was increased.

• Journal of Society of Preventive Korean Medicine
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• v.13 no.3
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• pp.113-126
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• 2009

Objective : This research aimed to investigate and analyze the opinions of Oriental Medical Doctors (O.M.D.) on covering herbal medicines into National Health Insurance scheme. Methods : Structured questionnaires were e-mailed to the O.M.D.s listed on member's DB of the Association of Korean Oriental Medicine. Collected data were analyzed with the SPSS 12.0 program. Results : The insurance coverage for herbal decoctions was supported by 80.8% of the responders, the median reasonable price for daily herbal decoctions was \9,517, the minimum price median of daily herbal decoctions considering its costs was \8,080, and the daily technical fee median was \4,379. On health insurance coverage for herbal decoctions, O.M.D.s were specially considering the standardization of herbal medicines. Conclusion : In this study, majority of O.M.D.s assented to health insurance coverage for herbal decoctions, but considered standardization of herbal medicines and optional prescription fee. It needs to prepare plan for insurance coverage of herbal decoctions that reflect the character of oriental medicine and oriental medical institutions.

• Industrial Engineering and Management Systems
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• v.9 no.1
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• pp.60-68
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• 2010

In this paper, a systematic methodology is proposed for developing an outcome-based undergraduate Industrial and Systems Engineering Program at the Systems Engineering Department of King Fahd University of Petroleum & Minerals (KFUPM) in Saudi Arabia. This program is an upgrade of the Industrial Engineering and Operations Research (IE/OR) option, which has been in existence since 1984 and has been revised several times since then. The methodology and process used is motivated by the Accreditation Board for Engineering and Technology (ABET) 2000 criteria and has been employed to develop the program's objectives and outcomes. Subsequently, a curriculum is designed that is expected to deliver the objectives and outcomes. The paper presents the methodology, objectives, outcomes and the developed curriculum of the outcome-based program.

• Journal of the Korean Physical Society
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• v.73 no.9
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• pp.1351-1355
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• 2018

The photocurrent characteristics of zinc-oxide (ZnO) thin-film transistors (TFTs) prepared using radio-frequency sputtering and spin-coating methods were investigated. Various characterization methods were used to compare the physical and the chemical properties of the sputtered and the spin-coated ZnO films. X-ray photoelectron spectroscopy was used to investigate the chemical composition and state of the ZnO films. The transmittance and the optical band gap were measured by using UV-vis spectrometry. The crystal structures of the prepared ZnO films were examined by using an X-ray diffractometer, and the surfaces of the films were investigated by using scanning electron microscopy. ZnO TFTs were prepared using both sputter and solution processes, both of which showed photocurrent characteristics when illuminated by light. The sputtered ZnO TFTs had a photoresponsivity of 3.08 mA/W under illumination with 405-nm light while the solution-processed ZnO TFTs had a photoresponsivity of 5.56 mA/W. This study provides useful information for the development of optoelectronics based on ZnO.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.1
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• pp.28.1-28.1
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• 2017

To investigate AGN outflows as a tracer of AGN feedback on the host galaxies, we perform integral-field spectroscopy of 20 type 2 AGNs at z<0.1 using the Magellan/IMACS and the VLT/VIMOS. The observed objects are luminous AGNs with the [O III] luminosity >$10^{41.5}erg/s$, and exhibit strong outflow signatures in the [O III] kinematics. We obtain the maps of the narrow and broad components of [O III] and $H{\alpha}$ lines by decomposing the emission-line profile. The broad components in both [O III] and $H{\alpha}$ represent the non-gravitational kinematics, (i.e., gas outflows), while the narrow components represent the gravitational kinematics (i.e., rotational disks), especially in $H{\alpha}$. By using the spatially integrated spectra within the flux-weighted size of the narrow-line region, we estimate the outflow energetics. The ionized gas mass is $(1.0-38.5){\times}10^5M_{\odot}$, and the mean mass outflow rate is $4.6{\pm}4.3M_{\odot}/yr$, which is a factor of ~260 higher than the mean mass accretion rate $0.02{\pm}0.01M_{\odot}/yr$. The mean energy injection rate is $0.8{\pm}0.6%$ of the AGN bolometric luminosity Lbol, while the mean momentum flux is $(5.4{\pm}3.6){\times}L_{bol}/c$, except for two most kinematically energetic AGNs. The estimated energetics are consistent with the expectations for energy-conserving outflows from AGNs, yet we do not find any supporting evidence of instantaneous star-formation quenching due to the outflows.

• The Transactions of the Korea Information Processing Society
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• v.5 no.5
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• pp.1151-1161
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• 1998

In this paper, we are considering a heterogeneous processor system in which each processor may have different performance and reliability characteristics. In other to fully utilize this diversity of processing power it is advantageous to assign the program modules of a distributed program to the processors in such a way that the execution time of the entire program is minimized. This assignment of tasks to processors to maximize performance is commonly called load balancing, since the overloaded processors can perform their own processing with the performance degradation. For the task assignment problem, we propose a new objective function which formulates this imbalancing cost. Thus the task assignment problem is to be carried out so that each module is assigned to a processor whose capabilities are most appropriate for the module, and the total cost is minimized that sum of inter-processor communication cost and execution cost and imbalance cost of the assignment. To find optimal assignment is known to be NP-hard, and thus we proposed an efficient heuristic algorithm with time complexity $O(n^2m)$ in case of m task modules and n processors.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.445.1-445.1
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• 2014

Dye-sensitized solar cells (DSSCs) have been widely investigated as a next-generation solar cell because of their simple structure and low manufacturing cost. The $TiO_2$ film with thickness of $8{\sim}10{\mu}m$, which consists of nanoparticles, acts as both a scaffold with a high surface-to-volume ratio for the dye loading and a pathway to remove the electrons. However, charge carriers have to move across many particle boundaries by a hopping mechanism. So, one dimensional nanostructures such as nanotubes, nanorods and nanowires should improve charge carrier transportation by providing a facile direct electron pathway and lowering the diffusion resistance. However, the efficiencies of DSSCs using one dimensional nanostructures are less than the $TiO_2$ nanoparticle-based DSSCs. In this work, the patterned $TiO_2$ film with thickness of $3{\mu}m$ was deposited using photolithography process to decrease of electron pathway and increase of surface area and transmittance of $TiO_2$ films. Properties of the patterned $TiO_2$ films were investigated by various analysis method such as X-ray diffraction, field emission scanning electron microscopy (FESEM) and UV-visible spectrophotometer.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.6
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• pp.1151-1158
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• 2020

In order to investigate the speed profile of data I/O of HDD, we have developed an utility program. The application to HDD reveals the detail properties of the speed profile of HDD and the relation between the cylinder structure of HDD and the velocity profile. For the extent application, the experiment of the large volume storage was performed, and the profile of SSD media, which is known as the new rapid media, was measured. The new M.2 NVME SSD, which has the ability of over 10Gbps, we can compare the velocities between cp under linux O/S and the utility, and shows that the performance of the utility can be reliable.

• Journal of the Korean Ceramic Society
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• v.43 no.3 s.286
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• pp.162-168
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• 2006

The perovskites with nominal compositions $La_{0.8}Sr_{0.2}Fe_{1-x}M_xO_3$ (M=Co, Mn, Ni, x=0.1-0.3) were fabricated by a solid-state reaction method as cathode materials of low-temperature operating Solid Oxide Fuel Cells (SOFCs). X-ray diffraction analysis and microstructure observation for the sintered samples were performed. The ac complex impedance were measured in the temperature range $600-900^{\circ}C$ in air and fitted with a Solatron ZView program. The electrical conductivity and polarization resistance of $La_{0.8}Sr_{0.2}Fe_{1-x}M_xO_3$ (M=Co, Mn, Ni, x=0.1-0.3) were characterized systematically. The porosities of the sintered samples were in the range of 25% to 38%. The polarization resistance of $La_{0.8}Sr_{0.2}Fe_{0.7}M_{0.3}O_3$ was $0.291{\Omega}cm^2\;at\;700^{\circ}C$.