• Journal of Environmental Science International
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• v.2 no.4
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• pp.347-356
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• 1993

The three natural zeolites collected in Yungil-gun, Kyungsangbuk-do, Korea, were analyzed by means of chemical wet methods and X-ray diffraction. The results indicated that the primary species of those zeolites were clinoptilolite mixed with heulandite, feldspar, montmorillonite, and quartz. These zeolites were chemically treated with NaOH, $\textrm{Ca(OH)}_2$, and HCl solution and their differences were also studied with X-ray diffraction method. The capabilities of removing $Cs^+$ and Sr^{2+}$ ions with chemically untreated zeolites, chemically treated zeolites, and also with synthetic zeolites were compared. The effect of other cations in removing Sr^{2+}$ ions was also studied. The experimental results showed that$Cs^+$ and Sr^{2+}$ ions could be removed up to 98% and 95% respectively out of 5 ppm with chemically untrearted natural zeolites. The treatment of 0.02N-$\textrm{Ca(OH)}_2$ and that of 2N-NaOH were most effective In removing $Cs^+$ and Sr^{2+}$ ions, respectively. It was found that the mountaintop of Sangjung 1-dong natural zeolite treated with 2N-NaOH was most efficient in removing Sr^{2+}$ ions mixed with other cations, compared with any other chemically treated and untreated natural zeolites in this work.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.10
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• pp.93-101
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• 1995

The evaluation of the logic capability and the library generation method of the multiplexor-based logic module is described. Optimizing logic module for silicon area and logic capability is essential to build a efficient FPGAs(Field-Programmable Gate Arrays). Because the multiplexor-based logic module can implement a large number of functions, it presents difficulties for library-based approaches. However, the logic functions of the logic module can be significantly reduced by lmiting the number of variables and sum-of-products and by removing same functions with different variable ordering using algorithm presented in this paper.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.209-210
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• 2012

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.639-640
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• 2013

• Nuclear Engineering and Technology
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• v.36 no.4
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• pp.304-315
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• 2004

The ageing effects of radionuclides in radioactive soil on remediation using the electrokinetic method were analyzed. Comparative experiments were conducted for the reactive soil around a TRIGA research? reactor contaminated with $^{137}Cs\;and\;^{60}Co$ for 15 years and the non-reactive soil that was intentionally contaminated with $Cs^+\;and\;Co^{2+}$ for 3 days. It was observed that because of an aging effect on $^{137}Cs$, the efficiency of removing it decreased. $H_{2}SO_4$ used as an additive to increase the removal efficiency showed a higher removal capability than other chemicals for both $^{137}Cs\;and\;^{60}Co$. The efficiency of removing radionuclides from the radioactive soil in the column was proportional to the capability of the added chemical to extract radionuclides. It took 10 days to achieve a $54\%$ removal of $^{137}Cs$ and a $97\%$ removal of $^{60}Co$ from the soil. The volume of the soil wastewater discharged from the soil column by the electrokinetic method was $20\%$ below that for soil washing.

• Journal of the Korea Computer Industry Society
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• v.3 no.7
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• pp.837-844
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• 2002

In general, software test is carried out to detect or repair errors in system during software development process. Namely, we can evaluate software reliability through collecting and removing the faults detected in testing phase. Software reliability growth model evaluates reliability of software mathematically. Many kinds of software reliability growth modeling which modeling the processes of detecting, revising and removing the faults detected in testing phase have been proposed in many ways. and, it is assumed that almost of these modeling have one typed detect and show the uniformed detection rate. In this study, significance levels of the faults detected in test phase are classified according to how they can affect on the whole system and then the fault detection capability of them is applied. From this point of view, We here by propose a software reliability growth model with faults detection capability according considering fault significance levels and apply some fault data to this proposed model and finally verify its validity by comparing and estimating with the existing modeling.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.218-221
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• 2009

Solid oxide fuel cells (SOFCs), as high-temperature fuel cells, have various advantages. In some merits of SOFCs, high temperature operation can lead to the capability for internal reforming, providing fuel flexibility. SOFCs can directly use CH4 and CO as fuels with sufficient steam feeds. However, hydrocarbons heavier than CH4, such as ethylene, ethane, and propane, induce carbon deposition on the Ni-based anodes of SOFCs. In the case of the ethylene steam reforming reaction on a Ni-based catalyst, the rate of carbon deposition is faster than among other hydrocarbons, even aromatics. In the reformates of heavy hydrocarbons (diesel, gasoline, kerosene and JP-8), the concentration of ethylene is usually higher than other low hydrocarbons such as methane, propane and butane. It is importatnt that ethylene in the reformate is removed for stlable operation of SOFCs. A new methodology, termed post-reforming was introduced for removing low hydrocarbons from the reformate gas stream. In this work, activity tests of some post-reforming catalysts, such as CGO-Ru, CGO-Ni, and CGO-Pt, are investigated. CGO-Pt catalyst is not good for removing ethylene due to low conversion of ethylene and low selectivity of ethylene dehydrogenation. The other hand, CGO-Ru and CGO-Ni catalysts show good ethylene conversion, and CGO-Ni catalyst shows the best reaction selectivity of ethylene dehydrogenation.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05a
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• pp.257-262
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• 1996

The characteristics of adjuster rods have been studied for the application to DUPIC core in two aspects: the half an hour xenon override capability and power flattening. The transient analysis has shown that the adjusters used for CANDU 6 have the reactivity worths more than required to override xenon load for DUPIC core. Parametric study has shown that removing 7 adjuster rods in the middle row and adjusting the strength of the rest of adjuster rods can provide the performances no worse than those of natural uranium core.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.3
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• pp.43-50
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• 2004

This study looked into the water quality improvement effect of reed (Phragmites communis), bur reed (Sparaganium stoloniferum), Alisma canaliculatum, and Hydrocharis dubia in order to develop native hydrophytes suitable to natural-type wetlands for ecological restoration. The result confirms that the concentration of wastewater was lowered in most plants indicating a possibility in wastewater treatment. Among four species, reed (Phragmites communis) and bur reed (Sparaganium stoloniferum) were most effective in removing a majority of contaminants. Considering that reed (Phragmites communis) is a species that has been used most often among hydrophytes, bur reed (Sparaganium stoloniferum), which is a native species in Korea, showed equivalent level of outstanding effect. In the physiological and growing activity and its relations to water quality improvement effect, each species appeared differently. Reed (Phragmites communis) and bur reed (Sparaganium stoloniferum) were best also in physiological and growing activity. In the case of Hydrocharis dubia, growth was strong in polluted water environment but its physiological activity was poor, indicating that it was under stress. The growth and physiological activity of Alisma canaliculatum were also poor, indicating that it too is being stressed. However, measuring organic contents in the plants of each species shows that the organic contents of Alisma canaliculatum was high. Alisma canaliculatum is a species effective in removing pollutants in water, although it is under stress. A unique phenomenon in removing water pollution with plants is that each species removed different pollutants. In the case of Alisma canaliculatum, which was relatively poor in removing pollution, it was remarkable in reducing nitrogen and phosphorus. Hydrocharis dubia was also effective in eliminating floating matter.

• Journal of the Korean Society of Visualization
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• v.22 no.1
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• pp.34-39
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• 2024

With the fine particulate matter (PM) poses a serious threat to public health and the environment. The ultrafine PM in particular can cause serious problems. This study investigates the effectiveness of a submicron dry fog system in removing fine PM. Two methods are used to create fine dust particles: burning incense and utilizing an aerosol generator. Results indicate that the dry fog system effectively removes fine dust particles, with a removal efficiency of up to 81.9% for PM₁₀ and 61.9% for PM_2.5 after 30 minutes of operation. The dry fog, characterized by a mean size of approximately 1.5 ㎛, exhibits superior performance in comparison to traditional water spraying methods, attributed to reduced water consumption and increased contact probability between water droplets and dust particles. Furthermore, experiments with uniform-sized particles which sizes are 1 ㎛ and 2 ㎛ demonstrate the system's capability in removing ultrafine PM. The proposed submicron dry fog system shows promise for mitigating fine dust pollution in various industrial settings, offering advantages such as energy consumption and enhanced safety for workers and equipment.