• Korean Chemical Engineering Research
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• v.49 no.6
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• pp.739-744
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• 2011

Activated carbon SCR(CSCR) catalyst that is used to remove $NO_x$ in exhaust gas including boron discharged from the production process of liquid crystal display(LCD) shows deactivation when boron is deposited to block the pores within the catalyst or to cover its active sites. The spent carbon catalyst is regenerated by washing with various surfactants, drying and calcination. For comparison of the physical and chemical properties before and after the regeneration with the variables, type of surfactants and calcination condition, element analysis by ICP, $N_{2}$ adsorption were conducted. $DeNO_{x}$ in SCR with $NH_3$ was carried out in a fixed bed reactor at $120^{\circ}C$. The activated carbon catalyst regenerated through washing with a non-ionic surfactant in $H_{2}O$ at $90^{\circ}C$ and calcination under $N_{2}$ gas at $550^{\circ}C$ shows similar level of surface area and $NO_x$ removal efficiency with those of fresh catalyst.

• Resources Recycling
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• v.23 no.3
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• pp.37-43
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• 2014

A study has been made on the recovery of tin and copper from waste solder stripper by oxalate precipitation. With the increasing of the oxalic acid addition, tin was precipitated effectively and removed above 99.5% of tin when the oxalic acid, in an amount 1.0-1.5 times the stoichometric requirement, was added. But, in this case, only 2.0% of copper was precipitated and lead, iron were not precipitated. So, tin was selectively removed from the waste solution. With the increasing of the reaction temperature, the removal percentage of tin was increased and maximum value at arounf $60^{\circ}C$ and decreased with increase in the temperature any more. After filtering the precipitate and drying in oven, $SnO_2$ was obtained from the precipitate. After removal of tin in stripping solution, above 91% of copper was selectively removed by Cu-oxalate by addition of oxalic acid.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.3
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• pp.615-620
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• 2008

We fabriacted thermal evaporated $10nm-Ni_{1-x}Co_x$(x=0.2, 0.6, and 0.7) films on 70 nm-thick polysilicon substrate with $0.5{\mu}m$ line width. NiCo composite silicide layers were formed by rapid thermal annealing (RTA) at the temperatures of $700^{\circ}C$ and $1000^{\circ}C$. Then, we checked the microstructure evaluation of silicide patterns. A FIB (focused ion beam) was used to micro-mill the interconnect patterns with low energy condition (30kV-10pA-2 sec). We investigated the possibility of selective removal of silicide layers. It was possible to remove low resistance silicide layer selectively with the given FIB condition for our proposed NiCo composite silicides. However, the silicides formed from $Ni_{40}Co_{60}$ and $Ni_{30}Co_{70}$ composition showed void defects in interconnect patterns. Those void defects hinder the selective milling for the NiCo composite silicides.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.24 no.4
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• pp.145-150
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• 2014

GaN nanorods were grown on the apex of GaN stripes by three dimensional selective growth method. $SiO_2$ mask was partially removed only on the apex area of the GaN stripes by an optimized photolithography for the selective growth. Metallic Au was deposited only on the apex of the GaN stripes and a selective growth of GaN nanorods was followed by a metal organic vapor phase epitaxy (MOVPE). We confirmed that the shape and size of the GaN nanorods depend on growth temperature and flow rates of group III precursor. GaN nanorods were grown having a taper shape which have sharp tip and triangle-shaped cross section. From the TEM result, we confirmed that threading dislocations were rarely observed in GaN nanorods because of the very small contact area for the selective growth. Stacking faults which might be originated from a difference of the crystal facet directions between the GaN stripe and the GaN nanorods were observed in the center area of the GaN nanorods.

• The Korean Journal of Applied Statistics
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• v.22 no.2
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• pp.297-307
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• 2009

Korean household debt is one of the main sources of the current financial crisis. This paper studies the impact of household members' attributes such as a type of housing(self-own or rent), education, age, average monthly income of the head of household, and the area of residence, on the stress level of the household members due to household debt. We analyze a real data set collected by KB Kookmin Bank in 2004. We consider low and high stress level as a binary response variable and use a logistic regression model with the attributes of household members as explanatory variables. A simple but well-fitting model is selected by backward elimination method based on the likelihood statistic for goodness-of-fit test, and the impact of the attributes on the stress level is studied from parameter estimates of the selected model. We also perform the similar analysis on a binary response variable which distinguishes households with no debt from the rest. From the analysis, the stress level tends to be low for households with self-own houses, high average monthly income, low education level, and young members.

• Journal of the Korea Society of Computer and Information
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• v.18 no.4
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• pp.19-26
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• 2013

Pseudo sample neural network (PSNN) is a variant of traditional neural network using pseudo samples to mitigate the local-optima-convergence problem when the size of training samples is small. PSNN can take advantage of the smoothed solution space through the use of pseudo samples. PSNN has a focus on the quantity problem in training, whereas, methods stressing the quality of training samples is presented in this paper to improve further the performance of PSNN. It is evident that typical samples and highly correlated features help in training. In this paper, therefore, kernel density estimation is used to select typical samples and correlation factor is introduced to select features, which can improve the performance of PSNN. Debris flow data set is used to demonstrate the usefulness of the proposed methods.

• Journal of The Korea Institute of Healthcare Architecture
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• v.17 no.2
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• pp.53-59
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• 2011

본 연구는 미국 텍사스 주의 소도시에 있는 스캇 앤 화이트 클리닉의 외부공간을 대상으로 하여 외래환자와 방문객들이 직면하는 길찾기의 문제점을 분석한다. 연구의 공간적 범위는 클리닉의 외부공간으로 한정하여 진입도로에서 진입하여 주차한 후 출입구에 도달하는 경로에서 관찰되는 행태적 특성을 분석한다. 분석의 초점은 진입도로에서 이루어지는 경로선택의 결정과 그것이 클리닉에 진입하기 위한 출입구 결정에 미치는 영향관계에 둔다. 분석은 외부공간에서의 길찾기에 관한 기존 연구문헌을 참고하여 작성한 연구모형에 의해 이루어진다. 구체적으로 보면, 이용자들이 보이는 날씨, 성별, 그리고 나이에 따른 길찾기 행태의 차이를 클리닉의 남동측 출입구와 남서측 출입구에서 발생하는 이용자들의 하차 빈도를 측정하였다. 또한 하차의 위치를 행태 지도에 기록하여 연구모델에 나타나는 상관성을 분석하였다. 길찾기 행태분석 결과를 통해 파악된 외부주차장에 주차한 후 클리닉에 접근하는 이용자들의 경로선택의 문제점과 클리닉의 입구 공간에서 하차한 이용자들의 입구선택에서 나타나는 문제점을 토대로 하여 외부공간에서 발생하는 길찾기 행위의 효율성을 증진시키기 위한 디자인 추천 사항을 다음과 같이 제시한다: (1) 시각적 단서를 제공하기 위해 남서쪽 출입구의 형태와 색채 차별화; (2) 도로에서 클리닉 진입공간에 위치한 안내판의 글자 크기 확대; (3) 학습된 길찾기 행태를 보조하기 위해 동쪽에 랜드마크 시설물 설치 및 목적 지점의 최종경관 개선; (4) 과도한 클리닉의 정보에 의해 감소되는 가독성을 고려하여 안내판의 정보 간략화; (5) 색채의 대조를 고려(출입구 벽에 설치된 클리닉의 이름이 갈색에 푸른색으로 설치되어 있어 색채의 대비가 낮아 가독성 떨어짐); (6) 클리닉 중앙 출입구의 하차 공간 상부에 설치된 캐노피 기둥의 과도한 크기에 의해 발생하는 가시공간의 감소에 의해 발생하는 하차 공간 사용의 혼잡 문제를 제거하기 위해 기둥규모 축소; (7) 하차점 6까지 캐노피를 확장하여 우천시에 발생하는 공간 사용의 문제점 제거; 그리고 (8) 올바른 하차공간 사용을 위해 진입 접근도로에 차선 설치.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.11
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• pp.1977-1983
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• 2000

SCR(selective catalytic reduction) pilot plant for reduction of the nitrogen oxides using diesel oil as a reductant was installed at the NG(natural gas) fired combined cycle and the activity of Pt(0.3%)/Zeolite catalyst was studied in real flue gas condition according to the amount of reductant. reaction temperature and space velocity. NOx conversion gradually increased with increasing the diesel oil concentration up to C/N ratio 5.5(C/N ratio: the ratio of the number of carbon atom to the number of NOx molecules included in the flue gas). Increasing the reaction temperature. NOx conversion increased and reached a maximum conversion of 50% at $190^{\circ}C$. NOx conversion did not changed with increasing the space velocity up to 18,500/hr and then gradually decreased. These results reveal the potential for diesel oil as a reductant for de-NOx SCR process.

• Journal of the Korean Vacuum Society
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• v.20 no.4
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• pp.294-299
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• 2011

In this study, single-walled carbon nanotubes (SWCNTs) were synthesized on a Fe/$Al_2O_3$/Si layer by thermal chemical vapor deposition. Metallic SWCNTs were selectively removed by microwave irradiation. Electrical and structural characterizations of the SWCNTs clearly revealed that the metallic SWCNTs were almost removed by microwave irradiation for 120 sec. The remained semiconducting SWCNTs with a high crystalline structure were obtained over 95%. This method would provide useful information for applications to SWCNTs-based field effect transistors and multifaceted nanoelectronics.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.37 no.1
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• pp.37-48
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• 2000

In this paper, we propose a new connected operator Using morphological grayscale reconstruction for region-based coding First, an effective method of reference-image creation lis proposed, which is based on the Size as well as the contrast. This improves the performance of simplification, because It preserves perceptually important components and removes unnecessary components The conventional connected operators are good for removing small regions, but have a serious drawback for low-contrast regions that are larger than the structuring element. That is, when the conventional connected operators are applied to tills region, the simplification becomes less effective or several meaningful regions are merged to one region to avoid this, the conventional geodesic dilation is modified to propose an adaptive operator to reduce the effect of inappropriate propagation, pixels reconstructed to the original values are excluded m the dilation operation Experimental results have shown that the proposed algorithm achieves better performance In terms of the reconstruction of flat zones. The Picture quality has also been improved by about 7dB, compared to the conventional methods.