• 한국태양에너지학회 논문집
• /
• 제31권1호
• /
• pp.100-106
• /
• 2011

This study proposes a $CO_2$ emission reduction method through correlation analysis of a sample building. First, energy saving factors of heating, cooling, lighting were determined for the correlation analysis and $CO_2$ emission contribution rate of the design parameters have been analyzed. Then optimal combination of each design parameter has been drawn. Heat transfer coefficient of walls and windows, air permeability, windows area ratio, and shading devices were selected as applicable energy saving factors of the sample building. Also computer simulation was conducted using experimental design by Orthogonal Arrays of the statistical method. And the contribution rate was estimated by Analysis of Variance-ANOVA. As a result, the $CO_2$ emission in heating was reduced to 51.9%; in cooling to 16.8%; and in lighting to 2% compared to the existing building. The majority of the reduction was presented by heating energy.

• Advances in nano research
• /
• 제10권3호
• /
• pp.295-312
• /
• 2021

A new ionic liquid functionalized magnetic silica nanoparticle was synthesized and characterized and tested as an adsorbent. The adsorbent was used for magnetic solid phase extraction on ICP-MS method. Simultaneous determination of precious metal Au has been addressed. The method is simple and fast and has been applied to standard water and surface water analysis. A new method for separation/analysis of trace precious metal Au by Magnetron Solid Phase Extraction (MSPE) combined with ICP-MS. The element to be tested is rapidly adsorbed on CoFe2O4@SiO2@[BMIM]PF6 composite nano-adsorbent and eluted with thiourea. The method has a preconcentration factor of 9.5-fold. This method has been successfully applied to the determination of gold in actual water samples. Hydrophobic Ionic Liquids (ILs) 1-butyl-3-methylimidazole hexafluorophosphate ([BMIM]PF6) coated CoFe2O4@SiO2 nanoparticles with core-shell structure to prepare magnetic solid phase extraction agent (CoFe2O4@SiO2@ILs) and establish a new method of MSPE coupled with inductively coupled plasma mass spectrometry for separation/analysis of trace gold. The results showed that trace gold was adsorbed rapidly by CoFe2O4@SiO2@[BMIM]PF6 and eluanted by thiourea. Under the optimal conditions, preconcentration factor of the proposed method was 9.5-fold. The linear range, detection limit, correlation coefficient (R) and relative standard deviation (RSD) were found to be 0.01~1000.00 ng·mL-1, 0.001 ng·mL-1, 0.9990 and 3.4% (n = 11, c = 4.5 ng·mL-1). The CoFe2O4@SiO2 nanoparticles could be used repeatedly for 8 times. This proposed method has been successfully applied to the determination of trace gold in water samples.

• 전기학회논문지P
• /
• 제59권2호
• /
• pp.212-217
• /
• 2010

When paper which was applied as insulation in oil-filled transformer was aged by thermal, its electrical, mechanical and chemical characteristics were changed and deteriorated. Therefore operating temperature was more higher, damage of paper was more quicker. Insulating paper which was generally made with cellulose was degraded, polymer of long length chain was decomposed as a monomer and CO, $CO_2$ gas and/or by-product such as furfural was produced from paper at the same time. In according with detection these gas and furfural by dissolved gas analysis(DGA) and high performance liquid chromatography(HPLC), we have investigated effects of CO, $CO_2$ gas and furfural on insulation of paper. Also we have analyzed for correlation between furfural and CO, $CO_2$ gas using linear regression method that was known as useful, credible statistical analysis.

• 한국산학기술학회논문지
• /
• 제14권11호
• /
• pp.5317-5322
• /
• 2013

본 연구에서는 ${\epsilon}$-NTU 방법을 사용하여 $CO_2$ 히트펌프 가스쿨러의 열전달 성능을 해석하였고, 공개된 실험결과와 비교하였다. $CO_2$ 히트펌프 가스쿨러의 열전달률, 냉매측/순환수측 출구온도를 EES로 계산하였다. 해석은 시험부를 하나의 구간으로 설정하여 냉매와 순환수측 입출구의 평균온도를 물성치로 적용한 평균해석과 시험부를 50구간으로 나누어 각 구간에서의 출구온도를 다음 구간의 입구온도로 사용한 국소해석으로 진행되었다. 실험결과로부터 평균해석보다는 국소해석의 결과가 실험값을 더 만족하였으며, 열전달률은 0.3~1.1%, 순환수측 출구온도는 1.31~1.88%, 냉매측 출구온도는 3.12~5.18% 정도의 오차를 보였다.

• 한국대기환경학회지
• /
• 제17권3호
• /
• pp.277-288
• /
• 2001

Continuous atmospheric CO$_2$measurements measured during the 1 year(1998.8∼1999.8) at Korea Global Atmosphere Watch Observatory (KGAWO) in Anmyeon-do are analyzed by the selecting method which is recommended by WDCGG to get background CO$_2$. This method can reject data based on two criteria: the instability of CO$_2$ concentration within 1 hour from hourly standard deviation (hourly variability$\leq$ 0.6 ppm first selection) and the large changes in the CO$_2$ concentration from one hour to the nex(∼$\leq$0.3 ppm, second selection). We could obtain hourly background CO$_2$ of 37% in first selection and 20% in second selection during the l year. That are a little less than those of Ryori station in Japan. especially, the cases of background CO$_2$ which is selected were few during the summer. That is caused by affection of vegetation and anthropogenic source. After the selecting methods are applied, the cases which is selected for easterly wind decrease remarkably according to the analysis of wind direction about continuous CO$_2$ .That was affected by anthropogenic source from the east area.

• 대한조선학회논문집
• /
• 제47권2호
• /
• pp.225-232
• /
• 2010

The requirement of design of High-Pressure/High-Temperature(HP/HT) pipelines on an seabed increases in recent years. The need of research on the analysis method to improve the design capacity is increasing. The purpose of this study is the development of the analysis method of thermal buckling of subsea pipeline structures. The analysis method of thermal buckling was established by using the commercial FEM code(ABAQUS) which shows the outstanding performance in non-linear static FE analysis. The developed method has been applied to the installation of subsea pipeline on the offshore project. For a validation, the comparative study has been carried out. This application to offshore project demonstrates the superiority of the analysis method of thermal buckling of subsea pipeline structures and testifies the application to detail design.

• Bulletin of the Korean Chemical Society
• /
• 제23권3호
• /
• pp.417-422
• /
• 2002

Comparison studies of the Quantitative Structure Activity Relationship (QSAR) methods with new imidazo-quinolinedione derivatives were conducted using Comparative Molecular Field Analysis (CoMFA), Comparative Molecular Similarity Indices Analysis (CoMSIA), and the Hologram Quantitative Structure Activity Relationship (HQSAR). When the CoMFA crossvalidation value, q2, was 0.625, the Pearson correlation coefficient, r2, was 0.973. In CoMSIA, q2 was 0.52 and r2 was 0.979. In the HQSAR, q2 was 0.501 and r2 was 0.924. The best result was obtained using the CoMSIA method according to a comparison of the calculated values with the real in vitro cytotoxic activities against human ovarian cancer cell lines.

• 한국정보통신학회:학술대회논문집
• /
• 한국해양정보통신학회 2010년도 추계학술대회
• /
• pp.493-496
• /
• 2010

본 논문에서는 주행중인 차량의 CO2 배출량을 추정하기 위한 방법들로, 주행거리에 따른 CO2 배출량 추정 방법, IPCC에 따른 CO2 배출량 추정 방법, MAF와 화학반응식을 이용한 CO2 배출량 추정 방법 등에 대해서 설명하고 각각의 방법들의 성능을 비교하기 위해 실차(제네시스 3.3)를 이용하여 약 5Km의 실제 도로 경로를 주행하며 각각의 CO2 추정 방법들에 대한 성능을 실증 분석하였다.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2010년도 춘계 학술발표회
• /
• pp.543-552
• /
• 2010

Due to increase in urban tunnelling as urban population and traffic volume increase, problems related with site security and civil appeal also increase. This paper presents a comparative analysis between conventional 2-arch tunnel method and non-pilot 2 arch tunnel method, which were performed in the basic design of Wie-Rae region. According to the analysis results, non-pilot 2-arch tunnel method is more efficient in terms of stability, constructability, and economic aspect. It is authors' wish that design procedure and method presented in this paper could help the design and construction of non-pilot 2-arch tunnel that should be planned in the near future.

• International Journal of Korean Welding Society
• /
• 제1권2호
• /
• pp.51-60
• /
• 2001

A prediction method for determining the welding residual stress by artificial neural network is proposed. A three-dimensional transient thermo-mechanical analysis has been performed for the $CO_2$ arc welding using the finite element method. The first part of numerical analysis performs a three-dimensional transient heat transfer analysis, and the second part then uses the results of the first part and performs a three-dimensional transient thermo-elastic-plastic analysis to compute transient and residual stresses in the weld. Data from the finite element method are used to train a back propagation neural network to predict the residual stress. Architecturally, the fully interconnected network consists of an input layer for the voltage and current, a hidden layer to accommodate the failure mechanism mapping, and an output layer for the residual stress. The trained network is then applied to the prediction of residual stress in the four specimens. It is concluded that the accuracy of the neural network predicting method is fully comparable with the accuracy achieved by the traditional predicting method.