• Steel and Composite Structures
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• 제43권3호
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• pp.341-351
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• 2022

This paper presents an inelastic buckling behavior analysis of rectangular hollow steel tubes with geometrical imperfections under elevated temperatures. The main variables are the temperature loads, slenderness ratios, and exposure conditions at high temperatures. The material and structural properties of steels at different temperatures are based on Eurocode (EN 1993-1-2, 2005). In the elastic buckling analysis, the buckling strength decreases linearly with the exposure conditions, whereas the inelastic buckling analysis shows that the buckling strength decreases in clusters based on the exposure conditions of strong and weak axes. The buckling shape of the rectangular steel column in the elastic buckling mode, which depicts geometrical imperfection, shows a shift in the position at which bending buckling occurs when the lower section of the member is exposed to high temperatures. Furthermore, lateral torsional buckling occurs owing to cross-section deformation when the strong axial plane of the model is exposed to high temperatures. The elastic buckling analysis indicates a conservative value when the model is exposed to a relatively low temperature, whereas the inelastic buckling analysis indicates a conservative value at a certain temperature or higher. The comparative results between the inelastic buckling analysis and Eurocode 3 show that a range exists in which the buckling strength in the design equation result is overestimated at elevated temperatures, and the shapes of the buckling curves are different.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2005년도 추계학술대회 학술발표 논문집 제15권 제2호
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• pp.345-348
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• 2005

In this paper, we suggested an evaluation model for satisfaction of e-Learning. This model was composed decision of evaluation criteria, analysis of consciousness structure for evaluation factors using the Fuzzy Structural Modeling method, decision of weights for evaluation factors considering intersectional dependence relations and evaluation of satisfaction of e-Learning. The case study of this model was done for comparative analysis between teachers and students of e-Learning in high school.

• 방사성폐기물학회지
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• 제17권1호
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• pp.47-58
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• 2019

The paper presents the results of a multi-criteria comparative evaluation of 12 feasible Russian nuclear energy deployment scenarios with thermal and fast reactors in a closed nuclear fuel cycle. The comparative evaluation was performed based on 6 performance indicators and 5 different MCDA methods (Simple Scoring Model, MAVT / MAUT, AHP, TOPSIS, PROMETHEE) in accordance with the recommendations elaborated by the IAEA/INPRO section. It is shown that the use of different MCDA methods to compare the nuclear energy deployment scenarios, despite some differences in the rankings, leads to well-coordinated and similar results. Taking into account the uncertainties in the weights within a multi-attribute model, it was possible to rank the scenarios in the absence of information regarding the relative importance of performance indicators and determine the preference probability for a certain nuclear energy deployment scenario. Based on the results of the uncertainty/sensitivity analysis and additional analysis of alternatives as well as the whole set of graphical and attribute data, it was possible to identify the most promising nuclear energy deployment scenario under the assumptions made.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.728-731
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• 2006

Ground subsidence near abandoned underground coal mines has become a serious social problem in Korea. The purpose of this study is to perform a comparative analysis between the ground subsidence area and the electrical resistivity measured by field survey at Samcheok City. A raster database composed of ground subsidence areas and electrical resistivity data was constructed for GIS. To analyze correlation between the two constructed raster datasets, we used a frequency ratio model. The results show that low and high electrical resistivity anomaly zones coincide with the existing subsidence areas. We infer that the high anomaly zone means saturated and low anomaly zone means vacant. It suggests that electrical resistivity might be a useful factor for analyzing ground subsidence hazard zone.

• 제어로봇시스템학회논문지
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• 제13권2호
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• pp.173-178
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• 2007

This paper is to establish an appropriate model for predicting the temperature decreases in the batch transferred from the refining process to the caster in steel-making companies. Mathematical modeling of the temperature decreases between the processes is difficult, since the reaction mechanism by which the temperature changes in a molten steel batch is dynamic, uncertain and complex. Three soft computing techniques are examined using the same data, namely the multiple regression, fuzzy regression, and neural net (NN) models. To compare the accuracy of these three models, a limited number of input variables are selected from those variables significantly affecting the temperature decrease. The results show that the difference in accuracy between the three models is not statistically significant. Nonetheless, the NN model is recommended because of its adaptive ability and robustness. The method presented in this paper allows the temperature decrease to be predicted without requiring any precise metallurgical knowledge.

• Molecular & Cellular Toxicology
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• 제2권3호
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• pp.216-221
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• 2006

The cholinesterase-inhibiting organophosphorous (OP) compounds known as nerve agents are highly toxic. The principal toxic mechanism of OP compounds is the inhibition of acethylcholine esterase (AChE) by phosphorylation of its catalytic site. The reversible competitive inhibition of AChE may prevent the subsequent OP intoxication. In this study, three-dimensional quantitative structure-activity relationship (3D-QSAR) was performed to investigate the relationship between the 29 compounds with structural diversity and their bioactivities against AChE. In particular, predictive models were constructed using the comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). The results indicate reasonable model for CoMFA ($q^{2}=0.453,\;r^{2}=0.697$) and CoMSIA ($q^{2}=0.518,\;r^{2}=0.696$). The presence of steric and hydophobic group at naphtyl moiety of the model may lead to the design of improved competitive inhibitors for organophosphorous intoxication.

• 경영과정보연구
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• 제5권
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• pp.81-101
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• 2000

The purpose of this comparative study is to compare and evaluate venture business of electronic and communication industry by Data Envelopment Analysis(DEA). DEA is a linear programming-based technique that converts multiple input and output measures into a single comprehensive measures of productive efficiency. In this paper, the CCR model and trend analysis model are used to examine the efficiency of 18 venture business. Input variables are number of employees. raw-material costs and production capability and output variables are real production, sales revenues and net income after taxes. DEA approach broad information like as efficiency level of each Decision Making Unit(DMU), reference group of efficiency improvement and trends of efficiency shift. Finally, the correlation of input and output variables are examined to examine the relationship among variables.

• 자원ㆍ환경경제연구
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• 제25권1호
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• pp.27-60
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• 2016

기후경제통합평가모형(Integrated assessment model of climate and the economy)은 기후변화에 관한 경제 분석과 정책제안을 위한 필수적인 도구가 되어왔다. 최근에는 기후변화에 대응하기 위한 정책적 노력들이 대부분 국가 또는 지역 수준에서 일어난다는 인식 하에 국가 또는 지역에서의 기후변화 영향과 정책수단의 효과를 평가할 수 있는 기후경제통합-지역평가모형(Regional integrated assessment model of climate and the economy)의 중요성이 더욱 커지고 있다. 이 논문에서는 국내에서 기후경제통합-지역평가모형을 개발하기 위한 첫 번째 단계로서 사회후생함수를 중심으로 기후경제통합-지역평가모형을 이론적으로 유형화했으며, RICE(Regional integrated climate-economy model) 모형을 통해 기후변화 대응전략에 따른 국가별 기후변화정책의 변화를 수치적으로 살펴보았다. 변화하는 국제 상황, 새롭게 드러나는 과학적 증거, 국내 여건 등을 모두 반영한 기후변화정책을 수립하기 위해서는 이를 분석할 수 있는 효과적인 도구를 갖추고 있어야 한다. 이 논문에서 살펴본 기후경제통합-지역평가모형은 이를 위한 유용한 도구가 될 수 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1047_1048
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• 2009

This paper describes comparative analysis results about the dynamic interaction of interconnected wind power system using the actual-size hardware simulator and the simulation model with PSCAD/EMTDC. The hardware simulator, which is composed of 2.0MVA induction motor with drive system and 1.5MW doubly-fed induction generator, was built and tested in Go-Chang Test Site of KEPCO for analyzing the dynamic interaction with the interconnected distribution system. The operation of hardware simulator was verified through comparative analysis between experimental results and simulation results obtained by simulation model with PSCAD/EMTDC. The developed hardware simulator and simulation model could be effectively used for analyzing the dynamic interaction, which has various phenomena depending on the wind variation and the network state of interconnected power system.

• 전기학회논문지P
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• 제58권3호
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• pp.263-269
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• 2009

This paper describes comparative analysis results about the dynamic interaction of interconnected wind power system using the actual-size hardware simulator and the simulation model with PSCAD/EMTDC. The hardware simulator, which is composed of 2.0MVA induction motor with drive system and 1.5MW doubly-fed induction generator, was built and tested in Go-Chang Test Site of KEPCO for analyzing the dynamic interaction with the interconnected distribution system. The operation of hardware simulator was verified through comparative analysis between experimental results and simulation results obtained by simulation model with PSCAD/EMTDC. The developed hardware simulator and simulation model could be effectively used for analyzing the dynamic interaction, which has various phenomena depending on the wind variation and the network state of interconnected power system.