• International Journal of Aeronautical and Space Sciences
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• v.18 no.4
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• pp.662-674
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• 2017

This paper describes the multidisciplinary design optimization (MDO) process of a tailless unmanned combat aerial vehicle (UCAV) using global variable fidelity aerodynamic analysis. The developed tailless UAV design framework combines multiple disciplines that are based on low-fidelity and empirical analysis methods. An automated high-fidelity aerodynamic analysis is efficiently integrated into the MDO framework. Global variable fidelity modeling algorithm manages the use of the high-fidelity analysis to enhance the overall accuracy of the MDO by providing the initial sampling of the design space with iterative refinement of the approximation model in the neighborhood of the optimum solution. A design formulation was established considering a specific aerodynamic, stability and control design features of a tailless aircraft configuration with a UCAV specific mission profile. Design optimization problems with low-fidelity and variable fidelity analyses were successfully solved. The objective function improvement is 14.5% and 15.9% with low and variable fidelity optimization respectively. Results also indicate that low-fidelity analysis overestimates the value of lift-to-drag ratio by 3-5%, while the variable fidelity results are equal to the high-fidelity analysis results by algorithm definition.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.237-240
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• 2002

Design rainfall using LH-moments following the consecutive duration were derived by the regional and at-site analysis using the observed and simulated data resulted from Monte Carlo techniques. RRMSE, RBIAS and RR in RRMSE for the design rainfall were computed and compared in the regional and at-site frequency analysis. Consequently, it was shown that the regional analysis can substantially more reduce the RRMSE, RBIAS and RR in RRMSE than at-site analysis in the prediction of design rainfall. RE for an optimal order of L-moments was also computed by the methods of L, L1, L2, L3 and L4-moments for GEV distribution. It was found that the method of L-moments is more effective than the others for getting optimal design rainfall according to the regions and consecutive durations in the regional frequency analysis. Diagrams for the design rainfall derived by the regional frequency analysis using L-moments were drawn according to the regions and consecutive durations by GIS techniques.

• Journal of the Korean Society of Costume
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• v.54 no.3
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• pp.73-85
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• 2004

The purpose of this study was to investigate the characteristic and sensibility of Japanism fashion designs which represented by Japanese designers and Western designers. The stimulus were 29 pictures of contemporary fashion designs which represented the Japanism style fashion designs from fashion collections. The data were analyzed by Cluster analysis, Factor analysis, Multidimensional Scaling Method and Regression Analysis. The specific objectives were as follows ; 1) As result of design analysis, Japanism fashion sensibility is unique and good-looking. 2) As result of the factor analysis. 4 factors which are Attractiveness, Attention, Maturity and Hardness and softness. 3) According to sensibility positioning, The Japanism fashion design was classified by Decorative-Simple, Hard-Soft. 4) As result of the Regression Analysis, The preference of Japanism fashion design was related to attractive factor. 5) As result of the Regression Analysis. The buying desirable of Japanism fashion design was related to attractive, attentive and mature factor.

• Magazine of the Korean Society of Agricultural Engineers
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• v.45 no.5
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• pp.97-109
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• 2003

This study is mainly conducted to derive the design drought rainfall by the consecutive duration using probability weighted moments with rainfall in the regional drought frequency analysis. It is anticipated to suggest optimal design drought rainfall of hydraulic structures for the water requirement and drought frequency of occurrence for the safety of water utilization through this study. Preferentially, this study was conducted to derive the optimal regionalization of the precipitation data that can be classified by the climatologically and geographically homogeneous regions all over the regions except Cheju and Ulreung islands in Korea. Five homogeneous regions in view of topographical and climatological aspects were accomplished by K-means clustering method. Using the L-moment ratio diagram and Kolmogorov-Smirnov test, generalized extreme value distribution was confirmed as the best fitting one among applied distributions. At-site and regional parameters of the generalized extreme value distribution were estimated by the method of L-moments. Design drought rainfalls using L-moments following the consecutive duration were derived by the at-site and regional analysis using the observed and simulated data resulted from Monte Carlo techniques. Relative root-mean-square error (RRMSE), relative bias (RBIAS) and relative reduction (RR) in RRMSE for the design drought rainfall derived by at-site and regional analysis in the observed an simulated data were computed and compared. In has shown that the regional frequency analysis procedure can substantially more reduce the RRMSE. RBIAS and RR in RRMSE than those of at-site analysis in the prediction of design drought rainfall. Consequently, optimal design drought rainfalls following the regions and consecutive durations were derived by the regional frequency analysis.

• Journal of the Ergonomics Society of Korea
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• v.27 no.4
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• pp.45-58
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• 2008

Ergonomic techniques have been required to analyze the effectiveness of functional clothing design improvement in a systematic and analytic manner. The goals of the present study are to: (1) comprehensively and analytically examine the effectiveness of clothing improvement by using the relationship analysis between clothing design components (D) and ergonomic evaluation measures (E) and (2) prove the usefulness of cost-effectiveness analysis for clothing design optimization. The cost effectiveness analysis is comprised of the preliminary evaluation based on expertise and the in-depth evaluation where the D-E relationship analysis is applied. As a result of the cost effectiveness analysis applied to flame-proof clothing, an optimal design was identified by analyzing costs and qualitative/quantitative effects. In the preliminary evaluation, the expected effectiveness of each design alternative on wear efficiency and wear comfort was estimated. In the in-depth evaluation, however, the effectiveness of each design alternative was analyzed by quantitative evaluation in a wearing test using a questionnaire prepared based on the D-E relationship analysis. It was concluded that the D-E relationship analysis and the cost-effectiveness analysis are useful for comprehensive evaluation and optimization of functional clothing design.

• The Research Journal of the Costume Culture
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• v.17 no.4
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• pp.691-708
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• 2009

The purpose of this study was to find the methodology of design plan that could raise the brand power by looking around the driving force of the design innovation through the case study of Louis Vuitton which has been evaluated to be successful in brand revolution by designer Marc Jacobs. Research methods were theoretical studies looking for various analysis and valuations about Louis Vuitton's design innovation and analysis about articles in International Herald Tribune and New York Times. Driving force of Louis Vuitton's design innovation could be summarized as designer's creativity and full supports for designers, establishment of BI by strategic cooperation between design and marketing parts, active design plans by collaboration with modern artists, existence of Logo as a symbol of brand, business mind pursuing adventures and dreams, and directors' artistic sensitivity and supports for culture and art.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.8
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• pp.175-184
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• 2003

A method of the shape design sensitivity analysis based on the boundary integral equation formulation is presented for two-dimensional inhomogeneous thermal conducting solids with multiple domains. Shape variation of the external and interface boundary is considered. A sensitivity formula of a general performance functional is derived by taking the material derivative to the boundary integral identity and by introducing an adjoint system. In numerical analysis, state variables of the primal and adjoint systems are solved by the boundary element method using quadratic elements. Two numerical examples of a compound cylinder and a thermal diffuser are taken to show implementation of the shape design sensitivity analysis. Accuracy of the present method is verified by comparing analyzed sensitivities with those by the finite difference. As application to the shape optimization, an optimal shape of the thermal diffuser is found by incorporating the sensitivity analysis algorithm in an optimization program.

• Journal of Engineering Education Research
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• v.25 no.6
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• pp.103-113
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• 2022

The purpose of this study is to correlation analysis between technological problem-solving traits and engineering design competency. To this end, correlation analysis and regression analysis between technological problem-solving traits and engineering design competency were used to analyze the relationship between each other. To collect data on individual characteristics, technological problem-solving traits, and engineering design competency, a survey was conducted with university students. As a result of the analysis, there was no difference in engineering design competency by gender, but there was a difference in technological problem-solving traits. There was no difference in technological problem-solving traits by major, but there was a difference in engineering design competency. As a result of correlation analysis, the correlation was found. In the case of regression analysis, a statistically significant result was found in the problem-solving trait domain, and the regression analysis model was found to be suitable. The results of the analysis of differences in engineering design competency according to technological problem-solving traits showed that the effective problem solvers were significantly higher.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1997.10a
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• pp.193-200
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• 1997

Current seismic design code is based of the assumption that the designed structures would be behaved inelastically during a severe earthquake ground motion. For this reason, seismic design forces calculated by seismic codes are much lower than the forces generated by design earthquakes which makes structures responding elastically. Present procedures for calculating seismic design forces are based on the use of elastic spectra reduced by a strength reduction factors known as "response modificaion factor". Because these factors were determined empirically, it is difficult to know how much inelastic behaviors of the structures exhibit. In this study, base shear forces required to maintain target ductility ratio were first calculated from nonlinear dynamic analysis on the single degree of freedom system. And then, base shear foeces specified in seismic design code compare with above results. If the strength(base shear) required strength should be filled by overstrength and/or redundancy. Therefore, overstrength of moment resisting frame structure will be estimated from the results of static nonlinear analysis(push-over analysis).analysis).

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.5 no.4
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• pp.82-89
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• 1996

In this study, to choose the drilling m/c with analysis model for dynamic design of machine tool strctures, are used substucture syntheis method for reduction to degrees of freedom of dynamic model and analysis evaluation of substructures The dynamic factors of substurctures are examined by substructure synthesis method. And that dynamic design of structures for energy balancing are performed. The computer program for calculated of the dynamic and energy distribution analysis was developed. Result of numerical analysis by developed program obtained to conclusion as following. The design of machine tool structures by dynamic avoid the resonances, and are known to considered based on the energy balancing. These methods can be used effectively for the performance evaluation, design modification and improvement of dynamic performance evaluation, design modification and improvement of dynamic performance of machine tools.