• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.6
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• pp.423-429
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• 2003

On this study. we improved the efficiency applying algorithm that is repeatedly using table of orthogonal array in discrete design space and filling a defect of gradient method in continuous design space. we showed optimal ply angle that maximized 1st natural frequency of CFRP laminated composite plate without a hole and with a hole by each aspect ratio. In the case of CFRP laminated composite plate without a hole, we confirmed the reliance and efficiency of algorithm in comparison with the result of optimization achievement repeatedly using statistical table of orthogonal array of experimental design and the BFGS optimal design method.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.5
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• pp.107-114
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• 2018

Korea Space Launch Vehicle (KSLV)-I flight test data and the modified 1-dimensional steady state modeling data from the critical design results of the KSLV-II liquid oxygen filling system operation are compared to validate the reliability of critical design modeling. A comparison of major flow rates and pressure values between test data and calculation results are conducted. The relative errors relative to maximum total flow rate for each cooling, filling, and replenishment mode are determined within 6.7%. Calculated pressure values at the outlet of the pump and the inlet of flow control valves are within 5.1%. The pressure at the inlet of the launch vehicle for each operation mode are within the measured pressure range.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.14 no.1
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• pp.36-42
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• 2006

Kriging has been effectively used to approximate for optimization. This study has been devised to improve efficiency and accuracy of approximate optimal design using Kriging. The design of experiments (DOE), the classical design and space-filling design, are used to provide maximum information using minimum number of design of experiments. The proposed methodology is applied to the designs of 3-bar truss and Sandgren's pressure vessel.

• Korean Institute of Interior Design Journal
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• v.21 no.1
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• pp.11-19
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• 2012

The purpose of this study is to categorize elderly people's behavior using the questionnaire filling up by oneself for 24hours and to analyze the time required according to behavior and space. Also, through analytical researches, we find a way to develop smart home service. In this study, we carry out a questionnaire targeting a number of 20 elderly people. The questionnaire is to survey elderly people's behaviors for 24hours. Questionnaire items consist of three parts : items for checking time required about a daily behavior, items for analyzing a space in daily lives, generalities. This study is analyzed through descriptive statistics. The results of this study were as follows. Firstly, the elderly people's behaviors were eight categories. Among these behavior's categories, the highest portion is the behavior related to Individual maintenance such as sleep, personal hygiene, nap, etc. by 49%. Secondly, the portion of time required in residence based on daily lives is higher than outside of residence by 73%. Lastly, analyzing each space in residence focused on time required of elderly people's behaviors, bed room is the highest portion by 49%, and followed by living room with 29% and kitchen with 15%, and bath room with 7%.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1362-1365
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• 2003

On this study. we improved the efficiency applying algorithm that is repeatedly using orthogonal array in discrete design space and filling a defect of gradient method in continuous design space. we showed optimal ply angle that maximized buckling strength of CFRP laminated composite plate without a hole and with a hole by each aspect ratio. In the case of CFRP laminated composite plate without a hole, we confirmed the reliance and efficiency of algorithm in comparison with the result optimization achievement repeatedly using statistical orthogonal array of experimental design.

• Fashion & Textile Research Journal
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• v.15 no.1
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• pp.1-11
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• 2013

This study analyzed the expressive characteristics of padding in contemporary fashion. The methodology of this study was quantified through documentaries, fashion collections, and internet news. The results of expressive characteristics and methods were as follow. First, variability showed the creation of dwelling space by air filling, detail mode by zipper, and diversity of recycled filling by zipper pocket. It reflected the pursuit of nomadism and subversion of permanence by change of filling. Second, it was sexual symbolicity that showed the blurred androgynous silhouette by air filling and padding bar design of the chest, stomach, shoulder for the male body silhouette. It emphasized male sexual identity and power through the expression of a modern ideal body. Third, decoration displayed various crafts (such as knitting), various fabric such as polapolis, suedette, corduroy, denim, leather, knit, and spangle. It reflected visual pleasure, scarcity and various interpretations. Fourth, playfulness character forms throug hair filling, unfamiliar fashion items, diversity of silhouette and change of uses. It reflected a pleasant feeling through astonishment and surprise, nostalgia involved in memory and childhood play and disembarrassment from reality. Fifth, simplicity showed the elimination of a sportswear's factor with regular wad quilting, elimination of wad quilting, wad quilting following the structural line of clothes and the structual line of clothes omitted. It reflected disembarrassment from stereotype and an emphasis on essential elements.

• Journal of Korean Association for Spatial Structures
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• v.5 no.2 s.16
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• pp.65-71
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• 2005

The reinforced concrete becomes deteriorated. In strengthening of reinforced concrete structure, it is recently useing FRP. In research, flexural strengthening of reinforced concrete beam can be Efficient design. But shear srengthening og reinforced concrte beam can't be Efficient design by variable cause. The purpose of this study is to investigate the shear resisting effect of filling-up CFRP in reinforced concrete beams with web reinforced. Ten specimens were manufactured and tested. In the test result, it was analysis. The main variables in the test were a space of web reinforcement and a direction of CFRP.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.781-783
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• 2011

The oxidizer filling system, ground facility of the launch complex, should accept difficult requirements from the launcher sufficiently. The launcher do not have unnecessary insulators for mass reduction and manages liquid oxygen mass fastidiously to satisfy the mission requirement. So, the ground facility should be able to accept its requirements, then we should make the operating process being adjusted. In this paper, the operating process design and verification results on the oxidizer filling ground facility for liquid rocket is demonstrated.

• Nuclear Engineering and Technology
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• v.54 no.11
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• pp.4005-4012
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• 2022

As high-level radioactive waste (HLW) generated from nuclear power plants is harmful to the human body, it must be safely disposed of by an engineered barrier system consisting of disposal canisters and buffer and backfill materials. A gap exists between the canister and buffer material in a HLW repository and between the buffer material and natural rock-this gap may reduce the water-blocking ability and heat transfer efficiency of the engineered barrier materials. Herein, the basic characteristics and thermal properties of granular bentonite, a candidate gap-filling material, were investigated, and their effects on the temperature change of the buffer material were analyzed numerically. Heat transfer by air conduction and convection in the gap were considered simultaneously. Moreover, by applying the Korean reference disposal system, changes in the properties of the buffer material were derived, and the basic design of the engineered barrier system was presented according to the gap filling material (GFM). The findings showed that a GFM with high initial thermal conductivity must be filled in the space between the buffer material and rock. Moreover, the target dry density of the buffer material varied according to the initial wet density, specific gravity, and water content values of the GFM.

• Structural Engineering and Mechanics
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• v.55 no.5
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• pp.979-999
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• 2015

This paper proposes a novel reliability analysis method which computes reliability index, most probable point and probability of failure of uncertain systems more efficiently and accurately with compared to Monte Carlo, first-order reliability and response surface methods. It consists of Initial and Simulation steps. In Initial step, a number of space-filling designs are selected throughout the variables space, and then in Simulation step, performances of most of samples are estimated via interpolation using the space-filling designs, and only for a small number of the samples actual performance function is used for evaluation. In better words, doing so, we use a simple interpolation function called "reduced" function instead of the actual expensive-to-evaluate performance function of the system to evaluate most of samples. By using such a reduced function, total number of evaluations of actual performance is significantly reduced; hence, the method can be called Reduced Function Evaluations method. Reliabilities of six examples including series and parallel systems with multiple failure modes with truncated and/or non-truncated random variables are analyzed to demonstrate efficiency, accuracy and robustness of proposed method. In addition, a reliability-based design optimization algorithm is proposed and an example is solved to show its good performance.