• Proceedings of the KSR Conference
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• 2005.05a
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• pp.391-396
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• 2005

Salt water spray test and salt water immersion test were experimentally conducted in order to investigate the durability of fiber reinforced composites under salt water environment. The specimens were made of glass fabric reinforcement and phenolic resin. Mechanical test was performed to obtain mechanical properties such as tensile properties, flexural properties, and shear properties by varying with exposure times. Also dynamic mechanical test and FTIR were conducted to investigate a change in chemical structure as well as thermal analysis properties such as storage shear modulus, loss shear moduls, and tan ${\delta}$. According to the results, salt water environment has effected on mechanical properties and thermal analysis properties and especially the durability of glass fabric/phenolic composites were severely affected on salt water immersion environment rather than salt water spray environment.

• Structural Engineering and Mechanics
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• v.55 no.3
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• pp.583-603
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• 2015

There are so many applications of perforated pates with various penetration patterns. If they are penetrated regularly, it can be represented by solid plate with equivalent material properties, which has a benefit of finite element modelling and reducing computation time for the analysis. Because the equivalent material properties suggested already are not proper to be applicable for the dynamic analysis, it is necessary to extract the equivalent material properties for the dynamic analysis. Therefore, in this study, the equivalent modulus of elasticity are obtained for the perforated plate with a triangular penetration pattern by comparing the natural frequencies of the perforated plate with those of solid plate, which are represented with respect to the ligament efficacy. Using the equivalent material properties suggested, the modal analyses of the partially perforated rectangular plate with a triangular penetration pattern are performed and its applicability is shown by comparing natural frequencies of perforated and homogeneous solid plates from finite element method and analytical method.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.773-780
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• 2003

The characteristics of soft clays is very important for the land development plan. This study is to investigate correlations between the engineering properties and the characteristics of clay minerals of the disturbed clay samples obtained from Sihwa area. This study included X-Ray Diffraction Analysis, X-Ray Fluorescence Spectrometer Analysis, Scanning Electron Microscopy Analysis and Energy Dispersive X-Ray Spectrometer Analysis. The correlations between the clay mineral properties and the laboratory and field testing results were investigated.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.2
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• pp.103-112
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• 1990

This study examines the characteristics of soil behavior which includes many uncertainties in seismic design, evaluates the dynamic soil properties and studies the soil-structure interaction to generalize the applicability and economy of the available sites. An example analysis is performed for soil-structure system response assuming a containment structure built on site which includes soil layers using both elastic halfspace analysis and FEM analysis against the seismic loads from the actual design. This exercise is performed as a part of the safety analysis and economic assessment of the nuclear power plant built on soils. It includes the preparation of computer program capable of incorporating large nonlinearity in the analysis, resonable evaluation procedures to determine input soil data. Nonlinear FEM analysis of Seed and Idriss model is found suitable for the accurate analysis of dynamic response of soils. Linear FEM analysis using dynamic soil properties at strain level obtained by one-dimensional seismic response, and elastic half-space analysis using dynamic soil properties at strain level under static loads are recommended to evaluate the dynamic soil properties.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.1 s.149
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• pp.83-93
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• 2006

The purpose of this study is to analyze the relationship among subjective textures, sensibilities and objective handle of knit fabrics and to provide useful information in planning and designing knit fabrics. We made 20 plain knit fabrics, as specimens, with a combination of 5 kinds of wool/rayon fiber contents and 4 kinds of stitch loop length. For the subjective evaluation, we used 29 questions of subjective textures and sensibilities and employed statistical analysis tools such as factor, Pearson's correlation analysis. An objective handle was measured by Kawabata evaluation system and HV and THV was calculated by KN-402-KT and KN-301-winter. The analysis of a Pearson's correlation with objective properties and handles and structural properties of knit fabrics demonstrated a highly linear relationship. Especially, wool/rayon contents and WT of tensile properties and loop stitch length and G of shear properties showed a correlation coefficient over 0.9. But a relationship of objective properties and subjective textures and sensibilities was non-linear and a linear multi-regression analysis showed that a objective handle had a lower prediction power in the area of subjective textures and sensibilities.

• Structural Engineering and Mechanics
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• v.6 no.1
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• pp.95-113
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• 1998

The extensive use of honeycomb sandwich structures has led to the need to understand and analyze their low velocity impact response. Commercially available finite element software provides a possible analysis tool for this type of problem, but the validity of their material properties models for honeycomb materials must be investigated. Three different problems that focus on the effect of differences in honeycomb material properties on static and dynamic response are presented and discussed. The first problem considered is a linear elastic static analysis of honeycomb sandwich beams. The second is a nonlinear elastic-plastic analysis of a circular honeycomb sandwich plate. The final problem is a dynamic analysis of circular honeycomb sandwich plates impacted by low velocity projectiles. Results are obtained using the ABAQUS final element code and compared against experimental results. The comparison indicates that currently available material properties models for honeycomb materials can be used to obtain a good approximation of the behavior of honeycomb sandwich structures under static and dynamic loading conditions.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.5
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• pp.845-855
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• 2001

Now the most important thing in fashion industry is find out the fashion sensibility and preference of customers exactly. Thus it is needed that fashion sensibility is connected with formative properties in clothing. The purpose of this study is to clarify the relationship between the fashion sensibility and the formative properties in clothing. 91 kinds of costume samples have been selected from photographs in fashion magazines under color combination, inside form, texture, pattern type in clothing. I have measured fashion sensibility by using Semantic Differential method. The obtained data were analyzed by GLM, discriminant analysis. The results of analysis are as follow; 1. The discriminative images were significant difference in formative properties - color combination was related to attractiveness, inner form to decorativeness, pattern to harmony and texture to surface of soft and hard in clothing. 2. fashion sensibility was significant relationship with formative properties especially inner form in clothing. And the trimming was identified as gorgeous and feminine. 3. Preference, Buying needs, Riches and Pleasant were significant relationship with formative properties in clothing especially color combination and texture.

• Fashion & Textile Research Journal
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• v.16 no.2
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• pp.301-311
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• 2014

This study finds information about the image and improvements of hiking gear and examines the influence of heat moisture, psychology, tactile sensation, and mobility/pressure related properties on wear comfort. The relationships of the four related properties and personal characteristics (such as sex, age, BMI and sensitivity) were also checked. Questionnaires were distributed to 400 people in their 40s and 50s; subsequently, 260 were used for data analysis. The questionnaires were comprised of questions about the general hiking characteristics, images and improvements in hiking gear, influence of the four properties on wear comfort, and demographic characteristics. Data were analyzed by frequency analysis, correlation analysis, ANOVA, T-test using SPSS 21 IBM for Windows. The results of this study are as follows. It was shown that people in their 40s and 50s usually went hiking two to four hours with friends or family once to three times a month. Jacket had the largest number of wearing frequency, followed by pants, t-shirts, and inner wear. Consumers' images of hiking gear were positive and the demands for improvements in hiking gear were price, unique design, and vivid color. The order of influence of the four properties on wear comfort was heat moisture, mobility/pressure, tactile sensation, and psychology related properties. The four properties of wear comfort were not influenced significantly by consumer sex, age, BMI, and sensibility.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1163-1167
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• 2003

Effective properties of ceramic matrix plain woven textile composites were calculated using finite element analysis. The considered geometry is a unit cell of plain weave and the analysis was performed by commercial finite element program, ANSYS. The materials for analysis are 3 types for matrix, 1 type for fiber with various volume fraction. The result indicates that the effective properties of ceramic matrix composites can be controlled by the volume fraction. The result can be used for numerical analysis using ceramic matrix composites.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.36 no.4
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• pp.259-264
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• 2023

In this study, we devised a parametric analysis workflow for efficiently analyzing the material properties of 3D woven materials. The parametric model uses wire spacing in the woven materials as a design parameter; we generated 2,500 numerical models with various combinations of these design parameters. Using MATLAB and ANSYS software, we obtained various material properties, such as bulk modulus, thermal conductivity, and fluid permeability of the woven materials, through a parametric batch analysis. We then used this large dataset of material properties to perform a regression analysis to validate the relationship between design variables and material properties, as well as the accuracy of numerical analysis. Furthermore, we constructed an artificial neural network capable of predicting the material properties of 3D woven materials on the basis of the obtained material database. The trained network can accurately estimate the material properties of the woven materials with arbitrary design parameters, without the need for numerical analyses.