• Advances in Computational Design
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• v.5 no.4
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• pp.397-416
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• 2020

Functionally graded material (FGM) illustrates a novel class of composites that consists of a graded pattern of material composition. FGM is engineered to have a continuously varying spatial composition profile. Current work focused on buckling analysis of beam made of stepwise linear and quadratic graded material in axial direction subjected to axial span-load with piecewise function and rested on shear layer based on classical beam theory. The various boundary and natural conditions including simply supported (S-S), pinned - clamped (P-C), axial hinge - pinned (AH-P), axial hinge - clamped (AH-C), pinned - shear hinge (P-SHH), pinned - shear force released (P-SHR), axial hinge - shear force released (AH-SHR) and axial hinge - shear hinge (AH-SHH) are considered. To the best of the author's knowledge, buckling behavior of this kind of Euler-Bernoulli beams has not been studied yet. The equilibrium differential equation is derived by minimizing total potential energy via variational calculus and solved analytically. The boundary conditions, natural conditions and deformation continuity at concentrated load insertion point are expressed in matrix form and nontrivial solution is employed to calculate first buckling loads and corresponding mode shapes. By increasing truncation order, the relative error reduction and convergence of solution are observed. Fast convergence and good compatibility with various conditions are advantages of the proposed method. A MATLAB code is provided in appendix to employ the numerical procedure based on proposed method.

• Structural Engineering and Mechanics
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• v.75 no.6
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• pp.713-722
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• 2020

This article aims to illustrate the damped dynamic responses of layered functionally graded (FG) thick 2D beam under dynamic pulse sinusoidal load by using finite element method, for the first time. To investigate the response of thick beam accurately, two-dimensional plane stress problem is assumed to describe the constitutive behavior of thick beam structure. The material is distributed gradually through the thickness of each layer by generalized power law function. The Kelvin-Voigt viscoelastic constitutive model is exploited to include the material internal damping effect. The governing equations are obtained by using Lagrange's equations and solved by using finite element method with twelve -node 2D plane element. The dynamic equation of motion is solved numerically by Newmark implicit time integration procedure. Numerical studies are presented to illustrate stacking sequence and material gradation index on the displacement-time response of cantilever beam structure. It is found that, the number of waves increases by increasing the graduation distribution parameter. The presented mathematical model is useful in analysis and design of nuclear, marine, vehicle and aerospace structures those manufactured from functionally graded materials (FGM).

• The Research Journal of the Costume Culture
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• v.14 no.6
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• pp.1042-1055
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• 2006

The purpose of this study is to consider the formative characteristics of dance sports from such points of view as shapes, colors, material and decorations, and to examine artistic characteristics that are expressed through those elements. As a result, this study shows five artistic characteristics as follows; First, rhythmic characteristic is expressed with repeat of lines that is formed by pleats, shirring or gather, with duplication of ruffle's wave, with gradation of colors, with Moire-effect that is generated with overlap of see-through material, with glossy material that reflects lights to a great extent, with fringe. Second, bodily characteristic emphasizes the beauty of human bodies through direct or indirect body exposure by way of cut-and-open, see-throughness or close adhesion. Third, decorative characteristic is shown with beads, fringe, ruffle, embroidery, shirring, binding, or feather. Fourth, the beauty of female body is manifested to express eroticism, which is culminated by body exposure, body consciousness, use of illuminating or see-through material or colorful trimming. Finally, elegant characteristic is revealed through feminity, sophistication, and harmony that are expressed with black and white colors, see-through material, or bead trimmings.

• Advances in concrete construction
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• v.10 no.6
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• pp.515-526
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• 2020

Cold-mixed asphalt mixture is a widely recommended asphalt pavement materials with potentially economic and environmental benefits. Due to the reduction of natural non-renewable mineral resources, powder minerals with similar properties are considered as new mineral fillers in asphalt mixtures. This study explored the feasibility of using cement to replace natural limestone powder (LP) in emulsified asphalt concrete modified by styrene-butadiene styrene copolymer. The experimental tests, including compressive strength, Marshall stability as well as moisture susceptibility test, were used to investigate the mechanical properties, the Marshall stability, flow value, as well as the moisture damage. In addition, the influence of material composition on the performance of asphalt concrete is explained by the microstructure evolution of the pore structure, the interface transition zone (ITZ), and the micromorphology. Due to mineralogical reactivity of cement, its replacement part of LP improved the mechanical properties, Marshall stability, but it will reduce the moisture susceptibility and flow value. This is because with the increase of the cement substitution rate, the pore structure of the asphalt concrete is refined, the width of ITZ becomes smaller, and the microstructure is more compact. In addition, asphalt concrete with a larger nominal particle size (AC-16) has relatively better performance.

• Steel and Composite Structures
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• v.45 no.3
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• pp.305-330
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• 2022

This article aims to investigate the static deflection and stress analysis of bi-directional functionally graded porous plate (BDFGPP) modeled by unified higher order kinematic theories to include the shear stress effects, which not be considered before. Different shear functions are described according to higher order models that satisfy the zero-shear influence at the top and bottom surfaces, and hence refrain from the need of shear correction factor. The material properties are graded through two spatial directions (i.e., thickness and length directions) according to the power law distribution. The porosities and voids inside the material constituent are described by different cosine functions. Hamilton's principle is implemented to derive the governing equilibrium equation of bi-directional FG porous plate structures. An efficient numerical differential integral quadrature method (DIQM) is exploited to solve the coupled variable coefficients partial differential equations of equilibrium. Problem validation and verification have been proven with previous prestigious work. Numerical results are illustrated to present the significant impacts of kinematic shear relations, gradation indices through thickness and length, porosity type, and boundary conditions on the static deflection and stress distribution of BDFGP plate. The proposed model is efficient in design and analysis of many applications used in nuclear, mechanical, aerospace, naval, dental, and medical fields.

• Steel and Composite Structures
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• v.50 no.1
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• pp.15-24
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• 2024

This research presents dynamical reaction investigation of pore-dependent and nano-thickness beams having functional gradation (FG) constituents exposed to a movable particle. The nano-thickness beam formulation has been appointed with the benefits of refined high orders beam paradigm and nonlocal strain gradient theory (NSGT) comprising two scale moduli entitled nonlocality and strains gradient modulus. The graded pore-dependent constituents have been designed through pore factor based power-law relations comprising pore volumes pursuant to even or uneven pore scattering. Therewith, variable scale modulus has been thought-out until process a more accurate designing of scale effects on graded nano-thickness beams. The motion equations have been appointed to be solved via Ritz method with the benefits of Chebyshev polynomials in cosine form. Also, Laplace transform techniques help Ritz-Chebyshev method to obtain the dynamical response in time domain. All factors such as particle speed, pores and variable scale modulus affect the dynamical response.

• Journal of the Korean Society of Costume
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• v.61 no.1
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• pp.58-68
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• 2011

With Expo 2012 Yeosu to be held in 2012, this study intends to propose designs for fashion cultural products into which the characteristics of local cultures of Yeosu are fused. Using symbols of Expo 2012 Yeosu and cultural symbols of Yeosu City as motifs, this study will develop patterns and then, apply them to neckties, handkerchiefs, and T-shirts. Adobe Illustrator CS2 and Adobe Photoshop CS2 will be used. This study developed basic motifs so that cultural resources using camellia, Odong Island, and the Turtle Ship, which represent Yeosu City, could be well harmonized with the topic of Expo 2012 Yeosu. This paper set three basic motifs of new formative images, using graphic images that were made by omission of forms, simplification, overlap, repetition, and calligraphy of the name of Yeosu holding the event. Each set motif was expanded to three motifs again through change, conversion, and mixture of colors, and three types of repetitive applied patterns were developed through revolution, symmetry, repetition, and reversal of each motif. The modern and refined image for neckties, to which the developed motif was applied, was made by directly applying the repetitive pattern of each motif or by making $45^{\circ}$ revolution. For handkerchiefs, revolution, enlargement, reduction, and gradation were applied to the motif so the pattern could be highlighted to the maximum and finally, a colorful image was developed. For T-shirts, three designs-a half-sleeved box type, a sleeveless round neckline type, and a sleeveless V-neckline tight type-were developed, through which availability of the design was increased. Through enlargement, reduction, revolution, and repetition of each motif, this paper layout the pattern on the whole part of a T-shirt, pursuing a decorative and casual image.

• Geotechnical Engineering
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• v.12 no.4
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• pp.61-74
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• 1996

Settlement induced by low -level vibration on granular soils is too complect to predict with one or two fact ors. Factors affecting vibration induced settlement were investigated, and a settlement prediction model on granular soils was developed using multifactorial experimental design(MED). Factors such as vibration amplitude, deviatoric stress, confining pressure, soil gradation, duration of vibration, moisture content, and relative density were considered in this study. A special vibratory frame was designed to shake a soil specimen within a triaxial cell. MED allowed the authors to investigate the effect of many factors using a relatively small number of experiments. The most significant factors on settlement were vibrati on amplitued, confining pressure, and defiatoric stress. Comparable settlement was occurred even under low-level vibration ranging from 2.5 to 18mm1sec, and stress am sotropy was found to be an important factor on settlement.

• Fashion & Textile Research Journal
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• v.15 no.5
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• pp.682-693
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• 2013

Camouflage is evaluated by scientific principle in the fields of biology, military science, and art. It has a strong influence on contemporary fashion and means exposure with concealment. This study analyzed the visual characteristics of camouflage patterns in fashion design through documentaries and fashion photos. The fashion design results areas follow. The simple blending of a disruptive motif indicated an inaccurate repetition of a disruptive motif, the discontinuous or continuous connection of disruptive motif, the irregular repetition of a disruptive animal silhouette, the collage of a different disruptive motif, the craft of a disruptive motif and the intensive color match of a disruptive motif. It represented the maximization of complication, fantastic and fanciness. The overlap of a disruptive motif showed the overlap of disruptive print patterns with transparency and an overlap of different fabrics with a disruptive pattern. It represented spatial relationships of three dimensions as well as the maximization of visual illusion and the reinforcement of attractiveness. The blurring of a disruptive motif showed the pointage of disruptive motif, the pointage of image, value gradation, the whole blurring of a disruptive pattern cluster and stained appearance. It represented the obscurity of motif form, the uncertainty of object and double meaning. The trompe l'oeil of a partial background object showed the realistic and the painterly imitation of color and texture for partial objects through a close-up. It represented amazement and pleasure by illusion, scarcity and the decoration of surface and synecdochical remind. In conclusion, camouflage in fashion was weakened and modified from a classical military context by a unique expression of various motifs.

• Journal of the Korean Geotechnical Society
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• v.29 no.8
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• pp.5-14
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• 2013

Coarse granular geomaterials containing large gravels are broadly used for construction of large geotechnical systems such as dams, levees, railways and backfills. It is necessary to evaluate deformation characteristics of these materials for dynamic analysis, e.g. seismic design. This study presents evaluation of dynamic deformation characteristics of coarse materials using large scale resonant column testing apparatus, which uses specimens with 200 mm in diameter and 400 mm in height, and the effects of gradation characteristics on maximum shear modulus, shear modulus reduction curve and damping characteristics were investigated. From experimental study using rock-fill materials for a dam, we could see that the largest or mean particle size affects the shape of shear modulus reduction curve. When the specimens are prepared under the same conditions for maximum particle size, the coefficient of uniformity affects the confining stress exponent of maximum shear modulus. It could be concluded that the maximum particle size is an factor which affects shear modulus reduction curve, and that the coefficient of uniformity is for small strain shear modulus, especially for the sensitivity to confining stress.