• Structural Engineering and Mechanics
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• v.11 no.5
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• pp.519-534
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• 2001

The effect of the initial imperfections on the nonlinear behaviors and ultimate strength of the thin-walled members subjected to the axial loads, obtained by the finite element stability analysis, are examined. As the initial imperfections, the bucking mode shapes of the members are adopted. The buckling mode shapes of the thin-walled members are obtained by the transfer matrix method. In the finite element stability analysis, isoparametric degenerated shell element is used, and the geometrical and material nonlinearity are considered based on the Green Lagrange strain definition and the Prandtl-Reuss stress-strain relation following the von Mises yield criterion. The U-, box- and I-section members subjected to the axial loads are adopted for numerical examples, and the effects of the initial imperfections on the nonlinear behaviors and ultimate strength of the members are examined.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.8 s.251
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• pp.906-915
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• 2006

This study concerns an advanced 3D surface reconstruction method that the vertices of surface model can be completely matched to the unstructured point cloud measured from arbitrary complex shapes. The concept of bounding voxel model is introduced to generate the mesh model well-representing the geometrical and topological characteristics of point cloud. In the reconstruction processes, the application of various methodologies such as shrink-wrapping, mesh simplification, local subdivision surface fitting, insertion of is isolated points, mesh optimization and so on, are required. Especially, the effectiveness, rapidity and reliability of the proposed surface reconstruction method are demonstrated by the simulation results for the geometrically and topologically complex shapes like dragon and human mouth.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.66-69
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• 2003

This paper presents the procedures for the evaluation of the maximum surface roughness and the shapes of the cut remainder employing the ridge method. The shapes and the heights of the cut remainder are estimated by overlapping adjacent ridges in consideration of the various machining parameters: the feedrate. the path interval. The maximum surface roughness in plane cutting modes are derived as a function of the maximum effective cutter radius, R$\_$eff,max/. and the path interval ratio, $\tau$$\_$fp/, The predicted results are compared with the values estimated by the conventional roughness model.

• Structural Engineering and Mechanics
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• v.64 no.3
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• pp.329-337
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• 2017

This study concerns the vibrational behavior of multi-walled nested silicon-carbide and carbon nanotubes using the finite element method. The beam elements are used to model the carbon-carbon and silicon-carbon bonds. Besides, spring elements are employed to simulate the van der Waals interactions between walls. The effects of nanotube arrangement, number of walls, geometrical parameters and boundary conditions on the frequencies of nested silicon-carbide and carbon nanotubes are investigated. It is shown that the double-walled nanotubes have larger frequencies than triple-walled nanotubes. Besides, replacing silicon carbide layers with carbon layers leads to increasing the frequencies of nested silicon-carbide and carbon nanotubes. Comparing the first ten mode shapes of nested nanotubes, it is observed that the mode shapes of armchair and zigzag nanotubes are almost the same.

• Proceedings of the IEEK Conference
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• 2001.06e
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• pp.93-96
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• 2001

Tactile display devices use an array of pins mounted in the form of a matrix to present three-dimensional shapes to the user by raising and lowering. With a denser matrix of mounted pins, it can be expected that shape identification will be become easier and the time required for identification will also become shorter, but that problems of difficulty in fabrication will arise. It is necessary to consider such trade-offs in the development of such devices. This study conducted experiments to study the effect of pin pitch on shape identification as Part of the fundamental investigation of this subject. The experiment used three tactile display devices with pin pitches of In, 2mm and 3mm for geometrical shape identification, with response time and rate of misidentification taken as the performance data. Surfaces, edgs and vertices of three-dimensional shapes were used as the shape primitives for displayed shapes and several of each type were selected for presentation. The results obtained revealed that performance has different relationships to pin pitch with different shape primitives.

• Journal of Environmental Science International
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• v.18 no.2
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• pp.221-230
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• 2009

In this study, a river basin with a lot of measured data such as water level, flow rate, current speed, and sediment rate from the past to now was selected and geometrical shape of a pier was re-analyzed, in order to study the effects of the flow around the pier area as well as the riverbed alternation characteristics. A finite element mesh of the entire river was prepared, and via parameter revision, the section that the pier has influence on was decided, to analyze the shape of the pier using RMA-2 and SED2D-WES models. With regards to the section that the pier has influence on, analysis was done on the four pier shapes, namely circle, square, rectangle, and octagon. The results showed that the shape with the least influence around the pier around is the octagon, followed by circle, rectangle, and square, showing the different geometrical effects that the shapes have on the pier. Furthermore, it was shown that the distribution of sediment concentration had effect from about (+) 110 m of the upstream to about (-) 130 m of the downstream, from the pier installation point. Also, it was shown after analyzing drag forces for different sediment particle distributions that the shape with the greatest drag is the octagon, followed by circle, square, and rectangle.

• Journal of the Korean Home Economics Association
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• v.41 no.8
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• pp.33-53
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• 2003

A Study on the color comparison of Korean Saek-dong and Italian futurist fashion It is generally recognized that the color scheme and its characteristics as a product of living culture are strongly reflected in clothing. This study concentrates on the color comparison of Korean Saek-dong which has been used in traditional Korean clothing and Italian futurist fashion which showed dynamic characteristics and brilliant colors. The purpose of this study is to investigate the external format, emotions, functions and meanings of the colors in Korean Saek-dong and Futurist fashion, and to find similarities and differences between them. The results of the study are as follows. The similarities between them are harmony of vivid colors like a rainbow, no-use of black color and expression of rhythm through repeated geometrical shapes. They have been used as festive costumes and have implied meaning of happiness and pleasure. The differences, in the external formats, are as follows. Korean Saek-dong has striped patterns including the color white, and has regular distances among the stripes. But, Futurist fashion includes luminous or fluorescent colors and metallic colors. In addition, it has repeated motifs of geometrical shapes and geometrically divided areas. While Saek-dong expresses Sangsaeng through the conceptual use of color, Futurist fashion shows simultaneity, speed and dynamics through spiritual functions of crossing and inter-penetration. In emotional aspect, Saek-dong expresses pleasure of children's mind and Futurist fashion expresses pleasure of city. In functional aspect, Saek-dons expresses a concept of ceremonial beauty, which is spiritual and symbolizes good auspices, holiness and sorcery. So it is used for ceremonial costume. But, Futurist fashion reflects the harmony of colors created from modem and urban images and shows the willingness and emotion of solving futuristic avant-garde, modernity, dynamics, transformation and bellicosity. So it is used for daywear. While Saek-dong represents succession of tradition, Futurist fashion represents resistance of tradition in cultural aspects.

• Journal of the Korea Society of Computer and Information
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• v.14 no.4
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• pp.47-57
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• 2009

Event detection and recognition is an active and challenging topic recent in Computer Vision. This paper describes a new method for recognizing events caused by human motion from video sequences in an office environment. The proposed approach analyzes human motions using Motion History Image (MHI) sequences, and is invariant to body shapes. types or colors of clothes and positions of target objects. The proposed method has two advantages; one is thant the proposed method is less sensitive to illumination changes comparing with the method using color information of objects of interest, and the other is scale invariance comparing with the method using a prior knowledge like appearances or shapes of objects of interest. Combined with edge detection, geometrical characteristics of the human shape in the MHI sequences are considered as the features. An advantage of the proposed method is that the event detection framework is easy to extend by inserting the descriptions of events. In addition, the proposed method is the core technology for event detection systems based on context-aware computing as well as surveillance systems based on computer vision techniques.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.1A
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• pp.15-24
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• 2008

This paper presents the analytical method for the long-term behavior of simply supported composite beams with precast decks prestressed in the longitudinal direction. The objectives of time-dependent analysis are to estimate losses of prestress on the concrete slab and long-term deflection due to creep and shrinkage of concrete, relaxation of prestressing steel. Also, the time-dependent analysis was carried out using the presented analytical method to evaluate the effects of several parameters on the long-term behavior of composite bridge with precast deck, including geometrical shapes of composite beams, compressive strength of concrete and magnitude of initial prestress. The results of the analysis indicated that, in the effects of geometrical shapes of composite beams, the main parameters affecting the losses of prestress and the long-term deflection were the cross sectional area and the moment of inertia of steel beam, respectively. Finally, the determination method for the required initial prestress was proposed by evaluation of the loss characteristics due to shrinkage and creep of concrete.

• Korean Journal of Human Ecology
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• v.17 no.5
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• pp.975-987
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• 2008

The purpose of this thesis is to conduct a thorough research on shoes of 2000s, understand the changes and analyze the differences and the characteristics of the shoe designs of the past and present in order to predict and indicate the future direction of the women shoe designs. The shoes of the millennium not only kept the old fashioned shapes but also showed futuristic shapes. With the increasing importance of shoes in fashion, shoes with various images were created. As far as the materials are concerned, natural materials and artificial materials were both used. The colors were vivid and the futuristic colors. On the other hand, pastel toned colors and romantic colors were used in many different designs and shapes regardlees of the seasons. Straps and hills differed from the oldies. Heavy decorations were added to strap shoes to form a whole new design and hills show geometrical platforms or the avantgarde like heights. Feminine images overwhelmed the shoe designs of the millennium. To elaborate, Pumps displayed feminine images the most for it showed a high frequency number regardless of the seasons. Shoes are presented in aesthetical perspective rather then functional or practical perspectives that are based on human nature. Cultural, social, environmental and some part religious factors had a great influence on the evolution on the shoes. Especially in the 2000s, future oriented concepts were implemented on shoe designs, resulting a wider range of expressiveness and in the end leading to a more creative shoe designing. Changes in shoe designs could be pointed out in many ways according to the shapes materials, colors, modeling of decorations or also with the diverting trends.