• Geomechanics and Engineering
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• v.16 no.3
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• pp.257-271
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• 2018

In this paper, the effect of the homogenization models on buckling and free vibration is presented for simply supported functionally graded plates (FGM) resting on elastic foundation. The majority of investigations developed in the last decade, explored the Voigt homogenization model to predict the effective proprieties of functionally graded materials at the macroscopic-scale for FGM mechanical behavior. For this reason, various models have been used to derive the effective proprieties of FGMs and simulate thereby their effects on the buckling and free vibration of FGM plates based on comparative studies that may differ in terms of several parameters. The refined plate theory, as used in this paper, is based on dividing the transverse displacement into both bending and shear components. This leads to a reduction in the number of unknowns and governing equations. Furthermore the present formulation utilizes a sinusoidal variation of displacement field across the thickness, and satisfies the stress-free boundary conditions on the upper and lower surfaces of the plate without requiring any shear correction factor. Equations of motion are derived from Hamilton's principle. Analytical solutions for the buckling and free vibration analysis are obtained for simply supported plates. The obtained results are compared with those predicted by other plate theories. This study shows the sensitivity of the obtained results to different homogenization models and that the results generated may vary considerably from one theory to another. Comprehensive visualization of results is provided. The analysis is relevant to aerospace, nuclear, civil and other structures.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3054-3059
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• 2009

Natural black diamonds of single crystal, polycrystalline, and agglomerated roughs become important for their industrial and gem stone application. We performed the conventional gemological tests of thermal diffusion, apparent density, scratch test, and magnification test as well as the advanced tests of Raman spectroscopy, X-ray diffraction test and Lang topography. We conclude that scratch test with SiC paper was the most efficient method in view point of speed and cost. Raman spectroscopy and XRD were useful for identification of diamond while Lang topography offered a good visualization method of the grain structure of polycrystalline black diamond roughs.

• Journal of Broadcast Engineering
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• v.26 no.2
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• pp.143-154
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• 2021

In this paper, we propose a method of compressing digital hologram standardized data provided by JPEG Pleno. In numerical reconstruction of digital holograms, the addition of random phases for visualization reduces speckle noise due to interference and doubles the compression efficiency of holograms. Holograms are composed of completely complex floating point data, and due to ultra-high resolution and speckle noise, it is essential to develop a compression technology tailored to the characteristics of the hologram. First, frequency characteristics of hologram data are analyzed using various wavelet filters to analyze energy concentration according to filter types. Second, we introduce the subband selection algorithm using energy concentration. Finally, the JPEG2000, SPIHT, H.264 results using the Daubechies 9/7 wavelet filter of JPEG2000 and the proposed method are used to compress and restore, and the efficiency is analyzed through quantitative quality evaluation compared to the compression rate.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.43-49
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• 2017

In recent years, the use of BIM in domestic construction has been increasing, but it is used mainly for internal and external visualization rather than for BIM design including drawings. For this reason, several studies have highlighted the lack of libraries and economic problems for BIM design. In other words, for the most economically small domestic design offices, activating the BIM design is a negative factor because it is difficult to invest the necessary manpower and cost to produce and use the required BIM library. The BIM design can be more applicable if the library can be supplied economically, easily, and quickly. In this study, BIM library business model and consideration factors that can provide BIM library service economically, easily, and quickly by considering the existing building material selection task and BIM library are presented. The proposed business model will increase the number of suppliers of BIM libraries, which are lacking in Korea, and will enable an effective BIM design at low cost and effort. If a service that reflects the business model proposed in this study is made, an integrated database that can consistently share information in the design, construction, and maintenance stages will be constructed. This can monitor the changes in material and equipment information during the life cycle of the building. The database can be used to monitor any changes in material and equipment information throughout the life cycle of a building, so that it can be used as historical data for effective design and maintenance as well as for material and equipment upgrades.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.1A
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• pp.31-37
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• 2012

The phase distribution in concrete materials strongly affects its material properties. It is important to identify the spatial distribution of void in concrete because the void in concrete materials affects mechanical behavior and permeability significantly. Therefore, a proper method to describe the void distribution of a material is needed. In this research, CT(computed tomography) is used to examine and to quantify the void distribution of porous concrete specimens. 3D concrete digital specimens are created by subsequent stacking of 2D cross-sectional images from CT. Then, probability distribution functions such as two-point correlation, lineal-path and two-point cluster functions are used for void distribution characterization. It is confirmed that probability distribution functions obtained from CT images are effective in characterizing void distributions including the anisotropy and percolation.

• Korean Journal of Construction Engineering and Management
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• v.7 no.1 s.29
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• pp.80-88
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• 2006

Construction graphical simulations usually do not reflect physical properties of construction equipment and material because there are restricted to the geometric model. The complete description of construction operations is difficult for graphical simulation without a physical modeling. The object of this research is to enhance the functionality of restricted simulation system to geometric model. And research is conducted to overcome the limitation of current construction graphical simulation system through the connection geometric model and physical model with the physical properties of construction equipment and material such as crane's cable oscillation. The motion equations for the oscillation of crane cable as a result of the trolley's movement and the boom's rotation were derived. The equations were solved through numerical analysis and the results were simulated visually. The realistic description with physical modeling of construction operations will contribute for ensuring preliminary against risks and improving constructability as well as the application of various fields.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.2
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• pp.336-344
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• 2010

Stage costumes are characterized by the importance as a medium of total visual expression on a synthetic art and need to be designed more effectively. This study followed the stage costumes of the play 'Long long time ago whuo-ee whuoee' which participated in the China-Japan-Korea University Theatre Festival. By consisting of the framework of a Korean story that tells and expands the visual expression province by the access method of a producer, the unique costume in the play was created by the dyeing of the traditional hangi. First, the use of hanji in theater represents originality and a fresh variation with the formative beauty of stage costumes in accordance with hanji that conforms to the recreation of tradition. Second, the dip dyeing technique made it possible to express colors limitlessly and the airbrush dyeing technique along with dyeing twice could account for the weak points of the color. As a result, the color brought effect as expected. Third, the weak points were supported by a Jumchi technique that created the fibroid material tangled with stronger adhesion in the creation of a hangi costume. In addition, dyed hangi was attached to the outer fabric. It allowed the costume to have a unique texture that was both soft and tough. This enforced the visualization of the costume and durability to prevent possible damage by the performers. Forth, pieces of hanji were attached to the damaged parts of the costume after re-visiting the dress rehearsal. As a result, the stage costumes represented the shabby clothes that express the social class of the characters. A new understanding of the excellence of traditional hanji was found and confirmed the possibility of it as a material for stage costumes through the study.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.3
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• pp.227-235
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• 2012

The void distribution in concrete materials strongly affects its material properties. Therefore, the identification of spatial distribution of void is important to understand and estimate material behavior. To examine and quantify the void distribution inside lightweight aggregates, CT(computed tomography) image is used. 3D lightweight aggregate images are generated by stacking of cross-sectional images from CT. Spatial distribution of void of aggregate along the direction is visualized on the sphere using probability distribution function. Stiffness of lightweight aggregate for the directions is also examined. It is confirmed that direction-based probability distribution and stiffness from CT images are effective in characterizing void distributions of aggregates.

• Smart Media Journal
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• v.8 no.3
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• pp.95-103
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• 2019

The global manufacturing industry has reached the limit to growth due to a long-term recession, the rise of labor cost and raw material. As a solution to these difficulties, we promote the 4th Industry Revolution based on ICT and sensor technology. Following this trend, this paper proposes the design of a model using manufacturing data in the protection film process for smart manufacturing innovation. In the protective film process, the manufacturing data of temperature, pressure, humidity, and motion and thermal image are acquired by various sensors for the raw material blending, stirring, extrusion, and inspection processes. While the acquired manufacturing data is stored in mass storage, A.I. platform provides time-series image analysis and its visualization.

• Journal of the Korea Convergence Society
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• v.12 no.11
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• pp.329-334
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• 2021

This thesis examined the characteristics of constructivism that brought about expanded expression of modern jewelry, and also organized how the constructivism was utilized for jewelry. The objective of this study is to examine the attempts of new materials based on constructivism and various expression styles, and also to understand the concept of constructivism developed into an element of complex formative expression. For this, this study organized the characteristics of constructivism that was initially expanded from Bau Haus in the aspect of expression through the composition of material and space, and also analyzed the jewelry artists' methods and attempts to express various materials. As a result, the constructivism showed the expansion of the formativeness of jewelry in the formative aspect of steric expression and in-depth concept through the composition of architectural pattern, visualization of space, and use of other materials, which becomes an example of basic formative element of modern jewelry design. However, it is limited to the material formative element of constructivism, so the expansion of design would be needed. Thus, there should be more researches on the expansion of various jewelry designs that could express the philosophy of constructivism.