• Structural Engineering and Mechanics
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• v.25 no.5
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• pp.501-518
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• 2007

In this work, a new approach is developed for dynamic analysis of a composite beam with an interply crack, based on finite element solution of partial differential equations with the use of the COMSOL Multiphysics package, allowing for fast and simple change of geometric characteristics of the delaminated area. The use of COMSOL Multiphysics package facilitates automatic mesh generation, which is needed if the problem has to be solved many times with different crack lengths. In the model, a physically impossible interpenetration of the crack faces is prevented by imposing a special constraint, leading to taking account of a force of contact interaction of the crack faces and to nonlinearity of the formulated boundary value problem. The model is based on the first order shear deformation theory, i.e., the longitudinal displacement is assumed to vary linearly through the beam's thickness. The shear deformation and rotary inertia terms are included into the formulation, to achieve better accuracy. Nonlinear partial differential equations of motion with boundary conditions are developed and written in the format acceptable by the COMSOL Multiphysics package. An example problem of a clamped-free beam with a piezoelectric actuator is considered, and its finite element solution is obtained. A noticeable difference of forced vibrations of the delaminated and undelaminated beams due to the contact interaction of the crack's faces is predicted by the developed model.

• Journal of Science of Art and Design
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• v.6
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• pp.226-248
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• 2004

The researcher has tried to develop the aesthetic value of the art and the function of metalwork in conjunction with our daily life. especially has been eager to develop the new possibility of metal urns through the investigation of ordinary metalwork. Funeral urns are vessels to fill the ashes of bodies. As the social issues, including problems of restricted land territory and environmental pollution are awakening, many people are much concerned about the use of urns in recent days. Although social concerns about cremation and urns are getting high, most urns in Korea have been made of ceramic and stone. The shape of old urns are pot style with lids, and their color is simple white or jade green. Moreover, old urns are expensive, unpractical, simple, and furthermore, the feature of urns has not preserved the sense of beauty. In this context, we have narrow choices to select urns, and it has been difficult for us to be familiar with the old-style urns. Therefore, the need for developing metal urns are necessary as the increase of public concerns towards cremation is widely spreading. As it is well known, metal is not only regarded as hard, antibacterial, pro-environmental material , but also regarded as good substance for urns. Metal is also suitable for making urns because of metal's characteristics of easy processing, mass production, and cheap price. The researcher has been tried to find the possibility of art of metalwork through the dissemination of metal urns to the public. The researcher has also attempted to represent the characteristics and symbolic implications of contemporary metal urns for ordinary people to adopt metal urns as their 'Rite Haven'.

• Journal of Pharmaceutical Investigation
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• v.22 no.2
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• pp.133-137
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• 1992

A novel oral controlled release tablet which may offer more uniform drug level in the body than simple zero-order was developed. The tablet is composed of three layers; outer film layer, middle part compression-coated hydroxypropylmethylcellulose (HPMC) matrix layer, and inner core layer. Each layer contains nicardipine HCl as a model drug. In vitro dissolution test showed that the tablet released the drug in clear three steps; a rapid initial release, followed by a constant rate of release, and then a second phase of fast release of drug. The dissolution characteristics could be modified easily by changing the grade of HPMC, thickness of matrix layer, content of methylcellulose in matrix layer, content of active ingredient in each layer. The pH of dissolution medium did not affect the release profile. This three-step release system is expected to raise the blood concentration rapidly to effective level and to maintain effective blood level longer than simple slow-release systems.

• International Journal of Ocean System Engineering
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• v.2 no.3
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• pp.151-159
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• 2012

The characteristics of an impact load and pressure were experimentally investigated. Drop tests were carried out using a modified Wigley with CB = 0.56. The vertical force, pressures, and vertical accelerations were measured. A 6-component load cell was used to measure the forces, piezo-electric sensors were used to capture the impact pressure, and strain-gauge type accelerometers were used to measure the vertical accelerations. A 50-kHz sampling rate was applied to capture the peak values. The repeatability of the measured data was confirmed and the basic characteristics of the impact load and pressure such as the linearity to the falling height were observed for all of the measurements. A simple formula was derived to extract the physical impact load from the measured force based on a simple mass-sensor-mass diagram, which was validated by comparing impact forces with existing data using the mathematical model of Faltinsen and Chezhian (2005). The effects of the elasticity of the model and change in acceleration during the water entry were investigated. It is interesting to observe that the impact loads occurred and reached peak values at the same time duration after water entry for all drop heights.

• Science of Emotion and Sensibility
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• v.21 no.2
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• pp.125-136
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• 2018

Although atypical sensory processing is a core feature of autism spectrum disorder (ASD), there is considerable heterogeneity among ASD individuals in the modality and symptoms of atypical sensory processing. The present study examined visual processing of children with ASD, focusing on the complexity and orientation of visual information. Age- and -IQ-matched Korean children (14 ASD and 14 typically-developing (TD) children) received an orientation discrimination task involving static spatial gratings varied in complexity (simple versus complex) and orientation (horizontal versus vertical). The results revealed that ASD children had difficulty perceiving complex information regardless of orientation, whereas TD children had more difficulty with vertical gratings than horizontal gratings. Thus, group-level differences between ASD and TD children appeared greater when gratings were presented horizontally. Unlike ASD adult literature, however, ASD children did not show superior performance on simple gratings. Our findings on typical and atypical processing of ASD children have implications for both understanding the characteristics of ASD children and developing diagnostic tools for ASD.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.4
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• pp.27-33
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• 2003

Circular Distributed-feedback (DFB) guiding structures can be incorporated in most of the semiconductor laser devices because of the frequency-selective property applicable as an optical filter in optical communications. In this paper, we present a novel and simple modal transmission-line theory (MTLT) using Floquet-Babinet's principle to analyze the optical filtering characteristics of Bragg gratings with cylindrical profile. The numerical results reveal that this method offers a simple and convenient algorithm to analyze the filtering characteristics of circular DFB configurations as well as is extended conveniently to evaluate the guiding problems of circular multi-layered periodic structures.

• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.2
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• pp.181-192
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• 2002

The purpose of this study is to clarify the expression of conceptual image by which the modern graphic artists use for creating new visual images and the characteristics in expression of the major fashion images in fashion illustration. In the present study, major findings on the basis of the analysis of expression of visual images in fashion illustration since 1980s are as follow: The conceptual image expression in the visual arts is based on the eight techniques. They are dual image, operation of image, copying·reproduction of image, deconstruction of image, pictorial image, symbolization of image, mystification of image, and making humorous image. Since 1980s, the major fashion images in fashion illustration are mainly classified as classic image, humor image, fantastic image, natural image, avant-garde image, simple image, casual image and feminine image. The characteristics in expression of these images in fashion illustration are; 1) fortification of dual image in classic image, 2) activation in humor image 3) grotesque fantastic image, 4) the modernization of natural image, etc. In addition that, the image of avant-garde is expressed by Postermodernism, Deconstructionism, Techno etc. since 1980s. Also, simple image of the modern composition, casual image of daily life, and feminine image which is emphasized with eroticism are also included in these characteristic in expression of images since 1980s.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.37 no.2
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• pp.33-40
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• 2000

In this study, a shape decomposition method using morphological operations is studied for decomposing the complex shape in 2-D image into its simple primitive elements. The serious drawback of conventional shape representation algorithm is that primitive elements are extracted too much to represent and to describe the shape. To solve these problems, a new shape decomposition algorithm using primitive elements that are similar to the geometrical characteristics of shape and 4 scan modes is proposed in this study. The multiple primitive elements as circle, square, and rhombus are extracted by using multiscan modes in a new algorithm. This algorithm have the characteristics that description error and number of primitive elements is reduced. Then, description efficiency is improved. The procedures is also simple and the processing time is reduced.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.105-108
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• 2003

In the framework of universal multimedia access, one challenge for video transmission (communication) is to deliver video content through heterogeneous network channels matching the diversity of client devices. As one of the many adaptation methods, media transcoding is commonly considered. Particularly, FD (Frame Dropping)/CD Coefficient Dropping) transcoding is used due to the low computational complexity and simple implementation. In this scheme, CD is simply implemented by truncating the high frequency AC DCT coefficient bits. But, the CD error tends to be propagated within single GOV. In this paper, we derive the distortion relationships between CD error and propagation error, and investigate the error characteristics by computer simulations. The CD error characteristics can be effectively used in the FD/CD transcoding scheme.

• Korean Institute of Interior Design Journal
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• v.19 no.3
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• pp.103-110
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• 2010

As ongoing construction of a new municipal government building leads to the destruction of the interior of the Kyungsung Municipal Government Building(currentlySeoul Metropolitan City Hall) despite its enormous historic value, this study aims to identify the unique features of spatial composition and interior design of the Kyungsung Municipal Government Building, which is widely known as a typical example of public architecture of the 1920s. The primary goal is to perform a systemic arrangement of its interior data and define the modern historic implications of its interior design, thereby laying the foundation for a compilation of the history of modern interior design. From a historical perspective, the Kyungsung Municipal Government Building-an explicit symbol of Japanese colonial supremacy-has served as the administrative hub of a hugecity for 19 years during the Japanese colonial rule and for 64 years following Korea's independence from Japan. From the perspective of architectural history, it also represents modern transitional buildingsin their shift from historicism into modernism, as manifested by its reasonable placement of interior space matching well with topographical form, easy access by citizens, open office space, and, excluding decoration, a simple and non-authoritarian exterior. Its interior design style follows Western historicist architecture, whereasits simple interior decoration embodies expressive characteristics of pragmatic simplicity. Such elements are notably found in the Grand Central Hall, the Municipal Head's Reception Room, and the Grand Conference Room.