• Korean Journal of Optics and Photonics
• /
• v.16 no.6
• /
• pp.494-499
• /
• 2005

We have demonstrated a fiber short-wavelength filter with a good cut-off property using dissimilar dispersive properties between? a thermally expanded cored fiber and an external medium. Side-polishing is applied to coupling between the fiber and the external medium. The experimental results revealed that the bend edge wavelength can be adjusted by controlling the degree of core expansion. Futhermore, the sharpness of wavelength response? was significantly? improved by employing expanded core fiber instead of a conventional single mode fiber. Tuning range of the band edge wavelength exceeded 400 m based on thermo-optic effect of the external medium.

• The Journal of the Korea Contents Association
• /
• v.10 no.1
• /
• pp.202-212
• /
• 2010

The purpose of this study is at clarifying what the genre oriented characteristics of virtual reality programs are. For this, the tests of 'We Are Married' being broadcasted in 'Sunday, Sunday Night' Part 1 of MBC from episode 1 to 8. As a result of analysis, this program was mixing together virtuality and reality by placing the image of virtual couple's life and presentness of entertainers existing in reality appearing at the studio. Also, it was forming sympathy with users as it satisfies fantasy and sense of reality toward marriage by the entertainer couples showing love and conflict that may happen between real couples after setting various categories of couple types. Also, through the device for the public space to confess private feelings through television, it shows the boundary between public domain and private domain breaking up. Along with this, it has implemented amusement characteristics by inspiring enjoyment of users by a substituted satisfaction through various forms of impressions presented to spouse such as materials, effort, gesture or language, etc. Accordingly, the virtual reality program shows authenticity, fiction and amusement by being mixed together and we can see that such genre oriented characteristics act as important strategy appealing to users based on breakup of boundary and genre oriented ambiguity.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.24 no.4
• /
• pp.91-99
• /
• 2020

Post-installed anchors were widely used due to its workable benefits. Regarding the resistance performance of anchors, the critical edge distance is presented to minimize the impact of concrete splitting. In the case of actual anchors, however, it is difficult to obtain the ideal edge distance. The purpose of this study is to identify resistance performance and behavior characteristics that contain complex elements such as concrete crack occurring under tensile load. Tensile tests were conducted based on the standard method. Failure shape and the resistance characteristics that do not have the critical edge distance were derived by tensile load. Parametric analysis according to the boundary condition was performed to simulate the actual tensile behavior, through a nonlinear finite element model based on the specimen. Consequently therefore, verifying analysis results the resistance mechanism can be applied through boundary conditions.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.9 no.5
• /
• pp.567-577
• /
• 1998

When continuous and discontinuous microstrip is analyzed with FDTD(Finite Difference Time Domain) method, we used Berenger's 3D-PML as absorbing boundary condition, and IST(Inner Source Technique) was used for source excitation instead of front excitation that is existing method. In the case using IST, we have observed that analyzed characteristic is not affected by the reduced computational domain of the side and top face in which evanescent field and radiation field is exist. Also, if we control the position of the inner source, we could effectively reject the influence of the reflective wave by mean of imperfective boundary condition. In this paper, by using IST, we have calculated dispersive characteristic and characteristic impedance of the microstrip. And we have calculated magnitude and phase of the scattering coefficient, and obtained equivalent circuit of the open microstrip end.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.32 no.4
• /
• pp.257-263
• /
• 2019

Multilayered structures include lamination by relatively thick plies and thin interlayers. For efficient peridynamic analysis of dynamic fracturing multilayered structures, the interlayer is modeled using ghost peridynamic particles while the ply is formulated via real peridynamics. With the nonlocal ghost interlayer, one may keep the discretization resolution low for the ply. In this study, the characteristics of dynamic wave propagation through the nonlocal ghost interlayer in peridynamic analysis are investigated. It is observed that the interlayer not only binds adjacent plies, but also significantly influences energy transfer between plies, and thereby their deformation and motion. In addition, near a surface or boundary, peridynamic particles do not have a full nonlocal neighborhoods. This causes the effective material properties near the surface to be different from those in the bulk. Surface correction based on neighborhood volumes is employed. The impact of surface correction on wave propagation in multilayered structures is investigated.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.23 no.12
• /
• pp.1520-1527
• /
• 2019

Superpixel methods are widely used in the preprocessing stage as a method to reduce computational complexity by simplifying images while maintaining the characteristics of images in the field of computer vision. It is common to generate superpixels with a regular size and form based on the pixel values rather than considering the characteristics of the image. In this paper, we propose a method to generate superpixels considering the characteristics of an image according to the application. The proposed method consists of two steps, and the first step is to oversegment an image so that the boundary information of the image is well preserved. In the second step, superpixels are merged based on similarity to produce the desired number of superpixels, where the form of superpixels are controlled by limiting the maximum size of superpixels. Experimental results show that the proposed method preserves the boundaries of an image more accurately than the existing method.

• Journal of Aerospace System Engineering
• /
• v.16 no.6
• /
• pp.99-105
• /
• 2022

This paper studied the mechanical characteristics of boom structures by verifying the modeling method of representing unit cells of triaxial woven fabric (TWF) composites. The modeling of the representative unit cell obtained the ABD matrix by analysing the behaviour of tensile, shear, bending, and torsion using the periodic boundary conditions for the beam element. This study aimed to validate the ABD matrix by comparing the tensile analysis output from a finite element program with the experimental results from an MTS 810 machine. Additionally, the mechanical characteristics of a TWF composite boom structure were determined through bending analysis and experiments. The findings of this research are expected to be beneficial for developing structures using TWF composites.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.29 no.4D
• /
• pp.509-521
• /
• 2009

In modern society the architecture surface involves a lot of meaning other than having simple physical functions. The interface space generated by the surface characteristics among those becomes to have many significances in modern society, and plays a role of symbolic space of a city. The interface space is threshold space that connects two separate spaces and revitalize its states. Nowadays, people have many chances to communicate each other through the interface space and also settle urban problems caused by spacial and functional discontinuity through the interface space. However, the interface space in Korea could not be built up well due to rapid growth of cities, and a lot of different natures in space and viewpoint have been appeared accordingly, which gives rise to a problem of the discontinuity of urban spaces. Therefore, this study aims at the research on the characteristics of interface space through architecture surface composing the major factor of a city; architecture integument in Nam-po Dong, Jung Gu, Busan City as the object of the study.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.29 no.2C
• /
• pp.41-49
• /
• 2009

Due to the increased size of civil infrastructure and the cost of materials, the needs exists for utilizing large sized cast-inplace piles in lieu of conventional precast piles. Among them, the barrette pile has become more commonly used in fields where a diaphragm wall is the retaining wall, to improve workability and economical efficiency, and to ensure hole stability under deep soil layers. In this paper, the bearing capacity and displacement characteristics of the barrette pile are evaluated by using the bi-directional loading test data obtained from four different sites. In addition, the design value of pile shaft resistance, ${\beta}$, is assessed with previous literatures and load transfer analysis. Finally, numerical analyses were performed to analyze the load-displacement behavior, and the interface effect on the piles, using the 3-dimensional finite element method.

• The Journal of Engineering Geology
• /
• v.22 no.2
• /
• pp.173-183
• /
• 2012

The nature of surface deformation of Tono granite was investigated using a confocal laser scanning microscope (CLSM) under water-saturated stress relaxation conditions. A new apparatus was developed for this experiment, enabling continuous measurements of stress-strain and simultaneous observations of surface deformation by CLSM. The amounts of grain contact deformation and intra-granular surface deformation were calculated using a finite element method. The results reveal that intense grain contact deformation and intra-granular surface deformation occurred during the period of stress relaxation, and that the intensity of this deformation increased with increasing applied stress. Finite element method (FEM) results show that the strain of grain boundary was greater than strain of inter-granular surface. Contour maps of these local strains were compiled for individual grains and their boundaries, revealing intense deformation at the boundaries between biotite and quartz under compressional stress. This result was a consequence of the mechano-chemical effect of biotite and quartz minerals. Biotite in granite has a layered structure of iron-magnesium-aluminum silicate sheets that are weakly bonded together by layers of potassium ions. In contrast, quartz occurs as stable spherical grains.