• Laser Solutions
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• v.13 no.1
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• pp.1-5
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• 2010

ln this work, the feasibility of using a UV laser for micromachining of powder injection molded parts is examined experimentally. The results, although preliminary, indicate that microfabrication of various parts by laser micromachining of the injection molded parts and then sintering is promising. Particularly, micromachining of a mixture composed of stainless steel particles and polyrner binders was studied using a KrF excimer laser.

• Journal of The Korean Astronomical Society
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• v.34 no.4
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• pp.237-241
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• 2001

Our goal is to present a simple volume-of-fluid type interface-tracking algorithm to compressible two-phase flow in two space dimensions. The algorithm uses a uniform underlying Cartesian grid with some cells cut by the tracked interfaces into two subcells. A volume-moving procedure that consists of two basic steps: (1) the update of volume fractions in each grid cell at the end of the time step, and (2) the reconstruction of interfaces from discrete set of volume fractions, is employed to follow the dynamical behavior of the interface motion. As in the previous work with a surface-tracking procedure for general front tracking (LeVeque & Shyue 1995, 1996), a high resolution finite volume method is then applied on the resulting slightly nonuniform grid to update all the cell values, while the stability of the method is maintained by using a large time step wave propagation approach even in the presence of small cells and the use of a time step with respect to the uniform grid cells. A sample preliminary numerical result for an underwater explosion problem is shown to demonstrate the feasibility of the algorithm for practical problems.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.60.1-60.1
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• 2011

We present the preliminary results of the pilot observations for the fringe survey at 43 GHz with the VLBI Exploration of Radio Astrometry (VERA). The main goals of the fringe survey are to establish a full list of phase calibrators for the VERA dual-beam astrometric observations, and for the KVN multi-frequency phase referencing observations. We performed two 24 hours experiments as a pilot observation to test the feasibility of the fringe survey. Each source from a list of 220 sources has been observed in one scan for 2 minutes. 67 sources were detected with the SNR threshold of 3.5. The correlated flux densities of the detected sources are presented in four ranges of projected baseline lengths.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.3
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• pp.1-6
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• 2012

This paper aims to suggest a validity analysis model that would be helpful for local governments considering u-City construction projects and a methodology for them to promote build-transfer-lease (BTL) u-City projects. This methodology mainly uses quantitative and qualitative analysis based on the Value For Money (VFM) designed by the Public and Private Infrastructure Investment Management Center (PIMAC) under the Korea Development Institute (KDI). BTL projects requires a large amount of capital and involves long-term investments. Therefore, multi-faceted validity analysis is required for the success of a project. This study will enumerate various factors to be considered in the pre-analysis of validity of BTL projects and suggest a methodology to verify them. A case study of a BTL project promoted by Ansan City assisted in designing this study in detail.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.7
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• pp.87-94
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• 2008

The displacement sensor using optical pickup head is presented. The measuring principle of optical pickup head in focusing direction is adopted to measure displacement. The preliminary tests were carried out to verify the feasibility of the optical pickup head as a displacement sensor and optical pickup head showed about $8\;{\mu}m$ measuring range and 10nm resolution. The methodology to expand measuring range is proposed and proved its validity. The proposed displacement sensors are applied to AFM(Atomic Force Microscope) probe head to measure the deflection of micro-cantilever.

• Journal of the Optical Society of Korea
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• v.13 no.3
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• pp.304-309
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• 2009

We tested the feasibility of measuring fat thickness using a miniaturized chip LED sensor module, testing 12 healthy female subjects. The module consisted of a single detector and four sources at four different source-detector distances (SD). A segmental curve-fitting procedure was applied, using an empirical algorithm obtained by Monte-Carlo simulation, and fat thicknesses were estimated. These thicknesses were compared to computed-tomography (CT) results; the correlation coefficient between CT and optical measurements was 0.932 for bicep sites. The mean percentage error between the two measurements was 13.12%. We conclude that fat thickness can be efficiently measured using the simple sensor module.

• Journal of the Korean institute of surface engineering
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• v.40 no.5
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• pp.203-208
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• 2007

Preliminary studies were conducted to develop a dimensionally stable anode (DSA)electrode prepared by reactive sputtering method. The microstructure, surface morphology and electrochemical properties of iridium oxide $(IrO_2)$ coatings synthesized by unbalanced magnetron sputtering (UBMS) and conventional DSA electrode were compared. In addition, the possibilities of $IrO_2$ films synthesized by UMB on a real DSA electrode were investigated by electro-chemical application test. The degree of non-stoichiometry and surface area were closely related to the electro-chemical activity of the $IrO_2$ electrode. The feasibility of making a DSA electrode prepared by PVD technique was demonstrated through the present work.

• ETRI Journal
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• v.27 no.6
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• pp.708-712
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• 2005

We propose a computational reconstruction technique in large-depth integral imaging where the elemental images have information of three-dimensional objects through real and virtual image fields. In the proposed technique, we reconstruct full volume information from the elemental images through both real and virtual image fields. Here, we use uniform mappings of elemental images with the size of the lenslet regardless of the distance between the lenslet array and reconstruction image plane. To show the feasibility of the proposed reconstruction technique, we perform preliminary experiments and present experimental results.

• ETRI Journal
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• v.31 no.2
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• pp.105-110
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• 2009

In this paper, we propose a curved projection integral imaging system to improve the horizontal and vertical viewing angles. The proposed system can be easily implemented by additional use of a large-aperture convex lens in conventional projection integral imaging. To obtain the simultaneous display of 3D images through real and virtual image fields, we propose a computer-generated pickup method based on ray optics and elemental images, which are synthesized for the proposed system. To show the feasibility of the proposed system, preliminary experiments are carried out. Experimental results indicate that our system improves the viewing angle and displays 3D images simultaneously in real and virtual image fields.

• Korean Journal of Child Studies
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• v.16 no.2
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• pp.81-95
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• 1995

The purpose of this study was to examine the feasibility of validating the Kaufman Assessment Battery for Children(K-ABC) with Korean preschoolers. Subjects were 197 preschoolers of 3,4 and 5 years of age. The mean of the MPC(Mental Processing Composite) scores was 111.7 and SD was 12.26. According to the item discriminant method, most subtests of Sequential Processing and the triangle subtest of Simultaneous Processing were significant, but the other subtests were insignificant. All subtests were highly correlated with MPC, and both the Sequential Processing Scale and Simultaneous Processing Scale were highly correlated with MPC; but the correlation between the two scales was low. Internal consistency was satisfactory on both scales(Cronbach' ${\alpha}$=.76 -.86). A further study is needed to diminish cultural discriminants and to include more samples from diverse subject groups.