• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.5
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• pp.305-308
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• 2004

The 7-dial inductive voltage divider(IVD) for application at low frequency range which can precisely divide the in put voltage up to resolution of $10^{-7}$ was fabricated by using the toroidal cores made by super-mumetal strips of 0.025 mm thick and special decade switches. The cores have the initial permeability of 200.000 and magnetic flux density of 0.5 T. The inphase and quadrature ratio errors for a fabricated 7-dial IVD are found to be less than $\pm$4${\times}$$10^{-7}$ and $\pm$5${\times}$$10^{-6}$ rad(k=2), respectively. by calibration using the IVD calibration system of KRISS. The fabrication techniques used and uncertainty evaluation are discussed in this paper.

• Journal of information and communication convergence engineering
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• v.6 no.4
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• pp.376-382
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• 2008

Developing highly cost-efficient and reliable embedded systems demands hardware/software co-design and co-simulation due to fast TTM and verification issues. So, it is essential that Platform-Based SoC design methodology be used for enhanced reusability. This paper addresses a reusable SoC platform based on OpenCores soft processor with reconfigurable architectures for hardware/software codesign methodology. The platform includes a OpenRISC microprocessor, some basic peripherals and WISHBONE bus and it uses the set of development environment including compiler, assembler, and debugger. The platform is very flexible due to easy configuration through a system configuration file and is reliable because all designed SoC and IPs are verified in the various test environments. Also the platform is prototyped using the Xilinx Spartan3 FPGA development board and is implemented to a single chip using the Magnachip cell library based on $0.18{\mu}m$ 1-poly 6-metal technology.

• Economic and Environmental Geology
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• v.27 no.3
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• pp.289-294
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• 1994

This paper describes an effective utilization method of well logging data and boring cores for understanding the geology of Keoje-do area. Six holes were drilled in 1988-1989, and all rock cores were recovered. Nevertheless, seven kinds of logs were carried out in each borehole. The geologic situations of the drilling sites are accurately evaluated from a comparison between core descriptions and well logging data. Porosities and clay contents of sedimentary rocks can be calculated using the data of density and gamma-ray logs. Fractured zones are easily detected from the change in inside diameter of borehole by caliper log. Sonic, density and gamma-ray logging data clearly indicate alternated and dyke zones; the former can be detceted from an acoustic wave attenuation and a decline of compaction by sonic and density logs, the latter can be detected from the amount of potassium contents of bed rock and dyke by gamma-ray log.

• Journal of Electrical Engineering and Technology
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• v.9 no.6
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• pp.2013-2018
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• 2014

According to the manufacturing process of the laminated stator core for an inserted permanent magnet synchronous motor (IPMSM), the iron loss may be different. It is because the mechanical stress imposed to electrical steel sheet is strongly dependent on the manufacturing process. This paper proposes a new iron loss measurement algorithm which utilizes the induced voltage of a search coil and exciting current. The method is effective even when the distribution of magnetic flux density is not uniform along the magnetic flux path as well as uniform. The developed iron loss measurement system is applied to bonded- and embossed-type segmented stator cores of an IPMSM, and the iron losses are quantitatively compared.

• Proceedings of the KIPE Conference
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• 2012.11a
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• pp.85-87
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• 2012

This paper describes the design and analysis of an integrated transformer magnetic core which comprises of two different power cores with PFC inductor and LLC resonant transformer magnetic cores. The equivalent magnetic circuit modeling approach is employed to analyze the variations in coupling coefficient and inductance in terms of air gaps under the operations of the respective power core. Simulation and experimental studies are performed with a fabricated prototype integrated core and their results are discussed.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.6 no.1
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• pp.18-31
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• 1997

By the concerns of esthetic restoration were increased recently. many all ceramic crowns were developed. But they except In-Ceram Alumina were used only single crown. In-Ceram Alumina, developed by Dr. Sadon, was revealed to have high flexural Strength(450MPa). So it could be used not only anterior bridges but also posterior bridges. But In-Ceram Alumina was seen to be opaque, a little green color in transillumination light by high content of alumina oxide(85%). So new all ceramics with high strength and high translucence were needed. Spinell($MgAl_2O_3$) have a high melting point, high flexural strength, low heat conductivity, high light conductivity. In-Ceram Spinell offers glasslike light transmission by using the spinell cores instead of the alumina cores. And they have a high translucency like to natural tooth, an excellent margin integrity and a high strength(350MPa). The purposes of this study are 1) to know about the construction method of In-Ceram Spinell System, 2) to investigate the its clinical possibiliy through patients and literature reviews.

• Journal of The Korean Astronomical Society
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• v.46 no.6
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• pp.243-251
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• 2013

We present results on the intrinsic brightness temperature of a sample of compact radio sources observed at 86 GHz using the Global Millimeter VLBI Array. We use the observed brightness temperatures at 86 GHz and the observed superluminal motions at 15 GHz for the sample in order to constrain the characteristic intrinsic brightness temperature of the sample. With a statistical method for studying the intrinsic brightness temperatures of innermost jet cores of compact radio sources, assuming that all sources have the same intrinsic brightness temperature and the viewing angles of their jets are around the critical value for the maximal apparent speed, we find that sources in the sample have a characteristic intrinsic brightness temperature, $T_0=4.8^{+2.6}_{-1.5}{\times}10^9K$, which is lower than the equipartition temperature for the condition that the particle energy equals to the magnetic field energy. Our results suggest that the VLBI cores seen at 86 GHz may be representing a jet region where the magnetic field energy dominates the total energy in the jet.

• Journal of the Korean Ceramic Society
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• v.29 no.3
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• pp.241-251
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• 1992

The effects of slip composition and processing conditions on the fabrication of ceramic heat exchanger cores by doctor blade process were investigated. Since the effects of those two variables were inter-dependent, the effects of binder system, binder plus plasticizer, were extensively studied for a limited range of processing conditions and a pre-determined ceramic composition. The content of binder system and the ratio of binder to plasticizer were identified as main variables to affect densities and mechanical properties of green sheets, compressive properties and bond strengths of laminates, and shrinkages and their anisotropy of sintered laminates. However, sintered densities and water absorptions of laminates were not influenced by either the content of binder system or the ratio of binder to plasticizer, when the debinded laminates had a relatively high density (relative density of >55% in this study).

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.3
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• pp.345-355
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• 2014

Today's System-on-a-Chip (SoC) is designed with reusable IP cores to meet short time-to-market requirements. However, the increasing cost of testing becomes a big burden in manufacturing a highly integrated SoC. In this paper, an efficient parallel scan test technique is introduced to minimize the test application time. Multiple scan enable signals are adopted to implement scan architecture to achieve optimal test application time for the test patterns scheduled for concurrent scan test. Experimental results show that testing times are considerably reduced with little area overhead.

• Steel and Composite Structures
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• v.16 no.4
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• pp.389-415
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• 2014

This study deals with dynamic model of composite sandwich panels with functionally graded flexible cores under low velocity impacts of multiple large or small masses using a new improved higher order sandwich panel theory (IHSAPT). In-plane stresses were considered for the functionally graded core and face sheets. The formulation was based on the first order shear deformation theory for the composite face sheets and polynomial description of the displacement fields in the core that was based on the second Frostig's model. Fully dynamic effects of the functionally graded core and face-sheets were considered in this study. Impacts were assumed to occur simultaneously and normally over the top and/or bottom of the face-sheets with arbitrary different masses and initial velocities. The contact forces between the panel and impactors were treated as internal forces of the system. Nonlinear contact stiffness was linearized with a newly presented improved analytical method in this paper. The results were validated by comparing the analytical, numerical and experimental results published in the latest literature.