• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.10a
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• pp.40-44
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• 2000

$Bi_2Sr_2Ca_nCu_{n+1}O_y$($n{\geq}0$; BSCCO)thin film is fabricated via two different processes using an ion beam sputtering method i.e. co-deposition and layer-by-layer deposition. A single phase of Bi2212 can be fabricated via the co-deposition process. While it cannot be obtained by the layer-by-layer process. Ultra-low growth rate in our ion beam sputtering system brings out the difference in Bi element adsorption between the two processes and results in only 30% adsorption against total incident Bi amount by layer-by-layer deposition, in contrast to enough Bi adsorption by co-deposition.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.9
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• pp.796-800
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• 2000

Bi$_2$Sr$_2$Ca$_{n}$Cu$_{n+1}$ O$_{y}$(n$\geq$0; BSCCO) thin film is fabricated via two different processes using an ion beam sputtering method i.e. co-deposition and layer-by-layer deposition. A single phase of Bi2212 can be fabricated via the co-deposition process. While it cannot be obtained by the layer-by-layer process. Ultra-low growth rate in our ion beam sputtering system brings out the difference in Bi element adsorption between the two processes and results in only 30% adsorption against total incident Bi amount by layer-by-layer deposition, in contrast to enough Bi adsorption by co-deposition.on.n.

• Journal of Trauma and Injury
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• v.22 no.2
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• pp.179-183
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• 2009

Purpose: This study was conducted to determine the level of medical care required for mass-gatherings and to describe the types of illness and injury that may occur during demonstrations. Methods: We conducted a retrospective review of the medical records for patients injured during demonstrations. Results: From May to August at 2008, a total of 932,000 participants attended demonstrations. Most patients were occurred from June to July, a total of 126 patients were evaluated and treated at the emergency center of our hospital. The mean patient age was $31.8{\pm}9.8$ years, and men predominated over women. The vast majority of patients were experienced trauma (88.9%). The diagnostic categories were contusion (49.2%), laceration (20.6%), fracture (6.3%), syncope/dizziness (5.5%), ocular injuries (3.9%), dyspnea (3.9%), other trauma (3.1%), and abdominal complaints (1.5%). Two patients were admitted. Conclusion: The rate and the acuity of patients seen at these demonstrations was low. Nevertheless, a full on-site physician and transportation system is recommended during similar incidents.

• Journal of the Korean Society of Safety
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• v.21 no.2 s.74
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• pp.1-6
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• 2006

It is well known that pipelines have the highest capacity and are the safest and least environmentally disruptive form of transporting oil and gas. However, pipeline damage caused by both internal and external corrosion is a major concern threatening the reliability of oil and gas transportation and the soundness of the pipeline structure. In this study, we estimate the allowable damage by comparing the ASTM B31G code to a modified theory considering diverse detailed corrosive forms. The ASTM B31 G code has been developed as the evaluation method for reliability and incident prevention of damaged pipelines based on the amount of loss due to corrosion and the yield strength of materials. Furthermore, we suggest a method for estimating the expected life span of used pipelines by utilizing the reliability method based on major variables such as the depth and length of damage and the corrosion rate affecting the life expectancy of the pipelines.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.11
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• pp.907-913
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• 2002

An experimental study on energy density distributions produced by dish solar concentrating system was performed to optimally design and rightly position a cavity receiver. This deemed also very useful to find and correct various errors associated with a concentrator. It is observed that the actual focal length is 2.17 m with a maximum energy density of 1.89 MW/$m^2$. By evaluating the position of flux centroid, it was found that there are errors within 2 cm from the target center. As a result of the percent power within radius, approximately 90% of the incident radiation is intercepted by about 0.06 m radius. The area concentration ratio normalized to 800 W/$m^2$ insolation and 90% mirror reflectivity was 347 suns. The total integrated power of 2467 W was measured under focal flux distributions, which corresponds to the intercept rate of 85.8%.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.10
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• pp.891-896
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• 1998

The relaxation and elimination characteristics of polarization-photoinduced dichroism have been investigated in amorphous chalcogenide thin films deposited having normal(0。) and obique (80。) vapor incident angles. The dark relaxation kinetics of dichroism from a saturation point(D\ulcorner\ulcorner) to a certain relaxation point(D\ulcorner\ulcorner) grew to be longer on subsequent cycles of switching on and off of the inducing light, and these decays are changed from simple exponential decay to stretched exponential decay. The dichroism induced by a long time(~3.3 hrs) exposure exhibited the characteristics of longer time maintenance and smaller decreasing rate, in contrast with that by a short time (~min) exposure. In addition, the dichroism was eliminated by the exposure of non-polarized He-Ne laser.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.230-234
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• 2000

Bi$_2$Sr$_2$Ca$_{n}$Cu$_{n+1}$ O$_{y}$(n$\geq$0; BSCCO)thin film is fabricated via two different processes using an ion beam sputtering method i.e. co-deposition and layer-by-layer deposition. A single phase of Bi2212 can be fabricated via the co-deposition process. While it cannot be obtained by the layer-by-layer process. Ultra-law growth rate in our ion beam sputtering system brings out the difference in Bi element adsorption between the two processes and results in only 30% adsorption against total incident Bi amount by layer-by-layer deposition, in contrast to enough Bi adsorption by co-deposition.on.n.

• Journal of electromagnetic engineering and science
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• v.14 no.3
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• pp.314-316
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• 2014

This letter presents two types of metamaterial-inspired absorbers adopting resistive trumpet structures at the X band. The unit cell of the first type is composed of a trumpet-shaped resonator loading a chip resistor, a metallic back plane, and a FR4 (${\varepsilon}_r=4.4-j0.02$) substrate between them (single-layer). The absorption rate is 99.5% at 13.3 GHz. The full width at half maximum (FWHM) is 95 % at 11.2 GHz (from 5.9 to 16.5 GHz). The size of unit cell is $5.6{\times}5.6{\times}2.4mm^3$. The second type has been optimized with a $7{\Omega}$/square uniform resistive coating, removing the chip resistors but leading to results comparable to the first type. The proposed absorbers are almost insensitive to polarizations of incident waves due to symmetric geometry.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.607-608
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• 2011

In this paper, we propose stopped vehicle detection algorithm in the tunnel. It is shown that our method distinguished objects from background estimated image, and then detected stopped vehicles efficiently based on the experimental analysis about the color information of their lamps. The simulation results show the detection rate is achieved over 95% in the tunnel image.

• Journal of Information Processing Systems
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• v.13 no.1
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• pp.83-94
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• 2017

Near-field source localization algorithms are very sensitive to sensor gain/phase response errors, and so it is important to calibrate the errors. We took into consideration the uniform linear array and are proposing a blind calibration algorithm that can estimate the directions-of-arrival and range parameters of incident signals and sensor gain/phase responses jointly, without the need for any reference source. They are estimated separately by using an iterative approach, but without the need for good initial guesses. The ambiguities in the estimations of 2-D electric angles and sensor gain/phase responses are also analyzed in this paper. We show that the ambiguities can be remedied by assuming that two sensor phase responses of the array have been previously calibrated. The behavior of the proposed method is illustrated through simulation experiments. The simulation results show that the convergent rate is fast and that the convergent precision is high.