• Journal of the Korea Computer Industry Society
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• v.10 no.4
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• pp.135-142
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• 2009

In this thesis, we designed and implemented a tracking filter which can be used for FH/2-FSK communication system in band of 40~60[MHz]. After measuring a performance of a tracking filter, an insertion loss was measured from 3.7 to 4.3 dB, depending upon a hopping center frequency. The 3 dB bandwidth of a tracking filter was specified 5.1 to 5.33% depend upon a hopping and 30/3 dB shape factor indication for interrupting property of a filter shows 6.828 to 6.98 satisfying a required specification. Also the attenuation $2{\times}f_0$, the characteristic parameter for interference degree, was specified 46~52dB, not satisfying a required specification.

• Journal of Trauma and Injury
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• v.28 no.3
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• pp.219-221
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• 2015

Subclavian injuries in blunt trauma are reported in less than 1% of all arterial injuries or chest related injuries. We report a female 68 yr-old patient whom has visited our emergency center due to a motorcycle traffic accident with complaints of right chest wall and shoulder pain. Her injury severity score was 22 and she was found with a comminuted clavicle fracture and subclavian artery injury. She developed delayed symptoms of pallor, pain and motor weakness with loss of pulse in her right arm. Attempts at intervention failed and thus, she underwent emergency artificial graft bypass from her subclavian artery to her brachial artery. Her postoperative course was uneventful and she is happy with the results. Although rare, a high index of suspicion for the injury must be noted and the inevitable surgical option must always be considered.

• Journal of Welding and Joining
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• v.23 no.1
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• pp.69-76
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• 2005

Recently, application of arc welding to galvanized carbon steel sheet is on the increasing Ould in the fields of automobile and construction industries. In arc welding process, zinc is evaporated in weld pool, even under the appropriate welding condition and produce blowhole and/or pit. Zinc gas cause instability of arc and increase spatter and fume. This research is purposed to minimize the heat-input and the formation of porosities in the welded joint of the galvanized carbon steel sheet using variable polarity AC wave pulse MIG welding system. An appropriate welding condition which showed low spatter and good bead appearance was acquired by applying the AC pulse MIG welding machine to DC duplicated MIG welding with the solid wire. When oxygen gas was added to shield gas of MIG welding for galvanized steel sheet, arc length was increased and arc stability was improved. In the AC duplicated welding, the loss of galvanized layer was decreased as the amount of heat-input was decreased when the EN ratio was increased under the condition that average welding current was evenly set.

• Journal of The Korean Society of Clinical Toxicology
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• v.1 no.1
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• pp.21-26
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• 2003

Methamphetamine (MA) is a major drug of abuse in Korea. Currently preliminary evidence suggests that MA dependence may cause long-term neural damage in human. Repeated exposure to psychostimulants such as methamphetamine results in behavioral sensitization, a paradigm thought to be relevant to drug craving and addiction in human. Sensitization alters neural circuitry involved in normal processes of incentrive, motivation, and reward. However the precise mechanism of this behavioral sensitization has not yet been fully elucidated. Repeated use of high dose MA causes neurotoxicity which is characterized by a long-lasting depletion of striatal dopamine (DA) and tyrosin hydroxylase activity of DA, DA-transporter binding sites in the striatum. The loss of DA transporters correlates with memory problems and lack of motor coordination. DA fuels motivation and pleasure, but it' s also crucial for learning and movement. This selective review provides a summary of studies that assess the neurobiological mechanisms of MA.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.344-345
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• 2011

A necessity to a superconducting cable in power transmission systems have been growing more and more due to high power density in urban areas and rapid increase of power demand. In view of these situation, it is a noteworthy fact that superconducting cable has remarkable advantages, such as lower power loss and 3-5 times higher power transmission capacity, compared with conventional power cable. For the last a few years, long-term reliability tests had been carried out in the KEPCO PT Center, and now it has been installed in KEPCO's real power grid for demonstrating commercial operation. This paper deals with the test results of dielectric properties performed at manufacturing factory for the joint box, termination and core of HTS cable system and whole system connected in real power grid.

• BMB Reports
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• v.44 no.4
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• pp.217-231
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• 2011

T cell exhaustion develops under conditions of antigen-persistence caused by infection with various chronic pathogens, such as human immunodeficiency virus (HIV) and myco-bacterium tuberculosis (TB), or by the development of cancer. T cell exhaustion is characterized by stepwise and progressive loss of T cell function, which is probably the main reason for the failed immunological control of chronic pathogens and cancers. Recent observations have detailed some of the intrinsic and extrinsic factors that influence the severity of T cell exhaustion. Duration and magnitude of antigenic activation of T cells might be associated with up-regulation of inhibitory receptors, which is a major intrinsic factor of T cell exhaustion. Extrinsic factors might include the production of suppressive cytokines, T cell priming by either non-professional antigenpresenting cells (APCs) or tolerogenic dendritic cells (DCs), and alteration of regulatory T (Treg) cells. Further investigation of the cellular and molecular processes behind the development of T cell exhaustion can reveal therapeutic targets and strategies for the treatment of chronic infections and cancers. Here, we report the properties and the mechanisms of T cell exhaustion in a chronic environment.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.3
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• pp.557-564
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• 2000

A microstrip band-pass filter using cross-coupled resonators is designed and studied experimentally. The cross-coupled microstrip hairpin resonator filters exhibit ripples in both passband and stopband. These ripples can improve both frequency selectivity and insertion loss. The cross-coupled filters are not only simple and compact in configuration, but also have great flexibility to form filters into a variety of size. In this paper, a microstrip band-pass filter using cross-coupled resonators is designed at the center frequency of 1.8GHz with bandwidth of 5.0% using Ensemble software. The experimental results show that the bandwidth is about 4.53% at 1.8GHz.

• Journal of Navigation and Port Research
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• v.41 no.2
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• pp.39-46
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• 2017

This study represents a fundamental research for a passenger-ship escape guidance system that is a ship-borne agent, and it is for the support of escape decision-making by providing accurate maritime safety information in real time. We conducted a passenger escaping experiment on a training ship, SAEYUDAL, using the situation-aware escape guidance system, which has been developed for on-board application based on products for buildings. It is shown that the system contributes to the shortening of the escape duration and the dispersion of the escaping persons by generating and guiding the safe escape routes which dangerous areas are considered. From the experiment on ship's heeling condition, it is revealed that the heeling angle is linearly related to the escape duration. Therefore, this study shows that the shortening of the escape duration enables a safe and rapid mustering that is the most important process under emergency and appropriate incident responses to minimize loss of lives.

• Journal of Power Electronics
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• v.18 no.4
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• pp.1178-1189
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• 2018

In grid-connected voltage-source inverters (VSIs), when compared with a simple inductive L filter, the LCL filter has a better performance in attenuating the high frequency harmonics caused by the pulse-width modulation of power switches. However, the resonance peaks generated by the filter inductors and capacitors can make a system unstable. In terms of simplicity and filter design cost, a passive damping method is generally preferred. However, its high power loss and degradation in high frequency harmonic attenuation are significant demerits. In this paper, a mathematical design solution for a passive LCL filter to derive filter parameters suppressing the high frequency current harmonics to 0.3% is proposed. The minimum filter inductance can be obtained to reduce the size of the filter. Furthermore, a minimum damping resistance design considering a current controller is analyzed for a stable closed-loop system. The proposed design method is verified by experimental results using a 5-kW three-phase prototype inverter.

• BMB Reports
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• v.30 no.1
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• pp.60-65
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• 1997

Expression of human Cu.Zn-superoxide dismutase (SOD) with activity comparable to human erythrocyte enzyme was achieved in E. coli B21(DE3) by using the pET-17b expression vector containing a T7 promoter. Recombinant human SOD was found in the cytosol of disrupted bacterial cells and represented > 25% of the total bacterial proteins. The protein produced by the E. coli cells was purified using a combination of ammonium sulfate precipitation, Sephacryl S-100 gel filtration and DEAE-Sephacel ion exchange chromatography. The recombinant Cu,Zn-SOD and human erythrocyte enzyme were compared using dismutation activity, SDS-PAGE and immunoblotting analysis. The mass of the subunits was determined to be 15,809 by using a electrospray mass spectrometer. The copper specific chelator. diethyldithiocarbamate (DOC) reacted with the recombinant Cu,Zn-SOD. At $50{\mu}M$ and $100{\mu}M$ concentrations of DOC, the dismutation activity was not inhibited for one hour but gradually reduced after one hour. This result suggests that the reaction of DOC with the enzyme occurred in two distinct phases (phase I and phase II). During phase I of this reaction, one DOC reacted with the copper center, with retention of the dismutation activity while the second DOC displaced the copper, with a loss of activity in phase II.