• Journal of the Korea Safety Management & Science
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• v.10 no.4
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• pp.173-179
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• 2008

The portion of air logistics is getting growing in the global logistics and customer need the rapidity and accuracy for freight delivery. But, the process of air logistics is so complicated because there are too many stakeholders involved in the process. So we suggest the way to make simple the process for improving ability of handling air freights. First, we analyze the AS-IS process and problems by studying previous documents and researching the field. Also we offer how to adopt the ways that are solutions concerning AS-IS process. Second, we suggest integrated information system that will make it simple the air logistics process and mitigate the intensive work load of air cargo. Also we show the reliance about our suggestion by simulation comparing TO-BE process to AS-IS process. We result in that this study will contribute to improve air logistics process by making simple the process.

• ETRI Journal
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• v.31 no.6
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• pp.795-802
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• 2009

This paper presents the design of an advanced terrestrial digital multimedia broadcasting (AT-DMB) baseband receiver SoC. The AT-DMB baseband is incorporated into a hierarchical modulation scheme consisting of high priority (HP) and low priority (LP) stream decoders. The advantages of the hierarchical modulation scheme are backward compatibility and an enhanced data rate. The structure of the HP stream is the same as that of the conventional T-DMB system; therefore, a conventional T-DMB service is possible by decoding multimedia data in an HP stream. An enhanced data rate can be achieved by using both HP and LP streams. In this paper, we also discuss a time deinterleaver that can deinterleave data for a time duration of 384 ms or 768 ms. The interleaving time duration is chosen using the LP symbol mapping scheme. Furthermore, instead of a Viterbi decoder, a turbo decoder is adopted as an inner error correction system to mitigate the performance degradation due to a smaller symbol distance in a hierarchically modulated LP symbol. The AT-DMB baseband receiver SoC is fabricated using 0.13 ${\mu}m$ technology and shows successful operation with a 50 mW power dissipation.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.6
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• pp.155-161
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• 2015

As the popularity of the smartphone becomes increase, indoor smartphone positioning technology has been actively studied. The acoustic signal generated from the smartphone is received from the several microphones at the relative positioning system, and the trigger signal is proposed to mitigate the multipath effect and the effect is verified. But for the simple trigger method, there would be error occurred according to the variation of the distance or surrounding noise. In this paper, in order to resolve the problems, the dynamic trigger threshold technology is proposed and its effect is verified by the experiment.

• Journal of the East Asian Society of Dietary Life
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• v.27 no.4
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• pp.477-490
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• 2017

The objective of this study was to analyze the relationship between blood pressure and serum mineral concentration in hypertension patients subjected to dehydration. The data were collected and analyzed for 7,109 patients who visited a hospital for their health checkup from 2011 till 2015. Respondents were classified into four groups depending upon their state of hypertension and dehydration: control group (no hypertension and no dehydrated), dehydrated group, hypertension group, and dehydrated with hypertension group. Hypertension group was found to have higher levels of serum sodium, calcium, and uric acid than the normal group, whereas the dehydrated group was found to have higher levels of serum sodium and potassium than the normal group. In effect, no significant correlation was directly observed between the hypertension group and dehydration group. However, there were significant negative correlations between dehydration of the old-aged group and their serum mineral concentrations, which are reportedly related to hypertension. Thus, dehydration prevention measures in the elderly over 65 could mitigate hypertension problems.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.4
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• pp.37-46
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• 1996

In this paper, we analyzed the performance improvement of the DS-CDMA/dPSK cellular mobile communication system with CCI canceller and RAKE receiver techniques in mobile radio channel which is characterized by AWGN, Multi-user interference (mUI) and frequency-selective rayleigh fading. System capacity i.e., number of user per cell has been derived and the evaluated results are shown in figuraes as a function of PN code sequence length, number of RAKE receiver tap, BER and E$_{b}$/N$_{o}$. The voice activity factor is assumed to be 3/8 the number of sectors in a cell 3 and MUI is modeled as gaussian process. From the results, the capacity of the DS-CDMA/DPSK cellular mobile communication system is improved by adopting CCI canceller. When we adopt the RAKE receiver to mitigate the multipath fading, the error performance is improved and the amount of improvement is proportional ot the number of taps L in the case that each tap contains a signal component and the better of improvement can be obtained, the smaller of the SNR difference in each tap. The system capacity is more increased when the CCI canceller and the RAKE receiver is used in cascade.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.1
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• pp.42-48
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• 2002

In this paper, a decision method using multiple threshold values for PN code acquisition in Direct Sequence Code Division Multiple Access (DS-CDMA) systems is described. We apply this technique to the conventional double dwell serial search algorithm and analyze it in terms of mean code acquisition time. For the analysis, we present mathematical model of proposed algorithm and also perform the simulation under IMT-2000 channel models. Numerical results show that our proposed scheme outperforms the conventional one by 0.2 - 0.5 sec with respect to the mean code acquisition time because multiple threshold values mitigate the possible decline in search performance caused by the use of a single threshold.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.3
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• pp.312-318
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• 2016

This paper presents a 2-6 GHz GaN HEMT power amplifier monolithic microwave integrated circuit (MMIC) with bridged-T all-pass filters and output-reactance-compensation shorted stubs using the $0.25{\mu}m$ GaN HEMT foundry process that is developed by WIN Semiconductors, Inc. The bridged-T filter is modified to mitigate the bandwidth degradation of impedance matching due to the inherent channel resistance of the transistor, and the shorted stub with a bypass capacitor minimizes the output reactance of the transistor to ease wideband load impedance matching for maximum output power. The fabricated power amplifier MMIC shows a flat linear gain of 20 dB or more, an average output power of 40.1 dBm and a power-added efficiency of 19-26 % in 2 to 6 GHz, which is very useful in applications such as communication jammers and electronic warfare systems.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.1
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• pp.76.2-76.2
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• 2013

SPICA(SPace Infrared Telescope for Cosmology and Astrophysics) is an infrared space observatory with cooled telescope of 3 m aperture. Because of its large aperture, near- and mid-infrared instruments onboard SPICA require fine guidance with attitude accuracy less than 0.1 arcsecond. The FPC-G is a focal plane camera to achieve this high attitude accuracy and KASI is leading its development. The SPICA project is now under the Risk Mitigation Phase 2 (RMP2) and one of major risks is to satisfy the requirement of pointing and attitude control. To assess the impacts of disturbance sources on the attitude control and devise methods to mitigate possible risks, a software simulator of the FPC-G is under the development. In this presentation, we report the status of development of the simulator and the development plan during the RMP2.

• Journal of Ecology and Environment
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• v.30 no.3
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• pp.265-269
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• 2007

The loss of nitrogen and phosphorus from sediments in two watersheds, one naturally regenerating and one artificially planted, in Sacheon-myun, Gangneung-si, Gangwon Province, were measured two years after a forest fire in 2000. Sediment losses occurred five times in the course of the year. In the artificially planted watershed, $50{\sim}140$ times more nitrogen and $54{\sim}139$ times more phosphorus were lost with sediments during heavy rains, from July to August, than in the naturally regenerating watershed. When the typhoon Rusa struck the country, 1,389 times more nitrogen and 1,647 times more phosphorus were lost from the artificial watershed. In spite of the limited scope of this study, these results suggest that artificially planted watersheds are extremely vulnerable to catastrophic natural disasters such as typhoons. Elevated loss of nutrients in the artificially planted watershed might have resulted from the mechanized silvicultural practices employed immediately after the fire. To maximize soil preservation, the timing and necessity of plantation practices should be reconsidered, and rapidly regenerating vegetation should be protected to promote nutrient uptake and to mitigate nutrient loss from burned forests.

• Journal of the Korean Electrochemical Society
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• v.19 no.2
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• pp.45-49
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• 2016

In order to mitigate oxidative degradation of polymer membrane during fuel cell operation, an organic radical quencher was introduced. Rutin was selected as a radical quencher and mixed with sulfonated poly(arylene ether sulfone) to prepare composite membrane. Physicochemical properties of the composite membranes such as water uptake and proton conductivity were characterized. Hydrogen peroxide exposure experiment, which can mimic accelerated oxidative stability test during fuel cell operation, was adopted to evaluate the oxidative stability of the membranes. The composite membranes containing Rutin showed similar proton conductivity and enhanced oxidative stability compared to pristine ones.