• 대한기관식도과학회지
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• 제4권2호
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• pp.240-243
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• 1998

Subcutaneous emphysema is an unusual and rarely reported complication of tonsillectomy. The more commen complications are hemorrhage, infection and following anesthesia, aspiration, cardiac arrhythmia, and laryngeal trauma can occur. Posttonsillectomy subcutaneous emphysema results directly from the introduction of air into the tonsillar bed either during the surgical procedure itself or in the postoperative period. This condition is generally benign and self limiting and usually requires treatment only for the primary respiratory disease. In this report, we describe a 40-year-old female patient in whom subcutaneous emphysema developed shortly after tonsillectomy. She was observed for 5 days, at which point subcutaneous emphysema was seen on the follow up soft tissue neck X-ray to disappeared.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.2413-2425
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• 2008

Until now, Many papers were written by graduate school students and consultents about railway station as main consideration. But there is no paper about specific private-invested station development. So in this paper, Just consider limiting Dong-Incheon private-invested station on a noncompetitive point of view that also constructed as a part of railway station development. This paper will be referenced of private-invested station management and direction of development in Korail railway station development. Private-invested station development is actively drived to now after Seoul private-invested station in 1989 as Korail's first induced private capital. Dong-Incheon private-invested station also built in 1989 and operated to now, but it can't keep up with current market and can't meet changeable commercial business. So in this paper, comparing Dong-Incheon private-invested station with one of the successful private-invested stations which is youngdengpo private-invested station and seeking the improvement direction of Dong-Incheon private-invested station as considering Dong-Incheon private-invested station's floating, traffic system, walking line, the range of station, the development type, facilities, and other nation's developing cases.

• Bulletin of the Korean Chemical Society
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• 제34권11호
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• pp.3372-3376
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• 2013

The kinetic studies on the reactions of ethyl methyl (2) and ethyl propyl (4) chlorothiophosphates with X-pyridines have been carried out in acetonitrile at $35.0^{\circ}C$. The free energy correlations with X show biphasic concave upwards with a break point at X = H (2) and 3-Ph (4), respectively. A stepwise mechanism with a rate-limiting leaving group expulsion from the intermediate is proposed based on the magnitudes of selectivity parameters for both substrates. The considerably large values of ${\beta}_X$ = 1.50(2) and 1.44(4) with strongly basic pyridines and relatively small values of ${\beta}_X$ = 0.43(2) and 0.36(4) with weakly basic pyridines are interpreted as a change of the attacking direction of the X-pyridines from a frontside to a backside attack toward the chloride leaving group.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1292-1293
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• 2006

A non-equilibrium powder metallurgy processing such as an MA/SPS (Mechanical Alloying / Spark Plasma Sintering) process is examined in a Ti-48moll%Al. TiAl intermetallic compound is a potential light-weight/high-temperature structural material. One of the major problems, however, limiting the practical use of the material is its poor workability. From this point, the powder metallurgy (PM) processing route has been attractive alternative of the conventional processing for such material The MA/SPS process is able to apply to a LIGA process. Optimization of the pseudo-superplasticity enables to fabricate micro-parts made of fine grained ceramics composites of TiAl by the LIGA process.

• 한국위성정보통신학회논문지
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• 제2권1호
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• pp.7-13
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• 2007

새롭고 효과적인 도플러 효과 보상 기법은 성상도 추정에 기반하며, 이론적 분석과 시뮬레이션 결과에서 알 수 있듯이 영점 성상도를 이용한 변형된 변조방식을 사용해 평균 파워를 감소시킬 수 있다. 제안된 기법은 위성 송수신기에서 고속으로 이동하는 단말로 보내는 파워를 줄여줌으로써 위성 OFDM 에서 매우 효과적으로 신호를 전달할 수 있다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
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• pp.35-38
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• 2004

The MAC protocol of HIPERLAN/2 is based on TDMA/TDD and AP (Access Point) can dynamically allocate the number of RCHs (Random CHannels). We propose a dynamic random channel allocation scheme improved by limiting the number of minimum RCHs. On a simulated scenario adopted practical Internet traffic, the proposed scheme is shown to achieve over $19\%$ lower delay than previously studied algorithm. This study will be a first step towards designing scope of RCHs for high-performance wireless packet network

• Bulletin of the Korean Chemical Society
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• 제35권4호
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• pp.1016-1022
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• 2014

The kinetic studies on the reactions of O-methyl N,N-diisopropylamino phosphonochloridothioate with X-anilines and X-pyridines have been carried out in acetonitrile. The free energy relationship with X in the anilines exhibits biphasic concave upwards with a break region between X = (H and 4-F), giving unusual negative ${\beta}_X$ and positive ${\rho}_X$ values with weakly basic anilines. The unusual phenomenon is rationalized by isokinetic relationship. A stepwise mechanism with a rate-limiting leaving group departure from the intermediate is proposed based on the selectivity parameter and variation trend of the deuterium kinetic isotope effects with X. The free energy relationship with X in the pyridines exhibits biphasic concave upwards with a break point at X = 3-MeO. A concerted mechanism is proposed based on relatively small ${\beta}_X$ value, and frontside and backside nucleophilic attack are proposed with strongly and weakly basic pyridines, respectively.

• Wind and Structures
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• 제3권4호
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• pp.255-266
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• 2000

Wind-induced interference effects on a building are the result of one or more adjacent buildings modifying the flow of wind around it, which may result in a significant increase or decrease in wind loads on the building. Wind loading standards and codes of practice offer little guidance to the designer for assessing the effects of interference. Experimental results on interference effects indicate that code recommendations may be significantly low (unsafe) or uneconomically conservative. The paper presents results of an extensive experimental program to study the wind flow mechanisms and to quantify the extent of wind load modifications on buildings due to interference effects. These results have been simplified and presented from the point-of-view of design and codification for the case of two buildings. Based on these results, general guidelines and limiting conditions defining wind interference are formulated and discussed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.2229-2231
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• 2005

Recently, damages of electronic equipments due to lightning surges coming from AC power lines are increasing. In this work, to propose the effective installation methods of surge protective devices(SPDs), the protective performances of SPDs in actual-sized test circuits were experimentally investigated. In order to obtain the lowest limiting voltage and best protection, long leads of SPDs in installation practices are significantly undesirable. An effective installation method of SPDs for AC mains was proposed. The way of installing SPDs at every branch circuits is more effective than that of installing a SPD near the point of entry.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.209-212
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• 1999

We studied the operating properties of resistive and inductive SFCLS with 100 $\Omega$ of quench impedance for a three-phase-fault in the 154 kV transmission system. The fault simulation at the phase angles 0$^{\circ}$ , 45$^{\circ}$ , and 90$^{\circ}$ showed that the resistive SFCL limited the fault current less than 16 kA without any DC component after one half cycle from the instant of the fault. On the other hand, the inductive SFCL suppressed the current below 11 kA, but with 3-4 kA of DC component which decreased to zero in 5 cycles. We concluded that the inductive SFCL had higher performance in current limiting but the resistive SFCL was better from the view point of DC components.