• Journal of the Korean Electrochemical Society
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• v.1 no.1
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• pp.14-17
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• 1998

Mesophase pitch-based carbon fibers(MPCF) have been investigated as an anode active material for lithium ion secondary battery. Graphitized MPCF gives high discharge capacity and good Ah efficiency. MPCF/Li cell shows an initial discharge capacity of 300 mAh/g and Ah efficiency above $90\%$ at a current density of 25 mA/g at $0\~1$ V. Cylindrical lithium ion secondary battery was fabricated using mixed carbon anode and $LiCoO_2$, cathode. In order to improve the cyclability of lithiun ion secondary battery, other carbons were added to the MPCF up to $10wt\%$. The cycle performance of lithium ion secondary battery using mixed carbons was superior to those using graphitized MPCF.

• Progress in Medical Physics
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• v.17 no.1
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• pp.32-39
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• 2006

To assess the ability of an extravasation detection accessory (EDA) system to detect clinically important extravascular injection of iodinated contrast material delivered with an automated power injector. Fifty patients referred for contrast material enhanced body computed tomography studied in a prospective, observation study in which the EDA system was used to identify and interrupt any injection associated with clinically Important extravasation. The presence or absence of extravasation was definitively established with multi-detector CT at the injection site (injection rate, $2.0{\sim}2.5$ mL/sec). There were two true positive, extravasation volumes $22{\sim}25$ mL. The EDA system had sensitivity in the detection of clinically important extravasation. The EDA system is easy to use, safe, and accurate In the monitoring of intravenous injections for extravasation, which may prove especially useful in CT applications.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.10
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• pp.1309-1316
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• 2016

This paper suggests adjusting TCP for smartphones that often have small size data transmission tendency. Usage of smartphones has been risen dramatically in recent years, including frequent usage of real-time map search, public transportation search, online games, and SNS. Because the small size data transmission ends before the phase of the TCP congestion avoidance, this paper suggests an algorithm that increases the transmission speed ahead of the traffic congestion event. The algorithm reduces unnecessary delay by data size-driven adjustment of the Linux Quick ACK and Nagle's algorithm. Therefore, TCP is improved to maintain a high transmission rate steadily in small data transmission.

• Journal of Advanced Navigation Technology
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• v.25 no.6
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• pp.530-535
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• 2021

In this paper, the design method for a chipless RFID tag using ELC resonators is proposed. A four-bit chipless RFID tag is designed in a two by two array configuration using three ELC resonators with different resonant peak frequencies and one compact IDC resonator. The resonant peak frequency of the bistatic RCS for the IDC resonator is 3.125 GHz, whereas those of the three ELC resonators are adjusted to be at 4.225 GHz, 4.825 GHz, and 5.240 GHz, respectively, by using the gap between the capacitor-shaped strips in the ELC resonator. The spacing between the resonators is 1 mm. Proposed four-bit tag is fabricated on an RF-301 substrate with dimensions of 50 mm×20 mm and a thickness of 0.8 mm. It is observed from experiment results that the resonant peak frequencies of the fabricated four-bit chipless RFID tag are 3.290 GHz, 4.295 GHz, 4.835 GHz, and 5.230 GHz, respectively, which is similar to the simulation results with errors in the range between -2.3% and 0.2%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.3851-3857
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• 2014

Shippers' requests of freight trains vary with time, but generating an additional schedule of freight trains is not easy due to many considerations, such as the line capacity, operation rules, and conflicts with existing trains. On the other hand, an additional freight train schedule has been continuously requested and manually processed by domestic train operation companies using empirical method, which is time consuming. This paper proposes a model to determine the additional freight train schedule that assesses the feasibility of the added freight trains, and generates as many additional schedules as possible, while minimizing the delay of the existing schedules. The problem is presented using time-space network, modeled as multi-commodity flow problem, and solved using the column generation method. Three levels of experiment were conducted to show validity of the proposed model in the computation time.

• KIPS Transactions on Computer and Communication Systems
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• v.4 no.1
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• pp.5-10
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• 2015

D2D (Device-to-Device) communication underlaying LTE-advanced networks is a promising technology to improve the system capacity and spectral efficiency. By sharing the same radio resources with cellular user equipments, D2D communications can significantly enhance the overall spectral efficiency. However, it may cause interference between D2D link and cellular link. Careful resource allocation and interference coordination between cellular and D2D communications are very important and need to be properly handled. This paper proposes a radio resource allocation scheme based on FFFR (Flexible Fractional Frequency Reuse) for D2D communication underlaying cellular networks. The base station selects randomly resource blocks assigned to cellular users, and reuses them for a D2D pair. Through simulations, we have confirmed that the proposed scheme improves the system throughput, reduces the computational complexity, and mitigates the interference of D2D link and cellular link.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.1C
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• pp.63-75
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• 2012

This paper researched the operation methods of software video teleconferencing on the tactical communication networks under 1Mbps. The tactical communication networks have limited bandwidths, frequent data losses and transmission delays due to the unstable networks. In addition, the bandwidth for video teleconferencing has to be much smaller since the Army Tactical Command Information System(ATCIS) has priority of using the bandwidth. This paper analyzed such restrictions of tactical communication networks, presented some methods to improve the quality of the software video teleconferencing on the tactical communication networks and their actual experiments as well. It is applied in the first place to re-transmit the lost packets and to reduce the image size for the data traffic. Nothing is better for the video teleconferencing than to provide the bandwidth enough for every user. However, on the tactical communication networks with the limited bandwidth, video teleconferencing can be improved by optimizing the compression rate of image data, the number of image frames, the audio codec and the usage of audio compensation data.

• Food Science and Preservation
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• v.19 no.1
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• pp.116-122
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• 2012

The antioxidant activities of $makgeolli$ and other alcoholic beverages were compared. Based on the same volume (70 ${\mu}L$ eq.) of the alcoholic beverages, the 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid ammonium salt) (ABTS+) radical-scavenging activities were as follows: whisky > $makgeolli$ crude extract (MCE) > rice wine (RW) > clarified $makgeolli$ (CM) > soju. Based on the same alcohol concentration (6%) of the alcoholic beverages, however, $makgeolli$ showed the highest activity. In addition, based on the same volume (70 ${\mu}L$ eq.), the inhibition effects against the formation of cholesteryl ester hydroperoxide (CE-OOH) were as follows: soju > whisky > RW > MCE > CM. Based on the same alcohol concentration (6%), however, the inhibition effects against the formation of CE-OOH were as follows: RW > MCE > soju > whisky > CM. Therefore, it was suggested that $makgeolli$ may contain radical-scavenging- and metal-ion-chelate-type antioxidants and may increase the antioxidant activity in the blood.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.1310-1315
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• 2004

용수수요 추정의 기본은 수도계획에 사용할 수 있는 실사용량에 대한 조사로 이에 대한 자료가 거의 없기 때문에 각 수도사업별로 제시되는 추정방법이 조금씩 상이하며, 추정방법의 진위를 가릴 수 없이 수요추정의 악순환을 초래하고 있는 실정이다. 기존 물사용량 예측은 급수량 기준의 도시 전체에 내한 평균 LPCD를 이용함에 따라 물사용 특성을 충분히 고려찬 수 없어 지역별 실제 물사용량과 큰 오차가 유발되었다. 그러므로 수도계획 및 설계에 사용할 수 있는 신뢰성 있는 설계인자를 도출하기가 불가능하여 물수요 관리정책 수립, 수도요금체계 조정 및 누수방지계획 수립 등 경제적인 수도시설의 건설에 애로를 겪고 있다. 본 연구에서는 생활용수 중 가정용수에 대하여 세탁기, 변기, 싱크대 등 수도전에 유량계를 설치 실제 가정에서 사용하고 있는 용도별 사용량을 실측, 파악하였으며, 이로부터 얻은 용도별 사용량에 대한 기간별 소비특성을 분석하였다. 이로부터 생활용수 사용량의 소비패턴 및 시간대별 부하율 산정이 가능하며, 각종 용도별 사용수량의 소비형태를 찾아낼 수 있었다. 또한 가정용수 중 용도별 물 사용비율은 세탁용수, 변기, 주방, 목욕용수의 순으로 나타났으며 주택유형별로는 아파트 연립주택, 다세대 주택, 단독주택의 순으로 단독주택에서의 물사용량이 가장 적게 나타났다. 생활용수 공급량에 내해서는 시간별, 주별, 월별 그리고 계절변동 총량을 파악하였으며 시간대별로는 오후 3시경이 최대 소비량을 보였고, 주별로는 월요일 그리고 월별로는 7월의 용수사용량이 가장 큰 것으로 조사 되었다. 본 연구로부터 도출된 용도별 실측 물사용량 자료 및 분석결과로부터, 지금까지 공급량 기준의 계획수립이 이루어져왔던 파종 수도시설 규모결정시 합리적인 용수수요예측 및 수요관리가 이루어질 수 있을 것으로 판단되며, 용수수요의 과다예측 오해 해소 등 경제적, 과학적 물관리 정책수립을 위한 기초자료를 제공할 수 있을 것으로 기대된다.는 경제적인 방법이 될 수 있다. 하천수 등의 상호 관계 분석을 통해 장기간의 유역 물순환체계 변화를 분석할 수 있었다.골풀과, 닭의장풀과가 각 1종씩으로, 조사지점( I )보다 좀 더 많은 종이 분포하는 것으로 조사되었다. 또한 어류는 조사지점( I )에서 3회에 걸쳐 총 396개체가 채집되어 3목 8과 21종이었다. 이 중 한국 고유종은 11종이었고, 외래 어종은 검정우럭과 2종이 조사되었으며, Zacco platypus(피라미), Zacco temmincki(갈겨니), Acheilongnathus koreanus(칼납자루), Odontobutis platycephala(동사리), Coreoleuciscus splendidus(쉬리) 순으로 분포하고 있었고, Acheilognathus signifer(묵납자루)는 댐 건설 전에는 많이 분포하였으나 현장조사에서 서식을 확인 할 수 언어 개체수의 큰 감소내지 멸종된 것으로 추정되었다.에서 동시에 시행하였다. 수술 후 1년 내 시행한 심초음파에서 모든 환아에서 단지 경등도 이하의 승모판 폐쇄 부전 소견을 보였다. 수술 후 조기 사망은 없었으며, 합병증으로는 유미흉이 한 명에서 있었다. 술 후 10개월째 허혈성 확장성 심근증이 호전되지 않아 Dor 술식을 시행한 후 사망한 예를 제외한 나머지 6명은 특이 증상 없이 정상 생활 중이다 결론: 좌관상동맥 페동맥이상 기시증은 드물기는 하나, 영유아기에 심근경색 및 허혈성 심근증 또는 선천성 승모판 폐쇄 부전등을 초래하는 심각한 선천성 심질환이다. 그러나 진단 즉시 직접 좌관상동맥-대동맥 이식술로 수술적 교정을 해줌으로써 좋은 성적을 기대할 수 있음을 보여주었다.특히 교사들이 중요하게 인식하는 해방적 행동에 대한 목표를 강조하여 적용할 필요가 있음을 시사하고 있다.교하여 유의한 차이가 관찰되지 않았다. 또한 HSP 환자군에서도 $IL1RN^{*}2$ allele 빈도와 carriage rat

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.5
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• pp.71-79
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• 2010

This paper presents a design of a LLC resonant controller IC. LLC resonant controller IC controls the voltage of the 2nd side by adjusting frequency the input frequency of the external resonant circuit. The clock generator is integrated to provide the pulse to the resonant circuit and its frequency is controlled by the external resistor. Also, the frequency of the VCO is adjusted by the feedback voltage. The protection circuits such as UVLO(Under Voltage Lock Out), brown out, fault detector are implemented for the reliable and stable operation. The HVG, and LVG drivers can provide the high current and voltage to the IGBT. The designed LLC resonant controller IC is fabricated with the 0.35 um 2P3M BCD process. The overall die size is $1400um{\times}1450um$, and supply voltage is 5V, 15V.