• 대한의용생체공학회:의공학회지
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• 제14권4호
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• pp.321-326
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• 1993

Recently, microcomputer technology has been developed rapidly and it provides not only graphic user interface that can be fraendly accessable but also large storage capacity to han- dle much hospital information. Almost all the order communication system for hospital has been developed under the concept of host and terminal environment since last 20 years. However, host-terminal system has not been successful in korea simply because most of physicians prescibe for rrlany patients a day(sometimes more than 150 patients a day). Also, under the host-terminal environment, programs are not friendly implemented for users. Since March 1991, we had developed order communication system for out-patients(named YONSEI-PC) using personal computer(PC) and local area network(LAN) . Since September 1992, we has applied succesfully in the Yonsei Cardiovascular Center, Sevrance Hospital, Yonsei University College of Medicine. This system consisted with Server and Clients which is communicated through LAN(Ethernet). The system also use the Host computer(IBM 9221 170) as a data bank and communicates to the Server with emulation card(3270 emulator, Interlink Inc., Korea) . After introducing this system, it enables patients to receive drugs witllin 20 minutes after prescription of 300-400 patients per day and it seemed to be effective system not to reduce waiting time for the patients but also to remove charge-troubling(due to His-entry of prescription) . This system also seems to be effective in terms of office automatism for hospital management. However users, usually physitions, required more friendly and easy system to operate and we thought that the most important one to successfully introduce order communication computer system in the hospital is user interface.

• Current Photovoltaic Research
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• 제5권1호
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• pp.20-24
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• 2017

Recently, three-dimensional (3D) light harvesting structures are highly attracted because of their high light harvesting capacity and charge collection efficiencies. In this study, we have fabricated $Cu_2ZnSn(S_xSe_{1-x})_4$ based 3D thin film solar cells on PR patterned Molybdenum (Mo) substrates using photolithography technique. Specifically, Mo patterns were deposited on PR patterned Mo substrates by sputtering and the thin Cu-Zn-Sn stacked layer was deposited over this Mo patterns by sputtering technique. The stacked Zn-Sn-Cu precursor thin films were sulfo-selenized to form CZTSSe pattern. Finally, CZTSSe absorbers were coated with thin CdS layer using chemical bath deposition and ZnO window layer was deposited over CZTSSe/CdS using DC sputtering technique. Fabricated 3-D solar cells were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF) analysis, Field-emission scanning electron microscopy (FE-SEM) to study their structural, compositional and morphological properties, respectively. The 3% efficiency is achieved for this kind of solar cell. Further efforts will be carried out to improve the performance of solar cell through various optimizations.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2003년도 춘계종합학술대회논문집
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• pp.277-290
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• 2003

최근 디지털콘텐츠가 국가 발전의 핵심적인 자원으로 인식되면서 지속적인 산업의 발전을 위해 기업에 대한 지원을 범국가적 차원에서 추진하고 있다. 정부뿐 만 아니라 기업도 보다 발전적인 모습을 모색하기 위해 종전의 콘텐츠 무료 제공에서 보다 질적으로 우수한 콘텐츠를 유료화하려는 노력이 계속되고 있다. 본 고에서는 이러한 콘텐츠에 대한 유료화를 영리를 목적으로 하는 일반기업이 아닌 일반국민을 대상으로 하는 공공 정보 서비스기관으로서 콘텐츠 유통을 맡고 있는 한국과학기술정보연구원의 콘텐츠유료화 사례를 중심으로 유료화 추진전략 및 방안과 콘텐츠산업의 발전을 위한 공공기관의 역할에 대하여 검토한다.

• 마이크로전자및패키징학회지
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• 제8권2호
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• pp.25-29
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• 2001

본 연구에서는 mesocarbon microbeads(MCMB)카본에 에폭시 수지(resin)를 코팅시킴으로 서 카본전극 표면개질에 따른 전지 성능의 개선효과에 관하여 고찰하였다. 에폭시 수지에 의한 카본의 표면코팅은 MCMB 분말을 에폭시 수지가 용해된 THF(tetrahydrofuran)용액에 넣어 혼합함으로서 표면에 에폭시 수지가 코팅 되도록 하였다. 이렇게 에폭시 수지가 코팅된 MCMB를 $1000^{\circ}C$이상의 온도로 열처리하여 고분해능 투과전자현미경으로 관찰한 결과, 코팅층은 비정질 카본 구조를 지님을 알 수 있었다. 또한, 에폭시 수지에 의하여 코팅된 MCMB는 코팅되지 않은 MCMB보다 더 높은 BET비 표면적을 나타내었으며, 더 우수한 충방전 용량과 싸이클 특성을 나타내었다. 카본표면에 코팅된 에폭시 수지가 얇은 비정질 막으로 표면에 존재함으로서 전해질과 카본결정과의 반응을 억제시키는 방지막 역할을 하기 때문에 전지특성이 개선된 것으로 해석된다.

• 농업과학연구
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• 제46권4호
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• pp.907-914
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• 2019

Ammonia (NH₃) that reacts with nitric or sulfuric acid in the air is the major culprit contributing to the formation of fine particulate matter (PM_2.5). NH₃ volatilization mainly originates from nitrogen fertilizer and livestock manure applied to arable soil. Cation exchange capacity (CEC) of peat moss (PM) and zeolite (ZL) is high enough to adsorb ammonium (NH₄⁺) in soil. Therefore, they might inhibit volatilization of NH₃. The objective of this study was to compare the effect of PM and ZL on NH₃ volatilization from upland soil. For this, a laboratory experiment was carried out, and NH₃ volatilization from the soil was monitored for 12 days. PM and ZL were added at the rate of 0, 1, 2, and 4% (wt wt^-1) with 354 N g m^-2 of urea. Cumulative NH₃-N volatilization decreased with increasing addition rate of both materials. Mean value of cumulative NH₃-N volatilization across application rate with PM was lower than that with ZL. CEC increased with increasing addition rate of both materials. While the soil pH increased with ZL, it decreased with PM. Increase in CEC resulted in NH₄⁺ adsorption on the negative charge of the external surface of both materials. In addition, decrease in soil pH hinders the conversion of NH₄⁺ to NH₃. Based on the above results, the addition of PM or ZL could be an optimum management to reduce NH₃ volatilization from the soil. However, PM was more effective in decreasing NH₃ volatilization than ZL due to the combined effect of CEC and pH.

• 전기화학회지
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• 제15권3호
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• pp.198-205
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• 2012

리튬-공기전지 공기극으로서 탄소 상에 직접 수열합성법으로 망간산화물을 생성한 탄소지지 망간산화물 촉매를 합성하였다. 각 수열합성 조건에 따라서 만들어진 복합체에 대한 XRD, FE-SEM 분석을 통하여, 복합체의 결정구조, 형태, 크기 등을 확인하였는데 특히, 수열합성 온도 및 시간이 각각 $170^{\circ}C$, 12시간인 조건에서 만들어진 산화망간은 길이가 40-50 nm인 막대 모양을 갖는 것으로 나타났다. 합성된 복합체를 사용하여 만든 공기극과 리튬금속을 음극으로 하는 코인셀 형태의 리튬-공기전지를 만들어 전기화학적 특성을 조사한 결과 초기 방전 용량이 3,852 mAh/g으로 높았고 충 방전 횟수가 4회 정도 발현되었다.

• 한국전기전자재료학회논문지
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• 제30권7호
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• pp.447-453
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• 2017

In this study, $Li_2MnSiO_4$ cathode material and LiPON solid electrolyte were manufactured into thin films, and the possibility of their use in thin-film batteries was researched. When the RTP treatment was performed after $Li_2MnSiO_4$ cathode thin-film deposition on the SUS substrate by a sputtering method, a ${\beta}-Li_2MnSiO_4$ cathode thin film was successfully manufactured. The LiPON solid electrolyte was prepared by a reactive sputtering method using a $Li_3PO_4$ target and $N_2$ gas, and a homogeneous and flat thin film was deposited on a $Li_2MnSiO_4$ cathode thin film. In order to evaluate the electrochemical properties of the $Li_2MnSiO_4$ cathode thin films, coin cells using only a liquid electrolyte were prepared and the charge/discharge test was conducted. As a result, the amorphous thin film of RTP treated at $600^{\circ}C$ showed the highest initial discharge capacity of about $60{\mu}Ah/cm^2$. In cases of coin cells using liquid/solid double electrolyte, the discharge capacities of the $Li_2MnSiO_4$ cathode thin films were comparable to those without solid LiPON electrolyte. It was revealed that $Li_2MnSiO_4$ cathode thin films with LiPON solid electrolyte were applicable in thin film batteries.

• 전기학회논문지
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• 제64권9호
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• pp.1391-1397
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• 2015

Recently, various researches are conducted in the application of regenerative energy produced during the operation of an electric locomotive. Regenerative energy is produced by a generator in the brake procedure. The generator is operated by kinetic energy of an electric railroad using an electric motor. The process of producing regenerative energy varies with the current type of a railroad and its running condition. The quality of electric power can be improved and electric energy can be utilized effectively, especially in the use of an energy storage system (ESS). Thus, it is necessary to apply ESS into AC section and high speed railway. This study analyses the composition of the regenerative ESS equipment installed in Yong-Jeong sectioning post, operational principle, charge and discharge algorithm and energy efficiency. The analysis shows that CO2 emissions can be reduced about 0.5 ton per a day. In addition, ESS helps saving the energy and the compensation of the voltage drop caused by the operation of high speed train when it is installed at the end of the feeder section. The number of high speed train will be increased continuously related to the electrification rate. Therefore, applying the ESS to high speed railway is expected to solve the instability of the feeder voltage and the equipment capacity problem caused by the high speed trains.

• Journal of Advanced Marine Engineering and Technology
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• 제36권4호
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• pp.430-436
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• 2012

본 연구에서는 납축전지가 장착된 소형 전기자동차의 여러 가지 주행 특성에 따른 배터리의 전압강하를 실증실험을 통하여 측정하였다. 실험을 통하여 2인승의 소형전기자동차의 에너지 소비량을 평가하고 주행거리 등을 점검하기 위하여 속도별 주행특성과 주행 중에 난방장치를 가동하였을 경우에 감소하는 주행거리를 평가하였다. 전기자동차의 주행속도는 10km/h에서 20km/h씩 증가시키면서 히터의 가동유무에 따른 에너지 소비량을 측정하였다. 실험결과 본 실험용 소형 전기자동차의 에너지효율이 가장 높은 경제속도는 35km/h로 나타났으며, 일회 충전으로 경제속도로 주행할 경우에 약 75km의 거리를 주행할 수 있으며, 일반적인 주행의 경우에는 약 58km를 주행할 수 있다. 또한 난방장치를 최대로 가동할 경우에는 약 35%의 에너지 소비가 증가하는 것을 알 수 있다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.240-244
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• 2001

Recycling process involving mechanical, thermal, hydrometallurgical, and sol-gel step has been applied to recover cobalt and lithium from spent lithium ion batteries and to synthesize LiCoO$_2$from leach liquor as cathodic active materials. Electrode materials containing lithium and cobalt could be concentrated with 2-step thermal and mechanical treatment. Leaching behaviors of the lithium and cobalt in nitric acid media was investigated in terms of reaction variables. Hydrogen peroxide in 1 M HNO$_3$solution turned out to be an effective reducing agent by enhancing the leaching efficiency. O f many possible processes to produce LiCoO$_2$, the amorphous citrate precursor process (ACP) has been applied to synthesize powders with a large specific surface area and an exact stoichiometry. After leaching used LiCoO$_2$with nitric acid, the molar ratio of Li/Co in the leach liquor was adjusted at 1.1 by adding a fresh LiNO$_3$solution. Then, 1 M citric acid solution at a 100% stoichiometry was also added to prepare a gelatinous precursor. When the precursor was calcined at 95$0^{\circ}C$ for 24 hr, purely crystalline LiCoO$_2$was successfully obtained. The particle size and specific surface area of the resulting crystalline powders were 20 пm and 30 $\textrm{cm}^2$/g, respectively The LiCoO$_2$powder was proved to have good characteristics as cathode active materials in charge/discharge capacity and cyclic performance.