• 제목/요약/키워드: w

검색결과 47,701건 처리시간 0.066초

W-TiN 금속 게이트를 사용한 금속-산화막-반도체 소자의 특성 분석 (Investigation of the W-TiN gate for Metal-Oxide-Semiconductor Devices)

  • 윤선필;노관종;양성우;노용한;장영철;김기수;이내응
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 2000년도 하계종합학술대회 논문집(2)
    • /
    • pp.318-321
    • /
    • 2000
  • We showed that the change of Ar to $N_2$flow during the TiN deposition by the reactive sputtering decides the crystallinity of LPCVD W, as well as the electrical properties of the W-TiN/SiO$_2$Si capacitor. In particular, the threshold voltage can be controlled by the Ar to $N_2$ratio. As compared to the results obtained from the LPCVD W/SiO$_2$/Si MOS capacitor, the insertion of approximately 50 nm TiN film effectively prohibits the fluorine diffusion during the deposition and annealing of W films, resulting in negligible leakage currents at the low electric fields.

  • PDF

3GPP 물리계층 시뮬레이터 설계를 이용한 W-CDMA 시스템 성능 분석 (Performance Analysis of W-CDMA Systems Using 3GPP Physical-Layer Simulator design)

  • 나인학;윤성재;김병기;우연식;김철성
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 2001년도 제14회 신호처리 합동 학술대회 논문집
    • /
    • pp.963-966
    • /
    • 2001
  • The wideband DS-CDMA (W-CDMA) system is one of the candidates for the next generation mobile communication system known as IMT-2000. The important concept of W-CDMA is the introduction of intercell asynchronous operation. In this paper, we design and analyze the system level simulator for the International Mobile Tele communication - 2000 (IMT-2000) 3-rd generation partnership project (3GPP) system. We confirm how the simulator works by BER over different Eb/NO. This study will be expected to use as reference data in the development of asynchronous IMT-2000. In this paper, we analyze a physical layer of W-CDMA system and design a transmitter and receiver by using ADS (Advanced Design System). Also, we simulated a link level performance in Rayleigh fading channel environment. This study will be useful in the analysis and design of W-CDMA system.

  • PDF

2차 가공이 와이어 컷 방전가공면 표면조도 분포에 미치는 영향에 관한 연구 (A study on the effects of second cut on the roughness of surfaces treated with wire-cut electric discharge machining (W-EDM))

  • 김세환;최계광
    • Design & Manufacturing
    • /
    • 제6권1호
    • /
    • pp.58-62
    • /
    • 2012
  • Unlike conventional single special cut methods, W-EDM is a combination of multiple-effects. This study focuses on the effects of second cut on the roughness of surfaces treated with W-EDM. W-EDM is, to a large extent, typical unmanned-machining equipment, which represents NC machining equipment that allows long-time full automation. W-EMD is getting popular as a precise machining technology and STD11 is frequently used in press die manufacture. In this study, the former is applied to the latter to look at the effects of second cut on the roughness of surfaces treated with W-EDM.

  • PDF

Glucoamylase Production in Batch and Fed-Batch Solid State Fermentation: Effect of Maltose or Starch Addition

  • Bertolin, Telma Elita;Jorge Alberto Vieira Costa;Gean Delise Leal Pasquali
    • Journal of Microbiology and Biotechnology
    • /
    • 제11권1호
    • /
    • pp.13-16
    • /
    • 2001
  • Maltose and soluble starch were used as secondary sources of carbon for glucoamylase production by Aspergillus awamori in solid state fermentation. During batch cultivation, maltose above 2.5%(w/w) repressed glucoamylase production, but, by adding either 2.5% (w/w) maltose or 1.25% (w/w) soluble starch to fed-batch cultivations, glucoamylase activity was increased by 15% and 170% over standard medium, respectively. The data showed that maltose is a weak inducer of glucoamylase production in solid stat fermentation.

  • PDF

풍력발전기 소음 성능 실증 (Noise Performance Test and Evaluation of a Wind Turbing Generator)

  • 김석현;김태형;박무열
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2005년도 춘계학술대회논문집
    • /
    • pp.241-245
    • /
    • 2005
  • This study introduces the wind turbine (W/T) noise evaluation procedure required in the international standard (IEC 61400-11) and monitoring system for the evaluation. Noise emission characteristics of a 750kW W/T generator is investigated. Test and evaluation are performed on J48 W/T model which is under operation in Daekwanryung Wind Test Site. With the noise signal, meteorological data and W/T operational data are monitored in real time by the integrated monitoring system using LabVIEW. From the measured noise data, acoustic power level and tonality of the W/T are estimated under the wind speeds required by the international standard.

  • PDF

KEPCO 전기자동차용 충전기 (KEPCO Charger for Electric Vehicle)

  • 정문규;양승권;송택호;김철우
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2011년도 제42회 하계학술대회
    • /
    • pp.1278-1279
    • /
    • 2011
  • 본 논문은 KEPCO에서 개발되어 실증이 완료된 3가지 종류의 충전기에 대해 설명한 것이다. 전기자동차용 충전기는 충전시간 및 용량에 따라 급속충전기, 완속충전스탠드, 홈충전기로 분류할 수 있으며, 설치장소 및 용도를 고려하여 설치하는 것이 바람직하다. 따라서 급속충전기는 50[kW]급의 기본형과 100[kW]급의 분리형으로, 완속충전스탠드는 7.7[kW]급의 기본형과 15.4[kW]급의 2소켓형으로, 홈충전기는 3.3 [kW]급의 단독형과 7.7[kW]급의 공동형으로 나누어 개발하도록 하였다. 본 논문에서는 이러한 충전기들을 정의하고, 구성을 설명하며, 기능 및 사양을 제시하고자 한다. 이를 통해 KEPCO에서 개발된 충전기와 충전기술 등이 국내 전기자동차 시장 활성화와 충전인프라 조기구축에 기여할 수 있음을 보이고자 한다.

  • PDF

인터로킹 블록의 품질에 미치는 물시멘트비와 화학혼화제의 영향 (Influences of Water to Cement Ratio and Chemical Admixtures on the Quality of Inter-Locking Block)

  • 이상태;김기철;신병철;김진선;한천구
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 1998년도 가을 학술발표회 논문집(I)
    • /
    • pp.157-160
    • /
    • 1998
  • KS F 4419, which is dealt with the Inter-Locking block, states that water to cement ratio for manufacturing inter-locking block should be less than 25% and in KS F4419, the use of admixture is shown to be reluctant to recommend. In this paper, reinvestigation of some regulations in KS F 4419 are carried out. According to the experimental results, as W/C increases, flexural strength and compressive strength are tended to decrease, whereas they increases within certain range, Flexural strength and compressive strength have higher values in 1:2(W/C=35%), 1:4(W/C=45%) and 1:6(W/C=55%) of mix proportions. Moreover they have rather higher values with the containment of high range AE water-reducing agent. The absorption ratios decrease with the increase of W/C and the containment of high range AE water-reducing agent. Therefore, the regulations on the W/C and admixture in KS F 4419 reguire revision.

  • PDF

Modeling Service based on XML Schema for MPEG Multimedia Middleware

  • Hendry Hendry;Kim Mun-Churl
    • 한국멀티미디어학회지
    • /
    • 제10권1호
    • /
    • pp.114-128
    • /
    • 2006
  • Recently MPEG (Moving Picture Experts Group) has started a new standardization activity called MPEG Multimedia Middleware (M3W). The M3W supports multimedia applications Independent of hardware and software such as operating systems so that the portability and interoperability of multimedia applications are greatly improved. In doing so, the M3W adopts the concept of a service-based middleware. The M3W standardizes a set of multimedia Application Programming Interfaces (APIs) and their implementations can be pro vided by third parties In the form of services. In this paper, we introduce the usage of XML metadata in describing the standard multimedia APIs and third party's services and also we explain the role of the XML Schema within the M3W in providing transparent access from application to the M3W services.

  • PDF

M/W대역 디지털 방송중계용 FPU 무선전송 시스템 분석과 시뮬레이터 설계 (Analysis and Simulator Design of Portable Microwave Digital FPU Transmission System)

  • 강희조;조성언;최용석
    • 한국정보통신학회논문지
    • /
    • 제7권4호
    • /
    • pp.658-666
    • /
    • 2003
  • 본 논문에서는 M/W 디지털 방송중계용 주파수의 공유방안에 관한 연구의 기초단계로서 AWGN 채널 환경에서 M/W 디지털 방송중계용 FPU(Field Pick Up) 무선전송 시스템 규격 및 특성을 분석하고 시뮬레이터 설계를 통하여 시스템 성능을 분석하였다. 국내 방송 중계용의 경우 디지털화 진행이 추진되고 있는바 향후 M/W 방송중계용 주파수 재배치를 위한 간섭평가 및 국내 방송중계용 표준화에 대한 기초 자료로 활용하고자 한다.

Pyridine의 수첨탈질 반응에 있어서 텅스텐 촉매에 대한 조촉매의 영향 (Influence of Promoters on the Tungsten - Catalysts in Hydrodenitrogenation of Pyridine)

  • 신동헌;박종희;김경림
    • 한국대기환경학회지
    • /
    • 제3권1호
    • /
    • pp.1-12
    • /
    • 1987
  • A series of supported sulfided Ni-W/$\gamma-Al_2O_3$ and Co-W/$\gamma-Al_2O_3$ catalysts with different nickel and cobalt contents were studied in the hydrodenitrogenation of pyridine dissolved in n-heptane. The ranges of experimental conditions were at the temperatures between 453 and 753 K, and the pressures between 30 and 50 Bar. The catalytic activities with different nickel and cobalt contents were shown to be maximum at Ni/Ni+W = 0.2 - 0.3, Co/Co+W = 0.3 - 0.4. Pyridine conversion increased with pressure and temperature and the step of piperidine formation was found to be irreversible. The reaction orders in Ni-W/$\gamma-Al_2O_3$ and Co-W/$\gamma-Al_2O_3$ catalysts were the first with respect to pyridine and reaction rate constants decreased with increase of initial pyridine concentration and their activation energies were 12.98 and 9.23 kcal/mol, respectively.

  • PDF