• 제목/요약/키워드: bulk-type

검색결과 640건 처리시간 0.03초

새로운 와이어 직조 다공질 금속의 압축 특성 (Compressive Characteristics of New Wire-woven Cellular Metal)

  • 고경득;이기원;강기주
    • 대한기계학회논문집A
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    • 제34권11호
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    • pp.1659-1666
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    • 2010
  • WBD(wire-woven bulk diamond)라고 명명한 와이어로 직조된 다공질 금속의 새로운 형태를 소개한다. WBD 는 기계적 열 특성과 공학적 응용면에서 몇 년 전에 소개되어진 WBK(wire-woven bulk Kaogme)와 같이 나선형 와이어로 구성된다. WBK 에서는 각 교차점에서 3 개의 와이어가 접하나 WBD 에서는 4 개의 와이어가 서로 접하여 배열된다. 압축하중 하에서 WBD 의 기계적 거동을 조사하고 그 결과를 WBK 와 비교하였다. 같은 세장비(d/c)에서 WBD 의 밀도 및 강도는 WBK 의 약 2 배이나, WBD 의 강성도는 WBK 보다 그만큼 높지 않다.

BSCCO 초전도 한류기의 동시퀜치 및 내력 시험 (Equal Quench and Endurance Test of the BSCCO Superconducting Fault Current Limiter)

  • 심정욱;박권배;이방욱;오일성;임성우;김혜림;현옥배
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 제38회 하계학술대회
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    • pp.933-934
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    • 2007
  • We fabricated and tested a resistive type superconducting fault current limiter (SFCL) based on BSCCO-2212 bulk coils. Each bulk coils of the SFCL was designed to have the rated voltage of 220 $V_{rms}$ and the critical current($I_C$) of 320$\sim$340 A at 77K. Ten components in series, make the SFCL having the rated voltage of 2.2 $kV_{rms}$ for equal quench test. The fault test was conducted at an input voltage of 2.2 $kV_{rms}$ and fault current of 25 $kA_{rms}$. In addition, we examined the endurance characteristics for all bulk coils through repeat fault test. Test results shows that the SFCL successfully limited the fault current of 25$kA_{rms}$ to below $7{\sim}8kA_{p}$ within minimum 1.1msec after fault occurred. All bulk coils quenched together upon faults and shared the rated voltage evenly. The endurance test results show an equivalent among repeat fault test. During the quench process, average temperature of all bulk coils did not exceed 250 K, and the SFCL was totally safe during the whole operation.

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SOI 소자 셀프-히팅 효과의 3차원적 해석 (Three-Dimensional Analysis of Self-Heating Effects in SOI Device)

  • 이준하;이흥주
    • 반도체디스플레이기술학회지
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    • 제3권4호
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    • pp.29-32
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    • 2004
  • Fully depleted Silicon-on-Insulator (FD-SOI) devices lead to better electrical characteristics than bulk CMOS devices. However, the presence of a thin top silicon layer and a buried SiO2 layer causes self-heating due to the low thermal conductivity of the buried oxide. The electrical characteristics of FDSOI devices strongly depend on the path of heat dissipation. In this paper, we present a new three-dimensional (3-D) analysis technique for the self-heating effect of the finger-type and bar-type transistors. The 3-D analysis results show that the drain current of the finger-type transistor is 14.7% smaller than that of the bar-type transistor due to the 3-D self-heating effect. We have learned that the rate of current degradation increases significantly when the width of a transistor is smaller that a critical value in a finger-type layout. The current degradation fro the 3-D structures of the finger-type and bar-type transistors is investigated and the design issues are also discussed.

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Efficient Thermal Annealing for FBAR Devices

  • Song Hae-il;Mai Linh;Yoon Giwan
    • Journal of information and communication convergence engineering
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    • 제3권4호
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    • pp.167-171
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    • 2005
  • In this paper, the resonance characteristics of SMR-type FBAR devices annealed by three different annealing methods are investigated and compared. The resonance characteristics could be effectively improved by the proposed efficient annealing method which optimizes the annealing conditions. It seems very useful for improving the performance of the SMR-type FBAR devices as a cost-effective way.

전기화학적 처리에 의한 다공질 실리콘 산화막의 형성과 감습 특성 (Formation and humidity-sensing properties of porous silicon oxide films by the electrochemical treatment)

  • 최복길;민남기;류지호;성영권
    • 대한전기학회논문지
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    • 제45권1호
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    • pp.93-99
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    • 1996
  • The formation properties and oxidation mechanism of electrochemically oxidized porous silicon(OPS) films have been studied. To examine the humidity-sensitive properties of OPS films, surface-type and bulk-type humidity sensors were fabricated. The oxidized thickness of porous silicon layer(PSL) increases with the charge supplied during electrochemical humidity sensor shows high sensitivity at high relative humidity in low temperature. The sensitivity and linearity can be improved by optimizing a porosity of PSL. (author). refs., figs.

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A semi-automatic cell type annotation method for single-cell RNA sequencing dataset

  • Kim, Wan;Yoon, Sung Min;Kim, Sangsoo
    • Genomics & Informatics
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    • 제18권3호
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    • pp.26.1-26.6
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    • 2020
  • Single-cell RNA sequencing (scRNA-seq) has been widely applied to provide insights into the cell-by-cell expression difference in a given bulk sample. Accordingly, numerous analysis methods have been developed. As it involves simultaneous analyses of many cell and genes, efficiency of the methods is crucial. The conventional cell type annotation method is laborious and subjective. Here we propose a semi-automatic method that calculates a normalized score for each cell type based on user-supplied cell type-specific marker gene list. The method was applied to a publicly available scRNA-seq data of mouse cardiac non-myocyte cell pool. Annotating the 35 t-stochastic neighbor embedding clusters into 12 cell types was straightforward, and its accuracy was evaluated by constructing co-expression network for each cell type. Gene Ontology analysis was congruent with the annotated cell type and the corollary regulatory network analysis showed upstream transcription factors that have well supported literature evidences. The source code is available as an R script upon request.

Impact of Nanoparticulates on Respiratory Health Effects

  • Warheit David B.
    • 한국환경성돌연변이발암원학회:학술대회논문집
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    • 한국환경성돌연변이발암원학회 2005년도 춘계 국제심포지엄 및 학술대회
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    • pp.40-50
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    • 2005
  • [ $\cdot$ ] Risk is a product of Hazard and Exposure $\cdot$ Cannot assume that nanomaterials are the same as their bulk counterpart $\cdot$ Each particle-type should be tested on a casse-by-case basis

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레이저 형광여기법(LIF)를 이용한 복잡 난류유동장의 혼합특성에 관한 연구 (A Study on the Mixing Characteristics in Complex Turbulent Flow by a Laser Induced Fluorescence Method)

  • 김경천;정은호
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 춘계학술대회논문집E
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    • pp.542-547
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    • 2001
  • A non-intrusive Planar Laser-Induced Fluorescence(PLIF) technique was applied to study the turbulent mixing process in a Rushton turbine reactor. Instantaneous and ensemble averaged concentration fields are obtained by measuring the fluorescence intensity of Rhodamine B tracer excited by a thin Nd:Yag laser sheet illuminating the whole center plane of the stirred tank. The gray level images captured by a 14-bit cooled CCD camera can be transformed to the local concentration values using a calibration matrix. The dye injection point was selected at the tank wall with three quarter height (3/4H) from the tank bottom to observe the mixing characteristics in upper bulk flow region. There exist distinct two time scales: the rapid decay of mean concentration in each region after the dye infusion reflects the large scale mixing while the followed slow decay reveals the small scale mixing. The temporal change of concentration probability functions conjectures the two sequential processes in the batch type mixing. An inactive column of water existed above the impeller disk, in which the fluid rotates with the shaft but is isolated from the mean bulk flow.

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