• Title/Summary/Keyword: 4W

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A Study on Thermal Properties of Rocks from Gyeonggi-do Gangwon-do, Chungchung-do, Korea (경기도, 강원도, 충청도 일대의 암석 열물성 특성 연구)

  • Park, Jeong-Min;Kim, Hyoung-Chan;Lee, Young-Min;Song, Moo-Young
    • Economic and Environmental Geology
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    • v.40 no.6
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    • pp.761-769
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    • 2007
  • We made 712 thermal property measurements on igneous, metamorphic and sedimentary rock samples from Gyeonggi-do, Gangwon-do and Chungchung-do, Korea. The average thermal conductivities of igneous, metamorphic and sedimentary rocks are 3.58W/m-K, 4.16W/m-K and 4.53W/m-K, respectively. Thermal conductivity of granite and gneiss are 2.13-5.87W/m-K and 2.26-6.67W/m-K, with average values of 3.57W/m-K and 3.945W/m-K, respectively. The average of thermal diffusivities are $1.43mm^2/sec\;and\;1.55mm^2/sec$, respectively; the average of specific heat values are 0.914J/gK, 0.912J/gK for granite and gneiss samples, respectively. The thermal conductivity of a rock type generally have a wide range because it depends on various factors such as dominant mineral phase, micro-structure, anisotropy, and so on.

Research on operation stability of 7kW Inverter for short distance vehicle using SiC Hybrid module (SiC 하이브리드 모듈을 적용한 근거리용 7kW Inverter 동작 안정성에 대한 연구)

  • Jeon, Joon-Hyeok;Kyoung, Sin-Su;Kim, Hee-Jun
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.12 no.5
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    • pp.499-506
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    • 2019
  • This paper is concerned with the operating stability of 7kW inverter using SIC hybrid module and verifies the validity of the simulation results by comparing the result of the loss equation and the simulation result, Simulation results using Si module and SiC hybrid module are compared to compare switch loss and diode loss. Through the loss equation calculation, the conduction loss of SiC Hybrid module is 168W, switching loss is 9.3W, diode loss is 10.5nW, When compared with the simulation results, similar values were shown. As a result of comparing the simulation results of the Si module and the SiC Hybrid module, The total device loss of the Si module was 246.2W, and the total device loss of the SiC Hybrid module was 189.9W. The loss difference was 56.3W, which was about 0.8W. thereby verifying the reverse recovery characteristics of the SiC SBD. In addition, temperature saturation test was conducted to confirm the stability of SiC Hybrid module and Si module under high temperature saturation, In the case of the Si module, the output power was stopped at 4kW, and the SiC Hybrid module was confirmed to operate at 7kW. Based on this, an efficiency graph and a temperature graph are presented, and the Si module is graphed up to 4kW and the SiC Hybrid module is graphed up to 7kW.

SiH4 Soak Effects in the W plug CVD Process (텡스텐 플러그 CVD 공정에서 SiH4 Soak의 영향)

  • 이우선;서용진;김상용;박진성
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.1
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    • pp.1-4
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    • 2003
  • The SiH$_4$soak step is widely used to prevent the WF$_{6}$ attack to the underlayer metal using the chemical vapor deposition (CVD) method. Reduction or skipping of the SiH$_4$soak process time if lead to optimizing W-plug deposition process on via. The electrical characteristics including via resistance and the structure of W-film are affected by the time of SiH$_4$soak process. The possibility of elimination of SiH$_4$soak process is confirmed In the case of W- film grown on the stable Ti/TiN underlayer.

FPGA Design of Turbo Code based on MAP (MAP 기반 터보코드의 FPGA 설계)

  • Seo, Young-Ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.3C
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    • pp.306-313
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    • 2007
  • In this paper, we efficiently implemented turbo code algorithm in FPGA H/W(hardware) resource. The used turbo code algorithm has the characteristics; the size of constraint is 3, encoder type is 1/3, the size of random interleaver is 2048. The proposed H/W consists of MAP block for calculating alpha and delta using delta value, storing buffer for each value, multiplier for calculating lamda, and lamda buffer. The proposed algorithm and H/W architecture was verified by C++ language and was designed by VHDL. Finally the designed H/W was programmed into FPGA and tested in wireless communication environment for field availability. The target FPGA of the implemented H/W is VERTEX4 XC4VFX12-12-SF363 and it is stably operated in 131.533MHz clock frequency (7.603ns).

Nucleation and Growth Rate of CVD-W on TiN (TiN상에서의 CVD-W의 핵생상 및 성장속도)

  • Kim, Eui-Song;Lee, Chong-Mu;Lee, Jong-Gil
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1992.11a
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    • pp.28-30
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    • 1992
  • Long incubation period of W nucleation on the TiN glue layer is a serious problem in blanket W process. In this study we investigated the dependence of W nucleation and growth rate on the preparation method of the TiN film, deposition temperature, chemistry, $SiH_4/WF_6$ ratio and sputter etching, ion implantation, and $SiH_4$ flushing pre-treatments. Incubation periods of W nucleation and deposition rates of W growth on three different TiNs are in the order of TiN>RTP-TiN> annealed TiN and TiN${\leq}$RTP-TiN${\leq}$ annealed TiN, respectively. $\beta$-W is not found on TiN substrate even for high $SiH_4/WF_6$ ratio. Sputter etching pre-treatment increases incubation period of W nucleation, while it decreases deposition rate. $SiH_4$ flushing pre-treatment decreases incubation period, but it slightly decreases deposition rate.

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The studies on wrinkle recovery improvement for silk fabrics (견직물의 방추성 개선연구)

  • 김병호;정진영
    • Journal of Sericultural and Entomological Science
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    • no.11
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    • pp.23-29
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    • 1970
  • This experiment is to improve the wrinkle recovery (W.R.) of silk fabrics. The silk fabrics is creased very well, and the crease is the serious defection of it. This experiment is to improve the nature by use of formaldehyde on fabrics. The reagents used were HCl, CH$_3$COOH, CaC$_2$, HCHO, Na$_2$CO$_3$, NH$_4$OH, NaOH and NaHCO$_3$. The silk fabrics was treated, to compare 1 he influence of conditions, by varying the quantities of reagents and the temperature of solution, and the reaction time. The cotton fabrics and the viscose rayon were sunk with the silk at the same condition to be compared the influence. 1) Those of the most suitable temperature to improve for the better W.R. are 75$^{\circ}C$ for silk, 35-45$^{\circ}C$ for cotton, and no particular temperature under 75$^{\circ}C$ for viscose rayon. 2) The W.R. improvements after treated at the temperature of 1) were 11% for silk and 33.4% for cotton. 3) There are the best treating time for every fabrics. They were 60 to 90 min. for viscose rayon when HAC Ras used for solvent. It took, however, 60min. of the best time for silk, 120 min. for cotton, and 40 min. for viscose rayon when acetic anhydride instead of HAC was used. 4) It was possible to improve 16.6% of W.R. for silk at the most suitable treating time, 25.0% for cotton, and 13.3% for viscose rayon. 5) Acetic anhydride was rather more effective to improve W.R. of both silk and viscose rayon than HAC. 6) Treating time was also shorter in case of using acetic anhydride than HAC. 7) The improvement of W.R. were 8.3% for silk at the 10 to 14 ml. of HCHO the best volume, 21. 5% for cotton at 18m!. of HCHO, and 70% of for viscose rayon at 14 to 18ml. of HCHO. 8) The most effective quantity of HCI is 14 ml. for both silk and cotton. The W.R. improvement of silk was 22.2%, and that of cotton 19.5%. 9) The W.R. of 83.3% the best for silk and 61. 6% for cotton were gained when 4.2gr. of NaHCO$_3$ brings down the percent of W.R. for both silk and cotton. 10) The more NaOH and NH$_4$OH as neutralizing agents, the less effectivity of W.R. until the quantities of the reagents are reached to a special range which are 3. 3m!. for silk and 3.3-6.6 ml. for cotton, and then we can see the W.R. increasing as the quantities of reagents are increased. These facts were evident in case of silk and cotton. We can also see with this fact that the reminder of 〔OH$\^$-/〕 neutralizing 〔CH$\^$+/〕in solution makes it possible to treat formaldehyde on fabrics. 11) Low curing temperature was comparatively better for silk, and high temperature better for cotton. 12) The result of this experiment shows that the Improvement of W.R. for silk was possible to 94% which means 22% W.R. increase compared to the untreated silk. This effect also shows that the improvement to W '||'&'||' W (wash and wear) of silk will be possible.

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Design and Implementation of Software Utilizing The SDR Software Platform (SDR S/W 폴랫폼을 활용한 S/W 설계 및 구현)

  • Park, Uram;Lee, Jae-Gyun
    • Proceedings of the Korea Information Processing Society Conference
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    • 2016.10a
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    • pp.485-486
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    • 2016
  • 본 논문에서는 SDR SW 플랫폼을 기반으로 활용 분야에 적용될 수 있는 4종 S/W를 제안한다. SDR SW 플랫폼은 openAPI로 제공되어 확장성과 활용성 및 유연성 측면에 장점이 있다. 웹 서비스를 기반으로 구현한 4종 SW는 교육용, 경계용, 감시용, 교통용으로 각 S/W의 목적성에 따라 사용하는 파형과 밴드를 설정하여 운용하도록 구성하였고, 운용시에 발생한 데이터를 그래프, 도표 등의 시각적으로 사용자에게 정보를 제공한다. 교육용 S/W는 다중대역, 다중파형 설정 및 다양한 정보 제공, 경계용 S/W는 실외 특정 구역 감시, 감시용 S/W는 실내 침입자 탐지, 교통용 S/W는 실시간 차량 현황과 과속 탐지 등 각 S/W에 따라 특정 활용 목적에 기능을 구생하여 구현하였다.

Pigment and Monacolin K Content of Beni-koji Fermented with Soybean Curd Residue (비지홍국의 색소 및 Monacolin K 함량)

  • 윤은경;김영희;김순동
    • Food Science and Preservation
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    • v.10 no.3
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    • pp.360-364
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    • 2003
  • This study was conducted to investigate the preparation possibility of Beni-koji by Monascus pilosus using dried soybean curd residue(Biji). The additional effect of water(0-50%), glucose(0-10%, w/w), monosodium glutamate(0-0.l%, w/w) and citrus peel water extracts (0-0.5%, v/w) on the pigment and monacolin K content of the Biji Beni-koji were examined. Optimal added amounts of water was 20% of dried Biji. The highest pigment content(OD at 500 nm) of Biji Beni-koji was 1.06 in 10% glucose, 2.26 in 0.01% monosodium glutamate and 2.61 in 0.4% citrus peel water extracts. The content of monacolin K in the Biji Beni-koji added with 10% glucose, 0.01% monosodium glutamate and 0.4% citrus peel water extracts showed 96.38 mg%(w/w), 118.25 mg%(w/w) and 104.50 mg%(w/w), respectively.

Sonolysis of Trichloroethylene in a Continuous Flow Reactor with the Multi Ultrasound Irradiation (연속식 다중 초음파 반응조에서 TCE의 초음파 분해)

  • Lee, Min-Ju;Oh, Je-Ill
    • Journal of Korean Society of Environmental Engineers
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    • v.31 no.6
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    • pp.419-427
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    • 2009
  • To test applicability for continuous flow treatment of ultrasound technology, sonolysis of TCE aqueous solution using 584 kHz multi irradiation reactor was performed under batch and continuous flow conditions. Under batch condition (3 and 4 sides irradiation, 600 W), first order degradation rate constant of TCE was higher under 4 sides than 3 sides irradiation conditions, while the generation of $H_2O_2$ and chloride was similar under both irradiation conditions. Under continuous flow condition with 4 sides irradiation, removal efficiencies of TCE in steady-state were decreased from 83 to 48% with increasing flow rate from 67 to 300 mL/min at 600 W, and were increased from 14 to 75% with increasing acoustic power from 100 to 600 W at 100 mL/min. Removal efficiency of TCE in groundwater was decreased 10% compared to in distilled water at 100 mL/min and 600 W.

A Study on the Mycelial Growth of Agrocybe aegerita in Flask Culture. (플라스크배양에서 버들송이버섯 균사체 배양에 관한 연구)

  • 차월석;이명렬;조배식;박세영;오동규
    • Journal of Life Science
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    • v.14 no.4
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    • pp.560-566
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    • 2004
  • Agrocybe aegerita is Hymenomycetes fungus belonging to the order Agaricales and family of Bolbitiaceae. Much less is known about liquid culture of Agrocybe aegerita. Thus, the present study was to investigate the liquid cultural characteristics of Agrocybe aegerita my-celium. The optimal medium for the mycelial growth and density was ME medium, optimal tem-perature and initial pH were 25$\pm$1$^{\circ}C$ and 5.5, respectively. And optimal culture time for mycelial growth was 12 days. The modified optimal medium compositions were dextrin 3% (w/v), yeast extract 2% (w/w), MgSO$_4$0.05% (w/v), and KH$_2$PO$_4$0.15% (w/v). Under optimal culture conditions, the mycelial growth of modified optimal medium was higher than that of ME medium.