• 제목/요약/키워드: SI cycle

검색결과 600건 처리시간 0.028초

대형 소프트웨어과제 관리 및 개발 모형에 관한 시스템 통합적 연구 (A Study on Management and Development Models of Large-Sized Software Projects Based On System Integration)

  • 한영근;이규봉;권순기
    • 산업경영시스템학회지
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    • 제19권40호
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    • pp.29-36
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    • 1996
  • In order to accomplish large-sized information systems successfully, one of the most important factor is the system integration(SI) of individual software projects which consist of the systems. Developers of each project should consider aspects of SI through the development cycle, and managers of the entire system should manage, control, and evaluate each from an SI point of view. In this research, management models for the system managers, development models for the developers of unit projects, and standardized output documents for the management and evaluation purpose are presented based on the SI concepts.

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비휘발성 메모리 응용을 위한 ALD법을 이용한 HfO2 절연막의 특성 (Properties of HfO2 Insulating Film Using the ALD Method for Nonvolatile Memory Application)

  • 정순원;구경완
    • 전기학회논문지
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    • 제59권8호
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    • pp.1401-1405
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    • 2010
  • We have successfully demonstrated of metal-insulator-semiconductor (MIS) capacitors with $HfO_2$/p-Si structures. The $HfO_2$ film was grown at $200^{\circ}C$ on H-terminated Si wafer by atomic layer deposition (ALD) system. TEMAHf and $H_2O$ were used as the hafnium and oxygen sources. A cycle of the deposition process consisted of 0.1 s of TEMAHf pulse, 10 s of $N_2$ purge, 0.1 s of $H_2O$ pulse, and 60 s of $N_2$ purge. The 5 nm thick $HfO_2$ layer prepared on Si substrate by ALD exhibited excellent electrical properties, including low leakage currents, no mobile charges, and a good interface with Si.

비휘발성 메모리 응용을 위한 ALD법을 이용한 $Al_2O_3$ 절연막의 특성 (Properties of $Al_2O_3$ Insulating Film Using the ALD Method for Nonvolatile Memory Application)

  • 정순원;이기식;구경완
    • 전기학회논문지
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    • 제58권12호
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    • pp.2420-2424
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    • 2009
  • We have successfully demonstrated of metal-insulator-semiconductor (MIS) capacitors with $Al_2O_3/p-Si$ structures. The $Al_2O_3$ film was grown at $200^{\circ}C$ on H-terminated Si wafer by atomic layer deposition (ALD) system. Trimethylaluminum [$Al(CH_3)_3$, TMA] and $H_2O$ were used as the aluminum and oxygen sources. A cycle of the deposition process consisted of 0.1 s of TMA pulse, 10 s of $N_2$ purge, 0.1 s of $H_2O$ pulse, and 60 s of $N_2$ purge. The 5 nm thick $Al_2O_3$ layer prepared on Si substrate by ALD exhibited excellent electrical properties, including low leakage currents, no mobile charges, and a good interface with Si.

Hafnium Oxide Nano-Film Deposited on Poly-Si by Atomic Layer Deposition

  • Wei, Hung-Wen;Ting, Hung-Che;Chang, Chung-Shu
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.496-498
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    • 2005
  • We reported that high dielectric hafnium oxide nano-film deposited by thermal atomic layer deposition on the poly-silicon film (poly-Si). The poly -Si film was produced by plasma enhanced chemical vapor deposition and excimer laser annealing. We used the hafniu m chloride ($HfCl_4$) and water as the precursors and analyzed the hafnium oxide film by transmission electron microscope and secondary ion mass spectrometer. Hafnium oxide produced by the ALD method showed very good coverage on the rough surface of poly-Si film. While deposited with 200 cycles, these hafnium oxide films revealed a relatively smooth surface and good uniformity, but the cumulative roughness produced by the incomplete reaction was apparent when the amount of deposition cycle increased to 600 cycles.

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리튬이온전지용 비정질 탄소 도전재의 표면적 및 흑연화도에 따른 SiOx 음극 활물질 특성 연구 (Effect of Surface Area and Crystallinity of Amorphous Carbon Conductive Agent in SiOx Anode on the Performance of Lithium Ion Battery )

  • 강형규;김성수
    • 한국전기전자재료학회논문지
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    • 제36권1호
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    • pp.29-35
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    • 2023
  • Herein we investigated the effect of the conductive agent on the electrochemical performance of the SiOx anode. SiOx anodes have a relatively low volume expansion (~160%) compared to Pure-silicon, but have a problem in that they have a poor electrical conductivity characteristic. In this study, physical and electrochemical measurements were performed using two 0-dimensional amorphous carbon conductive agents with different crystallinity and surface area. The crystal structure of the conductive agents and the local graphitization degree were analyzed through XRD and Raman, and the surface area of the particles was observed through BET. In addition, the electrical performance according to the graphitization degree of the conductive agents was confirmed through a 4-point probe. As a result of the electrochemical cycle and rate performance, it was confirmed that the performance of SiOx using a conductive agent having a low graphitization degree and a high surface area was improved. The results in this study suggest that the graphitization degree and surface area of the amorphous carbon conductive agent may play an important role in the SiOx electrode.

주형 합성법을 통해 합성된 다공성 주석 산화물을 적용한 리튬이차전지용 음극재 연구 (Template Synthesis of Ordered-Mesoporous Tin Oxide for Lithium-ion Battery Anode Materials)

  • 서경주;최재철;이용민;고창현
    • 전기화학회지
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    • 제17권2호
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    • pp.86-93
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    • 2014
  • 5 nm의 중형기공(mesopore)을 지녔으며 5~7 nm 굵기의 산화주석($SnO_2$) 나노선 다발이 잘 정렬된 meso-$SnO_2$를 주형합성법을 이용해서 제조하였다. 또한 주형합성법을 변형시켜서 5~7 nm 굵기의 동일한 나노선 다발 사이에 존재하는 중형기공에 주형으로 사용되었던 실리카($SiO_2$)를 일부 남긴 meso-$SnO_2$와 실리카의 복합체인 meso-$SnO_2$/$SiO_2$도 제조하였다. X-선 회절, 질소흡착법, 투과전자현미경을 이용해서 meso-$SnO_2$와 meso-$SnO_2$/$SiO_2$의 구조를 확인하였다. meso-$SnO_2$/$SiO_2$는 meso-$SnO_2$에 비해서 충방전시 발생하는 부피 팽창을 완화할 수 있을 것으로 예측했으며, 순환전압전류곡선, 교류 임피던스 분석, 충방전 전압 Profile 변화를 통해 부피 팽창 완화 효과를 확인하였다. 하지만, 수명 특성 측면에서는 구조 제어 효과가 미비하여, 향후 이를 개선하는 연구가 진행되어야 한다.

리튬이온이차전지용 고효율 음극(SiO-Graphite) (High Coulombic Efficiency Negative Electrode(SiO-Graphite) for Lithium Ion Secondary Battery)

  • 신혜민;도칠훈;김동훈;김효석;하경화;진봉수;김현수;문성인;김기원;오대희
    • 전기화학회지
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    • 제11권1호
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    • pp.47-50
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    • 2008
  • 현재 상용화 되어있는 흑연의 저용량 문제를 해결하기 위해 실리콘이나 주석계 등 고용량 비탄소계 음극전극재료들이 연구되고 있다. 이 중 산화실리콘(SiO)은 초기 충전(환원)과정에서 Li이 삽입되면서 $Li_2O$생성으로 비가역 비용량이 발생하여 초기 싸이클에서 쿨롱효율이 낮고, 싸이클링에 따라 리튬 탈 삽입 과정의 비용량이 증가하는 특징으로 실제의 전지를 설계할 시 문제점을 가진다. 본 연구에서는 고용랑 특성을 나타내는 비탄소계 실리콘을 포함하는 리튬이차전지용 음극활물질과 흑연의 복합체를 제조하여 흑연으로 실리콘의 부피팽창을 완화시키고, 사이클 특성을 향상시키는 실리콘(SiO-Graphite) 재료를 개발하고, 산화실리콘과 흑연 복합체의 높은 비가역 용량의 해소와 싸이클에 따른 리튬 탈삽입 과정의 용량증가를 해소하기 위한 전처리를 통하여 초기 효율을 향상한 전극의 제조에 대하여 연구하였다.

$SiH_2Cl_2와 NH_3$를 이용하여 원자층 증착법으로 형성된 실리콘 질화막의 특성 (The Characteristics of silicon nitride thin films prepared by atomic layer deposition method using $SiH_2Cl_2 and NH_3$)

  • 김운중;한창희;나사균;이연승;이원준
    • 한국진공학회지
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    • 제13권3호
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    • pp.114-119
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    • 2004
  • Si 원료물질로 $SiH_2Cl_2$, N 원료물질로 $NH_3$를 사용하여 증착온도 $550^{\circ}C$에서 P-type Si (100) 기판위에 실리콘 질화막을 원자층 증착 방법으로 형성하고 물리적, 전기적 특성을 평가하였다. 증착된 박막의 두께는 증착 주기의 횟수에 대해 선형적으로 증가하였고, Si와 N 원료물질의 공급량이 $3.0\times10^{9}$ L 일 때 0.13 nm/cycle의 박막 성장속도를 얻을 수 있었다. 원자층 증착된 박막의 물리적 특성을 기존의 저압화학증착 방법에 의해 증착된 박막과 비교한 결과, 원자층 증착 방법을 사용함으로써 기존의 방법보다 증착온도를 $200 ^{\circ}C$이상 낮추면서도 굴절률 및 습식에칭 속도 측면에서 유사한 물성을 가진 실리콘 질화막을 형성할 수 있었다. 특히, 원자층 증착된 박막의 누설 전류밀도는 3 MV/cm의 전기장에서 0.79 nA/$\textrm{cm}^2$로서 저압화학증착 방법에 의해 증착된 질화막의 6.95 nA/$\textrm{cm}^2$보다 우수하였다.

Down-regulation of the cyclin E1 oncogene expression by microRNA-16-1 induces cell cycle arrest in human cancer cells

  • Wang, Fu;Fu, Xiang-Dong;Zhou, Yu;Zhang, Yi
    • BMB Reports
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    • 제42권11호
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    • pp.725-730
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    • 2009
  • Cyclin E1 (CCNE1), a positive regulator of the cell cycle, controls the transition of cells from G1 to S phase. In numerous human tumors, however, CCNE1 expression is frequently dysregulated, while the mechanism leading to its dysregulation remains incompletely defined. Herein, we showed that CCNE1 expression was subject to post-transcriptional regulation by a microRNA miR-16-1. This was evident at protein level of CCNE1 as well as its mRNA level. Further evident by dual luciferase reporter assay revealed that two evolutionary conserved binding sites on 3' UTR of CCNE1 were the direct functional target sites. Moreover, we showed that miR-16-1 induced G0/G1 cell cycle arrest by targeting CCNE1 and siRNA against CCNE1 partially phenocopied miR-16-1-induced cell cycle phenotype whereas substantially rescued anti-miR-16-1- induced phenotype. Together, all these results demonstrate that miR-16-1 plays a vital role in modulating cellular process in human cancers and indicate the therapeutic potential of miR-16-1 in cancer therapy.

Successful treatment of a child with citrullinemia

  • Lee, Key-Hyoung;Park, Moon-Sung;Hahn, Si-Hoon
    • Journal of Genetic Medicine
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    • 제1권1호
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    • pp.5-10
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    • 1997
  • The amino acids formed by degradation of proteins ingested produce ammonia. The ammonia which is broken down and excreted as urea through a process known as the Klebs-Hensleit cycle or the urea cycle (Rezvani, 1995). The urea cycle consists of five enzymes necessary for the synthesis of carbamyl phosphate, citrulline, argininosuccinate, arginine, and urea: carbamyl phosphate synthetase (CPS), ornithine transcarbamylase (OTC), argininosuccinate synthetase (AS), argininosuccinate lyase (AL), and arginase (ARG) (Lloyd, 1992). Congenital deficiencies of the enzymes involved in the urea cycle are diseases that are almost fatal without treatment, showing symptoms like vomiting, lethargy, dyspnea, and coma due to hyperammonemia coming from the accumulation of ammonia and metabolic precursors resulting from the deficiency of one of these enzymes (Batshaw and Brusilow, 1983). Among these, the disease manifested by the congenital deficiency of argininosuccinate synthetase (AS) which is associated with the formation of argininosuccinate in citrulline is called argininosuccinate synthetase deficiency or citrullinemia. There have been two reports on this so far in Korea; one in July 1987 by Kim et al. and the other by Park et al. in 1995. We are to report a case of successful treatment of a child with citrullinemia who was transferred to our hospital due to dyspnea, lethargy, feeding difficulties, convulsions and cyanosis together with some document studies related to this case.

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