• 제목/요약/키워드: PNU

검색결과 322건 처리시간 0.027초

Ectopic Expression of Mitochondria Endonuclease Pnu1p from Schizosaccharomyces pombe Induces Cell Death of the Yeast

  • Oda, Kaoru;Kawasaki, Nami;Fukuyama, Masashi;Ikeda, Shogo
    • BMB Reports
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    • 제40권6호
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    • pp.1095-1099
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    • 2007
  • Endonuclease G (EndoG) is a mitochondrial non-specific nuclease that is highly conserved among the eukaryotes. Although the precise role of EndoG in mitochondria is not yet known, the enzyme is released from the mitochondria and digests nuclear DNA during apoptosis in mammalian cells. Schizosaccharomyces pombe has an EndoG homolog Pnu1p (previously named SpNuc1) that is produced as a precursor protein with a mitochondrial targeting sequence. During the sorting into mitochondria the signal sequence is cleaved to yield the functionally active endonuclease. From the analogy to EndoG, active extramitochondrial Pnu1p may trigger cell killing by degrading nuclear DNA. Here, we tested this possibility by expressing a truncated Pnu1p lacking the signal sequence in the extramitochondrial region of pnu1-deleted cells. The truncated Pnu1p was localized in the cytosol and nuclei of yeast cells. And ectopic expression of active Pnu1p led to cell death with fragmentation of nuclear DNA. This suggests that the Pnu1p is possibly involved in a certain type of yeast cell death via DNA fragmentation. Although expression of human Bak in S. pombe was lethal, Pnu1p nuclease is not necessary for hBak-induced cell death.

역전파 학습 신경망을 이용한 한글 숫자 인식에 관한 연구 (A Study on the Handwritten Korean Numeric Recognition using a Backpropagation Learning Neural Network)

  • 박창민;박귀순;김대원;이동춘;김명원;배현주;차의영
    • 한국정보과학회 언어공학연구회:학술대회논문집(한글 및 한국어 정보처리)
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    • 한국정보과학회언어공학연구회 1989년도 한글날기념 학술대회 발표논문집
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    • pp.137-141
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    • 1989
  • 본 논문에서는 신경망 구조의 한 모델인 feed-forward multi-layered network에 역전파 학습(back-propagation learning) 기법을 이용하여 필기체 한글 숫자를 인식하고 그 가능성을 보였다. 문자 인식에 있어 입력 대상의 모양이 왜곡되거나, 대상의 크기 혹은 위치의 변화 등과 같은 잡음 (noise)에 대해서 정확히 대상을 인식하는 데는 대상의 구조 추출에 크게 관여되므로 한글의 구조 추출에 적합하다고 생각되는 bar mask 투사법을 제안하였다. 모델의 학습을 필기체 한글 숫자 16자의 입력 패턴과 타겟 ( target) 입력의 쌍을 이용해 학습시켰다. 또한, 모델의 인식 정도를 측정해 보기 위해 시험패턴을 적용하여 훈련된 패턴과 훈련되지 않은 패턴간의 인식률을 비교하여 보았다.

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습식 브레이크의 소음 저감에 대한 연구 (Study on the Reduction of Wet-Brake Noise)

  • 구자함;권순홍;정성원;박종민;최원식;김종순;권순구
    • 한국기계가공학회지
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    • 제14권1호
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    • pp.57-62
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    • 2015
  • The wet brakes used on a forklift often produce noise upon engagement. The elimination or reduction of this squeal noise is an important task for the improvement of the comfort of those operating these machines. In this paper, a test rig was developed for the testing of brake noise, and the squeal noise was measured with this apparatus. Automatic transmission fluid and grooves in the material of the friction-plate pad were found to be the main factors causing squeal noise. In order to identify the characteristics of this type of noise, signal analyses of the noise were conducted using different frequency spectra. The experimental results showed that the viscosity of the automatic transmission fluid and the groove pattern on the friction-plate pad largely affected the reduction of the wet brake squeal noise made by an industrial forklift.

MEMS CMP에서 모니터링 시스템을 이용한 슬러리 특성 (The Surry Characteristic Using Monitoring System in MEMS CMP)

  • 박성민;정석훈;박범영;이상직;정원덕;장원문;정해도
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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    • pp.573-574
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    • 2006
  • The planarization technology of Chemical-mechanical polishing(CMP), used for the manufacturing of multi-layer various material interconnects for Large-scale Integrated Circuits (LSI), is also readily adaptable as an enabling technology in MicroElectroMechanical System (MEMS) fabrication, particularly polysilicon surface micromachining. However, general LSI device CMP has partly distinction aspects, the pattern scale and material sorts in comparison with MEMS CMP. This study performed preliminary CMP tests to identify slurry characteristic used in general IC device. The experiment result is possible to verify slurry characteristic in MEMS structure material.

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