• 제목/요약/키워드: subtractive

검색결과 289건 처리시간 0.029초

감산형 간섭제거기법을 적용한 DS-CDMA 다중사용자 검파기의 성능분석 (Performance Evaluation of Multi-User Detectors Employing Subtractive Interference Cancellation Schemes for a DS-CDMA System)

  • 서정욱;김영철;오창헌;고봉진;조성준
    • 한국항행학회논문지
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    • 제6권1호
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    • pp.17-26
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    • 2002
  • 본 논문에서는 비교적 구조가 간단하고 계산량이 적어 시스템에 적용하기가 쉬운 감산형 간섭제거(subtractive interference cancellation) 기법의 대표적인 방식인 순차 간섭제거(SIC : Successive Interference Cancellation) 기법과 병렬 간섭제거(PIC : Parallel Interference Cancellation) 기법의 성능을 분석하고, 이들을 결합한 복합 간섭제거(HIC : Hybrid Interference Cancellation) 기법의 성능을 분석한다. 잡음과 MAI (Multiple Access Interference)가 존재하는 채널환경에서 간섭제거를 위해 데이터를 추정할 때 연판정(soft decision)을 수행하는 SIC 기법과 HIC 기법의 오율식을 각각 유도하고, 각 간섭제거 방식의 성능을 수치계산과 시뮬레이션을 통해 각각 구하여 비교, 분석하였다. 그 결과, HIC 기법은 전력제어의 완전성 여부에 관계없이 다른 방식들에 비해 MAI를 효과적으로 제거하여 BER(Bit Error Rate) 성능을 향상시키며 시스템의 용량도 증가시킴을 알 수 있었다. 그 이유는 HIC 기법에서 전단에 사용하는 SIC에 의해 불완전 전력제어 하에서 발생되는 원근문제(near-far problem)가 해결되고, 후단에 사용하는 PIC에 의해 성능 개선이 이루어질 수 있기 때문이다.

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Detection of Differentially Expressed Genes in Glioblastoma by Suppression Subtractive Hybridization

  • Yu, Na-Mi;Ahn, Jung-Yong;Choi, Eun-Jin;Hong, Yong-Kil;Kim, Tai-Gyu;Kim, Chang-Hyun;Lee, Kyu-Sung;Kim, Dong-Seok;Kim, Jin-Kyeoung
    • Journal of Korean Neurosurgical Society
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    • 제37권6호
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    • pp.443-448
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    • 2005
  • Objective: A variety of genetic alterations in human glioblastoma comprises signal transduction and cell cycle arrest control of cellular processes. Subtractive hybridization is potentially a faster method for identifying differentially expressed genes associated with a particular disease state. Using the technique of subtraction, we isolated novel genes that are overexpressed in glioblastoma tissue as compared to normal brain tissue. Methods: We evaluated the differential expression of genes in each of hybridizing tester and driver cDNAs to digested 130 clones. After sequencing of 130 clones and homology search, this study performed to determine mRNA expression of the unknown gene, "clone 47", in brain tissue, glioblasoma, and several cancer cell lines by reverse transcription-polymerase chain reaction (RT-PCR). To test the time course for Go-phase arrest, serum stimulation and expression at various times for RT-PCR performed. Results: We identified 23 novel genes by BLAST of the digested 130 clones. The expressions of "clone 47" mRNA of glioblastoma and several cancer lines were significantly higher than normal brain tissues and several normal cell lines. We confirmed the mRNA expression of "clone 47" was up-regulation for $0.5{\sim}1hr$ of WI-38 cell differentiation. Conclusion: The novel gene, "Clone 47" is upregulated in glioblastoma tissue and several cancer cell lines. This gene is time dependent activation during time course of serum stimulation. This result suggests that "clone 47" playa role in brain tumorigenesis and the activation of this "clone 47" may be necessary for the development of cancer.

Identification of Genes Involved in Primordial-primary Follicle Transition by Suppression Subtractive Hybridization

  • Park, Chang-Eun;Yoon, Se-Jin;Jeon, Eun-Hyun;Kim, Young-Hoon;Lee, Sook-Hwan;Lee, Kyung-Ah
    • 한국수정란이식학회:학술대회논문집
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    • 한국수정란이식학회 2002년도 국제심포지엄
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    • pp.98-98
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    • 2002
  • Recruitment of primordial follicles(PMF) is crucial for female fertility. however, factors and mechanisms that regulate this process is poorly understood. The present study was conducted to obtain an inclusive view of the gene expression and to identify novel factors and their pathways of regulating PMF arrest and/or growth initiation. Ovaries from one-day neonatal(consists of oocyte and PMF) and five-day old(consists of PMF and primary follicles, PRIF) mice were collected, either total RNA or mRNA was isolated, and suppression subtractive hybridization(SSH) was used to isolate and clone genes that differentially expressed in day 1 and day 5 ovaries. Confirmation that some of these genes are differentially expressed in PMF and/or in PRIF was accomplished by using laser captured microdissection(LCM), RT-PCR. in situ hybridization(ISH) and/or immunohistochemistry(IHC). In toto, 357 clones were sequenced and analyzed by BLAST and RIKEN program. Sequences of 330 clones significantly matched database entries while 27 clones were novel. Forty-two and 47 different genes were identified as differentially expressed in day 1 and day 5 ovaries, respectively, while 7 genes were expressed in both stages of ovaries. Day 5-subtracted library included several genes known as markers far growing follicles, such as ZP2, MATER, and fetuin. Among the genes with assigned functions, 23.8% was associated with cell cycle/apoptosis regulation, 7.1% with cellular structure, 11.9% with metabolism, 26.2% with signal transduction, and 31.0% with gene/protein expression in day 1; while 10.6%, 17.0%, 23.5%, 25.5%, and 23.4% in day 5, respectively. Genes such as GDF-8, Lats2, Septin2, and Weel were the highly expressed genes in PMF, while HSP84, Laminin2, MATER, MTi7, PTP, and Wrn were highly expressed genes in PRIF. We have successfully discovered list of genes expressed in day 1 and day 5 ovaries and confirmed that some of them are differentially expressed in PMF and/or PRIF. Gene expression profile from the present study would provide insight for the future study on the mechanism(s) involved in primordial-primary follicular transition. This work was Supported by Korean Health 21 RND Project, Ministry of Health and Welfare, Korea (01-PJ10-PG6-01GN13-0002).

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저온 스트레스에 발현이 유도되는 콩의 L-asparaginase 유전자의 분리 (Isolation of cDNA Encoding Low Temperature-inducible L-asparaginase from Soybean (Glycin max))

  • 박성환;김기영;진량;이재헌
    • Journal of Plant Biotechnology
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    • 제29권2호
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    • pp.99-104
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    • 2002
  • Suppression subtractive hybridization (SSH)를 통해 저온에 의해 발현이 유도되는 cDNA들을 분리하였고, 그 중 하나인 slti182는 asparaginase 유전자들과 높은 유사성을 보였다. Slti182의 전체 cDNA인 GmASP1은 1258 bp 길이에 326개 아미노산으로 구성된 긴 Open reading frame (ORF)를 포함하고 있었다. GmASP1 단백질은 애기장대의 putative asparaginase (AB012247)와 84%의 유사성을 보였으나, 애기장대의 다른 isoform(Z34884)와는 55%의 유사성을 나타내었다. GmASP1 유전자는 저온 처리 후 3시간째부터 발현이 유도되어 6시간째에 최대발현을 나타내었고, 이후 점차 감소하여 48시간에는 저온처리전 수준으로 되돌아왔다. 또한, 식물체를 저온에서 48시간 둔 후에 다시 상온으로 옮겼을 때, 정상수준으로 떨어진 GmASP1의 발현이 다시 증가하는 양상을 보였다. 이러한 결과로 볼 때, GmASP1이 저온 스트레스에 반응 초기의 단백질 합성 촉진에 중요한 역할을 할 것으로 사료된다.

제작방법에 따른 임시 수복용 레진의 파절강도 및 굴곡강도에 관한 연구 (Comparison analysis of fracture load and flexural strength of provisional restorative resins fabricated by different methods)

  • 조원탁;최재원
    • 대한치과보철학회지
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    • 제57권3호
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    • pp.225-231
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    • 2019
  • 목적: 본 연구의 목적은 적층 가공법, 절삭 가공법 및 직접법에 의해 제작된 임시 수복용 레진의 파절강도와 굴곡강도를 비교하는 것이다. 재료 및 방법: 각각 다른 방법들로 제작된 5가지 방법의 임시 수복용 레진을 조사하였다: Stereolithography apparatus (SLA) 3D 프린터를 이용한 적층 가공법(S3Z군), 두 가지 digital light processing (DLP) 3D 프린터를 이용한 적층 가공법(D3Z군, D3P군), 절삭 가공법(MIL군), 전통적인 방식의 직접법(CON군). 파절강도 시험은 각 방법을 이용하여 소구치 형태의 시편을 준비하였고, 굴곡강도 시험은 각 방법을 이용하여 직사각형의 바 형태의 시편 ($25{\times}2{\times}2mm$)을 준비하여 universal testing machine (UTM)을 사용하여 평가하였다. 결과: 적층 가공을 이용해 제작된 S3Z군, D3Z군, D3P군의 파절강도는 MIL군 및 CON군의 파절강도와 유의한 차이가 없었다 (P > .05/10 = .005). 한편, S3Z군, D3P군, MIL군의 굴곡강도는 CON군의 굴곡강도보다 높았으나 (P < .05), D3Z군의 굴곡강도는 CON군보다 낮았다 (P < .05). 결론: 본 연구의 한계 내에서 적층 가공법으로 제작된 임시 수복용 레진은 절삭 가공법과 기존에 사용되었던 직접법에 의해 제작된 임시수복용 레진과 임상적으로 유사한 파절강도, 굴곡강도를 나타냈다.

Identification of Differentially Expressed Genes by Methylmercury in Neuroblastoma cell line using suppression subtractive hybridization (SSH) and cDNA Microarray

  • Kim, Youn-Jung;Chang, Suk-Tai;Yun, Hye-Jung;Ryu, Jae-Chun
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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    • pp.189.2-190
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    • 2003
  • Methylmercury (MeHg), one of the heavy metal compounds. can cause severe damage to the central nervous system in humans. Many reports have shown that MeHg is poisonous to human body through contaminated foods and has released into the environment. Despite many studies on the pathogenesis of MeHg-induced central neuropathy, no useful mechanism of toxicity has been established so far. (omitted)

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