• 제목/요약/키워드: Gram

검색결과 3,600건 처리시간 0.031초

영상검색엔진을 위한 가중치 N-Gram색인 방법 (Weighted N-Gram Indexing for Image Search Engine)

  • 이상열;정성호;황병곤
    • 한국산업정보학회:학술대회논문집
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    • 한국산업정보학회 2002년도 추계공동학술대회
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    • pp.412-416
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    • 2002
  • 멀티미디어 검색 시스템들은 아직까지 내용 기반에 의한 검색기술이 실용적으로 쓰일 만큼 높은 성능을 보이고 있지 않기 때문에 텍스트에 의한 검색만을 지원하고 있는 실정이다. HTML 문서에 나타나는 텍스트 중 이미지 아래에 붙은 표제나 이미지 링크에 붙어 있는 텍스트를 골라내어 이미지의 색인 정보로 이용하여 텍스트를 추출하는 기법을 제안하였다. 텍스트를 추출하기 위해 N-Gram 색인 방법을 사용하였으며 한편 검색 효율을 높이기 위해서 질의 의도가 큰 단어에 가중치를 부여하였다.

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그람 양성균인 Bacillus subtilis와 그람 음성균인 escherichia coli에서 protein secretion에 중요 역할을 하는 secY에 대한 비교 연구 (A comparative study of the major component of the protein secretion machinery, secY, in gram positive bacillus subtilis and gram negative escherichia coli.)

  • 서주원
    • 미생물과산업
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    • 제17권1호
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    • pp.10-18
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    • 1991
  • A phylogenetic comparison of homologous protein can often supplement genetic and biochemical analysis by revealing conserved structures that are critical for function(Waugh et al., 1989). I therefore isolated a secY homologue from B. subtilis, a gram positive bacterium evolutionary distant from E. coli. The comparison and interplay between these two bacterial systems should contribute greatly to our understanding of the functions and interactions within systems evolved for protein translocation in both prokaryotic and eukaryotic organisms.

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봉선화의 항균활성성분(抗菌活性成分)과 항균력(抗菌力)에 관(關)한 연구(硏究) (Isolation and Antimicrobial Activity of a Naphthoquinone from Impatiens balsamina)

  • 강수철;문영희
    • 생약학회지
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    • 제23권4호
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    • pp.240-247
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    • 1992
  • Impatiens balsamina Linne(Balsaminaceae) known as 'BONG SUN HWA' in Korea and has been used for the treatment of scrofulosis, carbunculus and dysenteria etc. Bioassay-guided fractionation of MeOH extract from the whole plants of Impatiens balsamina has afforded a simple naphthoquinone derivative, 2-methoxy-1,4-naphthoquinone. The structure of this compound was established by spectroscopic methods. This compound possessed strong antifungal activity against Candida albicans, AspergiIlus niger, Crytococcus neoformans and Epidermophyton floccusum. The activity of 2-methoxy-1,4-naphthoquinone on E. floccusum $(MIC{\;}:{\;}5.0{\;}{\mu}g/ml)$ was the same potency as that of nystatin. It showed also strong antibacterial activity against gram-positive bacteria Bacillus subtilis as well as gram-negative bacteria Salmonella typhimurium. Although the activity of this compound on gram-negative bacteria was lower than that of gram-positive bacteria.

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THE COMBINATION EFFECT OF SULFAMETHOXAZOLE AND TRIMETHOPRIM AGAINST ANIMAL INTESTINAL BACTERIA

  • Nakai, Y.;Matsumoto, H.;Ogimoto, K.
    • Asian-Australasian Journal of Animal Sciences
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    • 제4권3호
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    • pp.281-284
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    • 1991
  • Combination effects of sulfamethoxazole (SMX) and trimethoprim (TMP) against nine gram positive bacterial strains and 43 gram negative bacterial strains which included 40 strains of animal intestinal bacteria were studied in vitro. Minimum inhibitory concentrations (MICs) of SMX and TMP alone and 20:1 (SMX : TMP) mixture (ST) were investigated by the method recommended by Ad Hoc Committee of the Japan Society of Chemotherapy for the Evaluation of Sensitivity Testing Methods for Sulfamethoxazole and Trimethoprim. MICs of ST were more potentiated than those of SMX alone in 8 of 9 gram positive strains and 40 of 43 gram negative strains. Especially, 38 strains of 40 intestinal bacteria showed significant susceptibility to ST as compared to SMX. These results suggest a strong synergistic activity of ST mixture against animal intestinal bacteria, The activity was considered to be comparable to those of other current antibiotics.

Characterization of an Oxygen-Dependent Inducible Promoter Systems, the nar Promoter of Escherichia coli, and Gram negative host strains

  • 이길호;조무환;이종원
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2001년도 추계학술발표대회
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    • pp.762-766
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    • 2001
  • The nar promoter of Escherichia coli was known to induce maximally under anaerobic or microaerobic conditions in the presence of nitrate. In this study, the nar promoter was tested to see whether the expression level of a reporter gene which fused lacZ gene at nar promoter's downstream, in the some gram negative host strains(Agrobacterium, Pseudomonas and Rhizobium). A nar promoter system(Combination of nar promoter and gram negative strain) was grown under aerobic conditions to absorbance at 600 nm of nearly 2.0 and then, the nar promoter was induced by lowering DO to 1-2% with alternating microaerobic and aerobic condition in the fermentor cultures, using different gram negative hosts. For a wild type nar promoter (pNW61), it was possible to maintain production of ${\beta}-galactosidase$ activity per cell(specific ${\beta}-galactosidase$ activity) at 14,000, 9600, 45 Miller units in the presence of 1% nitrate. and for a nitrate - independent nar promoter (pNW618) at 12,000, 10,400 and 58 Miller units in the absence of nitrate ion, respectively.

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Gram-Schmidt 직교화를 이용한 LIFS 영상 부호화법에 관한 연구 -부호화 고속 알고리즘- (A Study on LIFS Image Coding via Gram-Schmidt Orthogonalization - Fast Coding Algorithm -)

  • 유현배
    • 한국산학기술학회논문지
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    • 제4권2호
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    • pp.96-101
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    • 2003
  • 최근, 새로운 영상 부호화로서 프랙탈 부호화가 높은 압축률의 가능성으로 폭넓게 연구되고 있다. 프랙탈 부호화는 초기에 흑백 영상과 선영상의 압축 방식으로서 검토되었다. 더욱이 Jacquin은 프랙탈 변환(LIFS)을 제안하여 프랙탈 부호화를 농담 영상으로 확장하였다. 현재, Gram-Schmidt 직교화 방식을 이용한 YTKT의 LIFS방식 등은 정지 영상 압축의 국제표준 방식인 JPEG와 경합이 가능할 정도의 압축률이 얻어졌다. 본 연구에서는 YTKT방식의 직교화 연산 알고리즘의 연산량을 크게 삭감할 수 있는 방법을 제안한다.

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Antibacterial Activities of Phenolic Components from Camellia sinensis L. on Pathogenic Microorganisms

  • Shin, Jung-Sook;Chung, Ha-Sook
    • Preventive Nutrition and Food Science
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    • 제12권3호
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    • pp.135-140
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    • 2007
  • Antibacterial activities of the major phenolic components from Camellia sinensis L. were investigated against several pathogenic microorganisms including Gram-positive strains like Staphylococcus aureus ATCC 29213 and Streptococcus pyogens 308A; and Gram-negative strains like Escherichia coli ATCC 25922, Escherichia coli 078, Pseudomonas aeruginosa 9027, and Enterobacter cloacae 1321E. The MIC values demonstrate that both (-)-epicatechin and (-)-epigallocatechin were more considerably toxic against Staphylococcus aureus ATCC 29213 than the other two catechins like (-)-epicatechingallate and (-)-epigallocatechin-3-gallate. (-)-Epicatechingallate and (-)-epigallocatechin-3-gallate were most inhibitory against Escherichia coli ATCC 25922. As a result, (-)-epicatechin showed predominant antibacterial activities among tea varieties. The contents of major polyphenolic components such as four catechins, theaflavin, and quercetin were different according to fermentation processes. The total contents of four catechins were ranged from 13.81 to 1.33%, with (-)-epigallocatechin-3-gallate being dominant among tea varieties; theaflavin was found the characteristic pigment in fully-fermented black tea.

Gram 음성세균에 의한 Aroclor 분해에 미치는 환경요소의 영향 (Effects of Environmental Factors on Degradation of Aroclors by Gram-negative Bacteria)

  • 김치경;김문식
    • 미생물학회지
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    • 제28권2호
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    • pp.145-150
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    • 1990
  • The effects of environmental factors on degradation of Aroclor 1242 were investigated with four Gram-negative bacterial isolates. Their biodegradabilities of the Aroclor were well correlated to their growth rates on the Aroclor added as a sole carbon and energy source. The optimum concentration of the Aroclor for biodegradation of the substrate in MM2 medium was 0.5mg/ml in HK-100, HK-123, and MS-1003 strains, but 1 mg/ml in DJ-26 strain. The optimum temperature and pH were $30^{\circ}C$ and 7.0, respectively, for all the strains. On the basis of the results which the strain of DJ-26 showed the highest degradability of the Aroclor as well as the highest growth rate under the optimum environmental conditions, the bacterial isolate identified as Pseudomonas sp. was found to be a strain usable for treatment of the toxic and recalcitrant chemical pollutants, such as polychlorinated aromatic hydrocarbons.

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대칭 조건부 확률과 TF-IDF 기반 텍스트 분류를 위한 N-gram 특질 선택 (N-gram Feature Selection for Text Classification Based on Symmetrical Conditional Probability and TF-IDF)

  • 최우식;김성범
    • 대한산업공학회지
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    • 제41권4호
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    • pp.381-388
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    • 2015
  • The rapid growth of the World Wide Web and online information services has generated and made accessible a huge number of text documents. To analyze texts, selecting important keywords is an essential step. In this paper, we propose a feature selection method that combines a term frequency-inverse document frequency technique and symmetrical conditional probability. The proposed method can identify features with N-gram, the sequential multiword. The effectiveness of the proposed method is demonstrated through a real text data from the machine learning repository, University of California, Irvine.

정보검색 기법과 동적 보간 계수를 이용한 N-gram 언어모델의 적응 (N- gram Adaptation Using Information Retrieval and Dynamic Interpolation Coefficient)

  • 최준기;오영환
    • 대한음성학회지:말소리
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    • 제56호
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    • pp.207-223
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    • 2005
  • The goal of language model adaptation is to improve the background language model with a relatively small adaptation corpus. This study presents a language model adaptation technique where additional text data for the adaptation do not exist. We propose the information retrieval (IR) technique with N-gram language modeling to collect the adaptation corpus from baseline text data. We also propose to use a dynamic language model interpolation coefficient to combine the background language model and the adapted language model. The interpolation coefficient is estimated from the word hypotheses obtained by segmenting the input speech data reserved for held-out validation data. This allows the final adapted model to improve the performance of the background model consistently The proposed approach reduces the word error rate by $13.6\%$ relative to baseline 4-gram for two-hour broadcast news speech recognition.

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