• 제목/요약/키워드: Natural source

검색결과 2,100건 처리시간 0.03초

Microbial Modification of Extracellular Polysaccharides

  • Jin Woo Lee
    • Journal of Life Science
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    • 제9권1호
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    • pp.69-80
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    • 1999
  • Some trials to alter the structure of extracellular polysaccharides by means of biotransformation and microbial modification have been reported. Seaweed alginate was acetylated by intact and resting cells of Pseudomonas syringae ATCC 19304. Glucose analogs such as 3-O-methyl-D-glucose used as sole carbon sources was directly incorporated into curdlan by agrobacterium sp. ATCC 31749. The 2-amino-2-deoxy-D-glucose (glucosamine)and 2-acetamido-2-deoxy-D-glucose (N-acetylglucosamine) were incorporated into microbial cellulose by Acetobacter xylinum ATCC 10245. The changed monomeric composition in pullulan by Aureobasidium pullulans ATCC 42023 as well as zooglan by Zoogoea ramigera ATCC 25935 was another effect of glucose analogs used a carbon source. There was no effect of glucose analogs found in polysacharide-7 (PS-7) produced by Beijerinckia indica. ATCC 21423.

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A Study on the Environmental Load of Office Buildings in Seoul

  • Lee, Sang-Hyung;Lee, Yun-Gyu;Yang, Kwan-Seob;Ahn, Tae-Kyung;Lee, Seung-Eon;Park, Hyo-Soon
    • International Journal of Air-Conditioning and Refrigeration
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    • 제9권1호
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    • pp.58-64
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    • 2001
  • This study is to examine the emission quantity of $CO_2$ gas as the environmental load in office buildings. After the investigation of monthly consumption of each energy source(electricity and natural gas), it is analyzed that the $CO_2$ emission quantity of 34 office buildings surveyed is 22.4 kg-c/$m^2$-year, which consists of 17.5 kg-c/$m^2$-year by consurunlelectncif. and 4.9 kg-c/$m^2$-year by consuming natural gas. And the $CO_2$ emission quantity of each load in those buildings consists of 68% emitted by general electricity, 16% by cooling load and 16% by beating load. It is also proposed that the $CO_2$ emission quantity of cooling and heating load is profoundly pertinent to the variation of outdoor temperature.

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자연어 이해를 위한 적대 학습 방법 (Adversarial Learning for Natural Language Understanding)

  • 이동엽;황태선;이찬희;임희석
    • 한국정보과학회 언어공학연구회:학술대회논문집(한글 및 한국어 정보처리)
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    • 한국정보과학회언어공학연구회 2018년도 제30회 한글 및 한국어 정보처리 학술대회
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    • pp.155-159
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    • 2018
  • 최근 화두가 되고있는 지능형 개인 비서 시스템에서 자연어 이해(NLU) 시스템은 중요한 구성요소이다. 자연어 이해 시스템은 사용자의 발화로부터 대화의 도메인(domain), 의도(intent), 의미적 슬롯(semantic slot)을 분류하는 역할을 한다. 하지만 자연어 이해 시스템을 학습하기 위해서는 많은 양의 라벨링 된 데이터를 필요로 하며 새로운 도메인으로 시스템을 확장할 때, 새롭게 데이터 라벨링을 진행해야 하는 한계점이 존재한다. 이를 해결하기 위해 본 연구는 적대 학습 방법을 이용하여 풍부한 양으로 구성된 기존(source) 도메인의 데이터부터 적은 양으로 라벨링 된 데이터로 구성된 대상(target) 도메인을 위한 슬롯 채우기(slot filling) 모델 학습 방법을 제안한다. 실험 결과 적대 학습을 적용할 경우, 적대 학습을 적용하지 않은 경우 보다 높은 f-1 score를 나타냄을 확인하였다.

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Characterization of the purple nonsulfur bacterium, rhodopseudomonas palustris strain P-1, degrading ferulate

  • Hee, Hong-Duck;Kim, Kyung-Hwan;Lee, Jai-Youl
    • 미생물학회지
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    • 제30권6호
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    • pp.495-500
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    • 1992
  • Photosynthetic bacteria which can utilize ferulate as a sole carbon source for their metabolic activities were isolated from soils by liquid enrichment culture technique. The strain P-1 was selected by the highest capability of degrading ferulate in aerobic and anaerobic conditions. The strain P-1 was rod-shaped with its motility, strained gram negatively and could not utilize sulfur compounds. This strain has the bacteriochlorophyll a group I carotenoid and membrane structures like lamellae. As the results of physiological, morphological and cultural charactderistics, the isolate was identified as Rhodopseudomonas plaustris, one of the purple nonsulfer bacteria. The strain P-1 utilized 2mM/day in aerobic condition and 0.86 mM/day in anaerobic condition.

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Influence of Roasting Treatment on the Antioxidant Activities and Color of Burdock Root Tea

  • Lee, Darye;Kim, Choon Young
    • Preventive Nutrition and Food Science
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    • 제22권1호
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    • pp.21-29
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    • 2017
  • The major trend in the antioxidant market is the growing consumer demand for natural antioxidants. Tea, one of the most widely consumed beverages in the world, is an easy way to obtain antioxidant components from a natural source. Our objective was to develop burdock root tea (BRT) with potent antioxidant activity and good color quality. In order to obtain maximum antioxidant activity and quality, the effect of roasting was determined. The antioxidant capacities and total phenolic contents of BRT increased as roasting increased. The color of BRT became darker with increased roasting, extraction time, and amount of burdock roots. Color of BRT was also positively correlated with total antioxidant capacity. Roasting significantly enhanced the total antioxidant activities and color quality of BRT. These results suggest that roasting BRT increases beneficial antioxidant components from burdock roots.

분리행렬의 가중 내적 제한조건을 이용한 FDICA 알고리즘의 수렴속도 향상 (Improvement of convergence speed in FDICA algorithm with weighted inner product constraint of unmixing matrix)

  • 전성일;배건성
    • 말소리와 음성과학
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    • 제7권4호
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    • pp.17-25
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    • 2015
  • For blind source separation of convolutive mixtures, FDICA(Frequency Domain Independent Component Analysis) algorithms are generally used. Since FDICA algorithm such as Sawada FDICA, IVA(Independent Vector Analysis) works on the frequency bin basis with a natural gradient descent method, it takes much time to converge. In this paper, we propose a new method to improve convergence speed in FDICA algorithm. The proposed method reduces the number of iteration drastically in the process of natural gradient descent method by applying a weighted inner product constraint of unmixing matrix. Experimental results have shown that the proposed method achieved large improvement of convergence speed without degrading the separation performance of the baseline algorithms.

Synthesis of Diamond Thin Film by Helicon Plasma Chemical Vapor Deposition

  • Hyun, Jun-Won;Kim, Yong-Kin
    • Transactions on Electrical and Electronic Materials
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    • 제1권1호
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    • pp.1-5
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    • 2000
  • Diamond films have been achieved on Si(100) substrates using helicon plasma chemical vapor deposition(HPCVD), Gas mixtures with methane and hydrogen have been used. The growth characteristics were investigated by means of X-ray photoelectroton spectroscopy, Atomic force microscopy and X-ray diffraction. We obtained a plasma density as high as 10$\^$10/~10$\^$11/ cm$\^$-3/ by helicon source. The smooth(100) faces of submicron diamond crystallites were found to exhibit pyramidal shaped architecture, The XPS spectrum for the nucleation layer indicates the presence of diamond at 285.4 eV, close to the reported value of 285.5 eV for diamond , XRD results demonstrates the existence of polycrystalline diamond as the diamond (111) and (220) peaks.

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Neural Learning Algorithms for Independent Component Analysis

  • 최승진
    • 전기전자학회논문지
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    • 제2권1호
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    • pp.24-33
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    • 1998
  • Independent Component analysis (ICA) is a new statistical method for extracting statistically independent components from their linear instantaneous mixtures which are generated by an unknown linear generative model. The recognition model is learned in unsupervised manner so that the recovered signals by the recognition model become the possibly scaled estimates of original source signals. This paper addresses the neural learning approach to ICA. As recognition models a linear feedforward network and a linear feedback network are considered. Associated learning algorithms for both networks are derived from maximum likelihood and information-theoretic approaches, using natural Riemannian gradient [1]. Theoretical results are confirmed by extensive computer simulations.

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An Anacardic acid Analog from the Jellyfish-derived Fungus Paecilomyces variotii

  • Liu, Juan;Li, Famei;Lee, Yoon-Mi;Li, Jian Lin;Hong, Jong-Ki;Yoon, Won-Duk;Kim, Eui-Kyung;Jung, Jee-H.
    • Natural Product Sciences
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    • 제18권1호
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    • pp.8-12
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    • 2012
  • An anacardic acid analog (1) was isolated from the fungus Paecilomyces variotii which was derived from the giant jellyfish Nemopilema nomurai. Compound 1 was isolated from a natural source for the first time and was evaluated for antibacterial activity against human and marine pathogens, including MDR (multidrugresistant) strains. Compound 1 exhibited mild antibacterial activity against Escherichia coli DC 2, Streptococcus iniae, and methicillin-resistant Staphylococcus aureus 3089 (MRSA).

Determination of Silybin B in the Different Parts of Silybum marianum using HPLC-UV

  • Rodriguez, Joyce P.;Quilantang, Norman G.;Lee, Ju Sung;Lee, Jeong Min;Kim, Hyun Young;Shim, Jae Suk;Lee, Sanghyun
    • Natural Product Sciences
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    • 제24권2호
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    • pp.82-87
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    • 2018
  • Silymarin is the standardized extract from Silybum marianum which consists mainly of flavonoids and polyphenols. It is highly regarded for its hepatoprotective ability. Silybin B is a flavonolignan and one of the active components of silymarin. The content of silybin B in various parts of S. marianum was analyzed by HPLC-UV. Results show that the extract of seeds contain the highest amount of silybin B (7.434 mg/g DW). The petioles of S. marianum showed a low content of silybin B. This study revealed that seeds of S. marianum contain high amount of silybin B and could be a good source of the compound.