• Title/Summary/Keyword: maeA

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Oleoresin Content and Physiological Activities of Fresh Red pepper by microwave-Assiated Extraction (마이크로웨이브 추출공정에 의한 홍고추 올레오레진의 함량 및 기능적 특성)

  • 권영주;정승원;김현구;권중호
    • Food Science and Preservation
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    • v.7 no.1
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    • pp.74-79
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    • 2000
  • Water and ethanol extracts of fresh red peppers were obtained by two methods, conventional extraction (CE) and microwave-assiated extraction (MAE), under different extraction conditions. Red pepper oleoresins extracted by CE and MAE were examined in oleoresin yield and physiological activities. The proper extraction time of MAE was about 5 minutes, whereas that of CE was 2 hours. therefore extraction time was decreased drastically by MAE but there was no significance in oleolesin yields. the electron donating abilities also showed negligible difference between two extracts obtained by CE and MAE, and 80% level in all extracts . the nitrite scavenging effect was reduced by increased of ph , and showed a high elimination effect over 85% at ph 1.2. All extracts had a high tyrosinase inhibitory effects of 100%. The angiotensin I-conventing enzyme effect showed higher activity with over 80% in MAE than 70% level in CE. the capsanthin was extracted with ethanol and was 11.4 and 12.9 ${\mu}$moles per 1 g of fresh red pepper by CE and MAE, respectively.

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Effect of Magneto-acoustic Emission of Reactor Pressure Vessel Materials Irradiated by Neutrons (중성자에 조사된 원자로 압력용기 재료(SA508)의 Magneto-acoustic emission 효과)

  • Ok, Chi-Il;Lee, Jong-Kyu;Park, Duck-Gun;Hong, Jun-Hwa;Kim, Jang-Whan
    • Journal of the Korean Society for Nondestructive Testing
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    • v.19 no.6
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    • pp.433-438
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    • 1999
  • Magneto-acoustic emission (MAE) energy and hardness were measured in the reactor pressure vessel steel (SA508 Steel) for the various neutron fluence, irradiated dose up to $10^{18}n/cm^2$. The hardness was nearly a constant up to $10^{16}n/cm^2$, but it was rapidly increased with an increase of the neutron irradiation above $10^{17}n/cm^2$. It may be considered that the increase of hardness is due to the hindrance of dislocation motion induced defect clusters by irradiation. On the other hand. the MAE energy was slowly decreased as the neutron irradiation increased up to $10^{16}n/cm^2$ and it was rapidly decreased with an increase of the neutron irradiation above $10^{17}n/cm^2$. The decrease of the MAE energy may be considered as an increase of the defect clusters which is very sensitive to the $90^{\circ}$ domain wall motion. Furthermore, the change of MAE energy and hardness had nearly a linear relationship. but the change of MAE energy was more significant than the change of the hardness. Therefore, MAE may be considered as a very useful technique for the nondestructive evaluation of irradiation damage.

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A Comprehensive Performance Evaluation in Collaborative Filtering (협업필터링에서 포괄적 성능평가 모델)

  • Yu, Seok-Jong
    • Journal of the Korea Society of Computer and Information
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    • v.17 no.4
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    • pp.83-90
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    • 2012
  • In e-commerce systems that deal with a large number of items, the function of personalized recommendation is essential. Collaborative filtering that is a successful recommendation algorithm, suffers from the sparsity, cold-start, and scalability restrictions. Additionally, this work raises a new flaw of the algorithm, inconsistent performance of recommendation. This is also not measurable by the current MAE-based evaluation that does not consider the deviation of prediction error, and furthermore is performed independently of precision and recall measurement. To evaluate the collaborative filtering comprehensively, this work proposes an extended evaluation model that includes the current criteria such as MAE, Precision, Recall, deviation, and applies it to cluster-based combined collaborative filtering.

A Study on the Maximizing Coverage for Recommender System

  • Lee, Hee-Choon;Lee, Seok-Jun;Park, Ji-Won;Kim, Chul-Seoung
    • 한국데이터정보과학회:학술대회논문집
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    • 2006.11a
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    • pp.119-128
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    • 2006
  • The similarity weight, the pearson's correlation coefficient, which is used in the recommender system has a weak point that it cannot predict all of the prediction value. The similarity weight, the vector similarity, has a weak point of the high MAE although the prediction coverage using the vector similarity is higher than that using the pearson's correlation coefficient. The purpose of this study is to suggest how to raise the prediction coverage. Also, the MAE using the suggested method in this study was compared both with the MAE using the pearson's correlation coefficient and with the MAE using the vector similarity, so was the prediction coverage. As a result, it was found that the low of the MAE in the case of using the suggested method was higher than that using the pearson's correlation coefficient. However, it was also shown that it was lower than that using the vector similarity In terms of the prediction coverage, when the suggested method was compared with two similarity weights as I mentioned above, it was found that its prediction coverage was higher than that pearson's correlation coefficient as well as vector similarity.

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Comparative Effects of Microwave-Assisted Process Under Atmospheric Pressure Condition and Conventional Process on Extraction Efficiencies Ginseng Components (상압조건의 마이크로파 공정과 현행 방법에 의한 인삼근 유용성분의 추출효율 비교 연구)

  • 권중호;김경은
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.3
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    • pp.586-592
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    • 1999
  • Microwave assisted extraction(MAE) is known as a more environmental friendly process with economic advantages in terms of less time, less solvent, less energy and less wastes than the current time consuming reflux method. It was applied to develop a rapid extraction method for soluble ginseng components that are major materials used for the processing of ginseng products. In a comparative study between pre established MAE(ethanol 60%, power 80 W, process time 4 min$\times$5) and current extraction method(ethanol 80%, temp. 85oC, time 8 hr$\times$5), MAE was more efficient than the current method to obtain an extract yield(soluble solid), but it was insufficient to extract individual ginsenosides, total phenols, reducing components and acidic polysaccharides. MAE with 80% ethanol by 5 times showed, however, that its extraction efficiency on soluble solid, crude saponin, major ginsenosides, and the other components was equal or superior to that of the current method, indicating that ethanol concentration is one of the critical parameters influencing the MAE process. The quality of ginseng extracts from MAE was assured by evaluating the corresponding standards and by comparing TLC and HPLC patterns with the control.

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Cloning and Sequence Analysis of the Cellobiohydrolase I Genes from Some Basidiomycetes

  • Chukeatirote, Ekachai;Maharachchikumbura, Sajeewa S.N.;Wongkham, Shannaphimon;Sysouphanthong, Phongeun;Phookamsak, Rungtiwa;Hyde, Kevin D.
    • Mycobiology
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    • v.40 no.2
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    • pp.107-110
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    • 2012
  • Genes encoding the cellobiohydrolase enzyme (CBHI), designated as cbhI, were isolated from the basidiomycetes Auricularia fuscosuccinea, Pleurotus giganteus, P. eryngii, P. ostreatus, and P. sajor-caju. Initially, the fungal genomic DNA was extracted using a modified cetyltrimethyl ammonium bromide (CTAB) protocol and used as a DNA template. The cbhI genes were then amplified and cloned using the pGEM-T Easy Vector Systems. The sizes of these PCR amplicons were between 700~800 bp. The DNA sequences obtained were similar showing high identity to the cbhI gene family. These cbhI genes were partial consisting of three coding regions and two introns. The deduced amino acid sequences exhibited significant similarity to those of fungal CBHI enzymes belonging to glycosyl hydrolase family 7.

Prevalence of Haplorchis taichui and Haplorchoides sp. Metacercariae in Freshwater Fish from Water Reservoirs, Chiang Mai, Thailand

  • Nithikathkul, Choosak;Wongsawad, Chalobol
    • Parasites, Hosts and Diseases
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    • v.46 no.2
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    • pp.109-112
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    • 2008
  • A parasitological investigation on trematode metacercariae was made on 62 freshwater fishes of 13 species in northern Thailand; Cyclocheilichthys apogon, Puntioplites proctozysron, Labiobarbus siamensis, Barbodes gonionotus, Barbodes altus, Henicorhynchus siamensis, Osteochilus hasselti, Notopterus notopterus, Mystacoleucus marginatus, Anabas testudineus, Systomus orphoides, Morulius chrysophykadian, and Hampala macrolepidota. The fish were caught over the summer period (February-May 2007) from 2 Chiang Mai water reservoirs, i.e., the Mae Ngad (UTM 47Q E 503200, 47Q N 2119300) and the Mae Kuang Udomtara (UTM 47Q E 513000, 47Q N 2092600) Reservoirs in Chiang Mai province, Thailand. The prevalence of heterophyid (Haplorchis taichui and Haplorchoides sp.) metacercariae in these fish was 83.9% and 74.2% in the Mae Ngad and Mae Kuang Udomtara Reservoirs, respectively. The highest intensity of heterophyid metacercariae in H. siamensis in the Mae Ngad was 120.4 and that in P. proctozysron in the Mae Kuang Udomtara was 180.0. The fish, A. testudineus, C. apogon, and M. chrysophykadian, were not found to be infected with H. taichui metacercariae. The results show that the freshwater fish in Chiang Mai water reservoirs are heavily infected with H. taichui and Haplorchoides sp. metacercariae.

Comparison of Conventional Solvent Extraction, Microwave-Assisted Extraction, and Ultrasound-Assisted Extraction Methods for Paclitaxel Recovery from Biomass (바이오매스로부터 파클리탁셀 회수를 위한 전통적 용매 추출, 마이크로웨이브를 이용한 추출, 초음파를 이용한 추출 방법 비교)

  • Kim, Jin-Hyun
    • Korean Chemical Engineering Research
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    • v.58 no.2
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    • pp.273-279
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    • 2020
  • In this study, conventional solvent extraction (CSE), microwave-assisted extraction (MAE), and ultrasound-assisted extraction (UAE) were compared for the recovery of paclitaxel from biomass. As a result of investigating the effect of the extraction solvent type (acetone, chloroform, ethanol, methanol, methylene chloride), methanol was the most suitable for all extraction methods. In the case of MAE and UAE using methanol, most of the paclitaxel (> 95%) was recovered by only one extraction. The recovery rate of paclitaxel increased with the increase of extraction temperature (25-45 ℃), microwave power (50-150 W), and ultrasonic power (180-380 W) for MAE and UAE. In addition, SEM analysis showed that the biomass surface structure was slightly corrugated in CSE, while in the MAE and UAE, it was very rough and destroyed by strong impact.

A Strategy to Increase Microbial Hydrogen Production, Facilitating Intracellular Energy Reserves

  • Lee, Hyo Jung;Park, Jihoon;Lee, Joo-Young;Kim, Pil
    • Journal of Microbiology and Biotechnology
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    • v.26 no.8
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    • pp.1452-1456
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    • 2016
  • Overexpression of the genes encoding phosphoeneolpyruvate carboxykinase (pckA) and NAD-dependent malic enzyme (maeA) facilitates higher intracellular ATP and NAD(P)H concentrations, respectively, under aerobic conditions in Escherichia coli. To verify a hypothesis that higher intracellular energy reserves might contribute to H2 fermentation, wild-type E. coli strains overexpressing pckA and maeA were cultured under anaerobic conditions in a glucose minimal medium. Overexpression of pckA and maeA enabled E. coli to produce 3-times and 4-times greater H2 (193 and 284 nmol, respectively) than the wild type (66 nmol H2). The pckA and maeA genes were further overexpressed in a hydrogenase-3-enhanced E. coli strain. The hydrogenase-3-enhanced strain (W3110+fhlA) produced 322 nmol H2, whereas the ATP-enhanced strain (W3110+fhlA+pckA) produced 50% increased H2 (443 nmol). Total H2 in the NAD(P)H-enhanced strain (W3110+fhlA+maeA) was similar to that in the control strain at 319 nmol H2. Possible explanations for the contribution of the increased cellular energy reserves to the enhanced hydrogen fermentation observed are discussed based on the viewpoint of metabolic engineering strategy.

A Two-Stage Fast Block Matching Algorithm Using Mean Absolute Error of Neighbor Search Point (이웃 탐색점에서의 평균 절대치 오차를 이용한 2단계 고속 블록 정합 알고리듬)

  • Cheong, Won-Sik;Lee, Bub-Ki;Kwon, Seong-Geun;Han, Chan-Ho;Shin, Yong-Dal;Sohng, Kyu-Ik;Lee, Kuhn-Il
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.37 no.3
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    • pp.41-56
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    • 2000
  • In this paper, we propose a two-stage fast block matching algorithm using the mean absolute error (MAE) of neighbor search point that can reduce the computational complexity to estimate motion vector while the motion estimation error performance is nearly the same as full search algorithm (FSA) In the proposed method, the lower bound of MAE 6at current search point IS calculated using the MAE of neighbor search point And we reduce the computational complexity by performing the block matching process only at the search point that has to be block matched using the lower bound of MAE The proposed algorithm is composed of two stages The experimental results show that the proposed method drastically reduces the computational complexity while the motion compensated error performance is nearly kept same as that of FSA.

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