• Title/Summary/Keyword: N-GRAM

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Structure and Properties of Cation Exchange Membrane made of Sulfonated Polyethersulfone

  • Nah, Sung-Soon;Lee, Sung-Min;Ryul, Min-Byung;Lee, Chang-So
    • Proceedings of the Membrane Society of Korea Conference
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    • 1999.07a
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    • pp.115-115
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    • 1999
  • In this work a new process was developed for the sulfonation of the chemicallly stable engineering polymer polyethersulfone as membrane materials for electrodialysis or a flow battery applications. Commercially available polyethersulfone polymer was partially sulfonated using a CSA sulfonating agent in a dichloromethane solvent, which sulfonated polyethersulfone with various sulfonation levels have been prepared. Sulfonated polyethersulfone (SPES) membranes with different ion capacities were prepared for the purpose of identifying cation exchange membrane properties, in an attempt to find a low cost replacement for Nafion, which most of the perfluorinated membranes, known to exhibit a prolonged service life, are expensive and difficult to process. The following features were determined: the degree of sulfonation, water uptake, thermal analysis, and electrochemical properties such as ion exchange capacities, resistivity, selectivity of ion permeation. The surface of the cation exchange membranes, decomposed with the H202-treatment, were observed by using scanning electron microscope. The area resistivities of SPES mebranes in 5N-NaOH decreased from $2,150{\;}{\Omega}-cm2$ to less than $15{\Omega}-cm2$ as the ion exchange capacity (IEC) increased from 0.62 to 1.73 millieequivlants per dry gram(meq/dg).eq/dg).

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Determining the Self-Assembly and Redox Process of a Viologen Monolayer by Electrochemical Quartz Crystal Microbalance (수정진동자를 이용한 Viologen 단분자막의 자기조립화와 산화,환원 반응 측정)

  • Ock, J.Y.;Song, S.H.;Shin, H.K.;Chang, J.S.;Chang, S.M.;Kwon, Y.S.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.05c
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    • pp.23-27
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    • 2003
  • Molecular self-assembled of surfactant viologen are of recent interest because they can from functional electrodes as well as micellar assemblies, which can be profitably utilized for display devices, photoelectrochemical studies and electrocatalysis as electron acceptor or electron mediator. Fromherz et al studied the self-assembly of thiol and disulfide derivatives of viologens bearing long n-alkyl chains on Au electrode surface. The electrochemical behavior of self-assembled viologen monolayer has been investigated with QCM, which has been known as nano-gram order mass detector. The self-assembly process of viologen was monitored using resonant frequency$({\Delta}F)$ and resonant resistance(R). The redox process of viologen was observed with resonant frequency $({\Delta}F)$.

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Electrochemical Properties of Self-Assembled Viologen Monolayer Using QCM (QCM을 이용한 자기조립화된 Viologen 단분자막의 전기화학적 특성 연구)

  • Ock, Jin-Young;Park, Sang-Hyun;Kim, Byoung-Sang;Shin, Hoon-Kyu;Kwon, Young-Soo
    • Proceedings of the KIEE Conference
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    • 2003.07c
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    • pp.1520-1522
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    • 2003
  • Molecular self-assembled of surfactant viologen are of recent interest because they can from functional electrodes as well as micellar assemblies, which can be Profitably utilized for display devices, photoelectrochemical studies and electrocatalysis as electron acceptor or electron mediator. Fromherz et al studied the self-assembly of thiol and disulfide derivatives of viologens bearing long n-alkyl chains on Au electrode surface. The electrochemical behavior of self-assembled viologen monolayer has been investigated with QCM, which has been known as nano-gram order mass detector. The self-assembly process of viologen was monitored using resonant frequency (${\Delta}$F) and resonant resistance (R). The redox process of viologen was observed with resonant frequency (${\Delta}$F).

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Isolation and characterization of a noval membrane-bound cytochrome $C_{553}$ from the strictly anaerobic phototroph, heliobacillus mobilis

  • Lee, Woo-Yiel;Bla;Kim, Seung-Ho
    • Journal of Microbiology
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    • v.35 no.3
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    • pp.206-212
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    • 1997
  • Heliobacillus mobilis is a strictly anaerobic Gram-positive bacterium which contains a primitive Photosystem I-type reaction center. The membrane-bound cytochrome $C_{553}$ from the heliobacterium suggested to be the immediate electron donor to the photooxidized pigment (P798+) has been isolated and characterized. The heme protein was visualized as a major component with an apparent molecular size of 17kDa in TMBZ-staining analysis of the membrane preparation and showed characteristic $\alpha$ (552.5 nm), $\beta$ (522nm), and Soret absorption (416 nm) peaks of a typical reduced c-type cytochrome in the partially purified sample. The internal 43 amino acid sequence of the electron donor was obtained by chemical agent and protease treatments followed by N-terminal sequencing of the resulting fragments. The internal sequence carries lots of lysine residues and a Cys-X-X-Cys-His sequence motif which are the characteristics of typical c-type cytochromes. The analysis of the sequence by FAST or FASTA program, however, did not show any significant similarity to other known heme proteins.

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TLR4 Mediates Pneumolysin-Induced ATF3 Expression through the JNK/p38 Pathway in Streptococcus pneumoniae-Infected RAW 264.7 Cells

  • Nguyen, Cuong Thach;Kim, Eun-Hye;Luong, Truc Thanh;Pyo, Suhkneung;Rhee, Dong-Kwon
    • Molecules and Cells
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    • v.38 no.1
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    • pp.58-64
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    • 2015
  • Activating transcription factor-3 (ATF3) acts as a negative regulator of cytokine production during Gram-negative bacterial infection. A recent study reported that ATF3 provides protection from Streptococcus pneumoniae infection by activating cytokines. However, the mechanism by which S. pneumoniae induces ATF3 after infection is still unknown. In this study, we show that ATF3 was upregulated via Toll-like receptor (TLR) pathways in response to S. pneumoniae infection in vitro. Induction was mediated by TLR4 and TLR2, which are in the TLR family. The expression of ATF3 was induced by pneumolysin (PLY), a potent pneumococcal virulence factor, via the TLR4 pathway. Furthermore, ATF3 induction is mediated by p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK). Thus, this study reveals a potential role of PLY in modulating ATF3 expression, which is required for the regulation of immune responses against pneumococcal infection in macrophages.

Energy Value of Carbohydrate and Lipids with Added Calcium for Growing Mice

  • Khalil, Dania A.;Owens, Fredric N.;Hanson, Christa F.
    • Preventive Nutrition and Food Science
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    • v.5 no.2
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    • pp.100-104
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    • 2000
  • The caloric contribution of diets supplemented with sucrose, corn oil, or tallow with or without additional calcium was examined using female CD1 weanling mice. Mice were limit-fed a semi-purified diet alone or with added isocaloric amounts from sucrose, corn oil, or tallow for 28 days. In addition, diets with suppelmental fat contained either 0.60% or 1.5% calcium. Fecal fat and fecal soap excretions were greater (p<0.06) for mice fed tallow than for those fed corn oil. Mean metabolizable energy values for sucrose, tallow, and corn oil averaged 4.01, 7.96, and 8.94 kcal, respectively. Retention of digested energy from sucrose, tallow and corn oil averaged 13%, 10% and 21%, respectively. Hence, per gram of added nutrient, retained energy from tallow averaged 1.60 and that from corn oil averaged 4.11 times that of added sucrose. Retained energy from added corn oil was greater (p<0.01) than from added tallow. On a retained energy basis, the relative value for corn oil was greater and the relative value for tallow was less than the metabolizable energy ratio of fat to carbohydrate proposed by Atwater of 2.25.Added calcium depressed(p<0.01) digestibilities of both dry matter and energy with a greater(p<0.01) effect on tallow than on corn oil. These findings imply that the source of fat and calcium in the diet influence the avail-ability energy in diets and should be considered in feed formulations.

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Score Image Retrieval to Inaccurate OMR performance

  • Kim, Haekwang
    • Journal of Broadcast Engineering
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    • v.26 no.7
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    • pp.838-843
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    • 2021
  • This paper presents an algorithm for effective retrieval of score information to an input score image. The originality of the proposed algorithm is that it is designed to be robust to recognition errors by an OMR (Optical Music Recognition), while existing methods such as pitch histogram requires error induced OMR result be corrected before retrieval process. This approach helps people to retrieve score without training on music score for error correction. OMR takes a score image as input, recognizes musical symbols, and produces structural symbolic notation of the score as output, for example, in MusicXML format. Among the musical symbols on a score, it is observed that filled noteheads are rarely detected with errors with its simple black filled round shape for OMR processing. Barlines that separate measures also strong to OMR errors with its long uniform length vertical line characteristic. The proposed algorithm consists of a descriptor for a score and a similarity measure between a query score and a reference score. The descriptor is based on note-count, the number of filled noteheads in a measure. Each part of a score is represented by a sequence of note-count numbers. The descriptor is an n-gram sequence of the note-count sequence. Simulation results show that the proposed algorithm works successfully to a certain degree in score image-based retrieval for an erroneous OMR output.

Perceptions and Trends of Digital Fashion Technology - A Big Data Analysis - (빅데이터 분석을 이용한 디지털 패션 테크에 대한 인식 연구)

  • Song, Eun-young;Lim, Ho-sun
    • Fashion & Textile Research Journal
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    • v.23 no.3
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    • pp.380-389
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    • 2021
  • This study aimed to reveal the perceptions and trends of digital fashion technology through an informational approach. A big data analysis was conducted after collecting the text shown in a web environment from April 2019 to April 2021. Key words were derived through text mining analysis and network analysis, and the structure of perception of digital fashion technology was identified. Using textoms, we collected 8144 texts after data refinement, conducted a frequency of emergence and central component analysis, and visualized the results with word cloud and N-gram. The frequency of appearance also generated matrices with the top 70 words, and a structural equivalent analysis was performed. The results were presented with network visualizations and dendrograms. Fashion, digital, and technology were the most frequently mentioned topics, and the frequencies of platform, digital transformation, and start-ups were also high. Through clustering, four clusters of marketing were formed using fashion, digital technology, startups, and augmented reality/virtual reality technology. Future research on startups and smart factories with technologies based on stable platforms is needed. The results of this study contribute to increasing the fashion industry's knowledge on digital fashion technology and can be used as a foundational study for the development of research on related topics.

Analysis of speech in game marketing video using text mining techniques (텍스트 마이닝 기법을 이용한 게임 마케팅 비디오에서의 스피치 분석)

  • Lee, Yeokyung;Kim, Jaejik
    • The Korean Journal of Applied Statistics
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    • v.35 no.1
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    • pp.147-159
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    • 2022
  • Nowadays, various social media platforms are widely spread and people closely use such platforms in daily life. By doing so, social influencers with a large number of subscribers, views, and comments have huge impact in our society. Following this trend, many companies are actively using influencers for marketing purpose to promote their products and services. In this study, we extract the speeches of influencers from videos for game marketing and analyze them using various text mining techniques. In the analysis, we distinguish game videos leading to successful marketing and failed marketing, and we explore and compare the linguistic features of the influencers for successful and failed marketings.

Modern Methods of Text Analysis as an Effective Way to Combat Plagiarism

  • Myronenko, Serhii;Myronenko, Yelyzaveta
    • International Journal of Computer Science & Network Security
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    • v.22 no.8
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    • pp.242-248
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    • 2022
  • The article presents the analysis of modern methods of automatic comparison of original and unoriginal text to detect textual plagiarism. The study covers two types of plagiarism - literal, when plagiarists directly make exact copying of the text without changing anything, and intelligent, using more sophisticated techniques, which are harder to detect due to the text manipulation, like words and signs replacement. Standard techniques related to extrinsic detection are string-based, vector space and semantic-based. The first, most common and most successful target models for detecting literal plagiarism - N-gram and Vector Space are analyzed, and their advantages and disadvantages are evaluated. The most effective target models that allow detecting intelligent plagiarism, particularly identifying paraphrases by measuring the semantic similarity of short components of the text, are investigated. Models using neural network architecture and based on natural language sentence matching approaches such as Densely Interactive Inference Network (DIIN), Bilateral Multi-Perspective Matching (BiMPM) and Bidirectional Encoder Representations from Transformers (BERT) and its family of models are considered. The progress in improving plagiarism detection systems, techniques and related models is summarized. Relevant and urgent problems that remain unresolved in detecting intelligent plagiarism - effective recognition of unoriginal ideas and qualitatively paraphrased text - are outlined.