• Title/Summary/Keyword: Research synthesize

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Role of Social Media in Online Radicalization: Literature Review and Research Agenda

  • Tanu Shree;Sumeet Gupta
    • Asia pacific journal of information systems
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    • v.29 no.2
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    • pp.268-282
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    • 2019
  • This study attempts to synthesize the literature on radicalization and examine the role of social media in promoting radicalization. The study is based on the review of prominent studies on radicalization in both offline and online settings. The study builds upon the literature in offline settings on radicalisation and presents a research agenda for radicalization in online settings. The study also presents a model of radicalization delineating the role of social media.

Characteristics of Silicon Nanoparticles Depending on H2 Gas Flow During Nanoparticle Synthesis via CO2 Laser Pyrolysis (CO2 레이저 열분해법을 이용한 실리콘 나노입자 합성 시 H2 유량이 나노입자 특성에 미치는 영향)

  • Lee, Jae Hee;Kim, Seongbeom;Kim, Jongbok;Hwang, Taekseong;Lee, Jeong Chul
    • Korean Journal of Materials Research
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    • v.23 no.5
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    • pp.260-265
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    • 2013
  • Silicon nanoparticle is a promising material for electronic devices, photovoltaics, and biological applications. Here, we synthesize silicon nanoparticles via $CO_2$ laser pyrolysis and study the hydrogen flow effects on the characteristics of silicon nanoparticles using high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and UV-Vis-NIR spectrophotometry. In $CO_2$ laser pyrolysis, used to synthesize the silicon nanoparticles, the wavelength of the $CO_2$ laser matches the absorption cross section of silane. Silane absorbs the $CO_2$ laser energy at a wavelength of $10.6{\mu}m$. Therefore, the laser excites silane, dissociating it to Si radical. Finally, nucleation and growth of the Si radicals generates various silicon nanoparticle. In addition, researchers can introduce hydrogen gas into silane to control the characteristics of silicon nanoparticles. Changing the hydrogen flow rate affects the nanoparticle size and crystallinity of silicon nanoparticles. Specifically, a high hydrogen flow rate produces small silicon nanoparticles and induces low crystallinity. We attribute these characteristics to the low density of the Si precursor, high hydrogen passivation probability on the surface of the silicon nanoparticles, and low reaction temperature during the synthesis.

A Meta-Research on User Information Seeking Models (이용자 정보추구 모형에 관한 메타적 연구)

  • 서은경
    • Proceedings of the Korean Society for Information Management Conference
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    • 1995.08a
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    • pp.25-28
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    • 1995
  • Whereas earlier research on information seeking efforts focused on system related concepts and observer constructs. the recent literature reflects a move toward user consturcts. The purpose of the study is to review, analyze and synthesize the various models on information seeking. The study suggests that the practice of intermediares can be both more efficient and effective if it is based on the conceptual assumptions that undergird the cognitive factors: systems designs or software access will also benefit if these cognitive factors are built into the information system as centeral design features.

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Preparation of LiCoO$_2$from Used Lithium Ion Battery by Hydrometallurgical Processes

  • Lee, Churl-Kyoung;Rhee, Kang-In;Yang, Dong-Hyo;Yu, Hyo-Shin
    • Proceedings of the IEEK Conference
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    • 2001.10a
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    • pp.240-244
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    • 2001
  • Recycling process involving mechanical, thermal, hydrometallurgical, and sol-gel step has been applied to recover cobalt and lithium from spent lithium ion batteries and to synthesize LiCoO$_2$from leach liquor as cathodic active materials. Electrode materials containing lithium and cobalt could be concentrated with 2-step thermal and mechanical treatment. Leaching behaviors of the lithium and cobalt in nitric acid media was investigated in terms of reaction variables. Hydrogen peroxide in 1 M HNO$_3$solution turned out to be an effective reducing agent by enhancing the leaching efficiency. O f many possible processes to produce LiCoO$_2$, the amorphous citrate precursor process (ACP) has been applied to synthesize powders with a large specific surface area and an exact stoichiometry. After leaching used LiCoO$_2$with nitric acid, the molar ratio of Li/Co in the leach liquor was adjusted at 1.1 by adding a fresh LiNO$_3$solution. Then, 1 M citric acid solution at a 100% stoichiometry was also added to prepare a gelatinous precursor. When the precursor was calcined at 95$0^{\circ}C$ for 24 hr, purely crystalline LiCoO$_2$was successfully obtained. The particle size and specific surface area of the resulting crystalline powders were 20 пm and 30 $\textrm{cm}^2$/g, respectively The LiCoO$_2$powder was proved to have good characteristics as cathode active materials in charge/discharge capacity and cyclic performance.

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Viewpoint interpolation of face images using an ellipsoid model (타원체 MODEL을 사용한 얼굴 영상의 시점합성에 관한 연구)

  • Yoon, Na-Ree;Lee, Byung-Uk
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.6C
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    • pp.572-578
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    • 2007
  • To establish eye contact in video teleconferencing, it is necessary to synthesize a front view image by viewpoint interpolation. We can find the viewing direction of a user, and interpolate an image seen from that viewpoint, which will result in a face image observed from the front. There are two categories of previous research: image based method and model based method. The former is simple to calculate, however, it shows limited performance for complex objects. And the latter is robust to noise while it is computationally expensive. We propose to approximate face images as ellipses and match them to build an ellipsoid and then synthesize a new image from a given virtual camera position. We show that it is simple and robust from various experiments.

An Analytical Synthesis Method of Dynamic Systems in Terms of Bond Graphs (본드선도를 이용한 동적시스템의 해석적 종합방법)

  • Park, Jeon-Su;Kim, Jong-Sik
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.11
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    • pp.3507-3515
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    • 1996
  • This paper presents an attempt to find the physical structure of dynamic systems which achieves the behavior of a given system function. The scheme pursued by the paper would be regarded as synthesizing dynamic systems, and a method to synthesize them analytically is proposed by means of bond graph prototypes. The method adopts several conceptsused to synthesize networks in the electrical field, but yet deconstrates its own strengths such as the freedom from assigning causality and determining junction types. Also, itis shown that this method has further advantages in reticulating a given specification into feedforward and feedback components relative to network synthesis and the method is examined though an example to trace the outline of the analytical synthesis of dynamic systems using bond graph prototypes.

Synthesis of Decapeptide of L-Aspartic Acid and Benzyl-L-Aspartic Acid by Solid Phase Peptide Synthesis

  • Yoo, Bong-K.;Jalil Miah, M.A.;Lee, Eung-Seok;Han, Kun
    • Archives of Pharmacal Research
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    • v.28 no.7
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    • pp.756-760
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    • 2005
  • Polyene macrolide amphotericin B (AmB) is the drug of choice for the treatment of disseminated fungal infections. However, because of its pronounced side effects, the drug has limited applicability. There are few interesting reports, which state that co-administration of the drug with homo-peptide of polyaspartic acid reduces the side effects of the drug. In our present study, an approach has been made to systematically synthesize low molecular weight heteropeptides consisting of L-aspartic acid and its derivative. It was hypothesized that such heteropeptides will reduce the toxic side effects of the drug by facile hydrophobic binding between the polymer and the drug. We have employed the strategy of solid phase peptide synthesis (SPPS) to synthesize low molecular weight hetero-peptides by using L-aspartic acid and benzyl-L-aspartic acid to induce the hydrophobic binding between the peptide and the drug. In future, the proposed methodology can be employed to tailor other polypeptides substituted with benzyl groups to reduce the nephrotoxicity of AmB.

Vapor Deposition Techniques for Synthesis of Two-Dimensional Transition Metal Dichalcogenides

  • Song, Jeong-Gyu;Park, Kyunam;Park, Jusang;Kim, Hyungjun
    • Applied Microscopy
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    • v.45 no.3
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    • pp.119-125
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    • 2015
  • Two-dimensional (2D) transition metal dichalcogenides (TMDCs) have attracted significant attention due to their unique and exotic properties attributed to their low dimensionality. In particular, semiconducting 2D TMDCs such as $MoS_2$, $WS_2$, $MoSe_2$, and $WSe_2$ have been demonstrated to be feasible for various advanced electronic and optical applications. In these regards, process to synthesize high quality 2D TMDCs layers with high reliability, wafer-scale uniformity, controllable layer number and excellent electronic properties is essential in order to use 2D TMDCs in practical applications. Vapor deposition techniques, such as physical vapor deposition, chemical vapor deposition and atomic layer deposition, could be promising processes to produce high quality 2D TMDCs due to high purity, thickness controllability and thickness uniformity. In this article, we briefly review recent research trend on vapor deposition techniques to synthesize 2D TMDCs.

Assessing Cognitive Attributes in the 8th grade Geometry (중학교 2학년 기하에서의 인지 속성 평가)

  • Kim, Sun-Hee
    • Journal of Educational Research in Mathematics
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    • v.19 no.4
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    • pp.531-543
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    • 2009
  • This study identified what cognitive attributes are required of eighth graders to solve geometrical problems such as 'Recall,' 'Analyze,' 'Justify,' 'Synthesize/Integrate,' and 'Solve Non-routine Problems' by using the cognitive diagnostic theory. The five attributes are proved as the skills for solving the geometric problems. Many students have not fully mastered the attributes of 'Justify' and 'Synthesize/Integrate'. There was high correlation between these attributes. 'Analyze' best predicted the changes in the geometric achievement. And while students with high levels of geometrical achievement have mastered all the five attributes, those in the mid- and low-level range of performance have mastered fewer attributes.

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Systematic review on the research of mathematical beliefs in Korean mathematical education (국내 수학교육의 수학적 신념 연구에 관한 체계적 분석)

  • Lee, Seonyoung;Han, Sunyoung
    • The Mathematical Education
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    • v.59 no.4
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    • pp.331-355
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    • 2020
  • The purpose of this study is to systematically analyze the results of the existing research on mathematical beliefs, compare and synthesize the valuable results and to suggest implications for mathematical beliefs and research. As a result of checking the methodological quality of 59 articles in total using the MQA(Methodological Quality Assessment) checklist, most of them surveyed mathematical beliefs using questionnaires, and most of the studies were conducted on prospective teachers. As a result of systematic review, the conceptual characteristics of mathematical beliefs, object-specific characteristics, and the educational influence of mathematical beliefs were able to synthesize the meaning. Mathematical beliefs had important educational influences in the practice of teachers, students, and math classes. As the results of the study, we emphasize the importance of changing the beliefs of students and teachers in order to solve the problem of mathematical education, where students rely on private education rather than activity thinking, and teachers do not pay attention to students thinking. It has been shown that concrete support is needed for practicing participatory instruction focused on mathematical thinking.