• Title/Summary/Keyword: dispersion effect

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Citations to arXiv Preprints by Indexed Journals and Their Impact on Research Evaluation

  • Ferrer-Sapena, Antonia;Aleixandre-Benavent, Rafael;Peset, Fernanda;Sanchez-Perez, Enrique A.
    • Journal of Information Science Theory and Practice
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    • v.6 no.4
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    • pp.6-16
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    • 2018
  • This article shows an approach to the study of two fundamental aspects of the prepublication of scientific manuscripts in specialized repositories (arXiv). The first refers to the size of the interaction of "standard papers" in journals appearing in the Web of Science (WoS)-now Clarivate Analytics-and "non-standard papers" (manuscripts appearing in arXiv). Specifically, we analyze the citations found in the WoS to articles in arXiv. The second aspect is how publication in arXiv affects the citation count of authors. The question is whether or not prepublishing in arXiv benefits authors from the point of view of increasing their citations, or rather produces a dispersion, which would diminish the relevance of their publications in evaluation processes. Data have been collected from arXiv, the websites of the journals, Google Scholar, and WoS following a specific ad hoc procedure. The number of citations in journal articles published in WoS to preprints in arXiv is not large. We show that citation counts from regular papers and preprints using different sources (arXiv, the journal's website, WoS) give completely different results. This suggests a rather scattered picture of citations that could distort the citation count of a given article against the author's interest. However, the number of WoS references to arXiv preprints is small, minimizing this potential negative effect.

Study on the Microstructure and Mechanical Properties of High Volume Fraction TiB2-Al1050 Metal Matrix Composites (고체적률 TiB2-Al1050 금속복합재료의 미세조직 및 기계적 특성 연구)

  • Ko, Seongmin;Park, Hyeonjae;Lee, Yeong-Hwan;Shin, Sangmin;Lee, Donghyun;Jo, Ilguk;Lee, Sang-Bok;Lee, Sang-Kwan;Cho, Seungchan
    • Composites Research
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    • v.32 no.1
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    • pp.1-5
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    • 2019
  • In this study, Al1050 composites reinforced with uniformly dispersed, high volume fraction $TiB_2$ particles were fabricated by liquid pressing process and analyzed to microstructure, mechanical properties. Hardness, ultimate tensile strength and compressive yield strength of the 56 vol.% $TiB_2$-Al1050 composite increased to 10, 4.5 and 9.8 times, respectively, compared with those of the Al1050 due to dispersion hardening effect of uniformly dispersed $TiB_2$ in the Al matrix.

Analysis of the Relationship between House Price, Income Inequality and Macroeconomic Variables (주택가격, 소득불평등 및 거시경제변수간의 관계분석)

  • Kwon, Sun-Hee;Hyun, Seong-Min
    • Journal of Digital Convergence
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    • v.17 no.1
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    • pp.55-62
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    • 2019
  • This study analyzed the relationship between housing price, purchase price, Gini coefficient, interest rate, and the employment, considering that the change in housing price was an important factor influencing macroeconomic variables and income inequality. The panel VAR model was constructed considering the panel data, and the Granger causality, Impulse response and Variance dispersion analysis were performed. As a result, when compared to before and after the global financial crisis, it was shown that the rent price had an effect on income inequality, but in the following period, both the rent price and the selling price affected the income inequality. And that it has a large impact on inequality. In addition, the causality between income inequality and employment rate, interest rate, and tax rate was confirmed. Therefore, it is expected that it will be a desirable policy to mitigate income inequality considering the influence of policy variables for economic activation including government real estate policy.

Probing the Feedback Process in Local Type-2 AGNs with Integral-Field Spectroscopy

  • Luo, Rongxin;Woo, Jong-Hak;Shin, Jaejin;Kang, Daeun;Bae, Hyun-Jin;Karouzos, Marios
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.1
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    • pp.36.3-36.3
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    • 2019
  • Feedback process is one of the most important topics in the study of AGNs since it plays a key role in linking the SMBHs and their host galaxies. In order to further understand the co-evolution of SMBHs and their host galaxies, we probe the feedback process in local type-2 AGNs with a series of integral-field-spectroscopy observations. In the first part of my talk, I will introduce our GMOS observations of luminous type-2 AGNs at z < 0.1, which are selected using the integrated [O III] kinematics. Based on the dedicated emission-line diagnostics and kinematic studies, we identify the signatures of AGN-driven outflows and quantify the outflow size in the targets with extreme [O III] kinematics. For the targets without extreme [O III] kinematics, we find the presence of weak AGN-driven outflows, which are indicated by the significant differences between the kinematics of gas and stars. Then, I will present our recent study of 40 type-2 AGNs based on the SNIFS IFU. By comparing the radial profile of velocity dispersion of gas and stars, we measure the size of AGN-driven outflows in these targets and extend the outflow size-AGN luminosity relation in our previous GMOS studies. We also discuss the feedback effect of AGN-driven outflows by connecting the outflow velocity and host galaxy properties. These results highlight the importance of spatially-resolved observation in investigating gas kinematics and identifying the signatures of AGN-driven outflows.

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Investigation of wave propagation in anisotropic plates via quasi 3D HSDT

  • Bouanati, Soumia;Benrahou, Kouider Halim;Atmane, Hassen Ait;Yahia, Sihame Ait;Bernard, Fabrice;Tounsi, Abdelouahed;Bedia, E.A. Adda
    • Geomechanics and Engineering
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    • v.18 no.1
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    • pp.85-96
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    • 2019
  • A free vibration analysis and wave propagation of triclinic and orthotropic plate has been presented in this work using an efficient quasi 3D shear deformation theory. The novelty of this paper is to introducing this theory to minimize the number of unknowns which is three; instead four in other researches, to studying bulk waves in anisotropic plates, other than it can model plates with great thickness ratio, also. Another advantage of this theory is to permits us to show the effect of both bending and shear components and this is carried out by dividing the transverse displacement into the bending and shear parts. Hamilton's equations are a very potent formulation of the equations of analytic mechanics; it is used for the development of wave propagation equations in the anisotropic plates. The analytical dispersion relationship of this type of plate is obtained by solving an eigenvalue problem. The accuracy of the present model is verified by confronting our results with those available in open literature for anisotropic plates. Moreover Numerical examples are given to show the effects of wave number and thickness on free vibration and wave propagation in anisotropic plates.

Wrinkling of Graphene Papers Placed on Stretchable Adhesive Films (신축성 접착 필름 위에 놓인 그래핀 종이의 주름 생성)

  • Kim, Sang-Yun;Jeong, Myeong Hee;Suk, Ji Won
    • Composites Research
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    • v.34 no.2
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    • pp.108-114
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    • 2021
  • Graphene flakes are generally mass-produced by converting graphene oxide into reduced graphene oxide using chemical or thermal reduction. These graphene flakes can be stacked to form a free-standing graphene paper, which can be used for various applications. However, a graphene paper lacks stretchability, which hinders its application in stretchable devices. In this work, we introduced wrinkles in a graphene paper to make it stretchable. A graphene paper fabricated by vacuum-filtering a graphene dispersion was placed on a pre-stretched adhesive film. When the pre-stretched adhesive film returned to the original state, the graphene paper was wrinkled. The effect of the pre-stretching and wet condition of the graphene papers was experimentally investigated by using scanning electron microscopy. In addition, we observed the change of the period of the wrinkles in the graphene paper depending on the pre-stretching.

Research on the Domain Formation of Living Base Space of Credit System High Schools - Focused on Japanese Comprehensive High Schools - (학점제 고등학교 생활거점공간의 영역 형성에 관한 연구 - 일본의 총합학과 고등학교를 대상으로 -)

  • Son, Suk-Eui;Kim, Seung-je
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.35 no.10
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    • pp.3-10
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    • 2019
  • The high school credit system is a system in which students select complete various subjects, depending on their career, and graduate when their accumulated credit reaches the standard. It is expected that the high school credit system, which guarantees the individual's right of choice, will bring an educational effect that can respond to the student's career aptitude. However, it is expected that problems in the aspect of school life, such as the weakening of class belongingness or difficulty of securing a stable base venue within the school building would be accompanied. This research analyzed students' usage condition depending on the living base space environment feature in schools that are implementing moving-selective class in the aspect of activity domain formation and contemplated the venue evaluation. The purpose is to provide the basic data of an architectural plan of a stable living base space within the school building through this. 'Living base center type' and 'living base dispersion type' school buildings among Japanese integral department high schools were used as the target to analyze the usage condition in the aspect of domain formation. As a result, a conclusion was deducted that student's securement of territory consciousness about the base space and venue construction for the community of various studying groups affects life satisfaction.

Cations of Soil Minerals and Carbon Stabilization of Three Land Use Types in Gambari Forest Reserve, Nigeria

  • Falade, Oladele Fisayo;Rufai, Samsideen Olabiyi
    • Journal of Forest and Environmental Science
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    • v.37 no.2
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    • pp.116-127
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    • 2021
  • Predicting carbon distribution of soil aggregates is difficult due to complexity in organo-mineral formation. This limits global warming mitigation through soil carbon sequestration. Therefore, knowledge of land use effect on carbon stabilization requires quantification of soil mineral cations. The study was conducted to quantify carbon and base cations on soil mineral fractions in Natural Forest, Plantation Forest and Farm Land. Five 0.09 ha were demarcated alternately along 500 m long transect with an interval of 50 m in Natural Forest (NF), Plantation Forest (PF) and Farm Land (FL). Soil samples were collected with soil cores at 0-15, 15-30 and 30-45 cm depths in each plot. Soil core samples were oven-dried at 105℃ and soil bulk densities were computed. Sample (100 g) of each soil core was separated into >2.0, 2.0-1.0, 1.0-0.5, 0.5-0.05 and <0.05 mm aggregates using dry sieve procedure and proportion determined. Carbon concentration of soil aggregates was determined using Loss-on-ignition method. Mineral fractions of soil depths were obtained using dispersion, sequential extraction and sedimentation methods of composite soil samples and sieved into <0.05 and >0.05 mm fractions. Cation exchange capacity of two mineral fractions was measured using spectrophotometry method. Data collected were analysed using descriptive and ANOVA at α0.05. Silt and sand particle size decreased while clay increased with increase in soil depth in NF and PF. Subsoil depth contained highest carbon stock in the PF. Carbon concentration increased with decrease in aggregate size in soil depths of NF and FL. Micro- (1-0.5, 0.5-0.05 and <0.05 mm) and macro-aggregates (>2.0 and 2-1.0 mm) were saturated with soil carbon in NF and FL, respectively. Cation exchange capacity of <0.05 mm was higher than >0.05 mm in soil depths of PF and FL. Fine silt (<0.05 mm) determine the cation exchange capacity in soil depths. Land use and mineral size influence the carbon and cation exchange capacity of Gambari Forest Reserve.

Effect of the Alignment of Milled Carbon Fiber Dispersed in Various Solvents (Solvent 별 분산에 따른 Milled Carbon Fiber의 배열성 연구)

  • Lee, Sung-Kwon;Choi, Sung-Woong
    • Composites Research
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    • v.35 no.1
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    • pp.47-51
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    • 2022
  • In order to efficiently control the heat generation of electronic devices, many research has been conducted on thermally conductive composite materials. In this study, milled carbon fiber was dispersed in four solvent to investigate the relationship of carbon fiber alignment according to dispersion by solvents, and carbon fiberreinforced composite material(CFRP) was manufactured using vacuum filtration. To evaluate the arrangement of CFRP the arrangement of the prepared specimen was observed under an optical microscope, and thermal conductivity was measured by Laser Flash Analysis. The Through-plane thermal conductivity of CFRP using NMP and Ethanol was 10.79 W/mK and 10.57 W/mK respectively, which were improved by 218% and 209% compared to the In-plane thermal conductivity. The high viscosity of the solvent greatly affects the shear of the fluid, and it seemed to determine the alignment of the filler.

GLOBAL Hɪ PROPERTIES OF GALAXIES VIA SUPER-PROFILE ANALYSIS

  • Kim, Minsu;Oh, Se-Heon
    • Journal of The Korean Astronomical Society
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    • v.55 no.5
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    • pp.149-172
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    • 2022
  • We present a new method which constructs an Hɪ super-profile of a galaxy which is based on profile decomposition analysis. The decomposed velocity profiles of an Hɪ data cube with an optimal number of Gaussian components are co-added after being aligned in velocity with respect to their centroid velocities. This is compared to the previous approach where no prior profile decomposition is made for the velocity profiles being stacked. The S/N improved super-profile is useful for deriving the galaxy's global Hɪ properties like velocity dispersion and mass from observations which do not provide sufficient surface brightness sensitivity for the galaxy. As a practical test, we apply our new method to 64 high-resolution Hɪ data cubes of nearby galaxies in the local Universe which are taken from THINGS and LITTLE THINGS. In addition, we also construct two additional Hɪ super-profiles of the sample galaxies using symmetric and all velocity profiles of the cubes whose centroid velocities are determined from Hermite h3 polynomial fitting, respectively. We find that the Hɪ super-profiles constructed using the new method have narrower cores and broader wings in shape than the other two super-profiles. This is mainly due to the effect of either asymmetric velocity profiles' central velocity bias or the removal of asymmetric velocity profiles in the previous methods on the resulting Hɪ super-profiles. We discuss how the shapes (𝜎n/𝜎b, An/Ab, and An/Atot) of the new Hɪ super-profiles which are measured from a double Gaussian fit are correlated with star formation rates of the sample galaxies and are compared with those of the other two super-profiles.