• Title/Summary/Keyword: FE/BE model

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Metadiscourse in the Bank Negara Malaysia Governor's Speech Texts

  • Aziz, Roslina Abdul;Baharum, Norzie Diana
    • Asia Pacific Journal of Corpus Research
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    • v.2 no.2
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    • pp.1-15
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    • 2021
  • The study aims to explore the use of metadiscourse in the Bank Negara Malaysia Governor's speeches based on Hyland's Interpersonal Model of Metadiscourse. The corpus data consist of 343 speech texts, which were extracted from the Malaysian Corpus of Financial English (MacFE), amounting to 688,778 tokens. Adopting both quantitative and qualitative approaches to data analysis the study investigates (1) the overall use of metadiscourse in the Bank Negara Governor's speech texts and (2) the functions of the most prominent metadiscourse resources used and their functions in the speech texts. The findings reveal that the Governor's speech texts to be interactional rather than interactive, revealing a rich distribution of interactional metadiscourse resources, namely engagement markers, self-mention, hedges, boosters and attitude markers throughout the texts. The interactional metadiscourse resources function to establish speaker-audience engagement and alignment of views, as well as to express degree of uncertainty and certainty and attitudes. The study concludes that the speech texts are not merely informational or propositional, but rather interpersonal.

Scale-dependent buckling of embedded thermo-electro-magneto-elastic cylindrical nano-shells with different edge conditions

  • Yifei Gui;Honglei Hu
    • Advances in nano research
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    • v.16 no.6
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    • pp.601-613
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    • 2024
  • A new analytical buckling solution of a thermo-electro-magneto-elastic (TEME) cylindrical nano-shell made of BiTiO3-CoFe2O4 materials is obtained based on Hamiltonian approach. The Winkler and Pasternak elastic foundations as well as thermo-electro-magneto-mechanical loadings are applied, and two different types of edge conditions are taken into the investigation. According to nonlocal strain gradient theory (NSGT) and surface elasticity theory in conjunction with the Kirchhoff-Love theory, governing equations of the nano-shell are acquired, and the buckling bifurcation condition is obtained by adopting the Navier's method. The detailed parameter study is conducted to investigate the effects of axial and circumferential wave numbers, scale parameters, elastic foundations, edge conditions and thermo-electro-magnetic loadings on the buckling behavior of the nano-shell. The proposed model can be applied in design and analysis of TEME nano components with multi-field coupled behavior, multiple edge conditions and scale effect.

Application of Cardiac Electromechanical FE Model for Predicting Pumping Efficacy of LVAD According to Heart Failure Severity (심부전 정도에 따른 좌심실보조장치의 박동효율예측을 위한 심장의 전기역학적 유한요소 모델의 응용)

  • Jung, Dae Hyun;Lim, Ki Moo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.38 no.8
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    • pp.715-720
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    • 2014
  • In order to maximize the effect of left ventricular assist device (LVAD) on ventricular unloading, the therapy should be begun at appropriate level of heart failure severity. We predicted pumping efficacy of LVAD according to the severity of heart failure theoretically. We used 3 dimensional finite element model of ventricle coupled with 6 Wind-kessel compartmental model of vascular system. Using the computational model, we predicted cardiac responses such as contractile ATP consumption of ventricle, left ventricular pressure, cardiac output, ejection fraction, and stroke work according to the severity of ventricular systolic dysfunction under the treatments of continuous LVAD. Contractile ATP consumption, which indicates the ventricular energetic loading condition decreased maximally at the $5^{th}$ level heart-failure under LVAD therapy. We conclude that optimal timing for LVAD treatment is $5^{th}$ level heart-failure when considering LVAD treatment as "bridge to recovery".

Source Identification of Ambient PM-10 Using the PMF Model (PMF 모델을 이용한 대기 중 PM-10 오염원의 확인)

  • 황인조;김동술
    • Journal of Korean Society for Atmospheric Environment
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    • v.19 no.6
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    • pp.701-717
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    • 2003
  • The objective of this study was to extensively estimate the air quality trends of the study area by surveying con-centration trends in months or seasons, after analyzing the mass concentration of PM-10 samples and the inorganic lements, ion, and total carbon in PM-10. Also, the study introduced to apply the PMF (Positive Matrix Factoriza-tion) model that is useful when absence of the source profile. Thus the model was thought to be suitable in Korea that often has few information about pollution sources. After obtaining results from the PMF modeling, the existing sources at the study area were qualitatively identified The PM-10 particles collected on quartz fiber filters by a PM-10 high-vol air sampler for 3 years (Mar. 1999∼Dec.2001) in Kyung Hee University. The 25 chemical species (Al, Mn, Ti, V, Cr, Fe, Ni, Cu, Zn, As, Se, Cd, Ba, Ce, Pb, Si, N $a^{#}$, N $H_4$$^{+}$, $K^{+}$, $Mg^{2+}$, $Ca^{2+}$, C $l^{[-10]}$ , N $O_3$$^{[-10]}$ , S $O_4$$^{2-}$, TC) were analyzed by ICP-AES, IC, and EA after executing proper pre - treatments of each sample filter. The PMF model was intensively applied to estimate the quantitative contribution of air pollution sources based on the chemical information (128 samples and 25 chemical species). Through a case study of the PMF modeling for the PM-10 aerosols. the total of 11 factors were determined. The multiple linear regression analysis between the observed PM-10 mass concentration and the estimated G matrix had been performed following the FPEAK test. Finally the regression analysis provided source profiles (scaled F matrix). So, 11 sources were qualitatively identified, such as secondary aerosol related source, soil related source, waste incineration source, field burning source, fossil fuel combustion source, industry related source, motor vehicle source, oil/coal combustion source, non-ferrous metal source, and aged sea- salt source, respectively.ively.y.

Subparametric Element Based on Partial-linear Layerwise Theory for the Analysis of Orthotropic Laminate Composites (직교이방성 적층구조 해석을 위한 부분-선형 층별이론에 기초한 저매개변수요소)

  • Ahn, Jae-Seok;Woo, Kwang-Sung
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.22 no.2
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    • pp.189-196
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    • 2009
  • This paper presents the subparametric finite element model formulated by partial-linear layerwise theory for the analysis of laminate composites. The proposed model is based on refined approximations of two dimensional plane for orthotropic thick laminate plate as well as thin case. Three dimensional problem can be reduced to two dimensional case by assuming piecewise linear variation of in-plane displacement and a constant value of out-of-plane displacement across the thickness. The integrals of Legendre polynomials are chosen to define displacement fields and Gauss-Lobatto numerical integration is implemented in order to directly obtain maximum values occurred at the nodal points of each layer without other extrapolation techniques. The validity and characteristics of the proposed model have been tested by using orthotropic multilayered plate problem as compared to the values available in the published references. In this study, the convergence test has been carried out to determine the optimal layer model in terms of central deflection and stresses. Also, the distribution of displacements and stresses across the thickness has been investigated as the number of layer is increased.

Design criteria for birdstrike damage on windshield

  • Marulo, Francesco;Guida, Michele
    • Advances in aircraft and spacecraft science
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    • v.1 no.2
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    • pp.233-251
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    • 2014
  • Each aircraft have to be certified for a specified level of impact energy, for assuring the capability of a safe flight and landing after the impact against a bird at cruise speed. The aim of this research work was to define a scientific and methodological approach to the study of the birdstrike phenomenon against several windshield geometries. A series of numerical simulations have been performed using the explicit finite element solver code LS-Dyna, in order to estimate the windshield-surround structure capability to absorb the bird impact energy, safely and efficiently, according to EASA Certification Specifications 25.631 (2011). The research considers the results obtained about a parametric numerical analysis of a simplified, but realistic, square flat windshield model, as reported in the last work (Grimaldi et al. 2013), where this model was subjected to the impact of a 1.8 kg bird model at 155 m/s to estimate the sensitivity of the target geometry, the impact angle, and the plate curvature on the impact response of the windshield structure. Then on the basis of these results in this paper the topic is focused about the development of a numerical simulation on a complete aircraft windshield-surround model with an innovative configuration. Both simulations have used a FE-SPH coupled approach for the fluid-structure interaction. The main achievement of this research has been the collection of analysis and results obtained on both simplified realistic and complete model analysis, addressed to approach with gained confidence the birdstrike problem. Guidelines for setting up a certification test, together with a design proposal for a test article are an important result of such simulations.

Influence of Temperature and pH on Adsorption of Ru(II) Dye from Aqueous Solution onto $TiO_2$ Films ($TiO_2$ 전극과 Ru(II) 염료와의 흡착에 있어서 온도 및 pH의 영향)

  • Hwang, Kyungjun;Yoo, Seungjoon;Shim, Wanggeum;Lee, Jaewook
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.11a
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    • pp.60.2-60.2
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    • 2010
  • A $TiO_2$ films in dye-sensitized solar cells was fabricated using $TiO_2$ colloidal sol prepared from titanium iso-propoxide used as a starting material by applying the sol-gel method. It was characterized by particle size analyzer, XRD, FE-SEM, and BET analysis. The adsorption isotherms of dye molecule on $TiO_2$ films were obtained at three different temperatures (30, 45, $60^{\circ}C$) and at three different pH (3, 5, 7). The adsorption kinetics of dye molecule on $TiO_2$ films were obtained at three different temperatures (30, 45, $60^{\circ}C$. The adsorption experimental data were correlated with Langmuir isotherm model and pseudo-second-order model. Also the isosteric enthalpies of dye adsorption were calculated by the Clausius-Clapeyron equation. In addition, the adsorption energy distribution functions which describe heterogeneous characteristics of nanocrystalline $TiO_2$ film surface were calculated by using the generalized nonlinear regularization method. We found that efficient adsorption of N719 dye from aqueous solution onto $TiO_2$ films can be successfully achieved by dye adsorption conditions and morphology of $TiO_2$ films.

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Finite element analysis of CFRP laminate repairs on damaged end regions of prestressed concrete bridge girders

  • Shaw, Ian D.;Andrawes, Bassem
    • Advances in Computational Design
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    • v.2 no.2
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    • pp.147-168
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    • 2017
  • Over the past couple decades, externally bonded fiber reinforced polymer (FRP) composites have emerged as a repair and strengthening material for many concrete infrastructure applications. This paper presents an analytical investigation of the use of carbon FRP (CFRP) for a specific problem that occurs in concrete bridge girders wherein the girder ends are damaged by excessive exposure to deicing salts and numerous freezing/thawing cycles. A 3D finite element (FE) model of a full scale prestressed concrete (PC) I-girder is used to investigate the effect of damage to the cover concrete and stirrups in the end region of the girder. Parametric studies are performed using externally bonded CFRP shear laminates to determine the most effective repair schemes for the damaged end region under a short shear span-to-depth ratio. Experimental results on shear pull off tests of CFRP laminates that have undergone accelerated aging are used to calibrate a bond stress-slip model for the interface between the FRP and concrete substrate and approximate the reduced bond stress-slip properties associated with exposure to the environment that causes this type of end region damage. The results of these analyses indicate that this particular application of this material can be effective in recovering the original strength of PC bridge girders with damaged end regions, even after environmental aging.

Experimental investigation of organic fouling mitigation in membrane filtration and removal by magnetic iron oxide particles

  • Jung, Jaehyun;Sibag, Mark;Shind, Bora;Cho, Jinwoo
    • Membrane and Water Treatment
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    • v.11 no.3
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    • pp.223-229
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    • 2020
  • Here magnetic iron oxide particles (MIOPs) were synthesized under atmospheric air and which size was controlled by regulating the flow rate of alkali addition and used for efficient removal of bovine serum albumin (BSA) from water. The MIOPs were characterized using field-emission scanning electron microscopy (FE-SEM), Fourier transformation-Infrared spectroscopy (FT-IR) and vibrating sample magnetometer (VSM). The results revealed a successful preparation of the MIOPs. The removal efficiency for BSA using MIOPs was found to be about 100% at lower concentrations (≥ 10 mg/L). The maximum adsorption of 64.7 mg/g for BSA was achieved as per the Langmuir adsorption model. In addition, microfiltration membrane for removal of BSA as model protein organic foulant is also studied. The effect of various MIOPs adsorbent sizes of 210, 680 and 1130 nm on the absorption capacity of BSA was investigated. Water permeability of the BSA integrated with the smallest size MIOPs membrane was increased by approximately 22% compared by the neat BSA membrane during dead-end filtration. Furthermore, the presence of small size MIOPs were also effective in increasing the permeate flux.

Effects of Shiitake Mushroom on Anti-platelet Aggregation and Anti-thrombotic (표고버섯 추출물의 항혈소판 응집 및 항혈전 효과)

  • Kim, Gye Yeop;Jeong, Hyun Woo;Jeong, Dong Jo;Song, Hyung Bong;Lee, Hong Gyun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.27 no.2
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    • pp.239-245
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    • 2013
  • In in vitro study, the anti-platelet aggregation effect of Shiitake mushroom extract was examined by measuring the collagen induced platelet aggregation and the DPPH radical scavenging. In in vitro study, anti-thrombotic effect of Shiitake mushroom extract was examined using the carotid artery thrombosis rat model. Carotid artery thrombosis rat model was made by 35% $FeCl_3$ treatment. After that, we investigate thrombus weight and blood flow. In platelet aggregation test, the extract significantly inhibited platelet aggregation in a concentration dependent manner(p<.001). Also, extract increased DPPH radical scavenging activity in a concentration dependent manner. Extract significantly inhibited thrombus weight to compare with control group. And blood passage time were shorter in the Shiitake mushroom extract supplemented groups than in control group. These results provide experimental evidence that Shiitake mushroom can be used to prevent platelet aggregation and thrombosis, then could apply the clinical diseases such as cardiovascular disease, and so on.