• Title/Summary/Keyword: effective size

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Mechanical Pretreatment of Municipal Waste Incineration Ash for Recovering Heavy Metals by the Horizontal Gyration Method

  • Park, Joonchul;Kaoru Masuda;Yamaguchi Hiroshi;Shigehisa Endoh
    • Proceedings of the IEEK Conference
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    • 2001.10a
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    • pp.664-667
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    • 2001
  • Segregation of binary particle systems in a horizontally gyrated bed has been experimentally studied to recover the heavy metals from municipal waste incineration (MWI) ash. Differences in density and size had less effect on segregation. Effective segregation took place under the centrifugal effect of 1 or less for any particle size ratio. Zn, Cu and Pb were concentrated in the upper side of bed by the horizontal vibration. However, there was less change in concentration for other metals such as Mg, Al and Fe etc. The separation system with the horizontal gyrating separator proved to be an effective method for the pretreatment of recovering Zn, Cu and Pb from incineration residues.

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Simulation of Physical Chemistry Phenomena Inside a Naturally Smoldering Cigarette (자연 연소중인 궐련내에서 일어나는 물리화학적 현상의 시뮬레이션)

  • 오인혁;김기환;정경락
    • Journal of the Korean Society of Tobacco Science
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    • v.20 no.1
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    • pp.87-94
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    • 1998
  • After we made the computer source code with mathematical model of Muramatsu et al. that was expressed by the set of simultaneous first-order ordinary differential equations in evaporation-pyrolysis zone of cigarette, we simulated the distribution profiles of temperature and density of flue-cured tobacco. Those equations were solved numerically with the Runge-Kutta-Gill algorithm assuming step size of 0.025mm by Muramatsu at at,, but in this study the advanced algorithm of Runge-Kutta 4th Order assuming step size of 0.0005mm. The initial conditions and physical parameters of Muramatsu et at. were used for solving them. The calculated values corresponded well with results of Muramatsu et al., especially the gradient of the temperature profile increased with smoldering speed and the thickness of the evaporation-pyrolysis zone decreased with increasing of smoldering speed. On the other hand, the temperature gradient decreased with increasing of the effective thermal-conductivity value and the thickness of the evaporation-pyrolysis zone increased with the effective thermal-conductivity value.

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Bayesian information criterion accounting for the number of covariance parameters in mixed effects models

  • Heo, Junoh;Lee, Jung Yeon;Kim, Wonkuk
    • Communications for Statistical Applications and Methods
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    • v.27 no.3
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    • pp.301-311
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    • 2020
  • Schwarz's Bayesian information criterion (BIC) is one of the most popular criteria for model selection, that was derived under the assumption of independent and identical distribution. For correlated data in longitudinal studies, Jones (Statistics in Medicine, 30, 3050-3056, 2011) modified the BIC to select the best linear mixed effects model based on the effective sample size where the number of parameters in covariance structure was not considered. In this paper, we propose an extended Jones' modified BIC by considering covariance parameters. We conducted simulation studies under a variety of parameter configurations for linear mixed effects models. Our simulation study indicates that our proposed BIC performs better in model selection than Schwarz's BIC and Jones' modified BIC do in most scenarios. We also illustrate an example of smoking data using a longitudinal cohort of cancer patients.

The Effective Factors of n Foam Generation Using Foam Condensate (포말 농축물에 의한 포말 생성의 영향인자)

  • SUH Kuen-Hack;SHIN Jeong-Sik;LEE Ju-Hwa
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.36 no.5
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    • pp.509-514
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    • 2003
  • We performed the experiment to determine the effective factors, such as the initial concentration of protein, pore size of air distributor, SAV (superficial air velocity), pH, salts and temperature related to foaming characteristics. The foam height in a foam generator was increased with the increase of the initial protein concentration and the decrease of pore size. As SAV was increased, the foam height was increased, and the optimum SAV was 0.84 cm/sec. The foam height was highest in the acid region and it was increased with the increase of salt concentration of NaCl and $NaHCO_3.$ The removal efficiencies of TSS (total suspended solid) and turbidity decreased with the increase of the initial protein concentration in the batch foam separator.

A High Pressure Fuel Control and its Injection Characteristics (고압 연료 제어와 분사 특성)

  • Kim, S.H.;Lee, Y.G.;Kim, J.U.;Kim, E.S.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.3 no.6
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    • pp.123-133
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    • 1995
  • An injection control valve(ICV) was designed to control the fuel flow between a common rail and an injector with two commercial solenoids. To improve the performance of ICV, the characteristic method was applied. With this method, the flow characteristics in the ICV and the injector were studied and the parameters which affect the injection characteristics were also studied. From this study, following results were obtained. The injection duration can be controlled and with modifications of the effective valve stroke of ICV, the injection quantity and duration can be reduced to desired amount. Also the injection quantity and pressure can be controlled by reducing the hole size of the injector without the variation of the injection duration. For some conditions, the desired injection characteristics can be obtained by the changes of the valve timing, the effective valve stroke, the open pressure of the injector and the hole size of the injector.

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Development of Functional Milk and Dairy Products by Nanotechnology (나노 기술을 이용한 기능성 우유 및 유제품의 개발 연구)

  • Gwak, Hae-Su
    • Journal of Dairy Science and Biotechnology
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    • v.23 no.1
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    • pp.27-37
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    • 2005
  • The development of functional foods started booming from several years ago in the world. The size of functional materials are in the range of micrometer level. This size can be much smaller into nanometer level to be more effective. We face some problems from the materials, such as flavor, taste, color, viscosity, etc. in functional materials. The problems can be solved by micro / nanoencapsulation technique. This paper showed some results of the research related on the technique for functional milks and dairy products. The nono / microcapsules are the form of liquid instead of solid. Coating materials used were fatty acid esters, and core materials were lactase, iron, ascorbic acid. isoflavone, and chitooligosaccharide. The ranges of capsules are from 100 nm to 200 ${\mu}$m. The sample milks added nano/microcapsules were homogeneous and prevented the defects of core materials. It was observed that nano / microcapsules in milk and dairy products were effective as functional material without defaults. It was indicated that targeted functional foods can be developed further in various foods by nanotechnology.

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Employing Response Surface Methodology for optimization of slow release Biostimulant ball in contaminated coastal sediments in Busan, South Korea

  • Song, Young-Chae;Subha, Bakthacachallam;Woo, Jung Hui
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2014.10a
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    • pp.87-88
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    • 2014
  • The Coastal sediment is highly contaminated due to ship transportation, industries discharges and urban sources. Various contaminants release into seawater and settle in marine sediment and it significantly affect marine eco system. In the present study evaluated the optimization of slow release biostimulant ball (BSB) in coastal sediment in busan. The effective variables like BSB size, distance and month variables on VS reduction was determined by using Response surface methodology(RSM). The analysis of variance (ANOVA) and coefficient determination (R2) of VS was 0.9369 and maximum reduction of VS was obtained in 3cm ball size and 5.5cm distance and 4 month interval time. This result revealed that the BSB in effective VS reduction in coastal sediment.

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An Empirical Study on Determinants of the Variability in Effective Tax Rates in Response to Corporate Tax Law Changes (세법변경에 따른 유효세율 변동성의 결정요인에 관한 실증연구)

  • Lee In-Jae;Roh Hyun-Sub;Kim Tae-Soo
    • Management & Information Systems Review
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    • v.11
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    • pp.91-109
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    • 2002
  • This study provides evidence on the determinants of variability in corporate ETRs(effective x rates). Specially, this study examined the association between ETRs, firm size, and variables proxying for firms' capital structure and asset mixes, while controlling for firms' profitability. Overall, results suggest that ETRs are associated with many firm-specific characteristics such as size, capital structure, asset mix, and profitability, and that some of these associations continued after Corporate Tax Law changes. In addition, although the results indicate that the association between ETRs and firm-specific characteristics have undergone a shift since tax law change, these firm-specific characteristics have continued to be associated with ETRs.

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A Meta-Analysis on the Effectiveness of Project Approach in Early Childhood Education (프로젝트 접근법의 효과에 대한 메타분석)

  • Han, Kyung-Hee;Chung, Chung-Hee;Chung, Han-Chul
    • Korean Journal of Child Studies
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    • v.25 no.6
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    • pp.131-152
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    • 2004
  • This study used meta-analysis to synthesize the effectiveness of the project approach. After reviewing 51 studies, we analyzed the effect size of 119 articles published between 1990 and 2002 using SAS 8.2 program. The grand average of the project approach effectiveness was 1.03. This implies that the experimental group that employing the project approach is more effective than control group by the 35 percentile. We also found that the project approach is more effective for preschool children group (1.21, 89%) than for the elementary school children group (0.88, 81%). Specific variables regarding the effectiveness of the project approach were analyzed and its consequences were discussed.

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Nondestructive crack detection in metal structures using impedance responses and artificial neural networks

  • Ho, Duc-Duy;Luu, Tran-Huu-Tin;Pham, Minh-Nhan
    • Structural Monitoring and Maintenance
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    • v.9 no.3
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    • pp.221-235
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    • 2022
  • Among nondestructive damage detection methods, impedance-based methods have been recognized as an effective technique for damage identification in many kinds of structures. This paper proposes a method to detect cracks in metal structures by combining electro-mechanical impedance (EMI) responses and artificial neural networks (ANN). Firstly, the theories of EMI responses and impedance-based damage detection methods are described. Secondly, the reliability of numerical simulations for impedance responses is demonstrated by comparing to pre-published results for an aluminum beam. Thirdly, the proposed method is used to detect cracks in the beam. The RMSD (root mean square deviation) index is used to alarm the occurrence of the cracks, and the multi-layer perceptron (MLP) ANN is employed to identify the location and size of the cracks. The selection of the effective frequency range is also investigated. The analysis results reveal that the proposed method accurately detects the cracks' occurrence, location, and size in metal structures.