• Title/Summary/Keyword: Macroscopic approach

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Macroscopic-Metacognitive Aspects of Mathematics Learning (수학 학습 활동에 대한 거시-메타인지적 고찰)

  • 백석윤
    • Journal of Educational Research in Mathematics
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    • v.11 no.1
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    • pp.1-10
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    • 2001
  • Most existing research into the metacognitive approach in mathematics learning has been concentrated mainly in the study of phenomena of metacognitive (including the affective) behaviour in the context of mathematical problem solving or more broadly mathematical content-elated learning. However, this study originally constructs the concept of "macroscopic metacognition" which could be differentiated with general metacognition, and draws out macroscopic-metacognitive factors among the elementary and middle school students through individual interview. Questionnaire research is executed to find out how the macroscopic metacognition is included into the students' mathematics learning and the relationship between their mathematics learning accomplishment and macroscopic metacognition. Thus, a considerable degree of the positive relationship between these two variables was found out.

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Fabrication of Multi-layered Macroscopic Hydrogel Scaffold Composed of Multiple Components by Precise Control of UV Energy

  • Roh, Donghyeon;Choi, Woongsun;Kim, Junbeom;Yu, Hyun-Yong;Choi, Nakwon;Cho, Il-Joo
    • BioChip Journal
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    • v.12 no.4
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    • pp.280-286
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    • 2018
  • Hydrogel scaffolds composed of multiple components are promising platform in tissue engineering as a transplantation materials or artificial organs. Here, we present a new fabrication method for implementing multi-layered macroscopic hydrogel scaffold composed of multiple components by controlling height of hydrogel layer through precise control of ultraviolet (UV) energy density. Through the repetition of the photolithography process with energy control, we can form several layers of hydrogel with different height. We characterized UV energy-dependent profiles with single-layered PEGDA posts photocrosslinked by the modular methodology and examined the optical effect on the fabrication of multi-layered, macroscopic hydrogel structure. Finally, we successfully demonstrated the potential applicability of our approach by fabricating various macroscopic hydrogel constructs composed of multiple hydrogel layers.

A Theoretical Study on Passenger Car Eguivalent Factors (승용차환산 계수에 관한 이론적 연구)

  • 박창호;김동녕
    • Journal of Korean Society of Transportation
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    • v.9 no.2
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    • pp.5-26
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    • 1991
  • Concepts of passenger car equivalent(PCE) based on various philosophies is reviewed. The headway method is redefined in two ways namely a macroscopic headway method and a microscopic headway method of which the concepts are confused in literature. As definition of the microscopic headway method is from intuitive approach so theoretical basis for this method is explained in connection with the macroscopic headway method. In addition new classification and evaluation of complicated existing theories was conducted to make the reader understand more easily.

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A Network Partition Approach for MFD-Based Urban Transportation Network Model

  • Xu, Haitao;Zhang, Weiguo;zhuo, Zuozhang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.11
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    • pp.4483-4501
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    • 2020
  • Recent findings identified the scatter and shape of MFD (macroscopic fundamental diagram) is heavily influenced by the spatial distribution of link density in a road network. This implies that the concept of MFD can be utilized to divide a heterogeneous road network with different degrees of congestion into multiple homogeneous subnetworks. Considering the actual traffic data is usually incomplete and inaccurate while most traffic partition algorithms rely on the completeness of the data, we proposed a three-step partitioned algorithm called Iso-MB (Isoperimetric algorithm - Merging - Boundary adjustment) permitting of incompletely input data in this paper. The proposed algorithm was implemented and verified in a simulated urban transportation network. The existence of well-defined MFD in each subnetwork was revealed and discussed and the selection of stop parameter in the isoperimetric algorithm was explained and dissected. The effectiveness of the approach to the missing input data was also demonstrated and elaborated.

Modeling and Energy Management Strategy in Energetic Macroscopic Representation for a Fuel Cell Hybrid Electric Vehicle

  • Dinh, To Xuan;Thuy, Le Khac;Tien, Nguyen Thanh;Dang, Tri Dung;Ho, Cong Minh;Truong, Hoai Vu Anh;Dao, Hoang Vu;Do, Tri Cuong;Ahn, Kyoung Kwan
    • Journal of Drive and Control
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    • v.16 no.2
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    • pp.80-90
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    • 2019
  • Fuel cell hybrid electric vehicle is an attractive solution to reduce pollutants, such as noise and carbon dioxide emission. This study presents an approach for energy management and control algorithm based on energetic macroscopic representation for a fuel cell hybrid electric vehicle that is powered by proton exchange membrane fuel cell, battery and supercapacitor. First, the detailed model of the fuel cell hybrid electric vehicle, including fuel cell, battery, supercapacitor, DC-DC converters and powertrain system, are built on the energetic macroscopic representation. Next, the power management strategy was applied to manage the energy among the three power sources. Moreover, the control scheme that was based on back-stepping sliding mode control and inversed-model control techniques were deduced. Simulation tests that used a worldwide harmonized light vehicle test procedure standard driving cycle showed the effectiveness of the proposed control method.

Approaches and Issues on the Research about Housing for the Elderly (노인주거 연구의 접근방법과 쟁점)

  • 지은영;홍형옥
    • Journal of Families and Better Life
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    • v.20 no.5
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    • pp.137-147
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    • 2002
  • Purpose of this study is to find the research direction to solve the housing problems for the elderly which based on approaches and issues in related studies. Research method was interpretative analysis of the articles issued from 1976 to 2002. Each approach (rationalistic approach, ecological approach, micro-sociological approach, typological approach, environment-psychological approach, welfare approach) produced helpful information and had relative merits. But the researchers must regard housing for the elderly as a social problem in macroscopic view to solve the housing problems for older people with welfare approach. As a result, to solve the housing problems with welfare approach for the elderly who live in their own place with community care, studies about lifetime home, care and repair, and management of housing for the elderly might be needed. And research about existing services, transfer system of services, financial problems, man power to manage the system might be needed to spread out the services to the middle class elderly.

Modeling of unilateral effect in brittle materials by a mesoscopic scale approach

  • Pituba, Jose J.C.;Neto, Eduardo A. Souza
    • Computers and Concrete
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    • v.15 no.5
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    • pp.735-758
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    • 2015
  • This work deals with unilateral effect of quasi-brittle materials, such as concrete. For this propose, a two-dimensional meso-scale model is presented. The material is considered as a three-phase material consisting of interface zone, matrix and inclusions - each constituent modeled by an appropriate constitutive model. The Representative Volume Element (RVE) consists of inclusions idealized as circular shapes randomly placed into the specimen. The interface zone is modeled by means of cohesive contact finite elements developed here in order to capture the effects of phase debonding and interface crack closure/opening. As an initial approximation, the inclusion is modeled as linear elastic as well as the matrix. Our main goal here is to show a computational homogenization-based approach as an alternative to complex macroscopic constitutive models for the mechanical behavior of the quasi-brittle materials using a finite element procedure within a purely kinematical multi-scale framework. A set of numerical examples, involving the microcracking processes, is provided. It illustrates the performance of the proposed model. In summary, the proposed homogenization-based model is found to be a suitable tool for the identification of macroscopic mechanical behavior of quasi-brittle materials dealing with unilateral effect.

Determination of the linear elastic stiffness and hygroexpansion of softwood by a multilayered unit cell using poromechanics

  • Gloimuller, Stefan;de Borst, Karin;Bader, Thomas K.;Eberhardsteiner, Josef
    • Interaction and multiscale mechanics
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    • v.5 no.3
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    • pp.229-265
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    • 2012
  • Hygroexpansion of wood is a known and undesired characteristic in civil engineering. When wood is exposed to changing environmental humidity, it adsorbs or desorbs moisture and warps. The resulting distortions or - at restrained conditions - cracks are a major concern in timber engineering. We herein present a multiscale model for prediction of the macroscopic hygroexpansion behavior of individual pieces of softwood from their microstructure, demonstrated for spruce. By applying poromicromechanics, we establish a link between the swelling pressure, driving the hygroexpansion of wood at the nanoscale, and the resulting macroscopic dimensional changes. The model comprises six homogenization steps, which are performed by means of continuum micromechanics, the unit cell method and laminate theory, all formulated in a poromechanical framework. Model predictions for elastic properties of wood as functions of the moisture content closely approach corresponding experimental data. As for the hygroexpansion behavior, the swelling pressure has to be back-calculated from macroscopic hygroexpansion data. The good reproduction of the anisotropy of wood hygroexpansion, based on only a single scalar calibration parameter, underlines the suitability of the model. The multiscale model constitutes a valuable tool for studying the effect of microstructural features on the macroscopic behavior and for assessing the hygroexpansion behavior at smaller length scales, which are inaccessible to experiments. The model predictions deliver input parameters for the analysis of timber at the structural scale, therewith enabling to optimize the use of timber and to prevent moisture-induced damage or failure.

Mesoscopic study on historic masonry

  • Sejnoha, J.;Sejnoha, M.;Zeman, J.;Sykora, J.;Vorel, J.
    • Structural Engineering and Mechanics
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    • v.30 no.1
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    • pp.99-117
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    • 2008
  • This paper presents a comprehensive approach to the evaluation of macroscopic material parameters for natural stone and quarry masonry. To that end, a reliable non-linear material model on a meso-scale is developed to cover the random arrangement of stone blocks and quasi-brittle behaviour of both basic components, as well as the impaired cohesion and tensile strength on the interface between the blocks and mortar joints. The paper thus interrelates the following three problems: (i) definition of a suitable periodic unit cell (PUC) representing a particular masonry structure; (ii) derivation of material parameters of individual constituents either experimentally or running a mixed numerical-experimental problem; (iii) assessment of the macroscopic material parameters including the tensile and compressive strengths and fracture energy.

An Analysis of the Economic effect on Free Trade Agreement between Korea and China through the Computable General Equilibrium model (일반균형분석을 통한 한.중 자유무역협정의 경제적 효과와 추진 타당성 고찰)

  • Park, Do-Joon
    • International Commerce and Information Review
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    • v.9 no.1
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    • pp.313-331
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    • 2007
  • In a rapidly changing environment of international trade, the purpose of this study is to examine economic benefits and losses of each country involved in the negotiation on the Free Trade Agreement (FTA) in Northeast Asia and to prepare strategies for the negotiation in the FTA between Korea and China. Previous researches on FTA have been made mainly from the macroeconomic perspective. The approach in this study is a combination of regulatory, reviewing regulations, and economic making quantitative analysis of the economic effects of FTA, which are the basic background of FTA. In economic analysis, I estimated the macroscopic economic effects of FTA by examining the effects of FTA on the trade balance, GDP and production of focal countries through the Computable General Equilibrium(CGE) model using GTAP data set.

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