• English Language & Literature Teaching
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• v.10 no.1
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• pp.77-106
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• 2004

This study aims to investigate how the four college students interact with one another to discuss and construct meaning in a small reading group. Additionally, this study attempts to examine how the participants played their roles in the group. Data sources consisted of transcripts of the students' interactions, questionnaires and informal interviews, and the researchers' observation notes. The data revealed that the participants contributed fairly steadily to the interactions by checking with own grammatical knowledge, providing lexical information, understanding the micro level context, and presenting the macro level context. Several pedagogical implications are presented for the practical classroom. Findings of the study suggest effective ways to implement group activities in reading classes and a teacher's role for optimum group learning.

• Structural Engineering and Mechanics
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• v.13 no.3
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• pp.345-353
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• 2002

Three noded plate and shell finite element and 3D beam element in conjunction with Lanczos method are used for studying the effect of boat tail angle on the free vibration characteristics of a typical payload fairing for three different cylinder diameters with height to diameter ratio 1.5. Configurations without boat tail structural member are also studied. One half of the one side fairing structure is considered for the analysis and symmetric boundary conditions are used.

• 전기의세계
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• v.29 no.4
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• pp.256-259
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• 1980

A singular pertubation theory is applied to obtain an approximate solution for suboptimal control of nuclear reactors with spatially distributed parameters. The inverse of the neutron velocity is regarded as a small perturbing parameter, and the model, adopted for simplicity, is a cylindrically symmetrical reactor whose dynamics are described by the one group diffusion equation with one delayed neutron group. The Helmholtz mode expansion is used for the application of the optimal theory for lumped parameter systems to the spatially distributed parameter systems. An asymptotic expansion of the feedback gain matrix is obtained with construction of the boundary layer correction up to the first order.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.24.4-24
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• 2001

Many livings form groups which we consider as collective systems. The collective motion of the group shows various dynamics and patterns, and many model equations are proposed to explain such phenomenon. In our previous work, We proposed simple deterministic model which shows various types of group behaviors. In this paper, we modify it in order to apply to a real robotic system. Here we assume that the space resolution of each robot´s sensors is low and that the sensors detect the nearest robots. It was confirmed the robots with modified model also shows various types of motion.

• Korean Chemical Engineering Research
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• v.59 no.4
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• pp.521-531
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• 2021

Vacuum Pressure Impregnation (VPI) is a process that enhances physical properties by coating some types of epoxy resins on windings of stator used in large rotators such as generators and motors. During vacuum and pressurization of the VPI process, resin gas is generated by vaporization of epoxy resin. When the tank is opened for curing after finishing impregnation, resin gas is leaked out of the tank. If the leaked resin gas spreads throughout the workplace, there are safety and environmental problems such as fire, explosion and respiratory problems. So, exhaust system for resin gas is required during the process. In this study, a case study of exhaust efficiency by location of vent was conducted using Computational Fluid Dynamics (CFD) in order to design a system for exhausting resin gas generated by the VPI process. The optimal exhaust system of this study allowed more than 90% of resin gas to be exhausted within 1,800 seconds and reduced the fraction of resin gas below the Low Explosive Limit (LEL).

• Journal of Microbiology and Biotechnology
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• v.8 no.1
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• pp.1-7
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• 1998

• Proceedings of the Korean Magnetic Resonance Society Conference
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• 2000.01a
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• pp.14-14
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• 2000

• Transactions of the KSME C: Technology and Education
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• v.3 no.2
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• pp.107-115
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• 2015

The analysis of multi-flexible-body dynamics (MFBD) has been an important issue in the area of the computational dynamics. This technique has been developed and improved in RecurDyn solver. This paper reviews the formulation which is applied in the RecurDyn solver. Basically, in order to solve the multi-flexible-body dynamics problem, an incremental finite element formulation using a corotational procedure is used. In particular, in order to solve the rigid and flexible bodies together, a constraint equation between a rigid body and a flexible body is applied, in which a virtual body and a flexible body joint are introduced.

• Journal of Digital Convergence
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• v.16 no.8
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• pp.393-400
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• 2018

The purpose of this study was to empirically investigate the emotional dynamics among sport issues, social structure changes and collective behaviors with time-series analysis. For the purpose, the doping scandal of Tae-Hwan Park was chosen and simplified into 10 episodes. And replies and articles on them were analysed by time-series analysis. As the conclusions, first, there was a clear causal relationship between sport issue and sport emotion. Second, sport emotion was a social being which interacting with social process. Third, the sport emotional dynamics was confirmed. With this study, the sport emotion dynamics was empirically verified, but more statistical approaches would be needed for stronger evidences.

• Membrane Journal
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• v.25 no.2
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• pp.162-170
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• 2015

In this study, gas permeability of polyimide materials having a various amine group was measured and molecular dynamics was used to analyze the dynamic characteristics of the gas molecules in the polyimide by calculating the position and velocity of the gas molecules with change of the time. The gas permeability of polyimide membrane having substitution site which increase free volume in the polymer was increased. However, polyimide with rigid structure showed decreased gas permeability. As a result of analyzing the change in the gas permeation behavior using molecular dynamics simulations, we confirmed that the results show the same tendency with actual measurements of the gas permeability.