• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.111.1-111.1
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• 2013

전자가속기는 대표적인 방사선 발생장치 중의 하나로서, 오랜 세월 동안 연구개발 되어왔으며 의료 및 산업현장에서 활용되어 왔고 그 이용분야도 매우 폭넓다. 전자가속기는 최근 들어 기술이 확산되고 성능이 고도화되면서 그 활용과 함께 전자가속기 개발 및 연구가 많이 진행되고 있다. 이러한 연구개발에 있어 전자가속기의 가속관 제작은 가장 기본이 되는 중요한 부분 중에 하나이다. 가속관제작에 있어서 RF parameter들인 resonance frequency, bandwidth, 10 GHz 범위의 higher order modes와 quality factor는 가속관에서 중요한 특성이다. 본 연구에서는 9, 6 MeV 에너지를 가지는 2856 MHz의 고주파 전자가속기의 가속관 설계, 제작 및 튜닝에 있어서 network analyzer를 이용하여 RF parameter를 측정하여 가속관의 특성을 분석한다.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.391-394
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• 2008

Durability of product is an important technical parameter of a current interception device (CID) filter. This parameter is influenced by several factors, such as: environment condition, external force, shape of device, heat and so on. In this study, the effect of the geometry of the device on durability was carried out. The effect of shape on durability of device is presented by force-carrying capacity that a device can sustain a maximum external force. Studied parameters of the CID filter's geometry include clearance, thickness, and corner radius. Fracture criterion of Cockcroft and Latham was also used to predict the maximum force-carrying capacity of device.

• Bulletin of the Korean Chemical Society
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• v.8 no.1
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• pp.19-26
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• 1987

A statistical thermodynamical treatment for polymer adsorption from solution is presented. The canonical partition function for the polymer solution in the presence of a surface or an impermeable interface is formulated on the basis of usual quasi-crystalline lattice model, Bragg-Williams approximation of random mixing, and Pak's simple treatment of liquid. The present theory gives the surface excess ${\Gamma}_{exc}$ and the surface coverage ${\phi}^s_2$ of the polymer as a function of the chain length x, the Flory-Huggins parameter x, the adsorption energy parameter $x_s$, and polymer concentration $v_2$. Present theory is also applicable to the calculation of interfacial tension of polymer solution against water. For the idealized flexible polymer, interfacial tensions according to our theory fit good to the experimental data to the agreeable degrees.

• Advances in nano research
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• v.7 no.1
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• pp.1-11
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• 2019

In this article, wave propagation characteristics in magneto-electro-elastic (MEE) nanotube considering shell model is studied in the framework nonlocal theory. To account for the small-scale effects, the Eringen's nonlocal elasticity theory of is applied. Nonlocal governing equations of MEE nanotube have been derived utilizing Hamilton's principle. The results of this investigation have been accredited by comparing them of previous studies. An analytical solution of governing equations is used to obtain phase velocities and wave frequencies. The influences of different parameters, such as different mode, nonlocal parameter, length parameter, geometry, magnetic field and electric field on wave propagation responses of MEE nanotube are expressed in detail.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.19-20
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• 2012

• International Journal of Control, Automation, and Systems
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• v.2 no.1
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• pp.68-75
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• 2004

In this paper, an estimator with an appropriate adaptive law for updating parameters is designed and analyzed based on the Lyapunov theory. The adaptive law is designed so that the estimation model follows the parameterized plant model. Using the proposed estimator, the parameters of the T-S fuzzy model can be estimated by observing the behavior of the system and it can be a basis for indirect adaptive fuzzy control.

• Computational Structural Engineering : An International Journal
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• v.1 no.2
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• pp.81-87
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• 2001

A framework for reliability analysis of structural components and systems under conditions of statistical and model uncertainty is presented. The Bayesian parameter estimation method is used to derive the posterior distribution of model parameters reflecting epistemic uncertainties. Point, predictive and bound estimates of reliability accounting for parameter uncertainties are derived. The bounds estimates explicitly reflect the effect of epistemic uncertainties on the reliability measure. These developments are enhance-ments of second-moment uncertainty analysis methods developed by A. H-S. Ang and others three decades ago.

• 한국전산유체공학회:학술대회논문집
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• 2009.04a
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• pp.191-195
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• 2009

A parametric study for for the water entry of a two dimensional symmetric wedge with deadrise angle of 10 degrees was carried out to find out the most dominant parameter. Water entry problem with constant velocity is simplified as the stationary wedge in the way of the upcoming water surface. The calculated impact loads showed that the effect of the viscosity was not so important in this problem. For a given grid system a suitable time step size can be found. The most sensitive parameter was found to be the grid size.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10a
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• pp.111-111
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• 2003

In our experiments using a new apparatus, the drape formation process was found to consist of three stages, seeds generation, their development and the final stabilizing stages. A new parameter R evaluating the shape of the drape was defined in terms of the vertical projection of the drape. Both drape coefficient and R-parameter are expected to be useful for analyzing the formation process of the fabric drape quantitatively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.7 no.5
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• pp.395-407
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• 1996

In this paper, we describe the crossover of the parasitic capacitance at the interconnections for the system miniature, analyse ground capacitance and mutual capacitance due to actually coupled line in the ICs or MCMs. From the results of deviding interconnection line with infinite parts, using Green's function with image charge method and moments, we could obtain 70% decrease of system runtime parasitic inductance because of simplicity of transforming formular.