• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.466-471
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• 2004

Efficient numerical finite element analysis of creeping concrete structures requires the use Kelvin or Maxwell chain model, which is most conveniently identified from a continuous retardation or relaxation spectrum, the spectrum in turn being determined from the given compliance or relaxation function. The method of doing that within the context of solidification theory for creep with aging was previously worked out by Bazant and Xi, but only for the case of a continuous retardation spectrum based on Kelvin chain. The present paper is motivated by the need to incorporate concrete creep into the recently published microplane model M4 for nonlinear triaxial behavior of concrete, including tensile fracturing and behavior under compression. In that context. the Maxwell chain is more effective than Kelvin chain. because of the kinematic constraint of the microplanes used in M4. Determination of the continuous relaxation spectrum for Maxwell chain. based on the solidification theory, is outlined and numerical examples are presented.

• Bulletin of the Korean Mathematical Society
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• v.55 no.3
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• pp.679-698
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• 2018

In this paper, with optimal normalized constants, the asymptotic expansions of the distribution and density of the normalized maxima from generalized Maxwell distribution are derived. For the distributional expansion, it shows that the convergence rate of the normalized maxima to the Gumbel extreme value distribution is proportional to 1/ log n. For the density expansion, on the one hand, the main result is applied to establish the convergence rate of the density of extreme to its limit. On the other hand, the main result is applied to obtain the asymptotic expansion of the moment of maximum.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.721-727
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• 2000

Impedance method was carried out to design the electrode that can measure the void fraction of the bubbly flow in pool reservoir. To find out the optimum electrode shape, Styrofoam-tests were performed in a specially designed acrylic reservoir. Three kinds of electrodes were designed to compare the characteristics of water-air flow. The resistance was increased as the void fraction increased and the capacitance was decreased as the void fraction increased. The resistance is a main parameter to express the nature of the water-air flow in impedance method. Almost all the values of impedance were involved in resistance. The degree of deviation from the mean-resistance values showed reasonable results. Electrode type-I expressed excellent results among the three electrode shapes. The impedance values in void fraction 0-10% were similar to those of Maxwell's equation. But the impedance values in void fraction 10-20% were not similar to those of Maxwell' equation because of the edge effect near electrode.

• Proceedings of the KIEE Conference
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• 2004.10a
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• pp.104-106
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• 2004

본 논문에서는 세탁기용 외전형 BLDC 전동기를 기본 모델로 하고, 이를 FEM 상용프로그램인 Maxwell을 이용하여 해석 및 설계를 하고자 한다. 본 논문에서 설계대상으로 하는 외전형 BLDC 전동기는 기존에 사용중인 모델로서, 내부의 고정 전기자는 기존의 모델에 맞도록 외경을 그대로 유지하면서 Teeth 등을 설계변수로 하였고, 외부의 회전 자석계자는 주어진 외경의 치수 범위 내에서 영구자석의 형상과 두께 회전자 요크의 두께 등을 설계 변수로 하여 코깅 토오크가 최소가 되도록 최적 설계를 하였다. 유한요소법을 적용하여 자속분포, 코깅 토오크, 토오크 둥을 해석하였고, 코깅 토오크의 최소화를 통하여 효율 및 전동기의 성능을 향상시켰다.

• Journal of Electrical Engineering and Technology
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• v.7 no.3
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• pp.336-341
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• 2012

Deformations in a cage-induction machine are investigated with simulations. The contribution of the Maxwell stress in the air gap and coil regions of the machine on the deformation is studied by comparing results obtained with and without inclusion of the stress into the calculation. The work attests the acceptability of an energy-based magneto-mechanical model for a 2D mesh of two different rotating electrical machines.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.769-771
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• 2000

저 주파수에서 인덕턴스를 정밀하게 측정하는 방법은 RLC를 이용한 resonance 방법과 교류브리지를 이용한 방법이 있다. 현재 선진 국가표준기관에서의 인덕턴스 표준유지는 약 5 ppm정도이고, 인덕턴스 측정브리지는 국가에 따라 자체 개발하여 사용하며 평균적으로 약 20 ppm의 불확도로 보급을 하고 있다. 이러한 세계적 수준으로 인덕턴스 표준을 유지, 보급하기 위하여 10nF의 전기용량 표준으로부터 10 mH의 인덕턴스를 유도할 수 있는 Maxwell-wein bridge가 개발이 되었다. 이 브리지가 개발됨으로서 10 mH의 경우 400 Hz$\sim$5 kHz의 주파수 범위내에서 약 8 ppm($2{\sigma}$)의 불화도로서 인덕턴스 표준을 유지할 수가 있게 되었다.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.4
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• pp.226-232
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• 2000

In magnetic systems, distribution of electromagnetic force density causes mechanical deformation, which results in noise and vibration. In this paper, Korteweg-Helmholtzs energy method and equivalent magnetic charge method are employed for comparison of their resulting distributions of force density. The force density from the Korteweg-Helmholtzs method is expresses with two Maxwell stresses on the inside and the outside fo magnetic material respectively. The other is calculated using the magnetic Coulombs law. In the numerical model of an electromagnet, their numerical results are compared. The distributions by the two methods are almost the same. And their total forces are also shown to be the same to the one calculated from the conventional Maxwell stress tensor. But the magnetic charge method is easier and more efficient in numerical calculation.

• Bulletin of the Korean Chemical Society
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• v.13 no.4
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• pp.413-419
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• 1992

The theoretical equation for the relaxation spectrum of nonlinear viscoelastic polymeric material was derived from the Ree-Eyring and Maxwell non-Newtonian model. This model consists of infinite number of hyperbolic sine law Maxwell elements coupled in parallel plus a spring without a dashpot. Infinite number of nonlinear viscoelastic Maxwell elements can be used by specifying distribution of relaxation times, hole volumes, molecular weights, crystallite size and conformational size, etc. The experimentals of stress relaxation were carried out using the tensile tester with the solvent chamber. The relaxation spectra of nylon 6 filament fibers in various electrolytic solutions were obtained by applying the experimental stress relaxation curves to the theoretical equation of relaxation spectrum. The determination of relaxation spectra was performed from computer calculation.

• Advances in nano research
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• v.13 no.1
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• pp.77-86
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• 2022

This paper studied the peristaltic transport of upper convected Maxwell nanofluid through a porous medium in a heated (isothermal) symmetric vertical channel. The nanofluid is assumed to be electrically conducting in the presence of a uniform magnetic field. These phenomena are modeled mathematically by a differential equations system by taking low Reynolds number and long-wavelength approximation, the yield differential equations have solved analytically. A suggested new technique to display and discuss the trapping phenomenon is presented. We discussed and analyzed the pumping characteristics, heat function, flow velocity and trapping phenomena which were illustrated graphically through a set of figures for various values of parameters of the problem. The numerical results show that, there are remarkable effects on the vertical velocity, pressure gradient and trapping phenomena with the thermal change of the walls.

• Nonlinear Functional Analysis and Applications
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• v.27 no.3
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• pp.471-497
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• 2022

In this paper, we study a system of nonlinear wave equations associated with the helical flows of Maxwell fluid. By constructing a N-order iterative scheme, we prove the local existence and uniqueness of a weak solution. Furthermore, we show that the sequence associated with N-order iterative scheme converges to the unique weak solution at a rate of N-order.