• Geomechanics and Engineering
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• v.4 no.1
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• pp.19-37
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• 2012

This paper presents the results of analytical and numerical analyses of the effects of performing a pressuremeter test or driving a pile in clay. The geometry of the problem has been simplified by the assumptions of plane strain and axial symmetry. Pressuremeter testing or installation of driven piles has been modelled as an undrained expansion of a cylindrical cavity. Stresses, pore water pressures, and deformations are found by assuming that the clay behaves like normally consolidated modified Cam clay. Closed-form solutions are obtained which allow the determination of the principal effective stresses and the strains around the cavity. The analysis which indicates that the intermediate principal stress at critical state is not equal to the mean of the other two principal stresses, except when the clay is initially isotropically consolidated, also permits finding the limit expansion and excess pore water pressures by means of the Almansi finite strain approach. Results are compared with published data which were determined using finite element and finite difference methods.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.1
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• pp.37-45
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• 2002

We described a method of resonant mode identification in dielectric-disc loaded cylindrical cavity resonators. The characteristic equations are solved using the ContourPlot graph of Mathematica. Contour graph method uses graphical method. It is comparable with numerical method. The numerical method is very difficult mode identification. The analysis is based on the approximated electromagnetic representation which is only concentrated on the calculation of resonant frequencies, and a mode identification of resonant frequencies has not been covered. However, It is possible to calculate precise resonant frequencies and to identify the mode of resonant frequencies using the contour graph method. The contour graph method is not a method using approximated representation of electromagnetic field variation at the outer area of dielectric in the resonators. It is a method using enact representation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.5
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• pp.407-411
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• 2005

A simulation investigation on the circular cylindrical reentrant cavity with axial ridges and a cylindrical circumferential slot is presented. This study indicates that by properly adjusting the dimensions of the ridge sand the slot, the size of the cavity can be miniaturized to around $\lambda_0$ The simulation results using CST MWS show good agreement with past theoretical predictions and provide useful insight into fundamental concerns associated with electrically small antennas.

• Geomechanics and Engineering
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• v.25 no.4
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• pp.267-273
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• 2021

In this work, we compare the analytical solutions with the numerical solutions for photothermal interactions in semiconductor medium containing cylindrical cavity. This paper is devoted to a study of the photothermal interactions in semiconductor medium in the context of the coupled photo-thermal model. The basic equations are formulated in the domain of Laplace transform and the eigenvalue scheme are used to get the analytical solutions. The numerical solution is obtained by using the implicit finite difference method (IFDM). A comparison between the analytical solution and the numerical solutions are obtained. It is found that the implicit finite difference method (IFDM) is applicable, simple and efficient for such problems.

• Proceedings of the Optical Society of Korea Conference
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• 1999.08a
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• pp.22-23
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• 1999

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.2
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• pp.1-12
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• 1998

In this paper, an incoherent imaging of a high-contrast cylindrical cavity illuminated by the time-harmonic cylindrical wave is obtained ia the back-projections of he incoherent intensity patterns, which si acquired by averaging out the multi-frequency intensities of the total electric field scattered from this object in the cross-borehole measurement configuration. Multi-freuqncy effect is shown numerically and is intepreted analytically by the mutual coherence function defined in the is frequency domain. This imaging method is validated by imaging high-contrast cylindrical cavidities and the conditions to get better image are investigated.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.6 no.1
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• pp.29-38
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• 1994

Particle contamination into and out of a cavity-cylindrical cavities with aspect ratios(width/depth) less than, equal to 1 and langer than 1, and also three dianensional T's attached to a cylindrical flow tube was studied numerically, using a finite difference method. In the process of unsteady particle diffusion, the particles contained in a concentration boundary layer near the tube wall plays an important role in the initial stage, after which a quasi-steady concentration profile is developed inside the cavity, resulting in an exponential change of concentration with time. Average concentration and its rate of change are observed to be closely correlated by a power law function in terms of Reynolds number and the logarithm of Schmidt number. Effects of the three parameters-Re, Sc, and aspect ratio-are analysed and well explained.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.6
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• pp.10-18
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• 1995

Diffraction patterns of the electromagnetic field scattered by a circular cylindrical cavity embedded in a dielectric medium are analyzed. When the wavelength of the incident wave is comparable to the radius of the cavity, strong double dips occur at the locations corresponding to the top and the bottom of the cavity. Furthermore, the phase changes abruptly about the dip points. The changes of the amplitude and the phase patterns are observed as the measuring distance and the signal frequency varies. The effects of the change of the medium dielectric constant on the diffraction pattern is also presented.

• Analytical Science and Technology
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• v.5 no.3
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• pp.263-268
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• 1992

A plasma source with cylindrical microwave cavity was used as atomic emission detector for gas chromatography. Detection limits of several elements were determined for this system. Detection limits for bromine and sulfur were 0.46 pg/s and 0.51 ng/s, respectively. The plasma was stable at the range of flow rate of 10 to 20mL/min.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.12
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• pp.74-79
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• 1995

A theoretical method has been considered for the analysis of an annular slot radiator in a metal-backed cylindrical cavity with coaxial feed. In order to check the validity of the method theoretical values of the input return loss and radiation pattern are compared with experimental values. There is good agreement between them.