• Proceedings of the IEEK Conference
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• 2000.06a
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• pp.271-274
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• 2000

In this paper, the distortion of an electrical pulse with rise/fall time resulting from dispersion and reflection as it propagates along a tapered microstrip line is investigated, and the delay time and distortion rate with respect to input and load impedances are analyzed on triangular and exponential tapered lines and analyzed the influence of the reflection and frequency dispersion on the distorted voltage wave in the tapered lines. The observed overshoot in front of the distorted wave is caused due to the frequency dispersion and the sustained tail of that comes from the reflection in the tapered line.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.8
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• pp.1-6
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• 1999

The only transmission characteristics in frequency domain is considered when using the tapered transmission line for wide-band impedance matching in MCM and MIC designs. In this paper, the distortion of an electrical pulse with rise/fall time resulting from dispersion and reflection as it propagates along a tapered microstrip line is investigated, and the delay time and distortion rate with respect to input and load impedances are analyzed on triangular and exponential tapered lines. A dispersion model of the phase constant proposed by Kirschning-Jansen is used to meet the frequency, accuracy and microstrip parametric requirements. The triangular tapered line shows both shorter delay time and higher distortion rate than those of the exponential tapered line. Furthermore, the amplitude of signal reflected from load point is calculated in time domain.

• Advances in aircraft and spacecraft science
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• v.10 no.1
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• pp.19-49
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• 2023

The present study proposes a theoretical and numerical investigation on the dynamic response behaviour of a functional graded (FG) ceramic-metal tapered rotor shaft system, by the differential quadrature finite elements method (DQFEM) to identify the natural frequencies for modelling and analysis of the structure with suitable validations. The purpose of this paper is to explore the influence of heat gradients on the natural frequency of rotation of FG shafts via three-dimensional solid elements, as well as a theoretical examination using the Timoshenko beam mode, which took into account the gyroscopic effect and rotational inertia. The functionally graded material's distribution is described by two distribution laws: the power law and the exponential law. To simulate varied thermal conditions, radial temperature distributions are obtained using the nonlinear temperature distribution (NLTD) and exponential temperature distribution (ETD) approaches. This work deals with the results of the effect on the fundamental frequencies of different material's laws gradation and temperature gradients distributions. Attempts are conducted to identify adequate explanations for the behaviours based on material characteristics. The effect of taper angle and material distribution on the dynamic behaviour of the FG conical rotor system is discussed.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.8
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• pp.45-51
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• 2000

The distortion of an electrical pulse, which has a rise/fall time due to the dispersion and the reflection, on tapered microstrip lines has investigated In time domain. The voltage and current transfer functions are shown for the tapered line. The dispersion distortion obtained by using these trans(or functions are represented for the nonideal square pulse along the triangular, Tchebycheff and exponential tapered lines, and analyzed the influence of the reflection and the frequency dispersion on the distorted voltage wave in the tapered lines. The observed overshoot in front of the distorted wane is caused due to the frequency dispersion and the sustained tail of that comes from the reflection in the tapered line.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.217-220
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• 2005

In this paper describes novel m antenna using aperture matched type slot structure. It substitutes edge diffractions by curved-surface diffractions which have a tendency to provide an undisturbed energy flow across the junction, around the curved surface, and into free-space. The proposed antenna is composed of a CPW feed structure, exponential tapered slot and the curved sectional at the edge. experimental resulte show that aperture matched type slot improve the performance of the UWB antenna.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.10a
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• pp.25-28
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• 2001

The problem considered is the buckling of a rectangular orthotropic plate, tapered in thickness in a direction parallel to two sides and compressed in that direction. Curves are presented showing the variation of buckling stress coefficient with the special loads. The type of thickness variation is exponential. While this paper is presented how to design for an efficient orthotropic plate taper from physical consideration.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.66 no.3
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• pp.105-109
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• 2017

In this paper is proposed wide band reconfiguration antenna by using PIN diode. The proposed antenna consisted of elliptical dipole and exponential taper balun. The proposed new matching method was exponential tapered balun in this paper. The research paper comprised of two PIN diode and Elliptical dipole. This paper used CPW to CPS feed. We obtained a good band width characteristics result by simulating. This antenna is designed to apply ISM and WiFi band.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.984-987
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• 2003

This paper discusses the lateral vibration of a bar which has its tip free. The uniform bar has a solution by summation of some simple exponential functions. But if its shape is not uniform, its solution could be by Bessel's function, or mathematical solution could not be existed. Even if the solution of Bessel's function exists. as Bessel function is a series function, we must get the solution by numerical method, Hereof the author proposes the solution of the matrix method by Ritz's method, and proposes a new deflection shape

• Structural Engineering and Mechanics
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• v.66 no.6
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• pp.737-748
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• 2018

The current study presents a new technique in the framework of the nonlocal elasticity theory for a comprehensive buckling analysis of Euler-Bernoulli nano-beams made up of bidirectional functionally graded material (BDFGM). The mechanical properties are considered by exponential and arbitrary variations for axial and transverse directions, respectively. The various circumstances including tapering, resting on two-parameter elastic foundation, step-wise or continuous variations of axial loading, various shapes of sections with various distribution laws of mechanical properties and various boundary conditions like the multi-span beams are taken into account. As far as we know, for the first time in the current work, the buckling analyses of BDFGM nano-beams are carried out under mentioned circumstances. The critical buckling loads and mode shapes are calculated by using energy method and a new technique based on calculus of variations and collocation method. Fast convergence and excellent agreement with the known data in literature, wherever possible, presents the efficiency of proposed technique. The effects of boundary conditions, material and taper constants, foundation moduli, variable axial compression and small-scale of nano-beam on the buckling loads and mode shapes are investigated. Moreover the analytical solutions, for the simpler cases are provided in appendices.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.10
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• pp.946-949
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• 2007

This paper discusses the lateral vibration of a beam with boundary condition of one end fixed and the other end free. The uniform beam has a solution by summation of some simple exponential functions. But if its shape is not uniform, its solution could be by Bessel's function or mathematical solution could not exist. Even if the solution of Bessel's function exists, as Bessel function is a series function, we must get the solution by numerical method. Author had proposed the solution of the matrix method by Ritz's method and a new mode shape function, and had earned the good results for a wedge beam. Hereby a vibration analysis for the tapered beam with circle cross section was executed, and so good results were showed.