• Journal of the Korean Ceramic Society
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• v.27 no.4
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• pp.553-559
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• 1990

The nonuniform shrinkage has been investigaed in pressureless sintering of $\alpha$-SiC, where born carbide and phenolic resin as a carbon source are used as densification aids. Compacted specimens, prepared from the granulated powder, were sintered at 215$0^{\circ}C$ for 30min in Ar atmosphere. Using the fresh and unseasoned graphite crucible, the upwarped specimens were obtained, while specimens were uniformly shrunk in the seasoned crucible. This effect is mainly due to the nonuniform distributjion of boron carbide during heatig, which originates in the reaction of boron carbide with CO gas, providing from the result of SiO2 reduction with carbon during heating.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.573-578
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• 2000

A bar with periodically nonuniform material properties is selected as a one-dimensional model of a flat-panel speaker. This paper describes a theoretical approach to the bending waves propagating in the nonuniform bar. The phase speed of the wave is obtained using perturbation techniques for small amplitude, sinusoidal modulation of the flexural rigidity and mass density. It is shown that the wave speed is decreased due to the nonuniformity of the material properties by the amount proportional to the square of the modulation amplitude.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.1
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• pp.40-44
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• 2006

In this paper, the distortion characteristics of an electrical pulse which has a rise/fall time due to the dispersion and the reflection, on nonuniform tapered microstrip lines has investigated in time domain. The transmission characteristics on uniform microstrip lines in time domain had represented already, but the results for the nonuniform tapered microstrip lines not represented yet. We investigated the transmission characteristics for pulse signal on the nonuniform tapered microstrip lines, and the result applied to design of wide band impedance matching circuit in design of MMIC. The voltage and current transfer functions are shown for the tapered line. The dispersion and distortion obtained by using these transfer functions are represented for the nonideal square pulse.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.4
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• pp.718-724
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• 2008

We present a novel joint barcode deblurring and nonuniform illumination compensation algorithm for barcode signals whose number of modules is known. The proposed algorithm is based on a penalized least squares method using a roughness penalty function for an illumination model and a double well penalty function for a barcode signal model. In simulations, the proposed method shows an improved performance compared with a conventional method without compensating nonuniform illumination effects. In addition, the proposed method converges quickly during optimization(within 15 iterations), thereby showing strong possibility for real time decoding of barcode signals.

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.40-42
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• 1998

Magnetization distribution in the ring magnet for BLDC motor is generally nonuniform because the structure of mutipole magnetizer is not symmetry and the air gap is not uniform. In this paper, the effect of the nonuniform magnetization on characteristics of the motor such as torque ripple, unbalanced force and current is examined. Time stepped finite element method is used for electromagnetic field analysis.

• Computers and Concrete
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• v.31 no.2
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• pp.139-149
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• 2023

This article investigates the statically analysis regarding the thermal buckling behavior of a nonuniform small-scale nanobeam made of functionally graded material based on classic beam theories along with the nonlocal Eringen elasticity. The material distribution of functionally graded structures is composed of temperature-dependent ceramic and metal phases in axial and thickness directions, called two-dimensional functionally graded (2D-FG). The partial differential (PD) formulations and end conditions are extracted by using to the conservation energy method. The porosity voids are assumed in the nonuniform functionally graded (FG) structure. The thermal loads are in the axial direction of the beam. The extracted nonlocal PD equations are also solved by employing generalized differential quadrature method (GDQM). Last but not least, the information acquired is used to produce miniature sensors, providing a unique perspective on the growth of nanoelectromechanical systems (NEMS).

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.04a
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• pp.303-312
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• 1994

The problem of optimally allocating available communication channels in a cellular mobile system with nonuniform traffic distribution is considered. This problem is to minimize the weighted average blocking probability subject to cochannel interference constraints. We use the concept of pattern to deal with the problem more conveniently. Using Lagrangian relaxation and subgradient optimization techniques, we obtain high-quality solutions with information about their deviations from true optimal solutions. Computational experiments show that our method works very well.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1997.10a
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• pp.37-40
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• 1997

This paper presents a performance improvement of distributed fuzzy control system by changing the triangular membership function widths according to the input variables. The control region consists of 4 parts according to the sign of error and change of error terms. Each control part is operated by the suitable nonuniform triangular membership function. Through the simulation for the boiler-turbin model of a fossil power plant using decentralized contol, it is verified this proposal

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.737-742
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• 2000

The paper describes a theoretical study on the flexural vibration of an elastic rectangular plate with periodically nonuniform material properties. The approximate solution of the natural frequency and mode shape has been obtained using the perturbation technique for sinusoidal modulation of the flexural rigidity and mass density. It has been shown that distributed modes exist in the plate which is a two-dimensional model of the flat panel speaker.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.443-446
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• 1990

Comparison between two approaches for analysis of nonuniform transmission line with linear taper is presented. The input impedance evaluated analytically for tapered angle $2^{\circ}$ is deviated about 2.5% from that of numerical approach. The validity of our analytic method is illustrated physically.