• Bulletin of the Korean Mathematical Society
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• v.49 no.4
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• pp.705-714
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• 2012

In this paper, we study nonlinear equation arising in MEMS modeling electrostatic actuation. We will prove the local and global existence of solutions of the generalized parabolic MEMS equation. We present that there exists a constant ${\lambda}^*$ such that the associated stationary problem has a solution for any ${\lambda}$ < ${\lambda}^*$ and no solution for any ${\lambda}$ > ${\lambda}^*$. We show that when ${\lambda}$ < ${\lambda}^*$ the global solution converges to its unique maximal steady-state as $t{\rightarrow}{\infty}$. We also obtain the condition for the existence of a touchdown time $T{\leq}{\infty}$ for the dynamical solution. Furthermore, there exists $p_0$ > 1, as a function of $p$, the pull-in voltage ${\lambda}^*(p)$ is strictly decreasing with respect to 1 < $p$ < $p_0$, and increasing with respect to $p$ > $p_0$.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.536-540
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• 2003

A new concept of adaptive focusing, using a Rotman lens, is presented in this paper. A Rotman lens is a microwave lens which is able to focus microwave power on its focal arc or generate multiple beams. By adding the array of phase shifters between a Rotman lens and antenna elements, the wavefront can be adaptively modulated to focus objects distributed in short range rather than far-field zone. From the optical point of view, the propagations of the lens have been simplified from the Fresnel diffraction integral to the Fourier transform. Using Fourier Transform, a beam propagation method has been developed to show improvement of the resolution by controlling wavefront of wave propagating from an aperture-type antenna array. The beam width(or spot size) and intensity have been calculated for a focused beam propagating from an array having $10{\lambda}$ of its size. For the beam with $20{\lambda},\;30{\lambda}$, and $50{\lambda}$ of geometrical focal length, the half-power beamwidth (spot size) is about $1.1{\lambda},\;1.3{\lambda}$, and $1.9{\lambda}$, respectively.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.4
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• pp.75-79
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• 2009

In this paper the method was proposed which uses ${\lambda}$-fuzzy measure to detect the edge of the features of the face region. In the conventional method the features was founded using valley, brightness and edge. This method had its drawbacks that it is so sensitive to the external noises and environments. This paper proposed ${\lambda}$-fuzzy measure to cope with this drawbacks. By considering each weight of the pixels the integral evaluation was considered using the center of area method. Thus the continuity of the edge was kept by way of the neighborhood information and the reduction of time complexity wad resulted in.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.263-265
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• 2007

An ultrasonic linear motor using lambda shape vibrators has been designed and fabricated. The multiway ultrasonic motors mainly consist of an lambda shape ultrasonic vibrator which generates elliptical motions in beat. The lambda shape ultrasonic linear motor use longitudinal and bending vibration mode. In order to high precision motion control and multiway moving, piezoceramics were adhered to lambda shape brass elastic material. The finite element method was used to optimize dimension of ultrasonic vibrator and direction of vibratory displacement. As a result of estimating the characteristics of the ultrasonic linear motor, The results have shown that the lambda shape ultrasonic linear motor can be moved multiwav by using the phase control. Close agreement between the FEM results and experimental results obtained for the lambda shape ultrasonic linear motor.

• The Korean Journal of Pesticide Science
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• v.8 no.3
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• pp.210-219
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• 2004

Susceptibility of Periplaneta americana male adults to 61 commercial insecticides was evaluated by diet dipping method. Among them eight insecticides of dichlorvos, benfuracarb, cypermethrin, deltamethrin, fenpropathrin, $\zeta$-cypermethrin, $\lambda$-cyhalothrin and fipronil showed 100% mortality. The insect was more susceptible to dichlorvos and fenpropathrin in filter paper contact method than in diet dipping one, but benfuracarb was vice versa. Toxicities of the seven chemicals were evaluated by application parts of the such as head, thorax, abdomen, and legs. Dichlorvos, benfuracarb and $\lambda$-cyhalothrin were more toxic when applied to head, and deltamethrin, fenpropathrin and cypermethrin were abdomen. $LT_{50}$ values by diet dipping method showed that dichlorvos, benfuracarb and $\lambda$-cyhalothrin acted more rapidly than boric acid and hydramethylnon. The values of the former three were 0.10, 0.29 and 0.12 days, and those of the latter two were 6.2 and 4.8 days, respectively.

• Journal of computational fluids engineering
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• v.16 no.2
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• pp.49-55
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• 2011

Turbulent flows with wavy wall are simulated using Residual-based Variational Multiscale Method (RB-VMS) which is proposed by Bazilves et al(2007) as new Large Eddy Simulation methodology. Incompressible Navier-Stokes equations are integrated using Isogeometric analysis which adopt the basis function as NURBS. The Reynolds number is 6760 based on the bulk velocity and averaged channel height. And the amplitude (${\alpha}/{\lambda}$) of wavy wall is 0.05. The computational domain is $2{\lambda}{\times}1.05{\lambda}{\times}{\lambda}$ in the streamwise, wall normal and spanwise direction. Mean quantities and turbulent statistics near wavy wall are compared with DNS results of Cherukat et al.(1998). The predicted results show good agreement with reference data.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.3
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• pp.1-6
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• 1990

When TE waves incident to the infinite conductor grating plane, current distributions on the strip is found by the spectral domain analysis and the moment method. Current distributions on the strip as the parameter of incident angle of waves are calculated for the grating plane of which strip space is $0.05{\lambda}{\sim}5{\lambda}$, and of which the ration of strip width to its space is 0.4 - 0.8 . In order to varify the validity of the present method, the numerical results are compared with other method.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.146-146
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• 2000

This paper presents field test results of the GPS precise positioning using carrier phase observable. The Least-squares AMBiguity Decorrelation Adjustment(LAMBDA) method is implemented to resolve integer ambiguity problem for two epoch Ll carrier phase measurement data. Field test results show that the GPS precise positioning of cm-level accuracy is obtainable with conventional low cost, single frequency C/A code GPS receivers.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.04a
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• pp.115-118
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• 2003

높은 정밀도를 갖는 상대위치결정은 매우 정밀한 반송파 측정값을 이용하며, 단기간에 높은 정밀도를 얻기 위해서는 미지정수가 결정되어야 한다. 본 논문에서는 LAMBDA 방법을 이용하여 이중차 미지정수를 해결하는 알고리즘을 정립하고, L1 반송파를 이용하여 상대위치를 결정하는 프로그램을 개발하였다.

• Economic and Environmental Geology
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• v.25 no.1
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• pp.73-77
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• 1992

This paper compares numerical quadrature techniques for computing an inverse Fourier transform integral in two-dimensional resistivity modeling. The quadrature techniques using exponential and cubic spline interpolations are examined for the case of a homogeneous earth model. In both methods the integral over the interval from 0 to ${\lambda}_{min}$, where ${\lambda}_{min}$, is the minimum sampling spatial wavenumber, is calculated by approximating Fourier transformed potentials to a logarithmic function. This scheme greatly reduces the inverse Fourier transform error associated with the logarithmic discontinuity at ${\lambda}=0$. Numrical results show that, if the sampling intervals are adequate, the cubic spline interpolation method is more accurate than the exponential interpolation method.