• Journal of applied mathematics & informatics
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• 제17권1_2_3호
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• pp.797-802
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• 2005

We generate simplex polynomials by using a method, which produces an OPS in (d + 1) variables from an OPS in d variables and the Jacobi polynomials. Also we obtain a partial differential equation of the form $${\Sigma}_{i,j=1}^{d+1}\;A_ij{\frac{{\partial}^2u}{{\partial}x_i{\partial}x_j}}+{\Sigma}_{i=1}^{d+1}\;B_iu\;=\;{\lambda}u$$, which has simplex polynomials as solutions, where ${\lambda}$ is the eigenvalue parameter.

• Korean Journal of Mathematics
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• 제17권4호
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• pp.495-505
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• 2009

By means of Green function and fixed point theorem related with cone theoretic method we show that there exist multiple nonnegative solutions of a Dirichlet problem $$\array{-[p(t)x^{\prime}(t)]^{\prime}={\lambda}q(t)f(x(t)),\;t{\in}I=[0,\;T]\\x(0)=0=x(T)}$$, and a mixed problem $$\array{-[p(t)x^{\prime}(t)]^{\prime}={\mu}q(t)f(x(t)),\;t{\in}I=[0,\;T]\\x^{\prime}(0)=0=x(T)}$$, where ${\lambda}$ and ${\mu}$ are positive parameters.

• Structural Engineering and Mechanics
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• 제3권4호
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• pp.383-390
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• 1995

A 2-D four-noded finite element which contains a ${\lambda}$ singularity is developed. The new element is compatible with quadratic standard isoparametric elements. The element is tested on two different examples. In the first example, an edge crack problem is analyzed using two different meshes and different integration orders. The second example is a crack perpendicular to the interface problem which is solved for different material properties and in turn different singularity order ${\lambda}$. The results of those examples illustrate the efficiency of the proposed element.

• 대한수학회지
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• 제53권1호
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• pp.147-159
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• 2016

In this paper, subordination results of analytic function $f{\in}{\mathcal{A}}_p$ involving linear operator ${\mathcal{K}}^{{\delta},{\lambda}}_{c,p}$ are obtained. By applying the differential subordination method, results are derived under some sufficient subordination conditions. On using some hypergeometric identities, corollaries of the main results are derived. Furthermore, convolution preserving properties for a class of multivalent analytic function associated with the operator ${\mathcal{K}}^{{\delta},{\lambda}}_{c,p}$ are investigated.

• 전자공학회논문지A
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• 제33A권7호
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• pp.245-252
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• 1996

$\lambda$/4 phase-shifted DFB lasers with nonideal grating structure have been studied by using an effective-index transfer matrix method where material dispersion, vwaveguide dispersion and waveguide-structuredependent loss are taken into consideration. Nonideal grating structure in the center phase-shift region does not incur serous degradation of laser characteristics. Phase-shift error from the ideal shift of $\pi$ causes a decrease in the threshold gain difference and lasing wavelength shift and should be less than $\pi$/4 when residual facet reflectivity is 0.7%. also, positional error of the phase-shift should be less than 9% of the cavity length in order for the threshold gain difference to be decreased less than 10%.

• 산업기술연구
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• 제15권
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• pp.123-135
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• 1995

In this paper, we performed the modeling of a tunable three section DFB-LD with continuous phase using the coupled-wave equation. It was also proposed new modeling method for ${\lambda}/4$ phase shifted one. We got the characteristics of oscillation wavelength, gain, and photon density profiles according to parameters such as coupling coefficient K and current into the third sections for two case of continuous phase and ${\lambda}/4$ shifted phase one. The simulations for ${\lambda}/4$ phase shifted tunable three section DFB-LD prove that the continuous tuning range is about 4.2nm for $K=120cm^{-1}$, $L=180{\mu}m$, and the oscillation mode be within the stop-bands. Also when changed a current of both end sections, it is shown that a photon density reaches the maximum at the center.

• Journal of Magnetics
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• 제11권3호
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• pp.139-142
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• 2006

We fabricated new one-dimensional magnetophotonic crystal (1D-MPC) utilizing the second and third photonic band gaps where localized modes existed. Structure of the 1D-MPC was $(Ta_{2}O_{5}/SiO_{2})_{5}/Bi:YIG/(SiO_{2}/Ta_{2}O_{5})_{5}$ with optical thicknesses of 3$\lambda$ /4 for $Ta_{2}O_{5} and $SiO_2$ dielectric layers and $\lambda$ /2 for Bi:YIG defect layer, where $\lambda$ is a wavelength of a localized mode in the second photonic band gap. Faraday rotation at the localized mode in the second photonic band gap was enhanced, which was confirmed by calculation using 4${\times}$4 matrix method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 A
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• pp.21-23
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• 1997

The analysis of the permanent type synchronous motor is performed by using the finite element method (FEM). The optimal design of the permanent magnet is presented for minimizing cogging torque in this paper. The cogging torque is expressed in terms of scalar potential computed by the virtual work formula. The minimization of cogging torque is achieved by using the ( ${\mu}$ + ${\lambda}$ ) Evolution Strategy (ES) and the selected flux densities are used to a constraint.

• 천문학회보
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• 제39권1호
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• pp.60.2-60.2
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• 2014

The dust cloud around ${\lambda}$-Orionis is seen to be circular symmetric with the large angular extent (${\sim}8^{\circ}$). However, whether the three dimensional structure of the cloud is shell or torus ring is not yet fully resolved. We studied the structure of the dust cloud using a three-dimensional Monte-Carlo simulation code, MoCafe (Monte Carlo radiative transfer). The dust density structure of the cloud was inferred based on the star-count method. We assumed that the cloud is a spherical shell or a torus ring and calculated the radial profiles of scattered light originating from a central OB association. Comparison of the results with the S2/68 ultraviolet observations indicates that the cloud is a spherical shell. We also compared the Av map around ${\lambda}$-Orionis with the optical depth obtained based on the star-count.

• Journal of Positioning, Navigation, and Timing
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• 제10권4호
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• pp.253-262
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• 2021

Global Navigation Satellite Systems (GNSS) based precise positioning using Real Time Kinematic (RTK) technique has been proposed as an enabler of the formation operation of moving vehicles. In RTK methods, the integer ambiguity of GNSS carrier phase measurements must be resolved. Although there have been many proposed algorithms for the integer ambiguity resolution, the widelane combination of carrier phase measurements and LAMBDA methods have gained the most popularity in literatures when dual frequency GNSS measurements were used. In this paper, we evaluated five alternative methods to determine relative positions of moving base and rover receivers; the round-off scheme of widelane carrier phase, instant least-squares and Kalman filter-based LAMBDA with widelane carrier phase, instant least-squares and Kalman filter-based LAMBDA with dual frequency measurements. The paper presented the performance of each method using flight test data, which showed their strength and weakness in the aspects of time-to-first-fix, ambiguity resolution success ratio, and relative position errors. Based on that, we provided practical recommendations of RTK operations for moving vehicles.