• 한국수학교육학회지시리즈B:순수및응용수학
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• 제25권2호
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• pp.161-170
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• 2018

In this paper, we introduce and solve the following additive (${\rho}_1,{\rho}_2$)-functional inequality (0.1) $${\parallel}f(x+y+z)-f(x)-f(y)-f(z){\parallel}{\leq}{\parallel}{\rho}_1(f(x+z)-f(x)-f(z)){\parallel}+{\parallel}{\rho}_2(f(y+z)-f(y)-f(z)){\parallel}$$, where ${\rho}_1$ and ${\rho}_2$ are fixed nonzero complex numbers with ${\mid}{\rho}_1{\mid}+{\mid}{\rho}_2{\mid}$ < 2. Using the fixed point method and the direct method, we prove the Hyers-Ulam stability of the additive (${\rho}_1,{\rho}_2$)-functional inequality (0.1) in complex Banach spaces.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제24권1호
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• pp.21-31
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• 2017

In this paper, we introduce and solve the following additive (${\rho}_1$, ${\rho}_2$)-functional inequality $${\Large{\parallel}}2f(\frac{x+y}{2})-f(x)-f(y){\Large{\parallel}}{\leq}{\parallel}{\rho}_1(f(x+y)+f(x-y)-2f(x)){\parallel}+{\parallel}{\rho}_2(f(x+y)-f(x)-f(y)){\parallel}$$ where ${\rho}_1$ and ${\rho}_2$ are fixed nonzero complex numbers with $\sqrt{2}{\mid}{\rho}_1{\mid}+{\mid}{\rho}_2{\mid}<1$. Using the fixed point method and the direct method, we prove the Hyers-Ulam stability of the additive (${\rho}_1$, ${\rho}_2$)-functional inequality (1) in complex Banach spaces.

• 대한수학회지
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• 제57권5호
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• pp.1119-1133
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• 2020

In this paper, we derive an upper bound for the distance from a point in the immediate basin of a root of a complex polynomial to the root itself. We establish that if z is a point in the immediate basin of a root α of a polynomial p of degree d ≥ 12, then ${\mid}z-{\alpha}{\mid}{\leq}{\frac{3}{\sqrt{d}}\(6{\sqrt{310}}/35\)^d{\mid}N_p(z)-z{\mid}$, where N_p is the Newton map induced by p. This bound leads to a new bound of the expected total number of iterations of Newton's method required to reach all roots of every polynomial p within a given precision, where p is normalized so that its roots are in the unit disk.

• JSTS:Journal of Semiconductor Technology and Science
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• 제17권2호
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• pp.180-185
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• 2017

In this research, we proposed the simple and efficient method to calculate the shear stresses by using the mid-point measurements in ${\pm}45^{\circ}$ semiconductor resistor-sensor pair. Compared to the previous works, the measurements became much simpler by combining the approximation theory with the technique of mid-point measurement. In addition, we proposed another novel method for the stress calculation in which we could increase the sensitivity of the stress sensor by controlling the applied voltage between the sensor-pair. For the applied voltage of 8 V, the sensitivity showed a significant increase by 100%.

• 대한기계학회논문집
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• 제18권6호
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• pp.1365-1373
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• 1994

Elasto-dynamic deformation of flexible linkage mechanism was analyzed using the finite element method. A computer program was constructed and applied to analyze a specific crank-level 4-bar mechanism, in which the elasto-dynamic deformation of the mechanism system was obtained using mode superposition method in the case of constant input speed and the effect of geometric stiffness on the mechanism is included. Experimental verification of numerical results was conducted by measuring the elasto-dynamic deformation of mid-points of coupler and lever for the 4-bar lingkage mechanism using high speed camera and image data processing systeem. For the elasto-dynamic deformation at the lever mid-point, the numerical results including geometric stiffness almost agree with the experimental ones. However, the numerical results excluding geometric stiffness good agree with the experimental ones at the couper mid-point.

• Journal of the Korean Data and Information Science Society
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• 제24권6호
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• pp.1309-1317
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• 2013

일반화 지수분포 (generalized exponential distribution)를 따르는 점진 제 1종 구간 중도절단 (progressive type-I interval censoring) 표본에서 모수 추정은 Chen과 Lio (2010)가 최대우도 추정법 (maximum likelihood estimation), 중간점 근사법 (mid-point approximation method), EM 알고리즘 (expectation maximization algorithm), 적률 추정법 (method of moments estimation; MME)으로 하였으며, 그 방법들 중 평균제곱오차 (mean square error; MSE)가 가장 작은 추정법은 중간점 근사법이다. 하지만 중간점 근사법을 바탕으로 최대우도 추정법을 이용하여 모수를 추정하려고 한다면 모수에 대한 해를 전개할 수 없기 때문에 수치 해석적인 방법을 이용하여 추정하여야 한다. 본 논문에서는 이러한 문제를 해결하기 위해서 근사 최대우도 추정법 (approximate maximum likelihood estimation)을 이용하여 두 종류의 모수를 추정하고, 모의실험을 통하여 수치해석학적인 방법을 이용한 중간점 근사법의 해 (estimate of mid-point approximation method; MP)와 제시한 두 가지 추정량을 평균제곱오차 측면에서 비교한다.

• International Journal of Aeronautical and Space Sciences
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• 제11권2호
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• pp.118-125
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• 2010

This paper describes a mid-course guidance strategy based on the earliest intercept geometry (EIG) guidance. An analytical solution and performance validation will be addressed for generalized mid-course guidance problems in area air-defence in order to improve reachability and performance. The EIG is generated for a wide range of possible manoeuvres of the challenging missile based on the guidance algorithm using differential geometry concepts. The main idea is that a mid-course guidance law can defend the area as long as it assures that the depending area and objects are always within the defended area defined by EIG. The velocity of Intercept Point in EIG is analytically derived to control the Intercept Geometry and the defended area. The proposed method can be applied in deciding a missile launch window and launch point for the launch phase.

• 한국세라믹학회지
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• 제32권11호
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• pp.1292-1300
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• 1995

The ionic conductivity of NASICON solid electrolytes was simulated by using Monte Carlo Method (MCM). There were included two conduction paths: (1) Na1-Na2 and (2) Na1-Na2 including Na2-Na2. We assumed that mid-Na ions provde an additional driving force for Na mobile ions due to the interionic repulsion between Na1 and Na2 ions. The inflection point of vacancy availability factor, V has been shown at nearby x=2, the maximum mid-Na ions. The inflection point of vacancy availability factor, V has been shown at nearby x=2, the maximum mid-Na sites are occupied. The effective jump frequency factor, V has been shown at nearby x=2, the maximum mid-Na sites are occupied. The effective jump frequency factor, W increased rapidly with the composition at low temperature, but decreased at high temperature region. On Na1-Na2 conduction path, the minimum of charge correlation factor, fc and the maximum of $\sigma$T were appeared at x=2.0. this indicated that mid-Na ions affect on the high ionic conductivity behavior. At the whole range of NASICON composition, 1n $\sigma$T vs. 1/T* plots have been shown Arrhenius behavior but 1n (VWFc) vs. 1/T* have been shown the Arrhenius type tendency at x=2, which mid-Na is being the maximum. The results of MCM agreed with the experimental one when the chosen saddle point value was 6$\varepsilon$ : 3$\varepsilon$. Here the calculated characteristic parameter of materials, K and the phase transition temperature were -4.001$\times$103 and 178$^{\circ}C$ (1/T*=1.92, 1000/T=2.22), respectively.

• 한국측량학회지
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• 제19권4호
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• pp.365-372
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• 2001

나라사이의 경계를 결정하기 위한 일반적인 방법은 등거리원칙이다. 등거리원칙은 각각의 기준선 또는 기준점의 경계에서 일정한 거리까지를 경계로 정하는 방법이다. 본 연구에서는 등거리 원칙을 기본으로 하는 알고리즘으로 폭넓게 사용되고 있는 Two-Point 알고리즘과 Three-Point 알고리즘을 정립한 후, 알고리즘을 적용한 결과와 오차를 확인할 수 있는 경계 획선 프로그램을 개발하였다. 이 프로그램은 인공지물이나 지형지물이 없어 경계를 결정하기 어려운 해양경계 획선시 특히 유용하게 사용될 수 있다. 그 중간점 계산결과 타원체상에서 등거리원칙에 기초한 알고리즘을 적용하면, 지도 투영에 의한 어떤 왜곡도 없이 적용할 수 있고 평면이나 구에서 적용한 것 보다 오차가 적었다. 경계 획선 프로그램 개발을 통하여 도면을 이용한 수작업에 의한 여러 오차를 제거 할 수 있고, 해양경계협상시 신속히 대처할 수 있다. 또한, 기준선의 기준점 위치에러는 계산된 중간선의 중간점으로 전파되는 것을 확인할 수 있었고 그 오차를 확인하여 적합한 기준면을 설정 할 수 있었다.

• 전기학회논문지
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• 제56권9호
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• pp.1527-1534
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• 2007

This paper proposes a new concept of optimal governor-response power flow (OGPF) to obtain an optimal set of control parameters when the systems are in mid-term conditions after disturbances, ignoring the system dynamics. The idea of GOPF simply comes from the attempt to find an optimal solution of the governor-response power flow (GPF), which is a pre-exiting tool that is used to get power flow solutions that would exist several seconds after an event is applied. GPF incorporates the simplified model of governors in the systems into the power flow equations. This paper explains the concept of OGPF and depicts the OGPF formulation and application of a nonlinear interior point method as the solution technique. Also, this paper includes an example with New England 39-bus test system to illustrate the effectiveness of GOPF.