• Journal of Astronomy and Space Sciences
• /
• 제25권4호
• /
• pp.415-424
• /
• 2008

곽영실 등(2008)의 연구로부터 고위도 하부 열권의 평균 수평바람 형태는 발산적인 흐름보다는 회전적인 흐름에 더 강하게 지배된다는 것이 확인되었다. 이 연구에서는, 곽영실 등(2008)의 연구의 연장으로, 회전적인 흐름의 척도인 소용돌이도(vorticity)를 유지시켜주는 강제(forcing)항들을 정량화하고 서로 비교 분석함으로써, 고위도 하부 열권에서의 전체 수평 바람장의 강한 회전 흐름을 유발시키는 주된 물리적인 과정을 규명하였다. 이 연구를 위하여 미 국립대기연구소(NCAR)의 열권-이온권 전기역학적 대순환 모델(Thermosphere-ionosphere Electrodynamic General Circulation Model, TIEGCM)을 이용하였다. 고위도 하부 열권의 소용돌이의 변화를 결정하고 유지시켜 주는 주된 강제항은 이온항력(ion drag)항과 수평 이류(horizontal advection)항으로 확인되었다. 늘림(stretching)항 또한 뚜렷한 기여를 하는 것으로 확인되었다. 소용돌이도 강제에 대한 IMF의 영향이 고도 105-110km부근까지 뚜렷하게 나타남이 확인되었다.

• Korean Journal of Mathematics
• /
• 제23권4호
• /
• pp.521-536
• /
• 2015

We investigate the nonlinear motions of discrete loaded cable with different periodic forcing. We present the numerical evidence of the nonlinear motions of the cable by solving initial value problems and obtaining the motions after a long time. There appeared to be various types of nonlinear oscillations over a wide range of frequencies and amplitudes for the periodic forcing term.

• 대한수학회지
• /
• 제60권2호
• /
• pp.465-477
• /
• 2023

In this study, we consider a heat equation with a variable-coefficient linear forcing term and a time-periodic boundary condition. Under some decay and smoothness assumptions on the coefficient, we establish the existence and uniqueness of a time-periodic solution satisfying the boundary condition. Furthermore, possible connections to the closed boundary layer equations were discussed. The difficulty with a perturbed leading order coefficient is demonstrated by a simple example.

• 한국지능시스템학회:학술대회논문집
• /
• 한국퍼지및지능시스템학회 2007년도 춘계학술대회 학술발표 논문집 제17권 제1호
• /
• pp.213-216
• /
• 2007

In this paper. we study the controllability for the semilinear fuzzy integrodifferential equations with nonlocal condition and forcing term with memory in $E_N$ by using the concept of fuzzy number whose values are normal, convex, upper semicontinuous and compactly supported interval in $E_N$.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• 제11권1호
• /
• pp.25-32
• /
• 2011

In this paper, we study the existence and uniqueness of solutions for the impulsive semilinear fuzzy integrodifferential equations with nonlocal conditions and forcing term with memory in n-dimensional fuzzy vector space ($E^n_N$, $d_{\varepsilon}$) by using Banach fixed point theorem. That is an extension of the result of Kwun et al. [9] to impulsive system.

• 한국컴퓨터산업학회논문지
• /
• 제7권1호
• /
• pp.33-38
• /
• 2006

케이블 뿐 아니라 현수교의 운동은 비선형 미분방정식에 지배된다. 미분방정식은 비선형성 때문에 진폭이 큰 해가 존재한다. 유한차분법을 이용하여 비선형 방정식의 주기근을 구한다. 일노드의 힘과 힘의 약간 변형된 형태를 이용하여 방정식의 해를 구한다.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• 제7권1호
• /
• pp.34-40
• /
• 2007

Balasubramaniam and Muralisankar (2004) proved the existence and uniqueness of fuzzy solutions for the semilinear fuzzy integrodifferential equations with nonlocal initial condition. Park et al. (2006) found the sufficient condition of this system. Recently, Kwun et al. (2006) proved the existence and uniqueness of solutions for the semilinear fuzzy integrodifferential equations with nonlocal initial conditions and forcing term with memory in $E_N$. In this paper, we study the controllability for this system by using the concept of fuzzy number whose values are normal, convex, upper semicontinuous and compactly supported interval in $E_N$.

• 한국공간구조학회논문집
• /
• 제15권4호
• /
• pp.73-80
• /
• 2015

The new rotary friction damper was developed using several two-nodal rotary frictional components with different clamping forces. Because of these components, the rotary friction damper can be activated by building movements due to lateral forces such as a wind and earthquake. In this paper, various dependency tests such as displacement amplitude, forcing frequency and long term cyclic loading were carried out to evaluate on the structural performance and the multi-slip mechanism of the new damper. Test results show that the multi-slip mechanism is verified and friction coefficients are dependent on displacement amplitute and forcing frequency except long term cyclic loading.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• 제6권4호
• /
• pp.288-292
• /
• 2006

Many authors have studied several concepts of fuzzy systems. Balasubramaniam and Muralisankar (2004) proved the existence and uniqueness of fuzzy solutions for the semilinear fuzzy integrodifferential equation with nonlocal initial condition. Recently, Park, Park and Kwun (2006) find the sufficient condition of nonlocal controllability for the semilinear fuzzy integrodifferential equation with nonlocal initial condition. In this paper, we study the existence and uniqueness of solutions for the semilinear fuzzy integrodifferential equations with nonlocal condition and forcing term with memory in $E_{N}$ by using the concept of fuzzy number whose values are normal, convex, upper semicontinuous and compactly supported interval in $E_{N}$.

• Kyungpook Mathematical Journal
• /
• 제56권1호
• /
• pp.29-40
• /
• 2016

In this paper, we consider the nonlinear hyperbolic equations with forcing term. Some suffcient conditions for the oscillation are derived by using integral averaging method and a generalized Riccati technique.