• 대한수학회보
• /
• 제46권5호
• /
• pp.905-915
• /
• 2009

Making use of a generalized differential operator we introduce some new subclasses of multivalent analytic functions in the open unit disk and investigate their inclusion relationships. Some integral preserving properties of these subclasses are also discussed.

• Kyungpook Mathematical Journal
• /
• 제51권2호
• /
• pp.217-232
• /
• 2011

Differential subordination and superordination results are obtained for multivalent meromorphic functions associated with the Liu-Srivastava linear operator in the punctured unit disk. These results are derived by investigating appropriate classes of admissible functions. Sandwich-type results are also obtained.

• 충청수학회지
• /
• 제7권1호
• /
• pp.123-139
• /
• 1994

In this paper we are concerned with optimal control problems whose costs are quadratic and whose states are governed by linear delay differential equations and general boundary conditions. The basic new idea of this paper is to introduce a new class of linear operators in such a way that the state equation subject to a starting function can be viewed as an inhomogeneous boundary value problem in the new linear operator equation. In this way we avoid the usual semigroup theory treatment to the problem and use only linear operator theory.

• Kyungpook Mathematical Journal
• /
• 제55권3호
• /
• pp.625-639
• /
• 2015

Differential subordinations and superordinations results are obtained for certain meromorphic functions in the punctured unit disk which are associated with an integral operator. These results are obtained by investigating appropriate classes of a dmissible functions. Sandwich-type results are also obtained.

• 한국산학기술학회논문지
• /
• 제11권5호
• /
• pp.1685-1692
• /
• 2010

정칙화 반복처리 과정에 사용되는 정칙화 연산자는 라플라시안 연산자를 주로 사용하고 있으나, 일반적으로 미분 연산자를 사용하게 되어있다. 본 논문에서는 정칙화 연산자로서의 일반적인 미분연산자들과 제안된 연산자의 성능을 비교, 검토하여 분석하였다. 가우시안에 의해 훼손된 영상에서는, 윤곽부분은 제안된 연산자가 기존에 사용된 연산자보다 수렴성 및 복원효과가 뛰어나며 평면부분에서는 기존의 연산자가 제안된 연산자보다 안정적으로 수렴함을 알 수 있었다. 정칙화 이론은 잡음의 평활화와 윤곽의 복원을 동시에 고려하여 처리하기 때문에 영역을 평면부분과 중간부분 그리고 윤곽부분으로 나누어서 처리결과를 비교하였다.

• 한국산업정보학회논문지
• /
• 제24권5호
• /
• pp.121-127
• /
• 2019

본 논문에서는 물류창고, 제조업, 협업 로봇 등 다양한 애플리케이션에 활용되고 있는 비홀로노믹 제약을 가진 차동 바퀴형 모바일 로봇의 용이한 운용을 위한 로컬 속도 생성 제어 알고리즘을 제안한다. 기존의 차동 바퀴형 모바일 로봇 운용 방법은 운용자가 자신의 좌표계가 아닌 로봇의 좌표계를 기준으로 인지하고 로봇의 속도를 직접 생성해야 하였으며, 이로 인해 운용의 직관성이 낮아지고 업무의 효율 저하 및 사고 발생률이 증가하게 된다. 본 연구에서는 이를 개선하여 운용자가 자신의 좌표계를 기준으로 로봇을 운용할 수 있도록 한다. 제안하는 알고리즘은 실제 차동 바퀴형 모바일 로봇을 활용한 실험을 통하여 알고리즘의 효용성을 검증한다.

• 대한수학회보
• /
• 제49권3호
• /
• pp.455-463
• /
• 2012

In this paper, by using degree theory, we consider a kind of higher-order Li$\acute{e}$enard type $p$-Laplacian differential equation as follows $$({\phi}_p(x^{(m)}))^{(m)}+f(x)x^{\prime}+g(t,x)=e(t)$$. Some new results on the existence of anti-periodic solutions for above equation are obtained.

• 충청수학회지
• /
• 제31권1호
• /
• pp.13-27
• /
• 2018

By using of the Banach fixed point theorem, the theory of a strongly continuous semigroup of operators and resolvent operator, we investigate the existence and uniqueness of S-asymptotically ${\omega}-periodic$ mild solutions for some differential (integrodifferential) equations with piecewise constant argument when specially ${\omega}$ is an integer.

• Korean Journal of Mathematics
• /
• 제27권1호
• /
• pp.119-129
• /
• 2019

Balance function is one of the joint factors to determine fall in risk theory. It helps to moderate the progression and riskiness of falls for detecting balance and fall risk factors. Nevertheless, the objective measures for balance function require expensive equipment with the assessment of any expertise. We establish the existence and uniqueness of a multi-order fractional differential equations based on ${\psi}$-Hilfer operator on time scales with balance function. This class describes the dynamic of time scales derivative. Our tool is based on the Schauder fixed point theorem. Here, sufficient conditions for Ulam-stability are given.

• 제어로봇시스템학회논문지
• /
• 제5권5호
• /
• pp.521-528
• /
• 1999

The nth-order, scalar, linear time-varying (LTV) systems can be dealt with operators on a differential ring. Using this differential algebraic structure and a classical result on differential operator factorizaitons developed by Floquet, a novel eigenstructure(eigenvalues, eigenvectors) concepts for linear time0varying systems are proposed. In this paper, Necessary and sufficient conditions for the existence of well-defined(free of finite-time singularities) SD- and PD- spectra for SPDOs with complex- and real-valued coefficients are also presented. Three numerical examples are presented to illustrate the proposed concepts.