• Journal of applied mathematics & informatics
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• 제31권3_4호
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• pp.577-594
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• 2013

In this paper, we study the global stability and the existence of almost periodic solution of high-order Hopfield neural networks with distributed delays of neutral type. Some sufficient conditions are obtained for the existence, uniqueness and global exponential stability of almost periodic solution by employing fixed point theorem and differential inequality techniques. An example is given to show the effectiveness of the proposed method and results.

• Journal of applied mathematics & informatics
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• 제28권3_4호
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• pp.823-835
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• 2010

In this paper, A FSQP algorithm for degenerate inequality constraints optimization problems is proposed. At each iteration of the proposed algorithm, a feasible direction of descent is obtained by solving a quadratic programming subproblem. To overcome the Maratos effect, a higher-order correction direction is obtained by solving another quadratic programming subproblem. The algorithm is proved to be globally convergent and superlinearly convergent under some mild conditions. Finally, some preliminary numerical results are reported.

• Nonlinear Functional Analysis and Applications
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• 제26권4호
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• pp.781-792
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• 2021

In this paper, we study well-posed problems and variational inequalities in locally convex Hausdorff topological vector spaces. The necessary and sufficient conditions are obtained for the existence of solutions of variational inequality problems and quasi variational inequalities even when the underlying set K is not convex. In certain cases, solutions obtained are not unique. Moreover, counter examples are also presented for the authenticity of the main results.

• 제어로봇시스템학회논문지
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• 제22권7호
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• pp.491-495
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• 2016

We deal with the regulation problem of nonlinear systems with time-varying delays in both the states and input. A new state feedback controller with dynamic gains is developed based on matrix inequality and non-predictor methods. The proposed control scheme is analyzed using the Razumikhin theorem, and its effectiveness is demonstrated with simulation results.

• Journal of applied mathematics & informatics
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• 제29권3_4호
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• pp.573-585
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• 2011

SQP method is one of the most important methods for solving nonlinear programming. But it may fail if the quadratic subproblem is inconsistent. In this paper, we propose a modified nonmonotone filter trust region method in which the QP subproblem is consistent. By means of nonmonotone filter, this method has no demand on the penalty parameter which is difficult to obtain. Moreover, the restoration phase is not needed any more. Under reasonable conditions, we obtain the global convergence of the algorithm. Some numerical results are presented.

• 호남수학학술지
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• 제44권2호
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• pp.281-295
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• 2022

This paper deals with the long - time behavior of global bounded solutions for a non-autonomous dispersive-dissipative equation with time-dependent nonlinear damping terms under the null Dirichlet boundary condition. By a new Lyapunov functional and Łojasiewicz-Simon inequality, we show that any global bounded solution converges to a steady state and get the rate of convergence as well, which depends on the decay of the non-autonomous term g(x, t), when damping coefficients are integral positive and positive-negative, respectively.

• 대한수학회지
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• 제48권2호
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• pp.223-240
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• 2011

In this paper, the problem on periodic solutions of the bidirectional associative memory neural networks with both periodic coefficients and periodic time-varying delays is discussed. By using degree theory, inequality technique and Lyapunov functional, we establish the existence, uniqueness, and global asymptotic stability of a periodic solution. The obtained results of stability are less restrictive than previously known criteria, and the hypotheses for the boundedness and monotonicity on the activation functions are removed.

• 대한수학회보
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• 제50권5호
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• pp.1555-1565
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• 2013

In this paper, some new generalized discrete Halanay inequalities are established. On the basis of these new established inequalities, we obtain the attracting set and the global asymptotic stability of the nonlinear discrete systems. Our results established here extend the main results in [R. P. Agarwal, Y. H. Kim, and S. K. Sen, New discrete Halanay inequalities: stability of difference equations, Commun. Appl. Anal. 12 (2008), no. 1, 83-90] and [S. Udpin and P. Niamsup, New discrete type inequalities and global stability of nonlinear difference equations, Appl. Math. Lett. 22 (2009), no. 6, 856-859].

• 한국지역지리학회지
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• 제19권3호
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• pp.551-565
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• 2013

이 연구는 오스트레일리아 NSW 주 지리 교육과정과 이에 근거하여 개발된 지리교과서에 나타난 개발교육을 분석한 것이다. 지리 교육과정 및 교과서에 나타난 개발교육의 특징을 분석한 결과는 다음과 같다. 먼저, 지리 교육과정에서 Stage 4와 Stage 5의 필수 지리는 개발교육을 구체적으로 명시화하지 않고 삶의 질의 차이와 원조 연계를 통해 개발교육에 접근하고 있는 반면, 심화 과목인 선택 지리의 경우 개발교육을 명시화하고 있다. 뿐만 아니라 Stage 6에서도 개발지리를 구체적으로 명시하여 보다 심화하여 학습하도록 하고 있다. 다음으로, 지리 교과서에서는 개발교육이 개발에 대한 학습에서 바로 시작하는 것이 아니라 일상생활에서의 삶의 질의 차이를 선행하여 학습한 후 개발 및 개발 척도를 다양한 관점에서 균형있게 이해하도록 하고, 이러한 글로벌 불평등 해소를 위해 개인 또는 조직으로서 어떻게 행동하고 실천해야 할 것인가에 대한 학습으로 계열화되어 있다. 이러한 분석 결과를 통해 얻을 수 있는 함의는 다음과 같다. 첫째, 중등학교 저학년에서는 개발을 직접적으로 다루기보다는 이와 관련한 삶의 질의 차이를 중심으로 내용을 구성하고, 중등학교 고학년에서는 개발지리에 대해 직접 학습하도록 할 필요가 있다. 둘째, 개발교육에서 등장하는 주요 개념인 개발, 개발 척도, 원조 등의 의미를 다양한 관점에서 균형 있게 다룰 필요가 있다. 셋째, 개발교육은 우리나라와 다른 국가와의 구체적인 개발 연계 사례를 통해 추상적인 상호의존성이라는 개념과 글로벌 시민성이라는 가치를 학습하고 실천할 수 있도록 할 필요가 있다. 마지막으로 글로벌 불평등을 줄이기 위한 노력을 당위적인 측면에서 기술하거나 정부 및 비정부기구 등과 같은 조직의 차원에 한정하지 않고, 개인적인 실천 사례를 통해 그들의 가치와 행위를 감정이입하도록 할 필요가 있다.

• The Journal of Asian Finance, Economics and Business
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• 제8권4호
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• pp.613-624
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• 2021

This paper analyzes the relationship between income distribution and energy consumption from a Pareto optimal approach. For this purpose, the causality relationship between electricity consumption per capita (kWh) with respect to country groups and energy consumption per capita (kg of oil equivalent) along with gross domestic product per capita was analyzed. In addition to this purpose, a Pareto analysis was conducted to determine the countries with the highest per capita national income, how much of the world total energy they consume, and whether the law of power in the energy and electricity markets exists. Finally, the impact of official development assistance provided to low-income countries by high-income countries on the low-income countries' electricity and energy consumption was analyzed. In other words, it was questioned whether pareto redistribution policies serve the purpose or not. The Engle-Granger causality approach was used in the analysis of the causality relationship between variables. Our analysis indicated that, first, the energy data of the country groups may be inadequate in revealing income inequalities. Second, the existence of Pareto law of power and global income inequality can be explained based on energy data. Finally, Pareto optimal redistribution policies to eliminate income inequality remain inadequate in practice.