• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.468_469
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• 2009

The application of renewable energy in electric power systems is growing rapidly in order to make provision for the inequality of the climate, the dwindling supplies of coal, oil and natural gas and a further rise in oil prices. Solar cell generators(SCG) is one of the fastest growing renewable energy. A study on the renewable energy is getting more important for the application of renewable energy. This paper presents the capacity factor of SCG by calculating the probabilistic production energy of SCG.

• Journal of Electrical Engineering and Technology
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• v.12 no.4
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• pp.1417-1426
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• 2017

Power system analysis, Non-Convex Economic Dispatch (NED) is considered as an open and demanding optimization problem. Despite the fact that realistic ED problems have non-convex cost functions with equality and inequality constraints, conventional search methods have not been able to effectively find the global answers. Considering the great potential of meta-heuristic optimization techniques, many researchers have started applying these techniques in order to solve NED problems. In this paper, a new and efficient approach is proposed based on imperialist competitive algorithm (ICA). The proposed algorithm which is named multi-operator ICA (MuICA) merges three operators with the original ICA in order to simultaneously avoid the premature convergence and achieve the global optimum answer. In this study, the proposed algorithm has been applied to different test systems and the results have been compared with other optimization methods, tending to study the performance of the MuICA. Simulation results are the confirmation of superior performance of MuICA in solving NED problems.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.28-33
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• 1994

An optimal controller, e.g. LQG controller, may not be realistic in the sense that the required control power may not be achieved by existing actuators, and the measured output is not satisfactory. To be realistic, the controller should meet such constraints as sensor or actuator limitation, performance limit, etc. In this paper, the lnput/Output Variance Constrained (IOVC) control problem will be considered from the viewpoint of mathematical programming. A dual version shall be developed to solve the IOVC control problem, whose objective is to find a stabilizing control law attaining a minimum value of a quadratic cost function subject to the inequality constraint on each input and output variance for a stabilizable and detectable plant. One approach to the constrained optimization problem is to use the Kuhn-Tucker necessary conditions for the optimality and to seek an optimal point by an iterative algorithm. However, since the algorithm uses only the necessary conditions, the convergent point may not be optimal solution. Our algorithm will guarantee a sufficiency.

• The Pure and Applied Mathematics
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• v.11 no.3
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• pp.189-196
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• 2004

In this article, using the L'Hospital rule, mathematical induction, the trigonometric power formulae and integration by parts, some integral formulae for the improper integrals ${\int}_0^{\infty}$[sin$^{2m}({\alpha}x)]/(x^{2n})dx$ AND ${\int}_0^{\infty}$[sin$^{2m+1}({\alpha}x)]/(x^{2n+1})dx$ are established, where m $\geq$ n are all positive integers and $\alpha$$\neq$ 0.

• Bulletin of the Korean Mathematical Society
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• v.47 no.1
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• pp.89-102
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• 2010

This paper concerns the problem of global robust stability of a time-delay discontinuous system with a positive-defined connection matrix under polytopic-type uncertainty. In order to give the stability condition, we firstly address the existence of solution and equilibrium point based on the properties of M-matrix, Lyapunov-like approach and the theories of differential equations with discontinuous right-hand side as introduced by Filippov. Second, we give the delay-independent and delay-dependent stability condition in terms of linear matrix inequalities (LMIs), and based on Lyapunov function and the properties of the convex sets. One numerical example demonstrate the validity of the proposed criteria.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.10
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• pp.995-1001
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• 2014

In the aftermath of the financial crisis of 2008, while numerous members of the general public lost their homes and jobs, many of the largest banks held responsible for the crisis have been successfully rescued by bailouts. In this paper, through the analysis of income inequality, unemployment, tax cuts, and bailouts, we show that the interests of the general public are different from the interests of politicians and bankers. While the small elite group of politicians and bankers could set the deregulation policies with inordinate power based on full information, most people were ignorant and unconcerned about the policies, and hence did not oppose them. Specifically, we model the credit change in the financial markets of the United States by a finite state machine, and design three local supervisors representing three groups with different interests. It is then shown that the deregulation policies were adopted according to the difference of the supervisors' powers.

• International Journal of Reliability and Applications
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• v.13 no.2
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• pp.57-69
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• 2012

Our goal in this paper is to establish inequalities for the moments of new better than used in the moment generating function class ($NBU_{mgf}$). Using these inequalities we propose a new test for exponentiality versus $NBU_{mgf}$ class. Pitman's asymptotic relative efficiency, power and critical values of this test are calculated to assess the performance of the test. We proposed also a new test for exponentiality versus $NBU_{mgf}$ in the right censored data. Sets of real data are used as an example to elucidate the use of the proposed test for practical problems.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.4
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• pp.227-238
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• 2013

Although several studies show close relationships between social capitals and their performances, a little is known about specific social capitals and their effects on organizational culture and behaviour leading to their innovative outcomes within small and medium sized enterprises(: SMEs). This study examines some dimensions of social capitals and their influences on creating innovative culture and employees' behaviour. The importance of these are regarded as an imperative for SMEs to overcome the inequality of financial leverage and competitive power over resources. For the empirical analysis, survey data were collected from 51 domestic SMEs and analyzed by partial least squares(: PLS) that is one of popular structural modeling and multi-variate projection techniques to latent variables. The findings confirm a positive support of social capitals and their influences on the innovative culture and bahaviour. This result implies that managing the capability of social capitals is important for SMEs to develop the innovative culture and bahaviour and create a competitive advantage.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10a
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• pp.529-531
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• 2004

Just-Just-in-Time 컴파일러를 이용하여 자바의 성능을 향상시키려면 여러 문제들을 극복하여야 한다. 이 문제 중 중요한 부분을 차지하는 것이 null check 코드와 array bound check코드를 어떻게 최적화하느냐는 것이다. Static한 컴파일 환경에서는 이미 많은 연구가 진행되어 매우 강력한 성능을 가지는 알고리즘이 알려져 있으나 이를 컴파일 시간이 수행시간의 일부인 Just-in-Time 컴파일 환경에 적응하기에는 컴파일 오버헤드가 너무 커서 적절하지 않다. 현재 Just-in-Time 컴파일러들은 가볍고 단순한 알고리즘을 적용하지만 중복된 array bounds check를 충분히 제거하지 못하거나 아니면 강력하지만 flow-insensitive한 SSA form을 기반으로 해야 하는 알고리즘을 사용하고 있다. SSA form의 적용은 SSA form으로의 변환과 되돌림에 의한 overhead로 가볍고 빠른 컴파일러를 지향하는 Just-in-Time 컴파일러에 부합되지 않는다. 본 논문은 변수간의 대소관계를 표현하는 그래프를 array bounds check 알고리즘에 적용해 충분한 power를 내면서도 flow-sensitive한 환경에서 동작하는 알고리즘을 제안한다.

• Bulletin of the Korean Mathematical Society
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• v.58 no.5
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• pp.1109-1127
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• 2021

We study the long-term dynamics for a family of incompressible three-dimensional Leray-α-like models that employ the spectral fractional Laplacian operators. This family of equations interpolates between incompressible hyperviscous Navier-Stokes equations and the Leray-α model when varying two nonnegative parameters 𝜃₁ and 𝜃₂. We prove the existence of a finite-dimensional global attractor for the continuous semigroup associated to these models. We also show that an operator which projects the weak solution of Leray-α-like models into a finite-dimensional space is determining if it annihilates the difference of two "nearby" weak solutions asymptotically, and if it satisfies an approximation inequality.