• 전기학회논문지
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• 제64권9호
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• pp.1347-1355
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• 2015

In this study, we compare the recognition performance using PCA and RBFNNs for introducing robust face recognition system to pose variations based on pose estimation. proposed face recognition system uses Honda/UCSD database for comparing recognition performance. Honda/UCSD database consists of 20 people, with 5 poses per person for a total of 500 face images. Extracted image consists of 5 poses using Multiple-Space PCA and each pose is performed by using (2D)²PCA for performing pose classification. Linear polynomial function is used as connection weight of RBFNNs Pattern Classifier and parameter coefficient is set by using Particle Swarm Optimization for model optimization. Proposed (2D)²PCA-based face pose classification performs recognition performance with PCA, (2D)²PCA and RBFNNs.

• 한국경영과학회지
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• 제32권4호
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• pp.51-60
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• 2007

In this study, we consider the minimum ADM problem which is the fundamental problem for the cost-effective design of SONET ADM embedded in WDM ring networks. To minimize the number of SONET ADMs, efficient algorithms for the routing and wavelength assignment are needed. We propose a mathematical model based on the graph theory for the problem and propose a branch-and-price approach to solve the suggested model effectively within reasonable time. By exploiting the mathematical structure of ring networks, we developed polynomial time algorithms for column generation subroutine at branch-and-bound tree. In a computer simulation study, the suggested approach can find the optimal solution for sufficient size networks and shows better performance than the greedy heuristic method.

• Journal of Electrical Engineering and Technology
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• 제3권3호
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• pp.308-313
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• 2008

This article proposes the study and simulation of an RST regulator based on a double fed induction machine. The RST polynomial controller can improve the double fed induction machine performance in terms of overshoot, rapidity, cancellation of disturbance, and capacity to maintain a high level of performance. A control law is synthesized using an RST controller. Simulation results indicate that the proposed regulator has better performance response to speed variation, sensitivity to perturbation, and robustness. The designed control algorithm is tested on a simulation matlab code.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 D
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• pp.791-793
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• 2000

The fuzzy inference system is a popular computing framework based on the concepts of fuzzy set theory, fuzzy if-then rules, and fuzzy reasoning. The advantage of fuzzy approach over traditional ones lies on the fact that fuzzy system does not require a detail mathematical description of the system while modeling. As modeling method. the Group Method of Data Handling(GMDH) is introduced by A.G. Ivakhnenko GMDH is an analysis technique for identifying nonlinear relationships between system's inputs and output. We study a Novel Neuro-Fuzzy Network (NNFN) in this paper. NNFN is a network resulting from the combination of a fuzzy inference system and polynomial neural network(PNN) (7) which is advanced structure of GMDH. Simulation involve a series of synthetic as well as experimental data used across various neurofuzzy systems.

• Management Science and Financial Engineering
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• 제9권1호
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• pp.11-27
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• 2003

In this study, we propose a mathematical model based on the graph theory for the wavelength assignment problem arising in the design of SDH (Synchronous Digital Hierarchy) over WDM (Wavelength Division Multiplexing) ring networks. We propose a branch- and -price algorithm to solve the suggested models effectively within reasonable time in realistic SDH over WDM ring networks. By exploiting the structure of ring networks, we developed a polynomial time algorithm for efficient column generation and a branching rule that conserves the structure of column generation. In a computer simulation study, the suggested approach can find the optimal solutions within reasonable time and show better performance than the existing heuristics.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제22권4호
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• pp.505-514
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• 2008

방정식의 가해성 탐구는 수학사의 중요한 연구주제의 하나였으며, 삼차방정식과 사차방정식의 일반적인 해법은 교사양성기관의 현대대수학 교과에서 다루는 중요한 내용이다. 본 연구에서는 norm형식의 개념을 바탕으로 이차방정식의 근의 공식에 대한 방법유추를 통해 삼차방정식의 근의 공식을 유도하고, 삼차방정식의 근의 공식에 대한 방법유추를 통해 사차방정식의 근의 공식을 유도하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.204-206
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• 2007

In this study, we introduce the optimization method of fuzzy inference systems that is based on Hierarchical Fair Competition-based Parallel Genetic Algorithms (HFCGA) and information data granulation, The granulation is realized with the aid of the Hard C-means clustering and HFCGA is a kind of multi-populations of Parallel Genetic Algorithms (PGA), and it is used for structure optimization and parameter identification of fuzzy model. It concerns the fuzzy model-related parameters such as the number of input variables to be used, a collection of specific subset of input variables, the number of membership functions, the order of polynomial, and the apexes of the membership function. In the optimization process, two general optimization mechanisms are explored. The structural optimization is realized via HFCGA and HCM method whereas in case of the parametric optimization we proceed with a standard least square method as well as HFCGA method as well. A comparative analysis demonstrates that the proposed algorithm is superior to the conventional methods. Particularly, in parameter identification, we use the UNDX operator which uses multiple parents and generate offsprings around the geographic center off mass of these parents.

• 한국멀티미디어학회논문지
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• 제14권5호
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• pp.658-668
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• 2011

지난 수 십 년간 통신 기술의 발전과 웹 서비스의 팽창은 인터넷 사용자 수의 폭발적인 증가와 화상회의, 가상 증감 현실, 인터넷 게임 등 실시간 멀티미디어 멀티캐스트 서비스의 급격한 증가를 초래했다. 고밀도 파장분할다중화기술에 기반한 DWDM(Dense-Wavelength Division Multiplexing) 기술은 인터넷 사용자의 증가와 그에 따른 대역폭 요구를 수용하기 위한 방안으로 국가나 글로벌 영역 범위의 차세대 인터넷망 구현을 위한 백본망 기술로 여겨지며, 이러한 DWDM 전달망에서는 멀티캐스트 연결 요구에 대해 최적의 경로를 선택하고 선택된 경로에 효율적으로 파장을 할당하는 멀티캐스트 RWA(Routing and Wavelength Assignment) 문제가 파장 대역폭의 효율적인 활용 측면에서 매우 중요하게 다루어지고 있다. 주어진 파장 수 환경에서 최대한 많은 수의 멀티캐스트 연결을 달성하는 문제는 일반적으로 Non -deterministic Polynomial-time-complete 문제로 여겨지는 데, 본 논문에서는 가상소스를 기반으로 노드의 능력에 따른 차등화로 우선 순위를 적용하여 휴리스틱하게 멀티캐스트 라우팅 경로를 효율적으로 선정하는 DVS-PMIPMR (Differentiated Virtual Source-based Priority Minimum Interference Path Multicast Routing) 알고리즘을 제안한다. 마지막으로 같은 조건에서 더 많은 수의 멀티캐스트 라우팅 패스의 연결이 가능함을 시뮬레이션 및 성능분석 증명한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.168-173
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• 2003

In this paper, we will present a deeper look on optimal design methods that are related to path-planning for a mobile robot. To control the motion of a mobile robot in a clustered environment, it's necessary to know a suitable trajectory assuming certain start and goal point. Up to now, there are many literatures that concern optimal path planning for an obstacle avoided mobile robot. Among those literatures, we have chosen 2 novel methods for our further analysis. The first approach [4] is based on HJB(Hamilton-Jacobi-Bellman) equation whose solution is the return-function that helps to generate a shortest path to the goal. The later [5] is called polynomial-path-planning approach, in this method, a shortest polynomial-shape path would become a solution if it was a collision-free path. The camera network plays the role as sensors to generate updated map which locates the static and dynamic objects in the space. Therefore, the exhibition of both path planning and dynamic obstacle avoidance by the updated map would be accomplished simultaneously. As we mentioned before, our research will include the motion control of a true mobile robot on those optimal planned paths which were generated by above algorithms. Base on the kinematic and dynamic simulation results, we can realize the affection of moving speed to the stable of motion on each generated path. Also, we can verify the time-optimal trajectory through velocity tuning. To simplify for our analysis, we assumed the obstacles are cylindrical circular objects with the same size.

• 한국자동차공학회논문집
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• 제21권4호
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• pp.16-22
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• 2013

In this study, we propose the method of optimally changing material of BIW for minimizing weight while satisfying vehicle requirements on static stiffness. First, we formulate a material selection optimization problem. Next, we establish the CAE procedure of evaluating static stiffness. Then, to enhance the efficiency of design work, we integrate and automate the established CAE procedure using a commercial process integration and design optimization (PIDO) tool, PIAnO. For effective optimization, we adopt the approach of metamodel based approximate optimization. As a sampling method, an orthogonal array (OA) is used for selecting sampling points. The response values are evaluated at the sampling points and then these response values are used to generate a metamodel of each response using the linear polynomial regression (PR) model. Using the linear PR model, optimization is carried out an evolutionary algorithm (EA) that can handle discrete design variables. Material optimization result reveals that the weight is reduced by 44.8% while satisfying all the design constraints.