• 통합자연과학논문집
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• 제15권3호
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• pp.99-110
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• 2022

Solar photovoltaic (PV) system shows a non-linear current (I) -voltage (V) characteristics, which depends on the surrounding environment factors, such as irradiance, temperature, and the wind. Solar PV system, with current (I) - voltage (V) and power (P) - Voltage (V) characteristics, specifies a unique operating point at where the possible maximum power point (MPP) is delivered. At the MPP, the PV array operates at maximum power efficiency. In order to continuously harvest maximum power at any point of time from solar PV modules, a good MPPT algorithms need to be employed. Currently, due to its simplicity and easy implementation, Perturb and Observe (P&O) algorithms are the most commonly used MPPT control method in the PV systems but it has a drawback at suddenly varying environment situations, due to constant step size. In this paper, to overcome the difficulties of the fast changing environment and suddenly changing the power of PV array due to constant step size in the P&O algorithm, least mean Square (LMS) methods is proposed together with P&O MPPT algorithm which is superior to traditional P&O MPPT. PV output power is predicted using LMS method to improve the tracking speed and deduce the possibility of misjudgment of increasing and decreasing the PV output. Simulation results shows that the proposed MPPT technique can track the MPP accurately as well as its dynamic response is very fast in response to the change of environmental parameters in comparison with the conventional P&O MPPT algorithm, and improves system performance.

• 한국정보통신학회논문지
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• 제14권3호
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• pp.565-571
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• 2010

본 논문에서는 퍼셉트론형 신경회로망에 오차역전파 알고리즘을 사용하여 학습을 실시하여, N비트의 패리티판별에 필요한 최소의 중간유닛수의 해석에 관한 연구이다. 따라서 본 논문은 제안한 퍼셉트론형 신경회로망의 중간 유닛의 수를 변화시켜 N비트의 패리티 판별 실험을 실시하였다. 본 시스템은 패라티 판별의 실험을 통하여 N비트 패리티 판별이 가능하다는 것을 실험으로 확인한다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.327-330
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• 1995

If a mobile robot is used in a real situation, robot must face a moving obstacles. In that case, the collision avoidance algorithm for moving obstacle is a indispensible element in mobile robot control. We csrried out a research to find and evaluate the advanced algorithm for mobile robot. At first we generate the continous path for mobi;e robot. Then by creating a curved path for avoidance, the mobile robot can change its path smoothly. Smoothed path made the robot adapt more effectively to the changing of path. Under time-varying condition, computer simulation was performed to show the validation of proposed algorithm.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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• pp.483-487
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• 1994

In this paper, we analize the effect of a steering water used in a unified phase I-phase II semi-infinite constrained optimization algorithm and present a new algorithm based on the facts that when the point x is far away from the feasible region where all the constraints are satisfied, reaching to the feasible region is more important than minimizing the cost function and that when the point x is near the region, it is more efficient to try to reach the feasible region and to minimize the cost function concurrently. Also, the angle between the search direction vector and the gradient of the cost function is considered when the steering parameter value is computed. Even though changing the steering parameter does not change the rate of convergence of the algorithm, we show through some examples that the proposed algorithm performs better than the other algorithms.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.35-37
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• 2005

In this study, a P- and T-wave detection algorithm in ECG, obtained by minimized filtering to prevent waveform distortion, has been realized. The algorithm uses two slope tracing waves, the descending slope tracing wave and the ascending slope tracing wave, developed for efficient determination of slope inverting points and sudden slope changing points. The algorithm generates the slope tracing waves which trace the original ECG wave, and subtracts one tracing wave from the other to detect P- and T-waves. The algorithm has been applied to MIT/BIH database in order to verify its efficacy and validity in practical applications.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.785-786
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• 2008

In this paper, we propose a fast Motion Estimation (ME) algorithm for low computational complexity based on spatial correlations. The proposed algorithm uses the motion vector of neighboring blocks, to decide the location of initial searching point. The number of searching point decreases by changing the location of initial searching point. Experimental results show that the proposed algorithm reduces searching points about $7{\sim}13%$ and increases PSNR about $0.1{\sim}0.5$(dB) compared with conventional algorithm.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.164.1-164
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• 2001

Q-learning is a recent reinforcement learning algorithm that does not need a modeling of environment and it is a suitable approach to learn behaviors for autonomous agents. But when it is applied to multi-agent learning with many I/O states, it is usually too complex and slow. To overcome this problem in the multi-agent learning system, we propose the successive Q-learning algorithm. Successive Q-learning algorithm divides state-action pairs, which agents can have, into several Q-functions, so it can reduce complexity and calculation amounts. This algorithm is suitable for multi-agent learning in a dynamically changing environment. The proposed successive Q-learning algorithm is applied to the prey-predator problem with the one-prey and two-predators, and its effectiveness is verified from the efficient avoidance ability of the prey agent.

• 전기학회논문지P
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• 제66권1호
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• pp.48-52
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• 2017

This paper proposes a hybrid algorithm of space-time block coding and space-frequency block coding using alternate time switch. The traditional alternate time-switched space-time or space-frequency block coding technique for orthogonal frequency division multiplexing system does not provide a good performance with a variety of communication environments. This hybrid algorithm has searched good performance ranges in various environments in view points of mobile speed and doppler frequency. In this paper, we investigate better performance ranges for two algorithms, suggest a hybrid algorithm for dynamically changing communication environments, propose a structure for transmitter and receiver, and show that its performance is better than the traditional algorithm by simulations.

• 산업공학
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• 제22권3호
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• pp.223-233
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• 2009

In this paper we developed a method for an optimal planning to reorganize Dong offices to enhance the administrative efficiency. First we defined a mathematical model for the optimal planning problem of reorganizing Dong office and developed a genetic algorithm to solve the problem. For the purpose of minimizing standard deviation of population, area and distance among reorganized offices, the constraints such as allocation, distance, area, population, etc. are considered and weights are applied to Dong offices in the downtown and shopping area. The developed algorithm was applied for reorganizing Dong offices in Jongro Gu, Seoul. The results showed that the developed algorithm could be applied for the real world problem. This study may be applied to the optimal decision of reorganization of offices in the similar reorganization or company M&A situations by changing constraints and weights.

• 대한전기학회논문지:전력기술부문A
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• 제51권6호
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• pp.302-310
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• 2002

This paper presents an application of a improved branch exchange (IBE) algorithm with a tie branch power (TBP) flow equation to solve the Optimal Routing problem for operation of a radial Power system including power distribution system. The main objective of the Optimal Routing problem usually is to minimize the network real power loss and to improve the voltage profile in the network. The new BE algorithm adopts newly designed methods which are composed by decision method of maximum loss reduction and new index of loss exchange in loop network Thus, the proposed algorithm in this paper can search the optimal topological structures of distribution feeders by changing the open/closed states of the sectionalizing and tie switches. The proposed algorithm has been evaluated with the practical IEEE 32, 69 bus test systems and KEPCO 148 bus test system to show favorable performance gained.