• 대한임베디드공학회논문지
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• 제19권2호
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• pp.107-114
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• 2024

Mobile ad hoc networks represent self-configuring networks of mobile devices that communicate without relying on a fixed infrastructure. However, traditional routing protocols in such networks encounter challenges in selecting efficient and reliable routes due to dynamic nature of these networks caused by unpredictable mobility of nodes. This often results in a failure to meet the low-delay and low-energy consumption requirements crucial for such networks. In order to overcome such challenges, our paper introduces a novel multi-objective and adaptive routing scheme based on the Q-learning reinforcement learning algorithm. The proposed routing scheme dynamically adjusts itself based on measured network states, such as traffic congestion and mobility. The proposed approach utilizes Q-learning to select routes in a decentralized manner, considering factors like energy consumption, load balancing, and the selection of stable links. We present a formulation of the multi-objective optimization problem and discuss adaptive adjustments of the Q-learning parameters to handle the dynamic nature of the network. To speed up the learning process, our scheme incorporates informative shaped rewards, providing additional guidance to the learning agents for better solutions. Implemented on the widely-used AODV routing protocol, our proposed approaches demonstrate better performance in terms of energy efficiency and improved message delivery delay, even in highly dynamic network environments, when compared to the traditional AODV. These findings show the potential of leveraging reinforcement learning for efficient routing in ad hoc networks, making the way for future advancements in the field of mobile ad hoc networking.

• 컴퓨터교육학회논문지
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• 제7권6호
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• pp.69-76
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• 2004

e러닝을 교육과 학습을 위하여 e비즈니스 기술 및 서비스를 사용하는 응용프로그램이다. 이는 원격지 자원과 서비스에 접근을 수월하게 함으로서 교육의 질을 높이기 위한 새로운 멀티미디어 및 인터넷 기술을 사용한다. 본 논문은 실제 TOEFL CBT에 기반을 두어 신중하게 설계되고 구현된 인터넷기반의 시험 시스템에 대하여 기술한다. 본 시스템은 콘텐츠 전달 기술, 컴퓨터 적응형 시험 알고리즘, 리뷰엔진으로 구성되어 있다. 본 논문에서는 컴퓨터기반 시험 시스템을 설계 및 구현 시 고려사항들에 대하여 서술한다.

• ETRI Journal
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• 제22권3호
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• pp.10-18
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• 2000

Although an n-th order cross-entropy (nCE) error function resolves the incorrect saturation problem of conventional error backpropagation (EBP) algorithm, performance of multilayer perceptrons (MLPs) trained using the nCE function depends heavily on the order of nCE. In this paper, we propose an adaptive learning rate to markedly reduce the sensitivity of MLP performance to the order of nCE. Additionally, we propose to limit error signal values at out-put nodes for stable learning with the adaptive learning rate. Through simulations of handwritten digit recognition and isolated-word recognition tasks, it was verified that the proposed method successfully reduced the performance dependency of MLPs on the nCE order while maintaining advantages of the nCE function.

• 제어로봇시스템학회논문지
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• 제4권2호
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• pp.178-186
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• 1998

In this paper, a robust.adaptive learning control scheme is presented for precise trajectory tracking of rigid mobile robots. In the proposed controller, a set of desired trajectories is defined and used in constructing the control input and learning rules which constitute the main part of the proposed controller. Stable operating characteristics such as precise trajectory tracking, parameter estimation, disturbance suppression, etc., are shown thorugh experiments and computer simulations.

• 전자공학회논문지B
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• 제33B권5호
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• pp.102-108
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• 1996

Adaptive resonance theory (ART2) characterized by its built-in mechanism of handling the stability-plasticity switching and by the adaptive learning without forgetting informations learned in the past, is based on an unsupervised template matching. We propose an improved tow-stage learning algorithm for aRT2: the original unsupervised learning followed by a new supervised learning. Each of the output nodes, after the unsupervised learning, is labeled according to the category informations to reinforce the template pattern associated with the target output node belonging to the same category some dominant classes from exhausting a finite number of template patterns in ART2 inefficiently. Experimental results on a set of 2545 FLIR images show that the ART2 trained by the two-stage learning algorithm yields better accuracy than the original ART2, regardless of th esize of the network and the methods of evaluating the accuracy. This improvement shows the effectiveness of the two-stage learning process.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.161.4-161
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• 2001

This paper presents adaptive control of robot manipulator using neuro-fuzzy controller Fuzzy logic is control incorrect system without correct mathematical modeling. And, neural network has learning ability, error interpolation ability of information distributed data processing, robustness for distortion and adaptive ability. To reduce the number of fuzzy rules of the FLS(fuzzy logic system), we consider the properties of robot dynamic. In fuzzy logic, speciality and optimization of rule-base creation using learning ability of neural network. This paper presents control of robot manipulator using neuro-fuzzy controller. In proposed controller, fuzzy input is trajectory following error and trajectory following error differential ...

• 문화기술의 융합
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• 제8권6호
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• pp.553-560
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• 2022

고등교육기관의 역량 중심 교육과정 운영을 위해서는 교과목 수준에서 교과 학습목표(성과기준)의 성취수준을 다각도로 평가하여 학습자의 역량 함양 정도를 파악하는 교과기반 학습평가 방법에 대한 연구가 지속적으로 필요하다. 본 연구에서는 교과목 학습성과, 학습주제, 학습개념 기반의 학습평가 모델 및 성취수준에 따른 개인화된 학습 피드백 모델을 제안한다. 먼저 데이터 모델링 과정에서 교과목의 계층화된 학습성과, 학습주제 및 학습개념 그래프 및 학습성과-평가 매트릭스 모델을 정의하고 이를 기반으로 학습성과별, 학습주제별, 학습자별 등 다각도의 학습성취 수준을 측정하고 피드백하는 알고리즘을 제안한다. 제안한 학습성취평가 모델의 유효성을 검증하기 위해 자바프로그래밍 교과목에 적용하여 실제 데이터를 기반으로 실험을 진행하였으며 그 결과 성취수준의 산출 및 학습 피드백이 가능함을 보였다.

• 말소리와 음성과학
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• 제3권3호
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• pp.91-98
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• 2011

In this paper, a multi-channel speech enhancement method using the linearly constrained minimum variance (LCMV) algorithm and a variable learning rate control is proposed. To control the learning rate for adaptive filters of the LCMV algorithm, the direction of arrival (DOA) is measured for each short-time input signal and the likelihood function of the target speech presence is estimated to control the filter learning rate. Using the likelihood measure, the learning rate is increased during the pure noise interval and decreased during the target speech interval. To optimize the parameter of the mapping function between the likelihood value and the corresponding learning rate, an exhaustive search is performed using the Bark's scale distortion (BSD) as the performance index. Experimental results show that the proposed algorithm outperforms the conventional LCMV with fixed learning rate in the BSD by around 1.5 dB.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.778_779
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• 2009

The maximum output torque developed by the machine is dependent on the allowable current rating and maximum voltage that the inverter can supply to the machine. Therefore, to use the inverter capacity fully, it is desirable to use the control scheme considering the voltage and current limit condition, which can yield the maximum torque per ampere over the entire speed range. The paper is proposed maximum torque control of induction motor drive using adaptive learning neuro fuzzy controller and artificial neural network(ANN). The control method is applicable over the entire speed range and considered the limits of the inverter's current and voltage rated value. For each control mode, a condition that determines the optimal d, q axis current $_i_{ds}$, $i_{qs}$ for maximum torque operation is derived. The proposed control algorithm is applied to induction motor drive system controlled adaptive learning neuro fuzzy controller and ANN controller, the operating characteristics controlled by maximum torque control are examined in detail. Also, this paper is proposed the analysis results to verify the effectiveness of the adaptive learning neuro fuzzy controller and ANN controller.

• 한국지능시스템학회논문지
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• 제6권4호
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• pp.49-60
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• 1996

본 논문의 목적은 신경망을 이용한 퍼지 하이퍼큐브의 적응 학습 제어알고리듬의 개발이다. 퍼지 시스템 규칙베이스 후건부의 실시간적인 수정, 초기 퍼지 제어규칙의 일시적인 안정성을 가정하여 퍼지제어기와 신경망의 장점만을 살린 지능형 제어시스템의 설계방법을 제안하였다. 퍼지 제어기로는 실현 가능한 퍼지 하이퍼큐브의 구조를 선택하였고, 퍼셉트론 신경만의 학습법칙을 적용하여 출력오차로써 퍼지 제어기의 규칙을 실시간적으로 수정해 나가는 방법을 사용하였다. 결과적으로 적응 퍼지-뉴로 제어시스템을 Cart-Pole 제어에 응용함으로써 이러한 지능형 제어기의 유효성과 강인성을 보였다.