• 제목/요약/키워드: Learning Functions

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신경 회로망을 사용한 로보트 매니퓰레이터의 학습 제어 (Learning control of a robot manipulator using neural networks)

  • 경계현;고명삼;이범희
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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    • pp.30-35
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    • 1990
  • Learning control of a robot manipulator is proposed using the backpropagation neural network. The learning controller is composed of both a linear feedback controller and a neural network-based feedforward controller. The stability analysis of the learning controller is presented. Three energy functions are selected in teaching the neural network controller : 1/2.SIGMA.vertical bar torque error vertical bar $^{2}$, 1/2.SIGMA..alpha. vertical bar position error vertical bar $^{2}$ + .betha. vertical bar velocity error vertical bar $^{2}$ + .gamma. vertical bar acceleration error vertical bar $^{2}$ and learning methods are presented. Simulation results show that the learning controller which is learned to minimize the third energy function performs better than the others in tracking problems. Some properties of the learning controller are discussed with simulation results.

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Machine Learning Applied to Uncovering Gene Regulation

  • Craven, Mark
    • 한국생물정보학회:학술대회논문집
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    • 한국생물정보시스템생물학회 2000년도 International Symposium on Bioinformatics
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    • pp.61-68
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    • 2000
  • Now that the complete genomes of numerous organisms have been ascertained, key problems in molecular biology include determining the functions of the genes in each organism, the relationships that exist among these genes, and the regulatory mechanisms that control their operation. These problems can be partially addressed by using machine learning methods to induce predictive models from available data. My group is applying and developing machine learning methods for several tasks that involve characterizing gene regulation. In one project, for example, we are using machine learning methods to identify transcriptional control elements such as promoters, terminators and operons. In another project, we are using learning methods to identify and characterize sets of genes that are affected by tumor promoters in mammals. Our approach to these tasks involves learning multiple models for inter-related tasks, and applying learning algorithms to rich and diverse data sources including sequence data, microarray data, and text from the scientific literature.

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퍼지 추론에 의한 리커런트 뉴럴 네트워크 강화학습 (Fuzzy Inferdence-based Reinforcement Learning for Recurrent Neural Network)

  • 전효병;이동욱;김대준;심귀보
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 1997년도 춘계학술대회 학술발표 논문집
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    • pp.120-123
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    • 1997
  • In this paper, we propose the Fuzzy Inference-based Reinforcement Learning Algorithm. We offer more similar learning scheme to the psychological learning of the higher animal's including human, by using Fuzzy Inference in Reinforcement Learning. The proposed method follows the way linguistic and conceptional expression have an effect on human's behavior by reasoning reinforcement based on fuzzy rule. The intervals of fuzzy membership functions are found optimally by genetic algorithms. And using Recurrent state is considered to make an action in dynamical environment. We show the validity of the proposed learning algorithm by applying to the inverted pendulum control problem.

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ON LEARNING OF CMAC FOR MANIPULATOR CONTROL

  • 최동엽;황현
    • 한국기계연구소 소보
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    • 통권19호
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    • pp.93-115
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    • 1989
  • Cerebellar Model Arithmetic Controller(CMAC) has been introduced as an adaptive control function generator. CMAC computes control functions referring to a distributed memory table storing functional values rather than by solving equations analytically or numerically. CMAC has a unique mapping structure as a coarse coding and supervisory delta-rule learning property. In this paper, learning aspects and a convergence of the CMAC were investigated. The efficient training algorithms were developed to overcome the limitations caused by the conventional maximum error correction training and to eliminate the accumulated learning error caused by a sequential node training. A nonlinear function generator and a motion generator for a two d. o. f. manipulator were simulated. The efficiency of the various learning algorithms was demonstrated through the cpu time used and the convergence of the rms and maximum errors accumulated during a learning process; A generalization property and a learning effect due to the various gains were simulated. A uniform quantizing method was applied to cope with various ranges of input variables efficiently.

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PDA기반 멀티미디어 학습시스템 설계 및 구현 (Design and Implementation of Multimedia Learning System based PDA)

  • 이순기;김창수;심규박
    • 수산해양교육연구
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    • 제16권2호
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    • pp.163-170
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    • 2004
  • The rapid exchanges of mobile computing environment and development of wireless communication are providing many effects for learning activity of students. Recently, PDA system developers which are studying memory capacity, communication speed and size of screen support techniques to be capable of learning from students in the wireless or moving environment. In this viewpoints, this paper has a purpose to design multimedia learning system to be able to do with sound lecture contents. The implemented system largely consists of two parts which have the teacher module and students module. The one manages learning progress of students, class management, bulletin board and etc. The other is capable of using studying and bulletin functions. The main idea of this research is focus to upgrade the effect of learning without almost treating the existing studies, which can be listening sound lecture and also seeing text and image at the same time.

활성화 함수에 따른 유출량 산정 인공신경망 모형의 성능 비교 (Comparison of Artificial Neural Network Model Capability for Runoff Estimation about Activation Functions)

  • 김마가;최진용;방재홍;윤푸른;김귀훈
    • 한국농공학회논문집
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    • 제63권1호
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    • pp.103-116
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    • 2021
  • Analysis of runoff is substantial for effective water management in the watershed. Runoff occurs by reaction of a watershed to the rainfall and has non-linearity and uncertainty due to the complex relation of weather and watershed factors. ANN (Artificial Neural Network), which learns from the data, is one of the machine learning technique known as a proper model to interpret non-linear data. The performance of ANN is affected by the ANN's structure, the number of hidden layer nodes, learning rate, and activation function. Especially, the activation function has a role to deliver the information entered and decides the way of making output. Therefore, It is important to apply appropriate activation functions according to the problem to solve. In this paper, ANN models were constructed to estimate runoff with different activation functions and each model was compared and evaluated. Sigmoid, Hyperbolic tangent, ReLU (Rectified Linear Unit), ELU (Exponential Linear Unit) functions were applied to the hidden layer, and Identity, ReLU, Softplus functions applied to the output layer. The statistical parameters including coefficient of determination, NSE (Nash and Sutcliffe Efficiency), NSEln (modified NSE), and PBIAS (Percent BIAS) were utilized to evaluate the ANN models. From the result, applications of Hyperbolic tangent function and ELU function to the hidden layer and Identity function to the output layer show competent performance rather than other functions which demonstrated the function selection in the ANN structure can affect the performance of ANN.

A Personalized English vocabulary learnin g system based on cognitive abilities relat ed to foreign language proficiency

  • Kwon, Dai-Young;Lim, Heui-Seok;Lee, Won-Gyu;Kim, Hyeon-Cheol;Jung, Soon-Young;Suh, Tae-Weon;Nam, Ki-Chun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제4권4호
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    • pp.595-617
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    • 2010
  • This paper proposes a novel of a personalized Computer Assisted Language Learning (CALL) system based on learner's cognitive abilities related to foreign language proficiency. In this CALL system, a strategy of retrieval learning, a method of learning memory cycle, and a method of repeated learning are applied for effective vocabulary memorization. The system is designed to offer personalized learning based on cognitive abilities related to the human language process. For this, the proposed CALL system has a cognitive diagnosis module which can measure five types of cognitive abilities. The results of this diagnosis are used to create dynamic learning scenarios for personalized learning and to evaluate user performance in the learning. This system is also designed in order to have users be able to create learning word lists and to share them simply with various functions based on open APIs. Additionally, through experiments, it has shown that this system helps students to learn English vocabulary effectively and enhances their foreign language skills.

스마트폰앱을 활용한 수학 토론학습 (Learning using smart phone application, Discussion-based learning of mathematics)

  • 채재선;강윤수
    • 한국수학교육학회지시리즈A:수학교육
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    • 제53권2호
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    • pp.239-261
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    • 2014
  • The purpose of this study is to analyze the influences of discussion-based learning of mathematics using smart phone application on the middle school students' mathematics learning. For this purpose, we selected 6 open problems suitable for learning mathematical reasoning and five 3rd grade middle school students as participants who expected to participate in 6 lessons of discussion-based learning of mathematics using smart phone application. From the analysis of 6 lessons, we found the following results. First, attending the lessons of discussion-based learning of mathematics using smart phone application makes students more interested in mathematics and change their mathematics learning attitudes more positively. Second, the lessons of discussion-based learning of mathematics using smart phone application facilitate students' mathematical communication with the help of various communication methods using many functions of smart phone applications. Third, the lessons of discussion-based learning of mathematics using smart phone application provide teachers with teaching-learning environment where teachers can easily give their students consultation about mathematics learning or daily life.

딥러닝을 활용한 무선 전송 및 접속 기술 동향 (Research Trends on Wireless Transmission and Access Technologies Using Deep Learning)

  • 김근영;명정호;서지훈
    • 전자통신동향분석
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    • 제33권5호
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    • pp.13-23
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    • 2018
  • Deep learning is a promising solution to a number of complex problems based on its inherent capability to approximate almost all types of functions without the demand for handcrafted feature extraction. New wireless transmission and access schemes based on deep learning are being increasingly proposed as substitutes for existing approaches, providing a lower complexity and better performance gain. Among such schemes, a communications system is viewed as an end-to-end autoencoder. The learning process applied in autoencoders can automatically deal with some nonlinear or unknown properties in communications systems. Deep learning can also be used to optimize each processing block for required tasks such as channel decoding, signal detection, and multiple access. On top of recent related research trends, we suggest appropriate research approaches for communications systems to adopt deep learning.

A Reinforcement Learning with CMAC

  • Kwon, Sung-Gyu
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제6권4호
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    • pp.271-276
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    • 2006
  • To implement a generalization of value functions in Adaptive Search Element (ASE)-reinforcement learning, CMAC (Cerebellar Model Articulation Controller) is integrated into ASE controller. ASE-reinforcement learning scheme is briefly studied to discuss how CMAC is integrated into ASE controller. Neighbourhood Sequential Training for CMAC is utilized to establish the look-up table and to produce discrete control outputs. In computer simulation, an ASE controller and a couple of ASE-CMAC neural network are trained to balance the inverted pendulum on a cart. The number of trials until the controllers are established and the learning performance of the controllers are evaluated to find that generalization ability of the CMAC improves the speed of the ASE-reinforcement learning enough to realize the cartpole control system.