• Title/Summary/Keyword: dynamic learning rate

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Stable Predictive Control of Chaotic Systems Using Self-Recurrent Wavelet Neural Network

  • Yoo Sung Jin;Park Jin Bae;Choi Yoon Ho
    • International Journal of Control, Automation, and Systems
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    • v.3 no.1
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    • pp.43-55
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    • 2005
  • In this paper, a predictive control method using self-recurrent wavelet neural network (SRWNN) is proposed for chaotic systems. Since the SRWNN has a self-recurrent mother wavelet layer, it can well attract the complex nonlinear system though the SRWNN has less mother wavelet nodes than the wavelet neural network (WNN). Thus, the SRWNN is used as a model predictor for predicting the dynamic property of chaotic systems. The gradient descent method with the adaptive learning rates is applied to train the parameters of the SRWNN based predictor and controller. The adaptive learning rates are derived from the discrete Lyapunov stability theorem, which are used to guarantee the convergence of the predictive controller. Finally, the chaotic systems are provided to demonstrate the effectiveness of the proposed control strategy.

A Dynamic Neural Networks for Nonlinear Control at Complicated Road Situations (복잡한 도로 상태의 동적 비선형 제어를 위한 학습 신경망)

  • Kim, Jong-Man;Sin, Dong-Yong;Kim, Won-Sop;Kim, Sung-Joong
    • Proceedings of the KIEE Conference
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    • 2000.07d
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    • pp.2949-2952
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    • 2000
  • A new neural networks and learning algorithm are proposed in order to measure nonlinear heights of complexed road environments in realtime without pre-information. This new neural networks is Error Self Recurrent Neural Networks(ESRN), The structure of it is similar to recurrent neural networks: a delayed output as the input and a delayed error between the output of plant and neural networks as a bias input. In addition, we compute the desired value of hidden layer by an optimal method instead of transfering desired values by back-propagation and each weights are updated by RLS(Recursive Least Square). Consequently. this neural networks are not sensitive to initial weights and a learning rate, and have a faster convergence rate than conventional neural networks. We can estimate nonlinear models in realtime by ESRN and learning algorithm and control nonlinear models. To show the performance of this one. we control 7 degree of freedom full car model with several control method. From this simulation. this estimation and controller were proved to be effective to the measurements of nonlinear road environment systems.

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Dynamic Resource Allocation in Distributed Cloud Computing (분산 클라우드 컴퓨팅을 위한 동적 자원 할당 기법)

  • Ahn, TaeHyoung;Kim, Yena;Lee, SuKyoung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38B no.7
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    • pp.512-518
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    • 2013
  • A resource allocation algorithm has a high impact on user satisfaction as well as the ability to accommodate and process services in a distributed cloud computing. In other words, service rejections, which occur when datacenters have no enough resources, degrade the user satisfaction level. Therefore, in this paper, we propose a resource allocation algorithm considering the cloud domain's remaining resources to minimize the number of service rejections. The resource allocation rate based on Q-Learning increases when the remaining resources are sufficient to allocate the maximum allocation rate otherwise and avoids the service rejection. To demonstrate, We compare the proposed algorithm with two previous works and show that the proposed algorithm has the smaller number of the service rejections.

Identification of Dynamic Systems Using a Self Recurrent Wavelet Neural Network: Convergence Analysis Via Adaptive Learning Rates (자기 회귀 웨이블릿 신경 회로망을 이용한 다이나믹 시스템의 동정: 적응 학습률 기반 수렴성 분석)

  • Yoo, Sung-Jin;Choi, Yoon-Ho;Park, Jin-Bae
    • Journal of Institute of Control, Robotics and Systems
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    • v.11 no.9
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    • pp.781-788
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    • 2005
  • This paper proposes an identification method using a self recurrent wavelet neural network (SRWNN) for dynamic systems. The architecture of the proposed SRWNN is a modified model of the wavelet neural network (WNN). But, unlike the WNN, since a mother wavelet layer of the SRWNN is composed of self-feedback neurons, the SRWNN has the ability to store the past information of the wavelet. Thus, in the proposed identification architecture, the SRWNN is used for identifying nonlinear dynamic systems. The gradient descent method with adaptive teaming rates (ALRs) is applied to 1.am the parameters of the SRWNN identifier (SRWNNI). The ALRs are derived from the discrete Lyapunov stability theorem, which are used to guarantee the convergence of an SRWNNI. Finally, through computer simulations, we demonstrate the effectiveness of the proposed SRWNNI.

Improvement of Retrieval Feedback Using Dynamic Interaction Function (동적 상호작용 함수를 애용한 검색 피드백의 개선)

  • Han, Jung-Soo
    • The Journal of the Korea Contents Association
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    • v.6 no.2
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    • pp.93-98
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    • 2006
  • The paper describes a method o( user feedback in order to enhance the retrieval system effectiveness. The existing fuzzification function adapting fuzzy technique has difficulty that 4 type graph is made each time user select components. In this paper, to overcome this weak point of feedback, we proposed the interaction function using gaussian function that gives different learning rate according to choice of components with same function. We suggest the most efficient dynamic interaction function based on comparison of retrieval performance according to parameter of function. And then, we will construct the efficient retrieval system.

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Retrieving Semantic Image Using Shape Descriptors and Latent-dynamic Conditional Random Fields

  • Mahmoud Elmezain;Hani M. Ibrahem
    • International Journal of Computer Science & Network Security
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    • v.24 no.10
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    • pp.197-205
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    • 2024
  • This paper introduces a new approach to semantic image retrieval using shape descriptors as dispersion and moment in conjunction with discriminative model of Latent-dynamic Conditional Random Fields (LDCRFs). The target region is firstly localized via the background subtraction model. Then the features of dispersion and moments are employed to k-mean procedure to extract object's feature as second stage. After that, the learning process is carried out by LDCRFs. Finally, SPARQL language on input text or image query is to retrieve semantic image based on sequential processes of Query Engine, Matching Module and Ontology Manger. Experimental findings show that our approach can be successful retrieve images against the mammals Benchmark with rate 98.11. Such outcomes are likely to compare very positively with those accessible in the literature from other researchers.

Dynamic Model for Open Innovation Network (개방형 혁신 네트워크의 동태적 모형)

  • Park, Chulsoon
    • Journal of the Korean Operations Research and Management Science Society
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    • v.40 no.1
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    • pp.5-19
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    • 2015
  • Literatures on open innovation have two major limitations. First, either on a firm level or on an industry level did they analyze the open innovation issues. The results of a firm's innovation can be diffused through the whole network and the firm can learn back from the network knowledge. Prior literatures did not consider the feedback loop among firms and network in which the firms are involved. Second, most open innovation research had a static perspective on firm's innovation performance. Since the diffusion, spill-over and learning among network members are involved over time, the open innovation is intrinsically dynamic. From the dynamic perspective, we can appreciate the fundamental attributes of the open innovation network which involves diverse firms, research institutes, and universities. In order to overcome the limitations, we suggest a dynamic model for open innovation network. We build an agent-based model which consists of heterogeneous firms. The firms are connected through a scale-free network which is formed by preferential attachment. Through the diverse scenario of simulation, we collect massive data on the firm level and analyze them both on firm and industry level. From the analysis, we found that, on industry level, the overall performance of open innovation increases as the internal research capability, absorptive capacity, and learning curve coefficient increase. Noticeably, as the deprecation rate of knowledge increases, the variability of knowledge increases. From the firm level analysis, we found that the industry-level variables had a significant effect on the firm's innovation performance lasting through all the time, whereas the firm-level variables had only on the early phase of innovation.

Design and Implementation of Intelligent Wireless Sensor Network Based Home Network System (무선 센서 네트워크 기반의 지능형 홈 네트워크 시스템 설계 및 구현)

  • Shin, Jae-Wook;Yoon, Ba-Da;Kim, Sung-Gil;Chung, Wan-Young
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2007.10a
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    • pp.465-468
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    • 2007
  • An intelligent home network system using low-power and low-cost sensor nodes was designed and implemented. In Intelligent Home Network System, active home appliances control is composed of RSSI (Received Signal Strength Indicator) based user indoor location tracking, dynamic multi-hop routing, and learning integration remote-control. Through the remote-control learning, home appliances can be controlled in wireless network environment. User location information for intelligent service is calculated using RSSI based Triangle measurement method, and then the received location information is passed to Smoothing Algorithm to reduce error rate. In order to service Intelligent Home Network, moreover, the sensor node is designed to be held by user. The gathered user data is transmitted through dynamic multi-hop routing to server, and real-time user location & environment information are displayed on monitoring program.

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Control of Left Ventricular Assist Device Using Neural Network Feedforward Controller (인공신경망 Feedforward 제어기를 이용한 좌심실 보조장치의 제어실험)

  • 정성택;김훈모;김상현
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.4
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    • pp.83-90
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    • 1998
  • In this paper, we present neural network for control of Left Ventricular Assist Device(LVAD) system with a pneumatically driven mock circulation system. Beat rate(BR), Systole-Diastole Rate(SDR) and flow rate are collected as the main variables of the LVAD system. System modeling is completed using the neural network with input variables(BR, SBR, their derivatives, actual flow) and output variable(actual flow). It is necessary to apply high perfomance control techniques, since the LVAD system represent nonlinear and time-varing characteristics. Fortunately. the neural network can be applied to control of a nonlinear dynamic system by learning capability In this study, we identify the LVAD system with neural network and control the LVAD system by PID controller and neural network feedforward controller. The ability and effectiveness of controlling the LVAD system using the proposed algorithm will be demonstrated by experiment.

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Leveraging Visibility-Based Rewards in DRL-based Worker Travel Path Simulation for Improving the Learning Performance

  • Kim, Minguk;Kim, Tae Wan
    • Korean Journal of Construction Engineering and Management
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    • v.24 no.5
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    • pp.73-82
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    • 2023
  • Optimization of Construction Site Layout Planning (CSLP) heavily relies on workers' travel paths. However, traditional path generation approaches predominantly focus on the shortest path, often neglecting critical variables such as individual wayfinding tendencies, the spatial arrangement of site objects, and potential hazards. These oversights can lead to compromised path simulations, resulting in less reliable site layout plans. While Deep Reinforcement Learning (DRL) has been proposed as a potential alternative to address these issues, it has shown limitations. Despite presenting more realistic travel paths by considering these variables, DRL often struggles with efficiency in complex environments, leading to extended learning times and potential failures. To overcome these challenges, this study introduces a refined model that enhances spatial navigation capabilities and learning performance by integrating workers' visibility into the reward functions. The proposed model demonstrated a 12.47% increase in the pathfinding success rate and notable improvements in the other two performance measures compared to the existing DRL framework. The adoption of this model could greatly enhance the reliability of the results, ultimately improving site operational efficiency and safety management such as by reducing site congestion and accidents. Future research could expand this study by simulating travel paths in dynamic, multi-agent environments that represent different stages of construction.