• Title/Summary/Keyword: self-adaptive method

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A design of neuro-fuzzy adaptive controller using a reference model following function (기준 모델 추종 기능을 이용한 뉴로-퍼지 적응 제어기 설계)

  • Lee, Young-Seog;Ryoo, Dong-Wan;Seo, Bo-Hyeok
    • Journal of Institute of Control, Robotics and Systems
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    • v.4 no.2
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    • pp.203-208
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    • 1998
  • This paper presents an adaptive fuzzy controller using an neural network and adaptation algorithm. Reference-model following neuro-fuzzy controller(RMFNFC) is invesgated in order to overcome the difficulty of rule selecting and defects of the membership function in the general fuzzy logic controller(FLC). RMFNFC is developed to tune various parameter of the fuzzy controller which is used for the discrete nonlinear system control. RMFNFC is trained with the identification information and control closed loop error. A closed loop error is used for design criteria of a fuzzy controller which characterizes and quantize the control performance required in the overall control system. A control system is trained up the controller with the variation of the system obtained from the identifier and closed loop error. Numerical examples are presented to control of the discrete nonlinear system. Simulation results show the effectiveness of the proposed controller.

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An intelligent optimization method for the HCSB blanket based on an improved multi-objective NSGA-III algorithm and an adaptive BP neural network

  • Wen Zhou;Guomin Sun;Shuichiro Miwa;Zihui Yang;Zhuang Li;Di Zhang;Jianye Wang
    • Nuclear Engineering and Technology
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    • v.55 no.9
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    • pp.3150-3163
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    • 2023
  • To improve the performance of blanket: maximizing the tritium breeding rate (TBR) for tritium self-sufficiency, and minimizing the Dose of backplate for radiation protection, most previous studies are based on manual corrections to adjust the blanket structure to achieve optimization design, but it is difficult to find an optimal structure and tends to be trapped by local optimizations as it involves multiphysics field design, which is also inefficient and time-consuming process. The artificial intelligence (AI) maybe is a potential method for the optimization design of the blanket. So, this paper aims to develop an intelligent optimization method based on an improved multi-objective NSGA-III algorithm and an adaptive BP neural network to solve these problems mentioned above. This method has been applied on optimizing the radial arrangement of a conceptual design of CFETR HCSB blanket. Finally, a series of optimal radial arrangements are obtained under the constraints that the temperature of each component of the blanket does not exceed the limit and the radial length remains unchanged, the efficiency of the blanket optimization design is significantly improved. This study will provide a clue and inspiration for the application of artificial intelligence technology in the optimization design of blanket.

Realistic and Real-Time Modeling of Numerous Trees Using Growing Environment (성장 환경을 활용한 다수의 나무에 대한 사실적인 실시간 모델링 기법)

  • Kim, Jin-Mo;Cho, Hyung-Je
    • Journal of Korea Multimedia Society
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    • v.15 no.3
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    • pp.398-407
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    • 2012
  • We propose a tree modeling method of expressing realistically and efficiently numerous trees distributed on a broad terrain. This method combines and simplifies the recursive hierarchy of tree branch and branch generation process through self-organizing from buds, allowing users to generate trees that can be used more intuitively and efficiently. With the generation process the leveled structure and the appearance such as branch length, distribution and direction can be controlled interactively by user. In addition, we introduce an environment-adaptive model that allows to grow a number of trees variously by controlling at the same time and we propose an efficient application method of growing environment. For the real-time rendering of the complex tree models distributed on a broad terrain, the rendering process, the LOD(level of detail) for the branch surfaces, and shader instancing are introduced through the GPU(Graphics Processing Unit). Whether the numerous trees are expressed realistically and efficiently on wide terrain by proposed models are confirmed through simulation.

A Study on the ACC Safety Evaluation Method Using Dual Cameras (듀얼카메라를 활용한 ACC 안전성 평가 방법에 관한 연구)

  • Kim, Bong-Ju;Lee, Seon-Bong
    • Journal of Auto-vehicle Safety Association
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    • v.14 no.2
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    • pp.57-69
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    • 2022
  • Recently, as interest in self-driving cars has increased worldwide, research and development on the Advanced Driver Assist System is actively underway. Among them, the purpose of Adaptive Cruise Control (ACC) is to minimize the driver's driving fatigue through the control of the vehicle's longitudinal speed and relative distance. In this study, for the research of the ACC test in the real environment, the real-road test was conducted based on domestic-road test scenario proposed in preceding study, considering ISO 15622 test method. In this case, the distance measurement method using the dual camera was verified by comparing and analyzing the result of using the dual camera and the result of using the measurement equipment. As a result of the comparison, two results could be derived. First, the relative distance after stabilizing the ACC was compared. As a result of the comparison, it was found that the minimum error rate was 0.251% in the first test of scenario 8 and the maximum error rate was 4.202% in the third test of scenario 9. Second, the result of the same time was compared. As a result of the comparison, it was found that the minimum error rate was 0.000% in the second test of scenario 10 and the maximum error rate was 9.945% in the second test of scenario 1. However, the average error rate for all scenarios was within 3%. It was determined that the representative cause of the maximum error occurred in the dual camera installed in the test vehicle. There were problems such as shaking caused by road surface vibration and air resistance during driving, changes in ambient brightness, and the process of focusing the video. Accordingly, it was determined that the result of calculating the distance to the preceding vehicle in the image where the problem occurred was incorrect. In the development stage of ADAS such as ACC, it is judged that only dual cameras can reduce the cost burden according to the above derivation of test results.

An Optimum-adaptive Intrusion Detection System Using a Mobile Code (모바일 코드를 이용한 최적적응 침입탐지시스템)

  • Pang Se-chung;Kim Yang-woo;Kim Yoon-hee;Lee Phil-Woo
    • The KIPS Transactions:PartC
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    • v.12C no.1 s.97
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    • pp.45-52
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    • 2005
  • A damage scale of information property has been increasing rapidly by various illegal actions of information systems, which result from dysfunction of a knowledge society. Reinforcement in criminal investigation requests of network security has accelerated research and development of Intrusion Detection Systems(IDSs), which report intrusion-detection about these illegal actions. Due to limited designs of early IDSs, it is hard for the IDSs to cope with tricks to go around IDS as well as false-positive and false-negative trials in various network environments. In this paper, we showed that this kind of problems can be solved by using a Virtual Protocol Stack(VPS) that possesses automatic learning ability through an optimum-adaptive mobile code. Therefore, the enhanced IDS adapts dynamically to various network environments in consideration of monitored and self-learned network status. Moreover, it is shown that Insertion/Evasion attacks can be actively detected. Finally, we discussed that this method can be expanded to an intrusion detection technique that possesses adaptability in the various mixed network environments.

Fast Motion Estimation Algorithm Using Motion Vector Prediction and Neural Network (움직임 예측과 신경 회로망을 이용한 고속 움직임 추정 알고리즘)

  • 최정현;이경환;이법기;정원식;김경규;김덕규
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.24 no.9A
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    • pp.1411-1418
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    • 1999
  • In this paper, we propose a fast motion estimation algorithm using motion prediction and neural network. Considering that the motion vectors have high spatial correlation, the motion vector of current block is predicted by those of neighboring blocks. The codebook of motion vector is designed by Kohonen self-organizing feature map(KSFM) learning algorithm which has a fast learning speed and 2-D adaptive chararteristics. Since the similar codevectors are closely located in the 2-D codebook the motion is progressively estimated from the predicted codevector in the codebook. Computer simulation results show that the proposed method has a good performance with reduced computational complexity.

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A Individualized Reasoning Strategy using Learner's Cognitive Union (학습자 인지 구조체를 이용한 추론의 개별화 전략)

  • Kim, Yong-Beom;Kim, Yungsik
    • The Journal of Korean Association of Computer Education
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    • v.9 no.5
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    • pp.31-39
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    • 2006
  • The change into the knowledge based information society requires a transformation of educational paradigm. Accordingly, intelligent learning and distance education are attracting a fair amount of attention. To apply the instructional learning method in this field, we need to consider a individualization of learning, as it were, abstraction of fact and path through learning, which is based on learner's traits, this focus entails a argument for individualized reasoning strategy. Therefore, in this paper, we design a learner's cognitive union, which is based on X-Neuronet(eXtended Neuronet), represent learner's hierarchical knowledge is able to self-learn, and grows adaptive union by proprietor. Additionally, we propose a individualized reasoning strategy, which relies upon learner's cognitive union, and verify the validity.

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Self-Tuning Predictive Control with Application to Steam Generator (증기 발생기 수위제어를 위한 자기동조 예측제어)

  • Kim, Chang-Hwoi;Sang Jeong lee;Ham, Chang-Shik
    • Nuclear Engineering and Technology
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    • v.27 no.6
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    • pp.833-844
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    • 1995
  • In self-tuning predictive control algorithm for steam generator is presented. The control algorithm is derived by suitably modifying the generalized predictive control algorithm. The main feature of the unposed method relies on considering the measurable disturbance and a simple adaptive scheme for obtaining the controller gain when the parameters of the plant are unknown. This feature makes the proposed approach particularly appealing for water level control of steam generator when measurable disturbance is used. In order to evaluate the performance of the proposed algorithm, computer simulations are done for an PWR steam generator model. Simulation result show satisfactory performances against load variations and steam flow rate estimation errors. It can be also observed that the proposed algorithm exhibit better responses than a conventional PI controller.

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Hybrid PI Controller for Performance Improvement of IPMSM Drive (IPMSM 드라이브의 성능 향상을 위한 하이브리드 PI 제어기)

  • Nam, Su-Myeong;Lee, Jung-Chul;Lee, Hong-Gyun;Choi, Jung-Sik;Ko, Jae-Sub;Park, Gi-Tae;Chung, Dong-Hwa
    • Proceedings of the KIEE Conference
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    • 2005.04a
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    • pp.191-193
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    • 2005
  • This paper presents Hybrid PI controller of IPMSM drive using fuzzy adaptive mechanism(FAM) control. To increase the robustness, fixed gam PI controller, Hybrid PI controller proposes a new method based self tuning PI controller. Hybrid PI controller is developed to minimize overshoot and settling time following sudden parameter changes such as speed, load torque, inertia, rotor resistance and self inductance. The results on a speed controller of IPMSM are presented to show the effectiveness of the proposed gain tuner. And this controller is better than the fixed gains one in terms of robustness, even under great variations of operating conditions and load disturbance.

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Digital Watermarking using HVS and Neural Network (HVS와 신경회로망을 이용한 디지털 워터마킹)

  • Lee, Young-Hee;Lee, Mun-Hee;Cha, Eui-Young
    • The Journal of Korean Association of Computer Education
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    • v.9 no.2
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    • pp.101-109
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    • 2006
  • We propose an adaptive digital watermarking algorithm using HVS(human visual system) and SOM(Self-Organizing Map) among neural networks. This method adjusts adaptively the strength of the watermark which is embedded in different blocks according to block classification in DCT(Discrete Cosine Transform) domain. All blocks in 3 classes out of 4 are selected to embed a watermark. Watermark sequences are embedded in 6 lowest frequency coefficients of each block except the DC component. The experimental results are excellent.

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