• Title/Summary/Keyword: Self-adaptive model

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Adaptive Speed Controller for high performance PMSM drive (영구자석 동기전동기의 고성능 구동을 위한 적응 퍼지 속도 제어기)

  • Kwon, Chung-Jin;Han, Woo-Yong;Lee, Chang-Goo;Kim, Sung-Joong;Kim, Bae-Sun
    • Proceedings of the KIEE Conference
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    • 2001.07b
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    • pp.1188-1190
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    • 2001
  • This paper presents a clustering adaptive controller to achieve robustness against parameter variations although it has simple structure and computational simplicity. The presented controller based on optimal fuzzy logic controller has an self-tuning characteristics with clustering. The controller requires no model of the system to be controlled. Simulation results show that the usefulness of the proposed controller.

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Offset elimination in adaptive control (적응제어에서의 오프셋 영향 제거)

  • 최두환;김영철;양홍식
    • 제어로봇시스템학회:학술대회논문집
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    • 1988.10a
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    • pp.236-241
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    • 1988
  • This note considers the class of controllers with integral action which arise directly from appropriate system models. Via internal model principle approach, a corresponding class of self-tuning controller is shown to have both integral action in controller and offset removal in the tuning algorithm. The key idea is to constrain the estimator in each step in order to ensure that dc gain of feedforward and feedback polynomial of adaptive controller are always equal, thus allowing the loop integrator to work properly.

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The Atomic-Scale Investigation of Friction at Hydrocarbon Interfaces via Molecular Dynamics Simulations ASIATRIB 2002

  • Harrison, J.A.;Gao, G;Chateauneuf, G.M.;Mikulski, P.T.
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2002.10b
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    • pp.59-60
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    • 2002
  • In this digest, we briefly review our current molecular dynamics (MD) simulations that utilize both the reactive empirical bond order potential (REBO) and the adaptive intermolecular REBO (AIREBO) potential energy functions. The AIREBO potential includes intermolecular interactions, so that self·assembled monolayers, and liquids, can be modeled. We have examined the mechanical and tribological properties of model self assembled monolayers and amorphous carbon films. Self-assembled monolayers are modeled by covalently bonding hydrocarbon chains to diamond substrates. Because the REBO potentials can model chemical reactions, specific compression and sliding induced chemical reactions were identified.

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Interweaving Method Between Requirements and Architecture For Self-Adaptive System (자가 적응 시스템의 개발을 위한 요구사항과 아키텍처의 인터위빙 방법)

  • Woo, Inhee;Lee, Seok-Won
    • Journal of KIISE:Software and Applications
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    • v.41 no.7
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    • pp.457-468
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    • 2014
  • Recently, several approaches are proposed to support developing Self-Adaptive System. However, they do not provide the way to accept interaction between requirements and architecture. It makes difficult to judge the impact of changing requirements, handle quickly, and understand adaptation process for stakeholder. To overcome above problems, this paper suggests the interweaving method for providing traceability based on the relationship between requirements and architecture. This traceability allows tracing the impact of changing requirements, and it provides the rationale of architectural decision for advanced degree of understanding. Example shows the usefulness through developing process and changing process on Smart Grid domain.

The Design of Adaptive Fuzzy Polynomial Neural Networks Architectures Based on Fuzzy Neural Networks and Self-Organizing Networks (퍼지뉴럴 네트워크와 자기구성 네트워크에 기초한 적응 퍼지 다항식 뉴럴네트워크 구조의 설계)

  • Park, Byeong-Jun;Oh, Sung-Kwun;Jang, Sung-Whan
    • Journal of Institute of Control, Robotics and Systems
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    • v.8 no.2
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    • pp.126-135
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    • 2002
  • The study is concerned with an approach to the design of new architectures of fuzzy neural networks and the discussion of comprehensive design methodology supporting their development. We propose an Adaptive Fuzzy Polynomial Neural Networks(APFNN) based on Fuzzy Neural Networks(FNN) and Self-organizing Networks(SON) for model identification of complex and nonlinear systems. The proposed AFPNN is generated from the mutually combined structure of both FNN and SON. The one and the other are considered as the premise and the consequence part of AFPNN, respectively. As the premise structure of AFPNN, FNN uses both the simplified fuzzy inference and error back-propagation teaming rule. The parameters of FNN are refined(optimized) using genetic algorithms(GAs). As the consequence structure of AFPNN, SON is realized by a polynomial type of mapping(linear, quadratic and modified quadratic) between input and output variables. In this study, we introduce two kinds of AFPNN architectures, namely the basic and the modified one. The basic and the modified architectures depend on the number of input variables and the order of polynomial in each layer of consequence structure. Owing to the specific features of two combined architectures, it is possible to consider the nonlinear characteristics of process system and to obtain the better output performance with superb predictive ability. The availability and feasibility of the AFPNN are discussed and illustrated with the aid of two representative numerical examples. The results show that the proposed AFPNN can produce the model with higher accuracy and predictive ability than any other method presented previously.

Joint frame rate adaptation and object recognition model selection for stabilized unmanned aerial vehicle surveillance

  • Gyu Seon Kim;Haemin Lee;Soohyun Park;Joongheon Kim
    • ETRI Journal
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    • v.45 no.5
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    • pp.811-821
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    • 2023
  • We propose an adaptive unmanned aerial vehicle (UAV)-assisted object recognition algorithm for urban surveillance scenarios. For UAV-assisted surveillance, UAVs are equipped with learning-based object recognition models and can collect surveillance image data. However, owing to the limitations of UAVs regarding power and computational resources, adaptive control must be performed accordingly. Therefore, we introduce a self-adaptive control strategy to maximize the time-averaged recognition performance subject to stability through a formulation based on Lyapunov optimization. Results from performance evaluations on real-world data demonstrate that the proposed algorithm achieves the desired performance improvements.

Seismic damage mitigation of bridges with self-adaptive SMA-cable-based bearings

  • Zheng, Yue;Dong, You;Chen, Bo;Anwar, Ghazanfar Ali
    • Smart Structures and Systems
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    • v.24 no.1
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    • pp.127-139
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    • 2019
  • Residual drifts after an earthquake can incur huge repair costs and might need to replace the infrastructure because of its non-reparability. Proper functioning of bridges is also essential in the aftermath of an earthquake. In order to mitigate pounding and unseating damage of bridges subjected to earthquakes, a self-adaptive Ni-Ti shape memory alloy (SMA)-cable-based frictional sliding bearing (SMAFSB) is proposed considering self-adaptive centering, high energy dissipation, better fatigue, and corrosion resistance from SMA-cable component. The developed novel bearing is associated with the properties of modularity, replaceability, and earthquake isolation capacity, which could reduce the repair time and increase the resilience of highway bridges. To evaluate the super-elasticity of the SMA-cable, pseudo-static tests and numerical simulation on the SMA-cable specimens with a diameter of 7 mm are conducted and one dimensional (1D) constitutive hysteretic model of the SMAFSB is developed considering the effects of gap, self-centering, and high energy dissipation. Two types of the SMAFSB (i.e., movable and fixed SMAFSBs) are applied to a two-span continuous reinforced concrete (RC) bridge. The seismic vulnerabilities of the RC bridge, utilizing movable SMAFSB with the constant gap size of 60 mm and the fixed SMAFSBs with different gap sizes (e.g., 0, 30, and 60 mm), are assessed at component and system levels, respectively. It can be observed that the fixed SMAFSB with a gap of 30 mm gained the most retrofitting effect among the three cases.

Analysis of The Effect of The Digital Divide on The Digital Daily Life of The Elderly (디지털 격차가 노인의 디지털 일상생활에 미치는 영향 분석)

  • Hu, Sung-Ho
    • Journal of Digital Convergence
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    • v.18 no.9
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    • pp.9-15
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    • 2020
  • This study is to analyze the influence of the digital divide on the digital daily life of the elderly. Adaptation tendencies for digital divide were measured and classified into groups for elderly people over 60 years old. And digital communication skills, digital confidence, digital self-control, and digital life satisfaction were measured. The research model used a cross over design model and a dual mediation model. As a result of the study, first, it was found that a group with high adaptive accessibility to the digital divide had a positive effect on the overall digital daily life. Second, a group with high adaptive literacy to the digital divide had a positive effect on the digital self-control. Third, digital communication skill has a positive effect on digital life satisfaction, and digital confidence and digital self-control play a mediating role. Based on these findings, we discussed strategies to overcome the digital divide in old age.

Moderation Effects of Computer Self-efficacy on the Relationship among Variables for Appropriation in using IT (정보기술 사용 전유에 관한 변수들 간의 관계에서 컴퓨터자기효능감의 조절효과)

  • Lee, Woong-Kyu
    • The Journal of Information Systems
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    • v.18 no.1
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    • pp.25-46
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    • 2009
  • According to adaptive structuration theory, faithfulness of appropriation(FOA), and consensus on appropriation(COA) are variables for measuring appropriation in use of IT. FOA is the level of interpreting and using the intentions of the IT designers objectively and COA is the level of agreement on ways of using IT among or with user group independently of designers' intention. In traditional theories of IT adoption, computer self-efficacy(CSE), self evaluation on abilities of using computer, has been considered as one of the important individual differences. which would influence on beliefs of using IT. Therefore, considering the relationship among CSE, FOA, COA and attitude, we can hypothesize that CSE would play a moderation varaible among appropriation related variables relationships, FOA-attitude and COA-attitude. The objective of this study is an analysis of CSE's moderation effects in causality relationship among appropriation measuring variables. For this purpose, we propose a research model where there are four hypotheses for moderation effects of CSE on the relationships between appropriation variables. We test these hypotheses by sampling ERP and groupware users. In result, our proposed hypotheses except moderation effect of COA-usefulness are accepted. Main contribution of this study is to identify the relationship between CSE and AST. This study implies that very careful consideration of users' CSE is necessary in order to perform managerial activities based on FOA and COA in IT management department.

Load Frequency Control using Parameter Self-Tuning fuzzy Controller (파라미터 자기조정 퍼지제어기를 이용한 부하주파수제어)

  • 탁한호;추연규
    • Journal of the Korean Institute of Intelligent Systems
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    • v.8 no.2
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    • pp.50-59
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    • 1998
  • This paper presents stabilization and adaptive control of flexible single link robot manipulator system by self-recurrent neural networks that is one of the neural networks and is effective in nonlinear control. The architecture of neural networks is a modified model of self-recurrent structure which has a hidden layer. The self-recurrent neural networks can be used to approximate any continuous function to any desired degree of accuracy and the weights are updated by feedback-error learning algorithm. When a flexible manipulator is rotated by a motor through the fixed end, transverse vibration may occur. The motor toroque should be controlled in such a way that the motor rotates by a specified angle, while simultaneously stabilizing vibration of the flexible manipuators so that it is arresed as soon as possible at the end of rotation. Accurate vibration control of lightweight manipulator during the large changes in configuration common to robotic tasks requires dynamic models that describe both the rigid body motions, as well as the flexural vibrations. Therefore, a dynamic models for a flexible single link robot manipulator is derived, and then a comparative analysis was made with linear controller through an simulation and experiment. The results are proesented to illustrate thd advantages and imporved performance of the proposed adaptive control ove the conventional linear controller.

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