• Title/Summary/Keyword: Inverted flag

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Prediction of Energy Harvesting Efficiency of an Inverted Flag Using Machine Learning Algorithms (머신 러닝 알고리즘을 이용한 역방향 깃발의 에너지 하베스팅 효율 예측)

  • Lim, Sehwan;Park, Sung Goon
    • Journal of the Korean Society of Visualization
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    • v.19 no.3
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    • pp.31-38
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    • 2021
  • The energy harvesting system using an inverted flag is analyzed by using an immersed boundary method to consider the fluid and solid interaction. The inverted flag flutters at a lower critical velocity than a conventional flag. A fluttering motion is classified into straight, symmetric, asymmetric, biased, and over flapping modes. The optimal energy harvesting efficiency is observed at the biased flapping mode. Using the three different machine learning algorithms, i.e., artificial neural network, random forest, support vector regression, the energy harvesting efficiency is predicted by taking bending rigidity, inclination angle, and flapping frequency as input variables. The R2 value of the artificial neural network and random forest algorithms is observed to be more than 0.9.

Evolving Neural Network Controller for Stabilization of Inverted Pendulum System (도립 진자 시스템의 안정화를 위한 진화형 신경회로망 제어기)

  • Sim, Yeong-Jin;Lee, Jun-Tak
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.49 no.3
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    • pp.157-163
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    • 2000
  • In this paper, an Evolving Neural Network Controller(ENNC) which its structure and its connection weights are optimized simultaneously by Real Variable Elitist Genetic Algoithm(RVEGA) was presented for stabilization of an Inverter Pendulum(IP) system with nonlinearity. This proposed ENNC was described by a simple genetic chromosome. And the deletion of neuron, the determinations of input or output neuron, the deleted neuron and the activation functions types are given according to the various flag types. Therefore, the connection weights, its structure and the neuron types in the given ENNC can be optimized by the proposed evolution strategy. Through the simulations, we showed that the finally acquired optimal ENNC was successfully applied to the stabilization control of an IP system.

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Implementation of Evolving Neural Network Controller for Inverted Pendulum System (도립진자 시스템을 위한 진화형 신경회로망 제어기의 실현)

  • 심영진;김태우;최우진;이준탁
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.14 no.3
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    • pp.68-76
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    • 2000
  • The stabilization control of Inverted Pendulum(IP) system is difficult because of its nonlinearity and structural unstability. Futhermore, a series of conventional techniques such as the pole placement and the optimal control based on the local linearizations have narrow stabilizable regions. At the same time, the fine tunings of their gain parameters are also troublesome. Thus, in this paper, an Evolving Neural Network Controller(ENNC) which its structure and its connection weights are optimized simultaneously by Real Variable Elitist Genetic Algorithm(RVEGA) was presented for stabilization of an IP system with nonlinearity. This proposed ENNC was described by a simple genetic chromosome. And the deletion of neuron, the according to the various flag types. Therefore, the connection weights, its structure and the neuron types in the given ENNC can be optimized by the proposed evolution strategy. And the proposed ENNC was implemented successfully on the ADA-2310 data acquisition board and the 80586 microprocessor in order to stabilize the IP system. Through the simulation and experimental results, we showed that the finally acquired optimal ENNC was very useful in the stabilization control of IP system.

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Membrane-associated Guanylate Kinase Inverted-3 Modulates Enterovirus Replication through AKT Signaling Activation (Membrane associated guanylate kinase inverted-3의 AKT signaling을 통한 enterovirus replication 조절)

  • Park, Jin-Ho;Namgung, Ye-Na;Lim, Byung-Kwan
    • Journal of Life Science
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    • v.26 no.10
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    • pp.1182-1188
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    • 2016
  • Membrane-associated guanylate kinase inverted-3 (MAGI-3) is a member of the family of membrane-associated guanylate kinases (MAGUKs). MAGI-3 modulates the kinase activity of protein kinase B (PKB)/AKT through interactions with phosphatase and tensin homolog (PTEN)/MMAC. Coxsackievirus B3 (CVB3) is a common causative agent of acute myocarditis and chronic dilated cardiomyopathy. Activation of AKT and extracellular signal-regulated kinases 1/2 (ERK1/2) is essential for CVB3 replication, but the relation between MAGI-3 signaling and CVB3 replication is not well understood. This study investigated the role of MAGI-3 in CVB3 infection and replication. MAGI-3 was overexpressed in HeLa cells by polyethylenimine (PEI) transfection. To optimize the transfection conditions, different ratios of plasmid DNA to PEI concentrations were used. MAGI-3 and empty plasmid DNA were transfected into the HeLa cells. MAGI-3 overexpression alone was not sufficient to efficiently activate AKT. However, expression of the CVB3 capsid protein VP1 dramatically increased in the HeLa cells overexpressing MAGI-3 24 h after CVB3 infection. In addition, the activities of AKT and ERK were significantly induced in the CVB3-infected MAGI-3 cells overexpressing HeLa. These results demonstrate that MAGI-3 expression upregulates CVB3 replication through AKT and ERK signaling activation. MAGI-3 may be an important target to control CVB3 replication.

A Study on Dynamic Analysis Model and Stability of Stone Cultural Properties of Inverted Pendulum Type with 5 Joints (5개의 연결부를 가지는 역진자형 석조문화재의 동적 해석모델 및 안정성 연구)

  • Choi, Jae-Sung
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.25 no.3
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    • pp.21-30
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    • 2021
  • Architectural cultural properties suffer a lot of damage due to various environmental factors. In order to preserve damaged cultural properties, preventive preservation and long-term preservation management are becoming more important. Therefore, research on a scientific non-destructive testing method applicable to regular inspection is required. For related research, DangGan with a high flag-pole shape was selected as the subject of study among various cultural properties. Among the preserved DangGans, a basic study was conducted on the analysis technique to evaluate the structural stability by selecting Treasure No. 49 Naju SeokDangGan. An idealized model was presented and a multi-degree of freedom equation of motion was derived. In addition, an equation for estimating the critical stiffness value for each joint position is presented.