• Title/Summary/Keyword: Reliable Method

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An efficient method for reliable optimum design of trusses

  • Dizangian, Babak;Ghasemi, Mohammad Reza
    • Steel and Composite Structures
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    • v.21 no.5
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    • pp.1069-1084
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    • 2016
  • This paper introduces a new and effective design amplification factor-based approach for reliable optimum design of trusses. This paper may be categorized as in the family of decoupled methods that aiming for a reliable optimum design based on a Design Amplification Factor (DAF). To reduce the computational expenses of reliability analysis, an improved version of Response Surface Method (RSM) was used. Having applied this approach to two planar and one spatial truss problems, it exhibited a satisfactory performance.

Reliable $H_\infty$ control for descriptor systems with actuator failures (구동기 고장을 가지는 특이시스템의 신뢰 $H_\infty$ 제어)

  • Kim, Jong-Hae
    • Proceedings of the KIEE Conference
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    • 2003.11b
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    • pp.135-138
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    • 2003
  • In this paper, we provide a reliable few controller design method for descriptor systems satisfying asymptotic stability with $H_\infty$ norm bound and all actuator failures occurred within the pre-specified subset. The proper condition for the existence of a reliable $H_\infty$ controller and the controller design method are proposed by linear matrix inequality(LMI), Schur complements, and singular value decomposition. All solutions can be obtained simultaneously because the presented sufficient condition can be expressed as an LMI form.

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High Temperature Creep Life Prediction of Friction Welded Joints by Initial Strain Method and the AE Evaluation (ISM에 의한 마찰용접재(SUH3-SUH35)의 고온크리프 수명예측에 관한 연구)

  • 오세규;이원석
    • Journal of Ocean Engineering and Technology
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    • v.11 no.4
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    • pp.40-48
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    • 1997
  • There are many research results as individual uni-axial tension creep test of heat-resisting materials. However, there are very few about the study on the high temperature creep test for the Initial Strain Method, and especially any study on it about the friction welded joints of SUH3 to SUH35. One of the important concerns is a reliable method of evaluating static creep properties. No reliable method seems available at present to evaluate or predict static creep properties. So, the reliable method to evaluate and predict them by the ISM and AE techniques was made.

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Development of reliable $H_\infty$ controller design algorithm for singular systems with failures (고장 특이시스템의 신뢰 $H_\infty$ 제어기 설계 알고리듬 개발)

  • 김종해
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.41 no.4
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    • pp.29-37
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    • 2004
  • This paper provides a reliable H$_{\infty}$ state feedback controller design method for delayed singular systems with actuator failures occurred within the prescribed subset. The sufficient condition for the existence of a reliable H$_{\infty}$ controller and the controller design method are presented by linear matrix inequality(LMI), singular value decomposition, Schur complements, and changes of variables. The proposed controller guarantees not only asymptotic stability but also H$_{\infty}$ norm bound in spite of existence of actuator failures. Since the obtained sufficient condition can be expressed as an LMI fen all variables can be calculated simultaneously. Moreover, the controller design method can be extended to the problem of robust reliable H$_{\infty}$ controller design method for singular systems with parameter uncertainties, time-varying delay, and actuator failures. A numerical example is given to illustrate the validity of the result.

A Logistic Regression for Random Noise Removal in Image Deblurring (영상 디블러링에서의 임의 잡음 제거를 위한 로지스틱 회귀)

  • Lee, Nam-Yong
    • Journal of Korea Multimedia Society
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    • v.20 no.10
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    • pp.1671-1677
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    • 2017
  • In this paper, we propose a machine learning method for random noise removal in image deblurring. The proposed method uses a logistic regression to select reliable data to use them, and, at the same time, to exclude data, which seem to be corrupted by random noise, in the deblurring process. The proposed method uses commonly available images as training data. Simulation results show an improved performance of the proposed method, as compared with the median filtering based reliable data selection method.

Kyphotic Angle Measurement Accuracy for Vertebral Osteoporotic Compression Fracture; Reliable Method for Kyphotic Angle Measurement

  • Hong, Jae-Taek;Lee, Sang-Won;Son, Byung-Chul;Sung, Jae-Hoon;Park, Choon-Keun;Kim, Moon-Chan
    • Journal of Korean Neurosurgical Society
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    • v.39 no.4
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    • pp.256-259
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    • 2006
  • Objective : Having a reliable and reproducible measurement technique to measure the sagittal contour in vertebral fractures is paramount to clinical decision making. This study is designed to determine the most reliable measurement technique in osteoporotic vertebral compression fracture. Methods : Fifteen lateral radiographs of thoracic and lumbar fractures were selected and measured on two separate occasions by three spine surgeons using six different measurement techniques [Centroid, Harrison Posterior Tangent Methods and 4 different types of modified Cobb method]. The radiograph quality was assessed and the center beam location was determined. Statistical analysis including ANOVA for repeated measures was carried out using the SAS software [v 8.0]. Results : The inter and intraobserver variance of the Cobb method 4 and Harrison posterior tangent method were significantly lower than the other four methods. The intraobserver correlation coefficients were the most consistent using the Cobb method 4 [0.982]. which was followed by the Harrison posterior tangent [0.953] and Cobb methods 1 [0.874]. The intraobserver agreement [% of repeated measures within 5 degrees of the original measurement] ranged from 42% to 98% for each technique for all three observers, with the Cobb method 4 showing the best agreement [97.8%] followed by the Harrison posterior tangent method [937%]. Conclusion : The Cobb method-4 and Harrison posterior tangent methods, when applied to measuring the kyphosis, are reliable and have a similar small error range. The Cobb method 4 shows the best overall reliability. However, the centroid method and Cobb method using a fractured endplate do not produce an accurate result due to inter and intraobserver differences in determining the baseline.

Reliable H Control : A Linlear Matrix Inequality Approach (신뢰성 있는 H 제어 : 선형 행렬 부등식 방법)

  • 이종민;김병국;김성우
    • Journal of Institute of Control, Robotics and Systems
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    • v.10 no.3
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    • pp.216-224
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    • 2004
  • In this paper we address reliable output feedback control problem for a class of linear systems with actuator/sensor failures. An output feedback control method is proposed which stabilizes the plant and guarantees $H_\inftyt$-norm constraint against all admissible actuator/sensor failures. The controller can be obtainer by solving some LMls that cover all failure cases. Effectiveness of this controller is validated via a numerical example. This paper addresses reliable output feedback control problem for a class of linear systems with actuator/sensor failures. An output feedback control method is proposed which stabilizes the plant and guarantees $H_\inftyt$-norm constraint against all admissible actuator/sensor failures. The controller can be obtained by solving some LMls that cover all failure cases. Effectiveness of this controller is validated via numerical example.

A Reliable Control of Nonlinear Systems via a Sum of Squares Approach (제곱합 접근법에 의한 비선형시스템의 신뢰성제어)

  • Yoo, Seog-Hwan
    • Journal of Applied Reliability
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    • v.12 no.2
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    • pp.121-129
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    • 2012
  • This paper deals with a design of reliable state feedback controllers for continuous time polynomial systems with actuator failures. The goal is to find an asymptotically stabilizing controller such that the closed loop system achieves the prescribed decay rate in the actuator failure cases. Based on a sum of squares (SOS) approach, a design method for reliable nonlinear controller is presented. In order to demonstrate our design method, a numerical example is shown.

Optimizing Reliable Network using Genetic Algorithm (유전자 알고리즘을 이용한 신뢰 통신망 최적화)

  • 이학종;강주락;권기호
    • Proceedings of the IEEK Conference
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    • 1999.11a
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    • pp.452-455
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    • 1999
  • Genetic algorithm is well known as the efficient algorithm which can solve a difficult problem. Network design considering reliability is NP-hard problem with cost, distance, and volume. Therefore genetic algorithm is considered as a good method for this problem. This paper suggests the reliable network which can be constructed with minimum cost using genetic algorithm and the rank method based on reliability for improving the performance. This method shows more excellent than existing method and confirms the result through simulation.

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Metaheuristics for reliable server assignment problems

  • Jang, Kil-Woong;Kim, Jae-Hwan
    • Journal of Advanced Marine Engineering and Technology
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    • v.38 no.10
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    • pp.1340-1346
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    • 2014
  • Previous studies of reliable server assignment considered only to assign the same cost of server, that is, homogeneous servers. In this paper, we generally deal with reliable server assignment with different server costs, i.e., heterogeneous servers. We formulate this problem as a nonlinear integer programming mathematically. Our problem is defined as determining a deployment of heterogeneous servers to maximize a measure of service availability. We propose two metaheuristic algorithms (tabu search and particle swarm optimization) for solving the problem of reliable server assignment. From the computational results, we notice that our tabu search outstandingly outperforms particle swarm optimization for all test problems. In terms of solution quality and computing time, the proposed method is recommended as a promising metaheuristic for a kind of reliability optimization problems including reliable sever assignment and e-Navigation system.