• Title/Summary/Keyword: performance robustness

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Supply Chain Agility: Achieving Robustness and Logistics Performance

  • Young-Kyou HA;Changjoon LEE
    • Journal of Distribution Science
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    • v.22 no.9
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    • pp.65-72
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    • 2024
  • Purpose: This study aims to empirically analyze the influence of supply chain agility and flexibility on supply chain robustness and logistics performance, addressing a research gap in the context of dynamic business environments. Research design, data and methodology: The study examines causal relationships between supply chain agility, flexibility, robustness, and logistics performance among businesses in South Korea. Data were collected through a survey of 300 workers in supply chain-related departments. A structural equation model was employed for hypothesis testing. Results: The empirical analysis shows that supply chain agility and flexibility positively and significantly influence supply chain robustness, which in turn has a significant positive impact on logistics performance. Conclusions: This study contributes by providing empirical evidence on the importance of supply chain agility, flexibility, and robustness in enhancing logistics performance. The findings suggest prioritizing the development of these capabilities for competitive advantage. Further research on the interrelationships between various supply chain capabilities and their impact on performance outcomes is highlighted.

Robustness analysis of pole assignment in a specified circle for perturbed systems (섭동 시스템에 대한 규정된 원 내로의 극점배치 견실성 해석)

  • Kim, Ga-Gue;Choi, Bong-Yeol
    • Journal of Institute of Control, Robotics and Systems
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    • v.1 no.2
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    • pp.78-82
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    • 1995
  • In this paper, we consider the robustness analysis problem in state space models with linear time invariant perturbations. Based upon the discrete-time Lyapunov approach, sufficient conditions are derived for the eigenvalues of perturbed matrix to be located in a circle, and robustness bounds on perturbations are obtained. Spaecially, for the case of a diagonalizable hermitian matrix the bound is given in terms of the nominal matrix without the solution of Lyapunov equation. This robustness analysis takes account not only of stability robustness but also of certain types of performance robustness. For two perturbation classes resulting bounds are shown to be improved over the existing ones. Examples given include comparison of the proposed analysis method with existing one.

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Optimum PI Controller Design for an Oil Cooler System Using GA (GA를 이용한 오일쿨러시스템의 최적 PI제어기 설계)

  • Jung, Young-Mi;Jeong, Seok-Kwon
    • Journal of Power System Engineering
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    • v.18 no.5
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    • pp.28-34
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    • 2014
  • This paper deals with optimum PI controller design using genetic algorithm to improve control performance and robustness for an oil cooler system. The optimum PI gain was found to minimize an object function, integrated absolute error, and to satisfy control design specifications such as overshoot and settling time based on practical transfer function of the oil cooler system. The control performance and robustness were investigated by comparing indicial responses and Bode diagram analysis with respect to three kinds of PI gains obtained from different gain decision manners. Moreover, the robustness against to input disturbances, sinusoidal wave form and abrupt single pulse, was evaluated. The computer simulation results showed that the suggested optimum gain can establish desirable control performance and strong robustness with easy design process.

Performance and Robustness of Discrete Perturbation Observer

  • Sangjoo Kwon;Chung, Wan-Kyun;Youngil Youm
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.31.5-31
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    • 2001
  • In conventional perturbation estimators such as disturbance observers(DOB) [1, 2] or time-delayed controllers(TDC) [3{5}, the low pass filter(so-called Q-filter) plays an important role in the stability and performance. However, a general design guideline or analysis for the Q-filter has not been researched yet. In this paper, a guideline for the design of discrete Q-filter is suggested in terms of the analysis of the relationship between the filter parameters and stability performance robustness in discrete-time domain. The analysis clarifies the discrete-time effect of the perturbation estimator and provides a transparent relationship between performance and robustness depending ...

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A Robust Eigenstructure Assignment Method with Application to EMRAAT Missile Control Design (견실성을 고려한 고유구조 지정기법 및 EMRAAT 미사일 제어에의 응용)

  • Kim, Joo-Ho;Park, Jae-Weon
    • Journal of Institute of Control, Robotics and Systems
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    • v.6 no.10
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    • pp.845-853
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    • 2000
  • In this paper, we introduce a relationship between the sensitivity and the robustness of a system, and we propose a robust eigenstructure assignment scheme using a novel performance index which can consider the performance and the robustness of the system simultaneously. We also propose an assignment accuracy measure and a robustness measure which are used for the performance examination of the proposed robust eigenstructure assignment scheme. The usefulness of the proposed algorithm and the measures are verified by applying to controller design of a simple numerical example and the EMRAAT missile.

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The Robustness of Coding and Modulation for Body-Area Networks

  • Biglieri, Ezio;Alrajeh, Nabil
    • Journal of Communications and Networks
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    • v.16 no.3
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    • pp.264-269
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    • 2014
  • We consider transmission over body area networks. Due to the difficulty in assessing an accurate statistical model valid for multiple scenarios, we advocate a system design technique favoring robustness. Our approach, which is based on results in [12] and generalizes them, examines the variation of a performance metric when the nominal statistical distribution of fading is replaced by the worst distribution within a given Kullback-Leibler divergence from it. The sensitivity of the performance metric to the divergence from the nominal distribution can be used as an indication of the design robustness. This concept is applied by evaluating the error probability of binary uncoded modulation and the outage probability-the first parameter is useful to assess system performance with no error-control coding, while the second reflects the performance when a near-optimal code is used. The usefulness of channel coding can be assessed by comparing its robustness with that of uncoded transmission.

Comparative Study on the Stability and the Performance in Bilateral Teleoperation

  • Kim, Jin-Wook;Kim, Hyung-Wook;Yi, Byung-Ju;Suh, Il-Hong
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.51.1-51
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    • 2001
  • Teleoperation is a rapidly progressing field promising to have significant application in space, mining, medical, and other areas. Unfortunately, significant communication delays are expected in teleoperation. With this problem, the two major issues in teleoperation are stability robustness and transparency performance. Recent work in bilateral teleoperation in the two-channel showed that for any two-channel control architecture, stability robustness is enhanced if the feedforward control parameters are lowered. In this paper, we analyze the stability and performance robustness of the three channels control architectures using the passivity-based Llewellyn´s absolute stability criterion as wall as the minimum values and Z-width´s of the operator and environment transmitted impedances. And the stability and the performance robustness of two and three channels control architectures are quantitatively compared.

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A Robustness Performance Improvement of MMA Adaptive Equalization Algorithm in QAM Signal Transmission (QAM 신호 전송에서 MMA 적응 등화 알고리즘의 Robustness 성능 개선)

  • Lim, Seung-Gag
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.19 no.2
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    • pp.85-90
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    • 2019
  • This paper related with the M-CMA adaptive equalization algorithm which is possible to improve the residual isi and robustness performance compare to the current MMA algorithm that is reduce the intersymbol interference occurs in channel when transmitting the QAM signal. The current MMA algorithm depend on the cost function and error function using fixed signal dispersion constant, but the M-CMA algorithm depend on the new proposed cost function and error function using multiple dispersion constant. By this, it is possible to having robustness of the CMA and simultaneous compensation of amplitude and phase of MMA. The computer simulation was performed in the same channel and noise environment for compare the proposed M-CMA and current MMA algorithm. The equalizer output signal constellation, residual isi, MD, MSE learning courves and SER, represents the robustness were used for performance index. As a result of simulation, the M-CMA has more superior to the MMA in robustness and other performance index.

Design of Disturbance Observer Considering Robustness and Control Performance (2) : It's Application for Optical Disc Drive Servo System (강인성과 제어 성능을 고려한 외란 관측기의 설계 (2) : 광 디스크 드라이브 서보 시스템에의 적용 실험)

  • 김홍록;최영진;서일홍;정완균;박명관;이경호
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.4
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    • pp.270-276
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    • 2003
  • The disturbance observer (DOB) has been widely utilized fer high precision and high speed motion control application. However, it still lacks the analysis for the robustness brought by using DOB. This paper summarizes six guidelines for the design of DOB taking into account the robustness and control performance in case of the second order system. For effectiveness of the proposed guideline, the actual implementation and experimental results of the DOB is compared in the Optical Disk Drive(ODD) servo system. In the DVD player and DVD-ROM drive, the guidelines of DOB are useful, and the disturbance rejection performance is improved under the DOB system.

Robustness of 2nd-order Iterative Learning Control for a Class of Discrete-Time Dynamic Systems

  • Kim, Yong-Tae
    • Journal of the Korean Institute of Intelligent Systems
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    • v.14 no.3
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    • pp.363-368
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    • 2004
  • In this paper, the robustness property of 2nd-order iterative learning control(ILC) method for a class of linear and nonlinear discrete-time dynamic systems is studied. 2nd-order ILC method has the PD-type learning algorithm based on both time-domain performance and iteration-domain performance. It is proved that the 2nd-order ILC method has robustness in the presence of state disturbances, measurement noise and initial state error. In the absence of state disturbances, measurement noise and initialization error, the convergence of the 2nd-order ILC algorithm is guaranteed. A numerical example is given to show the robustness and convergence property according to the learning parameters.