• Title/Summary/Keyword: operator systems

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FREE PRODUCTS OF OPERATOR SYSTEMS

  • Pop, Florin
    • Bulletin of the Korean Mathematical Society
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    • v.59 no.3
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    • pp.659-669
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    • 2022
  • In this paper we introduce the notion of universal free product for operator systems and operator spaces, and prove extension results for the operator system lifting property (OSLP) and operator system local lifting property (OSLLP) to the universal free product.

A Study on Singularly Perturbed Open-Loop Systems by Delta Operator Approach

  • Shim, Kyu-Hong;M. Edwin Sawan
    • Transactions on Control, Automation and Systems Engineering
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    • v.3 no.4
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    • pp.242-249
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    • 2001
  • In this paper, the open-loop state response of the two-time-scale systems by unified approach using the $\delta$-operator is presented with an example of the aircraft longitudinal dynamics. First, the $\delta$-operator system unifies both the continuous system and the discrete system simultaneously, and the $\delta$-operator approach improves the finite word-length characteristics. This saves more computing time than that of the discrete system. Second, the singular perturbation method by block diagonalization reduces the sizes and orders of the systems. This also reduces the floating-point operations (flops). The advantage of those two approaches is shown by comparing our results with the earlier ones in the illustrative example of the longitudinal motion of F-8 aircraft.

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A theory of linear quasi-time invariant filters

  • Lee, Heyoung;Bien, Zeungnam
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10a
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    • pp.362-367
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    • 1996
  • In this paper, the eigenstructure of a class of linear time varying systems, termed as linear quasi-time invariant(LQTI) systems, is investigated. A system composed of dynamic devices such as linear time varying capacitors and resistors can be an example of the class. To effectively describe and analyze the LQTI systems, a generalized differential operator G is introduced. Then the dynamic systems described by the operator G are studied in terms of eigenvalue, frequency characteristics, stability and an extended convolution. Some basic attributes of the operator G are compared with those of the differential operator D. Also the corresponding generalized Laplace transform pair is defined and relevant properties are derived for frequency domain analysis of the systems under consideration. As an application example, a LQTI circuit is examined by using the concept of eigenstructure of LQTI system. The LQTI filter processes the sinusoidal signals modulated by some functions.

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New decoupled wavelet bases for multiresolution structural analysis

  • Wang, Youming;Chen, Xuefeng;He, Yumin;He, Zhengjia
    • Structural Engineering and Mechanics
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    • v.35 no.2
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    • pp.175-190
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    • 2010
  • One of the intractable problems in multiresolution structural analysis is the decoupling computation between scales, which can be realized by the operator-orthogonal wavelets based on the lifting scheme. The multiresolution finite element space is described and the formulation of multiresolution finite element models for structural problems is discussed. Various operator-orthogonal wavelets are constructed by the lifting scheme according to the operators of multiresolution finite element models. A dynamic multiresolution algorithm using operator-orthogonal wavelets is proposed to solve structural problems. Numerical examples demonstrate that the lifting scheme is a flexible and efficient tool to construct operator-orthogonal wavelets for multiresolution structural analysis with high convergence rate.

A Systems Engineering Approach for CEDM Digital Twin to Support Operator Actions

  • Mousa, Mostafa Mohammed;Jung, Jae Cheon
    • Journal of the Korean Society of Systems Engineering
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    • v.16 no.2
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    • pp.16-26
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    • 2020
  • Improving operator performance in complex and time-critical situations is critical to maintain plant safety and operability. These situations require quick detection, diagnosis, and mitigation actions to recover from the root cause of failure. One of the key challenges for operators in nuclear power plants is information management and following the control procedures and instructions. Nowadays Digital Twin technology can be used for analyzing and fast detection of failures and transient situations with the recommender system to provide the operator or maintenance engineer with recommended action to be carried out. Systems engineering approach (SE) is used in developing a digital twin for the CEDM system to support operator actions when there is a misalignment in the control element assembly group. Systems engineering is introduced for identifying the requirements, operational concept, and associated verification and validation steps required in the development process. The system developed by using a machine learning algorithm with a text mining technique to extract the required actions from limiting conditions for operations (LCO) or procedures that represent certain tasks.

A Design on Robust Model Following Servo System Using $\delta$--Operator ($\delta$-연산자를 이용한 강인한 모델 추종형 서보 제어 시스템의 구성에 관한연구)

  • Kim, Chung-Tek;Hwang, Hyun-Joon
    • Journal of Institute of Control, Robotics and Systems
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    • v.6 no.2
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    • pp.121-126
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    • 2000
  • In the fast sampling limit the delta operator model tends to the analog system model. This fundamental property of the delta operator model unifies continuous and discrete time control system. In this paper we study robust linear optimal model following servo system in the presence of disturbances and parameter perturbations. A technique to directly design the generalized differential operator based unified control system that covers both differential operator based continuous time and delta operator based discrete time case is presented. The quadratic criterion function for a linear system is used to design the robust unified servo control system The characteristics of the proposed servo system are analysed and simulated to verify the robustness.

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An approach based on the generalized ILOWHM operators to group decision making

  • Park, Jin-Han;Park, Yong-Beom;Lee, Bu-Young;Son, Mi-Jung
    • Journal of the Korean Institute of Intelligent Systems
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    • v.20 no.3
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    • pp.434-440
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    • 2010
  • In this paper, we define generalized induced linguistic aggregation operator called generalized induced linguistic ordered weighted harmonic mean(GILOWHM) operator. Each object processed by this operator consists of three components, where the first component represents the importance degree or character of the second component, and the second component isused to induce an ordering, through the first component, over the third components which are linguistic variables and then aggregated. It is shown that the induced linguistic ordered weighted harmonic mean(ILOWHM) operator and linguistic ordered weighted harmonic mean(LOWHM) operator are the special cases of the GILOWHM operator. Based on the GILOWHM and LWHM operators, we develop an approach to group decision making with linguistic preference relations. Finally, a numerical example is used to illustrate the applicability of the proposed approach.

Delta-Operator-Based Digital Redesign of Linear Time-Invariant Systems

  • Lee, Ho-Jae;Park, Jin-Bae;Lee, Yeun-Woo;Joo, Young-Hoon
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.942-944
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    • 2004
  • This paper proposes a delta-operator-based digital redesign (DR) technique. An asymptotic property of the delta-operator-based DR is analyzed. The performance recovery is proved as a sampling time approaches zero.

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