• Title/Summary/Keyword: input-output matrix

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Data-based Control for Linear Time-invariant Discrete-time Systems

  • Park, U. S.;Ikeda, M.
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.1993-1998
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    • 2004
  • This paper proposes a new framework for control system design, called the data-based control approach or data space approach, in which the input and output data of a dynamical system is directly and solely used to analyze or design a control system without the employment of any mathematical models like transfer functions, state space equations, and kernel representations. Since, in this approach, most of the analysis and design processes are carried out in the domain of the data space, we introduce some notions of geometrical objects, e.g., the openloop and closed-loop data spaces, which serve as the system representations in the data space. In addition, we establish a relationship between the open-loop and closed-loop data spaces that the closed-loop data space is contained in the open-loop data space as one of its subspaces. By using this relationship, we can derive the data-based stabilization condition for a linear time-invariant discrete-time system, which leads to a linear matrix inequality with a rank constraint.

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Design rules of directional coupler optical switches in consideration of parasitic couplings in the input/output bending sections (Input/Output bending 영역에서의 parasitic coupling을 고려한 방향성 결합기 광 스위치의 설계 법칙)

  • 김동각;김창민
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.34D no.1
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    • pp.41-48
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    • 1997
  • Design rules of directional coupler optical switches are discussed in consideration of parasitic couplings in the bending section. The parasitic coupling phenomenon is analyzed based on the coupled-mode theory and the solutions are represented in the form of the transfer matrix. The modified switching conditions due to the parasitic coupling are derived and the resultant switching diagrams are illustrated. It is revealed that the parallel section's length needs to be adjustd less than the coupling length $l_c(=\pi/2\textsc{k}o)$ to obtain the desired crosstalk and that the adjustment depends on the strength of the parasitic coupling. However, it is discovered that, for weak parasitic coupling, the switching voltage does not need to be altered but may maintain the same value as if no parasitic coupling is taken into account.

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Spatial Multiuser Access for Reverse Link of Multiuser MIMO Systems

  • Shin, Oh-Soon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.10A
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    • pp.980-986
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    • 2008
  • Spatial multiuser access is investigated for the reverse link of multiuser multiple-input multiple-output (MIMO) systems. In particular, we consider two alternative a aches to spatial multiuser access that adopt the same detection algorithm at the base station: one is a closed-loop approach based on singular value decomposition (SVD) of the channel matrix, whereas the other is an open-loop approach based in space-time block coding (STBC). We develop multiuser detection algorithms for these two spatial multiuser access schemes based on the minimum mean square error (MMSE) criterion. Then, we compare the bit error rate (BER) performance of the two schemes and a single-user MIMO scheme. Interestingly, it is found that the STBC approach can provide much better BER performance than the SVD approach as well as than a single-user MIMO scheme.

Efficient Near-Optimal Detection with Generalized Sphere Decoder for Blind MU-MIMO Systems

  • Kim, Minjoon;Park, Jangyong;Kim, Hyunsub;Kim, Jaeseok
    • ETRI Journal
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    • v.36 no.4
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    • pp.682-685
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    • 2014
  • In this letter, we propose an efficient near-optimal detection scheme (that makes use of a generalized sphere decoder (GSD)) for blind multi-user multiple-input multiple-output (MU-MIMO) systems. In practical MU-MIMO systems, a receiver suffers from interference because the precoding matrix, the result of the precoding technique used, is quantized with limited feedback and is thus imperfect. The proposed scheme can achieve near-optimal performance with low complexity by using a GSD to detect several additional interference signals. In addition, the proposed scheme is suitable for use in blind systems.

Flexure Error Analysis of RLG based INS (링레이저 자이로 관성항법시스템의 편향 오차 해석)

  • Kim Kwang-Jin;Yu Myeong-Jong;Park Chan-Gook
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.6
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    • pp.608-613
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    • 2006
  • Any input acceleration that bends RLG dithering axis causes flexure error, which is a source of the noncommutative error that can not be compensated by simply using integrated gyro sensor output. This paper introduces noncommutative error equations that define attitude errors caused by flexure errors. In this paper, flexure error is classified as sensor level error if the sensing axis coincides with the dithering axis and as system level error if the two axes do not coincide. The relationship between gyro output and the rotation vector is introduced and is used to define the coordinate transformation matrix and angular motion. Equations are derived for both sensor level and system level flexure error analysis. These equations show that RLG based INS attitude error caused by flexure is directly proportional to time, amount of input acceleration and the dynamic frequency of the vehicle.

A DESIGN METHOD OF LYAPUNOV-STABLE MMG FUZZY CONTROLLER

  • Hara, Fumio;Yamamoto, Kazuomi
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1993.06a
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    • pp.873-876
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    • 1993
  • A fuzzy controller designed by mini-max-gravity(MMG) method is essentially nonlinear with respect to the controller's input and output relationship, and stability analysis is thus needed to construct a stable control system. This paper deals with a design method of a position-type MMG fuzzy controller stable in a sense of Lyapunov when considered is a single-input-single-output linear, stable plant. We first introduce a method to construct a Laypunov function by using an eigen-value of A matrix of the linear, stable plant dynamics and then we derive an asymtotic stability condition in terms of scale factors for fuzzy state variables and controller gain. The stability condition is found reasonably practical through comparing the theoretical stability region with that obtained from simulations.

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MIMO Precoding in 802.16e WiMAX

  • Li, Qinghua;Lin, Xintian Eddie;Zhang, Jianzhong (Charlie)
    • Journal of Communications and Networks
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    • v.9 no.2
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    • pp.141-149
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    • 2007
  • Multiple-input multiple-output (MIMO) transmit pre-coding/beamforming can significantly improve system spectral efficiency. However, several obstacles prevent precoding from wide deployment in early wireless networks: The significant feedback overhead, performance degradation due to feedback delay, and the large storage requirement at the mobile devices. In this paper, we propose a precoding method that addresses these issues. In this approach, only 3 or 6 bits feedback is needed to select a precoding matrix from a codebook. There are fifteen codebooks, each corresponding to a unique combination of antenna configuration (up to 4 antennas) and codebook size. Small codebooks are prestored and large codebooks are efficiently computed from the prestored codebook, modified Hochwald method and Householder reflection. Finally, the feedback delay is compensated by channel prediction. The scheme is validated by simulations and we have observed significant gains comparing to space-time coding and antenna selection. This solution was adopted as a part of the IEEE 802.16e specification in 2005.

Laboratory Validation of Bridge Finite Model Updating Approach By Static Load Input/Deflection Output Measurements (정적하중입력/변위출력관계를 이용한 단경간 교량의 유한요소모델개선기법: 실내실험검증)

  • Kim, Sehoon;Koo, Ki Young;Lee, Jong-Jae
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.20 no.3
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    • pp.10-17
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    • 2016
  • This paper presents a laboratory validation of a new approach for Finite Element Model Updating(FEMU) on short-span bridges by combining ambient vibration measurements with static load input-deflection output measurements. The conventional FEMU approach based on modal parameters requires the assumption on the system mass matrix for the eigen-value analysis. The proposed approach doesn't require the assumption and even provides a way to update the mass matrix. The proposed approach consists of two steps: 1) updating the stiffness matrix using the static input-deflection output measurements, and 2) updating the mass matrix using a few lower natural frequencies. For a validation of the proposed approach, Young's modulus of the laboratory model was updated by the proposed approach and compared with the value obtained from strain-stress tests in a Universal Testing Machine. Result of the conventional FEMU was also compared with the result of the proposed approach. It was found that proposed approach successfully estimated the Young's modulus and the mass density reasonably while the conventional FEMU showed a large error when used with higher-modes. In addition, the FE modeling error was discussed.

Multi-Step Commutation and Control Policies for Matrix Converters

  • Hofmann W.;Ziegler M.
    • Proceedings of the KIPE Conference
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    • 2001.10a
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    • pp.795-802
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    • 2001
  • The commutation and control in matrix converters is more complicated as in voltage source converters. Natural freewheeling paths do not exist and the theoretic absent storage elements result in a direct coupled system of load and line currents as well as voltages. The paper offers an overview about staggered commutation and control policies in matrix converters. Based on the knowledge about load current direction and the signs of the line to line input voltages different multi-step commutation policies were derived. This paper examines the application of that policies in the case of space vector modulation and direct control methods with the focus on the resulting effects to the reference output voltage deviation.

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Computerization of Matrix Analysis of Skeletal Structures (행렬해법에 의한 골조구조해석의 전산화)

  • 이재영
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.22 no.1
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    • pp.87-95
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    • 1980
  • General purpose programs are essential elements for the computerization of structural analysis. This paper is associated with actual formulation of such programs by matrix analysis. The basic theory of matrix analysis for skeletal structures, its implementation and techniques for developing efficient programs are discussed in this paper. Any shape of skeletal structure can be included in a single program for space frames. But in order to economize computing time and computer memory space, it is desirable to develop and operate seperate programs specialized into four categories; truss, planar frame, grid and space frame. As for general purpose programs, simplicity of input format and flexibility of output format should be duly considered. Compaction and solution of system equations are the most important aspects in computer programming of matrix analysis, and worth further study for more efficient computerization.

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