• Title/Summary/Keyword: Time-Weighting

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Generalized optimal active control algorithm with weighting matrix configuration, stability and time-delay

  • Cheng, Franklin Y.;Tian, Peter
    • Structural Engineering and Mechanics
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    • v.1 no.1
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    • pp.119-135
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    • 1993
  • The paper presents a generalized optimal active control algorithm for earthquake-resistant structures. The study included the weighting matrix configuration, stability, and time-delays for achieving control effectiveness and optimum solution. The sensitivity of various time-delays in the optimal solution is investigated for which the stability regions are determined. A simplified method for reducing the influence of time-delay on dynamic response is proposed. Numerical examples illustrate that the proposed optimal control algorithm is advantageous over others currently in vogue. Its feedback control law is independent of the time increment, and its weighting matrix can be flexibly selected and adjusted at any time during the operation of the control system. The examples also show that the weighting matrix based on pole placement approach is superior to other weighting matrix configurations for its self-adjustable control effectiveness. Using the time-delay correction method can significantly reduce the influence of time-delays on both structural response and required control force.

New Weighting Factor of 2D Isotropic-Dispersion Finite Difference Time Domain(ID-FDTD) Algorithm

  • Zhao, Meng;Koh, Il-Suek
    • Journal of electromagnetic engineering and science
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    • v.8 no.4
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    • pp.139-143
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    • 2008
  • In this paper, a new scheme to calculate the weighting factor of the 2-D isotropic-dispersion finite difference time domain(ID-FDTD) is proposed. The weighting factor in [1] was formulated in free space, so that it may not be optimal in dielectric media. Therefore, the weighting factor was reformulated by considering the material properties and using the least mean square method. As a result, a minimum numerical dispersion error for any dielectric media is guaranteed.

Using Time Use Data for Weighting Internet Survey Results (생활시간 조사를 이용한 가중치 부여방법: 인터넷 조사에 대한 적용 가능성 검토)

  • Cho, Sung-Kyum;Park, Ah-Hyun;Huh, Myung-Hoe
    • Survey Research
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    • v.12 no.2
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    • pp.145-157
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    • 2011
  • There are limitations as to how internet surveys can be used. Applying various weighting procedures has not always resulted in error reduction. A good reference survey would increase the effects of the weighting method, but it is very difficult to get a reference survey for non-demographic weighting variables, which restricts the use of internet surveys. We hypothesized that time use variables could be employed as weighting variables. The time use survey is conducted regularly by KOSTAT and includes various time-related variables. We tested our hypothesis using the 2009 survey results, which had been gathered by KOSTAT in 2009. When we applied weighting variables which were based on the 2004 time use survey results to the online version of the 2009 KOSTAT social survey, the gap between the online and off-line versions was slightly reduced. This result shows that we could use time use survey results to develop a better weighting scheme.

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Error Analysis of Muskingum-Cunge Flood Routing Method (Muskingum-Cunge 홍수추적 방법의 오차해석)

  • Kim, Dae-Geun;Seo, Il-Won
    • Journal of Korea Water Resources Association
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    • v.36 no.5
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    • pp.751-760
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    • 2003
  • Error analysis of finite difference equation on the Muskingum-Cunge flood routing method with free time and space weighting factor was carried out. The error analysis shows that the numerical solution of the Muskingum-Cunge method becomes diverged with time when the sum of time weighting factor and space weighting factor is greater than 1.0. Numerical diffusion increases when the sum of time weighting factor and space weighting factor decreases. Numerical diffusion and numerical oscillation increase when the grid resolution is coarse. Numerical experiments and field applications show that the Muskingum-Cunge method with free space weighting factor is more effective for simulating the flood routing with great peak diminution than conventional Muskingum-Cunge method with fixed space weighting factor, 0.5.

Receding Horizon Predictive Control for Nonlinear Time-delay Systems

  • Kwon, Wook-Hyun;Lee, Young-Sam;Han, Soo-Hee
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.27.2-27
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    • 2001
  • This paper proposes a receding horizon predictive control (RHPC) for nonlinear time-delay systems. The control law is obtained by minimizing finite horizon cost with a terminal weighting functional. An inequality condition on the terminal weighting functional is presented, under which the closed-loop stability of RHPC is guaranteed, A special class of nonlinear time-delay systems is introduced and a systematic method to find a terminal weighting functional satisfying the proposed inequality condition is given for these systems. Through a simulation example, it is demonstrated that the proposed RHPC has the guaranteed closed-loop stability for nonlinear time-delay systems.

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A Study on Tannin Treatment of Silk Fabrics(I) -Condensed Tannin- (견의 Tannin처리에 관한 연구(I) -축합형 Tannin을 중심으로-)

  • 설정화;최석철
    • Textile Coloration and Finishing
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    • v.6 no.1
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    • pp.19-27
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    • 1994
  • Mimosa and Quebracho are, in general, tanned with leather skin, finished silk fabrics according to temperature, treatment time, tannin concetration, pH, and studies that relation between tannin weighting and various factors. This makes fundamental study on characteristic of tannin treated fabrics. and the results are as fallows : 1. λ$_{max}$ was found at 278.5nm for Mimosa. 279.5nm for Quebracho. Also a stability was good in standing time and heating. 2. The higher tannin treatment temprature was, the better tannin weighting effect was. But they were slightly decreased at over 8$0^{\circ}C$, and K/S was slowly increased. 3. As tannin treatment time increased, tannin weighting effect increased but they were decreased at over 8$0^{\circ}C$, 90min. 4. As tannin concentration increased, tannin weighting was increased. 5. In tannin weighting effect according to various pH conditions, the it's best range of pH were 3.5~5.5 of Mimosa, 2.5~3.5 of Quebracho.o.

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The Comparison of the Adaptive Equalization Performance in MCMA Algorithm by the Weighting Factor (MCMA알고리즘에서 weighting factor에 의한 적응 등화 성능 비교)

  • Lim, Seung-Gag
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.10 no.4
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    • pp.137-143
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    • 2010
  • This paper deals with the performance comparison of self adaptive equalizer by the weighting factor of MCMA cost function for the compensate the amplitude and phase distortion which occurs in the communication channel. The MCMA is improves the cost function of present CMA at the output of equalizer for the minimize of error function in the amplitude and phase, the value of weighting factor is used at this time. When the comparison of equalizer performance, we classified to initial state and steady state, then it represents the convergence time and convergence speed and steady state operation of equalizer to the predetermined level, it is determined by the weighting factor. We confirm to the different result to this 2 state by weighting factor values using computer simulation. By using the result of this paper, if we appropriately choose the weighting factor values in the environment of communication channel, it is expected that the high quality digital transmission is possible.

A New Convolutional Weighting Function Method for Continuous-time Parameter Identification

  • Park, Hyun-Seob;Park, Poo-Gyeon
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.26.5-26
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    • 2001
  • This paper proposes a new approach to identifying the unknown parameters of continuous LTI systems. For parameter identification in continuous-time systems, the Linear Integral Filter (LIF) method generally has been used in the beginning. Especially, one of the most efficient LIF methods in the literature is to use a weighting function satisfying specific three constraints. In high order systems, even though the weighting function satisfies the three constraints, it is impossible to identify the exact parameters of the systems because of information loss arising from a great amount of magnitude differences among the weighting function and its high-order derivatives. This paper, using an LMI technique, shows the limitation in designing the weighting function of the existing methods, and ...

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Real-time Robotic Vision Control Scheme Using Optimal Weighting Matrix for Slender Bar Placement Task (얇은 막대 배치작업을 위한 최적의 가중치 행렬을 사용한 실시간 로봇 비젼 제어기법)

  • Jang, Min Woo;Kim, Jae Myung;Jang, Wan Shik
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.26 no.1
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    • pp.50-58
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    • 2017
  • This paper proposes a real-time robotic vision control scheme using the weighting matrix to efficiently process the vision data obtained during robotic movement to a target. This scheme is based on the vision system model that can actively control the camera parameter and robotic position change over previous studies. The vision control algorithm involves parameter estimation, joint angle estimation, and weighting matrix models. To demonstrate the effectiveness of the proposed control scheme, this study is divided into two parts: not applying the weighting matrix and applying the weighting matrix to the vision data obtained while the camera is moving towards the target. Finally, the position accuracy of the two cases is compared by performing the slender bar placement task experimentally.

Estimation of Quantitative Precipitation Rate Using an Optimal Weighting Method with RADAR Estimated Rainrate and AWS Rainrate (RADAR 추정 강수량과 AWS 강수량의 최적 결합 방법을 이용한 정량적 강수량 산출)

  • Oh, Hyun-Mi;Heo, Ki-Young;Ha, Kyung-Ja
    • Korean Journal of Remote Sensing
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    • v.22 no.6
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    • pp.485-493
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    • 2006
  • This study is to combine precipitation data with different spatial-temporal characteristics using an optimal weighting method. This optimal weighting method is designed for combination of AWS rain gage data and S-band RADAR-estimated rain data with weighting function in inverse proportion to own mean square error for the previous time step. To decide the optimal weight coefficient for optimized precipitation according to different training time, the method has been performed on Changma case with a long spell of rainy hour for the training time from 1 hour to 10 hours. Horizontal field of optimized precipitation tends to be smoothed after 2 hours training time, and then optimized precipitation has a good agreement with synoptic station rainfall assumed as true value. This result suggests that this optimal weighting method can be used for production of high-resolution quantitative precipitation rate using various data sets.