• Title/Summary/Keyword: Adaptive applications

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Selection of Data-adaptive Polynomial Order in Local Polynomial Nonparametric Regression

  • Jo, Jae-Keun
    • Communications for Statistical Applications and Methods
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    • v.4 no.1
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    • pp.177-183
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    • 1997
  • A data-adaptive order selection procedure is proposed for local polynomial nonparametric regression. For each given polynomial order, bias and variance are estimated and the adaptive polynomial order that has the smallest estimated mean squared error is selected locally at each location point. To estimate mean squared error, empirical bias estimate of Ruppert (1995) and local polynomial variance estimate of Ruppert, Wand, Wand, Holst and Hossjer (1995) are used. Since the proposed method does not require fitting polynomial model of order higher than the model order, it is simpler than the order selection method proposed by Fan and Gijbels (1995b).

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Self tuning control with offset elimination for nonminimum phase system (비최소 위상 시스템에 대하여 오프셋(offset) 제거 기능을 가진 자기 동조 제어)

  • 나종래;변증남
    • 제어로봇시스템학회:학술대회논문집
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    • 1986.10a
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    • pp.78-82
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    • 1986
  • In the process control applications of self tuning control, a major concern of the control problem is to handle an offset caused by load disturbances and random steps occuring at random instance of time. Conventionally an integrator is incorperated in the forward path of the controller to eliminate such an offset. But this approach causes a difficulty if the adaptive part of the resultant controller is to be evaluated. In this paper a method of analyzing the adaptive system and improving the offset effect is suggested for a class of referance model method in the self tuning adaptive control system.

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Adaptive Background Subtraction Algorithm with Auto Brightness Control for Consumer-type Cameras

  • Thongkamwitoon T.;Aramvith S.;Chalidabhongse T. H.
    • Journal of Broadcast Engineering
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    • v.10 no.2
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    • pp.156-165
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    • 2005
  • This paper presents a new auto brighoess control algorithm fur adaptive background subtraction. The algorithm is designed to cope with the problem of auto-brightness adjustment feature of consumer-type cameras. The experimental results show the proposed method improves performance of the classification. This will be beneficial to many computer vision applications in term of reducing the cost of implementation and making them more available to the mass consumer market.

Performance analysis of speaker verification system adopting the ACHARF ANC (ACHARF ANC를 채용한 화자인증시스템의 성능분석)

  • Lee Hyun Seung;Choi Hong Sub;Shin Yoon Ki
    • Proceedings of the KSPS conference
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    • 2002.11a
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    • pp.179-182
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    • 2002
  • The development of noise robust speech processing systems is becoming increasingly important as speech technology is currently widely applied in real world applications. Recently, to resolve such a noise problem, adaptive noise canceller(ANC) is frequently used, which is based upon adaptive filters. The adaptive recursive filters perform better than adaptive non-recursive filters due to the added poles, but the stability may be severely threatened. But these problems of adaptive recursive filters was solved by ACHARF algorithm. This paper presents a method which combines speaker verification system with ANC(Adaptive Noise Canceller) using the ACHARF algorithm. In the front-end stage, ANC is adopted to suppress the additive noise imposed on the speech signal. The results show that the performance of speaker verification system becomes better than before.

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A Study on Adaptive-Sliding Mode Control of SCARA Robot (스카라로보트의 적응 -슬라이딩모드 제어에 관한 연구)

  • 윤대식;차보남;김경년;한성현
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1994.10a
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    • pp.330-335
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    • 1994
  • In this paper, adaprive control and sliding mode control are combined to implement the proposed adaptive sliding mode control(ASMC) algorithm which is new approach to the control of industrial robot manipulator with external disturbances and parameter uncertainties. Adaptive control algorithm is designed by using the principle of the model reference adaptive control method based upon the hyperstability theory. The contribution of this method is that the parameters of the sliding surface are replaced by time varying parameters whose are calculated by an adaptation algorithm, which forces the errors to follow the behavior of a reference error model. Simulation results show that the proposed method not only improves the performance of the system but also reduces the chattering problem of sliding mode control. Consequently, it is expected that the new adaptive sliding mode control algorithm will be suited for various practical applications.

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Applications and analysis on the subband nonlinear adaptive Volterra filter (부대역 비선형 Volterra 적응필터의 응용과 성능분석)

  • Yang, Yoon Gi;Byun, Hee Jung
    • Journal of IKEEE
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    • v.17 no.2
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    • pp.111-118
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    • 2013
  • In this paper, the subband nonlinear adaptive Volterra filters are introduced and its analysis are presented. From the eigenvalue analysis of the input correlation matrix, we show that the proposed subband adaptive Volterra filter has superior convergence performance as compared to the conventional one, which shows that the it can be useful for the recently proposed subband nonlinear adaptive echo canceller. Also, the optimum filter in each subband are introduced and verified from the computer simulations.

A TRIPLE MIXED QUADRATURE BASED ADAPTIVE SCHEME FOR ANALYTIC FUNCTIONS

  • Mohanty, Sanjit Kumar
    • Nonlinear Functional Analysis and Applications
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    • v.26 no.5
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    • pp.935-947
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    • 2021
  • An efficient adaptive scheme based on a triple mixed quadrature rule of precision nine for approximate evaluation of line integral of analytic functions has been constructed. At first, a mixed quadrature rule SM1(f) has been formed using Gauss-Legendre three point transformed rule and five point Booles transformed rule. A suitable linear combination of the resulting rule and Clenshaw-Curtis seven point rule gives a new mixed quadrature rule SM10(f). This mixed rule is termed as triple mixed quadrature rule. An adaptive quadrature scheme is designed. Some test integrals having analytic function integrands have been evaluated using the triple mixed rule and its constituent rules in non-adaptive mode. The same set of test integrals have been evaluated using those rules as base rules in the adaptive scheme. The triple mixed rule based adaptive scheme is found to be the most effective.

5Gbps CMOS Adaptive Feed-Forward Equalizer Using Phase Detector Output for Backplane Applications (위상 검출기 출력을 이용한 백플레인용 5Gbps CMOS 적응형 피드포워드 이퀄라이저)

  • Lee, Gi-Hyeok;Seong, Chang-Gyeong;Choi, U-Yeong
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.44 no.5
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    • pp.50-57
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    • 2007
  • A 5Gbps CMOS adaptive feed-forward equalizer designed for backplane applications is described. The equalizer has adaptive feedback circuits to control the compensating gain of the equalizing filter, which uses a phase detector in clock recovery circuit to detect ISI (Inter-Symbol Interference) level. This makes the equalizer operate adaptively for a various channel length of backplane environments.

Bayesian methods in clinical trials with applications to medical devices

  • Campbell, Gregory
    • Communications for Statistical Applications and Methods
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    • v.24 no.6
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    • pp.561-581
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    • 2017
  • Bayesian statistics can play a key role in the design and analysis of clinical trials and this has been demonstrated for medical device trials. By 1995 Bayesian statistics had been well developed and the revolution in computing powers and Markov chain Monte Carlo development made calculation of posterior distributions within computational reach. The Food and Drug Administration (FDA) initiative of Bayesian statistics in medical device clinical trials, which began almost 20 years ago, is reviewed in detail along with some of the key decisions that were made along the way. Both Bayesian hierarchical modeling using data from previous studies and Bayesian adaptive designs, usually with a non-informative prior, are discussed. The leveraging of prior study data has been accomplished through Bayesian hierarchical modeling. An enormous advantage of Bayesian adaptive designs is achieved when it is accompanied by modeling of the primary endpoint to produce the predictive posterior distribution. Simulations are crucial to providing the operating characteristics of the Bayesian design, especially for a complex adaptive design. The 2010 FDA Bayesian guidance for medical device trials addressed both approaches as well as exchangeability, Type I error, and sample size. Treatment response adaptive randomization using the famous extracorporeal membrane oxygenation example is discussed. An interesting real example of a Bayesian analysis using a failed trial with an interesting subgroup as prior information is presented. The implications of the likelihood principle are considered. A recent exciting area using Bayesian hierarchical modeling has been the pediatric extrapolation using adult data in clinical trials. Historical control information from previous trials is an underused area that lends itself easily to Bayesian methods. The future including recent trends, decision theoretic trials, Bayesian benefit-risk, virtual patients, and the appalling lack of penetration of Bayesian clinical trials in the medical literature are discussed.

Adaptive Actuator Failure Compensation Designs for Linear Systems

  • Chen, Shuhao;Tao, Gang;Joshi, Suresh M.
    • International Journal of Control, Automation, and Systems
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    • v.2 no.1
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    • pp.1-14
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    • 2004
  • This paper surveys some existing direct adaptive feedback control schemes for linear time-invariant systems with actuator failures characterized by the failure pattern that some inputs are stuck at some unknown fixed or varying values at unknown time instants, and applications of those schemes to aircraft flight control system models. Controller structures, plant-model matching conditions, and adaptive laws to update controller parameters are investigated for the following cases for continuous-time systems: state tracking using state feed-back, output tracking using state feedback, and output tracking using output feedback. In addition, a discrete-time output tracking design using output feedback is presented. Robustness of this design with respect to unmodeled dynamics and disturbances is addressed using a modified robust adaptive law.