bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nonparametric multivariate control charts based on a linkage ranking algorithm
Authors: Bush Helen Meyers , Chongfuangprinya Panitarn , Chen Victoria C. P. , Sukchotrat Thuntee , Kim Seoung Bum 
Published: August 2010

AbstractControl charts have been widely recognized as important and critical tools in system monitoring for detection of abnormal behavior and quality improvement. In particular, multivariate control charts have been effectively used when a process involves a number of correlated quality characteristics. Most existing multivariate control charts were developed using the assumption of normally distributed quality characteristics. However, process data from modern industries often do not follow the normal distribution. Despite the great need for nonparametric control charts that can control the error rate regardless of the underlying distribution, few efforts have been made in this direction. In this paper, we propose a new nonparametric control chart (called the kLINK chart) based on a k‐linkage ranking algorithm that calculates the ranking of a new observation relative to the in‐control training data. A simulation study was performed to demonstrate the effectiveness of our kLINK chart and its superiority over the traditional Hotelling's T2 chart and the ranking depth control chart in nonnormal situations. In addition, to enable increased sensitivity to small shifts, we present an exponentially weighted moving average version of a kLINK chart. Copyright © 2010 John Wiley & Sons, Ltd.
A Bayesian approach for integration of physical and computer experiments for quality improvement in nano‐composite manufacturing
Authors: Vanli O. Arda , Zhang Chuck , Chen Li‐Jen , Wang Kan (Kevin) , Wang Ben 
Published: August 2010

AbstractThis paper presents a new Bayesian predictive approach for quality improvement in nano‐composite manufacturing that aims to improve the accuracy of computer model simulations by combining physical process data and computer model predictions. Such a data augmentation method is of crucial importance for capital‐intensive nano‐composite processes for which large experimental studies are usually very costly or impractical. A simulation example and a case study on a real vacuum‐assisted resin transfer molding (VARTM) composite manufacturing process are used to illustrate the proposed approach. The results of these studies show that the proposed approach can achieve more accurate predictions of the process variability than pure empirically based or pure simulation‐based methods for a given experimental data size. An important practical implication of the results of this work is that, by using the proposed Bayesian method that leverages computational methods with the experimental data, one can accomplish significant reduction in product development costs by reducing the number of physical experiments and improving the prediction accuracy of computer models. Copyright © 2010 John Wiley & Sons, Ltd.
Multiresponse optimization with consideration of probabilistic covariates
Authors: Hejazi T. H. , Bashiri Mahdi , Noghondarian Kazem , Atkinson A. C. 
Published: August 2010

AbstractIn many complex experiments, nuisance factor may have large effects that must be accounted for. Covariates are one of the most important kinds of nuisance factors that can be measured but cannot be controlled within the experimental runs. In this paper a novel approach is proposed, based on goal programming, to find the best combination of factors so as to optimize multiresponse‐multicovariate surfaces with consideration of location and dispersion effects. Furthermore, it is supposed that several covariates considered in the experiment have probability distributions of known form. One objective is to find the most probable values of each covariate. For this purpose, a multiobjective mathematical optimization model is proposed and its efficacy is demonstrated by two numerical examples. Copyright © 2010 John Wiley & Sons, Ltd.
Control charts based on models derived from differential equations
Authors: Weihs Claus , Messaoud Amor , Raabe Nils 
Published: August 2010

AbstractThe development of technical processes over time can often be adequately modelled by means of differential equations. In order to monitor such processes, control charts may be derived from stochastic models based on such differential equations. In this work, this is demonstrated for a deep‐hole drilling process used for producing holes with a high length‐to‐diameter ratio, good surface finish and straightness. The process is subject to dynamic disturbances classified as either chatter vibration or spiraling. For chatter, a differential equation for the drilling torque and a model known to well approximate processes with similar characteristics are used to set up monitoring procedures. For spiraling a control chart can be based on a statistical model for the spectrum of the structure‐born vibrations derived from a differential equation for the deflection of the boring bar. Copyright © 2010 John Wiley & Sons, Ltd.
Statistical monitoring of control loops performance: an improved historical‐data benchmark index
Authors: Rato Tiago J. , Reis Marco S. 
Published: August 2010

AbstractControl systems are key elements of virtually all industrial processes, whose performance directly impacts aspects as important as: product quality and variability, operations safety, process efficiency/costs and environmental impact. In this paper we address the problem of monitoring the performance of such control systems, and in particular a new historical‐data benchmark index is proposed (IM), which is able to discern between perturbations in the system's core modules, which are under the supervision of process owners, from those originated at the level of disturbances, usually involving other stakeholders. It is a generalization of the current index (Iv) as it can be shown that it reduces to this index for the particular case where the variability of the disturbances is the same as in the reference or benchmark period and in the monitoring period. The results obtained demonstrate that the proposed historical‐data benchmark index is able to maintain the target false alarm rate under situations where the variability of the disturbances increases, a situation where the current index, Iv, fails. When the disturbances variability is maintained, both indices present similar detection capability, as expected. The subsequent identification of the modules in fault was also analysed, and the results show that the proposed methodology is able to identify the general source of the degradation in the controller performance, namely, if it is due to a perturbation within the system's core (and which loop is affected) or at the level of the disturbances (increasing variability of the loads or change in their dynamical behaviour). Copyright © 2010 John Wiley & Sons, Ltd.
A high‐dimensional control chart for profile monitoring
Authors: Chen Shuohui , Nembhard Harriet Black 
Published: August 2010

AbstractProfile monitoring is an important and rapidly emerging area of statistical process control. In many industries, the quality of processes or products can be characterized by a profile that describes a relationship or a function between a response variable and one or more independent variables. A change in the profile relationship can indicate a change in the quality characteristic of the process or product and, therefore, needs to be monitored for control purposes. We propose a high‐dimensional (HD) control chart approach for profile monitoring that is based on the adaptive Neyman test statistic for the coefficients of discrete Fourier transform of profiles. We investigate both linear and nonlinear profiles, and we study the robustness of the HD control chart for monitoring profiles with stationary noise. We apply our control chart to monitor the process of nonlinear woodboard vertical density profile data of Walker and Wright (J. Qual. Technol. 2002; 34:118–129) and compare the results with those presented in Williams et al. (Qual. Reliab. Eng. Int. 2007; to appear). Copyright © 2010 John Wiley & Sons, Ltd.
Approaches to robust ℋ︁∞static output feedback control of discrete‐time piecewise‐affine systems with norm‐bounded uncertainties
Authors: Qiu Jianbin , Feng Gang , Gao Huijun 
Published: August 2010

AbstractThis paper investigates the problem of robust ℋ︁∞static output feedback controller design for a class of discrete‐time piecewise‐affine systems with norm‐bounded time‐varying parametric uncertainties. The objective is to design a piecewise‐linear static output feedback controller guaranteeing the asymptotic stability of the resulting closed‐loop system with a prescribed ℋ︁∞disturbance attenuation level. Based on a piecewise Lyapunov function combined with S‐procedure, Projection lemma, and some matrix inequality convexifying techniques, several novel approaches to the static output feedback controller analysis and synthesis are developed for the underlying piecewise‐affine systems. It is shown that the controller gains can be obtained by solving a set of strict linear matrix inequalities (LMIs) or a family of LMIs parameterized by one or two scalar variables, which are numerically efficient with commercially available software. Finally, three simulation examples are provided to illustrate the effectiveness of the proposed approaches. Copyright © 2010 John Wiley & Sons, Ltd.
Stabilization for a class of minimum phase hybrid systems under an average dwell‐time constraint
Authors: Teel A. R. , Marconi L. 
Published: August 2010

AbstractWe consider the class of nonlinear systems in normal form with unitary relative degree whose zero and output dynamics are affected by state jumps fulfilling an average dwell‐time constraint. Under a minimum‐phase assumption requiring the existence of a compact set, which is globally pre‐asymptotically stable for the hybrid zero dynamics, we show how to design continuous, global state‐ and semiglobal output‐feedback control laws. The proposed design methodology extends to the considered class of hybrid systems well‐known design techniques for robustly stabilizing the class of continuous‐time minimum‐phase nonlinear systems having unitary relative degree. Examples are given to show the usefulness of the technical result. Copyright © 2010 John Wiley & Sons, Ltd.
Robust generalized asymptotic regulation against non‐stationary sinusoidal disturbances with uncertain frequencies
Authors: Köroğlu Hakan , Scherer Carsten W. 
Published: August 2010

AbstractAttenuation of sinusoidal disturbances with uncertain and arbitrarily time‐varying frequencies is considered in the form of a generalized asymptotic regulation problem. The disturbances are modeled as the outputs of a parameter‐dependent, unexcited and neutrally stable exogenous system that evolves from nonzero initial conditions. The problem is considered for a plant that depends partially on the uncertain parameters. Moreover, both the plant and the exogenous system are allowed to have dependence on another parameter vector that is measurable during online operation. The problem is then formulated as the synthesis of a controller that is scheduled on the measurable parameter in a way to guarantee robust internal stability and attenuate the disturbance according to a desired profile in steady state. The main result of the paper is a synthesis procedure based on a convex optimization problem, which is identified by a set of parameter‐dependent linear matrix inequalities and can be rendered tractable through standard relaxation schemes. It is also clarified how the transient behavior of the controller can be improved by some additional constraints. The order of the synthesized controller is equal to the order of the plant plus the order of the exogenous system. Copyright © 2010 John Wiley & Sons, Ltd.
On l∞ stability and performance of spatiotemporally varying systems
Authors: Sarwar Azeem , Voulgaris Petros G. , Salapaka Srinivasa M. 
Published: August 2010

AbstractA characterization of stability for spatiotemporally varying systems based on input–output description of the plant and controller is presented. The overall controller is generated by a collection of controllers indexed in space and time, which are based on frozen spatially and temporally invariant descriptions of the plant. In particular, we consider the case where these frozen controllers are not necessarily adjusted for every instance in space and time, and hence are used for some fixed window in time and space. It is shown that the actual spatiotemporally varying system can be stabilized using frozen in space and time controllers, provided the variations in the spatiotemporal dynamics are small enough. We also show that the l∞ to l∞ performance of such systems cannot be much worse than that of the frozen spatially and temporally invariant systems. Copyright © 2010 John Wiley & Sons, Ltd.
Robust delay‐dependent ℋ︁∞control of time‐delay systems with state and input delays
Authors: Parlakçı M. N. Alpaslan , Küçükdemiral İbrahim B. 
Published: August 2010

AbstractThis paper studies the design problem of robust delay‐dependent ℋ︁∞controller for a class of time‐delay control systems with time‐varying state and input delays, which are assumed to be noncoincident. The system is subject to norm‐bounded uncertainties and ℒ︁2disturbances. Based on the selection of an augmented form of Lyapunov–Krasovskii (L‐K) functional, first a Bounded Real Lemma (BRL) is obtained in terms of linear matrix inequalities (LMIs) such that the nominal, unforced time‐delay system is guaranteed to be globally asymptotically stable with minimum allowable disturbance attenuation level. Extending BRL, sufficient delay‐dependent criteria are developed for a stabilizing ℋ︁∞controller synthesis involving a matrix inequality for which a nonlinear optimization algorithm with LMIs is proposed to get feasible solution to the problem. Moreover, for the case of existence of norm‐bounded uncertainties, both the BRL and ℋ︁∞stabilization criteria are easily extended by employing a well‐known bounding technique. A plenty of numerical examples are given to illustrate the application of the proposed methodology of this note. The achieved numerical results on the maximum allowable delay bound and minimum allowable disturbance attenuation level are exhibited to be less conservative in comparison to those of existing methods in the literature. Copyright © 2010 John Wiley & Sons, Ltd.
Output feedback observation and control for visual servoing of VTOL UAVs
Authors: Le Bras Florent , Hamel Tarek , Mahony Robert , Treil Aurélie 
Published: August 2010

AbstractThis paper considers the question of stabilizing vertical take‐off and landing (VTOL) unmanned aerial vehicles (UAVs) using a minimal and an inexpensive sensor suite. The sensor suite considered consists of rate gyros and a single embedded video camera system. The approach taken is based on the principles of dynamic image‐based visual servo control and extends the authors' earlier work by removing dependence on additional sensors, such as accelerometers and magnetometers. The technique presented has potential for mini‐UAVs evolving in urban areas where global positioning system signals may not be available. The control algorithms and coupled state observers are presented in details. The main result of the paper is synthesized in a theorem along with a rigorous stability analysis of the closed‐loop system. An estimate of the basin of attraction for the closed‐loop system is provided. Simulation results are performed to illustrate the performance of the proposed control. Copyright © 2010 John Wiley & Sons, Ltd.
Constructing consensus controllers for networks with identical general linear agents
Authors: Yang Tao , Roy Sandip , Wan Yan , Saberi Ali 
Published: August 2010

AbstractWe use a high‐gain methodology to construct linear decentralized controllers for consensus, in networks with identical but general multi‐input linear time‐invariant (LTI) agents and quite‐general time‐invariant and time‐varying observation topologies. Copyright © 2010 John Wiley & Sons, Ltd.
Leader‐following control for multiple inertial agents
Authors: Chen Gang , Lewis Frank L. 
Published: August 2010

AbstractThis paper investigates distributed controller design problem for a leader‐follower network in the presence of communication delays. Two main contributions are made in this work. First, the second‐order controlled consensus scheme for the weakly connected communication graph topology is proposed. A necessary and sufficient condition is given under which the exponential consensus is achieved. Meanwhile, the relationship among the agents' inertias, the allowable delay bound, the communication topology, the consensus convergence rate, and the control gains is unveiled. Second, the robustness performances of the distributed control scheme with respect to the communication failures and delays are provided. It is shown that if the communication failure rate and the topology switching frequency, respectively, satisfy the given bounds, the exponential second‐order controlled consensus can be achieved under a bounded delay. Numerical examples are given to illustrate the theoretical results. Copyright © 2010 John Wiley & Sons, Ltd.
Discrete‐time mixed ℋ︁2/ℋ︁∞nonlinear filtering
Authors: Aliyu M. D. S. , Boukas E. K. 
Published: August 2010

AbstractIn this paper, we consider the discrete‐time mixed ℋ︁2/ℋ︁∞filtering problem for affine nonlinear systems. Necessary and sufficient conditions for the solvability of this problem with a finite‐dimensional filter are given in terms of a pair of coupled discrete‐time Hamilton–Jacobi‐Isaac's equations (DHJIE) with some side‐conditions. For linear systems, it is shown that these conditions reduce to a pair of coupled discrete‐time algebraic‐Riccati‐equations (DAREs) or a system of linear matrix inequalities (LMIs) similar to the ones for the control case. Both the finite‐horizon and infinite‐horizon problems are discussed. Moreover, sufficient conditions for approximate solvability of the problem are also derived. These solutions are especially useful for computational purposes, considering the difficulty of solving the coupled DHJIEs. An example is also presented to demonstrate the approach. Copyright © 2010 John Wiley & Sons, Ltd.
RobustH∞output‐feedback control of retarded state‐multiplicative stochastic systems
Authors: Gershon E. , Shaked U. 
Published: August 2010

AbstractLinear, state‐delayed, continuous‐time systems are considered with both stochastic and norm‐bounded deterministic uncertainties in the state–space model. The problem of robust dynamicH∞output‐feedback control is solved, for the stationary case, via the input–output approach where the system is replaced by a nonretarded system with additional deterministic norm‐bounded uncertainties. A delay‐dependent result is obtained which involves the solution of a simple linear matrix inequality. In this problem, a cost function is defined which is the expected value of the standardH∞performance cost with respect to the stochastic parameters. A practical example taken from the field of guidance control is given that demonstrates the applicability of the theory. Copyright © 2010 John Wiley & Sons, Ltd.
Cooperative adaptive control for synchronization of second‐order systems with unknown nonlinearities
Authors: Das Abhijit , Lewis Frank L. 
Published: August 2010

AbstractThis paper studies synchronization to a desired trajectory for multi‐agent systems with second‐order integrator dynamics and unknown nonlinearities and disturbances. The agents can have different dynamics and the treatment is for directed graphs with fixed communication topologies. The command generator or leader node dynamics is also nonlinear and unknown. Cooperative tracking adaptive controllers are designed based on each node maintaining a neural network parametric approximator and suitably tuning it to guarantee stability and performance. A Lyapunov‐based proof shows the ultimate boundedness of the tracking error. A simulation example with nodes having second‐order Lagrangian dynamics verifies the performance of the cooperative tracking adaptive controller. Copyright © 2010 John Wiley & Sons, Ltd.
A Bayesian approach to simultaneously adjusting for verification and reference standard bias in diagnostic test studies
Authors: Lu Ying , Dendukuri Nandini , Schiller Ian , Joseph Lawrence 
Published: August 2010

AbstractVerification bias arises in diagnostic test evaluation studies when the results from a first test are verified by a reference test only in a non‐representative subsample of the original study subjects. This occurs, for example, when inclusion probabilities for the subsample depend on first‐stage results and/or on a covariate related to disease status. Reference standard bias arises when the reference test itself has imperfect sensitivity and specificity, but this information is ignored in the analysis. Reference standard bias typically results in underestimation of the sensitivity and specificity of the test under evaluation, since subjects that are correctly diagnosed by the test can be considered as misdiagnosed owing to the imperfections in the reference standard. In this paper, we describe a Bayesian approach for simultaneously addressing both verification and reference standard bias. Our models consider two types of verification bias, first when subjects are selected for verification based on initial test results alone, and then when selection is based on initial test results and a covariate. We also present a model that adjusts for a third potential bias that arises when tests are analyzed assuming conditional independence between tests, but some dependence exists between the initial test and the reference test. We examine the properties of our models using simulated data, and then apply them to a study of a screening test for dementia, providing bias‐adjusted estimates of the sensitivity and specificity. Copyright © 2010 John Wiley & Sons, Ltd.
Consonant closed likelihood ratio test procedures with application to dose–response study
Authors: Wang Bushi , Cui Xinping 
Published: August 2010

AbstractCoherence and Consonance are two important concepts in multiple testing procedures (MTP). Closed test is a well‐known coherent hypothesis testing procedure, which is not necessarily consonant. In this paper, we propose two consonant closed likelihood ratio tests which are compared with the step‐down Dunnett test (SD) and Dunnett–Tamhane step‐up test (SU) in several aspects. Simulation and dose–response study examples show that the new procedures have certain advantages over the SD and SU test. For example, the rejection region of our new procedures is larger than that of the SD test particularly when most of the null hypotheses are false. The new procedures control the family‐wise error rate (FWER) strongly without the equal correlation assumption, which is a necessary condition for the SU test. In terms of computing effort, the new procedures require similar moderate computation for critical constants as the SU test and they follow the same steps as any closed test procedures. We also provide guideline in applying consonance adjustment in multivariate analysis with mixed model and repeated measurements. Copyright © 2010 John Wiley & Sons, Ltd.