A least-mean-square (LMS) adaptive filter with a variable step size is introduced. The increases or decreases as the mean-square error decreases, allowing to track changes in system well produce small steady state error. convergence and steady-state behavior of algorithm are analyzed. results reduce well-known when specialized constant-step-size case. Simulation presented support analysis compare performance usual LMS another variable-step-size algorithm. They show that its compares...

A state-based approach for online passive fault diagnosis in systems modeled as finite-state automata is presented. In this framework, the system and diagnoser (the detection system) do not have to be initialized at same time. Furthermore, no information about state or even condition (failure status) of before initiation required. The design system, worst case, has exponential complexity. model reduction scheme with polynomial time complexity introduced reduce computational design....

Although cells firing at tremor frequency, called “tremor cells” (Guiot et al., 1962), have often been recorded in the thalamus of parkinsonian patients, extent correlation between these spike trains and has rarely assessed quantitatively. This paper describes spectral cross-correlation functions calculated activity electromyogram (EMG) signals from several muscles contralateral arm. The power occurring train frequency was described absolute terms by autopower, relation to average for all...

We show how a linear differential delay equation with delays in the control can be reformulated as an evolution bounded input operator. As simple application, we solve infinite time quadratic cost problem for equation. also point out our results, even when specialized to case where disappear, extend results previously published literature.

This paper focuses on a coding approach for effective analysis and design of secure watermark-based multimedia authentication systems. We provide framework semi-fragile such that both objectives robustness fragility are effectively controlled achieved. Robustness characterized as two types errors. The embedding verification structures the schemes derived implemented using lattice codes to minimize these Based specific security requirements authentication, cryptographic techniques...

We study the security of Cyber-Physical Systems (CPS) in context supervisory control layer. Specifically, we propose a general model CPS attacker framework Discrete Event (DES) and investigate problem synthesizing an attack strategy for given controlled system. Our captures class deception attacks, where has ability to modify subset sensor readings mislead supervisor, with goal inducing system into undesirable state. introduce new type bipartite transition structure, called...

A framework is introduced for fault diagnosis in timed discrete-event systems. In this approach, the required estimates system condition are updated only when output changes or deadlines associated with expire. Thus updates at every clock tick not required. This many cases results reduction online computing requirements and size of system, expense more offline design calculations. The issue failure diagnosability also discussed.

The deployment of control systems with network-connected components nowadays has made feedback vulnerable to attacks over the network. This paper considers problem intrusion detection and prevention in supervisory systems, where attacker ability enable actuator events that are disabled by supervisor. We present a mathematical model for system under such enablement propose defense strategy detects online disables all controllable after an attack is detected. develop algorithm verifying...

This paper presents an approximation method for estimating the average number of data packets in a SENET-concept integrated voice and system. The is simple to use its estimates are found be good agreement with simulation results. In general, applies any system that integrates packet traffic more slowly varying class can preempt portion transmission capacity.

We study the performance of robust digital watermarking approaches in presence lossy compression by introducing practical analysis methodologies. Correlation expressions between embedded watermark and extracted are derived to determine optimal domain maximize data hiding rates for spread spectrum quantization watermarking. It is determined both theoretically through simulations that embedding strategy, addition transform used compression, dictate Through analytic comparisons, we develop a...

A framework is introduced for passive online fault diagnosis in timed discrete-event systems (TDES). It extends the previous work of authors (1999) on a state-based approach to by incorporating timing information. This enhances accuracy diagnosis. In this methodology instead directly extending existing TDES, an alternative taken which, many cases, leads significant reduction computing requirements and size diagnoser at expense more off-line design calculations.

We study the security of control systems in context supervisory layer stochastic discrete-event systems. Control heavily rely on correct communication between plant and controller. In this work, we consider that such is partially compromised by a malicious attacker. The attacker has ability to modify subset sensor readings mislead supervisor, with goal inducing system into an unsafe state. problem from attacker's viewpoint investigate synthesis attack strategy for modeled as probabilistic...

The estimation and control of linear stochastic systems with delays in the state, control, observations are studied. First, deterministic optimal problem quadratic cost over an infinite time interval is examined. Using extended notion stabilizability, existence characterization law obtained. additional assumption detectability closed-loop system shown to be $L^2 $-stable. Next, filtering A new version duality relations between developed. This combined a suitable detectability, exploited show...

Most model-based approaches to fault diagnosis of discrete-event systems (DESs) require a complete and accurate model the system be diagnosed. However, may have arisen from abstraction simplification continuous time or through building input-output data. As such, it not capture dynamic behavior completely. In this paper, we address problem diagnosing faults, given an incomplete system. When is incomplete, discrepancies will arise between actual output predicted by model. We introduce...

Linear and nonlinear filtering for stochastic delay systems are studied. A representation theorem conditional moment functionals is obtained, which, in turn, used to derive differential equations describing the optimal linear or filter. complete characterization of filter given with Gaussian noises. Stability studied case where there no delays observations. Using duality between control, asymptotic stability proved. Finally, cascade deterministic quadratic control system shown be...

Most model-based approaches to fault diagnosis of discrete-event systems require a complete and accurate model the system be diagnosed. However, may have arisen from abstraction simplification continuous time system, or through building input-output data. As such, it not capture dynamic behavior completely. In previous paper, we addressed problem diagnosing faults given an incomplete system. We presented learning diagnoser which only diagnoses faults, but also attempts learn missing...

In this paper, a fault-tolerant control design that can gain schedule with the airspeed is developed for flexible aircraft actuator saturation and stuck surface faults. First, model captures coupling between rigid-body motions modes presented. Then, linear parameter-varying controller featuring proportional integral structure designed scenario, gains solved from set of set-invariant conditions represented by matrix inequalities. The controller, which schedules airspeed, able to eliminate...

In this article, we study the security of control systems in context supervisory layer stochastic discrete-event systems. Control heavily rely on correct communication between plant and controller. consider that such is partially compromised by a malicious attacker. The attacker has ability to modify subset sensor readings mislead supervisor, with goal inducing system into an unsafe state. We problem from attacker's viewpoint investigate synthesis attack strategy for modeled as probabilistic...

We determine the watermark domain that maximizes data hiding capacity. focus on situation in which watermarked signal undergoes lossy compression involving quantization a specified domain. A novel linear model for process of is proposed leads to analytical results estimating capacity various watermarking domains. Using this framework we predict appropriate transforms robust spread spectrum face JPEG compression. Simulation verify our theoretical observations. find repetition code used...

A state-based approach for online passive fault diagnosis in systems modelled as finite-state automata is presented. In this framework, the system and diagnoser (the detection system) do not have to be initialized at same time. Furthermore, no information about state or even condition (failure status) of before initiation required. The design system, worst case, has exponential time complexity. model reduction scheme with polynomial complexity introduced reduce computational design.

The mathematical modeling of manually controlled teleoperator systems using the well-known optimal control model (OCM) is considered. An experienced human operator can be modeled as an controller executing continuous in environment which system subject to random external disturbances. basic OCM theory extended allow have imperfect internal being controlled, and effects discrepancies between models are investigated. A mechanism for closed-form performance equipped with predictor displays also...