Engineering

An algorithm to decompose ground reaction forces and moments from a single force platform in walking gait
In walking experimental conditions, subjects are sometimes unable to perform two steps on two different forceplates. This leads the authors to develop methods for discerning right and left ground reaction data while they are summed during the double support in walking. The aim of this study is to propose an adaptive transition function that considers the walking speed and ground reaction forces...


Buckling analysis through a generalized beam model including section distortions
A geometrically nonlinear beam model suitable for describing complex 3D effects due to non-uniform warpings including non-standard in-plane distortions of the cross-section is presented and applied to the buckling analysis of beams. Each section is endowed with a corotational frame where statics and kinematics are described using a refined linear elastic model which exploits a semi-analytical s...
A new low cost cascaded transformer multilevel inverter topology using minimum number of components with modified selective harmonic elimination modulation
In this paper, a novel cascaded transformer multilevel inverter is proposed. The number of the switching devices is reduced in the proposed topology. This topology comprises of a DC source, several single phase low-frequency transformers, two main power switches and some bidirectional switching devices. In this topology, only one bidirectional switch is employed for each transformer. However, i...


State feedback integral control for a rotary direct drive servo valve using a Lyapunov function approach
This paper concerns a state feedback integral control using a Lyapunov function approach for a rotary direct drive servo valve (RDDV) while considering parameter uncertainties. Modeling of this RDDV servovalve reveals that its mechanical performance is deeply influenced by friction torques and flow torques; however, these torques are uncertain and mutable due to the nature of fluid flow. To eli...
Cantilever steel post damaged by wind
An analysis for the cause of fracture failure of a cantilever steel sign post damaged by wind has been carried out. An unusual cause of failure has been identified, which is the subject of this paper. Microscopy and microanalysis of the fracture surface showed that the failure was due to pre-existing cracks, from the fabrication of the post. This conclusion was reached after detecting and analy...


Failure analysis of the impellers of coke plant
Premature failure of the impeller blade of coke plant has been investigated. The component functioned during the CGC gas intake cycle. The component rotates at 1480rpm with a volumetric flow of 720 m3/min of flue gas with temperature about 200-300°C. The failed component reveals exposed surface of a crack that extended slightly beyond the assembly weld. From macro-structural observation under-...
Transfer function modeling in web software fault prediction implementing pre-whitening technique
The issue of Web reliability is gaining importance, as different Web-based applications are getting popularity with time. In order to enhance the reliability of a Web system, the Web administrator have to determine if there exists any relationship or correlation among different Web workload characteristics and the errors having an impact on the reliability of the Web system, so that he will be ...

Analysis of an Unconditionally Convergent Stabilized Finite Element Formulation for Incompressible Magnetohydrodynamics
In this work, we analyze a recently proposed stabilized finite element formulation for the approximation of the resistive magnetohydrodynamics equations. The novelty of this formulation with respect to existing ones is the fact that it always converges to the physical solution, even when it is singular. We have performed a detailed stability and convergence analysis of the formulation in a simp...
Newton-based stochastic optimization using q-Gaussian smoothed functional algorithms
We present the first q -Gaussian smoothed functional (SF) estimator of the Hessian and the first Newton-based stochastic optimization algorithm that estimates both the Hessian and the gradient of the objective function using q -Gaussian perturbations. Our algorithm requires only two system simulations (regardless of the parameter dimension) and estimates both the gradient and the Hessian at e...

Control strategy with adaptive quantizer’s parameters under digital communication channels
A stabilizing controller designed without considering quantization may not be effectively implemented for the systems with quantized information due to quantization errors. Hence, an interesting issue is how to design the quantizer such that the desired system performance can be still attained by the above controller. In this work, a new control strategy with on-line updating the quantizer’s ...
Unscented Kalman filter with advanced adaptation of scaling parameter
The paper deals with state estimation of the nonlinear stochastic systems by means of the unscented Kalman filter with a focus on specification of the σ -points. Their position is influenced by two design parameters—the scaling parameter determining the spread of the σ -points and a covariance matrix decomposition determining rotation of the σ -points. In this paper, a choice of the sca...

Data-driven realizations of kernel and image representations and their application to fault detection and control system design
This paper deals with the data-driven design of observer-based fault detection and control systems. We first introduce the definitions of the data-driven forms of kernel and image representations. It is followed by the study of their identification. In the context of a fault-tolerant architecture, the design of observer-based fault detection, feed-forward and feedback control systems are addres...
Error probability bounds for nuclear detection: Improving accuracy through controlled mobility
A collection of static and mobile radiation sensors is tasked with deciding, within a fixed time interval, whether a moving target carries radioactive material. Formally, this is a problem of detecting weak time-inhomogeneous Poisson signals (target radiation) concealed in another Poisson signal (naturally occurring background radiation). Each sensor locally processes its observations to form a...
Equal distribution of satellite constellations on circular target orbits
This paper addresses the problem of equal distribution of satellite constellations on circular target orbits. The control goal is to make the constellation converge to a circular target orbit, while spatially distributing the satellites at equal inter-satellite distances. The solution is defined in the port-Hamiltonian framework, which gives a clear physical interpretation of the obtained contr...
Stochastic model predictive control for constrained discrete-time Markovian switching systems
In this paper we study constrained stochastic optimal control problems for Markovian switching systems, an extension of Markovian jump linear systems (MJLS), where the subsystems are allowed to be nonlinear. We develop appropriate notions of invariance and stability for such systems and provide terminal conditions for stochastic model predictive control (SMPC) that guarantee mean-square stabili...