A Novel Graph-Based Approach for the Management of Health Data on Cloud-Based WSANs

Nowadays, healthcare applications become among the most important services that help to improve the public safety through, for example, the prevention of the propagation of some epidemic diseases from patient to another or better from a location to another. Wireless Body Area Networks (WBANs) are considered among the major sources that enable the collection of such kind of data that shares in most cases the properties of big data and that needs to be stored and managed in an efficient manner. Regarding this need, Wireless Storage Area Networks (WSANs) have been considered among the alternatives to store generated health data. Even if these infrastructures enable the storage of huge volumes of data, there are some issues related to the efficient storage and processing of health data that still not resolved and that are of interest for the research communities. In this context, this paper proposes a cloud-based WSAN approach that enables the storage and the management of health data in an efficient manner by representing the collected data and their dependencies using Temporal Conceptual Graphs (TCGs). The validity of the generated graphs is verified by the proposed graph checker that enables the localization of semantic errors in such structure to prevent some threats to be realized for stored health data and to ensure the privacy of patients. The efficiency of the proposed approach is illustrated for different defined scenarios of diseases and their associated health data represented through generated TCGs.     

Pseudopotential Periodic Hartree-Fock Study of the Cristobalite Phases of Silica and Germanium Dioxide

Periodic pseudopotential Hartree–Fock calculations have been performed on the cristobalite strucure of silica and germanium dioxide in order to investigate the topology of the ground-state Born–Oppenheimer energy surface. For both oxides the averaged X–O bond lengths, the two unequivalent O–X–O bond angles, and the tilt angle have been optimized. The tilt angle, which measures the rotation of the XO₄ tetrahedra around their local C ₂ axes, is directly related to the O–X–O bond angle and connects the low-temperature phase twin structures; its zero corresponds to the ideal β-phase. For SiO₂ the calculated values of these coordinates agree within 1% with 10 K experimental data whereas for GeO₂ the agreement between calculation and experiment is much less satisfactory. It is shown that the tilt angle is the most important structural parameter. The structure of β-cristobalite is rationalized on the basis of the energy dependence upon tilt angle and the absence of β-structure in GeO₂ is explained. The one-electron properties, i.e., band structure and density of states, have been calculated and are compared with the results of previous calculations carried out by other methods. As expected in Hartree-Fock calculations, the band gap is overestimated. The analysis of the calculated electron density and of density of states projected onto basis orbitals indicates that these oxides are mostly ionic. It is also shown that the GeO bond is more covalent than the SiO one, which explains the different behavior of these two oxides.     

Stabilisation of perturbed chains of integrators using Lyapunov-based homogeneous controllers

In this paper, we present a Lyapunov-based homogeneous controller for the stabilisation of a perturbed chain of integrators of arbitrary order r ≥ 1. The proposed controller is based on homogeneous controller for stabilisation of pure chain of integrators. The control of homogeneity degree is also introduced and various controllers are designed using this concept, namely a bounded-controller with minimum amplitude of discontinuous control and a controller with globally fixed-time convergence. The performance of the controller is validated through simulations.     

Velocity‐free attitude stabilization with inertial vector measurements

This paper deals with the attitude stabilization problem of a rigid body, where neither the angular velocity nor the attitude is used in the feedback; only body‐referenced vector measurements are needed. The proposed control scheme is based on an angular velocity observer‐like system relying solely on vector measurements. The proposed controller ensures almost global asymptotic stability and provides some interesting performance properties through an appropriate tuning of the control gains. The performance and effectiveness of the proposed control scheme are illustrated via simulation results where the control gains are adjusted using a nonlinear optimization. Copyright © 2015 John Wiley & Sons, Ltd.     

Towards a core ontology for robotics and automation

In this paper, we present the current results of the newly formed IEEE-RAS Working Group, named Ontologies for Robotics and Automation. In particular, we introduce a core ontology that encompasses a set of terms commonly used in Robotics and Automation along with the methodology we have adopted. Our work uses ISO/FDIS 8373 standard developed by the ISO/TC184/SC2 Working Group as a reference. This standard defines, in natural language, some generic terms which are common in Robotics and Automation such as robot, robotic device, etc. Furthermore, we discuss the ontology development process employed along with the problems and decisions taken.     

Quadrotors Formation Control

In this paper, the impact of the medium access protocols on the average consensus problem over wireless networks for a group of quadrotors is established. The stabilization of each helicopter is guaranteed using a simple and bounded nonlinear control strategy. We study the case of a group of quadrotors communicating over a wireless network considering both directed and undirected graphs of information flow. It turns out that the media access control (MAC) protocols have a direct impact in both convergence time and average consensus solution, i.e., the solution of the average consensus is no longer the average of the initial conditions. It will be shown that the solution for the average consensus problem over a wireless network depends directly on the MAC algorithm. Simulations are provided to demonstrate the theoretical results. In addition, to validate the control strategy some experimental tests have been carried out to control the yaw angle of two quadrotors.     

Toward the development of an innovative descaling and corrosion inhibiting solutions to protect mild steel equipment: an experimental and theoretical approach

Abstract

This work proposes a mixture of sulfamic and perchloric acids as a descaling solution and cetyltrimethyl ammonium bromide (CTAB) and imidazole for the improvement in the corrosion resistance of mild steel. The experiments were carried out at different temperatures using mass loss and electrochemical techniques. The samples were characterized by inductively coupled plasma spectrometry, SEM-EDS, and X-ray diffraction techniques. The study showed that CTAB and imidazole can serve as the efficient corrosion inhibitors for mild steel in descaling solution and were found to follow the model of Langmuir adsorption isotherm. Potentiodynamic polarization was performed at temperature 295, 305, 315, and 325?K, and it can be concluded that the CTAB/imidazole acted as mixed type corrosion inhibitors. Electrochemical impedance spectroscopy studies revealed that increase in imidazole concentration, resulted into the increased polarization resistance with simultaneous lowering of double-layer capacitance values. Computational techniques were used to support experimental results.     

Nested saturation based control of an actuated knee joint orthosis

Wearable robots have opened a new horizon for assistance and rehabilitation of dependent/elderly persons. The present study deals with the control of an actuated lower limb orthosis at the knee joint level. The dynamics of the shank–foot–orthosis system are expressed through a nonlinear second order model taking into account viscous, inertial and gravitational properties. Shank–foot–orthosis system parameters are identified experimentally. Since the underlying dynamic model is nonlinear, a robust control strategy is needed to guarantee an accurate and precise movement generation. The proposed control strategy ensures, at the same time, the stability of the closed-loop system. A bounded control torque is applied to guarantee the asymptotic stability of the shank–foot–orthosis. The generated control respects the physical constraints imposed by the system. The effectiveness of the proposed control strategy is shown in real-time in terms of stability, position tracking performances and robustness with respect to identification errors and external disturbances.