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Ultrasonic motors are compact actuators with high precision and high stall torque. They feature a friction-based actuation principle and offer an alternative to standard actuators such as direct current motors. However, their nonlinear dynamics, the presence of load-dependent dead zones and the difficulty to control low speeds often prohibit their use. Those issues can be overcome by proper design...
The execution of data-based applications on distributed environments is prone to different failures in the different steps of the process. These steps range from the search on available references and data to the adaptation of the applications of interest to the different platforms where they are going to be efficiently run, which requires a deep understanding of their specific characteristics. In...
A Stewart platform is a well-known mechanism which can be used for a wide variety of vibration control problems. In this paper, an LQR controller for a Stewart platform prototype is proposed which, combined with proportional derivative gain matrix, achieves a good performance when compared to the classical PID control system. By testing some trajectories, we observe that the tracking error between...
Signal representation is an important aspect to be taken into account for pattern classification. Recently, discriminative training methods have been applied to feature extraction for speech recognition. In this paper, we apply the Minimum Classification Error estimation to train the parameters of a feature extractor. This feature extractor is a linear transformation of the original representation...
This paper proposes a cryptosteganographic coding for signals (e.g. ECGs), periodic measurements (e.g. oxygen in blood, body temperature) and contextual data (e.g. allergies, medication of the user) gathered in body area networks. This information is acquired by a device with multiple interfaces and sensors connected to it. The acquiring device compresses the signals with the SPIHT coder; protects...
An observer-based controller for the single-phase induction motor is proposed in this paper. The scheme presented is formulated using block control feedback linearization technique and high order sliding mode algorithms with measurements of the rotor speed and stator currents. A second order sliding mode observer is included into the controller design in order to obtain estimates of the rotor flux...
DART model was extended for simulating satellite Lidar data of 3D Earth scenes with Monte Carlo based methods. 2 major modeling methods were developed. (1) Monte Carlo method for efficiently handling complex phase functions: once scattering directions with close occurrence probabilities are grouped within classes, a 1st random pulling gives the class of scattering directions, and a 2nd random pulling...
DART model was extended for simulating satellite lidar signal of Earth-Atmosphere systems. The adopted approach combines Monte Carlo and flux tracking methods. It improves a lot signal to noise ratios of simulated waveforms. For accurate simulation of atmosphere photon tracing, the atmosphere modelling was modified for obtaining continuous vertical distribution of extinction coefficients. It leads...
This paper proposes a watermarking method that can be applied to DICOM images to strengthen its security and privacy. A robust watermark is used to improve the identification/authentication of the image, even if it has been seriously modified, semifragile watermarks are used to embed information intended to vanish if the image losses its clinical/research value, and fragile watermarks are used to...
In the continuation of authors' studies on control and estimation methods for Single-Phase Induction Motor (SPIM), a new observer-based controller using High Order Sliding Mode (HOSM) algorithms is proposed here. This observer-controller scheme only uses measurements of the rotor speed and stator currents. The complete scheme is robust to uncertainties in the rotor resistance, and a bounded time-varying...
The neoclassical transport is a lower limit of the whole transport in plasmas confined in fusion devices, either stellarators or tokamaks. Even more, the determination of a vast database compiling monoenergetic and transport coefficients is very useful for coupling different codes, which can use those values as input data. The DKEsG application is able to obtain such parameters on Grid infrastructures...
A DART based data processing chain was developed for assessing the potential of a high spatial resolution geostationary satellite. It simulates time series of TOA and BOA radiance values and their spatial variability at any satellite spatial resolution, for any experimental, instrumental and view configuration (e.g., geosynchronous orbit). Account of sources of noise (e.g., atmosphere, sensor, anisotropy...
This paper analyzes the structure and content of the SCP-ECG standard to further design a tailor-made security extension. It is proposed to limit the access privileges of the users by means of role-based profiles (teaching/research, examination, diagnosis, storage) which are implemented with cryptographic elements (ciphering, digital certificates and signatures). A new security section is added to...
A fiber-optic ultrasound sensor is presented for acoustic detection of partial discharges in oil immersed set-ups. Its specifications are similar to R15i (optimized sensor for the detection on the walls of transformers) but for internal installation. It consists of an intrinsic fiber-optic sensing probe, an all-fiber interferometer, homodyne demodulation and an optoelectronic specific conditioning...
The chemical reactions at the higher-k LaLuO3/Ti1NX/poly-Si gate stack interfaces are studied after high temperature treatment. A Ti-rich TiN metal layer degrades the gate stack performance after high temperature annealing. The gate stack containing TiN/LaLuO3 with a near stoichiometric TiN layer is stable during 1000 °C, 5s anneals. Both electrical and structural characterization methods are employed...
ISDEP (Integrator of Stochastic Differential Equations for Plasmas) is a Monte Carlo code that solves the plasma dynamics in a fusion device and perfectly scales on distributed computing platforms. Montera is a recent framework developed for achieving Grid efficient executions of Monte Carlo applications, as ISDEP is. In this work, the improvement of performing the calculations of ISDEP with Montera,...
This work presents a simple method to estimate the radiation pattern of finite arrays of waveguide-fed apertures on an infinite ground plane. This method is based on the theory of Minimum-Scattering Antennas and the Generalized Scattering Matrix of a finite array in terms of spherical modes. Waveguide-fed apertures can be considered as short-circuited minimum-scattering antennas just in the aperture...
The current Internet does not enable easy introduction and deployment of new network technologies and services. This paper aims to progress the Future Internet (FI) by introduction of a service composition and execution environment that re-use existing components of access and core networks. This paper presents essential service-centric platforms and software systems that have been developed with...
We study two important problems in the area of robot grasping: i) the methodology and representations for grasp selection on known and unknown objects, and ii) learning from experience for grasping of similar objects. The core part of the paper is the study of different representations necessary for implementing grasping tasks on objects of different complexity. We show how to select a grasp satisfying...
Calculating neoclassical (NC) transport is a fundamental part of the complete simulation cycle of the behavior of plasmas inside all tokamaks and stellerators. Also, due to NC transport is mainly determined by the magnetic properties of the device, its study is mandatory to ensure the efficiency of a certain coil configuration before it is implemented in a Fusion reactor. Thus, improvements to already...
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