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Navigation and spatial memory impairments are reported by individuals with mild cognitive impairment (MCI), which is considered a transitional stage between normal aging and dementia. Spatial navigation is an embodied process that requires both bodily (e.g., motor commands, proprioception) and cognitive (e.g., decision-making, mental rotation) information. Immersive virtual reality (IVR) is a powerful tool that recruits this information as in real-world navigation. Given the crucial impact of spatial navigation impairments on daily life, its rehabilitation should be a primary objective of research. Nevertheless, current IVR solutions for spatial navigation rehabilitation in MCI are still in their infancy. In this usability study, eight MCI patients tested an IVR spatial navigation training demo and interacted with the CAVE using active stereo glasses, a foot-motion pad, and a joypad. During the demo, thoughts and issues were reported with the thinking-aloud procedure. Questionnaires about usability, presence, and cybersickness were administered at the end of the experience. Our results show that the first version of this system is usable by the patients even if the majority had no experience with PC/IVR. The system provided a moderate sense of spatial presence and very low negative effects. Issues found during the thinking-aloud procedure concerned visual aspects which affected the interaction user-system. Participants needed to practice more with the foot-motion pad even though the overall experience was positively evaluated. By identifying critical aspects, an improved version of the current system has been released.

With a radical energy transition fostered by the increased deployment of renewable non-programmable energy sources over conventional ones, the forecasting of distributed energy production and consumption is becoming a cornerstone to ensure grid security and efficient operational planning. Due to the distributed and fragmented design of such systems, real-time observability of Distributed Generation operations beyond the Transmission System Operator domain is not always granted. In this context, we propose a Machine Learning pipeline for forecasting distributed energy production and consumption in an electrical grid at the HV distribution substation level, where data from distributed generation is partially observable. The proposed methodology is validated on real data for a large Italian region. Results show that the proposed model is able to predict up to 7 days ahead the amount of load and distributed generation (and the net power flux by difference) at each HV distribution substation with a 24%-44% mean gain in out-of-sample accuracy against a non-naive baseline model, paving the way to advanced and more efficient power system management.

During the last years, organometallic lead halide perovskites (LHP) have been widely studied as outstanding materials for photovoltaics and photonics applications [1] . These emerging semiconductors are fabricated by cheap and straightforward solution process techniques on polycrystalline film of the compound CH 3 NH 3 PbX 3 (X=Cl, Br, I). Their outstanding properties of these films include large absorption coefficients above the bandgap, high electronic mobilities, high quantum yield of emission at room temperature or tunable band-gap with the composition [1] . In this work, we exploit the excellent light emitting and photodetection properties of CH 3 NH 3 PbI 3 thin films to integrate a waveguide amplifier and a photodetector within the same LHP thin film deposited in both rigid (SiO 2 /Si) and flexible (nanocellulose) substrates. As illustrated in Figure 1a , the device is based on the refractive index contrast between the LHP, a poly(methyl methacrylate) capping layer the substrate to engineer the number of propagating modes and their propagation constant [1] . In particular, the geometrical parameters of the structure were carefully designed to propagate an excitation beam injected at the input edge of the structure together with the photoluminescence (PL) emitted by the LHP through a mode that is extremely confined in the semiconductor film (see Fig. 1a ). As a result, this bilayer structure demonstrates amplified the spontaneous emission (ASE) with extraordinary low thresholds (2 nJ) [2] . Moreover, the incorporation of electrodes on the top of the LHP allows us to study a photocurrent dependent on the excitation light ( Fig. 1b ), and with it to monitor electrically the generation of PL and ASE ( Fig. 1c ). Experimental results (symbols in Fig. 3c) are properly reproduced with the simulations carried out with a rate equation model (solid lines in Fig. 3c). Here, we carefully compare the generation of optical gain and photocurrent in rigid and flexible substrates and demonstrate that the choice flexible substrate does not significantly alter the performances of the device [3] . Therefore, this approach illustrates a new amplifier-photodetector device that can pave the road towards a flexible and wearable technology LHP based technology.

En los sistemas de transmision de energia electrica, especificamente en lineas aereas de transmision de extra alta tension (del ingles extra high voltage, EHV), eventos tales como descargas atmosfericas o contactos momentaneos con objetos externos han producido mas del 80 % de las fallas. Debido a que estas fallas son transitorias, se utiliza un interruptor de potencia (del ingles circuit breaker, CB) con reconexion automatica para garantizar la estabilidad de la red. La reconexion de una linea luego de un tiempo muerto predefinido de ocurrida una falla es una practica comun que se realiza mediante un esquema de reconexion automatica monofasica (del ingles single-phase auto-reclosing, SPAR). Sin embargo, la posibilidad de reconectar con una falla permanente no despejada puede afectar la estabilidad de la red electrica y generar danos sobre la misma. Un esquema de reconexion automatica monofasica adaptativa (del ingles adaptive single-phase auto-reclosing, ASPAR) bloquea la reconexion del CB en fallas permanentes y permite la reconexion una vez que se extingue la misma. Por lo tanto, los esquemas de ASPAR son indispensables para el funcionamiento optimo y robusto de una red electrica bajo diversas circunstancias de falla. Con el objetivo de superar las limitaciones de los SPAR, se han propuesto muchas tecnicas de ASPAR basadas en caracteristicas presentes en la linea con falla. Este articulo presenta un estudio de esquemas de ASPAR que se aplican en las lineas de transmision de EHV con el objetivo de destacar aquellos que presentan el mejor desempeno y son plausibles de ser mejorados.

The upgrade of the Large Hadron Collider (LHC) into High Luminosity-LHC (HL-LHC) presents different challenges, among them, the development of the power converters supplying the inner triplet magnets with the required 18 kA DC currents. In order to reach the current required and to accomplish the stringent requirements associated to this kind of applications, even under a fault scenario, redundancy and modularity are foreseen in the converter design. Consequently, the development of a 18 kA power converter built from N parallel-connected sub-converters having M modules inside is carried out. Within the sub-converter, the goal is to achieve a proper interconnection of the high-power modules in order to minimize the effect of parasitic interconnection inductances. This work presents the analysis of the DC-link input filter stage. The effect of the different parasitic elements associated to both the copper busbars for the power connections and the filtering elements is evaluated. In addition, the importance of physical arrangement of the modules concerning their firing sequence is investigated. The impact of the location of the capacitance and damping network - which are included to mitigate the effect of the parasitic inductances associated to the busbars - is analyzed and evaluated by simulations.

In order to supply the new inner triplet magnets of the High Luminosity Large Hadron Collider (HL-LHC) with the required 18kA of DC current, new power converters are under development. Given the demanding requirements on current, efficiency, dynamic response, precision and availability, the use of a modular converter structure based on parallel operation of N sub-converters with M parallel H-bridges inside is adopted, as this strategy allows to continue operation even under a fault scenario. In this structure, it is expected that each sub-converter will operate autonomously and that their output current will be a fraction of the magnet current. Then, in order to keep the system modularity, a regulation strategy for sub-converter control that only requires local variables, i.e. no need for the information of the remaining sub-converters, is proposed.

We study the case of a financial entity that presented problems due to high wait times and high operation times in the credit process. A diagnosis was made by taking time and route analysis. Therefore, we opted for the implementation of a Lean Service methodology, in order to have an adequate project performance. The proper functioning of this methodology was verified by the application of a pilot project, were data was taken (time, route analysis, VSM). This achievement mitigated the excessive delays and rework in the evaluation phase of the process, thus achieving mayor customer satisfaction and a better working environment.

Power converters associated to inner triplet magnets of the Large Hadron Collider (LHC) are being updated. In this sense, conversion schemes with parallel association of H-bridge structures and integrated local energy storage systems are considered. Different topological structures, modulation techniques and interleaved operating modes are analyzed. A restrictive specification that these converters must satisfy on the load is the compliance of specific limits for each frequency component of the output common mode voltage; since they define Electromagnetic Compatibility (EMC) issues. The evaluation of the common mode voltage spectrum is not a simple operation, since these systems present multiple sources of input noise. The present work proposes a methodology to calculate a transfer function, from an equivalent single-input system, useful to determine the output common mode voltage spectrum. Simulations for a particular converter are presented.

Certain magnet power supplies for particle accelerators demand a high consumption of pulsed power, which generates perturbations in the electrical grids located in urban zones. Power supply systems with integrated local energy storage elements are under consideration as alternatives to mitigate these disturbances. Due to elevated magnitudes in the load current, a parallel association of full-bridge structures is proposed to control the energy flow between the storage units and the load. Different modulation methods and interleaved control techniques are used. In the present work, different strategies are analyzed in a comparative study, with the purpose of defining the most suitable one for the operational characteristics considered for both, the load and the storage elements. Simulations on a future power converter to be used in the High-Luminosity Large Hadron Collider (HL-LHC) at the European Organization for Nuclear Research (CERN) are presented.

Smart grids have become a tangible reality in most of the developed countries. The implementation of a large number of pilot programs and a multi-million dollar investment by major European countries, North America and China has successfully transformed the electricity grid. However, the road that still remains to be travelled is very long and there are many years of investment and development ahead. In the case of developing countries, such as those in Latin America, the gap is even greater, although in recent years there has been a significant increase in investment in the area. This paper presents an overview of the situation in Argentina, focused mainly from the point of view of smart metering systems, which have become the basic pieces for the development of a real smart grid. Although there is currently no general implementation programme in the country, there is a slow but persistent progress through uncoordinated regional or local initiatives. This report presents a state of the art of the area, supported by data from the commercial sector, and discusses some of the possible scenarios in the short and medium term. In the analysis are considered issues like communication technologies adopted, urban and/or rural environment, etc., and the impact of smart metering devices in the daily operation of the grid.

One of the main problems in the electrical networks is the occurrence of voltage disturbances as dips, swells and interruptions, commonly identified as events. In order to generate statisticals indexes to assess them, it is necessary to be able to detect and classify them. Three algorithms for classifying voltage events stand out from the specific bibliography. They classify voltage events correctly under ideal conditions. However, they fail under the presence of phase jumps and phase rotations, due to the impedance characteristics of the network, load and fault, and as result of the sensitivity of the fixed classification thresholds to deviations of the pre-fault voltage from the nominal value. In order to reduce these errors of classification, a new algorithm is proposed. It is demonstrated that presents an adequate performance in the classification of events affected by the disturbances previously described. Unlike the other algorithms in the bibliography, it does not use fixed thresholds, so it is better adapted to the normal changes in the pre-fault voltage produced in the network, as well as to the variations in the phase angles during the occurrence of the event.

This paper assesses the experimental implementation of three voltage events classification algorithms. They are known in the literature as symmetrical component algorithm, six-phase algorithm and space vector algorithm. They use the fundamental voltages and sequence's components estimated by a sequence detector proposed by the authors previously. This detector is synchronized with the network achieving phase and frequency adaptation and high rejection to the network disturbances. From implementation of classification algorithm and detector on a DSP (Digital Signal Processor), the performance of each algorithm in the classification of real events and their possible application in a PQM (Power Quality Monitor) was evaluated.

In this paper are evaluated three different three-phase voltage dip classification algorithms developed by the authors. All them are based in the information provided by a sequence detector developed in a previuos work. The first algorithm is a logical classifier, the second it is based on fuzzy logic, and the third algorithm is a neural network adequately trained for this purpose. This evaluation is part of a wider work, and it will be used to the potential development of a power quality monitor. The performance of the algorithms under test in the classification of voltage dips, in ideal conditions and with variations in the phase and frequency, and high harmonic content is assessed. The conclusions of this analysis are the basis for the development and implementation of some of the functions of this instrument.

This work presents a topology for a pulsed current power supply suitable for particle accelerator applications. The current pulse is generated from the energy provided by a structure tied to the electrical network and by one connected to a capacitor bank; which is used as local energy storage. By using both structures, disturbances on the electrical network are minimized, since the power obtained from the grid is limited to the average active power of the load; while the management of the reactive power lies on the energy storage structure. A control scheme for the power management of both structures is presented, and simulations are carried out taking into account the parameters of a particle accelerator transfer line.

This work investigates a grid interface for power supplies used in particle accelerators for cycling loads such as large electromagnets. Two topologies are discussed integrating magnetic energy recovery. For each topology, the associated energy management strategies are examined with the objective to control the grid current profile. A model is established for each of the proposed solutions and the simulation results are presented. A critical review of the investigated energy management solutions is attempted.

This paper provides the general description, design guidelines and implementation issues of a digital Thyristor Gate Control (TGC) system developed for particle accelerator facilities. The present proposal improves the TGC performance by replacing the conventional synchronization method based on a single phase zero crossing Phase Lock Loop (PLL) with a novel three-phase synchronous method known as Variable Sampling Period Filter PLL (VSPF-PLL). The proposal is implemented in a custom board and it is tested in a 6-phase power converter under a very distorted mains.

In this manuscript we present an overview of novel signal processing techniques developed by our group to reduce scoring time in the assessment of the severity of sleep-related breathing disorders in heart failure patients and to detect sleep/wake fluctuations during periodic breathing. Besides describing these methods, we present the results of validation experiments. Our work shows that novel signal processing techniques can reduce costs and resources needed to screen the patients and can provide relevant information for better understanding the role of wake/sleep transitions in the development and maintenance of breathing disorders.

In this paper, we present a novel fast algorithm for Transverse Waveform Relaxation (TWR) using waveform compression. The core concept of the algorithm is to eliminate redundancies in TWR waveforms signals both before and after the relaxation source update step of the traditional TWR process. The new TWR algorithm is implemented using the application programming interface of an industrial circuit simulation program and is illustrated on a test suite of on-chip data buses having up to 40 coupled transmission lines. Numerical simulations show that speedups as high as 12X can be achieved with respect to a TWR algorithm without waveform compression.

The aim of this study was to assess whether in chronic heart failure patients (CHF) linear and nonlinear indexes of heart rate variability (HRV) are associated with the plasma level of norepinephrine, a measure of tonic sympathetic nervous activity. In 99 CHF patients with a 24-hour Holter recording and plasma norepinephrine assay, the absolute (LFP) and normalized (LF_nu) power in the low frequency band (LF, 0.04-0.15 Hz), the percentage of 3 beats patterns with no variations (0VP) and with two unlike variations (2UVP) were computed. A significant negative association (Spearman correlation coefficient) was found between LFP and PNE (r = -0.45, p

Periodic Breathing (PB, cyclic waxing and waning of tidal volume) is very common in heart failure patients. It is commonly thought that PB is caused by an instability in the closed-loop chemical control of ventilation. Some investigators, however, have suggested that it may also result from fluctuations in sleep/wake state, namely state instability. The aim of this study was i) to set up a methodology for semi-automated state fluctuation analysis and ii) to assess whether state instability is a necessary condition for the development of PB. We carried out daytime and nighttime standard polysomnographic recordings in 9 patients. During daytime, 86% of state transitions were synchronous with an apneic event. Synchronous state and ventilatory changes were also observed during nighttime, but during the deeper stages of sleep PB occurred without concurrent state transitions. We conclude that state instability is not necessary for the development of PB.

This work proposes a new biasing technique to extend the dose measurement range of MOS dosimeters. The technique consists on alternating stages of positive oxide charge buildup with stages of radiation induced charge neutralization, maintaining an uniform sensitivity along the whole measurement. The technique was applied with 70 nm MOS dosimeters, extending the dose measurement range from less than a kilogray to more than 675 kGy without showing wear effects. An initial saturation of interface traps creation ensures repeatability in the responses.

Zero chirp operation across C-Band is reported for a 10 Gb/s zero-chirp MQW InP Mach-Zehnder modulator. The optimized design ensures low residual chirp over all wavelengths, confirmed by symmetric OSNR penalty measurements.

This work presents a synchronization method based on the implementation of a sliding-window digital-filter that uses the Goertzel algorithm. The proposed method filters the incoming power grid signal and specifies the input frequency by measuring the period of the output phase. The sampling frequency is adjusted to correct the phase errors introduced by the filter whenever variations in the frequency occur. Regardless of the magnitude of the input frequency variations, this method determines the input frequency with high accuracy.

This report presents the implementation of an all-digital high-speed closed-loop thyristor firing system based on the Cassel technique. Different aspects associated to digital implementations, like sampling frequency, synchronism and finite word-length are analyzed. Experimental results obtained on a CERN GEREG crate are presented.

A method for controlling line-commutated converters in discontinuous conduction mode is presented. The proposed strategy is based on the modification of the tiring angle alpha in order to produce the same effects on the average output current regardless the conduction mode. The compensation is based in an on-line estimation of the rectifier average output current in order to achieve the compensation angle. Simulations on a high-precision current control system are presented.