342 research outputs found

    Sensitivity-Based Adaptive SRUKF for State, Parameter, and Covariance Estimation on Mechatronic Systems

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    Since the initial developments in the state-space theory in the 1950s and 1960s, the state estimation has become an extensively researched and applied discipline. All systems that can be modelled mathematically are candidates for state estimators. The state estimators reconstruct the states that represent internal conditions and status of a system at a specific instant of time using a mathematical model and the information received from the system sensors. Moreover, the estimator can be extended for system parameter estimation. The resulting Kalman filter (KF) derivatives for state and parameter estimation also require knowledge about the noise statistics of measurements and the uncertainties of the system model. These are often unknown, and an inaccurate parameterization may lead to decreased filter performance or even divergence. Additionally, insufficient system excitation can cause parameter estimation drifts. In this chapter, a sensitivity-based adaptive square-root unscented KF (SRUKF) is presented. This filter combines a SRUKF and the recursive prediction-error method to estimate system states, parameters and covariances online. Moreover, local sensitivity analysis is performed to prevent parameter estimation drifts, while the system is not sufficiently excited. The filter is evaluated on two testbeds based on an axis serial mechanism and compared with the joint state and parameter UKF

    Experimental multiphase estimation on a chip

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    Multiparameter estimation is a general problem that aims at measuring unknown physical quantities, obtaining high precision in the process. In this context, the adoption of quantum resources promises a substantial boost in the achievable performances with respect to the classical case. However, several open problems remain to be addressed in the multiparameter scenario. A crucial requirement is the identification of suitable platforms to develop and experimentally test novel efficient methodologies that can be employed in this general framework. We report the experimental implementation of a reconfigurable integrated multimode interferometer designed for the simultaneous estimation of two optical phases. We verify the high-fidelity operation of the implemented device, and demonstrate quantum-enhanced performances in two-phase estimation with respect to the best classical case, post-selected to the number of detected coincidences. This device can be employed to test general adaptive multiphase protocols due to its high reconfigurability level, and represents a powerful platform to investigate the multiparameter estimation scenario.Comment: 10+7 pages, 7+4 figure

    Propuesta de mejora al proceso de corte de metales en la empresa JOJA SAC METALURGICA PERUANA- Talara 2021

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    El presente trabajo de investigación se centró en una propuesta de aplicación de corte de plasma como una opción viable debido a los escases de oxígeno industrial, que es una actividad fundamental para realizar el funcionamiento de los proyectos de la empresa JOJASAC. sus objetivos general del estudio es elaborar una propuesta de Aplicación de Corte por Plasma para dar Continuidad al proceso de corte de Metales en la Empresa JOJA SAC METALURGICA PERUANA, cuyo fin es dar la solución óptima debido a una necesidad específica partiendo con un previo diagnóstico (siempre es requerido en todo trabajo de investigación). La presente investigación es aplicada, descriptiva, cuantitativa y la investigación que se realiza esta tesis en la empresa JOJA SAC METALURGICA PERUANA tiene un diseño no experimental. Los resultados son definir el diagnostico situacional de manera precisa todos los aspectos que conlleva, en los segundo obtener y analizar los datos operativos de las máquinas que se va a evaluar, en el tercero analizar de manera visual, teniendo en cuenta los datos operativos de la calidad del corte por plasma y para ultimo analizar todos las componentes para sacar el VAN Y TIR. Y la conclusión de este tesis es ver si todo lo visto se logra si es rentable para la empresa para que haga el cambio

    Combining ontologies and workflows to design formal protocols for biological laboratories

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    Background Laboratory protocols in life sciences tend to be written in natural language, with negative consequences on repeatability, distribution and automation of scientific experiments. Formalization of knowledge is becoming popular in science. In the case of laboratory protocols two levels of formalization are needed: one for the entities and individuals operations involved in protocols and another one for the procedures, which can be manually or automatically executed. This study aims to combine ontologies and workflows for protocol formalization. Results A laboratory domain specific ontology and the COW (Combining Ontologies with Workflows) software tool were developed to formalize workflows built on ontologies. A method was specifically set up to support the design of structured protocols for biological laboratory experiments. The workflows were enhanced with ontological concepts taken from the developed domain specific ontology. The experimental protocols represented as workflows are saved in two linked files using two standard interchange languages (i.e. XPDL for workflows and OWL for ontologies). A distribution package of COW including installation procedure, ontology and workflow examples, is freely available from http://www.bmr-genomics.it/farm/cow webcite. Conclusions Using COW, a laboratory protocol may be directly defined by wet-lab scientists without writing code, which will keep the resulting protocol's specifications clear and easy to read and maintain

    Autonomous Observations in Antarctica with AMICA

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    The Antarctic Multiband Infrared Camera (AMICA) is a double channel camera operating in the 2-28 micron infrared domain (KLMNQ bands) that will allow to characterize and exploit the exceptional advantages for Astronomy, expected from Dome C in Antarctica. The development of the camera control system is at its final stage. After the investigation of appropriate solutions against the critical environment, a reliable instrumentation has been developed. It is currently being integrated and tested to ensure the correct execution of automatic operations. Once it will be mounted on the International Robotic Antarctic Infrared Telescope (IRAIT), AMICA and its equipment will contribute to the accomplishment of a fully autonomous observatory.Comment: 12 pages, 4 figures, Advances in Astronomy Journal, Special Issue "Robotic Astronomy", Accepted 11 February 201

    Reversible Holmes Tremor due to Middle Cerebral Artery Giant Aneurysm

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    A 40-year-old man presented with a 6-month history of mild but worsening tremor of variable intensity. The patient had a focal, irregular, rest and action tremor of middle amplitude and low frequency (about 4 Hz), limited to his right arm with oscillatory motion around the elbow. It was present inconsistently at rest, particularly during emotional activation, and enhanced by posture maintenance. It was evoked by various positions and tasks. Particularly, the tremor was present during fine motor skills such as writing, and it was increased by drinking and shaving, showing a minimal intentional component. The patient also reported slight loss in manual dexterity in his right hand

    Metrological needs and reliable solutions for optics fabrication related to E-ELT

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    In order to contribute and support the R&D activities related to the E-ELT (European Extremely Large Telescope) program, the INAF-OAB acquired a dedicated robotic polisher machine, the IRP1200 by Zeeko. It will be used in synergy with the ion beam figuring technique, already available at OAB for the realization of prototypes and advanced optical components, as the optics of the Multi-conjugate Adaptive Optics Relay module (MAORY). In this paper, starting from the discussion of the metrological needs to be fulfilled during the different parts of the machining for the different kind of optics, we define the metrological scheme that will be followed. Moreover, we present the concept for a new measurement machine based of non-contact scanning probes, capable of nanometer uncertainty and compatible with the optics design to be realized. škip 0.5c

    Environmental assessment of individual and collective manure management systems

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    In intensive livestock area with large nutrient surplus collective management systems can be a suitable solution. However, the collective system should carefully evaluated for environmental sustainability to avoid cross effects. The aim of this study was to evaluate the environmental effects of the introduction of a collective treatment plant for energy production and nitrogen removal. For this purpose an assessment methodology, for individual farms and collective treatments plants, has been defined to estimate the emissions of the main pollutants to the air (CO2, CH4, N2O, NH3) and to the soil (N). The method devised has been assessed in a case study (a treatment plant collecting manure from 12 farms). The main effect of the introduction of the collective management system from the environmental point of view is a reduction of greenhouse gases emissions of 61% due to methane emission reduction and renewable energy production. Furthermore, it reduces the amount of nitrogen to be applied to land from 430 kg ha-1 to about 220 kg ha-1, decreases the emission of ammonia in the air by about 17% due to lower amount of nitrogen that is managed by farms in the storage and spreading operations

    Stray light evaluation for the astrometric gravitation probe mission

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    The main goal of the Astrometric Gravitation Probe mission is the verification of General Relativity and competing gravitation theories by precise astrometric determination of light deflection, and of orbital parameters of selected Solar System objects. The key element is the coherent combination of a set of 92 circular entrance apertures, each feeding an elementary inverted occulter similar to the one developed for Solar Orbiter/METIS.1 This provides coronagraphic functions over a relevant field of view, in which all stars are observed for astrometric purposes with the full resolution of a 1 m diameter telescope. The telescope primary mirror acts as a beam combiner, feeding the 92 pupils, through the internal optics, toward a single focal plane. The primary mirror is characterized by 92 output apertures, sized according to the entrance pupil and telescope geometry, in order to dump the solar disk light beyond the instrument. The astronomical objects are much fainter than the solar disk, which is angularly close to the inner field of view of the telescope. The stray light as generated by the diffraction of the solar disk at the edges of the 92 apertures defines the limiting magnitude of observable stars. In particular, the stray light due to the diffraction from the pupil apertures is scattered by the telescope optics and follows the same optical path of the astronomical objects; it is a contribution that cannot be eliminated and must therefore be carefully evaluated. This paper describes the preliminary evaluation of this stray light contribution
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