931 resultados para Control system design


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Dissertação de mestrado em Engenharia Mecatrónica (área de especialização de Tecnologia de Manufatura)

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Aims: To evaluate the differences in linear and complex heart rate dynamics in twin pairs according to fetal sex combination [male-female (MF), male-male (MM), and female-female (FF)]. Methods: Fourteen twin pairs (6 MF, 3 MM, and 5 FF) were monitored between 31 and 36.4 weeks of gestation. Twenty-six fetal heart rate (FHR) recordings of both twins were simultaneously acquired and analyzed with a system for computerized analysis of cardiotocograms. Linear and nonlinear FHR indices were calculated. Results: Overall, MM twins presented higher intrapair average in linear indices than the other pairs, whereas FF twins showed higher sympathetic-vagal balance. MF twins exhibited higher intrapair average in entropy indices and MM twins presented lower entropy values than FF twins considering the (automatically selected) threshold rLu. MM twin pairs showed higher intrapair differences in linear heart rate indices than MF and FF twins, whereas FF twins exhibited lower intrapair differences in entropy indices. Conclusions: The results of this exploratory study suggest that twins have sex-specific differences in linear and nonlinear indices of FHR. MM twins expressed signs of a more active autonomic nervous system and MF twins showed the most active complexity control system. These results suggest that fetal sex combination should be taken into consideration when performing detailed evaluation of the FHR in twins.

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This paper presents the main operation modes for an electric vehicle (EV) battery charger framed in smart grids and smart homes, i.e., are discussed the present-day and are proposed new operation modes that can represent an asset towards EV adoption. Besides the well-known grid to vehicle (G2V) and vehicle to grid (V2G), this paper proposes two new operation modes: Home-to-vehicle (H2V), where the EV battery charger current is controlled according to the current consumption of the electrical appliances of the home (this operation mode is combined with the G2V and V2G); Vehicle-for-grid (V4G), where the EV battery charger is used for compensating current harmonics or reactive power, simultaneously with the G2V and V2G operation modes. The vehicle-to-home (V2H) operation mode, where the EV can operate as a power source in isolated systems or as an off-line uninterruptible power supply to feed priority appliances of the home during power outages of the electrical grid is presented in this paper framed with the other operation modes. These five operation modes were validated through experimental results using a developed 3.6 kW bidirectional EV battery charger prototype, which was specially designed for these operation modes. The paper describes the developed EV battery charger prototype, detailing the power theory and the voltage and current control strategies used in the control system. The paper presents experimental results for the various operation modes, both in steady-state and during transients.

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The purpose of this study was to evaluate the determinism of the AS-lnterface network and the 3 main families of control systems, which may use it, namely PLC, PC and RTOS. During the course of this study the PROFIBUS and Ethernet field level networks were also considered in order to ensure that they would not introduce unacceptable latencies into the overall control system. This research demonstrated that an incorrectly configured Ethernet network introduces unacceptable variable duration latencies into the control system, thus care must be exercised if the determinism of a control system is not to be compromised. This study introduces a new concept of using statistics and process capability metrics in the form of CPk values, to specify how suitable a control system is for a given control task. The PLC systems, which were tested, demonstrated extremely deterministic responses, but when a large number of iterations were introduced in the user program, the mean control system latency was much too great for an AS-I network. Thus the PLC was found to be unsuitable for an AS-I network if a large, complex user program Is required. The PC systems, which were tested were non-deterministic and had latencies of variable duration. These latencies became extremely exaggerated when a graphing ActiveX was included in the control application. These PC systems also exhibited a non-normal frequency distribution of control system latencies, and as such are unsuitable for implementation with an AS-I network. The RTOS system, which was tested, overcame the problems identified with the PLC systems and produced an extremely deterministic response, even when a large number of iterations were introduced in the user program. The RTOS system, which was tested, is capable of providing a suitable deterministic control system response, even when an extremely large, complex user program is required.

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Walking robot, legged robot, walking machine, walking vehicle, control system, force control, technical application, kinematics distributed control, embedded system

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Virtual Trainer Web Edition proporciona un sistema de gestión, planificación y control de un centro deportivo, ofreciendo interactividad entre técnicos, socios y personal de gerencia y facilitando todo el trabajo de un mantenimiento de información tradicional. A través de cualquier PC con conexión a Internet y sin instalación de software adicional, se accede a una completa aplicación con contenidos multimedia.

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Este proyecto consiste en la implantación de un sistema SCADA en una planta piloto de fabricación y envasado de líquidos. En este documento se muestra toda la información que ha sido necesaria para realizar el sistema de automatización en los tres niveles propios de un SCADA: nivel de campo, nivel de control y nivel de supervisión. El trabajo de campo ha sido, típicamente de revisión, puesto que el Departament de Telecomunicació i d’Enginyeria de Sistemes ya poseía la planta totalmente equipada, mientras que el sistema de control y el sistema de supervisión se han implantado totalmente.

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OBJECTIVES: To compare the level of sports practice between adolescents with chronic health conditions (CHCs) and control peers and to examine the reasons given by adolescents with CHCs for not practicing any sports in comparison with the control group. DESIGN: School survey. SETTING: Postmandatory schools. PARTICIPANTS: A total of 6790 students (3275 females) aged 16 to 20 years, grouped as adolescents with CHCs (355 females, 354 males) and control peers (2920 females, 3161 males). MAIN EXPOSURE: Chronic health condition was defined using a noncategorical approach including adolescents with a chronic disease and/or a physical handicap. MAIN OUTCOME MEASURES: Sports practice, barriers to sports practice among individuals not practicing any sports, and biological, psychological, socioeducative, and physical activity characteristics. RESULTS: Males with CHCs were less likely than control males to practice sports, whereas no significant difference was observed for females. Chronically ill youth were significantly more likely to report having a CHC as a barrier for not practicing sports. However, the most frequently reported barrier was preference for other activities for males with CHCs and lack of time for control males and for females with and without CHCs. CONCLUSIONS: Having a CHC seems to influence sports practice among males but not females. We recommend that practitioners dealing with adolescents remember to take into account sports practice as part of the care of young patients with CHCs.

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Treball de recerca realitzat per un alumne d'ensenyament secundari i guardonat amb un Premi CIRIT per fomentar l'esperit cientí­fic del Jovent l'any 2009. L'NXT és un robot creat per l'empresa Lego que disposa d'un controlador, de diversos servo motors i de sensors (tacte, llum, ultrasons, so...). Es programa mitjançant un programa especial, pensat per nois i noies de catorze anys, anomenat Lego Mindstorms. S'estudia el funcionament d'aquest programa i les parts del sistema de control del robot. L'estudi engloba el controlador, quatre sensors i els servomotors.

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This is the first study to adopt a configurational paradigm in an investigation of strategic management accounting (SMA) adoption. The study examines the alignment and effectiveness of strategic choice and strategic management accounting (SMA) system design configurations. Six configurations were derived empirically by deploying a cluster analysis of data collected from a sample of 193 large Slovenian companies. The first four clusters appear to provide some support for the central configurational proposition that higher levels of vertical and horizontal configurational alignments are associated with higher levels of performance. Evidence that contradicts the theory is also apparent, however, as the remaining two clusters exhibit high degrees of SMA vertical and horizontal alignment, but low performance levels. A particular contribution of the paper concerns its demonstration of the way that the configurational paradigm can be operationalised to examine management accounting phenomena and the nature of management accounting insights that can derive from applying the approach.

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The Athlete Biological Passport (ABP) is an individual electronic document that collects data regarding a specific athlete that is useful in differentiating between natural physiologic variations of selected biomarkers and deviations caused by artificial manipulations. A subsidiary of the endocrine module of the ABP, that which here is called Athlete Steroidal Passport (ASP), collects data on markers of an altered metabolism of endogenous steroidal hormones measured in urine samples. The ASP aims to identify not only doping with anabolic-androgenic steroids, but also most indirect steroid doping strategies such as doping with estrogen receptor antagonists and aromatase inhibitors. Development of specific markers of steroid doping, use of the athlete's previous measurements to define individual limits, with the athlete becoming his or her own reference, the inclusion of heterogeneous factors such as the UDPglucuronosyltransferase B17 genotype of the athlete, the knowledge of potentially confounding effects such as heavy alcohol consumption, the development of an external quality control system to control analytical uncertainty, and finally the use of Bayesian inferential methods to evaluate the value of indirect evidence have made the ASP a valuable alternative to deter steroid doping in elite sports. The ASP can be used to target athletes for gas chromatography/combustion/ isotope ratio mass spectrometry (GC/C/IRMS) testing, to withdraw temporarily the athlete from competing when an abnormality has been detected, and ultimately to lead to an antidoping infraction if that abnormality cannot be explained by a medical condition. Although the ASP has been developed primarily to ensure fairness in elite sports, its application in endocrinology for clinical purposes is straightforward in an evidence-based medicine paradigm.

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WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: The AMS 800 urinary control system is the gold standard for the treatment of urinary incontinence due to sphincter insufficiency. Despite excellent functional outcome and latest technological improvements, the revision rate remains significant. To overcome the shortcomings of the current device, we developed a modern electromechanical artificial urinary sphincter. The results demonstrated that this new sphincter is effective and well tolerated up to 3 months. This preliminary study represents a first step in the clinical application of novel technologies and an alternative compression mechanism to the urethra. OBJECTIVES: To evaluate the effectiveness in continence achievement of a new electromechanical artificial urinary sphincter (emAUS) in an animal model. To assess urethral response and animal general response to short-term and mid-term activation of the emAUS. MATERIALS AND METHODS: The principle of the emAUS is electromechanical induction of alternating compression of successive segments of the urethra by a series of cuffs activated by artificial muscles. Between February 2009 and May 2010 the emAUS was implanted in 17 sheep divided into three groups. The first phase aimed to measure bladder leak point pressure during the activation of the device. The second and third phases aimed to assess tissue response to the presence of the device after 2-9 weeks and after 3 months respectively. Histopathological and immunohistochemistry evaluation of the urethra was performed. RESULTS: Bladder leak point pressure was measured at levels between 1091 ± 30.6 cmH2 O and 1244.1 ± 99 cmH2 O (mean ± standard deviation) depending on the number of cuffs used. At gross examination, the explanted urethra showed no sign of infection, atrophy or stricture. On microscopic examination no significant difference in structure was found between urethral structure surrounded by a cuff and control urethra. In the peripheral tissues, the implanted material elicited a chronic foreign body reaction. Apart from one case, specimens did not show significant presence of lymphocytes, polymorphonuclear leucocytes, necrosis or cell degeneration. Immunohistochemistry confirmed the absence of macrophages in the samples. CONCLUSIONS: This animal study shows that the emAUS can provide continence. This new electronic controlled sequential alternating compression mechanism can avoid damage to urethral vascularity, at least up to 3 months after implantation. After this positive proof of concept, long-term studies are needed before clinical application could be considered.

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FacturaCloud és un disseny de un sistema de facturació al núvol.

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Anàlisi dels PDA, des del punt de vista de la facilitat d'ús i el disseny centrat en l'usuari, per comprovar fins a quin punt es té en compte aquesta expansió.

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El projecte Gestió de comandes d'un restaurant amb .NET consisteix en el disseny i implementació d'una solució integral per a gestionar el negoci d'un restaurant de forma completa.