902 resultados para power system control
Resumo:
La aparición de las armas nucleares hacia los años ’40 ha cambiado la forma en que ciertos Estados desarrollan sus relaciones bilaterales en materia de seguridad, debido a que la obtención de estas garantiza capacidad militar que no se tiene con las armas de carácter convencional. Tanto Estados Unidos como la Unión Soviética procuraron la producción de las armas nucleares a gran escala, lo cual conllevó a la consolidación de una carrera armamentista entre ambos que fue regulada por tratados bilaterales: esta situación generó un Dilema de Seguridad entre ambos Estados. Con la disolución de la Unión Soviética y el surgimiento de la Federación Rusa en el inicio de la década del ’90, el Sistema Internacional que se había configurado durante la Guerra Fría se alteró debido a que, si bien se había acabado el conflicto que existía en el periodo bipolar, aún existían las armas nucleares con las que se garantizaba la continuación del Dilema de Seguridad que había surgido en los años anteriores. Con la presente monografía pretende analizar el Dilema de Seguridad durante el periodo comprendido entre 1991 y 2010 entre Estados Unidos y la Federación Rusa.
Resumo:
Este documento explora las dinámicas de cambio y continuidad de los autoritarismos subnacionales (específicamente en las provincias) en los regímenes democráticos nacionales. Tomando contribuciones de teorías propias de la política territorial provee un marco para el análisis del contexto estratégico en el que élites autoritarias en el poder y sus oponentes locales y nacionales adelantan estrategias de control territorial y de oposición. El autoritarismo subnacional no debe ser entendido como un asunto local, sino como un resultado de dinámicas más amplias de gobernanza territorial nacional en regímenes democráticos. Los conflictos entre los autoritarismos y la oposición ocurren a través de múltiples ámbitos territoriales dentro del sistema político nacional. En regímenes democráticos nacionales las élites autoritarias adelantarán tres tipos de estrategias: la parroquialización del poder, la nacionalización de su influencia, y la monopolización de los vínculos institucionales entre lo nacional y lo subnacional. La democratización subnacional, cuando ocurra, resultará entonces de la intervención por parte de actores en espacios políticas nacionales. Para este fin se han hecho dos distinciones entre las “modalidades” de cambio político subnacional: las transiciones “lideradas por partidos políticos” y las transiciones “lideradas por el centro”.-----This document examines the dynamics established between change and continuity under sub-national authoritarianisms (more specifically in provinces) in national democratic regimes. Contributions taken from local theories on territorial politics constitute the framework for our analysis of the strategic context in the midst of which authoritarian elites in power, and their local and national opponents, put forward their territorial control and opposition strategies. Still, sub-national authoritarianism must not be considered a mere local issue, but rather the final result of wider national territorial governing dynamics within democratic regimes. That is, conflicts arising between different authoritarianisms and the opposition take place in myriad territorial arenas within an established national political system. In national democratic regimes, authoritarian elites will attempt three different types of strategies: establishing a parochial-style mode of exerting power, extending its influence nationwide, and monopolizing the extant institutional links between the national and sub-national spheres. Thus, the democratization of the sub-national realm, if and when it happens, will only take place via the intervention of actors and agents from national political arenas. In order to better understand this phenomenon, two main distinctions are made between two types or modes of sub-national political change: those transitions “led by political parties” and those “led by the center”.
Resumo:
Este trabajo pretende de una manera tanto teórica como práctica, estudiar la relación que pueda existir entre la interculturalidad y el Management Control System, para ello se realiza una revisión bibliográfica de los trabajos empíricos y teóricos desarrollados hasta el momento sobre el tema. Se comienza con la revisión de los diferentes conceptos que puedan hacer alusión a la interculturalidad, y los MCS (o contemple variables cercanas en relación a este), se delimita el tema y se procede a su clasificación hasta llegar a la estructuración de la definición de los constructos que integren los conceptos de interculturalidad y MCS. De igual manera, se operacionalizan las variables para poder generar un análisis practico utilizando estadística cuantitativa. Finalmente presentamos los resultados que demuestran el grado de importancia percibido por encuestados de filiales localizadas en diferentes países de Latino América de la empresa Agrocampo S.A.S, con el fin de presentar conclusiones que integren los dos temas de análisis.
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The presented work focuses on the theoretical and practical aspects concerning the design and development of a formal method to build a mission control system for autonomous underwater vehicles bringing systematic design principles for the formal description of missions using Petri nets. The proposed methodology compounds Petri net building blocks within it to de_ne a mission plan for which it is proved that formal properties, such as reachability and reusability, hold as long as these same properties are also guaranteed by each Petri net building block. To simplify the de_nition of these Petri net blocks as well as their composition, a high level language called Mission Control Language has been developed. Moreover, a methodology to ensure coordination constraints for teams of multiple robots as well as the de_nition of an interface between the proposed system and an on-board planner able to plan/replan sequences of prede_ned mission plans is included as well. Results of experiments with several real underwater vehicles and simulations involving an autonomous surface craft and an autonomous underwater vehicles are presented to show the system's capabilities.
Resumo:
The work presented in this PhD thesis includes various partial studies aimed at developing a decision support system for membrane bioreactor integrated control. The decision support systems (DSS) have as a main goal to facilitate the operation of complex processes due to the multiple variables that are processed. For this reason, the research used has focused on aspects related to nutrient removal, and on the development of indicators or sensors capable of facilitating, automating and controlling the filtration process in an integrated way with the biological processes that taking place. Work has also been done on the design, development, implementation and validation of tools based on the knowledge made available by the automatic control and the supervision of the MBRs
Resumo:
The thesis involves the development and implementation of a new and robust control system based on permeability trends but at the same time capable of reducing aeration proportionally to permeate flux. Permeability was made a key parameter for directly comparing temporary changes in membrane performance. Transmembrane pressure and flux were gathered every 10 seconds and permeability values were automatically calculated; different mathematical algorithms were applied for the signal filtering of on-line data. Short term and long term permeability trends were compared once a day, and a control action was applied proportionally to the short term/long term permeability ratio without exceeding the aeration flow recommended by the membrane suppliers.
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Este estudio analiza la potestad tributaria o de creación de tributos, los principios y cuestiones de orden tributario que obran en la Constitución Política, el sistema de control de la constitucionalidad de las leyes y de las normas, con especial aplicación al ámbito tributario, y los efectos de ese control. Se circunscribe principalmente a la legislación ecuatoriana, mas, brevemente se refiere a otros países. Incluye la jurisprudencia del Tribunal Constitucional del Ecuador.
Resumo:
A recent area for investigation into the development of adaptable robot control is the use of living neuronal networks to control a mobile robot. The so-called Animat paradigm comprises a neuronal network (the ‘brain’) connected to an external embodiment (in this case a mobile robot), facilitating potentially robust, adaptable robot control and increased understanding of neural processes. Sensory input from the robot is provided to the neuronal network via stimulation on a number of electrodes embedded in a specialist Petri dish (Multi Electrode Array (MEA)); accurate control of this stimulation is vital. We present software tools allowing precise, near real-time control of electrical stimulation on MEAs, with fast switching between electrodes and the application of custom stimulus waveforms. These Linux-based tools are compatible with the widely used MEABench data acquisition system. Benefits include rapid stimulus modulation in response to neuronal activity (closed loop) and batch processing of stimulation protocols.
Resumo:
Three experiments examine the effect of different forms of computer-generated advice on concurrent and subsequent performance of individuals controlling a simulated intensive-care task. Experiment 1 investigates the effect of optional and compulsory advice and shows that both result in an improvement in subjects' performance while receiving the advice, and also in an improvement in subsequent unaided performance. However, although the advice compliance displayed by the optional advice group shows a strong correlation with subsequent unaided performance, compulsory advice has no extra benefit over the optional use of advice. Experiment 2 examines the effect of providing users with on-line explanations of the advice, as well as providing less specific advice. The results show that both groups perform at the same level on the task as the advice groups from Experiment 1, although subjects receiving explanations scored significantly higher on a written post-task questionnaire. Experiment 3 investigates in more detail the relationship between advice compliance and performance. The results reveal a complex relationship between natural ability on the task and the following of advice, in that people who use the advice more tend to perform either better or worse than the more moderate users. The theoretical and practical implications of these experiments are discussed.
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This paper describes the design, implementation and characterisation of a contactless power transfer system for rotating applications. The power transfer system is based upon a zero-voltage-switched, full-bridge, DC-DC converter, but utilises a non-standard transformer. This transformer allows power transfer between its primary and secondary windings while also allowing free rotation between these windings. The aim of this research is to develop a solution that could replace mechanical slip-rings in certain applications where a non-contacting system would be advantageous. Based upon the design method presented in this paper, a 2 kW prototype system is constructed. Results obtained from testing the 2 kW prototype are presented and discussed. This discussion considers how the performance of the transformer varies with rotation and also the overall efficiency of the system
Resumo:
In applications such as radar and wind turbines, it is often necessary to transfer power across a constantly rotating interface. As the rotation is continuous, it would be impossible to use wires to transfer the power as they would soon become twisted and stretched and the system would fail. The widespread solution to this problem is to use a slip-ring.
Resumo:
Asynchronous Optical Sampling (ASOPS) [1,2] and frequency comb spectrometry [3] based on dual Ti:saphire resonators operated in a master/slave mode have the potential to improve signal to noise ratio in THz transient and IR sperctrometry. The multimode Brownian oscillator time-domain response function described by state-space models is a mathematically robust framework that can be used to describe the dispersive phenomena governed by Lorentzian, Debye and Drude responses. In addition, the optical properties of an arbitrary medium can be expressed as a linear combination of simple multimode Brownian oscillator functions. The suitability of a range of signal processing schemes adopted from the Systems Identification and Control Theory community for further processing the recorded THz transients in the time or frequency domain will be outlined [4,5]. Since a femtosecond duration pulse is capable of persistent excitation of the medium within which it propagates, such approach is perfectly justifiable. Several de-noising routines based on system identification will be shown. Furthermore, specifically developed apodization structures will be discussed. These are necessary because due to dispersion issues, the time-domain background and sample interferograms are non-symmetrical [6-8]. These procedures can lead to a more precise estimation of the complex insertion loss function. The algorithms are applicable to femtosecond spectroscopies across the EM spectrum. Finally, a methodology for femtosecond pulse shaping using genetic algorithms aiming to map and control molecular relaxation processes will be mentioned.
Resumo:
In Uganda, control of vector-borne diseases is mainly in form of vector control, and chemotherapy. There have been reports that acaricides are being misused in the pastoralist systems in Uganda. This is because of the belief by scientists that intensive application of acaricide is uneconomical and unsustainable particularly in the indigenous cattle. The objective of this study was to investigate the strategies, rationale and effectiveness of vector-borne disease control by pastoralists. To systematically carry out these investigations, a combination of qualitative and quantitative research methods was used, in both the collection and the analysis of data. Cattle keepers were found to control tick-borne diseases (TBDs) mainly through spraying, in contrast with the control of trypanosomosis for which the main method of control was by chemotherapy. The majority of herders applied acaricides weekly and used an acaricide of lower strength than recommended by the manufacturers. They used very little acaricide wash, and spraying was preferred to dipping. Furthermore, pastoralists either treated sick animals themselves or did nothing at all, rather than using veterinary personnel. Oxytetracycline (OTC) was the drug commonly used in the treatment of TBDs. Nevertheless, although pastoralists may not have been following recommended practices in their control of ticks and tick-borne diseases, they were neither wasteful nor uneconomical and their methods appeared to be effective. Trypanosomosis was not a problem either in Sembabule or Mbarara district. Those who used trypanocides were found to use more drugs than were necessary.