87 research outputs found
Geoacta | Volumen 23
- Análisis preliminar del balance sedimentario de la playa de PehuenCo, provincia de Buenos Aires, Argentina | Jorge Caló, Elba Fernández, Ángel Marcos y Héctor Aldacour
- Diferencias térmicas urbano-rural en la ciudad de Formosa, Argentina | Ricardo Merlo y María Cintia Piccolo
- Comportamiento flexural de la corteza que contiene a la cuenca de Ischigualasto Villa Unión (Provincias de San Juan y La Rioja, Argentina). | Francisco Ruiz y Antonio Introcaso
- Espectrometría de rayos gamma, área lago Musters, Provincia de Chubut | Luis E. López y Carlos J. Chernicoff
- Prony’s method applied to anomalies’ separation on an Andean cordillera section | Beatriz Introcaso
- Residual fluxes of mass, salt, temperature and suspended sediment through a section of Bahia Blanca | Daniel E. Perez y Gerardo M.E. Perillo
- Isostatic state of the upper rhine graben | Silvia Miranda and Antonio Introcaso
- Validación de las alturas geopotenciales de 1000 hPa obtenidas del modelo de diagnóstico del Servicio Meteorológico Nacional | Rosa Hilda Campagnucci y Diego Christian Araneo
- Sea level variations of both the South China Sea and the Malacca Straits due to the Northeast and the Southwest Monsoons | Alejandro L. Camerlengo, M. Nasir Saadon and Tetsuo YanagiAsociación Argentina de Geofísicos y Geodesta
Digital Filters and Signal Processing
Digital filters, together with signal processing, are being employed in the new technologies and information systems, and are implemented in different areas and applications. Digital filters and signal processing are used with no costs and they can be adapted to different cases with great flexibility and reliability. This book presents advanced developments in digital filters and signal process methods covering different cases studies. They present the main essence of the subject, with the principal approaches to the most recent mathematical models that are being employed worldwide
Radar Technology
In this book “Radar Technology”, the chapters are divided into four main topic areas: Topic area 1: “Radar Systems” consists of chapters which treat whole radar systems, environment and target functional chain. Topic area 2: “Radar Applications” shows various applications of radar systems, including meteorological radars, ground penetrating radars and glaciology. Topic area 3: “Radar Functional Chain and Signal Processing” describes several aspects of the radar signal processing. From parameter extraction, target detection over tracking and classification technologies. Topic area 4: “Radar Subsystems and Components” consists of design technology of radar subsystem components like antenna design or waveform design
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Inventing Intelligence: On the History of Complex Information Processing and Artificial Intelligence in the United States in the Mid-Twentieth Century
In the mid-1950s, researchers in the United States melded formal theories of problem solving and intelligence with another powerful new tool for control: the electronic digital computer. Several branches of western mathematical science emerged from this nexus, including computer science (1960s–), data science (1990s–) and artificial intelligence (AI). This thesis offers an account of the origins and politics of AI in the mid-twentieth century United States, which focuses on its imbrications in systems of societal control. In an effort to denaturalize the power relations upon which the field came into being, I situate AI’s canonical origin story in relation to the structural and intellectual priorities of the U.S. military and American industry during the Cold War, circa 1952 to 1961.
This thesis offers a detailed and comparative account of the early careers, research interests, and key outputs of four researchers often credited with laying the foundations for AI and machine learning—Herbert A. Simon, Frank Rosenblatt, John McCarthy and Marvin Minsky. It chronicles the distinct ways in which each sought to formalise and simulate human mental behaviour using digital electronic computers. Rather than assess their contributions as discontinuous with what came before, as in mythologies of AI's genesis, I establish continuities with, and borrowings from, management science and operations research (Simon), Hayekian economics and instrumentalist statistics (Rosenblatt), automatic coding techniques and pedagogy (McCarthy), and cybernetics (Minsky), along with the broadscale mobilization of Cold War-era civilian-led military science generally.
I assess how Minsky’s 1961 paper 'Steps Toward Artificial Intelligence' simultaneously consolidated and obscured these entanglements as it set in motion an initial research agenda for AI in the following two decades. I argue that mind-computer metaphors, and research in complex information processing generally, played an important role in normalizing the small- and large-scale structuring of social behaviour using mathematics in the United States from the second half of the twentieth century onward
Competitive power control of distributed power plants
Nowadays, the electrical energy sector is currently found in a dramatic changing paradigm, which moves towards an increasing trend in generating power at distribution levels, where electricity is typically consumed, by means of non-conventional/renewable based generation units. These new generation technologies, termed as distributed generation, not only offers a non-pollutant, cheap and efficient source of energy to cover increasing demand, but also enhance the reliability of supply to critical loads and reduce the need for additional grid reinforcements. Aside of the technical benefits provided, distributed generation will massively integrate renewable energy resources, with new type of loads and end-user actors, such as prosumers, demand responsive loads, or electric vehicles. Where these actors will actively participate in energy and auxiliary service markets, depending on their available or constrained energy needs. For this reason, the work presented in this Thesis deals with designing and implementing advanced hierarchical control solutions to renewable-based power plants with the purpose of achieving advanced grid conection performance while reaching maximum economic benefits from its optimum real-time operation. Initially, an extensive analysis on the main renewable-based power plant hierarchical control solutions currently on the shelf, is performed. This study not only covered the specific case of renewable-based power plants, but also advanced microgrid and smart grid control solutions. Once the main renewable-based power plant hierarchical solutions were analized, a novel Hierarchical Distributed Control Structure (HDCS) is proposed for increased management of renewable-based active distributed plants. This hierarchical control structure comprises all possible functional levels from the higher long-term economic scheduling layer, to the instantaneous supervisory control of the resource, emphasizing the entire operation and control functionalities needed for increasing the integration of active distributed power plants. In order to achieve real-time control capabilities in active distribution systems, the present thesis introduces a novel power sharing control strategy, based on the competitive operation of multiple active participating agents (distributed generators, demand response and energy storage systems) through the implementation of market rules. Such control capabilities are satisfied by applying a price control signal over the entire grid control architecture, being the final-end participating agent, the responsible entity in charge of deciding its own generation/demand involvement based on its marginal or affordable electricity costs. In addition, it reduces the information volume to be transmitted and processing requirements, as the higher control levels do not need to have knowledge on the detailed distribution system topology and contributing actors. In order to have a meaningful evaluation of the proposed competitive control capabilities, a wave power plant application has been selected, which constitutes a challenging scenario for the controller itself to achieve advanced real-time control capabilities in such an oscillating renewable energy resource. In order to suitably characterize the wave energy resource profile resulting from maximum energy absorption, this Thesis introduce a novel adaptive vector controller, which maximizes the energy extraction from the resource regardless of the dominant irregular wave frequency characteristics. For the specific wave power plant application considered, the competitive control does not only ensures real-time optimum resource allocation for satisfying a given production objective, but also provides optimum long term operation of the system. As a result, overall plant costs reductions can be achieved under the competitive operation, since the plant scheduled energy is satisfied by making use of the generation units with cheaper cumulative operation costsActualmente, el sector eléctrico se encuentra inmerso en un profundo proceso de restructuración, donde de cada vez más se tiende a generar energía a nivel de distribución, mediante el uso de generación no convencional/renovable. Estas nuevas tecnologías de generación, referidas como generación distribuida, no proporcionan unicamente una fuente de energía no-contaminante, barata y eficiente para cubrir el incremento de demanda, sinó que también pueden proporcionar seguridad de suministro a cargas críticas, así como reducir la necesidad de expansiones futuras de red. Además de las capacidades técnicas proporcionadas, la generación distribuida hará posible la integración masiva de sistemas de generación renovable, con nuevos tipos de cargas y usuarios finales, como prosumidores, cargas regulables, o vehiculos eléctricos, donde todos estos usuarios participaran activamente en mercados de energía y servicios auxiliares, dependiendo de sus requisitos de uso de energía. Por lo tanto, el trabajo realizado en esta tesis se centra en el diseño e implementación de soluciones jerárquicas de control avanzado en plantas de generación renovable, con el objetivo de obtener un comportamiento harmonioso de intercacción con la red, mientras la operación de la planta maximiza los beneficios derivados de su operación en tiempo real. Inicialmente, se ha llevado a cabo una revisión extensa sobre los sistemas de control jerárquico comunmente implementados en plantas de generación renovable, en microredes y en redes inteligentes. Una vez revisados los principales sistemas de control jerárquico en este tipo de aplicaciones, se propone un una novedosa estructura de control, que cubre todos los niveles de control posibles, desde el más alto nivel de gestión económica, hasta el control detallado del recurso de generación. Para lograr capacidades de control en tiempo real en sistemas activos de distribución, la presente tesis propone una nueva estrategia de control de reparto de potencia, basada en la operación competitiva de múltiples agentes participantes activos (generadores distribuidos, respuesta de demanda y sistemas de almacenamiento de energía) mediante la implementación de reglas del mercado. Dichas capacidades de control se satisfacen aplicando una señal de precio a lo largo de toda la arquitectura de control, siendo el agente de final, el ente responsable de decidir su propia participación en la generación/demanda en función de sus propios costes de electricidad marginales o asumibles. Además, reduce el volumen de información a transmitir y los requisitos de procesamiento de datos, ya que los niveles de control más altos no necesitan tener conocimiento sobre la topología del sistema de distribución detallado ni de la contribución de los actores adyacentes. Para llevar a cabo una evaluación significativa de las capacidades del controlador competitivo propuesto, se ha seleccionado una planta de generación undimotriz, como escenario más desfavorable, ya que el controlador debe asegurar un control estable de la potencia inyectada en un escenario altamente oscilante. Con el fin de caracterizar adecuadamente el perfil de recursos de energía de las olas resultante de la máxima absorción de energía, esta Tesis introduce un nuevo controlador de vector adaptativo, que maximiza la extracción de energía del recurso independientemente de las características dominantes de frecuencia de onda irregular. Para la aplicación de la planta de energía de onda específica considerada, el control competitivo no solo garantiza la asignación óptima de recursos en tiempo real para satisfacer un objetivo de producción dado, sino que también proporciona una operación óptima del sistema a largo plazo. Como resultado, se pueden lograr reducciones generales de los costos de la planta en el marco de la operación competitiva, ya que la energía programada de la planta se satisface haciendo uso de las unida
Electrical power optimisation of grid-connected wave energy converters using economic predictive control
This thesis investigates the advanced control algorithms used for optimally extracting energy from a wave-to-wire wave energy converter system. The research focuses on the wave-to-wire system model as a whole, instead of its separate subsystems. This allows maximum exportation of average electrical power onto the grid from a wave energy array, with minimum mechanical and electrical constraint infringement and acceptable power quality. An economic model predictive control algorithm is first described for a wave-to-DClink system with a single wave energy converter connected to a simulated linear generator. This work investigates the importance of including the linear generator’s resistive losses in the cost function. Linear mechanical and non-linear electrical constraints are introduced into the model predictive control algorithm, where the effects on the average electrical power harvest are presented. A model predictive control algorithm with a field weakening enabled cost function is introduced, where the feasible region is extended for low DC-link voltages. By including a uni-directional power flow constraint into the algorithm, the power exported onto the DC-link bus is guaranteed to be positive. A detailed analysis of the effect of uncertainty on performance was carried out, where the controller’s internal model is mismatched from the simulation model. The results indicate that the high fidelity of the controller’s internal model is not required and that a sufficient amount of average electrical power is extractable. A non-linear model predictive control algorithm is described, where the non-linear viscosity forces are incorporated into the control algorithm - extracting maximum energy from a viscous system. It was shown that given the constraints on the system that the non-linear action of the control algorithm could be approximated, a linear model predictive control algorithm with an estimated viscous term. This produces a computationally inexpensive control algorithm, while maintaining good performance. A move-blocking was also introduced to further reduce the computation expense. Finally the thesis considers multiple point absorbers in an array and analyses the potential benefits of using either decentralised or centralised model predictive control algorithms. This demonstrated that the performance of a decentralised controller becomes comparable to the centralised controller when linear mechanical constraints are introduced into the viscous hydrodynamic array. However, when an upper power limit is introduced into the control algorithm the advantages of the centralised controller become apparent
Abstracts on Radio Direction Finding (1899 - 1995)
The files on this record represent the various databases that originally composed the CD-ROM issue of "Abstracts on Radio Direction Finding" database, which is now part of the Dudley Knox Library's Abstracts and Selected Full Text Documents on Radio Direction Finding (1899 - 1995) Collection. (See Calhoun record https://calhoun.nps.edu/handle/10945/57364 for further information on this collection and the bibliography).
Due to issues of technological obsolescence preventing current and future audiences from accessing the bibliography, DKL exported and converted into the three files on this record the various databases contained in the CD-ROM.
The contents of these files are:
1) RDFA_CompleteBibliography_xls.zip [RDFA_CompleteBibliography.xls: Metadata for the complete bibliography, in Excel 97-2003 Workbook format; RDFA_Glossary.xls: Glossary of terms, in Excel 97-2003 Workbookformat; RDFA_Biographies.xls: Biographies of leading figures, in Excel 97-2003 Workbook format];
2) RDFA_CompleteBibliography_csv.zip [RDFA_CompleteBibliography.TXT: Metadata for the complete bibliography, in CSV format; RDFA_Glossary.TXT: Glossary of terms, in CSV format; RDFA_Biographies.TXT: Biographies of leading figures, in CSV format];
3) RDFA_CompleteBibliography.pdf: A human readable display of the bibliographic data, as a means of double-checking any possible deviations due to conversion
Redesigning the Austroads creep procedure for the evaluation of permanent deformation of asphalt pavements in Australia
The broad spectrum of dynamic creep tests developed over the last decade around the world is one of the more significant innovations in the prediction and analysis of the behaviour of asphalt pavements. Although current laboratory creep test methods have good potential for evaluating permanent plastic deformation of asphalt mixtures, there are serious concerns about their abilities to provide any precise prediction of asphalt susceptibility to permanent plastic deformation. These concerns have arisen when creep test outcomes have been unsuccessfully compared with data from field assessments.
In response to the critical questions about the adequacy of the various unconfined creep tests to predict permanent plastic deformation of asphalt, many researchers have been attempting to develop methods to improve laboratory test methods. It has been hypothesised that by providing a lateral pressure around the laboratory specimens, it would be possible to better simulate field conditions and obtain more relevant creep test outcomes.
In this study, a new methodology is explored to provide effective confinement for asphalt creep specimens. The proposed methodology is founded on the current Australian test, adapted to provide simulated field conditions. Finite Element Method (FEM) modelling is employed in the study to provide a formative view about the overall study. It is used to develop a correlation between the new confined test and in situ pavement conditions.
It has been established that the new confined dynamic creep test method (CDCT) is a superior test for duplicating in-situ conditions than the existing test methods. Outcomes of the study indicate that the CDCT will significantly decrease existing shortcomings associated with the existing Australian creep test. It is concluded that the CDCT is a much improved test method that better represents in-situ conditions and it can be used as a methodology for evaluating permanent deformation of asphaltic pavements
New advanced methods for the spectral analysis of time-varying waveforms in power systems
This thesis presents new advanced methods for the spectral analysis of time-varying waveforms in power systems.
First, the main non-parametric, parametric and hybrid methods are presented in details under an analytical review of the state of the art, stressing both their advantages and their weaknesses. Then, a new advanced modified parametric method and three new advanced hybrid methods are presented in this thesis. All of the proposed methods guarantee an accuracy typical of the parametric methods, though with a significantly lower computational efforts
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