949 resultados para Intersection Traffic Control Devices.
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The Distribution Network Operators (DNOs) role is becoming more difficult as electric vehicles and electric heating penetrate the network, increasing the demand. As a result it becomes harder for the distribution networks infrastructure to remain within its operating constraints. Energy storage is a potential alternative to conventional network reinforcement such as upgrading cables and transformers. The research presented here in this paper shows that due to the volatile nature of the LV network, the control approach used for energy storage has a significant impact on performance. This paper presents and compares control methodologies for energy storage where the objective is to get the greatest possible peak demand reduction across the day from a pre-specified storage device. The results presented show the benefits and detriments of specific types of control on a storage device connected to a single phase of an LV network, using aggregated demand profiles based on real smart meter data from individual homes. The research demonstrates an important relationship between how predictable an aggregation is and the best control methodology required to achieve the objective.
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GPS tracking of mobile objects provides spatial and temporal data for a broad range of applications including traffic management and control, transportation routing and planning. Previous transport research has focused on GPS tracking data as an appealing alternative to travel diaries. Moreover, the GPS based data are gradually becoming a cornerstone for real-time traffic management. Tracking data of vehicles from GPS devices are however susceptible to measurement errors – a neglected issue in transport research. By conducting a randomized experiment, we assess the reliability of GPS based traffic data on geographical position, velocity, and altitude for three types of vehicles; bike, car, and bus. We find the geographical positioning reliable, but with an error greater than postulated by the manufacturer and a non-negligible risk for aberrant positioning. Velocity is slightly underestimated, whereas altitude measurements are unreliable.
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The purpose of this study was to evaluate the antimicrobial effectiveness and dental applications of ozonated water generated by portable equipment (0.667 mg/L). Total elimination of C. albicans, E. coli and S. mutans planktonic cells was observed after 5 min. Reduction in the number of viable cells of biofilms formed on acrylic resin was observed for C. albicans, S. mutans and E. coli. The same effect was observed on biofilms of E. coli, S. aureus, S. mutans and C. albicans formed on stainless steel. Ozonated water was effective for the disinfection of experimentally contaminated toothbrushes.
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Reliability of power supply is related, among other factors, to the control and protection devices allocation in feeders of distribution systems. In this way, optimized allocation of sectionalizing switches and protection devices in strategic points of distribution circuits, improves the quality of power supply and the system reliability indices. In this work, it is presented a mixed integer non-linear programming (MINLP) model, with real and binary variables, for the sectionalizing switches and protection devices allocation problem, in strategic sectors, aimed at improving reliability indices, increasing the utilities billing and fulfilling exigencies of regulatory agencies for the power supply. Optimized allocation of protection devices and switches for restoration, allows that those faulted sectors of the system can be isolated and repaired, re-managing loads of the analyzed feeder into the set of neighbor feeders. Proposed solution technique is a Genetic Algorithm (GA) developed exploiting the physical characteristics of the problem. Results obtained through simulations for a real-life circuit, are presented. © 2004 IEEE.
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Networked control systems (NCS) are distributed control system where the sensors, actuators and controllers are physically separated and connected through communication networks. NCS represent the evolution of networked control architectures providing greater modularity and control decentralization, ease maintenance and diagnosis and lower cost of implementation. A recent trend in this research topic is the development of NCS using wireless networks (WNCS) enabling interoperability between existing wired and wireless systems. This paper evaluates a serial RS-232 ZigBee device as a wireless sensor link in NCS. In order to support this investigation, relevant performance metrics for wireless control applications such as jitter, time delay and messages lost are highlighted and calculated to evaluate the device capabilities. In addition the control performance of an implemented motor control system using the device is analyzed. Experimental results led to the conclusion that serial RS-232 ZigBee devices can be used to implement WNCS and the use of this device delay information in the PID controller discretization can improve the control performance of the system. © 2012 IEEE.
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Incluye Bibliografía
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Networked control systems (NCSs) are distributed control system in which sensors, actuators and controllers are physically separated and connected through communication networks. NCS represent the evolution of networked control architectures providing greater modularity and control decentralization, ease maintenance and diagnosis and lower cost of implementation. A recent trend in this research topic is the development of NCS using wireless networks(WNCS)which enable interoperability between existing wiredand wireless systems. This paper presents the feasibility analysis of using serial to wireless converter as a wireless sensor link in NCS. In order to support this investigation, relevant performance metrics for wireless control applications such as jitter, time delay and messages lost are highlighted and calculated to evaluate the wireless converter capabilities. In addition the control performance of an implemented motor control system using the converter is analyzed. Experimental results led to the conclusion that serial ZigBee device isrecommended against the Bluetooth as it provided better metrics for control applications. However, bothdevices can be used to implement WNCS providing transmission rates and closed control loop times which are acceptable for NCS applications.Moreoverthe use of thewireless device delay in the PID controller discretization can improve the control performance of the system.
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It may be useful to review some of the considerations that go into recommendations concerning bird management. Later I will make some comments concerning specific methods and devices being used in or promoted for bird control work regardless of whether or not they are new. Members of the National Pest Control Association provide a variety of services, such as fumigation, termite control and general pest control which includes rodent control. There are eight such categories listed in our roster, but only one member in five provides every service listed. Bird control is a rather recent development and is the newest category of service to be listed in the NPCA roster where it appeared for the first time in 1959. As of September 1, 1966, 45% of our members' offices indicated that they were prepared to offer bird control service. Less than 40% did so in 1964. Why is it that more of our members do not declare themselves as ready to do bird control work? I believe the most common answer you would find is that bird control is not yet sufficiently established that they can provide a service comparable in quality to that which is provided against termites or cockroaches or rats. Our members simply do not want to jeopardize their reputation on methods that are not certain or are too complex. Others recognize the emotional reaction evidenced by much of the population concerning control of birds and do not want to become involved in work that might offend some of their clientele. Still others simply do not agree that birds are their responsibility.
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La gestione del traffico è una delle principali problematiche delle città moderne, e porta alla definizione di nuove sfide per quanto riguarda l’ottimizzazione del flusso veicolare. Il controllo semaforico è uno degli elementi fondamentali per ottimizzare la gestione del traffico. Attualmente la rilevazione del traffico viene effettuata tramite sensori, tra i quali vengono maggiormente utilizzate le spire magnetiche, la cui installazione e gestione implica costi elevati. In questo contesto, il progetto europeo COLOMBO si pone come obiettivo l’ideazione di nuovi sistemi di regolazione semaforica in grado di rilevare il traffico veicolare mediante sensori più economici da installare e mantenere, e capaci, sulla base di tali rilevazioni, di auto organizzarsi, traendo ispirazione dal campo dell’intelligenza artificiale noto come swarm intelligence. Alla base di questa auto organizzazione semaforica di COLOMBO vi sono due diversi livelli di politiche: macroscopico e microscopico. Nel primo caso le politiche macroscopiche, utilizzando il feromone come astrazione dell’attuale livello del traffico, scelgono la politica di gestione in base alla quantità di feromone presente nelle corsie di entrata e di uscita. Per quanto riguarda invece le politiche microscopiche, il loro compito è quello di deci- dere la durata dei periodi di rosso o verde modificando una sequenza di fasi, chiamata in COLOMBO catena. Le catene possono essere scelte dal sistema in base al valore corrente della soglia di desiderabilità e ad ogni catena corrisponde una soglia di desiderabilità. Lo scopo di questo elaborato è quello di suggerire metodi alternativi all’attuale conteggio di questa soglia di desiderabilità in scenari di bassa presenza di dispositivi per la rilevazione dei veicoli. Ogni algoritmo complesso ha bisogno di essere ottimizzato per migliorarne le performance. Anche in questo caso, gli algoritmi proposti hanno subito un processo di parameter tuning per ottimizzarne le prestazioni in scenari di bassa presenza di dispositivi per la rilevazione dei veicoli. Sulla base del lavoro di parameter tuning, infine, sono state eseguite delle simulazioni per valutare quale degli approcci suggeriti sia il migliore.
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Abstract. During the last decade mobile communications increasingly became part of people's daily routine. Such usage raises new challenges regarding devices' battery lifetime management when using most popular wireless access technologies, such as IEEE 802.11. This paper investigates the energy/delay trade-off of using an end-user driven power saving approach, when compared with the standard IEEE 802.11 power saving algorithms. The assessment was conducted in a real testbed using an Android mobile phone and high-precision energy measurement hardware. The results show clear energy benefits of employing user-driven power saving techniques, when compared with other standard approaches.
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En la interacción con el entorno que nos rodea durante nuestra vida diaria (utilizar un cepillo de dientes, abrir puertas, utilizar el teléfono móvil, etc.) y en situaciones profesionales (intervenciones médicas, procesos de producción, etc.), típicamente realizamos manipulaciones avanzadas que incluyen la utilización de los dedos de ambas manos. De esta forma el desarrollo de métodos de interacción háptica multi-dedo dan lugar a interfaces hombre-máquina más naturales y realistas. No obstante, la mayoría de interfaces hápticas disponibles en el mercado están basadas en interacciones con un solo punto de contacto; esto puede ser suficiente para la exploración o palpación del entorno pero no permite la realización de tareas más avanzadas como agarres. En esta tesis, se investiga el diseño mecánico, control y aplicaciones de dispositivos hápticos modulares con capacidad de reflexión de fuerzas en los dedos índice, corazón y pulgar del usuario. El diseño mecánico de la interfaz diseñada, ha sido optimizado con funciones multi-objetivo para conseguir una baja inercia, un amplio espacio de trabajo, alta manipulabilidad y reflexión de fuerzas superiores a 3 N en el espacio de trabajo. El ancho de banda y la rigidez del dispositivo se han evaluado mediante simulación y experimentación real. Una de las áreas más importantes en el diseño de estos dispositivos es el efector final, ya que es la parte que está en contacto con el usuario. Durante este trabajo se ha diseñado un dedal de bajo peso, adaptable a diferentes usuarios que, mediante la incorporación de sensores de contacto, permite estimar fuerzas normales y tangenciales durante la interacción con entornos reales y virtuales. Para el diseño de la arquitectura de control, se estudiaron los principales requisitos para estos dispositivos. Entre estos, cabe destacar la adquisición, procesado e intercambio a través de internet de numerosas señales de control e instrumentación; la computación de equaciones matemáticas incluyendo la cinemática directa e inversa, jacobiana, algoritmos de detección de agarres, etc. Todos estos componentes deben calcularse en tiempo real garantizando una frecuencia mínima de 1 KHz. Además, se describen sistemas para manipulación de precisión virtual y remota; así como el diseño de un método denominado "desacoplo cinemático iterativo" para computar la cinemática inversa de robots y la comparación con otros métodos actuales. Para entender la importancia de la interacción multimodal, se ha llevado a cabo un estudio para comprobar qué estímulos sensoriales se correlacionan con tiempos de respuesta más rápidos y de mayor precisión. Estos experimentos se desarrollaron en colaboración con neurocientíficos del instituto Technion Israel Institute of Technology. Comparando los tiempos de respuesta en la interacción unimodal (auditiva, visual y háptica) con combinaciones bimodales y trimodales de los mismos, se demuestra que el movimiento sincronizado de los dedos para generar respuestas de agarre se basa principalmente en la percepción háptica. La ventaja en el tiempo de procesamiento de los estímulos hápticos, sugiere que los entornos virtuales que incluyen esta componente sensorial generan mejores contingencias motoras y mejoran la credibilidad de los eventos. Se concluye que, los sistemas que incluyen percepción háptica dotan a los usuarios de más tiempo en las etapas cognitivas para rellenar información de forma creativa y formar una experiencia más rica. Una aplicación interesante de los dispositivos hápticos es el diseño de nuevos simuladores que permitan entrenar habilidades manuales en el sector médico. En colaboración con fisioterapeutas de Griffith University en Australia, se desarrolló un simulador que permite realizar ejercicios de rehabilitación de la mano. Las propiedades de rigidez no lineales de la articulación metacarpofalange del dedo índice se estimaron mediante la utilización del efector final diseñado. Estos parámetros, se han implementado en un escenario que simula el comportamiento de la mano humana y que permite la interacción háptica a través de esta interfaz. Las aplicaciones potenciales de este simulador están relacionadas con entrenamiento y educación de estudiantes de fisioterapia. En esta tesis, se han desarrollado nuevos métodos que permiten el control simultáneo de robots y manos robóticas en la interacción con entornos reales. El espacio de trabajo alcanzable por el dispositivo háptico, se extiende mediante el cambio de modo de control automático entre posición y velocidad. Además, estos métodos permiten reconocer el gesto del usuario durante las primeras etapas de aproximación al objeto para su agarre. Mediante experimentos de manipulación avanzada de objetos con un manipulador y diferentes manos robóticas, se muestra que el tiempo en realizar una tarea se reduce y que el sistema permite la realización de la tarea con precisión. Este trabajo, es el resultado de una colaboración con investigadores de Harvard BioRobotics Laboratory. ABSTRACT When we interact with the environment in our daily life (using a toothbrush, opening doors, using cell-phones, etc.), or in professional situations (medical interventions, manufacturing processes, etc.) we typically perform dexterous manipulations that involve multiple fingers and palm for both hands. Therefore, multi-Finger haptic methods can provide a realistic and natural human-machine interface to enhance immersion when interacting with simulated or remote environments. Most commercial devices allow haptic interaction with only one contact point, which may be sufficient for some exploration or palpation tasks but are not enough to perform advanced object manipulations such as grasping. In this thesis, I investigate the mechanical design, control and applications of a modular haptic device that can provide force feedback to the index, thumb and middle fingers of the user. The designed mechanical device is optimized with a multi-objective design function to achieve a low inertia, a large workspace, manipulability, and force-feedback of up to 3 N within the workspace; the bandwidth and rigidity for the device is assessed through simulation and real experimentation. One of the most important areas when designing haptic devices is the end-effector, since it is in contact with the user. In this thesis the design and evaluation of a thimble-like, lightweight, user-adaptable, and cost-effective device that incorporates four contact force sensors is described. This design allows estimation of the forces applied by a user during manipulation of virtual and real objects. The design of a real-time, modular control architecture for multi-finger haptic interaction is described. Requirements for control of multi-finger haptic devices are explored. Moreover, a large number of signals have to be acquired, processed, sent over the network and mathematical computations such as device direct and inverse kinematics, jacobian, grasp detection algorithms, etc. have to be calculated in Real Time to assure the required high fidelity for the haptic interaction. The Hardware control architecture has different modules and consists of an FPGA for the low-level controller and a RT controller for managing all the complex calculations (jacobian, kinematics, etc.); this provides a compact and scalable solution for the required high computation capabilities assuring a correct frequency rate for the control loop of 1 kHz. A set-up for dexterous virtual and real manipulation is described. Moreover, a new algorithm named the iterative kinematic decoupling method was implemented to solve the inverse kinematics of a robotic manipulator. In order to understand the importance of multi-modal interaction including haptics, a subject study was carried out to look for sensory stimuli that correlate with fast response time and enhanced accuracy. This experiment was carried out in collaboration with neuro-scientists from Technion Israel Institute of Technology. By comparing the grasping response times in unimodal (auditory, visual, and haptic) events with the response times in events with bimodal and trimodal combinations. It is concluded that in grasping tasks the synchronized motion of the fingers to generate the grasping response relies on haptic cues. This processing-speed advantage of haptic cues suggests that multimodalhaptic virtual environments are superior in generating motor contingencies, enhancing the plausibility of events. Applications that include haptics provide users with more time at the cognitive stages to fill in missing information creatively and form a richer experience. A major application of haptic devices is the design of new simulators to train manual skills for the medical sector. In collaboration with physical therapists from Griffith University in Australia, we developed a simulator to allow hand rehabilitation manipulations. First, the non-linear stiffness properties of the metacarpophalangeal joint of the index finger were estimated by using the designed end-effector; these parameters are implemented in a scenario that simulates the behavior of the human hand and that allows haptic interaction through the designed haptic device. The potential application of this work is related to educational and medical training purposes. In this thesis, new methods to simultaneously control the position and orientation of a robotic manipulator and the grasp of a robotic hand when interacting with large real environments are studied. The reachable workspace is extended by automatically switching between rate and position control modes. Moreover, the human hand gesture is recognized by reading the relative movements of the index, thumb and middle fingers of the user during the early stages of the approximation-to-the-object phase and then mapped to the robotic hand actuators. These methods are validated to perform dexterous manipulation of objects with a robotic manipulator, and different robotic hands. This work is the result of a research collaboration with researchers from the Harvard BioRobotics Laboratory. The developed experiments show that the overall task time is reduced and that the developed methods allow for full dexterity and correct completion of dexterous manipulations.
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Esta tesis examina las implicaciones técnicas, políticas y espaciales del aire urbano, y en concreto, de la calidad del aire, para tenerlo en cuenta desde una perspectiva arquitectónica. En oposición a formas de entender el aire como un vacío o como una metáfora, este proyecto propone abordarlo desde un acercamiento material y tecnológico, trayendo el entorno al primer plano y reconociendo sus múltiples agencias. Debido a la escasa bibliografía detectada en el campo de la arquitectura, el objetivo es construir un marco teórico-analítico para considerar el aire urbano. Para ello el trabajo construye Aeropolis, una metáfora heurística que describe el ensamblaje sociotecnico de la ciudad. Situada en la intersección de determinadas ramas de la filosofía de la cultura, los estudios sobre ciencia y tecnología y estudios feministas de la ciencia este nuevo paisaje conceptual ofrece una metodología y herramientas para abordar el objeto de estudio desde distintos ángulos. Estas herramientas metodológicas han sido desarrolladas en el contexto específico de Madrid, ciudad muy contaminada cuyo aire ha sido objeto de controversias políticas y sociales, y donde las políticas y tecnologías para reducir sus niveles no han sido exitosas. Para encontrar una implicación alternativa con el aire esta tesis propone un método de investigación de agentes invisibles a partir del análisis de sus dispositivos epistémicos. Se centra, en concreto, en los instrumentos que miden, visualizan y comunican la calidad del aire, proponiendo que no sólo lo representan, sino que son también instrumentos que diseñan el aire y la ciudad. La noción de “sensing” (en castellano medir y sentir) es expandida, reconociendo distintas prácticas que reconstruyen el aire de Madrid. El resultado de esta estrategia no es sólo la ampliación de los espacios desde los que relacionarnos con el aire, sino también la legitimación de prácticas existentes fuera de contextos científicos y administrativos, como por ejemplo prácticas relacionadas con el cuerpo, así como la redistribución de agencias entre más actores. Así, esta tesis trata sobre toxicidad, la Unión Europea, producción colaborativa, modelos de computación, dolores de cabeza, kits DIY, gases, cuerpos humanos, salas de control, sangre o políticos, entre otros. Los dispositivos que sirven de datos empíricos sirven como un ejemplo excepcional para investigar infraestructuras digitales, permitiendo desafiar nociones sobre Ciudades Inteligentes. La tesis pone especial atención en los efectos del aire en el espacio público, reconociendo los procesos de invisibilización que han sufrido sus infraestructuras de monitorización. Para terminar se exponen líneas de trabajo y oportunidades para la arquitectura y el diseño urbano a través de nuevas relaciones entre infraestructuras urbanas, el medio construido, espacios domésticos y públicos y humanos y no humanos, para crear nuevas ecologías políticas urbanas (queer). ABSTRACT This thesis examines the technical, political and spatial implications of urban air, and more specifically "air quality", in order to consider it from an architectural perspective. In opposition to understandings of the air either as a void or as a metaphor, this project proposes to inspect it from a material and technical approach, bringing the background to the fore and acknowledging its multiple agencies. Due to the scarce bibliography within the architectural field, its first aim is to construct a theoretical and analytical framework from which to consider urban air. For this purpose, the work attempts the construction of Aeropolis, a heuristic metaphor that describes the city's aero socio-material assemblage. Located at the intersection of certain currents in cultural philosophy, science and technology studies as well as feminist studies in technoscience, this framework enables a methodology and toolset to be extracted in order to approach the subject matter from different angles. The methodological tools stemming from this purpose-built framework were put to the test in a specific case study: Madrid, a highly polluted city whose air has been subject to political and social controversies, and where no effective policies or technologies have been successful in reducing its levels of pollution. In order to engage with the air, the thesis suggests a method for researching invisible agents by examining the epistemic devices involved. It locates and focuses on the instruments that sense, visualise and communicate urban air, claiming that they do not only represent it, but are also instruments that design the air and the city. The notion of "sensing" is then expanded by recognising different practices which enact the air in Madrid. The work claims that the result of this is not only the opening up of spaces for engagement but also the legitimisation of existing practices outside science and policymaking environments, such as embodied practices, as well as the redistribution of agency among more actors. So this is a thesis about toxicity, the European Union, collaborative production, scientific computational models, headaches, DIY kits, gases, human bodies, control rooms, blood, or politicians, among many others. The devices found throughout the work serve as an exceptional substrate for an investigation of digital infrastructures, enabling to challenge Smart City tropes. There is special attention paid to the effects of the air on the public space, acknowledging the silencing processes these infrastructures have been subjected to. Finally there is an outline of the opportunities arising for architecture and urban design when taking the air into account, to create new (queer) urban political ecologies between the air, urban infrastructures, the built environment, public and domestic spaces, and humans and more than humans.