917 resultados para Automatic Control Theory


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One of the most important theories in the study of environmental governance and policy is the pathology of command and control, which describes the negative consequences of top-down, technocratic governance of social and ecological systems. However, to date, this theory has been expressed somewhat inconsistently and informally in the literature, even by the seminal works that have established its importance and popularized it. This presents a problem for the sustainability science community if it cannot be sure of the precise details of one of its most important theories. Without such precision, applications and tests of various elements of the theory cannot be conducted reliably to advance the knowledge of environmental governance. I address this problem by synthesizing several seminal works to formalize this theory. The formalization involves the identification of the individual elements of the theory and a diagrammatic description of their relationships with each other that unfold in a series of semi-independent causal paths. Ideally, with such a formalization, scholars can use this theory more reliably and more meaningfully in their future work. I conclude by discussing the implications this theory has for the governance of natural resources.

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Este estudio corresponde a la primera fase de investigación formativa recomendada en la teoría de la Acción Planeada para desarrollar una intervención. Nuestros objetivos son identificar las creencias modales sobre la realización de una pauta de ejercicio en personas con fibromialgia, probar los ítems para la evaluación directa de los constructos predictivos y explorar sus relaciones con la conducta. Evaluamos a 46 mujeres con fibromialgia. El análisis de contenido mostró un mayor número de consecuencias positivas que negativas asociadas a la ejecución de la pauta de ejercicio (creencias comportamentales); la familia y los amigos son los referentes importantes (creencias normativas) y se detectaron factores facilitadores e inhibidores de la ejecución de la conducta de ejercicio, relacionados con aspectos de la fibromialgia (creencias de control) como el dolor, la fatiga y el estado de ánimo. El índice de consistencia interna más bajo fue el de la escala de norma subjetiva (α= .78). Los resultados confirman el sedentarismo de la muestra (conducta previa: Media=3.67; rango=1-7) aunque también sugieren que estas personas tienen intención de realizar la conducta (Media= 5.67). Las relaciones obtenidas entre los constructos son las esperadas desde la teoría, apoyando la pertinencia de aplicarla en la conducta y población seleccionada.

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El cuestionamiento de las relaciones capitalistas de producción debe surgir a partir de su tendencia inherente a los desequilibrios y a la irracionalidad económica y no desde algún pre-juicio ideológico o político. En este contexto, la planificación económica se presenta como necesaria en la medida en que se requiera asegurar una autonomía humana de decisión con respecto a la distribución del ingreso, el acceso al empleo y la protección del medio ambiente. A partir de la constatación de este hecho, la planificación no sustituye a las relaciones mercantiles sino que cumple la función de garantizar una tendencia al equilibrio sobre la base de las relaciones mercantiles, lo que ningún automatismo del mercado puede garantizar. Se propone un principio de delimitación entre la planificación y la autonomía de las empresas (la reproducción de la vida humana), principio ampliable a la delimitación entre el Estado y las actividades de los grupos autónomos y de los mismos sujetos en general. Abstract The questioning of the capitalist relations of production must come from their inherent tendency to irrationality and economic imbalances and not from any ideological or political prejudice. In this context, economic planning is as necessary as it is required to ensure a human decision-making autonomy with respect to income distribution, access to employment and environmental protection. From the observation of this fact, planning is not a substitute for market relations but serves to ensure a tendency to balance on the basis of market relations, so no automatic of the market can guarantee. The article proposes a principle of demarcation between the planning and autonomy for enterprises (the reproduction of human life), expandable to top the demarcation between the state and the activities of autonomous groups and the same subjects in general.

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Mammography equipment must be evaluated to ensure that images will be of acceptable diagnostic quality with lowest radiation dose. Quality Assurance (QA) aims to provide systematic and constant improvement through a feedback mechanism to address the technical, clinical and training aspects. Quality Control (QC), in relation to mammography equipment, comprises a series of tests to determine equipment performance characteristics. The introduction of digital technologies promoted changes in QC tests and protocols and there are some tests that are specific for each manufacturer. Within each country specifi c QC tests should be compliant with regulatory requirements and guidance. Ideally, one mammography practitioner should take overarching responsibility for QC within a service, with all practitioners having responsibility for actual QC testing. All QC results must be documented to facilitate troubleshooting, internal audit and external assessment. Generally speaking, the practitioner’s role includes performing, interpreting and recording the QC tests as well as reporting any out of action limits to their service lead. They must undertake additional continuous professional development to maintain their QC competencies. They are usually supported by technicians and medical physicists; in some countries the latter are mandatory. Technicians and/or medical physicists often perform many of the tests indicated within this chapter. It is important to recognise that this chapter is an attempt to encompass the main tests performed within European countries. Specific tests related to the service that you work within must be familiarised with and adhered too.

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This paper presents MOTION, a modular on-line model for urban traffic signal control. It consists of a network and a local level and builds on enhanced traffic state estimation. Special consideration is given to the prioritization of public transit. MOTION provides possibilities for the interaction with integrated urban management systems.

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The last two decades have seen many exciting examples of tiny robots from a few cm3 to less than one cm3. Although individually limited, a large group of these robots has the potential to work cooperatively and accomplish complex tasks. Two examples from nature that exhibit this type of cooperation are ant and bee colonies. They have the potential to assist in applications like search and rescue, military scouting, infrastructure and equipment monitoring, nano-manufacture, and possibly medicine. Most of these applications require the high level of autonomy that has been demonstrated by large robotic platforms, such as the iRobot and Honda ASIMO. However, when robot size shrinks down, current approaches to achieve the necessary functions are no longer valid. This work focused on challenges associated with the electronics and fabrication. We addressed three major technical hurdles inherent to current approaches: 1) difficulty of compact integration; 2) need for real-time and power-efficient computations; 3) unavailability of commercial tiny actuators and motion mechanisms. The aim of this work was to provide enabling hardware technologies to achieve autonomy in tiny robots. We proposed a decentralized application-specific integrated circuit (ASIC) where each component is responsible for its own operation and autonomy to the greatest extent possible. The ASIC consists of electronics modules for the fundamental functions required to fulfill the desired autonomy: actuation, control, power supply, and sensing. The actuators and mechanisms could potentially be post-fabricated on the ASIC directly. This design makes for a modular architecture. The following components were shown to work in physical implementations or simulations: 1) a tunable motion controller for ultralow frequency actuation; 2) a nonvolatile memory and programming circuit to achieve automatic and one-time programming; 3) a high-voltage circuit with the highest reported breakdown voltage in standard 0.5 μm CMOS; 4) thermal actuators fabricated using CMOS compatible process; 5) a low-power mixed-signal computational architecture for robotic dynamics simulator; 6) a frequency-boost technique to achieve low jitter in ring oscillators. These contributions will be generally enabling for other systems with strict size and power constraints such as wireless sensor nodes.

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Jerne's idiotypic network theory postulates that the immune response involves inter-antibody stimulation and suppression as well as matching to antigens. The theory has proved the most popular Artificial Immune System (AIS) model for incorporation into behavior-based robotics but guidelines for implementing idiotypic selection are scarce. Furthermore, the direct effects of employing the technique have not been demonstrated in the form of a comparison with non-idiotypic systems. This paper aims to address these issues. A method for integrating an idiotypic AIS network with a Reinforcement Learning based control system (RL) is described and the mechanisms underlying antibody stimulation and suppression are explained in detail. Some hypotheses that account for the network advantage are put forward and tested using three systems with increasing idiotypic complexity. The basic RL, a simplified hybrid AIS-RL that implements idiotypic selection independently of derived concentration levels and a full hybrid AIS-RL scheme are examined. The test bed takes the form of a simulated Pioneer robot that is required to navigate through maze worlds detecting and tracking door markers.

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Jerne's idiotypic network theory postulates that the immune response involves inter-antibody stimulation and suppression as well as matching to antigens. The theory has proved the most popular Artificial Immune System (AIS) model for incorporation into behavior-based robotics but guidelines for implementing idiotypic selection are scarce. Furthermore, the direct effects of employing the technique have not been demonstrated in the form of a comparison with non-idiotypic systems. This paper aims to address these issues. A method for integrating an idiotypic AIS network with a Reinforcement Learning based control system (RL) is described and the mechanisms underlying antibody stimulation and suppression are explained in detail. Some hypotheses that account for the network advantage are put forward and tested using three systems with increasing idiotypic complexity. The basic RL, a simplified hybrid AIS-RL that implements idiotypic selection independently of derived concentration levels and a full hybrid AIS-RL scheme are examined. The test bed takes the form of a simulated Pioneer robot that is required to navigate through maze worlds detecting and tracking door markers.

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Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Mecânica, 2015.

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With global markets and global competition, pressures are placed on manufacturing organizations to compress order fulfillment times, meet delivery commitments consistently and also maintain efficiency in operations to address cost issues. This chapter argues for a process perspective on planning, scheduling and control that integrates organizational planning structures, information systems as well as human decision makers. The chapter begins with a reconsideration of the gap between theory and practice, in particular for classical scheduling theory and hierarchical production planning and control. A number of the key studies of industrial practice are then described and their implications noted. A recent model of scheduling practice derived from a detailed study of real businesses is described. Socio-technical concepts are then introduced and their implications for the design and management of planning, scheduling and control systems are discussed. The implications of adopting a process perspective are noted along with insights from knowledge management. An overview is presented of a methodology for the (re-)design of planning, scheduling and control systems that integrates organizational, system and human perspectives. The most important messages from the chapter are then summarized.

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International audience

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Les enfants d’âge préscolaire (≤ 5 ans) sont plus à risque de subir un traumatisme crânio-cérébral (TCC) que les enfants plus agés, et 90% de ces TCC sont de sévérité légère (TCCL). De nombreuses études publiées dans les deux dernières décennies démontrent que le TCCL pédiatrique peut engendrer des difficultés cognitives, comportementales et psychiatriques en phase aigüe qui, chez certains enfants, peuvent perdurer à long terme. Il existe une littérature florissante concernant l'impact du TCCL sur le fonctionnement social et sur la cognition sociale (les processus cognitifs qui sous-tendent la socialisation) chez les enfants d'âge scolaire et les adolescents. Or, seulement deux études ont examiné l'impact d'un TCCL à l'âge préscolaire sur le développement social et aucune étude ne s'est penchée sur les répercussions socio-cognitives d'un TCCL précoce (à l’âge préscolaire). L'objectif de la présente thèse était donc d'étudier les conséquences du TCCL en bas âge sur la cognition sociale. Pour ce faire, nous avons examiné un aspect de la cognition sociale qui est en plein essor à cet âge, soit la théorie de l'esprit (TE), qui réfère à la capacité de se mettre à la place d'autrui et de comprendre sa perspective. Le premier article avait pour but d'étudier deux sous-composantes de la TE, soit la compréhension des fausses croyances et le raisonnement des désirs et des émotions d'autrui, six mois post-TCCL. Les résultats indiquent que les enfants d'âge préscolaire (18 à 60 mois) qui subissent un TCCL ont une TE significativement moins bonne 6 mois post-TCCL comparativement à un groupe contrôle d'enfants n'ayant subi aucune blessure. Le deuxième article visait à éclaircir l'origine de la diminution de la TE suite à un TCCL précoce. Cet objectif découle du débat qui existe actuellement dans la littérature. En effet, plusieurs scientifiques sont d'avis que l'on peut conclure à un effet découlant de la blessure au cerveau seulement lorsque les enfants ayant subi un TCCL sont comparés à des enfants ayant subi une blessure n'impliquant pas la tête (p.ex., une blessure orthopédique). Cet argument est fondé sur des études qui démontrent qu'en général, les enfants qui sont plus susceptibles de subir une blessure, peu importe la nature de celle-ci, ont des caractéristiques cognitives pré-existantes (p.ex. impulsivité, difficultés attentionnelles). Il s'avère donc possible que les difficultés que nous croyons attribuables à la blessure cérébrale étaient présentes avant même que l'enfant ne subisse un TCCL. Dans cette deuxième étude, nous avons donc comparé les performances aux tâches de TE d'enfants ayant subi un TCCL à ceux d'enfants appartenant à deux groupes contrôles, soit des enfants n'ayant subi aucune blessure et à des pairs ayant subi une blessure orthopédique. De façon générale, les enfants ayant subi un TCCL ont obtenu des performances significativement plus faibles à la tâche évaluant le raisonnement des désirs et des émotions d'autrui, 6 mois post-blessure, comparativement aux deux groupes contrôles. Cette étude visait également à examiner l'évolution de la TE suite à un TCCL, soit de 6 mois à 18 mois post-blessure. Les résultats démontrent que les moindres performances sont maintenues 18 mois post-TCCL. Enfin, le troisième but de cette étude était d’investiguer s’il existe un lien en la performance aux tâches de TE et les habiletés sociales, telles qu’évaluées à l’aide d’un questionnaire rempli par le parent. De façon intéressante, la TE est associée aux habiletés sociales seulement chez les enfants ayant subi un TCCL. Dans l'ensemble, ces deux études mettent en évidence des répercussions spécifiques du TCCL précoce sur la TE qui persistent à long terme, et une TE amoindrie seraient associée à de moins bonnes habiletés sociales. Cette thèse démontre qu'un TCCL en bas âge peut faire obstacle au développement sociocognitif, par le biais de répercussions sur la TE. Ces résultats appuient la théorie selon laquelle le jeune cerveau immature présente une vulnérabilité accrue aux blessures cérébrales. Enfin, ces études mettent en lumière la nécessité d'étudier ce groupe d'âge, plutôt que d'extrapoler à partir de résultats obtenus avec des enfants plus âgés, puisque les enjeux développementaux s'avèrent différents, et que ceux-ci ont potentiellement une influence majeure sur les répercussions d'une blessure cérébrale sur le fonctionnement sociocognitif.

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The aim of this paper is to present new results on H-infinity control synthesis for time-delay linear systems. We extend the use of a finite order LTI system, called comparison system to H-infinity analysis and design. Differently from what can be viewed as a common feature of other control design methods available in the literature to date, the one presented here treats time-delay systems control design with classical numeric routines based on Riccati equations arisen from H-infinity theory. The proposed algorithm is simple, efficient and easy to implement. Some examples illustrating state and output feedback design are solved and discussed in order to put in evidence the most relevant characteristic of the theoretical results. Moreover, a practical application involving a 3-DOF networked control system is presented.

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This document is the Argo quality control manual for Dissolved oxygen concentration. It describes two levels of quality control: • The first level is the real-time system that performs a set of agreed automatic checks. • Adjustment in real-time can also be performed and the real-time system can evaluate quality flags for adjusted fields • The second level is the delayed-mode quality control system.

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In April 2017, CMEMS plans to launch the WAVES NRT products. This document is focused in the automatic RTQC of the collected wave data. The validation procedure includes the delayed mode quality control of the data and will be specified in another guideline. To perform any kind of quality control to wave data, first it’s necessary to know the nature of the measurements and the analysis performed to those measurements to obtain the wave parameters. For that reason next chapter is dedicated to show the usual wave analysis and the different parameters and estimators obtained.