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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Improvement of belt tension monitoring in a belt-driven automated material handling system

Musselman, Marcus William 23 December 2010 (has links)
The goal of the study presented in this thesis was the improvement of estimation and monitoring procedures for condition monitoring of belt tension and misalignment in belt-driven automated material handling systems widely used in modern semiconductor manufacturing systems. In pursuit of this goal, two 3-factor, 3-level experiments were designed to study how belt vibration characteristics depend on changes in belt length, belt tension, belt misalignment, and initial location of the excitation of belt vibration. Dependent variables in each of the experiments were drawn from a denoised frequency spectrum calculated from an Autoregressive model of the belt vibration time-series. A feature vector was developed from the Autoregressive features via variance based sensitivity analysis. Results showed that belt vibration characteristics were sensitive to changes in all of the independent variables examined. These results motivated the design of a device to improve the standardized technique widely used to monitor belt tension in belt-driven material handling systems. Reducing variance in the belt length and the location of the initial excitation of belt vibration yielded a reduction of tension estimate standard deviation an order of magnitude, as compared to a human performing the standardized technique. Thus, the use of this device provided higher belt tension estimate resolution. Future work that could lead to a less intrusive technique is presented. / text
2

A System Theoretical Approach to Situation Awareness : A holistic view of purposeful elements

Lagervik, Charlie January 2005 (has links)
<p>From the theories of Ackoff about system theory and how the management of an organization should perform, the concept of situation awareness is discussed. A short history of the situation awareness concept is given in the light of aviation and human cognition. Motives are given why it is of interest to explore the concept of SA. The Russian Theory of Activity (Activity Theory) is presented with the focus on the orientational activity to give the background for a comparison against the adaptive-learning management system as presented by Ackoff. As result a definition of SA is presented, the result of the comparison of theories is presented, discussed and summarized in a conceptual design and future research is presented.</p>
3

A System Theoretical Approach to Situation Awareness : A holistic view of purposeful elements

Lagervik, Charlie January 2005 (has links)
From the theories of Ackoff about system theory and how the management of an organization should perform, the concept of situation awareness is discussed. A short history of the situation awareness concept is given in the light of aviation and human cognition. Motives are given why it is of interest to explore the concept of SA. The Russian Theory of Activity (Activity Theory) is presented with the focus on the orientational activity to give the background for a comparison against the adaptive-learning management system as presented by Ackoff. As result a definition of SA is presented, the result of the comparison of theories is presented, discussed and summarized in a conceptual design and future research is presented.
4

Measuring Cognitive Workload in Automated Knowledge Work Environments

Shree Natasha Frazier (12878924) 17 June 2022 (has links)
<p>  </p> <p>Automation, as defined by Parasuraman et al. (2000, p. 287), is a “device or system that either partially or fully, accomplishes a function that was previously, partially, or fully accomplished by a human operator.” Traditionally, automation was introduced to (physical) work environments to alleviate workload associated with tedious and repetitive tasks. Over the past few decades, automation has begun to augment knowledge work, which includes high-level cognitive activities.  As automated systems expand to perform skill-based tasks, the work required of humans is inevitably altered, potentially affecting their cognitive workloads. Years of research has shown that automation can reduce cognitive workload, but other work suggests that cognitive workload may increase or remain unchanged when automation is introduced. These conflicting results prompt the need for further investigation to better delineate the relationship between automation and cognitive workload. </p> <p>A plethora of factors may explain why the relationship between automation and cognitive workload is inconsistent. Therefore, this research takes steps toward addressing knowledge gaps within the human-automation interaction literature related to understanding how automation used in knowledge work environments affects peoples’ task completion. Specifically, this work investigates how two moderators, task complexity and age, influence the automation and cognitive workload relationship. These moderators were of interest for two reasons. First, task complexity, which occurs when the structure of a task imposes demands on a person’s cognitive processes, increases the demands of a task, which can result in the use of more cognitive resources. Second, age is of interest because advanced technologies are increasingly being utilized by a wide user demographic, particularly the rapidly-growing older adult population.  </p> <p>The goals of this dissertation were achieved by employing both qualitative and quantitative methods to examine how (1) automation is assessed in knowledge work environments, (2) automation affects cognitive workload, and (3) task complexity and age moderate the relationship between automation and cognitive workload. These goals were first addressed via the construction of a conceptual framework that describes the effects that task complexity and age have on the relationship between automation and cognitive workload. Next, a systematic review of the human-automation interaction literature in knowledge work environments was performed to examine researchers’ use of cognitive workload measures. Finally, a controlled-laboratory experiment and a scenario-based survey were conducted to collect data from people of different ages about how task complexity and age influence the relationship between automation and cognitive workload. </p> <p>Findings from the systematic literature review showed that researchers primarily employ subjective and performance measures to assess cognitive workload. Results from the laboratory experiment suggested that automation improved measures of cognitive workload. Also, task complexity negatively affected the relationship between automation and cognitive workload, but age was not found to be a moderator. The scenario-based survey revealed that task performance was similar among younger, middle-aged, and older adults. However, younger adults had a more favorable opinion of automation compared to both middle-aged and older age groups. </p> <p>Overall, this research (1) enhances our knowledge of the relationship between automation and cognitive workload, (2) informs the design of future human-automation studies with strategically selected task types and measurement choices, based on patterns that emerged from the literature review, and (3) can ultimately guide designers in better developing technologies to support people in performing various activities in their work and leisure environments. </p>
5

An Automated System for the Stage of Hydrolysis and Filtration in the Extraction of Pectin from the Cocoa Shell

Ccencho, Maritza, Quijada, Valeria, Vinces, Leonardo 01 January 2021 (has links)
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Pectin obtained from cocoa husks has recently been investigated because of its gelling and stabilizing properties that have great potential for the food, cosmetic and pharmaceutical industries. However, its production at the industrial level has not been studied or developed in Peru. A fundamental part of the extraction process is the stage of hydrolysis and filtering of the cocoa shell. Because of this, an automated system for acid-thermal hydrolysis and shell filtration is proposed. The control of both processes is of great importance because the quality and efficiency of the extracted pectin will depend on it. The tests will be carried out in a cylindrical taper with a 100 L capacity which is adapted to contain a 20 L cylindrical filter, both made of AISI 304 stainless steel. The filter has a motor to homogenize the temperature and pH of the mix. The pH of the process is 2 and the temperature is 90 ± 2 °C, since in these ranges the pectin is released more easily from the cocoa shell. The method consists of the structural design of the tank and the filter, and in the design of the pH regulator and the heating system. The yield of the extraction process was achieved by 10%. / Revisión por pares
6

Design of a Self-Regulating Robotic Arm / Design av en självreglerande robotarm

Naesenius, Ludvig, Wikström, Viktor January 2022 (has links)
As the world rapidly propels further through the ever-evolving field of automation, there is also an increased demand for properly regulated robots. While the use of automated machines is nothing new, the industry remains in a continuous effort to develop systems that both push the number of manageable inputs and the limits of optimization. One of the most foundational parts of many automated machines is the robotic arm. During this project, a self-regulating robot arm with the ability to maintain a desired position based on multiple inputs was constructed and tested. The resulting design managed to maintain a set height with varying levels of flow and precision, enabling further development and optimization with stronger components. / I takt med att världen snabbt genomgår det ständigt föränderliga automationsområdet, finns det också en ökad efterfrågan på korrekt reglerade robotar. Även om användningen av automatiserade maskiner inte är något nytt, fortsätter branschen att arbeta kontinuerligt med att utveckla system som både ökar mängden hanterbar indata och tänjer på gränserna för optimering. En av de mest fundamentala delarna i många automatiserade maskiner är robotarmen. Under detta projekt konstruerades och testades en självreglerande robotarm med förmågan att bibehålla en önskad position baserat på flera insignaler. Den resulterande designen lyckades bibehålla en inställd höjd med varierande nivåer av jämnhet och precision, vilket möjliggör vidareutveckling och optimering med starkare komponenter.
7

Développement formel de systèmes automatisés / Formal development of automated systems

Mosbahi-Khalgui, Olfa 21 February 2008 (has links)
Le travail de thèse présente une méthode de développement de systèmes automatisés basée sur les méthodes formelles B et TLA+. Le développement par raffinement est au cœur de la méthode proposée. Un système automatisé est modélisé par deux composants, un contrôlé formé par le dispositif physique et son environnement et un contrôleur pilotant ce dernier. Il est exprimé par un produit synchronisé sur les actions de ces deux composants. La première contribution de la thèse concerne la proposition d'une approche qui combine le B événementiel et le langage de modélisation TLA+ pour la vérification des propriétés de vivacité. Nous définissons une extension syntaxique et sémantique du B événementiel permettant d'exprimer des propriétés de vivacité. Nous développons un prototype pour la transformation d'un modèle B en un module TLA+ sur lequel nous effectuons la preuve des propriétés de vivacité avec le model checker TLC. Pour la vérification de ce type de propriétés sur des systèmes infinis, nous proposons l'utilisation des diagrammes de prédicats qui sont des abstractions des systèmes modélisés en TLA+. La deuxième contribution est la proposition d'une technique pour représenter explicitement le temps en B événementiel. Cette technique s'appuie sur la réalisation d'un entrelacement entre un processus qui gère le temps avec les autres processus du système. Le temps modélisé est discret et son écoulement est modélisé par des événements. Cette approche est assez différente des systèmes temporisés où l'on considère que le temps s'écoule indépendamment du système. Dans la troisième contribution, nous proposons une approche de développement des systèmes automatisés en utilisant la technique de composition où il s'agit de développer conjointement le contrôleur et le composant physique qu'il contrôle et appliquer le raffinement aussi bien sur le contrôleur que le contrôlé. Le raffinement est une technique de base des méthodes que nous proposons et si notre objectif est de construire des contrôleurs corrects, le critère de correction porte sur le comportement du système automatisé qui résulte de la composition du contrôleur et du contrôlé. Nous présentons également un théorème de compositionnalité qui indique sous quelles conditions il est possible de déduire que le composé des raffinements des contrôleur et contrôlé est un raffinement du composé des contrôleur et contrôlé abstraits. La dernière contribution porte sur la définition, la preuve et l'utilisation d'un patron de raffinement pour les processus continus dans des systèmes de production manufacturière. Ce type de patron prouvé permet d'utiliser l'abstraction discrète de l'effet d'un processus continu agissant pendant un certain temps / This thesis deals with the development of automated systems while following the formal methods B and TLA+. We propose a formal methodology based on the refinement paradigm to specify and verify the system that we model by two components: the controlled system representing the physical device and its environment, and the controller that controls the system. A synchronised product on the actions of these two components is applied to specify the automated system. As a first contribution, we propose an approach combining the event B method and the language TLA+ in order to verify liveness properties defined in user requirements. Inspired by the temporal logic of actions TLA, we first extend the event B notation to specify liveness properties and we give semantics of this extended syntax over traces. Second, we give transformation rules from a temporal B model into a TLA+ module. We present, in particular, our prototype system called B2TLA+, that we have developed to support this transformation. To consider infinite systems, we use predicate diagrams as abstractions of systems modelled with TLA+. To consider the real-time concept in automated systems, we propose as a second contribution a technique explicitly representing time in B event systems. This technique is based on an interleaving between any event handling time and the other system events. By considering the well known co-design technique, we propose as a third contribution a refinement-based composition technique keeping a separation between controller and controlled systems in order to build correct automated systems satisfying user requirements. We prove a compositionality theorem with respect to refinement to get an efficient approach to verify the refinement of a synchronized composition between components. We verify the refinement of a synchronized composition by verifying separately the refinement of each component. Finally, we define, prove and use in a case study as a fourth contribution the concept of a refinement pattern for continuous processes in manufacturing systems. Such proven pattern allows us to use the discrete abstraction of the effect of continuous processes operating for a while
8

The medical management of casualties in a chemical contaminated environment : a start for the CBRNE defence research program for clinicians

Bourassa, Stephane 07 1900 (has links)
The main objective of this research program was to assess the status of clinical knowledge and evidence-based practice in the medical management of mass casualties, contaminated by exposure to a chemical weapon, during a medical evacuation, which is defined as from the incident site of a contaminated environment up-to a clean zone. First, in our published systematic review, we assessed past medical responses during a chemical attack. The lack of clinical data and intervention-related information, such as protection and decontamination capabilities, stresses not only the need to study acute or prehospital settings, but also a set of integrated competences in the contaminated environment (i.e.: protection, decontamination and clinical interventions) (Prospero registered CRD42019104473). Second, a method paper which presents an ongoing international retro-prospective observational study on the medical responses during a chemical attack has been submitted for publication. The goal of this study is to describe the acute clinical management of patients in the contaminated zone (1970-2036; US Clinical trial registered NCT05026645). Data gathering is currently ongoing with the use of a comprehensive online registry programmed by the Quebec Respiratory Health Research Network. In the third and fourth, we started the development of two technological innovations to improve the medical management of mass casualties, caused by a chemical weapon, in contaminated environments. The first is the creation of a mobile laboratory for the continuity of our work in both indoor and outdoor settings. The other is the launch of a research program, named VIMY Multi-System, which includes: (1) An electronic casualty card system integrating the United Kingdom National Early Warning System; (2) a forward-deployable telemedicine capability prototype – currently undergoing integration testing – that incorporates drone technology to monitor patients being clinically managed in a simulated chemically contaminated environment. Our fifth published paper, on the methods of oxygen conservation with an automated titration system (n= 60; US Clinical trial registered NCT02782936 and NCT02809807), showed that such an automated system may constitute a viable medical solution for interventions in a contaminated environment and also constitutes one of the possible solutions to improve therapeutic interventions. The system studied allows the maintenance of adequate oxygenation while reducing the use of oxygen in patients, making it possible to extend their treatment duration even under conditions of limited logistical resources in oxygen. The oxygen flow provided by the automated system allows a mean reduction in administered oxygen quantities of more than six-fold when decreasing the prescribed SpO2 target from 98 to 90% (5 L/min to1 L/min, p <0.001) in hospitalized patients with respiratory disorders. The comparison was conducted on the basis of conservative flow rate targets reported in the literature (2.5, 5.0, 10.0 and 15.0 l/min). When it comes to the automated correction of a hypoxemic condition in sick patients and healthy subjects wearing a gas mask, the prescribed SpO2 target resulted in maximum administered oxygen flow rates of 0.2 L/min and 2.9 L/min respectively. These results show a possible logistic and therapeutic optimization in the use of oxygen. Finally, these initial advances will be integrated as our research work progresses in order to improve clinical evidence-based practices in contaminated environments due to the use of chemical weapons. / L’objectif principal de cette recherche était d’évaluer l’état des connaissances et le savoir-faire de la pratique clinique dans la gestion d’un grand nombre de blessés, contaminés des suites d’une exposition à l’arme chimique, pendant leur évacuation médicale depuis le site de l’incident dans un environnement contaminé jusqu’à la zone propre. Premièrement, dans une revue systématique que nous avons publiée, nous avons évalué les réponses médicales passées lors d’attaques chimiques. Le manque de données cliniques et d’autres informations liées à l’intervention, tel que les capacités de protection et de décontamination, souligne non seulement la nécessité d’étudier l’environnement préhospitalier, mais aussi la gamme de compétences interdépendantes en milieu contaminé (c.-à-d. : protection, décontamination et interventions cliniques) (Prospero CRD42019104473). Deuxièmement, nous avons soumis pour publication la méthodologie d’une étude rétroprospective observationnelle internationale s’intéressant aux réponses médicales lors d’une attaque chimique. Le but consiste à décrire la gestion clinique en soins aigus des blessés dans la zone contaminée (1970-2036) (ClinicalTrials.gov NCT05026645). L’acquisition de données est en cours à l’aide d’un registre de données intégral en ligne qui a été programmé par le Réseau de recherche en santé respiratoire du Québec. En troisième et quatrième lieu, nous avons entrepris le développement de deux innovations technologiques afin d’améliorer la prise en charge médicale des patients en milieu contaminé à la suite de l’utilisation de l’arme chimique. L’un est la création d’un laboratoire mobile pour poursuivre nos travaux tant à l’intérieur qu’à l’extérieur. L’autre est la mise sur pied d’un programme de recherche, nommé VIMY Multi-Systèmes, qui inclut : (1) un système de carte de blessés électronique intégrant le système national d’alerte précoce du Royaume-Uni, (2) les premiers tests d’intégration d’un prototype d’une capacité de télémédecine de déploiement avancé, incluant la technologie du drone, pour une surveillance clinique globale des patients pris en charge en milieu contaminé chimique simulé. Notre cinquième publication, qui porte sur les méthodes de maintien de l’oxygénation par titrage automatisée (n=60 ; ClinicalTrials.gov NCT02782936 et NCT02809807), nous a permis de démontrer qu’un système automatisé peut constituer une solution médicale intéressante qui serait applicable dans les interventions en milieu contaminé et de surcroît comme une solution pour améliorer les actions thérapeutiques. Le système que nous avons étudié permet de maintenir une oxygénation adéquate tout en limitant la consommation d’oxygène des patients, prolongeant ainsi leur durée de traitement, notamment en cas de ressources en oxygène limitées. D’une part, le débit de l’oxygène fourni par le système automatisé a permis une réduction moyenne des quantités administrées de l’ordre de plus de six fois lors de la diminution de la cible de saturation en oxygène (SpO2) prescrite de 98 à 90 % (5 L/min à 1 L/min, p < 0,001) chez les patients hospitalisés atteints de maladies respiratoires. La comparaison s’est faite par rapport à des débits conservateurs rapportés dans la littérature (2,5, 5,0, 10,0 et 15,0 L/min). D’autre part, la correction automatisée d’une condition hypoxémique chez les patients malades et les sujets sains portant le masque à gaz, la cible SpO2 a engendré des débits maximaux d’oxygènes administrés de 2,5 et 2,9 L/min respectivement. Ainsi, nous avons démontré une optimalisation logistique et thérapeutique de la consommation de l’oxygène. Finalement, ces premières avancées seront intégrées au fur et à mesure de l’avancement de nos recherches afin d’améliorer le processus de soins en milieu contaminé issu de l’utilisation de l’arme chimique.
9

Utilisation des données de MAREL Carnot pour la compréhension des mécanismes des extrêmes dans la qualité des eaux à Boulogne-sur-Mer / Use of MAREL Carnot automatic biogeochemical data for understanding the mechanisms of extremes in water quality in Boulogne-sur-Mer

Derot, Jonathan 12 December 2014 (has links)
L'objectif principal de cette thèse est la caractérisation des dynamiques hautes fréquance en milieu côtier et en particulier leurs extrêmes, par l'intermédiaire de l'étude de série temporelle biogéochimiques à long terme enregistrées par des systèmes automatisés. Les bases de données hautes fréquences utilisées dans cette étude proviennent majoritairement du programme MAREL, qui a été mise en oeuvre par l'IFREMER. Des séries temporelles basses fréquences provenant des programmes de surveillance du littoral SOMLIT (CNRS, INSU) et SRN (Ifremer) sont mises à contribution pour appuyer l'importance des systèmes automatisés. La méthode EMD (Empirical Mode Decomposition) nous a servi de base dans de nombreuses analyses pour étudier ces séries temporelles. Nous avons aussi utilisé des méthodes plus classiques empruntées aux domaines de l'analyse numérique et de la turbulence. Cette études se décompose en 3 parties, et plusieurs annexes. Les matériels et méthodes sont présentés dans la première partie. Dans la seconde partie, la méthode EMD nous a permis de mettre en avant les fortes fluctuations contenues dans les blooms, ainsi que de mener des analyses spectrales grâce à un couplage avec la transformée de Hilbert. L'analyse en composante principale (ACP) a mis en avant les principaux forçages exercés sur la production primaire et les profils de température SOMLIT laissent supposer un impact de la stratification sur l'intensité des blooms. Dans la troisième partie, nous avons mené une étude comparative entre les données basses fréquences et hautes fréquences. Et deux méthodes de cross-corrélation (TDIC et co-spectre) nous ont permis de définir une échelle caractéristique de transition entre les températures de la Manche occidentale et orientale. En annexe, nous avons testé la robustesse de différentes méthodes d'analyses spectrales quant au manque de données dans les séries temporelles, qui est un problème inhérent aux bases de données enregistrées par des systèmes automatisés, et nous avons reproduit un article qui est en cours de soumission. / The main objective of this thesis is the characterization of high frequency dynamics in coastal areas and in particular their extremes, through the study of long-term biodeochemical time series registered by automated systems. The majority of high-frequency data sets used in this study came from MAREL program. The low-frequency time series from coastal monitoring programs SOMLIT (CNRS, INSU) and SRN (Ifremer) are employed to support the importance of automated systems. The EMD (Empirical Mode decomposition) method has provided a basis for us to study several of these time series. We also have used some methods more classical borrowed from numerical analysis field and turbulence. This study is organized in three chapters, and several appendices. The first chapter is devoted to the material and method. In the second chapter, using the EMD method we have highlighted the strong fluctuations contained in the blooms, and we have performed spectral analyzes. The principal component analysis (PCA) highlighted the main forcing exerted on primary production and SOMLIT temperature profiles suggest an impact of stratification on the intensity of blooms. In the third chapter, we conducted a comparative study between low-frequency and high-frequency data. Two cross-correlation methods (TDIC and co-spectra) allowed us to define a characteristic transition scale between the temperatures of the western and eastern English Cahnnel. In appendices we tested the robustness of different spectral analysis methods about the missing data in the time series, which is an underlying problem in the database registered by automated systems, and we reproduce a paper, which is under submission.
10

In Media Res

Sisk, Christopher Andrew 01 January 2018 (has links)
We are inundated by a constant feed of media that responds and adapts in real time to the impulses of our psyches and the dimensions of our devices. Beneath the surface, this stream of information is directed by hidden, automated controls and steered by political agendas. The transmission of information has evolved into a spiral of entropy, and the boundaries between author, content, platform, and receiver have blurred. This reductive space of responsive media is a catalyst for immense political and cultural change, causing us to question our notions of authority, truth, and reality.

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