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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.
51

Um sistema para a infer?ncia de vari?veis usando redes neurais artificiais

Brito, Paulo Eduardo Camboim de 01 April 2013 (has links)
Made available in DSpace on 2014-12-17T14:08:55Z (GMT). No. of bitstreams: 1 PauloECB_DISSERT.pdf: 998748 bytes, checksum: ca9ede6adc0bf3c38d53d423e9580270 (MD5) Previous issue date: 2013-04-01 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / This work aims to obtain a low-cost virtual sensor to estimate the quality of LPG. For the acquisition of data from a distillation tower, software HYSYS ? was used to simulate chemical processes. These data will be used for training and validation of an Artificial Neural Network (ANN). This network will aim to estimate from available simulated variables such as temperature, pressure and discharge flow of a distillation tower, the mole fraction of pentane present in LPG. Thus, allowing a better control of product quality / Este trabalho tem como objetivo a obten??o de um sensor virtual de baixo custo para estimar a qualidade do GLP. Para a simula??o dos dados gerados por uma torre de destila??o foi utilizado um software que simula processos qu?micos, chamado HYSYS?. Esses dados ser?o utilizados para treinamento e valida??o de uma Rede Neural Artificial (RNA). Essa rede ter? como objetivo estimar a partir de vari?veis dispon?veis em uma simula??o, como a temperatura, press?o e vaz?o de refluxo de uma torre de destila??o, a fra??o molar de pentano presente no GLP. Possibilitando, desta forma, um melhor controle de qualidade do produto final
52

Entwurf und experimentelle Untersuchung eines faseroptischen Oberflächenplasmonenresonanz-Sensors

Schuster, Tobias 23 March 2017 (has links) (PDF)
In der medizinischen Diagnostik, Bioverfahrenstechnik und Umwelttechnik besteht ein steigender Bedarf an kompakten Analysegeräten für die schnelle Vor-Ort-Detektion spezifischer biochemischer Substanzen. Im Rahmen der Arbeit wurde daher ein neuartiger faseroptischer Sensor entwickelt, der in der Lage ist kleinste Brechzahländerungen, z.B. durch molekulare Bindungsprozesse, zu detektieren. Die hohe Empfindlichkeit an der vergoldeten Spitze der Sensorfaser beruht auf der Oberflächenplasmonenresonanz (SPR) einer einzelnen Mantelmode, die durch ein langperiodisches Fasergitter (LPG) ermöglicht wird. Die Übertragungsfunktion des Sensors wurde unter Verwendung eines Schichtwellenleitermodells schnell und präzise modelliert. Es konnte gezeigt werden, dass in einem wässrigen Umgebungsmedium die höchste Empfindlichkeit im Spektralbereich um 660 nm unter Annahme einer rund 35~nm dicken und 2~mm langen Goldbeschichtung erreicht wird. Weiterhin wurde nachgewiesen, dass mit einer intermediale Schicht aus Cadmiumsulfid die SPR der Mantelmode in einen höheren Spektralbereich verschoben und damit die Empfindlichkeit deutlich verbessert werden kann. Um eine geringe Polarisationsabhängigkeit des Sensors sicherzustellen, wurde ein nasschemisches Abscheidungsverfahren für die allseitige Goldbeschichtung der Sensorfaser entwickelt. Die spezifischen optischen Eigenschaften dieser Abscheidungen wurden mit Hilfe von LPGs untersucht, die durch eine spezielle UV-Belichtung hergestellt wurden. Die Experimente ergaben, dass die komplexe Permittivität nasschemischer Abscheidungen mit Schichtdicken oberhalb von 50~nm mit aufgedampften Goldschichten vergleichbar ist. Die Verluste der adressierten Mantelmoden wurden mit einer äquivalenten Sensoranordnung aus zwei identischen LPG untersucht. Dabei konnte ein Skalierfaktor abgeleitet werden, der die effiziente Berechnung der Mantelmodendämpfung erlaubt. Es wurde nachgewiesen, dass die Brechzahlauflösung etablierter volumenoptischer SPR-Sensoren mit einer einfachen Transmissionsmessung an einer geeigneten Wellenlänge erreicht werden kann. Die äußerst kompakte Sensorfläche des faseroptischen Sensors ermöglicht darüber hinaus die Untersuchung deutlich kleinerer Probenvolumina ohne ein zusätzliches mikrofluidisches System zu benötigen. Es wurde gezeigt, dass sekundäre Brechzahländerungen aufgrund von Temperaturschwankungen oder unspezifische Ablagerungen durch eine differentielle Auswertung zweier identischer Sensoren kompensiert werden können. Die verbleibende Querempfindlichkeit wird durch die Polarisationsabhängigkeit der Sensoren bestimmt. Die geringste Querempfindlichkeit konnte daher mit einer homogenen nasschemischen abgeschiedenen Sensorfläche nachgewiesen werden. / Compact analysis devices which facilitate the rapid detection of specific biochemical substances are in increasing demand in the fields of point-of-care medical diagnostics, bioprocess engineering and environmental engineering. The aim of this work was therefore to design a novel fiber-optic sensor able to detect small refractive index changes such as those caused by molecular binding processes. The high level of sensitivity at the gold-plated tip of the sensor fiber stems from the surface plasmon resonance (SPR) of a single cladding mode, which is the result of a long-period fiber grating (LPG). The transfer function of the sensor was calculated quickly and accurately using a slab waveguide model. It was observed that the highest level of sensitivity in an aqueous ambient medium is achieved at a wavelength of 660 nm assuming a gold coating of 35 nm in thickness and 2 mm in length. Furthermore, it was demonstrated that an intermedial cadmium sulfide layer shifts the SPR of the cladding mode towards higher wavelengths, thus leading to significantly enhanced sensitivity. An electroless plating process for the omnidirectional deposition of gold on the sensor fiber was developed in order to minimize the sensor\'s dependency on polarization. The specific optical properties of the gold layer deposited were investigated with the aid of LPGs fabricated using a special UV exposure method. The experiments showed the complex permittivity of electroless platings with a thickness of over 50 nm to be comparable with that of evaporated gold layers. The losses of the addressed cladding modes were investigated using an equivalent sensor setup consisting of two identical LPGs. This facilitated the determination of a scaling factor enabling the effcient calculation of cladding mode attenuation. It was demonstrated that it is possible to obtain the refractive index resolution of established volume optical SPR sensors with the aid of simple transmission measurements at a specific wavelength. Moreover, the extremely compact sensing area of the fiber-optic sensor enables the investigation of smaller sample volumes without the need for an additional microfluidic system. Secondary refractive index changes caused by temperature fluctuations or unspecific binding events can be compensated for by means of the differential interrogation of two identical fiber-optic sensors. The residual cross sensitivity is determined by the polarisation dependency of the sensor. The lowest cross sensitivity was therefore demonstrated in combination with a homogeneous electroless plated sensor surface.
53

Alternativní pohon automobilů / Alternative Drive of Automobile

Novosád, Jan January 2009 (has links)
In this work is processed a survey of perspective alternative drives in motor vehicles. There are main characteristic for each mentioned drive, their advantages and disadvantages and problems associated with their use in vehicles. The work is aimed at gas engines, electro mobiles, hybrid drives and hydrogen, therefore the most likely drives the future.
54

Entwurf und experimentelle Untersuchung eines faseroptischen Oberflächenplasmonenresonanz-Sensors

Schuster, Tobias 13 April 2016 (has links)
In der medizinischen Diagnostik, Bioverfahrenstechnik und Umwelttechnik besteht ein steigender Bedarf an kompakten Analysegeräten für die schnelle Vor-Ort-Detektion spezifischer biochemischer Substanzen. Im Rahmen der Arbeit wurde daher ein neuartiger faseroptischer Sensor entwickelt, der in der Lage ist kleinste Brechzahländerungen, z.B. durch molekulare Bindungsprozesse, zu detektieren. Die hohe Empfindlichkeit an der vergoldeten Spitze der Sensorfaser beruht auf der Oberflächenplasmonenresonanz (SPR) einer einzelnen Mantelmode, die durch ein langperiodisches Fasergitter (LPG) ermöglicht wird. Die Übertragungsfunktion des Sensors wurde unter Verwendung eines Schichtwellenleitermodells schnell und präzise modelliert. Es konnte gezeigt werden, dass in einem wässrigen Umgebungsmedium die höchste Empfindlichkeit im Spektralbereich um 660 nm unter Annahme einer rund 35~nm dicken und 2~mm langen Goldbeschichtung erreicht wird. Weiterhin wurde nachgewiesen, dass mit einer intermediale Schicht aus Cadmiumsulfid die SPR der Mantelmode in einen höheren Spektralbereich verschoben und damit die Empfindlichkeit deutlich verbessert werden kann. Um eine geringe Polarisationsabhängigkeit des Sensors sicherzustellen, wurde ein nasschemisches Abscheidungsverfahren für die allseitige Goldbeschichtung der Sensorfaser entwickelt. Die spezifischen optischen Eigenschaften dieser Abscheidungen wurden mit Hilfe von LPGs untersucht, die durch eine spezielle UV-Belichtung hergestellt wurden. Die Experimente ergaben, dass die komplexe Permittivität nasschemischer Abscheidungen mit Schichtdicken oberhalb von 50~nm mit aufgedampften Goldschichten vergleichbar ist. Die Verluste der adressierten Mantelmoden wurden mit einer äquivalenten Sensoranordnung aus zwei identischen LPG untersucht. Dabei konnte ein Skalierfaktor abgeleitet werden, der die effiziente Berechnung der Mantelmodendämpfung erlaubt. Es wurde nachgewiesen, dass die Brechzahlauflösung etablierter volumenoptischer SPR-Sensoren mit einer einfachen Transmissionsmessung an einer geeigneten Wellenlänge erreicht werden kann. Die äußerst kompakte Sensorfläche des faseroptischen Sensors ermöglicht darüber hinaus die Untersuchung deutlich kleinerer Probenvolumina ohne ein zusätzliches mikrofluidisches System zu benötigen. Es wurde gezeigt, dass sekundäre Brechzahländerungen aufgrund von Temperaturschwankungen oder unspezifische Ablagerungen durch eine differentielle Auswertung zweier identischer Sensoren kompensiert werden können. Die verbleibende Querempfindlichkeit wird durch die Polarisationsabhängigkeit der Sensoren bestimmt. Die geringste Querempfindlichkeit konnte daher mit einer homogenen nasschemischen abgeschiedenen Sensorfläche nachgewiesen werden. / Compact analysis devices which facilitate the rapid detection of specific biochemical substances are in increasing demand in the fields of point-of-care medical diagnostics, bioprocess engineering and environmental engineering. The aim of this work was therefore to design a novel fiber-optic sensor able to detect small refractive index changes such as those caused by molecular binding processes. The high level of sensitivity at the gold-plated tip of the sensor fiber stems from the surface plasmon resonance (SPR) of a single cladding mode, which is the result of a long-period fiber grating (LPG). The transfer function of the sensor was calculated quickly and accurately using a slab waveguide model. It was observed that the highest level of sensitivity in an aqueous ambient medium is achieved at a wavelength of 660 nm assuming a gold coating of 35 nm in thickness and 2 mm in length. Furthermore, it was demonstrated that an intermedial cadmium sulfide layer shifts the SPR of the cladding mode towards higher wavelengths, thus leading to significantly enhanced sensitivity. An electroless plating process for the omnidirectional deposition of gold on the sensor fiber was developed in order to minimize the sensor\'s dependency on polarization. The specific optical properties of the gold layer deposited were investigated with the aid of LPGs fabricated using a special UV exposure method. The experiments showed the complex permittivity of electroless platings with a thickness of over 50 nm to be comparable with that of evaporated gold layers. The losses of the addressed cladding modes were investigated using an equivalent sensor setup consisting of two identical LPGs. This facilitated the determination of a scaling factor enabling the effcient calculation of cladding mode attenuation. It was demonstrated that it is possible to obtain the refractive index resolution of established volume optical SPR sensors with the aid of simple transmission measurements at a specific wavelength. Moreover, the extremely compact sensing area of the fiber-optic sensor enables the investigation of smaller sample volumes without the need for an additional microfluidic system. Secondary refractive index changes caused by temperature fluctuations or unspecific binding events can be compensated for by means of the differential interrogation of two identical fiber-optic sensors. The residual cross sensitivity is determined by the polarisation dependency of the sensor. The lowest cross sensitivity was therefore demonstrated in combination with a homogeneous electroless plated sensor surface.
55

ALTERNATIVE PROPULSION FOR AIRCRAFT OF GENERAL AVIATION CATEGORY / ALTERNATIVE PROPULSION FOR AIRCRAFT OF GENERAL AVIATION CATEGORY

Kaddour, Mirvat January 2016 (has links)
Letecká doprava jako všechny ostatní dopravy podílí na produkci emisí skleníkových plynů, což je hlavní důvod změn klimatu. Disertační práce je zaměřena na možnost využití alternativního zdroje energie (paliva, motor) v letectví, aby se snížily emise produkované letadel. Oblast,na která již pracuje je všeobecné letectví, zejména letadel kategorie LSA a VLA. Tři možnosti, alternativní zdroj energie, budou diskutovány. První používá LPG palivo, další je elektrické motory, a poslední přidání katalyzátoru a výfukového systému. U každého z nich bude uvedeno výhody a nevýhody, hlavní změnu pohon letadla nebo výfukového systému a různé výkonnosti letadla v důsledku těchto změn.
56

Sustainable Energy Carrier Investments : A case study on the drywall manufacturing industry

Hallberg, Kevin, Sandström, Kevin January 2022 (has links)
Background According to the United Nations, climate change is one of the most challenging and urgent problems. To reduce emissions, various regulations have been introduced. Emissions trading (EU-ETS) and carbon dioxide tax are two economic instruments aimed at reducing greenhouse gas emissions. The industrial sector in Sweden today accounts for 31% of carbon dioxide emissions, and a common fossil energy carrier used is liquified petroleum gas (LPG). When LPG is burned, carbon dioxide is produced, contributing to climate change. By replacing LPG with a sustainable energy carrier, industries can reduce costs associated with emissions and thus increase competitiveness while lowering environmental impact. Therefore, there is a need for a framework that deals with both the economic and environmental impact that arises if alternative sustainable energy carriers replace LPG. Objectives The study’s objective is to evaluate alternative energy carriers that can phase out the use of LPG. The contribution of this study is a framework that analyzes and visualizes the economic and sustainable benefits of changing energy carriers. Methods A techno-economic model was developed by evaluating economic and sustainable indicators. A case study was conducted on a company that uses LPG in its manufacturing process. Eight different scenarios were set up where various energy carriers are used. Data concerning the different scenarios were collected. The scenarios were compared and analyzed based on the model to see which alternative energy carriers generate economic and sustainable improvements. Results The results from the case study show that all scenarios had an increased environmental performance compared to LPG. Either by reduced CO2 emissions or by being carbon dioxide neutral. From an economic perspective, only one scenario is more favorable than LPG, Bio- LPG. Bio-LPG reduces the total cost by 28.5%. Conclusions The study presents a model that can evaluate alternative energy carriers from an economic and environmental perspective. In many cases, a trade-off was discovered either being sustainable at a high cost or paying fees for emissions at a lower price. Alternative energy carriers exist with less environmental impact. Still, the technology for many of them is not sufficiently developed for large-scale production and use, which means that the cost is too high. Depending on the company's business strategy, the model can visualize the effects of a possible change of energy carrier. / Bakgrund Klimatförändringarna är ett av de mest utmanande och brådskande problemen enligt Förenta nationerna, för att minska utsläppen har olika regleringar införts. Handel med utsläppsrättigheter (EU-ETS) och koldioxidskatt är två ekonomiska styrmedel med syfte att minska växthusgasutsläppen. Industrisektorn i Sverige står idag för 31% av koldioxidutsläppen och en vanlig fossil energibärare som används är gasol. När gasol förbrännas produceras koldioxid som bidrar till klimatförändringar. Genom att byta ut gasol mot en hållbar energibärare kan industrier minska kostnader som är förknippade med utsläpp och på sådant vis öka konkurrenskraft, samtidigt som man minskar miljöpåverkan. Det finns därav ett behov av ett ramverk som behandlar både den ekonomisk och miljömässig påverkan som uppkommer om gasol byts ut mot alternativa hållbara energibärare. Syfte Syftet med studien är att utvärdera alternativa energibärare som kan fasa ut användandet utav gasol. Bidraget från denna studie är ett ramverk som analyserar och visualiserar de ekonomiska och hållbara fördelarna med att byta energibärare. Metod En tekno-ekonomisk modell utvecklades genom att utvärdera ekonomiska och hållbara indikatorer. En fallstudie utfördes på ett företag som använder gasol i sin tillverkningsprocess. Åtta olika scenarier sattes upp där olika energibärare används. Data rörande de olika scenarierna samlades in. Scenarierna jämfördes och analyserades utifrån modellen för att se vilka alternativa energibärare som genererar ekonomiska och hållbara förbättringar. Resultat Resultaten från fallstudien visar att alla scenarier hade en ökad miljöprestanda jämfört med gasol. Antingen genom minskade CO2-utsläpp eller genom att vara koldioxidneutrala. Ur ett ekonomiskt perspektiv är endast ett scenario mer gynnsamt än gasol, biogasol. Biogasol minskar den totala kostnaden med 28.5 %. Slutsatser Studien presenterar en modell som kan användas för att utvärdera alternativa energibärare utifrån ett ekonomiskt och hållbart perspektiv. En avvägning upptäcktes i många fall, antingen vara hållbar till hög kostnad eller betala avgifter för utsläpp till en lägre kostnad. Alternativa energibärare existerar som har mindre miljöpåverkan, men teknologin för många utav dem är ej tillräckligt utvecklad för storskalig produktion och användning vilket medför att kostanden är för hög. Beroende på vilken affärsstrategi företag har kan modellen visualisera effekterna vid ett eventuellt byte av energibärare.
57

Development of an Optical Fiber Biosensor with Nanoscale Self-Assembled Affinity Layer

Zuo, Ziwei 29 January 2014 (has links)
Optical sensor systems that integrate Long-Period-Gratings (LPG) as the detection arm have been proven to be highly sensitive and reliable in many applications. With increasing public recognition of threats from bacteria-induced diseases and their potential outbreak among densely populated communities, an intrinsic, low-cost biosensor device that can perform quick and precise identification of the infection type is in high demand to respond to such challenging situations and control the damage those diseases could possibly cause. This dissertation describes the development of a biosensor platform that utilizes polymer thin films, known as ionic self-assembled multilayer (ISAM) films, to be the sensitivity- enhancing medium between an LPG fiber and specific, recognition layer. With the aid of cross- linking reactions, monoclonal antibodies (IgG) or DNA probes are immobilized onto the surface of the ISAM-coated fiber, which form the core component of the biosensor. By immersing such biosensor fiber into a sample suspension, the immobilized antibody molecules will bind the specific antigen and capture the target cells or cell fragments onto the surface of the fiber sensor, resulting in increasing the average thickness of the fiber cladding and changing the refractive index of the cladding. This change occurring at the surface of the fiber results in a decrease of optical power emerging from the LPG section of the fiber. By comparing the transmitted optical power before and after applying the sample suspension, we are able to determine whether or not certain bacterial species have attached to the surface of the fiber, and as a consequence, we are able to determine whether or not the solution contains the targeted bacteria. This platform has the potential for detection of a wide range of bacteria types. In our study, we have primarily investigated the sensitivity and specificity of the biosensor to methicillin- resistant Staphlococcus aureus (MRSA). The data we obtained have shown a sensitive threshold at as low as 102 cfu/ml with pure culture samples. A typical MRSA antibody-based biosensor assay with MRSA sample at this concentration has shown optical power reduction of 21.78%. In a detailed study involving twenty-six bacterial strains possessing the PBP2a protein that enables antibiotic resistance and sixteen strains that do not, the biosensor system was able to correctly identify every sample in pure culture samples at concentration of 104 cfu/ml. Further studies have also been conducted on infected mouse tissues and clinical swab samples from human ears, noses, and skin, and in each case, the system was in full agreement with the results of standard culture tests. However, the system is not yet able to correctly distinguish MRSA and non-MRSA infections in clinical swab samples taken from infected patient wounds. It is proposed that nonspecific binding due to insufficient blocking methods is the key issue. Other bacterial strains, such as Brucella and Francisella tularensis have also been studied using a similar biosensor platform with DNA probes and antibodies, respectively, and the outcomes are also promising. The Brucella DNA biosensor is able to reflect the existence of 3 Brucella strains at 100 cfu/ml with an average of 12.2% signal reduction, while negative control samples at 106cfu/ml generate an average signal reduction of -2.1%. Similarly, the F. tularensis antibodies biosensor has shown a 25.6% signal reduction to LVS strain samples at 100 cfu/ml, while for negative control samples at the same concentration, it only produces a signal reduction of 0.05%. In general, this biosensor platform has demonstrated the potential of detecting a wide range of bacteria in a rapid and relatively inexpensive manner. / Ph. D.
58

Die Herausbildung der Landwirtschaftlichen Produktionsgenossenschaften in der DDR, dargestellt an der Entwicklung des Kreises Haldensleben, Bezirk Magdeburg (1952 bis 1960)

Mahlich, Wolfgang 25 June 1999 (has links)
Die LPG-Bildung als wichtigstes Element der "sozialistischen Umgestaltung" der Landwirtschaft der DDR ist Hauptinhalt der vorliegenden Dissertation. Auf beschreibendem und analytischen Wege wird die gravierende Umwälzung der gesamten ländlichen Struktur als integrierter Bestandteil der Schaffung der Grundlagen des Sozialismus in seiner Komplexität und Widersprüchlichkeit dargestellt. Den Ausgangspunkt der Schrift bildet die Bodenreform in der Sowjetischen Besatzungszone als Voraussetzung für die späteren Veränderungen auf dem Lande. Im Mittelpunkt der Arbeit steht der Prozeß der LPG-Bildung in den Dörfern des Kreises Haldensleben. Besondere inhaltliche Schwerpunkte der Hauptarbeit bilden: - die wirtschaftlich organisatorische Festigung der LPG in den einzelnen Etappen der Genossenschaftsbildung; - die Rolle und Leistung des MAS/MTS während der "sozialistischen Umgestaltung der Landwirtschaft" - die Maßnahmen der Politik des "Neuen Kurses" und ihre Realisierung in der Landwirtschaft ; - der Wandel in der Einstellung der Parteiführung zu den Großbauern und ihre allmähliche Einbeziehung in den "Aufbau des Sozialismus" auf dem Lande; - die Leitung und Lenkung des Umgestaltungsprozesses durch die SED-Kreisleitung (SED-KL) Haldensleben und die staatlichen Organe des Kreises; - die kulturelle und bildungspolitische Entwicklung im ländlichen Raum des Kreises Haldensleben zwischen 1952 und 1960 / The of LPGs as the most important element for the "socialistic" reconstruction of the agriculture of the GDR (German Democratic Republic) is the main topic this dissertation deals with. In a descriptive and analytical way all major revolutions within the whole agricultural structure als an integrated part to build up a basis for socialism in all it's complexity and with all it's contradictions are described. As basis for this paper serves the land reform in the sowjet sector of Germany as preassumption for later changes in the rural areas. The focus of this work is on the process in which the LPGs around Haldensleben were set up. The main content deals with the following questions: - the economic and organizational strengthening of the LPGs within the several steps of the co-operatives; - the role and power of the MAS/MTS during the "socialist revolution" of the agriculture - the steps of the politics of the "Neuen Kurs" and the realization for the agriculture; - the change in the attitude of the party heads towards the owners of large farms and their integration into the process of builing up socialism in rural areas; - the management of the revolutonary process by the SED-Kreisleitung (regional leading group) Haldensleben and the gouvernmental institutions of the area; - the cultural and educational policy in the rural area of Haldensleben between 1952 and 1960
59

Développement d’une approche d’aide à la maitrise des risques dans les activités de maintenance d'une chaine logistique : Approche par modélisation et simulation basée sur les systèmes multi-agents / Development of an approach to risk management in supply chain maintenance activities : Modelling and Simulation approach based on multi-agent systems.

Gallab, Maryam 05 June 2017 (has links)
Cette thèse a pour objectif principal de développer un simulateur multi-agents pour concevoir un système d'aide à la maitrise des risques des activités de maintenance. Le but est d'explorer la complexité de la maintenance et de spécifier les interactions entre la fonction maintenance, l'analyse et l'évaluation des risques. Nous nous intéressons d’une part, à concevoir un modèle systémique permettant d’identifier et de modéliser un système industriel, à montrer les différentes interactions entre ses éléments, à analyser et évaluer les risques des activités de maintenance. Nous proposons la méthode MOSAR et le langage UML pour concevoir un modèle cognitif de référence. Ce modèle a servi de point de départ pour la conception d’une base de données à l’aide du langage SQL, qui est exploitée par le modèle Multi-Agents afin d’acquérir les informations nécessaires à son fonctionnement.D’autre part, nous développons une architecture d’un Système Multi-Agents qui a pour vocation d’anticiper les situations de défaillances et la prise de décisions à l’aide de la simulation du comportement du système étudié. Une comparaison entre les plateformes existantes dédiées aux Systèmes Multi-Agents est effectuée pour choisir la plateforme adéquate à notre problématique pour la réalisation de la simulation.Finalement, les modèles développés sont appliqués dans le cadre d’une chaîne logistique pour le chargement et le déchargement de GPL (Gaz de Pétrole Liquéfié). Un simulateur a été développé à l’aide de la plateforme AnyLogic dans le but d’étudier le comportement du système et de simuler les scénarios de défaillances choisis par l’industriel pour le calcul de la criticité à partir de trois paramètres (fréquence, gravité, détectabilité) et l’obtention d’un Tableau de Bord contenant un ensemble d’indicateurs de performance de la maintenance. Les modèles de simulation proposés permettent d’orienter les industries vers les bonnes décisions pour éviter les situations à risques pouvant déclencher des événements perturbateurs dommageables. / The main objective of this thesis is to develop a multi-agent approach to designing a model to overcome risks of maintenance activities. The aim is to explore the maintenance complexity and to indicate the interactions between the maintenance function and the risk assessment.Firstly, we are interested in designing a systemic model to identify and model the industrial system, to show the different interactions between its elements, to analyze and to evaluate risks of maintenance activities. We propose the MOSAR method and the UML language to design a cognitive reference model. This model served as a starting point for designing a database using the SQL language, which is operated by Multi-Agent model to acquire the necessary information for its operation.On the other hand, we develop a framework of a multi-agent system that aims to anticipate failures scenarios and the decision-making by simulating the studied system behaviour. A comparison between the existing platforms dedicated to Multi-Agent Systems is performed to choose the appropriate platform for the simulation.Finally, the developed models are applied in the LPG supply chain (Liquefied Petroleum Gas). A simulator was developed using the AnyLogic platform in order to study the system behaviour and to simulate the failure scenarios chosen by the industry, for the calculation of the criticality from three parameters (Frequency, severity, detectability), and for obtaining a Dashboard containing a set of maintenance performance indicators. The proposed simulation models help to guide the industries toward good decisions to avoid risky situations that may trigger disruptive events damaging.
60

A influência da implantação de um terminal aquaviário na dinâmica sedimentar local da Baía de Guanabara / The influence of the implantation of an aquaviary terminal in local dynamics sedimentary f the Guanabara Bay, RJ

Hurtado, Shanty Navarro 06 November 2008 (has links)
A Baía da Guanabara vem sofrendo alterações na sua bacia de drenagem desde o início do século XIX que resultaram em acentuada degradação ambiental. O presente trabalho discute a influência da implantação de um Terminal Aquaviário de Gás Natural Liquefeito (GNL) na Baía, e suas possíveis influências nos processos de sedimentação local e/ou re-disponibilização de sedimentos de fundo, e possíveis contaminantes associados. Os resultados dos modelos matemáticos mostram que as maiores velocidades das plumas termicas que atingem o fundo são em média 0,46 m3/s para as simulações de verão e 0,47 m3/s para as simulações de inverno, sendo que são necessários pelo menos de 0,50 m3/s para uma corrente erodir o fundo, porem velocidades na faixa de 20 a 50 m3/s são suficientes para causar erosão de sedimentos finos inconsolidados. Sendo assim, a influência das plumas térmicas geradas no processo de re-gaseificação do GNL é de pequena magnitude, e suas correntes só conseguem exportar estes sedimentos para distancias inferiores a 1000 m. Em relação a re-disponibilização de contaminantes associados aos sedimentos de fundo se mostrou pouco provável, dado o fato da qualidade dos sedimentos apresentarem, diferente da água, baixa concentração de contaminantes e da baixa competência de erosão, que eles tenham competência para erodir sedimentos consolidados. / Since the beginning of the XIX century, interventions on the Guanabara\'s Bay drainage basin result in severe environmental degradation. This work aimed to analyze the implementation of an Aquaviary Terminal of Liquefied Natural Gas (LNG), and its putative consequences on the local sedimentation processes, and the availability and possible associated contaminants of the bottom sediments. According to the mathematical models developed, the means of the greatest speeds of the thermal plumes that reach the bottom are 0.46m3/s for the summer simulations and 0.47m3/s for the winter. However, for a current to be able to erode the bottom it must be of at least 50m3/s. Currents with speeds ranging from 20 to 50m3/s are sufficient only to cause the erosion of fine and non-consolidated sediment. Therefore, the thermal plumes generated in the process of re-gasification of the LNG are of little magnitude, and will not be able to export these sediments to any distance greater than 1000 meters. The re-availability of the contaminants associated with the bottom sediments is not likely, once these sediments, differently from the water, showed little concentration of contaminants. In addition, with the low erosion capacity of the currents generated, the consolidated sediments are not likely to be eroded.

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