Dissertations / Theses on the topic 'Mesh of Things'

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1

Alm, Anton. "Internet of Things mesh network : Using the Thread networking protocol." Thesis, Karlstads universitet, Institutionen för matematik och datavetenskap (from 2013), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-70809.

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This thesis summarizes my project in setting up a Thread network. The idea of this project was presented by the company ÅF in Karlstad, Sweden. ÅF wishes to upgrade their current demonstrator for IoT. The current demonstrator includes Azure Cloud component, Raspberry Pi, Bluetooth and Arduino components. The upgrade includes implementing Thread technology together with Thread verified hardware from Nordic semiconductor and the Raspberry Pi Foundation. Thread is an IoT mesh networking protocol that was released year 2014. Compared to Bluetooth it offers IP communication (including IPv6) combined with higher reliability, performance and security. The process of installing, compiling and configuring the Thread network is explained. The result is an operational thread network that has sensor devices sending data to an HTTP web server, where the data is stored and monitored. Though, there are many improvements and functions that can be implemented to make this demonstrator more appealing.
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2

Quan, Yongyun. "Topology-based Device Self-identification in Wireless Mesh Networks." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-261147.

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In the context of the Internet of Things (IoT), commissioning is the process of securely adding a new device to a network. It covers many different tasks, including the physical deployment of devices and configuration of parameters. It is network installers who need to manually commission each device one by one with the help of commissioning tools. In practice, the first task for a network installer is to identify each device correctly before configuring it with proper parameters. Individually identifying each device, especially in a large network, is a very time-consuming process. This is also known as the identification problem. This project is going to address the problem.A novel device identification approach is presented in the thesis, and there is no human intervention involved in the identification process. Devices are trying to identify themselves based on predefined rules and given information. The approach is therefore called device self-identification, and it is implemented in two different algorithms. One is the centralized device selfidentification, and the other is the distributed device self-identification. In short, only one device participates in the device identification process in the centralized approach, and in the distributed counterpart, every device is part of the identification process.The results of the implementations show the potential of the new way to identify devices in IoT. Devices in both the centralized approach and the distributed approach are able to identify themselves given necessary information about the network. A detailed discussion regarding the two proposed algorithms and the network information is presented in the thesis.
I samband med Internet of Things (IoT) är igångkörning processen att säkert lägga till en ny enhet i ett nätverk. Den täcker många olika uppgifter, inklusive fysisk distribution av enheter och konfigurering av parametrar. Det är nätverksinstallatörer som måste manuellt beställa varje enhet en efter en med hjälp av installationsverktyg. I praktiken är den första uppgiften för en nätverksinstallatör att korrekt identifiera varje enhet innan den konfigureras med lämpliga parametrar. Att identifiera varje enhet speciellt i ett stort nätverk är en mycket tidskrävande process. Detta är också känt som identifieringsproblemet. Detta projekt kommer att ta itu med problemet.En nyhetsidentifieringsmetod presenteras i avhandlingen och det finns ingen mänsklig intervention involverad i identifieringsprocessen. Enheter försöker identifiera sig baserat på fördefinierade regler och information. Tillvägagångssättet kallas därför enhetens självidentifiering och det implementeras i två olika algoritmer, en är centraliserad enhetens självidentifiering och den andra är distribuerad enhetens självidentifiering. Kort sagt, endast en enhet deltar i enhetsidentifieringsprocessen i centraliserat tillvägagångssätt, och i distribuerad motsvarighet är varje enhet en del av identifieringsprocessen.Resultaten av implementationerna visar potentialen för det nya sättet att identifiera enheter i IoT. Enheter i både centraliserat tillvägagångssätt och distribuerat tillvägagångssätt kan identifiera sig med den information som krävs för nätverket. En detaljerad diskussion om de två föreslagna algoritmerna och nätverksinformationen presenteras i avhandlingen.
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3

Danielsson, Thomas. "DMX-communication over Bluetooth low energy mesh network." Thesis, Uppsala universitet, Signaler och System, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-388635.

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With the addition of mesh capability to Bluetooth low energy(BLE) in 2017 new possibilities open up for the Internet of Things applications of Bluetooth. With the rapidly increasing number of connected devices a few new standards are competing for being the standard protocol for low power mesh communication. BLE is mostly aimed towards low bandwidth data such as sensor readings or light control. However, this thesis attempts to investigate the viability of adapting BLE mesh nodes to communicate DMX-data which is a protocol widely used in lightning and stage effects. The system is implemented on Bluetooth development kits and the latency and power consumption are measured. The results show that the latency is significant and with high variance if the full DMX frame is transmitted, rendering the application non-applicable on many real-time applications. It can however be justified in some applications due to Bluetooth's well established eco-system of devices and functionality where the nodes could extend their capabilities by implementing already established BLE models. By only transmitting the updated channels the latency can be lowered to values that would in some applications be indistinguishable from wired connection. The energy consumption of BLE mesh suffers greatly with the addition of mesh due to its constant scanning but by implementing low power nodes which keep the radio off during certain intervals this consumption could be greatly decreased. The results also show a high variance of latency depending on the node configuration regarding to the placements and the number of hops required to reach the intended recipient.
Bluetooth har länge varit standardprotokollet för kommunikation mellan två stycken enheter. 2017 kom tillägget med mesh till Bluetooth. Mesh innebär att andra enheten i närheten ska skicka vidare meddelanden och därigenom tillåta kommunikation mellan enheter som är utanför direkt radiokontakt. DMX är ett protokoll som används inom ljus- och sceneffekter. Bluetooth mesh är utformat för att skicka små datamängder som till exempel sensordata eller styra glödlampor. Denna uppsats kommer utvärdera om det är användbart att skicka DMX-data över Bluetooth mesh. En implementation gjordes på Bluetooth utvecklingskort och resultatet visar på en signifikant fördröjning och med hög varians vid överföring av alla DMX-kanaler, vilket innebär att denna implementation inte är användbar vid många användningsområden. Men trots det kan den vid vissa fall vara användningsbar, mycket till hjälp av Bluetooths billiga och utbyggda ekosystem av produkter och tilläggsfunktioner. Eftersom Bluetooth mesh byggs in i en del befintliga byggnader kan de uppoffringar man får göra vid överföringar av DMX-data vara acceptabel då man kan uttnyttja befintliga nät. Strömförbrukningen ökar avsevärt vid mesh jämfört med klassisk lågenergi Bluetooth då mesh måste skanna radiotrafiken konstant. Vid implementationen av lågenergi noder kan dock radio vara i stand-by och starta endast vid speciella tidpunkter och man kan därigenom få avsevärt lägre strömförbrukning, med uppoffringen att DMX-datan inte kan överföras omgående. Det visade sig också att noduppställningen kraftigt påverkade variansen i överföringshastighet och att detta måste ta i hänsyn vid valet om DMX över Bluetooth mesh är användbart i just det fallet.
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Santos, Ana Patrícia Gonçalves dos. "Street lighting mesh network protocol." Master's thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/15970.

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Mestrado em Engenharia Eletrónica e Telecomunicações
The digital revolution of the 21st century contributed to stem the Internet of Things (IoT). Trillions of embedded devices using the Internet Protocol (IP), also called smart objects, will be an integral part of the Internet. In order to support such an extremely large address space, a new Internet Protocol, called Internet Protocol Version 6 (IPv6) is being adopted. The IPv6 over Low Power Wireless Personal Area Networks (6LoWPAN) has accelerated the integration of WSNs into the Internet. At the same time, the Constrained Application Protocol (CoAP) has made it possible to provide resource constrained devices with RESTful Web services functionalities. This work builds upon previous experience in street lighting networks, for which a proprietary protocol, devised by the Lighting Living Lab, was implemented and used for several years. The proprietary protocol runs on a broad range of lighting control boards. In order to support heterogeneous applications with more demanding communication requirements and to improve the application development process, it was decided to port the Contiki OS to the four channel LED driver (4LD) board from Globaltronic. This thesis describes the work done to adapt the Contiki OS to support the Microchip TM PIC24FJ128GA308 microprocessor and presents an IP based solution to integrate sensors and actuators in smart lighting applications. Besides detailing the system’s architecture and implementation, this thesis presents multiple results showing that the performance of CoAP based resource retrievals in constrained nodes is adequate for supporting networking services in street lighting networks.
A revolução digital do século 21 contribuiu para o surgimento da Internet das Coisas (IoT). Em breve triliões de dispositivos embutidos usando o Internet Protocol (IP) serão parte integrante da Internet. De modo a suportar tal gama de endereços, um novo protocolo de Internet, chamado Internet Protocol versão 6 (IPv6) está a ser adoptado. O IPv6 over Low power Wireless Personal Area Networks (6LoWPAN) acelerou a integração das redes sem-fios de sensores na Internet. Ao mesmo tempo, o Constrained Application Protocol (CoAP) tornou possível fornecer funcionalidades de serviços Web RESTful a dispositivos com recursos limitados. Este trabalho baseia-se em experiências anteriores em redes de iluminação pública, para os quais um protocolo proprietário, elaborado pelo Lighting Living Lab, foi implementado e usado durante vários anos. O protocolo proprietário tem sido utilizado numa ampla gama de placas de controlo de iluminação. De modo a suportar aplicações heterogéneas com requisitos de comunicação mais exigentes além de melhorar o processo de desenvolvimento de aplicações, adaptou-se o Contiki OS à placa LED driver de 4 canais (4LD) da Globaltronic. Esta dissertação descreve o trabalho conduzido para adaptar o Contiki OS ao microprocessador Microchip TM PIC24FJ128GA308 e apresenta uma solução baseada em IP para integrar sensores e atuadores em aplicações de iluminação inteligentes. Além da descrição da arquitetura e da implementação do sistema, este trabalho apresenta vários resultados que mostram que o desempenho do protocolo CoAP na placa 4LD é adequado para suportar serviços Web em redes de iluminação pública.
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5

Polya, Alexander, and Anders Lindén. "Förening av trådlösa mesh-nätverk och PLC-miljö för industriella behov." Thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH, Data- och elektroteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-28262.

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In conjunction with the possibility of inexpensive wireless communication, many products of tomorrow are developed with the support for wireless communication. The technology enables the possibilty of wireless communication to small plattforms at a realistic price. The cheap connectivity allows for great creativity and gives the developers imagination a wide discretion in the development of new products. This thesis aims to evaluate how the serial communication protocol Modbus RTU - RS232, performs and behaves when transported through meshed networks (Atmel lightweight mesh will be used in this thesis). The work was commissioned by M2M Solutions in J¨onk¨oping. The report will answer the following questions1. How does Modbus RTU behaves when transported through a meshed network. 2. How does Modbus RTU preform when transported through Atmel Lightweight Mesh.The authors have chosen to conduct action research to answer established questions. A test system consisting of both hardware and software was designed and created. With this system, several different tests were conducted and the results were observed and subjected to reflection. The different tests varied the distance, the network’s composition and location of the network infrastructure. Through observation of the test system and evaluation of the recorded data conclusions concering Modbus RTU’s performance and behavior during transport in Atmel lightweigh mesh has been drawn. The test system has been designed with the help of clients and previously made research. Modbus behaves nominally during transportation through Atmel lightweight mesh. Before the network is fully established, an inability to transport data has beend observed. The performance is evaluated by the time it takes to send data, the time is greatly affected by the following factors; Network composition and changes in signal strength (that creates changes in transport routes). For each additional node that traffic is transported through an increase of 5-10ms in the responstime was noted. The network’s ability to change the transport route is also expected to increase performance. The wireless communication provides a longer range than during transportation by standard conventional cable.Considering the results, the authors believe that Modbus RTU has the potential for use in transportation through wireless, meshed networks. One possible scenario is when several Modbus RTU masters are beeing used and data needs to be transported over large distances.
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6

Abade, Pedro António Carvalho. "VR-Banway: deploying a body area network gateway on single-board computers and mesh networks." Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/23569.

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Mestrado em Engenharia de Computadores e Telemática
Internet of Things (IoT) is a generic category of ICT architectures that includes the use of sensor-based, communication-enabled systems. A common architectural element in IoT is the sensors gateway that collects data from nearby sensors and relays them to higher-order remote services. The VR2Market project, in which this work is integrated, uses two implementations of the gateway, based on Android smartphones and RPI boards. With the new proposed IoT-inspired computing module, it is possible to migrate gateways to a smaller, more efficient hardware, while retaining the high-level programming abstraction. In this work, we propose and implement a new version of the gateway, named VR-Banway, using the Intel Edison compute module, taking into consideration the integration with additional service layers in VR2Market system, especially with respect to the required Ad hoc networks support. VR-Banway proved to be a solution capable of replacing the existing gateway component in the VR2Market system. The new approach uses a smaller module, reduces power consumption and is more portable. VR-Banway has been used in the context of firefighters monitoring, but is ready to be deployed in other domains.
A Internet of Things (IoT) é uma categoria genérica das arquiteturas de TIC que inclui o uso de sistemas baseados em sensores e comunicações. Um elemento comum das arquiteturas IoT é o agregador que recolhe dados de sensores nas proximidades e reencaminha-os para serviços remotos de mais alto nível. O projeto VR2Market, no qual este trabalho está integrado, usa duas implementações do agregador de dados, implementados em Android e RPI. Com o novo módulo proposto, inspirado na IoT, é possível migrar os agregadores de dados para dispositivos mais pequenos e mais eficientes mantendo a abstração de programação de alto nível. Neste trabalho, propomos e implementamos uma nova versão do agregador de dados, chamado VR-Banway, usando o módulo computacional Intel Edison, tendo em consideração a integração de novas camadas de serviços no VR2Market, especialmente no que diz respeito ao suporte de redes Ad hoc. VR-Banway provou ser uma solução capaz de substituir o componente de agregador de dados existente no sistema VR2Market. A nova abordagem usa um módulo mais pequeno, reduz o consumo de energia e é mais portátil. VR-Banway foi usado no contexto de monitorização de bombeiros, mas está preparado para ser implementado noutros domínios.
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Rowland, James Robert. "Reducing Residential Space Conditioning Costs with Novel HVAC System Design and Advanced Controls." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1420018735.

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8

Baccelli, Emmanuel. "IP-Disruptive Wireless Networking: Integration in the Internet." Habilitation à diriger des recherches, Université Pierre et Marie Curie - Paris VI, 2012. http://tel.archives-ouvertes.fr/tel-00770791.

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The super collision between the Internet phenomenon and the wireless communication revolution gives birth to a wealth of novel research problems, design challenges and standardization activities. Within this domain, spontaneous wireless IP networking are probably the most extreme example of new ''particles'' born from the collision. Indeed, these particles defy the laws of the Internet in many ways. The absorption of such peculiar particles in the global IP network has already started thanks to pioneering algorithmic and protocol work -- for instance OLSR -- and through the deployment of wireless mesh networks around the world, such as urban community wireless networks. With the recent revolutions in North Africa, and movements such as Occupy Wall Street, the prospect of spontaneous wireless IP networking has become even more attractive on social and political grounds. Dedicated conferences have recently been organized, and as a result, ambitious, multi-million dollar initiatives have been launched (e.g. the US Government-funded project Commotion Wireless, or the EU-funded initiative CONFINE). However, spontaneous IP wireless networks are not yet widely deployed because pioneer work such as OLSR is vastly insufficient to fully bridge the gap between the Internet and these new networks. This thesis presents work that analyzes this gap and proposes some solutions as to how to bridge it. The focus is put on three domains: a first part presents work in the domain of wireless mesh and ad hoc networks. A second part presents work on sensor networks and in the Internet of Things. And the last part presents work in the domain of delay tolerant networking and vehicular networks.
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Sieklik, Ivan. "Thread Smart Home Model." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-316420.

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This thesis is focused on smart buildings where communication and automatization technologies are deployed. It includes overview and description of frequently applied network protocols in smart homes and their side by side comparison with an emphasis on Thread networking protocol. The next chapters describe details and parameters of used development boards provided by NXP Semiconductors and their implementation in a smart home model. Subsequent chapters are focused on hardware and software components which are the basis for smart home model’s internal workings. The last chapter highlights how a physical model of a smart home was developed with suggestions for future improvements.
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PALMA, LORENZO. "Studio ed implementazione di architetture per l'IoT basate su rete mesh IPv6." Doctoral thesis, Università Politecnica delle Marche, 2017. http://hdl.handle.net/11566/245243.

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Questa tesi affronta lo studio e l’implementazione di architetture protocollari alla base dell’imponente sviluppo dell’Internet of Things. Si sono studiati ed implementati standard a tutti i livelli della pila protocollare, partendo dall’802.15.4 del basso livello, l’RDC per la gestione del risparmio energetico della radio, il 6LowPAN, il μIPv6 con protocollo di routing RPL ed UDP per il trasporto dei dati raccolti tramite applicativi http o CoAP. Si propone inoltre un protocollo per la gestione dell’aggiornamento del firmware over the air (FOTA) che consente di dare ulteriore flessibilità nello sviluppo e nella gestione delle potenziali installazioni. Sfruttando l’architettura sviluppata, si sono implementati innovativi sistemi di localizzazione indoor a basso costo, applicazioni per le Smart Cities, altre per l’agricoltura di precisione ed infine si è creato un ambiente di test Smart da esportare ed utilizzare per sistemi di Ambient Assisted Living integrati con strumenti per l’automazione domestica. Le performance dell’architettura sviluppata soddisfano a pieno i requisiti di scalabilità, interoperabilità, autoinstallazione ed automantenimento che una WSN per l’IoT deve garantire, inoltre i consumi dei dispositivi risultano anch’essi conformi alle aspettative di vita dell’ordine dei diversi mesi o anni che i sensori devono avere.
This thesis deals with the study and implementation of protocol architectures at the base of the impressive development of the Internet of Things. The implemented protocols are standard on all levels of the protocol stack, starting from 802.15.4 the low level, the DRC for the power management of the radio, the 6LoWPAN, the μIPv6 with RPL routing protocol and UDP are designed and implemented for transporting data collected through http or COAP application. It is also proposed a protocol for the management of the firmware update over the air (FOTA) that allows to give further flexibility in the development and management of potential installations. Taking advantage of the architecture developed, I have implemented an innovative and low cost indoor location systems , applications for Smart Cities, a prototype for precision agricolture and finally a Smart environment test is created to test and prove the interoperation between Ambient Assisted Living systems with integrated tools for home automation. The performance of the developed architecture fully meet the scalability requirements, interoperability, auto-installation and selfmaintenance that a WSN for the IoT must have. It also ensures a low power consumption of the devices that comply with the expected lifetime of several months or years that the sensors must have.
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Yoshida, H., Y. Ogawa, Y. Kawai, S. Hayashi, A. Hayashi, C. Otani, E. Kato, F. Miyamaru, and K. Kawase. "Terahertz sensing method for protein detection using a thin metallic mesh." American Institite of Physics, 2007. http://hdl.handle.net/2237/11978.

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Alharbi, Abdulghani Ragaa. "Numerical solution of thin-film flow equations using adaptive moving mesh methods." Thesis, Keele University, 2016. http://eprints.keele.ac.uk/2356/.

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Thin liquid films are found everywhere in nature. Their flows play a fundamental role in a wide range of applications and processes. They are central to a number of biological, industrial, chemical, geophysical and environmental applications. Thin films driven by external forces are susceptible to instabilities leading to the break-up of the film into fingering-type patterns. These fingering-type patterns are usually undesirable as they lead to imperfections and dry spots. This behaviour has motivated theoreticians to try to understand the behaviour of the flow and the mechanisms by which these instabilities occur. In the physically relevant case when surface tension is large, the film’s free surface exhibits internal layers where there is rapid spatial variation in the film’s curvature over very short lengthscales and away from these internal layers the film’s curvature is almost negligible. This provides the main motivation for this thesis which is to develop adaptive numerical solution techniques for thin film flow equations that fully resolve such internal layers in order to obtain accurate numerical solutions. We consider two thin film flow problems in one and two-dimensions to test the adaptive numerical solution techniques developed in this thesis. The first problem we consider is related to a liquid sheet or drop spreading down an inclined pre-wetted plane due to influence of gravity. The second problem we consider is also related to the spreading of a liquid sheet or drop down an inclined pre-wetted plane including surfactant-related effects in addition to gravity. We follow the r-adaptive moving mesh technique which uses moving mesh partial differential equations (MMPDEs) to adapt and move the mesh coupled to the underlying PDE(s). We show how this technique can accurately resolve the various one and two-dimensional structures observed in the above test problems as well as reduce the computational effort in comparison to numerical solutions using a uniform mesh.
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Kim, Byungmoon. "Simulation of fluids with reduced diffusion, thin liquid films, volume control, and a mesh filter in rational form." Diss., Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-11132006-003228/.

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Thesis (Ph. D.)--Computing, Georgia Institute of Technology, 2007.
Jarek Rossignac, Committee Chair ; Yingjie Liu, Committee Member ; Greg Turk, Committee Member ; Irfan Essa, Committee Member ; Xiangmin Jiao, Committee Member.
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Wang, Xu-sheng. "Microbridge tests on multi-layer thin films /." View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?MECH%202006%20WANGXS.

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Huang, Bin. "Mechanical characterization of thin films /." View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?MECH%202005%20HUANG.

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Ament, David Lloyd. "Boiling heat transfer in thin liquid films with a wire mesh screen on the liquid surface." Thesis, Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/19483.

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Heer, Joseph Michael. "FDTD Modeling of the Spectroscopy and Resonances of Thin Films and Particles on Plasmonic Nickel Mesh." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1293754711.

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Li, Zhiying. "Microbridge tests on galium[sic] nitride and parylene-c thin films /." View abstract or full-text, 2010. http://library.ust.hk/cgi/db/thesis.pl?MECH%202010%20LI.

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Liu, Lilin. "Materials science in pre-plated leadframes for electronic packages /." View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?MECH%202006%20LIUL.

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Law, Tak Wai. "Development of low temperature processable ceramic thin film embedded capacitors /." View Abstract or Full-Text, 2003. http://library.ust.hk/cgi/db/thesis.pl?MECH%202003%20LAW.

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Xu, Wei-Hua. "Mechanical properties of materials at micro/nano scales /." View abstract or full-text, 2003. http://library.ust.hk/cgi/db/thesis.pl?MECH%202003%20XU.

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Muñoz, Soto Jonathan Mauricio. "Km-scale Industrial Networking." Electronic Thesis or Diss., Sorbonne université, 2019. http://www.theses.fr/2019SORUS252.

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L'Internet des objets (IoT) a pour objectif de fournir une connectivité à des millions d'appareils utilisés au quotidien. Pour la majorité des applications, les connexions filaires sont peu pratiques et trop coûteuses. Par conséquent, les connexions sans fil sont le seul moyen réalisable de fournir une connectivité aux dispositifs. Une des nombreuses solutions sans fil est la norme IEEE802.15.4, conçue pour les réseaux maillés de faible consommation. Cette norme est largement utilisée pour les bâtiments intelligents, la domotique et les applications industrielles. Un amendement ultérieur, IEEE802.15.4g, définit 3 PHY (FSK, OFDM et O-QPSK). Cela cible les applications SUN (Smart Utility Networks), c’est-à-dire le comptage intelligent, tout en offrant une couverture étendue. Dans cette thèse, nous analysons l'utilisation de cette norme en dehors de l'environnement SUN et sur des applications industrielles. Premièrement, nous menons une série d’expériences avec IEEE802.15.4g-dispositifs afin de mesurer la portée des liens dans des scénarios extérieurs réels. Les résultats montrent que des communications très fiables avec des débits jusqu'à 800 kbps (avec OFDM) peuvent être atteintes en milieu urbain à 540 m entre les nœuds, et que la liaison radio la plus longue utile est obtenue à 779 m (FSK). Deuxièmement, nous comparons les performances de la norme IEEE802.15.4 à celle de la norme IEEE802.15.4g OFDM dans les bâtiments intelligents. A partir d'expériences, nous avons déterminé que l'OFDM IEEE802.15.4g surpasse l'IEEE802.15.4 et doit être considéré comme une solution pour les déploiements ultérieurs. Enfin, nous introduisons le concept du réseau agile: des nœuds pouvant modifier dynamiquement leur PHY en fonction de leurs besoins et de leur situation
The Internet of Things (IoT) aims to provide connectivity to millions of devices used in our day-to-day life. For the vast majority of applications, wired connections are unpractical and too expensive, therefore wireless connections is the only feasible way to provide connectivity to the devices. One of many wireless solutions is the standard IEEE802.15.4, specially designed for low power mesh networks. This standard is widely used for Smart Building, Home Automation and Industrial Applications.A subsequent amendment, the IEEE802.15.4g, defines 3 PHYs (FSK, OFDM and O-QPSK). This targets Smart Utility Networks(SUN) applications, i.e., Smart Metering, while providing extended coverage. In this thesis, we analyse the use of this standard outside the SUN environment and onto Industrial Networking applications.First, we conduct a series of experiments using IEEE802.15.4g compliant devices in order to measure the range coverage on radio links in real use case outdoor scenarios. Results show that highly reliable communications with data rates up to 800 kbps (with OFDM) can be achieved in urban environments at 540 m between nodes, and the longest useful radio link is obtained at 779 m (FSK). Sencond, regarding the robustness and high data rate of OFDM, we compare the performance of the IEEE802.15.4 with the IEEE802.15.4g OFDM in Smart Building scenarios. From experiments, we determine that IEEE802.15.4g OFDM outperforms IEEE802.15.4 and should be considered as a solution for further deployments in combination with a TSCH MAC approach. Finally, we introduce the concept of Network Agility: nodes that can dynamically change their PHY according to their needs and circumstances
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Ge, Xiang. "Electrochemical deposition of fluoridated calcium phosphate on titanium substrates /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?MECH%202008%20GE.

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Thiem, Deborah A. 1964. "Synthesis, purification, and metal complex formation properties of methyl 3-mercaptopropionate and solubility and stability constants of meso-2,3-dimercaptosuccinic acid." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277043.

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Methyl 3-mercaptopropionate was synthesized from 3-mercaptopropionic acid and purified by extraction into chloroform and column chromatography. The percent purity of the purchased material was determined by an iodine titration. Methyl 3-mercaptopropionate formed an insoluble complex with lead (II) when the pH was greater than 3. It also complexed with cobalt (II). The solubility of meso-dimercaptosuccinic acid was estimated by a spectrophotometric method using 5,5-dithiobis(2-nitrobenzoic acid) since the iodine titration did not give quantitative results. The acid dissociation constants were determined potentiometrically; two methods of calculation were used. Attempts to prepare crystals of the lead (II) complex of meso-dimercaptosuccinic acid in the following gels: agar, agarose, and gelatin, were unsuccessful.
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Ren, Yuxing. "Experiments on the elastic size dependence of LPCVD silicon nitride /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?MECH%202004%20REN.

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Ng, Kwok Leung. "Experimental study on wear properties of NiTi shape memory alloy thin film /." View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?MECH%202006%20NG.

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Farrell, Richard. "High temperature studies of thin film aluminum nitride and piezoelectric characterization of mesa structures." Morgantown, W. Va. : [West Virginia University Libraries], 2009. http://hdl.handle.net/10450/10299.

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Thesis (M.S.)--West Virginia University, 2009.
Title from document title page. Document formatted into pages; contains vi, 74 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 68-71).
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Barsaum, Peter, Paul Berg, and Andreas Hagman. "Acceptans av Internet of Things-teknik för distanssjukvård Vilken typ av IoT-teknik inom distanssjukvården är patienter och icke-patienter mest mottagliga för?" Thesis, Örebro universitet, Handelshögskolan vid Örebro Universitet, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-48920.

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29

LUZURIAGA, QUICHIMBO JORGE ELOY. "Managing Mobility for Distributed Smart Cities Services." Doctoral thesis, Universitat Politècnica de València, 2017. http://hdl.handle.net/10251/84744.

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The IoT refers to the idea of internetworking physical devices, vehicles, buildings, and any other item embedded with the appropriate electronics, software, sensors, actuators, and network connectivity to allows them to interchange data and to provide highly effective new services. In this thesis we focus on the communications issues of the IoT in relation to mobility and we provide different solutions to alleviate the impact of these potential problems and to guarantee the information delivery in mobile scenarios. Our reference context is a Smart City where various mobile devices collaboratively participate, periodically sending information from their sensors. We assume that these services are located in platforms based in cloud infrastructures where the information is protected through the use of virtualisation ensuring their security and privacy. This thesis is structured into seven chapters. We first detail our objectives and identify the current problems we intend to address. Next, we provide a thorough review of the state of the art of all the areas involved in our work, highlighting how we improved the existing solutions with our research. The overall approach of the solutions we propose in this thesis use prototypes that encompasses and integrates different technologies and standards in a small infrastructure, using real devices in real scenarios with two of the most commonly used networks around the world: WiFi and 802.15.4 to efficiently solve the problems we originally identified. We focussed on protocols based on a producer/consumer paradigm, namely AMQP and particularly MQTT. We observed the behaviour of these protocols using in lab experiments and in external environments, using a mesh wireless network as the backbone network. Various issues raised by mobility were taken into consideration, and thus, we repeated the tests with different messages sizes and different inter-message periodicity, in order to model different possible applications. We also present a model for dimensioning the number of sources for mobile nodes and calculating the number of buffers required in the mobile node as a function of the number of sources and the size of the messages. We included a mechanism for avoiding data loss based on intermediate buffering adapted to the MQTT protocol that, in conjunction with the use of an alternative to the Network Manager in certain contexts, improves the connection establishment for wireless mobile clients. We also performed a detailed study of the jitter behaviour of a mobile node when transmitting messages with this proposal while moving through a real outdoor scenario. To emulate simple IoT networks we used the Cooja simulator to study and determine the effects on the probability of delivering messages when both publishers and subscribers were added to different scenarios. Finally we present an approach that combines the MQTT protocol with DTN which we specifically designed for constrained environments and guarantees that important information will never be lost. The advantage of our proposed solutions is that they make an IoT system more resilient to changes in the point of attachment of the mobile devices in an IoT network without requiring IoT application & service developers to explicitly consider this issue. Moreover, our solutions do not require additional support from the network through protocols such as MobileIP or LISP. We close the thesis by providing some conclusions, and identifying future lines of work which we unable to address here.
Internet de las cosas (IoT) se refiere a la idea de interconectar sensores, actuadores, dispositivos físicos, vehículos, edificios y cualquier elemento dotado de la electrónica, así como del software y de la conectividad de red que los hace capaces de intercambiar datos para proporcionar servicios altamente efectivos. En esta tesis nos centramos en temas relacionados con la comunicación de sistemas IoT, específicamente en situaciones de movilidad y en los problemas que esto conlleva. Con este fin ofrecemos diferentes soluciones que alivian su impacto y garantizan la entrega de información en estas situaciones. El contexto de referencia es una ciudad inteligente donde varios dispositivos móviles participan de forma colaborativa enviando periódicamente información desde sus sensores hacia servicios ubicados en plataformas en la nube (cloud computing) donde mediante el uso de virtualización, la información está protegida garantizando su seguridad y privacidad. Las soluciones propuestas en esta tesis se enfocan en probar sobre una pequeña infraestructura un prototipo que abarca e integra diferentes tecnologías y estándares para resolver eficientemente los problemas previamente identificados. Hemos enfocado nuestro esfuerzo en el uso de dispositivos sobre escenarios reales con dos de las redes más extendidas en todo el mundo: WiFi y enlaces 802.15.4. Nos enfocamos en protocolos que ofrecen el paradigma productor/consumidor como el protocolo avanzado de colas de mensajes (AMQP) y particularmente el protocolo de transporte de mensajes telemétricos (MQTT), observamos su comportamiento a través de experimentos en laboratorio y en pruebas al aire libre, repitiendo las pruebas con diferentes tamaños de mensajes y diferente periodicidad entre mensajes. Para modelar las diferentes posibles aplicaciones de la propuesta, se tomaron en consideración varias cuestiones planteadas por la movilidad, resultando en un modelo para dimensionar eficientemente el número de fuentes para un nodo móvil y para calcular el tamaño requerido del buffer, en función del número de fuentes y del tamaño de los mensajes. Proponemos un mecanismo adaptado al protocolo MQTT que evita la pérdida de datos en clientes móviles, basado en un buffer intermedio entre la producción y publicación de mensajes que, en conjunto con el uso de una alternativa al gestor de conexiones inalámbricas "Network Manager", en ciertos contextos mejora el establecimiento de las conexiones. Para la evaluación de esta propuesta se presenta un estudio detallado de un nodo móvil que se mueve en un escenario real al aire libre, donde estudiamos el comportamiento del jitter y la transmisión de mensajes. Además, hemos utilizado emuladores de redes IoT para estudiar y determinar los efectos sobre la probabilidad de entrega de mensajes, cuando se agregan tanto publicadores como suscriptores a diferentes escenarios. Finalmente, se presenta una solución totalmente orientada a entornos con dispositivos de recursos limitados que combina los protocolos MQTT con redes tolerantes a retardos (DTN) para garantizar la entrega de información. La ventaja de las soluciones que proponemos reside en el hecho de que los sistemas IoT se vuelven resilientes a la movilidad y a los cambios de punto de acceso, permitiendo así que los desarrolladores creen fácilmente aplicaciones y servicios IoT evitando considerar estos problema. Otra ventaja de nuestras soluciones es que no necesitan soporte adicional de la red como sucede con protocolos como MobileIP o el protocolo que separa el identificador del localizador (LISP). Se destaca cómo hemos mejorado las soluciones existentes hasta el momento de la escritura de esta disertación, y se identifican futuras líneas de actuación que no han sido contempladas.
Internet de les coses (IoT) es refereix a la idea d'interconnectar sensors, actuadors, dispositius físics, vehicles, edificis i qualsevol element dotat de l'electrònica, així com del programari i de la connectivitat de xarxa que els fa capaces d'intercanviar dades per proporcionar serveis altament efectius. En aquesta tesi ens centrem en temes relacionats amb la comunicació de sistemes IoT, específicament en situacions de mobilitat i en els problemes que això comporta. A aquest efecte oferim diferents solucions que alleugeren el seu impacte i garanteixen el lliurament d'informació en aquestes situacions. El context de referència és una ciutat intel·ligent on diversos dispositius mòbils participen de forma col·laborativa enviant periòdicament informació des dels seus sensors cap a serveis situats en plataformes en el núvol (cloud computing) on mitjançant l'ús de virtualització, la informació està protegida garantint la seva seguretat i privadesa. Les solucions proposades en aquesta tesi s'enfoquen a provar sobre una xicoteta infraestructura un prototip que abasta i integra diferents tecnologies i estàndards per a resoldre eficientment els problemes prèviament identificats. Hem enfocat el nostre esforç en l'ús de dispositius sobre escenaris reals amb dos de les xarxes més esteses a tot el món: WiFi i enllaços 802.15.4. Ens enfoquem en protocols que ofereixen el paradigma productor/consumidor com el protocol avançat de cues de missatges (AMQP) i particularment el protocol de transport de missatges telemètrics (MQTT), observem el seu comportament a través d'experiments en laboratori i en proves a l'aire lliure, repetint les proves amb diferents grandàries de missatges i diferent periodicitat entre missatges. Per a modelar les diferents possibles aplicacions de la proposta, es van prendre en consideració diverses qüestions plantejades per la mobilitat, resultant en un model per a dimensionar eficientment el nombre de fonts per a un node mòbil i per a calcular la grandària requerida del buffer, en funció del nombre de fonts i de la grandària dels missatges. Proposem un mecanisme adaptat al protocol MQTT que evita la pèrdua de dades per a clients mòbils, basat en un buffer intermedi entre la producció i publicació de missatges que en conjunt amb l'ús d'una alternativa al gestor de connexions sense fils "Network Manager'', en certs contextos millora l'establiment de les connexions. Per a l'avaluació d'aquesta proposta es presenta un estudi detallat d'un node mòbil que es mou en un escenari real a l'aire lliure, on estudiem el comportament del jitter i la transmissió de missatges. A més, hem utilitzat emuladors de xarxes IoT per a estudiar i determinar els efectes sobre la probabilitat de lliurament de missatges, quan s'agreguen tant publicadors com subscriptors a diferents escenaris. Finalment, es presenta una solució totalment orientada a entorns amb dispositius de recursos limitats que combina els protocols MQTT amb xarxes tolerants a retards (DTN) per a garantir el lliurament d'informació. L'avantatge de les solucions que proposem resideix en el fet que els sistemes IoT es tornen resilients a la mobilitat i als canvis de punt d'accés, permetent així que els desenvolupadors creuen fàcilment aplicacions i serveis IoT evitant considerar aquests problema. Un altre avantatge de les nostres solucions és que no necessiten suport addicional de la xarxa com succeeix amb protocols com MobileIP o el protocol que separa l'identificador del localitzador (LISP). Es destaca com hem millorat les solucions existents fins al moment de l'escriptura d'aquesta dissertació, i s'identifican futures línies d'actuació que no han sigut contemplades.
Luzuriaga Quichimbo, JE. (2017). Managing Mobility for Distributed Smart Cities Services [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/84744
TESIS
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30

Neumann, Michael J. E. "An experimental investigation into the effectiveness of steel fibre-reinforced concrete relative to conventional mesh-reinforced concrete in thin shell construction." Master's thesis, University of Cape Town, 1988. http://hdl.handle.net/11427/8313.

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Includes bibliographical references.
This report presents the results of an investigation into the suitability of steel-fibre reinforced concrete (SFRC) as a building material. The performance of the SFRC is gauged relative to conventional steel mesh-reinforced concrete. The report begins with the historical background of fibre-reinforcing, its development and diversity in modern times. The theoretical principles governing the strength of SFRC are formulated, followed by an extensive review of factors influencing the fibre's potential and its subsequent effect on the mechanical properties of a concrete matrix. The experimental program is thereafter detailed in two stages: the "Efficiency and Proving Phase" followed by the "Application Phase". The former involves a series of tests to determine the most promising fibre of the five types available, while the latter compares the strength properties of slabs and arches reinforced with this fibre to those reinforced with wire mesh. The test results obtained from the two phases are evaluated and discussed in the succeeding two sections and the report ends with the conclusions drawn and recommendations regarding the effectiveness of SFRC relative to mesh-reinforced concrete.
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31

Zhou, Yang. "Parametric stability analyses for fluid-loaded thin membranes." Licentiate thesis, KTH, Strukturmekanik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-176030.

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Membrane structures are commonly used in many elds. The studies of thesestructures are of increasing interest. The two projects focus on the evaluations ofequilibrium states for uid-pressurized membranes under dierent loading conditions,and the corresponding instability behavior.The rst part of the current work discusses the instability behavior of a thin,planar, circular and initially horizontal membrane subjected to downwards or upwards uid pressure. The membrane structures exhibit large deformations under uid pressure. Various instability behaviors have been observed for dierent loadingparameters. Limit and bifurcation points have been detected for dierent loadingconditions. Dierent loading parameters have been used to interpret the instabilitybehavior. The eects on instability of parameters, the initial states of the membrane,and the chosen mesh have been discussed.The second part of the current work discusses instability behavior of a thin,spherical and closed membrane containing gas and uid placed on a horizontal rigidand non-friction plane. A multi-parametric loading has been described. By addingthe practically relevant controlling equations, the complex equilibrium paths werefollowed using the generalized path following algorithm, and the stability conclusionswere made dierently, according to the considered load parameters and theconstraints. A generalized eigenvalue analysis was used to evaluate the stabilitybehavior including the constraint eects. Fold line evaluations were performed toanalyze the parametric dependence of the instability behavior. A solution surfaceapproach was used to visualize the mechanical response under this multi-parametricsetting.

QC 20151029

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McCumiskey, Edward. "Mechanical Characterization of Nanocomposite CdSe Quantum Dot – MEH-PPV Polymer Thin Films via Nanoindentation." VCU Scholars Compass, 2009. http://scholarscompass.vcu.edu/etd/1731.

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Progress in the burgeoning field of organic electronics is enabling the development of novel technologies such as low-cost, printable solar cells and flexible, high-resolution displays. One exciting avenue of research in this field is nanostructured hybrid organics such as quantum dot (QD)-polymer devices. The incorporation of QDs can greatly improve a device’s efficiency and gives one the ability to tune its electrical and optical characteristics. In order for such technologies to be commercially viable, it is important to classify their mechanical integrity and reliability. Surprisingly little is known about the mechanical properties of QD-polymer thin films (<100 nm). This is in part due to challenges of: (1) isolating the mechanical response of a thin film from the underlying substrate, (2) obtaining a homogeneous dispersion of QDs in the film, and (3) the sensitivity of mechanical properties to the inherent rate dependence of polymer deformation (i.e., viscoelasticity). All of these challenges can introduce significant errors in the measurement of mechanical properties. Furthermore, the deformation mechanisms in nanocomposites are not well understood, so it is difficult to predict the effect of adding QDs on the mechanical behavior of films. In this thesis, these challenges are addressed for characterizing the mechanical properties of thin films of CdSe QD-poly[2-methoxy-5-2(2΄-ethylhexyloxy-p-phenylenevinylene)] (MEH-PPV) nanocomposites using quasi-static nanoindentation testing. Elastic modulus, hardness, and creep are measured as a function of QD concentration and loading and unloading rates. The QDs' ligands are removed by pyridine treatment prior to mixing with MEH-PPV to improve dispersion. The films are prepared via spin-coating onto glass substrates and subsequent annealing in air. Efforts are taken in the mechanical testing to minimize errors due to viscoelastic creep and interference from the substrate. Transmission electron microscopy reveals that the QDs are relatively well-dispersed in the polymer matrix. It is observed that adding QDs increases the elastic modulus (E) and hardness (H) of the films, while reducing the viscoelastic creep. Both E and H increase linearly with the volume percent of QDs. E ranges from 14.5 GPa to 52.7 GPa for pure MEH-PPV (0% QDs) and 100% QD films, respectively, while H ranges from 220 MPa to 1430 MPa for the same films, respectively. The films behave viscoelastically at lower QD loading, but assume a more granular character as the loading approaches 100%.
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Rodriguez, Kenneth Ralph. "The extraordinary infrared transmission of metal microarrays for enhanced absorption spectroscopy of monolayers, nanocoatings, and catalytic surface reactions." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1189549712.

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Nguyen, Vu Anh. "Blends of Polydioctylfluorene (PFO) with polymeric and monomeric energy acceptors: correlation of fluorescence energy transfer and film morphology in breath figures and films." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24609.

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Thesis (Ph.D.)--Chemistry and Biochemistry, Georgia Institute of Technology, 2008.
Committee Chair: Tolbert, Laren; Committee Member: Collard, David; Committee Member: Lyon, Andrew; Committee Member: Srinivasarao, Mohan; Committee Member: Wilkinson, Angus
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Mravec, Roman. "Návrh mezioperační dopravy ve výrobním podniku podle principů Průmyslu 4.0." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-449286.

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Based on the description and definition of technology and processes falling within the vision of the fourth industrial revolution with the aim of creating intelligent factories, this diploma thesis deals with the principles of the Industry 4.0 concept in Hilti's production plant with a focus on transport and supply of production equipment. The aim of the work is to create a comprehensive proposal that takes into account all the necessary aspects associated with upgrading the existing state of inter-operational transport in a particular production line to fully automated, flexible and autonomous transport of materials and products in the context of Industry 4.0. A prerequisite for creating a design is the connection of automatically guided vehicles (AGVs) serving individual transport orders. The selection of the vehicle was made taking into account the safety of movement, the method of charging, the system and network integrity of existing and proposed technologies and components. The intention is not only to automate the inter-operational service, but also on the basis of the created automation concept, the ability to autonomously procure the flow of material and products. The mathematical calculation of capacity planning in the production line helped to determine the total load and the number of vehicles needed for continuous procurement of transport requirements. The result of the design part is also the design of specific transport routes and transport conditions that AGV vehicles must comply with in order to maintain a high level of safety. Transparency and a constant overview of transported products is provided by the presented scheme for identification of production batches, Auto-ID system. The financial efficiency of the whole project elaborated in the diploma thesis is evaluated as payable after 4 years from the implementation of the proposal. The financial efficiency of the whole project elaborated in the diploma thesis is evaluated as payable after 4 years from the implementation of the proposal due to high labor costs.
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Zaidi, Houda. "Méthodologies pour la modélisation des couches fines et du déplacement en contrôle non destructif par courants de Foucault : application aux capteurs souples." Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00776931.

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Ce travail de thèse porte sur le développement d'outils de modélisation pour le contrôle non destructif (CND) par courants de Foucault (CF). Il existe actuellement une tendance à la mise en œuvre de capteurs souples qui représentent une solution pertinente pour inspecter des pièces ayant une surface complexe. L'objectif principal de cette thèse est l'élaboration de techniques permettant la modélisation de ce type de capteurs au sein de la méthode des éléments finis (MEF).Lors de la modélisation d'un capteur souple avec la MEF, trois problématiques se manifestent. La première concerne le maillage des milieux fins qui apparaissent dans ce type de configuration (distance capteur-pièce contrôlée, bobine plate, revêtement fin...). Le maillage de ces régions par des éléments simpliciaux peut poser des problèmes numériques (éléments déformés quand un maillage grossier est considéré et grand nombre d'inconnues quand un maillage fin est utilisé). La deuxième problématique concerne le déplacement du capteur. Si les différents sous-domaines géométriques (air, pièce, capteur...) sont convenablement remaillés pour chaque position du capteur, le temps total pourra être pénalisant. La troisième problématique relative à la modélisation d'un capteur souple porte sur l'imposition du courant dans des bobines déformées.Une comparaison de différentes approches nous a conduit à retenir la méthode overlapping, qui permet de considérer simultanément des milieux fins avec maillages non-conformes. Cette méthode permet d'effectuer le recollement de deux surfaces non planes et/ou de géométries différentes. La méthode overlapping a été implantée dans deux formulations duales (magnétique et électrique) en 2D et 3D intégrées dans le code de calcul DOLMEN (C++) du LGEP. La méthode overlapping a été validée pour la prise en compte de plusieurs types de régions minces (air, milieux conducteurs, milieux magnétiques, bobines plates...). La modélisation des capteurs souples nécessite aussi l'implantation d'une technique permettant d'imposer correctement les courants dans un inducteur de forme arbitraire. Une technique a été sélectionnée et programmée, d'abord pour des bobines classiques (volumiques) déformées puis pour des bobines plates flexibles. Afin de valider les développements réalisés, différentes configurations de test ont été traitées et les résultats comparés avec des solutions de référence analytiques ou expérimentales.
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Boilevin-Kayl, Ludovic. "Modeling and numerical simulation of implantable cardiovascular devices." Thesis, Sorbonne université, 2019. http://www.theses.fr/2019SORUS039.

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Cette thèse, réalisée dans le cadre du projet Mivana, est consacrée à la modélisation et à la simulation numérique de dispositifs cardiaques implantables. Ce projet est mené par les start-up Kephalios et Epygon, concepteurs de solutions chirurgicales non invasives pour le traitement de la régurgitation mitrale. La conception et la simulation de tels dispositifs nécessitent des méthodes numériques efficaces et précises capables de calculer correctement l’hémodynamique cardiaque. C’est le but principal de cette thèse. Dans la première partie, nous décrivons le système cardiovasculaire et les valves cardiaques avant de présenter quelques éléments de théorie concernant la modélisation mathématique de l’hémodynamique cardiaque. En fonction du degré de complexité adopté pour la modélisation des feuillets de la valve, deux approches sont identifiées : le modèle de surfaces résistives immergées et le modèle complet d’interaction fluide-structure. Dans la deuxième partie, nous étudions la première approche qui consiste à combiner une modélisation réduite de la dynamique des valves avec un découplage cinématique de l’hémodynamique cardiaque et de l’électromécanique. Nous l’enrichissons de données physiologiques externes pour la simulation correcte des phases isovolumétriques, pierres angulaires du battement cardiaque, permettant d’obtenir un modèle relativement précis qui évite la complexité des problèmes entièrement couplés. Ensuite, une série d’essais numériques sur des géométries 3D physiologiques, impliquant la régurgitation mitrale et plusieurs configurations de valves immergées, illustre la performance du modèle proposé. Dans la troisième et dernière partie, des modèles complets d’interaction fluide-structure sont considérés. Ce type de modélisation est nécessaire pour étudier des problèmes plus complexes où la précédente approche n’est plus satisfaisante, comme par exemple le prolapsus de la valve mitrale ou la fermeture d’une valve mécanique. D’un point de vue numérique, le développement de méthodes précises et efficaces est indispensable pour pouvoir simuler de tels cas physiologiques. Nous considérons alors une étude numérique complète dans laquelle plusieurs méthodes de maillages non compatibles sont comparées. Puis, nous présentons un nouveau schéma de couplage explicite dans le cadre d’une méthode de type domaine fictif pour lequel la stabilité inconditionnelle au sens de la norme en énergie est démontrée. Plusieurs exemples numériques en 2D sont proposés afin d’illustrer les propriétés et les performances de ce schéma. Enfin, cette méthode est finalement utilisée pour la simulation numérique 2D et 3D de dispositifs cardiovasculaires implantables dans un modèle complet d’interaction fluide-structure
This thesis, taking place in the context of the Mivana project, is devoted to the modeling and to the numerical simulation of implantable cardiovascular devices. This project is led by the start-up companies Kephalios and Epygon, conceptors of minimally invasive surgical solutions for the treatment of mitral regurgitation. The design and the simulation of such devices call for efficient and accurate numerical methods able to correctly compute cardiac hemodynamics. This is the main purpose of this thesis. In the first part, we describe the cardiovascular system and the cardiac valves before presenting some standard material for the mathematical modeling of cardiac hemodynamics. Based on the degree of complexity adopted for the modeling of the valve leaflets, two approaches are identified: the resistive immersed surfaces model and the complete fluidstructure interaction model. In the second part, we investigate the first approach which consists in combining a reduced modeling of the valves dynamics with a kinematic uncoupling of cardiac hemodynamics and electromechanics. We enhance it with external physiological data for the correct simulation of isovolumetric phases, cornerstones of the heartbeat, resulting in a relatively accurate model which avoids the complexity of fully coupled problems. Then, a series of numerical tests on 3D physiological geometries, involving mitral regurgitation and several configurations of immersed valves, illustrates the performance of the proposed model. In the third and final part, complete fluid-structure interaction models are considered. This type of modeling is necessary when investigating more complex problems where the previous approach is no longer satisfactory, such as mitral valve prolapse or the closing of a mechanical valve. From the numerical point of view, the development of accurate and efficient methods is mandatory to be able to compute such physiological cases. We then consider a complete numerical study in which several unfitted meshes methods are compared. Next, we present a new explicit coupling scheme in the context of the fictitious domain method for which the unconditional stability in the energy norm is proved. Several 2D numerical examples are provided to illustrate the properties and the performance of this scheme. Last, this method is finally used for 2D and 3D numerical simulation of implantable cardiovascular devices in a complete fluid-structure interaction framework
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38

Stragier, Anne-Sophie. "Elaboration et caractérisation de structures Silicium-sur-Isolant réalisées par la technologie Smart Cut™ avec une couche fragile enterrée en silicium poreux." Thesis, Lyon, INSA, 2011. http://www.theses.fr/2011ISAL0108.

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Au vu des limitations rencontrées par la miniaturisation des circuits microélectroniques, l’augmentation de performances des systèmes repose largement aujourd’hui sur la fabrication d’empilements de couches minces complexes et innovants pour offrir davantage de compacité et de flexibilité. L’intérêt grandissant pour la réalisation de structures innovantes temporaires, i.e. permettant de réaliser des circuits sur les deux faces d’un même film, nous a mené à évaluer les potentialités d’une technologie combinant le transfert de films minces monocristallins, i.e. la technologie Smart Cut™, et un procédé de de porosification partielle du silicium afin de mettre au point une technologie de double report de film monocristallin. En ce sens, des substrats de silicium monocristallin ont été partiellement porosifiés par anodisation électrochimique. La mise en œuvre de traitements de substrats partiellement poreux a nécessité l’emploi de techniques de caractérisation variées pour dresser une fiche d’identité des couches minces poreuses après anodisation et évaluer l’évolution des propriétés de ces couches en fonction des différents traitements appliqués. Les propriétés chimiques, structurales et mécaniques des couches de Si poreux ont ainsi été étudiées via l’utilisation de différentes techniques de caractérisation (XPS-SIMS, AFM-MEB-XRD, nanoindentation, technique d’insertion de lame, etc.). Ces études ont permis d’appréhender et de décrire les mécanismes physiques mis au jeu au cours des différents traitements et de déterminer les caractéristiques {porosité, épaisseur} optimales des couches poreuses compatibles avec les séquences de la technologie proposée. La technologie Smart Cut™ a ainsi été appliquée à des substrats partiellement porosifiés menant à la fabrication réussie d’une structure temporaire de type Silicium-sur-Isolant avec une couche de silicium poreux enterrée. Ces structures temporaires ont été « démontées » dans un second temps par collage polymère ou collage direct et insertion de lame menant au second report de film mince monocristallin par rupture au sein de la couche porosifiée et donc fragile. Les structures fabriquées ont été caractérisées pour vérifier leur intégrité et leurs stabilités chimique et mécanique. Les propriétés cristallines du film mince de Si monocristallin, reporté en deux temps, ont été vérifiées confirmant ainsi la compatibilité des structures fabriquées avec des applications microélectroniques telles que les applications de type « Back-Side Imager » nécessitant une implémentation de composants sur les deux faces du film. Ainsi une technologie prometteuse et performante a pu être élaborée permettant le double report de films minces monocristallins et à fort potentiel pour des applications variées comme les imageurs visibles ou le photovoltaïque
As scaling of microelectronic devices is confronted from now to fundamental limits, improving microelectronic systems performances is largely based nowadays on complex and innovative stack realization to offer more compaction and flexibility to structures. Growing interest in the fabrication of innovative temporary structures, allowing for example double sided layer processing, lead us to investigate the capability to combine one technology of thin single crystalline layer transfer, i.e. the Smart Cut™ technology, and partial porosification of silicon substrate in order to develop an original double layer transfer technology of thin single crystalline silicon film. To this purpose, single crystalline silicon substrates were first partially porosified by electrochemical anodization. Application of suitable treatments of porous silicon layer has required the use of several characterization methods to identify intrinsic porous silicon properties after anodization and to verify their evolution as function of different applied treatments. Chemical, structural and mechanical properties of porous silicon layers were studied by using different characterization techniques (XPS-SIMS, AFM-MEB-XRD, nanoindentation, razor blade insertion, etc.). Such studies allowed comprehending and describing physical mechanisms occurring during each applied technological steps and well determining appropriated {porosity, thickness} parameters of porous silicon layer with the developed technological process flow. The Smart Cut™ technology was successfully applied to partially porosified silicon substrates leading to the fabrication of temporary SOI-like structures with a weak embedded porous Si layer. Such structures were then “dismantled” thanks to a second polymer or direct bonding and razor blade insertion to produce a mechanical rupture through the fragile embedded porous silicon layer and to get the second thin silicon film transfer. Each fabricated structure was characterized step by step to check its integrity and its chemical and mechanical stabilities. Crystalline properties of the double transferred silicon layer were verified demonstrating the compatibility of such structures with microelectronic applications such as “Back-Side Imagers” needing double-sided layer processing. Eventually, a promising and efficient technology has been developed to allow the double transfer of thin single crystalline silicon layer which presents a high potential for various applications such as visible imagers or photovoltaic systems
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39

LIN, YOU-SHENG, and 林宥盛. "A Bluetooth Low Energy Indoor Positioning System of Location Based Mesh Network for Internet of Things." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/k85bmh.

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碩士
國立臺北科技大學
機械工程系機電整合碩士班
107
Internet of Things(IoT) has grasped great attention in recent years. Each constructed buildings tend to be “intelligent” to enhance the convenience and safety of occupants. Therefore, Indoor Positioning System (IPS) using Bluetooth Low Energy (BLE) technology to construct Location Based Service(LBS) is currently becoming real and available. However, this technology exists various challenges related to the behavior of the advertising channel 37、38、39 and the multipath effect. Because of these factors, they will lead to the Received Signal Strength Indicator (RSSI) fluctuations and precision. In order to mitigate these effects, this paper presents an IPS based on BLE, that improves accuracy while reducing power consumption and costs. The main point of this technique is that using PeTacom Protocol to establish Location Based Mesh Network (LBMN) and realize interactive communication between people to objects. Simultaneously, the system integrates various sensors, algorithms, and system design to establish an IPS. The analysis of the results proves that all the proposals improve the precision of the system, which precise goes up to 1.5 m for moving in area 45m×31m for devices.
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40

Vijay, Rathinamala. "Characterization of Interconnections in Smart-X Applications." Thesis, 2022. https://etd.iisc.ac.in/handle/2005/6100.

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Smart-X applications are realized by interconnecting several objects to achieve real-time capability by improving safety, reliability, and efficiency. These interconnections can be broadly classified as physical connections and logical network connections. A malfunction or damage in a physical connection may be catastrophic, leading to system downtime and sometimes fatal accidents. Thus, monitoring these connections is crucial to identify the onset of damage or a malfunction. Logical network connections are used in several applications to track and monitor a mesh-connected group of things called the Mesh of Things (MoT). In our research work, we focus on the characterization of physical and logical network connections. We apply these characterizations to: (a) reliably detect insulation damage in signaling and indoor power cables, (b) reliably detect and report a detangled MoT network, and (c) develop a suitable testbed to demonstrate measures and algorithms for anomaly reasoning in Smart-X connectivity. \\ In our first use case, we implement Power Line Communication (PLC) based measurement methods and propose algorithms to detect, classify and localize cable insulation faults. The solution considers factors such as the type and length of the cable, the width, and length of the fault, the structure of the network wiring, and source and load variations on the cable. In order to increase the accuracy of cable fault detection and localization, we use a conglomerate diagnostic solution. We perform extensive measurements using an in-situ non-invasive Software Defined Radio (SDR) based composite diagnostic kit. We develop a Bayesian inversion framework to estimate the Health Index (HI) of the cable. The HI assists in determining the cable state in real time and thus can suggest the need for preventive maintenance. Secondly, we develop an anomaly reasoning framework for the cable insulation fault by utilizing our experimental data collected from the testbed. Since source and load variations can contribute to an anomaly, we derive insights using measures such as SNR, S parameter, and Reflectogram. We identify the most probable root cause for an anomaly in a cable section. In particular, we are interested in estimating the belief for the severity of a cable insulation fault.\\ In our second use case, we are interested in the real-time detection of a detangled MoT. Our solution uses Bluetooth Low Energy (BLE) based mesh and PLC backbone network. Measures such as latency and Packet Delivery Ratio (PDR) are characterized for this heterogeneous network which is subjected to interference and impulse noise. Our use case is related to air cargo monitoring and tracking within an airport terminal. Finally, we analyze the performance of the integrated BLE-PLC network through numerical simulations. We use the generalized Noisy-OR model for mesh reliability and Dijkstra’s shortest path model for latency analysis. For the backbone network, we use a measurement-aided channel frequency response model for latency and reliability analysis. We validate the simulation results with our empirical setup.
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41

Chien, Ming-Yung, and 簡銘雍. "Fabrication and characterization of transparent conductive Ag nanowires mesh thin films." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/3r3nnk.

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碩士
國立中興大學
電機工程學系所
106
One-dimensional metal nanostructures, such as wire, rod, and ribbon structures, have received extensive attention due to their unique electrical and optical properties. Among them, silver nanowires (AgNW) have attracted much attention in many possible candidate metal structures because of their low sheet resistance and high thermal conductivity. The method of synthesizing silver nanowires is most widely used in the polyol method. Many studies have suggested that the reaction rate can be controlled by controlling the heating time and the amount of sodium chloride at a fixed reaction time. The proper addition of chloride ions in the polyol method can effectively promote the formation of silver nanowires. In this experiment, silver nitrate (AgNO3) was added to ethylene glycol by the polyol method, and it was reduced to silver nanoparticles at 155 °C, and the reaction was supplemented by adding sodium chloride and polyvinylpyrrolidone (PVP) was used as a seal. The end agent limits its growth direction. In this study, by fine-tuning PVP, silver nitrate, sodium chloride and reaction temperature, it is hoped that a suitable formula can be found to make a silver nanowire and coated into a transparent conductive film to compare the tablets. Resistance and penetration. The results show that when the adjustment of sodium chloride is changed from 0.0002M, 0.0004M and 0.0012M, it can be observed through the color change of the reaction liquid. Concentrated sodium chloride will slow down the overall reaction rate due to sodium chloride. It reacts with silver to form silver chloride, and slowly releases silver ions to slow down the reaction rate. The sodium ions act as a protective agent to prevent the oxidized silver ions from being affected by oxidation. The PVP concentration can be used as a method to adjust the diameter of the silver nanowire. The diameter of the PVP silver wire will increase by adjusting the concentration. This can be seen from the previous section from 0.061M to 0.071M. Phenomenon, but PVP at lower concentrations will be detrimental to function as a directing agent. In this experiment, we successfully synthesized silver nanowires with an aspect ratio of about 180 in the best formulation. The length can reach 15~18um and the diameter is 100~125nm. Only two layers need to be coated after dilution. It can reach a 20Ω/sq film resistor with a penetration of 83% at a wavelength of 400~700nm.
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42

Weng, Chen-Hui, and 翁承輝. "Enhancement of optoelectronic properties on Al-doped ZnO thin film by inserting nano-silver quasi-mesh structures." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/5sm5mk.

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43

Chen, Cheng-Wei, and 陳正偉. "Constructing the nano-Au quasi-mesh structures to enhance the optoelectronic properties of Al-doped ZnO thin film." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/6u5y64.

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碩士
義守大學
電子工程學系
103
In this study, the lower cost Au-nano particles(Au-NPs) has been obtained by chemical reduction and inserted in the Al-doped Zinc Oxide layer to enhance the optoelectronic properties. At first the improved AZO thin film had been treated as seed layer, and then the Au-NPs were dropped on the etched surface of seed layer. In order to construct the optimum nano-Au quasi-mesh structure, the proper treatment as thermal and spin had been done before the deposition of AZO capping layer, and then the AZO/ Au-NPs/AZO thin film was finished. The transmission electron microscope (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to analysis the structure of Au nano particles, distribution and the crystalline intensity of AZO thin film, the optoelectronic properties were measured by UV-VIS-NIR Spectrophotometer and Hall-effect measurement system, respectively. The result shown after the optimum optoelectronic properties of AZO/Au-NPs/AZO thin film was measured after 800℃、10min thermal treatment and 3000rpm spin speed. The resistance reduces to 3.57×10-3Ω-cm, the average transmittance in visible increases to 84.15% , and the optimum figure of merit is 3.99×10-4Ω-1, which means the optimum nano-Au quasi-mesh structure had been constructed in this study.
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44

Chang, Pai-Yu, and 張百裕. "Applying the Internet of Things (IoT) Technology to the Integrated Manufacturing Execution System (MES) – Using Optical Grinding Plant for Example." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/jw8qd4.

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碩士
淡江大學
管理科學學系碩士班
101
In view of Taiwan''s traditional manufacturing facing changes in the global economy, business management is experiencing the demanding challenges, such as production lead time reduction, the suppliers demand fast delivery, orders reduction as well as changeable customized demands. How to upgrade and improve the management mode of internal operation effectively is the enterprises’ primary task to be dealt with. General enterprises tend to import the ERP system, but modular ERP systems are lower application for the traditional manufacturing. However, the program of customized modification is high cost and risk of failure, coupled with the factors of the low E degree of internal staffs, enterprises eventually choose traditional management mode. However, traditional management mode can’t control personnel, equipments, materials and costs effectively, or further provide the just-in-time management reports. The study focuses on the characteristics of the traditional manufacturing, to explore how the IoT technology combined with MES system via the concept of a rapid response system establishes an applicable Internet of things using scenarios. The collection of information through IoT technology integrates application and feedback in the MES system to generate a report. Finally, this study develops a set of information system of the IoT in current management needs combined with MES through the actual case of the traditional mold manufacturing execution to find out the applicable situations and conditions in exploring the promoting improvement and management effectiveness.
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45

Tseng, Chien-Wen, and 曾健文. "Applications of Meso-porous TiO2 thin Films and TiO2 powder for Dye-Sensitized Solar Cells." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/47398733133567462589.

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碩士
國立中正大學
化學工程所
97
The study is mainly to investigate the effects of mesoporous TiO2 thin films and TiO2 nanoparticles on the performance of the dye-sensitized solar cells(DSSCs).The fabrication methods of mesoporous TiO2 thin films and TiO2 nanoparticles were of the simple, low cost, uniformly size, and highly thermal stable. The mesoporous TiO2 thin films and TiO2 nanoparticles can be directly formed by sol-gel method and evaporation -induced self-assembly method, respectively. By XRD, TGA, EDS, SEM and TEM analysis , TiO2 nanoparticles were confirmed as anatase phase, after calcination above 350℃, which is favorable to the performance of solar cells. By UV-vis and N2 adsorption/ desorption isotherm analysis, the band gap and the highest specific surface area of TiO2 nanoparticles were 3.2 eV and 194.36 (m2/g), respectively The mesoporous TiO2 thin films was applied as an interfacial layer between the TiO2 nanoparticles film and the FTO electrode in dye-sensitized solar cells. The introduction of mesoporous TiO2 thin films increased Isc from 0.48 to 1.65 mA/cm2. As a result, the photovoltaic conversion efficiency (η) was improved from 0.75% to 2.32%. In addition, the presence of interfacial organized mesoporous TiO2 provided excellent adhesion between the FTO IV and the TiO2 nanoparticles layer, suppressed the back-transport reaction by blocking direct contact between the electrolyte and FTO electrode. By increasing the thickness of the TiO2 nanoparticles layer from 1.2 μm to 12 μm, the the best efficiency of 5.027% can be achieved.
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46

Huang, Tsung-Hui, and 黃宗輝. "Conductance and Morphology Characterization of MEH-PPV and Polythiophene Thin Films Formed on Mica." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/11789322003509692780.

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碩士
逢甲大學
化學工程學所
95
In this paper, the experiments we performed are to deposit poly[2-methoxy-5-(2-ehtylhexoy)- 1,4 - phenylene vinylene] (MEH-PPV) thin films on insulating mica by spin-coating, and to deposit polythiophene thin films on insulating mica by admicellar polymerization (AP). Morphology imaging using atomic force microscopy (AFM) and conductance measurements by a sub-femto-amp SourceMeter were performed. The current-voltage (I-V) curves were obtained at several different concentrations. AFM images observe the fractal structure on MEH-PPV coated surface, and conductance measurements by sub-femto-amp SourceMeter exhibit a non-linear relationships with concentrations. The result agrees with the power law relationship of fractal analysis. In the experiments of AP procedures in two solutions, we can see different polymer distribution and shapes caused by different surfactants, and the effect of surfactant in the first solution on monomer adsorbed on mica surface. In addition, the surfactants exist or not in second solution are essential to the completeness and the distribution of the thin films.
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47

Wu, Der-Chin, and 吳德清. "The electron transport mecahnics of organic MEH-PPV thin film which blends Ga(2Meq)2Piv." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/38641426301237420623.

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48

Chen, Sheng-wei, and 陳盛煒. "Study on the Effect of Blending Alq3 into MEH-PPV/ Short-Length Carbon Nanotubes Photovoltaic Thin Film." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/17425116988173575925.

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碩士
國立中山大學
光電工程研究所
94
For organic solar cells: exciton generation, exciton diffusion, charge transfer, and charge transport of a photoactive layer are the important factors in photocurrent generation. In this thesis, we blend small molecular material tris(8-hydroxyquinoline)aluminum (Alq3) into poly [ 2-methoxy-5-(2''-ethyl-hexyloxy)-1,4-phenylene-vinylene ]:short-length carbon nanotubes (MEH-PPV:SLCNTs) films to increase the light absorption, in the range of 300 to 450 nm, and hence increase the exciton generation. The comparison of the photoluminescence (PL) of a donor with that of the Donor-Acceptor composite provides an important and simple method to detect the charge transfer phenomenon. Furthermore, the degree of photoluminescence quenching may be representative of the efficiency of charge transfer. [1-6] Using this concept and method, we obtain that at the mix ratio of 1:0.5 (MEH-PPV:SLCNTs) by weight, 33 wt.% SLCNTs, probably have the maximum of charge transfer efficiency. To further check that at this concentration might have the maximum efficiency of the charge transfer, we also used time-resolved fluorescence spectrometer to measure the fluorescence lifetime of MEH-PPV. The shortest MEH-PPV fluorescence lifetime of 0.15 ns at 33 wt.% SLCNTs corresponds with our conjecture. For simplicity to discuss next experiment results, we make two assumptions at this mix ratio: (1) The efficiency of the charge transfer process is very high, so the competing processes can be neglected. Because of the forward electron transfer process occurs in the sub-picosecond time domain; (2) The exciton diffusion efficiency is approximately unity in the bulk heterojunction photoactive layer. Based on this assumption, the higher degree of photoluminescence quenching of MEH-PPV:Alq3 and MEH-PPV:Alq3:SLCNTs system demonstrates blending alq3 into MEH-PPV:SLCNTs films maybe can increase the charge photogeneration. The PL and UV/VIS absorption spectra are employed to examine the energy transfer process between Alq3 and MEH-PPV. When MEH-PPV:Alq3 films are excited at the wavelength of 380 nm which is in the main absorption region of Alq3, the increase in PL intensity of MEH-PPV at 577nm and the absent emission spectra of Alq3 illustrates Alq3 transfer its energy to MEH-PPV. By scanning electron microscopy, we observed that the surface pinholes became less than that of MEH-PPV films. This result suggests the devices utilizing the MEH-PPV:Alq3 composites as electron donor materials may have smaller electrode contact resistance. From all above the experiment data, we believe using MEH-PPV:Alq3:SLCNT as a photoactive layer perhaps can enhance the device performance.
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49

Pereira, André Filipe Marques. "MANUFACTURING EXECUTION SYSTEM." Master's thesis, 2021. http://hdl.handle.net/10400.8/6258.

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This report describes the tasks performed during the internship that took place at the Lusiaves facilities, in which the knowledge acquired during the Master of Engineering and Mobile Computing, namely with regard to the use of project management tools, management code and knowledge acquired at the project development level, among others, were crucial for this stage. The internship took 12 months, and all development tasks are related with the construction of a mobile application, with the objective to aid slaughterhouses in their management. Throughout the years, with the evolution of techonologies, the Lusiaves Group had the need to optimize most processes, which would allow for a greater overview of all processes, and shared information between all companies of the group. As such, this software was developed from scratch. For the construction of this solution, a software was created for the mobile environment, to be used by people that are within slaughterhouses, for those that are receiveing products. This software was built specifically for Android devices, even though this can be used in an iOS device. In this internship, two modules were created for this application; the Reception module, with which a user would be receiving products to insert in Reception Documents, throughout the usage of the Picking feature; and the Production module, with which a user would start products in Production Documents, throughout the usage of the same Picking feature. This picking feature can successfully read both barcodes and QRCodes, without the assistance of any external tools. This was made possible with the usage of the MC3300k, the device that will be used in slaughterhouses. In this report, most functionalities will be discussed, alongside some testing, and the justification for the choices that were done will also be provided.
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50

Lee, Kuo-Yuan, and 李國源. "Mixed-Solvent Influence of MEH-PPV Polymerization and Opto-Electronic Properties of this Polymer Blended with Liquid Crystal Molecule." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/cx9b2a.

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碩士
國立臺北科技大學
有機高分子研究所
94
The study of this thesis has shown the importance of two features. The first is the relation between mixed-solvent influence and molecular weight of poly(2-methoxy-5- (2’-ethylhexyloxy) -1,4-phenylenevinylene) (MEH-PPV). The second is the morphology about MEH-PPV blending with the liquid crystal molecule. Part I:The solvents of the first system consists of tetrahydrofuran (THF) and N,N-Dimethylformamide (DMF). The molecular weight of MEH-PPV, can be controlled by the various ratios of DMF. The polydispersity index (PDI) of MEH-PPV can be controlled, too. The molecular weight of MEH-PPV is decreased when the weight ratio of THF increases. Part II:The research of the second system is about MEH-PPV blending with 4-Cyano-4''-N-Heptylbiphenyl (7CB). The morphology of the system has been studied by polarized optical microscope (POM). The changes of the morphology in the blending system is dependent on the weight ratio of 7CB. The optimal opto-electronic properties of the system can be found out. It is an optimal weight ratio that the weight ratio of 7CB is 0.4.
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