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Wagner, Michael. "Concepts for In-memory Event Tracing." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-172882.
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This thesis contributes to the field of performance analysis in High Performance Computing with new concepts for in-memory event tracing.
Event tracing records runtime events of an application and stores each with a precise time stamp and further relevant metrics. The high resolution and detailed information allows an in-depth analysis of the dynamic program behavior, interactions in parallel applications, and potential performance issues. For long-running and large-scale parallel applications, event-based tracing faces three challenges, yet unsolved: the number of resulting trace files limits scalability, the huge amounts of collected data overwhelm file systems and analysis capabilities, and the measurement bias, in particular, due to intermediate memory buffer flushes prevents a correct analysis.
This thesis proposes concepts for an in-memory event tracing workflow. These concepts include new enhanced encoding techniques to increase memory efficiency and novel strategies for runtime event reduction to dynamically adapt trace size during runtime. An in-memory event tracing workflow based on these concepts meets all three challenges: First, it not only overcomes the scalability limitations due to the number of resulting trace files but eliminates the overhead of file system interaction altogether. Second, the enhanced encoding techniques and event reduction lead to remarkable smaller trace sizes. Finally, an in-memory event tracing workflow completely avoids intermediate memory buffer flushes, which minimizes measurement bias and allows a meaningful performance analysis.
The concepts further include the Hierarchical Memory Buffer data structure, which incorporates a multi-dimensional, hierarchical ordering of events by common metrics, such as time stamp, calling context, event class, and function call duration. This hierarchical ordering allows a low-overhead event encoding, event reduction and event filtering, as well as new hierarchy-aided analysis requests.
An experimental evaluation based on real-life applications and a detailed case study underline the capabilities of the concepts presented in this thesis. The new enhanced encoding techniques reduce memory allocation during runtime by a factor of 3.3 to 7.2, while at the same do not introduce any additional overhead. Furthermore, the combined concepts including the enhanced encoding techniques, event reduction, and a new filter based on function duration within the Hierarchical Memory Buffer remarkably reduce the resulting trace size up to three orders of magnitude and keep an entire measurement within a single fixed-size memory buffer, while still providing a coarse but meaningful analysis of the application.
This thesis includes a discussion of the state-of-the-art and related work, a detailed presentation of the enhanced encoding techniques, the event reduction strategies, the Hierarchical Memory Buffer data structure, and a extensive experimental evaluation of all concepts.
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Luu, D. (Duc). "OTSS: Oulu traffic simulation system." Master's thesis, University of Oulu, 2017. http://jultika.oulu.fi/Record/nbnfioulu-201710112981.
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Abstract. This thesis presents the design and the implementation of Oulu Traffic Simulation System (OTSS), a traffic simulation system for the City of Oulu, Finland. Following agent-based approach, the simulation generates artificial agents that represent the population synthesis of the City of Oulu. Data from several sources, including official statistics, government-organized open data and crowdsourced information were collected and used as input for the simulation. Two traffic demand models are presented in this thesis: (1) the random model which generates traffic trips as random, discrete events; and (2) the activity-based model which defines traffic trips as sequential events in the agents’ day plan. The software development of the system follows the spiral model of software development and enhancement. During the implementation, several development cycles were conducted before the UML software design. The system was executed on two computation systems to test its real-time performance. To evaluate the traffic models, data extracted from the simulation was compared with aggregated survey data from Finnish Transport Agency and traffic count stations around the city. The results showed that a typical server is capable of running the simulation, and even though there were differences in the duration and distance of individual trips, the simulation reflects real-life traffic count significantly well.
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Lang, Ursula Friederike. "Oktoberfest-Triage-Evaluationsstudie 1998 (OTES ’98)." Diss., lmu, 2001. http://nbn-resolving.de/urn:nbn:de:bvb:19-3638.
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Kuai, Wenlin. "Faisabilité de transistors organiques à effet de champ fabriqués entièrement en solution." Thesis, Rennes 1, 2017. http://www.theses.fr/2017REN1S013/document.
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Le travail entre dans le cadre de la nouvelle tendance à la recherche d’une électronique mécaniquement flexible basée sur des transistors en couche mince constitués uniquement de matériaux organiques (OTFT). OTFT de type n et de type p ont été fabriqués par la technique de dépôt par impression (inkjet) et étudiés. Les paramètres d’impression (jetabilité, mouillabilité, imprimabilité et possibilité d’obtention de différentes formes), de chaque encre permettant le dépôt de couches conductrices, isolantes et semiconductrices, ont été systématiquement étudiés. Les OTFT de type n basés sur du C60 se sont montrés non fiables, principalement du fait de la faible solubilité du C60 dans les solvants organiques. Les OTFT de type basés sur du Tips-pentacene ont montré par contre une grande fiabilité. Le travail global constitue une large revue des problèmes et difficultés rencontrés dans la fabrication de transistors fabriqués entièrement par impression jet d’encre. Des solutions ont été trouvées et de nouvelles idées sont proposéesPresent work deals with the new trend to get highly flexible electronics by using fully Organic Thin-Film Transistor (OTFT) as the basic element of this electronics. Fully organic n-type as well as p-type OTFT processed by inkjet printing are studied. Printing parameters of each ink, jettability, wetting, printability, and patterns optimization, leading to the deposition of conductive contacts, gate insulator and semiconducting active layer are studied. Process of n-type OTFT based on C60 is shown as unreliable, mainly due to the poor solubility of C60 in organic solvent. In the contrary, p-type OTFTs based on Tips-pentacene are much more reliable. The work is a large overview of the issues and the difficulties that have been to jump and to solve in the way to fabricate fully printed organic transistors. Some solutions have been given and new ideas have been proposed
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Burnside, John. "Reintroduction and conservation of the Great Bustard Otis tarda." Thesis, University of Bath, 2013. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.604569.
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Conservation reintroduction aims to establish an organism into an area from where it has disappeared or was extirpated. Monitoring is essential to identify the factors that underpin successful establishment and persistence of a self-sustaining population. The Great Bustard (Otis tarda) is globally threatened and became extinct as a breeding species in the United Kingdom (UK) in 1832. Trial releases began in 2004 to reintroduce the Great Bustard to the UK based on the release of captive-reared chicks transported from a source population in Russia. The aim of this research was to investigate the factors influencing the establishment of a founder population of Great Bustards in the UK. In Chapter 1, I set the context of the reintroduction science and management in the world today and explore the issues surrounding it. Chapter 2 sets the baseline by which to measure the Great Bustard reintroduction project using the first five years of releases (2004 – 2008). Estimating vital rates and modelling population growth, I show that low recruitment to the founder population is a limitation for establishment. Chapters 3 and 4 investigate post-release survival and dispersal, both important variables in population establishment. By modelling individual post-release survival I show that earlier date of release can improve survival and could be used to improve recruitment. Conversely, post-release dispersal had mixed implication for the management of the reintroduced population. Surviving Great Bustards incorporated the release site into their annual range and as their breeding site. However, the birds had traversed large areas reducing our ability to monitor and control the environment of individuals. In Chapter 5, the research focus moves from the reintroduction project to an examination of the impact of disturbance and conspecific attraction (presence of conspecifics positively influences the movement of individuals) in habitat selection in a small extant population of Great Bustards. I show that the spatial distribution of display sites is influenced by anthropogenic disturbance; however, the number of males attending the display sites is influenced by the abundance of female conspecifics. The management implications of this result are that the attraction to conspecifics is an important factor in habitat selection. Finally, in Chapter 6, I discuss project limitations, potential interventions and identify future areas of research.
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Líčeník, Lukáš. "Motivace a stimulace zaměstnanců ve firmě OTIS a. s." Master's thesis, Vysoké učení technické v Brně. Fakulta podnikatelská, 2012. http://www.nusl.cz/ntk/nusl-223466.
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The subject of my diploma thesis is motivation and stimulation of employees in the Otis Company. This thesis is divided into two parts and includes theoretical and practical elaboration of the issue. The first part provides a theoretical basis related to motivation, stimulating and remuneration of employees. In the practical part I analysed the current situation of the chosen company. Based on detected results I identified key problem areas and I made a proposal for improving of existing incentive system.
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Belgardt, Christian. "Herstellung mikrostrukturierter OTS-Monolagen auf Siliziumoxidoberflächen." Master's thesis, Universitätsbibliothek Chemnitz, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-86379.
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Die Oberflächeneigenschaften eines Festkörpers können mit Hilfe dünner, durch Selbstorganisation gebildeter Molekülschichten aus Alkoxysilan-Molekülen gezielt verändert werden. Mikrostrukturierte selbstangeordnete Monolagen (SAM) können für die Anwendung in Bauelementen aus organischen Halbleitern von großem Interesse sein. Mikrokontaktdruck und Photolithographie sind zwei etablierte Verfahren, die jedoch Vorlagen und Masken zur Strukturierung benötigen. Dadurch entstehen bei häufig wechselnden Strukturen nicht zu vernachlässigende Rüstzeiten und Kosten. In der vorliegenden Arbeit wird die Erzeugung lateral strukturierter Schichten von Octadecyltrichlorsilan (OTS) auf Siliziumoxidoberflächen am konkreten Beispiel zweier alternativer, sowohl maskenloser als auch kontaktloser Methoden demonstriert: (i) Tintenstrahlverfahren als rein additive Strukturierung, und (ii) laserinduzierte, photothermische Desorption als subtraktive Strukturierung einer OTS-SAM . Für das Tintenstrahldruckverfahren wird an einem Kontaktwinkelmessgerät eine Methode zur Beobachtung und Auswertung der Tropfenverdampfung implementiert und ein Modell für kleine Tropfen entwickelt. Für die subtraktive Strukturierung werden an einem selbst entwickelten Versuchsaufbau die leistungs- und geschwindigkeitsabhängige Strukturbreite untersucht. Die Ergebnisse der beiden Technologieansätze werden verglichenWith help of thin layers of alkoxysilane molecules formed by self-assembly, the surface properties of solids can be controlled. Microstructured self-assembled monolayers (SAMs) are interesting for applications in components based on organic semiconductors. Two established technologies for the structuring of molecular monolayers are microcontact printing and photolithography, for which templates and masks need to be structured. In this way, setting times and costs are high if variable patterns have to be structured. In this work, the fabrication of laterally structured monolayers from octadecyltrichlorosilane (OTS) is demonstrated for two examples of alternative, both template-free and maskless technologies: (i) inkjet as a purely additive method, and (ii) photothermal laser desorption as a subtractive structuring of an OTS-SAM. For the inkjet technology, a method for the observation and analysis of the evaporation of a droplet is implemented at a goniometer and a mathematical model for small inkjet droplets is extrapolated, For the subtractive laser structuring, the achievable patterning resolution is investigated as a function of laser intensity and scanning speed. The results of both technological approaches are compared
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Schmidt, Rüdiger. "Perylene bisimide and acene derivatives as organic semiconductors in OTFTs." kostenfrei, 2008. http://nbn-resolving.de/urn/resolver.pl?urn=nbn:de:bvb:20-opus-29314.
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Hizon, John Richard. "Reconfigurable CMOS OTAs for filters in a multi-standard receiver." Thesis, Imperial College London, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.540631.
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Za'aba, Nor. "Electrical, environmental and optical stress effects on PS-DNTT OTFTs." Thesis, Bangor University, 2018. https://research.bangor.ac.uk/portal/en/theses/electrical-environmental-and-optical-stress-effects-on-psdntt-otfts(d44daf1d-ab86-4c14-92ae-c0f21ba8f0de).html.
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Exposure to moisture and elevated temperatures in organic thin film transistor (OTFT) usually results in significant degradation in the electrical performance. In this thesis the effects of temperature, T, and relative humidity, RH, on PS-DNTT OTFTs are investigated. Device characteristics were measured after 30-min exposure to RH that was gradually increased from 20% to 80% with T fixed at 20 oC and also for T increasing from 20 oC to 90 oC with RH held at 10%. The turn-on and threshold voltages show a negative shift with minimal change in mobility upon exposure to higher RH and T. A very minimal change was observed in the deeper states in the density of states (DoS) that was extracted from transfer characteristics in the linear regime using the Grünewald approach. These results suggest that OTFT instability is due to the flatband voltage shift caused by hole trapping/detrapping in the polystyrene gate dielectric or at the polystyrene/DNTT interface. Understanding the origin of electrical instability in OTFTs over long periods of time is also essential to realize high performance circuits. In this thesis, the effects of bias stress on PS-DNTT OTFTs is investigated over a range of temperature and relative humidity. It was found that the threshold voltage, VT, always shifted in the direction of the applied gate voltage. It was also observed that the threshold voltage shift, ΔVT, reduced as the drain voltage increased. The time-dependences of ΔVT in both linear and saturation regimes are well described by the stretched exponential function. Contrary to most previous reports, the threshold voltage at long times, VT(∞), asymptotes to a value well below the applied gate voltage. The VT change is minimal with increasing humidity under saturation bias and temperature. In all cases, the DoS exhibits similar behavior with weak features appearing at the deeper states. This is unlikely to be related to DNTT as there is no change in the gate-voltage dependence of mobility, but rather due to a changing flat-band voltage when electron/hole occupancy of interface states changes as the device turns on. Effect of illumination on the electrical performance as well the underlying physics of these effects are important for the development of several applications such as the backplane for display technology and photosensors. In this thesis the effect of illumination on PS-DNTT OTFTs has been investigated with light of different wavelengths and intensities. The greatest effect was observed at 460 nm with significant changes occuring in the subthreshold slope. Interestingly the profile of the deeper states in the DoS spectrum did apparently change. It was also found that changes in threshold voltage, turn-on voltage, subthreshold slope and responsivity all appear to saturate at higher light intensity due to a trap limited effect. Since there is no significant change observed in mobility, the DoS changes can be explained by (i) trapping of photogenerated electrons, (ii) an unstable shift in the light-induced flat-band ΔVFB, caused by detrapping or neutralization of electrons as the transistor is turned on so that ΔVT(∞) < ΔVON(∞), (iii) accumulation of electrons in DNTT near to source contact or (iv) the effect of the electron quasi Fermi level, QFL. The effect of bias stress and illumination on PS-DNTT has also been investigated with different wavelengths, time and intensity. It was observed that the transfer characteristic shows a parallel shift toward more positive voltages under positive bias stress (PBS) regardless of the wavelength. However under negative bias stress (NBS) at λ ≥ 520 mm, the transfer characteristic shifts negatively due to the dominant effect of hole trapping at the PS-DNTT interface.
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Díaz, José Antonio, and Virendra N. Mahajan. "Diffraction and geometrical optical transfer functions: calculation time comparison." SPIE-INT SOC OPTICAL ENGINEERING, 2017. http://hdl.handle.net/10150/626488.
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In a recent paper, we compared the diffraction and geometrical optical transfer functions (OTFs) of an optical imaging system, and showed that the GOTF approximates the DOTF within 10% when a primary aberration is about two waves or larger [Appl. Opt., 55, 3241-3250 (2016)]. In this paper, we determine and compare the times to calculate the DOTF by autocorrelation or digital autocorrelation of the pupil function, and by a Fourier transform (FT) of the point-spread function (PSF); and the GOTF by a FT of the geometrical PSF and its approximation, the spot diagram. Our starting point for calculating the DOTF is the wave aberrations of the system in its pupil plane, and the ray aberrations in the image plane for the GOTF. The numerical results for primary aberrations and a typical imaging system show that the direct integrations are slow, but the calculation of the DOTF by a FT of the PSF is generally faster than the GOTF calculation by a FT of the spot diagram.
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Montško, Marián. "Návrh, implementace a správa firemních VoIP sítí." Master's thesis, Vysoká škola ekonomická v Praze, 2008. http://www.nusl.cz/ntk/nusl-3338.
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Tato diplomová práce se zabývá návrhem, implementací a správou datové a VoIP sítě. První část práce pojednává o teoretických poznatcích, které se dělí na dvě oblasti: ITIL (IT Infrastructure Library) a VoIP (Voice over IP). Druhou částí práce je praktický příklad, kde postupně řeším návrh, implementaci a správu služeb dle ITIL v nástroji OTRS.
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Williams, Robert Stansell Roslin. "Ecology and population dynamics of the long-eared owl Asio otus." Thesis, University of East Anglia, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338230.
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Aguiar, André Filipe Oliveira. "Populações de Strix aluco e Otus scops em áreas agro-florestais." Master's thesis, Universidade de Aveiro, 2009. http://hdl.handle.net/10773/892.
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Mestrado em Ecologia, Biodiversidade e Gestão de EcossistemasO presente estudo tem como objectivo estudar as populações de Coruja-domato e de Mocho-d'orelhas em áreas agro-florestais, nomeadamente as suas distribuições, densidades e estimativas populacionais, influência de factores ambientais e temporais, comportamento a vocalizações da mesma e espécie e de outras e selecção de habitat. A nebulosidade afectou a detectabilidade da Coruja-do-mato e o vento a detectabilidade do Mocho-d'orelhas. A actividade vocal destas espécies decai ao longo da noite, sendo que normalmente estas espécies não se deslocam durante a emissão de vocalizações. As espécies encontram-se associadas a manchas florestais próximas de estradas não asfaltadas. A distribuição de Coruja-do-mato é influenciada pela presença de ruínas e edifícios abandonados. A distribuição de Mocho-d'orelhas é influenciada pela presença de vizinhos conspecíficos e de áreas de matos. Salienta-se a importância da realização de mais estudos do género, em particular para o Mocho-d'orelhas. ABSTRACT: This study aim to study the Tawny Owl and Scops Owl populations in farmland woodland areas, specially their distributions, population and densities estimations, temporal and environmental factors influence, behavior towards conspecific and other owl species vocalizations and habitat selection. The sky cover affects the Tawny Owl detectability and the wind the Scops Owl detectability. The vocal activity decay during the night, and these species do not move during the vocalizations playback. These species are associated with woodland areas near to non pavemented roads. Tawny owl distribution is influenced by the presence of ruins and abandoned buildings. Scops owl distribution is influenced by the presence of conspecífico neighbors and shrubland areas. The importance of more of this kind of studies, particularly with Scops Owl, is highlighted.
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Cinnirella, Alessandro. "Nanoindentazione dello strato di pentacene in otft sottoposti a irraggiamento ionico." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amslaurea.unibo.it/5950/.
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In questa tesi abbiamo presentato i risultati sperimentali di nanoindentazione su pentacene in transistor organici a film sottile (OTFT) sottoposti ad irraggiamento ionico. Nella prima parte si ripercorre lo sviluppo della tecnica di indentazione strumentata, con una focalizzazione particolare sui modelli matematici proposti per l'interpretazione dei dati forza-spostamento ricavati da queste misure. In particolare, viene diffusamente esposta l'implementazione della tecnica di analisi proposta da Oliver e Pharr, che è utilizzata in questa tesi. Il secondo capitolo espone le caratteristiche generali (strutturali ed elettriche) degli OTFT. Un paragrafo è dedicato al pentacene, che rappresenta lo strato attivo dei transistor organici su cui sono state effettuate le misure in laboratorio. L'ultima parte del capitolo consiste in una panoramica dell'interazione tra radiazioni e polimeri. Vengono quindi presentati i risultati sperimentali: si confrontano le proprietà di durezza e modulo di Young per campioni caratterizzati da differenti specie ioniche, dosi ed energie di irraggiamento (unitamente a campioni reference, per permettere un confronto con il pentacene sottoposto a bombardamento).
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Haddad, Clara. "Fabrication, caractérisation électrique et fiabilité des OTFTs imprimés sur substrat plastique." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAT116/document.
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Cette thèse porte sur l’étude de la stabilité et de la fiabilité de transistors organiques imprimés au CEA-Liten. Des OTFTs de type P ont été fabriqués sur plastique, avec un polymère semi-conducteur (SCO) de type P (SP400 de Merck) et un fluoropolymère en tant que diélectrique. Tout d’abord, un protocole expérimental pour la caractérisation électrique a été mis en place afin de s’affranchir de potentiels effets dus à l’environnement, la mesure ou le vieillissement des OTFTs. Puis un modèle basé sur l’expression de la charge d’accumulation dans le transistor a été développé. Ce modèle a permis l’extraction des paramètres des OTFTs lors de mesures à basses températures, qui ont mis en évidence un transport de charges en température dans le SCO. Enfin, l’impact du stress électrique de grille négatif sur les caractéristiques des transistors a été étudié. La stabilité électrique des P-OTFTs a été mesurée sur plusieurs empilements afin d’étudier l’influence du diélectrique ou de sa méthode de dépôt et l’influence de la grille (électrode en encre argent imprimée ou en or pulvérisée)This thesis project is about the study of stability and reliability of organic transistors printed at CEA-Liten. P-Type OTFTs were manufactured on plastic substrate, with a p-type polymer semiconductor (SP400 from Merck) and a fluoropolymer as dielectric. First, an experimental protocol for electrical characterization was determined in order to overcome potential effects due to environment, measurements or aging of OTFTs. Then a model based on the expression of the accumulation charge in the transistor was developed. This model allowed the OTFT parameters’ extraction during low temperature measurements, which showed a temperature-activated charges transport in the OSC. Finally, the impact of negative gate bias stress on OTFTs’ characteristics was studied. The electrical stability of the P-OTFTs was measured on several stacks to study the influence of the dielectric material or its deposition method and the influence of the gate (printed silver ink or sputtered gold electrode)
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Bernát, Michal. "Zavádění systému řízení kvality pro projekt Metro Londýn v OTIS a.s." Master's thesis, Vysoké učení technické v Brně. Fakulta podnikatelská, 2014. http://www.nusl.cz/ntk/nusl-224703.
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This thesis deals with the implementation of quality management system in the project of Metro of London, implemented by Otis a.s. The theoretical part describes quality management tools. In the analytical part, there are mapped processes of project of Metro of London and identified problems and opportunities for improvement of processes of this project. Based on this analysis of outputs, there are designed corrective moves and their evaluation for defined problems.
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Illinger, Mario. "Bibliotheksbenutzer als personalisierte OTRS-Kunden - Verwendung vorhandener Authentifizierungs- und Stammdaten für die automatisierte Personalisierung von eingehenden Benutzertickets im OTRS zur Verbesserung des Kundenservices und Vereinfachung des Supportaufwands." Master's thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-99336.
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Die vorliegende Arbeit untersucht Möglichkeiten zur Verbesserung des Kundenservices und Vereinfachung des Supportaufwands im Zusammenhang mit dem Open Ticket Request System der Sächsischen Landesbibliothek - Staats- und Universitätsbibliothek Dresden. Die dazu spezifizierte Aufgabe ist eine automatisierte Personalisierung der Benutzertickets unter Verwendung vorhandener Stammdaten der Benutzer. Diese Aufgabe ist, anhand gestellter Anforderungen, in geeignete Bestandteile aufgegliedert, für welche einzeln Lösungsansätze vorgestellt und bewertet wurden. Diese theoretischen Betrachtungen sind in einem prototypischen System umgesetzt, um die praktische Umsetzbarkeit zu bewerten.
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Phelan, Richard B. "OTF DGPS for estuarine dredging and sounding surveys." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ30017.pdf.
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Webb, Timothy Dayton. "The Booking Window Evolution and its Impact on Hotel Revenue Management Forecasting." Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/90789.
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Travel booking behavior has changed substantially over the past two decades. The emergence of new technology and online intermediaries has provided travelers with the flexibility to book up until the date of stay. This has created a fast-paced, dynamic booking environment that disrupts traditional revenue management strategies focused on pricing and allocating rooms based on the time of purchase. The study explores the joint effects of technology and the economy on booking window lead times. It also evaluates a range of forecasting techniques and the importance of utilizing the booking curve for forecasting in dynamic booking environments.PHD
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Niebling, Frank. "Entwurf und Realisierung einer Configuration Management Database nach ITIL für den Service Desk der SLUB Dresden." Master's thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-62906.
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In der Arbeit wird der Entwurf und die Realisierung einer Configuration Management Database für den Service Desk der SLUB Dresden betrachtet. Es wird auf Grundlage von ITIL und den Anforderungen der SLUB ein Konzept zum Aufbau und zur Strukturierung der dabei relevanten Daten vorgestellt. Für den Import der Daten wird ein automatisiertes System geschaffen, das Daten aus verschiedenen Quellen mit der Configuration Management Database in regelmäßigen Abständen abgleicht. Der Service Desk erhält dadurch einen zentralen Zugriff auf Daten zu physikalischen Geräten sowie virtuellen Maschinen und kann diese in die Arbeitsprozesse integrieren. Zusätzlich wird das System durch den scriptbasierten Import von Verlinkungen zwischen virtuellen und physikalischen Servern und Ergebnissen aus der Geräte- und Netzwerküberwachung ergänzt. Schließlich wird betrachtet, welche
weiteren Entwicklungsschritte auf Grundlage der vorgenommenen Änderungen möglich worden und welche Aspekte bei der Umsetzung dieser Schritte eine Rolle spielen.
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Travaglini, Lorenzo. "In-situ detection of defect formation in organic flexible electronics by Kelvin Probe Force Microscopy." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/10380/.
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Organic semiconductor technology has attracted considerable research interest in view of its great promise for large area, lightweight, and flexible electronics applications. Owing to their advantages in processing and unique physical properties, organic semiconductors can bring exciting new opportunities for broad-impact applications requiring large area coverage, mechanical flexibility, low-temperature processing, and low cost. In order to achieve highly flexible device architecture it is crucial to understand on a microscopic scale how mechanical deformation affects the electrical performance of organic thin film devices. Towards this aim, I established in this thesis the experimental technique of Kelvin Probe Force Microscopy (KPFM) as a tool to investigate the morphology and the surface potential of organic semiconducting thin films under mechanical strain.
KPFM has been employed to investigate the strain response of two different Organic Thin Film Transistor with active layer made by 6,13-bis(triisopropylsilylethynyl)-pentacene (TIPS-Pentacene), and Poly(3-hexylthiophene-2,5-diyl) (P3HT). The results show that this technique allows to investigate on a microscopic scale failure of flexible TFT with this kind of materials during bending. I find that the abrupt reduction of TIPS-pentacene device performance at critical bending radii is related to the formation of nano-cracks in the microcrystal morphology, easily identified due to the abrupt variation in surface potential caused by local increase in resistance. Numerical simulation of the bending mechanics of the transistor structure further identifies the mechanical strain exerted on the TIPS-pentacene micro-crystals as the fundamental origin of fracture.
Instead for P3HT based transistors no significant reduction in electrical performance is observed during bending. This finding is attributed to the amorphous nature of the polymer giving rise to an elastic response without the occurrence of crack formation.
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Jensen, Courtney LeAnn. "AGE, ATTENTION, AND OTS IN A CONSTRAINED VS UNCONSTRAINED TASK." UKnowledge, 2012. http://uknowledge.uky.edu/rehabsci_etds/4.
Full textAbstract:
The discourse of older healthy adults is commonly described as lengthy and off-topic and thought to be associated with a general cognitive decline that occurs in healthy aging. This study investigated the overall decline in attention associated with healthy aging and its relationship to instances of off-topic speech (OTS) in a constrained and unconstrained language production task. Ninety cognitively healthy adults participated and comprised three age cohorts (40 – 75+). Participants completed cognitive measures of attention and two discourse tasks that included recounting personal events and describing a procedure. Older adults exhibited poorer scores on measures of selective and shifting attention, and elderly adults produced more OTS as compared to middle-aged (40s) and older (60s) adults in the unconstrained task only. Poorer scores of shifting attention were significantly correlated with more OTS in the older adults (60s) only. Overall, a marked increase in variability of language production was observed with advancing age. Results indicated the need for further research on the relationships between age, attention, OTS, and task type in healthy aging to determine an underlying cause for increasing variability of language production with age.
24
Machač, Stanislav. "Inovace výroby soudečků valivých ložisek objemovým tvářením za studena (OTS)." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2008. http://www.nusl.cz/ntk/nusl-228248.
Full textAbstract:
MACHAČ Stanislav: Spherical rollers process innovation by applicaton of cold bulk forming. Diploma thesis of the attendance engineer´s studies, Institute of technology, 2nd year, 2nd level – summer term, study group 5O / 51, school year 2007 / 2008. FSI VUT Brno, department of forming and plastics, May 2008, 75 pages, 6 tables, 4 enclosures. The topic of this thesis is production innovation of spherical rollers for bearings. The innovation is based on the technology of cold bulk forming. According to the literary research and according to the current stage of production is proposed and conceived manufacturing process for cold upsetting instead of turning using in current spherical rollers production. This manufacturing process is dedicated for the bearing type 22226EJ. The production process is conceived with regard to determinate knuckle-joint press LLR 1000 (Smeral Brno, a.s.). Also with regard to determinate half-closed die upsetting and with regard to formability of the steel 100CrMn6. The proposal and check-up of tool functional parts are designed regarding the current setting of particular parts of the press. In the next part of this thesis the proposal of work-room layout dedicated for hand-filling of semi-factured product is conceived. In conclusion the comparison of spherical roller production budget between cold upsetting and turning is conceived.
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Perlman, Yoav. "Responses of Great Bustard (Otis tarda) subpopulations to land-use changes in southwestern Iberia." Thesis, University of East Anglia, 2018. https://ueaeprints.uea.ac.uk/70109/.
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Land-use change is the single most important cause of global biodiversity loss. Over millennia, European grassland birds concentrated in low-intensity agro-steppe habitats that are now experiencing intensification largely in line with European market forces. Great Bustard (Otis tarda, GB) is a globally threatened species and a symbol of the Iberian agro-steppes. In Extremadura (Spain) and Alentejo (Portugal) the conservation status of GB and other agro-steppe species is unclear. GB subpopulations were monitored in these two regions between 1985 and 2015, and their trends were related to land-use changes using open-access databases. There was regional variation in trends, and I report here a sharp decline in numbers across the study area since 2010. Trends were not related to moderate reduction of agro-steppe habitats, but were negatively related to changes in livestock densities, implying that livestock management of habitats is crucial for conservation. Using field counts in spring 2017 across a network of EU Special Protected Areas (SPAs) designated to protect GB, I found that GB is not a good indicator for other agro-steppe species of conservation concern. Selection of further indicator species is recommended for better conservation of agro-steppe bird assemblage. In an SPA in Extremadura, GB productivity rates decreased dramatically between 2005 and 2016. If current productivity rates continue, population modelling predicts a steep decline in numbers at this site. Results of this study raise concerns over the function of the SPA network in Extremadura and Alentejo to protect GB and their agro-steppe habitat. To sustain numbers of GB and other agro-steppe species, their habitats need to be better protected from further intensification, including control of livestock densities, preferably using agro-environmental schemes in PAs.
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Bebiche, Sarah. "OTFTs de type N à base de semiconducteurs π-conjugués : fabrication, performance et stabilité." Thesis, Rennes 1, 2015. http://www.theses.fr/2015REN1S105/document.
Full textAbstract:
L'objectif de ce travail de recherche est l'élaboration et l'optimisation de transistors à effet de champ organiques de type N (OTFTs). Des transistors en structure Bottom Gate Bottom Contact sont fabriqués à basse température T<120°C. Trois différentes molécules organiques conductrices d'électrons, déposées par évaporation thermiques, sont utilisées pour la couche active. Les OTFTs à base de la première molécule à corps LPP présentent de faibles mobilités à effet de champ de l'ordre de 10-5cm2/V.s. L'étude d'optimisation menée sur les conditions de dépôt de cette dernière n'a pas permis d'améliorer ses performances électriques. L'étude de stabilité électrique ''Gate Bias Stress'' a mis en évidence les instabilités de cette molécule. Les OTFTs à base des deux dérivés indénofluorènes (IF) possèdent des mobilités plus importantes. Dans les conditions optimales la molécule IF(CN2)2 méta permet d'atteindre une mobilité d'effet de champ µFE=2.1x10-4 cm2/V, alors que la molécule IF(CN2)2 para permet d'obtenir des mobilités µFE=1x10-2cm2/V.s après recuit. L'étude de stabilité électrique a mis en évidence une meilleure stabilité des OTFTs à base de IF(CN2)2 para. Une étude des phénomènes de transport de charges est menée pour les deux types de molécules. Les OTFTs de type N réalisés sont utilisés pour la réalisation d'un circuit logique de type inverseur pseudo-CMOS. Finalement, ce procédé basse température nous a permis de réaliser des OTFTs sur substrat flexibleThe main goal of this present work consists in the fabrication and optimization of N type organic field effect transistors. Bottom Gate Bottom Contact transistors are performed at low temperature T<120°C. Three different electro-deficient organic molecules are thermally evaporated and used as active layer. OTFTs based on LPP core molecule present low field effect mobility around 10-5cm2/V.s. The optimization study investigated on deposition parameters of this molecule on OTFTs performances does not allow improving this mobility. Moreover gate bias stress measurements reveal important instabilities related to this molecule. Indenfluorene derivatives core (IF) based OTFTs show better performances. Field effect mobility µFE=2.1x10-4 cm2/V is reached using IF(CN2)2 meta in optimized deposition conditions and µFE=1x10-2 cm2/V.s is obtained using IF(CN2)2 para after annealing treatment. The investigated gate bias stress study highlights the good electrical stability of IF(CN2)2 para based OTFTs. Temperature measurements allow us studying the charge transport phenomenon in these indenofluorene derivatives. Fabricated N-type OTFTs are used to perform a first electronic circuit that consists in a logic gate (invertor).Finally this low temperature process led us to achieve OTFTs devices on flexible substrates (PEN)
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Naikoti, Ashwitha. "OTFS Transceivers Design using Deep Neural Networks." Thesis, 2021. https://etd.iisc.ac.in/handle/2005/5640.
Full textAbstract:
Next generation wireless systems are envisioned to provide a variety of services with a wide range of performance requirements. Particularly, demand for high-mobility use cases involving high-speed trains, UAVs/drones, and aeroplanes is increasing. Also, wireless spectrum in the millimeter wave band (e.g., 28-60 GHz) is used to meet the growing bandwidth requirements. Communication in high-mobility and high-carrier frequency scenarios is challenging as it involves high Doppler shifts. Widely used modulation schemes such as orthogonal frequency division multiplexing (OFDM) perform poorly in such high-Doppler scenarios. Orthogonal time frequency space (OTFS) is a recently proposed modulation scheme which is robust to high Doppler shifts. It operates in the delay-Doppler domain and converts a high-Doppler channel into an almost static channel. In this thesis, we focus on the design of OTFS transceivers using deep neural networks (DNNs). The key contributions in the thesis can be summarized into three parts: 1) design of a low-complexity DNN architecture for OTFS signal detection, 2) design of a multi-DNN architecture for delay-Doppler channel training and detection, along with IQ imbalance (IQI) compensation, and 3) bit error rate (BER) analysis of OTFS in the presence of imperfect channel state information (CSI).
First, we consider a DNN architecture in which each information symbol multiplexed in the delay-Doppler (DD) grid is associated with a separate DNN. The considered symbol-level DNN has fewer parameters to learn compared to a full DNN that takes into account all symbols in an OTFS frame jointly, and therefore has less complexity. When the noise model deviates from the standard i.i.d. Gaussian model (e.g., non-Gaussian noise with t-distribution) the proposed symbol-DNN detection is found to outperform maximum-likelihood (ML) detection, because of the ability of the DNN to learn the distribution. A similar performance advantage is observed in MIMO-OTFS systems where the noise across multiple received antennas are correlated.
Next, we propose a multi-DNN transceiver architecture for DD channel training and detection, along with IQI compensation. The proposed transceiver learns the DD channel over a spatial coherence interval and detects the information symbols using a single DNN trained for this purpose at the receiver. The proposed transceiver also learns the IQ imbalances present in the transmitter and receiver and effectively compensates them. The transmit IQI compensation is realized using a single DNN at the transmitter which learns and provides a compensating modulation alphabet without explicitly estimating the transmit gain and phase imbalances. The receive IQI imbalance compensation is realized using two DNNs at the receiver, one DNN for explicit estimation of receive gain and phase imbalances and another DNN for compensation. Simulation results show that the proposed DNN-based architecture provides very good performance.
Finally, we analyze the effect of imperfect CSI on the BER performance of OTFS. We carry out the BER analysis when a mismatched ML detector is used, i.e., when an estimated channel matrix is used for detection in place of the true channel matrix. We derive an exact expression for the pairwise error probability (PEP) using the characteristic function of the decision statistic. Using the PEP, an upper bound on the BER is obtained. Our results show that the BER bound is tight at high SNR values. We also obtain the decision rule for the true ML detector in the presence of imperfect CSI, which takes into account the channel estimation error statistics. We quantify the performance gap between the true ML detector and the mismatched ML detector through simulations.
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Sinha, Sujata. "OTFS Modulation in MIMO Visible Light Communication Systems." Thesis, 2022. https://etd.iisc.ac.in/handle/2005/5739.
Full textAbstract:
Visible light communication (VLC) technology is emerging as an attractive technology for wireless communication in indoor and vehicular environments. In VLS systems, light emitting diodes (LED) and photo diodes (PD) are used for wireless signal transmission and reception, respectively, using the visible light spectrum. VLC systems are gaining popularity because of their ability to provide lighting and short-range communication simultaneously. Recently, a new modulation scheme called orthogonal time frequency space (OTFS) modulation has been introduced in the radio frequency (RF) communications domain, where it has been shown that OTFS achieves significantly better performance compared to the widely used orthogonal frequency division multiplexing (OFDM). OTFS is a two-dimensional (2D) modulation scheme, where MN information symbols are multiplexed in the delay-Doppler (DD) domain using M Doppler bins and N delay bins. This is in contrast to OFDM where information symbols are multiplexed in the time-frequency (TF) domain. Because of the demonstrated superiority of OTFS in the RF communication domain, research in OTFS for VLC systems has gained importance recently. In this context, it is of interest to 1) adapt OTFS waveform to VLC settings, and 2) investigate the performance OTFS in indoor VLC environments. In this thesis, we propose efficient multi-LED OTFS modulation schemes suited for visible light communication and analyze their bit error performance in indoor communication environments.
First, we propose two dual-LED transmission schemes, namely, non-DC-biased OTFS (NDC-OFTS) scheme and dual-LED complex modulation OTFS (DCM-OTFS) scheme. The NDC-OTFS scheme uses 2D Hermitian symmetry operation to convert complex signals to positive, real-valued signals suitable for transmission in the optical domain, and the DCM-OTFS scheme achieves this by exploiting the polar representation of complex signals. We obtain analytical upper bounds on the bit error performance of the proposed schemes, which are found to be tight at high signal-to-noise ratios (SNRs). Our analytical and simulation results show that the proposed OTFS schemes achieve better performance compared to their OFDM counterparts reported in the VLC literature. Further, using the ratio of the minimum distance of different normalized received signal sets as a metric, we quantify the spatial distribution of the SNR gain of the OTFS schemes compared to their OFDM counterparts.
Next, we propose two quad-LED architectures, namely, quad-LED complex modulation OTFS (QCM-OTFS) scheme and spatial modulation DCM-OTFS (SM-DCM-OTFS) scheme. The QCM-OTFS scheme sends the magnitudes of real and imaginary parts of complex signals through intensity modulation and their sign information through spatial indexing of LEDs. The proposed SM-DCM-OTFS scheme sends the magnitude and phase of complex signals (polar representation) through a pair of LEDs and frame indexing across two pairs of LEDs. We also propose two multi-LED OTFS schemes, namely, quadrature spatial modulation OTFS (QSM-OTFS) scheme and dual mode index modulation OTFS (DMIM-OTFS) scheme. The proposed schemes use the dual-LED complex modulation block as the basic building block and offer enhanced rates compared to conventional index modulation schemes. The proposed schemes have the advantage of not requiring the Hermitian symmetry and DC bias operations to obtain real, positive-valued signals suited for intensity modulation of LEDs. Our results show that the proposed OTFS based schemes perform better than their OFDM counterparts. Finally, to mitigate the effect of channel correlation and achieve improved system performance, we investigate the use of the pairwise coding technique and singular value decomposition precoding in multiple-input multiple-output (MIMO) VLC systems. Our simulation results show that the pairwise coding is effective in alleviating the effect of spatial correlation.
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Surabhi, G. D. "On Orthogonal Time Frequency Space Modulation for Wireless Communications." Thesis, 2020. https://etd.iisc.ac.in/handle/2005/4461.
Full textAbstract:
Future wireless communication systems are envisioned to support diverse requirements that include high mobility application scenarios such as high-speed trains, and vehicle-to-vehicle and vehicle-toinfrastructure communications. The dynamic nature of wireless channels in such scenarios makes them doubly-dispersive in nature. Orthogonal time frequency space (OTFS) modulation is a recent two-dimensional (2D) modulation technique specially suited for doubly-dispersive wireless channels. A fundamental feature of OTFS modulation is that the information symbols in OTFS modulation are multiplexed in delay-Doppler domain rather than in time-frequency domain as done in conventional multicarrier modulation techniques. An advantage of signaling in the delay-Doppler domain is that a channel rapidly varying in time manifests as a slowly varying sparse channel when viewed in the delay-Doppler domain, which simplifies channel estimation in rapidly time varying wireless channels. In this thesis, we focus on various fundamental and key aspects of OTFS modulation, which include asymptotic diversity analysis, peak-to-average power ratio analysis, design of low-complexity equalizers, OTFS based multiple access systems, and the performance of OTFS in millimeter wave (28 GHz and 60 GHz) channels in the presence of oscillator phase noise.
First, we provide a formal analysis of the asymptotic diversity order achieved by OTFS modulation in doubly-dispersive channels. Our analysis and simulations show that the asymptotic diversity order of OTFS modulation with maximum likelihood detection is one. We propose a phase rotation scheme for OTFS that achieves full diversity in the delay-Doppler domain. We extend the diversity analysis and the proposed phase rotation scheme to OTFS in multiple-input-multiple-output (MIMO) setting as well. We also propose the use of space-time coding to achieve full diversity in both spatial and delay-Doppler domains. We present an analysis of the peak-to-average-power ratio (PAPR) performance of OTFS modulation. We derive an upper bound on the maximum PAPR in OTFS and analytically characterize the complementary cumulative distribution function of the PAPR of OTFS.
Design of low-complexity equalizers is an important requirement for communication in fading channels. We propose low-complexity linear equalizers for OTFS signal detection in doublydispersive channels in both SISO and MIMO settings. The proposed equalizers exploit the block circulant nature of the OTFS channel matrix and achieve exact solutions at a significantly lower complexity compared to that of the conventional approach. We finally consider OTFS based multiple access (OTFS-MA), where delay-Doppler bins serve as the resource blocks for multiple access, in contrast to conventional multiple access schemes where resource blocks are defined in the TF plane. We carry out a comprehensive investigation of key issues in OTFS-MA, such as signal detection , channel estimation , and PAPR characteristics on the multiuser uplink, and compare them with those of OFDMA and SC-FDMA. Finally, we address the problem of high oscillator phase noise in millimeterwave communication systems. We investigate the effect of phase noise on the performance of OTFS modulation in mmWave communications and show that the OTFS is robust to oscillator phase noise.
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Ni, Jen-Shyang, and 倪偵翔. "Development of soluble OTFT materials." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/26092851999167812401.
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碩士國立中央大學
化學研究所
94
Via the Diels-Alder reaction to overcome the low pentacene solubility problem in the organic thin film field-effect transistors (OTFTs) is our goal. Pentacene precursor B (11) had been successfully synthesized from the reaction of N-sulfinyl-methanesulfonamide (10) and pentacene (1) catalyzed by [Pd(dppp)(PhCN)2](BF4)2 (9), which has been charactered spectroscopically by DSC, IR, MS, NMR, TGA, and UV. The kinetic study of pentacene precursor B (11) has been investigated (activation energy, Ea = 108.44 kJ/mol). In solid state, lower conversion temperature (166 ℃, no acid catalyst) of pentacene precursor B (11) was found. In the solution state (CDCl3 or acetone-d6), the lowest conversion temperature (room temperature) of pentacene precursor B (11) was obtained (lifetime is 14 minute in CDCl3). The performance of pentacene precursor B (11) in the OTFT by the solution process will be examined later.
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Fang, Chun Chieh, and 方俊傑. "Ultraviolet Light Protective Layer for OTFTs Encapsulation." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/28361866999927670765.
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碩士國立交通大學
顯示科技研究所
97
In this thesis, we fabricated N,N′-bis(naphthalen-1-y)-N,N′-bis(phenyl) benzidine (NPB) passivation to protect the organic thin-film transistors (OTFTs) from degradation under UV-light illumination. With a thermally-deposited NPB film on the OTFTs, it was found that UV-light induced degradation could be significantly reduced. For example, after about 120 minutes UV-light the change of field effect mobility was only 37 % and the change of threshold voltage was within 10%. On the contrary, the OTFTs without NPB film suffered serious degradation. The field-effect mobility was reduced by about 90%, and the threshold voltage was increased by more than 40%. UV-light induced degradation on OTFTs was also discussed; Through surface morphology analysis by atomic force microscopy ( AFM ) and electron Spectroscopy for Chemical Analysis ( ESCA ) , the surface oxidation and destroyed pentacene grains pentacene film was the dominative factor that influenced OTFT’s properties. We conclude that our NPB passivation is a promising way to protect pentacene TFTs. Finally, I would like to address that the work is conducted under the leading of my supervisor and also Mr. Kuo-His Yen, Ph. D student in our lab. The result is shared with all the co-workers in this research.
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Yeh, Je-Yuan, and 葉哲源. "Novel Methods of Performance Enhancement for OTFT." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/9r6an9.
Full textAbstract:
博士國立中正大學
化學工程研究所
102
Field effect transistors (FETs) were first proposed by Lilienfeld in 1930, and then the first inorganic metal-oxide-semiconductor FET (MOSFET) was fabricated by Kahng and Atalla in 1960. In 1983, F.Ebisawa et al. used polyacetylene as a novel organic active layer material to produce the first organic field-effect transistor (or organic thin film transistor; OTFT). After that time, OTFT have been widely studied. Nonetheless, OTFT are not suitable for applications requiring high switching speed due to their lower mobility and lower On/Off ratio than inorganic thin film transistors (e.g. single-crystal inorganic thin film transistors). However, advantages of OTFT are many, such as a low- temperature production(~ 180 ℃), lightweight, low cost, solution processability, simple packaging, compatibility with flexible plastic substrates and potential applicability to flexible device display…etc. Therefore, OTFT can be widely used to make e-books, e-paper, electronic identification cards for active matrix driving, sensors, flexible circuits, radio-frequency identification (RFID) devices and display operation…etc. In the future, OTFT will have even greater applications in academic and industry. My dissertation is divided into five chapters. In chapter one, the introduction of conjugated polymer and OTFT is provided. In chapter two, the synthesized hydroxyethyl-terminated poly (3-hexylthiophene) (P3HT-OH) is used as a novel active layer material for fabrication OTFT. The hydroxyl group creates the hydrogen bounding between the hydrophobic P3HT polymer chain and the hydrophilic surface of SiO2 wafer, and this leads to regulated polymer chains on the surface of SiO2 wafer and enhances OTFT properties. Compared against the hydrophobic P3HT without hydroxyl group, hydroxyl groups at a 7.5% weight content lead to more chain regularity when polymer is bonded to SiO2 wafer surface and thus enhance the performance of OTFT device, such as an 114.2% increase in On/Off ratio, an 12.4% increase in mobility, a 23.3% decrease in threshold voltage and a 30.1% decrease in surface roughness. However, in a architecture (Si/SiO2/P3HT-OH) without any extra dielectric layer between P3HT and SiO2, many disadvantages appear, such as large leakage current and threshold voltage. To eliminate those disadvantages, in chapter three, we used a self-assembled monolayer, 3-azidopropyltriethoxysilane as a novel dielectric layer to modify the interface between the SiO2 and active layer, and replace simultaneously P3HT-OH with pentacene. Compared to the commonly used alkyl siliane C18 dielectric, 3-azidopropyltriethoxysilane which possesses stable formal charges is far more effective in increasing the On/Off ratio of OTFT device with an improvement of nearly three orders of magnitude. However, this novel SAM does not significantly enhance the other electrical properties except the On/Off ratio duo to the lower dielectric constant of 3-azidopropyltriethoxysilane than alkyl silane C18. Moreover, literatures show the use of silane as a modifying dielectric material is limited to SiO2 surface because the SiO2 surface has reactive hydroxyl groups. In other words, silane types of SAM can not be used in ITO or flexible substrates. In order to fix such problems, we will develop a new dielectric material with a high dielectric constant for all substrates in next chapter. Literatures show that polymeric dielectric layer materials (such as polyethylene phenol Poly (Vinyl Phenol); PVP) was used in ITO substrate because the polymer can be fabricated via spin-coating method on ITO glass. Although PVP is a commonly used polymeric dielectric material, its dielectric constant of PVP is not high (K <4), and literatures show that minimum thickness of polymeric dielectric layer is usually higher than 300nm and a higher operating voltage, 60V are needed for lowering the Pin-Holes effect. In order for OTFT devices to have a dielectric layer with high K (K>4.0)、small minimum thickness (< 300nm) and an ultra-low operating voltage ( < 1V), herein, in chapter four, we aim to design and synthesize an acrylic-based and multiply-polarized dielectric polymer material (because acrylics has the highest dielectric constant than all other polymers). In chapter four, we report a novel crosslinked polyacrylic dielectric material, poly(MMA-co-HEMA-g-AA), which is made via a crosslinking esterification between a specifically synthesized poly(MMA-co-HEMA) and poly(acrylic acid). When used in an ultra-low voltage (operating voltage Vt <1V) pentacene-based organic thin-film transistor (OTFT) as a Gate dielectric, poly(MMA-co-HEMA-g-AA) results in remarkable device performance and exhibits a higher dielectric constant (K=4.2) than those traditionally used crosslinked PMMA (K<3.9; Vt >1V) because of its multiple polarization structures, such as the dipole polarization from ester group of MMA and HEMA, and the ionic polarization from carboxylic acid group of AA. Moreover, the crosslinking esterification temperature for forming poly(MMA-co- HEMA-g-AA) (140℃) is lower than the glass transition temperature (Tg = 185℃) of most widely used plastic substrates, including poly(ether sulfones), and this is very advantageous for being a Gate dielectric. Furthermore, poly(MMA-co-HEMA-g- AA), being an acrylic (refractive index 1.4914 at 587.6 nm), transmits up to 92% of visible light (at 3 mm thickness) and reflects about 4% from its surface, and thus are more suitable than other polymers for fabrication of highly transparent OTFT devices, e.g. electronic papers. Overall, the experimental procedures from the chapter two to chapter four show that the dielectric constant and regulated active layer play very important roles in improving the performance of organic thin film transistors.
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Yan, Ruei-Chih, and 顏睿志. "UV-enhanced Photo responsivity on PMMA-OTFTs." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/64100638432926075374.
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碩士國立交通大學
顯示科技研究所
95
In this study, with the thermal solidification method, the soluble Polymethylmethacrylate (PMMA) was used as the gat-dielectric of organic thin film transistors (OTFTs). Furthermore, we treated the PMMA gate-dielectric with the UV-light treatment. According to our observation, the OTFTs with UV-light treatment on gate-dielectric, the threshold voltage will be reduced, the subthreshold swing will be increased, however, no significant change in field-effect mobility was observed. In the OTFT experiments under light-irradiation, the devices was irradiated with a ray at a wavelength about 460nm. Among the OTFTs with UV-light treatment on gate-dielectric, when the light-irradiation was turn on, a larger threshold voltage shift and phonic responsivity will be found. If we further analyzed the time-dependent OTFT characteristics after the light-irradiation, the OTFTs with UV-light treatment will show a shorter saturation time and a longer recovering time. In order to find out the origin of UV-light treatment on OTFT property variation, we tried to introduce the material analysis and dielectric-leakage analysis to rule out the effects of UV-light treatment on organic semiconductor inertial structure and the traps inside the dielectric film, respectively. Finally, we presumed the OTFT property variation should be dominated by the interface traps between the organic semiconductor film and the dielectric film, which may be created by the UV-light treatment. The proposed assumption is also verified by a serious time-constant analysis.
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Darwis, Darmawati. "Fabricating nanoparticulate organic thin film transistor (OTFT) and organic photovoltaic (OPV) devices using inkjet printing." Thesis, 2013. http://hdl.handle.net/1959.13/1038771.
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Research Doctorate - Doctor of Philosophy (PhD)This thesis presents a systematic study on two types of semiconducting polymer nanoparticulate suspensions prepared using: (1) a surfactant-containing mini-emulsion method, and (2) a surfactant-free precipitation method. Both methods are performed in more environmentally friendly solvents compared with the harmful organic solvents used in conventional organic electronic device fabrication processes. The nanoparticle dispersions and thin films have been examined and characterised by the use of a combination of spectroscopic and microscopic techniques. Subsequently, the nanoparticles have been used to fabricate two types of organic electronic devices: (a) nanoparticulate organic thin film transistors (NPOTFTs) and (b) nanoparticulate organic photovoltaics (NPOPVs). For the NPOTFT fabrication, we have successfully produced low voltage solution-processible top gate NPOTFTs based on hygroscopic dielectrics using both surfactant-containing and surfactant-free P3HT nanoparticle suspensions. The nanoparticulate devices exhibited similar I-V characteristics to transistors based on P3HT films processed from organic solvent. We have also used P3HT:PCBM nanoparticles (prepared by the mini-emulsion and precipitation methods) to fabricate NPOPVs which also achieved a comparable device performance to conventional OPV devices processed in organic solvents. We present preliminary data showing, for the first time, the use of surfactant-free P3HT:PCBM nanoparticles in NPOPV devices. In addition, the application of surfactant-containing nanoparticles to produce for the first time preliminary proof-of-concept printed NPOTFTs and printed NPOPVs based on aqueous dispersion active layer using inkjet printing technique is also presented.
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Yu-Cheng, Hsu. "Molecular Ecology of Elegant Scops Owl (Otus elegans)." 2005. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-2507200510162100.
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陳猛飛. "Study of process variation on P3HT-Based OTFTs." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/85869978277581240961.
Full textAbstract:
碩士國立交通大學
電機學院微電子奈米科技產業專班
97
A procedure is studying and using the solution-process to fabricate P3HT-based organic thin film transistor. Using appropriated solvent and weight percentage is needed. And then the P3HT solution will be spun and deposited to be as active layer for organic electronic. P3HT organic material is to be classified to conjugated polymer. One of advantages is a property of self-organization and based on this structure to form a long chain. This long chain will be formed a lamella structure. If this lamella were packing closely, it would result a high regioregularity, which could obtain high mobility. Due to different process method, this lamella will be formed edge-on or face-on result. In my experiment, First of all, using chloroform to be a solvent with 0.1 weight percentages to fabricated OTFT can obtain better performance than xylene made, due to solubility and like dissolves like. Subsequently, we study the difference between regioregularity and molecular weight, two solutes were purchased from two different companies, dissolved them in the same solvent, chloroform. The result is that the difference of molecular weight is more importance than regioregularity. Moreover, fabricated by spin speed at 1500rpm and curing at 150℃ for 3 minutes can exhibit optimized result and in the meantime, observe that the oxygen concentration is less and less in the thin film analyzed by Auger electronic and ECSA surface elemental. Known a basic process procedure, there is a Schottky barrier between metal and organic material resulting less the current transport. However, S/D deposited with gold and an appropriated adhesion layer can reduce this barrier height, due to their closest work function and surface chemical property. In addition to previous results, to use surface treatment (HMDS) is a good idea to improve the packing and ordering for strong chain interaction and lead to exhibit high mobility and approximate to VG=0 of threshold voltage. In end of this thesis, we discuss about stability characteristics. Storage in the atmosphere, all of organic material will degrade as time goes by. This result is the same as P3HT polymer when it has been stored for one month. But the off current can be “healed” by annealing process at 180℃ for 30 minutes in furnace with N2 flow. Extra, low molecular weight comes to the same thing. Meanwhile, a device undergoing a serious process procedure can obtain a better performance, too. The on/off ratio is improved from 6x104 to 8~6x106; suspect that oxygen molecule can be driven off during annealing process. Unfortunately, the mobility is not to be improved and reduce down to 0.3x10-3 from 6x10-3 slightly and Vth is shifted to more negative, due to chain torsion. Last, constant voltage stress is applied to see how the drain current change. During stress, the drain increases with stress time going by when only drain electrode is applied at -60 voltages. There is no any gate current to be observed. We find out that the basic electrical result of the same device is changing after stress. A slight movement in off current, compared with just annealing one. So we suspect that the oxygen may diffuse into the film during stress.
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Chen, Hong-jhe, and 陳弘哲. "Multi-chamber thin-film deposition for OTFT-application." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/94863789405456246182.
Full textAbstract:
碩士國立臺灣科技大學
電子工程系
95
In this thesis, because organic material extraordinary sensitivity to aqueous vapor and oxygen, so last encapsulation make apparent extraordinary importance Cheng, we design in succession continuing Shen accumulate, make Cheng newly in view of this, are not sending to the glove case after completing the organic material, but encapsulate directly under the environment of vacuum of the same machine platform directly, this way not only can reduce aqueous vapor and invading chance of oxygen, can also not need to use glass as and seal covering again, reduce thickness and manufacturing cost of products greatly, too because this machine for make Cheng at low temperature platform, so can spend on making and application of the forgiving base plate in the future. In the course of experiment, we make from a new one Cheng find out suitable parameter and procedure most, design various material test ways, and erect various gas pipelines, in order to make out the intact finished product, as the final purpose. Finally, after designing and testing, we not only finish the erecting of new apparatus, finish, make best foundation of parameter Cheng newly too. Finish making of component even more, with have now, make component Cheng make performance and characteristic compare, probe into feasibility of practical application its in addition, until orientation march towards by direction larger in future.
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Hsu, Yu-Cheng, and 許育誠. "Molecular Ecology of Elegant Scops Owl (Otus elegans)." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/08689464339765680683.
Full textAbstract:
博士國立臺灣大學
生態學與演化生物學研究所
93
Chapter 1 Isolation and characterization of microsatellite DNA markers from the Lanyu Scops Owl (Otus elegans botelensis) and their cross-species application in four species of strigidae Abstract From a genomic library enriched for GATA/CTAT and GAAA/CTTT repeats, eighteen polymorphic microsatellite markers were developed for the Lanyu Scops Owl (Otus elegans botelensis). Polymorphism of these loci was evaluated in a sample of 100 adult individuals of unknown relationship. The allele numbers of each locus were from 5 to 28 and the observed heterozygosity of each locus ranges from 0.59 to 0.95. All loci conformed to Hardy-Weinberg expectations. In addition, we cross-species tested these microsatellite primer pairs on four other species of owls (O. lettia, O. spilocephalus, O. sunia, and Ninox scutulata). Results showed that the degree of polymorphism decreased with increasing phylogenetic distance to O. elegans. Most loci (12, 15, and 18) were polymorphic in the three Otus owls but only five loci were polymorphic in N. scutulata. These microsatellites should be very useful genetic markers in studying the mating system, population genetics, and conservation genetics of other little studied Old World Otus owls. Chapter 2 Genetic mating system of Lanyu Scops Owls (Otus elegans botelensis) Abstract The genetic mating system is known for only a few species of owls. Most of them are genetically monogamous. The Lanyu Scops Owl (Otus elegans botelensis) breeds in high density in the forests of Lanyu (Orchid Island), southeast of Taiwan. Because extra-pair copulations (EPCs) have frequently been observed, we suspected a high degree of extra-pair fertilizations (EPFs). Using a set of 12 microsatellite loci, we assigned the parentage of 200 offspring from 108 families collected between 1999 and 2004. Parentage analysis revealed only two cases of parentage mismatch among 108 broods. The first case was most likely a case of brood usurpation, which would be the first case reported in the Strigidae. The second case was an EPF resulting in one offspring. Our study found that Lanyu Scops Owls are essentially genetically monogamous. Therefore, field monitoring data has provided reliable estimates of the lifetime reproductive success of this species. Chapter 3 Phylogeography of the Elegant Scops Owl (Otus elegans) on East Asian Islands Abstract The phylogeography of birds reflects the influence of both the geographic history of the area and the dispersal ability of the species. Islands have proven to be ideal sites for such studies due to the nature of their isolation. Elegant Scops Owl (Otus elegans) is a small owl found only in the forests of some East Asian islands. We used complete mitochondrial DNA (mtDNA) cytochrome b and NADH dehydrogenase subunit 6 genes (1665 bp in total) and 13 polymorphic microsatellite loci to analyze the population genetic structure of this owl on 10 islands in the Ryukyu Archipelago, Japan and on Lanyu (Orchid Island), Taiwan, in an attempt to infer the genetic diversity, population differentiation, gene flow, and demographic history of this species. Based on blood samples from 164 owls, we found higher genetic diversity on more northerly islands than on more southerly islands. No mtDNA variations were detected in remote island populations (Minami Daito and Lanyu). Pairwise Fst values between islands showed population differentiation on most islands. A deep divergence between northern and southern Ryukyu populations indicated a long period of north-south isolation. Bayesian estimation using the MDIV program revealed that the divergent time and the rate of gene flow differed among island pairs. Maximum likelihood estimates using MIGRATE found that the gene flow between islands was low and directionally asymmetrical, with a more northerly migration than the reverse. Maximum likelihood analysis using FLUCTUATE revealed that Ryukyu owl population sizes have been increasing since the last glaciation, but the rate of increase are lower in the north than in the south.
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Cheng, Ting-shiuan, and 鄭庭軒. "Device Mechanism and Reliability of Pentacene-based OTFTs." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/69483939461982021262.
Full textAbstract:
碩士國立交通大學
光電工程系所
94
Due to fixable, low temperature process and low cost, application of organic thin film transistor on flat plane display is very suitable to fabricate low cost device. Usually, surface treatment is used to increase mobility of carrier transport in organic thin film transistor. Until now, without anyone analyze reliability of device which is treated. Therefore this paper studies variation of device with and without surface treatment under different DC and AC stress condition. Firstly, we design Gated-Four-Probe (GFP) structure to extract characteristic of device in channel. Analysis of voltage distribution from Gated-Four-Probe can find that carrier transport mechanism of OTFT is consistent with carrier drift mechanism. Subsequently we fabricate Gated-Four-Probe (GFP) structure on different surface treatment substrate. The devices in this paper are separate to standard and two kinds of surface treatment. Standard device is cleaned by RCA clean and the other devices are treated by HMDS or ODMS. Initially, under DC stress condition we can find threshold voltage shift at positive gate bias stress is larger than at negative gate bias stress. Whether at positive or negative gate bias stress condition, Vth shift of devices with surface treatment are larger than standard devices. The extracted parameters from Gated-Four-Probe (GFP) indicate that pentacene film is not changed with time. Therefore reliability issues lie in the gate insulator or SAM layer degradation. Under AC stress condition, Vth shift of standard devices are obvious decrease. It appears that standard devices have better reliability at AC operation. But Vth shift of devices with HMDS and ODMS still have lager value.
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Mong, Fan-Chi, and 孟繁琦. "Dielectric Hydroxyl Groups Effects in Pentacene-based OTFTs." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/40268470512697662826.
Full textAbstract:
碩士國立交通大學
光電工程系所
97
Organic thin film transistors compared with the conventional amorphous silicon thin film transistors have many advantages, such as: low-temperature process, low cost, flexible ... and so on. However, poor reliability and short life time is its application greatest weaknesses. So far, carrier capture defects are recognized as the main reason that causes threshold voltage shift and mobility degradation. In this thesis, dielectric hydroxyl groups (OH groups) defects forming mechanism influenced by the environment is studied. We use methyl methacrylate (PMMA) and poly-4-vinyl phenol (PVP) as the dielectric surface treatment material and make two kinds of OTFTs. PVP-OTFTs have OH groups on its interface while PMMA-OTFTs do not. By comparing PMMA and PVP devices’ hysteresis in dark and under light, we find OH groups can form defects and trap electrons. Illumination will photogenerate electron-hole pair in the organic semiconductor and provides the source of trapped electrons.Then, PMMA and PVP devices positive gate bias stress experiment in dark/light environment indicated that positive gate bias stress can make semiconductor’s energy band bending, some originally do not filled defect states will tend to trap photogenerated electrons and thus cause threshold voltage shift. In addition, positive gate bias stress experiment taken in vacuum environment further proved OH group should react with H2O and O2 in the air then electron defects could be formed. OH groups defects can cause threshold voltage shift on matter it was in dark or light environment. In order to realize OTFTs’ application, passivation layer that could protect organic semiconductor from environment effect is needed. On the other hand, significant threshold voltage shift caused by OH groups implicate OTFTs application on moisture/light sensor.
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Pan, Huang-Wei, and 潘皇維. "The DC/AC Reliability of Pentacene-based OTFT." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/90012163897659604515.
Full textAbstract:
碩士國立交通大學
顯示科技研究所
95
As organic thin film transistor has lots of advantage of low temperature fabrication、low cost and easy fabrication, it has good potential for application on flexible display、sensor、radio-frequency identification tags and other electronics. Although studies have been made on DC gate bias stress without drain bias, the drain bias and AC bias stress in actual operation of organic electronic device is unknown. So we focus on the study of DC gate bias with drain bias stress and AC bias stress in this thesis. First, in the DC gate bias stress without drain bias, the dependence of the threshold voltage shift on the stressing time is found to follow a stretched-exponential function. It is the same as the many recent researchs. When the drain bias is applied, the threshold voltage shift will decrease and be suppressed as the drain bias becomes more negative. Since the threshold voltage shift is proportional to the carrier density, as the drain bias becomes more negative, the carrier concentration in channel is decrease such that the threshold voltage shift is reduced. Therefore, a channel charge normalization factor was used to describe the influence of drain bias and to modify the conventional stretched-exponential function. The threshold voltage shift has strong frequency dependence-the higher frequency same duty ratio, the smaller the magnitude of threshold voltage shift. We used an simple RC equivalent circuit to simulate the device under negative pulsed bias stress. The RC circuit consists of the insulator capacitance Ci, pentacene capacitance Cs, and a effective pentacene resistance Rs for hole conduction and injection. Th effective channel carrier concentration considering the RC delay can successfully explain the dependence of threshold voltage shift on the pulse width of the stressing signal. The channel charge normalization also can be used as the DC bias effect modeto describe the influence of AC bias stress and to modify the conventional stretched-exponential function.
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Huang, Peng-Yi, and 黃鵬毅. "Soluble ADT and diamine-terphenyl derivatives for OTFT material." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/77804112553194711003.
Full textAbstract:
碩士國立中央大學
化學研究所
95
Two new soluble organic semiconductor material systems were investigated. The first system is based on anthradithiophene (ADT), three new organic semiconductor materials: 5,11-dithien-2-ylanthradithiophene (DTADT), 5,11-bis(5-carbaldehydethien-2-yl)anthradithiophene (BATADT), and 5,11-bis(5-carbaldbutylaminothien-2-yl)anthradithiophene (BBTADT) were synthesized. The second system is based on p-terphenyl diamine (TDA), two new organic semiconductor materials: N,N’-bis[(5-butyl-2-thienyl)methylene]-p-terphenyl diamine (BTTDA), and N,N’-bis[(5-triethylsilyl-2-thienyl)methylene]-p-terphenyl diamine (TES-TTDA) were prepared. BATADT with an electron withdrawing aldehyde functional group on the central thiophene shows the stability enhancement and demonstrates a p-type character with current mobility of 2.1x10-5 cm2/Vs, on/off ratio ~ 104 and threshold voltage -31V. The devices fabrication of all the five materials are currently assisted by Tobin J. Marks group at Northwestern University, where the solution process and vacuum deposition will be examined. Hopefully, better mobilities and easier fabrication will be obtained in the future.
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Song, Ho-Tsung, and 宋和璁. "The Application of Aluminum Nitride on Pentacene Based OTFTs." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/69969215165430112414.
Full textAbstract:
碩士國立交通大學
顯示科技研究所
96
The study of pentacene based organic thin film transistors (OTFTs) has been a major area of research on organic semiconducting materials and devices. OTFTs have many advantages such as low process temperature, low cost and simple process fabrication, structure flexibility. However, the high operating-voltage remains a limitation on organic transistors. To lowering the operating-voltage, a high-k materials, aluminum nitride (AlN), has been proposed as a low operating-voltage gate-dielectrics in pentacene based OTFTs. This work was studied with my senior classmate, Cheng-Wei Chou. In this thesis, the AlN dielectric application and aging effect in pentacene based OTFTs are reported. To prevent cross-talk between transistors in close proximity and to achieve a low off-current in OTFTs array, it is necessary to pattern the organic semiconductor layer. A pentacene patterning method on the AlN dielectric surface that can be combined with conventional lithography to pattern pentacene film was reported. The AlN surface was patterned using a conventional photo lithography process and then treated with oxygen (O2) plasma on uncovered AlN to modify surface polarity. The surface energy of O2 plasma treated region was increased drastically. Following pentacene deposition, the sample was dipped in water to remove pentacene from the O2 plasma treated area. The polar surface energy was attributed to the increase of Al-O bonds on the surface based on XPS measurements. The enhancement of the polar surface energy explains the water-removable pentacene patterning mechanism. Likewise, the lowered AlN surface energy over time when the AlN film stored aged in a non-vacuum environment was observed. To confirm the AlN aging effect, the relationship between the aged AlN film and the pentacene based OTFTs were demonstrated in this thesis. The lowered surface energy over the aging time was due to the carbon absorption on the AlN surface. Pentacene based OTFTs fabricated on the aged AlN surface showed a higher performance in electrical characteristics. The mobility was enhanced from 0.05 cm2/Vs to 0.67 cm2/Vs with the limited aging time (14 days). This improved mobility was due to the carbon accumulation on the AlN surface, lowers the surface energy and increased the pentacene coverage in the first few layers.
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Wu, Cheng-Hua, and 吳承華. "The Effect of Illumination for Characteristics of Pentacene-OTFTs." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/23059866459329841758.
Full textAbstract:
碩士國立成功大學
光電科學與工程研究所
94
Thin film transistors (TFTs) based on conjugated organic materials, both small molecules and polymers have emerged recently due to their potential in low-cost, low-temperature fabrication and, the possibility of producing flexible devices. Several groups have proposed or reported successful integration of such devices with Organic light-emitting diodes. The OTFTs exhibiting photoresponsivity, which could act as light sensors, photoswitches or optoelectronic memory elements, open new avenues of research into promising device applications. In our study, we investigated the effect of illumination for characteristics of Pentacene-OTFTs when they integrated with OLEDs. And we found that the Pentacene-OTFTs can be operated as light sensors and optoelectronic memory devices. In first part, we observed the characteristics of Pentacene-OTFFs were affected by illumination. And we observed full recovery of these devices after the illumination was removed at room temperature. In second part, we investigated the dependence between characteristics of Pentacene-OTFTs and illumination intensity. We found that the performance of Pentacene-OTFTs decreased with increasing illumination intensity. In third part, we investigated the characteristics of Pentacene-OTFTs under illumination for a long time. We observed the performance of Pentacene-OTFTs decreased with increasing illumination time. In final part, we found that the Pentacene-OTFTs are sensitive to light signal, but they can not be operated as a fast photodetectors because of their slow response time. But, maybe they can be used as optoelectronic memory elements. In conclusion, the Pentacene-OTFTs were sensitive to light signal, and the performance decreased significantly with illumination.
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Zhang, Pi Lie, and 張丕烈. "Novel current-mode circuits using CCIIs, OTAs or CFAs." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/44293336321499237114.
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Fraitágová, Iveta. "Migrace kalouse ušatého (Asio otus) v podmínkách střední Evropy." Master's thesis, 2014. http://www.nusl.cz/ntk/nusl-334761.
Full textAbstract:
The aim of the present thesis is to give a review of the ringing recoveries of the Long - eared owl (Asio otus) in the territory of the former Czechoslovakia and the Czech Republic. The bird ringing data used in this thesis come from the archive of the National Museum in Prague. The parts of the thesis are as follows:1) history of the ringing in the Czech Republic; 2) bird adaptation on the flight and migration; 3) control of the migration; 4) the data of the Long- eared owls ringed as the young birds in the nest (pulli); 5) the data of the Long - eared owls ringed as adults (ad), that were caught and checked during their wintering in the Czech Republic; 6) the recoveries of the Long- eared owls ringed by various European Bird Ringing Centres and found in the Czech Republic; 7) cause of the mortality of the Long eared owl;8) census of the Long - eared owl recoveries in the Czech Republic from 1934 till 2011 (appendix). Key words: Migration, the Long-eared Owl, Ringing, Ringing Recoveries, Mortality
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Tang, Jia-Shuian, and 湯佳軒. "Study on OTFTs with 3-D Multiple Nano Channels." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/81373509049580321010.
Full textAbstract:
碩士國立暨南國際大學
電機工程學系
100
In this thesis, the characterizations of OTFTs with 3-D multiple nano channels were studied. The nano channels were fabricated using nanoimprint lithography and reactive ion etching. To improve the preferred orientation of pentacene, the self-assembled layer was used for the SiO2 and HfO2 dielectrics. The pentacene and S/D electrode were deposited by thermal evaporation. The surface morphologies and cross-sections of samples were investigated by AFM and SEM. The device performances were studied by HP-4156 and HP-4294. In our results, from the SEM images, the nano channels with various line/space ratios were fabricated successfully. In the AFM images, the preferred orientations of pentacene were improved with the line/space ratio of about 1/2. Besides, the OTFTs on the nano channels with the line/space ratio of about 1/2 and line/space of about 600/1200 nm show the best performance among all samples. The proposed process will be suitable for the future flexible electronics applications.
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Rega, Romina. "OTFTs FOR ELECTRONIC SYSTEMS:DEVICES FABRICATION, CHARACTERISATION, ANALYSIS AND RELIABILITY." Tesi di dottorato, 2014. http://www.fedoa.unina.it/9921/1/PhD.%20REGA_ROMINA.pdf.
Full textAbstract:
Field-effect transistor (FET) is an electronic device that relies on the electric field to control a current through a "conductive channel" made of a semiconducting material. When the active layer is fabricated from organic semiconductors, the device is referred to as an organic field-effect transistor (OFET). The most common configuration of an OFET is the organic thin film transistor (OTFT).
In this thesis it has been proposed to study and characterize innovative solution process OTFTs made using organic semiconductors and insulators, and in particular the influence of some process parameters for their behaviour under various stress conditions.
Solution-processed organic materials used for electronic devices have been deposited and processed employing very cheap and simple methods, like spin-coating and drop casting. The properties of organic materials strongly depend on their morphology, which depends on the method of deposition. Morphology also influences the behaviour of the interfaces between the materials, so can be very important for the performances of the device, in particular for OTFTs.
Device instability and limited lifetime have been so far the hurdles to commercialization of organic electronics. Through electrical characterizations and microscopy techniques, much progress has been made in understanding the stress mechanism that limits the stability of organic field-effect transistors.
In this thesis, one device architecture and different technological configurations have been applied, while three distinct sources of stress have been used (voltage, environment and light) to study their actions on the properties of the devices, to deduce the influence of the devices’ processing on their stability and to enable controllable and reproducible devices fabrication.
The kinetics and the mechanisms of charge trapping in organic semiconductors are found able to explain the observed instability behaviours in OTFTs.
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Ismail, Ahmad G. "Photolithography Patterning of Complementary Organic Circuits." Thesis, 2011. http://hdl.handle.net/10222/13691.
Full textAbstract:
The application of organic electronics to display technologies, large area electronic paper
(or plastics), organic light emitting diodes (OLEDs), organic solar cells, radio frequency
identification tags, smart cards and chemical sensors has received a great deal of attention
in recent years. The main advantages of using organic semiconductors (OSCs) are lowcost,
low processing temperature, flexibility, light weight and rugged design. The
substantial progress in this field has been driven not just by existing technologies, such as
flat panel displays, but also by new applications, such as flexible solid-state lighting, lowcost
printed integrated circuits, and plastic solar cells, to name a few.
Performance-wise, organic thin-film transistors (OTFTs) are on par with their a-Si
(amorphous silicon) counterparts. Since OTFT fabrication offers lower processing
temperatures and lower cost, it has the potential to replace a-Si in the near future. To
date, all organic complementary circuits have used stencil mask patterning. Stencil mask
patterning is not practical for mass manufacturing; hence, a way to pattern organic
complementary metal-oxide-semiconductor (O-CMOS) using photolithography is
paramount. This is the goal of this thesis. In this dissertation the design and fabrication
of improved OTFTs for electronic displays and complementary circuits are illustrated.
Here, we demonstrated OTFTs that have excellent stability; hence, they are more suitable
for the above-mentioned electronic applications. In addition, for the first time, successful
photolithographic patterning of an n-channel organic semiconductor is demonstrated.
These important results have enabled us to integrate the n-channel and p-channel organic
materials using a complete photolithographic process in realizing O-CMOS.
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Bravencová, Lada. "Restrukturalizace podniku." Master's thesis, 2008. http://www.nusl.cz/ntk/nusl-94403.
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