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Dissertations / Theses on the topic 'FFF technology'
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Håkansson, Joel, and Otto Gårdebäck. "Elastiskt Ekvivalenta Modeller av Aortaaneurysm : Via 3D-printing med FFF-teknik." Thesis, KTH, Skolan för teknikvetenskap (SCI), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-257782.
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En aortaaneurysm är en komplicerad sjukdom med väldigt begränsade behandlingsmetoder. En bättre förståelse kring sjukdomen är därmed väsentligt för utvecklingen av ny medicin. Den här rapporten behandlar möjligheten att skriva ut modeller av aortaaneurysmer med samma materiella beteede som en riktig. Sådana modeller skulle vara en stor fördel i utveckling av ny medicin, eftersom de skulle tillåta forskare och läkare att både billigt och enkelt skapa pålitliga modeller i forskningssyfte. Skrivaren som undersökts är en Fused Filament Fabrication 3D-skrivare med polymeren TPU 95A som val av material. Detta genomfördes via två olika processer. Den första var materialtester med dragprovkurvor för vald polymer, samt undersökning av begränsningar med FFF-skrivare. Den andra var en finit elementanalys av en aortaaneurysm, från en röntgen med CT-angiografi. Resultaten från de två tillvägagångssätten har sedan jämförts och analyserats. Dragproverna gav TPU 95A en töjning på 2-4 %. Detta bedömdes för styvt i jämförelse med FEM-analysen, som uppmätte en cirka fem gånger större töjning. Om ett elastiskt material som uppfyller nödvändig töjning skulle användas har FFF-metoden fortfarande problem. Dessa problem innefattar instabilitet under utskrift samt ett större behov av supportmaterial, vilket riskerar att blockera flödet genom modellen. 3D-utskrift med FFF-metoden ansågs därmed ej lämpad för elastiskt ekvivalenta aneurysmmodeller, om inte tester med små deformationer utförs.An abdominal aorta aneurysm is a very complicated condition with limited medical treatments. A better understanding of the disease is therefore vital for development of new treatment methods. This report covers the ability to print models of an aortic aneurysm with the same material properties as the real ones. Such models would be of great benefit as it would allow scientists and doctors to both easily and cheaply produce viable models for their research. The printer tested was a Fused Filament Fabrication printer with TPU 95A polymer as choice of material. This was done with a two-step process. The first step being material testing, producing stress-strain curves of the polymer and evaluating the limitations of FFF printing. The second being a finite element analysis of an aortic aneurysm from a CT angiography scan. The results from the two approaches then were compared. The material testing gave TPU 95A an elongation of 2-4 % which was deemed to stiff when compared to the FEM-analysis, that had an elongation approximately five times larger. If an elastic material to satisfy the required elongation were used, the FFF printing method still would have to deal with print stability problems and an increased need of support structures that could block the polymer blood vessel. As such FFF printing was seemed inadequate for printing elastic equivalent aortic aneurysm models unless for specific tests with small deformations.
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Jiroušek, Jan. "Analýza mechanických vlastností plastových vzorků zhotovených technologií 3D tisku." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-444289.
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The master's thesis deals with the determination of mechanical properties of materials used for 3D printing (PLA, PETG, ABS, ASA). The theoretical part contains characteristics of polymer materials and describes testing of mechanical properties and additive technologies. In the experimental part, the standardized samples produced by the technology Fused Filament Fabrication were analysed using mechanical tests (tensile test and hardness test). Some of the examples were exposed to the selected factors of degradation. Selected parameters from mechanical testing (tensile strength, modulus of elasticity in tension, elongation and Shore hardness) were statistically processed. The conclusion of the thesis evaluates the impact of the factors of degradation on particular materials and compares them subsequently.
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Ansari, Mubashir Qamar. "Generation of Thermotropic Liquid Crystalline Polymer (TLCP)-Thermoplastic Composite Filaments and Their Processing in Fused Filament Fabrication (FFF)." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/99885.
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One of the major limitations in Fused Filament Fabrication (FFF), a form of additive manufacturing, is the lack of composites with superior mechanical properties. Traditionally, carbon and glass fibers are widely used to improve the physical properties of polymeric matrices. However, the blending methods lead to fiber breakage, preventing generation of long fiber reinforced filaments essential for printing load-bearing components. Our approach to improve tensile properties of the printed parts was to use in-situ composites to avoid fiber breakage during filament generation. In the filaments generated, we used thermotropic liquid crystalline polymers (TLCPs) to reinforce acrylonitrile butadiene styrene (ABS) and a high performance thermoplastic, polyphenylene sulfide (PPS). The TLCPs are composed of rod-like monomers which are highly aligned under extensional kinematics imparting excellent one-dimensional tensile properties. The tensile strength and modulus of the 40 wt.% TLCP/ABS filaments was improved by 7 and 20 times, respectively. On the other hand, the 67 wt.% TLCP/PPS filament tensile strength and modulus were improved by 2 and 12 times, respectively.
The filaments were generated using dual extrusion technology to produce nearly continuously reinforced filaments and to avoid matrix degradation. Rheological tests were taken advantage of to determine the processing conditions. Dual extrusion technology allowed plasticating the matrix and the reinforcing polymer separately in different extruders. Then continuous streams of TLCP were injected below the TLCP melting temperature into the matrix polymer to avoid matrix degradation. The blend was then passed through a series of static mixers, subdividing the layers into finer streams, eventually leading to nearly continuous fibrils which were an order of magnitude lower in diameter than those of the carbon and glass fibers.
The composite filaments were printed below the melting temperature of the TLCPs, and the conditions were determined to avoid the relaxation of the order in the TLCPs. On printing, a matrix-like printing performance was obtained, such that the printer was able to take sharp turns in comparison with the traditionally used fibers. Moreover, the filaments led to a significant improvement in the tensile properties on using in FFF and other conventional technologies such as injection and compression molding.Doctor of Philosophy
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ANDERSSON, AXEL. "Automation of Fused Filament Fabrication : Realizing Small Batch Rapid Production." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-299447.
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In this bachelor thesis, I examine how automation of fused filament fabrication (FFF) can be implemented, and what the limitations are for different kinds of automation solutions for FFF. Fused filament fabrication is a 3D-printing technology where a material is extruded through a nozzle, layer by layer, to create a print. The thesis also provides a calculation for the commercial feasibility of small batch rapid production with the implementation of an automation solution for FFF. The approach was a qualitative study containing five interviews, combined with empirical knowledge and data from the additive manufacturing company Svensson 3D. This was complemented with an analysis of which criteria to use when evaluating FFF automation solutions, and a framework for looking at FFF from an operator perspective. To calculate commercial feasibility of automation solutions for FFF, Internal Rate of Return and Payback Time were used. This resulted in six criteria to evaluate solutions for automation of FFF, three evaluations of problems within three solutions for automation of FFF, and a finding showing that small batch rapid production is commercially feasible with automated FFF. Lastly, the thesis contains a discussion regarding what the future is for FFF, and the limitations of the framework presented for evaluating automated FFF systems. Possible promising solutions for automated FFF are presented, together with ideas for how design for additive manufacturing can help shape the future of automated FFF.I det här kandidatarbetet undersöker jag hur automatisering inom fused filament fabrication (FFF) kan implementeras, och vad begränsningarna är för olika sorters automatiseringslösningar för FFF. Det läggs även fram en uträkning för den kommersiella gångbarheten för small batch rapid production med implementeringen av ett automatiskt FFF-system. Tillvägagångsättet bestod av en kvalitativ studie baserad på fem intervjuer, kombinerad med empirisk kunskap och data från additiva tillverkningsföretaget Svensson 3D. Det här kompletterades med en analys av vilka parametrar som bör användas för att utvärdera lösningar för FFF-automatisering, och ett ramverk där automatiseringslösningarna betraktas ur ett operatörs-perspektiv. För att räkna ut den kommersiella gångbarheten för automatiseringslösningar av FFF användes internränta och återbetalningstid. Det här resulterade i sex parametrar för att utvärdera automatiseringslösningar för FFF, tre utvärderingar av vilka problem som finns i tre existerande automatiseringslösningar, och slutsatsen att small batch rapid production är kommersiellt gångbart för automatiserad FFF. Slutligen innehåller arbetet en diskussion gällande framtiden för FFF och begränsningarna hos det ramverk som presenterades för att utvärdera automatiserade FFF system. Möjliga lovande lösningar för automatiserad FFF presenteras och hur design för additiv tillverkning kan hjälpa till att forma framtiden för automatiserad FFF.
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Järleblad, Henrik. "Att lösapartiella differentialekvationermed FFT i fri rymd." Thesis, KTH, Skolan för teknikvetenskap (SCI), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-210860.
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Detta kandidatexamensarbete har till syfte att belysa och utforska hur partiella differentialekvationer kan lösas på ett enkelt, effektivt och noggrant sätt i fri rymd, dvs då området är obegränsat (Rn). Lösningsmetoder som fungerar bra på begränsade domäner är generellt inte speciellt effektiva för dessa typer av problem, då artificiella randvillkor måste sättas, och beräkningsdomänen måste göras stor för att få en god noggrannhet i lösningen. Arbetet baseras på en artikel av Vico et al. som publicerades i juli 2016 och som introducerar en metod baserad på trunkerade Greens-funktioner och snabba Fouriertransformen (FFT). Den har spektral konvergens, och är relativt enkel att implementera. Jämfört med periodiska problem, för vilka FFT-baserade metoder är optimala, så måste man för samma spatiella upplösning öka gridstorleken för transformen med en översamplingsfaktor i varje rumsdimension. Metoden har komplexitet O(N log N) där N är antalet gridpunkter. För att påvisa denna metods användningspotential så visar detta projekt hur metoden kan användas för att lösa både Poissons och Helmholtz ekvationer i två respektive tre dimensioner, och demonstrerar också metodens spektrala noggrannhet och förväntade beräkningskomplexitet.
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Ivebrink, Pontus, and Peter Ytterström. "Frekvensuppdelning med FPGA." Thesis, Linköping University, Department of Electrical Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-56238.
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Examensarbetets syfte var att skapa ett frekvensspektrum för ljud. För att representera detta frekvensspektrum används staplar av lysdioder. Systemet implementeras på ett Altera DE2 utvecklingskort. Olika sätt för att skapa dessa frekvensuppdelningar har testats och olika metoder för att lösa dessa har också testats.
Den slutliga implementeringen består av en filterbank som utnyttjar nersampling för att återanvända filter och sänka ordningen på dessa. Det största problemet var att få plats med allt på den FPGA som användes. Genom att byta till en lite mer komplicerad men effektivare filterstruktur så löstes detta problem och vi fick även gott om utrymme över.
Manualer och datablad har inte alltid varit lätta att tolka och ibland har andra metoder använts än de som beskrivs i dessa manualer med tips från support forum och handledare. Det finns vissa förbättringar att göra och vissa saker skulle kunnat göras annorlunda för att spara resurser med ett lite sämre resultat. När projektet var klart hade alla krav som ställts uppfyllts.
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Bien, Franklin Young-Jae. "Reconfigurable equalization for 10-Gb/sec serial data links in a 0.18-μm CMOS technology." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/14026.
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The objective of the proposed research is to realize a 10-Gb/sec serial data link over band-limited channels, such as backplanes, multi-mode fiber, and copper-based cables that were originally designed for data rates less than 1Gb/sec. This is achieved using electrical equalization implemented in an integrated circuit (IC). To successfully compensate for various band-limited channels at the targeted data rate with a single equalizer IC, a reconfigurable equalizer topology is proposed.
In order to realize the proposed goal, various channels are characterized of their forward transmission frequency response. Based on the measured channel data, system simulations are performed to identify the required specifications for IC implementation. This provides information such as optimal number of taps, fractionally-spaced tap delay, and tap coefficients for the proposed IC. With the obtained system requirements, IC building blocks are designed and fabricated in a 0.18- and #956;m CMOS technology.
The fully-integrated reconfigurable CMOS equalizer provides a single-chip solution for compensating various band-limited channels. This enables 10-Gb/sec serial data transmission achieving signal integrity beyond their designed specifications.
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Dahlbäck, Niklas. "Implementation of a fast method for reconstruction of ISAR images." Thesis, Linköping University, Department of Electrical Engineering, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2073.
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By analyzing ISAR images, the characteristics of military platforms with respect to radar visibility can be evaluated. The method, which is based on the Discrete-Time Fourier Transform (DTFT), that is currently used to calculate the ISAR images requires large computations efforts. This thesis investigates the possibility to replace the DTFT with the Fast Fourier Transform (FFT). Such a replacement is not trivial since the DTFT is able to compute a contribution anywhere along the spatial axis while the FFT delivers output data at fixed sampling, which requires subsequent interpolation. The interpolation leads to a difference in the ISAR image compared to the ISAR image obtained by DTFT. On the other hand, the FFT is much faster. In this quality-and-time trade-off, the objective is to minimize the error while keeping high computational efficiency.
The FFT-approach is evaluated by studying execution time and image error when generating ISAR images for an aircraft model in a controlled environment. The FFT method shows good results. The execution speed is increased significantly without any visible differences in the ISAR images. The speed-up- factor depends on different parameters: image size, degree of zero-padding when calculating the FFT and the number of frequencies in the input data.
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Teixeira, Duarte Filipe Pereira. "Microsoft-Nokia : stategy and valuation." Master's thesis, Instituto Superior de Economia e Gestão, 2015. http://hdl.handle.net/10400.5/10888.
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Mestrado em FinançasA constante necessidade de inovação no setor tecnológico é uma grande condicionante para o sucesso de uma empresa desse sector. A Microsoft, uma das maiores empresas do setor, tem ficado para trás dos seus principais concorrentes (Apple e Samsung), não beneficiando das novas tendências de mercado: móvel e cloud. Esta necessidade de inovar, aliada à turbulência financeira que estamos a viver, levaram a Microsoft a reagir e aproveitar a oportunidade de adquirir o segmento de telemóveis da Nokia. Para o fazer, a Microsoft predispôs-se a pagar $9,500 milhões pelo segmento de "Devices and Services". Fusões e aquisições são consideradas uma das melhores formas para as empresas aumentarem o valor para os seus acionistas, apesar das dificuldades inerentes ao processo. O objetivo deste projeto é compreender as motivações por trás do negócio, do ponto de vista da Microsoft, estimar as possíveis sinergias e avaliar a empresa que resultou desta aquisição.
The constant need for innovation in the technology sector is a major drive for a company?s success. Microsoft, one of the largest companies in the sector was lagging behind its competitors (such as Apple and Samsung), not being able to benefit from new market trends: mobile and cloud. The need to innovate, alongside the financial turmoil we are living in, led Microsoft to react and seize the opportunity to acquire Nokia?s phone segment. To do that, Microsoft paid Nokia $9,500 million for its "Devices and Services" segment. Mergers and Acquisitions are considered one of the best forms for companies to achieve value growth for their shareholders despite the inherent difficulties. The goal of this project is to understand the motivations behind the deal (from Microsoft's perspective), evaluate the possible synergies, and perform a valuation of the company that resulted from this acquisition.
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Paditz, Ludwig. "Using ClassPad-technology in the education of students of electricalengineering (Fourier- and Laplace-Transformation)." Proceedings of the tenth International Conference Models in Developing Mathematics Education. - Dresden : Hochschule für Technik und Wirtschaft, 2009. - S. 469 - 474, 2012. https://slub.qucosa.de/id/qucosa%3A1799.
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By the help of several examples the interactive work with the ClassPad330 is considered. The student can solve difficult exercises of practical applications step by step using the symbolic calculation and the graphic possibilities of the calculator. Sometimes several fields
of mathematics are combined to solve a problem. Let us consider the ClassPad330 (with the actual operating system OS 03.03) and discuss on some new exercises in analysis, e.g. solving a linear differential equation by the help of the Laplace transformation and using the inverse Laplace transformation or considering the Fourier transformation in discrete time (the Fast Fourier Transformation FFT and the inverse FFT). We use the FFT- and IFFT-function to study periodic signals, if we only have a sequence generated by sampling the time signal. We know several ways to get a solution. The techniques for studying practical applications fall into the following three categories: analytic, graphic and numeric. We can use the
Classpad software in the handheld or in the PC (ClassPad emulator version of the handheld).
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Tompkins, Nicholas William. "Design of a Machine Condition Monitoring System with Bluetooth Low Energy." Thesis, University of North Texas, 2017. https://digital.library.unt.edu/ark:/67531/metadc984239/.
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Paditz, Ludwig. "Using ClassPad-technology in the education of students of electrical engineering (Fourier- and Laplace-Transformation)." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-80814.
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By the help of several examples the interactive work with the ClassPad330 is considered. The student can solve difficult exercises of practical applications step by step using the symbolic calculation and the graphic possibilities of the calculator. Sometimes several fields
of mathematics are combined to solve a problem. Let us consider the ClassPad330 (with the actual operating system OS 03.03) and discuss on some new exercises in analysis, e.g. solving a linear differential equation by the help of the Laplace transformation and using the inverse Laplace transformation or considering the Fourier transformation in discrete time (the Fast Fourier Transformation FFT and the inverse FFT). We use the FFT- and IFFT-function to study periodic signals, if we only have a sequence generated by sampling the time signal. We know several ways to get a solution. The techniques for studying practical applications fall into the following three categories: analytic, graphic and numeric. We can use the
Classpad software in the handheld or in the PC (ClassPad emulator version of the handheld).
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Larsson, Kim, and Emil Karlsson. "St1 Refinery - Biotreater : Optimering och utvecklingsmöjligheter med hänseende till miljön." Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-14976.
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Vatten är en viktig komponent för alla oljeraffinaderier, både för kylning och för själva destillationsprocessen. Vatten som har kommit i kontakt med olja, sulfider, kväveföreningar samt andra miljöfarliga ämnen, kallas processvatten och måste renas innan det släpps ut i recipient. Processvattnet renas i vattenreningsverk som kan se olika ut och ha olika uppbyggnad.St1 Refinery AB ligger på Hisingen i Göteborg vid Göta älv och har ett biologiskt vattenreningsverk som kallas Biotreatern. Biotreatern har i uppgift att rena processvattnet främst ifrån kväveföreningar, men även olja och andra miljöfarliga ämnen med hjälp av bakterier. Biotreatern har problem med så kallat slamflykt, detta kan påverka att utsläppskrav för bl.a. mängden olja och kväveföreningar i renat vatten överskrids. Om utsläppskraven överskrids kan detta leda till höga bötersbelopp för företaget och en ökad negativ påverkan på miljön. Syftet med rapporten är att ta fram förslag på förbättringar och nya tekniska lösningar till Biotreatern för att minska slamflykten. I rapporten redovisas resultat som främst handlar om nya filtreringstekniker, hur dessa fungerar och var i anläggningen de kan appliceras för att undvika slamflykt. Vilka huvudsakliga faktorer som styr reningsprocessen och vad begreppet slamflykt innebär, beskrivs i rapporten. Det beskrivs också hur reningsprocessen fungerar, tillsammans med uppritat flödesschema över anläggningen. De förbättringsförslag som presenteras i rapporten, kan minska och eventuellt eliminera problemet med slamflykt som Biotreatern lider av idag.
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Spencer, Darren W. "The Unmanned Aerial Systems (UASs) Industry and the Business Impacts of the Evolution of the Federal Regulatory Environment." Scholar Commons, 2018. https://scholarcommons.usf.edu/etd/7576.
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Despite the explosion of popularity of UASs, and the recognition that such systems must find a way to safely operate alongside manned aviation, a literature review by this author as well as interviews with three commercial aerial photography companies in Tampa Bay, Florida, indicate that regulatory restrictions are still the greatest obstacle to law abiding commercial UAS operators. It can take six to eight months with a backlog of 12,000 waiver applications to get either a Part 333 or Part 107 exemption, which grants FAA permission for a commercial operator to fly a UAS inside controlled airspace (Gardner, 2018). A manned pilot can file a flight plan and hover a helicopter over the same area in just a few hours.
The purpose of this research was to determine what industry experts perceive the future of UAS regulations hold, and how the industry will be impacted in both the short term of 5 years and less, and long-term of 5 years or more. UAS industry expert interviews were conducted in the “reflection of the meaning”, semi-structured style, with each interviewee given the latitude to discuss topics as they came to mind. A preset approved bank of questions helped to guide the interview, but in many cases as experts in the field, the interviewees naturally discussed the topics covered in the preset questions and the interview adapted to avoid unnecessary repetition. One interview was conducted in-person, but the rest were via phone calls due to geographical separation.
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Molosky, Vincent. "The Influence of Identifiable Personality Traits on Nurses’ Intention to Use Wireless Implantable Medical Devices." Diss., NSUWorks, 2019. https://nsuworks.nova.edu/gscis_etd/1078.
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Technically-driven medical devices such as wireless implantable medical devices (WIMD) have become ubiquitous within healthcare. The use of these devices has changed the way nurses administer patient care. Consequently, the nursing workforce is large and diverse, and with it comes an expected disparity in personalities. Research involving human factors and technology acceptance in healthcare is not new. Yet due to the changing variables in the manner of which patient care is being administered, both in person and in the mechanism of treatment, recent research suggests that individual human factors such as personality traits may hold unknown implications involving more successful adoption of emerging technologies for patient care.
The purpose of this research was to empirically investigate the influence of personality traits on a nurse’s intention to use WIMDs for patient care. One hundred and two nurses from a tertiary teaching hospital in Michigan were surveyed to determine if their identifiable personality traits statistically related to their intention to use a WIMD. A predictive model was developed by combining constructs from the unified theory of acceptance and use of technology (UTAUT) model and the Five Factor personality trait model (FFM). The model used moderated multiple regression (MMR) to statistically identify if the personality traits of openness, conscientiousness, extraversion, agreeableness, and neuroticism, moderated one or more statistically significant relationships between 1) performance expectancy (PE) and intention to use (IU), 2) effort expectancy (EE) and IU, 3) and social influence (SI) and IU. It was predicted that PE, EE, and SI would show statistical significance on a nurse’s IU of a WIMD when moderated by one or more of the five personality traits. Results showed statistical significance between PE and IU, and EE and IU, but not between SI and IU, when moderated by extraversion. Results showed no statistical significance between PE and IU, EE and IU, or SI and IU when moderated by openness, conscientiousness, agreeableness, or neuroticism.
This research has contributed by conducting an investigation on individual human factors that may impact nurses’ intention to use emerging technologies; and by providing statistical evidence that may help to better predict the role personality traits have on a nurse’s adoption of WIMDs for patient care.
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Barlas, Sofia, and Sofie Johansson. "Management and leadership within the FFE : Management-and leadership effects on time efficacy within the Fuzzy Front End of the New Product Development process." Thesis, Högskolan i Jönköping, Internationella Handelshögskolan, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-39805.
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Today's fast-paced and increasingly competitive market has added pressure on companies and NPD-teams to improve both the quality of the products they provide, as well as the speed in which the products are introduced to the market. The main purpose within this study was to investigate two research questions; (a) How can various management- and leadership styles improve time efficacy without impairing the successes of the FFE of the NPD process; and (b) How can/does the uncertainty within the FFE affect project managers within the NPD process?Qualitative methods have been used within this study to gain a greater understating of the tasks and activities management have applied within the FFE to reduce and save time. A multiple case study, in the form of interviews, was performed in order to obtain raw empirical data. Eight interviews were conducted with individuals whom possessed managerial roles such as project managers, within the NPD process. The information was later analyzed and evaluated with the help of a thematic analysis.The main findings within this thesis contradict previous studies and literature which state the need for “more time” within the FFE of the NPD process. The result within this study suggest that project managers do not seek to extend the time provided within the FFE, rather identify task and methods which can enable them to use the time afforded wisely and efficiently. The managers do not seek to eliminate any tasks or activities; however, they do wish to identify less relevant activities in order to spend more time on valuable and beneficial tasks which increase the likely-hood of developing high quality products.
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Strömberg, Isak. "Characterization of creping marks in paper." Thesis, Linköpings universitet, Datorseende, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-148632.
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The cost and environmental damage of reclaims is a large problem within thepaper industry. With certain types of paper, so called crepe marks on the paper’ssurface is a common issue, leading to printing defects and consequentlyreclaims. This thesis compares four different image analysis methods for evaluatingcrepe marks and predicting printing results. The methods evaluated consistsof one established methods, two adaptations of established methods andone novel method. All methods were evaluated on the same data, topographicheight images of paper samples from 4 paper rolls of similar type but differingin roughness. The method based on 1D Fourier analysis and the method basedon fully convolutional networks performs best, depending on if speed or detailedcharacteristics is a priority.
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Rigot, David. "Contribution à l'étude de l'érosion des électrodes de torches à plasma d'arc pour la projection par suivi en ligne des signaux de tension et de son." Limoges, 2003. http://aurore.unilim.fr/theses/nxfile/default/76eed5c7-37ed-4a93-a31a-2f2c4c44acdb/blobholder:0/2003LIMO0053.pdf.
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En projection thermique, les conséquences de l'érosion des électrodes d'une torche plasma peuvent être dommageables pour un dépôt en cours de réalisation (écaillage, mauvaise qualité, etc. ). Ce travail de thèse a consisté à suivre dans le temps de fonctionnement de la torche, depuis la mise en place d'électrodes neuves, jusqu'à leur remplacement, l'évolution de nombreux paramètres liés aux signaux émis par la torche (tension aux bornes des électrodes et signal acoustique) et à choisir ceux qui étaient les plus pertinents pour rendre compte de l'érosion. Les trois paramètres retenus sont la tension moyenne et l'écart quadratique moyen du signal de tension ainsi que la fréquence du pic principal du spectre du signal acoustique. Cette étude a été menée avec un logiciel d'acquisition et de traitement des données que nous avons développé sous Labview, dont l'algorithme est désormais intégré dans un module autonome construit autour d'un DSP (Digital Signal Processor) qui affiche suivant la comparaison avec deux seuils, l'état des trois paramètres. Un modèle thermique de l'érosion est également proposéIn plasma spraying, the consequences of the wear of the electrodes of d. C. Plasma torches may be catastrophic for a coating (bad quality, peeling, etc. ). This paper presents a new method that has consisted in monitoring along the working hours of the torch, starting with brand new electrodes ("initial time"), till they are replaced, the evolution of many parameters in relation with the signals emitted by the torch (voltage at the edges of the electrodes and sound). This study has allowed choosing those parameters that were the more relevant for giving an account of the erosion. They are the mean voltage, the root mean square value of the voltage, and the frequency of the main peak in the spectrum of the sound and especially the evolution of theirs ratio relatively to the values obtained at the initial time. This study was performed with a software, developed with Labview on a PC, now replaced by an electronic device. The latter, designed with the DSP (Digital Signal Processor) technology, displays, on light indicators, the state of the three parameters according to their comparison with two thresholds. A thermal simulation of the erosion is also proposed
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Hussain, Shahid Abrar. "VHDL Implementation of Flexible Frequency-Band Reallocation (FFBR) Network." Thesis, Linköpings universitet, Institutionen för systemteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-69390.
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In digital communication systems, satellites give us world wide services. These satellites should effectively use the available bounded frequency spectrum and, therefore, to carry out flexible frequency-band reallocation (FFBR), on-board signal processing implementation on FFBR network is needed. In the future, to design desired dynamic communication systems, very flexible digital signal processing structures will be needed. The hardware, in the system, shall not be changed as simple changes in the software will be made. The purpose of this thesis is to implement an N-channel FFBR network, where N=20. A 20-channel FFBR network consists of different blocks, e.g., DFT, IDFT, complex multipliers, input/output commutators and polyphase components. The whole 20-channel FFBR network will be implemented in VHDL. In a 20-channel FFBR network, it is a 20-point FFT/IFFT required. This 20-point FFT/IFFT is built by a combination of radix-4 and radix-5 butterflies. The Cooley-Tukey FFT algorithm is chosen to build the 20-point FFT/IFFT. The main aim is to build 20-point FFT/IFFT. There are 20 complex multipliers before the IFFT block and 20 complex multipliers after the IFFT block. In the same way, 20 complex multipliers are used before the FFT block and 20 complex multipliers are used after the FFT block. At the input/output to this FFBR network, 20 FIR filters (polyphase components) are used, respectively.
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Movin, Andreas, and Jonathan Jilg. "Kan datorer höra fåglar?" Thesis, KTH, Skolan för teknikvetenskap (SCI), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-254800.
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Ljudigenkänning möjliggörs genom spektralanalys, som beräknas av den snabba fouriertransformen (FFT), och har under senare år nått stora genombrott i samband med ökningen av datorprestanda och artificiell intelligens. Tekniken är nu allmänt förekommande, i synnerhet inom bioakustik för identifiering av djurarter, en viktig del av miljöövervakning. Det är fortfarande ett växande vetenskapsområde och särskilt igenkänning av fågelsång som återstår som en svårlöst utmaning. Även de främsta algoritmer i området är långt ifrån felfria. I detta kandidatexamensarbete implementerades och utvärderades enkla algoritmer för att para ihop ljud med en ljuddatabas. En filtreringsmetod utvecklades för att urskilja de karaktäristiska frekvenserna vid fem tidsramar som utgjorde basen för jämförelsen och proceduren för ihopparning. Ljuden som användes var förinspelad fågelsång (koltrast, näktergal, kråka och fiskmås) så väl som egeninspelad mänsklig röst (4 unga svenska män). Våra resultat visar att framgångsgraden normalt är 50–70%, den lägsta var fiskmåsen med 30% för en liten databas och den högsta var koltrasten med 90% för en stor databas. Rösterna var svårare för algoritmen att särskilja, men de hade överlag framgångsgrader mellan 50% och 80%. Dock gav en ökning av databasstorleken generellt inte en ökning av framgångsgraden. Sammanfattningsvis visar detta kandidatexamensarbete konceptbeviset bakom fågelsångigenkänning och illustrerar såväl styrkorna som bristerna av dessa enkla algoritmer som har utvecklats. Algoritmerna gav högre framgångsgrad än slumpen (25%) men det finns ändå utrymme för förbättring eftersom algoritmen vilseleddes av ljud av samma frekvenser. Ytterligare studier behövs för att bedöma den utvecklade algoritmens förmåga att identifiera ännu fler fåglar och röster.Sound recognition is made possible through spectral analysis, computed by the fast Fourier transform (FFT), and has in recent years made major breakthroughs along with the rise of computational power and artificial intelligence. The technology is now used ubiquitously and in particular in the field of bioacoustics for identification of animal species, an important task for wildlife monitoring. It is still a growing field of science and especially the recognition of bird song which remains a hard-solved challenge. Even state-of-the-art algorithms are far from error-free. In this thesis, simple algorithms to match sounds to a sound database were implemented and assessed. A filtering method was developed to pick out characteristic frequencies at five time frames which were the basis for comparison and the matching procedure. The sounds used were pre-recorded bird songs (blackbird, nightingale, crow and seagull) as well as human voices (4 young Swedish males) that we recorded. Our findings show success rates typically at 50–70%, the lowest being the seagull of 30% for a small database and the highest being the blackbird at 90% for a large database. The voices were more difficult for the algorithms to distinguish, but they still had an overall success rate between 50% and 80%. Furthermore, increasing the database size did not improve success rates in general. In conclusion, this thesis shows the proof of concept and illustrates both the strengths as well as short-comings of the simple algorithms developed. The algorithms gave better success rates than pure chance of 25% but there is room for improvement since the algorithms were easily misled by sounds of the same frequencies. Further research will be needed to assess the devised algorithms' ability to identify even more birds and voices.
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Mayilvaganan, Naveen, and Juet Jacob. "Integrating Market-based Partners Into Fuzzy Front End of New Product Development." Thesis, Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-40671.
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Background: It is argued that most of the new product do not fail in the end but it fails in the beginning of the innovation. Managing front end of NPD, is the most important and difficult challenges facing the innovation managers. Effectively promoting front end activities can contribute directly to the success of the new product. So, integrating market-based partners (suppliers and customers) in the front-end phase enhances the quantity and quality of ideas. Problem discussion: Authors have suggested the involvement of market-based partners as early as possible in the NPD process will reduce the fuzziness in front end phase. The collaboration process with market-based partners implies that combining the idiosyncratic resources in unique ways, firms would relish greater innovation success. But this process of integration or collaboration with market-based partners are not that easy as it entails different appropriation and coordination concerns. Majority of the literature is concentrated on integrating market-based partners in the back-end activities of NPD, leaving a bit of void in the front-end phase of NPD. Method: The methodological choice of this thesis follows an exploratory study to seek new insights into an existing subject. The thesis is a following a deductive approach and is qualitative in the research choice. Purpose: To provide insights on integrating market-based partners in the front-end phase of new product development where the information is scattered around. This thesis identifies a structure that facilitates the integration of market-based partners in the fuzzy front end of NPD to mitigate the appropriation concerns and challenges.
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Alamri, Shuaa. "Les usages et effets des TIC sur le développement de la compétence de compréhension orale de futures interprètes français-arabe : une recherche expérimentale menée à l'Université du Roi Saoud sur un dispositif numérique à visée professionnalisante." Thesis, Université de Lorraine, 2021. https://docnum.univ-lorraine.fr/ulprive/DDOC_T_2021_0014_ALAMRI.pdf.
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Ce travail de thèse vise à évaluer l’efficience de l’utilisation des TIC pour l’apprentissage de la compétence de compréhension orale dans le cadre de la formation au métier d’interprète français-arabe dispensée aux étudiantes saoudiennes de l’Université du Roi Saoud de Riyad. Ayant constaté que l’actuelle formation universitaire ne dote pas suffisamment les étudiantes des compétences nécessaires à la pratique professionnelle de l’interprétation, notamment en ce qui concerne la compréhension orale des discours authentiques, nous avons élaboré et expérimenté un dispositif didactique fondé sur l’utilisation d’outils numériques. Celui-ci vise, d’une part, à confronter les étudiantes à des documents authentiques qui leur permettent de mieux comprendre la langue et la culture françaises, et d’autre part à développer chez elles de nouveaux usages des TIC afin qu’elles soient outillées pour faire face aux exigences du métier. Pour évaluer ce dispositif, nous avons choisi une démarche expérimentale quantitative et qualitative qui nous permet de comparer les progrès en compréhension orale d’un groupe d’apprenantes utilisant notre dispositif à ceux d’un groupe témoin ne l’utilisant pas, au moyen de tests de performance effectués avant et après l’expérimentation. Nous avons croisé ces résultats aux données recueillies par un questionnaire interrogeant leurs usages des TIC avant l’expérimentation, et un questionnaire de retour d’expérience après l’expérimentation. Nous avons constaté ainsi d’une part que notre dispositif avait permis d’améliorer considérablement la compétence de compréhension orale des apprenantes, et d’autre part qu’il avait été accueilli favorablement par les étudiantes qui ont apprécié l’utilisation des TIC dans le cadre de leur formation. Notre dispositif semble capable de répondre à la fois aux besoins de formation à la compétence de compréhension orale dans l’activité d’interprétation, et à l’attrait des étudiantes saoudiennes pour les TIC. Dans un contexte dans lequel les femmes saoudiennes investissent le marché du travail, et sont formées dans des universités non mixtes, notre recherche prend en compte cette dimension genréeThis thesis aims to assess the efficiency of the use of ICT for the acquisition of listening comprehension skills, as part of the French-Arabic interpreting training provided to Saudi students of the women’s section at the King Saud University (Riyadh). Having noted that the current training does not sufficiently equip students with the necessary skills for interpreting as a professional practice, notably as regards the listening comprehension of authentic oral speeches, the research has developed and tested a didactic device based on use of digital tools. This device aims, on the one hand, at confronting the students with authentic documents which allow them to better understand the French language and culture, and on the other hand, to allow them to develop new uses of ICT so that their learning practices meet the requirements of the profession. To asses this device, a quantitative and qualitative experimental approach has been choosen to compare progress in the listening comprehension skills of an experimental group of learners - using the device - with that of a control group - not using it – by means of performance tests carried out before and after the experiment. these results were crossed with data collected by a survey questioning the students’ use of ICTs before the experimentation, and a satisfaction questionnaire after the experimentation. It has been noted that the device has effect on the improvement of the listening comprehension skills of learners. Also, the device has been favorably received by the students who appreciated the use of ICT being part of their training. Moreover, the used device would allow us to address both the training needs in listening comprehension skills in the interpreting activity, and the attractiveness of Saudi female students for ICT. In a context in which Saudi women are entering the labor market, and are trained in single-sex education system, this research takes into account the gender dimension
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Phoshoko, Silas M. "Radio frequency spectrum monitoring : Officers' acceptance of minitoring technologies such as fixed direction finders. /." Thesis, University of the Western Cape, 2006. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_7879_1256198977.
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The research focuses on the acceptance of new technologies within the telecommunications industry. The study examines three models namely Innovation theory, Theory of Reason Action (TRA), and Technology Acceptance Model (TAM). This study explores the technology acceptance models in order to explain why certain monitoring officers at ICASA would prefer specific technologies over others. Models of interest could be the innovation theory, TRA and TAM. After reviewing both models, the author will examine the TAM in detail as a model of interest in this study. In turn, this model is expected to assist us to understand why monitoring officer's at ICASA would prefer a particular frequency monitoring technology over the other.
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Cardholm, Lucas. "Adding value to business performance through cost benefit analyses of information security investments : MBA-thesis in marketing." Thesis, University of Gävle, Department of Business Administration and Economics, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-238.
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The purpose of this thesis is to present an approach for good practice with regards to using cost benefit analysis (CBA) as a value-adding activity in the information security investment process for large enterprises. The approach is supported by empirical data.
From a MIO model perspective, this report is focused on the phase of strategic choices regarding organization, i.e. trying to find optimal investments for efficient operations. To assess, improve and monitor the operational effectiveness and management’s internal control environment is essential in today’s business execution. Executive management and boards are increasingly looking for an information security governance framework that encompasses information technology and information security: a single framework through which all information assets and activities within the organisation can be governed, to provide the optimum capability for meeting the organisation’s objectives, in terms of functionality and security.
The investment decision is one of the most visible and controversial key decisions in an enterprise. Some projects are approved, others are bounced, and the rest enter the organisational equivalent of suspended animation with the dreaded request from the decision makers to “redo the business case” or “provide more information.”
The concept of cost benefit analyses of information security helps management to make decisions on which initiatives to fund with how much, as there needs to be an approach for measuring and comparing different alternatives and how they meet business objectives of the enterprise. Non-financial metrics are identified using different approaches: governance effectiveness, risk analysis, business case analysis or game theory. The financial performance metrics are driven by the main value disciplines of an enterprise. These lead to the use of formulas enabling the measurement of asset utilisation, profit or growth: ROI (ROIC), NPV, IRR (MIRR), FCF, DCF, Payback Period, TCO, TBO, EVA, and ROSI.
The author shows research in the field of good corporate governance and the investment approval process, as well as case studies from two multinational enterprises. The case from Motorola demonstrates how IT governance principles are equally applicable to information security governance, while the case from Ericsson demonstrates how an information security investment decision can be supported by performing a cost benefit analysis using traditional marketing approaches of business case analysis (BCA) and standard financial calculations.
The suggested good practice presented in this thesis is summarised in four steps:
1. Understand main rationale for the security investment
2. Identify stakeholders and strategic goals
3. Perform Cost Benefit Analysis (non-financial and financial performance metrics)
4. Validate that the results are relevant to stakeholders and strategic goals
DISCLAIMER
This report is intended for academic training only and should not be used for any other purposes. The contents are not to be considered legal or otherwise professional advice. No liability is taken, whatsoever, by the author.
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Rydahl, Björn. "A VFX ocean toolkit with real time preview." Thesis, Linköping University, Department of Science and Technology, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-50850.
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Björk, Anders. "Chemometric and signal processing methods for real time monitoring and modeling : applications in the pulp and paper industry." Doctoral thesis, KTH, Kemi, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4383.
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In the production of paper, the quality of the pulp is an important factor both for the productivity and for the final quality. Reliable real-time measurements of pulp quality are therefore needed. One way is to use acoustic or vibration sensors that give information-rich signals and place the sensors at suitable locations in a pulp production line. However, these sensors are not selective for the pulp properties of interest. Therefore, advanced signal processing and multivariate calibration are essential tools. The current work has been focused on the development of calibration routes for extraction of information from acoustic sensors and on signal processing algorithms for enhancing the information-selectivity for a specific pulp property or class of properties. Multivariate analysis methods like Principal Components Analysis (PCA), Partial Least Squares (PLS) and Orthogonal Signal Correction (OSC) have been used for visualization and calibration. Signal processing methods like Fast Fourier Transform (FFT), Fast Wavelet Transform (FWT) and Continuous Wavelet Transform (CWT) have been used in the development of novel signal processing algorithms for extraction of information from vibrationacoustic sensors. It is shown that use of OSC combined with PLS for prediction of Canadian Standard Freeness (CSF) using FFT-spectra produced from vibration data on a Thermo Mechanical Pulping (TMP) process gives lower prediction errors and a more parsimonious model than PLS alone. The combination of FFT and PLS was also used for monitoring of beating of kraft pulp and for screen monitoring. When using regular FFT-spectra on process acoustic data the obtained information tend to overlap. To circumvent this two new signal processing methods were developed: Wavelet Transform Multi Resolution Spectra (WT-MRS) and Continuous Wavelet Transform Fibre Length Extraction (CWT-FLE). Applying WT-MRS gave PLS-models that were more parsimonious with lower prediction error for CSF than using regular FFT-Spectra. For a Medium Consistency (MC) pulp stream WT-MRS gave predictions errors comparable to the reference methods for CSF and Brightness. The CWT-FLE method was validated against a commercial fibre length analyzer and good agreement was obtained. The CWT-FLE-curves could therefore be used instead of other fibre distribution curves for process control. Further, the CWT-FLE curves were used for PLS modelling of tensile strength and optical parameters with good results. In addition to the mentioned results a comprehensive overview of technologies used with acoustic sensors and related applications has been performed.Vid framställning av pappersprodukter är kvaliteten på massan en viktig faktor för produktiviteten och kvalitén på slutresultatet. Det är därför viktigt att ha tillgång till tillförlitliga mätningar av massakvalitet i realtid. En möjlighet är att använda akustik- eller vibrationssensorer i lämpliga positioner vid enhetsoperationer i massaprocessen. Selektiviteten hos dessa mätningar är emellertid relativt låg i synnerhet om mätningarna är passiva. Därför krävs avancerad signalbehandling och multivariat kalibrering. Det nu presenterade arbetet har varit fokuserat på kalibreringsmetoder för extraktion av information ur akustiska mätningar samt på algoritmer för signalbehandling som kan ge förbättrad informationsselektivitet. Multivariata metoder som Principal Component Analysis (PCA), Partial Least Squares (PLS) and Orthogonal Signal Correction (OSC) har använts för visualisering och kalibrering. Signalbehandlingsmetoderna Fast Fourier Transform (FFT), Fast Wavelet Transform (FWT) och Continuous Wavelet Transform (CWT) har använts i utvecklingen av nydanande metoder för signalbehandling anpassade till att extrahera information ur signaler från vibrations/akustiska sensorer. En kombination av OSC och PLS applicerade på FFT-spektra från raffineringen i en Termo Mechnaical Pulping (TMP) process ger lägre prediktionsfel för Canadian Standard Freeness (CSF) än enbart PLS. Kombinationen av FFT och PLS har vidare använts för monitorering av malning av sulfatmassa och monitorering av silning. Ordinära FFT-spektra av t.ex. vibrationssignaler är delvis överlappande. För att komma runt detta har två signalbehandlingsmetoder utvecklats, Wavelet Transform Multi Resolution Spectra (WT-MRS) baserat på kombinationen av FWT och FFT samt Continuous Wavelet Transform Fibre Length Extraction (CWT-FLE) baserat på CWT. Tillämpning av WT-MRS gav enklare PLS-modeller med lägre prediktionsfel för CSF jämfört med att använda normala FFT-spektra. I en annan tillämpning på en massaström med relativt hög koncentration (Medium Consistency, MC) kunde prediktioner för CSF samt ljushet erhållas med prediktionsfel jämförbart med referensmetodernas fel. Metoden CWT-FLE validerades mot en kommersiell fiberlängdsmätare med god överensstämmelse. CWT-FLE-kurvorna skulle därför kunna användas i stället för andra fiberdistributionskurvor för processtyrning. Vidare användes CWT-FLE kurvor för PLS modellering av dragstyrka samt optiska egenskaper med goda resultat. Utöver de nämnda resultaten har en omfattande litteratursammanställning gjorts över området och relaterade applikationer.
QC 20100629
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Barnhart, Samuel. "Design and Development of a Coherent Detection Rayleigh Doppler Lidar System for Use as an Alternative Velocimetry Technique in Wind Tunnels." University of Dayton / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1595276402371536.
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El, Gholami Khalid. "La gestion de la qualité de service temps-réel dans les réseaux de capteurs sans fil." Thesis, Clermont-Ferrand 2, 2014. http://www.theses.fr/2014CLF22537/document.
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Le monde des réseaux de capteurs sans fil ‘RCSF’ a connu de grands progrès au cours de ces dernières années. Ainsi, les RCSF ont pu intégrer divers champs d’application (environnement, militaire, médecine, domotique ...) dont quelques-uns ayant des exigences en termes de qualité de service ‘QdS’. Cependant, la garantie de la QdS dans un RCSF pose des problèmes de recherche non triviaux, à cause de la nature peu fiable de la communication sans fil et des limitations des ressources des nœuds RCSF (processeur, mémoire, énergie ...). Dans le cadre de cette thèse, nous nous sommes focalisés sur les protocoles MAC afin d’améliorer le support de QdS dans les RCSF. Plus particulièrement, le standard IEEE 802.15.4. Les mécanismes de conservation d’énergie proposés par ce standard sont efficaces et présentent une flexibilité par rapport aux besoins des applications. Néanmoins, le temps de sommeil des nœuds affecte considérablement le délai de communication, donnant naissance à un compromis énergie/délai. Pour résoudre ce problème, nous avons amélioré ce standard pour un meilleur support des applications temps-réel. L’approche proposée permet de réduire le délai de communication de manière significative, même pour de faibles rapports cycliques, grâce au nouveau format de la supertrame. Les performances ont été validées par simulation et sur des plateformes de nœuds RCSF réelles. Nous avons proposé également un modèle de simulation pour le standard IEEE 802.15.4 sous le simulateur NS-3In the last years, Wireless Sensor Networks ‘WSN’ knew a tremendous evolution which attracted many applications. WSN has several characteristics that make it a unique research field, such as, WSN nodes’ constraints and the unreliable (lossy) wireless communication. The IEEE 802.15.4 standard is the first standard designed for this type of networks known as LR-WPANs ‘Low-Rate Wireless Personal Area Network’. The energy conservation mechanism proposed by the current standard is quite efficient and very flexible. This flexibility comes from the ability to configure different duty cycles to meet specific applications’ requirements. However, this mechanism has a considerable impact on the end-to-end delay. Our approach resolves the energy/delay trade-off by avoiding the storage of the real-time data in the coordinator during sleep time, more particularly in Multi-source Multi-sink networks. A new superframe structure is adopted and a deterministic reception scheduling is used. In this thesis, we also proposed a new WPAN model for the Network Simulator 3 ‘NS-3’
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Bannani, Rouaissia Sabrina. "Pour une prise en charge des difficultés de la compréhension orale en FLE : cas des collégiens tunisiens issus des milieux défavorisés." Thesis, Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0466.
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Ce travail s’inscrit dans le champ de la didactique de l’oral et a pour objet l’étude des interactions verbales dans les classes de collèges tunisiens, pour les apprenants en difficulté, issus des milieux défavorisés.Malgré les efforts investis par les enseignants, et parce qu’ils sont individuels et conçus anarchiquement, ils sont vains et la démotivation est d’une telle ampleur qu’elle inhibe tout acte d’apprentissage aussi réduit qu’il soit. Les enseignants sont conscients de la nécessité de faire acquérir la compétence orale à ces apprenants, la considérant comme accessible mais ils oublient parfois que contrairement aux milieux favorisés, la majorité des apprenants issus des milieux défavorisés exercent un oral d’une langue étrangère qu’ils ne pratiquent jamais en dehors de l’école. Comment former les élèves aux compétences de compréhension et de production de l’oral, compte tenu du contexte particulier des classes de FLE dans les milieux défavorisés ?Quel projet de prise en charge propose-t-on pour éviter l’échec et amener les apprenants en difficulté à avoir des représentations objectives et positives, vis-à-vis d’eux-mêmes, d’une part, de l’école voire de l’apprentissage en général, et du français en particulier d’autre part.Nous cherchons ainsi à déterminer quel contexte peut favoriser l’émancipation des apprenants en difficulté par leurs prises de parole, afin de contribuer à la didactique de l’oral et proposer quelques pistes didactiques qui rendraient ces apprenants actifs en classe, leur donnant l’occasion de prouver leur existence par la participation d’une part, et l’engagement dans la construction du savoir qui leur est enseigné d’autre partThis research fits in the field of oral didactics and it aims to study the verbal interactions in the classes of Tunisian middle schools, for learners in difficulty, coming from underprivileged backgrounds.Despite of the efforts, invested by the teachers, and because they are individual and conceived anarchically, they are vain and the demotivation is of such a magnitude that it inhibits any act of learning however small it can be.Teachers are now aware of the need to develop the oral skill for these learners in difficulty, considering it as accessible but they sometimes forget that unlike the privileged areas, the majority of learners from underprivileged areas practice speaking a foreign language which they never use outside of school.What do the FFL methodologies tangibly offer, for teaching oral skills, taking into account students in difficulty?How to train students in oral comprehension and production skills, given the particular context of FFL classes in underprivileged areas?What support plan is proposed to prevent failure and to bring learners in difficulty to have objective and positive representations, vis-à-vis themselves, on one hand, the school alike learning in general, and French in particular on the other hand?In that way, we seek to determine which context can favor the emancipation of learners in difficulty by their speaking up in order to contribute to the oral didactics field and to propose some didactic paths that would make these learners active in the classroom, thus giving them the opportunity to prove their existence through participation, on one hand, and commitment to building the knowledge that is taught to them on the other hand
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Fenollosa, Artés Felip. "Contribució a l'estudi de la impressió 3D per a la fabricació de models per facilitar l'assaig d'operacions quirúrgiques de tumors." Doctoral thesis, Universitat Politècnica de Catalunya, 2019. http://hdl.handle.net/10803/667421.
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La present tesi doctoral s’ha centrat en el repte d’aconseguir, mitjançant Fabricació Additiva (FA), models per a assaig quirúrgic, sota la premissa que els equips per fer-los haurien de ser accessibles a l’àmbit hospitalari. L’objectiu és facilitar l’extensió de l’ús dels prototips com a eina de preparació d’operacions quirúrgiques, transformant la pràctica mèdica actual de la mateixa manera que en el seu moment ho van fer tecnologies com les que van facilitar l’ús de radiografies. El motiu d’utilitzar FA, en lloc de tecnologies més tradicionals, és la seva capacitat de materialitzar de forma directa les dades digitals obtingudes de l’anatomia del pacient mitjançant sistemes d’escanejat tridimensional, fent possible l’obtenció de models personalitzats. Els resultats es centren en la generació de nou coneixement sobre com aconseguir equipaments d’impressió 3D multimaterials accessibles que permetin l’obtenció de models mimètics respecte als teixits vius. Per facilitar aquesta buscada extensió de la tecnologia, s’ha focalitzat en les tecnologies de codi obert com la Fabricació per Filament Fos (FFF) i similars basades en líquids catalitzables. La recerca s’alinea dins l’activitat de desenvolupament de la FA al CIM UPC, i en aquest àmbit concret amb la col·laboració amb l’Hospital Sant Joan de Déu de Barcelona (HSJD). El primer bloc de la tesi inclou la descripció de l’estat de l’art, detallant les tecnologies existents i la seva aplicació a l’entorn mèdic. S’han establert per primer cop unes bases de caracterització dels teixits vius -sobretot tous- per donar suport a la selecció de materials que els puguin mimetitzar en un procés de FA, a efectes de millorar l’experiència d’assaig dels cirurgians. El caràcter rígid dels materials majoritàriament usats en impressió 3D els fa poc útils per simular tumors i altres referències anatòmiques. De forma successiva, es tracten paràmetres com la densitat, la viscoelasticitat, la caracterització dels materials tous a la indústria, l’estudi del mòdul elàstic de teixits tous i vasos, la duresa d’aquests, i requeriments com l’esterilització dels models. El segon bloc comença explorant la impressió 3D mitjançant FFF. Es classifiquen les variants del procés des del punt de vista de la multimaterialitat, essencial per fer models d’assaig quirúrgic, diferenciant entre solucions multibroquet i de barreja al capçal. S’ha inclòs l’estudi de materials (filaments i líquids) que serien més útils per mimetitzar teixits tous. Es constata com en els líquids, en comparació amb els filaments, la complexitat del treball en processos de FA és més elevada, i es determinen formes d’imprimir materials molt tous. Per acabar, s’exposen sis casos reals de col·laboració amb l’HJSD, una selecció d’aquells en els que el doctorand ha intervingut en els darrers anys. L’origen es troba en la dificultat de l’abordatge d’operacions de resecció de tumors infantils com el neuroblastoma, i a la iniciativa del Dr. Lucas Krauel. Finalment, el Bloc 3 té per objecte explorar nombrosos conceptes (fins a 8), activitat completada al llarg dels darrers cinc anys amb el suport dels mitjans del CIM UPC i de l’activitat associada a treballs finals d’estudis d’estudiants de la UPC, arribant-se a materialitzar equipaments experimentals per validar-los. La recerca ampla i sistemàtica al respecte fa que s’estigui més a prop de disposar d’una solució d’impressió 3D multimaterial de sobretaula. Es determina que la millor via de progrés és la de disposar d’una pluralitat de capçals independents a fi de capacitar la impressora 3D per integrar diversos conceptes estudiats, materialitzant-se una possible solució. Cloent la tesi, es planteja com seria un equipament d’impressió 3D per a models d’assaig quirúrgic, a fi de servir de base per a futurs desenvolupaments.La presente tesis doctoral se ha centrado en el reto de conseguir, mediante Fabricación Aditiva (FA), modelos para ensayo quirúrgico, bajo la premisa que los equipos para obtenerlos tendrían que ser accesibles al ámbito hospitalario. El objetivo es facilitar la extensión del uso de modelos como herramienta de preparación de operaciones quirúrgicas, transformando la práctica médica actual de la misma manera que, en su momento, lo hicieron tecnologías como las que facilitaron el uso de radiografías. El motivo de utilizar FA, en lugar de tecnologías más tradicionales, es su capacidad de materializar de forma directa los datos digitales obtenidos de la anatomía del paciente mediante sistemas de escaneado tridimensional, haciendo posible la obtención de modelos personalizados. Los resultados se centran en la generación de nuevo conocimiento para conseguir equipamientos de impresión 3D multimateriales accesibles que permitan la obtención de modelos miméticos respecto a los tejidos vivos. Para facilitar la buscada extensión de la tecnología, se ha focalizado en las tecnologías de código abierto como la Fabricación por Hilo Fundido (FFF) y similares basadas en líquidos catalizables. Esta investigación se alinea dentro de la actividad de desarrollo de la FA en el CIM UPC, y en este ámbito concreto con la colaboración con el Hospital Sant Joan de Déu de Barcelona (HSJD). El primer bloque de la tesis incluye la descripción del estado del arte, detallando las tecnologías existentes y su aplicación al entorno médico. Se han establecido por primera vez unas bases de caracterización de los tejidos vivos – principalmente blandos – para dar apoyo a la selección de materiales que los puedan mimetizar en un proceso de FA, a efectos de mejorar la experiencia de ensayo de los cirujanos. El carácter rígido de los materiales mayoritariamente usados en impresión 3D los hace poco útiles para simular tumores y otras referencias anatómicas. De forma sucesiva, se tratan parámetros como la densidad, la viscoelasticidad, la caracterización de materiales blandos en la industria, el estudio del módulo elástico de tejidos blandos y vasos, la dureza de los mismos, y requerimientos como la esterilización de los modelos. El segundo bloque empieza explorando la impresión 3D mediante FFF. Se clasifican las variantes del proceso desde el punto de vista de la multimaterialidad, esencial para hacer modelos de ensayo quirúrgico, diferenciando entre soluciones multiboquilla y de mezcla en el cabezal. Se ha incluido el estudio de materiales (filamentos y líquidos) que serían más útiles para mimetizar tejidos blandos. Se constata como en los líquidos, en comparación con los filamentos, la complejidad del trabajo en procesos de FA es más elevada, y se determinan formas de imprimir materiales muy blandos. Para acabar, se exponen seis casos reales de colaboración con el HJSD, una selección de aquellos en los que el doctorando ha intervenido en los últimos años. El origen se encuentra en la dificultad del abordaje de operaciones de resección de tumores infantiles como el neuroblastoma, y en la iniciativa del Dr. Lucas Krauel. Finalmente, el Bloque 3 desarrolla numerosos conceptos (hasta 8), actividad completada a lo largo de los últimos cinco años con el apoyo de los medios del CIM UPC y de la actividad asociada a trabajos finales de estudios de estudiantes de la UPC, llegándose a materializar equipamientos experimentales para validarlos. La investigación amplia y sistemática al respecto hace que se esté más cerca de disponer de una solución de impresión 3D multimaterial de sobremesa. Se determina que la mejor vía de progreso es la de disponer de una pluralidad de cabezales independientes, a fin de capacitar la impresora 3D para integrar diversos conceptos estudiados, materializándose una posible solución. Para cerrar la tesis, se plantea cómo sería un equipamiento de impresión 3D para modelos de ensayo quirúrgico, a fin de servir de base para futuros desarrollos.
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Castro, Francisco Forte Alvim de. "Análise da influência da pigmentação na qualidade de peças impressas por FFF em PLA e PETG." Dissertação, 2021. https://hdl.handle.net/10216/135101.
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Castro, Francisco Forte Alvim de. "Análise da influência da pigmentação na qualidade de peças impressas por FFF em PLA e PETG." Master's thesis, 2021. https://hdl.handle.net/10216/135101.
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Gonsalves, Kiran. "Memory design for FFT processor in 3DIC technology." 2009. http://www.lib.ncsu.edu/theses/available/etd-03132009-142234/unrestricted/etd.pdf.
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Ravach, Tashi Arthur. "Performance analysis of OFDM technology on radio-over-fiber systems." Master's thesis, 2011. http://hdl.handle.net/10400.1/3125.
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Dissertação de mest., Engenharia Eletrónica e Telecomunicações, Faculdade de Ciências e Tecnologia, Univ. do Algarve, 2011Nowadays, the demand for high speed, high quality and diversity in distributed services presents a challenge for telecommunication technology. Wireless systems provide the accessibility to end-user, but are not the solution for long distance links. Currently, the ideal technology for long-range transmissions at high data rates is optical fiber. Hence, a new concept for high capacity networks emerges, with centralized services into Base Stations (BS) engineered to provide flexibility and control over the system, and to perform operations such as electrical to optical domain conversion and modulation. Such Radio-over-Fiber (RoF) networks also appear as an attractive technology because they are efficient and cost effective. Orthogonal Frequency Division Multiplexing (OFDM) technology is widely used in a number of standards. For instance, it is actually the Multi-Carrier Modulation (MCM) technique applied in 802.11a/g/n wireless standards and in Digital Video Broadcasting-Terrestrial (DVB-T), among other prevailing systems, which makes this subject one particularly pertinent to study. OFDM systems are an appealing choice for waveform modulation, as they are very bandwidth efficient comparing to others MCM, and provide flexibility in data transmission rates. Additionally, an important advantage dwells in its natural robustness against severely interfering environments. In this thesis, fundamentals on OFDM technology are extensively described, and its application to wireless and optical fiber networks is introduced. The combined channel effects of these technologies on OFDM signals are investigated. In terms of performance analysis, this exposition focuses on understanding the importance of OFDM modulation parameters, and explores some OFDM signal properties. To achieve this, a simulator was implemented with Matlab to create arbitrary OFDM waveforms and emulate channel effects. This study also investigates the efficiency of OFDM technology over a real Radio Frequency (RF) system with an ideal communication channel. Finally, an experimental RoF configuration is implemented and its performance is assessed.
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Wooten, Kate 1988. "Identification of Stem Concepts Associated with Junior Livestock Projects: A Delphi Study." Thesis, 2012. http://hdl.handle.net/1969.1/148336.
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Science, technology, engineering, and mathematics (STEM) education is intended to provide students with a cross-subject, contextual learning experience. In order to more fully prepare our nation's students for entering the globally competitive workforce, STEM integration allows students to make connections between the abstract concepts learned in core subject classrooms and real-world situations. FFA and 4-H programs, by nature, are intended to provide students with hands-on learning opportunities where abstract core subject principles can be applied and more fully understood. Junior livestock projects through FFA and 4-H can provide rich connections for students between what they learn in school and how it is applied in the real world through their livestock project.
Using a modified Delphi technique, this study identified STEM concepts associated with junior livestock projects. The study also examined whether STEM concepts should be integrated into the supervision of junior livestock projects and identified barriers which would prevent the incorporation of STEM concepts into local 4-H and FFA programming and instruction. The experts identified several (13 of 19) STEM concepts associated with junior livestock projects, four reasons local 4-H and FFA leaders/advisors should incorporate STEM concepts into their programming and instruction, and no barriers which would prevent local 4-H and FFA leaders/advisors from incorporating STEM concepts into their programming and instruction. This paper explores rationale regarding why STEM integration is important and makes recommendations for the integration of STEM concepts into the supervision of junior livestock projects.