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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
521

Personalized Interaction with High-Resolution Wall Displays

von Zadow, Ulrich 14 May 2018 (has links)
Fallende Hardwarepreise sowie eine zunehmende Offenheit gegenüber neuartigen Interaktionsmodalitäten haben in den vergangen Jahren den Einsatz von wandgroßen interaktiven Displays möglich gemacht, und in der Folge ist ihre Anwendung, unter anderem in den Bereichen Visualisierung, Bildung, und der Unterstützung von Meetings, erfolgreich demonstriert worden. Aufgrund ihrer Größe sind Wanddisplays für die Interaktion mit mehreren Benutzern prädestiniert. Gleichzeitig kann angenommen werden, dass Zugang zu persönlichen Daten und Einstellungen — mithin personalisierte Interaktion — weiterhin essentieller Bestandteil der meisten Anwendungsfälle sein wird. Aktuelle Benutzerschnittstellen im Desktop- und Mobilbereich steuern Zugriffe über ein initiales Login. Die Annahme, dass es nur einen Benutzer pro Bildschirm gibt, zieht sich durch das gesamte System, und ermöglicht unter anderem den Zugriff auf persönliche Daten und Kommunikation sowie persönliche Einstellungen. Gibt es hingegen mehrere Benutzer an einem großen Bildschirm, müssen hierfür Alternativen gefunden werden. Die daraus folgende Forschungsfrage dieser Dissertation lautet: Wie können wir im Kontext von Mehrbenutzerinteraktion mit wandgroßen Displays personalisierte Schnittstellen zur Verfügung stellen? Die Dissertation befasst sich sowohl mit personalisierter Interaktion in der Nähe (mit Touch als Eingabemodalität) als auch in etwas weiterer Entfernung (unter Nutzung zusätzlicher mobiler Geräte). Grundlage für personalisierte Mehrbenutzerinteraktion sind technische Lösungen für die Zuordnung von Benutzern zu einzelnen Interaktionen. Hierzu werden zwei Alternativen untersucht: In der ersten werden Nutzer via Kamera verfolgt, und in der zweiten werden Mobilgeräte anhand von Ultraschallsignalen geortet. Darauf aufbauend werden Interaktionstechniken vorgestellt, die personalisierte Interaktion unterstützen. Diese nutzen zusätzliche Mobilgeräte, die den Zugriff auf persönliche Daten sowie Interaktion in einigem Abstand von der Displaywand ermöglichen. Einen weiteren Teil der Arbeit bildet die Untersuchung der praktischen Auswirkungen der Ausgabe- und Interaktionsmodalitäten für personalisierte Interaktion. Hierzu wird eine qualitative Studie vorgestellt, die Nutzerverhalten anhand des kooperativen Mehrbenutzerspiels Miners analysiert. Der abschließende Beitrag beschäftigt sich mit dem Analyseprozess selber: Es wird das Analysetoolkit für Wandinteraktionen GIAnT vorgestellt, das Nutzerbewegungen, Interaktionen, und Blickrichtungen visualisiert und dadurch die Untersuchung der Interaktionen stark vereinfacht. / An increasing openness for more diverse interaction modalities as well as falling hardware prices have made very large interactive vertical displays more feasible, and consequently, applications in settings such as visualization, education, and meeting support have been demonstrated successfully. Their size makes wall displays inherently usable for multi-user interaction. At the same time, we can assume that access to personal data and settings, and thus personalized interaction, will still be essential in most use-cases. In most current desktop and mobile user interfaces, access is regulated via an initial login and the complete user interface is then personalized to this user: Access to personal data, configurations and communications all assume a single user per screen. In the case of multiple people using one screen, this is not a feasible solution and we must find alternatives. Therefore, this thesis addresses the research question: How can we provide personalized interfaces in the context of multi-user interaction with wall displays? The scope spans personalized interaction both close to the wall (using touch as input modality) and further away (using mobile devices). Technical solutions that identify users at each interaction can replace logins and enable personalized interaction for multiple users at once. This thesis explores two alternative means of user identification: Tracking using RGB+depth-based cameras and leveraging ultrasound positioning of the users' mobile devices. Building on this, techniques that support personalized interaction using personal mobile devices are proposed. In the first contribution on interaction, HyDAP, we examine pointing from the perspective of moving users, and in the second, SleeD, we propose using an arm-worn device to facilitate access to private data and personalized interface elements. Additionally, the work contributes insights on practical implications of personalized interaction at wall displays: We present a qualitative study that analyses interaction using a multi-user cooperative game as application case, finding awareness and occlusion issues. The final contribution is a corresponding analysis toolkit that visualizes users' movements, touch interactions and gaze points when interacting with wall displays and thus allows fine-grained investigation of the interactions.
522

Kollaborative Erstellung von Mind-Maps mit persönlichen Linsen an interaktiven Display Walls

Gräf, Maximilian 28 October 2015 (has links)
Mind-Mapping ist eine effiziente und universelle Kreativitätstechnik, die es ermöglicht, in einer Gruppe ein komplexes Thema aufzuschlüsseln. Dabei wird eine Assoziation verschiedener Schlüsselwörter, Notizen und Grafiken zu einem zentralen Begriff vorgenommen und dadurch eine Möglichkeit zur schrittweisen kompakten Visualisierung eines Themengebietes geschaffen. Große interaktive Display Walls erlauben durch ihre Fläche und ihre interaktiven Möglichkeiten das kollaborative Erstellen von Mind-Maps, so dass jeder Nutzer individuell Teile kreieren und der gemeinsamen Mind-Map beifügen kann. In dieser Ausarbeitung werden geeignete Interaktionskonzepte zur Erstellung von Mind-Maps an interaktiven Display Walls vorgestellt. Dabei liegt der Fokus auf den Möglichkeiten der Erkennung der Nutzerposition vor der Display Wall, um jedem Benutzer eine persönliche Linse und damit Zugriff auf persönliche Werkzeuge zu ermöglichen, sowie der Interaktion mittels Stift und Touch zum Zwecke der Erstellung und Platzierung von Mind-Map Elementen. Dafür werden zunächst verwandte Arbeiten aus den Bereichen: Mind-Maps, Kollaboration und Interaktion mit interaktiven Display Walls und Magische Linsen analysiert. Basierend auf einem Grundverständnis dieser drei Domänen wurden Konzepte zur kollaborativen Erstellung von Mind-Maps an interaktiven Display Walls mit persönlichen Linsen präsentiert. Ausgewählte Konzepte wurden dabei in einer prototypischen Implementierung umgesetzt und boten erste aussichtsreiche Einblicke, wie das Mind-Mapping der Zukunft erfolgen könnte. Dabei wurde insbesondere der Nutzen einer persönlichen Linse, als individuelle Visualisierungs- und Interaktions-Schnittstelle erkannt.:Einleitung Verwandte Arbeiten Konzepte zur kollaborativen Erstellung von Mind-Maps mit persönlichen Linsen an interaktiven Display Walls Prototypische Implementierung Fazit und Ausblick / Mind-mapping is an effective and universal creativity technique, which allows to break down complex topics in a group activity. Therefore keywords, notes or images are being associated to a superordinate topic, in order to gradually create a compact visualization of a topic. Large interactive display walls allow the collaborative creation of mind-maps due to their size and options for interaction so that the users can individually create parts and integrate them into the collective mind-map. As part of this thesis, suitable concepts for the creation of mind-maps on interactive display walls are being presented. In this context, the emphasis is lying on the possibilities of using the position of the user in front the display wall, in order to offer every user a personal lens and thus access to personal tools, as well as the interaction with pen and touch in order to create and move mind-map-elements. Therefore related work of the topic areas: mind-maps, collaboration and interaction at interactive display walls and Magic Lenses will be analysed at first. Based on a fundamental understanding of these three domains, concepts for the collaborative creation of mind-maps on interactive display walls using personal lenses are being presented. Selected concepts were prototypically implemented and offered first promising insights on how the mind-mapping of the future could be done. In the process the particular benefit of a personal lens as an individual visualization- and interaction-interface has been recognized.:Einleitung Verwandte Arbeiten Konzepte zur kollaborativen Erstellung von Mind-Maps mit persönlichen Linsen an interaktiven Display Walls Prototypische Implementierung Fazit und Ausblick
523

Den vertikala trädgårdens utveckling : En design research studie för framtagning av ett teoretiskt väggsnitt bestående av en halvsandwich med en infäst levande fasad / Development of the vertical garden : A design research study for the development of a theoretical wall consisting of a half-sandwich wall with an attached living facade

Backnäs, Johanna, Svensson, Lisa January 2022 (has links)
Introduction: There is a housing shortage in Sweden and the green space factor must be taken into account when building. The green space factor includes living façades that have a positive effect on people and society. The company Butong, in which the work has been done in collaboration, has patented solutions within living façades. The company currently mounts the façade solutions on a prefabricated concrete sandwich wall, but lacks a solution for mounting on a half sandwich wall. The purpose of a solution with a half sandwich wall was to avoid unnecessary material consumption, reduce environmental impact, and reduce the thickness of the wall. The work examined a half sandwich wall with three insulation materials: cellular plastic, PIR and Kooltherm. Method: The chosen method for the study was design research methodology, which contains a total of seven steps. The first two steps were used in this study. The first step consisted of a literature study. The second step was supplemented with empirical data in form of interviews and further literature studies. Calculations for carbon dioxide equivalents were performed by calculating the footprint of each material. The calculations were based on the material thickness of 1 m2 wall area. Data were obtained from environmental product declarations for construction products (EPDs) based on factors A1-A3.   Results and Analysis: For all half sandwich walls, a roofboard in stone wool was chosen as the utmost layer. This was based on conditions for fire safety for the materials cellular plastic and PIR, and based on attachment for the material Kooltherm. The use of a polypropylene plastic mat to obtain an air gap was decided for all materials based on moisture safety. Furthermore, the results showed three possible fastening methods for mounting Butong's façade solution on a half-sandwich walls: cast plastic profiles (SFS-profiles), vertically cast L-profiles and horizontally cast L-profiles. The result also reported that replacing a full sandwich wall with a half sandwich wall reduces material consumption, and reduces emissions of carbon dioxide equivalents by up to 31%. This is based on the EPD factors A1-A3 where a comparison of the half sandwich wall was made with a full sandwich wall.  Discussion: The thickness of the walls could be reduced by 60-80 mm when a full sandwich wall was replaced with a half sandwich wall. The variation depended on insulation material. The insulation material Kooltherm resulted in the thinnest wall. The material PIR varied in fire classification. The reason was discussed to be the difference in supply of products in different countries. The choice of attachment method was reported to be dependent on the situation. Cellulose showed the lowest emissions of carbon dioxide equivalents. Both with regard to the production phase, and with regard to the percentage reduction when comparing full sandwich walls and half sandwich walls. In conclusion, the choice of insulation material depends on individual preferences. Cellular plastic should be used when prioritizing at least emissions of carbon dioxide equivalents. Kooltherm is suitable when prioritizing the degree of utilization, considering that the wall is thinnest. / Introduktion och syfte: Det är bostadsbrist i Sverige och det måste tas hänsyn till grönytefaktorn vid bebyggelse. I grönytefaktorn ingår levande fasader som påverkar människor samt samhälle positivt. Företaget Butong, som arbetet har skett i samarbete med, har patenterade lösningar för levande fasader. Företaget monterar idag fasadlösningarna på ett helsandwichelement, men saknar lösning för att montera på ett halvsandwichelement. Syftet med halvsandwichelement var att undvika onödig materialåtgång, minska miljöpåverkan, samt erhålla en tunnare tjocklek på elementet. Arbetet undersökte ett halvsandwichelement utifrån tre ingående isoleringsmaterial: cellplast, PIR och Kooltherm. Metod: Vald metod för arbetet var design research methodology som totalt innehåller sju steg. De två första stegen användes i studien. Första steget bestod av en litteraturstudie. Det andra steget kompletterades med hjälp av empiri i form av intervjuer och fortsatta litteraturstudier. Beräkningar för koldioxidekvivalenter utfördes genom att beräkna respektive materials avtryck. Beräkningarna utgick från materialets tjocklek på 1 m2 väggyta. Data hämtades från miljövarudeklarationer för byggprodukter (EPD:er) utifrån faktorerna A1-A3. Resultat och Analys: För samtliga halvsandwichelement valdes en takboard av stenull som yttersta skikt. Detta utifrån brandsäkerhet för materialen cellplast och PIR respektive utifrån infästning för materialet Kooltherm. Användning av platonmatta för att erhålla en luftspalt bestämdes för samtliga material utifrån fuktsäkerhet. Vidare visade resultatet tre möjliga infästningsmetoder för att montera Butongs fasadlösning på ett halvsandwichelement: ingjutna plastprofiler (SFS-fästen), vertikalt ingjutna L-profiler samt horisontellt ingjutna L-profiler. Resultatet redovisade även att ersätta helsandwichelement med halvsandwichelementet minskar materialåtgång, samt minskar utsläpp av koldioxidekvivalenter med upp till 31%. Detta utifrån EPD-faktorerna A1-A3 där en jämförelse av halvsandwichelementet gjordes med ett helsandwichelement utifrån samma funktionsvärde.  Diskussion: Tjockleken på elementen kunde minskas med 60-80 mm med den nya lösningen. Variationen var beroende av isoleringsmaterial. Isoleringsmaterialet Kooltherm resulterade i tunnast element. Materialet PIR varierade i brandklassning. Anledningen diskuterades vara skillnaden i utbud av produkter i olika länder. Val av infästningsmetod redovisades vara beroende av situation. Cellplast visade lägst utsläpp av koldioxidekvivalenter. Både avseende produktionsfasen, samt med hänsyn till procentuell minskning vid jämförelse av helsandwichelement och halvsandwichelement. Avslutningsvis kunde slutsatsen konstateras att val av isoleringsmaterial beror på individuella preferenser. Cellplast bör användas vid prioritering inom minst utsläpp av koldioxidekvivalenter. Respektive Kooltherm är lämpligt vid prioritering av utnyttjandegrad, då elementet är tunnast.
524

Heat And Fluid Flow Characterization Of A Single-hole-per-row Impingement Channel At Multiple Impingement Heights

Claretti, Roberto 01 January 2013 (has links)
The present work studies the relationship between target and sidewall surfaces of a multirow, narrow impingement channel at various jet heights with one impingement hole per row. Temperature sensitive paint and constant flux heaters are used to gather heat transfer data on the target and side walls. Jet-to-target distance is set to 1, 2, 3, 5, 7 and 9 jet diameters. The channel width is 4 jet diameters and the jet stream wise spacing is 5 jet diameters. All cases were run at Reynolds numbers ranging from 5,000 to 30,000. Pressure data is also gathered and used to calculate the channel mass flux profiles, used to better understand the flow characteristics of the impingement channel. While target plate heat transfer profiles have been thoroughly studied in the literature, side wall data has only recently begun to be studied. The present work shows the significant impact the side walls provide to the overall heat transfer capabilities of the impingement channel. It was shown that the side walls provide a significant amount of heat transfer to the channel. A channel height of three diameters was found to be the optimum height in order to achieve the largest heat transfer rates out of all channels.
525

Intraglottal Glottal Pressure Distributions for Three Oblique Glottal Angles

Li, Jun 18 August 2010 (has links)
No description available.
526

Collapse Experiments and Assessment of Masonry Wall Buildings

Li, Kai January 2017 (has links)
No description available.
527

THE NEXT GENERATION OF COUPLING BEAMS

FORTNEY, PATRICK JOSEPH 13 July 2005 (has links)
No description available.
528

Development and validation of an improved wall-function boundary condition for computational aerodynamics / Utveckling och validering av ett förbättrat väggfunktionsranvillkor för aerodynamiska beräkningar

Palombo, Carlo Loris January 2021 (has links)
Computational Fluid Dynamics is a powerful and widely used tool for developing projectsthat concern flow motion, in very different fields. Industrial CFD solvers are continuouslydeveloped with the aim of improving accuracy and reducing the computational cost of thesimulations. Turbulent wall-flow cases are particular demanding as the presence of a solidsurfaceinterface generates steep gradients in the proximity of the wall. Resolving suchgradients can be crucial to obtain a consistent solution but also very expensive in terms ofgrid refinement, and hence computational time. Wall functions are widely used and offersignificant computational savings when it comes to near-wall flow resolution. Previous wallfunction implemented in the M-Edge solver suffered by poor performances in complex flowscharacterized by strong pressure-gradient phenomena, such as separation. A new formulationhas been developed and validated for k − omega and Spalart-Allmaras turbulence models. Testsimulations started from simple and near-ideal cases (2D zero pressure gradient flat plate)and advanced to always more complex flow cases and geometries (full 3D general fighter).Every case has been run coupling the wall-function boundary condition with three differentturbulence models: the Menter SST, the Menter BSL with an EARSM and the Spalart-Allmaras one-equation model. Overall results showed the upgraded performance of new wallfunction in flow resolution together with more agile grid requirements, faster and deeperconvergence of the residuals and a general reduction in computational time. / Berör strömmande fluider inom mycket olika områden. Industriella CFD-lösare utvecklaskontinuerligt i syfte att förbättra noggrannheten och minska beräkningskostnaderna försimuleringarna. Turbulent strömning nära väggar är särskilt krävande eftersom närvaron avett fast ytgränssnitt genererar stora gradienter i närheten av väggen. Att lösa upp sådanagradienter kan vara avgörande för att få en konsistent lösning men också mycket beräkningskrävandepå grund av nödvändig nätförfining.Väggfunktioner används ofta och ger betydandereduktioner i beräkningstid när det gäller att lösa upp strömningen nära vägg. En tidigareväggfunktion implementerad i M-Edge-lösaren led av dåliga prestanda i komplexa flödenmed starka tryckgradienter, såsom separation. En ny formulering har utvecklats och valideratsför k − omega och Spalart-Allmaras turbulensmodeller. Den har testats för enkla generiska fall(2D-plan platta utan tryckgradient) och för mer avancerade och komplexa strömningsfall ochgeometrier (komplett 3D-stridsflygplan).Varje fall har körts med väggfunktionens randvillkorkopplat med tre olika turbulensmodeller: Menter SST, Menter BSL med EARSM och Spalart-Allmaras enekvationsmodell. De övergripande resultaten visar att nya väggfunktionen gerbetydande förbättringar i att beskriva strömningen tillsammans med reducerade krav pånätupplösning, snabbare och djupare konvergens av lösningen och en allmän minskning avberäkningstiden.
529

Characterisation of thermal radiation in the near-wall region of a packed pebble bed / Maritza de Beer

De Beer, Maritza January 2014 (has links)
The heat transfer phenomena in the near-wall region of a randomly packed pebble bed are important in the design of a Pebble Bed Reactor (PBR), especially when considering the safety case during accident conditions. At higher temperatures the contribution of the radiation heat transfer component to the overall heat transfer in a PBR increases significantly. The wall effect present in the near-wall region of a packed pebble bed affects the heat transfer in this region. Various correlations exist to predict the effective thermal conductivity through a packed pebble bed, but not all of the correlations consider the contribution of radiation and some are only applicable to the bulk region. Experimental research has been done on the heat transfer through a packed pebble bed. However, most of the results are case specific and cannot necessarily be used to validate models or simulations to predict the effective thermal conductivity of a pebble bed. The objective of this study is to develop a methodology that uses experimental work together with Computational Fluid Dynamics (CFD) simulations to predict the effective thermal conductivity in the near-wall region of a randomly packed pebble bed, and to separate the conduction and radiation components of the effective thermal conductivity. The proposed methodology inter alia includes experimental tests and the calibration of a CFD model to obtain numerical results that correlate well with the experimental results. To illustrate the proposed methodology the newly constructed Near-wall Effect Thermal Conductivity Test Facility (NWETCTF) was used to gather experimental results for the temperature and heat transfer distribution through a randomly packed pebble bed. Two identical but separate experimental tests were performed and the results of the two tests were in good agreement. From the experimental results the effective thermal conductivity was derived. The effect of the near-wall region on the heat transfer and the significance of radiation at higher temperatures are evident from the results. Recommendations were made for future experimental work with the NWETCTF from the findings of the investigation. A numerically packed pebble bed that is representative of the experimental pebble bed was generated using the Discrete Element Method (DEM) and a CFD model was set up for the heat transfer through the pebble bed using STAR-CCM+.. The CFD results showed trends similar to that of the experimental results. However, some discrepancies were identified that must be addressed in future studies by calibrating the CFD model. The effective thermal conductivity for the numerical simulation was determined using the CFD results and the conduction and radiation components were separated. / MSc (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015
530

Characterisation of thermal radiation in the near-wall region of a packed pebble bed / Maritza de Beer

De Beer, Maritza January 2014 (has links)
The heat transfer phenomena in the near-wall region of a randomly packed pebble bed are important in the design of a Pebble Bed Reactor (PBR), especially when considering the safety case during accident conditions. At higher temperatures the contribution of the radiation heat transfer component to the overall heat transfer in a PBR increases significantly. The wall effect present in the near-wall region of a packed pebble bed affects the heat transfer in this region. Various correlations exist to predict the effective thermal conductivity through a packed pebble bed, but not all of the correlations consider the contribution of radiation and some are only applicable to the bulk region. Experimental research has been done on the heat transfer through a packed pebble bed. However, most of the results are case specific and cannot necessarily be used to validate models or simulations to predict the effective thermal conductivity of a pebble bed. The objective of this study is to develop a methodology that uses experimental work together with Computational Fluid Dynamics (CFD) simulations to predict the effective thermal conductivity in the near-wall region of a randomly packed pebble bed, and to separate the conduction and radiation components of the effective thermal conductivity. The proposed methodology inter alia includes experimental tests and the calibration of a CFD model to obtain numerical results that correlate well with the experimental results. To illustrate the proposed methodology the newly constructed Near-wall Effect Thermal Conductivity Test Facility (NWETCTF) was used to gather experimental results for the temperature and heat transfer distribution through a randomly packed pebble bed. Two identical but separate experimental tests were performed and the results of the two tests were in good agreement. From the experimental results the effective thermal conductivity was derived. The effect of the near-wall region on the heat transfer and the significance of radiation at higher temperatures are evident from the results. Recommendations were made for future experimental work with the NWETCTF from the findings of the investigation. A numerically packed pebble bed that is representative of the experimental pebble bed was generated using the Discrete Element Method (DEM) and a CFD model was set up for the heat transfer through the pebble bed using STAR-CCM+.. The CFD results showed trends similar to that of the experimental results. However, some discrepancies were identified that must be addressed in future studies by calibrating the CFD model. The effective thermal conductivity for the numerical simulation was determined using the CFD results and the conduction and radiation components were separated. / MSc (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015

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