In der heutigen Filmindustrie bietet das 3D-Design ein anerkanntes Mittel, um virtuelle Welten oder Charaktere zu erschaffen. Doch das 3D-Design dringt mittlerweile auch in andere Bereiche vor, so etwa der Medizin und der Architektur. Dabei bietet die virtuelle Rekonstruktion auch vielfältige Möglichkeiten für die Archäologie/Ägyptologie. Beispielsweise können von kleineren Objekten oder Papyri virtuelle 3D-Modelle erstellt werden. Der große Vorteil dabei ist, dass die Originale nicht beschädigt werden und mehrere Wissenschaftler zur gleichen Zeit an ein und demselben Objekt forschen können. Selbst für die Bauforschung dürfte das 3D-Design immer bedeutender werden. Gebäude, die sich heute nur in ihren Grundrissen erhalten haben, können mithilfe des 3D-Designs nahezu vollständig rekonstruiert werden. Nicht zu unterschätzen ist dabei auch die Wirkung, die virtuelle Rekonstruktionen von ägyptischen Tempeln, Gräbern, Gebäuden auf die Gesellschaft erzielen. Durch die 3DRekonstruktionen kann nicht nur Wissenschaftlern, sondern auch Interessierten ein anschaulicher Eindruck von der Lebenswelt des Alten Ägypten vermittelt werden. Bislang steht das 3D-Design allerdings in dem Ruf, besonders schwer erlernbar und sehr kostenintensiv zu sein. Doch gibt es neben einigen aufwendigen 3D-Design-Programmen auch nahezu kostenfreie Alternativen, die man sowohl privat wie beruflich nutzen kann. Diese Programme sind dabei sehr anwenderfreundlich gestaltet und relativ leicht zu erlernen. Ziel des Vortrages ist es, diese Programme und ihre Möglichkeiten für die Ägyptologie vorzustellen.

<div>Cost estimation is an integral part of any project, and accuracy in the cost estimation process is critical in achieving a successful project. Manually computing cost estimates is mentally draining, difficult to compute, and error-prone. Manual cost estimate computation is a task that requires experience. The use of automated techniques can improve the accuracy of estimates and vastly improve the cost estimation process. Two main gaps in the automation of construction cost estimation are: (1) the lack of interoperability between different software platforms, and (2) the need for manual inputs to complete quantity take-off (QTO) and cost estimation. To address these gaps, this research proposed a new systems to support the computing of cost estimation using Model View Definition (MVD)-based checking, industry foundation classes (IFC) geometric analysis, logic-based reasoning, natural language processing (NLP), and automated 3D image generation to reduce/eliminate the labor-intensive, tedious, manual efforts needed in completing construction cost estimation. In this research, new IFC-based systems were developed: (1) Modeling – an automated IFC-based system for generating 3D information models from 2D PDF plans; (2) QTO - a construction MVD specification for IFC model checking to prepare for cost estimation analysis and a new algorithm development method that computes quantities using the geometric analysis of wooden building objects in an IFC-based building information modeling (BIM) and extracts the material variables needed for cost estimation through item matching based on natural language processing; and (3) Costing – an ontology-based cost model for extracting design information from construction specifications and using the extracted information to retrieve the pricing of the materials for a robust cost information provision.</div><div><br></div><div>These systems developed were tested on different projects. Compared with the industry’s current practices, the developed systems were more robust in the automated processing of drawings, specifications, and IFC models to compute material quantities and generate cost estimates. Experimental results showed that: (1) Modeling - the developed component can be utilized in developing algorithms that can generate 3D models and IFC output files from Portable Document Format (PDF) bridge drawings in a semi-automated fashion. The developed algorithms utilized 3.33% of the time it took using the current state-of-the-art method to generate a 3D model, and the generated models were of comparative quality; (2) QTO – the results obtained using the developed component were consistent with the state-of-the-art commercial software. However, the results generated using the proposed component were more robust about the different BIM authoring tools and workflows used; (3) Extraction – the algorithms developed in the extraction component achieved 99.2% precision and 99.2% recall (i.e., 99.2% F1-measure) for extracted design information instances; 100% precision and 96.5% recall (i.e., 98.2% F1-measure) for extracted materials from the database; and (4) Costing - the developed algorithms in the costing component successfully computed the cost estimates and reduced the need for manual input in matching building components with cost items.</div>

Les activités basées sur l'exploitation de données vidéo se sont développées de manière fulgurante ces dernières années : nous assisté à une démocratisation de certaines de ces activités (vidéo-surveillance) mais également à une diversification importante des applications opérationnelles (suivi de ressources naturelles, reconnaissance etc). Cependant, le volume de données vidéo généré est aujourd'hui astronomique et l'efficacité de ces activités est limitée par le coût et la durée nécessaire à l'interprétation humaine des données vidéo. L'analyse automatique de flux vidéos est donc devenue une problématique cruciale pour de nombreuses applications. L'approche semi-automatique développée dans le cadre de cette thèse se concentre plus spécifiquement sur l'analyse de vidéos aériennes, et permet d'assister l'analyste image dans sa tâche en suggérant des zones d'intérêt potentiel par détection de changements. Pour cela, nous effectuons une modélisation tridimensionnelle des apparences observées dans les vidéos de référence. Cette modélisation permet ensuite d'effectuer une détection en ligne des changements significatifs dans une nouvelle vidéo, en identifiant les déviations d'apparence par rapport aux modèles de référence. Des techniques spécifiques ont également été proposées pour effectuer l'estimation des paramètres d'acquisition ainsi que l'atténuation des effets de l'illumination. De plus, nous avons développé plusieurs techniques de consolidation permettant d'exploiter la connaissance a priori relative aux changements à détecter. L'intérêt et les bonnes performances de notre approche a été minutieusement démontré à l'aide de données réelles et synthétiques. / Business activities based on the use of video data have developed at a dazzling speed these last few years: not only has the market of some of these activities widely expanded (video-surveillance) but the operational applications have also greatly diversified (natural resources monitoring, intelligence etc). However, nowadays, the volume of generated data has become overwhelming and the efficiency of these activities is now limited by the cost and the time required by the human interpretation of this video data. Automatic analysis of video streams has hence become a critical problem for numerous applications. The semi-autmoatic approach developed in this thesis focuses more specifically on the automatic analysis of aerial videos and enables assisting the image analyst in his task by suggesting areas of potential interest identified using change detection. For that purpose, our approach proceeds to a tridimensional modeling of the appearances observed in the reference videos. Such a modeling then enables the online detection of significant changes in a new video, by identifying appearance deviations with respect to the reference models. Specific techniques have also been developed to estimate the acquisition parameters and to attenuate illumination effects. Moreover, we developed several consolidation techniques making use of a priori knowledge related to targeted changes, in order to improve detection accuracy. The interest and good performance of our change detection approach has been carefully demonstrated using both real and synthetical data.

No description available.

Byggnadsinformationsmodellering (BIM) som begrepp har existerat i mer än 20 år och arbetssätt som innefattar BIM är fortfarande ett område i stark utveckling. BIM är ett arbetssätt som använder sig av digitala modeller med särskilt fokus på att knyta an- och dela information. En BIM-integrering medför en stor kostnad vilket har begränsat arbetssättet till de större företagen. Därav har det inte spridits till de mindre företagen i samma omfattning.  Denna fallstudie använde sig av en Trimble X12 och terrester laserskanning som metod för att utforska möjligheterna kring digital integrering hos ett mindre tillverkningsföretag. Detta skedde genom att skapa en nerskalad BIM-modell över en utvald CNC-maskin med dess tillbehör med hjälp av punktmoln och RGB-bilder i mjukvaran Autodesk Inventor. Datainsamling, utförandet och analys av punktmolnskvalitet genomfördes med hjälp av en kvantitativ process. RMS (Root Mean Square) beräknades genom att ta referensmått på CNC-maskinen med måttband för jämförelse med mått i punktmoln. Informationen till den nerskalade BIM-modellen utformades efter företagets behov. Med hjälp av semistrukturerade intervjuer hämtades information in gällande BIM och digitala tvillingar i form av tillvägagångsätt, metodutförande och utmaningar. Punktmolnet bearbetades i Autodesk ReCap för vidare modellering och hade ett medelöverlapp på 56 %, medelosäkerhet på 0,5 mm med ett RMS-värde på CNC-maskinens punktmoln på 6,5 mm. Terrester laserskanning visar sig vara otillräcklig för att noggrannt skanna in den utvalda CNC-maskinen, då den har flera reflektiva och mörka ytor. Detta förhindrar en låg osäkerhetsnivå. Studien föreslår därav andra möjliga alternativ som kan komplettera TLS för att förbättra punktmolnets kvalitet, men som kräver ytterliggare forskning. BIM-modellen berikades med information med hjälp av en ritningsfunktion i Autodesk Inventor i PDF-format. Ritningar presenteras i olika vyer tillsammans med informationstabeller och dimensionsmått efter företagets val av information. Ritningarna, BIM-modeller och arbetssätt utvärderades med företaget i fråga. BIM-modellen visade sig vara detaljmässigt överflödig för företagets intressen. Modellen tog två veckor att framarbeta, vilket anses vara för kostsamt för företaget i fråga. Men den information som modellen var berikad med gav positiva tankar kring framtida BIM-integrering i verksamheten, speciellt inom underhåll och komplettering av underlag för äldre och modifierade maskiner. Studien visar på att mer forskning kring digital integrering i mindre tillverkningsindustrier behövs. / Building information modeling (BIM) is a term that has existed for more than 20 years and is still developing. BIM utilizes enhanced digital models with attributes that focus on adding and sharing information. BIM is very costly to implement, limitingits use to mainly the larger companies. Thus, BIM has not been as widespread regarding smaller businesses. This case study explores the area of digital integration of a BIM-model of a CNC-machine in a smaller manufacturing company. With the aid of a Trimble X12 and terrestrial laser scanning, the study investigated the process of creating a scaled down BIM-model detailing a selected CNC-machine by using point clouds and RGB-images in the software Autodesk Inventor. The data collection, execution, and point cloud quality were analysed with a quantitative process along with RMS-calculations of measurements in the point cloud to reference measurements. The information assigned to the model was according to the company's needs. Using semi-structured interviews, the area of BIM and digital twins regarding the process, methods and challenges were discussed.  The point cloud was processed in Autodesk ReCap for further modeling and had an average overlap of 56 %, an average uncertainty of 0,5 mm with an RMS-value of the CNC-machines point cloud of 6,5 mm. Terrestrial laser scanning proved to be insufficient when it comes to scanning the CNC-machine, as it had multiple reflective and dark surfaces, which prevented a low level of uncertainty. Thus this study proposes several other techniques that can be combined with TLS to improve the point cloud quality, which will require further research. The BIM-model was enriched with information by using Inventors' drawing features. These were then presented in different views together with tables of information and dimensions after the company’s chosen information. The drawings, BIM-models and workflow were then evaluated with the Aknes Mekaniska company. In terms of its level of detail The BIM-model proved to be superfluous, for the company’s interests. The model took two weeks to produce, which was deemed too costly for the company in question. But the information attached to the model resulted in positive thoughts from the company regarding future BIM-integration, specifically in maintenance and supplementing documentation of older or modified machines. In summary, the results of the study points to the need of further research of digital integration in smaller manufacturing companies.

Idiopathic clubfoot causes severe deformity of the foot and lower leg. Due to the complex anatomy and small size of the foot, the condition is difficult to define and describe. This study focused on 3D modeling of different foot positions associated with clubfoot relapse, and investigation of muscle parameters. The 3D modeling was performed in the AnyBody Modeling System to retrieve information about muscle length. Musculoskeletal modeling could provide further understanding of the condition and contribute to assessment and treatment evaluation. Five children that received clubfoot treatment as infants, and five typically developing children, serving as a control group, participated in the study. Despite treatment with the Ponseti method, Achilles tenotomy and use of an abduction orthosis, all participants of the clubfoot group showed signs of relapse. In total, seven affected legs were studied. Data from gait analyses of all participants were compiled and interpreted in the AnyBody Modeling System. The Plug-in-Gait Model for lower extremities and the Oxford Foot Model were used as marker protocol for the study. Studied lower leg muscles were Gastrocnemius Lateralis, Gastrocnemius Medialis, Soleus Lateralis and Soleus Medialis. Muscle length, defined as length of contractile element, for each leg and participant were evaluated using the AnyBody model template LowerExtremity. Compared to the control group, the models of the clubfoot group presented shorter mean muscle lengths of all investigated muscles. / Idiopatisk klumpfot orsakar allvarlig deformation av fot och underben. På grund av fotens anatomi och ringa storlek kan tillståndet vara svårt att beskriva och definiera. Denna studie innefattade 3Dmodellering av olika fotpositioner orakade av recidivklumpfot, för att undersöka muskelegenskaper. AnyBody Modeling System användes för att generera 3D-modeller och ta fram information om muskellängd. Muskuloskeletal modellering skulle kunna öka förståelsen för sjukdomen och bidra till förbättringar av initial bedömning och utvärdering av behandling. Fem barn som behandlades för klumpfot efter födseln deltog i studien. Även fem typiskt utvecklade barn medverkade och fungerade som en kontrollgrupp. Trots behandling med Ponseti-metoden, hälseneförlängning och användning av abduktionsortos, uppvisade samtliga barn i klumpfotsgruppen tecken på återfall. Totalt studerades sju ben med recidivklumpfot. Data från gånganalyser av deltagarna sammanställdes och analyserades i AnyBody Modeling System. Plug-in-Gait Model för nedre extremiteter och Oxford Foot Model användes som markörprotokoll. Under studien analyserades underbensmusklerna Gastrocnemius Lateralis, Gastrocnemius Medialis, Soleus Lateralis och Soleus Medialis. Muskellängd (längd av kontraktilelement) för varje patient och ben beräknades med hjälp av modellmallen LowerExtremity i AnyBody Modeling System. Jämfört med kontrollgruppen visade klumpfotsgruppen kortare medelmuskellängder för samtliga av de analyserade musklerna.

Since the advent of recommendations for placing infants in the supine position during sleep to reduce the incidence of sudden infant death syndrome, clinicians have noted an increase in the frequency of cranial asymmetry due to deformation of suture sections of the infants’ skulls as a result of constant concentrated stress in one area at the back of their head. This specific form of cranial deformation is known as positional plagiocephaly and its rate of occurrence has increased from 0.3% in 8.2% within the past 30 years. Current treatments and methodologies for preventing and correcting positional plagiocephaly such as stretching exercises, bedding pillows, and cranial molding are not optimized for effectiveness and comfort. Literature surrounding the implementation of these methodologies or devices often assesses the relative effectiveness of each treatment through statistical means, or studies complications associated with their use. There is a lack of quantified mechanical analysis for determining the effectiveness of each treatment or engineered solutions. In this study, a finite element model was created and validated to study the effect of wearing a cranial helmet, as the most effective non-surgical device for treatment of positional plagiocephaly, on reducing concentrated stress from the back of the baby’s head during sleep. The results from this model were then compared to two other finite element models with a healthy baby sleeping in supine position on a pillow, and a patient diagnosed with a severe case of positional plagiocephaly sleeping on the flat side of his head in supine position. The geometries representing the head of the babies in these models are the refined 3D laser-scanned file of a patient’s head contour at Hanger Clinic as well as the cavity inside the cranial helmet that was used for treatment of the baby. After successfully assigning section and contact properties to different regions of the models, applying proper loading and boundary conditions, and performing mesh convergence studies for each of the three models, the average Von Mises stress values of each of the 13 different suture segments of each model were summarized in tables and evaluated using mathematical and qualitative methods. The stress value data obtained from different suture regions of the model with the cranial helmet resulted in the smallest standard deviation among all three populations which supports that wearing the cranial helmet helps to reduce stress concentrations. Use of the cranial helmet during sleep also showed a significant decrease of the average Von Mises stress within the posterior fontanelle by 90% compared to the healthy baby sleeping in supine position and 73.4% compared to the deformed head sleeping on the flat surface of the head. The major limitations of this study are correlated with the simplifying assumptions and geometries in generating and validating the models. Future studies need to focus on overcoming these limitations and generating more complex models using a similar approach. The methods used in this study and the results obtained from the models can serve as a basis for future development of engineered solutions that are more effective than the existing solutions in the market and reduce the side-effects and complications associated with their use.

Avatars are used more and more in online communication, in both games and socialmedia. At the same time technology for facial puppetry, where expressions of the user aretransferred to the avatar, has developed rapidly. Why is it that facial puppetry, despite this,is conspicuous by its absence? This thesis analyzes the available and upcoming solutions for facial puppetry, if a com-mon framework or library can exist and what can be done to simplify the process for de-velopers who wants to implement facial puppetry. A survey was conducted to get a better understanding of the technology. It showedthat there is no standard yet for how to describe facial expressions, but part of the marketis converging towards a common format. It also showed that there is no existing inter-face that can handle communication with tracking devices or translation between differentexpression formats. Several prototypes for recording and streaming facial expression data from differentsources were implemented as a practical test. This was done to evaluate the complexity ofimplementing real-time facial puppetry. It showed that it is not always possible to integratethe available tracking solutions into an existing project. When integration was possible itrequired a lot of work. The best way to get tracking right now seems to be to implement astandalone program for tracking that streams the tracked data to the main application. In summary it is the poor integrability of the solutions that makes it problematic forthe developers, together with a wide variety of facial expression formats. A software thatacts like a bridge between the tracking solutions and the game could allow for translationbetween different formats and simplify implementation of support. In the future, instead of working towards making all tracking solutions output stan-dardized tracking data, research further how to build a framework that can handle differ-ent configurations. / <p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>

Die jüngst beobachteten Hochwasserereignisse zogen eine Überarbeitung der hydrologischen Daten zahlreicher Talsperren nach sich. Im Ergebnis wiesen viele der Anlagen nicht die erforderliche Hochwassersicherheit auf. Aus diesem Grund ist auch für die in Sachsen gelegene Talsperre Lehnmühle eine Ertüchtigung der Hochwasserentlastungsanlage geplant. Die Vorzugsvariante zur Wiederherstellung der Überflutungssicherheit sieht die Absenkung der Wehrkrone einzelner Überlauffelder vor. Die damit verbundene Leistungssteigerung erfordert eine Überprüfung der Abflussverhältnisse im nachgeschalteten Tosbecken. Im Rahmen der Arbeit werden die Strömungsverhältnisse im bestehenden Tosbecken mit Hilfe dreidimensionaler numerischer Modellierungen abgebildet. Mit dem Ziel einer verbesserten Energieumwandlung wird darüber hinaus die Wirksamkeit von Prallblöcken untersucht und bewertet.:1 Einleitung 2 Grundlagen der numerischen Strömungsberechnung 2.1 Numerische Modellierung im Vergleich 2.1.1 Prinzip der numerischen Strömungsberechnung 2.1.2 Exkurs: Physikalische Modellierung 2.1.3 Vor- und Nachteile der numerischen und physikalischen Modellierung 2.2 Vollständige Navier-Stokes-Gleichungen 2.3 Berechnungsmethoden 2.4 Turbulenzmodellierung 2.4.1 k-ε-Modell 2.4.2 k-ω-Modell 2.4.3 SST-Modell 2.5 Diskretisierung 2.5.1 Definieren der Geometrie 2.5.2 Berechnungsnetze 2.5.2.1 Strukturierte Netze 2.5.2.2 Unstrukturierte Netze 2.5.2.3 Hybride Netze 2.5.3 Räumliche Diskretisierung 2.5.4 Zeitliche Diskretisierung 2.5.5 Anfangs- und Randbedingungen 2.6 Wichtige Eigenschaften numerischer Berechnungsverfahren 3 Hochwasserentlastungsanlagen 3.1 Funktion 3.2 Begrifflichkeiten und Regelwerke 3.3 Aufbau 3.3.1 Einlaufbauwerk 3.3.2 Transportbauwerk 3.3.3 Energieumwandlungsanlagen 3.3.3.1 Der Prozess der Energieumwandlung 3.3.3.2 Konstruktionsmöglichkeiten 3.4 Hydraulische Bemessung 3.4.1 Hochwasserbemessungsfälle 3.4.2 Bemessungsabflüsse und Überschreitungswahrscheinlichkeiten 3.4.3 Freibordbemessung 4 Methodik 4.1Die Talsperre Lehnmühle 4.2Hydrologie 4.3Untersuchungsumfang 4.4Erstellung der numerischen Modelle 4.4.1Geometrie 4.4.1.1Wehrüberfall 4.4.1.2Tosbecken 4.4.1.3Tosbeckeneinbauten 4.4.2Numerische Modelle 4.4.2.1Modell des Wehrüberfalls 4.4.2.2Modell des Tosbeckens 4.4.3Berechnungsnetze 4.4.4Modellkonfiguration 5Ergebnisse der numerischen Berechnungen 5.1Numerik versus Physik 5.2Überfallmodellierungen 5.2.1Sensitivitätsuntersuchungen 5.2.2Ermittlung der Eingangsbedingungen für die Tosbeckenmodellierung 5.3Szenario 1 - Modellierung des bestehenden Tosbeckens 5.3.1Ergebnisse 5.3.2Sensitivitätsuntersuchungen 5.3.2.1Plausibilisierung der Randbedingung für die überströmte Tosbeckenwand 5.3.2.2Einfluss der Turbulenzmodellierung 5.3.2.3Einfluss der Rauigkeit 5.4Tosbeckenoptimierung 5.4.1Grundlegende Aussagen 5.4.2Wasserspiegellagen 5.4.3Fließgeschwindigkeiten 5.4.4Abfluss über die Tosbeckenwand 5.4.5Schubspannungen / Recent flood events called for a revision of hydrological data for numerous dams. As a result, many constructions have been found to not possess necessary flood safety. On this account, the flood spillway of the Saxon Lehnmühle dam is designated to be upgraded. In order to ensure an overflow-proof construction, the favored solution is to lower the crest of several weir fields. The resulting increased performance requires a revision of the runoff characteristics in the stilling basin. Firstly, this thesis shows the flow conditions of the existing stilling basin, using 3D numerical modeling. Secondly, with the goal of enhanced energy dissipation the effectiveness of baffle blocks will be examined and evaluated.:1 Einleitung 2 Grundlagen der numerischen Strömungsberechnung 2.1 Numerische Modellierung im Vergleich 2.1.1 Prinzip der numerischen Strömungsberechnung 2.1.2 Exkurs: Physikalische Modellierung 2.1.3 Vor- und Nachteile der numerischen und physikalischen Modellierung 2.2 Vollständige Navier-Stokes-Gleichungen 2.3 Berechnungsmethoden 2.4 Turbulenzmodellierung 2.4.1 k-ε-Modell 2.4.2 k-ω-Modell 2.4.3 SST-Modell 2.5 Diskretisierung 2.5.1 Definieren der Geometrie 2.5.2 Berechnungsnetze 2.5.2.1 Strukturierte Netze 2.5.2.2 Unstrukturierte Netze 2.5.2.3 Hybride Netze 2.5.3 Räumliche Diskretisierung 2.5.4 Zeitliche Diskretisierung 2.5.5 Anfangs- und Randbedingungen 2.6 Wichtige Eigenschaften numerischer Berechnungsverfahren 3 Hochwasserentlastungsanlagen 3.1 Funktion 3.2 Begrifflichkeiten und Regelwerke 3.3 Aufbau 3.3.1 Einlaufbauwerk 3.3.2 Transportbauwerk 3.3.3 Energieumwandlungsanlagen 3.3.3.1 Der Prozess der Energieumwandlung 3.3.3.2 Konstruktionsmöglichkeiten 3.4 Hydraulische Bemessung 3.4.1 Hochwasserbemessungsfälle 3.4.2 Bemessungsabflüsse und Überschreitungswahrscheinlichkeiten 3.4.3 Freibordbemessung 4 Methodik 4.1Die Talsperre Lehnmühle 4.2Hydrologie 4.3Untersuchungsumfang 4.4Erstellung der numerischen Modelle 4.4.1Geometrie 4.4.1.1Wehrüberfall 4.4.1.2Tosbecken 4.4.1.3Tosbeckeneinbauten 4.4.2Numerische Modelle 4.4.2.1Modell des Wehrüberfalls 4.4.2.2Modell des Tosbeckens 4.4.3Berechnungsnetze 4.4.4Modellkonfiguration 5Ergebnisse der numerischen Berechnungen 5.1Numerik versus Physik 5.2Überfallmodellierungen 5.2.1Sensitivitätsuntersuchungen 5.2.2Ermittlung der Eingangsbedingungen für die Tosbeckenmodellierung 5.3Szenario 1 - Modellierung des bestehenden Tosbeckens 5.3.1Ergebnisse 5.3.2Sensitivitätsuntersuchungen 5.3.2.1Plausibilisierung der Randbedingung für die überströmte Tosbeckenwand 5.3.2.2Einfluss der Turbulenzmodellierung 5.3.2.3Einfluss der Rauigkeit 5.4Tosbeckenoptimierung 5.4.1Grundlegende Aussagen 5.4.2Wasserspiegellagen 5.4.3Fließgeschwindigkeiten 5.4.4Abfluss über die Tosbeckenwand 5.4.5Schubspannungen

<p>The use of lower airspace for air taxi and cargo applications opens up exciting prospects for futuristic Unmanned Aircraft Systems (UAS). However, ensuring the safety and security of these UAS within densely populated urban areas presents significant challenges. Most modern aircraft systems, whether unmanned or otherwise, rely on the Global Navigation Satellite System (GNSS) as a primary sensor for navigation. From satellite navigations point of view, the dense urban environment compromises positioning accuracy due to signal interference, multipath effects, etc. Furthermore, civilian GNSS receivers are susceptible to spoofing attacks since they lack encryption capabilities. Therefore, in this thesis, we focus on examining the safety and cybersecurity assurance of UAS in dense urban environments, from both theoretical and experimental perspectives. </p> <p>To facilitate the verification and validation of the UAS, the first part of the thesis focuses on the development of a realistic GNSS sensor emulation using a Gazebo plugin. This plugin is designed to replicate the complex behavior of the GNSS sensor in urban settings, such as multipath reflections, signal blockages, etc. By leveraging the 3D models of the urban environments and the ray-tracing algorithm, the plugin predicts the spatial and temporal patterns of GNSS signals in densely populated urban environments. The efficacy of the plugin is demonstrated for various scenarios including routing, path planning, and UAS cybersecurity. </p> <p>Subsequently, a robust state estimation algorithm for dynamical systems whose states can be represented by Lie Groups (e.g., rigid body motion) is presented. Lie groups provide powerful tools to analyze the complex behavior of non-linear dynamical systems by leveraging their geometrical properties. The algorithm is designed for time-varying uncertainties in both the state dynamics and the measurements using the log-linear property of the Lie groups. When unknown disturbances are present (such as GNSS spoofing, and multipath effects), the log-linearization of the non-linear estimation error dynamics results in a non-linear evolution of the linear error dynamics. The sufficient conditions under which this non-linear evolution of estimation error is bounded are derived, and Lyapunov stability theory is employed to design a robust filter in the presence of an unknown-but-bounded disturbance. </p>