Mit 3D-Netzmodellen werden Objekte der materiellen Welt oder unserer Vorstellung computergestützt abgebildet. In digitalen Produktentwicklungsprozessen werden mit ihnen sowohl die Objektgestalt als auch anwendungsspezifische Informationen von Objekten und von Prozessen definiert. Mit flächenhaften Netzen (z. B. Dreiecksnetze) wird die Oberfläche von Objekten in diskreter Form repräsentiert, mit volumenhaften Netzen (z. B. Tetraedernetze) zusätzlich das Objektinnere. 3D-Netzmodelle werden bei der Erzeugung und der Manipulation, der Analyse und der Validierung, in fertigungsvorbereitenden Prozessen sowie zur Präsentation digitaler 3D-Objekte angewandt.

3D scanning has grown to become an important tool in a wide variety of applications. Still, acquiring high-quality 3D models using scanning technology is a challenging task. In this thesis, we present various ways that reduce the hurdles of existing 3D scanning pipelines with the ultimate goal of bringing this technology closer to the end user. To achieve this goal, we focus on three sub problems of traditional scanning pipelines: First, we present a novel algorithm that can be used to consistently orient the normals of huge point clouds. We achieve this by formulating the orientation problem as a graph-based energy minimization problem and applying out-of core methods. Second, we introduce interactivity into the scanning pipeline by presenting an online surface reconstruction method that produces high-quality semi-regular meshes. The resulting interactive pipeline is highly efficient because it reduces the turn-around between presentation of the final result and possible corrections by the user. Third, we develop a robust method to texture-map semi-regular meshes. This approach is based on a generalization of motorcycle graphs, which partitions arbitrary meshes into quadrilateral patches. These patches then serve as the parametrization domains of the texture atlas. Finally, we present an application from the area of cave science. The application is targeted at quantitatively and objectively assessing a cave's size. To achieve this goal, we present methods to analyze the structure of caves, especially to distinguish chambers from passages.

Microservice architectures are the base of modern cloud applications. With the adoption of microservices, application teams manage to reduce codebase complexity and write more modular services that can run inter-dependently. Despite all the advantages offered by microservices over monolithic architectures, they introduce additional complexities, such as handling inter-service communication, ensuring security, introducing traceability, and achieving acceptable performance. To manage all these microservices, the orchestrator tool Kubernetes has shown promising results, but it is not sufficient to tackle all the cross-cutting concerns of the applications. With more complex architectures, it becomes difficult to troubleshoot and trace inter-service application programming interface calls. For this purpose, the service mesh technology emerged and is being introduced in many companies. There are different implementations available for service mesh, with some being more compatible with specific cloud providers than others. The selection of an adequate service mesh shapes the entire application deployment process. If chosen wrongly, it might introduce further complexities or performance losses. This thesis investigates ways to make this decision more efficiently. It takes into account the company’s needs of service mesh and compares implementations to meet performance expectations with minimal deployment efforts. Specially, we perform different testing scenarios to compare AWS cloud specific, AWS App Mesh with most widely used, Istio service mesh. The outcome suggests that AWS App Mesh performs consistently for all cases with acceptable latency ranges, but, Istio outperforms AWS App Mesh under standard conditions, such as high but manageable request load on the application. In addition, Istio can achieve the same deployment with less lines of code as compared to that of AWS App Mesh. On the other hand, resource utilization by these service meshes is found to be a non-conclusive factor for selecting the service mesh implementation. With these outcomes, application teams can make more well-informed decisions to run the production-grade workloads with an efficient service mesh implementation. / Mikroservicearkitekturer är basen för moderna containerapplikationer. Med antagandet av mikrotjänster lyckas applikationsteam minska kodbaskomplexiteten och skriva fler modulära tjänster som kan köras beroende av varandra. Trots alla fördelar som mikrotjänster erbjuder framför monolitiska arkitekturer, introducerar de ytterligare komplexitet, såsom kommunikation mellan tjänster, säkerhet, spårbarhet och prestanda. För att hantera alla dessa mikrotjänster har orkestreringsverktyget Kubernetes visat lovande resultat, men det är inte tillräckligt för att ta itu med alla övergripande problem med applikationerna. Med mer komplexa arkitekturer blir det svårt att felsöka och få synlighet i mikrotjänster. För detta ändamål växte servicemesh-tekniken fram och introduceras i många företag. Det finns olika implementeringar tillgängliga för servicemesh, där vissa är mer kompatibla med specifika molnleverantörer än andra. Valet av ett adekvat servicenät formar hela applikationsdistributionsprocessen. Om det väljs fel kan det leda till ytterligare komplexitet eller prestandaförluster. Denna avhandling undersöker sätt att göra detta beslut mer effektivt. Den tar hänsyn till företagets behov av servicenät och jämför implementeringar för att möta prestandaförväntningar med minimala implementeringsinsatser. Speciellt genomför vi olika scenarier för prestandatestning för att jämföra AWS App Mesh med Istio servicemesh. Resultatet tyder på att AWS App Mesh presterar konsekvent för alla fall med acceptabla latensintervall, men Istio överträffar AWS App Mesh under standardförhållanden, såsom hög men hanterbar förfrågningsbelastning på applikationen. Istio kan uppnå samma distribution med färre rader kod jämfört med AWS App Mesh. Resursutnyttjande av dessa tjänstenät har visat sig vara en icke avgörande faktor för val av tjänstenätimplementering. Med dessa utfall kan företaget där detta examensarbete genomförs, Infor (Sweden) AB, fatta mer välinformerade beslut för att driva de produktionsmässiga arbetsbelastningarna med en effektiv implementering av servicenät.

No description available.

This report is the result of a Master’s Thesis done at the Machine Design Department at the Royal Institute of Technology. The project was carried out at Svea Teknik AB in cooperation with Atlas Copco Rock Drills AB and the Mining and Rock Excavation division in Örebro. Atlas Copco is currently developing a new TBM for mechanical rock excavation, which have been named the RVM (Remote Vein Miner. When doing the excavation, stresses and cracks are induced in the tunnel walls and roof, why it is necessary to reinforce the tunnel so that is does not collapse. In this case this is done by drilling holes and inserting rock bolts into the tunnel walls, and at the same time clothe the walls with a chain link mesh. The operators that are doing this are working in an unsecured part of the tunnel and are hence exposed to a safety risk. It is therefore of interest to make this mesh mounting procedure automated. The project’s purpose was to develop a design concept for the mesh handling and mounting for the RVM that require less manual hands-on work by the operators, i.e. replacing the existing semi-manual mesh handling to a solution that instead can be automatized and remote controlled. Brainstorming was used to generate 6 different concepts, 4 for the mesh handling and 2 for the bolt handling, which were evaluated in two separate Pugh’s evaluation matrices. The two concepts that was deemed most promising, the bolt carrousel and an arm handling solution for mesh rolls, were further developed. CAD models of the included components and systems were made and used to verify the arm’s range and that it fulfilled all of the constraints related to the spatial limitations on the machine. The hydraulic cylinders were dimensioned with forces obtained from an ADAMS simulation. The final conceptual design did fulfil the requirements, but was considered to be very complex and concerns were made regarding how it would handle the harsh environment in the tunnel. / Denna rapport är resultatet av ett examensarbete som utförts på Institutionen för Maskinkonstruktion på KTH. Projektet gjordes med Svea Teknik AB i samarbete med Atlas Copco Rock Drills AB och deras avdelning för Gruv- och Bergbrytningsteknik i Örebro. Atlas Copco håller för närvarande på att utveckla en ny TBM för mekanisk bergavverkning, som har fått namnet RVM (Remote Vein Miner). När bergavverkning sker så induceras spänningar och sprickor i berget som omger tunneln och det är därför nödvändigt att förstärka tunneln så att den inte rasar samman. I detta fall så sker denna förstärkning genom att borra hål i tunnelväggen och sätta in bergbultar, och samtidigt klä väggarna med ett skyddande nät. När operatörerna utför detta arbete så befinner de sig i en del av tunneln som inte är säkrad och de är således utsatta för säkerhetsrisker. Det är därför av intresse att göra denna nätmonteringsprocess automatiserad. Syftet med detta projekt var att utveckla en konceptkonstruktion för näthanteringen- och monteringen för RVM-maskinen som innebär mindre manuellt arbete av operatörerna, alltså att ersätta den nuvarande semi-manuella näthanteringslösningen med en lösning som istället kan automatiseras och fjärrstyras. Brainstormning användes för att ta fram 6 stycken olika koncept, 4 gällande näthanteringen och 2 för bulthanteringen. Dessa koncept utvärderades i två separata Pugh matriser. De två koncept som ansågs vara de mest lovande, bultkarusellen och en armkonstruktion för hantering av nätrullar, utvecklades vidare. CAD-modeller av de inkluderade komponenterna och systemen gjordes och användes för att verifiera armens räckvidd och att den uppfyllde att hålla sig inom maskinens platsbegränsningar. De hydrauliska cylindrarna dimensionerades utifrån krafter som erhölls från en ADAMS-simulering. Den slutgiltiga konstruktionen uppfyllde alla specificerade krav, men ansågs vara väldigt komplex och det ansågs osäkert hur och om den skulle klara av den mycket tuffa miljön i tunnelgången.

An adaptive remeshing algorithm has been developed for multiphase flow simulations using the moving-mesh interface tracking (MMIT) technique. The edge-swapping algorithm uses the Delaunay criterion (in 2D) and a dynamic programming technique (in 3D) to maximize the quality of mesh primitives surrounding edges in the mesh, and performs local remeshing to minimize interpolation errors. Edge bisection and contraction operations are also performed to adjust the mesh resolution around important features like fluid-interfaces, driven by a local length scale estimation algorithm that is efficient and easily parallelized. Flow-field interpolation after reconnection is achieved using a conservative, second-order accurate remapping scheme that can be extended to arbitrary mesh pairs. To minimize the number of mesh reconnection operations, vertices in the mesh are also moved in a manner that optimizes the quality of cells at every time step, using a spring-analogy based Laplacian smoother for surface meshes, and an optimization-based smoothing approach for interior points. To facilitate the simulation of large-scale problems, all smoothing and reconnection algorithms in this work have been parallelized for shared- and distributed-memory paradigms. This approach allows meshes to undergo very large deformations which are characteristic of multiphase flows, and the method is versatile enough to extend its applicability to a broad range of problems including error-driven mesh refinement, reciprocating machinery, fluid-structure interation, and wing flapping simulations.

<p dir="ltr">Precise measurement of the flowrate is crucial for both process control and energy consumption evaluation. The main aim of this work is to develop a methodology to calibrate mechanical flowmeters, designed to measure high viscosity fluids, in water. In order to accomplish this, a series of computational fluid dynamics (CFD) analysis are carried out to determine how the motion of the mechanical component varies with different flow rates of water and high viscosity fluids. This data is recorded and analyzed to develop calibration curves that relate the motion of the mechanical component the flow rates. From the calibration curves, it can be determined the required water flow rate to achieve the equivalent motion of the mechanical component in a specified viscosity. This method provides an efficient and cost-effective calibration process because it eliminates the need for calibrating using heated engine oil to achieve the fluid viscosity of the flow meter is designed. Flowmeter sensitivity analysis was also performed and it was observed that the motion of the mechanical component curves converges as the size of the flowmeter increases suggesting that the effect of viscosity on flowmeter sensitivity decreases as the size of the flowmeter is increased, likely due to reduced resistance to flow and smaller pressure drops. </p><p dir="ltr">The Kanbara Reactor ladle is a commonly used method in the steelmaking industry for hot-metal desulfurization pre-treatment. The impeller's configuration is pivotal to the reactor's performance, yet its precise function remains partially understood. This study introduces a 3-dimensional Volume-of-Fluid (VOF) model integrated with the sliding mesh technique, investigating the influence of five different impeller speeds. After Validating the model through experimental data, this numerical model is applied to investigate the typical developmental phenomena and the consequences of impeller speed variations on fluid flow characteristics, interface profile, and vortex core depth. The findings reveal that the rotational impeller induces a double-recirculation flow pattern in the axial direction due to the centrifugal discharging flow. With increasing impeller rotation speed, the vortex core depth also rises, emphasizing the substantial impact of impeller speed on vortex core depth.</p>

A mesh network is a technology that is being repopularized and becoming commonly used by the general public. As this increase in use is observed, technologies such as Bluetooth are being adapted to create mesh variants. In this thesis, a Bluetooth mesh network is created and tested using raspberry pi 4’s and the Bluetooth interface, btferret. This thesis attempts to approach the limits of this technology using accessible tools, outlining the performance the network possesses to serve as a guideline to determine if it suitable for use for tasks at hand. Experimentation is split into two overarching methods where a test for latency and throughput is conducted. The thesis goes on to expose these tests to different stressors, categorized as either internal or external. The data collected aims to show the impacts of internal properties, in this case size of the packets transmitted, the size of the network, and finally the number of hops a packet is able to make within the network. The external factors tested for consists of various environmental properties in the form of obstacles and interference. Walls and a microwaves were used as obstacles while WiFi and other Bluetooth signals were used for interference. The results show that Bluetooth Low Energy (BLE) mesh networks are clearly affected by several internal and external factors. From the experimentation conducted, the thesis illustrates the relative effects of each property the tests are exposed to. / Ett mesh nätverk är en teknik som blivit populär igen och används ofta av allmänheten. Eftersom denna ökade användning observeras, tekniker som Bluetooth anpassas för att skapa mesh nätverksvarianter. I denna avhandling skapas och testas ett Bluetoothnätverk med Raspberry pi 4’s och Bluetoothgränssnittet, btferret. Denna uppsats försöker nå gränserna för denna teknik med hjälp av tillgängliga verktyg, definiera nätverks prestandan som en riktlinje för att avgöra om det är lämpligt för användning för uppgifter till hands. Resultaten visar att BLE mesh nätverk har tydliga begränsningar som avslöjar sig i olika sammanhang. I denna raport så undersöks paket storlek och antal hopp som ett paket kan göra inom nätverket utan signifikant prestandafall. Dessutom har olika andra faktorer, såsom väggar och andra störande radiofrekvenser visat sig påverka nätverket. Från alla experiment som genomförts så illustreras relativa effekt av det olika faktorer.

No description available.

No / Wireless local area networks (WLANs) have risen in popularity for in-car networking systems that are designed to make driving safer. Wireless mesh networks (WMNs) are widely deployed to expand the coverage of high-speed WLANs and to support last-mile connectivity for mobile users anytime and anywhere at low cost. Many recent measurement studies have shown that the traffic arrival process in wireless networks exhibits the bursty and correlated nature. A new analytical model is developed in this paper as a cost-effective performance tool to investigate the quality-of-service (QoS) of the WMN that interconnects multiple WLANs in the presence of bursty and correlated traffic. After validating its accuracy via extensive simulation experiments, the analytical model is then used to investigate the performance of the hybrid wireless networks.