This paper presents a comprehensive research study that investigates the perspectives of video game preservation from three distinct target groups consisting of game developers, game museums, and video game enthusiasts. Each target group expressed their thoughts and opinions regarding game preservation efforts and the use of emulation as a preservation method. Through a mixed-method approach, including questionnaires and semi-structured interviews, the study collected both quantitative and qualitative data from 148 respondents. By examining the responses, different challenges, obstacles, and possible improvements were identified for each target group. The findings of this study revealed several common themes among the participants. The importance of collaboration and communication between all three target groups can help improve current video game preservation efforts.

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This study aims to investigate how an emulator could be developed as a testing tool for Battery Management Systems (BMS) by emulating the Analog Front­end (AFE) circuit communicating with a control unit for monitoring of Lithium­Ion Batteries. All of the research was conducted in the context of the company Northvolt. By analysing data collected through a questionnaire, it was evident that an emulator testing tool could potentially make the BMS development process significantly more efficient. A demonstrator was developed as a part of the study. It fulfilled almost all of the requirements initially stated, but required the control unit to send commands in a fixed sequence, which the current BMS control unit did not. A fixed sequence would however enable the incorporation of the developed emulator, as well as introducing other advantages such as predictability. The study showed that the most important factor to consider for developing an AFE communication emulator for BMS testing was robustness and repeatability of the timings of the communication signals. / Syftet med denna studie var att undersöka hur ett testverktyg baserat på en emulator skulle kunna utvecklas för batteristyrsystem. Studien genomfördes på batteriföretaget Northvolt. Genom att analysera data insamlad via ett frågeformulär framgick det tydligt att ett testverktyg baserat på en emulator hade god potential att göra utvecklingsprocessen av batteristyrsystem mer effektiv. En prototyp utvecklades som en del av studien. Denna uppfyllde nästan alla de initialt uppsatta kraven, men var anpassad för kommunikation i en fix sekvens, till skillnad från det aktuella systemet hos företaget. Via studien fann man att implementationen av en fix kommunikationssekvens skulle medföra önskvärda egenskaper hos systemet såsom förutsägbarhet. Vidare visade studien att den viktigaste faktorn att ta i beaktning för utveckling av en emulator var robusthet och repeterbarhet hos timingen av kommunikationssignalerna. Detta eftersom kommunkationen mellan enheter förlitar sig på korrekt timing av varje skickad bit för korrekt inlästa meddelanden.

The fifth-generation (5G) of mobile communication networks are expected to support a large number of vertical industries requiring services with diverging requirements. To accommodate this, mobile networks are undergoing a significant transformation to enable a variety of services to coexist on the same infrastructure through network slicing. Additionally, the introduction of distributed user-plane and multi-access edge computing (MEC) technology allows the deployment of virtualised applications close to the network edge. The first part of this dissertation focuses on end-to-end network slice provisioning for various vertical industries with different service requirements. Two slice provisioning strategies are explored, by formulating a mixed integer linear programming (MILP) problem. Further, a genetic algorithm (GA)-based approach is proposed with the aim to improve search-space exploration. Simulation results show that the proposed approach is effective in providing near-optimal solutions while drastically reducing computational complexity. In a later stage, the study focuses on building a measurement-based digital twin (DT) for the highly heterogeneous MEC ecosystem. The DT operates as an intermediate and collaborative layer, enabling the orchestration layer to better understand network behavior before making changes to the physical network. Assisted by proper AI/ML solutions, the DT is envisioned to play a crucial role in automated network management. The study utilizes an emulated and physical test-bed to gather network key performance indicators (KPIs) and demonstrates the potential of graph neural network (GNN) in enabling closed loop automation with the help of DT. These findings offer a foundation for future research in the area of DT models and carbon footprint-aware orchestration.

A mobile ad hoc network (MANET) is a wireless network that uses multi-hop peer-to-peer routing instead of static network infrastructure to provide network connectivity. MANETs have applications in rapidly deployed and dynamic military and civilian systems. The network topology in a MANET usually changes with time. Therefore, there are new challenges for routing protocols in MANETs since traditional routing protocols may not be suitable for MANETs. For example, some assumptions used by these protocols are not valid in MANETs or some protocols cannot efficiently handle topology changes. Researchers are designing new MANET routing protocols and comparing and improving existing MANET routing protocols before any routing protocols are standardized using simulations. However, the simulation results from different research groups are not consistent with each other. This is because of a lack of consistency in MANET routing protocol models and application environments, including networking and user traffic profiles. Therefore, the simulation scenarios are not equitable for all protocols and conclusions cannot be generalized. Furthermore, it is difficult for one to choose a proper routing protocol for a given MANET application. According to the aforementioned issues, my Ph.D. research focuses on MANET routing protocols. Specifically, my contributions include the characterization of differ- ent routing protocols using a novel systematic relay node set (RNS) framework, design of a new routing protocol for MANETs, a study of node mobility, including a quantitative study of link lifetime in a MANET and an adaptive interval scheme based on a novel neighbor stability criterion, improvements of a widely-used network simulator and corresponding protocol implementations, design and development of a novel emulation test bed, evaluation of MANET routing protocols through simulations, verification of our routing protocol using emulation, and development of guidelines for one to choose proper MANET routing protocols for particular MANET applications. Our study shows that reactive protocols do not always have low control overhead, as people tend to think. The control overhead for reactive protocols is more sensitive to the traffic load, in terms of the number of traffic flows, and mobility, in terms of link connectivity change rates, than other protocols. Therefore, reactive protocols may only be suitable for MANETs with small number of traffic loads and small link connectivity change rates. We also demonstrated that it is feasible to maintain full network topology in a MANET with low control overhead. This dissertation summarizes all the aforementioned methodologies and corresponding applications we developed concerning MANET routing protocols. / Ph. D.

The development of Unmanned Aerial Vehicles (UAVs) and fifth-generation (5G) wireless technology provides more possibilities for wireless networks. The application of UAVs is gradually evolving from individual UAVs performing tasks to UAV swarm performing tasks in concert. A UAV swarm network is when many drones work cooperatively in a swarm mode to achieve a particular goal. Due to the UAV swarm's easy deployment, self-organization, self-management, and high flexibility, it can provide robust and efficient wireless communications in some unique scenarios, such as emergency communications, hotspot region coverage, sensor networks, and vehicular networks. Therefore, UAV networks have attracted more and more attention from commercial and military; however, many problems need to be resolved before UAV cellular communications become a reality. One of the most challenging core components is the routing protocol design in the UAV swarm network. Due to the high mobility of UAVs, the position of each UAV changes dynamically, so problems such as high latency, high packet loss rate, and even loss of connection arise when UAVs are far apart. These problems dramatically reduce the transmission rate and data integrity for traditional routing protocols based on path discovery. This thesis focuses on developing, emulating, and optimizing a flooding-based routing protocol for UAV swarm using Random Linear Network Coding (RLNC) to improve the latency and bit rate and solve the packet loss problem without routing information and network topology. RLNC can reduce the number of packets demand in some hops. Due to this feature of RLNC, when relay transmitter UAVs or the destination receiver UAV receive sufficient encoded packets from any transmitter UAVs, the raw data can be decoded. For those relay transmitter UAVs in the UAV swarm network that already received some encoded packets in previous hops but not enough to decode the raw data, only need to receive the rest of the different encoded packets needed for decoding. Thus, flooding-based routing protocol significantly improves transmission efficiency in the UAV swarm network. / Master of Science / People are used to using fiber, 4G, and Wi-Fi in the city, but numerous people still live in areas without Internet access. Moreover, in some particular scenarios like large-scale activities, remote areas, and military operations, when the cellular network cannot provide enough bandwidth or good signal, UAV wireless network would be helpful and provide stable Internet access. Successful UAV test flights can last for several weeks, and researchers' interest in high-altitude long-endurance (HALE) UAVs are booming. HALE UAVs will create Wi-Fi or other network signals for remote areas, including polar regions, which will allow millions of people to enter the information society and connect to the Internet. The development of UAV and 5G provides more possibilities for wireless networks. UAV applications have evolved from individual UAV performing tasks to UAV swarm performing tasks. A UAV swarm network is where multiple drones work in tandem to achieve a particular goal. It can provide robust and efficient wireless communications in unique scenarios. As a result, UAVs are receiving attention from both commercial and military. However, there are still many problems that need to be resolved before the actual use of UAVs. One of the biggest challenges is routing protocol which is how UAVs communicate with each other and select routes. As the location of UAVs is constantly changing, this leads to delays, data loss, or complete loss of connectivity. Ultimately these issues can lead to slow transmission speed and lack of data integrity for traditional routing protocols based on path discovery. This thesis focuses on developing, emulating, and optimizing a flooding-based routing protocol for the UAV swarm. Specifically, this protocol uses RLNC, which can reduce the number of packets demand in some hops so that the latency and transmission speed will be improved, and the data loss problem will also be solved. Due to this feature of RLNC, when any receiver receives enough encoded packets from any transmitter, the original data can be decoded. Some receivers that already received some encoded packets in the previous transmission only need to receive the rest of the different encoded packets needed for decoding. Therefore, flooding-based routing protocol significantly improves transmission efficiency for UAV swarm networks.

The increasing scale and complexity of network applications and protocols motivates the need for tools to aid in the understanding of network dynamics at similarly large scales. While current network simulation tools achieve large scale modeling, they do so by ignoring much of the intra-program state that plays an important role in the overall system's behavior. This work presents The Distributed Open Network Emulator, a scalable distributed network model that incorporates application program state to achieve high fidelity modeling. The Distributed Open Network Emulator, or DONE for short, is a parallel and distributed network simulation-emulation hybrid that achieves both scalability and the capability to run existing application code with minimal modification. These goals are accomplished through the use of a protocol stack extracted from the Linux kernel, a new programming model based on C, and a scaled real-time method for distributed synchronization. One of the primary challenges in the development of DONE was in reconciling the opposing requirements of emulation and simulation. Emulated code directly executes in real-time which progresses autonomously. In contrast, simulation models are forced ahead by the execution of events, an explicitly controlled mechanism. Relativistic time is used to integrate these two paradigms into a single model while providing efficient distributed synchronization. To demonstrate that the model provides the desired traits, a series of experiments are described. They show that DONE can provide super-linear speedup on small clusters, nearly linear speedup on moderate sized clusters, and accurate results when tuned appropriately. / Master of Science

This thesis is focused on gaining a better knowledge of how to design and test Phillips screwdriver bits. Wear is the primary concern in applications where the bit is used in a power driver. Such applications include drywalling, decking and other construction and home projects. To pursue an optimal design, designers must have an understanding how the bit geometry changes with wear. To make use of the geometrical data, the designer must also have an understanding of the fundamentals of the bit/screw surface contact and its effect on force distribution. This thesis focuses on three areas. First, understanding how the tool and bit are used, and what factors contribute to bit wear. With this understanding, a test rig has been designed to emulate typical users and, in doing so, produce the factors that cause wear. Second, there must be a means to analyze geometric changes in the bit as it wears. A method for doing this was developed and demonstrated for a Phillips bit, but the process can be applied to other bits. Finally, the fundamentals of surface contact must be understood in order to apply the geometrical information obtained to improved bit design. / Master of Science

Field-programmable gate arrays (FPGAs) are excellent devices for high-performance computing, system-on-chip realization, and rapid system prototyping. While FPGAs offer flexibility and performance, they continue to lag behind application specific integrated circuit (ASIC) performance and power consumption. As manufacturing technology improves and IC feature size decreases, FPGAs may further lag behind ASICs due to interconnection scalability issues. To improve FPGA scalability, this thesis proposes an architectural enhancement to improve global communications in large FPGAs, where chip-length programmable interconnects are slow. It is expected that this architectural enhancement, based on wire emulation techniques, can reduce chip-length communication latency and routing congestion. A prototype wire emulation system that uses FPGA self-reconfiguration as a non-traditional means of intra-FPGA communication is implemented and verified on a Xilinx Virtex-II XC2V1000 FPGA. Wire emulation benefits and impact to FPGA architecture are examined with quantitative and qualitative analysis. / Master of Science