Whole Slide Images (WSIs) are digital scans containing rich pathology information. There are many available WSI datasets that can be used for a wide range of purposes such as diagnostic tasks and analysis, but the availability of labeled WSI datasets is very limited since the annotation process is both very costly and time consuming. Self-supervised learning is a way of training neural networks to learn and predict the underlying structure of input data without any labels.  AstraZeneca have developed a self-supervised learning feature extractor, the Drug-development Image Model Embeddings (DIME) pipeline, that trains on unlabeled WSIs and produces numerical embedding representations of WSI. This thesis applies the DIME-embeddings to a binary tumour classification task on the annotated Camelyon16 dataset by using the DIME pipeline as a feature extractor and train a simple binary classifier on the embedding representations instead of the WSI patches. The results are then compared to previous fully-supervised learning approaches to see if the embedding features generated by the DIME pipeline are sufficiently predictive with simple classifiers for the downstream task of binary classification.  The DIME embeddings were trained using Logistic Regression, Multi-Layer Perceptron and Gradient Boosting and the best performing model, a Multi-Layer Perceptron neural network trained on the DIME embeddings produced with an inpainting algorithm achieved a patch-level classification accuracy of 97.3%. This is very competitive results to the fully-supervised algorithms trained on the Camelyon16 dataset, beating some of them, while having a 1.1% gap to the best performing fully-supervised model. In addition to this, the performance of the DIME embeddings on reduced training sets also shows that the features captured in the DIME embeddings are sufficient.

There are a number of authentication methods for wireless local area networks. The IEEE 802.1x standard is one such method. This standard specifies a port-based access control protocol. There are three entities involved: a supplicant (a device that wishes to have network access and perhaps other services), an Access Point (AP) or other port to which access is to be controlled, and an Authentication Server (AS). The goal of this project was to design, implement, and evaluate a prototype of a non-binary alternative to IEEE 802.1x authentication. This report focuses on the supplicant. Specifically it describes the design, implementation, and evaluation of a supplicant program to test and stress the authenticator, in order to evaluate a non-binary authentication process. Following, a brief introduction is given to the problem that is to be solved, a number of existing IEEE 802.1x supplicants are described and compared. Following this, a number of potential non-binary authentication processes are analyzed. The ability of a supplicant to send and receive packets before and after authentication is also examined. Based upon our implementation and evaluation of a supplicant and an emulation of the non-binary authentication process, we conclude that non-binary authentication is both feasible and valuable. Furthermore, the thesis evaluates why and how non-binary authentication is valuable from the viewpoint of a supplicant. Additional future work is suggested at the end of this thesis. / Det finns ett antal metoder för trådlösa lokala nätverk. IEEE 802.1x-standarden är en sådan metod. Denna standard anger en port-baserad passagekontroll protokollet. Det finns tre enheter som är inblandade: en supplikant (en enhet som vill ha tillträde till nät och kanske andra tjänster), ett Access Point (AP) eller annan hamn som tillgång är att vara kontrollerad, och en Authentication Server (AS). Målet med projektet var att utforma, genomföra och utvärdera en prototyp av en icke-binära alternativ till IEEE 802.1x-autentisering. Denna rapport fokuserar på supplikant. Specifikt beskrivs utformning, genomförande och utvärdering av en supplikant program för att testa och betona authenticator, för att utvärdera ett icke-binära autentiseringsprocessen. Efter en kort introduktion ges till de problem som ska lösas, ett antal befintliga IEEE 802.1x supplikants beskrivs och jämförs. Efter detta har ett antal potentiella icke-binära autentisering processer analyseras. Möjligheten för en supplikant att skicka och ta emot paket före och efter autentisering är också undersökas. Baserat på vårt genomförande och utvärdering av en supplikant och en emulering av den icke-binära autentisering kan vi dra slutsatsen att icke-binära autentisering är både möjligt och värdefullt. Dessutom, avhandlingen utvärderar varför och hur icke-binära autentisering är värdefull ur ett supplikant. Ytterligare framtida arbetet föreslås i slutet av denna uppsats.

Authentication, authorization, and accounting (AAA) are key elements in network security. In many networks, clients can use resources only after they have been authenticated by an authentication server and authorized to use these resources. In some cases the server will also maintain accounting records in order for an operator (a provider of resources) to charge the account/subscriber for using the service. There are four main AAA protocols being used today. Of these RADIUS is the mostly widely used. This thesis starts with an introduction to AAA protocols, and then goes in the details of RADIUS. In order to perform a practical evaluation of how the AAA could be improved, FreeRADIUS was selected as the base code for this project; because this implementation is one of the most widely used RADIUS servers. A proposal for how to improve AAA performance is introduced and the implementation steps needed to realize these improvements are shown. Additionally, some experiments have been conducted to show both the correct functioning of the resulting implementation and to examine if there is a performance improvement. Following this some conclusions are drawn based upon a comparison with a traditional AAA server. A key element of the change in AAA which is proposed is the use of a non-binary IEEE 802.1x process. This new non-binary solution introduces a new type of AAA server and requires the re-thinking of a number of traditional AAA design decisions. It is expected that this change will have a significant impact, but will require some time for exposure, implementation by others, and a more extensive evaluation that was possible during the period of this thesis project. One of the most important conclusions drawn during this thesis is the difficulty of making a change in authentication and authorization, because of the large amount of interaction between both the various protocols and the standards which have been developed for these protocols. Thus one of the difficult aspects of the task is how to introduce a change in a protocol while maintaining backward compatibility for others who have not adopted this change -- without requiring the addition of a protocol version field. A second important conclusion is that doing this implementation in three separate parts with different students being responsible for the different parts revealed just how complex the interaction of protocol design decisions are. While a working version of the entire set of changes proved to be impossible, it was observed that the different parts could be decoupled more than initially expected.

<div>Dynamic Binary Instrumentation (DBI) is one way to monitor a distributed system in real-time without modifying source code. Previous work has shown it is possible to instrument distributed systems using standards-based distributed middleware. Existing work, however, only applies to a single middleware, such as CORBA.</div><div><br></div><div>This thesis therefore presents a tool named the Standards-based Distributed Middleware Monitor (SDMM), which generalizes two modern standards-based distributed middleware, the Data Distribution Service (DDS) and gRemote Procedure Call (gRPC). SDMM uses DBI to extract values and other data relevant to monitoring a distributed system in real-time. Using dynamic instrumentation allows SDMM to capture information without a priori knowledge of the distributed system under instrumentation. We applied SDMM to systems created with two DDS vendors, RTI Connext DDS and OpenDDS, as well as gRPC which is a complete remote procedure call framework. Our results show that the data collection process contributes to less than 2% of the run-time overhead in all test cases.</div>

In this work, we use pulsed-field gradient (PFG) NMR to probe molecular diffusion of liquids inside mesoporous structures and assess the influence of surface modifications, namely, deposition of palladium (Pd) nanoparticles over alumina (Al2O3) surfaces and passivation of titania (TiO2) surfaces with alkyl chains, on the diffusion pattern.

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A common type of problems that exist in both industrial and scientific spaces are optimization problems. These problems can be found in among other things manufacturing, pathfinding, network routing and more. Because of the wide area of application, optimization is well a studied area. One solution to these types of problems is the Ant Colony Optimization algorithm that has been around since 1991 and has undergone a lot of developments over the years. This algorithm draws inspiration from real ant colonies and their procedure for foraging. However, a common criticism of this algorithm is its poor scalability. To tackle the scalability problem this thesis will combine the concept of binary space partitioning with the Ant Colony Optimization algorithm. The goal is to examine the algorithms convergence times and lengths of the paths produced. The results are measured in intervals by calculating the best possible path found at every interval. The findings showed that given an unlimited execution time the original Ant Colony Optimization algorithm produced shorter paths. But when a limit on execution time was introduced and the problem sizes grew the performance began to favor the partitioned versions. These findings could be useful in areas where complex optimization problems need to be solved within a limited timeframe. / <p>The presentation took place via an online conference call using the software "Zoom"</p>

>Magister Scientiae - MSc / The majority of the global energy is sourced from conventional fossil fuels. The high demand for energy is accelerating along with the depletion of these fossil fuels. Hence, the shift to renewable energy sources and technology becomes indispensable. Hydrogen is considered a promising alternative to fossil fuels. Polymer electrolyte membrane water electrolysers offer an environmentally friendly technique for the production of hydrogen from renewable energy sources. However, the high overpotential and acidic environment at the anode is one of the challenges faced by polymer electrolyte membrane water electrolysers. This harsh environment requires distinct electrocatalysts which currently consist of expensive precious metals such as Ir, Ru and their oxides.

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