Evolutionary Approach for Concurrency Testing of Ripple Blockchain Consensus Algorithm

Blockchain systems are prone to concurrency bugs due to the nondeterminism in the delivery order of messages between the distributed nodes. These bugs are hard to detect since they can only be triggered by a specific order or timing of concurrent events in the execution. <br/>Systematic concurrency testing techniques, which explore all possible...

Benchmarking Checkpoint-based Fault Tolerance Algorithms in Stateful Stream Processing

Major advances in the fault tolerance of distributed stream processing systems provided the systems with the capacity to produce strictly consistent results under failures. Consistent fault tolerance has been one of the catalysts fueling the maturity of streaming systems and boosting their widespread adoption not only for analytics use cases,...

Fusion of radar data from multiple MIMO systems to achieve higher angular resolution

In today's automotive applications, radar is widely used to estimate the target position and velocity with respect to the radar position. Estimating the position of the target in terms of range and velocity is fairly advanced and accurate. However, resolving two closely spaced targets in the azimuth domain which have the same range and relative...

Multi-­Robot Exploration and Planning in Limited Communication Environments

Distributed cooperative robots can be highly beneficial in mapping disaster environments and assisting with search and rescue operations. In most situations such environments only allow for only limited communication between robots. This thesis reports on simulation experiments conducted to test the impact of having only partial communication...

Byzantine Reliable Broadcast on partially connected networks with signatures

In this paper, we consider Byzantine reliable broadcast on partially connected networks using signatures. Byzantine reliable broadcast in partially connected and authenticated networks can be achieved by combining two algorithms, Gabriel Bracha's double-echo broadcast protocol and Danny Dolev's reliable communication protocol. Bracha's algorithm...

Fairness and Freedom for Artists: Towards a Robot Economy for the Music Industry

During the last decades of explosive growth in economic value on the Internet, we observe the trend of platformization: a shift of economic activity from happening on a wide range of companies to a few major platforms run by Big Tech corporations. This trend is highly susceptible to the rise of monopolies and oligarchs, as...

Integrating vulnerability analysis into the early stage distributed ship system design process

Naval ships need to be able to conduct missions in a variety of circumstances. This includes the ability to fulfil specific tasks in a damaged state. Vulnerability reduction measures are taken during the early stage distributed ship system design process, to ensure the availability of the required systems in damaged state. Traditionally these...

Scaling up data analytics in Python using multiple FPGAs

Big data applications are becoming more commonplace due to an abundance of digital data and increasingly powerful hardware. One of these classes of hardware devices are FPGAs, which are being used today in various ways such as data centers and embedded systems. High performance, power efficiency, and reprogrammability are the primary reasons...

The Opencraft Messaging System

The aim of this project is to improve the scalability of the Opencraft server. The Opencraft server is based on an open-source implementation of the vanilla Minecraft server. This thesis focuses on improving the messaging system of the Opencraft server. The existing implementation of the messaging system is very basic. It went through all online...

ECCO: Edge-cloud chaining and orchestration framework for road context assessment

For road safety, detecting and reacting efficiently to road hazards is crucial and yet challenging due to practical restrictions such as limited data availability, which relies on network support. Moreover, from a system perspective we lack a computational model capable of providing to vehicles reliable and real-time assessment of the road...

Edge chaining framework for black ice road fingerprinting

Detecting and reacting efficiently to road condition hazards are challenging given practical restrictions such as limited data availability and lack of infrastructure support. In this paper, we present an edge-cloud chaining solution that bridges the cloud and road infrastructures to enhance road safety. We exploit the roadside infrastructure...

A Markov-based vulnerability assessment for the design of on-board distributed systems in the concept phase

Naval ships are designed to operate in a hostile environment. As such, vulnerability is an important aspect that needs to be assessed during the design. With the increased interest in electrification and automation on board naval ships, the vulnerability of distributed systems has become a major topic of interest. However, assessing this is...

Towards a novel design perspective for system vulnerability using a Markov chain

In order to investigate to which extent naval ships can execute their operational scenario after damage, an early stage assessment of the vulnerability of distributed systems needs to be carried out. Such assessments are currently mostly done by evaluating the performance of predefined concepts. However, such an approach does not necessarily...

When Willeke can get rid of paperwork: A lean infrastructure for qualified information exchange based on trusted identities

As a frequent participant in eSociety, Willeke is often preoccupied with paperwork because there is no easy to use, affordable way to act as a qualified person in the digital world. Confidential interactions take place over insecure channels like e-mail and post. This situation poses risks and costs for service providers, civilians and...

Velocity Templates for Dense Swarms of Flying Robots

In the near future many tasks could be performed by swarms of flying robots. To successfully implement multiple of these swarms in the same airspace they will have to be decentralised, autonomously cope with high densities and even resolve conflicting objectives of other swarms, while remaining controllable by operators through high-level...

A distributed networked approach for fault detection of large-scale systems

Networked systems present some key new challenges in the development of fault-diagnosis architectures. This paper proposes a novel distributed networked fault detection methodology for large-scale interconnected systems. The proposed formulation incorporates a synchronization methodology with a filtering approach in order to reduce the effect...

Share scheduling in distributed systems