Florian Blum

University of Duisburg-Essen | uni-due · paluno - The Ruhr Institute for Software Technology

Users must pay a fee depending on resource consumption when using smart contracts on the Ethereum blockchain. As even the most basic operations cost several dollars under moderate network load, developers may actively reduce user-paid fees by optimizing the smart contract resource consumption (’gas costs’). Previous works suggested patterns and too...

Construction projects usually involve signing various contracts with specific billing procedures. In practice, dealing with complex contract structures causes significant problems, especially with regard to timely payment and guaranteed cash flow. Furthermore, a lack of transparency leads to a loss of trust. As a result, late or non-payment is a co...

Research in the field of blockchain technology and applications is increasing at a fast pace. Although the Bitcoin whitepaper by Nakamoto is already ten years old, the field can still be seen as immature and at an early stage. Current research in this area is lacking a commonly shared knowledge and consensus about terms used to describe the technol...

Autonomous agents not only need to make decisions, but also might need to negotiate situations with other autonomous systems and arrange how to proceed. Architecting such systems requires developers to weigh several options and decide, whether a central authority is beneficial or if consensus can be delegated to the agents themselves. We present a...

The expansion of blockchain technologies from financial applications to other fields intensifies the problem of an increasing size of data stored in the blockchain. Unfortunately, new participants of the blockchain network are required to download the whole blockchain to gain an overview about the state of the system and to validate incoming transa...

Adding blockchain technology to existing systems instead of building them from the ground up poses several challenges. It is difficult to find out which attributes of blockchains are important for a given use case (e.g. immutable, trustless, anonymous) and to decide which elements of an architecture should employ blockchain technologies. Current ap...

Cyber-Physical Systems (CPS) are interconnected systems that can measure, manipulate, and adapt their environment via sensors and actors. The high number of measured data means that a reliable and scalable communication infrastructure is indispensable, especially if data is processed in real time. Data can be available in different measurement qual...

Feature selection is one of the important challenges in variability-intensive systems. The FCORE model is used for the description of the functional and non-functional requirements of a system from a systems engineering point of view. In addition we demonstrate a solution for feature selection using a regulator algorithm (RGA). The RGA is a two dim...

The engineering of cyber-physical systems (CPS) imposes a huge challenge for today’s software engineering processes. Not only are CPS very closely related to real objects and processes, also their internal structures are more heterogeneous than classical information systems. In this experience report, we account on a prototypical implementation for...

Distributed systems, such as cloud systems or cyber-physical systems, involve the orchestration of different variability-intensive, adaptive sub-systems. Each of these sub-systems may perform adaptations simultaneously and independently from each other. Yet, if dependencies between the adaptations of the sub-systems are not considered, this may lea...

A cloud environment is a complex environment composed of many different entities and layers. Each of these cloud entities may be furnished with mechanisms offering various management actions. For any given situation, different management actions may be applicable and often simultaneously. Enforcing isolated management actions or combining contradic...

Cloud developers have to make several decisions when running their application in a cloud environment that may lead to conflicting objectives, inefficient deployment, and inappropriate or not existing adaptation strategies. Proper decision-support tools and processes are therefore needed to make cloud developers aware of the issues that need to be...

Current technology for cloud application adaptation fails to capture two fundamental aspect of cloud environments: multiple adaptation options and interferences and dependencies among these multiple mechanisms. Addressing these aspects requires a significant extension of existing cloud tools and frameworks for engineering and executing cloud applic...