The complex system environment of data processing applications makes it very challenging to achieve high resource efficiency. In this thesis, we develop solutions that improve resource efficiency at multiple system levels by focusing on three scenarios that are relevant—but not limited—to database management systems. First, we address the challenge of understanding complex systems by analyzing memory access characteristics via efficient memory tracing. Second, we leverage information about me...

As of today, personalized item suggestions provided by an automated recommender system have become a crucial part of many online services, e.g., online shops or media streaming applications, and extensive evidence exists that such systems increase both the user experience as well as the revenue of the providers. In academia, the recommendation problem is often framed as finding suitable items that a user is not yet aware of based on his long-term preference profile. In the real world, however...

Large data sets are often stored distributedly to increase the reliability of systems and the efficiency of query evaluation in them. While some query operators -- like selections and projections -- are intrinsically conform with parallel evaluation, others -- like joins -- demand specific distribution patterns. For relational databases, a common approach to evaluate queries in parallel relies on the use of rather simple distribution patterns for binary joins and the computation of the que...

The increasing complexity of software systems entailed by the imposed requirements and involved stakeholders creates new challenges towards software development and turns it into a complex task. Nowadays, sophisticated development approaches and tools are needed to handle this complexity. Model-Driven Engineering (MDE) provides means to abstract from the details of a software system during the development phase by using models. Domain-Specific Modeling (DSM), a branch of MDE, tack...

Property testing considers decision problems in the regime of sublinear complexity. Most classical decision problems require at least linear time complexity in order to read the whole input. Hence, decision problems are relaxed by introducing a gap between “yes” and “no” instances: A property tester for a property Π (e. g., planarity) is a randomized algorithm with constant error probability that accepts objects that have Π (planar graphs) and that rejects objects that have linear edit distan...

In dieser Dissertation betrachten wir die parallele Konstruktion von Text-Indizes. Text-Indizes stellen Zusatzinformationen über Texte bereit, die Anfragen hinsichtlich dieser Texte beschleunigen können. Ein Beispiel hierfür sind Volltext-Indizes, welche für eine effiziente Phrasensuche genutzt werden, also etwa für die Frage, ob eine Phrase in einem Text vorkommt oder nicht. Diese Dissertation befasst sich hauptsächlich, aber nicht ausschließlich mit der parallelen Konstruktion von Text-Indi...

We give a memory-friendly algorithm computing the compression scheme plcpcomp or lex-parse in linear or near-linear time.

Linked data arise in many real-world settings - from chemical molecules, and protein-protein interaction networks, to social networks. Hence, in recent years, machine learning methods for graphs have become an important area of research. The present work deals with (supervised) graph classification, i.e., given a set of (class) labeled graphs we want to train a model such that it can predict the labels of unlabeled graphs. Thereto, we want to map a graph to a (usually) high-dimensional vector...

The visualization of a protein is hardly imaginable without secondary structure elements (SSEs). But SSEs play a by far more important role in the field of chemical biology, apart from the creation of fancy protein images. They are essential in structure-based analyses due to their impact on secondary structure prediction and structural protein alignment. However, their proper classification is a challenging issue. There are more than 30 tools available that underline the subjective char...

Wird in einem Fabriksystem ein Anpassungsbedarf erkannt, muss ein Anpassungsprozess gestartet werden. Ein solcher Prozess beinhaltet in der Regel eine Planungsphase, in der ein Projektteam ein Vorgehen erarbeitet, wie die Anpassung vorzunehmen ist. Während Produktions-, Logistik- und Fertigungsprozesse bereits weitgehend automatisiert wurden und werden, findet die Entwicklung eines solchen Planungsprozesses in der Regel nach wie vor manuell und individuell statt. Das Planungsteam entwickelt d...

A mobile system that can detect viruses in real time is urgently needed, due to the combination of virus emergence and evolution with increasing global travel and transport. A biosensor called PAMONO (for Plasmon Assisted Microscopy of Nano-sized Objects) represents a viable technology for mobile real-time detection of viruses and virus-like particles. It could be used for fast and reliable diagnoses in hospitals, airports, the open air, or other settings. For analysis of the images provided ...

Focusing on real-time scheduling theory, the thesis demonstrates how essential realistic scheduling models and analyses are when guaranteeing timing correctness without over-provisioning the necessary system resources. It details potential pitfalls of the de facto standards for theoretical examination of scheduling algorithms and schedulability tests, namely resource augmentation bounds and utilization bounds, and proposes parametric augmentation functions to improve their meaningfulness. Con...

Whenever a database is changed, any previously computed and stored result of a query evaluation on that database becomes invalid and needs to be updated. This update can in principle be conducted by re-evaluating the query from scratch. However, this approach might be too inefficient, especially for large databases. Instead, it is often advantageous to make use of the old query result and possibly further stored auxiliary information. A descriptive framework for studying this dynamic s...