Code coverage analysis plays an important role in the software testing process. More recently, the remarkable effectiveness of coverage feedback has triggered a broad interest in feedback-guided fuzzing. In this work, we discuss static instrumentation techniques for binary-level coverage analysis without compiler support. We show that the proposed techniques are precise, efficient, and transparent significantly beyond the state of the art. We implement these techniques into two tools, namely, Spedi and bcov. Both tools are open source and publicly available. Spedi shows that the disassembly and function identification of stripped binaries can be highly accurate without resort to any external information. We build on these important results in bcov where we statically instrument x86-64 ELF binaries to track code coverage. However, improving efficiency and scaling to large real-world software required an orchestrated effort combining several techniques. First, we bring a well-known probe pruning technique, for the first time, to binary-level instrumentation and effectively leverage its notion of superblocks to reduce overhead. Second, we introduce sliced microexecution, a robust technique for jump table analysis which improves CFG precision and enables us to instrument jump table entries. Additionally, smaller instructions in x86-64 pose a challenge for inserting detours. To address this challenge, we aggressively exploit padding bytes. Also, we introduce a greedy scheme to systematically host detours in neighboring basic blocks. We evaluate bcov on a corpus of 95 binaries compiled from eight popular and well-tested packages like FFmpeg and LLVM. Two instrumentation policies, with different edge-level precision, are used to patch all functions in this corpus - over 1.6 million functions. Our precise policy has average performance and memory overheads of 14% and 22%, respectively. Instrumented binaries do not introduce any test regressions. The reported coverage is highly accurate with an average F-score of 99.86%. Finally, our jump table analysis is comparable to that of IDA Pro on gcc binaries and outperforms it on clang binaries. Our work demonstrates that static instrumentation can offer unique advantages in comparison to established methods like compiler instrumentation and dynamic binary instrumentation. It also opens the door for many interesting applications of static instrumentation, which can go well beyond coverage analysis.

The construction of number fields with given Galois group fits into the framework of the inverse Galois problem. This problem remains still unsolved, although many partial results have been obtained over the last century. Shafarevich proved in 1954 that every solvable group is realizable as the Galois group of a number field. Unfortunately, the proof does not provide a method to explicitly find such a field. This work aims at producing a constructive version of the theorem by solving the following task: given a solvable group $G$ and a $B\in \mathbf N$, construct all normal number fields with Galois group $G$ and absolute discriminant bounded by $B$. Since a field with solvable Galois group can be realized as a tower of abelian extensions, the main role in our algorithm is played by class field theory, which is the subject of the first part of this work. The second half is devoted to the study of the relation between the group structure and the field through Galois correspondence. In particular, we study the existence of obstructions to embedding problems and some criteria to predict the Galois group of an extension.

Mussel-inspired catechol-containing polymers provide a promising basis for developing strong biogenic adhesives (see chapter 1). In order to develop a biomimetic adhesive, solvent stable laccases were investigated for their application as biochemical catalyst for the functionalization of natural polymers (see chapter 2), such as chitosan and lignin, with catechols. Investigation of the laccase-catalysed C–N bond formation between primary amines and catechols, such as protocatechuic acid (PCA) and dihydrocaffeic acid (DHC), suggest that the reaction is promoted by a low pKa value of the primary amine used and a neutral or mildly acidic reaction pH. Since the pKa of chitosan’s amine groups is below 7, spontaneous reactions with catechols were possible, resulting in a PCA-functionalized chitosan, which achieved a tensile strength of 4.56 MPa ± 0.54 MPa on aluminum surfaces blasted with corundum (see chapter 3). For the functionalization of lignin, which was extracted with the Organosolv (OS) process, a two-step concept was required, where first L-lysine and subsequently DHC and PCA were grafted onto lignin. For DHC-lignin, a tensile strength of 169.3 kPa ± 130.6 kPa was measured (see chapter 4). Since the functionalization and curing processes use naturally occurring substances exclusively and are free of toxic chemicals, novel and sustainable bioadhesives were developed. Moreover, differential scanning calorimetry (DSC) analysis was used to characterize the mussel-inspired chitosan adhesive (see chapter 5). Furthermore, DSC measurements were validated for monitoring biodegradation quantitatively using small sample quantities and simple sample preprocessing. Using only DSC measurements, quantifiable detection of degradation progress was possible, while at the same time qualitative assessment of changes in crystallinity (indicating incomplete biodegradation) was obtained. The implemented method is recommended for the quantification of the biodegradability of the PCA-chitosan adhesive. This work introduces novel bio-based adhesives, as well as a new measuring technique for measuring biodegradability of various material.

Reflectance anisotropy spectroscopy (RAS), which was originally invented to monitor epitaxial growth, can—as we have previously shown—also be used to monitor the reactive ion etching of III/V semiconductor samples in situ and in real time, as long as the etching rate is not too high and the abrasion at the etch front is not totally chaotic. Moreover, we have proven that— using RAS equipment and optical Fabry-Perot oscillations due to the ever-shrinking thickness of the uppermost etched layer—the in situ etch-depth resolution can be as good as +/-0.8 nm, employing a Vernier-scale type measurement and evaluation procedure. Nominally, this amounts to +/-1.3 lattice constants in our exemplary material system, AlGaAsSb, on a GaAs or GaSb substrate. In this contribution, we show that resolutions of about +/-5.6 nm can be reliably achieved without a Vernier scale protocol by employing thin doped layers or sharp interfaces between differently doped layers or quantum-dot (QD) layers as etch-stop indicators. These indicator layers can either be added to the device layer design on purpose or be part of it incidentally due to the functionality of the device. For typical etch rates in the range of 0.7 to 1.3 nm/s (that is, about 40 to 80 nm/min), the RAS spectrum will show a distinct change even for very thin indicator layers, which allows for the precise termination of the etch run.

The present work investigates the role of higher education experience in the process of students’ adult identity formation. In the broadest sense, adult identity is “seeing oneself as an adult” (Macmillan, 2007: 20), and it lays in the core of intensive processes of personal identity formation in the years following adolescence, which are for an increasing number of youth over the past decades spent in higher education. Approaches to adulthood in prior studies reveal ongoing discussions and attempts at re-conceptualisation against changing conditions and regimes of transition to adulthood. Traditionally, the so-called “objective markers” of adulthood have dominated the discourses for a long time, emphasising role transitions and demographic features as criteria for adulthood. The new research venues adding biographical approaches and subjective experiences reveal significance of inner, psychological processes of becoming an adult. However, the problem of the role of higher education in the process of students’ adult identity has not been fully illuminated thus far. The reason for this might be sought within the domain of disciplinary orientation of the field of higher education and Educational Sciences. Higher education research focuses on the overall, “grand” effects of education, while traditional Educational Sciences have not been showing much interest in higher education topics. Substantial work has been produced from developmental sciences, psychology in particular, which has revealed an intricate forest of today’s adulthood and conditions for its attainment, leaving open a whole set of educational, social, economic, cultural antecedents, correlates and experiences affecting transition to adulthood. Besides, as analyses presented in Chapter 2 show, students’ position in dominant discourses marked by political and economic imperatives is marginal. Their experiences and voices are in a sense excluded, making it almost impossible to infer on actual students’ personal benefits of the higher education process. The theoretical framework for this research consists of Erikson’s (Erikson, 1959; 1963; 1968) positions on human development in post-adolescent years, and McAdams’s model of narrative identity (1988; 2011; 2018), which also arose from Eriksonian tradition. Psychosocial theory (Erikson, 1959; 1963; 1968) assumes that social institutions provide structure and guidance to personal development, whereby they create a niche for psychosocial moratorium enabling youth a period of “identity work” before taking on long-term adult commitments. Research over recent decades reporting that higher education provides opportunities for students’ self-growth, exploration and resolving key identity questions in a variety of fields (e.g., Adams and Fitch, 1983; Arnett, 2004a; Berman, Kennerley, Kennerley, 2008; Mayhew, Rockenbach, Bowman, Seifert, Wolniak, Pascarella, Terenzin, 2016) supports such theoretical stances. The present research intends to extend existing knowledge raising the central question: What role of higher education experience students perceive in their adult identity formation? The empirical part reports on biographical research into senior year students’ lived experiences of their developmental path and their meaning to the higher education process. Students’ experiences are approached using the qualitative technique of problem-centred interviewing (PCI), which helps focus participants’ narration on the researcher’s interest and subsequent in-depth analysis of collected experiences. In total, 40 senior year students coming from diverse backgrounds were interviewed. Data were analysed in Atlas.ti software, which enabled the coding system’s better organization and browsing through transcripts. The qualitative analysis process consisted of both inductive and deductive approaches, wherein open and thematic coding techniques were performed interchangeably. Research findings indicate that in certain groups of students – but not in all – higher education experience facilitates and enriches the process of adult identity formation granting orientation and guidelines. Students identify experiences with the highest adult identity formational potential organised in the four broad categories: relationships with teachers and peers, respectively, teaching approach and study material, and extra-curricular activities. Based on the obtained findings, four patterns of thinking about the role of higher education in students’ adult identity formation have been identified: generator of adult identity formation, a safe-zone for exploration processes, interim phase leading to adulthood, and higher education suspending adult identity formation. This formed the basis for constructing the four student types; proactive, explorer, comfort-zone and atypical student. Research findings give the rationale for rethinking the educative potential of higher education in terms of its relevance for diverse students personally – for their self-growth and forming their personal identities, in addition to the professional ones.