TY - CHAP A1 - Ramsauer, Ralf A1 - Lohmann, Daniel A1 - Mauerer, Wolfgang ED - Wassermann, Tony T1 - Observing Custom Software Modifications: A Quantitative Approach of Tracking the Evolution of Patch Stacks T2 - Proceedings of the 12th International Symposium on Open Collaboration (OpenSym '16) N2 - Modifications to open-source software (OSS) are often provided in the form of "patch stacks" -- sets of changes (patches) that modify a given body of source code. Maintaining patch stacks over extended periods of time is problematic when the underlying base project changes frequently. This necessitates a continuous and engineering-intensive adaptation of the stack. Nonetheless, long-term maintenance is an important problem for changes that are not integrated into projects, for instance when they are controversial or only of value to a limited group of users. We present and implement a methodology to systematically examine the temporal evolution of patch stacks, track non-functional properties like integrability and maintainability, and estimate the eventual economic and engineering effort required to successfully develop and maintain patch stacks. Our results provide a basis for quantitative research on patch stacks, including statistical analyses and other methods that lead to actionable advice on the construction and long-term maintenance of custom extensions to OSS. KW - CADOS KW - collaboration KW - Linux KW - maintenance KW - patch stacks Y1 - 2016 U6 - https://doi.org/10.1145/2957792.2957810 SP - 1 EP - 4 PB - ACM CY - New York ER - TY - CHAP A1 - Hofmann, Gottfried A1 - Riehle, Dirk A1 - Kolassa, Carsten A1 - Mauerer, Wolfgang T1 - A Dual Model of Open Source License Growth T2 - Open Source Software: Quality Verification : 9th IFIP WG 2.13 International Conference, OSS 2013, Koper-Capodistria, Slovenia, June 25-28, 2013, Proceedings N2 - Every open source project needs to decide on an open source license. This decision is of high economic relevance: Just which license is the best one to help the project grow and attract a community? The most common question is: Should the project choose a restrictive (reciprocal) license or a more permissive one? As an important step towards answering this question, this paper analyses actual license choice and correlated project growth from ten years of open source projects. It provides closed analytical models and finds that around 2001 a reversal in license choice occurred from restrictive towards permissive licenses. KW - Dual Model KW - Free Software Foundation KW - Open Source KW - Open Source License Y1 - 2013 U6 - https://doi.org/10.1007/978-3-642-38928-3_18 VL - 404 SP - 245 EP - 256 PB - Springer CY - Berlin ER - TY - VIDEO A1 - Mauerer, Wolfgang A1 - Wagner, Daniel T1 - Cyclic Tests Unleashed: Large-Scale RT Analysis with Jitterdebugger T2 - Open Source Summit, North America, 17.07.2019 Y1 - 2019 UR - https://www.youtube.com/watch?v=wNQ24TFjzCw ER - TY - CHAP A1 - Mauerer, Wolfgang T1 - Are any big brothers watching you, and if yes, what can they tell about Debian T2 - DebConf18 Hsinchu, Taiwan N2 - Debian, as a collection of software packages and components, is known to be one of the largest software projects in the history of mankind. Combined with a traceable history over many years, the artefacts created by Debian developers and users make it one of science’s favourite targets to quantitatively or qualitatively understand how real-world software development works (or does not), how people collaborate, and many other other related questions. Unfortunately, while scientists make ample use of the resources and artefacts created by FLOSS and friends, the exchange of insights and ideas does not seem to extend in both directions: Developers, users and integrators are often unaware of results obtained in science. This talk will introduce the Debian community to a selection the most important results obtained by scientific (software engineering) research, with a special focus on large-scale socio-technical analysis of projects like Debian, and the possible implications and improvements these may bring to Debian development itself. Y1 - 2018 UR - https://meetings-archive.debian.net/pub/debian-meetings/2018/DebConf18/2018-08-03/are-any-big-brothers-watching-you-and-if.webm ER - TY - VIDEO A1 - Mauerer, Wolfgang A1 - Ramsauer, Ralf T1 - Torturing Git for Fun and Profit T2 - Microsoft Developer Meetup Regensburg 02.04.2019 N2 - In diesem Talk blicken Prof. Dr. Wolfgang Mauerer und Ralf Ramsauer unter die Haube des verteilten Versionskontrollsystems Git. Neben einer genauen Beschreibung der Strukturen und Plumbing APIs, mit denen Git intern Commits erzeugt und verknüpft, gehen die Vortragenden auch auf nützliche Features und Standards ein, welche die Kollaborition in großen Open-Source Projekten erleichtern. Y1 - 2019 UR - https://www.youtube.com/watch?v=CrUwmO4tvLI ER - TY - JOUR A1 - Feld, Sebastian A1 - Roch, Christoph A1 - Gabor, Thomas A1 - Seidel, Christian A1 - Neukart, Florian A1 - Galter, Isabella A1 - Mauerer, Wolfgang A1 - Linnhoff-Popien, Claudia T1 - A Hybrid Solution Method for the Capacitated Vehicle Routing Problem Using a Quantum Annealer JF - Frontiers in ICT N2 - he Capacitated Vehicle Routing Problem (CVRP) is an NP-optimization problem (NPO) that has been of great interest for decades for both, science and industry. The CVRP is a variant of the vehicle routing problem characterized by capacity constrained vehicles. The aim is to plan tours for vehicles to supply a given number of customers as efficiently as possible. The problem is the combinatorial explosion of possible solutions, which increases superexponentially with the number of customers. Classical solutions provide good approximations to the globally optimal solution. D-Wave's quantum annealer is a machine designed to solve optimization problems. This machine uses quantum effects to speed up computation time compared to classic computers. The problem on solving the CVRP on the quantum annealer is the particular formulation of the optimization problem. For this, it has to be mapped onto a quadratic unconstrained binary optimization (QUBO) problem. Complex optimization problems such as the CVRP can be translated to smaller subproblems and thus enable a sequential solution of the partitioned problem. This work presents a quantum-classic hybrid solution method for the CVRP. It clarifies whether the implementation of such a method pays off in comparison to existing classical solution methods regarding computation time and solution quality. Several approaches to solving the CVRP are elaborated, the arising problems are discussed, and the results are evaluated in terms of solution quality and computation time. Y1 - 2019 U6 - https://doi.org/10.3389/fict.2019.00013 VL - 6 SP - 1 EP - 13 PB - Frontiers ER - TY - CHAP A1 - Ramsauer, Ralf A1 - Bulwahn, Lukas A1 - Lohmann, Daniel A1 - Mauerer, Wolfgang ED - Zhang, Yinqian ED - Sion, Radu T1 - The Sound of Silence : Mining Security Vulnerabilities from Secret Integration Channels in Open-Source Projects T2 - Proceedings of the 2020 ACM SIGSAC Conference on Cloud Computing Security Workshop: 09.11.2020, virtual event N2 - Public development processes are a key characteristic of open source projects. However, fixes for vulnerabilities are usually discussed privately among a small group of trusted maintainers, and integrated without prior public involvement. This is supposed to prevent early disclosure, and cope with embargo and non-disclosure agreement (NDA) rules. While regular development activities leave publicly available traces, fixes for vulnerabilities that bypass the standard process do not. We present a data-mining based approach to detect code fragments that arise from such infringements of the standard process. By systematically mapping public development artefacts to source code repositories, we can exclude regular process activities, and infer irregularities that stem from non-public integration channels. For the Linux kernel, the most crucial component of many systems, we apply our method to a period of seven months before the release of Linux 5.4. We find 29 commits that address 12 vulnerabilities. For these vulnerabilities, our approach provides a temporal advantage of 2 to 179 days to design exploits before public disclosure takes place, and fixes are rolled out. Established responsible disclosure approaches in open development processes are supposed to limit premature visibility of security vulnerabilities. However, our approach shows that, instead, they open additional possibilities to uncover such changes that thwart the very premise. We conclude by discussing implications and partial countermeasures. Y1 - 2020 SN - 9781450380843 U6 - https://doi.org/10.1145/3411495.3421360 SP - 147 EP - 157 PB - ACM CY - New York, NY, USA ER - TY - CHAP A1 - Mauerer, Wolfgang A1 - Silberhorn, Christine T1 - Numerical Analysis of Parametric Downconversion T2 - AIP Conference Proceedings N2 - Parametric downconversion (PDC) is a popular technique to produce twin beams of photons that are entangled in multiple degrees of freedom. The generated states form the basis for numerous applications that require entanglement. An exact quantification of this resource is therefore essential, for instance for quantum cryptography that relies on a complete knowledge of the correlation contained in the state. While the determination of an entanglement monotone for the PDC process is only possible analytically in special cases, an exact calculation must usually be performed numerically. Recent work by Mikhailova et al. [2] analyses a certain class of PDC states for which the concurrence entanglement measure can be obtained by an analytical approximation. In this contribution, we analyse the validity of the approximation by comparison with exact numerical methods. Y1 - 2009 U6 - https://doi.org/10.1063/1.3131312 VL - 1110 IS - 1 PB - AIP Publishing ER - TY - GEN A1 - Mauerer, Wolfgang T1 - OSS Community, Health and Ecosystem Research: Theory and, or Theory versus Practice? T2 - 2nd International Workshop on Software Health (SoHEAL@ICSE, Montréal), 2019 Y1 - 2019 ER - TY - CHAP A1 - Ramsauer, Ralf A1 - Lohmann, Daniel A1 - Mauerer, Wolfgang T1 - System Software for Manufacturing Systems T2 - Proc. First European Advances in Digital Transformation Conference, (2018) Y1 - 2018 ER -