@inproceedings{RaspSahinbasReisingeretal., author = {Rasp, Franziska and Sahinbas, Burak and Reisinger, Thomas and Leitgeb, Erich and Hipp, Susanne}, title = {Polarization-based peak distortion mitigation for 5G sidelink positioning}, series = {2025 International Conference on Software, Telecommunications and Computer Networks (SoftCOM), 18-20 September 2025, Split, Coratia}, booktitle = {2025 International Conference on Software, Telecommunications and Computer Networks (SoftCOM), 18-20 September 2025, Split, Coratia}, publisher = {IEEE}, address = {Split}, isbn = {978-953-290-143-6}, issn = {1847-358X}, pages = {6}, abstract = {For cooperative driving both environmental perception and communication with other vehicles and the infrastructure are essential to avoid safety critical situations. The 5G Sidelink, as part of the Cellular Vehicle to Everything framework, enables both communication and, since 3GPP Release 18, positioning for distance estimation between vehicles. Due to the expected bandwidth limitations of 5G Sidelink in the Intelligent Transportation System band, combined with signal distortion caused by multi-path superposition, achieving submeter positioning accuracy is a significant challenge. Polarization diversity is investigated as a potential approach to mitigate errors resulting from signal distortion and subsequent peak shifts due to multi-path superposition. This work investigates the potential for reduced peak shift errors through the use of dual-polarized receive antennas. The received signals are processed using a polarization scan algorithm and compared to the accuracy achieved with single-antenna systems. The analysis is conducted using the Quasi Deterministic Radio Channel Generator framework with statistical Vehicle-to-Everything channel models. Simulation results show that polarization scan-based postprocessing reduces peak shifts and improves robustness in scenarios with polarization-mismatched antenna configurations.}, language = {en} } @unpublished{LaubmannReschke, author = {Laubmann, Julia and Reschke, Johannes}, title = {Tackling fake images in cybersecurity - interpretation of a StyleGAN and lifting its black-box}, doi = {10.48550/arXiv.2507.13722}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-83930}, pages = {11}, abstract = {In today's digital age, concerns about the dangers of AI-generated images are increasingly common. One powerful tool in this domain is StyleGAN (style-based generative adversarial networks), a generative adversarial network capable of producing highly realistic synthetic faces. To gain a deeper understanding of how such a model operates, this work focuses on analyzing the inner workings of StyleGAN's generator component. Key architectural elements and techniques, such as the Equalized Learning Rate, are explored in detail to shed light on the model's behavior. A StyleGAN model is trained using the PyTorch framework, enabling direct inspection of its learned weights. Through pruning, it is revealed that a significant number of these weights can be removed without drastically affecting the output, leading to reduced computational requirements. Moreover, the role of the latent vector -- which heavily influences the appearance of the generated faces -- is closely examined. Global alterations to this vector primarily affect aspects like color tones, while targeted changes to individual dimensions allow for precise manipulation of specific facial features. This ability to finetune visual traits is not only of academic interest but also highlights a serious ethical concern: the potential misuse of such technology. Malicious actors could exploit this capability to fabricate convincing fake identities, posing significant risks in the context of digital deception and cybercrime.}, language = {en} } @article{Zellner, author = {Zellner, Gregor}, title = {Ein Grundriss der Wissenschaftsdisziplin Wirtschaftsinformatik}, series = {BIT Banking and Information Technology}, volume = {Band 25, M{\"a}rz 2024}, journal = {BIT Banking and Information Technology}, number = {1}, pages = {9}, abstract = {Dieser Beitrag gibt einen Grundriss der Wissenschaftsdisziplin Wirtschaftsinformatik (WI) und ihrer Entwicklung. Hierzu wird zun{\"a}chst der Gegenstand der WI n{\"a}her betrachtet, n{\"a}mlich die Informationssysteme. Dann wird erl{\"a}utert, welche Ziele die WI verfolgt. Da WI ein interdisziplin{\"a}res Fach ist, werden anschließend die bestimmenden Basiswissenschaften der WI im Rahmen des Grundsystems der Wissenschaften dargestellt. Dabei wird deutlich, dass der Einfluss unterschiedlicher Disziplinen den Methodenpluralismus in der WI bef{\"o}rdert. Im Beitrag werden die zwei grundlegenden Forschungsparadigmen in Form des verhaltensorientierten und des gestaltungsorientierten Ansatzes n{\"a}her betrachtet. Nach einem kurzen Einblick in die zeitliche Entwicklung der deutschsprachigen WI werden die Themen-und T{\"a}tigkeitsfelder der WI n{\"a}her er{\"o}rtert. Abschließend wird ein Ausblick auf die Herausforderungen in der WI gegeben.}, language = {de} } @phdthesis{Kratzer, author = {Kratzer, Simon}, title = {The Fractional CIO as a new form of IT management for SMEs : essays on current issues and new developments in IT executive management}, url = {http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa2-894186}, pages = {27, 46, 85-87, 119-120, 131, 148, 172-173}, abstract = {For decades, the importance of information technology (IT) for organizations has continuously increased. To ensure effective IT management and operations, to enable the business, and to stay competitive, many large organizations appoint a Chief Information Officer (CIO) as their highest-ranked IT executive (Preston et al., 2008). While many small to medium-sized enterprises (SMEs) face similar challenges concerning IT, they often lack the resources to employ a full-time IT executive (Bhagwat \& Sharma, 2007; Cragg et al., 2013). However, Kamariotou and Kitsios (2022) find that strategic planning and alignment with IT are important determinants for increasing an SME's business value. An increasing number of SMEs started to employ CIOs part-time to avoid the risk of not staying competitive and losing business value (Moise, 2021; Pratt, 2022). Such so-called "Fractional CIOs" are often highly experienced and skilled individuals working for multiple SMEs simultaneously (Kratzer et al., 2022). By contracting a Fractional CIO, SMEs benefit in various ways. First, they get an experienced IT leader at a fraction of the cost. Second, they remain flexible concerning billable hours and the time horizon of the engagement. Third, they are receiving an outside-in perspective and might profit from the Fractional CIO's experience gained from simultaneous engagements. Even though the Fractional CIO role benefits SMEs, adoption and awareness are still low. Further, substantial research on the novel role is missing. This dissertation aims to establish a new stream in CIO research that explores the role of the Fractional CIO. Our comprehensive literature review of the CIO research field provides the basis for this research (Kratzer et al., 2023b). As we explore this novel phenomenon, we are also interested in how to best report research findings. We, therefore, aim to conceptualize techniques to convey novel phenomena in information systems (IS) research in an illustrative way. Hence, we posed the following overarching research questions: RQ1: How can novel phenomena be communicated in an illustrative yet rigorous way in research papers? RQ2: What is the state-of-the-art in the CIO research field, and what are further avenues for research? RQ3: What concepts provide SMEs with the experienced IT executive management they need? RQ4: What makes Fractional CIO engagements successful? RQ5: How does the role of the Fractional CIO take shape in practice in the German market? These overarching research questions are answered through six consecutive publications. 1) 'Literary Sketches in Information Systems Research: Conceptualization and Guidance for Using Vignettes as a Narrative Form' This paper is conceptual and has a methodological focus on the use of vignettes. The paper contributes to the usage of vignettes as a narrative form in academic research, providing a taxonomy that structures vignettes and identifies three archetypes. By conceptualizing vignettes through a taxonomy and archetypes, we create transparency for the usage of vignettes, encourage the use of vignettes, and provide recommendations how to use them more rigorously. Long term, this might contribute to a better exchange between academia and practice through better comprehensibility of academic papers. 2) 'Four Decades of Chief Information Officer Research: A Literature Review and Research Agenda Based on Main Path Analysis' In this paper, we conducted a bibliographic literature review using main path analysis, which helped to objectively identify existing topics based on their importance. We also illustrated the knowledge flow in CIO research by identifying major and emerging research streams and analyzing their evolution over time. Additionally, we aggregated central papers in CIO research and developed a research agenda to provide guidance for future research. Overall, this paper helps to advance the understanding of the CIO research field and provides insights for researchers and practitioners. 3) 'The Fractional CIO in SMEs: Conceptualization and Research Agenda' With this paper, we were the first to conceptualize the role of the Fractional CIO and to develop a research agenda for this novel research field. The results from this paper contribute to research and practice in several ways. First, we are the first authors to conceptualize the role of the Fractional CIO, derive a definition, compare it to existing CIO role research, and derive four engagement types. Second, we develop a research agenda to guide future research in the new Fractional CIO research field. Third, we contribute to practice by promoting the role's awareness among potential Fractional CIOs and organizations. Fourth, we show that Fractional CIO services are versatile and can benefit organizations of different sizes and maturity levels, and there are diverse possibilities for evolution. 4) 'What Makes Fractional CIO Engagements in SMEs Successful? - A Research Framework' In this paper, we developed a research framework for Fractional CIO engagement success. It makes contributions to research and practice. First, we propose a research framework for Fractional CIO engagement success and, therefore, develop a common ground for future research. Second, we provide practical advice for Fractional CIOs and SMEs regarding factors for engagement success. Third, we raise awareness about the Fractional CIO role that may benefit many SMEs around the world. 5) 'Factors for Fractional CIO Engagement Success' In this paper, we used Q-methodology to empirically evaluate the relative importance of factors influencing Fractional CIO engagement success and to identify different viewpoints on engagement success. Our paper makes several contributions to research and practice. First, our paper is the first to identify and evaluate the importance of factors for Fractional CIO engagement success. Therefore, it serves as a basis for further research in the new Fractional CIO research field. Second, we find that upper echelon theory (Hambrick \& Mason, 1984) can be applied to executives independent of their contractual relationship in cases of comparable responsibilities. Third, by thoroughly applying Q-methodology, we showcase an exploratory tool for identifying opinions and preferences of participants and clustering them accordingly. This approach provides guidance for other IS scholars to apply it. Fourth, we develop preliminary archetypes of Fractional CIOs and, based on that, provide tentative advice for Fractional CIOs and organizations that hire them. These preliminary archetypes enabled us to identify further theoretical explanations of this phenomenon. In addition to transaction cost theory, agency theory, and upper echelon perspective, we found that stewardship theory and dynamic capabilities explain additional characteristics of Full-ownership CIOs and Change Agents. 6) 'Mehr als Vollzeit: Fractional CIOs in KMUs' This paper summarizes the results of our previous studies regarding the Fractional CIO role in German language and conducts semi-structured interviews with three Fractional CIOs from Germany to complement it with a perspective on the German market. Overall, we find that the Fractional CIO role in the German market is performed similarly to the international market. The interviewed German Fractional CIOs/CTOs could not clearly identify any hurdles that might explain the low adoption of the role. However, all three German Fractional CIOs agree that German SMEs would strongly benefit from Fractional CIOs. (References to be found in the full text)}, language = {en} } @article{HecknerSchneidermeierHastreiteretal., author = {Heckner, Markus and Schneidermeier, Tim and Hastreiter, Isabella and Wolff, Christian}, title = {Der Newbie, der Fortgeschrittene und der Power-User. Warum es nicht reicht, "einfach mal die Nutzer zu fragen"}, series = {i-com}, volume = {11}, journal = {i-com}, number = {3}, publisher = {DeGruyter}, doi = {10.1524/icom.2012.0038}, pages = {47 -- 50}, abstract = {Innerbetriebliche Software entwickelt sich h{\"a}ufig {\"u}ber Jahre hinweg inkrementell weiter, sammelt so Schritt f{\"u}r Schritt Funktionen an und verliert an {\"U}bersichtlichkeit. Soll diese Software hinsichtlich ihrer Gebrauchstauglichkeit optimiert werden, m{\"u}ssen aus Sicht eines externen Usability-Beraters zun{\"a}chst die Dom{\"a}ne des Kunden verstanden und die Arbeitsprozesse analysiert werden. In der Analyse muss insbesondere der Umgang unterschiedlicher Nutzergruppen mit der Software ber{\"u}cksichtigt werden, um fundierte Neuvorschl{\"a}ge in einem Redesign erarbeiten zu k{\"o}nnen. In diesem Erfahrungsbericht beschreiben wir anhand eines konkreten Praxisbeispiels Eigenschaften von Nut-zergruppen und deren Einfluss auf die Analyse, und warum es nicht reicht, die Nutzer „einfach mal zu fragen, wie sie die Software denn finden".}, language = {de} } @masterthesis{Bachl, type = {Bachelor Thesis}, author = {Bachl, Hannes}, title = {Initial 5G synchronisation using a time-domain correlator}, address = {Regensburg}, doi = {10.35096/othr/pub-8904}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-89048}, school = {Ostbayerische Technische Hochschule Regensburg}, pages = {x, 63, XXI}, abstract = {The following Bachelor's thesis explores the implementation of a fre- quency correlator in the time-domain as required for the initial synchro- nisation in 5G mobile networks. Exact time domain synchronisation is required for modern mobile networks to allow reconstruction of the em- ployed physical modulations schemes without producing excessive amounts of interference. This is the first step in the discovery process of mobile radio cells. Initial the theoretical foundations of time synchronisation mechanisms as used in 5G networks are explored, including the physical modulation schemes employed. The different implementations of the synchronisa- tion algorithms are considered and a single algorithm is chosen for im- plementation. The chosen algorithm is then implemented and the implementation and findings are discussed. The hardware basis for the implementation is a Xilinx RFSoC, a high speed FPGA with associated analog-to-digital con- verts designed for RF signal processing. Finally there will be a discussion of possible optimisations and problems encountered during implementation.}, language = {en} }