TY  - GEN
A1  - Al Laban, Firas
A1  - Reger, Martin
A1  - Lucke, Ulrike
T1  - Closing the Policy Gap in the Academic Bridge
T2  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - The highly structured nature of the educational sector demands effective policy mechanisms close to the needs of the field. That is why evidence-based policy making, endorsed by the European Commission under Erasmus+ Key Action 3, aims to make an alignment between the domains of policy and practice. Against this background, this article addresses two issues: First, that there is a vertical gap in the translation of higher-level policies to local strategies and regulations. Second, that there is a horizontal gap between educational domains regarding the policy awareness of individual players. This was analyzed in quantitative and qualitative studies with domain experts from the fields of virtual mobility and teacher training. From our findings, we argue that the combination of both gaps puts the academic bridge from secondary to tertiary education at risk, including the associated knowledge proficiency levels. We discuss the role of digitalization in the academic bridge by asking the question: which value does the involved stakeholders expect from educational policies? As a theoretical basis, we rely on the model of value co-creation for and by stakeholders. We describe the used instruments along with the obtained results and proposed benefits. Moreover, we reflect on the methodology applied, and we finally derive recommendations for future academic bridge policies.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1310 
KW  - policy evaluation
KW  - higher education
KW  - virtual mobility
KW  - teacher training
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-583572
SN  - 1866-8372
IS  - 1310
ER  - 
TY  - THES
A1  - Melnichenko, Anna
T1  - Selfish Creation of Realistic Networks
N2  - Complex networks like the Internet or social networks are fundamental parts of our everyday lives. It is essential to understand their structural properties and how these networks are formed. A game-theoretic approach to network design problems has become of high interest in the last decades. The reason is that many real-world networks are the outcomes of decentralized strategic behavior of independent agents without central coordination. Fabrikant, Luthra, Maneva, Papadimitriou, and Schenker proposed a game-theoretic model aiming to explain the formation of the Internet-like networks. In this model, called the Network Creation Game, agents are associated with nodes of a network. Each agent seeks to maximize her centrality by establishing costly connections to other agents. The model is relatively simple but shows a high potential in modeling complex real-world networks. In this thesis, we contribute to the line of research on variants of the Network Creation Games. Inspired by real-world networks, we propose and analyze several novel network creation models. We aim to understand the impact of certain realistic modeling assumptions on the structure of the created networks and the involved agents’ behavior.
The first natural additional objective that we consider is the network’s robustness. We consider a game where the agents seek to maximize their centrality and, at the same time, the stability of the created network against random edge failure.
Our second point of interest is a model that incorporates an underlying geometry. We consider a network creation model where the agents correspond to points in some underlying space and where edge lengths are equal to the distances between the endpoints in that space. The geometric setting captures many physical real-world networks like transport networks and fiber-optic communication networks.
We focus on the formation of social networks and consider two models that incorporate particular realistic behavior observed in real-world networks. In the first model, we embed the anti-preferential attachment link formation. Namely, we assume that the cost of the connection is proportional to the popularity of the targeted agent. Our second model is based on the observation that the probability of two persons to connect is inversely proportional to the length of their shortest chain of mutual acquaintances.
For each of the four models above, we provide a complete game-theoretical analysis. In particular, we focus on distinctive structural properties of the equilibria, the hardness of computing a best response, the quality of equilibria in comparison to the centrally designed socially optimal networks. We also analyze the game dynamics, i.e., the process of sequential strategic improvements by the agents, and analyze the convergence to an equilibrium state and its properties.
N2  - Komplexe Netzwerke, wie das Internet oder soziale Netzwerke, sind fundamentale Bestandteile unseres Alltags. Deshalb ist es wichtig, ihre strukturellen Eigenschaften zu verstehen und zu wissen, wie sie gebildet werden. Um dies zu erreichen, wurden in den letzten Jahrzehnten spieltheoretische Ansätze für Netzwerkdesignprobleme populär. Der Grund dafür ist, dass viele reale Netzwerke das Ergebnis von dezentralem strategischem Verhalten unabhängiger Agenten ohne zentrale Koordination sind. Fabrikant, Luthra, Maneva, Papadimitriou und Schenker haben ein solches spieltheoretisches Modell vorgeschlagen, um die Entstehung von internetähnlichen Netzwerken zu erklären.
In diesem Modell, dem sogenannten Network Creation Game, repräsentieren die Agenten die Knoten eines Netzwerks. Jeder Agent versucht, durch den Kauf von Verbindungen zu anderen Agenten seine Zentralität im erzeugten Netzwerk zu maximieren. Dieses Modell ist relativ einfach, aber es hat ein großes Potenzial, reale Netzwerke modellieren zu können. In der vorliegenden Arbeit tragen wir zur aktuellen Forschungsrichtung, die sich der Untersuchung von Varianten der Network Creation Games widmet, bei. Inspiriert von realen Netzwerken, schlagen wir verschiedene neuartige Netzwerkbildungsmodelle vor und analysieren diese. Wir wollen hierbei die Auswirkungen bestimmter realistischer Modellierungsannahmen auf die Struktur der erstellten Netzwerke und das Verhalten der beteiligten Agenten verstehen.
Die erste natürliche zusätzliche Modellierungsannahme, die wir betrachten, ist ein Fokus auf die Robustheit des erzeugten Netzwerks. In diesem Modell haben die Agenten das Ziel, ihre Zentralität zu maximieren und gleichzeitig das erstellte Netzwerk robust gegenüber zufällige Verbindungsausfälle zu machen.
Das zweite neue Modell, das wir hier betrachten, bezieht eine zu Grunde liegende Geometrie mit ein. Hierbei entspricht jeder Agent einem Punkt in einem gegebenen Raum und die Länge einer Netzwerkverbindung entspricht der Distanz zwischen den jeweiligen Endpunkten in diesem Raum. Diese geometrische Variante erlaubt die Modellierung vieler realer physischer Netzwerke, wie z.B. Transportnetzwerke und Glasfaserkommunikationsnetzwerke.
Des Weiteren fokussieren wir uns auf die Bildung von sozialen Netzwerken und betrachten zwei Modelle, die ein bestimmtes realistisches Verhalten einbeziehen, das in realen sozialen Netzwerken beobachtet werden kann. Das erste Modell basiert auf einer anti-präferentiellen Kantenerzeugung. Dabei nehmen wir an, dass die Kosten einer Verbindung proportional zur Popularität des Agenten am anderen Endpunkt sind. Das zweite betrachtete Modell basiert auf der Beobachtung, dass die Wahrscheinlichkeit, dass zwei Personen verbunden sind, proportional zur Länge ihrer kürzesten Kette von gegenseitigen Bekanntschaften ist.
Für jedes der vier oben genannten Modelle liefern wir eine komplette spieltheoretische Analyse. Insbesondere fokussieren wir uns auf charakteristische strukturelle Eigenschaften der spieltheoretischen Gleichgewichte, die Komplexität der Berechnung einer optimalen Strategie und die Qualität der Gleichgewichte im Vergleich zu den zentral entworfenen sozial optimalen Netzwerken. Außerdem analysieren wir die Spieldynamik, d.h. den Prozess von sequentiellen verbessernden Strategieänderungen der Agenten. Dabei untersuchen wir die Konvergenz zu einem Gleichgewichtszustand und die Eigenschaften solcher Konvergenzprozesse.
T2  - Spieltheoretische Erzeugung von realistischen Netzwerken
KW  - Algorithmic Game Theory
KW  - Network Creation Game
KW  - Price of Anarchy
KW  - Nash Equilibrium
KW  - Game Dynamics
KW  - Computational Hardness
KW  - Algorithmische Spieltheorie
KW  - Network Creation Game
KW  - Preis der Anarchie
KW  - Spieldynamik
KW  - Komplexität der Berechnung
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-548141
ER  - 
TY  - THES
A1  - Haarmann, Stephan
T1  - WICKR: A Joint Semantics for Flexible Processes and Data
N2  - Knowledge-intensive business processes are flexible and data-driven. Therefore, traditional process modeling languages do not meet their requirements: These languages focus on highly structured processes in which data plays a minor role. As a result, process-oriented information systems fail to assist knowledge workers on executing their processes. We propose a novel case management approach that combines flexible activity-centric processes with data models, and we provide a joint semantics using colored Petri nets. The approach is suited to model, verify, and enact knowledge-intensive processes and can aid the development of information systems that support knowledge work.

Knowledge-intensive processes are human-centered, multi-variant, and data-driven. Typical domains include healthcare, insurances, and law. The processes cannot be fully modeled, since the underlying knowledge is too vast and changes too quickly. Thus, models for knowledge-intensive processes are necessarily underspecified. In fact, a case emerges gradually as knowledge workers make informed decisions. Knowledge work imposes special requirements on modeling and managing respective processes. They include flexibility during design and execution, ad-hoc adaption to unforeseen situations, and the integration of behavior and data. However, the predominantly used process modeling languages (e.g., BPMN) are unsuited for this task.

Therefore, novel modeling languages have been proposed. Many of them focus on activities' data requirements and declarative constraints rather than imperative control flow. Fragment-Based Case Management, for example, combines activity-centric imperative process fragments with declarative data requirements. At runtime, fragments can be combined dynamically, and new ones can be added. Yet, no integrated semantics for flexible activity-centric process models and data models exists.

In this thesis, Wickr, a novel case modeling approach extending fragment-based Case Management, is presented. It supports batch processing of data, sharing data among cases, and a full-fledged data model with associations and multiplicity constraints. We develop a translational semantics for Wickr targeting (colored) Petri nets. The semantics assert that a case adheres to the constraints in both the process fragments and the data models. Among other things, multiplicity constraints must not be violated. Furthermore, the semantics are extended to multiple cases that operate on shared data. Wickr shows that the data structure may reflect process behavior and vice versa. Based on its semantics, prototypes for executing and verifying case models showcase the feasibility of  Wickr. Its applicability to knowledge-intensive and to data-centric processes is evaluated using well-known requirements from related work.
N2  - Traditionelle Prozessmodellierungssprachen sind auf hoch strukturierte Prozesse ausgelegt, in denen Daten nur eine Nebenrolle spielen. Sie eignen sich daher nicht für wissensintensive Prozesse, die flexibel und datengetrieben sind. Deshalb können prozessorientierte Informationssysteme Fachexperten nicht gänzlich unterstützen. Diese Arbeit beinhaltet eine neue Modellierungssprache, die flexible Prozessmodelle mit Datenmodellen kombiniert. Die Semantik dieser Sprache ist mittels gefärbten Petri-Netzen formal definiert. Wissensintensive Prozesse können so modelliert, verifiziert und ausgeführt werden.

Wissensintensive Prozesse sind variantenreich und involvieren Fachexperten, die mit ihren Entscheidungen die Prozessausführung prägen. Typische Anwendungsbereiche sind das Gesundheitswesen, Rechtswesen und Versicherungen. Diese Prozesse können i.d.R. nicht vollständig spezifiziert werden, da das zugrundeliegende Wissen zu umfangreich ist und sich außerdem zu schnell verändert. Die genaue Reihenfolge der Aktivitäten wird erst durch die Fachexperten zur Laufzeit festgelegt. Deshalb erfordern dieser Prozesse Flexibilität sowohl zur Entwurfszeit wie zur Laufzeit, Daten und Verhalten müssen in enger Beziehung betrachtet werden. Zudem muss es möglich sein, den Prozess anzupassen, falls eine unvorhergesehene Situation eintreten. Etablierte Prozessmodellierungssprachen, wie z.B. BPMN, sind daher ungeeignet.

Deshalb werden neue Sprachen entwickelt, in denen sich generell zwei Tendenzen beobachten lassen: ein Wechseln von imperativer zu deklarativer Modellierung und eine zunehmende Integration von Daten. Im Fragment-Basierten-Case-Management können imperative Prozessfragmente zur Laufzeit flexibel kombiniert werden, solange spezifizierten Datenanforderungen erfüllt sind.

In dieser Arbeit wird Wickr vorgestellt. Dabei handelt es sich um eine Modellierungssprache, die das
Fragment-Basierte-Case-Management erweitert. Wickr kombiniert Prozessfragmente mit einem Datenmodell inklusive Assoziationen und zwei Arten an Multiplizitätseinschränkungen: Die erste Art muss immer gelten, wohingegen die zweite nur am Ende eines Falls gelten muss. Zusätzlich unterstützt Wickr Stapelverarbeitung und Datenaustausch zwischen Fällen.
Des Weiteren entwickeln wir eine translationale Semantik, die Wickr in gefärbte Petri-Netze übersetzt. Die Semantik berücksichtigt sowohl die Vorgaben des Prozessmodells wie auch die des Datenmodells. Die Semantik eignet sich nicht nur  für die Beschreibung eines einzelnen Falls, sondern kann auch mehrere untereinander in Beziehung stehende Fälle abdecken. Durch Prototypen wird die Umsetzbarkeit von Wickr demonstriert und mittels bekannten Anforderungslisten die Einsatzmöglichkeit für wissensintensive und datengetriebene Prozesse evaluiert.
T2  - Wickr: Eine gemeinsame Semantik für flexible Prozesse und Daten
KW  - Case Management
KW  - Business Process Management
KW  - Process Modeling
KW  - Data Modeling
KW  - Execution Semantics
KW  - Geschäftsprozessmanagement
KW  - Fallmanagement
KW  - Datenmodellierung
KW  - Ausführungssemantiken
KW  - Prozessmodellierung
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-546137
ER  - 
TY  - JOUR
A1  - Ullrich, André
A1  - Vladova, Gergana
A1  - Eigelshoven, Felix
A1  - Renz, André
T1  - Data mining of scientific research on artificial intelligence in teaching and administration in higher education institutions
BT  - a bibliometrics analysis and recommendation for future research
JF  - Discover artificial intelligence
N2  - Teaching and learning as well as administrative processes are still experiencing intensive changes with the rise of artificial intelligence (AI) technologies and its diverse application opportunities in the context of higher education. Therewith, the scientific interest in the topic in general, but also specific focal points rose as well. However, there is no structured overview on AI in teaching and administration processes in higher education institutions that allows to identify major research topics and trends, and concretizing peculiarities and develops recommendations for further action. To overcome this gap, this study seeks to systematize the current scientific discourse on AI in teaching and administration in higher education institutions. This study identified an (1) imbalance in research on AI in educational and administrative contexts, (2) an imbalance in disciplines and lack of interdisciplinary research, (3) inequalities in cross-national research activities, as well as (4) neglected research topics and paths. In this way, a comparative analysis between AI usage in administration and teaching and learning processes, a systematization of the state of research, an identification of research gaps as well as further research path on AI in higher education institutions are contributed to research.
Y1  - 2022
U6  - https://doi.org/10.1007/s44163-022-00031-7
SN  - 2731-0809
VL  - 2
PB  - Springer
CY  - Cham
ER  - 
TY  - THES
A1  - Dehnert, Maik
T1  - Studies on the Digital Transformation of Incumbent Organizations
T1  - Studien zur Digitalen Transformation traditioneller Organisationen
BT  - Causes, Effects and Solutions for Banking
BT  - Ursachen, Wirkungen und Lösungen für das Bankwesen
N2  - Traditional organizations are strongly encouraged by emerging digital customer behavior and digital competition to transform their businesses for the digital age. Incumbents are particularly exposed to the field of tension between maintaining and renewing their business model. Banking is one of the industries most affected by digitalization, with a large stream of digital innovations around Fintech. Most research contributions focus on digital innovations, such as Fintech, but there are only a few studies on the related challenges and perspectives of incumbent organizations, such as traditional banks. Against this background, this dissertation examines the specific causes, effects and solutions for traditional banks in digital transformation − an underrepresented research area so far.

The first part of the thesis examines how digitalization has changed the latent customer expectations in banking and studies the underlying technological drivers of evolving business-to-consumer (B2C) business models. Online consumer reviews are systematized to identify latent concepts of customer behavior and future decision paths as strategic digitalization effects. Furthermore, the service attribute preferences, the impact of influencing factors and the underlying customer segments are uncovered for checking accounts in a discrete choice experiment. The dissertation contributes here to customer behavior research in digital transformation, moving beyond the technology acceptance model. In addition, the dissertation systematizes value proposition types in the evolving discourse around smart products and services as key drivers of business models and market power in the platform economy.

The second part of the thesis focuses on the effects of digital transformation on the strategy development of financial service providers, which are classified along with their firm performance levels. Standard types are derived based on fuzzy-set qualitative comparative analysis (fsQCA), with facade digitalization as one typical standard type for low performing incumbent banks that lack a holistic strategic response to digital transformation. Based on this, the contradictory impact of digitalization measures on key business figures is examined for German savings banks, confirming that the shift towards digital customer interaction was not accompanied by new revenue models diminishing bank profitability. The dissertation further contributes to the discourse on digitalized work designs and the consequences for job perceptions in banking customer advisory. The threefold impact of the IT support perceived in customer interaction on the job satisfaction of customer advisors is disentangled.

In the third part of the dissertation, solutions are developed design-oriented for core action areas of digitalized business models, i.e., data and platforms. A consolidated taxonomy for data-driven business models and a future reference model for digital banking have been developed. The impact of the platform economy is demonstrated here using the example of the market entry by Bigtech. The role-based e3-value modeling is extended by meta-roles and role segments and linked to value co-creation mapping in VDML. In this way, the dissertation extends enterprise modeling research on platform ecosystems and value co-creation using the example of banking.
N2  - Traditionelle Unternehmen sehen sich angesichts des zunehmend digitalen Kundenverhaltens und gesteigerten digitalen Wettbewerbs damit konfrontiert, ihr Geschäftsmodell adäquat für das digitale Zeitalter weiterzuentwickeln. Insbesondere etablierte Unternehmen befinden sich dabei in einem Spannungsfeld aus Bewahrung und Erneuerung. Der Großteil jüngerer Forschungsbeiträge zum Bankwesen fokussiert sich auf digitale Fintech-Innovationen, nur wenige Studien befassen sich mit Herausforderungen und Perspektiven traditioneller Banken. Vor diesem Hintergrund untersucht die Dissertation die Ursachen und Wirkungen der Digitalen Transformation im Bankwesen und zeigt Lösungswege für traditionelle Banken auf.

Der erste Teil der Dissertation untersucht die Ursachen der Digitalen Transformation im Banking. Neuartige Einflussfaktoren und Entscheidungspfade im Kundenverhalten werden als strategische Digitalisierungstreiber für Banken identifiziert. Darauf aufbauend werden in einem Discrete-Choice-Experiment die Präferenzen deutscher Bankkunden hinsichtlich digitaler und nicht-digitaler Dienstleistungsattribute am Beispiel von Girokonten untersucht. Die Arbeit leistet einen über das Technologieakzeptanzmodell hinausgehenden Beitrag zur Erforschung des Kundenverhaltens in der Digitalen Transformation. Ein weiterer Forschungsbeitrag systematisiert anschließend wesentliche Charakteristika smarter Produkte und Dienstleistungen als Treiber von Geschäftsmodellen und Marktmacht in der Plattformökonomie.

Der zweite Teil der Arbeit befasst sich zunächst mit den Auswirkungen der Digitalen Transformation auf die Strategieentwicklung von traditionellen Finanzdienstleistern, die mittels Fallstudien entlang ihres Finanzerfolgs typologisiert werden. Die Fassadendigitalisierung wird als Standardtyp traditioneller Anbieter systematisiert, die zwar zunehmend auf digitale Kundeninteraktion setzen, aber die Geschäftsmodelldimension der Digitalen Transformation vernachlässigen. Darauf aufbauend werden in Panelregressionsanalysen die Auswirkungen der Digitalisierung auf deutsche Sparkassen auf betriebswirtschaftliche Kennzahlen untersucht. Eine weitere quantitative Studie untersucht die Wirkungen neuartiger IT-Beratungswerkzeuge auf die Arbeitszufriedenheit von Bankkundenberatern. Die Dissertation leistet hiermit einen Beitrag zur Transformationsforschung in den Bereichen Bankstrategie und Arbeitsprozesse.

Im dritten Teil der Dissertation werden gestaltungsorientiert Lösungsartefakte für die zentralen Handlungsfelder digitalisierter Geschäftsmodelle - Daten und Plattformen - entwickelt. Dies schließt einerseits eine konsolidierte Taxonomie für datengetriebene Geschäftsmodelle und andererseits ein Referenzmodell für zukünftige plattformbasierte Bankenökosysteme ein. Die rollenbasierte Referenzmodellierungsmethodik e3-value wird um Meta-Rollen und Rollensegmente erweitert, um die die strategischen Auswirkungen plattformbasierter Geschäftsmodelle aufzuzeigen. Hiermit erweitert die Dissertation die Unternehmensmodellierungsforschung im Bereich digitaler Plattform-Ökosysteme am Beispiel des Bankwesens.
KW  - digital transformation
KW  - digitalization
KW  - digital strategy
KW  - consumer behavior
KW  - platform ecosystems
KW  - value co-creation
KW  - Fintech
KW  - incumbent
KW  - bank
KW  - Digitale Transformation
KW  - Digitalisierung
KW  - Digitalstrategie
KW  - Kundenverhalten
KW  - Plattform-Ökosysteme
KW  - Wertschöpfungskooperation
KW  - Fintech
KW  - traditionelle Unternehmen
KW  - Bank
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-548324
ER  - 
TY  - JOUR
A1  - Steinert, Fritjof
A1  - Stabernack, Benno
T1  - Architecture of a low latency H.264/AVC video codec for robust ML based image classification how region of interests can minimize the impact of coding artifacts
JF  - Journal of Signal Processing Systems for Signal, Image, and Video Technology
N2  - The use of neural networks is considered as the state of the art in the field of image classification. A large number of different networks are available for this purpose, which, appropriately trained, permit a high level of classification accuracy. Typically, these networks are applied to uncompressed image data, since a corresponding training was also carried out using image data of similar high quality. However, if image data contains image errors, the classification accuracy deteriorates drastically. This applies in particular to coding artifacts which occur due to image and video compression. Typical application scenarios for video compression are narrowband transmission channels for which video coding is required but a subsequent classification is to be carried out on the receiver side. In this paper we present a special H.264/Advanced Video Codec (AVC) based video codec that allows certain regions of a picture to be coded with near constant picture quality in order to allow a reliable classification using neural networks, whereas the remaining image will be coded using constant bit rate. We have combined this feature with the ability to run with lowest latency properties, which is usually also required in remote control applications scenarios. The codec has been implemented as a fully hardwired High Definition video capable hardware architecture which is suitable for Field Programmable Gate Arrays.
KW  - H.264
KW  - Advanced Video Codec (AVC)
KW  - Low Latency
KW  - Region of Interest
KW  - Machine Learning
KW  - Inference
KW  - FPGA
KW  - Hardware accelerator
Y1  - 2022
U6  - https://doi.org/10.1007/s11265-021-01727-2
SN  - 1939-8018
SN  - 1939-8115
VL  - 94
IS  - 7
SP  - 693
EP  - 708
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Bonifati, Angela
A1  - Mior, Michael J.
A1  - Naumann, Felix
A1  - Noack, Nele Sina
T1  - How inclusive are we?
BT  - an analysis of gender diversity in database venues
JF  - SIGMOD record / Association for Computing Machinery, Special Interest Group on Management of Data
N2  - ACM SIGMOD, VLDB and other database organizations have committed to fostering an inclusive and diverse community, as do many other scientific organizations. Recently, different measures have been taken to advance these goals, especially for underrepresented groups. One possible measure is double-blind reviewing, which aims to hide gender, ethnicity, and other properties of the authors. <br /> We report the preliminary results of a gender diversity analysis of publications of the database community across several peer-reviewed venues, and also compare women's authorship percentages in both single-blind and double-blind venues along the years. We also obtained a cross comparison of the obtained results in data management with other relevant areas in Computer Science.
Y1  - 2022
U6  - https://doi.org/10.1145/3516431.3516438
SN  - 0163-5808
SN  - 1943-5835
VL  - 50
IS  - 4
SP  - 30
EP  - 35
PB  - Association for Computing Machinery
CY  - New York
ER  - 
TY  - JOUR
A1  - Alnoor, Alhamzah
A1  - Tiberius, Victor
A1  - Atiyah, Abbas Gatea
A1  - Khaw, Khai Wah
A1  - Yin, Teh Sin
A1  - Chew, XinYing
A1  - Abbas, Sammar
T1  - How positive and negative electronic word of mouth (eWOM) affects customers’ intention to use social commerce?
BT  - a dual-stage multi group-SEM and ANN analysis
JF  - International journal of human computer interaction
N2  - Advances in Web 2.0 technologies have led to the widespread assimilation of electronic commerce platforms as an innovative shopping method and an alternative to traditional shopping. However, due to pro-technology bias, scholars focus more on adopting technology, and slightly less attention has been given to the impact of electronic word of mouth (eWOM) on customers’ intention to use social commerce. This study addresses the gap by examining the intention through exploring the effect of eWOM on males’ and females’ intentions and identifying the mediation of perceived crowding. To this end, we adopted a dual-stage multi-group structural equation modeling and artificial neural network (SEM-ANN) approach. We successfully extended the eWOM concept by integrating negative and positive factors and perceived crowding. The results reveal the causal and non-compensatory relationships between the constructs. The variables supported by the SEM analysis are adopted as the ANN model’s input neurons. According to the natural significance obtained from the ANN approach, males’ intentions to accept social commerce are related mainly to helping the company, followed by core functionalities. In contrast, females are highly influenced by technical aspects and mishandling. The ANN model predicts customers’ intentions to use social commerce with an accuracy of 97%. We discuss the theoretical and practical implications of increasing customers’ intention toward social commerce channels among consumers based on our findings.
Y1  - 2022
U6  - https://doi.org/10.1080/10447318.2022.2125610
SN  - 1044-7318
SN  - 1532-7590
SP  - 1
EP  - 30
PB  - Taylor & Francis
CY  - New York
ER  - 
TY  - JOUR
A1  - Richly, Keven
A1  - Schlosser, Rainer
A1  - Boissier, Martin
T1  - Budget-conscious fine-grained configuration optimization for spatio-temporal applications
JF  - Proceedings of the VLDB Endowment
N2  - Based on the performance requirements of modern spatio-temporal data mining applications, in-memory database systems are often used to store and process the data. To efficiently utilize the scarce DRAM capacities, modern database systems support various tuning possibilities to reduce the memory footprint (e.g., data compression) or increase performance (e.g., additional indexes). However, the selection of cost and performance balancing configurations is challenging due to the vast number of possible setups consisting of mutually dependent individual decisions. In this paper, we introduce a novel approach to jointly optimize the compression, sorting, indexing, and tiering configuration for spatio-temporal workloads. Further, we consider horizontal data partitioning, which enables the independent application of different tuning options on a fine-grained level. We propose different linear programming (LP) models addressing cost dependencies at different levels of accuracy to compute optimized tuning configurations for a given workload and memory budgets. To yield maintainable and robust configurations, we extend our LP-based approach to incorporate reconfiguration costs as well as a worst-case optimization for potential workload scenarios. Further, we demonstrate on a real-world dataset that our models allow to significantly reduce the memory footprint with equal performance or increase the performance with equal memory size compared to existing tuning heuristics.
KW  - General Earth and Planetary Sciences
KW  - Water Science and Technology
KW  - Geography, Planning and Development
Y1  - 2022
U6  - https://doi.org/10.14778/3565838.3565858
SN  - 2150-8097
VL  - 15
IS  - 13
SP  - 4079
EP  - 4092
PB  - Association for Computing Machinery (ACM)
CY  - [New York]
ER  - 
TY  - BOOK
A1  - Eichenroth, Friedrich
A1  - Rein, Patrick
A1  - Hirschfeld, Robert
T1  - Fast packrat parsing in a live programming environment
BT  - improving left-recursion in parsing expression grammars
T3  - Technische Berichte des Hasso-Plattner-Instituts für Digital Engineering an der Universität Potsdam
N2  - Language developers who design domain-specific languages or new language features need a way to make fast changes to language definitions. Those fast changes require immediate feedback. Also, it should be possible to parse the developed languages quickly to handle extensive sets of code.

Parsing expression grammars provides an easy to understand method for language definitions. Packrat parsing is a method to parse grammars of this kind, but this method is unable to handle left-recursion properly. Existing solutions either partially rewrite left-recursive rules and partly forbid them, or use complex extensions to packrat parsing that are hard to understand and cost-intensive. We investigated methods to make parsing as fast as possible, using easy to follow algorithms while not losing the ability to make fast changes to grammars.

We focused our efforts on two approaches.

One is to start from an existing technique for limited left-recursion rewriting and enhance it to work for general left-recursive grammars. The second approach is to design a grammar compilation process to find left-recursion before parsing, and in this way, reduce computational costs wherever possible and generate ready to use parser classes.

Rewriting parsing expression grammars is a task that, if done in a general way, unveils a large number of cases such that any rewriting algorithm surpasses the complexity of other left-recursive parsing algorithms. Lookahead operators introduce this complexity. However, most languages have only little portions that are left-recursive and in virtually all cases, have no indirect or hidden left-recursion. This means that the distinction of left-recursive parts of grammars from components that are non-left-recursive holds great improvement potential for existing parsers.

In this report, we list all the required steps for grammar rewriting to handle left-recursion, including grammar analysis, grammar rewriting itself, and syntax tree restructuring. Also, we describe the implementation of a parsing expression grammar framework in Squeak/Smalltalk and the possible interactions with the already existing parser Ohm/S. We quantitatively benchmarked this framework directing our focus on parsing time and the ability to use it in a live programming context. Compared with Ohm, we achieved massive parsing time improvements while preserving the ability to use our parser it as a live programming tool.

The work is essential because, for one, we outlined the difficulties and complexity that come with grammar rewriting. Also, we removed the existing limitations that came with left-recursion by eliminating them before parsing.
T3  - Technische Berichte des Hasso-Plattner-Instituts für Digital Engineering an der Universität Potsdam - 135 
KW  - packrat parsing
KW  - parsing expression grammars
KW  - left recursion
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-491242
SN  - 978-3-86956-503-3
SN  - 1613-5652
SN  - 2191-1665
IS  - 135
PB  - Universitätsverlag Potsdam
CY  - Potsdam
ER  - 
TY  - BOOK
A1  - Freund, Rieke
A1  - Rätsch, Jan Philip
A1  - Hradilak, Franziska
A1  - Vidic, Benedikt
A1  - Heß, Oliver
A1  - Lißner, Nils
A1  - Wölert, Hendrik
A1  - Lincke, Jens
A1  - Beckmann, Tom
A1  - Hirschfeld, Robert
T1  - Implementing a crowd-sourced picture archive for Bad Harzburg
N2  - Pictures are a medium that helps make the past tangible and preserve memories. Without context, they are not able to do so. Pictures are brought to life by their associated stories. However, the older pictures become, the fewer contemporary witnesses can tell these stories.
Especially for large, analog picture archives, knowledge and memories are spread over many people. This creates several challenges: First, the pictures must be digitized to save them from decaying and make them available to the public. Since a simple listing of all the pictures is confusing, the pictures should be structured accessibly. Second, known information that makes the stories vivid needs to be added to the pictures. Users should get the opportunity to contribute their knowledge and memories. To make this usable for all interested parties, even for older, less technophile generations, the interface should be intuitive and error-tolerant.
The resulting requirements are not covered in their entirety by any existing software solution without losing the intuitive interface or the scalability of the system.
Therefore, we have developed our digital picture archive within the scope of a bachelor project in cooperation with the Bad Harzburg-Stiftung. For the implementation of this web application, we use the UI framework React in the frontend, which communicates via a GraphQL interface with the Content Management System Strapi in the backend. The use of this system enables our project partner to create an efficient process from scanning analog pictures to presenting them to visitors in an organized and annotated way. To customize the solution for both picture delivery and information contribution for our target group, we designed prototypes and evaluated them with people from Bad Harzburg. This helped us gain valuable insights into our system’s usability and future challenges as well as requirements.
Our web application is already being used daily by our project partner. During the project, we still came up with numerous ideas for additional features to further support the exchange of knowledge.
N2  - Bilder können dabei helfen, die Vergangenheit greifbar zu machen und Erinnerungen zu bewahren, doch alleinstehende Bilder ohne Kontext erreichen das nur schwer. Der große Wert besteht in den Geschichten, die mit den Bildern verbunden sind. Je älter die Bilder jedoch werden, desto weniger Zeitzeugen können von diesen Geschichten berichten.
Besonders für große analoge Bildarchive, bei denen sich das Wissen und die Erinnerungen auf viele Personen verteilen, entstehen dadurch verschiedene Herausforderungen: Zunächst müssen die Bilder digitalisiert werden, um sie vor dem Zerfall zu schützen und um sie der Öffentlichkeit zugänglich machen zu können. Da eine einfache Aufreihung aller Bilder unübersichtlich ist, sollten die Bilder in eine zugängliche Struktur gebracht werden. Des Weiteren müssen zu den Bildern bekannte Informationen, aus denen ihre Geschichten erfahrbar werden, hinzugefügt werden. Nutzende sollen die Möglichkeit haben, eigenes Wissen und Erinnerungen beizutragen. Um dies für alle Interessierten, auch für ältere, evtl. wenig technikaffine Personen, nutzbar zu machen, sollte die Oberfläche eine intuitive und fehlertolerante Nutzung ermöglichen.
Die sich daraus ergebenden Anforderungen werden von keiner existierenden Softwarelösung im Gesamten abgedeckt, ohne die intuitive Oberfläche oder die Skalierbarkeit des Systems zu verlieren.

Daher haben wir im Rahmen eines Bachelorprojekts in Zusammenarbeit mit der Bad Harzburg-Stiftung ein eigenes digitales Bildarchiv entwickelt. Für die Umsetzung dieser Webapplikation nutzen wir das UI-Framework React im Frontend, welches über eine GraphQL-Schnittstelle mit dem Content Management System Strapi im Backend kommuniziert. Die Nutzung dieses Systems ermöglicht unserem Projektpartner einen effizienten Prozess vom Scannen der analogen Bilder bis zum geordneten und annotierten Darstellen für Besuchende. Um die Lösung sowohl für das Bereitstellen der Bilder als auch für das Beitragen von Informationen auf unsere Zielgruppe zuzuschneiden, haben wir Prototypen entworfen und mit Menschen aus Bad Harzburg getestet, um ihre Eindrücke auszuwerten. Mit diesen konnten wir wertvolle Erkenntnisse über die Nutzbarkeit und noch offene Herausforderungen und Anforderungen gewinnen.
Unsere Webanwendung ist bei unserem Projektpartner bereits im täglichen Einsatz. Trotzdem haben wir während des Projekts noch zahlreiche Ideen für zusätzliche Funktionen erarbeitet, um den Wissensaustausch weiter zu fördern.
T3  - Technische Berichte des Hasso-Plattner-Instituts für Digital Engineering an der Universität Potsdam - 149 
KW  - digital picture archive
KW  - analog-to-digital conversion
KW  - user-generated content
KW  - intuitive interfaces
KW  - digitales Bildarchiv
KW  - Analog-zu-Digital-Konvertierung
KW  - benutzergenerierte Inhalte
KW  - intuitive Benutzeroberflächen
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-560291
SN  - 978-3-86956-545-3
SN  - 1613-5652
SN  - 2191-1665
IS  - 149
PB  - Universitätsverlag Potsdam
CY  - Potsdam
ER  - 
TY  - BOOK
A1  - Schneider, Sven
A1  - Maximova, Maria
A1  - Giese, Holger
T1  - Invariant Analysis for Multi-Agent Graph Transformation Systems using k-Induction
N2  - The analysis of behavioral models such as Graph Transformation Systems (GTSs) is of central importance in model-driven engineering. However, GTSs often result in intractably large or even infinite state spaces and may be equipped with multiple or even infinitely many start graphs. To mitigate these problems, static analysis techniques based on finite symbolic representations of sets of states or paths thereof have been devised. We focus on the technique of k-induction for establishing invariants specified using graph conditions. To this end, k-induction generates symbolic paths backwards from a symbolic state representing a violation of a candidate invariant to gather information on how that violation could have been reached possibly obtaining contradictions to assumed invariants. However, GTSs where multiple agents regularly perform actions independently from each other cannot be analyzed using this technique as of now as the independence among backward steps may prevent the gathering of relevant knowledge altogether.

In this paper, we extend k-induction to GTSs with multiple agents thereby supporting a wide range of additional GTSs. As a running example, we consider an unbounded number of shuttles driving on a large-scale track topology, which adjust their velocity to speed limits to avoid derailing. As central contribution, we develop pruning techniques based on causality and independence among backward steps and verify that k-induction remains sound under this adaptation as well as terminates in cases where it did not terminate before.
N2  - Die Analyse von Verhaltensmodellen wie Graphtransformationssystemen (GTSs) ist von zentraler Bedeutung im Model Driven Engineering. GTSs führen jedoch häufig zu unhanhabbar großen oder sogar unendlichen Zustandsräumen und können mit mehreren oder sogar unendlich vielen Startgraphen ausgestattet sein. Um diese Probleme abzumildern, wurden statische Analysetechniken entwickelt, die auf endlichen symbolischen Darstellungen von Mengen von Zuständen oder Pfaden basieren. Wir konzentrieren uns auf die Technik der k-Induktion zur Ermittlung von Invarianten, die unter Verwendung von Graphbedingungen spezifiziert sind. Zum Zweck der Analyse erzeugt die k-Induktion symbolische Rückwärtspfade von einem symbolischen Zustand, der eine Verletzung einer Kandidateninvariante darstellt, um Informationen darüber zu sammeln, wie diese Verletzung erreicht werden konnte, wodurch möglicherweise Widersprüche zu angenommenen Invarianten gefunden werden. GTSs, bei denen mehrere Agenten regelmäßig unabhängig voneinander Aktionen ausführen, können derzeit jedoch nicht mit dieser Technik analysiert werden, da die Unabhängigkeit zwischen Rückwärtsschritten das Sammeln von relevantem Wissen möglicherweise verhindert.

In diesem Artikel erweitern wir die k-Induktion auf GTSs mit mehreren Agenten und unterstützen dadurch eine breite Palette zusätzlicher GTSs. Als laufendes Beispiel betrachten wir eine unbegrenzte Anzahl von Shuttles, die auf einer großen Tracktopologie fahren und die ihre Geschwindigkeit an Geschwindigkeitsbegrenzungen anpassen, um ein Entgleisen zu vermeiden. Als zentralen Beitrag entwickeln wir Beschneidungstechniken basierend auf Kausalität und Unabhängigkeit zwischen Rückwärtsschritten und verifizieren, dass die k-Induktion unter dieser Anpassung korrekt bleibt und in Fällen terminiert, in denen sie zuvor nicht terminierte.
T3  - Technische Berichte des Hasso-Plattner-Instituts für Digital Engineering an der Universität Potsdam - 143 
KW  - k-inductive invariant checking
KW  - causality
KW  - parallel and sequential independence
KW  - symbolic analysis
KW  - bounded backward model checking
KW  - k-induktive Invariantenprüfung
KW  - Kausalität
KW  - parallele und Sequentielle Unabhängigkeit
KW  - symbolische Analyse
KW  - Bounded Backward Model Checking
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-545851
SN  - 978-3-86956-531-6
SN  - 1613-5652
SN  - 2191-1665
IS  - 143
PB  - Universitätsverlag Potsdam
CY  - Potsdam
ER  - 
TY  - BOOK
A1  - Schneider, Sven
A1  - Maximova, Maria
A1  - Giese, Holger
T1  - Probabilistic metric temporal graph logic
N2  - Cyber-physical systems often encompass complex concurrent behavior with timing constraints and probabilistic failures on demand. The analysis whether such systems with probabilistic timed behavior adhere to a given specification is essential. When the states of the system can be represented by graphs, the rule-based formalism of Probabilistic Timed Graph Transformation Systems (PTGTSs) can be used to suitably capture structure dynamics as well as probabilistic and timed behavior of the system. The model checking support for PTGTSs w.r.t. properties specified using Probabilistic Timed Computation Tree Logic (PTCTL) has been already presented. Moreover, for timed graph-based runtime monitoring, Metric Temporal Graph Logic (MTGL) has been developed for stating metric temporal properties on identified subgraphs and their structural changes over time.

In this paper, we (a) extend MTGL to the Probabilistic Metric Temporal Graph Logic (PMTGL) by allowing for the specification of probabilistic properties, (b) adapt our MTGL satisfaction checking approach to PTGTSs, and (c) combine the approaches for PTCTL model checking and MTGL satisfaction checking to obtain a Bounded Model Checking (BMC) approach for PMTGL. In our evaluation, we apply an implementation of our BMC approach in AutoGraph to a running example.
N2  - Cyber-physische Systeme umfassen häufig ein komplexes nebenläufiges Verhalten mit Zeitbeschränkungen und probabilistischen Fehlern auf Anforderung. Die Analyse, ob solche Systeme mit probabilistischem gezeitetem Verhalten einer vorgegebenen Spezifikation entsprechen, ist essentiell. Wenn die Zustände des Systems durch Graphen dargestellt werden können, kann der regelbasierte Formalismus von probabilistischen gezeiteten Graphtransformationssystemen (PTGTSs) verwendet werden, um die Strukturdynamik sowie das probabilistische und gezeitete Verhalten des Systems geeignet zu erfassen. Die Modellprüfungsunterstützung für PTGTSs bzgl. Eigenschaften, die unter Verwendung von Probabilistic Timed Computation Tree Logic (PTCTL) spezifiziert wurden, wurde bereits entwickelt. Darüber hinaus wurde das gezeitete graphenbasierte Laufzeitmonitoring mittels metrischer temporaler Graphlogik (MTGL) entwickelt, um metrische temporale Eigenschaften auf identifizierten Untergraphen und ihre strukturellen Änderungen über die Zeit zu erfassen.

In diesem Artikel (a) erweitern wir MTGL auf die probabilistische metrische temporale Graphlogik (PMTGL), indem wir die Spezifikation probabilistischer Eigenschaften zulassen, (b) passen unseren MTGL-Prüfungsansatz auf PTGTSs an und (c) kombinieren die Ansätze für PTCTL-Modellprüfung und MTGL-Prüfung, um einen beschränkten Modellprüfungsansatz (BMC-Ansatz) für PMTGL zu erhalten. In unserer Auswertung wenden wir eine Implementierung unseres BMC-Ansatzes in AutoGraph auf ein Beispiel an.
T3  - Technische Berichte des Hasso-Plattner-Instituts für Digital Engineering an der Universität Potsdam - 146 
KW  - cyber-physical systems
KW  - probabilistic timed systems
KW  - qualitative analysis
KW  - quantitative analysis
KW  - bounded model checking
KW  - cyber-physische Systeme
KW  - probabilistische gezeitete Systeme
KW  - qualitative Analyse
KW  - quantitative Analyse
KW  - Bounded Model Checking
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-545867
SN  - 978-3-86956-532-3
SN  - 1613-5652
SN  - 2191-1665
IS  - 146
PB  - Universitätsverlag Potsdam
CY  - Potsdam
ER  - 
TY  - BOOK
A1  - Klinke, Paula
A1  - Verhoeven, Silvan
A1  - Roth, Felix
A1  - Hagemann, Linus
A1  - Alnawa, Tarik
A1  - Lincke, Jens
A1  - Rein, Patrick
A1  - Hirschfeld, Robert
T1  - Tool support for collaborative creation of interactive storytelling media
N2  - Scrollytellings are an innovative form of web content. Combining the benefits of books, images, movies, and video games, they are a tool to tell compelling stories and provide excellent learning opportunities. Due to their multi-modality, creating high-quality scrollytellings is not an easy task. Different professions, such as content designers, graphics designers, and developers, need to collaborate to get the best out of the possibilities the scrollytelling format provides. Collaboration unlocks great potential. However, content designers cannot create scrollytellings directly and always need to consult with developers to implement their vision. This can result in misunderstandings. Often, the resulting scrollytelling will not match the designer’s vision sufficiently, causing unnecessary iterations. Our project partner Typeshift specializes in the creation of individualized scrollytellings for their clients. Examined existing solutions for authoring interactive content are not optimally suited for creating highly customized scrollytellings while still being able to manipulate all their elements programmatically. Based on their experience and expertise, we developed an editor to author scrollytellings in the lively.next live-programming environment. In this environment, a graphical user interface for content design is combined with powerful possibilities for programming behavior with the morphic system. The editor allows content designers to take on large parts of the creation process of scrollytellings on their own, such as creating the visible elements, animating content, and fine-tuning the scrollytelling. Hence, developers can focus on interactive elements such as simulations and games. Together with Typeshift, we evaluated the tool by recreating an existing scrollytelling and identified possible future enhancements. Our editor streamlines the creation process of scrollytellings. Content designers and developers can now both work on the same scrollytelling. Due to the editor inside of the lively.next environment, they can both work with a set of tools familiar to them and their traits. Thus, we mitigate unnecessary iterations and misunderstandings by enabling content designers to realize large parts of their vision of a scrollytelling on their own. Developers can add advanced and individual behavior. Thus, developers and content designers benefit from a clearer distribution of tasks while keeping the benefits of collaboration.
N2  - Scrollytellings sind innovative Webinhalte. Indem sie die Vorteile von Büchern, Bildern, Filmen und Videospielen vereinen, sind sie ein Werkzeug um Geschichten fesselnd zu erzählen und Lehrinhalte besonders effektiv zu vermitteln. Die Erstellung von Scrollytellings ist aufgrund ihrer Multimodalität keine einfache Aufgabe. Verschiedene Berufszweige wie Content-Designer:innen, Grafikdesigner:innen und Entwickler:innen müssen zusammenarbeiten, um das volle Potential des Scrollytelingformats auszuschöpfen. Jedoch können ContentDesigner:innen Scrollytellings nicht direkt selbst erstellen, sondern müssen ihre Vision stets gemeinsam mit Entwickler:innen umsetzen. Dabei können unnötige Iterationen über das Scrollytelling auftreten, wenn dieses den Visionen der Content-Designer:innen noch nicht entspricht. Außerdem können Missverständnisse entstehen. Unser Projektpartner Typeshift hat sich auf die Erstellung von, für seine Kund:innen individualisierten, Scrollytellings spezialisiert. Aufbauend auf Typeshifts Erfahrungen und Expertise haben wir einen Editor entwickelt, um Scrollytellings in der Live-Programmierumgebung lively.next zu erstellen. In lively.next wird eine graphische Oberfläche für die Erstellung von Inhalten mit weitreichenden Möglichkeiten zur Programmierung von Verhalten durch das Morphic-System kombiniert. Der Editor erlaubt es Content-Designer:innen eigenständig große Teile des Erstellungsprozesses von Scrollytellings durchzuführen, zum Beispiel das Erzeugen visueller Elemente, deren Animation sowie die Feinjustierung des gesamten Scrollytellings. So können Entwickler:innen sich auf die Erstellung von komplexen interaktiven Elementen, wie Simulationen oder Spiele, konzentrieren. Zusammen mit Typeshift haben wir die Nutzbarkeit unseres Editors durch die Nachbildung eines bereits existierenden Scrollytellings evaluiert und mögliche Verbesserungen identifiziert. Unser Editor vereinfacht den Erstellungsprozess von Scrollytellings. Content Designer:innen und Entwickler:innen können jetzt beide an demselben Scrollytelling arbeiten. Durch den Editor, der in lively.next integriert ist, können beide Parteien mit den ihnen bekannten und vertrauten Werkzeugen arbeiten. Durch den Editor verringern wir unnötige Iterationen und Missverständnisse und erlauben Content-Designer:innen große Teile ihrer Vision eines Scrollytellings eigenständig umzusetzen. Entwickler:innen können zusätzliches, individuelles Verhalten hinzufügen. So profitieren Entwickler:innen und Content-Designer:innen von einer besseren Aufgabenteilung, während die Vorteile von Zusammenarbeit bestehen bleiben.
T3  - Technische Berichte des Hasso-Plattner-Instituts für Digital Engineering an der Universität Potsdam - 141 
KW  - scrollytelling
KW  - interactive media
KW  - web-based development
KW  - Lively Kernel
KW  - Scrollytelling
KW  - interaktive Medien
KW  - webbasierte Entwicklung
KW  - Lively Kernel
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-518570
SN  - 978-3-86956-521-7
SN  - 1613-5652
SN  - 2191-1665
IS  - 141
PB  - Universitätsverlag Potsdam
CY  - Potsdam
ER  - 
TY  - BOOK
A1  - Dürsch, Falco
A1  - Rein, Patrick
A1  - Mattis, Toni
A1  - Hirschfeld, Robert
T1  - Learning from failure
BT  - a history-based, lightweight test prioritization technique connecting software changes to test failures
N2  - Regression testing is a widespread practice in today's software industry to ensure software product quality. Developers derive a set of test cases, and execute them frequently to ensure that their change did not adversely affect existing functionality. As the software product and its test suite grow, the time to feedback during regression test sessions increases, and impedes programmer productivity: developers wait longer for tests to complete, and delays in fault detection render fault removal increasingly difficult.

Test case prioritization addresses the problem of long feedback loops by reordering test cases, such that test cases of high failure probability run first, and test case failures become actionable early in the testing process. We ask, given test execution schedules reconstructed from publicly available data, to which extent can their fault detection efficiency improved, and which technique yields the most efficient test schedules with respect to APFD?

To this end, we recover regression 6200 test sessions from the build log files of Travis CI, a popular continuous integration service, and gather 62000 accompanying changelists. We evaluate the efficiency of current test schedules, and examine the prioritization results of state-of-the-art lightweight, history-based heuristics. We propose and evaluate a novel set of prioritization algorithms, which connect software changes and test failures in a matrix-like data structure.

Our studies indicate that the optimization potential is substantial, because the existing test plans score only 30% APFD. The predictive power of past test failures proves to be outstanding: simple heuristics, such as repeating tests with failures in recent sessions, result in efficiency scores of 95% APFD. The best-performing matrix-based heuristic achieves a similar score of 92.5% APFD. In contrast to prior approaches, we argue that matrix-based techniques are useful beyond the scope of effective prioritization, and enable a number of use cases involving software maintenance.

We validate our findings from continuous integration processes by extending a continuous testing tool within development environments with means of test prioritization, and pose further research questions. We think that our findings are suited to propel adoption of (continuous) testing practices, and that programmers' toolboxes should contain test prioritization as an existential productivity tool.
N2  - Regressionstests sind in der heutigen Softwareindustrie weit verbreitete Praxis um die Qualität eines Softwareprodukts abzusichern. Dabei leiten Entwickler von den gestellten Anforderungen Testfälle ab und führen diese wiederholt aus, um sicherzustellen, dass ihre Änderungen die bereits existierende Funktionalität nicht negativ beeinträchtigen. Steigt die Größe und Komplexität der Software und ihrer Testsuite, so wird die Feedbackschleife der Testausführungen länger, und mindert die Produktivität der Entwickler: Sie warten länger auf das Testergebnis, und die Fehlerbehebung gestaltet sich umso schwieriger, je länger die Ursache zurückliegt.

Um die Feedbackschleife zu verkürzen, ändern Testpriorisierungs-Algorithmen die Reihenfolge der Testfälle, sodass Testfälle, die mit hoher Wahrscheinlichkeit fehlschlagen, zuerst ausgeführt werden. Der vorliegende Bericht beschäftigt sich mit der Frage nach der Effizienz von Testplänen, welche aus öffentlich einsehbaren Daten rekonstruierbar sind, und welche anwendbaren Priorisierungs-Techniken die effizienteste Testreihenfolge in Bezug auf APFD hervorbringen.

Zu diesem Zweck werden 6200 Testsitzungen aus den Logdateien von Travis CI, einem oft verwendeten Dienst für Continuous Integration, und über 62000 Änderungslisten rekonstruiert. Auf dieser Grundlage wird die Effizienz der derzeitigen Testpläne bewertet, als auch solcher, die aus der Neupriorisierung durch leichtgewichtige, verlaufsbasierte Algorithmen hervorgehen. Zudem schlägt der vorliegende Bericht eine neue Gruppe von Ansätzen vor, die Testfehlschläge und Softwareänderungen mit Hilfe einer Matrix in Bezug setzt.

Da die beobachteten Testreihenfolgen nur 30% APFD erzielen, liegt wesentliches Potential für Optimierung vor. Dabei besticht die Vorhersagekraft der unmittelbar vorangegangen Testfehlschläge: einfache Heuristiken, wie das Wiederholen von Tests, welche kürzlich fehlgeschlagen sind, führen zu Testplänen mit einer Effizienz von 95% APFD. Matrix-basierte Ansätze erreichen eine Fehlererkennungsrate von bis zu 92.5% APFD. Im Gegensatz zu den bisher bekannten Ansätzen sind die matrix-basierten Techniken auch über den Zweck der Testpriorisierung hinaus nützlich, und sind in der Softwarewartung anwendbar.

Zusätzlich werden die Ergebnisse der vorliegenden Studie für Continuous Integration Systeme im Kontext integrierter Entwicklungsumgebungen validiert, indem ein Tool für Continuous Testing um Testpriorisierung erweitert wird. Dies führt zu neuen Forschungsfragen. Die Untersuchungsergebnisse sind geeignet die Einführung von Continuous Testing zu befördern, und untermauern, dass Werkzeuge der Testpriorisierung für produktive Softwareentwicklung essenziell sind.
T3  - Technische Berichte des Hasso-Plattner-Instituts für Digital Engineering an der Universität Potsdam - 145 
KW  - test case prioritization
KW  - continuous integration
KW  - regression testing
KW  - version control
KW  - live programming
KW  - heuristics
KW  - data set
KW  - test results
KW  - GitHub
KW  - Java
KW  - Testpriorisierungs
KW  - kontinuierliche Integration
KW  - Regressionstests
KW  - Versionsverwaltung
KW  - Live-Programmierung
KW  - Heuristiken
KW  - Datensatz
KW  - Testergebnisse
KW  - GitHub
KW  - Java
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-537554
SN  - 978-3-86956-528-6
SN  - 1613-5652
SN  - 2191-1665
IS  - 145
PB  - Universitätsverlag Potsdam
CY  - Potsdam
ER  - 
TY  - JOUR
A1  - Bläsius, Thomas
A1  - Friedrich, Tobias
A1  - Lischeid, Julius
A1  - Meeks, Kitty
A1  - Schirneck, Friedrich Martin
T1  - Efficiently enumerating hitting sets of hypergraphs arising in data profiling
JF  - Journal of computer and system sciences : JCSS
N2  - The transversal hypergraph problem asks to enumerate the minimal hitting sets of a hypergraph. If the solutions have bounded size, Eiter and Gottlob [SICOMP'95] gave an algorithm running in output-polynomial time, but whose space requirement also scales with the output. We improve this to polynomial delay and space. Central to our approach is the extension problem, deciding for a set X of vertices whether it is contained in any minimal hitting set. We show that this is one of the first natural problems to be W[3]-complete. We give an algorithm for the extension problem running in time O(m(vertical bar X vertical bar+1) n) and prove a SETH-lower bound showing that this is close to optimal. We apply our enumeration method to the discovery problem of minimal unique column combinations from data profiling. Our empirical evaluation suggests that the algorithm outperforms its worst-case guarantees on hypergraphs stemming from real-world databases.
KW  - Data profiling
KW  - Enumeration algorithm
KW  - Minimal hitting set
KW  - Transversal hypergraph
KW  - Unique column combination
KW  - W[3]-Completeness
Y1  - 2022
U6  - https://doi.org/10.1016/j.jcss.2021.10.002
SN  - 0022-0000
SN  - 1090-2724
VL  - 124
SP  - 192
EP  - 213
PB  - Elsevier
CY  - San Diego
ER  - 
TY  - THES
A1  - Elsaid, Mohamed Esameldin Mohamed
T1  - Virtual machines live migration cost modeling and prediction
T1  - Modellierung und Vorhersage der Live-Migrationskosten für Virtuelle Maschinen
N2  - Dynamic resource management is an essential requirement for private and public cloud computing environments. With dynamic resource management, the physical resources assignment to the cloud virtual resources depends on the actual need of the applications or the running services, which enhances the cloud physical resources utilization and reduces the offered services cost. In addition, the virtual resources can be moved across different physical resources in the cloud environment without an obvious impact on the running applications or services production. This means that the availability of the running services and applications in the cloud is independent on the hardware resources including the servers, switches and storage failures. This increases the reliability of using cloud services compared to the classical data-centers environments.
In this thesis we briefly discuss the dynamic resource management topic and then deeply focus on live migration as the definition of the compute resource dynamic management. Live migration is a commonly used and an essential feature in cloud and virtual data-centers environments. Cloud computing load balance, power saving and fault tolerance features are all dependent on live migration to optimize the virtual and physical resources usage. As we will discuss in this thesis, live migration shows many benefits to cloud and virtual data-centers environments, however the cost of live migration can not be ignored. Live migration cost includes the migration time, downtime, network overhead, power consumption increases and CPU overhead.
IT admins run virtual machines live migrations without an idea about the migration cost. So, resources bottlenecks, higher migration cost and migration failures might happen. The first problem that we discuss in this thesis is how to model the cost of the virtual machines live migration. Secondly, we investigate how to make use of machine learning techniques to help the cloud admins getting an estimation of this cost before initiating the migration for one of multiple virtual machines. Also, we discuss the optimal timing for a specific virtual machine before live migration to another server. Finally, we propose practical solutions that can be used by the cloud admins to be integrated with the cloud administration portals to answer the raised research questions above.
Our research methodology to achieve the project objectives is to propose empirical models based on using VMware test-beds with different benchmarks tools. Then we make use of the machine learning techniques to propose a prediction approach for virtual machines live migration cost. Timing optimization for live migration is also proposed in this thesis based on using the cost prediction and data-centers network utilization prediction. Live migration with persistent memory clusters is also discussed at the end of the thesis. The cost prediction and timing optimization techniques proposed in this thesis could be practically integrated with VMware vSphere cluster portal such that the IT admins can now use the cost prediction feature and timing optimization option before proceeding with a virtual machine live migration.
Testing results show that our proposed approach for VMs live migration cost prediction shows acceptable results with less than 20% prediction error and can be easily implemented and integrated with VMware vSphere as an example of a commonly used resource management portal for virtual data-centers and private cloud environments. The results show that using our proposed VMs migration timing optimization technique also could save up to 51% of migration time of the VMs migration time for memory intensive workloads and up to 27% of the migration time for network intensive workloads. This timing optimization technique can be useful for network admins to save migration time with utilizing higher network rate and higher probability of success.
At the end of this thesis, we discuss the persistent memory technology as a new trend in servers memory technology. Persistent memory modes of operation and configurations are discussed in detail to explain how live migration works between servers with different memory configuration set up. Then, we build a VMware cluster with persistent memory inside server and also with DRAM only servers to show the live migration cost difference between the VMs with DRAM only versus the VMs with persistent memory inside.
N2  - Die dynamische Ressourcenverwaltung ist eine wesentliche Voraussetzung für private und öffentliche Cloud-Computing-Umgebungen. Bei der dynamischen Ressourcenverwaltung hängt die Zuweisung der physischen Ressourcen zu den virtuellen Cloud-Ressourcen vom tatsächlichen Bedarf der Anwendungen oder der laufenden Dienste ab, was die Auslastung der physischen Cloud-Ressourcen verbessert und die Kosten für die angebotenen Dienste reduziert. Darüber hinaus können die virtuellen Ressourcen über verschiedene physische Ressourcen in der Cloud-Umgebung verschoben werden, ohne dass dies einen offensichtlichen Einfluss auf die laufenden Anwendungen oder die Produktion der Dienste hat. Das bedeutet, dass die Verfügbarkeit der laufenden Dienste und Anwendungen in der Cloud unabhängig von den Hardwareressourcen einschließlich der Server, Netzwerke und Speicherausfälle ist. Dies erhöht die Zuverlässigkeit bei der Nutzung von Cloud-Diensten im Vergleich zu klassischen Rechenzentrumsumgebungen.
In dieser Arbeit wird das Thema der dynamischen Ressourcenverwaltung kurz erörtert, um sich dann eingehend mit der Live-Migration als Definition der dynamischen Verwaltung von Compute-Ressourcen zu beschäftigen. Live-Migration ist eine häufig verwendete und wesentliche Funktion in Cloud- und virtuellen Rechenzentrumsumgebungen. Cloud-Computing-Lastausgleich, Energiespar- und Fehlertoleranzfunktionen sind alle von der Live-Migration abhängig, um die Nutzung der virtuellen und physischen Ressourcen zu optimieren. Wie wir in dieser Arbeit erörtern werden, zeigt die Live-Migration viele Vorteile für Cloud- und virtuelle Rechenzentrumsumgebungen, jedoch können die Kosten der Live-Migration nicht ignoriert werden. Zu den Kosten der Live-Migration gehören die Migrationszeit, die Ausfallzeit, der Netzwerk-Overhead, der Anstieg des Stromverbrauchs und der CPU-Overhead.
IT-Administratoren führen Live-Migrationen von virtuellen Maschinen durch, ohne eine Vorstellung von den Migrationskosten zu haben. So kann es zu Ressourcenengpässen, höheren Migrationskosten und Migrationsfehlern kommen. Das erste Problem, das wir in dieser Arbeit diskutieren, ist, wie man die Kosten der Live-Migration virtueller Maschinen modellieren kann. Zweitens untersuchen wir, wie maschinelle Lerntechniken eingesetzt werden können, um den Cloud-Administratoren zu helfen, eine Schätzung dieser Kosten zu erhalten, bevor die Migration für eine oder mehrere virtuelle Maschinen eingeleitet wird. Außerdem diskutieren wir das optimale Timing für eine bestimmte virtuelle Maschine vor der Live-Migration auf einen anderen Server. Schließlich schlagen wir praktische Lösungen vor, die von den Cloud-Admins verwendet werden können, um in die Cloud-Administrationsportale integriert zu werden, um die oben aufgeworfenen Forschungsfragen zu beantworten.
Unsere Forschungsmethodik zur Erreichung der Projektziele besteht darin, empirische Modelle vorzuschlagen, die auf der Verwendung von VMware-Testbeds mit verschiedenen Benchmark-Tools basieren. Dann nutzen wir die Techniken des maschinellen Lernens, um einen Vorhersageansatz für die Kosten der Live-Migration virtueller Maschinen vorzuschlagen. Die Timing-Optimierung für die Live-Migration wird ebenfalls in dieser Arbeit vorgeschlagen, basierend auf der Kostenvorhersage und der Vorhersage der Netzwerkauslastung des Rechenzentrums. Die Live-Migration mit Clustern mit persistentem Speicher wird ebenfalls am Ende der Arbeit diskutiert.
Die in dieser Arbeit vorgeschlagenen Techniken zur Kostenvorhersage und Timing-Optimierung könnten praktisch in das VMware vSphere-Cluster-Portal integriert werden, so dass die IT-Administratoren nun die Funktion zur Kostenvorhersage und die Option zur Timing-Optimierung nutzen können, bevor sie mit einer Live-Migration der virtuellen Maschine fortfahren.
Die Testergebnisse zeigen, dass unser vorgeschlagener Ansatz für die VMs-Live-Migrationskostenvorhersage akzeptable Ergebnisse mit weniger als 20\% Fehler in der Vorhersagegenauigkeit zeigt und leicht implementiert und in VMware vSphere als Beispiel für ein häufig verwendetes Ressourcenmanagement-Portal für virtuelle Rechenzentren und private Cloud-Umgebungen integriert werden kann. Die Ergebnisse zeigen, dass mit der von uns vorgeschlagenen Technik zur Timing-Optimierung der VMs-Migration auch bis zu 51\% der Migrationszeit für speicherintensive Workloads und bis zu 27\% der Migrationszeit für netzwerkintensive Workloads eingespart werden können. Diese Timing-Optimierungstechnik kann für Netzwerkadministratoren nützlich sein, um Migrationszeit zu sparen und dabei eine höhere Netzwerkrate und eine höhere Erfolgswahrscheinlichkeit zu nutzen.
Am Ende dieser Arbeit wird die persistente Speichertechnologie als neuer Trend in der Server-Speichertechnologie diskutiert. Die Betriebsarten und Konfigurationen des persistenten Speichers werden im Detail besprochen, um zu erklären, wie die Live-Migration zwischen Servern mit unterschiedlichen Speicherkonfigurationen funktioniert. Dann bauen wir einen VMware-Cluster mit persistentem Speicher im Server und auch mit Servern nur mit DRAM auf, um den Kostenunterschied bei der Live-Migration zwischen den VMs mit nur DRAM und den VMs mit persistentem Speicher im Server zu zeigen.
KW  - virtual
KW  - cloud
KW  - computing
KW  - machines
KW  - live migration
KW  - machine learning
KW  - prediction
KW  - Wolke
KW  - Computing
KW  - Live-Migration
KW  - maschinelles Lernen
KW  - Maschinen
KW  - Vorhersage
KW  - virtuell
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-540013
ER  - 
TY  - THES
A1  - Bartz, Christian
T1  - Reducing the annotation burden: deep learning for optical character recognition using less manual annotations
N2  - Text is a ubiquitous entity in our world and daily life. We encounter it nearly everywhere in shops, on the street, or in our flats. Nowadays, more and more text is contained in digital images. These images are either taken using cameras, e.g., smartphone cameras, or taken using scanning devices such as document scanners. The sheer amount of available data, e.g., millions of images taken by Google Streetview, prohibits manual analysis and metadata extraction. Although much progress was made in the area of optical character recognition (OCR) for printed text in documents, broad areas of OCR are still not fully explored and hold many research challenges. With the mainstream usage of machine learning and especially deep learning, one of the most pressing problems is the availability and acquisition of annotated ground truth for the training of machine learning models because obtaining annotated training data using manual annotation mechanisms is time-consuming and costly. In this thesis, we address of how we can reduce the costs of acquiring ground truth annotations for the application of state-of-the-art machine learning methods to optical character recognition pipelines. To this end, we investigate how we can reduce the annotation cost by using only a fraction of the typically required ground truth annotations, e.g., for scene text recognition systems. We also investigate how we can use synthetic data to reduce the need of manual annotation work, e.g., in the area of document analysis for archival material. In the area of scene text recognition, we have developed a novel end-to-end scene text recognition system that can be trained using inexact supervision and shows competitive/state-of-the-art performance on standard benchmark datasets for scene text recognition. Our method consists of two independent neural networks, combined using spatial transformer networks. Both networks learn together to perform text localization and text recognition at the same time while only using annotations for the recognition task. We apply our model to end-to-end scene text recognition (meaning localization and recognition of words) and pure scene text recognition without any changes in the network architecture.

In the second part of this thesis, we introduce novel approaches for using and generating synthetic data to analyze handwriting in archival data. First, we propose a novel preprocessing method to determine whether a given document page contains any handwriting. We propose a novel data synthesis strategy to train a classification model and show that our data synthesis strategy is viable by evaluating the trained model on real images from an archive. Second, we introduce the new analysis task of handwriting classification. Handwriting classification entails classifying a given handwritten word image into classes such as date, word, or number. Such an analysis step allows us to select the best fitting recognition model for subsequent text recognition; it also allows us to reason about the semantic content of a given document page without the need for fine-grained text recognition and further analysis steps, such as Named Entity Recognition. We show that our proposed approaches work well when trained on synthetic data. Further, we propose a flexible metric learning approach to allow zero-shot classification of classes unseen during the network’s training. Last, we propose a novel data synthesis algorithm to train off-the-shelf pixel-wise semantic segmentation networks for documents. Our data synthesis pipeline is based on the famous Style-GAN architecture and can synthesize realistic document images with their corresponding segmentation annotation without the need for any annotated data!
N2  - Text umgibt uns überall. Wir finden Text in allen Lebenslagen, z.B. in einem Geschäft, an Gebäuden, oder in unserer Wohnung. Viele dieser Textentitäten können heutzutage auch in digitalen Bildern gefunden werden, welche auf verschiedene Art und Weise erstellt werden können, z.B. mittels einer Kamera in einem Smartphone oder durch einen Dokumentenscanner. Die Anzahl verfügbarer digitaler Bilder, z.B. Millionen – wenn nicht Milliarden von Bildern – in Google Streetview, macht eine manuelle Analyse der Bilddaten unmöglich. Obwohl es im Gebiet der Optical Character Recognition (OCR) in den letzten Jahren viel Fortschritt gab, gibt es doch noch viele Bereiche, die noch nicht vollständig erforscht worden sind. Der immer zunehmende Einsatz von Methoden des maschinellen Lernens, insbesondere der Einsatz von Deep Learning Technologien, im Bereich der OCR, führt zu dem großen Problem der Verfügbarkeit von annotierten Trainingsdaten. Die Beschaffung annotierter Daten mittels manueller Annotation ist zeitintensiv und sehr teuer. In dieser Arbeit zeigen wir neue Wege und Verfahren auf, wie das Problem der Beschaffung annotierter Daten für die Anwendung von modernsten Deep Learning Verfahren im Bereich der OCR gelöst werden könnte. Hierbei zeigen wir neue Verfahren in zwei Unterbereichen der OCR. Einerseits untersuchen wir, wie wir die Annotationskosten reduzieren könnten, indem wir inexakte Annotationen benutzen um z.B. die Kosten der Annotation von echten Daten im Bereich der Texterkennung aus natürlichen Bildern zu reduzieren. Dieses System wird mittels weak supervision trainiert und erreicht Ergebnisse, die auf dem Stand der Technik bzw. darüber liegen. Unsere Methode basiert auf zwei unabhängigen neuronalen Netzwerken, die mittels eines Spatial Transformers verbunden werden. Beide Netzwerke werden zusammen trainiert und lernen zusammen, wie Text gefunden und gelesen werden kann. Dabei nutzen wir aber nur Annotationen und Supervision für das Lesen (recognition) des Textes, nicht für die Textfindung. Wir zeigen weiterhin, dass unser System für eine Mehrzahl von Aufgaben im Bereich der Texterkennung aus natürlichen Bildern genutzt werden kann, ohne Veränderungen im Netzwerk vornehmen zu müssen. Andererseits untersuchen wir, wie wir Verfahren zur Erstellung von synthetischen Daten benutzen können, um die Kosten und den Aufwand der manuellen Annotation zu verringern und zeigen Ergebnisse aus dem Bereich der Analyse von Handschrift in historischen Archivdokumenten. Zuerst präsentieren wir ein System zur Erkennung, ob ein Bild überhaupt Handschrift enthält. Hier schlagen wir eine neue Datengenerierungsmethode vor. Die generierten Daten werden zum Training eines Klassifizierungsmodells genutzt. Unsere experimentellen Ergebnisse belegen, dass unsere Idee auch auf echten Daten aus einem Archiv eingesetzt werden kann.

Als Zweites führen wir einen neuen Schritt in einer Dokumentenanalyseplattform ein: Handschriftklassifizierung. Hier ordnen wir Bilder einzelner handgeschriebener Wörter anhand ihrer visuellen Struktur in Klassen, wie Zahlen, Datumsangaben oder Wörter ein. Die Einführung dieses Analyseschrittes erlaubt es uns den besten Algorithmus für den nächsten Schritt, die eigentliche Handschrifterkennung, zu finden. Der Analyseschritt erlaubt es uns auch, bereits Aussagen über den semantischen Inhalt eines Dokumentes zu treffen, ohne weitere Analyseschritte, wie Named Entity Recognition, durchführen zu müssen. Wir zeigen, dass unser Ansatz sehr gut funktioniert, wenn er auf synthetischen Daten trainiert wird; wir zeigen weiterhin, dass unser Ansatz auch für zero-shot Klassifikation eingesetzt werden kann. Zum Schluss präsentieren wir ein neues Verfahren zur Generierung von Trainingsdaten für die pixelgenaue semantische Segmentierung in Bildern von Dokumenten. Unser Verfahren basiert auf der bekannten StyleGAN Architektur und ist in der Lage Bilder mit entsprechender Annotation automatisch zu generieren. Hierbei werden keine echten annotierten Daten benötigt und das Verfahren kann auf jeder Form von Dokumenten eingesetzt werden.
KW  - computer vision
KW  - optical character recognition
KW  - archive analysis
KW  - data synthesis
KW  - weak supervision
KW  - Archivanalyse
KW  - maschinelles Sehen
KW  - Datensynthese
KW  - Texterkennung
KW  - schwach überwachtes maschinelles Lernen
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-555407
ER  - 
TY  - BOOK
A1  - Meinel, Christoph
A1  - Willems, Christian
A1  - Staubitz, Thomas
A1  - Sauer, Dominic
A1  - Hagedorn, Christiane
T1  - openHPI
T1  - openHPI
BT  - 10 Years of MOOCs at the Hasso Plattner Institute
BT  - 10 Jahre MOOCs am Hasso-Plattner-Institut
N2  - On the occasion of the 10th openHPI anniversary, this technical report provides information about the HPI MOOC platform, including its core features, technology, and architecture.

In an introduction, the platform family with all partner platforms is presented; these now amount to nine platforms, including openHPI. This section introduces openHPI as an advisor and research partner in various projects. 

In the second chapter, the functionalities and common course formats of the platform are presented. The functionalities are divided into learner and admin features. The learner features section provides detailed information about performance records, courses, and the learning materials of which a course is composed: videos, texts, and quizzes. In addition, the learning materials can be enriched by adding external exercise tools that communicate with the HPI MOOC platform via the Learning Tools Interoperability (LTI) standard. Furthermore, the concept of peer assessments completed the possible learning materials.
The section then proceeds with further information on the discussion forum, a fundamental concept of MOOCs compared to traditional e-learning offers. The section is concluded with a description of the quiz recap, learning objectives, mobile applications, gameful learning, and the help desk.

The next part of this chapter deals with the admin features. The described functionality is restricted to describing the news and announcements, dashboards and statistics, reporting capabilities, research options with A/B testing, the course feed, and the TransPipe tool to support the process of creating automated or manual subtitles. The platform supports a large variety of additional features, but a detailed description of these features goes beyond the scope of this report.
The chapter then elaborates on common course formats and openHPI teaching activities at the HPI. The chapter concludes with some best practices for course design and delivery.

The third chapter provides insights into the technology and architecture behind openHPI. A special characteristic of the openHPI project is the conscious decision to operate the complete application from bare metal to platform development. Hence, the chapter starts with a section about the openHPI Cloud, including detailed information about the data center and devices, the used cloud software OpenStack and Ceph, as well as the openHPI Cloud Service provided for the HPI.

Afterward, a section on the application technology stack and development tooling describes the application infrastructure components, the used automation, the deployment pipeline, and the tools used for monitoring and alerting. The chapter is concluded with detailed information about the technology stack and concrete platform implementation details. The section describes the service-oriented Ruby on Rails application, inter-service communication, and public APIs. It also provides more information on the design system and components used in the application. The section concludes with a discussion of the original microservice architecture, where we share our insights and reasoning for migrating back to a monolithic application.

The last chapter provides a summary and an outlook on the future of digital education.
N2  - Anlässlich des 10-jährigen Jubiläums von openHPI informiert dieser technische Bericht über die HPI-MOOC-Plattform einschließlich ihrer Kernfunktionen, Technologie und Architektur.
In einer Einleitung wird die Plattformfamilie mit allen Partnerplattformen vorgestellt; diese belaufen sich inklusive openHPI aktuell auf neun Plattformen. In diesem Abschnitt wird außerdem gezeigt, wie openHPI als Berater und Forschungspartner in verschiedenen Projekten fungiert. 

Im zweiten Kapitel werden die Funktionalitäten und gängigen Kursformate der Plattform präsentiert. Die Funktionalitäten sind in Lerner- und Admin-Funktionen unterteilt. Der Bereich Lernerfunktionen bietet detaillierte Informationen zu Leistungsnachweisen, Kursen und den Lernmaterialien, aus denen sich ein Kurs zusammensetzt: Videos, Texte und Quiz. Darüber hinaus können die Lernmaterialien durch externe Übungstools angereichert werden, die über den Standard Learning Tools Interoperability (LTI) mit der HPI MOOC-Plattform kommunizieren. Das Konzept der Peer-Assessments rundet die möglichen Lernmaterialien ab.
Der Abschnitt geht dann weiter auf das Diskussionsforum ein, das einen grundlegenden Unterschied von MOOCs im Vergleich zu traditionellen E-Learning-Angeboten darstellt. Zum Abschluss des Abschnitts folgen eine Beschreibung von Quiz-Recap, Lernzielen, mobilen Anwendungen, spielerischen Lernens und dem Helpdesk.

Der nächste Teil dieses Kapitels beschäftigt sich mit den Admin-Funktionen. Die Funktionalitätsbeschreibung beschränkt sich Neuigkeiten und Ankündigungen, Dashboards und Statistiken, Berichtsfunktionen, Forschungsoptionen mit A/B-Tests, den Kurs-Feed und das TransPipe-Tool zur Unterstützung beim Erstellen von automatischen oder manuellen Untertiteln. Die Plattform unterstützt außerdem eine Vielzahl zusätzlicher Funktionen, doch eine detaillierte Beschreibung dieser Funktionen würde den Rahmen des Berichts sprengen.
Das Kapitel geht dann auf gängige Kursformate und openHPI-Lehrveranstaltungen am HPI ein, bevor es mit einigen Best Practices für die Gestaltung und Durchführung von Kursen schließt.
Zum Abschluss des technischen Berichts gibt das letzte Kapitel eine Zusammenfassung und einen Ausblick auf die Zukunft der digitalen Bildung. 

Ein besonderes Merkmal des openHPI-Projekts ist die bewusste Entscheidung, die komplette Anwendung von den physischen Netzwerkkomponenten bis zur Plattformentwicklung eigenständig zu betreiben. Bei der vorliegenden deutschen Variante handelt es sich um eine gekürzte Übersetzung des technischen Berichts 148, bei der kein Einblick in die Technologien und Architektur von openHPI gegeben wird. Interessierte Leser:innen können im technischen Bericht 148 (vollständige englische Version) detaillierte Informationen zum Rechenzentrum und den Geräten, der Cloud-Software und dem openHPI Cloud Service aber auch zu Infrastruktur-Anwendungskomponenten wie Entwicklungstools, Automatisierung, Deployment-Pipeline und Monitoring erhalten. Außerdem finden sich dort weitere Informationen über den Technologiestack und konkrete Implementierungsdetails der Plattform inklusive der serviceorientierten Ruby on Rails-Anwendung, die Kommunikation zwischen den Diensten, öffentliche APIs, sowie Designsystem und -komponenten. Der Abschnitt schließt mit einer Diskussion über die ursprüngliche Microservice-Architektur und die Migration zu einer monolithischen Anwendung.
T3  - Technische Berichte des Hasso-Plattner-Instituts für Digital Engineering an der Universität Potsdam - 148 
KW  - openHPI
KW  - MOOC
KW  - digital learning platform
KW  - digital enlightenment
KW  - lifelong learning
KW  - openHPI
KW  - MOOC
KW  - digitale Lernplattform
KW  - digitale Aufklärung
KW  - lebenslanges Lernen
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-560208
SN  - 978-3-86956-544-6
SN  - 1613-5652
SN  - 2191-1665
IS  - 148
PB  - Universitätsverlag Potsdam
CY  - Potsdam
ER  - 
TY  - JOUR
A1  - Ihde, Sven
A1  - Pufahl, Luise
A1  - Völker, Maximilian
A1  - Goel, Asvin
A1  - Weske, Mathias
T1  - A framework for modeling and executing task
BT  - specific resource allocations in business processes
JF  - Computing : archives for informatics and numerical computation
N2  - As resources are valuable assets, organizations have to decide which resources to allocate to business process tasks in a way that the process is executed not only effectively but also efficiently. Traditional role-based resource allocation leads to effective process executions, since each task is performed by a resource that has the required skills and competencies to do so. However, the resulting allocations are typically not as efficient as they could be, since optimization techniques have yet to find their way in traditional business process management scenarios. On the other hand, operations research provides a rich set of analytical methods for supporting problem-specific decisions on resource allocation. This paper provides a novel framework for creating transparency on existing tasks and resources, supporting individualized allocations for each activity in a process, and the possibility to integrate problem-specific analytical methods of the operations research domain. To validate the framework, the paper reports on the design and prototypical implementation of a software architecture, which extends a traditional process engine with a dedicated resource management component. This component allows us to define specific resource allocation problems at design time, and it also facilitates optimized resource allocation at run time. The framework is evaluated using a real-world parcel delivery process. The evaluation shows that the quality of the allocation results increase significantly with a technique from operations research in contrast to the traditional applied rule-based approach.
KW  - Process Execution
KW  - Business Process Management
KW  - Resource Allocation
KW  - Resource Management
KW  - Activity-oriented Optimization
Y1  - 2022
U6  - https://doi.org/10.1007/s00607-022-01093-2
SN  - 0010-485X
SN  - 1436-5057
VL  - 104
SP  - 2405
EP  - 2429
PB  - Springer
CY  - Wien
ER  - 
TY  - JOUR
A1  - Roostapour, Vahid
A1  - Neumann, Aneta
A1  - Neumann, Frank
A1  - Friedrich, Tobias
T1  - Pareto optimization for subset selection with dynamic cost constraints
JF  - Artificial intelligence
N2  - We consider the subset selection problem for function f with constraint bound B that changes over time. Within the area of submodular optimization, various greedy approaches are commonly used. For dynamic environments we observe that the adaptive variants of these greedy approaches are not able to maintain their approximation quality. Investigating the recently introduced POMC Pareto optimization approach, we show that this algorithm efficiently computes a phi=(alpha(f)/2)(1 - 1/e(alpha)f)-approximation, where alpha(f) is the submodularity ratio of f, for each possible constraint bound b <= B. Furthermore, we show that POMC is able to adapt its set of solutions quickly in the case that B increases. Our experimental investigations for the influence maximization in social networks show the advantage of POMC over generalized greedy algorithms. We also consider EAMC, a new evolutionary algorithm with polynomial expected time guarantee to maintain phi approximation ratio, and NSGA-II with two different population sizes as advanced multi-objective optimization algorithm, to demonstrate their challenges in optimizing the maximum coverage problem. Our empirical analysis shows that, within the same number of evaluations, POMC is able to perform as good as NSGA-II under linear constraint, while EAMC performs significantly worse than all considered algorithms in most cases.
KW  - Subset selection
KW  - Submodular function
KW  - Multi-objective optimization
KW  - Runtime analysis
Y1  - 2022
U6  - https://doi.org/10.1016/j.artint.2021.103597
SN  - 0004-3702
SN  - 1872-7921
VL  - 302
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Krasnova, Hanna
A1  - Gundlach, Jana
A1  - Baumann, Annika
T1  - Coming back for more
BT  - the effect of news feed serendipity on social networking site sage
T2  - PACIS 2022 proceedings
N2  - Recent spikes in social networking site (SNS) usage times have launched investigations into reasons for excessive SNS usage. Extending research on social factors (i.e., fear of missing out), this study considers the News Feed setup. More specifically, we suggest that the order of the News Feed (chronological vs. algorithmically assembled posts) affects usage behaviors. Against the background of the variable reward schedule, this study hypothesizes that the different orders exert serendipity differently. Serendipity, termed as unexpected lucky encounters with information, resembles variable rewards. Studies have evidenced a relation between variable rewards and excessive behaviors. Similarly, we hypothesize that order-induced serendipitous encounters affect SNS usage times and explore this link in a two-wave survey with an experimental setup (users using either chronological or algorithmic News Feeds). While theoretically extending explanations for increased SNS usage times by considering the News Feed order, practically the study will offer recommendations for relevant stakeholders.
Y1  - 2022
UR  - https://aisel.aisnet.org/pacis2022/271
SN  - 9781958200018
PB  - AIS Electronic Library (AISeL)
CY  - [Erscheinungsort nicht ermittelbar]
ER  - 
TY  - JOUR
A1  - Ndashimye, Felix
A1  - Hebie, Oumarou
A1  - Tjaden, Jasper
T1  - Effectiveness of WhatsApp for measuring migration in follow-up phone surveys
BT  - lessons from a mode experiment in two low-income countries during COVID contact restrictions
JF  - Social science computer review
N2  - Phone surveys have increasingly become important data collection tools in developing countries, particularly in the context of sudden contact restrictions due to the COVID-19 pandemic. So far, there is limited evidence regarding the potential of the messenger service WhatsApp for remote data collection despite its large global coverage and expanding membership. WhatsApp may offer advantages in terms of reducing panel attrition and cutting survey costs. WhatsApp may offer additional benefits to migration scholars interested in cross-border migration behavior which is notoriously difficult to measure using conventional face-to-face surveys. In this field experiment, we compared the response rates between WhatsApp and interactive voice response (IVR) modes using a sample of 8446 contacts in Senegal and Guinea. At 12%, WhatsApp survey response rates were nearly eight percentage points lower than IVR survey response rates. However, WhatsApp offers higher survey completion rates, substantially lower costs and does not introduce more sample selection bias compared to IVR. We discuss the potential of WhatsApp surveys in low-income contexts and provide practical recommendations for field implementation.
KW  - WhatsApp
KW  - survey mode
KW  - migration
KW  - Covid
KW  - phone
Y1  - 2022
U6  - https://doi.org/10.1177/08944393221111340
SN  - 0894-4393
SN  - 1552-8286
PB  - Sage
CY  - Thousand Oaks
ER  - 
TY  - JOUR
A1  - Spiekermann, Sarah
A1  - Krasnova, Hanna
A1  - Hinz, Oliver
A1  - Baumann, Annika
A1  - Benlian, Alexander
A1  - Gimpel, Henner
A1  - Heimbach, Irina
A1  - Koester, Antonia
A1  - Maedche, Alexander
A1  - Niehaves, Bjoern
A1  - Risius, Marten
A1  - Trenz, Manuel
T1  - Values and ethics in information systems
BT  - a state-of-the-art analysis and avenues for future research
JF  - Business & information systems engineering
Y1  - 2022
U6  - https://doi.org/10.1007/s12599-021-00734-8
SN  - 2363-7005
SN  - 1867-0202
VL  - 64
IS  - 2
SP  - 247
EP  - 264
PB  - Springer Gabler
CY  - Wiesbaden
ER  - 
TY  - BOOK
A1  - Gerken, Stefanie
A1  - Uebernickel, Falk
A1  - de Paula, Danielly
T1  - Design Thinking: a Global Study on Implementation Practices in Organizations
T1  - Design Thinking: eine globale Studie über Implementierungspraktiken in Organisationen
BT  - Past - Present - Future
BT  - Vergangenheit - Gegenwart - Zukunft
N2  - These days design thinking is no longer a “new approach”. Among practitioners, as well as academics, interest in the topic has gathered pace over the last two decades. However, opinions are divided over the longevity of the phenomenon: whether design thinking is merely “old wine in new bottles,” a passing trend, or still evolving as it is being spread to an increasing number of organizations and industries. Despite its growing relevance and the diffusion of design thinking, knowledge on the actual status quo in organizations remains scarce. With a new study, the research team of Prof. Uebernickel and Stefanie Gerken investigates temporal developments and changes in design thinking practices in organizations over the past six years comparing the results of the 2015 “Parts without a whole” study with current practices and future developments. Companies of all sizes and from different parts of the world participated in the survey. The findings from qualitative interviews with experts, i.e., people who have years of knowledge with design thinking, were cross-checked with the results from an exploratory analysis of the survey data. This analysis uncovers significant variances and similarities in how design thinking is interpreted and applied in businesses.
N2  - Heutzutage ist Design Thinking kein "neuer Ansatz" mehr. Unter Praktikern und Akademikern hat das Interesse an diesem Thema in den letzten zwei Jahrzehnten stark zugenommen. Die Meinungen sind jedoch geteilt, ob Design Thinking lediglich "alter Wein in neuen Schläuchen" ist, ein vorübergehender Trend, oder ein sich weiterentwickelndes Phänomen, welches in immer mehr Organisationen und Branchen Fuß fast. Trotz der wachsenden Relevanz und Verbreitung von Design Thinking ist das Wissen über den tatsächlichen Status quo in Organisationen nach wie vor spärlich. Mit einer neuen Studie untersucht das Forschungsteam von Prof. Uebernickel, Stefanie Gerken und Dr. Danielly de Paula die zeitlichen Entwicklungen und Veränderungen von Design Thinking Praktiken in Organisationen über die letzten sechs Jahre und vergleicht die Ergebnisse der Studie "Parts without a whole" aus dem Jahr 2015 mit aktuellen Praktiken und perspektivischen Entwicklungen. An der Studie haben Unternehmen aller Größen und aus verschiedenen Teilen der Welt teilgenommen. Um dem komplexen Untersuchungsgegenstand gerecht zu werden, wurde eine Mixed-Method-Ansatz gewählt: Die Erkenntnisse aus qualitativen Experteninterviews, d.h. Personen, die sich seit Jahren mit dem Thema Design Thinking in der Praxis beschäftigen, wurden mit den Ergebnissen einer quantitativen Analyse von Umfragedaten abgeglichen. Die vorliegende Studie erörtert signifikante Unterschiede und Gemeinsamkeiten bei der Interpretation und Anwendung von Design Thinking in Unternehmen.
KW  - Design Thinking
KW  - Agile
KW  - Implementation in Organizations
KW  - life-centered
KW  - human-centered
KW  - Innovation
KW  - Behavior change
KW  - Problem Solving
KW  - Creative
KW  - Solution Space
KW  - Process
KW  - Mindset
KW  - Tools
KW  - Wicked Problems
KW  - VUCA-World
KW  - Ambiguity
KW  - Interdisciplinary Teams
KW  - Multidisciplinary Teams
KW  - Impact
KW  - Measurement
KW  - Ideation
KW  - Agilität
KW  - agil
KW  - Ambiguität
KW  - Verhaltensänderung
KW  - Kreativität
KW  - Design Thinking
KW  - Ideenfindung
KW  - Auswirkungen
KW  - Implementierung in Organisationen
KW  - Innovation
KW  - interdisziplinäre Teams
KW  - Messung
KW  - Denkweise
KW  - multidisziplinäre Teams
KW  - Problemlösung
KW  - Prozess
KW  - Lösungsraum
KW  - Werkzeuge
KW  - Aktivitäten
KW  - verzwickte Probleme
KW  - menschenzentriert
KW  - lebenszentriert
KW  - VUCA-World
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-534668
SN  - 978-3-86956-525-5
PB  - Universitätsverlag Potsdam
CY  - Potsdam
ER  - 
TY  - BOOK
A1  - Flotterer, Boris
A1  - Maximova, Maria
A1  - Schneider, Sven
A1  - Dyck, Johannes
A1  - Zöllner, Christian
A1  - Giese, Holger
A1  - Hély, Christelle
A1  - Gaucherel, Cédric
T1  - Modeling and Formal Analysis of Meta-Ecosystems with Dynamic Structure using Graph Transformation
T3  - Technische Berichte des Hasso-Plattner-Instituts für Digital Engineering an der Universität Potsdam
N2  - The dynamics of ecosystems is of crucial importance. Various model-based approaches exist to understand and analyze their internal effects. In this paper, we model the space structure dynamics and ecological dynamics of meta-ecosystems using the formal technique of Graph Transformation (short GT). We build GT models to describe how a meta-ecosystem (modeled as a graph) can evolve over time (modeled by GT rules) and to analyze these GT models with respect to qualitative properties such as the existence of structural stabilities. As a case study, we build three GT models describing the space structure dynamics and ecological dynamics of three different savanna meta-ecosystems. The first GT model considers a savanna meta-ecosystem that is limited in space to two ecosystem patches, whereas the other two GT models consider two savanna meta-ecosystems that are unlimited in the number of ecosystem patches and only differ in one GT rule describing how the space structure of the meta-ecosystem grows. In the first two GT models, the space structure dynamics and ecological dynamics of the meta-ecosystem shows two main structural stabilities: the first one based on grassland-savanna-woodland transitions and the second one based on grassland-desert transitions. The transition between these two structural stabilities is driven by high-intensity fires affecting the tree components. In the third GT model, the GT rule for savanna regeneration induces desertification and therefore a collapse of the meta-ecosystem. We believe that GT models provide a complementary avenue to that of existing approaches to rigorously study ecological phenomena.
N2  - Die Dynamik von Ökosystemen ist von entscheidender Bedeutung. Es gibt verschiedene modellbasierte Ansätze, um ihre internen Effekte zu verstehen und zu analysieren. In diesem Beitrag modellieren wir die Raumstrukturdynamik und ökologische Dynamik von Metaökosystemen mit der formalen Technik der Graphtransformation (kurz GT). Wir bauen GT-Modelle, um zu beschreiben, wie sich ein Meta-Ökosystem (modelliert als Graph) im Laufe der Zeit entwickeln kann (modelliert durch GT-Regeln) und analysieren diese GT-Modelle hinsichtlich qualitativer Eigenschaften wie das Vorhandensein struktureller Stabilitäten. Als Fallstudie bauen wir drei GT-Modelle, die die Dynamik der Raumstruktur und die ökologische Dynamik von drei verschiedenen Savannen-Meta-Ökosystemen beschreiben. Das erste GT-Modell betrachtet ein Savannen-Meta-Ökosystem, das räumlich auf zwei Ökosystem-Abschnitte begrenzt ist, während die anderen beiden GT-Modelle zwei Savannen-Meta-Ökosysteme betrachten, die in der Anzahl von Ökosystem-Abschnitten uneingeschränkt sind und sich nur in einer GT-Regel unterscheiden, die beschreibt, wie die Raumstruktur des Meta-Ökosystems wächst. In den ersten beiden GT-Modellen zeigen die Raumstrukturdynamik und die ökologische Dynamik des Metaökosystems zwei Hauptstrukturstabilitäten: die erste basiert auf Grasland-Savannen-Wald-Übergängen und die zweite basiert auf Grasland-Wüsten-Übergängen. Der Übergang zwischen diesen beiden strukturellen Stabilitäten wird durch hochintensive Brände angetrieben, die die Baumkomponenten beeinträchtigen. Beim dritten GT-Modell führt die Savannenregeneration beschreibende GT-Regel zur Wüstenbildung und damit zum Kollaps des Meta-Ökosystems. Wir glauben, dass GT-Modelle eine gute Ergänzung zu bestehenden Ansätzen darstellen, um ökologische Phänomene rigoros zu untersuchen.
T3  - Technische Berichte des Hasso-Plattner-Instituts für Digital Engineering an der Universität Potsdam - 147 
KW  - dynamic systems
KW  - discrete-event model
KW  - qualitative model
KW  - savanna
KW  - trajectories
KW  - desertification
KW  - dynamische Systeme
KW  - diskretes Ereignismodell
KW  - qualitatives Modell
KW  - Savanne
KW  - Trajektorien
KW  - Wüstenbildung
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-547643
SN  - 978-3-86956-533-0
SN  - 1613-5652
SN  - 2191-1665
IS  - 147
PB  - Universitätsverlag Potsdam
CY  - Potsdam
ER  - 
TY  - JOUR
A1  - Gévay, Gábor E.
A1  - Rabl, Tilmann
A1  - Breß, Sebastian
A1  - Madai-Tahy, Loránd
A1  - Quiané-Ruiz, Jorge-Arnulfo
A1  - Markl, Volker
T1  - Imperative or functional control flow handling
BT  - why not the best of both worlds?
JF  - SIGMOD record / Association for Computing Machinery, Special Interest Group on Management of Data
N2  - Modern data analysis tasks often involve control flow statements, such as the iterations in PageRank and K-means. To achieve scalability, developers usually implement these tasks in distributed dataflow systems, such as Spark and Flink. Designers of such systems have to choose between providing imperative or functional control flow constructs to users. Imperative constructs are easier to use, but functional constructs are easier to compile to an efficient dataflow job. We propose Mitos, a system where control flow is both easy to use and efficient. Mitos relies on an intermediate representation based on the static single assignment form. This allows us to abstract away from specific control flow constructs and treat any imperative control flow uniformly both when building the dataflow job and when coordinating the distributed execution.
Y1  - 2022
U6  - https://doi.org/10.1145/3542700.3542715
SN  - 0163-5808
VL  - 51
IS  - 1
SP  - 60
EP  - 67
PB  - Association for Computing Machinery
CY  - New York
ER  - 
TY  - JOUR
A1  - Stauffer, Maxime
A1  - Mengesha, Isaak
A1  - Seifert, Konrad
A1  - Krawczuk, Igor
A1  - Fischer, Jens
A1  - Serugendo, Giovanna Di Marzo
T1  - A computational turn in policy process studies
BT  - coevolving network dynamics of policy change
JF  - Complexity
N2  - The past three decades of policy process studies have seen the emergence of a clear intellectual lineage with regard to complexity. Implicitly or explicitly, scholars have employed complexity theory to examine the intricate dynamics of collective action in political contexts. However, the methodological counterparts to complexity theory, such as computational methods, are rarely used and, even if they are, they are often detached from established policy process theory. Building on a critical review of the application of complexity theory to policy process studies, we present and implement a baseline model of policy processes using the logic of coevolving networks. Our model suggests that an actor's influence depends on their environment and on exogenous events facilitating dialogue and consensus-building. Our results validate previous opinion dynamics models and generate novel patterns. Our discussion provides ground for further research and outlines the path for the field to achieve a computational turn.
Y1  - 2022
U6  - https://doi.org/10.1155/2022/8210732
SN  - 1076-2787
SN  - 1099-0526
VL  - 2022
PB  - Wiley-Hindawi
CY  - London
ER  - 
TY  - JOUR
A1  - Wendering, Philipp
A1  - Nikoloski, Zoran
T1  - COMMIT
BT  - Consideration of metabolite leakage and community composition improves microbial community reconstructions
JF  - PLoS Computational Biology : a new community journal / publ. by the Public Library of Science (PLoS) in association with the International Society for Computational Biology (ISCB)
N2  - Composition and functions of microbial communities affect important traits in diverse hosts, from crops to humans. Yet, mechanistic understanding of how metabolism of individual microbes is affected by the community composition and metabolite leakage is lacking. Here, we first show that the consensus of automatically generated metabolic reconstructions improves the quality of the draft reconstructions, measured by comparison to reference models. We then devise an approach for gap filling, termed COMMIT, that considers metabolites for secretion based on their permeability and the composition of the community. By applying COMMIT with two soil communities from the Arabidopsis thaliana culture collection, we could significantly reduce the gap-filling solution in comparison to filling gaps in individual reconstructions without affecting the genomic support. Inspection of the metabolic interactions in the soil communities allows us to identify microbes with community roles of helpers and beneficiaries. Therefore, COMMIT offers a versatile fully automated solution for large-scale modelling of microbial communities for diverse biotechnological applications. <br /> Author summaryMicrobial communities are important in ecology, human health, and crop productivity. However, detailed information on the interactions within natural microbial communities is hampered by the community size, lack of detailed information on the biochemistry of single organisms, and the complexity of interactions between community members. Metabolic models are comprised of biochemical reaction networks based on the genome annotation, and can provide mechanistic insights into community functions. Previous analyses of microbial community models have been performed with high-quality reference models or models generated using a single reconstruction pipeline. However, these models do not contain information on the composition of the community that determines the metabolites exchanged between the community members. In addition, the quality of metabolic models is affected by the reconstruction approach used, with direct consequences on the inferred interactions between community members. Here, we use fully automated consensus reconstructions from four approaches to arrive at functional models with improved genomic support while considering the community composition. We applied our pipeline to two soil communities from the Arabidopsis thaliana culture collection, providing only genome sequences. Finally, we show that the obtained models have 90% genomic support and demonstrate that the derived interactions are corroborated by independent computational predictions.
Y1  - 2022
U6  - https://doi.org/10.1371/journal.pcbi.1009906
SN  - 1553-734X
SN  - 1553-7358
VL  - 18
IS  - 3
PB  - Public Library of Science
CY  - San Fransisco
ER  - 
TY  - GEN
A1  - Benlian, Alexander
A1  - Wiener, Martin
A1  - Cram, W. Alec
A1  - Krasnova, Hanna
A1  - Maedche, Alexander
A1  - Mohlmann, Mareike
A1  - Recker, Jan
A1  - Remus, Ulrich
T1  - Algorithmic management
BT  - Bright and dark sides, practical implications, and research opportunities
T2  - Zweitveröffentlichungen der Universität Potsdam : Wirtschafts- und Sozialwissenschaftliche Reihe
T3  - Zweitveröffentlichungen der Universität Potsdam : Wirtschafts- und Sozialwissenschaftliche Reihe - 174 
Y1  - 0202
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-607112
SN  - 2363-7005
SN  - 1867-0202
SN  - 1867-5808
IS  - 6
ER  - 
TY  - JOUR
A1  - Benlian, Alexander
A1  - Wiener, Martin
A1  - Cram, W. Alec
A1  - Krasnova, Hanna
A1  - Maedche, Alexander
A1  - Mohlmann, Mareike
A1  - Recker, Jan
A1  - Remus, Ulrich
T1  - Algorithmic management
BT  - bright and dark sides, practical implications, and research opportunities
JF  - Business and information systems engineering
Y1  - 2022
U6  - https://doi.org/10.1007/s12599-022-00764-w
SN  - 2363-7005
SN  - 1867-0202
VL  - 64
IS  - 6
SP  - 825
EP  - 839
PB  - Springer Gabler
CY  - Wiesbaden
ER  - 
TY  - CHAP
A1  - Sultanow, Eldar
A1  - Chircu, Alina
A1  - Wüstemann, Stefanie
A1  - Schwan, André
A1  - Lehmann, Andreas
A1  - Sept, André
A1  - Szymaski, Oliver
A1  - Venkatesan, Sripriya
A1  - Ritterbusch, Georg David
A1  - Teichmann, Malte Rolf
T1  - Metaverse opportunities for the public sector
T2  - International Conference on Information Systems 2022 : Special Interest Group on Big Data : Proceedings
N2  - The metaverse is envisioned as a virtual shared space facilitated by emerging technologies such as virtual reality (VR), augmented reality (AR), the Internet of Things (IoT), 5G, artificial intelligence (AI), big data, spatial computing, and digital twins (Allam et al., 2022; Dwivedi et al., 2022; Ravenscraft, 2022; Wiles, 2022). While still a nascent concept, the metaverse has the potential to “transform the physical world, as well as transport or extend physical activities to a virtual world” (Wiles, 2022). Big data technologies will also be essential in managing the enormous amounts of data created in the metaverse (Sun et al., 2022). Metaverse technologies can offer the public sector a host of benefits, such as simplified information exchange, stronger communication with citizens, better access to public services, or benefiting from a new virtual economy. Implementations are underway in several cities around the world (Geraghty et al., 2022). In this paper, we analyze metaverse opportunities for the public sector and explore their application in the context of Germany’s Federal Employment Agency. Based on an analysis of academic literature and practical examples, we create a capability map for potential metaverse business capabilities for different areas of the public sector (broadly defined). These include education (virtual training and simulation, digital campuses that offer not just online instruction but a holistic university campus experience, etc.), tourism (virtual travel to remote locations and museums, virtual festival participation, etc.), health (employee training – as for emergency situations, virtual simulations for patient treatment – for example, for depression or anxiety, etc.), military (virtual training to experience operational scenarios without being exposed to a real-world threats, practice strategic decision-making, or gain technical knowledge for operating and repairing equipment, etc.), administrative services (document processing, virtual consultations for citizens, etc.), judiciary (AI decision-making aids, virtual proceedings, etc.), public safety (virtual training for procedural issues, special operations, or unusual situations, etc.), emergency management (training for natural disasters, etc.), and city planning (visualization of future development projects and interactive feedback, traffic management, attraction gamification, etc.), among others. We further identify several metaverse application areas for Germany's Federal Employment Agency. These applications can help it realize the goals of the German government for digital transformation that enables faster, more effective, and innovative government services. They include training of employees, training of customers, and career coaching for customers. These applications can be implemented using interactive learning games with AI agents, virtual representations of the organizational spaces, and avatars interacting with each other in these spaces. Metaverse applications will both use big data (to design the virtual environments) and generate big data (from virtual interactions). Issues related to data availability, quality, storage, processing (and related computing power requirements), interoperability, sharing, privacy and security will need to be addressed in these emerging metaverse applications (Sun et al., 2022). Special attention is needed to understand the potential for power inequities (wealth inequity, algorithmic bias, digital exclusion) due to technologies such as VR (Egliston & Carter, 2021), harmful surveillance practices (Bibri & Allam, 2022), and undesirable user behavior or negative psychological impacts (Dwivedi et al., 2022). The results of this exploratory study can inform public sector organizations of emerging metaverse opportunities and enable them to develop plans for action as more of the metaverse technologies become a reality. While the metaverse body of research is still small and research agendas are only now starting to emerge (Dwivedi et al., 2022), this study offers a building block for future development and analysis of metaverse applications.
Y1  - 2022
UR  - https://aisel.aisnet.org/sigbd2022/5/
PB  - AIS
CY  - Atlanta
ER  - 
TY  - GEN
A1  - Seewann, Lena
A1  - Verwiebe, Roland
A1  - Buder, Claudia
A1  - Fritsch, Nina-Sophie
T1  - “Broadcast your gender.”
BT  - A comparison of four text-based classification methods of German YouTube channels
T2  - Zweitveröffentlichungen der Universität Potsdam : Wirtschafts- und Sozialwissenschaftliche Reihe
N2  - Social media platforms provide a large array of behavioral data relevant to social scientific research. However, key information such as sociodemographic characteristics of agents are often missing. This paper aims to compare four methods of classifying social attributes from text. Specifically, we are interested in estimating the gender of German social media creators. By using the example of a random sample of 200 YouTube channels, we compare several classification methods, namely (1) a survey among university staff, (2) a name dictionary method with the World Gender Name Dictionary as a reference list, (3) an algorithmic approach using the website gender-api.com, and (4) a Multinomial Naïve Bayes (MNB) machine learning technique. These different methods identify gender attributes based on YouTube channel names and descriptions in German but are adaptable to other languages. Our contribution will evaluate the share of identifiable channels, accuracy and meaningfulness of classification, as well as limits and benefits of each approach. We aim to address methodological challenges connected to classifying gender attributes for YouTube channels as well as related to reinforcing stereotypes and ethical implications.
T3  - Zweitveröffentlichungen der Universität Potsdam : Wirtschafts- und Sozialwissenschaftliche Reihe - 152 
KW  - text based classification methods
KW  - gender
KW  - YouTube
KW  - machine learning
KW  - authorship attribution
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-566287
SN  - 1867-5808
IS  - 152
ER  - 
TY  - JOUR
A1  - Seewann, Lena
A1  - Verwiebe, Roland
A1  - Buder, Claudia
A1  - Fritsch, Nina-Sophie
T1  - “Broadcast your gender.”
BT  - A comparison of four text-based classification methods of German YouTube channels
JF  - Frontiers in Big Data
N2  - Social media platforms provide a large array of behavioral data relevant to social scientific research. However, key information such as sociodemographic characteristics of agents are often missing. This paper aims to compare four methods of classifying social attributes from text. Specifically, we are interested in estimating the gender of German social media creators. By using the example of a random sample of 200 YouTube channels, we compare several classification methods, namely (1) a survey among university staff, (2) a name dictionary method with the World Gender Name Dictionary as a reference list, (3) an algorithmic approach using the website gender-api.com, and (4) a Multinomial Naïve Bayes (MNB) machine learning technique. These different methods identify gender attributes based on YouTube channel names and descriptions in German but are adaptable to other languages. Our contribution will evaluate the share of identifiable channels, accuracy and meaningfulness of classification, as well as limits and benefits of each approach. We aim to address methodological challenges connected to classifying gender attributes for YouTube channels as well as related to reinforcing stereotypes and ethical implications.
KW  - text based classification methods
KW  - gender
KW  - YouTube
KW  - machine learning
KW  - authorship attribution
Y1  - 2022
U6  - https://doi.org/10.3389/fdata.2022.908636
SN  - 2624-909X
IS  - 5
PB  - Frontiers
CY  - Lausanne, Schweiz
ER  - 
TY  - JOUR
A1  - Chen, Junchao
A1  - Lange, Thomas
A1  - Andjelkovic, Marko
A1  - Simevski, Aleksandar
A1  - Lu, Li
A1  - Krstić, Miloš
T1  - Solar particle event and single event upset prediction from SRAM-based monitor and supervised machine learning
JF  - IEEE transactions on emerging topics in computing / IEEE Computer Society, Institute of Electrical and Electronics Engineers
N2  - The intensity of cosmic radiation may differ over five orders of magnitude within a few hours or days during the Solar Particle Events (SPEs), thus increasing for several orders of magnitude the probability of Single Event Upsets (SEUs) in space-borne electronic systems. Therefore, it is vital to enable the early detection of the SEU rate changes in order to ensure timely activation of dynamic radiation hardening measures. In this paper, an embedded approach for the prediction of SPEs and SRAM SEU rate is presented. The proposed solution combines the real-time SRAM-based SEU monitor, the offline-trained machine learning model and online learning algorithm for the prediction. With respect to the state-of-the-art, our solution brings the following benefits: (1) Use of existing on-chip data storage SRAM as a particle detector, thus minimizing the hardware and power overhead, (2) Prediction of SRAM SEU rate one hour in advance, with the fine-grained hourly tracking of SEU variations during SPEs as well as under normal conditions, (3) Online optimization of the prediction model for enhancing the prediction accuracy during run-time, (4) Negligible cost of hardware accelerator design for the implementation of selected machine learning model and online learning algorithm. The proposed design is intended for a highly dependable and self-adaptive multiprocessing system employed in space applications, allowing to trigger the radiation mitigation mechanisms before the onset of high radiation levels.
KW  - Machine learning
KW  - Single event upsets
KW  - Random access memory
KW  - monitoring
KW  - machine learning algorithms
KW  - predictive models
KW  - space missions
KW  - solar particle event
KW  - single event upset
KW  - machine learning
KW  - online learning
KW  - hardware accelerator
KW  - reliability
KW  - self-adaptive multiprocessing system
Y1  - 2022
U6  - https://doi.org/10.1109/TETC.2022.3147376
SN  - 2168-6750
VL  - 10
IS  - 2
SP  - 564
EP  - 580
PB  - Institute of Electrical and Electronics Engineers
CY  - [New York, NY]
ER  - 
TY  - JOUR
A1  - Taleb, Aiham
A1  - Rohrer, Csaba
A1  - Bergner, Benjamin
A1  - De Leon, Guilherme
A1  - Rodrigues, Jonas Almeida
A1  - Schwendicke, Falk
A1  - Lippert, Christoph
A1  - Krois, Joachim
T1  - Self-supervised learning methods for label-efficient dental caries classification
JF  - Diagnostics : open access journal
N2  - High annotation costs are a substantial bottleneck in applying deep learning architectures to clinically relevant use cases, substantiating the need for algorithms to learn from unlabeled data. 

In this work, we propose employing self-supervised methods. To that end, we trained with three self-supervised algorithms on a large corpus of unlabeled dental images, which contained 38K bitewing radiographs (BWRs). We then applied the learned neural network representations on tooth-level dental caries classification, for which we utilized labels extracted from electronic health records (EHRs). Finally, a holdout test-set was established, which consisted of 343 BWRs and was annotated by three dental professionals and approved by a senior dentist. 

This test-set was used to evaluate the fine-tuned caries classification models. Our experimental results demonstrate the obtained gains by pretraining models using self-supervised algorithms. These include improved caries classification performance (6 p.p. increase in sensitivity) and, most importantly, improved label-efficiency. 
In other words, the resulting models can be fine-tuned using few labels (annotations). 

Our results show that using as few as 18 annotations can produce >= 45% sensitivity, which is comparable to human-level diagnostic performance. 
This study shows that self-supervision can provide gains in medical image analysis, particularly when obtaining labels is costly and expensive.
KW  - unsupervised methods
KW  - self-supervised learning
KW  - representation learning
KW  - dental caries classification
KW  - data driven approaches
KW  - annotation
KW  - efficient deep learning
Y1  - 2022
U6  - https://doi.org/10.3390/diagnostics12051237
SN  - 2075-4418
VL  - 12
IS  - 5
PB  - MDPI
CY  - Basel
ER  - 
TY  - BOOK
A1  - Rana, Kaushik
A1  - Mohapatra, Durga Prasad
A1  - Sidorova, Julia
A1  - Lundberg, Lars
A1  - Sköld, Lars
A1  - Lopes Grim, Luís Fernando
A1  - Sampaio Gradvohl, André Leon
A1  - Cremerius, Jonas
A1  - Siegert, Simon
A1  - Weltzien, Anton von
A1  - Baldi, Annika
A1  - Klessascheck, Finn
A1  - Kalancha, Svitlana
A1  - Lichtenstein, Tom
A1  - Shaabani, Nuhad
A1  - Meinel, Christoph
A1  - Friedrich, Tobias
A1  - Lenzner, Pascal
A1  - Schumann, David
A1  - Wiese, Ingmar
A1  - Sarna, Nicole
A1  - Wiese, Lena
A1  - Tashkandi, Araek Sami
A1  - van der Walt, Estée
A1  - Eloff, Jan H. P.
A1  - Schmidt, Christopher
A1  - Hügle, Johannes
A1  - Horschig, Siegfried
A1  - Uflacker, Matthias
A1  - Najafi, Pejman
A1  - Sapegin, Andrey
A1  - Cheng, Feng
A1  - Stojanovic, Dragan
A1  - Stojnev Ilić, Aleksandra
A1  - Djordjevic, Igor
A1  - Stojanovic, Natalija
A1  - Predic, Bratislav
A1  - González-Jiménez, Mario
A1  - de Lara, Juan
A1  - Mischkewitz, Sven
A1  - Kainz, Bernhard
A1  - van Hoorn, André
A1  - Ferme, Vincenzo
A1  - Schulz, Henning
A1  - Knigge, Marlene
A1  - Hecht, Sonja
A1  - Prifti, Loina
A1  - Krcmar, Helmut
A1  - Fabian, Benjamin
A1  - Ermakova, Tatiana
A1  - Kelkel, Stefan
A1  - Baumann, Annika
A1  - Morgenstern, Laura
A1  - Plauth, Max
A1  - Eberhard, Felix
A1  - Wolff, Felix
A1  - Polze, Andreas
A1  - Cech, Tim
A1  - Danz, Noel
A1  - Noack, Nele Sina
A1  - Pirl, Lukas
A1  - Beilharz, Jossekin Jakob
A1  - De Oliveira, Roberto C. L.
A1  - Soares, Fábio Mendes
A1  - Juiz, Carlos
A1  - Bermejo, Belen
A1  - Mühle, Alexander
A1  - Grüner, Andreas
A1  - Saxena, Vageesh
A1  - Gayvoronskaya, Tatiana
A1  - Weyand, Christopher
A1  - Krause, Mirko
A1  - Frank, Markus
A1  - Bischoff, Sebastian
A1  - Behrens, Freya
A1  - Rückin, Julius
A1  - Ziegler, Adrian
A1  - Vogel, Thomas
A1  - Tran, Chinh
A1  - Moser, Irene
A1  - Grunske, Lars
A1  - Szárnyas, Gábor
A1  - Marton, József
A1  - Maginecz, János
A1  - Varró, Dániel
A1  - Antal, János Benjamin
ED  - Meinel, Christoph
ED  - Polze, Andreas
ED  - Beins, Karsten
ED  - Strotmann, Rolf
ED  - Seibold, Ulrich
ED  - Rödszus, Kurt
ED  - Müller, Jürgen
T1  - HPI Future SOC Lab – Proceedings 2018
N2  - The “HPI Future SOC Lab” is a cooperation of the Hasso Plattner Institute (HPI) and industry partners. Its mission is to enable and promote exchange and interaction between the research community and the industry partners.
  The HPI Future SOC Lab provides researchers with free of charge access to a complete infrastructure of state of the art hard and software. This infrastructure includes components, which might be too expensive for an ordinary research environment, such as servers with up to 64 cores and 2 TB main memory. The offerings address researchers particularly from but not limited to the areas of computer science and business information systems. Main areas of research include cloud computing, parallelization, and In-Memory technologies.
  This technical report presents results of research projects executed in 2018. Selected projects have presented their results on April 17th and November 14th 2017 at the Future SOC Lab Day events.
N2  - Das Future SOC Lab am HPI ist eine Kooperation des Hasso-Plattner-Instituts mit verschiedenen Industriepartnern. Seine Aufgabe ist die Ermöglichung und Förderung des Austausches zwischen Forschungsgemeinschaft und Industrie.
  Am Lab wird interessierten Wissenschaftler:innen eine Infrastruktur von neuester Hard- und Software kostenfrei für Forschungszwecke zur Verfügung gestellt. Dazu zählen Systeme, die im normalen Hochschulbereich in der Regel nicht zu finanzieren wären, bspw. Server mit bis zu 64 Cores und 2 TB Hauptspeicher. Diese Angebote richten sich insbesondere an Wissenschaftler:innen in den Gebieten Informatik und Wirtschaftsinformatik. Einige der Schwerpunkte sind Cloud Computing, Parallelisierung und In-Memory Technologien. 
  In diesem Technischen Bericht werden die Ergebnisse der Forschungsprojekte des Jahres 2018 vorgestellt.  Ausgewählte Projekte stellten ihre Ergebnisse am 17. April und 14. November 2018 im Rahmen des Future SOC Lab Tags vor.
T3  - Technische Berichte des Hasso-Plattner-Instituts für Digital Engineering an der Universität Potsdam - 151 
KW  - Future SOC Lab
KW  - research projects
KW  - multicore architectures
KW  - in-memory technology
KW  - cloud computing
KW  - machine learning
KW  - artifical intelligence
KW  - Future SOC Lab
KW  - Forschungsprojekte
KW  - Multicore Architekturen
KW  - In-Memory Technologie
KW  - Cloud Computing
KW  - maschinelles Lernen
KW  - künstliche Intelligenz
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-563712
SN  - 978-3-86956-547-7
SN  - 1613-5652
SN  - 2191-1665
IS  - 151
PB  - Universitätsverlag Potsdam
CY  - Potsdam
ER  - 
TY  - THES
A1  - Grüner, Andreas
T1  - Towards practical and trust-enhancing attribute aggregation for self-sovereign identity
N2  - Identity management is at the forefront of applications’ security posture. It separates the unauthorised user from the legitimate individual. Identity management models have evolved from the isolated to the centralised paradigm and identity federations. Within this advancement, the identity provider emerged as a trusted third party that holds a powerful position. Allen postulated the novel self-sovereign identity paradigm to establish a new balance. Thus, extensive research is required to comprehend its virtues and limitations. Analysing the new paradigm, initially, we investigate the blockchain-based self-sovereign identity concept structurally. Moreover, we examine trust requirements in this context by reference to patterns. These shapes comprise major entities linked by a decentralised identity provider. By comparison to the traditional models, we conclude that trust in credential management and authentication is removed. Trust-enhancing attribute aggregation based on multiple attribute providers provokes a further trust shift. Subsequently, we formalise attribute assurance trust modelling by a metaframework. It encompasses the attestation and trust network as well as the trust decision process, including the trust function, as central components. A secure attribute assurance trust model depends on the security of the trust function. The trust function should consider high trust values and several attribute authorities. Furthermore, we evaluate classification, conceptual study, practical analysis and simulation as assessment strategies of trust models. For realising trust-enhancing attribute aggregation, we propose a probabilistic approach. The method exerts the principle characteristics of correctness and validity. These values are combined for one provider and subsequently for multiple issuers. We embed this trust function in a model within the self-sovereign identity ecosystem. To practically apply the trust function and solve several challenges for the service provider that arise from adopting self-sovereign identity solutions, we conceptualise and implement an identity broker. The mediator applies a component-based architecture to abstract from a single solution. Standard identity and access management protocols build the interface for applications. We can conclude that the broker’s usage at the side of the service provider does not undermine self-sovereign principles, but fosters the advancement of the ecosystem. The identity broker is applied to sample web applications with distinct attribute requirements to showcase usefulness for authentication and attribute-based access control within a case study.
N2  - Das Identitätsmanagement ist Kernbestandteil der Sicherheitsfunktionen von Applikationen. Es unterscheidet berechtigte Benutzung von illegitimer Verwendung. Die Modelle des Identitätsmanagements haben sich vom isolierten zum zentralisierten Paradigma und darüber hinaus zu Identitätsverbünden weiterentwickelt. Im Rahmen dieser Evolution ist der Identitätsanbieter zu einer mächtigen vertrauenswürdigen dritten Partei aufgestiegen. Zur Etablierung eines bis jetzt noch unvorstellbaren Machtgleichgewichts wurde der Grundgedanke der selbstbestimmten Identität proklamiert. Eine tiefgehende Analyse des neuen Konzepts unterstützt auf essentielle Weise das generelle Verständnis der Vorzüge und Defizite. Bei der Analyse des Modells untersuchen wir zu Beginn strukturelle Komponenten des selbstbestimmten Identitätsmanagements basierend auf der Blockchain Technologie. Anschließend erforschen wir Vertrauensanforderungen in diesem Kontext anhand von Mustern. Diese schematischen Darstellungen illustrieren das Verhältnis der Hauptakteure im Verbund mit einem dezentralisierten Identitätsanbieter. Im Vergleich zu den traditionellen Paradigmen, können wir festellen, dass kein Vertrauen mehr in das Verwalten von Anmeldeinformationen und der korrekten Authentifizierung benötigt wird. Zusätzlich bewirkt die Verwendung von vertrauensfördernder Attributaggregation eine weitere Transformation der Vertrauenssituation. Darauffolgend formalisieren wir die Darstellung von Vertrauensmodellen in Attribute Assurance mit Hilfe eines Meta-Frameworks. Als zentrale Komponenten sind das Attestierungs- und Vertrauensnetzwerk sowie der Vertrauensentscheidungsprozess, einschließlich der Vertrauensfunktion, enthalten. Ein sicheres Vertrauensmodell beruht auf der Sicherheit der Vertrauensfunktion. Hohe Vertrauenswerte sowie mehrere Attributaussteller sollten dafür berücksichtigt werden. Des Weiteren evaluieren wir Klassifikation, die konzeptionelle und praktische Analyse sowie die Simulation als Untersuchungsansätze für Vertrauensmodelle. Für die Umsetzung der vertrauensfördernden Attributaggregation schlagen wir einen wahrscheinlichkeitstheoretischen Ansatz vor. Die entwickelte Methode basiert auf den primären Charakteristiken der Korrektheit und Gültigkeit von Attributen. Diese Indikatoren werden für einen und anschließend für mehrere Merkmalsanbieter kombiniert. Zusätzlich betten wir die daraus entstehende Vertrauensfunktion in ein vollständiges Modell auf Basis des Ökosystem von selbstbestimmten Identitäten ein. Für die praktische Anwendung der Vertrauensfunktion und die Überwindung mehrerer Herausforderungen für den Dienstanbieter, bei der Einführung selbstbestimmter Identitätslösungen, konzipieren und implementieren wir einen Identitätsbroker. Dieser Vermittler besteht aus einer komponentenbasierten Architektur, um von einer dedizierten selbstbestimmten Identitätslösung zu abstrahieren. Zusätzlich bilden etablierte Identitäts- und Zugriffsverwaltungsprotokolle die Schnittstelle zu herkömmlichen Anwendungen. Der Einsatz des Brokers auf der Seite des Dienstanbieters unterminiert nicht die Grundsätze der selbstbestimmten Identität. Im Gegensatz wird die Weiterentwicklung des entsprechenden Ökosystems gefördert. Innerhalb einer Fallstudie wird die Verwendung des Identitätsbrokers bei Anwendungen mit unterschiedlichen Anforderungen an Benutzerattribute betrachtet, um die Nützlichkeit bei der Authentifizierung und Attributbasierten Zugriffskontrolle zu demonstrieren.
KW  - identity
KW  - self-sovereign identity
KW  - trust
KW  - attribute assurance
KW  - Identität
KW  - selbst-souveräne Identitäten
KW  - Vertrauen
KW  - Attributsicherung
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-567450
ER  - 
TY  - GEN
A1  - Panzer, Marcel
A1  - Bender, Benedict
A1  - Gronau, Norbert
T1  - Neural agent-based production planning and control
BT  - an architectural review
T2  - Zweitveröffentlichungen der Universität Potsdam : Wirtschafts- und Sozialwissenschaftliche Reihe
N2  - Nowadays, production planning and control must cope with mass customization, increased fluctuations in demand, and high competition pressures. Despite prevailing market risks, planning accuracy and increased adaptability in the event of disruptions or failures must be ensured, while simultaneously optimizing key process indicators. To manage that complex task, neural networks that can process large quantities of high-dimensional data in real time have been widely adopted in recent years. Although these are already extensively deployed in production systems, a systematic review of applications and implemented agent embeddings and architectures has not yet been conducted. The main contribution of this paper is to provide researchers and practitioners with an overview of applications and applied embeddings and to motivate further research in neural agent-based production. Findings indicate that neural agents are not only deployed in diverse applications, but are also increasingly implemented in multi-agent environments or in combination with conventional methods — leveraging performances compared to benchmarks and reducing dependence on human experience. This not only implies a more sophisticated focus on distributed production resources, but also broadening the perspective from a local to a global scale. Nevertheless, future research must further increase scalability and reproducibility to guarantee a simplified transfer of results to reality.
T3  - Zweitveröffentlichungen der Universität Potsdam : Wirtschafts- und Sozialwissenschaftliche Reihe - 172 
KW  - production planning and control
KW  - machine learning
KW  - neural networks
KW  - systematic literature review
KW  - taxonomy
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-604777
SN  - 1867-5808
ER  - 
TY  - JOUR
A1  - Panzer, Marcel
A1  - Bender, Benedict
A1  - Gronau, Norbert
T1  - Neural agent-based production planning and control
BT  - an architectural review
JF  - Journal of Manufacturing Systems
N2  - Nowadays, production planning and control must cope with mass customization, increased fluctuations in demand, and high competition pressures. Despite prevailing market risks, planning accuracy and increased adaptability in the event of disruptions or failures must be ensured, while simultaneously optimizing key process indicators. To manage that complex task, neural networks that can process large quantities of high-dimensional data in real time have been widely adopted in recent years. Although these are already extensively deployed in production systems, a systematic review of applications and implemented agent embeddings and architectures has not yet been conducted. The main contribution of this paper is to provide researchers and practitioners with an overview of applications and applied embeddings and to motivate further research in neural agent-based production. Findings indicate that neural agents are not only deployed in diverse applications, but are also increasingly implemented in multi-agent environments or in combination with conventional methods — leveraging performances compared to benchmarks and reducing dependence on human experience. This not only implies a more sophisticated focus on distributed production resources, but also broadening the perspective from a local to a global scale. Nevertheless, future research must further increase scalability and reproducibility to guarantee a simplified transfer of results to reality.
KW  - production planning and control
KW  - machine learning
KW  - neural networks
KW  - systematic literature review
KW  - taxonomy
Y1  - 2022
U6  - https://doi.org/10.1016/j.jmsy.2022.10.019
SN  - 0278-6125
SN  - 1878-6642
VL  - 65
SP  - 743
EP  - 766
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - GEN
A1  - Monti, Remo
A1  - Rautenstrauch, Pia
A1  - Ghanbari, Mahsa
A1  - Rani James, Alva
A1  - Kirchler, Matthias
A1  - Ohler, Uwe
A1  - Konigorski, Stefan
A1  - Lippert, Christoph
T1  - Identifying interpretable gene-biomarker associations with functionally informed kernel-based tests in 190,000 exomes
T2  - Zweitveröffentlichungen der Universität Potsdam : Reihe der Digital Engineering Fakultät
N2  - Here we present an exome-wide rare genetic variant association study for 30 blood biomarkers in 191,971 individuals in the UK Biobank. We compare gene- based association tests for separate functional variant categories to increase interpretability and identify 193 significant gene-biomarker associations. Genes associated with biomarkers were ~ 4.5-fold enriched for conferring Mendelian disorders. In addition to performing weighted gene-based variant collapsing tests, we design and apply variant-category-specific kernel-based tests that integrate quantitative functional variant effect predictions for mis- sense variants, splicing and the binding of RNA-binding proteins. For these tests, we present a computationally efficient combination of the likelihood- ratio and score tests that found 36% more associations than the score test alone while also controlling the type-1 error. Kernel-based tests identified 13% more associations than their gene-based collapsing counterparts and had advantages in the presence of gain of function missense variants. We introduce local collapsing by amino acid position for missense variants and use it to interpret associations and identify potential novel gain of function variants in PIEZO1. Our results show the benefits of investigating different functional mechanisms when performing rare-variant association tests, and demonstrate pervasive rare-variant contribution to biomarker variability.
T3  - Zweitveröffentlichungen der Universität Potsdam : Reihe der Digital Engineering Fakultät - 16 
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-586078
IS  - 16
ER  - 
TY  - JOUR
A1  - Monti, Remo
A1  - Rautenstrauch, Pia
A1  - Ghanbari, Mahsa
A1  - Rani James, Alva
A1  - Kirchler, Matthias
A1  - Ohler, Uwe
A1  - Konigorski, Stefan
A1  - Lippert, Christoph
T1  - Identifying interpretable gene-biomarker associations with functionally informed kernel-based tests in 190,000 exomes
JF  - Nature Communications
N2  - Here we present an exome-wide rare genetic variant association study for 30 blood biomarkers in 191,971 individuals in the UK Biobank. We compare gene- based association tests for separate functional variant categories to increase interpretability and identify 193 significant gene-biomarker associations. Genes associated with biomarkers were ~ 4.5-fold enriched for conferring Mendelian disorders. In addition to performing weighted gene-based variant collapsing tests, we design and apply variant-category-specific kernel-based tests that integrate quantitative functional variant effect predictions for mis- sense variants, splicing and the binding of RNA-binding proteins. For these tests, we present a computationally efficient combination of the likelihood- ratio and score tests that found 36% more associations than the score test alone while also controlling the type-1 error. Kernel-based tests identified 13% more associations than their gene-based collapsing counterparts and had advantages in the presence of gain of function missense variants. We introduce local collapsing by amino acid position for missense variants and use it to interpret associations and identify potential novel gain of function variants in PIEZO1. Our results show the benefits of investigating different functional mechanisms when performing rare-variant association tests, and demonstrate pervasive rare-variant contribution to biomarker variability.
Y1  - 2022
U6  - https://doi.org/10.1038/s41467-022-32864-2
SN  - 2041-1723
VL  - 13
PB  - Nature Publishing Group UK
CY  - London
ER  - 
TY  - CHAP
A1  - Hagemann, Linus
A1  - Abramova, Olga
T1  - Crafting audience engagement in social media conversations
BT  - evidence from the U.S. 2020 presidential elections
T2  - Proceedings of the 55th Hawaii International Conference on System Sciences
N2  - Observing inconsistent results in prior studies, this paper applies the elaboration likelihood model to investigate the impact of affective and cognitive cues embedded in social media messages on audience engagement during a political event. Leveraging a rich dataset in the context of the 2020 U.S. presidential elections containing more than 3 million tweets, we found the prominence of both cue types. For the overall sample, positivity and sentiment are negatively related to engagement. In contrast, the post-hoc sub-sample analysis of tweets from famous users shows that emotionally charged content is more engaging. The role of sentiment decreases when the number of followers grows and ultimately becomes insignificant for Twitter participants with a vast number of followers. Prosocial orientation (“we-talk”) is consistently associated with more likes, comments, and retweets in the overall sample and sub-samples.
KW  - mediated conversation
KW  - big data
KW  - engagement
KW  - sentiment analysis
KW  - social media
Y1  - 2022
SN  - 978-0-9981331-5-7
SP  - 3222
EP  - 3231
PB  - HICSS Conference Office University of Hawaii at Manoa
CY  - Honolulu
ER  - 
TY  - JOUR
A1  - Wittig, Alice
A1  - Miranda, Fabio Malcher
A1  - Hölzer, Martin
A1  - Altenburg, Tom
A1  - Bartoszewicz, Jakub Maciej
A1  - Beyvers, Sebastian
A1  - Dieckmann, Marius Alfred
A1  - Genske, Ulrich
A1  - Giese, Sven Hans-Joachim
A1  - Nowicka, Melania
A1  - Richard, Hugues
A1  - Schiebenhoefer, Henning
A1  - Schmachtenberg, Anna-Juliane
A1  - Sieben, Paul
A1  - Tang, Ming
A1  - Tembrockhaus, Julius
A1  - Renard, Bernhard Y.
A1  - Fuchs, Stephan
T1  - CovRadar
BT  - continuously tracking and filtering SARS-CoV-2 mutations for genomic surveillance
JF  - Bioinformatics
N2  - The ongoing pandemic caused by SARS-CoV-2 emphasizes the importance of genomic surveillance to understand the evolution of the virus, to monitor the viral population, and plan epidemiological responses. Detailed analysis, easy visualization and intuitive filtering of the latest viral sequences are powerful for this purpose. We present CovRadar, a tool for genomic surveillance of the SARS-CoV-2 Spike protein. CovRadar consists of an analytical pipeline and a web application that enable the analysis and visualization of hundreds of thousand sequences. First, CovRadar extracts the regions of interest using local alignment, then builds a multiple sequence alignment, infers variants and consensus and finally presents the results in an interactive app, making accessing and reporting simple, flexible and fast.
Y1  - 2022
U6  - https://doi.org/10.1093/bioinformatics/btac411
SN  - 1367-4803
SN  - 1367-4811
VL  - 38
IS  - 17
SP  - 4223
EP  - 4225
PB  - Oxford Univ. Press
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Wiemker, Veronika
A1  - Bunova, Anna
A1  - Neufeld, Maria
A1  - Gornyi, Boris
A1  - Yurasova, Elena
A1  - Konigorski, Stefan
A1  - Kalinina, Anna
A1  - Kontsevaya, Anna
A1  - Ferreira-Borges, Carina
A1  - Probst, Charlotte
T1  - Pilot study to evaluate usability and acceptability of the 'Animated Alcohol Assessment Tool' in Russian primary healthcare
JF  - Digital health
N2  - Background and aims: Accurate and user-friendly assessment tools quantifying alcohol consumption are a prerequisite to effective prevention and treatment programmes, including Screening and Brief Intervention. Digital tools offer new potential in this field. We developed the ‘Animated Alcohol Assessment Tool’ (AAA-Tool), a mobile app providing an interactive version of the World Health Organization's Alcohol Use Disorders Identification Test (AUDIT) that facilitates the description of individual alcohol consumption via culturally informed animation features. This pilot study evaluated the Russia-specific version of the Animated Alcohol Assessment Tool with regard to (1) its usability and acceptability in a primary healthcare setting, (2) the plausibility of its alcohol consumption assessment results and (3) the adequacy of its Russia-specific vessel and beverage selection. Methods: Convenience samples of 55 patients (47% female) and 15 healthcare practitioners (80% female) in 2 Russian primary healthcare facilities self-administered the Animated Alcohol Assessment Tool and rated their experience on the Mobile Application Rating Scale – User Version. Usage data was automatically collected during app usage, and additional feedback on regional content was elicited in semi-structured interviews. Results: On average, patients completed the Animated Alcohol Assessment Tool in 6:38 min (SD = 2.49, range = 3.00–17.16). User satisfaction was good, with all subscale Mobile Application Rating Scale – User Version scores averaging >3 out of 5 points. A majority of patients (53%) and practitioners (93%) would recommend the tool to ‘many people’ or ‘everyone’. Assessed alcohol consumption was plausible, with a low number (14%) of logically impossible entries. Most patients reported the Animated Alcohol Assessment Tool to reflect all vessels (78%) and all beverages (71%) they typically used. Conclusion: High acceptability ratings by patients and healthcare practitioners, acceptable completion time, plausible alcohol usage assessment results and perceived adequacy of region-specific content underline the Animated Alcohol Assessment Tool's potential to provide a novel approach to alcohol assessment in primary healthcare. After its validation, the Animated Alcohol Assessment Tool might contribute to reducing alcohol-related harm by facilitating Screening and Brief Intervention implementation in Russia and beyond.
KW  - Alcohol use assessment
KW  - Alcohol Use Disorders Identification Test
KW  - screening tools
KW  - digital health
KW  - mobile applications
KW  - Russia
KW  - primary healthcare
KW  - usability
KW  - acceptability
Y1  - 2022
U6  - https://doi.org/10.1177/20552076211074491
SN  - 2055-2076
VL  - 8
PB  - Sage Publications
CY  - London
ER  - 
TY  - THES
A1  - Jiang, Lan
T1  - Discovering metadata in data files
N2  - It is estimated that data scientists spend up to 80% of the time exploring, cleaning, and transforming their data. A major reason for that expenditure is the lack of knowledge about the used data, which are often from different sources and have heterogeneous structures. As a means to describe various properties of data, metadata can help data scientists understand and prepare their data, saving time for innovative and valuable data analytics. However, metadata do not always exist: some data file formats are not capable of storing them; metadata were deleted for privacy concerns; legacy data may have been produced by systems that were not designed to store and handle meta- data. As data are being produced at an unprecedentedly fast pace and stored in diverse formats, manually creating metadata is not only impractical but also error-prone, demanding automatic approaches for metadata detection.

In this thesis, we are focused on detecting metadata in CSV files – a type of plain-text file that, similar to spreadsheets, may contain different types of content at arbitrary positions. We propose a taxonomy of metadata in CSV files and specifically address the discovery of three different metadata: line and cell type, aggregations, and primary keys and foreign keys.

Data are organized in an ad-hoc manner in CSV files, and do not follow a fixed structure, which is assumed by common data processing tools. Detecting the structure of such files is a prerequisite of extracting information from them, which can be addressed by detecting the semantic type, such as header, data, derived, or footnote, of each line or each cell. We propose the supervised- learning approach Strudel to detect the type of lines and cells. CSV files may also include aggregations. An aggregation represents the arithmetic relationship between a numeric cell and a set of other numeric cells. Our proposed AggreCol algorithm is capable of detecting aggregations of five arithmetic functions in CSV files. Note that stylistic features, such as font style and cell background color, do not exist in CSV files. Our proposed algorithms address the respective problems by using only content, contextual, and computational features.

Storing a relational table is also a common usage of CSV files. Primary keys and foreign keys are important metadata for relational databases, which are usually not present for database instances dumped as plain-text files. We propose the HoPF algorithm to holistically detect both constraints in relational databases. Our approach is capable of distinguishing true primary and foreign keys from a great amount of spurious unique column combinations and inclusion dependencies, which can be detected by state-of-the-art data profiling algorithms.
N2  - Schätzungen zufolge verbringen Datenwissenschaftler bis zu 80% ihrer Zeit mit der Erkundung, Bereinigung und Umwandlung ihrer Daten. Ein Hauptgrund für diesen Aufwand ist das fehlende Wissen über die verwendeten Daten, die oft aus unterschiedlichen Quellen stammen und heterogene Strukturen aufweisen.
Als Mittel zur Beschreibung verschiedener Dateneigenschaften können Metadaten Datenwissenschaftlern dabei helfen, ihre Daten zu verstehen und aufzubereiten, und so wertvolle Zeit die Datenanalysen selbst sparen.
Metadaten sind jedoch nicht immer vorhanden: Zum Beispiel sind einige Dateiformate nicht in der Lage, sie zu speichern; Metadaten können aus Datenschutzgründen gelöscht worden sein; oder ältere Daten wurden möglicherweise von Systemen erzeugt, die nicht für die Speicherung und Verarbeitung von Metadaten konzipiert waren. Da Daten in einem noch nie dagewesenen Tempo produziert und in verschiedenen Formaten gespeichert werden, ist die manuelle Erstellung von Metadaten nicht nur unpraktisch, sondern auch fehleranfällig, so dass automatische Ansätze zur Metadatenerkennung erforderlich sind.

In dieser Arbeit konzentrieren wir uns auf die Erkennung von Metadaten in CSV-Dateien - einer Art von Klartextdateien, die, ähnlich wie Tabellenkalkulationen, verschiedene Arten von Inhalten an beliebigen Positionen enthalten können. Wir schlagen eine Taxonomie der Metadaten in CSV-Dateien vor und befassen uns speziell mit der Erkennung von drei verschiedenen Metadaten: Zeile und Zellensemantischer Typ, Aggregationen sowie Primärschlüssel und Fremdschlüssel.

Die Daten sind in CSV-Dateien ad-hoc organisiert und folgen keiner festen Struktur, wie sie von gängigen Datenverarbeitungsprogrammen angenommen wird. Die Erkennung der Struktur solcher Dateien ist eine Voraussetzung für die Extraktion von Informationen aus ihnen, die durch die Erkennung des semantischen Typs jeder Zeile oder jeder Zelle, wie z. B. Kopfzeile, Daten, abgeleitete Daten oder Fußnote, angegangen werden kann. Wir schlagen den Ansatz des überwachten Lernens, genannt „Strudel“ vor, um den strukturellen Typ von Zeilen und Zellen zu klassifizieren. CSV-Dateien können auch Aggregationen enthalten. Eine Aggregation stellt die arithmetische Beziehung zwischen einer numerischen Zelle und einer Reihe anderer numerischer Zellen dar. Der von uns vorgeschlagene „Aggrecol“-Algorithmus ist in der Lage, Aggregationen von fünf arithmetischen Funktionen in CSV-Dateien zu erkennen. Da stilistische Merkmale wie Schriftart und Zellhintergrundfarbe in CSV-Dateien nicht vorhanden sind, die von uns vorgeschlagenen Algorithmen die entsprechenden Probleme, indem sie nur die Merkmale Inhalt, Kontext und Berechnungen verwenden.

Die Speicherung einer relationalen Tabelle ist ebenfalls eine häufige Verwendung von CSV-Dateien. Primär- und Fremdschlüssel sind wichtige Metadaten für relationale Datenbanken, die bei Datenbankinstanzen, die als reine Textdateien gespeichert werden, normalerweise nicht vorhanden sind. Wir schlagen den „HoPF“-Algorithmus vor, um beide Constraints in relationalen Datenbanken ganzheitlich zu erkennen. Unser Ansatz ist in der Lage, echte Primär- und Fremdschlüssel von einer großen Menge an falschen eindeutigen Spaltenkombinationen und Einschlussabhängigkeiten zu unterscheiden, die von modernen Data-Profiling-Algorithmen erkannt werden können.
KW  - data preparation
KW  - metadata detection
KW  - data wrangling
KW  - Datenaufbereitung
KW  - Datentransformation
KW  - Erkennung von Metadaten
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-566204
ER  - 
TY  - JOUR
A1  - Rosin, Paul L.
A1  - Lai, Yu-Kun
A1  - Mould, David
A1  - Yi, Ran
A1  - Berger, Itamar
A1  - Doyle, Lars
A1  - Lee, Seungyong
A1  - Li, Chuan
A1  - Liu, Yong-Jin
A1  - Semmo, Amir
A1  - Shamir, Ariel
A1  - Son, Minjung
A1  - Winnemöller, Holger
T1  - NPRportrait 1.0: A three-level benchmark for non-photorealistic rendering of portraits
JF  - Computational visual media
N2  - Recently, there has been an upsurge of activity in image-based non-photorealistic rendering (NPR), and in particular portrait image stylisation, due to the advent of neural style transfer (NST). However, the state of performance evaluation in this field is poor, especially compared to the norms in the computer vision and machine learning communities. Unfortunately, the task of evaluating image stylisation is thus far not well defined, since it involves subjective, perceptual, and aesthetic aspects. To make progress towards a solution, this paper proposes a new structured, three-level, benchmark dataset for the evaluation of stylised portrait images. Rigorous criteria were used for its construction, and its consistency was validated by user studies. Moreover, a new methodology has been developed for evaluating portrait stylisation algorithms, which makes use of the different benchmark levels as well as annotations provided by user studies regarding the characteristics of the faces. We perform evaluation for a wide variety of image stylisation methods (both portrait-specific and general purpose, and also both traditional NPR approaches and NST) using the new benchmark dataset.
KW  - non-photorealistic rendering (NPR)
KW  - image stylization
KW  - style transfer
KW  - portrait
KW  - evaluation
KW  - benchmark
Y1  - 2022
U6  - https://doi.org/10.1007/s41095-021-0255-3
SN  - 2096-0433
SN  - 2096-0662
VL  - 8
IS  - 3
SP  - 445
EP  - 465
PB  - Springer Nature
CY  - London
ER  - 
TY  - JOUR
A1  - Ulrich, Jens-Uwe
A1  - Lutfi, Ahmad
A1  - Rutzen, Kilian
A1  - Renard, Bernhard Y.
T1  - ReadBouncer
BT  - precise and scalable adaptive sampling for nanopore sequencing
JF  - Bioinformatics
N2  - Motivation: 
Nanopore sequencers allow targeted sequencing of interesting nucleotide sequences by rejecting other sequences from individual pores. This feature facilitates the enrichment of low-abundant sequences by depleting overrepresented ones in-silico. Existing tools for adaptive sampling either apply signal alignment, which cannot handle human-sized reference sequences, or apply read mapping in sequence space relying on fast graphical processing units (GPU) base callers for real-time read rejection. Using nanopore long-read mapping tools is also not optimal when mapping shorter reads as usually analyzed in adaptive sampling applications. 

Results: 
Here, we present a new approach for nanopore adaptive sampling that combines fast CPU and GPU base calling with read classification based on Interleaved Bloom Filters. ReadBouncer improves the potential enrichment of low abundance sequences by its high read classification sensitivity and specificity, outperforming existing tools in the field. It robustly removes even reads belonging to large reference sequences while running on commodity hardware without GPUs, making adaptive sampling accessible for in-field researchers. Readbouncer also provides a user-friendly interface and installer files for end-users without a bioinformatics background.
Y1  - 2022
U6  - https://doi.org/10.1093/bioinformatics/btac223
SN  - 1367-4803
SN  - 1367-4811
VL  - 38
IS  - SUPPL 1
SP  - 153
EP  - 160
PB  - Oxford Univ. Press
CY  - Oxford
ER  -