TY - JOUR
A1 - von Steinau-Steinrück, Robert
A1 - Beismann, Lukas
T1 - (Corona-)Homeoffice und betriebliche Übung
JF - NJW spezial
N2 - Homeoffice und mobiles Arbeiten haben sich infolge der Covid-19-Pandemie bei vielen Unternehmen bekanntlich etabliert. Die Anweisung bzw. „Duldung“ des Homeoffice beruhte allerdings meist mehr auf tatsächlicher als auf rechtlicher Grundlage. Letztere könnte aber aus betrieblicher Übung erwachsen. Dieser Beitrag geht dem rechtlichen Rahmen dafür nach.
Y1 - 2020
UR - https://beck-online.beck.de/Bcid/Y-300-Z-NJW-SPEZIAL-B-2020-S-626-N-1
SN - 1613-4621
VL - 17
IS - 20
SP - 626
EP - 627
PB - C.H. Beck
CY - München
ER -
TY - CHAP
T1 - 11. Workshop Testmethoden und Zuverlässigkeit von Schaltungen und Systemen
BT - vom 28. Februar bis 2. März, Potsdam-Hermannswerder, Inselhotel
Y1 - 1999
SN - 978-3-9806494-1-4
PB - Universitätsverlag Potsdam
CY - Potsdam
ER -
TY - JOUR
A1 - Kaitoua, Abdulrahman
A1 - Rabl, Tilmann
A1 - Markl, Volker
T1 - A distributed data exchange engine for polystores
JF - Information technology : methods and applications of informatics and information technology
JF - Information technology : Methoden und innovative Anwendungen der Informatik und Informationstechnik
N2 - There is an increasing interest in fusing data from heterogeneous sources. Combining data sources increases the utility of existing datasets, generating new information and creating services of higher quality. A central issue in working with heterogeneous sources is data migration: In order to share and process data in different engines, resource intensive and complex movements and transformations between computing engines, services, and stores are necessary.
Muses is a distributed, high-performance data migration engine that is able to interconnect distributed data stores by forwarding, transforming, repartitioning, or broadcasting data among distributed engines' instances in a resource-, cost-, and performance-adaptive manner. As such, it performs seamless information sharing across all participating resources in a standard, modular manner. We show an overall improvement of 30 % for pipelining jobs across multiple engines, even when we count the overhead of Muses in the execution time. This performance gain implies that Muses can be used to optimise large pipelines that leverage multiple engines.
KW - distributed systems
KW - data migration
KW - data transformation
KW - big data
KW - engine
KW - data integration
Y1 - 2020
U6 - https://doi.org/10.1515/itit-2019-0037
SN - 1611-2776
SN - 2196-7032
VL - 62
IS - 3-4
SP - 145
EP - 156
PB - De Gruyter
CY - Berlin
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 - Kreowsky, Philipp
A1 - Stabernack, Christian Benno
T1 - A full-featured FPGA-based pipelined architecture for SIFT extraction
JF - IEEE access : practical research, open solutions / Institute of Electrical and Electronics Engineers
N2 - Image feature detection is a key task in computer vision. Scale Invariant Feature Transform (SIFT) is a prevalent and well known algorithm for robust feature detection. However, it is computationally demanding and software implementations are not applicable for real-time performance. In this paper, a versatile and pipelined hardware implementation is proposed, that is capable of computing keypoints and rotation invariant descriptors on-chip. All computations are performed in single precision floating-point format which makes it possible to implement the original algorithm with little alteration. Various rotation resolutions and filter kernel sizes are supported for images of any resolution up to ultra-high definition. For full high definition images, 84 fps can be processed. Ultra high definition images can be processed at 21 fps.
KW - Field programmable gate arrays
KW - Convolution
KW - Signal processing
KW - algorithms
KW - Kernel
KW - Image resolution
KW - Histograms
KW - Feature extraction
KW - Scale-invariant feature transform (SIFT)
KW - field-programmable gate array
KW - (FPGA)
KW - image processing
KW - computer vision
KW - parallel processing
KW - architecture
KW - real-time
KW - hardware architecture
Y1 - 2021
U6 - https://doi.org/10.1109/ACCESS.2021.3104387
SN - 2169-3536
VL - 9
SP - 128564
EP - 128573
PB - Inst. of Electr. and Electronics Engineers
CY - New York, NY
ER -
TY - JOUR
A1 - Schneider, Sven
A1 - Lambers, Leen
A1 - Orejas, Fernando
T1 - A logic-based incremental approach to graph repair featuring delta preservation
JF - International journal on software tools for technology transfer : STTT
N2 - We introduce a logic-based incremental approach to graph repair, generating a sound and complete (upon termination) overview of least-changing graph repairs from which a user may select a graph repair based on non-formalized further requirements. This incremental approach features delta preservation as it allows to restrict the generation of graph repairs to delta-preserving graph repairs, which do not revert the additions and deletions of the most recent consistency-violating graph update. We specify consistency of graphs using the logic of nested graph conditions, which is equivalent to first-order logic on graphs. Technically, the incremental approach encodes if and how the graph under repair satisfies a graph condition using the novel data structure of satisfaction trees, which are adapted incrementally according to the graph updates applied. In addition to the incremental approach, we also present two state-based graph repair algorithms, which restore consistency of a graph independent of the most recent graph update and which generate additional graph repairs using a global perspective on the graph under repair. We evaluate the developed algorithms using our prototypical implementation in the tool AutoGraph and illustrate our incremental approach using a case study from the graph database domain.
KW - Nested graph conditions
KW - Graph repair
KW - Model repair
KW - Consistency
KW - restoration
KW - Delta preservation
KW - Graph databases
KW - Model-driven
KW - engineering
Y1 - 2021
U6 - https://doi.org/10.1007/s10009-020-00584-x
SN - 1433-2779
SN - 1433-2787
VL - 23
IS - 3
SP - 369
EP - 410
PB - Springer
CY - Berlin ; Heidelberg
ER -
TY - JOUR
A1 - Hartung, Niklas
A1 - Borghardt, Jens Markus
T1 - A mechanistic framework for a priori pharmacokinetic predictions of orally inhaled drugs
JF - PLoS Computational Biology : a new community journal
N2 - Author summary
The use of orally inhaled drugs for treating lung diseases is appealing since they have the potential for lung selectivity, i.e. high exposure at the site of action -the lung- without excessive side effects. However, the degree of lung selectivity depends on a large number of factors, including physiochemical properties of drug molecules, patient disease state, and inhalation devices. To predict the impact of these factors on drug exposure and thereby to understand the characteristics of an optimal drug for inhalation, we develop a predictive mathematical framework (a "pharmacokinetic model"). In contrast to previous approaches, our model allows combining knowledge from different sources appropriately and its predictions were able to adequately predict different sets of clinical data. Finally, we compare the impact of different factors and find that the most important factors are the size of the inhaled particles, the affinity of the drug to the lung tissue, as well as the rate of drug dissolution in the lung. In contrast to the common belief, the solubility of a drug in the lining fluids is not found to be relevant. These findings are important to understand how inhaled drugs should be designed to achieve best treatment results in patients.
The fate of orally inhaled drugs is determined by pulmonary pharmacokinetic processes such as particle deposition, pulmonary drug dissolution, and mucociliary clearance. Even though each single process has been systematically investigated, a quantitative understanding on the interaction of processes remains limited and therefore identifying optimal drug and formulation characteristics for orally inhaled drugs is still challenging. To investigate this complex interplay, the pulmonary processes can be integrated into mathematical models. However, existing modeling attempts considerably simplify these processes or are not systematically evaluated against (clinical) data. In this work, we developed a mathematical framework based on physiologically-structured population equations to integrate all relevant pulmonary processes mechanistically. A tailored numerical resolution strategy was chosen and the mechanistic model was evaluated systematically against data from different clinical studies. Without adapting the mechanistic model or estimating kinetic parameters based on individual study data, the developed model was able to predict simultaneously (i) lung retention profiles of inhaled insoluble particles, (ii) particle size-dependent pharmacokinetics of inhaled monodisperse particles, (iii) pharmacokinetic differences between inhaled fluticasone propionate and budesonide, as well as (iv) pharmacokinetic differences between healthy volunteers and asthmatic patients. Finally, to identify the most impactful optimization criteria for orally inhaled drugs, the developed mechanistic model was applied to investigate the impact of input parameters on both the pulmonary and systemic exposure. Interestingly, the solubility of the inhaled drug did not have any relevant impact on the local and systemic pharmacokinetics. Instead, the pulmonary dissolution rate, the particle size, the tissue affinity, and the systemic clearance were the most impactful potential optimization parameters. In the future, the developed prediction framework should be considered a powerful tool for identifying optimal drug and formulation characteristics.
Y1 - 2020
U6 - https://doi.org/10.1371/journal.pcbi.1008466
SN - 1553-734X
SN - 1553-7358
VL - 16
IS - 12
PB - PLoS
CY - San Fransisco
ER -
TY - JOUR
A1 - Navarro, Marisa
A1 - Orejas, Fernando
A1 - Pino, Elvira
A1 - Lambers, Leen
T1 - A navigational logic for reasoning about graph properties
JF - Journal of logical and algebraic methods in programming
N2 - Graphs play an important role in many areas of Computer Science. In particular, our work is motivated by model-driven software development and by graph databases. For this reason, it is very important to have the means to express and to reason about the properties that a given graph may satisfy. With this aim, in this paper we present a visual logic that allows us to describe graph properties, including navigational properties, i.e., properties about the paths in a graph. The logic is equipped with a deductive tableau method that we have proved to be sound and complete.
KW - Graph logic
KW - Algebraic methods
KW - Formal modelling
KW - Specification
Y1 - 2021
U6 - https://doi.org/10.1016/j.jlamp.2020.100616
SN - 2352-2208
SN - 2352-2216
VL - 118
PB - Elsevier Science
CY - Amsterdam [u.a.]
ER -
TY - JOUR
A1 - Neher, Dieter
A1 - Kniepert, Juliane
A1 - Elimelech, Arik
A1 - Koster, L. Jan Anton
T1 - A New Figure of Merit for Organic Solar Cells with Transport-limited Photocurrents
JF - Scientific reports
N2 - Compared to their inorganic counterparts, organic semiconductors suffer from relatively low charge carrier mobilities. Therefore, expressions derived for inorganic solar cells to correlate characteristic performance parameters to material properties are prone to fail when applied to organic devices. This is especially true for the classical Shockley-equation commonly used to describe current-voltage (JV)-curves, as it assumes a high electrical conductivity of the charge transporting material. Here, an analytical expression for the JV-curves of organic solar cells is derived based on a previously published analytical model. This expression, bearing a similar functional dependence as the Shockley-equation, delivers a new figure of merit α to express the balance between free charge recombination and extraction in low mobility photoactive materials. This figure of merit is shown to determine critical device parameters such as the apparent series resistance and the fill factor.
KW - Electronic and spintronic devices
KW - Semiconductors
Y1 - 2016
U6 - https://doi.org/10.1038/srep24861
SN - 2045-2322
VL - 6
PB - Nature Publishing Group
CY - London
ER -
TY - CHAP
A1 - Grüner, Andreas
A1 - Mühle, Alexander
A1 - Gayvoronskaya, Tatiana
A1 - Meinel, Christoph
T1 - A quantifiable trustmModel for Blockchain-based identity management
T2 - IEEE 2018 International Congress on Cybermatics / 2018 IEEE Conferences on Internet of Things, Green Computing and Communications, cyber, physical and Social Computing, Smart Data, Blockchain, Computer and Information Technology
KW - Blockchain
KW - distributed ledger technology
KW - digital identity
KW - self-sovereign identity
KW - trust
KW - identity management
Y1 - 2019
SN - 978-1-5386-7975-3
U6 - https://doi.org/10.1109/Cybermatics_2018.2018.00250
SP - 1475
EP - 1482
PB - IEEE
CY - New York
ER -
TY - JOUR
A1 - Doerr, Benjamin
A1 - Krejca, Martin Stefan
T1 - A simplified run time analysis of the univariate marginal distribution algorithm on LeadingOnes
JF - Theoretical computer science
N2 - With elementary means, we prove a stronger run time guarantee for the univariate marginal distribution algorithm (UMDA) optimizing the LEADINGONES benchmark function in the desirable regime with low genetic drift. If the population size is at least quasilinear, then, with high probability, the UMDA samples the optimum in a number of iterations that is linear in the problem size divided by the logarithm of the UMDA's selection rate. This improves over the previous guarantee, obtained by Dang and Lehre (2015) via the deep level-based population method, both in terms of the run time and by demonstrating further run time gains from small selection rates. Under similar assumptions, we prove a lower bound that matches our upper bound up to constant factors.
KW - Theory
KW - Estimation-of-distribution algorithm
KW - Run time analysis
Y1 - 2021
U6 - https://doi.org/10.1016/j.tcs.2020.11.028
SN - 0304-3975
SN - 1879-2294
VL - 851
SP - 121
EP - 128
PB - Elsevier
CY - Amsterdam
ER -
TY - JOUR
A1 - Respondek, Tobias
T1 - A workflow for computing potential areas for wind turbines
JF - Process design for natural scientists: an agile model-driven approach
N2 - This paper describes the implementation of a workflow model for service-oriented computing of potential areas for wind turbines in jABC. By implementing a re-executable model the manual effort of a multi-criteria site analysis can be reduced. The aim is to determine the shift of typical geoprocessing tools of geographic information systems (GIS) from the desktop to the web. The analysis is based on a vector data set and mainly uses web services of the “Center for Spatial Information Science and Systems” (CSISS). This paper discusses effort, benefits and problems associated with the use of the web services.
Y1 - 2014
SN - 978-3-662-45005-5
IS - 500
SP - 200
EP - 215
PB - Springer
CY - Berlin
ER -
TY - JOUR
A1 - Krause, Hannes-Vincent
A1 - Große Deters, Fenne
A1 - Baumann, Annika
A1 - Krasnova, Hanna
T1 - Active social media use and its impact on well-being
BT - an experimental study on the effects of posting pictures on Instagram
JF - Journal of computer-mediated communication : a journal of the International Communication Association
N2 - Active use of social networking sites (SNSs) has long been assumed to benefit users' well-being. However, this established hypothesis is increasingly being challenged, with scholars criticizing its lack of empirical support and the imprecise conceptualization of active use. Nevertheless, with considerable heterogeneity among existing studies on the hypothesis and causal evidence still limited, a final verdict on its robustness is still pending. To contribute to this ongoing debate, we conducted a week-long randomized control trial with N = 381 adult Instagram users recruited via Prolific. Specifically, we tested how active SNS use, operationalized as picture postings on Instagram, affects different dimensions of well-being. The results depicted a positive effect on users' positive affect but null findings for other well-being outcomes. The findings broadly align with the recent criticism against the active use hypothesis and support the call for a more nuanced view on the impact of SNSs.
Lay Summary Active use of social networking sites (SNSs) has long been assumed to benefit users' well-being. However, this established assumption is increasingly being challenged, with scholars criticizing its lack of empirical support and the imprecise conceptualization of active use. Nevertheless, with great diversity among conducted studies on the hypothesis and a lack of causal evidence, a final verdict on its viability is still pending. To contribute to this ongoing debate, we conducted a week-long experimental investigation with 381 adult Instagram users. Specifically, we tested how posting pictures on Instagram affects different aspects of well-being. The results of this study depicted a positive effect of posting Instagram pictures on users' experienced positive emotions but no effects on other aspects of well-being. The findings broadly align with the recent criticism against the active use hypothesis and support the call for a more nuanced view on the impact of SNSs on users.
KW - social networking sites
KW - social media
KW - Instagram
KW - well-being
KW - experiment
KW - randomized control trial
Y1 - 2022
U6 - https://doi.org/10.1093/jcmc/zmac037
SN - 1083-6101
VL - 28
IS - 1
PB - Oxford Univ. Press
CY - Oxford
ER -
TY - GEN
A1 - Hesse, Günter
A1 - Matthies, Christoph
A1 - Sinzig, Werner
A1 - Uflacker, Matthias
T1 - Adding Value by Combining Business and Sensor Data
BT - an Industry 4.0 Use Case
T2 - Database Systems for Advanced Applications
N2 - Industry 4.0 and the Internet of Things are recent developments that have lead to the creation of new kinds of manufacturing data. Linking this new kind of sensor data to traditional business information is crucial for enterprises to take advantage of the data’s full potential. In this paper, we present a demo which allows experiencing this data integration, both vertically between technical and business contexts and horizontally along the value chain. The tool simulates a manufacturing company, continuously producing both business and sensor data, and supports issuing ad-hoc queries that answer specific questions related to the business. In order to adapt to different environments, users can configure sensor characteristics to their needs.
KW - Industry 4.0
KW - Internet of Things
KW - Data integration
Y1 - 2019
SN - 978-3-030-18590-9
SN - 978-3-030-18589-3
U6 - https://doi.org/10.1007/978-3-030-18590-9_80
SN - 0302-9743
SN - 1611-3349
VL - 11448
SP - 528
EP - 532
PB - Springer
CY - Cham
ER -
TY - THES
A1 - Grütze, Toni
T1 - Adding value to text with user-generated content
N2 - In recent years, the ever-growing amount of documents on the Web as well as in closed systems for private or business contexts led to a considerable increase of valuable textual information about topics, events, and entities. It is a truism that the majority of information (i.e., business-relevant data) is only available in unstructured textual form. The text mining research field comprises various practice areas that have the common goal of harvesting high-quality information from textual data. These information help addressing users' information needs.
In this thesis, we utilize the knowledge represented in user-generated content (UGC) originating from various social media services to improve text mining results. These social media platforms provide a plethora of information with varying focuses. In many cases, an essential feature of such platforms is to share relevant content with a peer group. Thus, the data exchanged in these communities tend to be focused on the interests of the user base. The popularity of social media services is growing continuously and the inherent knowledge is available to be utilized. We show that this knowledge can be used for three different tasks.
Initially, we demonstrate that when searching persons with ambiguous names, the information from Wikipedia can be bootstrapped to group web search results according to the individuals occurring in the documents. We introduce two models and different means to handle persons missing in the UGC source. We show that the proposed approaches outperform traditional algorithms for search result clustering. Secondly, we discuss how the categorization of texts according to continuously changing community-generated folksonomies helps users to identify new information related to their interests. We specifically target temporal changes in the UGC and show how they influence the quality of different tag recommendation approaches. Finally, we introduce an algorithm to attempt the entity linking problem, a necessity for harvesting entity knowledge from large text collections. The goal is the linkage of mentions within the documents with their real-world entities. A major focus lies on the efficient derivation of coherent links.
For each of the contributions, we provide a wide range of experiments on various text corpora as well as different sources of UGC.
The evaluation shows the added value that the usage of these sources provides and confirms the appropriateness of leveraging user-generated content to serve different information needs.
N2 - Die steigende Zahl an Dokumenten, welche in den letzten Jahren im Web sowie in geschlossenen Systemen aus dem privaten oder geschäftlichen Umfeld erstellt wurden, führte zu einem erheblichen Zuwachs an wertvollen Informationen über verschiedenste Themen, Ereignisse, Organisationen und Personen. Die meisten Informationen liegen lediglich in unstrukturierter, textueller Form vor. Das Forschungsgebiet des "Text Mining" befasst sich mit dem schwierigen Problem, hochwertige Informationen in strukturierter Form aus Texten zu gewinnen. Diese Informationen können dazu eingesetzt werden, Nutzern dabei zu helfen, ihren Informationsbedarf zu stillen.
In dieser Arbeit nutzen wir Wissen, welches in nutzergenerierten Inhalten verborgen ist und aus unterschiedlichsten sozialen Medien stammt, um Text Mining Ergebnisse zu verbessern. Soziale Medien bieten eine Fülle an Informationen mit verschiedenen Schwerpunkten. Eine wesentliche Funktion solcher Medien ist es, den Nutzern zu ermöglichen, Inhalte mit ihrer Interessensgruppe zu teilen. Somit sind die ausgetauschten Daten in diesen Diensten häufig auf die Interessen der Nutzerbasis ausgerichtet. Die Popularität sozialer Medien wächst stetig und führt dazu, dass immer mehr inhärentes Wissen verfügbar wird. Dieses Wissen kann unter anderem für drei verschiedene Aufgabenstellungen genutzt werden.
Zunächst zeigen wir, dass Informationen aus Wikipedia hilfreich sind, um Ergebnisse von Personensuchen im Web nach den in ihnen diskutierten Personen aufzuteilen. Dazu führen wir zwei Modelle zur Gruppierung der Ergebnisse und verschiedene Methoden zum Umgang mit fehlenden Wikipedia Einträgen ein, und zeigen, dass die entwickelten Ansätze traditionelle Methoden zur Gruppierung von Suchergebnissen übertreffen. Des Weiteren diskutieren wir, wie die Klassifizierung von Texten auf Basis von "Folksonomien" Nutzern dabei helfen kann, neue Informationen zu identifizieren, die ihren Interessen entsprechen. Wir konzentrieren uns insbesondere auf temporäre Änderungen in den nutzergenerierten Inhalten, um zu zeigen, wie stark ihr Einfluss auf die Qualität verschiedener "Tag"-Empfehlungsmethoden ist. Zu guter Letzt führen wir einen Algorithmus ein, der es ermöglicht, Nennungen von Echtweltinstanzen in Texten zu disambiguieren und mit ihren Repräsentationen in einer Wissensdatenbank zu verknüpfen. Das Hauptaugenmerk liegt dabei auf der effizienten Erkennung von kohärenten Verknüpfungen.
Wir stellen für jeden Teil der Arbeit eine große Vielfalt an Experimenten auf diversen Textkorpora und unterschiedlichen Quellen von nutzergenerierten Inhalten an. Damit heben wir das Potential hervor, das die Nutzung jener Quellen bietet, um die unterschiedlichen Informationsbedürfnisse abzudecken.
T2 - Mehrwert für Texte mittels nutzergenerierter Inhalte
KW - nutzergenerierte Inhalte
KW - text mining
KW - Klassifikation
KW - Clusteranalyse
KW - Entitätsverknüpfung
KW - user-generated content
KW - text mining
KW - classification
KW - clustering
KW - entity linking
Y1 - 2018
ER -
TY - CHAP
A1 - Rojahn, Marcel
A1 - Ambros, Maximilian
A1 - Biru, Tibebu
A1 - Krallmann, Hermann
A1 - Gronau, Norbert
A1 - Grum, Marcus
ED - Rutkowski, Leszek
ED - Scherer, Rafał
ED - Korytkowski, Marcin
ED - Pedrycz, Witold
ED - Tadeusiewicz, Ryszard
ED - Zurada, Jacek M.
T1 - Adequate basis for the data-driven and machine-learning-based identification
T2 - Artificial intelligence and soft computing
N2 - Process mining (PM) has established itself in recent years as a main method for visualizing and analyzing processes. However, the identification of knowledge has not been addressed adequately because PM aims solely at data-driven discovering, monitoring, and improving real-world processes from event logs available in various information systems. The following paper, therefore, outlines a novel systematic analysis view on tools for data-driven and machine learning (ML)-based identification of knowledge-intensive target processes. To support the effectiveness of the identification process, the main contributions of this study are (1) to design a procedure for a systematic review and analysis for the selection of relevant dimensions, (2) to identify different categories of dimensions as evaluation metrics to select source systems, algorithms, and tools for PM and ML as well as include them in a multi-dimensional grid box model, (3) to select and assess the most relevant dimensions of the model, (4) to identify and assess source systems, algorithms, and tools in order to find evidence for the selected dimensions, and (5) to assess the relevance and applicability of the conceptualization and design procedure for tool selection in data-driven and ML-based process mining research.
KW - data mining
KW - knowledge engineering
KW - various applications
Y1 - 2023
SN - 978-3-031-42504-2
SN - 978-3-031-42505-9
U6 - https://doi.org/10.1007/978-3-031-42505-9_48
SP - 570
EP - 588
PB - Springer
CY - Cham
ER -
TY - JOUR
A1 - Brewka, Gerhard
A1 - Ellmauthaler, Stefan
A1 - Kern-Isberner, Gabriele
A1 - Obermeier, Philipp
A1 - Ostrowski, Max
A1 - Romero, Javier
A1 - Schaub, Torsten H.
A1 - Schieweck, Steffen
T1 - Advanced solving technology for dynamic and reactive applications
JF - Künstliche Intelligenz
Y1 - 2018
U6 - https://doi.org/10.1007/s13218-018-0538-8
SN - 0933-1875
SN - 1610-1987
VL - 32
IS - 2-3
SP - 199
EP - 200
PB - Springer
CY - Heidelberg
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 - Abramova, Olga
A1 - Gladkaya, Margarita
A1 - Krasnova, Hanna
T1 - An unusual encounter with oneself
BT - exploring the impact of self-view on online meeting outcomes
T2 - ICIS 2021: IS and the future of work
N2 - Helping overcome distance, the use of videoconferencing tools has surged during the pandemic. To shed light on the consequences of videoconferencing at work, this study takes a granular look at the implications of the self-view feature for meeting outcomes. Building on self-awareness research and self-regulation theory, we argue that by heightening the state of self-awareness, self-view engagement depletes participants’ mental resources and thereby can undermine online meeting outcomes. Evaluation of our theoretical model on a sample of 179 employees reveals a nuanced picture. Self-view engagement while speaking and while listening is positively associated with self-awareness, which, in turn, is negatively associated with satisfaction with meeting process, perceived productivity, and meeting enjoyment. The criticality of the communication role is put forward: looking at self while listening to other attendees has a negative direct and indirect effect on meeting outcomes; however, looking at self while speaking produces equivocal effects.
Y1 - 2021
UR - https://aisel.aisnet.org/icis2021/is_future_work/is_future_work/16
PB - AIS Electronic Library (AISeL)
CY - [Erscheinungsort nicht ermittelbar]
ER -
TY - THES
A1 - Heinze, Theodor
T1 - Analyse von Patientendaten und Entscheidungsunterstützung in der Telemedizin
Y1 - 2015
ER -
TY - JOUR
A1 - Schindler, Daniel
A1 - Moldenhawer, Ted
A1 - Stange, Maike
A1 - Lepro, Valentino
A1 - Beta, Carsten
A1 - Holschneider, Matthias
A1 - Huisinga, Wilhelm
T1 - Analysis of protrusion dynamics in amoeboid cell motility by means of regularized contour flows
JF - PLoS Computational Biology : a new community journal
N2 - Amoeboid cell motility is essential for a wide range of biological processes including wound healing, embryonic morphogenesis, and cancer metastasis. It relies on complex dynamical patterns of cell shape changes that pose long-standing challenges to mathematical modeling and raise a need for automated and reproducible approaches to extract quantitative morphological features from image sequences. Here, we introduce a theoretical framework and a computational method for obtaining smooth representations of the spatiotemporal contour dynamics from stacks of segmented microscopy images. Based on a Gaussian process regression we propose a one-parameter family of regularized contour flows that allows us to continuously track reference points (virtual markers) between successive cell contours. We use this approach to define a coordinate system on the moving cell boundary and to represent different local geometric quantities in this frame of reference. In particular, we introduce the local marker dispersion as a measure to identify localized membrane expansions and provide a fully automated way to extract the properties of such expansions, including their area and growth time. The methods are available as an open-source software package called AmoePy, a Python-based toolbox for analyzing amoeboid cell motility (based on time-lapse microscopy data), including a graphical user interface and detailed documentation. Due to the mathematical rigor of our framework, we envision it to be of use for the development of novel cell motility models. We mainly use experimental data of the social amoeba Dictyostelium discoideum to illustrate and validate our approach.
Author summary Amoeboid motion is a crawling-like cell migration that plays an important key role in multiple biological processes such as wound healing and cancer metastasis. This type of cell motility results from expanding and simultaneously contracting parts of the cell membrane. From fluorescence images, we obtain a sequence of points, representing the cell membrane, for each time step. By using regression analysis on these sequences, we derive smooth representations, so-called contours, of the membrane. Since the number of measurements is discrete and often limited, the question is raised of how to link consecutive contours with each other. In this work, we present a novel mathematical framework in which these links are described by regularized flows allowing a certain degree of concentration or stretching of neighboring reference points on the same contour. This stretching rate, the so-called local dispersion, is used to identify expansions and contractions of the cell membrane providing a fully automated way of extracting properties of these cell shape changes. We applied our methods to time-lapse microscopy data of the social amoeba Dictyostelium discoideum.
Y1 - 2021
U6 - https://doi.org/10.1371/journal.pcbi.1009268
SN - 1553-734X
SN - 1553-7358
VL - 17
IS - 8
PB - PLoS
CY - San Fransisco
ER -
TY - JOUR
A1 - Schaub, Torsten H.
A1 - Woltran, Stefan
T1 - Answer set programming unleashed!
JF - Künstliche Intelligenz
N2 - Answer Set Programming faces an increasing popularity for problem solving in various domains. While its modeling language allows us to express many complex problems in an easy way, its solving technology enables their effective resolution. In what follows, we detail some of the key factors of its success. Answer Set Programming [ASP; Brewka et al. Commun ACM 54(12):92–103, (2011)] is seeing a rapid proliferation in academia and industry due to its easy and flexible way to model and solve knowledge-intense combinatorial (optimization) problems. To this end, ASP offers a high-level modeling language paired with high-performance solving technology. As a result, ASP systems provide out-off-the-box, general-purpose search engines that allow for enumerating (optimal) solutions. They are represented as answer sets, each being a set of atoms representing a solution. The declarative approach of ASP allows a user to concentrate on a problem’s specification rather than the computational means to solve it. This makes ASP a prime candidate for rapid prototyping and an attractive tool for teaching key AI techniques since complex problems can be expressed in a succinct and elaboration tolerant way. This is eased by the tuning of ASP’s modeling language to knowledge representation and reasoning (KRR). The resulting impact is nicely reflected by a growing range of successful applications of ASP [Erdem et al. AI Mag 37(3):53–68, 2016; Falkner et al. Industrial applications of answer set programming. K++nstliche Intelligenz (2018)]
Y1 - 2018
U6 - https://doi.org/10.1007/s13218-018-0550-z
SN - 0933-1875
SN - 1610-1987
VL - 32
IS - 2-3
SP - 105
EP - 108
PB - Springer
CY - Heidelberg
ER -
TY - JOUR
A1 - von Steinau-Steinrück, Robert
A1 - Jöris, Nils
T1 - Arbeitsschutz bei Corona
BT - Versuch einer Entwirrung
JF - NJW spezial
N2 - Den Überblick im Arbeitsschutzrecht zu behalten, ist schwierig. Der Arbeitsschutz spielt sich in unterschiedlichen Bereichen und auf verschiedenen Ebenen ab. Außerdem sind die einschlägigen Rechtsnormen überaus verästelt. Der folgende Beitrag soll daher zur Entwirrung beitragen.
Y1 - 2020
UR - https://beck-online.beck.de/Bcid/Y-300-Z-NJW-SPEZIAL-B-2020-S-370-N-1
SN - 1613-4621
VL - 17
IS - 12
SP - 370
EP - 371
PB - C.H. Beck
CY - München
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 - Schäfer, Robin
A1 - Stede, Manfred
T1 - Argument mining on twitter
BT - a survey
JF - Information technology : it ; Methoden und innovative Anwendungen der Informatik und Informationstechnik ; Organ der Fachbereiche 3 und 4 der GI e.V. und des Fachbereichs 6 der ITG
N2 - In the last decade, the field of argument mining has grown notably. However, only relatively few studies have investigated argumentation in social media and specifically on Twitter. Here, we provide the, to our knowledge, first critical in-depth survey of the state of the art in tweet-based argument mining. We discuss approaches to modelling the structure of arguments in the context of tweet corpus annotation, and we review current progress in the task of detecting argument components and their relations in tweets. We also survey the intersection of argument mining and stance detection, before we conclude with an outlook.
KW - Argument Mining
KW - Twitter
KW - Stance Detection
Y1 - 2021
U6 - https://doi.org/10.1515/itit-2020-0053
SN - 1611-2776
SN - 2196-7032
VL - 63
IS - 1
SP - 45
EP - 58
PB - De Gruyter
CY - Berlin
ER -
TY - JOUR
A1 - Grüner, Andreas
A1 - Mühle, Alexander
A1 - Meinel, Christoph
T1 - ATIB
BT - Design and evaluation of an architecture for brokered self-sovereign identity integration and trust-enhancing attribute aggregation for service provider
JF - IEEE access : practical research, open solutions / Institute of Electrical and Electronics Engineers
N2 - Identity management is a principle component of securing online services. In the advancement of traditional identity management patterns, the identity provider remained a Trusted Third Party (TTP). The service provider and the user need to trust a particular identity provider for correct attributes amongst other demands. This paradigm changed with the invention of blockchain-based Self-Sovereign Identity (SSI) solutions that primarily focus on the users. SSI reduces the functional scope of the identity provider to an attribute provider while enabling attribute aggregation. Besides that, the development of new protocols, disregarding established protocols and a significantly fragmented landscape of SSI solutions pose considerable challenges for an adoption by service providers. We propose an Attribute Trust-enhancing Identity Broker (ATIB) to leverage the potential of SSI for trust-enhancing attribute aggregation. Furthermore, ATIB abstracts from a dedicated SSI solution and offers standard protocols. Therefore, it facilitates the adoption by service providers. Despite the brokered integration approach, we show that ATIB provides a high security posture. Additionally, ATIB does not compromise the ten foundational SSI principles for the users.
KW - Blockchains
KW - Protocols
KW - Authentication
KW - Licenses
KW - Security
KW - Privacy
KW - Identity management systems
KW - Attribute aggregation
KW - attribute assurance
KW - digital identity
KW - identity broker
KW - self-sovereign identity
KW - trust model
Y1 - 2021
U6 - https://doi.org/10.1109/ACCESS.2021.3116095
SN - 2169-3536
VL - 9
SP - 138553
EP - 138570
PB - Institute of Electrical and Electronics Engineers
CY - New York, NY
ER -
TY - BOOK
A1 - Kunze, Matthias
A1 - Weske, Mathias
T1 - Behavioural Models
BT - From Modelling Finite Automata to Analysing Business Processes
N2 - This textbook introduces the basis for modelling and analysing discrete dynamic systems, such as computer programmes, soft- and hardware systems, and business processes. The underlying concepts are introduced and concrete modelling techniques are described, such as finite automata, state machines, and Petri nets. The concepts are related to concrete application scenarios, among which business processes play a prominent role.
The book consists of three parts, the first of which addresses the foundations of behavioural modelling. After a general introduction to modelling, it introduces transition systems as a basic formalism for representing the behaviour of discrete dynamic systems. This section also discusses causality, a fundamental concept for modelling and reasoning about behaviour. In turn, Part II forms the heart of the book and is devoted to models of behaviour. It details both sequential and concurrent systems and introduces finite automata, state machines and several different types of Petri nets. One chapter is especially devoted to business process models, workflow patterns and BPMN, the industry standard for modelling business processes. Lastly, Part III investigates how the behaviour of systems can be analysed. To this end, it introduces readers to the concept of state spaces. Further chapters cover the comparison of behaviour and the formal analysis and verification of behavioural models.
The book was written for students of computer science and software engineering, as well as for programmers and system analysts interested in the behaviour of the systems they work on. It takes readers on a journey from the fundamentals of behavioural modelling to advanced techniques for modelling and analysing sequential and concurrent systems, and thus provides them a deep understanding of the concepts and techniques introduced and how they can be applied to concrete application scenarios.
Y1 - 2016
SN - 978-3-319-44958-6
PB - Springer
CY - Cham
ER -
TY - JOUR
A1 - von Steinau-Steinrück, Robert
A1 - Jöris, Nils
T1 - Brexit-Arbeitsrecht und die Folgen
JF - NJW spezial
N2 - Die Corona-Pandemie hat den Brexit ein wenig in den Hintergrund gedrängt. Dabei hat er gerade im Arbeitsrecht ganz erhebliche Auswirkungen. Über sie geben wir einen Überblick.
Y1 - 2021
UR - https://beck-online.beck.de/Bcid/Y-300-Z-NJW-SPEZIAL-B-2021-S-242-N-1
SN - 1613-4621
VL - 18
IS - 8
SP - 242
EP - 243
PB - C.H. Beck
CY - München
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 - JOUR
A1 - Huang, Yizhen
A1 - Richter, Eric
A1 - Kleickmann, Thilo
A1 - Wiepke, Axel
A1 - Richter, Dirk
T1 - Classroom complexity affects student teachers’ behavior in a VR classroom
JF - Computers & education : an international journal
N2 - Student teachers often struggle to keep track of everything that is happening in the classroom, and particularly to notice and respond when students cause disruptions. The complexity of the classroom environment is a potential contributing factor that has not been empirically tested. In this experimental study, we utilized a virtual reality (VR) classroom to examine whether classroom complexity affects the likelihood of student teachers noticing disruptions and how they react after noticing. Classroom complexity was operationalized as the number of disruptions and the existence of overlapping disruptions (multidimensionality) as well as the existence of parallel teaching tasks (simultaneity). Results showed that student teachers (n = 50) were less likely to notice the scripted disruptions, and also less likely to respond to the disruptions in a comprehensive and effortful manner when facing greater complexity. These results may have implications for both teacher training and the design of VR for training or research purpose. This study contributes to the field from two aspects: 1) it revealed how features of the classroom environment can affect student teachers' noticing of and reaction to disruptions; and 2) it extends the functionality of the VR environment-from a teacher training tool to a testbed of fundamental classroom processes that are difficult to manipulate in real-life.
KW - Augmented and virtual reality
KW - Simulations
KW - Improving classroom
KW - teaching
KW - Media in education
KW - Pedagogical issues
Y1 - 2021
U6 - https://doi.org/10.1016/j.compedu.2020.104100
SN - 0360-1315
SN - 1873-782X
VL - 163
PB - Elsevier
CY - Oxford
ER -
TY - THES
A1 - Schnjakin, Maxim
T1 - Cloud-RAID
BT - eine Methode zur Bereitstellung zuverlässiger Speicherressourcen in öffentlichen Clouds
Y1 - 2014
ER -
TY - JOUR
A1 - Torkura, Kennedy A.
A1 - Sukmana, Muhammad Ihsan Haikal
A1 - Cheng, Feng
A1 - Meinel, Christoph
T1 - CloudStrike
BT - chaos engineering for security and resiliency in cloud infrastructure
JF - IEEE access : practical research, open solutions
N2 - Most cyber-attacks and data breaches in cloud infrastructure are due to human errors and misconfiguration vulnerabilities. Cloud customer-centric tools are imperative for mitigating these issues, however existing cloud security models are largely unable to tackle these security challenges. Therefore, novel security mechanisms are imperative, we propose Risk-driven Fault Injection (RDFI) techniques to address these challenges. RDFI applies the principles of chaos engineering to cloud security and leverages feedback loops to execute, monitor, analyze and plan security fault injection campaigns, based on a knowledge-base. The knowledge-base consists of fault models designed from secure baselines, cloud security best practices and observations derived during iterative fault injection campaigns. These observations are helpful for identifying vulnerabilities while verifying the correctness of security attributes (integrity, confidentiality and availability). Furthermore, RDFI proactively supports risk analysis and security hardening efforts by sharing security information with security mechanisms. We have designed and implemented the RDFI strategies including various chaos engineering algorithms as a software tool: CloudStrike. Several evaluations have been conducted with CloudStrike against infrastructure deployed on two major public cloud infrastructure: Amazon Web Services and Google Cloud Platform. The time performance linearly increases, proportional to increasing attack rates. Also, the analysis of vulnerabilities detected via security fault injection has been used to harden the security of cloud resources to demonstrate the effectiveness of the security information provided by CloudStrike. Therefore, we opine that our approaches are suitable for overcoming contemporary cloud security issues.
KW - cloud security
KW - security chaos engineering
KW - resilient architectures
KW - security risk assessment
Y1 - 2020
U6 - https://doi.org/10.1109/ACCESS.2020.3007338
SN - 2169-3536
VL - 8
SP - 123044
EP - 123060
PB - Institute of Electrical and Electronics Engineers
CY - Piscataway
ER -
TY - JOUR
A1 - Angeleska, Angela
A1 - Omranian, Sara
A1 - Nikoloski, Zoran
T1 - Coherent network partitions
BT - Characterizations with cographs and prime graphs
JF - Theoretical computer science : the journal of the EATCS
N2 - We continue to study coherent partitions of graphs whereby the vertex set is partitioned into subsets that induce biclique spanned subgraphs. The problem of identifying the minimum number of edges to obtain biclique spanned connected components (CNP), called the coherence number, is NP-hard even on bipartite graphs. Here, we propose a graph transformation geared towards obtaining an O (log n)-approximation algorithm for the CNP on a bipartite graph with n vertices. The transformation is inspired by a new characterization of biclique spanned subgraphs. In addition, we study coherent partitions on prime graphs, and show that finding coherent partitions reduces to the problem of finding coherent partitions in a prime graph. Therefore, these results provide future directions for approximation algorithms for the coherence number of a given graph.
KW - Graph partitions
KW - Network clustering
KW - Cographs
KW - Coherent partition
KW - Prime graphs
Y1 - 2021
U6 - https://doi.org/10.1016/j.tcs.2021.10.002
SN - 0304-3975
VL - 894
SP - 3
EP - 11
PB - Elsevier
CY - Amsterdam [u.a.]
ER -
TY - JOUR
A1 - Lagriffoul, Fabien
A1 - Andres, Benjamin
T1 - Combining task and motion planning
BT - A culprit detection problem
JF - The international journal of robotics research
N2 - Solving problems combining task and motion planning requires searching across a symbolic search space and a geometric search space. Because of the semantic gap between symbolic and geometric representations, symbolic sequences of actions are not guaranteed to be geometrically feasible. This compels us to search in the combined search space, in which frequent backtracks between symbolic and geometric levels make the search inefficient.We address this problem by guiding symbolic search with rich information extracted from the geometric level through culprit detection mechanisms.
KW - combined task and motion planning
KW - manipulation planning
Y1 - 2016
U6 - https://doi.org/10.1177/0278364915619022
SN - 1741-3176
SN - 0278-3649
VL - 35
IS - 8
SP - 890
EP - 927
PB - Sage Science Press
CY - Thousand Oaks
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 - 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.
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 - JOUR
A1 - Puri, Manish
A1 - Varde, Aparna S.
A1 - Melo, Gerard de
T1 - Commonsense based text mining on urban policy
JF - Language resources and evaluation
N2 - Local laws on urban policy, i.e., ordinances directly affect our daily life in various ways (health, business etc.), yet in practice, for many citizens they remain impervious and complex. This article focuses on an approach to make urban policy more accessible and comprehensible to the general public and to government officials, while also addressing pertinent social media postings. Due to the intricacies of the natural language, ranging from complex legalese in ordinances to informal lingo in tweets, it is practical to harness human judgment here. To this end, we mine ordinances and tweets via reasoning based on commonsense knowledge so as to better account for pragmatics and semantics in the text. Ours is pioneering work in ordinance mining, and thus there is no prior labeled training data available for learning. This gap is filled by commonsense knowledge, a prudent choice in situations involving a lack of adequate training data. The ordinance mining can be beneficial to the public in fathoming policies and to officials in assessing policy effectiveness based on public reactions. This work contributes to smart governance, leveraging transparency in governing processes via public involvement. We focus significantly on ordinances contributing to smart cities, hence an important goal is to assess how well an urban region heads towards a smart city as per its policies mapping with smart city characteristics, and the corresponding public satisfaction.
KW - Commonsense reasoning
KW - Opinion mining
KW - Ordinances
KW - Smart cities
KW - Social
KW - media
KW - Text mining
Y1 - 2022
U6 - https://doi.org/10.1007/s10579-022-09584-6
SN - 1574-020X
SN - 1574-0218
VL - 57
SP - 733
EP - 763
PB - Springer
CY - Dordrecht [u.a.]
ER -
TY - JOUR
A1 - Perscheid, Cindy
T1 - Comprior
BT - Facilitating the implementation and automated benchmarking of prior knowledge-based feature selection approaches on gene expression data sets
JF - BMC Bioinformatics
N2 - Background
Reproducible benchmarking is important for assessing the effectiveness of novel feature selection approaches applied on gene expression data, especially for prior knowledge approaches that incorporate biological information from online knowledge bases. However, no full-fledged benchmarking system exists that is extensible, provides built-in feature selection approaches, and a comprehensive result assessment encompassing classification performance, robustness, and biological relevance. Moreover, the particular needs of prior knowledge feature selection approaches, i.e. uniform access to knowledge bases, are not addressed. As a consequence, prior knowledge approaches are not evaluated amongst each other, leaving open questions regarding their effectiveness.
Results
We present the Comprior benchmark tool, which facilitates the rapid development and effortless benchmarking of feature selection approaches, with a special focus on prior knowledge approaches. Comprior is extensible by custom approaches, offers built-in standard feature selection approaches, enables uniform access to multiple knowledge bases, and provides a customizable evaluation infrastructure to compare multiple feature selection approaches regarding their classification performance, robustness, runtime, and biological relevance.
Conclusion
Comprior allows reproducible benchmarking especially of prior knowledge approaches, which facilitates their applicability and for the first time enables a comprehensive assessment of their effectiveness
KW - Feature selection
KW - Prior knowledge
KW - Gene expression
KW - Reproducible benchmarking
Y1 - 2021
U6 - https://doi.org/10.1186/s12859-021-04308-z
SN - 1471-2105
VL - 22
SP - 1
EP - 15
PB - Springer Nature
CY - London
ER -
TY - GEN
A1 - Combi, Carlo
A1 - Oliboni, Barbara
A1 - Weske, Mathias
A1 - Zerbato, Francesca
ED - Trujillo, JC Davis
T1 - Conceptual modeling of processes and data
BT - Connecting different perspectives
T2 - Conceptual Modeling, ER 2018
N2 - Business processes constantly generate, manipulate, and consume data that are managed by organizational databases. Despite being central to process modeling and execution, the link between processes and data is often handled by developers when the process is implemented, thus leaving the connection unexplored during the conceptual design. In this paper, we introduce, formalize, and evaluate a novel conceptual view that bridges the gap between process and data models, and show some kinds of interesting insights that can be derived from this novel proposal.
Y1 - 2018
SN - 978-3-030-00847-5
SN - 978-3-030-00846-8
U6 - https://doi.org/10.1007/978-3-030-00847-5_18
SN - 0302-9743
SN - 1611-3349
VL - 11157
SP - 236
EP - 250
PB - Springer
CY - Cham
ER -
TY - JOUR
A1 - Kaya, Adem
A1 - Freitag, Melina A.
T1 - Conditioning analysis for discrete Helmholtz problems
JF - Computers and mathematics with applications : an international journal
N2 - In this paper, we examine conditioning of the discretization of the Helmholtz problem. Although the discrete Helmholtz problem has been studied from different perspectives, to the best of our knowledge, there is no conditioning analysis for it. We aim to fill this gap in the literature. We propose a novel method in 1D to observe the near-zero eigenvalues of a symmetric indefinite matrix. Standard classification of ill-conditioning based on the matrix condition number is not true for the discrete Helmholtz problem. We relate the ill-conditioning of the discretization of the Helmholtz problem with the condition number of the matrix. We carry out analytical conditioning analysis in 1D and extend our observations to 2D with numerical observations. We examine several discretizations. We find different regions in which the condition number of the problem shows different characteristics. We also explain the general behavior of the solutions in these regions.
KW - Helmholtz problem
KW - Condition number
KW - Ill-conditioning
KW - Indefinite
KW - matrices
Y1 - 2022
U6 - https://doi.org/10.1016/j.camwa.2022.05.016
SN - 0898-1221
SN - 1873-7668
VL - 118
SP - 171
EP - 182
PB - Elsevier Science
CY - Amsterdam
ER -
TY - JOUR
A1 - Lis, Monika
ED - Lambrecht, Anna-Lena
ED - Margaria, Tiziana
T1 - Constructing a Phylogenetic Tree
JF - Process Design for Natural Scientists: an agile model-driven approach
N2 - In this project I constructed a workflow that takes a DNA sequence as input and provides a phylogenetic tree, consisting of the input sequence and other sequences which were found during a database search. In this phylogenetic tree the sequences are arranged depending on similarities. In bioinformatics, constructing phylogenetic trees is often used to explore the evolutionary relationships of genes or organisms and to understand the mechanisms of evolution itself.
Y1 - 2014
SN - 978-3-662-45005-5
SN - 1865-0929
IS - 500
SP - 101
EP - 109
PB - Springer Verlag
CY - Berlin
ER -
TY - JOUR
A1 - Borchert, Florian
A1 - Mock, Andreas
A1 - Tomczak, Aurelie
A1 - Hügel, Jonas
A1 - Alkarkoukly, Samer
A1 - Knurr, Alexander
A1 - Volckmar, Anna-Lena
A1 - Stenzinger, Albrecht
A1 - Schirmacher, Peter
A1 - Debus, Jürgen
A1 - Jäger, Dirk
A1 - Longerich, Thomas
A1 - Fröhling, Stefan
A1 - Eils, Roland
A1 - Bougatf, Nina
A1 - Sax, Ulrich
A1 - Schapranow, Matthieu-Patrick
T1 - Correction to: Knowledge bases and software support for variant interpretation in precision oncology
JF - Briefings in bioinformatics
Y1 - 2021
U6 - https://doi.org/10.1093/bib/bbab246
SN - 1467-5463
SN - 1477-4054
VL - 22
IS - 6
PB - Oxford Univ. Press
CY - Oxford
ER -
TY - JOUR
A1 - Göbel, Andreas
A1 - Lagodzinski, Gregor J. A.
A1 - Seidel, Karen
T1 - Counting homomorphisms to trees modulo a prime
JF - ACM transactions on computation theory : TOCT / Association for Computing Machinery
N2 - Many important graph-theoretic notions can be encoded as counting graph homomorphism problems, such as partition functions in statistical physics, in particular independent sets and colourings. In this article, we study the complexity of #(p) HOMSTOH, the problem of counting graph homomorphisms from an input graph to a graph H modulo a prime number p. Dyer and Greenhill proved a dichotomy stating that the tractability of non-modular counting graph homomorphisms depends on the structure of the target graph. Many intractable cases in non-modular counting become tractable in modular counting due to the common phenomenon of cancellation. In subsequent studies on counting modulo 2, however, the influence of the structure of H on the tractability was shown to persist, which yields similar dichotomies.
Our main result states that for every tree H and every prime p the problem #pHOMSTOH is either polynomial time computable or #P-p-complete. This relates to the conjecture of Faben and Jerrum stating that this dichotomy holds for every graph H when counting modulo 2. In contrast to previous results on modular counting, the tractable cases of #pHOMSTOH are essentially the same for all values of the modulo when H is a tree. To prove this result, we study the structural properties of a homomorphism. As an important interim result, our study yields a dichotomy for the problem of counting weighted independent sets in a bipartite graph modulo some prime p. These results are the first suggesting that such dichotomies hold not only for the modulo 2 case but also for the modular counting functions of all primes p.
KW - Graph homomorphisms
KW - modular counting
KW - complexity dichotomy
Y1 - 2021
U6 - https://doi.org/10.1145/3460958
SN - 1942-3454
SN - 1942-3462
VL - 13
IS - 3
SP - 1
EP - 33
PB - Association for Computing Machinery
CY - New York
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 - 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 - Noack, Franziska
T1 - CREADED: Colored-Relief application for digital elevation data
JF - Process design for natural scientists: an agile model-driven approach
N2 - In the geoinformatics field, remote sensing data is often used for analyzing the characteristics of the current investigation area. This includes DEMs, which are simple raster grids containing grey scales representing the respective elevation values. The project CREADED that is presented in this paper aims at making these monochrome raster images more significant and more intuitively interpretable. For this purpose, an executable interactive model for creating a colored and relief-shaded Digital Elevation Model (DEM) has been designed using the jABC framework. The process is based on standard jABC-SIBs and SIBs that provide specific GIS functions, which are available as Web services, command line tools and scripts.
Y1 - 2014
SN - 978-3-662-45005-5
SN - 1865-0929
IS - 500
SP - 186
EP - 199
PB - Springer
CY - Berlin
ER -
TY - JOUR
A1 - Kind, Josephine
T1 - Creation of topographic maps
JF - Process design for natural scientists: an agile model-driven approach
N2 - Location analyses are among the most common tasks while working with spatial data and geographic information systems. Automating the most frequently used procedures is therefore an important aspect of improving their usability. In this context, this project aims to design and implement a workflow, providing some basic tools for a location analysis. For the implementation with jABC, the workflow was applied to the problem of finding a suitable location for placing an artificial reef. For this analysis three parameters (bathymetry, slope and grain size of the ground material) were taken into account, processed, and visualized with the The Generic Mapping Tools (GMT), which were integrated into the workflow as jETI-SIBs. The implemented workflow thereby showed that the approach to combine jABC with GMT resulted in an user-centric yet user-friendly tool with high-quality cartographic outputs.
Y1 - 2014
SN - 978-3-662-45005-5
IS - 500
SP - 229
EP - 238
PB - Springer
CY - Berlin
ER -
TY - JOUR
A1 - Bin Tareaf, Raad
A1 - Berger, Philipp
A1 - Hennig, Patrick
A1 - Meinel, Christoph
T1 - Cross-platform personality exploration system for online social networks
BT - Facebook vs. Twitter
JF - Web intelligence
N2 - Social networking sites (SNS) are a rich source of latent information about individual characteristics. Crawling and analyzing this content provides a new approach for enterprises to personalize services and put forward product recommendations. In the past few years, commercial brands made a gradual appearance on social media platforms for advertisement, customers support and public relation purposes and by now it became a necessity throughout all branches. This online identity can be represented as a brand personality that reflects how a brand is perceived by its customers. We exploited recent research in text analysis and personality detection to build an automatic brand personality prediction model on top of the (Five-Factor Model) and (Linguistic Inquiry and Word Count) features extracted from publicly available benchmarks. Predictive evaluation on brands' accounts reveals that Facebook platform provides a slight advantage over Twitter platform in offering more self-disclosure for users' to express their emotions especially their demographic and psychological traits. Results also confirm the wider perspective that the same social media account carry a quite similar and comparable personality scores over different social media platforms. For evaluating our prediction results on actual brands' accounts, we crawled the Facebook API and Twitter API respectively for 100k posts from the most valuable brands' pages in the USA and we visualize exemplars of comparison results and present suggestions for future directions.
KW - Big Five model
KW - personality prediction
KW - brand personality
KW - machine
KW - learning
KW - social media analysis
Y1 - 2020
U6 - https://doi.org/10.3233/WEB-200427
SN - 2405-6456
SN - 2405-6464
VL - 18
IS - 1
SP - 35
EP - 51
PB - IOS Press
CY - Amsterdam
ER -
TY - JOUR
A1 - Oosthoek, Kris
A1 - Dörr, Christian
T1 - Cyber security threats to bitcoin exchanges
BT - adversary exploitation and laundering techniques
JF - IEEE transactions on network and service management : a publication of the IEEE
N2 - Bitcoin is gaining traction as an alternative store of value. Its market capitalization transcends all other cryptocurrencies in the market. But its high monetary value also makes it an attractive target to cyber criminal actors. Hacking campaigns usually target an ecosystem's weakest points. In Bitcoin, the exchange platforms are one of them. Each exchange breach is a threat not only to direct victims, but to the credibility of Bitcoin's entire ecosystem. Based on an extensive analysis of 36 breaches of Bitcoin exchanges, we show the attack patterns used to exploit Bitcoin exchange platforms using an industry standard for reporting intelligence on cyber security breaches. Based on this we are able to provide an overview of the most common attack vectors, showing that all except three hacks were possible due to relatively lax security. We show that while the security regimen of Bitcoin exchanges is subpar compared to other financial service providers, the use of stolen credentials, which does not require any hacking, is decreasing. We also show that the amount of BTC taken during a breach is decreasing, as well as the exchanges that terminate after being breached. Furthermore we show that overall security posture has improved, but still has major flaws. To discover adversarial methods post-breach, we have analyzed two cases of BTC laundering. Through this analysis we provide insight into how exchange platforms with lax cyber security even further increase the intermediary risk introduced by them into the Bitcoin ecosystem.
KW - Bitcoin
KW - Computer crime
KW - Cryptography
KW - Ecosystems
KW - Currencies
KW - Industries
KW - Vocabulary
KW - cryptocurrency exchanges
KW - cyber
KW - security
KW - cyber threat intelligence
KW - attacks
KW - vulnerabilities
KW - forensics
Y1 - 2021
U6 - https://doi.org/10.1109/TNSM.2020.3046145
SN - 1932-4537
VL - 18
IS - 2
SP - 1616
EP - 1628
PB - IEEE
CY - New York
ER -
TY - JOUR
A1 - Kleemann, Steven
T1 - Cyber warfare and the "humanization" of international humanitarian law
JF - International journal of cyber warfare and terrorism
N2 - Cyber warfare is a timely and relevant issue and one of the most controversial in international humanitarian law (IHL). The aim of IHL is to set rules and limits in terms of means and methods of warfare. In this context, a key question arises: Has digital warfare rules or limits, and if so, how are these applicable? Traditional principles, developed over a long period, are facing a new dimension of challenges due to the rise of cyber warfare. This paper argues that to overcome this new issue, it is critical that new humanity-oriented approaches is developed with regard to cyber warfare. The challenge is to establish a legal regime for cyber-attacks, successfully addressing human rights norms and standards. While clarifying this from a legal perspective, the authors can redesign the sensitive equilibrium between humanity and military necessity, weighing the humanitarian aims of IHL and the protection of civilians-in combination with international human rights law and other relevant legal regimes-in a different manner than before.
KW - cyber-attack
KW - cyberwar
KW - IHL
KW - IHRL
KW - international human rights
KW - international humanitarian law
KW - law and technology
KW - new technologies
Y1 - 2021
SN - 978-1-7998-6177-5
U6 - https://doi.org/10.4018/IJCWT.2021040101
SN - 1947-3435
SN - 1947-3443
VL - 11
IS - 2
SP - 1
EP - 11
PB - IGI Global
CY - Hershey
ER -