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 - Mattis, Toni
A1 - Beckmann, Tom
A1 - Rein, Patrick
A1 - Hirschfeld, Robert
T1 - First-class concepts
BT - Reified architectural knowledge beyond dominant decompositions
JF - Journal of object technology : JOT / ETH Zürich, Department of Computer Science
N2 - Ideally, programs are partitioned into independently maintainable and understandable modules. As a system grows, its architecture gradually loses the capability to accommodate new concepts in a modular way. While refactoring is expensive and not always possible, and the programming language might lack dedicated primary language constructs to express certain cross-cutting concerns, programmers are still able to explain and delineate convoluted concepts through secondary means: code comments, use of whitespace and arrangement of code, documentation, or communicating tacit knowledge.
Secondary constructs are easy to change and provide high flexibility in communicating cross-cutting concerns and other concepts among programmers. However, such secondary constructs usually have no reified representation that can be explored and manipulated as first-class entities through the programming environment.
In this exploratory work, we discuss novel ways to express a wide range of concepts, including cross-cutting concerns, patterns, and lifecycle artifacts independently of the dominant decomposition imposed by an existing architecture. We propose the representation of concepts as first-class objects inside the programming environment that retain the capability to change as easily as code comments. We explore new tools that allow programmers to view, navigate, and change programs based on conceptual perspectives. In a small case study, we demonstrate how such views can be created and how the programming experience changes from draining programmers' attention by stretching it across multiple modules toward focusing it on cohesively presented concepts. Our designs are geared toward facilitating multiple secondary perspectives on a system to co-exist in symbiosis with the original architecture, hence making it easier to explore, understand, and explain complex contexts and narratives that are hard or impossible to express using primary modularity constructs.
KW - software engineering
KW - modularity
KW - exploratory programming
KW - program
KW - comprehension
KW - remodularization
KW - architecture recovery
Y1 - 2022
U6 - https://doi.org/10.5381/jot.2022.21.2.a6
SN - 1660-1769
VL - 21
IS - 2
SP - 1
EP - 15
PB - ETH Zürich, Department of Computer Science
CY - Zürich
ER -
TY - JOUR
A1 - Schmidl, Sebastian
A1 - Papenbrock, Thorsten
T1 - Efficient distributed discovery of bidirectional order dependencies
JF - The VLDB journal
N2 - Bidirectional order dependencies (bODs) capture order relationships between lists of attributes in a relational table. They can express that, for example, sorting books by publication date in ascending order also sorts them by age in descending order. The knowledge about order relationships is useful for many data management tasks, such as query optimization, data cleaning, or consistency checking. Because the bODs of a specific dataset are usually not explicitly given, they need to be discovered. The discovery of all minimal bODs (in set-based canonical form) is a task with exponential complexity in the number of attributes, though, which is why existing bOD discovery algorithms cannot process datasets of practically relevant size in a reasonable time. In this paper, we propose the distributed bOD discovery algorithm DISTOD, whose execution time scales with the available hardware. DISTOD is a scalable, robust, and elastic bOD discovery approach that combines efficient pruning techniques for bOD candidates in set-based canonical form with a novel, reactive, and distributed search strategy. Our evaluation on various datasets shows that DISTOD outperforms both single-threaded and distributed state-of-the-art bOD discovery algorithms by up to orders of magnitude; it can, in particular, process much larger datasets.
KW - Bidirectional order dependencies
KW - Distributed computing
KW - Actor
KW - programming
KW - Parallelization
KW - Data profiling
KW - Dependency discovery
Y1 - 2021
U6 - https://doi.org/10.1007/s00778-021-00683-4
SN - 1066-8888
SN - 0949-877X
VL - 31
IS - 1
SP - 49
EP - 74
PB - Springer
CY - Berlin ; Heidelberg ; New York
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 - 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 - JOUR
A1 - Bender, Benedict
A1 - Körppen, Tim
T1 - Integriert statt isoliert
BT - Technologien für die erfolgreiche Umsetzung von datengetriebenem Management
JF - Digital business : cloud
N2 - Dass Daten und Analysen Innovationstreiber sind und nicht mehr nur einen Hygienefaktor darstellen, haben viele Unternehmen erkannt. Um Potenziale zu heben, müssen Daten zielführend integriert werden. Komplexe Systemlandschaften und isolierte Datenbestände erschweren dies. Technologien für die erfolgreiche Umsetzung von datengetriebenem Management müssen richtig eingesetzt werden.
N2 - The fact that data and analyses are innovation drivers and no longer just represent a hygiene factor is nowadays understood by many companies. An important step for the development of this hidden potential is the target-oriented utilization of the existing data stocks in one's own company. In doing so, many companies face the hurdle of complex system landscapes and isolated data stocks. This article provides an overview of solutions for analysis-oriented data integration and helps decision-makers to select a suitable technology for their own company.
KW - data analytics
KW - data requirements
KW - software selection
Y1 - 2022
UR - https://www.wiso-net.de/document/DBC__584ddfcbfbc5ff400cb2ffb0f31eba6e6903fb3d
SN - 2510-344X
VL - 26
IS - 1
SP - 26
EP - 27
PB - WIN-Verlag GmbH & Co. KG
CY - Vaterstetten
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.
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 -