University of Siegen
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Publication Access status: Metadata only , Video Conferencing(2023); The COVID-19 pandemic has reorganized existing methods of exchange, turning comparatively marginal technologies into the new normal. Multipoint videoconferencing in particular has become a favored means for web-based forms of remote communication and collaboration without physical copresence. Taking the recent mainstreaming of videoconferencing as its point of departure, this anthology examines the complex mediality of this new form of social interaction. Connecting theoretical reflection with material case studies, the contributors question practices, politics and aesthetics of videoconferencing and the specific meanings it acquires in different historical, cultural and social contexts.Source Type:Book4 - Some of the metrics are blocked by yourconsent settings
Publication Access status: Metadata only , 1 - Some of the metrics are blocked by yourconsent settings
Publication Access status: Metadata only , Analysis of the sound insulation performance of periodic wall structures by a virtual acoustic laboratoryThe propagation of acoustic waves in periodic structures, also known as phononic crystals or PCs, is prohibited in certain frequency ranges, which are referred to as the frequency band-gaps. The existence, the location and the width of the frequency band-gaps are mainly determined by the geometrical parameters and the material properties of the PCs. In this work, a virtual acoustic laboratory based on a fully coupled fluid-structure interaction (FSI) model is developed to determine the sound insulation capacity of one-dimensional (1D) and two-dimensional (2D) periodic walls. The FSI model is discretized using the frequency-domain spectral element method (FDSEM), which is an advanced finite element method (FEM) using special high-order shape functions. Following the guidelines of the ISO10140, the setup of the developed FSI model allows us to take into account the essential physical phenomena, especially the interaction of the wall structure with the fluid domains (air). The FSI model based on the FDSEM increases the computational efficiency and accuracy in comparison with the standard FEM. Several numerical examples will be presented and discussed to show that the designed periodic walls in certain frequency ranges within the band-gaps may exhibit much better sound insulation capabilities than monolithic walls.Source Type:Article3 - Some of the metrics are blocked by yourconsent settings
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Publication Access status: Metadata only , Acquisition of English relative clauses by native speakers of Kurdish Sorani(2023)The present study investigates several linguistic factors that might be determinants of differences in the ease of acquisition of relative clauses (RCs) in L2 contexts, using the acquisition of English relative clauses by Kurdish Sorani native speakers. The analysis of 1440 subject and object RCs formed by Kurdish Sorani-speaking learners of English in a sentence combination task and a sentence translation task indicates that the syntactic functions of the noun phrase (NP) relativized in the RC, the position of the RC in the matrix clause (whether centre- or right-embedded), and the properties of RCs in L1 affect the acquisition and the formation of RCs in L2. The study also provides evidence that the syntactic functions of the relativized NP in the matrix clause, and the consistency/inconsistency of word orders in L1 and L2 do not influence the acquisition of RCs in L2.Source Type:Article2 - Some of the metrics are blocked by yourconsent settings
Publication Access status: Metadata only , Subgroup Membership in GL(2,Z)(2023)It is shown that the subgroup membership problem for a virtually free group can be decided in polynomial time when all group elements are represented by so-called power words, i.e., words of the form $p_1^{z_1} p_2^{z_2} \cdots p_k^{z_k}$. Here the $p_i$ are explicit words over the generating set of the group and all $z_i$ are binary encoded integers. As a corollary, it follows that the subgroup membership problem for the matrix group $\textsf{GL}(2,\mathbb {Z})$ can be decided in polynomial time when elements of $\textsf{GL}(2,\mathbb {Z})$ are represented by matrices with binary encoded integers. For the same input representation, it also shown that one can compute in polynomial time the index of a given finitely generated subgroup of $\textsf{GL}(2,\mathbb {Z})$.Source Type:Article3 - Some of the metrics are blocked by yourconsent settings
Publication Access status: Metadata only , The Connectivity of Things(2024)A media history of the material and infrastructural features of networking practices, a German classic translated for the first time into English. Nets hold, connect, and catch. They ensnare, bind, and entangle. Our social networks owe their name to a conceivably strange and ambivalent object. But how did the net get into the network? And how can it reasonably represent the connectedness of people, things, institutions, signs, infrastructures, and even nature? The Connectivity of Things by Sebastian Giessmann, the first media history that addresses the overwhelming diversity of networks, attempts to answer all these questions and more. Reconstructing the decisive moments in which networking turned into a veritable cultural technique, Giessmann takes readers below the street to the Parisian sewers and to the Suez Canal, into the telephone exchanges of Northeast America, and on to the London Underground. His brilliant history explains why social networks were discovered late, how the rapid rise of mathematical network theory was able to take place, how improbable the invention of the internet was, and even what diagrams and conspiracy theories have to do with it all. A primer on networking as a cultural technique, this translated German classic explains everything one ever could wish to know about networks.Source Type:Book2 - Some of the metrics are blocked by yourconsent settings
Publication Access status: Metadata only , On time-horizons based post-processing of flow forecasts(2024); ; Post-processing raw stream flow forecasts are generally understood as estimating the univariate predictive density of stage or discharge values at selected future time steps, which is conditional on a single or multiple streamflow forecasts and observations up to the forecast start time t o . The predictive density indicates to a forecaster in the most comprehensive way which flood level is likely to be expected. To this end, a variety of post-processing methods were proposed, which have respective strengths and weaknesses. These methods focus near-exclusively on the probabilistic forecast of the predictand at a single set future time t i , without addressing the predictive capability over the sequence of temporal sub-horizons ( t o , t 1 ] ⊂ ( t o , t 2 ] ⊂ … ⊂ ( t o , t k ] nested into the overall forecast horizon. Here, we demonstrate the advantages of time-horizon dependent processing of streamflow forecasts, which evaluates the evolution of the predictive density over the sub-horizons by considering the temporal correlation among forecast ensemble members in addition to their cross-correlation with observations. The resulting probabilistic forecast consists of a multivariate distribution of stages and/or discharges at lagged forecasting times. These multivariate predictive distributions have the advantage of providing the likelihood of exceeding a critical threshold during the forecasting horizon while simultaneously offering valuable insights into the expected time of such exceedance. This approach supports not only decisions on issuing timely flood warnings but also the planing and roll-out of mitigating actions.Source Type:Article3 - Some of the metrics are blocked by yourconsent settings
Publication Access status: Metadata only , Counter-practices: Understanding sensor datafication through subversive action(2024); Sensors have become embedded in all kinds of environments. Their ubiquity has prompted a boom in scholarly engagement centered around the effects of digitally interconnected sensor media and the data traces they ceaselessly produce. This research generally focuses either on theoretical or philosophical macro-perspectives—approaching the topic “from above,” so to speak—or it is ethnographic, “from below,” analyzing the practices of sensory (self-)surveillance, for example in the context of the quantified self-movement. In this article, we propose a situated, praxeological approach that combines both foci: expanding on the epistemically productive concepts of glitches and breakdowns, we follow three strands of what we call “counter-practices”—hiding in plain sight, dis/simulation, and the exploitation of sensor logics—through which we explore the inherent operations of technological sensing and sensemaking. We trace these counter-practices through historic and recent contexts, considering the interrelation of bodies, media and environments, and extrapolating epistemological conclusions that are meaningful for critiquing the codes, logics, and logistics of recent sensor-media societies. Asking how certain practices elude and subvert intended processes of sensor datafication provides a methodological blueprint for media studies and cultural theory that are faced with an algorithmic and technological situation that has rendered itself largely unobservable.Source Type:Article3 - Some of the metrics are blocked by yourconsent settings
Publication Access status: Metadata only , Effects of renormalon scheme and perturbative scale choices on determinations of the strong coupling from ${e}^{+}{e}^{−}$ event shapesWe study the role of renormalon cancellation schemes and perturbative scale choices in extractions of the strong coupling constant <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msub><a:mi>α</a:mi><a:mi>s</a:mi></a:msub><a:mo stretchy="false">(</a:mo><a:msub><a:mi>m</a:mi><a:mi>Z</a:mi></a:msub><a:mo stretchy="false">)</a:mo></a:math> and the leading nonperturbative shift parameter <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:msub><e:mi mathvariant="normal">Ω</e:mi><e:mn>1</e:mn></e:msub></e:math> from resummed predictions of the <h:math xmlns:h="http://www.w3.org/1998/Math/MathML" display="inline"><h:msup><h:mi>e</h:mi><h:mo>+</h:mo></h:msup><h:msup><h:mi>e</h:mi><h:mo>−</h:mo></h:msup></h:math> event shape thrust. We calculate the thrust distribution to <j:math xmlns:j="http://www.w3.org/1998/Math/MathML" display="inline"><j:mrow><j:mi mathvariant="normal">N</j:mi><j:mrow><j:mmultiscripts><j:mrow><j:mi mathvariant="normal">L</j:mi></j:mrow><j:mprescripts/><j:none/><j:mrow><j:mn>3</j:mn></j:mrow></j:mmultiscripts></j:mrow><j:msup><j:mrow><j:mi mathvariant="normal">L</j:mi></j:mrow><j:mrow><j:mo>′</j:mo></j:mrow></j:msup></j:mrow></j:math> resummed accuracy in soft-collinear effective theory (SCET) matched to the fixed-order <o:math xmlns:o="http://www.w3.org/1998/Math/MathML" display="inline"><o:mi mathvariant="script">O</o:mi><o:mo stretchy="false">(</o:mo><o:msubsup><o:mi>α</o:mi><o:mi>s</o:mi><o:mn>2</o:mn></o:msubsup><o:mo stretchy="false">)</o:mo></o:math> prediction, and perform a new high-statistics computation of the <t:math xmlns:t="http://www.w3.org/1998/Math/MathML" display="inline"><t:mi mathvariant="script">O</t:mi><t:mo stretchy="false">(</t:mo><t:msubsup><t:mi>α</t:mi><t:mi>s</t:mi><t:mn>3</t:mn></t:msubsup><t:mo stretchy="false">)</t:mo></t:math> matching in , although we do not include the latter in our final <y:math xmlns:y="http://www.w3.org/1998/Math/MathML" display="inline"><y:msub><y:mi>α</y:mi><y:mi>s</y:mi></y:msub></y:math> fits due to some observed systematics that require further investigation. We are primarily interested in testing the phenomenological impact sourced from varying amongst three renormalon cancellation schemes and two sets of perturbative scale profile choices. We then perform a global fit to available data spanning center-of-mass energies between 35–207 GeV in each scenario. Relevant subsets of our results are consistent with prior SCET-based extractions of <ab:math xmlns:ab="http://www.w3.org/1998/Math/MathML" display="inline"><ab:msub><ab:mi>α</ab:mi><ab:mi>s</ab:mi></ab:msub><ab:mo stretchy="false">(</ab:mo><ab:msub><ab:mi>m</ab:mi><ab:mi>Z</ab:mi></ab:msub><ab:mo stretchy="false">)</ab:mo></ab:math>, but we are also led to a number of novel observations. Notably, we find that the combined effect of altering the renormalon cancellation scheme and profile parameters can lead to few-percent-level impacts on the extracted values in the <eb:math xmlns:eb="http://www.w3.org/1998/Math/MathML" display="inline"><eb:msub><eb:mi>α</eb:mi><eb:mi>s</eb:mi></eb:msub><eb:mo>−</eb:mo><eb:msub><eb:mi mathvariant="normal">Ω</eb:mi><eb:mn>1</eb:mn></eb:msub></eb:math> plane, indicating a potentially important systematic theory uncertainty that should be accounted for. We also observe that fits performed over windows dominated by dijet events are typically of a higher quality than those that extend into the far tails of the distributions, possibly motivating future fits focused more heavily in this region. Finally, we discuss how different estimates of the three-loop soft matching coefficient <hb:math xmlns:hb="http://www.w3.org/1998/Math/MathML" display="inline"><hb:msubsup><hb:mi>c</hb:mi><hb:mover accent="true"><hb:mi>S</hb:mi><hb:mo stretchy="false">˜</hb:mo></hb:mover><hb:mn>3</hb:mn></hb:msubsup></hb:math> can also lead to measurable changes in the fitted <lb:math xmlns:lb="http://www.w3.org/1998/Math/MathML" display="inline"><lb:mo stretchy="false">{</lb:mo><lb:msub><lb:mi>α</lb:mi><lb:mi>s</lb:mi></lb:msub><lb:mo>,</lb:mo><lb:msub><lb:mi mathvariant="normal">Ω</lb:mi><lb:mn>1</lb:mn></lb:msub><lb:mo stretchy="false">}</lb:mo></lb:math> values. Published by the American Physical Society 2024Source Type:Article1
