@article{25212, abstract = {{Finding a good query plan is key to the optimization of query runtime. This holds in particular for cost-based federation engines, which make use of cardinality estimations to achieve this goal. A number of studies compare SPARQL federation engines across different performance metrics, including query runtime, result set completeness and correctness, number of sources selected and number of requests sent. Albeit informative, these metrics are generic and unable to quantify and evaluate the accuracy of the cardinality estimators of cost-based federation engines. To thoroughly evaluate cost-based federation engines, the effect of estimated cardinality errors on the overall query runtime performance must be measured. In this paper, we address this challenge by presenting novel evaluation metrics targeted at a fine-grained benchmarking of cost-based federated SPARQL query engines. We evaluate five cost-based federated SPARQL query engines using existing as well as novel evaluation metrics by using LargeRDFBench queries. Our results provide a detailed analysis of the experimental outcomes that reveal novel insights, useful for the development of future cost-based federated SPARQL query processing engines.}}, author = {{Qudus, Umair and Saleem, Muhammad and Ngonga Ngomo, Axel-Cyrille and Lee, Young-Koo}}, issn = {{2210-4968}}, journal = {{Semantic Web}}, keywords = {{SPARQL, benchmarking, cost-based, cost-free, federated, querying}}, number = {{6}}, pages = {{843--868}}, publisher = {{ISO Press}}, title = {{{An Empirical Evaluation of Cost-based Federated SPARQL Query Processing Engines}}}, doi = {{10.3233/SW-200420}}, volume = {{12}}, year = {{2021}}, } @inbook{54587, abstract = {{With significant growth in RDF datasets, application developers demand online availability of these datasets to meet the end users’ expectations. Various interfaces are available for querying RDF data using SPARQL query language. Studies show that SPARQL end-points may provide high query runtime performance at the cost of low availability. For example, it has been observed that only 32.2% of public endpoints have a monthly uptime of 99–100%. One possible reason for this low availability is the high workload experienced by these SPARQL endpoints. As complete query execution is performed at server side (i.e., SPARQL endpoint), this high query processing workload may result in performance degradation or even a service shutdown. We performed extensive experiments to show the query processing capabilities of well-known triple stores by using their SPARQL endpoints. In particular, we stressed these triple stores with multiple parallel requests from different querying agents. Our experiments revealed the maximum query processing capabilities of these triple stores after which point they lead to service shutdowns. We hope this analysis will help triple store developers to design workload-aware RDF engines to improve the availability of their public endpoints with high throughput.}}, author = {{Khan, Hashim and Manzoor, Ali and Ngonga Ngomo, Axel-Cyrille and Saleem, Muhammad}}, booktitle = {{Studies on the Semantic Web}}, issn = {{1868-1158}}, publisher = {{IOS Press}}, title = {{{When is the Peak Performance Reached? An Analysis of RDF Triple Stores}}}, doi = {{10.3233/ssw210042}}, year = {{2021}}, } @inproceedings{27551, author = {{Ludwig, Janis and Kykal, Carsten and Schmid, Hans-Joachim}}, booktitle = {{Book of abstracts for the 2021 European Aerosol Conference}}, keywords = {{aerosol spreading, SARS-CoV-2, indoor air filtration}}, title = {{{Assessing spreading and removal of virus laden aerosols in different settings using an aerosol method (oral presentation)}}}, year = {{2021}}, } @article{61802, author = {{Giermindl, Lisa Marie and Strich, Franz and Christ, Oliver and Leicht-Deobald, Ulrich and Redzepi, Abdullah}}, issn = {{0960-085X}}, journal = {{European Journal of Information Systems}}, number = {{3}}, pages = {{410--435}}, publisher = {{Informa UK Limited}}, title = {{{The dark sides of people analytics: reviewing the perils for organisations and employees}}}, doi = {{10.1080/0960085x.2021.1927213}}, volume = {{31}}, year = {{2021}}, } @article{61913, author = {{Diekmann, Isabell and Greschner, Deniz and von der Heyde, Judith and Logeswaran, Araththy and Reinhardt, Anna C. and Strube, Sonja A.}}, isbn = {{978-3-9820349-4-2}}, journal = {{Perspektiven. Soziale Arbeit in der Migrationsgesellschaft und muslimische Wohlfahrtspflege}}, number = {{1}}, pages = {{7 – 10}}, publisher = {{Universität Osnabrück}}, title = {{{Perspektiven auf Ungleichheit und Ungleichwertigkeit im Kontext Sozialer Arbeit. Eine Einleitung}}}, volume = {{2021}}, year = {{2021}}, } @article{61914, author = {{Diekmann, Isabell}}, isbn = {{978-3-9820349-4-2}}, journal = {{Perspektiven. Soziale Arbeit in der Migrationsgesellschaft und muslimische Wohlfahrtspflege }}, number = {{1}}, pages = {{77 – 89}}, publisher = {{Universität Osnabrück}}, title = {{{Differenzierung von Islam- und Muslim*innenfeindlichkeit – Potenziale für die Praxis}}}, volume = {{2021}}, year = {{2021}}, } @article{29209, abstract = {{We demonstrate an optical arbitrary waveform measurement (OAWM) system that exploits a bank of silicon photonic (SiP) frequency-tunable coupled-resonator optical waveguide (CROW) filters for gapless spectral slicing of broadband optical signals. The spectral slices are coherently detected using a frequency comb as a multi-wavelength local oscillator (LO) and stitched together by digital signal processing (DSP). For high-quality signal reconstruction, we have implemented a maximum-ratio combining (MRC) technique based on precise calibration of the complex-valued opto-electronic transfer functions of all detection paths. In a proof-of-concept experiment, we demonstrate the viability of the scheme by implementing a four-channel system that offers an overall detection bandwidth of 140 GHz. Exploiting a femtosecond laser with precisely known pulse shape for calibration along with dynamic amplitude and phase estimation, we reconstruct 100 GBd QPSK, 16QAM and 64QAM optical data signals. The reconstructed signals show improved quality compared to that obtained with a single high-speed intradyne receiver, while the electronic bandwidth requirements of the individual coherent receivers are greatly reduced.}}, author = {{Fang, Dengyang and Zazzi, Andrea and Müller, Juliana and Dray, Daniel and Fullner, Christoph and Marin-Palomo, Pablo and Tabatabaei Mashayekh, Alireza and Dipta Das, Arka and Weizel, Maxim and Gudyriev, Sergiy and Freude, Wolfgang and Randel, Sebastian and Scheytt, J. Christoph and Witzens, Jeremy and Koos, Christian}}, issn = {{0733-8724}}, journal = {{Journal of Lightwave Technology}}, keywords = {{Atomic and Molecular Physics, and Optics}}, pages = {{1--1}}, publisher = {{Institute of Electrical and Electronics Engineers (IEEE)}}, title = {{{Optical Arbitrary Waveform Measurement Using Silicon Photonic Slicing Filters}}}, doi = {{10.1109/jlt.2021.3130764}}, year = {{2021}}, } @article{29211, abstract = {{Electrical-optical signal processing has been shown to be a promising path to overcome the limitations of state-of-the-art all-electrical data converters. In addition to ultra-broadband signal processing, it allows leveraging ultra-low jitter mode-locked lasers and thus increasing the aperture jitter limited effective number of bits at high analog signal frequencies. In this paper, we review our recent progress towards optically enabled time- and frequency-interleaved analog-to-digital converters, as well as their monolithic integration in electronic-photonic integrated circuits. For signal frequencies up to 65 GHz, an optoelectronic track-and-hold amplifier based on the source-emitter-follower architecture is shown as a power efficient approach in optically enabled BiCMOS technology. At higher signal frequencies, integrated photonic filters enable signal slicing in the frequency domain and further scaling of the conversion bandwidth, with the reconstruction of a 140 GHz optical signal being shown. We further show how such optically enabled data converter architectures can be applied to a nonlinear Fourier transform based integrated transceiver in particular and discuss their applicability to broadband optical links in general.}}, author = {{Zazzi, Andrea and Müller, Juliana and Weizel, Maxim and Koch, Jonas and Fang, Dengyang and Moscoso-Martir, Alvaro and Tabatabaei Mashayekh, Ali and Das, Arka D. and Drays, Daniel and Merget, Florian and Kartner, Franz X. and Pachnicke, Stephan and Koos, Christian and Scheytt, J. Christoph and Witzens, Jeremy}}, issn = {{2644-1349}}, journal = {{IEEE Open Journal of the Solid-State Circuits Society}}, pages = {{209--221}}, publisher = {{Institute of Electrical and Electronics Engineers (IEEE)}}, title = {{{Optically Enabled ADCs and Application to Optical Communications}}}, doi = {{10.1109/ojsscs.2021.3110943}}, volume = {{1}}, year = {{2021}}, } @article{29212, author = {{Fang, Dengyang and Zazzi, Andrea and Müller, Juliana and Daniel, Drayß and Füllner, Christoph and Marin-Palomo, Pablo and Mashayekh, Ali Tabatabaei and Das, Arka Dipta and Weizel, Maxim and Gudyriev, Sergiy and Freude, Wolfgang and Randel, Sebastian and Scheytt, J. Christoph and Witzens, Jeremy and Koos, Christian}}, isbn = {{978-1-943580-86-6}}, journal = {{OSA Technical Digest}}, title = {{{Optical Arbitrary Waveform Measurement (OAWM) on the Silicon Photonic Platform}}}, doi = {{10.1109/JLT.2021.3130764}}, year = {{2021}}, } @article{23476, author = {{Weizel, Maxim and Scheytt, J. Christoph and Kärtner, Franz X. and Witzens, Jeremy}}, issn = {{1094-4087}}, journal = {{Optics Express}}, title = {{{Optically clocked switched-emitter-follower THA in a photonic SiGe BiCMOS technology}}}, doi = {{10.1364/oe.425710}}, year = {{2021}}, } @article{58746, abstract = {{AbstractStudent dropout is a multi-causal process. Different theoretical models on student dropout consider dysfunctional study behavior (e.g., academic procrastination) and low study satisfaction as possible determinants of students’ dropout intentions during their university studies. However, these models neglect contemporary conceptualizations that assume reverse relationships between dropout intentions and other determinants of the dropout process. Until now, empirical evidence on these assumptions is scant. The present three-wave longitudinal study explored the reciprocal relationships between academic procrastination, study satisfaction, and dropout intentions over one semester. To this end, we used data of N = 326 undergraduate students enrolled in mathematics and law. Our latent cross-lagged panel model replicated existing empirical cross-sectional findings between the variables (i.e., academic procrastination, study satisfaction, and dropout intentions). Regarding the longitudinal relations, as expected, the cross-lagged effects showed that higher dropout intentions significantly related to subsequent higher academic procrastination and lower study satisfaction. Unexpectedly, academic procrastination did not significantly relate to subsequent dropout intentions. Additionally, higher study satisfaction significantly associated with subsequent higher dropout intentions—possibly due to unfulfilled expectations. Further, higher study satisfaction significantly related to subsequent higher procrastination—possibly due to more confidence among satisfied students. Our results broaden the view on dropout intentions as part of the dynamic interplay of student dropout determinants and the need to refine dropout models’ assumptions accordingly. Practically, realistic expectations seem important to reduce dropout intentions. Further, student counselors should have a closer look at the reasons for academic procrastination to develop individual solutions for this dysfunctional behavior.}}, author = {{Scheunemann, Anne and Schnettler, Theresa and Bobe, Julia and Fries, Stefan and Grunschel, Carola}}, issn = {{0256-2928}}, journal = {{European Journal of Psychology of Education}}, number = {{4}}, pages = {{1141--1164}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{A longitudinal analysis of the reciprocal relationship between academic procrastination, study satisfaction, and dropout intentions in higher education}}}, doi = {{10.1007/s10212-021-00571-z}}, volume = {{37}}, year = {{2021}}, } @article{35421, author = {{Korsmeier, Theresa and Bobe, Julia and Klingsieck, Katrin B.}}, journal = {{Zeitschrift für Beratung und Studium}}, pages = {{22--27}}, title = {{{Prokrastination bei Studierenden verringern durch Anwendung eines Ratgebers im Gruppensetting}}}, volume = {{16}}, year = {{2021}}, } @article{37947, author = {{Paradies, Jan and Andexer, Jennifer and Beifuss, Uwe and Beuerle, Florian and Brasholz, Malte and Breinbauer, Rolf and Ernst, Martin and Ganardi, Ruth and Gulder, Tobias A. M. and Hüttel, Wolfgang and Kath‐Schorr, Stephanie and Körber, Karsten and Kordes, Markus and Lehmann, Matthias and Lindel, Thomas and Luy, Burkhard and Mück‐Lichtenfeld, Christian and Muhle‐Goll, Claudia and Niemeyer, Jochen and Pfau, Roland and Pietruszka, Jörg and Röckl, Johannes L. and Schaschke, Norbert and Senge, Mathias O. and Straub, Bernd F. and Waldvogel, Siegfried R. and Werner, Thomas and Werz, Daniel B. and Winter, Christian}}, issn = {{1439-9598}}, journal = {{Nachrichten aus der Chemie}}, keywords = {{General Chemical Engineering, General Chemistry}}, number = {{3}}, pages = {{38--68}}, publisher = {{Wiley}}, title = {{{Organische Chemie}}}, doi = {{10.1002/nadc.20214105947}}, volume = {{69}}, year = {{2021}}, } @article{37950, author = {{Hu, Yuya and Wei, Zhihong and Frey, Anna and Kubis, Christoph and Ren, Chang‐Yue and Spannenberg, Anke and Jiao, Haijun and Werner, Thomas}}, issn = {{1864-5631}}, journal = {{ChemSusChem}}, keywords = {{T1}}, number = {{1}}, pages = {{363--372}}, publisher = {{Wiley}}, title = {{{Catalytic, Kinetic, and Mechanistic Insights into the Fixation of CO2 with Epoxides Catalyzed by Phenol‐Functionalized Phosphonium Salts}}}, doi = {{10.1002/cssc.202002267}}, volume = {{14}}, year = {{2021}}, } @article{37946, abstract = {{AbstractThe facile synthesis of highly functionalized building blocks with potential biological activity is of great interest to medicinal chemistry. The benzoxepinone core structures commonly exhibit biological activity. Thus, a short and efficient synthetic route towards benzoxepine containing scaffold, which enables late stage modification was developed. Namely, base-free catalytic Wittig reactions enabled the synthesis of bromobenzoxepinones from readily available starting materials. Subsequent, Suzuki–Miyaura and Stille reactions proved to be suitable methods to access a variety of benzoxepinone diaryl derivatives by late stage modification in only three steps. This three-step reaction sequence is suitable for high throughput applications and gives facile access to highly complex molecular structures, which are suitable for further functionalization. The antiproliferative properties of selected arylbenzoxepinones­ were tested in vitro on monolayer tumor cell line A549. Notably, in this initial screening, these compounds were found to be active in the micromolar range.}}, author = {{Werner, Thomas and Grandane, Aiga and Pudnika, Linda and Domraceva, Ilona and Zalubovskis, Raivis}}, issn = {{0039-7881}}, journal = {{Synthesis}}, keywords = {{T2, T4, CSSD}}, number = {{19}}, pages = {{3545--3554}}, publisher = {{Georg Thieme Verlag KG}}, title = {{{Base-Free Catalytic Wittig-/Cross-Coupling Reaction Sequence as Short Synthetic Strategy for the Preparation of Highly Functionalized Arylbenzoxepinones}}}, doi = {{10.1055/a-1509-6078}}, volume = {{53}}, year = {{2021}}, } @article{37944, abstract = {{

A Mn–PNP complex proved to be a suitable catalyst for the transfer hydrogenation of amides, carbamates, urea derivatives and even polyurethanes.

}}, author = {{Liu, Xin and Werner, Thomas}}, issn = {{2041-6520}}, journal = {{Chemical Science}}, keywords = {{T1, T3, CSSD}}, number = {{31}}, pages = {{10590--10597}}, publisher = {{Royal Society of Chemistry (RSC)}}, title = {{{Indirect reduction of CO2 and recycling of polymers by manganese-catalyzed transfer hydrogenation of amides, carbamates, urea derivatives, and polyurethanes}}}, doi = {{10.1039/d1sc02663a}}, volume = {{12}}, year = {{2021}}, } @article{37945, abstract = {{

PMHS proved to be a suitable terminal reductant for P(iii)/P(v) redox cycling with a methyl-substituted phosphetane as catalyst and BuOAc as solvent. The formation of water by silanol condensation was identified as main pathway of siloxane formation.

}}, author = {{Tönjes, Jan and Longwitz, Lars and Werner, Thomas}}, issn = {{1463-9262}}, journal = {{Green Chemistry}}, keywords = {{T2, CSSD}}, number = {{13}}, pages = {{4852--4857}}, publisher = {{Royal Society of Chemistry (RSC)}}, title = {{{Poly(methylhydrosiloxane) as a reductant in the catalytic base-free Wittig reaction}}}, doi = {{10.1039/d1gc00953b}}, volume = {{23}}, year = {{2021}}, } @article{62098, author = {{Stefanow, Vivian and Grandane, Aiga and Eh, Marcus and Panten, Johannes and Spannenberg, Anke and Werner, Thomas}}, issn = {{1083-6160}}, journal = {{Organic Process Research & Development}}, keywords = {{T4, CSSD}}, number = {{1}}, pages = {{89--97}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Stereoselective Synthesis of acis-Cedrane-8,9-diol as a Key Intermediate for an Amber Odorant}}}, doi = {{10.1021/acs.oprd.0c00423}}, volume = {{25}}, year = {{2021}}, } @article{62099, author = {{Stefanow, Vivian and Grandane, Aiga and Eh, Marcus and Panten, Johannes and Spannenberg, Anke and Werner, Thomas}}, issn = {{1083-6160}}, journal = {{Organic Process Research & Development}}, keywords = {{T4, CSSD}}, number = {{1}}, pages = {{89--97}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Stereoselective Synthesis of acis-Cedrane-8,9-diol as a Key Intermediate for an Amber Odorant}}}, doi = {{10.1021/acs.oprd.0c00423}}, volume = {{25}}, year = {{2021}}, } @article{37943, author = {{Wirth, Marisa A. and Longwitz, Lars and Kanwischer, Marion and Gros, Peter and Leinweber, Peter and Werner, Thomas}}, issn = {{0147-6513}}, journal = {{Ecotoxicology and Environmental Safety}}, keywords = {{T4, CSSD}}, publisher = {{Elsevier BV}}, title = {{{AMPA-15N – Synthesis and application as standard compound in traceable degradation studies of glyphosate}}}, doi = {{10.1016/j.ecoenv.2021.112768}}, volume = {{225}}, year = {{2021}}, }