TY - GEN A1 - Welk, Martin A1 - Kleefeld, Andreas A1 - Breuß, Michael T1 - Quantile Filtering of Colour Images via Symmetric Matrices T2 - Mathematical Morphology - Theory and Applications N2 - Quantile filters, or rank-order filters, are local image filters which assign quantiles of intensities of the input image within neighbourhoods as output image values. Combining a multivariate quantile definition developed in matrix-valued morphology with a recently introduced mapping between the RGB colour space and the space of symmetric 2 × 2 matrices, we state a class of colour image quantile filters, along with a class of morphological gradient filters derived from these.We consider variants of these filters based on three matrix norms – the nuclear, Frobenius, and spectral norm – and study their differences. We investigate the properties of the quantile and gradient filters and their links to dilation and erosion operators. Using amoeba structuring elements,we devise image-adaptive versions of our quantile and gradient filters. Experiments are presented to demonstrate the favourable properties of the filters, and compare them to existing approaches in colour morphology. KW - quantile KW - rank-order filter KW - colour image KW - matrix field KW - amoebas Y1 - 2016 U6 - https://doi.org/10.1515/mathm-2016-0008 SN - 2353-3390 VL - 1 IS - 1 SP - 136 EP - 174 ER - TY - PAT A1 - Trautmann, Martin A1 - Sanftl, Benedikt A1 - Kölpin, Alexander A1 - Heckel, Thomas A1 - Frey, Lothar A1 - Ditze, Stefan A1 - Endruschat, Achim A1 - Joffe, Christopher A1 - Rosskopf, Andreas A1 - Schriefer, Thomas T1 - System zur drahtlosen Übertragung von Energie und Daten Y1 - 2016 ER - TY - GEN A1 - Bambach, Markus A1 - Sizova, Irina A1 - Sviridov, Alexander A1 - Stendal, Johan Andreas A1 - Günther, Martin T1 - Batch Processing in Preassembled Die Sets - A New Process Design for Isothermal Forging of Titanium Aluminides T2 - Journal of Manufacturing and Materials Processing Y1 - 2018 U6 - https://doi.org/doi:10.3390/jmmp2010001 SN - 2504-4494 VL - 2 IS - 1 ER - TY - GEN A1 - Kammerer, Sarah A1 - Sokolowski, Armin Andreas A1 - Hackl, Hubert A1 - Platzer, Dieter A1 - Jahn, Stephan Wenzel A1 - El-Heliebi, Amin A1 - Schwarzenbacher, Daniela A1 - Stiegelbauer, Verena A1 - Pichler, Martin A1 - Rezania, Simin A1 - Fiegl, Heidelinde A1 - Peintinger, Florentia A1 - Regitnig, Peter A1 - Höfler, Gerald A1 - Schreibmayer, Wolfgang A1 - Bauernhofer, Thomas T1 - KCNJ3 is a new independent prognostic marker for estrogen receptor positive breast cancer patients T2 - OncoTarget : open access impact journal N2 - Numerous studies showed abnormal expression of ion channels in different cancer types. Amongst these, the potassium channel gene KCNJ3 (encoding for GIRK1 proteins) has been reported to be upregulated in tumors of patients with breast cancer and to correlate with positive lymph node status. We aimed to study KCNJ3 levels in different breast cancer subtypes using gene expression data from the TCGA, to validate our findings using RNA in situ hybridization in a validation cohort (GEO ID GSE17705), and to study the prognostic value of KCNJ3using survival analysis. In a total of > 1000 breast cancer patients of two independent data sets we showed a) that KCNJ3 expression is upregulated in tumor tissue compared to corresponding normal tissue (p < 0.001), b) that KCNJ3 expression is associated with estrogen receptor (ER) positive tumors (p < 0.001), but that KCNJ3 expression is variable within this group, and c) that ER positive patients with high KCNJ3 levels have worse overall (p < 0.05) and disease free survival probabilities (p < 0.01), whereby KCNJ3 is an independent prognostic factor (p <0.05). In conclusion, our data suggest that patients with ER positive breast cancer might be stratified into high risk and low risk groups based on the KCNJ3 levels in the tumor. Y1 - 2016 U6 - https://doi.org/10.18632/oncotarget.13224 VL - 7 IS - 51 SP - 84705 EP - 84717 ER - TY - CHAP A1 - Zaussinger, Florian A1 - Egbers, Christoph A1 - Driebe, Thomas A1 - Heintzmann, Pascal A1 - Canfield, Peter A1 - Meier, Martin A1 - Travnikov, Vadim A1 - Froitzheim, Andreas A1 - Haun, Peter T1 - ATMOFLOW - Simulating atmosphere flows on the international space station. Part II: Experiments and numerical simulations T2 - 69th International Astronautical Congress, 1 - 5 October 2018, Bremen, Germany Y1 - 2018 UR - https://iafastro.directory/iac/paper/id/42847/abstract-pdf/IAC-18,A2,7,18,x42847.brief.pdf?2018-08-31.10:50:07 ER - TY - CHAP A1 - Panchenko, Andriy A1 - Lanze, Fabian A1 - Zinnen, Andreas A1 - Henze, Martin A1 - Pennekamp, Jan A1 - Engel, Thomas A1 - Wehrle, Klaus T1 - Website Fingerprinting at Internet Scale T2 - Proceedings of the 23rd Internet Society (ISOC) Network and Distributed System Security Symposium (NDSS 2016), San Diego, USA, February 2016 Y1 - 2016 SN - 1-891562-41-X PB - Internet Society CY - Reston, VA ER - TY - GEN A1 - Boch, Steffen A1 - Allan, Eric A1 - Birkhofer, Klaus A1 - Bossdorf, Oliver A1 - Blüthgen, Nico A1 - Christ-Breulmann, Sabina A1 - Diekötter, Tim A1 - Dormann, Carsten F. A1 - Gossner, Martin M. A1 - Hallmann, Christine A1 - Hemp, Andreas A1 - Hölzel, Norbert A1 - Jung, Kirsten A1 - Klaus, Valentin H. A1 - Klein, Alexandra M. A1 - Kleinebecker, Till A1 - Lange, Markus A1 - Müller, Jörg A1 - Nacke, Heiko A1 - Prati, Daniel A1 - Renner, Swen C. A1 - Rothenwöhrer, Christoph A1 - Schall, Peter A1 - Schulze, Ernst-Detlef A1 - Socher, Stephanie A. A1 - Tscharntke, Teja A1 - Türke, Manfred A1 - Weiner, Christiane N. A1 - Weisser, Wolfgang W. A1 - Westphal, Catrin A1 - Wolters, Volkmar A1 - Wubet, Tesfaye A1 - Fischer, Markus T1 - Extensive und jährlich wechselnde Nutzungsintensität fördert den Artenreichtum im Grünland T2 - ANLIEGEN NATUR Y1 - 2016 UR - https://www.biom.uni-freiburg.de/mitarbeiter/dormann/boch2016anliegennatur.pdf SN - 1864-0729 VL - 38 IS - 1 SP - 86 EP - 95 ER - TY - GEN A1 - Hauschildt, Katja A1 - Stark, Andreas A1 - Schell, Norbert A1 - Müller, Martin A1 - Pyczak, Florian T1 - The transient liquid phase bonding process of a γ-TiAl alloy with brazing solders containing Fe or Ni T2 - Intermetallics Y1 - 2019 SN - 0966-9795 VL - 106 SP - 48 EP - 58 ER - TY - GEN A1 - Zaussinger, Florian A1 - Canfield, Peter A1 - Froitzheim, Andreas A1 - Travnikov, Vadim A1 - Haun, Peter A1 - Meier, Martin A1 - Meyer, Antoine A1 - Heintzmann, Pascal A1 - Driebe, Thomas A1 - Egbers, Christoph T1 - AtmoFlow - Investigation of Atmospheric-Like Fluid Flows Under Microgravity Conditions T2 - Microgravity Science and Technology : An International Journal for Microgravity and Space Exploration Related Research Y1 - 2019 UR - https://link.springer.com/article/10.1007/s12217-019-09717-7 UR - 1875-0494 UR - https://www-docs.b-tu.de/fg-aerodynamik-stroemungslehre/public/PDF/Pubs/ELGRA2019_Book-of-abstracts.pdf U6 - https://doi.org/10.1007/s12217-019-09717-7 SN - 0938-0108 SP - 1 EP - 19 PB - Springer ER - TY - GEN A1 - Fügenschuh, Armin A1 - Homfeld, Henning A1 - Huck, Andreas A1 - Martin, Alexander A1 - Yuan, Zhi T1 - Scheduling Locomotives and Car Transfers in Freight Transport T2 - Transportation Science Y1 - 2008 U6 - https://doi.org/10.1287/trsc.1080.0248 SN - 1526-5447 SN - 0041-1655 VL - 42 IS - 4 SP - 478 EP - 491 ER - TY - GEN A1 - Kuebart, Andreas A1 - Stabler, Martin T1 - Infectious Diseases as Socio‐Spatial Processes: The COVID‐19 Outbreak In Germany T2 - Tijdschrift voor economische en sociale geografie = Journal of economic and social geography N2 - This paper argues that outbreaks of infectious diseases should be understood as socio‐spatial processes with complex geographies. Considering the different dimensions of space through which an outbreak unfolds, facilitates analysing spatial diffusion of infectious disease in contemporary societies. We attempt to highlight four relevant dimensions of space by applying the TPSN framework to the case of the recent COVID‐19 outbreak in Germany. By identifying key processes of disease diffusion in space, we can explain the spatial patterns of the COVID‐19 outbreak in Germany, which did not feature the well‐known patterns of spatially contagious as in or hierarchical diffusion. In contrast, we find superspreading events and especially relocation diffusion based on existing networks, on which the pathogen travelled like a blind passenger, to be more relevant. For us, these findings prove the value of combining relational thinking with geographic analysis for understanding epidemic outbreaks in contemporary societies. Y1 - 2020 U6 - https://doi.org/10.1111/tesg.12429 SN - 1467-9663 SN - 0040-747X VL - 111 IS - 3 SP - 482 EP - 496 ER - TY - CHAP A1 - Kuebart, Andreas A1 - Stabler, Martin ED - Stegbauer, Christian ED - Clemens, Iris T1 - Infektionsnetzwerke und Infektionsorte–Super-spreading-Ereignisse in der Epidemie T2 - Corona-Netzwerke–Gesellschaft im Zeichen des Virus N2 - Für die Analyse von Ausbrüchen von Infektionskrankheiten wie der neuartigen Coronaviruskrankheit COVID-19, die sich über Tröpfchen, Aerosole oder Kontaktinfektion ausbreiten, bietet ein netzwerktheoretischer Ansatz einen besonderen Mehrwert, da eine Ansteckung von einer Person auf die andere notwendigerweise einen direkten Kontakt unter Kopräsenz impliziert und der Ausbruch im größeren Maßstab somit ein Netzwerkmuster aufweist. Neben dem für ein Infektionsgeschehen notwendigen Kontakt zwischen einem infektiösen und einem infizierbaren Individuum gibt es mit dem Ort des Infektionsprozesses allerdings noch eine weitere Variable, die die Rahmenbedingungen bestimmt und von erheblicher Bedeutung sein kann. Y1 - 2020 SN - 978-3-658-31394-4 SN - 978-3-658-31393-7 U6 - https://doi.org/10.1007/978-3-658-31394-4_4 SP - 35 EP - 43 PB - Springer CY - Wiesbaden ET - 1. Auflage ER - TY - GEN A1 - Kuebart, Andreas A1 - Stabler, Martin T1 - Risikoprozesse statt Risikogebiete : Raumdimensionen der COVID-19-Pandemie in Deutschland T2 - Informationen zur Raumentwicklung Y1 - 2021 UR - https://elibrary.steiner-verlag.de/article/99.105010/izr202102004001 VL - 48 IS - 2 SP - 40 EP - 49 ER - TY - RPRT A1 - Böhm, Uwe A1 - Kücken, Martin A1 - Ahrens, Wilfried A1 - Block, Alexander A1 - Hauffe, Detlef A1 - Keuler, Klaus A1 - Rockel, Burkhardt A1 - Will, Andreas T1 - CLM - The Climate Version of LM: Brief Description and Long-Term Applications Y1 - 2006 UR - http://www.cosmo-model.org/content/model/documentation/newsLetters/newsLetter06/cnl6_clm.pdf PB - COSMO Newsletter CY - Offenbach, Germany ER - TY - GEN A1 - Martin, Titus A1 - Braun, Alexander A1 - Michel, Sven A1 - Wendler, Johannes A1 - Nocke, Andreas A1 - Cherif, Chokri A1 - Ibarlucea, Bergoi A1 - Cuniberti, Gianaurelio T1 - Development of textile-based and planar sensors for continuous non-invasive real-time recording of the lactate value curve for diagnostics according to clinical requirements N2 - We hereby present the findings for a new technology to produce portable, flexible, long- term stable and high-resolution sensors and measuring systems for individual lactate value recording in body sweat for regenerative and sports. A main goal of this study has been the identification of application sites according to body sweat quality and quantity, as well as easy accessibility and handling of the measurement site. For the continuous recording of the lactate value curve with integrated temperature compensation, new types of multifunctional sensor constructions and evaluation algorithms have been developed that can detect and evaluate these parameters precisely and interference-free in real time in body sweat in order to establish a diagnostic correlation with the clinical, therapeutic and sports medicine performance- oriented application scenarios. For this purpose, suitable planar sensor principles have been investigated and a planar sensor was developed. A textile-based sensor suitable for long-term use (several hours to several days of use) has been developed as a braided construction. In particular, a functionalized chitosan layer with a sensitive enzyme and several required electrodes wires have been purposefully used. Due to a high selectivity, i.e. clear signal interpretation even in the presence of other substances in body sweat, enzymatic measuring systems in an amperometric measure- ment design were primarily investigated. The preferred solution of the developed planar sensor is to be used as a reference sensor for calibration and, together with the preferred solution of the textile sensor, is to be integrated into the demonstrators. From the intended project results, an immediate direct benefit can be derived for SMEs in the textile manufacturing, finishing and medical products sectors and for the measurement and sensor technology sector. Y1 - 2021 UR - https://www.aachen-dresden-denkendorf.de/fileadmin/user_upload/itc/teilnehmerbereich/Poster/56_Martin_4_BTU_Development_of_textile-based_sensors.pdf PB - ADD International Textile Conference 2021 ER - TY - GEN A1 - Strobel, Carsten A1 - Alvarado Chavarin, Carlos A1 - Richter, Karola A1 - Knaut, Martin A1 - Reif, Johanna A1 - Völkel, Sandra A1 - Jahn, Andreas A1 - Albert, Matthias A1 - Wenger, Christian A1 - Kirchner, Robert A1 - Bartha, Johann Wolfgang A1 - Mikolajick, Thomas T1 - Novel Graphene Adjustable-Barrier Transistor with Ultra-High Current Gain T2 - ACS Applied Materials & Interfaces N2 - A graphene-based three terminal barristor device was proposed to overcome the low on/off ratios and insufficient current saturation of conventional graphene field effect transistors. In this study, we fabricated and analyzed a novel graphene-based transistor, which resembles the structure of the barristor but uses a different operating condition. This new device, termed graphene adjustable-barriers transistor (GABT), utilizes a semiconductor-based gate rather than a metal−insulator gate structure to modulate the device currents. The key feature of the device is the two graphene-semiconductor Schottky barriers with different heights that are controlled simultaneously by the gate voltage. Due to the asymmetry of the barriers, the drain current exceeds the gate current by several orders of magnitude. Thus, the GABT can be considered an amplifier with an alterable current gain. In this work, a silicon−graphene−germanium GABT with an ultra-high current gain (ID/IG up to 8 × 106) was fabricated, and the device functionality was demonstrated. Additionally, a capacitance model is applied to predict the theoretical device performance resulting in an on−off ratio above 106, a swing of 87 mV/dec, and a drivecurrent of about 1 × 106 A/cm2. KW - Graphene KW - Transistor Y1 - 2022 U6 - https://doi.org/10.1021/acsami.2c10634 SN - 1944-8244 SN - 1944-8252 VL - 14 IS - 34 SP - 39249 EP - 39254 ER - TY - CHAP A1 - Dally, Ortwin A1 - Maischberger, Martin A1 - Schneider, Peter Irenäus A1 - Scholl, Andreas T1 - The Town Center of Miletus from Roman Imperial Times to Late Antiquity T2 - Archaeology and the Cities of Asia Minor in Late Antiquity Y1 - 2011 SN - 978-0-974-18735-8 SP - 81 EP - 101 PB - Kelsey Museum of Archaeology CY - Ann Arbor ER - TY - GEN A1 - Pennekamp, Jan A1 - Henze, Martin A1 - Zinnen, Andreas A1 - Lanze, Fabian A1 - Wehrle, Klaus A1 - Panchenko, Andriy T1 - CUMUL & Co: High-Impact Artifacts for Website Fingerprinting Research T2 - 38th Annual Computer Security Applications Conference (ACSAC 2022), Austin, Texas, USA, December 5-9, 2022. N2 - Anonymous communication on the Internet is about hiding the relationship between communicating parties. At NDSS ’16, we presented a new website fingerprinting approach, CUMUL, that utilizes novel features and a simple yet powerful algorithm to attack anonymization networks such as Tor. Based on pattern observation of data flows, this attack aims at identifying the content of encrypted and anonymized connections. Apart from the feature generation and the used classifier, we also provided a large dataset to the research community to study the attack at Internet scale. In this paper, we emphasize the impact of our artifacts by analyzing publications referring to our work with respect to the dataset, feature extraction method, and source code of the implementation. Based on this data, we draw conclusions about the impact of our artifacts on the research field and discuss their influence on related cybersecurity topics. Overall, from 393 unique citations, we discover more than 130 academic references that utilize our artifacts, 61 among them are highly influential (according to SemanticScholar), and at least 43 are from top-ranked security venues. This data underlines the significant relevance and impact of our work as well as of our artifacts in the community and beyond. KW - Traffic Analysis;Website Fingerprinting; Privacy; Anonymous Communication; Onion Routing; Web Privacy Y1 - 2022 UR - https://www.acsac.org/2022/program/artifacts_competition/ ER - TY - GEN A1 - Villasmunta, Francesco A1 - Steglich, Patrick A1 - Villringer, Claus A1 - Schrader, Sigurd A1 - Schenk, Harald A1 - Mai, Andreas A1 - Regehly, Martin ED - Schröder, Henning ED - Chen, Ray T. T1 - Design, fabrication, and characterization of integrated optical through-silicon waveguides for 3D photonic interconnections T2 - Optical Interconnects XXIV Y1 - 2024 U6 - https://doi.org/10.1117/12.3003146 PB - SPIE ER - TY - GEN A1 - Herrmann, Andreas A1 - Ferchau, Erik A1 - Lee, Roh Pin A1 - Simon, Marc-René A1 - Wasner, Jenny A1 - Gräbner, Martin T1 - Biogas as a renewable carbon carrier for the chemical industry T2 - The 12th International Freiberg Conference on Circular Carbon Technologies will take place from 23–26 September 2024 in Shanghai, China KW - Biogas KW - Chemical Industry KW - Carbon Carrier Y1 - 2024 UR - https://www.myqnapcloud.com/share/777675897p84o2275st97y10_6b6fhh5527po230816tuv7b858c12542#!/home SN - 2363-8702 N1 - Poster No. 15 ER - TY - GEN A1 - Kuebart, Andreas A1 - Stabler, Martin T1 - Waves in time, but not in space-An analysis of pandemic severity of COVID-19 in Germany based on spatio-temporal clustering T2 - medRxiv Y1 - 2023 UR - https://www.medrxiv.org/content/10.1101/2023.01.27.23285105v1 U6 - https://doi.org/10.1101/2023.01.27.23285105 SP - 1 EP - 20 ER - TY - GEN A1 - Kuebart, Andreas A1 - Stabler, Martin T1 - Waves in time, but not in space – an analysis of pandemic severity of COVID-19 in Germany T2 - Spatial and spatio-temporal epidemiology N2 - While pandemic waves are often studied on the national scale, they typically are not distributed evenly within countries. This study presents a novel approach to analyzing the spatial-temporal dynamics of the COVID-19 pandemic in Germany. By using a composite indicator of pandemic severity and subdividing the pandemic into fifteen phases, we were able to identify similar trajectories of pandemic severity among all German counties through hierarchical clustering. Our results show that the hotspots and cold spots of the first four waves were relatively stationary in space. This highlights the importance of examining pandemic waves on a regional scale to gain a more comprehensive understanding of their dynamics. By combining spatial autocorrelation and spatial-temporal clustering of time series, we were able to identify important patterns of regional anomalies, which can help target more effective public health interventions on a regional scale. Y1 - 2023 U6 - https://doi.org/10.1016/j.sste.2023.100605 SN - 1877-5845 VL - 47 SP - 1 EP - 9 ER - TY - GEN A1 - Strobel, Carsten A1 - Alvarado Chavarin, Carlos A1 - Völkel, Sandra A1 - Jahn, Andreas A1 - Hiess, Andre A1 - Knaut, Martin A1 - Albert, Matthias A1 - Wenger, Christian A1 - Steinke, Olaff A1 - Stephan, Ulf A1 - Röhlecke, Sören A1 - Mikolajick, Thomas T1 - Enhanced Electrical Properties of Optimized Vertical Graphene-Base Hot Electron Transistors T2 - ACS Applied Electronic Materials N2 - The arrival of high-mobility two-dimensional materials like graphene leads to the renaissance of former vertical semiconductor–metal–semiconductor (SMS) hot electron transistors. Because of the monolayer thickness of graphene, improved SMS transistors with a semimetallic graphene-base electrode are now feasible for high-frequency applications. In this study we report about a device that consists of amorphous silicon, graphene, and crystalline silicon. For the first time, this device is fabricated by a four-mask lithography process which leads to significant improvements in the device performance. A strongly increased common-emitter current gain of 2% could be achieved while the on–off ratio improved to 1.6 × 105, which is already higher than predicted theoretically. This could be mainly attributed to better interface characteristics and decreased lateral dimensions of the devices. A cutoff frequency of approximately 26 MHz could be forecasted based on the DC measurements of the device. KW - Graphene KW - Transistor Y1 - 2023 U6 - https://doi.org/10.1021/acsaelm.2c01725 SN - 2637-6113 VL - 5 IS - 3 SP - 1670 EP - 1675 ER - TY - GEN A1 - Stabler, Martin A1 - Kuebart, Andreas T1 - Tempo-spatial dynamics of COVID-19 in Germany: A phase model based on a pandemic severity indicator T2 - medRxiv Y1 - 2023 U6 - https://doi.org/10.1101/2023.02.17.23286084 ER - TY - GEN A1 - Kahra, Marvin A1 - Breuß, Michael A1 - Kleefeld, Andreas A1 - Welk, Martin T1 - An Approach to Colour Morphological Supremum Formation using the LogSumExp Approximation T2 - arXiv N2 - Mathematical morphology is a part of image processing that has proven to be fruitful for numerous applications. Two main operations in mathematical morphology are dilation and erosion. These are based on the construction of a supremum or infimum with respect to an order over the tonal range in a certain section of the image. The tonal ordering can easily be realised in grey-scale morphology, and some morphological methods have been proposed for colour morphology. However, all of these have certain limitations. In this paper we present a novel approach to colour morphology extending upon previous work in the field based on the Loewner order. We propose to consider an approximation of the supremum by means of a log-sum exponentiation introduced by Maslov. We apply this to the embedding of an RGB image in a field of symmetric 2×2 matrices. In this way we obtain nearly isotropic matrices representing colours and the structural advantage of transitivity. In numerical experiments we highlight some remarkable properties of the proposed approach. Y1 - 2023 U6 - https://doi.org/10.48550/arXiv.2312.13792 SP - 1 EP - 12 ER - TY - GEN A1 - Kahra, Marvin A1 - Breuß, Michael A1 - Kleefeld, Andreas A1 - Welk, Martin T1 - An Approach to Colour Morphological Supremum Formation Using the LogSumExp Approximation T2 - Lecture Notes in Computer Science N2 - Mathematical morphology is a part of image processing that has proven to be fruitful for numerous applications. Two main operations in mathematical morphology are dilation and erosion. These are based on the construction of a supremum or infimum with respect to an order over the tonal range in a certain section of the image. The tonal ordering can easily be realised in grey-scale morphology, and some morphological methods have been proposed for colour morphology. However, all of these have certain limitations. In this paper we present a novel approach to colour morphology extending upon previous work in the field based on the Loewner order. We propose to consider an approximation of the supremum by means of a log-sum exponentiation introduced by Maslov. We apply this to the embedding of an RGB image in a field of symmetric matrices. In this way we obtain nearly isotropic matrices representing colours and the structural advantage of transitivity. In numerical experiments we highlight some remarkable properties of the proposed approach. KW - mathematical morphology KW - colour image KW - matrix-valued image KW - symmetric matrix KW - transitivity Y1 - 2024 SN - 9783031577925 U6 - https://doi.org/10.1007/978-3-031-57793-2_25 SN - 0302-9743 VL - 14605 SP - 325 EP - 337 PB - Springer Nature Switzerland CY - Cham ER - TY - GEN A1 - Fünning, Tabea A1 - Paul, Martin A1 - Manganelli, Costanza Lucia A1 - Wenger, Christian A1 - Mai, Andreas A1 - Steglich, Patrick T1 - Comparative simulation analysis of photonic ultrasound sensors based on silicon waveguides T2 - Scientific reports N2 - Pressure sensors based on photonic integrated circuits (PIC) offer the prospect of outstanding sensitivities, extreme miniaturization and have the potential for highly scalable production using CMOS compatible processing. PIC-based pressure sensors detect the change in optical properties, i.e. the intensity or phase of the optical carrier wave inside miniaturized waveguide structures. The detection of ultrasound is achieved by engineering the waveguide architecture such that a pressure causes a high change in the effective refractive index of the waveguide. A range of PIC-based pressure sensors have been reported, but a comparison of the sensitivity of the different approaches is not straightforward, since different pressure sensitive waveguide architectures as well as photonic layouts and measurement setups impact the performance. Additionally, the used sensitivity unit is not uniform throughout the different studies, further complicating a comparison. In this work, a detailed simulation study is carried out by finite element modeling of different pressure sensitive waveguide architectures for a consistent comparison. We analyze three different sensor architectures: (A) a free standing membrane located within a tiny air gap above the waveguide, (B) a waveguide located on top of a deflectable membrane as well as (C) a waveguide embedded inside a pressure-sensitive polymer cladding. The mechanical response of the structures and the resulting changes in mode propagation, i.e. the change of the effective refractive index, are analyzed. The waveguide sensitivities in RIU/MPa for different waveguide types (strip, slot) and polarization states (TE, TM) are compared. The results reveal inherent limitations of the different waveguide designs and create a basis for the selection of suitable designs for further ultrasound sensor development. Possibilities for enhancing waveguide sensitivity are identified and discussed. Additionally, we have shown that the studied approaches are extensible to SiN waveguides. KW - Ultrasound sensor Y1 - 2025 U6 - https://doi.org/10.1038/s41598-025-01953-9 SN - 2045-2322 VL - 15 IS - 1 SP - 1 EP - 13 PB - Springer Science and Business Media LLC CY - [London] ER - TY - GEN A1 - Kahra, Marvin A1 - Breuß, Michael A1 - Kleefeld, Andreas A1 - Welk, Martin T1 - Matrix-valued LogSumExp approximation for colour morphology T2 - Journal of mathematical imaging and vision N2 - Mathematical morphology is a part of image processing that employs a moving window to modify pixel values through the application of specific operations. The supremum and infimum are pivotal concepts, yet defining them in a general sense for high-dimensional data such as colour is a challenging endeavour. As a result, a number of different approaches have been taken to try to find a solution, with certain compromises being made along the way. In this paper, we present an analysis of a novel approach that replaces the supremum within a morphological operation with the LogExp approximation of the maximum for matrix-valued colours. This approach has the advantage of extending the associativity of dilation from the one-dimensional to the higher-dimensional case. Furthermore, the minimality property is investigated and a relaxation specified to ensure that the approach is continuously dependent on the input data. KW - Mathematical morphology KW - Colour image KW - Matrix-valued image KW - Positive definite matrix KW - Symmetric matrix KW - Supremum Y1 - 2025 U6 - https://doi.org/10.1007/s10851-025-01267-5 SN - 0924-9907 SN - 1573-7683 VL - 67 IS - 5 PB - Springer US CY - New York ER - TY - GEN A1 - Villasmunta, Francesco A1 - Heise, Patrick A1 - Breiter, Manuela A1 - Schrader, Sigurd A1 - Schenk, Harald A1 - Regehly, Martin A1 - Mai, Andreas T1 - Monolithically integrated optical through-silicon waveguides for 3D chip-to-chip photonic interconnects T2 - IEEE journal of selected topics in quantum electronics N2 - The scaling limitations of electrical interconnects are driving the demand for efficient optical chip-to-chip links. We report the first monolithic integration of air-clad optical through-silicon waveguides in silicon, fabricated via Bosch and cryogenic deep reactive-ion etching. Rib, single-bridge, and double-bridge designs with 50 μm cores and up to 150 μm propagation lengths have been evaluated. Cryogenic-etched rib waveguides achieve the highest median transmission (66%, −1.80 dB), compared to Bosch-etched ribs (62%, −2.08 dB). Across all geometries, 3 dB alignment windows range from 9.3 μm to 49.2 μm, with Bosch-etched double-bridge waveguides providing the broadest tolerance. We show that geometric fidelity outweighs sidewall roughness for transmission and alignment in these large-core, multimode optical through-silicon waveguides. This technology provides a scalable, complementary metal-oxide semiconductor-compatible pathway toward 3D photonic interconnects. KW - Optical interconnections KW - Silicon photonics KW - Three-dimensional integrated circuits KW - Through-silicon vias (TSV) Y1 - 2026 U6 - https://doi.org/10.1109/JSTQE.2025.3615001 SN - 1077-260X SN - 1558-4542 VL - 32 IS - 2: 3-D Horizons in Photonics SP - 1 EP - 15 PB - Institute of Electrical and Electronics Engineers (IEEE) CY - New York, NY ER - TY - GEN A1 - Racheva, Miroslava A1 - Basalo Lourido, Javier A1 - Gurdal, Enise Ece A1 - Herbst, Martin A1 - Bayar, Seyhmus A1 - Radzik, Daniela A1 - Bähr, Elen A1 - Zwies, Constanze A1 - Neffe, Axel T. A1 - Pietzsch, Markus A1 - Lendlein, Andreas A1 - Wischke, Christian T1 - Tyrosinase cross-linked PEG hydrogels with DAT and DATT as artificial substrates : design, structure, and functions T2 - Biomacromolecules N2 - Enzymes such as oxidases are sustainable tools for hydrogel synthesis, but complex competing reactions have limited the mechanistic understanding and biomedical applications of these materials. Guided by molecular docking and MM-GBSA calculations, we identified two artificial substrates, desaminotyrosine (DAT) and desaminotyrosyltyrosine (DATT), that were experimentally more efficiently converted by mushroom tyrosinase (mTyr) than the natural substrate tyrosine. These substrates were used to synthesize hydrogels from DAT/DATT-functionalized star-shaped oligoethylene glycol (sOEG). Model reactions elucidated the chemical nature and functionality of the hydrogel netpoints. Material properties were systematically investigated depending on sOEG molecular weight (5, 10, 20 kDa), substrate type, and mTyr concentration. Functional mesh sizes and controlled release functions were investigated with fluorescent dextrans (4–500 kDa) and heparin. Cell culture studies with L929 fibroblasts and THP-1 monocytes suggested inertness of the material. These findings provide fundamental insight into mTyr-catalyzed hydrogel formation and support further exploration for in situ hydrogel synthesis. KW - Hydrogel KW - Enzymatic synthesis KW - Biomaterial Y1 - 2026 U6 - https://doi.org/10.1021/acs.biomac.5c01929 SN - 1525-7797 VL - 27 IS - 2 SP - 1317 EP - 1336 PB - American Chemical Society (ACS) CY - Washington, DC ER -