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Poster: The Potential of Erroneous Outbound Traffic Analysis to Unveil Silent Internal Anomalies
No full textNetwork administrators have long relied on passive measurement to detect malicious activity, diagnose misconfigurations, and ensure network health. Under the assumption that threats and issues originate externally, prior studies [1] have predominantly focused on the analysis of inbound traffic — i.e., traffic initiated by external hosts and targeting internal destinations. Conversely, outbound traffic — i.e., originating from internal hosts toward external destinations — has received comparatively less attention, despite carrying strong indicators of security-relevant anomalies [2].This work was supported by xInternet (eXplainableInternet20225CETN9)underthePRIN2022program, funded by the European Union-NextGenerationEU
On The Sharpness of a Korn’s Inequality For Piecewise H1 Space and Its Applications
No full textIn this paper, we investigate the sharpness of a Korn’s inequality for piecewise H1 space and its applications. We first revisit a Korn’s inequality for the piecewise H1 space based on general polygonal or polyhedral decompositions of the domain. We express the Korn’s inequality with minimal jump terms. Then we prove that such minimal jump conditions are sharp for achieving the Korn’s inequality. The sharpness of the Korn’s inequality and explicitly given minimal conditions can be used to test whether any given finite element spaces satisfy Korn’s inequality, immediately as well as to build or modify nonconforming finite elements for Korn’s inequality to hold.The author Qingguo Hong acknowledges the support from NSF Grant NSF DMS-2419033. The author Young-Ju Lee acknowledges the partial support of Shapiro Fellowship from Penn State in Spring of 2022 and the partial support from NSF DMS-2208499
Beyond Locations: A Motion Range-Aware Similarity Join
No full textWith the proliferation of GPS-enabled devices such as smartphones, the querying of moving objects has attracted substantial attention, with studies covering joins, range and kNN queries, similarity queries, etc. Challenges arise due to variable sampling frequencies, potential inaccuracies in location samples, and the unavailability of locations between samples. Existing similarity joins often rely on discrete location samples, which fail to capture movement uncertainty and may miss meaningful interactions. To address this limitation, we propose Intersection Similarity Join (IS-Join), a novel approach that identifies object pairs based on the overlap of their motion ranges rather than location-based proximity. We define motion ranges as the spatial regions an object may traverse within a given time period, and introduce an intersection similarity measure that quantifies their overlap. To efficiently process IS-Join queries, we develop a Hybrid Ball-tree indexing structure with a repartitioning strategy, enabling scalable candidate filtering. Additionally, we introduce pre-checking and pruning techniques to further reduce computational overhead. Extensive experiments on two real-world trajectory datasets demonstrate that IS-Join significantly outperforms well-designed baselines, achieving up to a 3x reduction in runtime. Our work opens new opportunities for applications such as urban mobility analysis, traffic monitoring, wildlife tracking, and contact tracing
Climate-driven warming, deoxygenation, and desertification in large marine ecosystems
No full textThis study explores Large Marine Ecosystems (LME) impacts caused by climate-induced changes in sea surface temperature (SST), surface dissolved oxygen concentrations (O2), and surface phytoplankton concentrations (CHL). It spans pre-industrial (1850–1900) to future (2015–2099) epochs under Shared Socioeconomic Pathways (SSPs) medium (SSP-2.45) and high (SSP-5.85) CO2 emission scenarios. Across the 66 LMEs, we observed consistent warming, deoxygenation, and desertification, with more pronounced changes in SSP-5.85. SST trends (°C/decade) varied from 0.04 to 0.29 (SSP-2.45) and 0.12 to 0.63 (SSP-5.85), resulting in net increases from >3 °C (SSP-2.45) to >4.5 °C (SSP-5.85). O2 exhibited trends (μmol/kg/decade) of −0.04 to −1.97 (SSP-2.45), with substantial declines in SSP-5.85 (−0.86 to −3.93), and significant net decreases (μmol/kg) of >−18 (SSP-2.45) and >−25 (SSP-5.85). CHL showed significant decreases (kg/m3) up to −0.31 (SSP-2.45) and −0.36 (SSP-5.85), with negative trends (kg/m3/decade) up to −0.0097 (SSP-2.45) and −0.0159 (SSP-5.85), except the Black Sea and Antarctica which exhibited positive trends. Climate indices reveal that LMEs experiencing the least impacts across all indicators occur in the East Siberian Sea, Faroe Plateau, Central Arctic, and Gulf of Mexico, in both scenarios. However, under the SSP-2.45 scenario, additional the Laptev Sea, Insular Pacific-Hawaiian also experienced lower impacts. In SSP-5.85, reduced impacts are observed in the South Brazil Shelf, East Brazil Shelf, Agulhas Current, West Central Australian Shelf, and Canadian High Arctic-North Greenland. Conversely, the most impacted LMEs, including the Barents Sea, Norwegian Sea, Oyashio Current, West Bering Sea, and the Aleutian Islands are affected in both scenarios. Additionally, the Pacific Central-American Coastal region, the Gulf of Alaska, Benguela Current, and the Sea of Japan are affected in the SSP-2.45 scenario. Only the Scotian Shelf experienced high impacts in SSP-5.85. Antarctica exhibited low impacts in both scenarios but substantial increases in SST, O2, and CHL.We thank anonymous reviewers for comments improving the manuscript, Dr. Dhage for his advice on CMIP6 datasets and pre-processing steps, and Amy Vandehey for helpful suggestions during preparation
Characterization of Detonation Waves with High-Speed Rayleigh Scattering and Single-Pulse Laser-Induced Fluorescence
No full textThis study characterizes a Chapman–Jouguet (CJ) hydrogen–air detonation using high-speed Rayleigh scattering and single-shot planar laser-induced fluorescence of nitric oxide (NO-PLIF). Firstly, we demonstrate that a Nd:YAG laser cluster can be employed to conduct high-speed (2.5 MHz) Rayleigh scattering visualizations of hydrogen–air detonations at 25 kPa. This multipulse Rayleigh scattering diagnostic is complementary to the existing techniques: 1) it enables the characterization of any detonation, from CJ to marginal detonations; 2) it is significantly less expensive than typical burst-mode lasers; 3) it has adjustable visualization frequency, which can go beyond 10 MHz with the same energy per pulse, and 4) it is easily applicable to higher initial pressures because the Rayleigh signal scales with number density. Secondly, we combine this multipulse Rayleigh scattering with NO-PLIF to complement the average speed and speed decay measurements with local induction zone length (
) measurements. This five-beam configuration provides measurement capabilities similar to our previous three-beam configuration, outside of the local speed decay. Furthermore, a combined experimental and computational evaluation of the Rayleigh signals reveals that
measurements appear theoretically possible from Rayleigh scattering visualizations, but these experimental measurements are challenging due to the limited image quality in the current multipulse configuration
Real-time imaging of rotation during synthesis by the replisome
No full textDuring chromosome replication, unwinding by the helicase and synthesis by the polymerases can lead to overwinding and supercoiling of DNA. The mechanical consequences of these events and resulting local dynamics at the replication fork are not well understood. To address these issues, we developed a transverse DNA flow-stretching approach to spatially resolve the parental, leading and lagging strands in real-time. Using bacteriophage T7 as a model system, this approach revealed bursts of high-speed replisome rotation that support continuous DNA synthesis. Surprisingly, excessive rotation does not reduce replisome speed, but increases pausing, reduces processivity, and increases polymerase exchange. Taken together, our observations reveal intrinsic pathways to overcome challenges posed by unfavorable DNA topologies during DNA replication.We are grateful to Margot Riggi of the Max Planck Institute of Biochemistry for help in making renderings of the replisome displayed in the manuscript. We would like to thank Fritz Simmel, Hannes Mustchler, Matthias Rief, and Martin Zacharias for critical feedback and support. This work was supported by grant from Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) SFB863-11166240, grants from the European Research Council (Project Number: 804098, REPLISOMEBYPASS, Project Number: 101125005, ChromoMemInMotion), and the Max Planck Societ
Selectivity and Microkinetic Insights on Ethylene Oligomerization over Ni Encapsulated in a Brønsted-less Hollow ZSM-5 Zeolite
No full textWe encapsulated Ni nanoparticles in a hollow ZSM-5 zeolite catalyst using the dissolution-recrystallization method to catalyze ethylene oligomerization. Our aim is to engineer an idealized catalyst free of Brønsted acid contributions to kinetics or deactivation, having isolated and encapsulated Ni2⁺–zeolite species, to study the intrinsic oligomerization kinetics on Ni2⁺–zeolite through an experimental and microkinetic standpoint. We proved how the hollow architecture encapsulates both Ni2⁺ and NiO species, being the former significantly more active and selective toward dimerization. A comprehensive microkinetic model, grounded in the Cossee-Arlman mechanism and parameterized using experimental data, provides a detailed understanding of the reaction network on isolated Ni2⁺ sites. The model reveals that while linear butene formation dominates, its selectivity decreases with increasing ethylene conversion, temperature, and pressure, highlighting the contribution of isomerization pathways at elevated temperatures. This study focuses on the method to develop isolated oligomerization sites and then studies the intrinsic microkinetic pathways and rates.This work was financially supported by the King Abdullah University of Science and Technology (KAUST, BAS/1/1403). The authors thank KAUST Core Labs for the analytical instruments and the expertise provided
Structural Modeling and Cryo-ET Analysis of Focal Adhesion Complexes In Situ
No full textFocal adhesions are dynamic protein structures that attach the cytoskeleton to the extracellular matrix and are critical for mechano-transduction, migration, and signaling. Although extensive biochemical studies and imaging experiments have revealed protein constituents, the three-dimensional spatial arrangement of these structures within cells is not well known. Here, we seek to advance the long-term objective of reconstructing the overall three-dimensional architecture of focal adhesions at molecular resolution. Our aim was to construct a representative fundamental model of the focal adhesion complex, which consists of integrin, talin-1, kindlin-2, paxillin, vinculin, and F-actin. These were modeled together to create a three-dimensional model of the complex, utilizing MesoCraft, a visual modeling tool for building biological mesoscale structures, with subsequent refinements conducted manually. Comparisons of the model were conducted with focal adhesion sites from cryo-electron tomography datasets. Spatial verification of the predicted complex was possible through tomogram segmentation. This combination approach, which encompassed predicted structures, spatial modeling, and cryo-imaging, yields new perspectives on a first trial into the architecture of focal adhesions and provides a platform for future reconstructions of the complete molecular organization of these structures in situ
Aerial Relay to Achieve Covertness and Secrecy
No full textIn this work, we investigate a delay-tolerant covert and secure communication framework relayed by an uncrewed aerial vehicle (UAV). In this framework, a legitimate UAV serves as an aerial relay to facilitate communication when the direct link between the terrestrial transmitter and receiver is blocked. Additionally, the UAV also acts as a friendly jammer and adopts a random jamming transmit power technique to assist the covert communications. In order to achieve optimal trade-offs between these dual functionalities, a phase transition mechanism has been developed, regulated through a phase-switching factor. Given the uncertainty of the malicious nodes' positions, we formulate a robust fractional programming optimization problem aimed at maximizing the covert and secure energy efficiency by jointly optimizing the UAV's trajectory, the transmitter's power, and the phase-switching factor. An alternating optimization-based algorithm is then proposed to solve the fractional programming problem. To ensure low computational complexity, we solve the phase-switching factor sub-problem with a primal-dual search-based algorithm and the others with successive convex approximation-based algorithms. The effectiveness of the proposed algorithm is validated through numerical results
60 cm2 perovskite-silicon tandem solar cells with an efficiency of 28.9% by homogenous passivation
No full textInverted perovskite solar cells face performance limitations due to non-radiative recombination at the perovskite surfaces in devices, including functional layers. Advanced characterization and density functional theory reveal that phosphonic acids passivate perovskite surface defects, while piperazinium chloride mitigates interface recombination by improving energy level alignment, introducing a field effect, and homogenizing the surface. Together, the quasi-Fermi level splitting of the perovskite is homogeneously increased by ca. 100mV. This enables two-terminal perovskite-on-silicon tandems to achieve a certified open-circuit voltage of 2V for a 1 cm² device and high performance in excess of 31%. The scalability of the passivation is furthermore demonstrated with homogenously passivated devices reaching certified efficiencies of 28.9% for an active area of 60 cm².The authors thank Patrick Wyss for wet chemical processing of the Si wafers, Joël Spitznagel and Sylvain Dunand for the 1cm2 Si bottom cell fabrications, Julien Gay for the SiOx-np supply, Adrien Theytaz and Jean-David Decoppet for SnOx atomic layer deposition and screen printing for the large area tandems and Antoine Descoeudres, Vanessa Gainche and Bertrand Paviet-Salomon for the fabrication of 4 cm2 and 60 cm2 Si bottom cells, Gabriel Christmann for PL imaging of 60 cm2 devices, and Pascal Alexander Schouwink for GIWAXS measurements and analysis.The authors acknowledge funding from the European Union's Horizon 2020 and innovation program (VIPERLAB, 101006715), the Swiss State Secretariat for Education Research and Innovation (SERI) (TRIUMPH, 101075725), the Swiss National Science Foundation (PAPET, 200021_197006; A3P, 40B2-0_1203626, Radicals, CRSII5_216647), the Swiss Federal Office of Energy (PRESTO, PERSISTARS, BESTOBOT), (COMET, 502791-01) and the ETH Domain through an AM grant (AMYS), European Commission and the Swiss State Secretariat for Education, Research and Innovation (SERI) (PEPPERONI). MO, DT and AK acknowledge funding from the European Union's Horizon 2020 research and innovation program under a Marie Skłodowska-Curie grants (945363 and 101034260). DT acknowledges the State Secretariat for Education, Research, and Innovation for an FCS/ESKAS Swiss Government Excellence Scholarship. The research reported in this publication was supported by funding from King Abdullah University of Science and Technology (KAUST). For computer time, this research used Shaheen III and Ibex managed by the Supercomputing Core Laboratory at KAUST