cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Adhesion to the bone marrow niche - podosome-like structures in hematopoietic stem cells
Creators: name: Frommer, Miriam
Publisher: name: Hannover : Institutionelles Repositorium der Leibniz Universität Hannover
Year: 2024
Subjects: subject: hematopoiesis
subject: Hematopoietic stem cells
subject: bone marrow niche
subject: adhesion
subject: podosomes
subject: contains research data
subject: Adhäsion
subject: enthält Forschungsdaten
subject: Hämatopoese
subject: Hämatopoetische Stammzellen
subject: Knochenmark Nische
subject: Podosomen
subject: Dewey Decimal Classification::500 | Naturwissenschaften

description: Maintenance and homeostasis of the hematopoietic system is enabled by hematopoietic stem and progenitor cells (HSPC). These multipotent cells ensure the replenishment of all hematopoietic cells by giving rise to progeny with the ability to differentiate into respective cells while also self-renewing themselves. A crucial factor to regulate this essential feature of HSPC is their interaction with a specific microenvironment – the hematopoietic stem cell niche in the bone marrow (BM). The interaction of HSPC with their niche provides the signals necessary for the cells to maintain their stemness and to sustain the HSPC population. In order to provide these signals constantly, adhesion of the stem cells to the extracellular matrix (ECM) of the BM niche is of the utmost importance. Yet, the way in which HSPC anchor to their specific microenvironment is not well understood. In the here presented work, the adhesion structures established by HSPC upon contact with fibronectin are investigated in regard to their appearance, maturity state and composition of cell adhesion molecules (CAM). By investigating the spatial distribution of native and mature adhesion structure markers alongside the actin cytoskeleton in adherent HSPC using super resolution microscopy it was found, that HSPC adhere in a dynamic manner and display varying morphologies that can contain protrusions and/or structures resembling podosomes. Further investigation of these podosome-like structures (PLS) revealed that these structures are defined by an F-actin spot strongly co-localizing with phosphorylated PYK2 (pPYK2). Assessment of the spatial distribution of pPYK2, alongside the classic podosome proteins vinculin and paxillin, showed a distribution of these molecules towards the periphery of the F-actin spot. This distribution pattern became more pronounced - resembling classic podosomes more - in cells with round morphology and increased number of PLS. Additionally, examining the differentiation state of HSPC with different morphologies, it was found that the round, PLS containing cells were less differentiated compared to cells with deviating observed morphologies. Together, these findings indicate a highly dynamic adhesion behavior of HSPC, involving PLS. Given the importance of proper stem cell retention in the BM niche environment, for full function of the hematopoietic system, understanding the adhesion processes involved is an essential step in gaining insight into hematopoiesis in health and disease.
sj-docx-1-pie-10.1177_09544089231170984 - Supplemental material for Investigation on the effects of powder mixing method on mechanical properties and wear resistance of Al/graphene composites
Creators: name: Rashidi, Kambiz
name: Moazami-Goudarzi, Mohammad
name: Masoudi, Afshin
Publisher: name: SAGE Journals
Year: 2023
Subjects: subject: 99999 Engineering not elsewhere classified
subject: FOS: Other engineering and technologies
subject: 91299 Materials Engineering not elsewhere classified
subject: FOS: Materials engineering

description: Supplemental material, sj-docx-1-pie-10.1177_09544089231170984 for Investigation on the effects of powder mixing method on mechanical properties and wear resistance of Al/graphene composites by Kambiz Rashidi, Mohammad Moazami-Goudarzi and Afshin Masoudi in Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering
SED2AM: Solving Multi-Trip Time-Dependent Vehicle Routing Problem using Deep Reinforcement Learning
Creators: name: Mozhdehi, Arash
name: Wang, Yunli
name: Sun, Sun
name: Wang, Xin
Publisher: name: arXiv
Year: 2025
Subjects: subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Deep reinforcement learning (DRL)-based frameworks, featuring Transformer-style policy networks, have demonstrated their efficacy across various vehicle routing problem (VRP) variants. However, the application of these methods to the multi-trip time-dependent vehicle routing problem (MTTDVRP) with maximum working hours constraints -- a pivotal element of urban logistics -- remains largely unexplored. This paper introduces a DRL-based method called the Simultaneous Encoder and Dual Decoder Attention Model (SED2AM), tailored for the MTTDVRP with maximum working hours constraints. The proposed method introduces a temporal locality inductive bias to the encoding module of the policy networks, enabling it to effectively account for the time-dependency in travel distance or time. The decoding module of SED2AM includes a vehicle selection decoder that selects a vehicle from the fleet, effectively associating trips with vehicles for functional multi-trip routing. Additionally, this decoding module is equipped with a trip construction decoder leveraged for constructing trips for the vehicles. This policy model is equipped with two classes of state representations, fleet state and routing state, providing the information needed for effective route construction in the presence of maximum working hours constraints. Experimental results using real-world datasets from two major Canadian cities not only show that SED2AM outperforms the current state-of-the-art DRL-based and metaheuristic-based baselines but also demonstrate its generalizability to solve larger-scale problems.
description: Accepted by ACM TKDD: https://dl.acm.org/doi/10.1145/3721983
sj-docx-1-asp-10.1177_00037028231169971 - Supplemental material for Reconstruction of Raman Spectra of Biochemical Mixtures Using Group and Basis Restricted Non-Negative Matrix Factorization
Creators: name: Milligan, Kirsty
name: Scarrott, Kendra
name: Andrews, Jeffrey L.
name: Brolo, Alexandre G.
name: Lum, Julian J.
name: Jirasek, Andrew
Publisher: name: SAGE Journals
Year: 2023
Subjects: subject: 99999 Engineering not elsewhere classified
subject: FOS: Other engineering and technologies

description: Supplemental material, sj-docx-1-asp-10.1177_00037028231169971 for Reconstruction of Raman Spectra of Biochemical Mixtures Using Group and Basis Restricted Non-Negative Matrix Factorization by Kirsty Milligan, Kendra Scarrott, Jeffrey L. Andrews, Alexandre G. Brolo, Julian J. Lum and Andrew Jirasek in Applied Spectroscopy
OPG-Policy: Occluded Push-Grasp Policy Learning with Amodal Segmentation
Creators: name: Ding, Hao
name: Zeng, Yiming
name: Wan, Zhaoliang
name: Cheng, Hui
Publisher: name: arXiv
Year: 2025
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: Goal-oriented grasping in dense clutter, a fundamental challenge in robotics, demands an adaptive policy to handle occluded target objects and diverse configurations. Previous methods typically learn policies based on partially observable segments of the occluded target to generate motions. However, these policies often struggle to generate optimal motions due to uncertainties regarding the invisible portions of different occluded target objects across various scenes, resulting in low motion efficiency. To this end, we propose OPG-Policy, a novel framework that leverages amodal segmentation to predict occluded portions of the target and develop an adaptive push-grasp policy for cluttered scenarios where the target object is partially observed. Specifically, our approach trains a dedicated amodal segmentation module for diverse target objects to generate amodal masks. These masks and scene observations are mapped to the future rewards of grasp and push motion primitives via deep Q-learning to learn the motion critic. Afterward, the push and grasp motion candidates predicted by the critic, along with the relevant domain knowledge, are fed into the coordinator to generate the optimal motion implemented by the robot. Extensive experiments conducted in both simulated and real-world environments demonstrate the effectiveness of our approach in generating motion sequences for retrieving occluded targets, outperforming other baseline methods in success rate and motion efficiency.
sj-docx-1-asp-10.1177_00037028231170234 - Supplemental material for Adversarial Data Augmentation and Transfer Net for Scrap Metal Identification Using Laser-Induced Breakdown Spectroscopy Measurement of Standard Reference Materials
Creators: name: Srivastava, Ekta
name: Kim, Hyebin
name: Lee, Jaepil
name: Shin, Sungho
name: Jeong, Sungho
name: Hwang, Euiseok
Publisher: name: SAGE Journals
Year: 2023
Subjects: subject: 99999 Engineering not elsewhere classified
subject: FOS: Other engineering and technologies

description: Supplemental material, sj-docx-1-asp-10.1177_00037028231170234 for Adversarial Data Augmentation and Transfer Net for Scrap Metal Identification Using Laser-Induced Breakdown Spectroscopy Measurement of Standard Reference Materials by Ekta Srivastava, Hyebin Kim, Jaepil Lee, Sungho Shin, Sungho Jeong and Euiseok Hwang in Applied Spectroscopy
sj-pdf-1-hpp-10.1177_15248399231153171 – Supplemental material for He Looks Like My Father
Creators: name: White Jones, Ashley
Publisher: name: SAGE Journals
Year: 2023
Subjects: subject: 111708 Health and Community Services
subject: FOS: Health sciences
subject: 111799 Public Health and Health Services not elsewhere classified
subject: Sociology
subject: FOS: Sociology

description: Supplemental material, sj-pdf-1-hpp-10.1177_15248399231153171 for He Looks Like My Father by Ashley White Jones in Health Promotion Practice
Therapeutic Management of Bovine Puerperal Metritis in a Cow
Creators: name: 1Ankit Kumar, 2Bhavna Dabas
Publisher: name: veterinary today
Year: 2024

description: Abstract : A cow was presented with recent calving, continuous straining and expulsion of foul-smelling mucopurulent discharge from the vagina. The cases were diagnosed as puerperal metritis, sequalae to retention of placenta. The animal was successfully managed with systemic antibiotic and the uterus was washed with diluted potassium permanganate solution, along with povidone iodine & metronidazole douches and other supportive drugs. Animal responded well to treatment and recovered completely after one week of treatment.

Keywords: Cow; fetid; puerperal metritis; uterine discharge.
Continuous-variable tomography of solitary electrons
Creators: name: Fletcher, J. D.
name: Johnson, N.
name: Locane, E.
name: See, P.
name: Griffiths, J. P.
name: Farrer, I.
name: Ritchie, D. A.
name: Brouwer, Piet W.
name: Kashcheyevs, V.
name: Kataoka, M.
Publisher: name: Freie Universität Berlin
Year: 2019
Subjects: subject: Electronic and spintronic devices
subject: Nanoscale devices
subject: Quantum dots
subject: 500 Naturwissenschaften und Mathematik::510 Mathematik::510 Mathematik

description: A method for characterising the wave-function of freely-propagating particles would provide a useful tool for developing quantum-information technologies with single electronic excitations. Previous continuous-variable quantum tomography techniques developed to analyse electronic excitations in the energy-time domain have been limited to energies close to the Fermi level. We show that a wide-band tomography of single-particle distributions is possible using energy-time filtering and that the Wigner representation of the mixed-state density matrix can be reconstructed for solitary electrons emitted by an on-demand single-electron source. These are highly localised distributions, isolated from the Fermi sea. While we cannot resolve the pure state Wigner function of our excitations due to classical fluctuations, we can partially resolve the chirp and squeezing of the Wigner function imposed by emission conditions and quantify the quantumness of the source. This tomography scheme, when implemented with sufficient experimental resolution, will enable quantum-limited measurements, providing information on electron coherence and entanglement at the individual particle level.
Fractional Correspondence Framework in Detection Transformer
Creators: name: Zareapoor, Masoumeh
name: Shamsolmoali, Pourya
name: Zhou, Huiyu
name: Lu, Yue
name: García, Salvador
Publisher: name: arXiv
Year: 2025
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: The Detection Transformer (DETR), by incorporating the Hungarian algorithm, has significantly simplified the matching process in object detection tasks. This algorithm facilitates optimal one-to-one matching of predicted bounding boxes to ground-truth annotations during training. While effective, this strict matching process does not inherently account for the varying densities and distributions of objects, leading to suboptimal correspondences such as failing to handle multiple detections of the same object or missing small objects. To address this, we propose the Regularized Transport Plan (RTP). RTP introduces a flexible matching strategy that captures the cost of aligning predictions with ground truths to find the most accurate correspondences between these sets. By utilizing the differentiable Sinkhorn algorithm, RTP allows for soft, fractional matching rather than strict one-to-one assignments. This approach enhances the model's capability to manage varying object densities and distributions effectively. Our extensive evaluations on the MS-COCO and VOC benchmarks demonstrate the effectiveness of our approach. RTP-DETR, surpassing the performance of the Deform-DETR and the recently introduced DINO-DETR, achieving absolute gains in mAP of +3.8% and +1.7%, respectively.
Generalizability of Neural Networks Minimizing Empirical Risk Based on Expressive Ability
Creators: name: Yu, Lijia
name: Miao, Yibo
name: Zhu, Yifan
name: Gao, Xiao-Shan
name: Zhang, Lijun
Publisher: name: arXiv
Year: 2025
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Statistics Theory (math.ST)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: The primary objective of learning methods is generalization. Classic uniform generalization bounds, which rely on VC-dimension or Rademacher complexity, fail to explain the significant attribute that over-parameterized models in deep learning exhibit nice generalizability. On the other hand, algorithm-dependent generalization bounds, like stability bounds, often rely on strict assumptions. To establish generalizability under less stringent assumptions, this paper investigates the generalizability of neural networks that minimize or approximately minimize empirical risk. We establish a lower bound for population accuracy based on the expressiveness of these networks, which indicates that with an adequate large number of training samples and network sizes, these networks, including over-parameterized ones, can generalize effectively. Additionally, we provide a necessary condition for generalization, demonstrating that, for certain data distributions, the quantity of training data required to ensure generalization exceeds the network size needed to represent the corresponding data distribution. Finally, we provide theoretical insights into several phenomena in deep learning, including robust generalization, importance of over-parameterization, and effect of loss function on generalization.
Time-delay matrix, midgap spectral peak, and thermopower of an Andreev billiard
Creators: name: Marciani, M.
name: Brouwer, Piet W.
name: Beenakker, C. W. J.
Publisher: name: Freie Universität Berlin
Year: 2014
Subjects: subject: 500 Naturwissenschaften und Mathematik::530 Physik

description: We derive the statistics of the time-delay matrix (energy derivative of the scattering matrix) in an ensemble of superconducting quantum dots with chaotic scattering (Andreev billiards), coupled ballistically to M conducting modes (electron-hole modes in a normal metal or Majorana edge modes in a superconductor). As a first application we calculate the density of states ρ0 at the Fermi level. The ensemble average ⟨ρ0⟩=δ−10M[max(0,M+2α/β)]−1 deviates from the bulk value 1/δ0 by an amount depending on the Altland-Zirnbauer symmetry indices α,β. The divergent average for M=1,2 in symmetry class D (α=−1, β=1) originates from the midgap spectral peak of a closed quantum dot, but now no longer depends on the presence or absence of a Majorana zero mode. As a second application we calculate the probability distribution of the thermopower, contrasting the difference for paired and unpaired Majorana edge modes.
title: BCaT Field Trip to the National Museum of African American History and Culture Flier
Creators: name: Walcott, Rianna
Publisher: name: University of Michigan
Year: 2024

description: The BCaT Lab hosted a field trip on November 20th to the National Museum of African American History and Culture. There, they had lunch in the Sweet Home Cafe and received a guided tour of the Power of Place exhibition. This tour helped provide insights into the ways BCaT can explore developing their Black Homeplaces Co(Lab)!
Spin-wave-induced correction to the conductivity of ferromagnets
Creators: name: Danon, J.
name: Ricottone, A.
name: Brouwer, Piet W.
Publisher: name: Freie Universität Berlin
Year: 2014
Subjects: subject: 500 Naturwissenschaften und Mathematik::530 Physik

description: We calculate the correction to the conductivity of a disordered ferromagnetic metal due to spin-wave-mediated electron-electron interactions. This correction is the generalization of the Altshuler-Aronov correction to spin- wave-mediated interactions. We derive a general expression for the conductivity correction to lowest order in the spin-wave-mediated interaction and for the limit that the exchange splitting Δ is much smaller than the Fermi energy. For a “clean” ferromagnet with Δτel/ℏ≫1, with τel being the mean time for impurity scattering, we find a correction δσ∝−T5/2 at temperatures T above the spin-wave gap. In the opposite, “dirty” limit, Δτel/ℏ≪1, the correction is a nonmonotonous function of temperature.
Trace metals contamination in groundwater and implications on human health: comprehensive assessment using hydrogeochemical and geostatistical methods
Creators: name: Brindha, Karthikeyan
name: Paul, Rajib
name: Walter, Julien
name: Tan, Mou Leong
name: Singh, Mahesh Kumar
Publisher: name: Freie Universität Berlin
Year: 2020
Subjects: subject: heavy metals
subject: iron
subject: faecal coliforms
subject: PHREEQC
subject: empirical Bayesian kriging
subject: factor analysis
subject: 500 Naturwissenschaften und Mathematik::550 Geowissenschaften, Geologie::551 Geologie, Hydrologie, Meteorologie

description: Monitoring the groundwater chemical composition and identifying the presence of pollutants is an integral part of any comprehensive groundwater management strategy. The present study was conducted in a part of West Tripura, northeast India, to investigate the presence and sources of trace metals in groundwater and the risk to human health due to direct ingestion of groundwater. Samples were collected from 68 locations twice a year from 2016 to 2018. Mixed Ca–Mg–HCO3, Ca–Cl and Ca–Mg–Cl were the main groundwater types. Hydrogeochemical methods showed groundwater mineralization due to (1) carbonate dissolution, (2) silicate weathering, (3) cation exchange processes and (4) anthropogenic sources. Occurrence of faecal coliforms increased in groundwater after monsoons. Nitrate and microbial contamination from wastewater infiltration were apparent. Iron, manganese, lead, cadmium and arsenic were above the drinking water limits prescribed by the Bureau of Indian Standards. Water quality index indicated 1.5% had poor, 8.7% had marginal, 16.2% had fair, 66.2% had good and 7.4% had excellent water quality. Correlation and principal component analysis reiterated the sources of major ions and trace metals identified from hydrogeochemical methods. Human exposure assessment suggests health risk due to high iron in groundwater. The presence of unsafe levels of trace metals in groundwater requires proper treatment measures before domestic use.
Saving on the Phone - Evidence from Ghanaian Cocoa Farmers
Creators: name: Possner, Annkathrin
name: Rosero, Gabriel
name: Musshoff, Oliver
name: Possner, Annkathrin
name: Rosero, Gabriel
name: Musshoff, Oliver
Publisher: name: Unknown
Year: 2022
Subjects: subject: Agricultural Finance
subject: Consumer/Household Economics
subject: Digital Finance
subject: Mobile Financial Services
subject: Gender
subject: Micro Savings
subject: Interval regression
subject: Sample Selection
subject: Ghana

description: The poor and rural population in Sub Saharan Africa suffers from low financial inclusion. Yet, excluding population parts from accessing formal financial services means lost opportunity for household level, as well as for the whole economy. Evidence suggests that formal saving helps to accumulate larger amounts: Recent studies show how saving contributes to smoothing consumption and increasing resilience. A powerful tool for enhancing marginalized groups’ financial inclusion are mobile financial services. In Ghana’s rapidly developing banking and savings sector open questions remain. We investigate factors affecting Ghanaian cocoa farmers decision to save, as well as their savings amount. Among other factors, we focus on different savings instruments such as mobile saving on the phone, bank accounts or the traditional group saving method Susu. We employ data from a structured telephone survey conducted in 2021 among 405 randomly sampled cocoa farmers. The results of a two-step Heckman approach show that, while Susu or a bank account enhance savings, saving on the phone is associated with lower amounts. However, female farmers seem to benefit from this technology. In the light of recent policies issued by the Ghanaian government, directed at fortifying the digital finance sector, our results provide valuable information for public policy makers as well as the private sector.
title: Magia daemoniaca, magia naturalis, zouber
title: Schreibweisen von Magie und Alchemie in Mittelalter und Früher Neuzeit
titleType: Subtitle
Creators: name: Alt, Peter-André (Ed.)
name: Eming, Jutta (Ed.)
name: Renz, Tilo (Ed.)
name: Wels, Volkhard (Ed.)
Publisher: name: Freie Universität Berlin
Year: 2015
Subjects: subject: Wissensgeschichte
subject: 900 Geschichte und Geografie::900 Geschichte::901 Geschichtsphilosophie, Geschichtstheorie

description: Dem Forschungsprogramm des Sonderforschungsbereichs 980 „Episteme in Bewegung“ entsprechend, widmen sich die Beiträge des Bandes unterschiedlichen Transfers zwischen den Wissensbereichen der Magie, der Alchemie und der Dichtung vom Mittelalter bis in die Frühe Neuzeit. Dabei stehen ‚Schreibweisen‘ als die jeweiligen Formen der Darstellung von Wissen im Zentrum des Interesses. Magische und alchemische Texte haben in der Geschichte einen ebenso exklusiven wie prekären Status und bedienen sich daher häufig Verfahren der sprachlichen Verschlüsselung. Aus heutiger Perspektive können diese Verfahren als literarische charakterisiert werden; im historischen Kontext haben sie eigene Funktionen, die teilweise erst noch bestimmt werden müssen. Darüber hinaus ist magisches und alchemisches Wissen vielfach in die Literatur überführt worden und hat dabei wiederum formale und inhaltliche Veränderungen erfahren. Der Band widmet sich damit der doppelten Fragestellung, wie Wissen über Magie und Alchemie im Mittelalter und in der Frühen Neuzeit vermittelt wird und auf welche Weisen gerade literarische Texte dieses Wissen spiegeln, verarbeiten und modifizieren.
LiteChain: A Lightweight Blockchain for Verifiable and Scalable Federated Learning in Massive Edge Networks
Creators: name: Chen, Handi
name: Zhou, Rui
name: Chan, Yun-Hin
name: Jiang, Zhihan
name: Chen, Xianhao
name: Ngai, Edith C. H.
Publisher: name: arXiv
Year: 2025
Subjects: subject: Cryptography and Security (cs.CR)
subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: FOS: Computer and information sciences

description: Leveraging blockchain in Federated Learning (FL) emerges as a new paradigm for secure collaborative learning on Massive Edge Networks (MENs). As the scale of MENs increases, it becomes more difficult to implement and manage a blockchain among edge devices due to complex communication topologies, heterogeneous computation capabilities, and limited storage capacities. Moreover, the lack of a standard metric for blockchain security becomes a significant issue. To address these challenges, we propose a lightweight blockchain for verifiable and scalable FL, namely LiteChain, to provide efficient and secure services in MENs. Specifically, we develop a distributed clustering algorithm to reorganize MENs into a two-level structure to improve communication and computing efficiency under security requirements. Moreover, we introduce a Comprehensive Byzantine Fault Tolerance (CBFT) consensus mechanism and a secure update mechanism to ensure the security of model transactions through LiteChain. Our experiments based on Hyperledger Fabric demonstrate that LiteChain presents the lowest end-to-end latency and on-chain storage overheads across various network scales, outperforming the other two benchmarks. In addition, LiteChain exhibits a high level of robustness against replay and data poisoning attacks.
title: Mixing positive and negative valence
title: Affective-semantic integration of bivalent words
titleType: Subtitle
Creators: name: Kuhlmann, Michael
name: Hofmann, Markus
name: Briesemeister, Benny B.
name: Jacobs, Arthur M.
Publisher: name: Freie Universität Berlin
Year: 2016
Subjects: subject: 100 Philosophie und Psychologie::150 Psychologie::152 Sinneswahrnehmung, Bewegung, Emotionen, Triebe
subject: 100 Philosophie und Psychologie::150 Psychologie::153 Kognitive Prozesse, Intelligenz

description: Single words have affective and aesthetic properties that influence their processing. Here we investigated the processing of a special case of word stimuli that are extremely difficult to evaluate, bivalent noun-noun-compounds (NNCs), i.e. novel words that mix a positive and negative noun, e.g. ‘Bombensex’ (bomb-sex). In a functional magnetic resonance imaging (fMRI) experiment we compared their processing with easier-to-evaluate non-bivalent NNCs in a valence decision task (VDT). Bivalent NNCs produced longer reaction times and elicited greater activation in the left inferior frontal gyrus (LIFG) than non-bivalent words, especially in contrast to words of negative valence. We attribute this effect to a LIFG-grounded process of semantic integration that requires greater effort for processing converse information, supporting the notion of a valence representation based on associations in semantic networks.
title: Συστήματα μεταφοράς ενέργεΙας HVDC και εφαρμογές
title: HVDC power transmission systems and applications
titleType: AlternativeTitle
Creators: name: Πασλαμούσκας, Δήμος
Publisher: name: Πανεπιστήμιο Πελοποννήσου
Year: 2024
Subjects: subject: Συστήματα ηλεκτρικής ενέργειας, συστήματα μεταφοράς ενέργειας HVDC, τεχνολογία υψηλών τάσεων, εφαρμογές

description: Τα συστήματα HVDC είναι μια τεχνολογία μεταφοράς που χρησιμοποιεί ηλεκτρονικά ισχύος για τη μετατροπή υψηλής τάσης εναλλασσόμενου ρεύματος σε υψηλή τάση συνεχούς ρεύματος και πάλι σε υψηλή τάση εναλλασσόμενου ρεύματος. Τα συστήματα αυτά χρησιμοποιούν συνεχές ρεύμα (DC) για τη μεταφορά ισχύος, σε αντίθεση με τα πιο συνηθισμένα συστήματα που χρησιμοποιούν εναλλασσόμενο ρεύμα (AC). Τα συστήματα αυτά χρησιμοποιούνται συνήθως για τη μετάδοση ισχύος σε μεγάλες αποστάσεις, είτε σε υπόγειες, εναέριες ή ακόμη και υποθαλάσσιες γραμμές μεταφοράς. Στην παρούσα διπλωματική εργασία γίνεται μία εκτενής θεωρητική ανάλυση η οποία περιλαμβάνει την διάρθρωση, την λειτουργία, τις τεχνολογίες ως αναφορά στα πλεονεκτήματα και τα μειονεκτήματα των συστημάτων μεταφοράς HVDC, παραδείγματα εφαρμογών και πώς μπορεί να εξελιχθούν στο μέλλον.
Quenching of the E2 phonon line in the Raman spectra of wurtzite GaAs nanowires caused by the dielectric polarization contrast
Creators: name: Ramsteiner, M.
name: Brandt, Oliver
name: Kusch, P.
name: Breuer, Steffen
name: Reichm, S.
name: Geelhaar, L.
Publisher: name: Freie Universität Berlin
Year: 2013
Subjects: subject: 500 Naturwissenschaften und Mathematik::530 Physik

description: We investigate the Raman intensity of EH2 phonons in wurtzite GaAs nanowire ensembles as well as single nanowires as a function of excitation wavelength. For nanowires with radii in the range of 25 nm, an almost complete quenching of the EH2 phonon line is observed for excitation wavelengths larger than 600 nm. The observed behavior is quantitatively explained by the dielectric polarization contrast for the coupling of light into the GaAs nanowires. Our results define the limits of Raman spectroscopy for the detection of the wurtzite phase in semiconductor nanowires.
Role of the iodide–methylammonium interaction in the ferroelectricity of CH3NH3PbI3
Creators: name: Breternitz, Joachim
name: Lehmann, F.
name: Barnett, S. A.
name: Nowell, H.
name: Schorr, S.
Publisher: name: Freie Universität Berlin
Year: 2019
Subjects: subject: ferroelectricity
subject: hybrid perovskites
subject: inorganic chemistry
subject: photovoltaic materials
subject: structure elucidation
subject: 500 Naturwissenschaften und Mathematik::540 Chemie::549 Mineralogie

description: Excellent conversion efficiencies of over 20 % and facile cell production have placed hybrid perovskites at the forefront of novel solar cell materials, with CH3NH3PbI3 being an archetypal compound. The question why CH3NH3PbI3 has such extraordinary characteristics, particularly a very efficient power conversion from absorbed light to electrical power, is hotly debated, with ferroelectricity being a promising candidate. This does, however, require the crystal structure to be non‐centrosymmetric and we herein present crystallographic evidence as to how the symmetry breaking occurs on a crystallographic and, therefore, long‐range level. Although the molecular cation CH3NH3+ is intrinsically polar, it is heavily disordered and this cannot be the sole reason for the ferroelectricity. We show that it, nonetheless, plays an important role, as it distorts the neighboring iodide positions from their centrosymmetric positions.
title: Αεροδυναμική μελέτη γύρω από το πτερύγιο αεροπλάνου ONERA M6 για διαφορετικά μοντέλα τύρβης RANS
title: Aerodynamic study around ONERA M6 airfoil for different RANS turbulence models
titleType: AlternativeTitle
Creators: name: Βάρσος, Ευρυσθένης
Publisher: name: Πανεπιστήμιο Δυτικής Αττικής
Year: 2024
Subjects: Πτερύγια
ONERA M6
Αεροδυναμικοί συντελεστές
RANS
SimScale

description: Η παρούσα εργασία ασχολείται με τον σχεδιασμό και τη βελτιστοποίηση αεροπορικών πτερυγίων, εστιάζοντας ειδικά στο πτερύγιο με γεωμετρία ONERA M6. Ιδιαίτερη προσοχή δίνεται στα γεωμετρικά χαρακτηριστικά, τους αεροδυναμικούς συντελεστές, καθώς και την επίδραση της γωνίας επίθεσης. Η ανάλυση περιλαμβάνει προσομοιώσεις τυρβώδους ροής με χρήση των μοντέλων RANS (Reynolds-Averaged Navier-Stokes) και τα μοντέλα τύρβης k-epsilon και k-ω SST, με στόχο την αξιολόγηση της ακρίβειας και αποτελεσματικότητάς τους. Οι υπολογισμοί πραγματοποιήθηκαν μέσω του λογισμικού OpenFoam, ενώ για την παρούσα μελέτη χρησιμοποιήθηκε το Simscale, ένα εργαλείο ανοιχτού κώδικα για υπολογιστική ρευστοδυναμική. Τα αποτελέσματα της ανάλυσης περιλαμβάνουν διαγράμματα ταχύτητας και πίεσης τα οποία δημιουργήθηκαν με το ParaView 5.9.1. Επιπλέον, από το post-processing στο SimScale προέκυψαν διαγράμματα σύγκλισης για τους συντελεστές άντωσης και οπισθέλκουσας, που αποτελούν βασικά κριτήρια για την αξιολόγηση της απόδοσης.
Large contribution of fermi arcs to the conductivity of topological metals
Creators: name: Breitkreiz, M.
name: Brouwer, Piet W.
Publisher: name: Freie Universität Berlin
Year: 2019
Subjects: subject: anomalous Hall effect
subject: electrical conductivity
subject: 2-dimensional systems
subject: Weyl semimetal
subject: condensed matter
subject: materials physics
subject: 500 Naturwissenschaften und Mathematik::530 Physik::539 Moderne Physik

description: Surface-state contributions to the dc conductivity of most homogeneous metals exposed to uniform electric fields are usually as small as the system size is large compared to the lattice constant. In this Letter, we show that surface states of topological metals can contribute with the same order of magnitude as the bulk, even in large systems. This effect is intimately related to the intrinsic anomalous Hall effect, in which an applied voltage induces chiral surface-state currents proportional to the system size. Unlike the anomalous Hall effect, the large contribution of surface states to the dc conductivity is also present in time-reversal invariant Weyl semimetals, where the surface states come in counterpropagating time-reversed pairs. While the Hall voltage vanishes in the presence of time-reversal symmetry, the twinned chiral surface currents develop similarly as in the time-reversal-broken case. For this effect to occur, the relaxation length associated with scattering between time-reversed partner states needs to be larger than the separation of contributing surfaces, which results in a characteristic size dependence of the resistivity and a highly inhomogeneous current-density profile across the sample.
Quantum Transport of Disordered Weyl Semimetals at the Nodal Point
Creators: name: Sbierski, Björn
name: Pohl, Gregor
name: Bergholtz, Emil J.
name: Brouwer, Piet W.
Publisher: name: Freie Universität Berlin
Year: 2014
Subjects: subject: 500 Naturwissenschaften und Mathematik::530 Physik

description: Weyl semimetals are paradigmatic topological gapless phases in three dimensions. We here address the effect of disorder on charge transport in Weyl semimetals. For a single Weyl node with energy at the degeneracy point and without interactions, theory predicts the existence of a critical disorder strength beyond which the density of states takes on a nonzero value. Predictions for the conductivity are divergent, however. In this work, we present a numerical study of transport properties for a disordered Weyl cone at zero energy. For weak disorder, our results are consistent with a renormalization group flow towards an attractive pseudoballistic fixed point with zero conductivity and a scale-independent conductance; for stronger disorder, diffusive behavior is reached. We identify the Fano factor as a signature that discriminates between these two regimes.
PKC in motorneurons underlies self-learning, a form of motor learning in Drosophila
Creators: name: Colomb, Julien
name: Brembs, Björn
Publisher: name: Freie Universität Berlin
Year: 2016
Subjects: subject: Motor learning
subject: Habit
subject: Operant learning
subject: FoxP
subject: Skill learning
subject: Procedural memory
subject: Motor adaptation
subject: Egocentric strategy
subject: 500 Naturwissenschaften und Mathematik::570 Biowissenschaften; Biologie

description: Tethering a fly for stationary flight allows for exquisite control of its sensory input, such as visual or olfactory stimuli or a punishing infrared laser beam. A torque meter measures the turning attempts of the tethered fly around its vertical body axis. By punishing, say, left turning attempts (in a homogeneous environment), one can train a fly to restrict its behaviour to right turning attempts. It was recently discovered that this form of operant conditioning (called operant self-learning), may constitute a form of motor learning in Drosophila. Previous work had shown that Protein Kinase C (PKC) and the transcription factor dFoxP were specifically involved in self- learning, but not in other forms of learning. These molecules are specifically involved in various forms of motor learning in other animals, such as compulsive biting in Aplysia, song-learning in birds, procedural learning in mice or language acquisition in humans. Here we describe our efforts to decipher which PKC gene is involved in self-learning in Drosophila. We also provide evidence that motorneurons may be one part of the neuronal network modified during self-learning experiments. The collected evidence is reminiscent of one of the simplest, clinically relevant forms of motor learning in humans, operant reflex conditioning, which also relies on motorneuron plasticity.
title: Quantum transport in Dirac materials
title: Signatures of tilted and anisotropic Dirac and Weyl cones
titleType: Subtitle
Creators: name: Trescher, M.
name: Sbierski, B.
name: Brouwer, Piet W.
name: Bergholtz, Emil J.
Publisher: name: Freie Universität Berlin
Year: 2015
Subjects: subject: 500 Naturwissenschaften und Mathematik::530 Physik

description: We calculate conductance and noise for quantum transport at the nodal point for arbitrarily tilted and anisotropic Dirac or Weyl cones. Tilted and anisotropic dispersions are generic in the absence of certain discrete symmetries, such as particle-hole and lattice point group symmetries. Whereas anisotropy affects the conductance g, but leaves the Fano factor F (the ratio of shot noise power and current) unchanged, a tilt affects both g and F. Since F is a universal number in many other situations, this finding is remarkable. We apply our general considerations to specific lattice models of strained graphene and a pyrochlore Weyl semimetal.
Von Der Schwierigkeit, "Fake News" Zu Regulieren
Creators: name: Heldt, Amélie
Publisher: name: Zenodo
Year: 2018
Subjects: fake news
Gesetzesvorhaben
Falschinformation
Transparenz
Eilverfahren
Overblocking

description: Anfang 2018 kündigte Präsident Macron ein Gesetz gegen „fake news“ an. Auslöser war die Verbreitung falscher Informationen während des Wahlkampfs und die generelle Befürchtung, das Verbreiten von Falschinformationen im Netz könnte eine zunehmende Verfälschung des politischen Diskurses vorantreiben. Seit Mai 2018 liegt der Entwurf der Regierung vor und es handelt sich nun um ein Gesetz gegen „Informationsmanipulation“. Damit versucht der französische Gesetzgeber, das weiterhin diffuse Phänomen rund um den Begriff „fake news“ zu vermeiden und stattdessen an der Verbreitung von Falschinformationen anzusetzen. Amélie Heldt schafft einen Überblick zum Gesetzesvorhaben.
A Comparative Structural Study in Monolayers of GPI Fragments and Their Binary Mixtures
Creators: name: Stefaniu, C.
name: Vilotijevic, I.
name: Brezesinski, Gerald
name: Seeberger, P. H.
name: Silva, D. Varón
Publisher: name: Freie Universität Berlin
Year: 2014
Subjects: subject: 500 Naturwissenschaften und Mathematik::540 Chemie

description: Glycosylphosphatidylinositols (GPIs), natural complex glycolipids essential for a range of biological functions, are poorly understood with regard to their interactions and arrangements in cellular membranes. To evaluate the role of the head group in the structure formation in 2D model membranes (monolayers formed at the soft air/liquid interface), we employed the highly surface sensitive grazing incidence X-ray diffraction technique to investigate three GPI-fragments bearing the same hydrophobic part but different head groups. Condensed monolayers of simple GPI fragments are defined only by ordered alkyl chains. The monolayers of more complex fragments are additionally characterized by highly ordered head groups. Due to the strong H-bond network formed by the head groups, GPI-fragment 3 both segregates and induces order into a model membrane phospholipid (POPC) that mimics the liquid-disordered phase of cell membranes. Here, we show that the strong van der Waals interactions between hydrophobic chains overcome the head group interactions and dominate the structure formation in mixtures of GPI-fragment 3 with lipids that form liquid-condensed phases. This behaviour can be linked to the GPIs affinity for the lipid rafts.
Anomaly close to an electronic topological semimetal-insulator transition in elemental fcc-Yb under pressure
Creators: name: Enderlein, Carsten
name: Ramos, Scheilla M.
name: Bittencourt, Magda
name: Continentino, Mucio A.
name: Brewer, William D.
name: Baggio-Saitovich, Elisa
Publisher: name: Freie Universität Berlin
Year: 2013
Subjects: subject: 500 Naturwissenschaften und Mathematik::530 Physik

description: The Lifshitz-type semimetal-insulator transition, which is a transition of the electronic topology, has been considered as the most fundamental metal- insulator transition. Here, we present resistivity measurements under pressure in the vicinity of the quantum critical point of fcc Yb. We apply a previously suggested scaling for this type of transition and identify its universality class. Moreover, we observe an anomaly in the screening coefficient A of the T 2 term in the resistivity at low temperatures in the metallic phase. We suggest an interpretation of this phenomenon as an effect of doping by Ca impurities unintentionally present in the Yb crystals. The observed behavior may very well be applicable to any doped system in the vicinity of such a transition.
Christliches Gesangbuch, oder, Sammlung auserlesener Psalmen und geistlicher Lieder, über alle wichtigen Wahrheiten der Glaubens- und Sittenlehre : mit den beliebtesten Psalm- und vielen neuen, sehr leichten, vierstimmigen Choral-Melodien ...
Creators: name: Däniker, Jacob
Publisher: name: gedrukt bey Johann Kaspar Ziegler
Year: 1789

description: [Hans Jakob Däniker]
An Encoding of Interaction Nets in OCaml
Creators: name: Huber, Nikolaus
name: Yi, Wang
Publisher: name: arXiv
Year: 2025
Subjects: subject: Programming Languages (cs.PL)
subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: Interaction nets constitute a visual programming language grounded in graph transformation. Owing to their distinctive properties, they inherently facilitate parallelism in the rewriting step. This paper showcases a simple and concise approach to encoding interaction nets within the programming language OCaml, emphasising correctness guarantees. To achieve this objective, we encode not only the interaction net primitives, but also Lafont's original type system.
description: In Proceedings GCM 2023 and 2024, arXiv:2503.19632
A decision underlies phototaxis in an insect
Creators: name: Gorostiza, E. Axel
name: Colomb, Julien
name: Brembs, Björn
Publisher: name: Freie Universität Berlin
Year: 2016
Subjects: subject: behavioural flexibility
subject: octopamine
subject: dopamine
subject: decision-making
subject: Drosophila
subject: invertebrates
subject: 500 Naturwissenschaften und Mathematik::570 Biowissenschaften; Biologie

description: Like a moth into the flame—phototaxis is an iconic example for innate preferences. Such preferences probably reflect evolutionary adaptations to predictable situations and have traditionally been conceptualized as hard- wired stimulus–response links. Perhaps for that reason, the century-old discovery of flexibility in Drosophila phototaxis has received little attention. Here, we report that across several different behavioural tests, light/dark preference tested in walking is dependent on various aspects of flight. If we temporarily compromise flying ability, walking photopreference reverses concomitantly. Neuronal activity in circuits expressing dopamine and octopamine, respectively, plays a differential role in photopreference, suggesting a potential involvement of these biogenic amines in this case of behavioural flexibility. We conclude that flies monitor their ability to fly, and that flying ability exerts a fundamental effect on action selection in Drosophila. This work suggests that even behaviours which appear simple and hard-wired comprise a value-driven decision-making stage, negotiating the external situation with the animal's internal state, before an action is selected.
Легенды Бессарабии. К вопросу прочтения легенд на медных монетах из ордынского монетного двора в с. Костешты-Гырля (Республика Молдова)
Creators: name: Petrov, Alexander
Publisher: name: figshare
Year: 2022
Subjects: subject: History
subject: 140203 Economic History
subject: FOS: Economics and business
subject: Archaeology
subject: 200406 Language in Time and Space (incl. Historical Linguistics, Dialectology)
subject: FOS: Languages and literature

description: Статья посвящается переводу одного слова в ранее непрочитанных легендах на медных деньгах из ордынского монетного двора в с. Костешты-Гырля, Республика Молдова Edition: Научное Publisher: Русь Литва Орда в памятниках нумизматики и сфрагистики, 2019 г., выпуск 7. ISBN: 978-5-905154-62-1
sj-docx-1-tra-10.1177_14604086231165127 - Supplemental material for Increase in traumatic injury burden amidst COVID-19 was disproportionately shouldered by racial and ethnic minority patients: An urban case study
Creators: name: Tomas, CW
name: Flynn-O’Brien, KT
name: Harris, J
name: Kostelac, C
name: Moore, R
name: Cassidy, LD
name: deRoon-Cassini, TA
Publisher: name: SAGE Journals
Year: 2023
Subjects: subject: 111708 Health and Community Services
subject: FOS: Health sciences
subject: 110305 Emergency Medicine
subject: FOS: Clinical medicine

description: Supplemental material, sj-docx-1-tra-10.1177_14604086231165127 for Increase in traumatic injury burden amidst COVID-19 was disproportionately shouldered by racial and ethnic minority patients: An urban case study by CW Tomas, KT Flynn-O’Brien, J Harris, C Kostelac, R Moore, LD Cassidy and TA deRoon-Cassini in Trauma
sj-docx-1-pec-10.1177_03010066231100880 - Supplemental material for A category contingent aftereffect for faces labelled with different religious affiliation is seen 7 days after adaptation
Creators: name: Foglia, Victoria
name: Rutherford, M.D.
Publisher: name: SAGE Journals
Year: 2023
Subjects: subject: 110904 Neurology and Neuromuscular Diseases
subject: FOS: Clinical medicine
subject: 170199 Psychology not elsewhere classified
subject: FOS: Psychology
subject: 110319 Psychiatry (incl. Psychotherapy)

description: Supplemental material, sj-docx-1-pec-10.1177_03010066231100880 for A category contingent aftereffect for faces labelled with different religious affiliation is seen 7 days after adaptation by Victoria Foglia and M.D. Rutherford in Perception
Compact and fully functional high-frequency sine wave gating InGaAs/InP single-photon detector module
Creators: name: Xu, Qi
name: Yu, Chao
name: Cui, Dajian
name: Zhang, Xuan-Yi
name: Chen, Wei
name: Fang, Yu-Qiang
name: Jiang, Lianjun
name: Tong, Qixia
name: Zhao, Jianglin
name: Zhang, Jun
Publisher: name: arXiv
Year: 2025
Subjects: subject: Optics (physics.optics)
subject: Instrumentation and Detectors (physics.ins-det)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: High-frequency sine wave gating (SWG) InGaAs/InP single-photon detectors (SPDs) are widely used for synchronous near-infrared single-photon detection. For practical use, the size of SPD is one of the most concerning features for system integration. Here we present, to the best of our knowledge, the most compact and fully functional high-frequency SWG InGaAs/InP SPD. We develop a sine wave gating integrated circuit (SWGIC) using system-in-package technology that supports functions including large amplitude sine wave gate generation, coincidence gate generation, phase regulation, amplitude monitoring, and amplitude modulation. Moreover, we design and fabricate a high-performance multi-mode fiber coupled InGaAs/InP single-photon avalanche diode (SPAD) with a compact butterfly package. Furthermore, we implement a monolithically integrated readout circuit (MIRC) to extract the weak avalanche signal from large capacitance response of SWG. Finally, the SWGIC, SPAD, MIRC, and the affiliated circuits are integrated into a single module with a size of 6 cm x 5.7 cm x 1.7 cm. After characterization, the SPD module exhibits a photon detection efficiency of 40%, a dark count rate of 9 kcps, and an afterpulse probability of 4.6% at an operation temperature of 238 K and a hold-off time of 160 ns. Our work provides a practical solution for applications necessitating highly integrated near-infrared single-photon detection.
description: Published by IEEE Journal of Selected Topics in Quantum Electronics