cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Semimartingale price systems in models with transaction costs beyond efficient friction
Creators: name: Kühn, Christoph
name: Molitor, Alexander
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mathematical Finance (q-fin.MF)
subject: FOS: Economics and business
subject: 91G10, 60H05, 26A42, 60G40

description: A standing assumption in the literature on proportional transaction costs is efficient friction. Together with robust no free lunch with vanishing risk, it rules out strategies of infinite variation, as they usually appear in frictionless markets. In this paper, we show how the models with and without transaction costs can be unified. The bid and the ask price of a risky asset are given by cádlág processes which are locally bounded from below and may coincide at some points. In a first step, we show that if the bid-ask model satisfies "no unbounded profit with bounded risk" for simple strategies, then there exists a semimartingale lying between the bid and the ask price process. In a second step, under the additional assumption that the zeros of the bid-ask spread are either starting points of an excursion away from zero or inner points from the right, we show that for every bounded predictable strategy specifying the amount of risky assets, the semimartingale can be used to construct the corresponding self-financing risk-free position in a consistent way. Finally, the set of most general strategies is introduced, which also provides a new view on the frictionless case.
description: 48 pages
Electric Utility Alignment with the SDGs & the Paris Climate Agreement
Creators: name: Toledano, Perrine
name: Shah, Aniket
name: Maennling, Nicolas Wolfram
name: Lasnick, Ryan J.
Publisher: name: Columbia University
Year: 2020
Subjects: Sustainable development
Sustainable development--Evaluation
Electric utilities
Climate change mitigation

description: The purpose of this report is to provide a conceptual framework to guide corporate alignment of the electric utility sector with the Sustainable Development Goals (SDGs) and the Paris Climate Agreement (PCA). The electric-utility sector, being at the core of the global energy system, will play a central role in achieving the decarbonization of the world economy and, therefore, efforts to achieve sustainable development. The utility sector is central to global decarbonization efforts with electricity and heat generation making up 41 percent of global emissions in 2017. Furthermore, electricity demand is forecasted to grow significantly, driven by population and economic growth, as well as efforts for broad-based electrification to reduce emissions from the industrial and transport sectors. The decisions of the electric utility sector, through its role in power generation and distribution, will be crucial in determining whether decarbonization of the energy system happens at the needed pace to prevent catastrophic impacts of climate change. We believe that the creation of a clear conceptual framework for specific sectors can be a powerful way of focusing the attention of a broad set of stakeholders to pursue meaningful changes for sustainable development. This report is motivated by a belief that conceptual clarity is needed in re-thinking how businesses are or are not promoting sustainable development in general, and the SDGs and PCA specifically. We are hoping to bring rigor to reporting standards to hold companies to account for their real actions, not only their rhetoric. This should result in clearly distinguishing between good and weak performers in the electric utility sector.
Water and an escaping helium tail detected in the hazy and methane-depleted atmosphere of HAT-P-18b from JWST NIRISS/SOSS
Creators: name: Fu, Guangwei
name: Espinoza, Néstor
name: Sing, David K.
name: Lothringer, Joshua D.
name: Santos, Leonardo A. Dos
name: Rustamkulov, Zafar
name: Deming, Drake
name: Kempton, Eliza M. -R.
name: Komacek, Thaddeus D.
name: Knutson, Heather A.
name: Albert, Loïc
name: Pontoppidan, Klaus
name: Volk, Kevin
name: Filippazzo, Joseph
Publisher: name: arXiv
Year: 2022
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: JWST is here. The early release observation program (ERO) provides us with the first look at the scientific data and the spectral capabilities. One of the targets from ERO is HAT-P-18b, an inflated Saturn-mass planet with an equilibrium temperature of $\sim$850K. We present the NIRISS/SOSS transmission spectrum of HAT-P-18b from 0.6 to 2.8$μm$ and reveal the planet in the infrared beyond 1.6$μm$ for the first time. From the spectrum, we see clear water and escaping helium tail features in an otherwise very hazy atmosphere. Our free chemistry retrievals with ATMO show moderate Bayesian evidence (3.79) supporting the presence of methane, but the spectrum does not display any clearly identifiable methane absorption features. The retrieved methane abundance is $\sim$2 orders of magnitude lower than that of solar composition. The methane-depleted atmosphere strongly rejects simple equilibrium chemistry forward models with solar metallicity and C/O ratio and disfavors high metallicity (100 times) and low C/O ratio (0.3). This calls for additional physical processes such as vertical mixing and photochemistry which can remove methane from the atmosphere.
description: Accepted to ApJL, JWST is awesome!
title: Υπολογισμός του εντατικοπαραμορφωσιακού πεδίου γύρω από υπόγεια εκσκαφή με τη μέθοδο των συνοριακών στοιχείων
Creators: name: Λάμπρου Ελευθέριος
Publisher: name: Technical University of Crete
Year: 1993

description: Μη διαθέσιμο
The Evolutionary Vaccination Dilemma in Complex Networks
Creators: name: Cardillo, Alessio
name: Reyes-Suárez, Catalina
name: Naranjo, Fernando
name: Gómez-Gardeñes, Jesús
Publisher: name: arXiv
Year: 2013
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Social and Information Networks (cs.SI)
subject: Populations and Evolution (q-bio.PE)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences
subject: FOS: Biological sciences

description: In this work we analyze the evolution of voluntary vaccination in networked populations by entangling the spreading dynamics of an influenza-like disease with an evolutionary framework taking place at the end of each influenza season so that individuals take or not the vaccine upon their previous experience. Our framework thus put in competition two well-known dynamical properties of scale-free networks: the fast propagation of diseases and the promotion of cooperative behaviors. Our results show that when vaccine is perfect scale-free networks enhance the vaccination behavior with respect to random graphs with homogeneous connectivity patterns. However, when imperfection appears we find a cross-over effect so that the number of infected (vaccinated) individuals increases (decreases) with respect to homogeneous networks, thus showing up the competition between the aforementioned properties of scale-free graphs.
description: 7 pages, 5 figures. Manuscript final version
title: Χαρακτηρισμός και μοντελοποίηση θορύβου χαμηλής συχνότητας σε τρανζίστορ MOS
Creators: name: Ψαλτόπουλος Βασίλης
Publisher: name: Technical University of Crete
Year: 2012

description: Μη διαθέσιμο
A positive cosmological constant as a geometrical artifact
Creators: name: Apostolopoulos, Pantelis S.
name: Tsipogiannis, Christos
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We revisit the classical mechanism to produce $d-$dimensional spacetimes via Kaluza-Klein compactification. We made the assumption that the $\left(d+1\right) -$dimensional bulk geometry $\mathcal{M}$ admits a Homothetic Vector Field (HVF) $\mathbf{H}$ relaxing the existence of a zero i.e. $\mathbf{H}\neq 0$ holds on $\mathcal{M}$ and the homothetic bivector $F_{ab}(\mathbf{H})=0$. Under these circumstances we identify the origin of a positive cosmological constant in the $d-$dimensional spacetime as the homothetic factor representing a geometrical artifact of late time state of the $\left( d+1\right) -$dimensional bulk spacetime.
description: 6 pages, no figures, uses iop class style; (v2) some minor corrections, version to appear in Modern Physics Letter A
Moïse. Figures d’un prophète. Ausstellung im Musée d’art et d’histoire de Judaïsme (MahJ) / Exposition du Musée d’art et d’histoire du Judaïsme (MahJ)
Creators: name: Redaktion, Die
Publisher: name: Deutsches Forum für Kunstgeschichte (DFK Paris): Jahresbericht / Rapport annuel
Year: 2016

description: -
description: Deutsches Forum für Kunstgeschichte (DFK Paris): Jahresbericht / Rapport annuel, Jahresbericht / Rapport annuel 2014/2015
Cinematique Dope Tape
Creators: name: (:Unav)
Publisher: name: Columbia University
Year: 2019

description: Bowling Green' by unknown artist, 'Take a Whip on Me' by unknown artist, 'Blowing in the Wind' by unknown artist, 'The Nectar of God' by Pat Sky, 'La Cucaracha' by unknown artist, 'Oh, What we grow down in old Mexico' by unknown artist
Die Suche nach Byzanz: Die wissenschaftlichen Missionen der Forscher/-innen der byzantinischen Kunst in den Balkanländern zu Beginn des 20. Jahrhunderts / Chercher Byzance: les missions scientifiques des historiens de l'art byzantin dans les Balkans au début du XXe siècle
Creators: name: Soria, Judith
Publisher: name: Deutsches Forum für Kunstgeschichte (DFK Paris): Jahresbericht / Rapport annuel
Year: 2017

description: -
description: Deutsches Forum für Kunstgeschichte (DFK Paris): Jahresbericht / Rapport annuel, Jahresbericht / Rapport annuel 2015/2016
Exploring Supervised Machine Learning for Multi-Phase Identification and Quantification from Powder X-Ray Diffraction Spectra
Creators: name: Greasley, Jaimie
name: Hosein, Patrick
Publisher: name: arXiv
Year: 2022
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Machine Learning (cs.LG)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Powder X-ray diffraction analysis is a critical component of materials characterization methodologies. Discerning characteristic Bragg intensity peaks and assigning them to known crystalline phases is the first qualitative step of evaluating diffraction spectra. Subsequent to phase identification, Rietveld refinement may be employed to extract the abundance of quantitative, material-specific parameters hidden within powder data. These characterization procedures are yet time-consuming and inhibit efficiency in materials science workflows. The ever-increasing popularity and propulsion of data science techniques has provided an obvious solution on the course towards materials analysis automation. Deep learning has become a prime focus for predicting crystallographic parameters and features from X-ray spectra. However, the infeasibility of curating large, well-labelled experimental datasets means that one must resort to a large number of theoretic simulations for powder data augmentation to effectively train deep models. Herein, we are interested in conventional supervised learning algorithms in lieu of deep learning for multi-label crystalline phase identification and quantitative phase analysis for a biomedical application. First, models were trained using very limited experimental data. Further, we incorporated simulated XRD data to assess model generalizability as well as the efficacy of simulation-based training for predictive analysis in a real-world X-ray diffraction application.
Probing Dark Matter Axions using the Hyperfine Structure Splitting of Hydrogen Atoms
Creators: name: Yang, Qiaoli
name: Dong, Shiqin
Publisher: name: arXiv
Year: 2019
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: Atomic and Molecular Clusters (physics.atm-clus)
subject: FOS: Physical sciences

description: QCD axions can be a substantial part of dark matter if their mass $m_a\sim10^{-5}$eV. Since the axions were created by the misalignment mechanism, their local energy spectrum density is large. Consequently, the axion-induced atomic transition rate is enhanced if the atomic energy gap matches the axion mass. The hyperfine splitting between the spin 0 singlet ground state and the spin 1 triplet state of hydrogen is $0.59\times10^{-5}$eV, which is close to the preferred mass of dark matter axions. With an energy gap adjustment by applying a weak Zeeman magnetic field, dark matter axions can induce atomic hydrogen transitions. Furthermore, because the total spins of the hydrogen triplet and singlet differ, the axion-induced transitions are detectable by a Stern--Gerlach apparatus or a sensitive magnetic field detector. A potential realization of the proposed scheme can be similar to existing hydrogen masers.
description: 17 pages, 6 figures; Version published in Phys.Lett.B
title: Σχεδίαση ταλαντωτή ελεγχόμενου από τάση (VCO) στα 5-6 GHz με τεχνολογία CMOS
Creators: name: Δεριζιώτης Ιωάννης Ρωμανός
Publisher: name: Technical University of Crete
Year: 2012

description: Μη διαθέσιμο
Testing of Support Tools for Plagiarism Detection
Creators: name: Foltýnek, Tomáš
name: Dlabolová, Dita
name: Anohina-Naumeca, Alla
name: Razı, Salim
name: Kravjar, Július
name: Kamzola, Laima
name: Guerrero-Dib, Jean
name: Çelik, Özgür
name: Weber-Wulff, Debora
Publisher: name: arXiv
Year: 2020
Subjects: subject: Digital Libraries (cs.DL)
subject: Information Retrieval (cs.IR)
subject: FOS: Computer and information sciences
subject: H.3.7

description: There is a general belief that software must be able to easily do things that humans find difficult. Since finding sources for plagiarism in a text is not an easy task, there is a wide-spread expectation that it must be simple for software to determine if a text is plagiarized or not. Software cannot determine plagiarism, but it can work as a support tool for identifying some text similarity that may constitute plagiarism. But how well do the various systems work? This paper reports on a collaborative test of 15 web-based text-matching systems that can be used when plagiarism is suspected. It was conducted by researchers from seven countries using test material in eight different languages, evaluating the effectiveness of the systems on single-source and multi-source documents. A usability examination was also performed. The sobering results show that although some systems can indeed help identify some plagiarized content, they clearly do not find all plagiarism and at times also identify non-plagiarized material as problematic.
Probing the tidal disruption event iPTF16axa with CLOUDY and disc-wind models
Creators: name: Mageshwaran, T.
name: Shaw, Gargi
name: Bhattacharyya, Sudip
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We present both a disc-wind model on the optical/UV emission continuum and CLOUDY modelling on the spectral lines of the tidal disruption event (TDE) iPTF16axa to understand the disc-wind emission and the properties of the atmosphere that impacts the line luminosity of the TDE. Assuming the optical/UV emission from the wind due to the disc super-Eddington phase, we use the steady structured disc-wind model with a spherical wind with constant velocity to fit the observations on multiple days. The extracted parameters are stellar-mass $M_{\star} = 6.20 \pm 1.19 M_{\odot}$, disc radiative efficiency $\log_{\rm 10}(η) = -1.22 \pm 1.327$, wind inner radius $r_l = (2.013 \pm 0.551) \times 10^{14}~{\rm cm}$ and velocity $v_w = 18999.4 \pm 1785.1 ~{\rm km~s^{-1}}$. The photosphere temperature for wind emission is $ \sim 2 \times 10^4~{\rm K}$ and the disc single blackbody temperature is $\sim 0.995 \times 10^5~{\rm K}$. We also perform CLOUDY modelling to explain the observed He and H line luminosities that estimate a wind inner radius $r_l = 7.07 \times 10^{14}~{\rm cm}$ and velocity $v_w = 1.3 \times 10^4~{\rm km~s^{-1}}$. The independent analyses of iPTF16axa using CLOUDY and disc-wind models show comparable results that agree with observations. The CLOUDY modelling finds that both the super solar abundance of He and a smaller He II line optical depth is responsible for the enhancement of He II line luminosity over the H$α$ line luminosity. The super-solar abundance of He II agrees with a relatively large stellar mass and suggests that the disrupted star might have been a red giant.
description: 12 pages, 5 figures, accepted for publication in Monthly Notices of the Royal Astronomical Society
Ensuring Economic Viability & Sustainability of Coffee Production
Creators: name: Sachs, Jeffrey D.
name: Cordes, Kaitlin Y.
name: Rising, James
name: Toledano, Perrine
name: Maennling, Nicolas Wolfram
Publisher: name: Columbia University
Year: 2019
Subjects: Economics
Sustainable development
Coffee industry
Coffee growers

description: For this report, we developed a new economic model of supply and demand in the coffee sector, which forms the core of our quantitative analysis. The model simulates a global price equilibrium between 136 consuming countries and the farming decisions in 3024 coffee-growing regions. Our report is also grounded in extensive desk research and at least 72 interviews with 86 people, representing producers, small and large companies, civil society organizations and multi-stakeholder platforms, research institutions and academics, and others. It has also been strengthened by feedback we have received through other channels, including via email and particularly in response to public presentations at events organized by the ICO and the European Coffee Federation in June 2019 and by the World Coffee Producers Forum in July 2019.
An Analytical Fourier-Transformation Model for the Production of Hard and Soft X-Ray Time Lags in AGNs: Application to 1H 0707-495
Creators: name: Baughman, David C.
name: Becker, Peter A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The variability of the X-ray emission from active galactic nuclei is often characterized using time lags observed between soft and hard energy bands in the detector. The time lags are usually computed using the complex cross spectrum, which is based on the Fourier transforms of the hard and soft time series data. It has been noted that some active galactic nuclei display soft X-ray time lags, in addition to the more ubiquitous hard lags. Hard time lags are thought to be produced via propagating fluctuations, spatial reverberation, or via the thermal Comptonization of soft seed photons injected into a hot electron cloud. The physical origin of the soft lags has been a subject of debate over the last decade. Currently, the reverberation interpretation is recognized as a leading theory. In this paper, we explore the alternative possibility that the soft X-ray time lags result partially from the thermal and bulk Comptonization of monochromatic seed photons, which in the case of the narrow-line Seyfert 1 galaxy 1H 0707-495, may correlate with fluorescence of iron L-line emission. In our model, the seed photons are injected into a hot, quasi-spherical corona in the inner region of the accretion flow. We develop an exact, time-dependent analytical model for the thermal and bulk Comptonization of the seed photons based on a Fourier-transformed radiation transport equation, and we demonstrate that the model successfully reproduces both the hard and soft time lags observed from 1H 0707-495.
Documentation of microsimulation and additional figures from Population age and household structures shape transmission dynamics of emerging infectious diseases: a longitudinal microsimulation approach
Creators: name: Møgelmose, Signe
name: Vijnck, Laurens
name: Neven, Frank
name: Neels, Karel
name: Beutels, Philippe
name: Hens, Niel
Publisher: name: The Royal Society
Year: 2023
Subjects: classificationCode: 490102
subject: Biological mathematics

description: Host population demographics and patterns of host-to-host interactions are important drivers of heterogeneity in infectious disease transmission. To improve our understanding of how population structures and changes therein influence disease transmission dynamics at the individual and population level, we model a dynamic age- and household-structured population using longitudinal microdata drawn from Belgian census and population registers. At different points in time, we simulate the spread of a close-contact infectious disease and vary the age profiles of infectiousness and susceptibility to reflect specific infections (e.g. influenza and SARS-CoV-2) using a two-level mixing model, which distinguishes between exposure to infection in the household and exposure in the community. We find that the strong relationship between age and household structures, in combination with social mixing patterns and epidemiological parameters, shape the spread of an emerging infection. Disease transmission in the adult population in particular is to a large degree explained by differential household compositions and not just household size. Moreover, we highlight how demographic processes alter population structures in an ageing population and how these in turn affect disease transmission dynamics across population groups.
A Geometric Approach to Joint Inversion with Applications to Contaminant Source Zone Characterization
Creators: name: Aghasi, Alireza
name: Mendoza-Sanchez, Itza
name: Miller, Eric L.
name: Ramsburg, C. Andrew
name: Abriola, Linda M.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Geophysics (physics.geo-ph)
subject: FOS: Physical sciences

description: This paper presents a new joint inversion approach to shape-based inverse problems. Given two sets of data from distinct physical models, the main objective is to obtain a unified characterization of inclusions within the spatial domain of the physical properties to be reconstructed. Although our proposed method generally applies to many types of inversion problems, the main motivation here is to characterize subsurface contaminant source-zones by processing down gradient hydrological data and cross-gradient electrical resistance tomography (ERT) observations. Inspired by Newton's method for multi-objective optimization, we present an iterative inversion scheme that suggests taking descent steps that can simultaneously reduce both data-model misfit terms. Such an approach, however, requires solving a non-smooth convex problem at every iteration, which is computationally expensive for a pixel-based inversion over the whole domain. Instead, we employ a parametric level set (PaLS) technique that substantially reduces the number of underlying parameters, making the inversion computationally tractable. The performance of the technique is examined and discussed through the reconstruction of source zone architectures that are representative of dense non-aqueous phase liquid (DNAPL) contaminant release in a statistically homogenous sandy aquifer. In these examples, the geometric configuration of the DNAPL mass is considered along with additional information about its spatial variability within the contaminated zone, such as the identification of low and high saturation regions. Comparison of the reconstructions with the true DNAPL architectures highlights the superior performance of the model-based technique and joint inversion scheme.
SATVSR: Scenario Adaptive Transformer for Cross Scenarios Video Super-Resolution
Creators: name: Chen, Yongjie
name: Wu, Tieru
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Video Super-Resolution (VSR) aims to recover sequences of high-resolution (HR) frames from low-resolution (LR) frames. Previous methods mainly utilize temporally adjacent frames to assist the reconstruction of target frames. However, in the real world, there is a lot of irrelevant information in adjacent frames of videos with fast scene switching, these VSR methods cannot adaptively distinguish and select useful information. In contrast, with a transformer structure suitable for temporal tasks, we devise a novel adaptive scenario video super-resolution method. Specifically, we use optical flow to label the patches in each video frame, only calculate the attention of patches with the same label. Then select the most relevant label among them to supplement the spatial-temporal information of the target frame. This design can directly make the supplementary information come from the same scene as much as possible. We further propose a cross-scale feature aggregation module to better handle the scale variation problem. Compared with other video super-resolution methods, our method not only achieves significant performance gains on single-scene videos but also has better robustness on cross-scene datasets.
Contact structures, deformations and taut foliations
Creators: name: Bowden, Jonathan
Publisher: name: arXiv
Year: 2013
Subjects: subject: Geometric Topology (math.GT)
subject: Dynamical Systems (math.DS)
subject: Symplectic Geometry (math.SG)
subject: FOS: Mathematics

description: Using deformations of foliations to contact structures as well as rigidity properties of Anosov foliations we provide infinite families of examples which show that the space of taut foliations in a given homotopy class of plane fields is in general not path connected. Similar methods also show that the space of representations of the fundamental group of a hyperbolic surface to the group of smooth diffeomorphisms of the circle with fixed Euler class is in general not path connected. As an important step along the way we resolve the question of which universally tight contact structures on Seifert fibered spaces are deformations of taut or Reebless foliations when the genus of the base is positive or the twisting number of the contact structure in the sense of Giroux is non-negative.
description: 37 pages, 2 figures; Improved exposition incorporating referee's comments mainly in Sections 5 and 9. (To appear in Geom. Topol.)
The Southeastern Vegetable Processing Industry: Location and Number of Plants -- Composition, Volume, and Value of Pack, 1960
Creators: name: Williams, F. W.
name: Allen, M. B.
name: Williams, F. W.
name: Allen, M. B.
Publisher: name: Unknown
Year: 1962
Subjects: subject: Crop Production/Industries
subject: Marketing
subject: FOS: Economics and business
subject: Productivity Analysis

description: Excerpts from the report: The purpose of this research program is to provide an appraisal of the economic feasibility of processing as an outlet for vegetables produced in the Southeast. This requires research designed to evaluate production potentials, alternative markets, the relative profitability of investing productive resources in processing operations, and present and projected future markets for Southeastern processed vegetables. The specific objectives of this report are to describe the size, geographic distribution, and composition of the vegetable processing industry in the Southeast.
Multidecadal Basal Melt Rates and Structure of the Ross Ice Shelf, Antarctica, Using Airborne Ice Penetrating Radar
Creators: name: Das, Indrani
name: Padman, Laurie
name: Bell, Robin E.
name: Fricker, Helen A.
name: Tinto, Kirsteen J.
name: Hulbe, Christina L.
name: Siddoway, Christine S.
name: Dhakal, Tejendra
name: Frearson, Nicholas P.
name: Mosbeux, Cyrille
name: Cordero, S. Isabel
name: Siegfried, Matthew R.
Publisher: name: Columbia University
Year: 2020
Subjects: subject: Geophysics
subject: FOS: Earth and related environmental sciences
subject: Geomorphology
subject: Ice shelves
subject: Ice sheets
subject: Ice sheets--Remote sensing

description: Basal melting of ice shelves is a major source of mass loss from the Antarctic Ice Sheet. In situ measurements of ice shelf basal melt rates are sparse, while the more extensive estimates from satellite altimetry require precise information about firn density and characteristics of near‐surface layers. We describe a novel method for estimating multidecadal basal melt rates using airborne ice penetrating radar data acquired during a 3‐year survey of the Ross Ice Shelf. These data revealed an ice column with distinct upper and lower units whose thicknesses change as ice flows from the grounding line toward the ice front. We interpret the lower unit as continental meteoric ice that has flowed across the grounding line and the upper unit as ice formed from snowfall onto the relatively flat ice shelf. We used the ice thickness difference and strain‐induced thickness change of the lower unit between the survey lines, combined with ice velocities, to derive basal melt rates averaged over one to six decades. Our results are similar to satellite laser altimetry estimates for the period 2003–2009, suggesting that the Ross Ice Shelf melt rates have been fairly stable for several decades. We identify five sites of elevated basal melt rates, in the range 0.5–2 m a⁻¹, near the ice shelf front. These hot spots indicate pathways into the sub‐ice‐shelf ocean cavity for warm seawater, likely a combination of summer‐warmed Antarctic Surface Water and modified Circumpolar Deep Water, and are potential areas of ice shelf weakening if the ocean warms.
title: Εισαγωγή στις στοχαστικές διαφορικές εξισώσεις
Creators: name: Βαρδουλάκη Μαρία
Publisher: name: Technical University of Crete
Year: 2012

description: Κεφ. 1: Στοχαστικές διαδικασίες -- Κεφ. 2: Στοχαστικές διαδικασίες δεύτερης τάξης -- Κεφ. 3: Συνέχεια, διαφορησιμότητα και ολοκληρωσιμότητα στοχαστικών διαδικασιών δεύτερης τάξης -- Κεφ. 4: Στοχαστικές διαφορικές εξισώσεις
Hacky Racers: Exploiting Instruction-Level Parallelism to Generate Stealthy Fine-Grained Timers
Creators: name: Xiao, Haocheng
name: Ainsworth, Sam
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cryptography and Security (cs.CR)
subject: Hardware Architecture (cs.AR)
subject: FOS: Computer and information sciences

description: Side-channel attacks pose serious threats to many security models, especially sandbox-based browsers. While transient-execution side channels in out-of-order processors have previously been blamed for vulnerabilities such as Spectre and Meltdown, we show that in fact, the capability of out-of-order execution \emph{itself} to cause mayhem is far more general. We develop Hacky Racers, a new type of timing gadget that uses instruction-level parallelism, another key feature of out-of-order execution, to measure arbitrary fine-grained timing differences, even in the presence of highly restricted JavaScript sandbox environments. While such environments try to mitigate timing side channels by reducing timer precision and removing language features such as \textit{SharedArrayBuffer} that can be used to indirectly generate timers via thread-level parallelism, no such restrictions can be designed to limit Hacky Racers. We also design versions of Hacky Racers that require no misspeculation whatsoever, demonstrating that transient execution is not the only threat to security from modern microarchitectural performance optimization. We use Hacky Racers to construct novel \textit{backwards-in-time} Spectre gadgets, which break many hardware countermeasures in the literature by leaking secrets before misspeculation is discovered. We also use them to generate the first known last-level cache eviction set generator in JavaScript that does not require \textit{SharedArrayBuffer} support.
description: This paper is accepted at ASPLOS 2023
A mixed-initiative framework for multi-agent human-robot teams
Creators: name: Duncan, John Alexander
Publisher: name: The University of Texas at Austin
Year: 2020
Subjects: Robotics
Shared control
Human-robot interaction
Mixed-initiative interaction
Flexible autonomy
Multi-agent systems

description: Robots and autonomous systems are expanding into more complex, dynamic, and human-centered operating domains. In such domains, neither full autonomy nor full human control are ideal and the appropriate level of autonomy is contextually-dependent. Mixed-initiative systems enable flexible autonomy, making them ideal for complex operating environments. However, most mixed-initiative research does not consider multi-agent human-robot systems, and a multi-agent mixed-initiative robot control framework is not readily available. This project explores the requirements for a mixed-initiative human-robot control framework and proposes an initial design. The mixed-initiative framework was deployed onto a mobile robot, where three different agents could take, transfer, share, enable, or disable robot control. Compared to single-agent systems, the multi-agent mixed-initiative system completed a series of navigation tasks more quickly. The multi-agent system also completed navigation tasks that a single-agent autonomous system could not. Further design improvements and applications for mixed-initiative systems are discussed.
Distributed Set-Based Observers Using Diffusion Strategies
Creators: name: Alanwar, Amr
name: Rath, Jagat Jyoti
name: Said, Hazem
name: Johansson, Karl Henrik
name: Althoff, Matthias
Publisher: name: arXiv
Year: 2020
Subjects: subject: Systems and Control (eess.SY)
subject: Signal Processing (eess.SP)
subject: Optimization and Control (math.OC)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Mathematics

description: We propose two distributed set-based observers using strip-based and set-propagation approaches for linear discrete-time dynamical systems with bounded modeling and measurement uncertainties. Both algorithms utilize a set-based diffusion step, which decreases the estimation errors and the size of estimated sets, and can be seen as a lightweight approach to achieve partial consensus between the distributed estimated sets. Every node shares its measurement with its neighbor in the measurement update step. In the diffusion step, the neighbors intersect their estimated sets using our novel lightweight zonotope intersection technique. A localization example demonstrates the applicability of our algorithms.
description: Accepted at Journal of the Franklin Institute
title: Δένδρα (martingales) σε χώρους Banach, αριθμοί εντροπίας τελεστών στον L1
Creators: name: Παπαδεράκη Ιωάννα
Publisher: name: Technical University of Crete
Year: 2012

description: 1. Βασικοί ορισμοί -- 2. Η ιδιότητα Radon-Nikodym -- 3. Αναπαραστάσιμοι τελεστές -- 4. Martingales -- 5. Αριθμοί εντροπίας (προσέγγισης) τελεστών -- 6. Ημιεμφυτεύσεις σε χώρους Banach
Moving bumps in theta neuron networks
Creators: name: Laing, Carlo R.
name: Omel'chenko, Oleh
Publisher: name: arXiv
Year: 2020
Subjects: subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: FOS: Physical sciences

description: We consider large networks of theta neurons on a ring, synaptically coupled with an asymmetric kernel. Such networks support stable "bumps" of activity, which move along the ring if the coupling kernel is asymmetric. We investigate the effects of the kernel asymmetry on the existence, stability and speed of these moving bumps using continuum equations formally describing infinite networks. Depending on the level of heterogeneity within the network we find complex sequences of bifurcations as the amount of asymmetry is varied, in strong contrast to the behaviour of a classical neural field model.
description: To appear in Chaos
OLIA: an open-source digital lock-in amplifier
Creators: name: Harvie, Andrew J.
name: de Mello, John C.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Signal Processing (eess.SP)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: The Open Lock-In Amplifier (OLIA) is a microcontroller-based digital lock-in amplifier built from a small number of inexpensive and easily sourced electronic components. Despite its small credit card-sized form-factor and low build-cost of around US$35, OLIA is a capable instrument that offers many features associated with far costlier commercial devices. Key features include dual-phase lock-in detection at multiple harmonic frequencies up to 50 kHz, internal and external reference modes, adjustable levels of input gain, a choice between low-pass filtering and synchronous filtering, noise estimation, and a comprehensive programming interface for remote software control. OLIA comes with an optional optical breakout board that allows noise-tolerant optical detection down to the 40 pW level. OLIA and its breakout board are released here as open hardware, with technical diagrams, full parts-lists, and source-code for the firmware provided as Supporting Information.
The description of phase transition in a black hole with conformal anomaly in the Ehrenfest's scheme
Creators: name: Man, Jingyun
name: Cheng, Hongbo
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We make use of the Ehrenfest's equation to explore the phase transition of a black hole with conformal anomaly. The first order phase transition is ruled out because no discontinuity appears in entropy of the black holes. We find that the phase transition of black holes belong to the second order subject to the Ehrenfest's equations. Further we also show that the second order phase transition will not happen for the black holes without conformal anomaly.
description: 8 pages, 5 figures
Photoproduction of the $B_c$ meson at the future $e^+e^-$ colliders
Creators: name: Zhan, Xi-Jie
name: Wu, Xing-Gang
name: Zheng, Xu-Chang
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In the present paper, we study the photoproduction of various $S$-wave $B_c$ states, i.e. $B_c(1{}^1S_0)$, $B_c^*(1{}^1S_0)$, $B_c(2{}^1S_0)$ and $B^*_c(2{}^3S_1)$, at future $e^+e^-$ colliders within the framework of non-relativistic QCD. Two sources of the initial photons can be realized in the production, i.e., the LBS photon and the WWA photon. In addition to the direct photoproduction via the sub-process, $γ+ γ\rightarrow B_c + b + \bar{c}$, we also calculate the resolved photoproduction via the sub-processes, $γ+ g \rightarrow B_c + b + \bar{c}$ and $q + \bar{q} \rightarrow B_c + b + \bar{c}$ with $q=u,d,s,g$, respectively. Numerical results indicate that the contributions from the single resolved photoproduction are significant and even dominant at certain collision configuration. At the future high-energy and high-luminosity $e^+e^-$ colliders, the $B_c$ meson generated via the photoproduction mechanism is promisingly observable and can be well studied.
Bulk--Boundary Correspondence and Boundary Zero Modes in a Non-Hermitian Kitaev Chain Model
Creators: name: Sakaguchi, Tetsuro
name: Nishijima, Hiroto
name: Takane, Yositake
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We study a non-Hermitian Kitaev chain model that contains three sources of non-Hermiticity: a constant imaginary potential, asymmetry between hopping amplitudes $t_{\rm R}$ and $t_{\rm L}$ in the right and left directions, and imbalance in pair potentials $Δ_{\rm c}$ and $Δ_{\rm a}$ for pair creation and annihilation, respectively. We show that bulk--boundary correspondence holds in this system; two topological invariants defined in bulk geometry under a modified periodic boundary condition correctly describe the presence or absence of a pair of boundary zero modes in boundary geometry under an open boundary condition. One topological invariant characterizes a topologically nontrivial phase with a line gap and the other characterizes that with a point gap. The latter appears only in the asymmetric hopping case of $t_{\rm R} \neq t_{\rm L}$. These two nontrivial phases are essentially equivalent except for their gap structures. Indeed, the boundary zero modes do not disappear across the boundary between them. We also show that the boundary zero modes do not satisfy the Majorana condition if $Δ_{\rm c} \neq Δ_{\rm a}$ and/or $t_{\rm R} \neq t_{\rm L}$.
description: 10 pages, 7 figures
Colliding localized, lumpy holographic shocks with a granular nuclear structure
Creators: name: Waeber, Sebastian
name: Yaffe, Laurence G.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We apply a recent and simple technique which speeds up the calculation of localized collisions in holography to study more realistic models of heavy ion collisions via the gauge/gravity duality. The initial data takes into account the lumpy nuclear structure of real heavy ions and the projectiles' aspect ratio mimics the Lorentz contraction of nuclei during RHIC collisions. At the hydrodynamization time of the central region of the quark gluon plasma developed during the collision, we find that most of the vorticity three vector's absolute value is deposited far away from the hydrodynamized part of the plasma. Only the relativistic corrections to the thermal vorticity in the hydrodynamized region are non-negligible. We compare the transverse flow after the collision determined in this work with previous results, without granular initial conditions and determine the proper energy density and fluid velocity in a hydrodynamized subregion of the plasma.
description: 25 pages, 13 figures, figures 7,8,11,12 were added, introduction, result section and conclusion were expanded, typos were fixed
Dansgaard–Oeschger-like events of the penultimate climate cycle: the loess point of view
Creators: name: Rousseau, Denis-Didier
name: Antoine, Pierre
name: Boers, Niklas
name: Lagroix, France
name: Ghil, Michael
name: Lomax, Johanna
name: Fuchs, Markus
name: Debret, Maxime
name: Hatté, Christine
name: Moine, Olivier
name: Gauthier, Caroline
name: Jordanova, Diana
name: Jordanova, Neli
Publisher: name: Columbia University
Year: 2020
Subjects: Paleoclimatology
Paleopedology
Climatic changes
Loess

description: The global character of the millennial-scale climate variability associated with the Dansgaard–Oeschger (DO) events in Greenland has been well-established for the last glacial cycle. Mainly due to the sparsity of reliable data, however, the spatial coherence of corresponding variability during the penultimate cycle is less clear. New investigations of European loess records from Marine Isotope Stage (MIS) 6 reveal the occurrence of alternating loess intervals and paleosols (incipient soil horizons), similar to those from the last climatic cycle. These paleosols are correlated, based on their stratigraphical position and numbers as well as available optically stimulated luminescence (OSL) dates, with interstadials described in various Northern Hemisphere records and in GLt_syn, the synthetic 800 kyr record of Greenland ice core δ18O. Therefore, referring to the interstadials described in the record of the last climate cycle in European loess sequences, the four MIS 6 interstadials can confidently be interpreted as DO-like events of the penultimate climate cycle. Six more interstadials are identified from proxy measurements performed on the same interval, leading to a total of 10 interstadials with a DO-like event status. The statistical similarity between the millennial-scale loess–paleosol oscillations during the last and penultimate climate cycle provides direct empirical evidence that the cycles of the penultimate cycle are indeed of the same nature as the DO cycles originally discovered for the last glacial cycle. Our results thus imply that their underlying cause and global imprint were characteristic of at least the last two climate cycles.
Postgraduate Students’ Perception of the Use of E-portfolios as a Teaching Tool to Support their Learning in an Open and Distance Education Institution
Creators: name: Modise, Mpho-Entle
Publisher: name: figshare
Year: 2021
Subjects: subject: 130306 Educational Technology and Computing
subject: FOS: Educational sciences
subject: 130303 Education Assessment and Evaluation
subject: 139999 Education not elsewhere classified
subject: Education
subject: 130199 Education systems not elsewhere classified

description: E-portfolios have been used for decades in education; however, it is still a new trend in some developing countries as they continue to adopt e-learning practices. The study investigated postgraduate students’ experiences and perceptions of using an e-portfolio as a teaching tool to support their learning in an open and distance e-learning (ODeL) university in South Africa. A sample of 74 students registered for an online module were selected and an online questionnaire administered via Lime Survey. The results show that more than half of the respondents (71%) were using the e-portfolio for the first time. The study also revealed the contrasting views of the support received from the lecturer and institution for the e-portfolio platform, especially with technical issues. This study suggests that distance education institutions that are using e-portfolios need to strategically choose user-friendly technology tools and design appropriate student support strategies for delivering online modules. Higher education institutions that are planning to implement e-portfolios may find the results of this paper useful; however, further investigation of the learners’ needs, and available tools may assist with creative and appropriate designs of support strategies for their contexts.
MODERN METHODS AND TECHNOLOGIES IN PSYCHOLOGY AND PEDAGOGY
Creators: name: Qushoqova, Umida
Publisher: name: Zenodo
Year: 2023

description: This scientific article explores the integration of modern methods and technologies in the fields of psychology and pedagogy. It delves into the innovative approaches, tools, and techniques that are shaping the way educators and psychologists understand and enhance human development and learning. The article highlights the potential benefits and challenges associated with the application of technology in these domains, emphasizing the need for a balanced and evidence-based approach. This scientific article provides a comprehensive review of the modern methods and technologies that have revolutionized the fields of psychology and pedagogy. The integration of cutting-edge technologies and innovative approaches in these disciplines has not only enhanced our understanding of human behavior and learning but has also transformed the way educators and psychologists engage with their subjects. The article explores the implications of these advancements and their potential impact on shaping the future of education and mental health.
title: Θέματα αποκατάστασης και διατήρησης παραδοσιακών συστημάτων συλλογής υδάτων - εφαρμογή σε ομβροδεξαμενές από ξερολιθιά
Creators: name: Κεχαγιά Άννα
Publisher: name: Technical University of Crete
Year: 2012

description: Κεφ. 1: Εισαγωγή -- Κεφ. 2: Τεχνολογία συλλογής ομβρίων υδάτων -- Κεφ. 3: Ιστορική αναδρομή της τεχνολογίας RWH" -- Κεφ. 4: Ξερολιθικοί τοίχοι αντιστήριξης -- Κεφ. 5: Μελέτη ξερολιθικών τοίχων υδατοδεξαμενών με τη μέθοδο πεπερασμένων στοιχείων
title: Εκτίμηση δυναμικών χαρακτηριστικών κατασκευών με ενόργανη παρακολούθηση σε πραγματικό χρόνο
Creators: name: Τραχαλάκη Σοφία
Publisher: name: Technical University of Crete
Year: 2012

description:  Περιγραφή του κτιρίου -- 2. Λειτουργική ιδιομορφική ανάλυση -- 3. Όργανα πειραματικού ελέγχου -- 4. Διαδικασία μετρήσεων