cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Total Unimodularity and Strongly Polynomial Solvability of Constrained Minimum Input Selections for Structural Controllability: an LP-based Method
Creators: name: Zhang, Yuan
name: Xia, Yuanqing
name: Zhan, Yufeng
Publisher: name: arXiv
Year: 2021
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: This paper investigates several cost-sparsity induced optimal input selection problems for structured systems. Given are an autonomous system and a prescribed set of input links, where each input link has a non-negative cost. The problems include selecting the minimum cost of input links, and selecting the input links with the smallest possible cost with a bound on their cardinality, all to ensure system structural controllability. Current studies show that in the dedicated input case (i.e., each input can actuate only a state variable), the former problem is polynomially solvable by some graph-theoretic algorithms, while the general nontrivial constrained case is largely unexploited. We show these problems can be formulated as equivalent integer linear programming (ILP) problems. Subject to a certain condition on the prescribed input configurations that contains the dedicated input one as a special case, we demonstrate that the constraint matrices of these ILPs are totally unimodular. This property allows us to solve those ILPs efficiently simply via their linear programming (LP) relaxations, leading to a unifying algebraic method for these problems with polynomial time complexity. It is further shown those problems could be solved in strongly polynomial time, independent of the size of the costs and cardinality bounds. Finally, an example is provided to illustrate the power of the proposed method.
description: 8 pages, 4 figures. rearranged, add some materials
On the rate of convergence to the asymptotic cone for nilpotent groups and subFinsler geometry
Creators: name: Breuillard, Emmanuel
name: Donne, Enrico Le
Publisher: name: arXiv
Year: 2012
Subjects: subject: Group Theory (math.GR)
subject: Differential Geometry (math.DG)
subject: Metric Geometry (math.MG)
subject: FOS: Mathematics
subject: 53C17, 22E25

description: Addressing a question of Gromov, we give a rate in Pansu's theorem about the convergence in Gromov-Hausdorff metric of a finitely generated nilpotent group equipped with a left-invariant word metric scaled by a factor 1/n towards its asymptotic cone. We show that due to the possible presence of abnormal geodesics in the asymptotic cone, this rate cannot be better than n^{1/2} for general non-abelian nilpotent groups. As a corollary we also get an error term of the form vol(B(n))=cn^d + O(n^{d-2/(3r)}) for the volume of Cayley balls of a nilpotent group with nilpotency class r. We also state a number of related conjectural statements.
description: 18 pages, 5 figures
Fast Fits for Lattice QCD Correlators
Creators: name: Hornbostel, K.
name: Lepage, G. P.
name: Davies, C. T. H.
name: Dowdall, R. J.
name: Na, H.
name: Shigemitsu, J.
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We illustrate a technique for fitting lattice QCD correlators to sums of exponentials that is significantly faster than traditional fitting methods --- 10--40 times faster for the realistic examples we present. Our examples are drawn from a recent analysis of the Upsilon spectrum, and another recent analysis of the D -> pi semileptonic form factor. For single correlators, we show how to simplify traditional effective-mass analyses.
description: 5 pages, 4 figures
Characterization of Population III Stars with Stellar Atmosphere and Evolutionary Modeling and Predictions of their Observability with the James Webb Space Telescope
Creators: name: Larkin, Mikaela M.
name: Gerasimov, Roman
name: Burgasser, Adam J.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Population III stars were the first stars to form after the Big Bang, and are believed to have made the earliest contribution to the metal content of the universe beyond the products of the Big Bang Nucleosynthesis. These stars are theorized to have had extremely short lifespans, and therefore would only be observable at high redshifts ($z \geq 3-17$) and faint apparent magnitudes ($m_{AB} \gtrsim 40$). The direct detection of Population III stars therefore remains elusive. However, the recently launched James Webb Space Telescope (JWST) may be capable of detecting stars in the relevant magnitude range in the event of favorable gravitational lensing. Theoretical models are required to interpret these future observations. In this study, new evolutionary models and non-equilibrium model atmospheres were used to characterize the observable properties of zero-age main sequence Population III stars. The calculated models cover a wide range of possible Population III stellar masses, from the minimum mass predicted by star formation studies to the maximum mass capable of maintaining hydrostatic equilibrium. Synthetic photometry and theoretical color-magnitude diagrams were calculated for the bands of the Near-Infrared Camera (NIRCam) on JWST. The final results are compared to the scales of known lensing events and JWST magnitude limits. The purpose of this study is to calculate the observable parameters of Population III stars in the most optimal JWST bands in order to provide a theoretical foundation for anticipated future observations of this stellar population.
Resolving multiple supermassive black hole binaries with pulsar timing arrays
Creators: name: Babak, Stanislav
name: Sesana, Alberto
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We study the capability of a pulsar timing array (PTA) to individually resolve and localize in the sky monochromatic gravitational wave (GW) sources. Given a cosmological population of inspiralling massive black hole binaries, their observable signal in the PTA domain is expected to be a superposition of several nearly-monochromatic GWs of different strength. In each frequency bin, the signal is neither a stochastic background nor perfectly resolvable in its individual components. In this context, it is crucial to explore how the information encoded in the spatial distribution of the array of pulsars might help recovering the origin of the GW signal, by resolving individually and locating in the sky the strongest sources. In this paper we develop a maximum-likelihood based method finalized to this purpose. We test the algorithm against noiseless data showing that up to P/3 sources can be resolved and localized in the sky by an array of P pulsars. We validate the code by performing blind searches on both noiseless and noisy data containing an unknown number of signals with different strengths. Even without employing any proper search algorithm, our analysis procedure performs well, recovering and correctly locating in the sky almost all the injected sources.
description: 14 pages, 11 figures, submitted to Phys. Rev. D
Scattering and bound states of spin-0 particles in a nonminimal vector double-step potential
Creators: name: de Oliveira, L. P.
name: de Castro, A. S.
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The problem of spin-0 particles subject to a nonminimal vector double-step potential is explored in the context of the Duffin-Kemmer-Petiau theory. Surprisingly, one can never have an incident wave totally reflected and the transmission amplitude has complex poles corresponding to bound states. The interesting special case of bosons embedded in a sign potential with its unique bound-state solution is analyzed as a limiting case.
description: 1 figure
Deep Investigation of Neutral Gas Origins (DINGO): HI stacking experiments with early science data
Creators: name: Rhee, Jonghwan
name: Meyer, Martin
name: Popping, Attila
name: Bellstedt, Sabine
name: Driver, Simon P.
name: Robotham, Aaron S. G.
name: Whiting, Matthew
name: Baldry, Ivan K.
name: Brough, Sarah
name: Brown, Michael J. I.
name: Bunton, John D.
name: Dodson, Richard
name: Holwerda, Benne W.
name: Hopkins, Andrew M.
name: Koribalski, Bärbel S.
name: Lee-Waddell, Karen
name: López-Sánchez, Ángel R.
name: Loveday, Jon
name: Mahony, Elizabeth
name: Roychowdhury, Sambit
name: Rozgonyi, Kristóf
name: Staveley-Smith, Lister
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present early science results from Deep Investigation of Neutral Gas Origins (DINGO), an HI survey using the Australian Square Kilometre Array Pathfinder (ASKAP). Using ASKAP sub-arrays available during its commissioning phase, DINGO early science data were taken over $\sim$ 60 deg$^{2}$ of the Galaxy And Mass Assembly (GAMA) 23 h region with 35.5 hr integration time. We make direct detections of six known and one new sources at $z < 0.01$. Using HI spectral stacking, we investigate the HI gas content of galaxies at $0.04 < z< 0.09$ for different galaxy colours. The results show that galaxy morphology based on optical colour is strongly linked to HI gas properties. To examine environmental impacts on the HI gas content of galaxies, three sub-samples are made based on the GAMA group catalogue. The average HI mass of group central galaxies is larger than those of satellite and isolated galaxies, but with a lower HI gas fraction. We derive a variety of HI scaling relations for physical properties of our sample, including stellar mass, stellar mass surface density, $NUV-r$ colour, specific star formation rate, and halo mass. We find that the derived HI scaling relations are comparable to other published results, with consistent trends also observed to $\sim$0.5 dex lower limits in stellar mass and stellar surface density. The cosmic HI densities derived from our data are consistent with other published values at similar redshifts. DINGO early science highlights the power of HI spectral stacking techniques with ASKAP.
description: 27 pages, 25 figures, 10 tables, accepted for publication in MNRAS
Cross Layer QoS Support Architecture with Integrated CAC and Scheduling Algorithms for WiMAX BWA Networks
Creators: name: Chowdhury, Prasun
name: Misra, Iti Saha
name: Sanyal, Salil K
Publisher: name: arXiv
Year: 2012
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: In this paper, a new technique for cross layer design, based on present Eb/N0 (bit energy per noise density) ratio of the connections and target values of the Quality of Service (QoS) information parameters from MAC layer, is proposed to dynamically select the Modulation and Coding Scheme (MCS) at the PHY layer for WiMAX Broadband Wireless Access (BWA) networks. The QoS information parameter includes New Connection Blocking Probability (NCBP), Hand off Connection Dropping Probability (HCDP) and Connection Outage Probability (COP). In addition, a Signal to Interference plus Noise Ratio (SINR) based Call Admission Control (CAC) algorithm and Queue based Scheduling algorithm are integrated for the cross layer design. An analytical model using the Continuous Time Markov Chain (CTMC) is developed for performance evaluation of the algorithms under various MCS. The effect of Eb/No is observed for QoS information parameters in order to determine its optimum range. Simulation results show that the integrated CAC and packet Scheduling model maximizes the bandwidth utilization and fair allocation of the system resources for all types of MCS and guarantees the QoS to the connections.
description: 17 pages, (IJACSA) International Journal of Advanced Computer Science and Applications, Vol. 3, No. 1, 2012. arXiv admin note: text overlap with arXiv:1012.2518 and arXiv:1110.0147 by other authors
Parameters not empirically identifiable or distinguishable, including correlation between Gaussian observations
Creators: name: Hennig, Christian
Publisher: name: arXiv
Year: 2021
Subjects: subject: Statistics Theory (math.ST)
subject: FOS: Mathematics
subject: 62F99, 62G99, 62H30

description: Note: Accepted version, published in Statistical Papers, https://doi.org/10.1007/s00362-023-01414-3. It is shown that some theoretically identifiable parameters cannot be empirically identified, meaning that no consistent estimator of them can exist. An important example is a constant correlation between Gaussian observations (in presence of such correlation not even the mean can be empirically identified). Empirical identifiability and three versions of empirical distinguishability are defined. Two different constant correlations between Gaussian observations cannot even be empirically distinguished. A further example are cluster membership parameters in $k$-means clustering. Several existing results in the literature are connected to the new framework. General conditions are discussed under which independence can be distinguished from dependence.
description: 27 pages, no figures
Characteristics of flares on giant stars
Creators: name: Oláh, Katalin
name: Seli, Bálint
name: Kővári, Zsolt
name: Kriskovics, Levente
name: Vida, Krisztián
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Although late-type dwarfs and giant stars are substantially different, their flares are thought to originate in similar physical processes and differ only by a scale factor in the energy levels. We study the validity of this approach. We search for characteristics of flares on active giants, which might be statistically different from those on main-sequence stars. We used nearly 4000 flares of 61 giants and 20 stars of other types that were observed with Kepler in long-cadence mode, which is the only suitable database for this comparative study. For every flare, we derived the duration and energy and gathered stellar parameters. Correlations between the flare characteristics and various stellar parameters were investigated. Strong correlations are found between the flare duration and the surface gravity, luminosity, and radii of the stars. Scaled flare shapes appear to be similar on giants and dwarfs with a 30 min cadence. The logarithmic relation of flare energy and duration is steeper for stars with lower surface gravity. Observed flares are longer and more energetic on giants than on dwarfs on average. The generalized linear scaling for the logarithmic relation of flare energy and duration with a universal theoretical slope of $\approx$1/3 should slightly be modified by introducing a dependence on surface gravity.
description: 7 pages, 8 figures, 2 tables, accepted by A&A
title: Graph-based Methods for the Design of DNA Computations
title: Graphbasierte Methoden für die Gestaltung der DNA-Berechnungen
titleType: AlternativeTitle
Creators: name: Torgasin, Svetlana
Publisher: name: TUHH Universitätsbibliothek
Year: 2012
Subjects: subject: DNS-Hybridisierung
subject: minimale freie Energie
subject: DNS-Berechnungen
subject: DNA (cross)-hybridization
subject: minimum free energy
subject: DNA strand design.
classificationCode: 54.72
subject: Künstliche Intelligenz

description: Die Zuverlässigkeit von DNA-basierten Berechnungen hängt stark ab von den DNA-Sequenzen, die die Informationseinheiten repräsentieren. Eine optimale Zusammensetzung derartiger Sequenzen wird mit konventionellen Rechenverfahren ermittelt. Als Maß für die Sequenzerstellung wird die freie Energie der Hybridizierung zweier DNA-Einzelstränge herangezogen. Die Arbeit befasst sich mit zwei Kernpunkten in diesem Bereich. Erstens, mit dem Auffinden einer Sekundärstruktur eines DNA/DNA-Komplexes mit minimaler freier Energie. Zu diesem Zweck wurde eine neue graphbasierte Darstellung von DNA/DNA-Komplexen erarbeitet. Auf diesem Modell wurden zwei Berechnungsmethoden entwickelt, die auf dem Prinzip der dynamischen Programmierung beruhen. Zweitens, die Validierung der vorgegebenen Menge von DNA-Wörtern, die die Informationseinheiten eines mathematischen Problems kodieren. Die entwickelte Methode beruht auf der Abschätzung der freien Energie. Sie zielt auf DNA-Berechnungsmodelle ab, die zwei voneinander abhängige Arten von Informationseinheiten benutzen. Eine weitere Errungenschaft dieser Arbeit bezieht sich auf die Optimierung des Algorithmus' von Floyd-Warshall, der die kürzesten Wege zwischen je zwei Knoten in einem gewichteten Graphen liefert. Der entwickelte Ansatz führt zu einer Speicherreduktion für den Fall der bipartiten Graphen.
description: The reliability of results in DNA based computations strongly depends on the DNA sequences representing the units of information. The task of finding appropriate sequences is currently handled by means of conventional computing. The most accurate criterium for this purpose is the free energy of hybridization complexes built by two DNA single strands. This thesis addresses two issues in this area. First, finding of a secondary structure of DNA/DNA complexes having minimal free energy. For this, a novel graph-based representation of DNA/DNA complexes is introduced and two advanced methods calculating the free energy based on dynamic programming are proposed. Second, the validation of a given set of DNA words to encode a particular assignment of a mathematical problem. For this, a method is developed based on free energy assessment. It is suitable for DNA computing models that are based on an interdependent encoding of DNA words, which represent two different types of entities in the mathematical problem. Another accomplishment of the thesis is an optimization of the Floyd-Warshall algorithm for finding shortest paths in a weighted graph. A memory reduction method for the particular case of bipartite graphs is established.
Identification of the dynamic force and moment characteristics of annular gaps using linear independent rotor whirling motions
Creators: name: Kuhr, Maximilian M. G.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Nowadays, most studies on the dynamic properties of annular gaps focus only on the force characteristics due to translational motions, while the tilt and moment coefficients are less well studied. Therefore, there is hardly any reliable experimental data for the additional coefficients that can be used for validation purpose. To improve this, a test rig first presented by Kuhr (2022) is used to experimentally determine the dynamic force and moment characteristics of three annuli of different lengths. By using active magnetic bearings, the rotor is excited with user-defined frequencies and the rotor position and the forces and moments induced by the flow field in the annulus are measured. To obtain accurate and reliable experimental data, extensive preliminary studies are carried out to determine the known characteristics of the test rig rotor and the added mass and inertia imposed by the test rig. Subsequently, an elaborate uncertainty quantification is carried out to quantify the measurement uncertainties. The experimental results, i.e. the 48 rotordynamic coefficients, are compared to a new calculation method. It is shown that the presented experimental data agree well with the calculation method, especially for the additional rotordynamic tilt and moment coefficients. Furthermore, it is shown that the annulus length significantly influences the coefficients of the first sub-matrix. A dependence of the additional coefficients on the length is recognisable, but less pronounced. Even for the shortest investigated annulus, i.e. L = 1, the stiffness coefficients due to the forces from the angular motion of the rotor are of the same order of magnitude as the stiffness coefficients due to the forces from the translational motion. This supports recent results, indicating that the additional coefficients become relevant much earlier than assumed throughout the literature, cf. Childs (1993).
Extremal Binary PFAs with Small Number of States
Creators: name: Cambie, Stijn
name: de Bondt, Michiel
name: Don, Henk
Publisher: name: arXiv
Year: 2021
Subjects: subject: Formal Languages and Automata Theory (cs.FL)
subject: FOS: Computer and information sciences
subject: F.1.1
subject: 68Q45

description: The largest known reset thresholds for DFAs are equal to $(n-1)^2$, where $n$ is the number of states. This is conjectured to be the maximum possible. PFAs (with partial transition function) can have exponentially large reset thresholds. This is still true if we restrict to binary PFAs. However, asymptotics do not give conclusions for fixed $n$. We prove that the maximal reset threshold for binary PFAs is strictly greater than $(n-1)^2$ if and only if $n\geq 6$. These results are mostly based on the analysis of synchronizing word lengths for a certain family of binary PFAs. This family has the following properties: it contains the well-known Černý automata; for $n\leq 10$ it contains a binary PFA with maximal possible reset threshold; for all $n\geq 6$ it contains a PFA with reset threshold larger than the maximum known for DFAs. Analysis of this family reveals remarkable patterns involving the Fibonacci numbers and related sequences such as the Padovan sequence. We derive explicit formulas for the reset thresholds in terms of these recurrent sequences. Asymptotically the Černý family gives reset thresholds of polynomial order. We prove that PFAs in the family are not extremal for $n\geq 41$. For that purpose, we present an improvement of Martyugin's prime number construction of binary PFAs.
description: Even more extended than the IJFCS publication referenced below, which is an extended version of a publication in the proceedings of DLT 2021 titled 'Extremal Binary PFAs in a Cerny Family'
The Anisotropic Circumgalactic Medium of Massive Early-Type Galaxies
Creators: name: Zhang, Huanian
name: Zaritsky, Dennis
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Using measurements of the [O III], H$α$ and [N II] emission line fluxes originating in the cool (T $\sim10^4$ K) gas that populates the halos of massive early-type galaxies with stellar mass greater than $10^{10.4}$ M$_\odot$, we explore the recent conjecture that active galactic nucleus (AGN) activity preferentially removes the circumgalactic medium (CGM) along the polar (minor-axis) direction. We find deficits in the mean emission line flux of [O III] and H$α$ (65 and 43%, respectively) along the polar vs. planar directions, although due to the large uncertainties in these difficult measurements the results are of marginal statistical significance (1.5$σ$). More robustly (97 to 99.9% confidence depending on the statistical test), diagnostic line ratios show stronger AGN ionization signatures along the polar direction at small radii than at other angles or radii. Our results are consistent with the conjecture of an anisotropic CGM in massive, early type galaxies, suggested on independent grounds, that is tied to AGN activity and begin to show the potential of CGM mapping using emission lines.
description: 7 pages, accepted for publication in ApJ
Photoemission Evidence for Valence Fluctuations and Kondo Resonance in YbAl2
Creators: name: Matsunami, M.
name: Chainani, A.
name: Taguchi, M.
name: Eguchi, R.
name: Takata, Y.
name: Oura, M.
name: Yabashi, M.
name: Tamasaku, K.
name: Nishino, Y.
name: Ishikawa, T.
name: Kosaka, M.
name: Shin, S.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We use hard x-ray photoemission spectroscopy (HAXPES) to investigate the electronic structure of YbAl2, for which the Yb valence has not been consistently reported to date. The bulk sensitivity and the analytical simplicity provided by the Yb 3d core-level HAXPES allow a reliable determination of the mean valence of Yb ions. For YbAl2, it is evaluated to be +2.20, which remains nearly unchanged below 300 K. The Kondo resonance peak with an extremely high Kondo temperature (above 2000 K) is clearly identified in the valence-band spectra. The results indicate that a coherent Kondo state can be robust even in a nearly divalent system.
Mechanisms influencing adult adherence to physiotherapist-delivered rehabilitation for Achilles tendinopathy: a longitudinal qualitative study
Creators: name: Phillips, Rebecca
name: Morrissey, Dylan
name: Malliaras, Peter
name: Farlie, Melanie K.
Publisher: name: Taylor & Francis
Year: 2025
Subjects: subject: Space Science
subject: Medicine
subject: Cell Biology
subject: Pharmacology
subject: Sociology
subject: FOS: Sociology
subject: Biological Sciences not elsewhere classified

description: Achilles tendinopathy rehabilitation can be complex to deliver. Outcomes are variable, with low adherence a likely contributory factor. We aimed to identify the mechanisms influencing adult adherence behaviour to physiotherapist-delivered rehabilitation for Achilles tendinopathy. We applied interpretative descriptive design, utilising semi-structured interviews of 30 adults with Achilles tendinopathy who were interviewed at six-timepoints across 52-weeks. Data were analysed using Framework Analysis. We identified twelve mechanisms influencing adherence behaviour and grouped these into four themes: Tendinopathy paradigm consisted of “meaning-making of load and pain”, “comprehension of new knowledge” and “operationalising knowledge.” Self-management skills consisted of “internal self-management capability”, “external life-rhythm management” and “managing physical capability.” Therapeutic relationship consisted of “pre-scheduled regular check-ins”, “personal and professional connection”, and “coaching support.” Focus on outcome consisted of “motivation to maintain functional ability with progressing age”, “framing success” and, “it’s a trial.” Three delivery profiles were identified guiding clinicians in the application of the mechanisms to optimise adherence. Identification of mechanisms influencing adult adherence behaviour to physiotherapist-delivered rehabilitation for Achilles tendinopathy and delivery profiles to support implementation may optimise adherence, with the potential to improve outcomes.
Situated Conditional Reasoning
Creators: name: Casini, Giovanni
name: Meyer, Thomas
name: Varzinczak, Ivan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Artificial Intelligence (cs.AI)
subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences

description: Conditionals are useful for modelling, but are not always sufficiently expressive for capturing information accurately. In this paper we make the case for a form of conditional that is situation-based. These conditionals are more expressive than classical conditionals, are general enough to be used in several application domains, and are able to distinguish, for example, between expectations and counterfactuals. Formally, they are shown to generalise the conditional setting in the style of Kraus, Lehmann, and Magidor. We show that situation-based conditionals can be described in terms of a set of rationality postulates. We then propose an intuitive semantics for these conditionals, and present a representation result which shows that our semantic construction corresponds exactly to the description in terms of postulates. With the semantics in place, we proceed to define a form of entailment for situated conditional knowledge bases, which we refer to as minimal closure. It is reminiscent of and, indeed, inspired by, the version of entailment for propositional conditional knowledge bases known as rational closure. Finally, we proceed to show that it is possible to reduce the computation of minimal closure to a series of propositional entailment and satisfiability checks. While this is also the case for rational closure, it is somewhat surprising that the result carries over to minimal closure.
description: 51 pages
Photonic Band Gaps in 3D Network Structures with Short-range Order
Creators: name: Liew, Seng Fatt
name: Yang, Jin-Kyu
name: Noh, Heeso
name: Schreck, Carl F.
name: Dufresne, Eric R.
name: O'Hern, Corey S.
name: Cao, Hui
Publisher: name: arXiv
Year: 2011
Subjects: subject: Optics (physics.optics)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We present a systematic study of photonic band gaps (PBGs) in three-dimensional (3D) photonic amorphous structures (PAS) with short-range order. From calculations of the density of optical states (DOS) for PAS with different topologies, we find that tetrahedrally connected dielectric networks produce the largest isotropic PBGs. Local uniformity and tetrahedral order are essential to the formation of PBGs in PAS, in addition to short-range geometric order. This work demonstrates that it is possible to create broad, isotropic PBGs for vector light fields in 3D PAS without long-range order.
description: 6 pages, 8 figures
Estimation of Sparse MIMO Channels with Common Support
Creators: name: Barbotin, Yann
name: Hormati, Ali
name: Rangan, Sundeep
name: Vetterli, Martin
Publisher: name: arXiv
Year: 2011
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: We consider the problem of estimating sparse communication channels in the MIMO context. In small to medium bandwidth communications, as in the current standards for OFDM and CDMA communication systems (with bandwidth up to 20 MHz), such channels are individually sparse and at the same time share a common support set. Since the underlying physical channels are inherently continuous-time, we propose a parametric sparse estimation technique based on finite rate of innovation (FRI) principles. Parametric estimation is especially relevant to MIMO communications as it allows for a robust estimation and concise description of the channels. The core of the algorithm is a generalization of conventional spectral estimation methods to multiple input signals with common support. We show the application of our technique for channel estimation in OFDM (uniformly/contiguous DFT pilots) and CDMA downlink (Walsh-Hadamard coded schemes). In the presence of additive white Gaussian noise, theoretical lower bounds on the estimation of SCS channel parameters in Rayleigh fading conditions are derived. Finally, an analytical spatial channel model is derived, and simulations on this model in the OFDM setting show the symbol error rate (SER) is reduced by a factor 2 (0 dB of SNR) to 5 (high SNR) compared to standard non-parametric methods - e.g. lowpass interpolation.
description: 12 pages / 7 figures. Submitted to IEEE Transactions on Communication
Discovery of a filamentary synchrotron structure connected to the coherent magnetic field in the outer Galaxy
Creators: name: West, J. L.
name: Campbell, J. L.
name: Bhaura, P.
name: Kothes, R.
name: Safi-Harb, S.
name: Stil, J. M.
name: Taylor, A. R.
name: Foster, T.
name: Gaensler, B. M.
name: George, S. J.
name: Gibson, S. J.
name: Ricci, R.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Using data from the Galactic Arecibo L-band Feed Array Continuum Transit Survey (GALFACTS), we report the discovery of two previously unidentified, very compressed, thin, and straight polarized filaments approximately centred at Galactic coordinates, $(l,b)=(182.5^\circ,-4.0^\circ)$, which we call G182.5--4.0. Using data from the Isaac Newton Telescope Galactic Plane Survey (IGAPS), we also find straight, long, and extremely thin H$α$ filaments coincident with the radio emission. These filaments are positioned in projection at the edge of the Orion-Eridanus superbubble and we find evidence indicating that the filaments align with the coherent magnetic field of the outer Galaxy. We find a lower limit on the total radio flux at 1.4~GHz to be $0.7\pm0.3$~Jy with an average linearly polarized fraction of $40\substack{+30 \\ -20}\%$. We consider various scenarios that could explain the origin of these filaments, including a shell-type supernova remnant (SNR), a bow shock nebula associated with a pulsar, or relic fragments from one or more supernova explosions in the adjacent superbubble, with a hybrid scenario being most likely. This may represent an example of a new class of objects that is neither an SNR nor a bow shock. The highly compressed nature of these filaments and their alignment with Galactic plane suggests a scenario where this object formed in a magnetic field that was compressed by the expanding Orion-Eridanus superbubble, suggesting that the object is related to this superbubble and implying a distance of $\sim$400~pc.
description: 17 pages, 9 figures, accepted to Astrophysical Journal
Applications of heavy metal-based nanoparticles in cosmetics: a comprehensive review
Creators: name: Naveed, Malaika
name: Javed, Tariq
name: Zawar, Muhammad Danish
name: Shafqat, Uswa
name: Taj, Muhammad Babar
name: Wasim, Muhammad
name: Batool, Maryam
name: Zawar, Muhammad Amir
Publisher: name: Taylor & Francis
Year: 2025
Subjects: subject: Space Science
subject: Medicine
subject: Molecular Biology
subject: Pharmacology
subject: Biotechnology
subject: Chemical Sciences not elsewhere classified
subject: Ecology
subject: FOS: Biological sciences
subject: Astronomical and Space Sciences not elsewhere classified
subject: Biological Sciences not elsewhere classified
subject: Developmental Biology
subject: Cancer

description: The utilisation of heavy metal-based nanoparticles in cosmetic products has been steadily increasing because of their extraordinary physicochemical properties and benefits. In this thorough review, we will delve into the various types of nanoparticles, such as green nanoparticles, metallic nanoparticles, and carbon-based nanoparticles, with a special focus on heavy metal-based nanoparticles. These heavy metal-based nanoparticles exhibit exceptional physical and mechanical properties, making them suitable materials for cosmetic and personal care products. Silver nanoparticles effectively treat acne and have strong antimicrobial properties, while gold nanoparticles have anti-ageing and anti-inflammatory properties. ZnO and TiO2 nanoparticles are commonly used in sunscreens as ultraviolet (UV) filters to protect against ultraviolet-A (UVA) and ultraviolet-B (UVB) radiation. Certain metals like nickel, chromium, and cobalt are major allergens, frequently causing contact dermatitis and allergic reactions in sensitive individuals. Extensive use of materials such as cadmium, lead, mercury, and arsenic (metalloid) in cosmetics poses long-term health risks, including carcinogenicity, neurotoxicity, and organ damage. The utilisation of herbal extracts containing heavy metals in cosmetics further improves the effectiveness of personal care products due to their antioxidant properties. Consumer awareness and regulatory concerns, especially among those with metal allergies, are crucial for understanding the potential risks associated with heavy metal-containing cosmetics. Looking ahead, future research efforts should concentrate on the development of safer, non-toxic, natural nanomaterials and biocompatible alternatives to heavy metal-based nanoparticles.
The volume of a unit vector field in 2 dimensions via calibrations
Creators: name: Albuquerque, Rui
Publisher: name: arXiv
Year: 2021
Subjects: subject: Differential Geometry (math.DG)
subject: Complex Variables (math.CV)
subject: FOS: Mathematics
subject: 53C38, 57M50, 57R25,

description: We use the theory of calibrations to write the equation of a minimal volume vector field on a given Riemann surface.
Deep absorption in SDSS J110511.15+530806.5
Creators: name: Marculewicz, Marcin
name: Nikolajuk, Marek
name: Różańska, Agata
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We study the origin of the anomalous deep absorption in a spectrum of the SDSS J110511.15+530806.5 distant quasar (z=1.929) obtained by the Sloan Digital Sky Survey in Data Release 7 of the optical catalog. We aim to estimate the velocity of absorbing material, and we show that this material considerably affects our measurements of the black hole (BH) mass in massive quasars with the use of common virial mass estimators. The spectral shape of the quasar was modeled assuming that the accretion disk emission is influenced by a hot corona, warm skin, and absorbing material located close to the nucleus. The whole analysis was undertaken with XSPEC models and tools. The overall spectral shape was represented with the AGNSED model, while the deep absorption is well described by two Gaussians. The observed spectrum and the fitting procedure allowed us to estimate the BH mass in the quasar as $3.52 \pm 0.01 \times 10^9 M_{\odot}$, the nonzero BH spin is $a_* = 0.32 \pm 0.04$, and the accretion rate is $\dot m=0.274 \pm 0.001$. The velocities of the detected absorbers lie in the range of 6330-108135 km/s. When we consider that absorption is caused by the CIV ion, one absorber is folding toward the nucleus with a velocity of 73887 km/s. We derived a BI index of about 20300 km/s and a mass outflow rate up to 38.5 % of the source accretion rate. The high absorption observed in SDSS J110511.15+530806.5 is evidence of fast winds that place the source in the group of objects on the border with UFO (ultra-fast outflows), strong broad absorption line (BAL), and fast failed radiatively accelerated dusty outflow (FRADO). This absorption affects the BH mass measurement by two orders of magnitude as compared to virial mass estimation.
description: Accepted for publication in Astronomy & Astrophysics (A&A). 10 pages, 7 figures
Occurrence of Fermi Pockets without Pseudogap Hypothesis and Clarification of the Energy Distribution Curves of Angle-Resolved Photoemission Spectroscopy in Underdoped Cuprate Superconductors
Creators: name: Kamimura, Hiroshi
name: Sasaoka, Kenji
name: Ushio, Hideki
Publisher: name: arXiv
Year: 2011
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Central issues in the electronic structure of underdoped cuprate superconductors are to clarify the shape of the Fermi surfaces and the origin of the pseudogap. On the basis of the model proposed by Kamimura and Suwa, which bears important features originating from the interplay of Jahn-Teller physics and Mott physics, the feature of Fermi surfaces in underdoped cuprates is the presence of Fermi pockets constructed from doped holes under the coexistence of a metallic state and a local antiferromagnetic order. Below $T_{\rm c}$, the holes on Fermi pockets form Cooper pairs with d-wave symmetry in the nodal region. In the antinodal region, there are no Fermi surfaces. In this study we calculate the energy distribution curves (EDCs) of angle-resolved photoemission spectroscopy (ARPES) below $T_{\rm c}$. It is shown that the feature of ARPES profiles of underdoped cuprates consists of a coherent peak in the nodal region and real transitions of photoexcited electrons from occupied states below the Fermi level to a free-electron state above the vacuum level in the antinodal region, where the latter transitions form a broad hump. From this feature, the origin of the two distinct gaps observed by ARPES is elucidated without introducing the concept of the pseudogap. Finally, a remark is made on the phase diagram of underdoped cuprates.
description: arXiv admin note: significant text overlap with arXiv:1006.0586
Assessing relative resilience potential of coral reefs to inform management in the Commonwealth of the Northern Mariana Islands.
Creators: name: Maynard, J.
name: McKagan, Steven C.
name: Raymundo, Laurie J.
name: Johnson, S.
name: Ahmadia, G.
name: Houk, Peter
name: Williams, G.
name: Kendall, Matthew S.
name: Heron, Scott Fraser
name: Mcleod, Elizabeth, 1976-
Publisher: name: U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Ocean Service, Office for Coastal Management, Coral Reef Conservation Program.
Year: 2015
Subjects: subject: Coral Reef Conservation Program (U.S.)--Research--Northern Mariana Islands.
subject: Coral reef conservation--Northern Mariana Islands--Management.
subject: Corals--Effect of stress on--Monitoring--Northern Mariana Islands.

description: Coral reef managers face the challenge of reducing vulnerability to the effects of climate change by reducing other sources of stress to support the resilience of reef systems. Resiliencebased management (RBM) has been developed to overcome the challenges of reducing vulnerability in this era of rapid change. RBM of coral reefs can include assessing spatial variation in resilience potential and then targeting and tailoring appropriate actions, which is the focus of the project reported on here.
Numerical experiments to help understand cause and effect in massive star evolution
Creators: name: Farrell, Eoin
name: Groh, Jose
name: Meynet, Georges
name: Eldridge, JJ
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The evolution of massive stars is affected by a variety of physical processes including convection, rotation, mass loss and binary interaction. Because these processes modify the internal chemical abundance profiles in multiple ways simultaneously, it can be challenging to determine which properties of the stellar interior are primarily driving the overall evolution. Building on previous work, we develop a new modelling approach called SNAPSHOT that allows us to isolate the key features of the internal abundance profile that drive the evolution of massive stars. Using our approach, we compute numerical stellar structure models in thermal equilibrium covering key phases of stellar evolution. For the main sequence, we demonstrate that models with the same mass and very similar surface properties can have different internal distributions of hydrogen and convective core masses. We discuss why massive stars expand after the main sequence and the fundamental reasons for why they become red, blue or yellow supergiants. For the post-main sequence, we demonstrate that small changes in the abundance profile can cause very large effects on the surface properties. We also discuss the effects that produce blue supergiants and the cause of blue loops. Our models show that massive stars with lower metallicity tend to be more compact due to the combined effect of lower CNO abundances in the burning regions and lower opacity in the envelope.
description: Accepted in MNRAS
Quantal effects and MaxEnt
Creators: name: Holik, Federico
name: Plastino, Angel
Publisher: name: arXiv
Year: 2011
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Convex operational models (COMs) are considered as great extrapolations to larger settings of any statistical theory. In this article we generalize the maximum entropy principle (MaxEnt) of Jaynes' to any COM. After expressing Max-Ent in a geometrical and latttice theoretical setting, we are able to cast it for any COM. This scope-amplification opens the door to a new systematization of the principle and sheds light into its geometrical structure.
Gibbs measure for the focusing fractional NLS on the torus
Creators: name: Liang, Rui
name: Wang, Yuzhao
Publisher: name: arXiv
Year: 2021
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 35Q55, 60H40, 60H30

description: We study the construction of the Gibbs measures for the {\it focusing} mass-critical fractional nonlinear Schrödinger equation on the multi-dimensional torus. We identify the sharp mass threshold for normalizability and non-normalizability of the focusing Gibbs measures, which generalizes the influential works of Lebowitz-Rose-Speer (1988), Bourgain (1994), and Oh-Sosoe-Tolomeo (2021) on the one-dimensional nonlinear Schrödinger equations. To this purpose, we establish an almost sharp fractional Gagliardo-Nirenberg-Sobolev inequality on the torus, which is of independent interest.
description: 23 pages
Towards FAIR Principles for Open Hardware
Creators: name: Miljković, Nadica
name: Trisovic, Ana
name: Peer, Limor
Publisher: name: arXiv
Year: 2021
Subjects: subject: Digital Libraries (cs.DL)
subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: The lack of scientific openness is identified as one of the key challenges of computational reproducibility. In addition to Open Data, Free and Open-source Software (FOSS) and Open Hardware (OH) can address this challenge by introducing open policies, standards, and recommendations. However, while both FOSS and OH are free to use, study, modify, and redistribute, there are significant differences in sharing and reusing these artifacts. FOSS is increasingly supported with software repositories, but support for OH is lacking, potentially due to the complexity of its digital format and licensing. This paper proposes leveraging FAIR principles to make OH findable, accessible, interoperable, and reusable. We define what FAIR means for OH, how it differs from FOSS, and present examples of unique demands. Also, we evaluate dissemination platforms currently used for OH and provide recommendations.
description: 12 pages, 3 figures, 2 tables
Antiferromagnetic order and domains in Sr3Ir2O7 probed by x-ray resonant scattering
Creators: name: Boseggia, S.
name: Springell, R.
name: Walker, H. C.
name: Boothroyd, A. T.
name: Prabhakaran, D.
name: Wermeille, D.
name: Bouchenoire, L.
name: Collins, S. P.
name: McMorrow, D. F.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: This article reports a detailed x-ray resonant scattering study of the bilayer iridate compound, Sr3Ir2O7, at the Ir L2 and L3 edges. Resonant scattering at the Ir L3 edge has been used to determine that Sr3Ir2O7 is a long-range ordered antiferromagnet below TN 230K with an ordering wavevector, q=(1/2,1/2,0). The energy resonance at the L3 edge was found to be a factor of ~30 times larger than that at the L2. This remarkable effect has been seen in the single layer compound Sr2IrO4 and has been linked to the observation of a Jeff=1/2 spin-orbit insulator. Our result shows that despite the modified electronic structure of the bilayer compound, caused by the larger bandwidth, the effect of strong spin-orbit coupling on the resonant magnetic scattering persists. Using the programme SARAh, we have determined that the magnetic order consists of two domains with propagation vectors k1=(1/2,1/2,0) and k2=(1/2,-1/2,0), respectively. A raster measurement of a focussed x-ray beam across the surface of the sample yielded images of domains of the order of 100 microns size, with odd and even L components, respectively. Fully relativistic, monoelectronic calculations (FDMNES), using the Green's function technique for a muffin-tin potential have been employed to calculate the relative intensities of the L2,3 edge resonances, comparing the effects of including spin-orbit coupling and the Hubbard, U, term. A large L3 to L2 edge intensity ratio (~5) was found for calculations including spin-orbit coupling. Adding the Hubbard, U, term resulted in changes to the intensity ratio <5%.
description: 9 pages, 9 figures