cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
An embedded--hybridized discontinuous Galerkin finite element method for the Stokes equations
Creators: name: Rhebergen, Sander
name: Wells, Garth N.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Numerical Analysis (math.NA)
subject: Computational Engineering, Finance, and Science (cs.CE)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences
subject: 65F08, 65M15, 65N12, 65N30, 76D07

description: We present and analyze a new embedded--hybridized discontinuous Galerkin finite element method for the Stokes problem. The method has the attractive properties of full hybridized methods, namely an $H({\rm div})$-conforming velocity field, pointwise satisfaction of the continuity equation and \emph{a priori} error estimates for the velocity that are independent of the pressure. The embedded--hybridized formulation has advantages over a full hybridized formulation in that it has fewer global degrees-of-freedom for a given mesh and the algebraic structure of the resulting linear system is better suited to fast iterative solvers. The analysis results are supported by a range of numerical examples that demonstrate rates of convergence, and which show computational efficiency gains over a full hybridized formulation.
First NuSTAR observations of the BL Lac - type blazar PKS~2155-304: constraints on the jet content and distribution of radiating particles
Creators: name: Madejski, G. M.
name: Nalewajko, K.
name: Madsen, K. K.
name: Chiang, J.
name: Baloković, M.
name: Paneque, D.
name: Furniss, A. K.
name: Hayashida, M.
name: Urry, C. M.
name: Sikora, M.
name: Ajello, M.
name: Blandford, R. D.
name: Harrison, F. A.
name: Sanchez, D.
name: Giebels, B.
name: Stern, D.
name: Alexander, D. M.
name: Barret, D.
name: Boggs, S. E.
name: Christensen, F. E.
name: Craig, W. W.
name: Forster, K.
name: Giommi, P.
name: Grefenstette, B.
name: Hailey, C.
name: Hornstrup, A.
name: Kitaguchi, T.
name: Koglin, J. E.
name: Mao, P. H.
name: Miyasaka, H.
name: Mori, K.
name: Perri, M.
name: Pivovaroff, M. J.
name: Puccetti, S.
name: Rana, V.
name: Westergaard, N. J.
name: Zhang, W. W.
name: Zoglauer, A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We report the first hard X-ray observations with NuSTAR of the BL Lac type blazar PKS 2155-304, augmented with soft X-ray data from XMM-Newton and gamma-ray data from the Fermi Large Area Telescope, obtained in April 2013 when the source was in a very low flux state. A joint NuSTAR and XMM spectrum, covering the energy range 0.5 - 60 keV, is best described by a model consisting of a log-parabola component with curvature beta = 0.3(+0.2,-0.1) and a (local) photon index 3.04 +/- 0.15 at photon energy of 2 keV, and a hard power-law tail with photon index 2.2 +/- 0.4. The hard X-ray tail can be smoothly joined to the quasi-simultaneous gamma-ray spectrum by a synchrotron self-Compton component produced by an electron distribution with index p = 2.2. Assuming that the power-law electron distribution extends down to the minimum electron Lorentz factor gamma_min = 1 and that there is one proton per electron, an unrealistically high total jet power L_p of roughly 10^47 erg/s is inferred. This can be reduced by two orders of magnitude either by considering a significant presence of electron-positron pairs with lepton-to-proton ratio of at least 30, or by introducing an additional, low-energy break in the electron energy distribution at the electron Lorentz factor gamma_br1 of roughly 100. In either case, the jet composition is expected to be strongly matter-dominated.
description: Astrophysical Journal, in press
Trace Metal Based Eco-Biological and Health Risk Status of Surface Water and Sediments of Noyyal River Basin, Tamil Nadu, India
Creators: name: Abirami, Subramanian
name: Kadirvelu, Krishna
name: Baskar, Sushmitha
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Biotechnology
subject: Environmental Sciences not elsewhere classified
subject: Chemical Sciences not elsewhere classified
subject: Ecology
subject: FOS: Biological sciences
subject: Astronomical and Space Sciences not elsewhere classified
subject: Sociology
subject: FOS: Sociology
subject: Biological Sciences not elsewhere classified
subject: Inorganic Chemistry
subject: FOS: Chemical sciences

description: Pollution in the Noyyal river is a well-known and documented issue and recently, heavy metal contamination has become a serious issue requiring immediate attention. So, to understand the severity of heavy metal contamination in the surface water and sediments of the Noyyal river, a comprehensive study was conducted. About 27 surface water samples and 25 sediment samples were collected at different sites along the Noyyal river. The concentrations of heavy metals were determined using inductively coupled plasma mass spectrometry (ICP-MS). The Noyyal river’s surface water showed significant variations with nickel (Ni), copper (Cu), and zinc (Zn) concentrations exceeding acceptable limits for irrigation and aquatic life. Lead (Pb) concentrations were within acceptable limits for irrigation but potentially harmful to aquatic organisms. Noyyal river sediments also contained varying concentrations of chromium (Cr), copper (Cu), nickel (Ni), zinc (Zn), and gallium (Ga). Various assessment indices were employed to assess the eco-biological and human health risks associated with heavy metal contamination. The results highlighted alarming ecological and biological risks due to the accumulation of trace metals. Sediments exhibited high ecological risk (ERI values ranging from 43.81 to 371.43), while surface water samples intended for irrigation and aquatic purposes displayed extreme risks (ERI values exceeding 1200) to agricultural crops and aquatic organisms. The probability of toxicity to aquatic organisms, particularly benthic communities, was over 76% according to the biological risk assessment. The study also identified potential non-carcinogenic risks associated with metals like chromium (Cr), copper (Cu), nickel (Ni), and zinc (Zn) in the sediments. Moreover, elevated levels of Cr, Ni, and Cu in both sediments and surface water were likely to pose significant carcinogenic risks to exposed adults. Additionally, the heavy metal toxicity load in both surface water and sediments exceeded permissible limits, highlighting the urgent need for efficient removal strategies.
Global optimization of atomistic structure enhanced by machine learning
Creators: name: Bisbo, Malthe K.
name: Hammer, Bjørk
Publisher: name: arXiv
Year: 2020
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Global Optimization with First-principles Energy Expressions (GOFEE) is an efficient method for identifying low energy structures in computationally expensive energy landscapes such as the ones described by density functional theory (DFT), van der Waals-enabled DFT, or even methods beyond DFT. GOFEE relies on a machine learned surrogate model of energies and forces, trained on-the-fly, to explore configuration space, eliminating the need for expensive relaxations of all candidate structures using first-principles methods. In this paper we elaborate on the importance of the use of a Gaussian kernel with two length scales in the Gaussian Process Regression (GPR) surrogate model. We further explore the role of the use in GOFEE of the lower confidence bound for relaxation and selection of candidate structures. In addition, we present two improvements to the method: 1) the population generation now relies on a clustering of all low-energy structures evaluated with DFT, with the lowest energy member of each cluster making up the population. 2) the very final relaxations in well-sampled basins of the energy landscape, the final exploitation steps, are now performed as continued relaxation paths within the first-principles method, to allow for arbitrarily fine relaxations of the best structures, independently of the predictive resolution of the surrogate model. The versatility of the GOFEE method is demonstrated by applying it to identify the low-energy structures of gas-phase fullerene-type 24-atom carbon clusters and of dome-shaped 18-atom carbon clusters supported on Ir(111).
ARC: Alignment-based Redirection Controller for Redirected Walking in Complex Environments
Creators: name: Williams, Niall L.
name: Bera, Aniket
name: Manocha, Dinesh
Publisher: name: arXiv
Year: 2021
Subjects: subject: Graphics (cs.GR)
subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: We present a novel redirected walking controller based on alignment that allows the user to explore large and complex virtual environments, while minimizing the number of collisions with obstacles in the physical environment. Our alignment-based redirection controller, ARC, steers the user such that their proximity to obstacles in the physical environment matches the proximity to obstacles in the virtual environment as closely as possible. To quantify a controller's performance in complex environments, we introduce a new metric, Complexity Ratio (CR), to measure the relative environment complexity and characterize the difference in navigational complexity between the physical and virtual environments. Through extensive simulation-based experiments, we show that ARC significantly outperforms current state-of-the-art controllers in its ability to steer the user on a collision-free path. We also show through quantitative and qualitative measures of performance that our controller is robust in complex environments with many obstacles. Our method is applicable to arbitrary environments and operates without any user input or parameter tweaking, aside from the layout of the environments. We have implemented our algorithm on the Oculus Quest head-mounted display and evaluated its performance in environments with varying complexity. Our project website is available at https://gamma.umd.edu/arc/.
DeepOIS: Gyroscope-Guided Deep Optical Image Stabilizer Compensation
Creators: name: Li, Haipeng
name: Liu, Shuaicheng
name: Wang, Jue
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Mobile captured images can be aligned using their gyroscope sensors. Optical image stabilizer (OIS) terminates this possibility by adjusting the images during the capturing. In this work, we propose a deep network that compensates the motions caused by the OIS, such that the gyroscopes can be used for image alignment on the OIS cameras. To achieve this, first, we record both videos and gyroscopes with an OIS camera as training data. Then, we convert gyroscope readings into motion fields. Second, we propose a Fundamental Mixtures motion model for rolling shutter cameras, where an array of rotations within a frame are extracted as the ground-truth guidance. Third, we train a convolutional neural network with gyroscope motions as input to compensate for the OIS motion. Once finished, the compensation network can be applied for other scenes, where the image alignment is purely based on gyroscopes with no need for images contents, delivering strong robustness. Experiments show that our results are comparable with that of non-OIS cameras, and outperform image-based alignment results with a relatively large margin. Code and dataset are available at https://github.com/lhaippp/DeepOIS
Analysis and Assessment of the Soil Environment Around a Plateau Municipal Solid Waste Incineration Plant
Creators: name: Zhou, Wenwu
name: Dan, Zeng
name: Meng, Dean
name: Guo, Jiachen
name: Zhou, Peng
name: Chen, Guanyi
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Biochemistry
subject: Cell Biology
subject: Molecular Biology
subject: Biotechnology
subject: Environmental Sciences not elsewhere classified
subject: Chemical Sciences not elsewhere classified
subject: Ecology
subject: FOS: Biological sciences

description: To understand the source, distribution and degree of pollution of heavy metals in the soil around a plateau municipal solid waste incineration plant, a municipal solid waste incineration plant in Lhasa was taken as the research object in this study. The soil surrounding the facility was sampled, and the contents of heavy metals, including Cu, Pb, Zn, Cr, Ni, Cd, As, and Hg, in the soil were analyzed. Then, heavy metal pollution and risk assessments were conducted using the geoaccumulation index method, Nemerow index method, and potential ecological risk index method. Additionally, correlation and principal component analysis were used to determine the correlation between heavy metals in the soil and their sources of pollution. The results showed that based on the Nemerow comprehensive pollution index, the soil surrounding the incineration plant generally had a low level of pollution. Through the analysis of individual potential ecological risk indices, it was found that only the heavy metal Cd presented moderate potential risks, while the other seven heavy metals had mild potential risks. The average value of the total potential risk coefficient was 107.31, which was less than 150, indicating that there was a slight potential risk associated with the soil around the incineration plant. There was significant correlation between six heavy metals, namely, Cu, Pb, Zn, Cr, Ni, and Cd, in the soil around the incineration plant. Their pollution sources were similar, and their levels tended to be affected by the incineration plant. However, there was no significant correlation between the heavy metals As and Hg and the other six heavy metals. These two heavy metals had independent sources of pollution but were also influenced by human activities.
Hybrid Trilinear and Bilinear Programming for Aligning Partially Overlapping Point Sets
Creators: name: Lian, Wei
name: Zuo, Wangmeng
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: In many applications, we need algorithms which can align partially overlapping point sets and are invariant to the corresponding transformations. In this work, a method possessing such properties is realized by minimizing the objective of the robust point matching (RPM) algorithm. We first show that the RPM objective is a cubic polynomial. We then utilize the convex envelopes of trilinear and bilinear monomials to derive its lower bound function. The resulting lower bound problem has the merit that it can be efficiently solved via linear assignment and low dimensional convex quadratic programming. We next develop a branch-and-bound (BnB) algorithm which only branches over the transformation variables and runs efficiently. Experimental results demonstrated better robustness of the proposed method against non-rigid deformation, positional noise and outliers in case that outliers are not mixed with inliers when compared with the state-of-the-art approaches. They also showed that it has competitive efficiency and scales well with problem size.
A comprehensive search for stellar bowshock nebulae in the Milky Way: a catalog of 709 mid-infrared selected candidates
Creators: name: Kobulnicky, Henry A.
name: Chick, William T.
name: Schurhammer, Danielle P.
name: Andrews, Julian E.
name: Povich, Matthew S.
name: Munari, Stephan A.
name: Olivier, Grace M.
name: Sorber, Rebecca L.
name: Wernke, Heather N.
name: Dale, Daniel A.
name: Dixon, Don M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We identify 709 arc-shaped mid-infrared nebula in 24 micron Spitzer Space Telescope or 22 micron Wide Field Infrared Explorer surveys of the Galactic Plane as probable dusty interstellar bowshocks powered by early-type stars. About 20% are visible at 8 microns or shorter mid-infrared wavelengths as well. The vast majority (660) have no previous identification in the literature. These extended infrared sources are strongly concentrated near Galactic mid-Plane with an angular scale height of ~0.6 degrees. All host a symmetrically placed star implicated as the source of a stellar wind sweeping up interstellar material. These are candidate "runaway" stars potentially having high velocities in the reference frame of the local medium. Among the 286 objects with measured proper motions, we find an unambiguous excess having velocity vectors aligned with the infrared morphology --- kinematic evidence that many of these are "runaway" stars with large peculiar motions responsible for the bowshock signature. We discuss a population of "in-situ" bowshocks (103 objects) that face giant HII regions where the relative motions between the star and ISM may be caused by bulk outflows from an overpressured bubble. We also identify 58 objects that face 8 micron bright-rimmed clouds and apparently constitute a sub-class of in-situ bowshocks where the stellar wind interacts with a photo-evaporative flow from an eroding molecular cloud interface (i.e., "PEF bowshocks"). Orientations of the arcuate nebulae exhibit a correlation over small angular scales, indicating that external influences such as HII regions are responsible for producing some bowshock nebulae. However, the vast majority of this sample appear to be isolated (499 objects) from obvious external influences.
description: Accepted for publication in The Astrophysical Journal. A full version with complete color figures (including Appendix) may be found at http://physics.uwyo.edu/~chip/Papers/BowshocksI/Kobulnicky_etal_2016_Bowshocks.pdf
Detection of solar-like oscillations in relics of the Milky Way: asteroseismology of K giants in M4 using data from the NASA K2 mission
Creators: name: Miglio, A.
name: Chaplin, W. J.
name: Brogaard, K.
name: Lund, M. N.
name: Mosser, B.
name: Davies, G. R.
name: Handberg, R.
name: Milone, A. P.
name: Marino, A. F.
name: Bossini, D.
name: Elsworth, Y. P.
name: Grundahl, F.
name: Arentoft, T.
name: Bedin, L. R.
name: Campante, T. L.
name: Jessen-Hansen, J.
name: Jones, C. D.
name: Kuszlewicz, J. S.
name: Malavolta, L.
name: Nascimbeni, V.
name: Sandquist, E. L.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Asteroseismic constraints on K giants make it possible to infer radii, masses and ages of tens of thousands of field stars. Tests against independent estimates of these properties are however scarce, especially in the metal-poor regime. Here, we report the detection of solar-like oscillations in 8 stars belonging to the red-giant branch and red-horizontal branch of the globular cluster M4. The detections were made in photometric observations from the K2 Mission during its Campaign 2. Making use of independent constraints on the distance, we estimate masses of the 8 stars by utilising different combinations of seismic and non-seismic inputs. When introducing a correction to the Delta nu scaling relation as suggested by stellar models, for RGB stars we find excellent agreement with the expected masses from isochrone fitting, and with a distance modulus derived using independent methods. The offset with respect to independent masses is lower, or comparable with, the uncertainties on the average RGB mass (4-10%, depending on the combination of constraints used). Our results lend confidence to asteroseismic masses in the metal poor regime. We note that a larger sample will be needed to allow more stringent tests to be made of systematic uncertainties in all the observables (both seismic and non-seismic), and to explore the properties of RHB stars, and of different populations in the cluster.
description: 6 pages, 3 figures, accepted for publication in MNRAS
Characterization of Microplastics and Associated Heavy Metals in Urban Soils Affected by Anthropogenic Littering: Distribution, Spatial Variation, and Influence of Soil Properties
Creators: name: Prajapati, Archana
name: Jadhao, Pradip Sahebrao
name: Khare, Ankur
name: Vaidya, Atul Narayan
name: Kumar, Asirvatham Ramesh
name: Das, Sera
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Biochemistry
subject: Genetics
subject: FOS: Biological sciences
subject: Molecular Biology
subject: Environmental Sciences not elsewhere classified
subject: Chemical Sciences not elsewhere classified
subject: Ecology
subject: Biological Sciences not elsewhere classified
subject: Hematology

description: Microplastics (MPs) are ubiquitous in terrestrial and marine environments. This research work studied the occurrence, distribution of MPs and heavy metals associated with these MPs in soils of different land- use types viz. residential, commercial, and industrial areas. We identified 15 types of MP polymers, of which polypropylene (15.51%), polyethylene (12.28%), polyamide (9.57%) were dominant. MPs abundance ranged from 8.54 × 104 to 8.51 × 105 particles/kg of soil. Average abundance of MPs in the three fractions viz.  < 1 mm, 1–2 mm, and 2–5 mm were 1.85 × 105, 1.31 × 105, and 697.5 particles/kg of soil, respectively. Among the three land use types, MPs abundance in < 1 mm and 1–2 mm soil fractions were significantly higher in residential areas than that in commercial and industrial areas, i.e. <1 mm: 3.4 × 105, 1.26 × 104 and 9.0 × 104, and 1–2 mm: 2.35 × 105, 8.36 × 104, and 7.50 × 104 particles/kg, respectively, for residential, commercial and industrial areas respectively. The average concentration of Cr, Fe, Mn, Cd, Co, Ni, Cu and Pb in soils were 31.79, 11047.29, 423.92, 0.05, 11.86, 17.53, 125.95 and 28.29 mg/kg, respectively, whereas that in MPs were 6.27, 2181.64, 277.36, 0.24, 6.43, 8.29, 47.05 and 9.24 mg/kg, respectively. Concentration of Cd sorbed on MPs was higher than those found in soils. Also, Pb and Cd in MPs were positively correlated to MPs abundance, indicating MPs can be vectors of heavy metals in soils. The synergistic effect of MPs and heavy metals might put soil organisms at risk.
Projective Cones for Sequential Dispersing Billiards
Creators: name: Demers, Mark F.
name: Liverani, Carlangelo
Publisher: name: arXiv
Year: 2021
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics

description: We construct Birkhoff cones for dispersing billiards, which are contracted by the action of the transfer operator. This construction permits the study of statistical properties not only of regular dispersing billiards but also of sequential billiards (the billiard changes at each collision in a prescribed manner), open billiards (the dynamics exits some region or dies when hitting some obstacle) and many other examples. In particular, we include applications to chaotic scattering and the random Lorentz gas.
Expanding measures: Random walks and rigidity on homogeneous spaces
Creators: name: Prohaska, Roland
name: Sert, Cagri
name: Shi, Ronggang
Publisher: name: arXiv
Year: 2021
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics
subject: Primary 60B15, Secondary 22F30, 60G50, 37A45, 28A80

description: Let $G$ be a real Lie group, $Λ
description: 63 pages; revised the presentation of the proof of Corollary 1.2 and made other small changes and corrections. Accepted for publication by Forum of Mathematics, Sigma
Heavy Metals Pollution in Various Grain Sizes Under Different Land-Use Types in Urban Surface Dust in Shenyang City, China
Creators: name: Wang, Hui
name: Guo, Dongrui
name: Zhao, Yangfan
name: Huang, Xuetang
name: Wang, Yinggang
name: Wu, Hao
name: Wang, Xiaoxu
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Space Science
subject: Environmental Sciences not elsewhere classified
subject: Chemical Sciences not elsewhere classified
subject: Ecology
subject: FOS: Biological sciences
subject: Biological Sciences not elsewhere classified

description: In this study, surface dust samples were collected within the second ring road of Shenyang City under different land-use types, and the concentration and chemical speciation of metals in different particle sizes under different land-use types were analyzed. Dust samples were separated into four particle size fractions (＜50, 50–100, 100–500, 500–2000 μm), and particles in the range of 100–500 µm were the highest representing one-third of the dust mass. The results revealed that metals were detected in order Zn > Cr > Pb > Cu > Ni > As > Cd in different particle sizes of dust under different land-use types. The relative contribution of individual particle-size fractions for seven metals was different, but the results showed preferential partitioning to small particle-size fractions. The relative contribution of metals in individual particle-size fractions and chemical speciation were significantly affected by the type of land use. Metals concentrated on the smaller particles in the traffic area, and the particles (<50 µm) contained the highest percentage of metals but Cr. The residual fractions (F5) of Ni, Cr, As and Cu overall represented the predominant portion in different particle size of fractions under different land-use types, Zn and Pb were mostly bound to the Fe–Mn oxides-bound fraction (F3), and the exchangeable fraction (F1) accounted for a relatively large proportion of Cd. The results of the risk assessment code (RAC) of Cd indicated that the risk of Zn was medium, and it was high for Cd in the dust of Shenyang City.
Controversy of the GRO J1655-40 black hole mass and spin estimates and its possible solutions
Creators: name: Stuchlík, Zdeněk
name: Kološ, Martin
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Estimates of the black hole mass $M$ and dimensionless spin $a$ in the microquasar GRO J1655-40 implied by strong gravity effects related to the timing and spectral measurements are controversial, if the mass restriction determined by the dynamics related to independent optical measurements, $M_{\rm opt}=(5.4\pm0.3) M_{\odot}$, are applied. The timing measurements of twin high-frequency (HF) quasiperiodic oscillations (QPOs) with frequency ratio $3:2$ and the simultaneously observed low-frequency (LF) QPO imply the spin in the range $a\in(0.27-0.29)$ if models based on the frequencies of the geodesic epicyclic motion are used to fit the timing measurements, and correlated creation of the twin HF QPOs and the LF QPO at a common radius is assumed. On the other hand, the spectral continuum method implies $a\in(0.65-0.75)$, and the Fe-line-profile method implies $a\in(0.94-0.98)$. This controversy can be cured, if we abandon the assumption of the occurrence of the twin HF QPOs and the simultaneously observed LF QPO at a common radius. We demonstrate that the epicyclic resonance model of the twin HF QPOs is able to predict the spin in agreement with the Fe-profile method, but no model based on the geodesic epicyclic frequencies can be in agreement with the spectral continuum method. We also show that the non-geodesic string loop oscillation model of twin HF QPOs predicts spin $a>0.3$ under the optical measurement limit on the black hole mass, in agreement with both the spectral continuum and Fe-profile methods.
description: 10 pages, 3 figures, 2 tables
One-parameter family of acquisition functions for efficient global optimization
Creators: name: Kanazawa, Takuya
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Bayesian optimization (BO) with Gaussian processes is a powerful methodology to optimize an expensive black-box function with as few function evaluations as possible. The expected improvement (EI) and probability of improvement (PI) are among the most widely used schemes for BO. There is a plethora of other schemes that outperform EI and PI, but most of them are numerically far more expensive than EI and PI. In this work, we propose a new one-parameter family of acquisition functions for BO that unifies EI and PI. The proposed method is numerically inexpensive, is easy to implement, can be easily parallelized, and on benchmark tasks shows a performance superior to EI and GP-UCB. Its generalization to BO with Student-t processes is also presented.
description: 13 pages, 6 figures. Accepted to IJCNN 2022
Innovations in business process digitalisation in the forest-wood sector in Slovenia
Creators: name: Slavec, Ana
name: Burnard, Michael D.
Publisher: name: Zenodo
Year: 2023

description: Digital technology can help businesses automate and streamline various processes to optimise resource use and improve the efficiency of their operations and reduce costs. The aim of this paper is to study digitalisation in Slovenia’s forest-wood sector which is important to the country’s smart specialisation strategy. Based on a survey we conducted among 294 enterprises in this sector we study a subsample of innovators that were asked if they introduced or are planning to introduce innovations in business process digitalisation such as collaboration with IT or data experts, implementation of sensor technologies, digital modelling and simulation, collaborative platforms, and other technologies that can help the sector to improve manufacturing and production processes, logistics and sales. The results show that the adoption of digital technologies is correlated with enterprise strategy, investments in research and development, collaboration with universities and research institutes, share of employees with a tertiary degree and in research, development, and innovation positions, and with enterprise size.
description: The study was funded by the European Commission within the InnoRenew project [Grant Agreement #739574] under the Horizon 2020 Widespread-Teaming program, the Republic of Slovenia (investment funding from the Republic of Slovenia and the European Regional Development Fund) and the Slovenian Research Agency within the project Using questionnaires to measure attitudes and behaviours of building users (Z5-1879).
On the Determination of Star Bodies from Their Half-Sections
Creators: name: Rubin, Boris
Publisher: name: arXiv
Year: 2016
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 44A12

description: We obtain explicit inversion formulas for the Radon-like transform that assigns to a function on the unit sphere the integrals of that function over hemispheres lying in lower dimensional central cross-sections. The results are applied to determination of star bodies from the volumes of their central half-sections.
description: 7 pages
Postmortem changes in brain cell structure: a review
Creators: name: Krassner, Margaret
name: Kauffman, Justin
name: Sowa, Allison
name: Cialowicz, Katarzyna
name: Walsh, Samantha
name: Farrell, Kurt
name: Crary, John
name: McKenzie, Andrew
Publisher: name: Free Neuropathology
Year: 2023
Subjects: Postmortem changes
Oncotic necrosis
Autolysis
Staining methods
Species differences
Brain mapping

description: Brain cell structure is a key determinant of neural function that is frequently altered in neurobiological disorders. Following the global loss of blood flow to the brain that initiates the postmortem interval (PMI), cells rapidly become depleted of energy and begin to decompose. To ensure that our methods for studying the brain using autopsy tissue are robust and reproducible, there is a critical need to delineate the expected changes in brain cell morphometry during the PMI. We searched multiple databases to identify studies measuring the effects of PMI on the morphometry (i.e. external dimensions) of brain cells. We screened 2119 abstracts, 361 full texts, and included 172 studies. Mechanistically, fluid shifts causing cell volume alterations and vacuolization are an early event in the PMI, while the loss of the ability to visualize cell membranes altogether is a later event. Decomposition rates are highly heterogenous and depend on the methods for visualization, the structural feature of interest, and modifying variables such as the storage temperature or the species. Geometrically, deformations of cell membranes are common early events that initiate within minutes. On the other hand, topological relationships between cellular features appear to remain intact for more extended periods. Taken together, there is an uncertain period of time, usually ranging from several hours to several days, over which cell membrane structure is progressively lost. This review may be helpful for investigators studying human postmortem brain tissue, wherein the PMI is an unavoidable aspect of the research.
description: Free Neuropathology, Bd. 4 (2023)
Begriff und Wert der Autonomie in Wissenschaft, Kunst und Politik
Creators: name: Franzen, Martina
name: Jung, Arlena
name: Kaldewey, David
name: Korte, Jasper
Publisher: name: Zeitschrift für Theoretische Soziologie
Year: 2014

description: Von Autonomie ist in Forschung wie Öffentlichkeit häufig dann die Rede, wenn Grenzziehungen legitimiert oder problematisiert werden sollen. Neben dieser normativen Begriffsverwendung wird der Autonomiebegriff aber auch deskriptiv und analytisch verwendet: Zum einen um die Ordnung der Gesellschaft und ihrer Teilbereiche zu beschreiben, zum anderen um die Verschiebung innergesellschaftlicher Grenzen im Zuge gesellschaftlichen Wandels zu thematisieren. Mit der Diagnose eines Autonomieverlusts oder eines Autonomiegewinns werden beispielsweise Veränderungen im Verhältnis zwischen unterschiedlichen gesellschaftlichen Bereichen, Institutionen, Akteuren und Akteurkonstellationen charakterisiert. Besonders deutlich ist dies in Feldern wie der Wissenschaft, der Kunst und der Politik. Aus einer differenzierungstheoretischen Perspektive liegt jedoch die Vermutung auf der Hand, dass sich auch in anderen Bereichen, etwa im Recht, in der Wirtschaft, in der Medizin oder im Erziehungssystem Autonomiefragen verschiedenster Art stellen. Im Blick auf solche gesellschaftlichen Strukturen zeigt sich die genuin soziologische Dimension des Autonomiebegriffs: Es geht hier nicht um philosophische und anthropologische Fragen der Willensfreiheit oder der individuellen Selbstbestimmung, auch nicht um die pädagogische Frage nach dem Zusammenhang von Autonomie, Emanzipation, Identität und Subjektivität im Rahmen der Erziehung von Personen, sondern um vielfältige Formen der Autonomie sozialer Entitäten, um die für die soziale Realität konstitutive Verschränkung von Autonomie und Heteronomie sowie um komplexe Interdependenzen zwischen gesellschaftlichen Teilbereichen.
description: Zeitschrift für Theoretische Soziologie, 2014: Sonderband №2 // Autonomie revisited. Beiträge zu einem umstrittenen Grundbegriff in Wissenschaft, Kunst und Politik
Filtered K-theory for graph algebras
Creators: name: Eilers, Søren
name: Restorff, Gunnar
name: Ruiz, Efren
name: Sørensen, Adam P. W.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Rings and Algebras (math.RA)
subject: Operator Algebras (math.OA)
subject: FOS: Mathematics
subject: 16B99, 46L05, 46L55

description: We introduce filtered algebraic $K$-theory of a ring $R$ relative to a sublattice of ideals. This is done in such a way that filtered algebraic $K$-theory of a Leavitt path algebra relative to the graded ideals is parallel to the gauge invariant filtered $K$-theory for graph $C^*$-algebras. We apply this to verify the Abrams-Tomforde conjecture for a large class of finite graphs.
description: 16 pages
Paradoxe Autonomie
Creators: name: Stichweh, Rudolf
Publisher: name: Zeitschrift für Theoretische Soziologie
Year: 2014

description: Der Aufsatz schlägt einen systemtheoretischen Begriff von Autonomie vor, der mit Autonomie nicht die Selbständigkeit oder weitgehende Unabhängigkeit eines Systems meint, sondern die Entstehung einer inneren Steuerungsebene des Systems, die Selbstkontrollen einrichtet, die zugleich Einflusswege markieren, die von allen Versuchen der externen Fremdkontrolle des Systems benutzt werden müssen. Autonomie bezeichnet also ein Steigerungsverhältnis von Fremd- und Selbstkontrollen, das sowohl der Informationsabhängigkeit der Systeme Rechnung trägt und damit dem Sachverhalt, dass sie in sich selbst keine hinreichende Gründe für Bestimmungen finden, wie sie zugleich Informationen und Kontrollversuche so kanalisiert, dass an der Selbstbestimmung des Systems kein Zweifel bestehen kann. Je diversifizierter die Mechanismen der Selbstkontrolle sind, desto mehr externe Abhängigkeiten kann sich das System leisten. Der Text schlägt mit dieser Überlegung ein allgemeines Modell für die Theorie der sozialen Systeme vor, das zugleich seine Eignung darin erweisen muss, dass es differenzierte historische und empirische Analysen verschiedenster Systeme zulässt. Dieser Versuch wird paradigmatisch an den beiden Anwendungsfällen Universität (als Organisation zwischen Erziehungs- und Wissenschaftssystem) und Wissenschaft (als Funktionssystem der modernen Gesellschaft) ausprobiert.
description: Zeitschrift für Theoretische Soziologie, 2014: Sonderband №2 // Autonomie revisited. Beiträge zu einem umstrittenen Grundbegriff in Wissenschaft, Kunst und Politik
Jointly setting upper limits on multiple components of an anisotropic stochastic gravitational-wave background
Creators: name: Suresh, Jishnu
name: Agarwal, Deepali
name: Mitra, Sanjit
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: With the increasing sensitivities of the gravitational wave (GW) detectors and more detectors joining the international network, the chances of detection of a stochastic GW background (SGWB) are progressively increasing. Different astrophysical and cosmological processes are likely to give rise to backgrounds with distinct spectral signatures and distributions on the sky. The observed SGWB will therefore be a superposition of these components. Hence, one of the first questions that will come up after the first detection of a SGWB will likely be about identifying the dominant components and their distributions on the sky. Both these questions were addressed separately in the literature, namely, how to separate components of isotropic backgrounds and how to probe the anisotropy of a single component. Here, we address the question of how to separate distinct anisotropic backgrounds with (sufficiently) different spectral shapes. We first obtain the combined Fisher information matrix from folded data using an efficient analysis pipeline PyStoch, which incorporates covariances between pixels and spectral indices. This is necessary for estimating the detection statistic and setting upper limits. However, based on a recent study, we ignore the pixel-to-pixel noise covariance that does not have a significant effect on the results at the present sensitivity levels of the detectors. We show that the joint analysis accurately separates and estimates backgrounds with different spectral shapes and different sky distributions with no major bias. This does come at the cost of increased variance. Thus making the joint upper limits safer, though less strict than the individual analysis. We finally set joint upper limits on the multicomponent anisotropic background using Advanced LIGO data taken up to the first half of the third observing run.
description: 14 pages, 10 figures, 2 tables
Autonomie als Resistenz gegen Beeinflussung
Creators: name: Gläser, Jochen
name: Schimank, Uwe
Publisher: name: Zeitschrift für Theoretische Soziologie
Year: 2014

description: Wegen seiner theoretischen Unterbestimmtheit wird der Begriff der Autonomie in der Wissenschafts- und Hochschulforschung häufig nur sehr pauschal zur Charakterisierung von individuellen und korporativen Akteuren benutzt. In diesem Beitrag entwickeln wir einen handlungstheoretisch begründeten Autonomiebegriff, der differenzierte vergleichende Beschreibungen von Autonomie und damit theoriegeleitete und -entwickelnde Forschung unterstützt. Ausgehend von diesem Begriff und einer daraus abgeleiteten systematischen Differenzierung von Möglichkeiten der Autonomiewahrung und -beschränkung demonstrieren wir unser Konzept an drei analytisch wichtigen und miteinander zusammenhängenden Anwendungsfällen: der Autonomie von Wissenschaftlern, der Autonomie von Hochschulen in den Hochschulreformen und der Autonomie der Wissenschaft als Teilsystem in einer handlungstheoretisch basierten Differenzierungstheorie.
description: Zeitschrift für Theoretische Soziologie, 2014: Sonderband №2 // Autonomie revisited. Beiträge zu einem umstrittenen Grundbegriff in Wissenschaft, Kunst und Politik
Reflexive Autonomie der Wissenschaft
Creators: name: Wehling, Peter
Publisher: name: Zeitschrift für Theoretische Soziologie
Year: 2014

description: Während Wissenschaftsautonomie im politischen Diskurs von vorneherein als vorteilhaft unterstellt wird, benötigt die Soziologie einen Autonomiebegriff, der auf Distanz zu solchen normativen Vorannahmen bleibt. In dem Beitrag wird ein analytischer Begriff der relativen, empirisch variablen Wissenschaftsautonomie aus Pierre Bourdieus Theorie sozialer Felder entwickelt. Aus feldtheoretischer Perspektive gibt es keinen Grund, die Autonomie sozialer Felder für per se wünschenswert zu halten; gleichwohl war Bourdieu selbst immer ein entschiedener Verfechter größtmöglicher wissenschaftlicher Autonomie. Diese normativ-politische Bewertung steht jedoch in Konflikt mit der Feldtheorie und beruht auf fragwürdigen erkenntnistheoretischen Vorannahmen. Im Kontrast dazu wird abschließend die Idee einer „reflexiven Autonomie“ der Wissenschaft skizziert; externe gesellschaftliche Einflüsse werden dabei weniger als Einschränkung, sondern als Bedingung autonomer Wissenschaft begriffen.
description: Zeitschrift für Theoretische Soziologie, 2014: Sonderband №2 // Autonomie revisited. Beiträge zu einem umstrittenen Grundbegriff in Wissenschaft, Kunst und Politik
Nuclear Physics and Astrophysics of Neutrino Oscillations
Creators: name: Balantekin, A. B.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Nuclear Theory (nucl-th)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: For a long time very little experimental information was available about neutrino properties, even though a minute neutrino mass has intriguing cosmological and astrophysical implications. This situation has changed in recent decades: intense experimental activity to measure many neutrino properties took place. Some of these developments and their implications for astrophysics and cosmology are briefly reviewed with a particular emphasis on neutrino magnetic moments and collective neutrino oscillations
description: NIC 2016 Conference Proceedings
A high-order corrector estimate for a semi-linear elliptic system in perforated domains
Creators: name: Khoa, Vo Anh
Publisher: name: arXiv
Year: 2016
Subjects: subject: Analysis of PDEs (math.AP)
subject: Functional Analysis (math.FA)
subject: FOS: Mathematics

description: We derive in this note a high-order corrector estimate for the homogenization of a microscopic semi-linear elliptic system posed in perforated domains. The major challenges are the presence of nonlinear volume and surface reaction rates. This type of correctors justifies mathematically the convergence rate of formal asymptotic expansions for the two-scale homogenization settings. As main tool, we follow the standard approach by the energy-like method to investigate the error estimate between the micro and macro concentrations and micro and macro concentration gradients. This work aims at generalizing the results reported in [2, 7].
description: 6 pages, 1 figure
Professionelle Autonomie
Creators: name: Torka, Marc
Publisher: name: Zeitschrift für Theoretische Soziologie
Year: 2014

description: Autonomie ist konstitutiv für professionelle Berufe. Deshalb arbeitet die Professionssoziologie mit einer mehrdimensionalen Autonomieanalytik, die in diesem Beitrag auf Wissenschaft bezogen wird. Autonomie tritt dort als Wert- und Wissensbindung, Institutionalisierung spezieller Praxisformen, eigendynamische Interaktion, distinkter Habitus und als Bezugsproblem von Interventionen in Erscheinung. Diese Analytik hat mehrere Vorteile. Erstens erlaubt sie den Vergleich zwischen Autonomieproblematiken verschiedener Berufe. Zweitens fasst sie Autonomie nicht als fest eingerichteten Zustand, sondern als ständig operierendes Bewährungs- und Herstellungsproblem auf. Drittens fügt sie der Wissenschaftsforschung weitere Autonomiedimensionen hinzu. Und viertens zeigt sie, dass den Autonomiedimensionen unterschiedliche Autonomiebegriffe zu Grunde liegen, die nicht zwingend zusammen fallen. Zur Illustration wird das gegenwärtig unter Veränderungsdruck stehende deutsche Promotionswesen herangezogen.
description: Zeitschrift für Theoretische Soziologie, 2014: Sonderband №2 // Autonomie revisited. Beiträge zu einem umstrittenen Grundbegriff in Wissenschaft, Kunst und Politik
Variational Bihamiltonian Cohomologies and Integrable Hierarchies I: Foundations
Creators: name: Liu, Si-Qi
name: Wang, Zhe
name: Zhang, Youjin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Differential Geometry (math.DG)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: This series of papers is devoted to the study of deformations of Virasoro symmetries of the principal hierarchies associated to semisimple Frobenius manifolds. The main tool we use is a generalization of the bihamiltonian cohomology called the variational bihamiltonian cohomology. In the present paper, we give its definitions and compute the associated cohomology groups that will be used in our study of deformations of Virasoro symmetries. To illustrate its application, we classify the conformal bihamiltonian structures with semisimple hydrodynamic limits.
Passive Power Filters
Creators: name: Künzi, R.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Accelerator Physics (physics.acc-ph)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: Power converters require passive low-pass filters which are capable of reducing voltage ripples effectively. In contrast to signal filters, the components of power filters must carry large currents or withstand large voltages, respectively. In this paper, three different suitable filter structures for d.c./d.c. power converters with inductive load are introduced. The formulas needed to calculate the filter components are derived step by step and practical examples are given. The behaviour of the three discussed filters is compared by means of the examples. Practical aspects for the realization of power filters are also discussed.
description: 25 pages, contribution to the 2014 CAS - CERN Accelerator School: Power Converters, Baden, Switzerland, 7-14 May 2014
Protected couplings and BPS dyons in half-maximal supersymmetric string vacua
Creators: name: Bossard, Guillaume
name: Cosnier-Horeau, Charles
name: Pioline, Boris
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We analyze four- and six-derivative couplings in the low energy effective action of $D=3$ string vacua with half-maximal supersymmetry. In analogy with an earlier proposal for the $(\nablaΦ)^4$ coupling, we propose that the $\nabla^2(\nablaΦ)^4$ coupling is given exactly by a manifestly U-duality invariant genus-two modular integral. In the limit where a circle in the internal torus decompactifies, the $\nabla^2(\nablaΦ)^4$ coupling reduces to the $D^2 F^4$ and $R^2 F^2$ couplings in $D=4$, along with an infinite series of corrections of order $e^{-R}$, from four-dimensional 1/4-BPS dyons whose wordline winds around the circle. Each of these contributions is weighted by a Fourier coefficient of a meromorphic Siegel modular form, explaining and extending standard results for the BPS index of 1/4-BPS dyons.
description: 6 pages