cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Costs and Benefits of Breeding Cooperatively in Fluctuating Environments in African Starlings
Creators: Guindre-Parker, Sarah Laurence
Publisher: name: Columbia University
Year: 2017
Subjects: subject: Ecology
subject: FOS: Biological sciences
subject: Starlings
subject: Birds--Breeding
subject: Climatic changes

description: Global climate change is expected to increase the frequency of extreme and unpredictable weather in many parts of the world. As a result, a critical goal for biologists is to predict how organisms may come to cope with increased environmental variability. The key to making these predictions will be to understand how animals currently living in fluctuating environments are able to survive and reproduce under these conditions. Sociality (i.e. group living) and cooperative breeding (i.e. where more than two individuals care for young together) may both facilitate the colonization of highly fluctuating environments. However, the relative benefits of group living and engaging in alloparental care under variable conditions remain unclear. My dissertation examines the fitness consequences of living in one of the world’s most unpredictable habitats—the African savanna—in a population of free-living cooperatively breeding superb starlings (Lamprotornis superbus). In chapter 1, I examine whether adults benefit from living in large social groups of up to 50 individuals, which are among the largest known for any cooperatively breeding bird. In addition, I test whether group size serves to buffer against harsh environmental conditions. In chapter 2, I examine whether breeders gain reproductive benefits by having alloparents at their nest—I explore the type of reproductive benefits gained (i.e. improved reproductive success versus offspring care load-lightening), as well as whether these benefits occur in both harsh and benign conditions (i.e. temporal variability hypothesis), or are greatest under harsh conditions only (i.e. hard life hypothesis). In chapter 3, I explore whether offspring care load-lightening reduces the cost of reproduction incurred by breeders and alloparents by comparing four physiological mechanisms known to mediate reproductive costs. Lastly, in chapter 4 I test the long-standing assumption that cooperatively breeding species face reduced costs of reproduction by sharing offspring care relative to non-cooperatively breeding species. I compare the oxidative cost of reproduction in superb starlings to greater blue-eared glossy starlings (L. chalybaeus), a synoptic non-cooperatively breeding species. Taken together my dissertation findings demonstrate that group living and alloparental care do not solely buffer against harsh conditions in superb starlings, but instead provide individuals with the flexibility to modify their offspring care behavior according to environmental conditions, to the behavior of other group members, and to their physiological condition prior to breeding—this behavioral flexibility may in turn serve to mitigate fluctuations in the cost of living and breeding in variable environments.
Uniform error bounds of time-splitting methods for the nonlinear Dirac equation in the nonrelativistic regime without magnetic potential
Creators: name: Bao, Weizhu
name: Cai, Yongyong
name: Yin, Jia
Publisher: name: arXiv
Year: 2019
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: 65N35

description: Super-resolution of the Lie-Trotter splitting ($S_1$) and Strang splitting ($S_2$) is rigorously analyzed for the nonlinear Dirac equation without external magnetic potentials in the nonrelativistic regime with a small parameter $0
description: 26 pages, 2 figures and 8 tables
Operator interpretation of resonances arising in spectral problems for 2 x 2 operator matrices
Creators: name: Mennicken, R.
name: Motovilov, A. K.
Publisher: name: arXiv
Year: 1997
Subjects: subject: Functional Analysis (math.FA)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: Operator Algebras (math.OA)
subject: Spectral Theory (math.SP)
subject: Nuclear Theory (nucl-th)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 47A56 47Nxx (Primary) 47N50 47A40 (Secondary)

description: We consider operator matrices {\bf H}= (A_0 B_{01} \\ B_{10} A_{1}) with self-adjoint entries A_i, i=0,1, and bounded B_{01}=B_{10}^*, acting in the orthogonal sum {\cal H}={\cal H}_0\oplus{\cal H}_1 of Hilbert spaces {\cal H}_0 and {\cal H}_1. We are especially interested in the case where the spectrum of, say, A_1 is partly or totally embedded into the continuous spectrum of A_0 and the transfer function M_1(z)=A_1-z+V_1(z), where V_1(z)=B_{10}(z-A_0)^{-1}B_{01}, admits analytic continuation (as an operator-valued function) through the cuts along branches of the continuous spectrum of the entry A_0 into the unphysical sheet(s) of the spectral parameter plane. The values of z in the unphysical sheets where M_1^{-1}(z) and consequently the resolvent (H-z)^{-1} have poles are usually called resonances. A main goal of the present work is to find non-selfadjoint operators whose spectra include the resonances as well as to study the completeness and basis properties of the resonance eigenvectors of M_1(z) in {\cal H}_1. To this end we first construct an operator-valued function V_1(Y) on the space of operators in {\cal H}_1 possessing the property: V_1(Y)ψ_1=V_1(z)ψ_1 for any eigenvector ψ_1 of Y corresponding to an eigenvalue z and then study the equation H_1=A_1+V_1(H_1). We prove the solvability of this equation even in the case where the spectra of A_0 and A_1 overlap. Using the fact that the root vectors of the solutions H_1 are at the same time such vectors for M_1(z), we prove completeness and even basis properties for the root vectors (including those for the resonances).
description: LaTeX 2e (REVTeX style), 62 pages. A slightly extended version. In particular a figure was added. A number of corrections was made. Submitted to Math. Nachr
"I have no idea what they're trying to accomplish:" Enthusiastic and Casual Signal Users' Understanding of Signal PINs
Creators: name: Bailey, Daniel V.
name: Markert, Philipp
name: Aviv, Adam J.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Cryptography and Security (cs.CR)
subject: Human-Computer Interaction (cs.HC)
subject: FOS: Computer and information sciences

description: We conducted an online study with $n = 235$ Signal users on their understanding and usage of PINs in Signal. In our study, we observe a split in PIN management and composition strategies between users who can explain the purpose of the Signal PINs (56%; enthusiasts) and users who cannot (44%; casual users). Encouraging adoption of PINs by Signal appears quite successful: only 14% opted-out of setting a PIN entirely. Among those who did set a PIN, most enthusiasts had long, complex alphanumeric PINs generated by and saved in a password manager. Meanwhile more casual Signal users mostly relied on short numeric-only PINs. Our results suggest that better communication about the purpose of the Signal PIN could help more casual users understand the features PINs enable (such as that it is not simply a personal identification number). This communication could encourage a stronger security posture.
description: To appear at Symposium on Usable Privacy and Security (SOUPS) 2021
¿Por qué cambiamos la hora, por qué la cambiamos ahora y qué tiene que ver con los horarios de trabajo?
Creators: name: Martín-Olalla, José María
Publisher: name: Politikon
Year: 2014
Subjects: Daylight Saving Time
Cambio estacional de hora
Cambio de hora
latitud

description: Se analiza el cambio estacional de la hora y su relación con el amanecer invernal. Por extensión se describe la relación entre el cambio estacional de la hora y el inicio de la jornada laboral.
The deconfining phase transition in SU(N) gauge theories
Creators: name: Lucini, B.
name: Teper, M.
name: Wenger, U.
Publisher: name: arXiv
Year: 2002
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We report on our ongoing investigation of the deconfining phase transition in SU(4) and SU(6) gauge theories. We calculate the critical couplings while taking care to avoid the influence of a nearby bulk phase transition. We determine the latent heat of the phase transition and investigate the order and the strength of the transition at large N. We also report on our determination of the critical temperature expressed in units of the string tension in the large N limit.
description: Lattice 2002 (nonzerot), 3 pages, 2 figures
Characterization of the Spectrum of the Landau Hamiltonian with Delta Impurities
Creators: name: Dorlas, T. C.
name: Macris, N.
name: Pulé, J. V.
Publisher: name: arXiv
Year: 1999
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We consider a random Schrodinger operator in an external magnetic field. The random potential consists of delta functions of random strengths situated on the sites of a regular two-dimensional lattice. We characterize the spectrum in the lowest N Landau bands of this random Hamiltonian when the magnetic field is sufficiently strong, depending on N. We show that the spectrum in these bands is entirely pure point, that the energies coinciding with the Landau levels are infinitely degenerate and that the eigenfunctions corresponding to energies in the remainder of the spectrum are localized with a uniformly bounded localization length. By relating the Hamiltonian to a lattice operator we are able to use the Aizenman-Molchanov method to prove localization.
description: To appear in Commun. Math. Phys. (1999)
The Bargmann-Wigner Formalism for Spin 2
Creators: name: Dvoeglazov, Valeri V.
Publisher: name: arXiv
Year: 1998
Subjects: subject: Mathematical Physics (math-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We proceed to derive equations for the symmetric tensor of the second rank on the basis of the Bargmann-Wigner formalism in a straightforward way. The symmetric multispinor of the fourth rank is used. It is constructed out of the Dirac 4-spinors. Due to serious problems with the interpretation of the results obtained on using the standard procedure we generalize it and obtain the spin-2 relativistic equations, which are consistent with the previous one. The importance of the 4-vector field (and its gauge part) is pointed out.
description: ReVTeX file, 6pp
Nonparametric Statistical Inference via Metric Distribution Function in Metric Spaces
Creators: name: Wang, Xueqin
name: Zhu, Jin
name: Pan, Wenliang
name: Zhu, Junhao
name: Zhang, Heping
Publisher: name: arXiv
Year: 2021
Subjects: subject: Methodology (stat.ME)
subject: Statistics Theory (math.ST)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: Distribution function is essential in statistical inference, and connected with samples to form a directed closed loop by the correspondence theorem in measure theory and the Glivenko-Cantelli and Donsker properties. This connection creates a paradigm for statistical inference. However, existing distribution functions are defined in Euclidean spaces and no longer convenient to use in rapidly evolving data objects of complex nature. It is imperative to develop the concept of distribution function in a more general space to meet emerging needs. Note that the linearity allows us to use hypercubes to define the distribution function in a Euclidean space, but without the linearity in a metric space, we must work with the metric to investigate the probability measure. We introduce a class of metric distribution functions through the metric between random objects and a fixed location in metric spaces. We overcome this challenging step by proving the correspondence theorem and the Glivenko-Cantelli theorem for metric distribution functions in metric spaces that lie the foundation for conducting rational statistical inference for metric space-valued data. Then, we develop homogeneity test and mutual independence test for non-Euclidean random objects, and present comprehensive empirical evidence to support the performance of our proposed methods.
Detecting composite orders in layered models via machine learning
Creators: name: Rzadkowski, W.
name: Defenu, N.
name: Chiacchiera, S.
name: Trombettoni, A.
name: Bighin, G.
Publisher: name: arXiv
Year: 2019
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Computational Physics (physics.comp-ph)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Determining the phase diagram of systems consisting of smaller subsystems 'connected' via a tunable coupling is a challenging task relevant for a variety of physical settings. A general question is whether new phases, not present in the uncoupled limit, may arise. We use machine learning to study layered spin models, in which the spin variables constituting each of the uncoupled systems (to which we refer as layers) are coupled to each other via an interlayer coupling. In such systems, in general, composite order parameters involving spins of different layers may emerge as a consequence of the interlayer coupling. We focus on the layered Ising and Ashkin-Teller models as a paradigmatic case study, determining their phase diagram via the application of a machine learning algorithm to the Monte Carlo data. Remarkably our technique is able to correctly characterize all the system phases also in the case of hidden order parameters, i.e., order parameters whose expression in terms of the microscopic configurations would require additional preprocessing of the data fed to the algorithm. We correctly retrieve the three known phases of the Ashkin-Teller model with ferromagnetic couplings, including the phase described by a composite order parameter. For the bilayer and trilayer Ising models the phases we find are only the ferromagnetic and the paramagnetic ones. Within the approach we introduce, owing to the construction of convolutional neural networks, naturally suitable for layered image-like data with arbitrary number of layers, no preprocessing of the Monte Carlo data is needed, also with regard to its spatial structure. The physical meaning of our results is discussed and compared with analytical data, where available. Yet, the method can be used without any a priori knowledge of the phases one seeks to find and can be applied to other models and structures.
description: Significantly expanded compared to v1. 16 pages, 6 figures
Additional file 1 of Effect of Automated Closed-loop ventilation versus convenTional VEntilation on duration and quality of ventilation in critically ill patients (ACTiVE) – study protocol of a randomized clinical trial
Creators: name: Botta, Michela
name: Tsonas, Anissa M.
name: Sinnige, Jante S.
name: De Bie, Ashley J. R.
name: Bindels, Alexander J. G. H.
name: Ball, Lorenzo
name: Battaglini, Denise
name: Brunetti, Iole
name: Buiteman–Kruizinga, Laura A.
name: van der Heiden, Pim L. J.
name: de Jonge, Evert
name: Mojoli, Francesco
name: Robba, Chiara
name: Schoe, Abraham
name: Paulus, Frederique
name: Pelosi, Paolo
name: Neto, Ary Serpa
name: Horn, Janneke
name: Schultz, Marcus J.
Publisher: name: figshare
Year: 2022
Subjects: Medicine
Biotechnology
Biological Sciences not elsewhere classified
Information Systems not elsewhere classified
Cancer

description: Additional file 1: Appendix. List of participating hospitals. Definitions of clinical outcome variables. EQ-5D-5L Quality of Life Questionnaire
Additional file 1: of Mental health and mindfulness amongst Australian fire fighters
Creators: name: Counson, Isabelle
name: Hosemans, Dominic
name: Lal, Tara
name: Mott, Brendan
name: Harvey, Samuel
name: Joyce, Sadhbh
Publisher: name: figshare
Year: 2019
Subjects: subject: Microbiology
subject: FOS: Biological sciences
subject: Evolutionary Biology
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Sociology
subject: FOS: Sociology
subject: 69999 Biological Sciences not elsewhere classified
subject: Science Policy

description: Table S1. Regression Coefficients and Squared Semi-Partial Correlations for the Hierarchical Multiple Linear Regression Using Years Worked with FRNSW and Mindfulness to Predict Depression. Table S2. Regression Coefficients and Squared Semi-Partial Correlations for the Hierarchical Multiple Linear Regression Using Years Worked with FRNSW and Mindfulness to Predict Anxiety. Table S3. Regression Coefficients and Squared Semi-Partial Correlations for the Hierarchical Multiple Linear Regression Using Years Worked with FRNSW and Mindfulness to Predict Well-Being. (DOCX 23 kb)
Modeling Univariate and Multivariate Stochastic Volatility in R with stochvol and factorstochvol
Creators: name: Hosszejni, Darjus
name: Kastner, Gregor
Publisher: name: arXiv
Year: 2019
Subjects: subject: Computation (stat.CO)
subject: Econometrics (econ.EM)
subject: Computational Finance (q-fin.CP)
subject: Statistical Finance (q-fin.ST)
subject: FOS: Computer and information sciences
subject: FOS: Economics and business
subject: G.3; J.4
subject: 62-04 (Primary) 62F15, 62M10, 62P20 (Secondary)

description: Stochastic volatility (SV) models are nonlinear state-space models that enjoy increasing popularity for fitting and predicting heteroskedastic time series. However, due to the large number of latent quantities, their efficient estimation is non-trivial and software that allows to easily fit SV models to data is rare. We aim to alleviate this issue by presenting novel implementations of four SV models delivered in two R packages. Several unique features are included and documented. As opposed to previous versions, stochvol is now capable of handling linear mean models, heavy-tailed SV, and SV with leverage. Moreover, we newly introduce factorstochvol which caters for multivariate SV. Both packages offer a user-friendly interface through the conventional R generics and a range of tailor-made methods. Computational efficiency is achieved via interfacing R to C++ and doing the heavy work in the latter. In the paper at hand, we provide a detailed discussion on Bayesian SV estimation and showcase the use of the new software through various examples.
Dense Supervision Propagation for Weakly Supervised Semantic Segmentation on 3D Point Clouds
Creators: name: Wei, Jiacheng
name: Lin, Guosheng
name: Yap, Kim-Hui
name: Liu, Fayao
name: Hung, Tzu-Yi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Semantic segmentation on 3D point clouds is an important task for 3D scene understanding. While dense labeling on 3D data is expensive and time-consuming, only a few works address weakly supervised semantic point cloud segmentation methods to relieve the labeling cost by learning from simpler and cheaper labels. Meanwhile, there are still huge performance gaps between existing weakly supervised methods and state-of-the-art fully supervised methods. In this paper, we train a semantic point cloud segmentation network with only a small portion of points being labeled. We argue that we can better utilize the limited supervision information as we densely propagate the supervision signal from the labeled points to other points within and across the input samples. Specifically, we propose a cross-sample feature reallocating module to transfer similar features and therefore re-route the gradients across two samples with common classes and an intra-sample feature redistribution module to propagate supervision signals on unlabeled points across and within point cloud samples. We conduct extensive experiments on public datasets S3DIS and ScanNet. Our weakly supervised method with only 10% and 1% of labels can produce compatible results with the fully supervised counterpart.
The averaged null energy condition for general quantum field theories in two dimensions
Creators: name: Verch, Rainer
Publisher: name: arXiv
Year: 1999
Subjects: subject: Mathematical Physics (math-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: It is shown that the averaged null energy condition is fulfilled for a dense, translationally invariant set of vector states in any local quantum field theory in two-dimensional Minkowski spacetime whenever the theory has a mass gap and possesses an energy-momentum tensor. The latter is assumed to be a Wightman field which is local relative to the observables, generates locally the translations, is divergence-free, and energetically bounded. Thus the averaged null energy condition can be deduced from completely generic, standard assumptions for general quantum field theory in two-dimensional flat spacetime.
description: LateX2e, 16 pages, 1 eps figure
Court in the Market: The 'Business' of a Princely Court  in the Burgundian Netherlands, 1467-1503
Creators: Cho, Jun Hee
Publisher: name: Columbia University
Year: 2013
Subjects: Commerce
Feudalism
Courts and courtiers
History

description: This dissertation examines the relations between court and commerce in Europe at the onset of the modern era.  Focusing on one of the most powerful princely courts of the period, the court of Charles the Bold, duke of Burgundy, which ruled over one of the most advanced economic regions in Europe, the greater Low Countries, it argues that the Burgundian court was, both in its institutional operations and its cultural aspirations, a commercial enterprise. Based primarily on fiscal accounts, corroborated with court correspondence, municipal records, official chronicles, and contemporary literary sources, this dissertation argues that the court was fully engaged in the commercial economy and furthermore that the culture of the court, in enacting the ideals of a largely imaginary feudal past, was also presenting the ideals of a commercial future.  It uncovers courtiers who, despite their low rank yet because of their market expertise, were close to the duke and in charge of acquiring and maintaining the material goods that made possible the pageants and ceremonies so central to the self-representation of the Burgundian court.  It exposes the wider network of court officials, urban merchants and artisans who, tied by marriage and business relationships, together produced and managed the ducal liveries, jewelries, tapestries and finances that realized the splendor of the court.  It shows how the princely court adapted to and harnessed the commercial economy of the urban network, employing nominally feudal titles and structures.  Furthermore, it reveals how courtly understandings of magnificence and honor were also demonstrations of commercial prowess and acknowledgements of commercial wealth, even as these discourses were framed in terms of chivalric ideals.  The princely court was neither merely a predatory expropriator of urban wealth nor a rapacious consumer of luxury goods, but also an active participant in the commercial economy. By examining the 'business' of a princely court, this dissertation seeks to contribute to our understanding of the socio-cultural manifestations of state and market formation during the late medieval and early modern era.  This study is one testimony of how Europeans sought to make sense of, and more importantly, to channel and control the tides of commercialization, utilizing the institutional and cultural frameworks they inherited from their past.  The intertwined relationship between the princely court and the commercial economy in the Burgundian Netherlands draws our attention to the common processes, institutions and cultures that laid the groundwork for the modern state and the capitalist economy.
Cove-Edge Graphene Nanoribbon Semiconductors: from Molecules to Devices
Creators: Etkin, Grisha
Publisher: name: Columbia University
Year: 2018
Subjects: Chemistry
Semiconductors
Graphene
Materials

description: This dissertation presents research conducted on the structure-property relationships of cove-edge graphene nanoribbon (GNR) semiconductors from the scale of molecular conformation to device performance. The ribbons described here are made derived from perylene-3,4,9,10-tetracarboxylic acid diimide (PDI) and adopt a helical conformation so we call them helical PDI (hPDI). They are n-type semiconductors with exceptional performance in field-effect transistors (FETs), organic photovoltaics (OPVs), narrowband photodetectors, and electron transporting materials in perovskite solar cells. In this work, reaction chemistry is used to design and synthesize new derivatives of hPDI to shine light on their molecular, bulk, and device properties.
      The first chapter concerns the incorporation of hPDI into alternating donor- acceptor (D-A) macromolecules to create materials with internal charge transfer (CT). Computational and spectroscopic techniques, including femtosecond transient absorption spectroscopy (fsTA), are used to probe the CT character of these materials. A large dihedral angle between donor and acceptor portions limits orbital overlap, leading to lowest energy excited state with HOMO localized on the donor and LUMO localized on the acceptor. Notably, internal CT improves the OPV performance of these oligomers over their parent hPDI, while analogous macromolecules without internal CT exhibit reduced OPV performance.
      Chapter 2 details a method for side chain engineering of hPDI by installing the side chain in the final step of the synthesis, rather than the first. The aromatic core of hPDI is built up with esters, rather than imides, appending the edges of the ribbons. The ester-appended ribbons are readily transformed into a late-stage intermediate for divergent installation of any desired side chains, including those that pose synthetic challenges when they are introduced into the parent PDI from the beginning. These side chains have a profound effect on the optical, thermal, and charge transport properties of hPDI in the solid state. This strategy of introducing imide side-chains into PDI-based materials in the final step can be generalized to other systems.
      Chapter 3 demonstrates a method for controlling the conformation of cove-edge GNRs by changing the chemical substitution pattern at their edges. All-sp2 substituents that lock adjacent edge positions into a ring rigidify the aromatic core of these ribbons. When substituents at adjacent edge positions are no longer locked into a ring, the aromatic core becomes flexible. Modulating this flexibility dictates how these ribbons contort to accommodate their cove-edges, with rigid cores contorting into chiral helixes, and flexible cores contorting into a butterfly conformation. This may point the way forward for the use of GNRs in applications that rely on precise control of molecular conformation
Crack is Wack: Activism, Rhetoric, and the Creation of a Crisis Surrounding the Regulation of Prenatal Drug Use in New York City from 1987-1997
Creators: Bhaman, Salonee
Publisher: name: Columbia University
Year: 2014
Subjects: Drug control
History, Modern
Substance abuse in pregnancy
History
Public policy (Law)
Public health

description: This thesis first explores the legal landscape surrounding prenatal drug use in New York City in the late 80s and early 90s, then moves on to provide a brief history and profile of some of the progressive organizations that were created during the reform efforts of this period. Next, I explore the differences between these organizations and the Office of Mayor Giuliani through analysis of two bills proposed simultaneously in the New York State legislature in 1997. The New York State Hearing about one of them, Assembly Bill A-8217, acts as a useful case study into the various positions held within the debate.
abess: A Fast Best Subset Selection Library in Python and R
Creators: name: Zhu, Jin
name: Wang, Xueqin
name: Hu, Liyuan
name: Huang, Junhao
name: Jiang, Kangkang
name: Zhang, Yanhang
name: Lin, Shiyun
name: Zhu, Junxian
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (stat.ML)
subject: Machine Learning (cs.LG)
subject: Computation (stat.CO)
subject: FOS: Computer and information sciences

description: We introduce a new library named abess that implements a unified framework of best-subset selection for solving diverse machine learning problems, e.g., linear regression, classification, and principal component analysis. Particularly, the abess certifiably gets the optimal solution within polynomial times with high probability under the linear model. Our efficient implementation allows abess to attain the solution of best-subset selection problems as fast as or even 20x faster than existing competing variable (model) selection toolboxes. Furthermore, it supports common variants like best group subset selection and $\ell_2$ regularized best-subset selection. The core of the library is programmed in C++. For ease of use, a Python library is designed for conveniently integrating with scikit-learn, and it can be installed from the Python library Index. In addition, a user-friendly R library is available at the Comprehensive R Archive Network. The source code is available at: https://github.com/abess-team/abess.
A weighted finite difference method for subdiffusive Black Scholes Model
Creators: name: Krzyżanowski, Grzegorz
name: Magdziarz, Marcin
name: Płociniczak, Łukasz
Publisher: name: arXiv
Year: 2019
Subjects: subject: Computational Engineering, Finance, and Science (cs.CE)
subject: Numerical Analysis (math.NA)
subject: Computational Finance (q-fin.CP)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics
subject: FOS: Economics and business
subject: G.1.8; G.3
subject: 65M22, 91G20, 91G60

description: In this paper we focus on the subdiffusive Black Scholes model. The main part of our work consists of the finite difference method as a numerical approach to the option pricing in the considered model. We derive the governing fractional differential equation and the related weighted numerical scheme being a generalization of the classical Crank-Nicolson scheme. The proposed method has $2-α$ order of accuracy with respect to time where $α\in(0,1)$ is the subdiffusion parameter, and $2$ with respect to space. Further, we provide the stability and convergence analysis. Finally, we present some numerical results.
I-concurrence and tangle for isotropic states
Creators: name: Rungta, Pranaw
name: Caves, Carlton M.
Publisher: name: arXiv
Year: 2002
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We discuss properties of entanglement measures called I-concurrence and tangle. For a bipartite pure state, I-concurrence and tangle are simply related to the purity of the marginal density operators. The I-concurrence (tangle) of a bipartite mixed state is the minimum average I-concurrence (tangle) of ensemble decompositions of pure states of the joint density operator. Terhal and Vollbrecht [Phys. Rev. Lett. 85, 2625 (2000)] have given an explicit formula for the entanglement of formation of isotropic states in arbitrary dimensions. We use their formalism to derive comparable expressions for the I-concurrence and tangle of isotropic states.
description: 15 pages, 5 figures
Rényi’s information transfer between financial time series
Creators: name: Jizba, Petr
name: Kleinert, Hagen
name: Shefaat, Mohammad
Publisher: name: Freie Universität Berlin
Year: 2012
Subjects: subject: 500 Naturwissenschaften und Mathematik::530 Physik

description: In this paper, we quantify the statistical coherence between financial time series by means of the Rényi entropy. With the help of Campbell’s coding theorem, we show that the Rényi entropy selectively emphasizes only certain sectors of the underlying empirical distribution while strongly suppressing others. This accentuation is controlled with Rényi’s parameter qq. To tackle the issue of the information flow between time series, we formulate the concept of Rényi’s transfer entropy as a measure of information that is transferred only between certain parts of underlying distributions. This is particularly pertinent in financial time series, where the knowledge of marginal events such as spikes or sudden jumps is of a crucial importance. We apply the Rényian information flow to stock market time series from 11 world stock indices as sampled at a daily rate in the time period 02.01.1990–31.12.2009. Corresponding heat maps and net information flows are represented graphically. A detailed discussion of the transfer entropy between the DAX and S&P500; indices based on minute tick data gathered in the period 02.04.2008–11.09.2009 is also provided. Our analysis shows that the bivariate information flow between world markets is strongly asymmetric with a distinct information surplus flowing from the Asia–Pacific region to both European and US markets. An important yet less dramatic excess of information also flows from Europe to the US. This is particularly clearly seen from a careful analysis of Rényi information flow between the DAX and S&P500; indices.
Crafting Across Time and Space: Artistic Exchange and Archaic Greek Sanctuaries in the Eastern Mediterranean
Creators: Schneller, David H.
Publisher: name: Columbia University
Year: 2021
Subjects: Art, Ancient
Archaeology
Civilization, Classical
Classical antiquities
Terra-cotta sculpture, Greek
Terra-cotta sculpture, Cypriot

description: Portable objects made of terracotta, stone, and bronze, among other materials, stylistically linked to cultural spheres around the eastern Mediterranean basin and further inland in the Near East, Cyprus, and Egypt, were dedicated with fervor at Greek sanctuaries during the Archaic period. Previously, such votive offerings were superficially interpreted as “foreign imports” and enumerated in oversimplified tallies and exoticizing lists of “orientalia” and/or “aegyptiaca.” They have been embedded as the stimuli of the so-called “Orientalizing” phenomenon—a 19th-century paradigm and enduring trend in scholarship that interprets aspects of culture as originating in the east and moving westward during the early first millennium. Focus was limited to identifying their geographical places of manufacture and attempting to reveal the identities of the dedicators. This paradigm limits attention to the origins of such objects and restricts interpretations of them to one-directional understandings of artistic “influence.” Informed by theories of materiality, modes of acquisition, the exchange of skilled crafting knowledge, and the movement of raw materials, finished products, craftspeople as well as their patrons in the eastern Mediterranean cosmos during the 7th and 6th centuries, this dissertation approaches the corpus through object biographies. It foregrounds three case studies—Cypriot style terracotta figurines from the Heraion of Samos, Egyptian sculptures from East Greek sanctuaries, and the composite North Syrian and Cretan sphyrelata korai from Olympia—to temper the broader theoretical discussions of intercultural artistic exchange during this time. The study explores a diverse array of artistic processes of material transformation ranging from the destruction, reuse, adaptation, and modification of objects to the local production of objects that can be stylistically linked to places far afield. By examining the materials from which and the manufacturing techniques by which such objects were made, it reevaluates where, when, and by whom they were crafted. The analysis identifies the tangible processes of artistic transmission to illuminate the exchanges of and interactions among the eastern Mediterranean craftspeople tasked with the fabrication of the dedications and the patrons who commissioned them. Ultimately, as singular artistic products, it is argued that the objects in the case studies represent intercultural attempts at unique votive object manufacture and communicate meaning by inhabiting more than one geographical space and temporally remote moments in time.
DIELECTRIC CHARACTERISTICS OF citronella oil
Creators: name: Dedi Wahyudi
Publisher: name: PT. Jasa Niaga Digital Indonesia
Year: 2024

description: Rapid testing of the levels of citronella oil components is very important in modern industry. This research aims to measure the quality of citronella oil by looking at its dielectric characteristics, especially the capacitance value at various concentrations of the geraniol compound contained in the oil. The test method uses a capacitor plate connected by a clamp to the LCR meter connector to analyze the dielectric characteristics in the frequency range 100-2000 Hz. The research results revealed that the overall dielectric characteristics of citronella oil showed an exponential decrease in capacitance values in the frequency range 100-2000 Hz. The same thing also happened to the dielectric constant value for each variation in geraniol concentration in citronella oil. These findings have important implications in the citronella oil industry because they can be used as an effective method to measure and monitor the quality of citronella oil quickly and accurately. In addition, this research provides further insight into the relationship between geraniol compound content and the dielectric characteristics of citronella oil. This knowledge can be used to increase the production and quality of citronella oil in industries that require high quality raw materials.
Crafting Digital Narratives: Black Girls' Literacies, Social Media, and Identity Formation
Creators: Odlum, Lakisha Renee
Publisher: name: Columbia University
Year: 2021
Subjects: Education
Teenage girls, Black
Literacy--Study and teaching
Engineering--Study and teaching
Minorities--Education
COVID-19 (Disease)--Social aspects

description: This qualitative dissertation explored the digital literacy practices of adolescent Black girls who actively engaged on social media in the midst of the 2020 COVID-19 pandemic, mandatory school shutdowns, and the aftermath of the murders of Breonna Taylor and George Floyd. I employ the Black Girls’ Literacies (BGL) framework (Haddix & Muhammad, 2016) to analyze the TikTok accounts of two adolescent Black girl influencers, as well as six qualitative interviews I conducted with adolescent Black girls who avidly used video sharing social media apps during that time. The data analysis aligned with the following components of the BGL Framework: Black girls’ literacies are multiple; Black girls’ literacies are tied to identities; and Black girls’ literacies are intellectual, political, and critical. Moreover, the data analysis also revealed that Black girls espoused three different identities while using social media to address the COVID-19 pandemic and anti-Black violence. These themes were: Crafting Digital Narratives of the Self as Educators, Crafting Digital Narratives of the Self as Nurturers, and Crafting Digital Narratives of the Self as Digital Activists. My findings suggested that for English educators, prioritizing racial literacy in the English classroom, creating learning experiences that are informed by critical media literacy, and creating a space that honors and supports Black girls’ desires to be activists within their communities are critical for their success within and outside of the English classroom.
Normalizers and Approximate Units for Inclusions of C*-Algebras
Creators: name: Pitts, David R.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Operator Algebras (math.OA)
subject: FOS: Mathematics
subject: 46L05

description: For an inclusion of C*-algebras $D\subseteq A$ with $D$ abelian, we show that when $n\in A$ normalizes $D$, $n^*n$ and $nn^*$ commute with $D$. As a corollary, when $D$ is a regular MASA in $A$, every approximate unit for $D$ is also an approximate unit for $A$. This permits removal of the non-degeneracy hypothesis from the definition of a Cartan MASA in the non-unital case.
 We give examples of singular MASA inclusions: for some, every approximate unit for $D$ is an approximate unit for $A$, while for others, no approximate unit for $D$ is an approximate unit for $A$. Our results imply that if the unitization of an inclusion $D\subseteq A$ is a C*-diagonal, then $D$ is regular in $A$. In contrast, we give an example of a non-regular inclusion whose unitization is a Cartan inclusion.
 If $D$ is a MASA in $A$, we ask when $A$ is a subalgebra of $B$ with $D$ a regular MASA in $B$. When $D$ is a MASA in $\mathcal B(\ell^2(\mathbb N))$, no such $B$ exists.
description: To appear in Indiana University Mathematics Journal. 14 pages. Added Proposition 3.2 and a reference; other results unchanged from v.4
Harmonic flow of $\mathrm{Spin}(7)$-structures
Creators: name: Dwivedi, Shubham
name: Loubeau, Eric
name: Earp, Henrique N. Sá
Publisher: name: arXiv
Year: 2021
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 53C15, 53C43, 58J35, 58J60

description: We formulate and study the isometric flow of $\mathrm{Spin}(7)$-structures on compact $8$-manifolds, as an instance of the harmonic flow of geometric structures. Starting from a general perspective, we establish Shi-type estimates and a correspondence between harmonic solitons and self-similar solutions for arbitrary isometric flows of $H$-structures. We then specialise to $H=\mathrm{Spin}(7)\subset\mathrm{SO}(8)$, obtaining conditions for long-time existence, via a monotonicity formula along the flow, which actually leads to an $\varepsilon$-regularity theorem. Moreover, we prove Cheeger--Gromov and Hamilton-type compactness theorems for the solutions of the harmonic flow, and we characterise Type-$\mathrm{I}$ singularities as being modelled on shrinking solitons.We also establish a Bryant-type description of isometric $\mathrm{Spin}(7)$-structures, based on squares of spinors, which may be of independent interest.
description: v2-minor changes in the presentation and exposition. 47 pages
Tetragnathidae MENGE 1866
Creators: name: Álvarez-Padilla, Fernando
name: Hormiga, Gustavo
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Tetragnathidae

description: TETRAGNATHIDAE MENGE, 1866   Type genus: Tetragnatha Latreille, 1804.
 Diagnosis: Tetragnathid females can be differentiated from other araneoids by the following combination of features: cheliceral boss present with its cuticle either smooth or similar to the rest of the anterior surface of chelicerae (Figs 9C, 23D, E, 57D, 101D); clypeus more than one AME diameter high; labium trapezoidal and rebordered (Figs 19G, 23C, 47G); a flat epigynum, when present (124-0 Figs 79A, 81D, 89A); ALS piriform spigot bases separated from the spigot shaft by a torus (Fig. 66B arrow in insert box points to the torus area wrapping the piriform spigot shaft), absent in Meta and Mollemeta (Figs 56B, 82E); absence of aciniform spigots on the PMS, present in Azilia and Meta (4-0: Figs 13G, 56C, 71A, 109D); and cylindrical spigots on the PLS peripheral in position (Figs 26D, 77E). Males of Tetragnathidae are distinguished from other araneoids by their large cymbial tarsal organ, larger than the surrounding macrosetal bases; absence of tegular apophyses, except for the conductor (contra Archer, 1951: 4–5); conductor and embolus coiled together; apical position of the embolic division; and by having the embolus connected to the tegulum by a membrane. Tetragnathids differ from nephilids by the absence of cheliceral denticles (Fig. 93D), except in Nanometinae (Figs 73C, 88D) and by their cylindrical paracymbium (Fig. 112D). The paracymbium of nephilids is more rectangular (Fig. 138D). The webs of nephilids have secondary and tertiary radii (Figs 6B, 7A), whereas the radii of most tetragnathid webs are undivided (Figs 4C, F, 5D), and usually have open hubs, few radii, and few spirals of sticky silk (fewer than 20), although exceptions exist, such as the webs of Azilia and Dolichognatha species, which are denser and can have secondary radii (Fig. 3C, E). Secondary radii can also be found in some Glenognatha species (G. Hormiga, unpubl. data). Tetragnathid phylogenetic relationships are discussed in the previous sections. The monophyly of Tetragnathidae is supported by seven morphological synapomorphies: piriform spigot base edges separated from the spigot shaft (2-1: Fig. 66B), cymbium tarsal organ diameter larger than the contiguous macrosetae bases (24-1: Fig. 112C), oval to spherical tegulum (47-0: Fig. 112A), carapace moderately hirsute (98-1: Fig. 62A), femora IV mesal surface without basal macrosetae (174-1: Fig. 14H); male palpal patella with one macroseta (180-1: Fig. 29F); and male palpal tibia length approximately two times the widest point of the tibia (181-1: Fig. 69C).
description: Published as part of Álvarez-Padilla, Fernando & Hormiga, Gustavo, 2011, Morphological and phylogenetic atlas of the orb-weaving spider family Tetragnathidae (Araneae: Araneoidea), pp. 713-879 in Zoological Journal of the Linnean Society 162 (4) on page 741, DOI: 10.1111/j.1096-3642.2011.00692.x, http://zenodo.org/record/5440885
BANK KREDITLARI ASOSIDA MOLIYALASHTIRISHNING IQTISODIY SAMARADORLIGINI OSHIRISHDA RISKLARNI BOSHQARISH STRATEGIYALARI
Creators: name: Raimov, Mirzohid
Publisher: name: Zenodo
Year: 2025

description: Ushbu tezisda bank kreditlari orqali moliyalashtirish jarayonida yuzaga keladigan asosiy risklar, ularning moliyaviy samaradorlikka ta’siri hamda ushbu risklarni kamaytirish va boshqarish strategiyalari tahlil qilinadi. Risklarni boshqarish orqali investitsion loyihalarning daromadliligini oshirish, kreditga qobiliyatli korxonalarni aniqlash, garov siyosatini kuchaytirish va sug‘urta mexanizmlaridan foydalanish kabi chora-tadbirlarning iqtisodiy ahamiyati yoritilgan. Shuningdek, banklar va korxonalar o‘rtasida samarali axborot almashinuvini tashkil qilish orqali qarz oluvchining to‘lov qobiliyatini oldindan baholash usullari muhokama qilinadi.
Holographic entanglement first law for d + 1 dimensional rotating cylindrical black holes
Creators: name: Nadi, Hamideh
name: Mirza, Behrouz
name: Sherkatghanad, Zeinab
name: Mirzaiyan, Zahra
Publisher: name: arXiv
Year: 2019
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We calculate the holographic entanglement entropy for the rotating cylindrical black holes in $d+1$ dimensions as perturbations over $AdS_{d+1}$. This is accomplished based on the first order variation of the area functional in arbitrary dimensions. For these types of black holes, the angular momentum appears at the first order of the perturbative expansion of the holographic entanglement entropy for spacetime dimensions of d +1 $\geq$ 4. We obtain a form of holographic entanglement first law in the presence of both energy and angular momentum.
description: 14 Pages, 7 figures