cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
title: Mapping Work-based Learning in Peace and Security Studies
title: INCOPS Report
Creators: name: Runge, Lena
name: Vértes, Sára
Publisher: name: Philipps-Universität Marburg
Year: 2021
Subjects: subject: Social sciences
subject: FOS: Social sciences
subject: Sozialwissenschaften, Soziologie

description: Veröffentlichung um Rahmen des Projekts: Integration of Work-based Learning in Conflict, Peace and Security Studies (INCOPS). Erasmus+ Strategic Partnership 2020-1-DE01-KA203-005661
description: In recent years, the incorporation of practical experiences into university curricula increasingly became a standard across various disciplines and study programmes. Likewise, in the field of Peace, Conflict and Security Studies (PCS) both scholars and employers have stressed the necessity for a closer integration of academic skills with practical experience. The project ‘Integration of Work-based Learning in Conflict, Peace and Security Studies’ primarily aims to strengthen the structural integration of practical skill development in MA level curricula of higher education institutions in Europe. Therefore, this report lays grounds for the project by analysing potential benefits of Workbased Learning (WBL) for the field, by providing a conceptual base and by both quantitatively and qualitatively investigating forms of WBL within Europe that have been used in PCS so far. For the research, we scrutinised the six project members’ programmes in PCS and collected insights from eight additional institutes engaged in peace, conflict and security education. The Qualitative Survey and the analysis of its results mainly focused on the diversity of WBL activities, the operationalisation and integration of WBL experience into the curriculum, as well as the (institutional) assistance and assessment of WBL modules. The project’s ‘working definition’ of WBL summarises common points extracted from the inspected academic literature and debates within the project’s consortium to align all project partners’ understanding of the WBL practices. WBL is defined as: An approach in higher education, which aims to merge theory and practice. It entails students working in or with organisations in the field, gaining practical experience, while utilising and reflecting on their academic skills. Secondly, it yields an increase in educational resources, new impressions, networks, innovative ideas and critical reflection on the applicability of learnt theories. In addition, WBL brings together different stakeholders such as teachers, students and professional organisations.
Towards a systematic design of isotropic bulk magnetic metamaterials using the cubic point groups of symmetry
Creators: name: Baena, J. D.
name: Jelinek, L.
name: Marques, R.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: In this paper a systematic approach to the design of bulk isotropic magnetic metamaterials is presented. The role of the symmetries of both the constitutive element and the lattice are analyzed. For this purpose it is assumed that the metamaterial is composed by cubic SRR resonators, arranged in a cubic lattice. The minimum symmetries needed to ensure an isotropic behavior are analyzed, and some particular configurations are proposed. Besides, an equivalent circuit model is proposed for the considered cubic SRR resonators. Experiments are carried out in order to validate the proposed theory. We hope that this analysis will pave the way to the design of bulk metamaterials with strong isotropic magnetic response, including negative permeability and left-handed metamaterials.
description: Submitted to Physical Review B, 23 pages
C*-Algebra Relations
Creators: name: Loring, Terry A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Operator Algebras (math.OA)
subject: FOS: Mathematics
subject: 46L05, 46L85

description: We investigate relations on elements in C*-algebras, including *-polynomial relations, order relations and all relations that correspond to universal C*-algebras. We call these C*-relations and define them axiomatically. Within these are the compact C*-relations, which are those that determine universal C*-algebras, and we introduce the more flexible concept of a closed C*-relation. In the case of a finite set of generators, we show that closed C*-relations correspond to the zero-sets of elements in a free sigma -C*-algebra. This provides a solid link between two of the previous theories on relations in C*-algebras. Applications to lifting problems are briefly considered in the last section.
description: Added a few examples. 24 pages
Nonlinear effects in the excited states of many-fermion Einstein-Dirac solitons
Creators: name: Leith, Peter E. D.
name: Hooley, Chris A.
name: Horne, Keith
name: Dritschel, David G.
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present an analysis of excited-state solutions for a gravitationally localized system consisting of a filled shell of high-angular-momentum fermions, using the Einstein-Dirac formalism introduced by Finster, Smoller, and Yau [Phys. Rev. D 59, 104020 (1999)]. We show that, even when the particle number is relatively low ($N_f\ge 6$), the increased nonlinearity in the system causes a significant deviation in behavior from the two-fermion case. Excited-state solutions can no longer be uniquely identified by the value of their central redshift, with this multiplicity producing distortions in the characteristic spiraling forms of the mass-radius relations. We discuss the connection between this effect and the internal structure of solutions in the relativistic regime.
description: 18 pages, 12 figures
Active Frequency Measurement on Superradiant Strontium Clock Transitions
Creators: name: Zhang, Yuan
name: Shan, Chongxin
name: Mølmer, Klaus
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We develop a stochastic mean-field theory to describe active frequency measurements of pulsed superradiant emission, studied in recent experiments with strontium-87 atoms trapped in an optical lattice inside an optical cavity [M. Norcia, et al., Phys. Rev. X 8, 21036 (2018)]. Our theory reveals the intriguing dynamics of atomic ensembles with multiple transition frequencies, and it reproduces the superradiant beats signal, noisy power spectra, and frequency uncertainty in remarkable agreement with the experiments. Moreover, by reducing the number of atoms, elongating the superradiant pulses and shortening the experimental duty cycle, we predict a short-term frequency uncertainty $9\times10^{-16} \sqrt{τ/s}$, which makes active frequency measurements with superradiant transitions comparable with the record performance of current frequency standards [M. Schioppo, et al., Nat. Photonics, 11, 48 (2017)]. Our theory combines cavity-quantum electrodynamics and quantum measurement theory, and it can be readily applied to explore conditional quantum dynamics and describe frequency measurements for other processes such as steady-state superradiance and superradiant Raman lasing.
description: 10 pages, 9 figures
title: MRI claustrophobia: The reason is the decrease in oxygen saturation in the magnetic field?
Creators: name: Akay, Sinan
Publisher: name: European Congress of Radiology
Year: 2019
Subjects: subject: Biological effects
subject: Experimental investigations
subject: MR
subject: MR physics

description: Aims and objectives Methods and materials Results Conclusion Personal information References
description: Aims and objectives: Since the introduction of magnetic resonance imaging (MRI) in the 1980s, it has become one of the most popular and important diagnostic radiologic modalities. MRI examination usually includes the patient being put into a relatively narrow bore and...
The Church Synthesis Problem with Parameters
Creators: name: Rabinovich, Alexander
Publisher: name: arXiv
Year: 2007
Subjects: subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences
subject: F.4.1; F.4.3

description: For a two-variable formula ψ(X,Y) of Monadic Logic of Order (MLO) the Church Synthesis Problem concerns the existence and construction of an operator Y=F(X) such that ψ(X,F(X)) is universally valid over Nat. Büchi and Landweber proved that the Church synthesis problem is decidable; moreover, they showed that if there is an operator F that solves the Church Synthesis Problem, then it can also be solved by an operator defined by a finite state automaton or equivalently by an MLO formula. We investigate a parameterized version of the Church synthesis problem. In this version ψ might contain as a parameter a unary predicate P. We show that the Church synthesis problem for P is computable if and only if the monadic theory of is decidable. We prove that the Büchi-Landweber theorem can be extended only to ultimately periodic parameters. However, the MLO-definability part of the Büchi-Landweber theorem holds for the parameterized version of the Church synthesis problem.
On some generalizations of Newton non degeneracy for hypersurface singularities
Creators: name: Kerner, Dmitry
Publisher: name: arXiv
Year: 2008
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14B05, 14J17, 14J70, 32S05, 32S10, 32S25

description: We introduce two generalizations of Newton-non-degenerate (Nnd) singularities of hypersurfaces. Roughly speaking, an isolated hypersurface singularity is called topologically Newton-non-degenerate (tNnd) if the local embedded topological singularity type can be restored from a collection of Newton diagrams (for some coordinate choices). A singularity that is not tNnd is called essentially Newton-degenerate. For plane curves we give an explicit characterization of tNnd singularities; for hypersurfaces we provide several examples. Next, we treat the question: whether Nnd or tNnd is a property of singularity types or of particular representatives. Namely, is the non-degeneracy preserved in an equi-singular family? This fact is proved for curves. For hypersurfaces we give an example of a Nnd hypersurface whose equi-singular deformation consists of essentially Newton-degenerate hypersurfaces. Finally, we define the directionally Newton-non-degenerate germs, a subclass of tNnd germs. For such singularities the classical formulas for the Milnor number and the zeta function of the Nnd hypersurface are generalized.
description: Final version, to appear in the Journal of the London Mathematical Society. 18 pages; uses packages: amssymb,curves. Some new results were added
Non-equilibrium Relaxation Analysis on Two-dimensional Melting
Creators: name: Watanabe, Hiroshi
Publisher: name: arXiv
Year: 2008
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: The melting transition in the hard-disk system is considered. Non-equilibrium relaxation analysis of the six-fold bond-orientational order parameter has been carried out. The critical point between the hexatic and the fluid phase is determined on the basis of the dynamic scaling hypothesis. The value of the critical exponent $η$ is determined from the fluctuation of the order parameter at the criticality as $η= 0.25(2)$ which is consistent with the prediction by the Kosterlitz-Thouless-Halperin-Nelson-Young theory.
description: 8 pages, 5 figures. submitted to Prog. Theor. Phys. Suppl. as a proceedings of Symposium on the 50th anniversary of the Alder transition
Mode stability in delta Scuti stars: linear analysis versus observations in open clusters
Creators: name: Suarez, J. C.
name: Michel, E.
name: Houdek, G.
name: Hernandez, F. Perez
name: Lebreton, Y.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: A comparison between linear stability analysis and observations of pulsation modes in five delta Scuti stars, belonging to the same cluster, is presented. The study is based on the work by Michel et al. (1999), in which such a comparison was performed for a representative set of model solutions obtained independently for each individual star considered. In this paper we revisit the work by Michel et al. (1999) following, however, a new approach which consists in the search for a single, complete, and coherent solution for all the selected stars, in order to constrain and test the assumed physics describing these objects. To do so, refined descriptions for the effects of rotation on the determination of the global stellar parameters and on the adiabatic oscillation frequency computations are used. In addition, a crude attempt is made to study the role of rotation on the prediction of mode instabilities.The present results are found to be comparable with those reported by Michel et al. (1999). Within the temperature range log T_eff = 3.87-3.88 agreement between observations and model computations of unstable modes is restricted to values for the mixing-length parameter alpha_nl less or equal to 1.50. This indicates that for these stars a smaller value for alpha_nl is required than suggested from a calibrated solar model. We stress the point that the linear stability analysis used in this work still assumes stellar models without rotation and that further developments are required for a proper description of the interaction between rotation and pulsation dynamics.
description: 8 pages, 4 figures, 3 tables. (MNRAS, in press)
Effects of nutrient media on vegetative growth of Lemna minor and Landoltia punctata during in vitro and ex vitro cultivation
Creators: name: Chokchai Kittiwongwattana
name: Supachai Vuttipongchaikij
Publisher: name: Maejo University
Year: 2013
Subjects: Lemna minor,Landoltia punctata,effects of nutrient media,in vitro cultivation,ex vitro cultivation, frond proliferation,biomass production,root elongation

description: 1, 7, Maejo International Journal of Science and Technology
Energy Savings by Task Offloading to a Fog Considering Radio Front-End Characteristics
Creators: name: Kryszkiewicz, Pawel
name: Idzikowski, Filip
name: Bossy, Bartosz
name: Kopras, Bartosz
name: Bogucka, Hanna
Publisher: name: arXiv
Year: 2021
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: Signal Processing (eess.SP)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Fog computing can be used to offload computationally intensive tasks from battery powered Internet of Things (IoT) devices. Although it reduces energy required for computations in an IoT device, it uses energy for communications with the fog. This paper analyzes when usage of fog computing is more energy efficient than local computing. Detailed energy consumption models are built in both scenarios with the focus set on the relation between energy consumption and distortion introduced by a Power Amplifier (PA). Numerical results show that task offloading to a fog is the most energy efficient for short, wideband links.
description: IEEE International Symposium on Personal, Indoor and Mobile Radio Communications 2019
Feedback from Multiple Supernova Explosions inside a Wind-Blown Bubble
Creators: name: Cho, Hyunjin
name: Kang, Hyesung
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We study the evolution of multiple supernova (SN) explosions inside a pre-exiting cavity blown by winds from massive progenitor stars. Hydrodynamic simulations in one-dimensional spherical geometry, including radiative cooling and thermal conduction, are carried out to follow first the development of the wind-blown bubble during the main sequence and then the evolution of the SN-driven bubble. We find the size and mass of the SN-driven bubble shell depend on the structure of the pre-existing wind bubble as well as the SN explosion energy E_{SN} (= N_{SN} 10^{51} ergs). The hot cavity inside the bubble is 2-3 times bigger in volume and hotter than that of a bubble created by SNe exploded in a uniform interstellar medium (ISM). For an association with 10 massive stars in the average ISM, the SN-driven shell has an outer radius of R_{ss} ~ (85 pc) N_{SN}^{0.1} and a mass of M_{ss} ~ (10^{4.8} Msun) N_{SN}^{0.3}at 10^6 years after the explosion. By that time most of the explosion energy is lost via radiative cooling, while ~10% remains as kinetic energy and ~10% as thermal energy. We also calculate the total integrated spectrum of diffuse radiation emitted by the shock-heated gas of the SN bubble. For the models with 0.1 solar metalicity, the radiative energy loss is smaller and the fraction of non-ionizing photons is larger, compared to those with solar metalicity. We conclude the photoionization/heating by diffuse radiation is the most dominant form of feedback from SN explosions into the surrounding medium.
description: 31 pages, 10 figures, to appear in New Astronomy
Measuring information exchange and brokerage capacity of healthcare teams
Creators: name: Grippa, F.
name: Bucuvalas, J.
name: Booth, A.
name: Alessandrini, E.
name: Colladon, A. Fronzetti
name: Wade, L. M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Social and Information Networks (cs.SI)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences
subject: J.4

description: Purpose: The purpose of this paper is to explore possible factors impacting team performance in healthcare, by focusing on information exchange within and across hospital's boundaries. Design/methodology/approach: Through a web-survey and group interviews, the authors collected data on the communication networks of 31 members of four interdisciplinary healthcare teams involved in a system redesign initiative within a large US children's hospital. The authors mapped their internal and external social networks based on management advice, technical support and knowledge dissemination within and across departments, studying interaction patterns that involved more than 700 actors. The authors then compared team performance and social network metrics such as degree, closeness and betweenness centrality, and computed cross ties and constraint levels for each team. Findings: The results indicate that highly effective teams were more inwardly focused and less connected to outside members. Moreover, highly recognized teams communicated frequently but, overall, less intensely than the others. Originality/value: Mapping knowledge flows and balancing internal focus and outward connectivity of interdisciplinary teams may help healthcare decision makers in their attempt to achieve high value for patients, families and employees.
The rank of a hypergeometric system
Creators: name: Berkesch, Christine
Publisher: name: arXiv
Year: 2008
Subjects: subject: Algebraic Geometry (math.AG)
subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 33C70, 14M25, 16E30, 20M25, 13N10

description: The holonomic rank of the A-hypergeometric system M_A(β) is the degree of the toric ideal I_A for generic parameters; in general, this is only a lower bound. To the semigroup ring of A we attach the ranking arrangement and use this algebraic invariant and the exceptional arrangement of nongeneric parameters to construct a combinatorial formula for the rank jump of M_A(β). As consequences, we obtain a refinement of the stratification of the exceptional arrangement by the rank of M_A(β) and show that the Zariski closure of each of its strata is a union of translates of linear subspaces of the parameter space. These results hold for generalized A-hypergeometric systems as well, where the semigroup ring of A is replaced by a nontrivial weakly toric module M contained in \CC[\ZZ A]. We also provide a direct proof of the result of M. Saito and W. Traves regarding the isomorphism classes of M_A(β).
description: 32 pages. To appear in Compositio Mathematica. Revisions have been made to the exposition, and the notation has been simplified
Structural shrinkage of nonparametric spectral estimators for multivariate time series
Creators: name: Böhm, Hilmar
name: von Sachs, Rainer
Publisher: name: arXiv
Year: 2008
Subjects: subject: Statistics Theory (math.ST)
subject: FOS: Mathematics

description: In this paper we investigate the performance of periodogram based estimators of the spectral density matrix of possibly high-dimensional time series. We suggest and study shrinkage as a remedy against numerical instabilities due to deteriorating condition numbers of (kernel) smoothed periodogram matrices. Moreover, shrinking the empirical eigenvalues in the frequency domain towards one another also improves at the same time the Mean Squared Error (MSE) of these widely used nonparametric spectral estimators. Compared to some existing time domain approaches, restricted to i.i.d. data, in the frequency domain it is necessary to take the size of the smoothing span as "effective or local sample size" into account. While Böhm and von Sachs (2007) proposes a multiple of the identity matrix as optimal shrinkage target in the absence of knowledge about the multidimensional structure of the data, here we consider "structural" shrinkage. We assume that the spectral structure of the data is induced by underlying factors. However, in contrast to actual factor modelling suffering from the need to choose the number of factors, we suggest a model-free approach. Our final estimator is the asymptotically MSE-optimal linear combination of the smoothed periodogram and the parametric estimator based on an underfitting (and hence deliberately misspecified) factor model. We complete our theoretical considerations by some extensive simulation studies. In the situation of data generated from a higher-order factor model, we compare all four types of involved estimators (including the one of Böhm and von Sachs (2007)).
description: Published in at http://dx.doi.org/10.1214/08-EJS236 the Electronic Journal of Statistics (http://www.i-journals.org/ejs/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Coulomb correlations do not fill the e'_g hole pockets in Na_{0.3}CoO_2
Creators: name: Liebsch, A.
name: Ishida, H.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: There exists presently considerable debate over the question whether local Coulomb interactions can explain the absence of the small e'_g Fermi surface hole pockets in photoemission studies of Na_{0.3}CoO_2. By comparing dynamical mean field results for different single particle Hamiltonians and exact diagonalization as well as quantum Monte Carlo treatments, we show that, for realistic values of the Coulomb energy U and Hund exchange J, the e'_g pockets can be slightly enhanced or reduced compared to band structure predictions, but they do not disappear.
description: 4 pages, 2 figures
Possible nodeless superconductivity in the noncentrosymmetric superconductor Mg_(12-delta)Ir_19B_16
Creators: name: Mu, Gang
name: Wang, Yue
name: Shan, Lei
name: Wen, Hai-Hu
Publisher: name: arXiv
Year: 2007
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We measured the resistivity, diamagnetization, and low-temperature specific heat of the newly discovered noncentrosymmetric superconductor Mg_(12-delta)Ir_19B_16. The temperature dependence of specific heat is consistent with the model of an isotropic s-wave gap with value Delta_0 = 0.94 meV for the sample Tc = 5.7 K, and the ratio Delta_0/k_BTc = 1.91 indicates a slightly moderate coupling for the superconductivity. The correlations among the normal state Sommerfeld constant gamma_n, the slope -dHc2(T)/dT near Tc, and the condensation energy Ec are all consistent with the slightly moderate coupling picture. Based on the data of phonon contribution, Tc and the McMillan formula, we obtained an electron-phonon coupling strength lambda_(e-ph) = 0.66, which suggests that the superconductivity here is induced by the electron-phonon coupling.
description: 6 pages, 7 figures
Implementation of Departmental and Periodical Examination Analyzer System
Creators: name: Garcia, Julius G.
name: Aunario, Connie C.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computers and Society (cs.CY)
subject: FOS: Computer and information sciences

description: Administering examinations both in public and private academic institutions can be tedious and unmanageable. The multiplicity of problems affecting the conduct of departmental and periodical examination can be greatly reduced by automating the examination process. The purpose of this action research is to provide an alternative technical solution in administering test through the use of Examination System. This software application can facilitate a plenitude of examinees for different subjects that implements a random questioning technique and can generate item analysis and test results. The Departmental and Periodical Examination System was developed using Visual Basic language. The software modules were tested using the functional testing method. Using the criteria and metrics of ISO 9126 software quality model, the system was evaluated by a group of students, teachers, school administrators and information technology professionals and has received an overall weighted mean of 4.56585 with an excellent descriptive rating. Therefore, the performance of the application software provides solution that can surmount the gargantuan problems of test administration and post-examination issues and performs all the operations specified in the objectives.
Identification and biocellulose production of Gluconacetobacter strains isolated from tropical fruits in Thailand
Creators: name: Daungjai Ochaikul
name: Amornrat Suwanposri
name: Pattaraporn Yukphan
name: Yamada, Yuzo
Publisher: name: Maejo University
Year: 2013
Subjects: biocellulose-producing bacteria,Gluconacetobacter,tropical fruit,16S rRNA gene sequence analysis

description: 1, 7, Maejo International Journal of Science and Technology
Optical polarimetric study of open clusters: Distribution of Interstellar matter towards NGC 654
Creators: name: Medhi, Biman J.
name: G, Maheswar.
name: Pandey, J. C.
name: Kumar, T. S.
name: Sagar, Ram
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present new B, V and R linear polarimetric observations for 61 stars towards the region of the young open cluster NGC 654. In this study we found evidence for the presence of at least two layers of dust along the line of sight to the cluster. The distances to the two dust layers are estimated to be ~ 200 pc and ~ 1 kpc which are located much closer to the Sun than the cluster (~ 2.4 kpc). Both the dust layers have their local magnetic field orientation nearly parallel to the direction of the Galactic plane. The foreground dust layer is found to have a ring morphology with the central hole coinciding with the center of the cluster. The foreground dust grains are suggested to be mainly responsible for both the observed differential reddening and the polarization towards the cluster.
description: 24 pages, 10 figures, 4 tables, Accepted for publication in MNRAS
Accretion Properties of MAXI J1813-095 during its Failed Outburst in 2018
Creators: name: Jana, Arghajit
name: Jaisawal, Gaurava K.
name: Naik, Sachindra
name: Kumari, Neeraj
name: Chatterjee, Debjit
name: Chatterjee, Kaushik
name: Bhowmick, Riya
name: Chakrabarti, Sandip K.
name: Chang, Hsiang-Kuang
name: Debnath, Dipak
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We present the results obtained from detailed timing and spectral studies of a black hole candidate MAXI~J1813-095 using {\it Swift}, {\it NICER}, and {\it NuSTAR} observations during its 2018 outburst. The timing behaviour of the source is mainly studied by using {\it NICER} light curves in a $0.5-10$ keV range. We did not find any signature of quasi-periodic oscillations in the power density spectra of the source. We carry out spectral analysis with a combined disk blackbody \& power-law model, and a physical two-component advective flow (TCAF) model. From the combined {\tt disk blackbody} \& {\tt power-law} model, we extracted thermal and non-thermal fluxes, photon index, and inner disk temperature. We also find evidence for weak reflection in the spectra. We have tested the physical TCAF model on a broadband spectrum from {\it NuSTAR} and {\it Swift}/XRT. The parameters like mass accretion rates, the size of the Compton clouds and the shock strength are extracted. Our result shows that the source remained in the hard state during the entire outburst which indicates a `failed' outburst. We estimate the mass of the black hole as $7.4 \pm 1.5$ $M_{\odot}$ from the spectral study with the TCAF model. We use {\tt LAOR} model for the Fe K$α$ line emission. From this, the spin parameter of the black hole is estimated as $a^* > 0.76$. The inclination angle of the system is estimated to be in the range of $28^{\circ} - 45^{\circ}$ from the reflection model. We estimate the source distance to be $\sim 6$ kpc.
description: 15 pages, 7 figures, 3 tables. Accepted for publication in Research in Astronomy & Astrophysics
Surface Growth in Deformable Solids using an Eulerian Formulation
Creators: name: Naghibzadeh, Kiana
name: Walkington, Noel
name: Dayal, Kaushik
Publisher: name: arXiv
Year: 2021
Subjects: subject: Analysis of PDEs (math.AP)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: Growth occurs in a wide range of systems ranging from biological tissue to additive manufacturing. This work considers surface growth, in which mass is added to the boundary of a continuum body from the ambient medium or from within the body. In contrast to bulk growth in the interior, the description of surface growth requires the addition of new continuum particles to the body. This is challenging for standard continuum formulations for solids that are meant for situations with a fixed amount of material. Recent approaches to handle this have used time-evolving reference configurations. In this work, an Eulerian approach to this problem is formulated, enabling the side-stepping of the issue of constructing the reference configuration. However, this raises the complementary challenge of determining the stress response of the solid, which typically requires the deformation gradient that is not immediately available in the Eulerian formulation. To resolve this, the approach introduces additional kinematic descriptors, namely the relaxed zero-stress deformation and the elastic deformation; in contrast to the deformation gradient, these have the important advantage that they are not required to satisfy kinematic compatibility. The resulting model has only the density, velocity, and elastic deformation as variables in the Eulerian setting. The introduction in this formulation of the relaxed deformation and the elastic deformation provides a description of surface growth whereby the added material can bring in its own kinematic information. Loosely, the added material "brings in its own reference configuration" through the specification of the relaxed deformation and the elastic deformation of the added material. This kinematic description enables, e.g., modeling of non-normal growth using a standard normal growth velocity and a simple approach to prescribing boundary conditions.
description: In press at the Journal of the Mechanics and Physics of Solids
Brittle to ductile transitions in glasses: Roles of soft defects and loading geometry
Creators: name: Richard, David
name: Lerner, Edan
name: Bouchbinder, Eran
Publisher: name: arXiv
Year: 2021
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Understanding the fracture toughness of glasses is of prime importance for science and technology. We study it here using extensive atomistic simulations in which the interaction potential, glass transition cooling rate and loading geometry are systematically varied, mimicking a broad range of experimentally accessible properties. Glasses' nonequilibrium mechanical disorder is quantified through $A_{\rm g}$, the dimensionless prefactor of the universal spectrum of nonphononic excitations, which measures the abundance of soft glassy defects that affect plastic deformability. We show that while a brittle-to-ductile transition might be induced by reducing the cooling rate, leading to a reduction in $A_{\rm g}$, iso-$\!A_{\rm g}$ glasses are either brittle or ductile depending on the degree of Poisson contraction under unconstrained uniaxial tension. Eliminating Poisson contraction using constrained tension reveals that iso-$\!A_{\rm g}$ glasses feature similar toughness, and that varying $A_{\rm g}$ under these conditions results in significant toughness variation. Our results highlight the roles played by both soft defects and loading geometry (which affects the activation of defects) in the toughness of glasses.
description: 14 pages, 6 figures (including Methods) + Supplementary Material (8 pages, 7 figures)
On the Theory of Surfaces in the Four-dimensional Euclidean Space
Creators: name: Ganchev, Georgi
name: Milousheva, Velichka
Publisher: name: arXiv
Year: 2007
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 53A07 (Primary) 53B25 (Secondary)

description: For a two-dimensional surface in the four-dimensional Euclidean space we introduce an invariant linear map of Weingarten type in the tangent space of the surface, which generates two invariants k and kappa. The condition k = kappa = 0 characterizes the surfaces consisting of flat points. The minimal surfaces are characterized by the equality kappa^2=k. The class of the surfaces with flat normal connection is characterized by the condition kappa = 0. For the surfaces of general type we obtain a geometrically determined orthonormal frame field at each point and derive Frenet-type derivative formulas. We apply our theory to the class of the rotational surfaces, which prove to be surfaces with flat normal connection, and describe the rotational surfaces with constant invariants.
description: 14 pages
Refined Young inequality and its application to divergences
Creators: name: Furuichi, Shigeru
name: Minculete, Nicuşor
Publisher: name: arXiv
Year: 2021
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Information Theory (cs.IT)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences
subject: 26D15, 26E60, 94A17

description: We give bounds on the difference between the weighted arithmetic mean and the weighted geometric mean. These imply refined Young inequalities and the reverses of the Young inequality. We also study some properties on the difference between the weighted arithmetic mean and the weighted geometric mean. Applying the newly obtained inequalities, we show some results on the Tsallis divergence, the Rényi divergence, the Jeffreys-Tsallis divergence and the Jensen-Shannon-Tsallis divergence.
description: 16 pages
Hamilton-Jacobi Theory and Moving Frames
Creators: name: MacArthur, Joshua D.
name: McLenaghan, Raymond G.
name: Smirnov, Roman G.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mathematical Physics (math-ph)
subject: Differential Geometry (math.DG)
subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: The interplay between the Hamilton-Jacobi theory of orthogonal separation of variables and the theory of group actions is investigated based on concrete examples.
description: This is a contribution to the Vadim Kuznetsov Memorial Issue on Integrable Systems and Related Topics, published in SIGMA (Symmetry, Integrability and Geometry: Methods and Applications) at http://www.emis.de/journals/SIGMA/
A Geometrical Characterization of the Twin Paradox and its Variants
Creators: name: Szekely, Gergely
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mathematical Physics (math-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Logic (math.LO)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: The aim of this paper is to provide a logic-based conceptual analysis of the twin paradox (TwP) theorem within a first-order logic framework. A geometrical characterization of TwP and its variants is given. It is shown that TwP is not logically equivalent to the assumption of the slowing down of moving clocks, and the lack of TwP is not logically equivalent to the Newtonian assumption of absolute time. The logical connection between TwP and a symmetry axiom of special relativity is also studied.
description: 22 pages, 3 figures
2D histology meets 3D topology: Cytoarchitectonic brain mapping with Graph Neural Networks
Creators: name: Schiffer, Christian
name: Harmeling, Stefan
name: Amunts, Katrin
name: Dickscheid, Timo
Publisher: name: arXiv
Year: 2021
Subjects: subject: Image and Video Processing (eess.IV)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Cytoarchitecture describes the spatial organization of neuronal cells in the brain, including their arrangement into layers and columns with respect to cell density, orientation, or presence of certain cell types. It allows to segregate the brain into cortical areas and subcortical nuclei, links structure with connectivity and function, and provides a microstructural reference for human brain atlases. Mapping boundaries between areas requires to scan histological sections at microscopic resolution. While recent high-throughput scanners allow to scan a complete human brain in the order of a year, it is practically impossible to delineate regions at the same pace using the established gold standard method. Researchers have recently addressed cytoarchitectonic mapping of cortical regions with deep neural networks, relying on image patches from individual 2D sections for classification. However, the 3D context, which is needed to disambiguate complex or obliquely cut brain regions, is not taken into account. In this work, we combine 2D histology with 3D topology by reformulating the mapping task as a node classification problem on an approximate 3D midsurface mesh through the isocortex. We extract deep features from cortical patches in 2D histological sections which are descriptive of cytoarchitecture, and assign them to the corresponding nodes on the 3D mesh to construct a large attributed graph. By solving the brain mapping problem on this graph using graph neural networks, we obtain significantly improved classification results. The proposed framework lends itself nicely to integration of additional neuroanatomical priors for mapping.
Formation of Multipartite Entanglement Using Random Quantum Gates
Creators: name: Most, Yonatan
name: Shimoni, Yishai
name: Biham, Ofer
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The formation of multipartite quantum entanglement by repeated operation of one and two qubit gates is examined. The resulting entanglement is evaluated using two measures: the average bipartite entanglement and the Groverian measure. A comparison is made between two geometries of the quantum register: a one dimensional chain in which two-qubit gates apply only locally between nearest neighbors and a non-local geometry in which such gates may apply between any pair of qubits. More specifically, we use a combination of random single qubit rotations and a fixed two-qubit gate such as the controlled-phase gate. It is found that in the non-local geometry the entanglement is generated at a higher rate. In both geometries, the Groverian measure converges to its asymptotic value more slowly than the average bipartite entanglement. These results are expected to have implications on different proposed geometries of future quantum computers with local and non-local interactions between the qubits.
description: 7 pages, 5 figures
Detecting Personality and Emotion Traits in Crowds from Video Sequences
Creators: name: Favaretto, Rodolfo Migon
name: Knob, Paulo
name: Musse, Soraia Raupp
name: Vilanova, Felipe
name: Costa, Ângelo Brandelli
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: This paper presents a methodology to detect personality and basic emotion characteristics of crowds in video sequences. Firstly, individuals are detected and tracked, then groups are recognized and characterized. Such information is then mapped to OCEAN dimensions, used to find out personality and emotion in videos, based on OCC emotion models. Although it is a clear challenge to validate our results with real life experiments, we evaluate our method with the available literature information regarding OCEAN values of different Countries and also emergent Personal distance among people. Hence, such analysis refer to cultural differences of each country too. Our results indicate that this model generates coherent information when compared to data provided in available literature, as shown in qualitative and quantitative results.
title: The physical structure of high-pressure supersonic gas jets flowing from circular vents
Creators: name: Keogh, Thomas
Publisher: name: University of Kent
Year: 2024

description: A puncture in the wall of a high pressure gas reservoir leads to a supersonic jet that is associated with many astrophysical, planetary and aerodynamical phenomena, from radio galaxies to volcanic plumes and rockets. We undertake a systematic numerical analysis of a range of different physical parameters focusing on jet pressures exceeding that of its surroundings. We take a particular interest in the first shock generated by the jet, known as the stand off shock, as these are the brightest and easiest to detect in observation. We have shown there is a relationship where the location of the stand off shock not only depends on the overpressure but also on density through a feedback process and we have defined laws for this. We conclude that even steady uniform outflows will rapidly evolve into one of three distinct flow patterns, taking the form of turbulent plumes at high over-pressures and regular oscillations at low over-pressures. We also explore how energy is transferred into the environment as over-pressured jets are thought to contribute to the regulation of star and galaxy formation through the generation of noise and screeching.
Light Front Formalism for Composite Systems and Some of Its Applications in Particle and Relativistic Nuclear Physics
Creators: name: Garsevanishvili, V. R.
name: Khelashvili, A. A.
name: Menteshashvili, Z. R.
name: Nioradze, M. S.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Light front formalism for composite systems is presented. Derivation of equations for bound state and scattering problems are given. Methods of constructing of elastic form factors and scattering amplitudes of composite particles are reviewed. Elastic form factors in the impulse approximation are calculated. Scattering amplitudes for relativistic bound states are constructed. Some model cases for transition amplitudes are considered. Deep inelastic form factors (structure functions) are expressed through light front wave functions. It is shown that taking into account of transverse motion of partons leads to the violation of Bjorken scaling and structure functions become square of transverse momentum dependent. Possible explanation of the EMC-effect is given. Problem of light front relativization of wave functions of lightest nuclei is considered. Scaling properties of deuteron, ${}^3He$ and ${}^4He$ light front wave functions are checked in a rather wide energy range.
description: Review paper, Submitted to Phys. Rep., 89 pages, 23 figures
Method of Moments Estimation of Ornstein-Uhlenbeck Processes Driven by General Lévy Process
Creators: name: Spiliopoulos, Konstantinos
Publisher: name: arXiv
Year: 2008
Subjects: subject: Probability (math.PR)
subject: Statistics Theory (math.ST)
subject: FOS: Mathematics

description: Ornstein-Uhlenbeck processes driven by general Lévy process are considered in this paper. We derive strongly consistent estimators for the moments of the underlying Lévy process and for the mean reverting parameter of the Ornstein-Uhlenbeck process. Moreover, we prove that the estimators are asymptotically normal. Finally, we test the empirical performance of our estimators in a simulation study and we fit the model to real data.
description: 15 pages, 4 Postscript figures; corrected minor typos, final published version
Understanding Program Complementarities: Estimating the Dynamic Effects of Head Start with Multiple Alternatives
Creators: name: Chan, M.
name: Dalla-Zuanna, A.
name: Liu, K.
Publisher: name: Faculty of Economics, University of Cambridge
Year: 2023
Subjects: Head Start
program evaluation
treatment effects
complementarity
child care

description: We use experimental data from the Head Start Impact Study to examine the effects of childcare program pathways on cognitive outcomes. Using a sequential choice model with state dependence and dynamic selection, we identify and estimate joint returns and complementarities across skill investment programs. Our results indicate differential returns by the sequencing of program participation, and support engaging low-ability children with prolonged center-based care and high-ability children with some home care. We then use a dynamic structural model to evaluate a counterfactual reform which limits children to one year of Head Start, showcasing the importance of accounting for dynamic behavior.
Red supergiants in M31 and M33 II. The Mass Loss Rate
Creators: name: Wang, Tianding
name: Jiang, Biwei
name: Ren, Yi
name: Yang, Ming
name: Li, Jun
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Mass loss is an important activity for red supergiants (RSGs) which can influence their evolution and final fate. Previous estimations of mass loss rates (MLRs) of RSGs exhibit significant dispersion due to the difference in method and the incompleteness of sample. With the improved quality and depth of the surveys including the UKIRT/WFCAM observation in near infrared, LGGS and PS1 in optical, a rather complete sample of RSGs is identified in M31 and M33 according to their brightness and colors. For about 2000 objects in either galaxy from this ever largest sample, the MLR is derived by fitting the observational optical-to-mid infrared spectral energy distribution (SED) with the DUSTY code of a 1-D dust radiative transfer model. The average MLR of RSGs is found to be around $2.0\times10^{-5}{\text{M}_\odot}/\text{yr}$ with a gas-to-dust ratio of 100, which yields a total contribution to the interstellar dust by RSGs of about $1.1\times10^{-3}{\text{M}_\odot}/\text{yr}$ in M31 and $6.0 \times10^{-4}{\text{M}_\odot}/\text{yr}$ in M33, a non-negligible source in comparison with evolved low-mass stars. The MLRs are divided into three types by the dust properties, i.e. amorphous silicate, amorphous carbon and optically thin, and the relations of MLR with stellar parameters, infrared flux and colors are discussed and compared with previous works for the silicate and carbon dust group respectively.
description: 25 pages, 17 figures, Accepted by The Astrophysical Journal on 8/03/2021