cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
IS2N: Intent-Driven Security Software-Defined Network with Blockchain
Creators: name: Song, Yanbo
name: Feng, Tao
name: Yang, Chungang
name: Mi, Xinru
name: Jiang, Shanqing
name: Guizani, Mohsen
Publisher: name: arXiv
Year: 2023
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: Software-defined network (SDN) is characterized by its programmability, flexibility, and the separation of control and data planes. However, SDN still have many challenges, particularly concerning the security of network information synchronization and network element registration. Blockchain and intent-driven networks are recent technologies to establish secure and intelligent SDN. This article investigates the blockchain-based architecture and intent-driven mechanisms to implement intent-driven security software-defined networks (IS2N). Specifically, we propose a novel four-layer architecture of the IS2N with security capabilities. We integrate an intent-driven security management mechanism in the IS2N to achieve automate network security management. Finally, we develop an IS2N platform with blockchain middle-layer to achieve security capabilities and security store network-level snapshots, such as device registration and OpenFlow messages. Our simulations show that IS2N is more flexible than conventional strategies at resolving problems during network operations and has a minimal effect on the SDN.
description: Published in: IEEE Network ( Early Access )
Lanthanide impurities in wide bandgap semiconductors: a possible roadmap for spintronic devices
Creators: name: Caroena, G.
name: Machado, W. V. M.
name: Justo, J. F.
name: Assali, L. V. C.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The electronic properties of lanthanide (from Eu to Tm) impurities in wurtzite gallium nitride and zinc oxide were investigated by first principles calculations, using an all electron methodology plus a Hubbard potential correction. The results indicated that the 4f-related energy levels remain outside the bandgap in both materials, in good agreement with a recent phenomenological model, based on experimental data. Additionally, zinc oxide doped with lanthanide impurities became an n-type material, showing a coupling between the 4f-related spin polarized states and the carriers. This coupling may generate spin polarized currents, which could lead to applications in spintronic devices.
description: 11 pages, 3 figures
Stability of thermally bistable states and their switching in superconducting weak link
Creators: name: Biswas, Sourav
name: Wahi, Pankaj
name: Gupta, Anjan Kumar
Publisher: name: arXiv
Year: 2022
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Superconducting weak link (WL), acting as a Josephson junction (JJ), is one of the widely used elements in superconductor science and quantum circuits. A hysteretic JJ with robust switching between its superconducting and resistive state is an excellent candidate for single-photon detection. However, the ubiquitous fluctuations in the junction strongly influence the stability of the states and, thus, the transition from one to the other. Here, we present an experimental study of switching statistics of critical and retrapping currents of a JJ based on niobium WL in its hysteretic regime. The mean lifetimes of the two metastable states, namely, the zero-voltage superconducting state and finite-voltage resistive state, are estimated from the distributions. Further, close to the hysteresis crossover temperature, observed telegraphic noise in the time domain due to random switching between the states provides their lifetimes directly. We present a thermal model introducing a double-well (bistable) feature with an intriguing quantity with respect to the devices' temperature states. The effects of temperature fluctuations on the stability of the states are shown. We discuss our results toward further improvement of the efficiency of superconducting WL or nanowire single-photon detectors.
description: 10 pages, 11 figures, Appendices
Nuclear Structure Properties of even-even Chromium Isotopes and the E ect of Deformation on Calculated Electron Capture Cross Sections
Creators: name: Nabi, Jameel-Un
name: Boyukata, Mahmut
name: Ullah, Asim
name: Riaz, Muhammad
Publisher: name: arXiv
Year: 2025
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: In this study, we investigate the role of nuclear deformation on the calculated electron capture cross section (ECC) of even-even chromium (Cr) isotopes. We first determined the nuclear structure properties of these nuclei within the interacting boson model-1 (IBM-1). The energy spectra and E2 transition probabilities were calculated by fitting the parameters in the model formalism. The analysis of the potential energy surface was also performed to predict the geometric shape of the Cr nuclei by plotting their contour plot in the plane of (beta, gamma) deformation parameters. Later, we calculated the ECC within the proton-neutron quasiparticle random phase approximation (pn-QRPA) model. In particular, we studied how the calculated ECC changed with different values of the nuclear deformation parameter. The calculated Gamow-Teller (GT) strength distributions were widely spread among the daughter states. The total GT strength decreased with increasing value of the beta parameter. The computed ECC values, however, increased with increasing beta values of the Cr isotopes.
description: 28 Pages, 7 Figures, 3 Tables
Sparse Semantic Map-Based Monocular Localization in Traffic Scenes Using Learned 2D-3D Point-Line Correspondences
Creators: name: Chen, Xingyu
name: Xue, Jianru
name: Pang, Shanmin
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Vision-based localization in a prior map is of crucial importance for autonomous vehicles. Given a query image, the goal is to estimate the camera pose corresponding to the prior map, and the key is the registration problem of camera images within the map. While autonomous vehicles drive on the road under occlusion (e.g., car, bus, truck) and changing environment appearance (e.g., illumination changes, seasonal variation), existing approaches rely heavily on dense point descriptors at the feature level to solve the registration problem, entangling features with appearance and occlusion. As a result, they often fail to estimate the correct poses. To address these issues, we propose a sparse semantic map-based monocular localization method, which solves 2D-3D registration via a well-designed deep neural network. Given a sparse semantic map that consists of simplified elements (e.g., pole lines, traffic sign midpoints) with multiple semantic labels, the camera pose is then estimated by learning the corresponding features between the 2D semantic elements from the image and the 3D elements from the sparse semantic map. The proposed sparse semantic map-based localization approach is robust against occlusion and long-term appearance changes in the environments. Extensive experimental results show that the proposed method outperforms the state-of-the-art approaches.
PDR Model Mapping of Obscured H2 Emission and the Line-of-Sight Structure of M17-SW
Creators: name: Sheffer, Yaron
name: Wolfire, Mark G.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We observed H2 line emission with Spitzer-IRS toward M17-SW and modeled the data with our PDR code. Derived gas density values of up to few times 10^7 cm^-3 indicate that H2 emission originates in high-density clumps. We discover that the PDR code can be utilized to map the amount of intervening extinction obscuring the H2 emission layers, and thus we obtain the radial profile of A_V relative to the central ionizing cluster NGC 6618. The extinction has a positive radial gradient, varying between 15--47 mag over the projected distance of 0.9--2.5 pc from the primary ionizer, CEN 1. These high extinction values are in good agreement with previous studies of A_V toward stellar targets in M17-SW. The ratio of data to PDR model values is used to infer the global line-of-sight structure of the PDR surface, which is revealed to resemble a concave surface relative to NGC 6618. Such a configuration confirms that this PDR can be described as a bowl-shaped boundary of the central H II region in M17. The derived structure and physical conditions are important for interpreting the fine-structure and rotational line emission from the PDR.
description: 14 pp, 4 figs, 1 table
Wir nahmen Platz an einer Tafel von 25. Gedenkens; [1848]
Creators: name: Vischer, Friedrich Theodor von
Publisher: name: Universitätsbibliothek der Ludwig-Maximilians-Universität München
Year: 2018

description: Flugblatt mit Karikatur auf den Abgeordneten der Frankfurter Nationalversammlung Johann Gustav Wilhelm Heckscher, der essend an einem Tisch sitzt
Drop size characteristics of sprays emanating from circular and non-circular orifices in the atomization regime
Creators: name: Rajesh, K. R.
name: Kulkarni, V.
name: Vankeswaram, S.
name: Sakthikumar, R.
name: Deivandren, S.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Traditionally, circular orifices have been used for generating aerosols, however in recent times non-circular orifices are being considered due to their superior atomization and mixing features. In this work, we experimentally investigate spray morphology and drop size characteristics of kerosene (Jet A-1) jets issuing from three non-circular orifices geometries (elliptic, triangular and, square) and one circular orifice with the same exit cross sectional area. Our results show an unexpected and yet unreported coarsening of atomization for non-circular orifice jets quantified by an increase in the Sauter Mean Diameter (SMD) at all tested exit velocities represented by the liquid Weber number, $We_l$. We attribute this to two distinct spray morphologies: filament and core breakup which generate large size liquid structures identified as filaments and ligaments, noticeable in non-circular orifices jets compared to circular orifice jets. On exploring this further by undertaking an examination of the drop size volume probability distribution at lower $We_l$ corresponding to the location marking the end of primary breakup we see a bimodality due to a dominant distribution of fragments of small and larger sizes owing to the spray morphology. At higher $We_l$ and larger distances from the injector exit we observe the bimodality converts to a unimodal distribution for all orifice jets with a single peak situated at lower drop diameters. Filament breakup is reasoned to be the cause of higher number of smaller drop sizes in triangular sprays among all non-circular orifice jets while thinner filaments in circular orifice sprays lead to smaller drop sizes compared to their triangular counterparts showing the same breakup morphology. We expect our results to help applications as diverse as engine fuel combustion, pharmaceutical sprays and CO$_2$ capture by NaOH sprays.
Singlet-Triplet Superconducting Quantum Magnetometer
Creators: name: Alidoust, Mohammad
name: Halterman, Klaus
name: Linder, Jacob
Publisher: name: arXiv
Year: 2013
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Motivated by the recent experimental realization of a quantum interference transistor based on the superconducting proximity effect, we here demonstrate that the inclusion of a textured ferromagnet both strongly enhances the flux sensitivity of such a device and additionally allows for singlet-triplet switching by tuning a bias voltage. This functionality makes explicit use of the induced spin-triplet correlations due to the magnetic texture. Whereas the existence of such triplet correlations is well-known, our finding demonstrates how spin-triplet superconductivity may be utilized for concrete technology, namely to improve the functionality of ultra-sensitive magnetometers.
description: 5 pages, 3 figures. To Appear in Physical Review B
Synchronous control of dual-channel all-optical multi-state switching
Creators: name: Sheng, Jiteng
name: Wang, Junfeng
name: Xiao, Min
Publisher: name: arXiv
Year: 2013
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We have experimentally observed optical multistabilities (OMs) simultaneously on both the signal and generated Stokes fields in an optical ring cavity with a coherently-prepared multilevel atomic medium. The two observed OMs, which are governed by different physical processes, are coupled via the multilevel atomic medium and exhibit similar threshold behaviors. By modulating the cavity input (signal) field with positive or negative pulses, dual-channel all-optical multi-state switching has been realized and synchronously controlled, which can be useful for increasing communication and computation capacities.
Company management system estimation on the basis of adaptive correlation to the environment
Creators: name: Masaev S., N.
name: Dorrer M., G.
Publisher: name: Сибирский журнал науки и технологий
Year: 2010
Subjects: КОРРЕЛЯЦИЯ
АДАПТАЦИЯ
ПРОЦЕСС
СИСТЕМНЫЙ АНАЛИЗ
УПРАВЛЕНИЕ
CORRELATION
ADAPTATION
PROCESS
SYSTEM ANALYSIS
MANAGEMENT

description: The method of the structure and indicators analysis of company business processes based on the calculation of simple correlation between historic series of expenses is offered.
Using Detection, Tracking and Prediction in Visual SLAM to Achieve Real-time Semantic Mapping of Dynamic Scenarios
Creators: name: Chen, Xingyu
name: Xue, Jianru
name: Fang, Jianwu
name: Pan, Yuxin
name: Zheng, Nanning
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: In this paper, we propose a lightweight system, RDS-SLAM, based on ORB-SLAM2, which can accurately estimate poses and build semantic maps at object level for dynamic scenarios in real time using only one commonly used Intel Core i7 CPU. In RDS-SLAM, three major improvements, as well as major architectural modifications, are proposed to overcome the limitations of ORB-SLAM2. Firstly, it adopts a lightweight object detection neural network in key frames. Secondly, an efficient tracking and prediction mechanism is embedded into the system to remove the feature points belonging to movable objects in all incoming frames. Thirdly, a semantic octree map is built by probabilistic fusion of detection and tracking results, which enables a robot to maintain a semantic description at object level for potential interactions in dynamic scenarios. We evaluate RDS-SLAM in TUM RGB-D dataset, and experimental results show that RDS-SLAM can run with 30.3 ms per frame in dynamic scenarios using only an Intel Core i7 CPU, and achieves comparable accuracy compared with the state-of-the-art SLAM systems which heavily rely on both Intel Core i7 CPUs and powerful GPUs.
Stability and superconductivity of Ca-B phases at ambient and high pressure
Creators: name: Shah, Sheena
name: Kolmogorov, Aleksey N.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: In the search for MgB2-like phonon-mediated superconductors we have carried out a systematic density functional theory study of the Ca-B system, isoelectronic to Mg-B, at ambient and gigapascal pressures. A remarkable variety of candidate high-pressure ground states have been identified with an evolutionary crystal structure search, including a stable alkaline-earth monoboride oI8-CaB, a superconductor with an expected critical temperature (Tc) of 5.5 K. We have extended our previous study of CaB6 [Phys. Rev. Lett. 108, 102501 (2012)] to nearby stoichiometries of CaB[6+x], finding that extra boron further stabilizes the proposed B24 units. Here an explanation is given for the transformation of cP7-CaB6 into the more complex oS56 and tI56 polymorphs at high pressure. The stability of the known metallic tP20 phase of CaB4 at ambient pressure is explained from a crystal structure and chemical bonding point of view. The tP20 structure is shown to destabilize at 19 GPa relative to a semiconducting MgB4-like structure due to chemical pressure from the metal ion. The hypothetical AlB2-type structure of CaB2, previously shown to have favorable superconducting features, is demonstrated here to be unstable at all pressures; two new metallic CaB2 polymorphs with unusual boron networks stabilize at elevated pressures above 8 GPa but are found to have very low critical temperatures (Tc ~1 K). The stability of all structures has been rationalized through comparison with alkaline-earth analogs, emphasizing the importance of the size of the metal ion for the stability of borides. Our study illustrates the inverse correlation between the thermodynamic stability and superconducting properties and the necessity to carefully examine both in the design of new synthesizable superconducting materials.
Selective Activation of Aromatic C-H Bonds Catalyzed by Single Gold Atoms at Room Temperature
Creators: name: Lowe, Benjamin
name: Hellerstedt, Jack
name: Matěj, Adam
name: Mutombo, Pingo
name: Kumar, Dhaneesh
name: Ondráček, Martin
name: Jelinek, Pavel
name: Schiffrin, Agustin
Publisher: name: arXiv
Year: 2023
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Selective activation and controlled functionalization of C-H bonds in organic molecules is one of the most desirable processes in synthetic chemistry. Despite progress in heterogeneous catalysis using metal surfaces, this goal remains challenging due to the stability of C-H bonds and their ubiquity in precursor molecules, hampering regioselectivity. Here, we examine the interaction between 9,10-dicyanoanthracene (DCA) molecules and Au adatoms on a Ag(111) surface at room temperature (RT). Characterization via low-temperature scanning tunneling microscopy, spectroscopy, and noncontact atomic force microscopy, supported by theoretical calculations, revealed the formation of organometallic DCA-Au-DCA dimers, where C atoms at the ends of the anthracene moieties are bonded covalently to single Au atoms. The formation of this organometallic compound is initiated by a regioselective cleaving of C-H bonds at RT. Hybrid quantum mechanics/molecular mechanics calculations show that this regioselective C-H bond cleaving is enabled by an intermediate metal-organic complex which significantly reduces the dissociation barrier of a specific C-H bond. Harnessing the catalytic activity of single metal atoms, this regioselective on-surface C-H activation reaction at RT offers promising routes for future synthesis of functional organic and organometallic materials.
description: Main: 28 pages, 5 figures, 1 TOC figure and SI: 32 pages, 16 figures
Meteor Showers on Earth from Sungrazing Comets
Creators: name: Sekhar, A.
name: Asher, D. J.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Sungrazing comets have always captured a lot of interest and curiosity among the general public as well as scientists since ancient times. The perihelion passage of comet C/2012 S1 (ISON) at the end of this year (on 2013 November 28) is an eagerly awaited event. In this work, we do a mathematical study to check whether meteoroids ejected from this comet during its journey around the sun can produce spectacular meteor phenomena on Earth. Our calculations show that although the orbital elements of this comet are much more favourable than for most sungrazers to have its descending node near the Earth's orbit, even ejection velocities as high as 1 km/s do not induce sufficient nodal dispersion to bring meteoroids to Earth intersection during present times. A similar result applies to Newton's comet C/1680 V1 which has surprisingly similar orbital elements, although it is known to be a distinct comet from C/2012 S1. Our analysis also shows that for meteoroids ejected from all known sungrazing groups during recent epochs, only the Marsden family (with required ejection velocities of some hundreds of m/s) can produce meteor phenomena during present times. In a broader sense, we indicate why we do not observe visually brilliant meteor showers from frequently observed sungrazers.
description: 5 pages, 2 figures, 3 tables, Accepted by MNRAS Letters
On the necessity of composition-dependent low-temperature opacity in metal-poor AGB stars
Creators: name: Constantino, Thomas
name: Campbell, Simon
name: Gil-Pons, Pilar
name: Lattanzio, John
Publisher: name: arXiv
Year: 2014
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The vital importance of composition-dependent low-temperature opacity in low-mass (M < 3Msun) asymptotic giant branch (AGB) stellar models of metallicity Z > 0.001 has recently been demonstrated (e.g. Marigo 2002; Ventura & Marigo 2010). Its significance to more metal-poor, intermediate mass (M > 2.5Msun) models has yet to be investigated. We show that its inclusion in lower-metallicity models ([Fe/H] < -2) is essential, and that there exists no threshold metallicity below which composition-dependent molecular opacity may be neglected. We find it to be crucial in all intermediate-mass models investigated ([Fe/H] < -2 and 2.5 < M/Msun < 5), because of the evolution of the surface chemistry, including the orders of magnitude increase in the abundance of molecule-forming species. Its effect on these models mirrors that previously reported for higher-metallicity models - increase in radius, decrease in Teff, faster mass loss, shorter thermally pulsing AGB lifetime, reduced enrichment in third dredge-up products (by a factor of three to ten), and an increase in the mass limit for hot bottom burning. We show that the evolution of low-metallicity models with composition-dependent low-temperature opacity is relatively independent of initial metal abundance because its contribution to the opacity is far outweighed by changes due to dredge-up. Our results imply a significant reduction in the expected number of nitrogen-enhanced metal-poor stars, which may help explain their observed paucity. We note that these findings are partially a product of the macrophysics adopted in our models, in particular the Vassiliadis & Wood (1993) mass loss rate which is strongly dependent on radius.
description: 13 pages, 13 figures, 2 tables; accepted for publication in The Astrophysical Journal
DL-QAT: Weight-Decomposed Low-Rank Quantization-Aware Training for Large Language Models
Creators: name: Ke, Wenjin
name: Li, Zhe
name: Li, Dong
name: Tian, Lu
name: Barsoum, Emad
Publisher: name: arXiv
Year: 2025
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Improving the efficiency of inference in Large Language Models (LLMs) is a critical area of research. Post-training Quantization (PTQ) is a popular technique, but it often faces challenges at low-bit levels, particularly in downstream tasks. Quantization-aware Training (QAT) can alleviate this problem, but it requires significantly more computational resources. To tackle this, we introduced Weight-Decomposed Low-Rank Quantization-Aware Training (DL-QAT), which merges the advantages of QAT while training only less than 1% of the total parameters. Specifically, we introduce a group-specific quantization magnitude to adjust the overall scale of each quantization group. Within each quantization group, we use LoRA matrices to update the weight size and direction in the quantization space. We validated the effectiveness of our method on the LLaMA and LLaMA2 model families. The results show significant improvements over our baseline method across different quantization granularities. For instance, for LLaMA-7B, our approach outperforms the previous state-of-the-art method by 4.2% in MMLU on 3-bit LLaMA-7B model. Additionally, our quantization results on pre-trained models also surpass previous QAT methods, demonstrating the superior performance and efficiency of our approach.
Three Dimensional Hydrodynamic Simulations of Multiphase Galactic Disks with Star Formation Feedback: I. Regulation of Star Formation Rates
Creators: name: Kim, Chang-Goo
name: Ostriker, Eve C.
name: Kim, Woong-Tae
Publisher: name: arXiv
Year: 2013
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The energy and momentum feedback from young stars has a profound impact on the interstellar medium (ISM), including heating and driving turbulence in the neutral gas that fuels future star formation. Recent theory has argued that this leads to a quasi-equilibrium self-regulated state, and for outer atomic-dominated disks results in the surface density of star formation $Σ_{SFR}$ varying approximately linearly with the weight of the ISM (or midplane turbulent + thermal pressure). We use three-dimensional numerical hydrodynamic simulations to test the theoretical predictions for thermal, turbulent, and vertical dynamical equilibrium, and the implied functional dependence of $Σ_{SFR}$ on local disk properties. Our models demonstrate that all equilibria are established rapidly, and that the expected proportionalities between mean thermal and turbulent pressures and $Σ_{SFR}$ apply. For outer disk regions, this results in $Σ_{SFR} \propto Σ\sqrt{ρ_{sd}}$, where $Σ$ is the total gas surface density and $ρ_{sd}$ is the midplane density of the stellar disk (plus dark matter). This scaling law arises because $ρ_{sd}$ sets the vertical dynamical time in our models (and outer disk regions generally). The coefficient in the star formation law varies inversely with the specific energy and momentum yield from massive stars. We find proportions of warm and cold atomic gas, turbulent-to-thermal pressure, and mean velocity dispersions that are consistent with Solar-neighborhood and other outer-disk observations. This study confirms the conclusions of a previous set of simulations, which incorporated the same physics treatment but was restricted to radial-vertical slices through the ISM.
description: 20 pages, 17 figures. Accepted for publication in ApJ
Matrices similar to centrosymmetric matrices
Creators: name: Itzá-Ortiz, Benjamín A.
name: Martínez-Avendaño, Rubén A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics
subject: 15B99 (Primary) 15A15, 15A24 (Secondary)

description: In this paper we give conditions on a matrix which guarantee that it is similar to a centrosymmetric matrix. We use this conditions to show that some $4 \times 4$ and $6 \times 6$ Toeplitz matrices are similar to centrosymmetric matrices. Furthermore, we give conditions for a matrix to be similar to a matrix which has a centrosymmetric principal submatrix, and conditions under which a matrix can be dilated to a matrix similar to a centrosymmetric matrix.
description: 15 pages
PyStructureFactor: A Python code for the molecular structure factor in tunneling ionization rates
Creators: name: Song, Shanshan
name: Zhu, Mingyu
name: Ni, Hongcheng
name: Wu, Jian
Publisher: name: arXiv
Year: 2023
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Tunneling ionization is at the core of strong-field and attosecond science. In this paper, we present PyStructureFactor - a general Python code towards the calculation of the structure factor in the tunneling ionization rate of common molecules under intense laser fields. The numerical implementation is based on the well-developed weak-field asymptotic theory in the integral representation. The information of the electronic structure of the molecules is obtained via the PySCF quantum chemistry package. PyStructureFactor is a general computational framework that can be utilized to compute the molecular structure factor of various types of molecules, including polar and non-polar diatomic molecules, degenerate molecules, and open-shell molecules. Examples are given that are benchmarked against known results with good agreements. The present PyStructureFactor is implemented in an efficient manner and is easily applicable towards larger molecules.
description: 26 pages, 9 figures and 2 tables. Repository link: https://github.com/TheStarAlight/PyStructureFactor Licensing provisions: Apache-2.0
Thermodynamic Stability of Mg-based Ternary Long-Period Stacking Ordered Structures
Creators: name: Saal, James E.
name: Wolverton, C.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Mg alloys containing long-period stacking ordered (LPSO) structures exhibit remarkably high tensile yield strength and ductility. They have been found in a variety of ternary Mg systems of the general form Mg-XL-XS, where XL and XS are elements larger and smaller than Mg, respectively. In this work, we examine the thermodynamic stability of these LPSO precipitates with density functional theory, using a newly proposed structure model based on the inclusion of a Mg interstitial atom. We predict the stabilities for 14H and 18R LPSO structures for many Mg-XL-XS ternary systems: 85 systems consisting of XL=rare earths (RE) Sc,Y,La-Lu and XS=Zn,Al,Cu,Co,Ni. We predict thermodynamically stable LPSO phases in all systems where LPSO structures are observed. In addition, we predict several stable LPSO structures in new, as-yet-unobserved Mg-RE-XS systems. Many non-RE XL elements are also explored on the basis of size mismatch between Mg and XL, including Tl,Sb,Pb,Na,Te,Bi,Pa,Ca,Th,K,Sr --- an additional 55 ternary systems. XL=Ca, Sr, and Th are predicted to be most promising to form stable LPSO phases, particularly with XS=Zn. Lastly, several previously observed trends amongst known XL elements are examined. We find that favorable mixing energy between Mg and XL on the FCC lattice and the size mismatch together serve as excellent criteria determining XL LPSO formation.
A high resolution spectroscopic atlas of M subdwarfs - Effective temperature and metallicity
Creators: name: Rajpurohit, A. S.
name: Reyle, C.
name: Allard, F.
name: Scholz, R. -D.
name: Homeier, D.
name: Schultheis, M.
name: Bayo, A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Context. M subdwarfs are metal poor and cool stars. They are important probes of the old galactic populations. However, they remain elusive due to their low luminosity. Observational and modeling efforts are required to fully understand their physics and to investigate the effects of metallicity in their cool atmospheres. Aims. We perform a detailed study of a sample of subdwarfs to determine their stellar parameters and constrain the stat-of-the art atmospheric models. Methods. We present UVES/VLT high resolution spectra of three late-K subdwarfs and 18 M subdwarfs. Our atlas covers the optical region from 6400 AA up to the near infrared at 8900 AA. We show spectral details of cool atmospheres at very high resolution (R= 40 000) and compare with synthetic spectra computed from the recent BT-Settl atmosphere models. Results. Our comparison shows that molecular features (TiO, VO, CaH), and atomic features (Fe I, Ti I, Na I, K I) are well fitted by current models. We produce an effective temperature versus spectral type relation all over the subdwarf spectral sequence. Thanks to the high resolution of our spectra, we perform a detailed comparison of line profiles of individual elements such as Fe I, Ca II, Ti I, and are able to determine accurate metallicities of these stars. These determinations contribute to calibrate the relation between metallicity and molecular band strength indices from low-resolution spectra. Conclusions. This work shows that the new generation of models are able to reproduce various spectral features of M subdwarfs. Working with these high resolution spectra allowed us to disentangle the atmospheric parameters (effective temperature, gravity, metallicity), which is not possible when using low resolution spectroscopy or photometry.
description: 15 pages, 20 figures, 2 tables, accepted for publication in Astronomy and Astrophysics
Anzeige. Die Volkssouveränität ist verloren gegangen!!! wer zu deren Wiedererlangung behülflich ist erhält eine Belohnung (keinen Orden); [1848]
Creators: name: (:Unav)
Publisher: name: Universitätsbibliothek der Ludwig-Maximilians-Universität München
Year: 2018

description: Vorlageform der Veröffentlichungsangabe: Verlag v. Wilh. Müller Fahrgasse No. 53 Frkfrt a/M.
Thermoluminescence measurements of neutron streaming through JET Torus Hall ducts
Creators: name: Obryk, Barbara
name: Batistoni, Paola
name: Conroy, Sean
name: Syme, Brian D.
name: Popovichev, Sergey
name: Stamatelatos, Ion E.
name: Vasilopoulou, Theodora
name: Bilski, Paweł
name: Contributors, JET EFDA
Publisher: name: arXiv
Year: 2014
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: Thermoluminescence detectors (TLD) were used for dose measurements at JET. Several hundreds of LiF detectors of various types, standard LiF:Mg,Ti and highly sensitive LiF:Mg,Cu,P were produced. LiF detectors consisting of natural lithium are sensitive to slow neutrons, their response to neutrons being enhanced by 6Li-enriched lithium or suppressed by using lithium consisting entirely of 7Li. Pairs of 6LiF/7LiF detectors allow distinguishing between neutron/non-neutron components of a radiation field. For detection of neutrons of higher energy, polyethylene (PE-300) moderators were used. TLDs, located in the centre of cylindrical moderators, were installed at eleven positions in the JET hall and the hall labyrinth in July 2012, and exposure took place during the last two weeks of the experimental campaign. Measurements of the gamma dose were obtained for all positions over a range of about five orders of magnitude variation. As the TLDs were also calibrated in a thermal neutron field, the neutron fluence at the experimental position could be derived. The experimental results are compared with calculations using the MCNP code. The results confirm that the TLD technology can be usefully applied to measurements of neutron streaming through JET Torus Hall ducts.
description: Presented at the 11th International Symposium on Fusion Nuclear Technology (ISFNT), held in Barcelona, Spain, from 16-20 September 2013
Entanglement entropy of compressible holographic matter: loop corrections from bulk fermions
Creators: name: Swingle, Brian
name: Huijse, Liza
name: Sachdev, Subir
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Entanglement entropy is a useful probe of compressible quantum matter because it can detect the existence of Fermi surfaces, both of microscopic fermionic degrees of freedom and of "hidden" gauge charged fermions. Much recent attention has focused on holographic efforts to model strongly interacting compressible matter of interest for condensed matter physics. We complete the entanglement analysis initiated in Huijse {\em et al.}, Phys. Rev. B 85, 035121 (2012) (arXiv:1112.0573) and Ogawa {\em et al.}, JHEP 1, 125 (2012) (arXiv:1111.1023) using the recent proposal of Faulkner {\em et al.} (arXiv:1307.2892) to analyze the entanglement entropy of the visible fermions which arises from bulk loop corrections. We find perfect agreement between holographic and field theoretic calculations.
description: 10 pages, 4 figures
Zum 200-Jahr-Jubiläum des josefinischen Toleranzpatents (13. Oktober 1781)
Creators: name: Schwarz, Karl
Publisher: name: Lutherische Kirche in der Welt
Year: 1970

description: Lutherische Kirche in der Welt, Bd. 28 (1981): Lutherische Kirche in der Welt, Band 28
On the Quantum Nature of a Fireball Created in Ultrarelativistic Nuclear Collisions
Creators: name: Kizka, V. A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Physics (physics.gen-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: In the article, the fireball formed in the collision of relativistic nuclei is considered as a quantum object. Based on this, an attempt is made to explain the difference in the measurements of hyperon yields in the two experiments - NA49 and NA57. Using the basic principles of quantum mechanics, it was shown that a fireball can have two quantum states - with and without ignited Quark-Gluon Plasma (QGP). With an increase of the collision energy of heavy ions, the probability of QGP ignition increases. At the same time, the probability of the formation of fireball without QGP ignition also remains nonzero even at nuclear collision energies that are much higher than the threshold QGP formation energy, which may be erroneously considered to be fixed and which is intensively sought in modern heavy ion accelerators. Thus, at SPS energy of heavy ion collisions \sqrt{s_{NN}} = 17.3 GeV, which is much higher than the assumed threshold energy of QGP formation in the region around or slightly above of \sqrt{s_{NN}} = 3 GeV, only half of the central collisions of heavy ions bring to the formation of a fireball consisted of deconfined matter, the remaining half of the collisions lead to the formation of a fireball from only hadronic matter.
description: 8 pages, 1 table, 1 figure; published as book chapter in "New Frontiers in Physical Science Research" 2022, 1, 52-62
Structural control of magnetic anisotropy in a strain driven multiferroic EuTiO3 thin film
Creators: name: Ke, X.
name: Birol, T.
name: Misra, R.
name: Lee, J. -H.
name: Kirby, B. J.
name: Schlom, D. G.
name: Fennie, C. J.
name: Freeland, J. W.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Octahedral distortion plays a key role in engineering the physical properties of heterostructures composed of perovskite oxides. We observe a strong in-plane uniaxial magnetic anisotropy in a strain-enabled multiferroic EuTiO3 thin film epitaxially grown on a (110)o DyScO3 substrate. First principles calculations show that the magnetic anisotropy is closely correlated with the uniaxial TiO6 octahedral tilting and the ferroelectric polarization of the film, indicating potential strong magnetoelectric coupling in the strain-engineered multiferroic system.
description: Accepted by Phys. Rev. B
Joint Multi-grained Popularity-aware Graph Convolution Collaborative Filtering for Recommendation
Creators: name: Liu, Kang
name: Xue, Feng
name: He, Xiangnan
name: Guo, Dan
name: Hong, Richang
Publisher: name: arXiv
Year: 2022
Subjects: subject: Information Retrieval (cs.IR)
subject: FOS: Computer and information sciences

description: Graph Convolution Networks (GCNs), with their efficient ability to capture high-order connectivity in graphs, have been widely applied in recommender systems. Stacking multiple neighbor aggregation is the major operation in GCNs. It implicitly captures popularity features because the number of neighbor nodes reflects the popularity of a node. However, existing GCN-based methods ignore a universal problem: users' sensitivity to item popularity is differentiated, but the neighbor aggregations in GCNs actually fix this sensitivity through Graph Laplacian Normalization, leading to suboptimal personalization. In this work, we propose to model multi-grained popularity features and jointly learn them together with high-order connectivity, to match the differentiation of user preferences exhibited in popularity features. Specifically, we develop a Joint Multi-grained Popularity-aware Graph Convolution Collaborative Filtering model, short for JMP-GCF, which uses a popularity-aware embedding generation to construct multi-grained popularity features, and uses the idea of joint learning to capture the signals within and between different granularities of popularity features that are relevant for modeling user preferences. Additionally, we propose a multistage stacked training strategy to speed up model convergence. We conduct extensive experiments on three public datasets to show the state-of-the-art performance of JMP-GCF.
Prevalence of multistability and nonstationarity in driven chemical networks
Creators: name: Nicolaou, Zachary G.
name: Nicholson, Schuyler B.
name: Motter, Adilson E.
name: Green, Jason R.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Molecular Networks (q-bio.MN)
subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: External flows of energy, entropy, and matter can cause sudden transitions in the stability of biological and industrial systems, fundamentally altering their dynamical function. How might we control and design these transitions in chemical reaction networks? Here, we analyze transitions giving rise to complex behavior in random reaction networks subject to external driving forces. In the absence of driving, we characterize the uniqueness of the steady state and identify the percolation of a giant connected component in these networks as the number of reactions increases. When subject to chemical driving (influx and outflux of chemical species), the steady state can undergo bifurcations, leading to multistability or oscillatory dynamics. By quantifying the prevalence of these bifurcations, we show how chemical driving and network sparsity tend to promote the emergence of these complex dynamics and increased rates of entropy production. We show that catalysis also plays an important role in the emergence of complexity, strongly correlating with the prevalence of bifurcations. Our results suggest that coupling a minimal number of chemical signatures with external driving can lead to features present in biochemical processes and abiogenesis.
description: 12 pages, 4 figures
Generating News-Centric Crossword Puzzles As A Constraint Satisfaction and Optimization Problem
Creators: name: Majima, Kaito
name: Ishihara, Shotaro
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computation and Language (cs.CL)
subject: Data Structures and Algorithms (cs.DS)
subject: FOS: Computer and information sciences

description: Crossword puzzles have traditionally served not only as entertainment but also as an educational tool that can be used to acquire vocabulary and language proficiency. One strategy to enhance the educational purpose is personalization, such as including more words on a particular topic. This paper focuses on the case of encouraging people's interest in news and proposes a framework for automatically generating news-centric crossword puzzles. We designed possible scenarios and built a prototype as a constraint satisfaction and optimization problem, that is, containing as many news-derived words as possible. Our experiments reported the generation probabilities and time required under several conditions. The results showed that news-centric crossword puzzles can be generated even with few news-derived words. We summarize the current issues and future research directions through a qualitative evaluation of the prototype. This is the first proposal that a formulation of a constraint satisfaction and optimization problem can be beneficial as an educational application.
description: 32nd ACM International Conference on Information and Knowledge Management (short paper track)
On Parallel or Distributed Asynchronous Iterations with Unbounded Delays and Possible Out of Order Messages or Flexible Communication for Convex Optimization Problems and Machine Learning
Creators: name: Baz, Didier El
Publisher: name: arXiv
Year: 2022
Subjects: subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: Machine Learning (cs.LG)
subject: Neural and Evolutionary Computing (cs.NE)
subject: FOS: Computer and information sciences

description: We describe several features of parallel or distributed asynchronous iterative algorithms such as unbounded delays, possible out of order messages or flexible communication. We concentrate on the concept of macroiteration sequence which was introduced in order to study the convergence or termination of asynchronous iterations. A survey of asynchronous iterations for convex optimization problems is also presented. Finally, a new result of convergence for parallel or distributed asynchronous iterative algorithms with flexible communication for convex optimization problems and machine learning is proposed.
Strangeness at high temperatures
Creators: name: Schmidt, Christian
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We use up to fourth order cumulants of net strangeness fluctuations and their correlations with net baryon number fluctuations to extract information on the strange meson and baryon contribution to the low temperature hadron resonance gas, the dissolution of strange hadronic states in the crossover region of the QCD transition and the quasi-particle nature of strange quark contributions to the high temperature quark-gluon plasma phase.
description: Talk presented at the international conference "Strangeness in Quark Matter" (SQM2013), 4 pages, 2 figures
Evaluating and Optimizing the Effectiveness of Neural Machine Translation in Supporting Code Retrieval Models: A Study on the CAT Benchmark
Creators: name: Phan, Hung
name: Jannesari, Ali
Publisher: name: arXiv
Year: 2023
Subjects: subject: Software Engineering (cs.SE)
subject: Information Retrieval (cs.IR)
subject: FOS: Computer and information sciences

description: Neural Machine Translation (NMT) is widely applied in software engineering tasks. The effectiveness of NMT for code retrieval relies on the ability to learn from the sequence of tokens in the source language to the sequence of tokens in the target language. While NMT performs well in pseudocode-to-code translation, it might have challenges in learning to translate from natural language query to source code in newly curated real-world code documentation/ implementation datasets. In this work, we analyze the performance of NMT in natural language-to-code translation in the newly curated CAT benchmark that includes the optimized versions of three Java datasets TLCodeSum, CodeSearchNet, Funcom, and a Python dataset PCSD. Our evaluation shows that NMT has low accuracy, measured by CrystalBLEU and Meteor metrics in this task. To alleviate the duty of NMT in learning complex representation of source code, we propose ASTTrans Representation, a tailored representation of an Abstract Syntax Tree (AST) using a subset of non-terminal nodes. We show that the classical approach NMT performs significantly better in learning ASTTrans Representation over code tokens with up to 36% improvement on Meteor score. Moreover, we leverage ASTTrans Representation to conduct combined code search processes from the state-of-the-art code search processes using GraphCodeBERT and UniXcoder. Our NMT models of learning ASTTrans Representation can boost the Mean Reciprocal Rank of these state-of-the-art code search processes by up to 3.08% and improve 23.08% of queries' results over the CAT benchmark.
description: Accepted as Full Paper in Proceedings of the 32nd ACM International Conference on Information and Knowledge Management (CIKM), Birmingham, UK, October 2023