cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Amplification of Molecular Traffic Control in catalytic grains with novel channel topology design
Creators: name: Brzank, Andreas
name: Schuetz, Gunter M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We investigate the conditions for reactivity enhancement of catalytic processes in porous solids by use of molecular traffic control (MTC). With dynamic Monte-Carlo simulations and continuous-time master equation theory applied to the high concentration regime we obtain a quantitative description of the MTC effect for a network of intersecting single-file channels in a wide range of grain parameters and for optimal external operating conditions. Implementing the concept of MTC in models with specially designed alternating bimodal channels we find the efficiency ratio (compared with a topologically and structurally similar reference system without MTC) to be enhanced with increasing grain diameter, a property verified for the first time for an MTC system. Even for short intersection channels, MTC leads to a reactivity enhancement of up to approximately 65%. This suggests that MTC may significantly enhance the efficiency of a catalytic process for small as well as large porous particles with a suitably chosen binary channel topology.
description: 15 pages, 12 figures
Condensation and extremes for a fluctuating number of independent random variables
Creators: name: Godrèche, Claude
Publisher: name: arXiv
Year: 2020
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Probability (math.PR)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We address the question of condensation and extremes for three classes of intimately related stochastic processes: (a) random allocation models and zero-range processes, (b) tied-down renewal processes, (c) free renewal processes. While for the former class the number of components of the system is fixed, for the two other classes it is a fluctuating quantity. Studies of these topics are scattered in the literature and usually dressed up in other clothing. We give a stripped-down account of the subject in the language of sums of independent random variables in order to free ourselves of the consideration of particular models and highlight the essentials. Besides giving a unified presentation of the theory, this work investigates facets so far unexplored in previous studies. Specifically, we show how the study of the class of random allocation models and zero-range processes can serve as a backdrop for the study of the two other classes of processes central to the present work -- tied-down and free renewal processes. We then present new insights on the extreme value statistics of these three classes of processes which allow a deeper understanding of the mechanism of condensation and the quantitative analysis of the fluctuations of the condensate.
description: 55 pages, 12 figures, final version, to be published in Journal of Statistical Physics
Imperial exiles: emigration and counterrevolution in the colonial Atlantic
Creators: name: Harris, Patrick
Publisher: name: No Publisher Supplied
Year: 2021

description: The crisis of French colonial society during the Revolutionary and Napoleonic eras produced fragmentation along factional and racial lines and the displacement of more than 30,000 people around the Atlantic World. Émigrés, refugees, and other assorted displaced people became central to debates about the future of the colonial system, and they forged new transimperial ties of interest and ideology. This dissertation explores the experience and consequences of colonial exile and its connections to the broader questions of property, race, and imperial mission for both revolutionary France and its imperial rival, Britain. It argues that exile and counterrevolution helped to transform the relationship between European empires at turn of the nineteenth century, cementing a more pan-European conception of imperial rule over the non-European world.Attempts to classify, monitor, and regulate displaced people by a jostling assortment of colonial, metropolitan, and diplomatic actors became central to the politics of revolution in the Caribbean, while the economic ventures of both exiles and the property they left behind became inextricable from the fate of the slave-based plantation economy. The British occupation of French colonies and alliance with colonial counterrevolutionaries newly entangled the British empire with French problems and perspectives surrounding racial hierarchy and colonial law and governance. Meanwhile, exiles played a vital role in shaping historical understandings of the colonial crisis, above all the successful challenge to slavery by the Haitian Revolution. In all these respects, the reactions to and against the revolutionary upheavals in the colonial world helped to shape the global order that would succeed them.
The Climate Change Squeeze Facing the United States and US Agriculture
Creators: name: Sohngen, Brent
name: McCarl, Bruce A.
name: Sohngen, Brent
name: McCarl, Bruce A.
Publisher: name: Unknown
Year: 2004
Subjects: Environmental Economics and Policy

description: Agriculture and forestry in the United States face pressures from the eventual effects of climate change and from efforts to control greenhouse gasses. This set of papers looks at the economic consequences from both pressures.
A lattice version of the Atiyah-Singer index theorem
Creators: name: Yamashita, Mayuko
Publisher: name: arXiv
Year: 2020
Subjects: subject: Differential Geometry (math.DG)
subject: High Energy Physics - Lattice (hep-lat)
subject: Mathematical Physics (math-ph)
subject: K-Theory and Homology (math.KT)
subject: Quantum Algebra (math.QA)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: We formulate and prove a lattice version of the Atiyah-Singer index theorem. The main theorem gives a $K$-theoretic formula for an index-type invariant of operators on lattice approximations of closed integral affine manifolds. We apply the main theorem to an index problem of Wilson-Dirac operators in lattice gauge theory.
description: 27 pages, final version
Non-extremal instantons and wormholes in string theory
Creators: name: Bergshoeff, E.
name: Collinucci, A.
name: Gran, U.
name: Roest, D.
name: Vandoren, S.
Publisher: name: arXiv
Year: 2004
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We construct the most general non-extremal spherically symmetric instanton solution of a gravity-dilaton-axion system with $SL(2,R)$ symmetry, for arbitrary euclidean spacetime dimension $D\geq 3$. A subclass of these solutions describe completely regular wormhole geometries, whose size is determined by an invariant combination of the $SL(2,R)$ charges. Our results can be applied to four-dimensional effective actions of type II strings compactified on a Calabi-Yau manifold, and in particular to the universal hypermultiplet coupled to gravity. We show that these models contain regular wormhole solutions, supported by regular dilaton and RR scalar fields of the universal hypermultiplet.
description: 10 pages, to appear in the proceedings of the RTN2004 workshop, Kolymbari, Crete, 5-10 September, Greece
“Would it be weird to live here without a car?”: using Reddit to understand car-free lifestyle decisions
Creators: name: Iacobucci, Evan
Publisher: name: No Publisher Supplied
Year: 2021

description: Car use is associated with negative social, economic, and environmental externalities. Encouraging people to adopt a car-free lifestyle is one way to address these harms, since car ownership is a major predictor of driving. Nevertheless, few people in the US voluntarily live without a car. In this dissertation, I seek 1) to understand why people decide to live car-free, and 2) to investigate the potential that more people could adopt car-free lifestyles. I use threads scraped from Reddit, an online social media platform, to address these issues, employing content analysis to examine data from seven US cities in which Reddit commenters discuss car ownership decisions. I find that the car-free are multimodal, employ contingency plans, rely on ridehailing and carsharing services to fill mobility gaps, and readily get used to car-free living. Among car owners, I find that while some need cars, others keep them for convenience. Costs are a primary motivator in ownership decisions, especially parking costs. Awareness of these costs motivates shedding of cars, while lowered costs, e.g., via free parking, encourage ownership. Accessible neighborhoods facilitate car-free life, with commenters describing walking and using transit to access common destinations. Changes in car ownership are catalyzed in two ways: 1) Key life events (e.g., moving) cause changes in travel needs or available choices, or 2) People reevaluate their available options and make new choices, unspurred by a key event.I conclude that there are groups, like those who keep cars for convenience, or those whose needs could be met by alternative modes, that display high potential to become car-free. Changes in cost structure and policy may be leveraged to bring these changes about.
VLA H92 Alpha and H53 Alpha Radio Recombination Line Observations of M82
Creators: name: Rodriguez-Rico, C. A.
name: Viallefond, F.
name: Zhao, J. -H.
name: Goss, W. M.
name: Anantharamaiah, K. R.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present high angular resolution (0.6'') observations made with the VLA of the radio continuum at 8.3 and 43 GHz as well as H92 Alpha and H53 Alpha radio recombination lines from the nearby (3 Mpc) starburst galaxy M82. In the continuum we report 19 newly identified sources at 8.3 GHz and 5 at 43 GHz that were unknown previously. The spatial distribution of the H92 Alpha line is inhomogeneous; we identify 27 features. The line and continuum emission are modeled using a collection of HII regions at different distances from the nucleus assuming a single-density component and two-density components. The high-density component has a density of 4 X 10^{4} cm^{-3}. However, the bulk of the ionization is in regions with densities which are typically a factor 10 lower. The gas kinematics, using the H92 Alpha line, confirms the presence of steep velocity gradient (26 km s^{-1} arcsec^{-1}) in the nuclear region. As this steep gradient is observed not only on the major axis but also at large distances along a band of PA of 150 degrees, the interpretation in terms of x2 orbits elongated along the minor axis of the bar, which would be observed at an angle close to the inclination of the main disk, seems inadequate. Ad-hoc radial motions must be introduced to reproduce the pattern of the velocity field. Different families of orbits are indicated as we detect a signature in the kinematics at the transition between the two plateaus observed in the NIR light distribution. The H92 Alpha line also reveals the base of the outflow where the injection towards the halo on the Northern side occurs. The kinematical pattern suggests a connection between the gas flowing in the plane of M82 towards the center; this behavior most likely originates due to the presence of a bar and the outflow out of the plane.
description: 45 pages, 11 figures and 6 tables. Accepted for publication in ApJ
The phase transition of triplet reaction-diffusion models
Creators: name: Odor, Geza
Publisher: name: arXiv
Year: 2005
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: The phase transitions classes of reaction-diffusion systems with multi-particle reactions is an open challenging problem. Large scale simulations are applied for the 3A -> 4A, 3A -> 2A and the 3A -> 4A, 3A->0 triplet reaction models with site occupation restriction in one dimension. Static and dynamic mean-field scaling is observed with signs of logarithmic corrections suggesting d_c=1 upper critical dimension for this family of models.
description: 4 pages, 4 figures, updated version prior publication in PRE
Asymptotic behavior of $L^2$-normalized eigenfunctions of the Laplace-Beltrami operator on a closed Riemannian manifold
Creators: name: Xu, Bin
Publisher: name: arXiv
Year: 2005
Subjects: subject: Spectral Theory (math.SP)
subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 35P20, 35L05

description: Let $e(x,y,ł)$ be the spectral function and $χ_ł$ the unit band spectral projection operator, with respect to the Laplace-Beltrami operator $\D_M$ on a closed Riemannian manifold $M$. We firstly review the one-term asymptotic formula of $e(x,x,ł)$ as $ł\to\infty$ by H{\" o}rmander (1968) and the one of $\p^\al_x\p^\bt_y e(x,y,ł)|_{x=y}$ as $ł\to\infty$ in a geodesic normal coordinate chart by the author (2004) and the sharp asymptotic estimates from above of the mapping norm $\|χ_ł\|_{L_2\to L_p}$ ($2\leq p\leq\infty$) by Sogge (1988 $&$ 1989) and of the mapping norm $\|χ_ł\|_{L_2\to {\rm Sobolev} L_p}$ by the author (2004). In the paper we show the one term asymptotic formula for $e(x,y,ł)$ as $ł\to\infty$, provided that the Riemannian distance between $x$ and $y$ is ${\rm O}(1/ł)$. As a consequence, we obtain the sharp estimate of the mapping norm $\|χ_ł\|_{L_2\to C^\d}$ ($0
description: 20 pages, misprints corrected. to appear in the Proceedings of Harmonic Analysis and its Applications at Osaka
Gene Algebra from a Genetic Code Algebraic Structure
Creators: name: Sanchez, Robersy
name: Morgado, Eberto
name: Grau, Ricardo
Publisher: name: arXiv
Year: 2004
Subjects: subject: Quantitative Methods (q-bio.QM)
subject: Genomics (q-bio.GN)
subject: FOS: Biological sciences

description: The biological distinction between the base positions in the codon, the chemical types of bases (purine and pyrimidine) and their hydrogen bond number have been the most relevant codon properties used in the genetic code analysis. Now, these properties have allowed us to build a Genetic Code ring isomorphic to the ring (Z64, +,*) of the integer module 64. On the Z64-algebra of the set of 64^N codon sequences of length N, gene mutations are described by means of endomorphisms F: (Z64)^N->(Z64)^N. Endomorphisms and automorphisms helped us describe the gene mutation pathways. For instance, 77.7% mutations in 749 HIV protease gene sequences correspond to unique diagonal endomorphisms of the wild type strain HXB2. In particular, most of the reported mutations that confer drug resistance to the HIV protease gene correspond to diagonal automorphisms of the wild type. What is more, in the human beta-globin gene a similar situation appears where most of the single codon mutations correspond to automorphisms. Hence, in the analyses of molecular evolution process on the DNA sequence set of length N, the Z64-algebra will help us explain the quantitative relationships between genes.
description: 27 pages, without figures
title: The patronage of the Spiritual Franciscans : the roles of the Orsini and Colonna cardinals, key lay patrons and their patronage networks
Creators: name: Graham, Emily E.
Publisher: name: University of St Andrews
publisherIdentifier: https://ror.org/02wn5qz54
publisherIdentifierScheme: ROR
Year: 2009

description: The survival and success of religious reform groups in the late medieval period was often due to the efforts of an ecclesiastical patron, a powerful and often wealthy individual who exerted their influence on behalf of the group or their leaders and spokesmen. This thesis uses the wealth of documentation available on the Spiritual Franciscans to explore the origin, development and wider effect of the relationships between the most powerful ecclesiastical patrons of the reformers and their clients, spokesmen for the Italian Spirituals at the papal court who were taken into the patrons’ households for years or even decades. During that time, the political fortunes of the different groups of Spiritual Franciscans fluctuated dramatically: in only a handful of years they went from hopeful expectation at the Council of Vienne c. 1311 to heresy trials, imprisoned spokesmen and friars burned at the stake c.1317-1318. Using testaments from the patrons’ families and the patrons themselves, the thesis explores the possible reasons for the patrons’ initial attraction to their Spiritual Franciscan clients. Letters, chronicles and exegetical texts written by the clients during and after their time in the patrons’ households are examined along with papal registers and other narrative and epistolary sources to develop models of the nature and progression of the patronage relationship, and how it survived in the face of periods of intense disapproval and harassment from the papacy, other prelates and some members of the Franciscan hierarchy. After establishing a framework for the progression of the patronage relationship, evidence of art patronage and other religious and patronage interests that the patrons and clients shared is used to develop a deeper understanding of how the patrons’ choice to involve themselves with the Spiritual Franciscans positively or negatively affected others in their orbit, especially their other clients.
Climate Change Impacts and Adaptation in Forestry: Responses by Trees and Markets
Creators: name: Alig, Ralph J.
name: Adams, Darius M.
name: Joyce, Linda
name: Sohngen, Brent
name: Alig, Ralph J.
name: Adams, Darius M.
name: Joyce, Linda
name: Sohngen, Brent
Publisher: name: Unknown
Year: 2004
Subjects: Environmental Economics and Policy

description: Total US forestry production is estimated to increase over the next century under several climate change projections. Consumers would likely benefit from lower prices, although profitability in the industry could decline. Regional shifts could well occur, with the Southern US forest industry appearing most susceptible.
Phase space structure and escape time dynamics in a Van der Waals model for exothermic reactions
Creators: name: Montoya, Francisco Gonzalez
name: Wiggins, Stephen
Publisher: name: arXiv
Year: 2020
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences
subject: 70K05, 70H99

description: We study the phase space structures that control the transport in a classical Hamiltonian model for a chemical reaction. This model has been proposed to study the yield of products in an ultracold exothermic reaction. In the considered model, two elements determine the evolution of the system: a Van der Waals force and short-range force associated with the many-body interactions. In the previous work has been used small random periodic changes in the direction of the momentum to simulate the short-range many-body interactions. In the present work, random Gaussian bumps have been added to the Van der Waals potential energy simulate the short-range effects between the particles in the system. We compare both variants of the model and explain their differences similarities and differences from a phase space perspective. In order to visualize the structures that direct the dynamics in the phase space, we construct a natural Lagrangian descriptor for Hamiltonian systems based on the Maupertuis action $S_0$.
Compaction Self-Assembly of Ultralow-Binder-Content Thermoplastic Composites Based on Lunar Soil Simulant
Creators: name: Oh, Kiwon
name: Chen, Tzehan
name: Kou, Rui
name: Yi, Haozhe
name: Qiao, Yu
Publisher: name: arXiv
Year: 2020
Subjects: subject: Applied Physics (physics.app-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: In a recent study, we developed ultralow-binder-content (UBC) structural materials based on lunar soil simulant and thermoset binders. In the current research, we investigated thermoplastic binders. Compared to thermosets, advanced thermoplastics could be more UV resistant, more durable, more robust, and recyclable. Our main technology is the compaction self-assembly (CSA). By using only ~4 wt% polyetherketoneketone (PEKK) binder, the thermoplastic-binder UBC composite was stronger than typical steel-reinforced concrete. The CSA operation was separate from the curing process. This study may provide an important in-situ resource utilization method for large-scale construction on Moon.
description: 14 pages, 5 figures
Entanglement in SU(2)-invariant quantum systems: The positive partial transpose criterion and others
Creators: name: Schliemann, John
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study entanglement in mixed bipartite quantum states which are invariant under simultaneous SU(2) transformations in both subsystems. Previous results on the behavior of such states under partial transposition are substantially extended. The spectrum of the partial transpose of a given SU(2)-invariant density matrix $ρ$ is entirely determined by the diagonal elements of $ρ$ in a basis of tensor-product states of both spins with respect to a common quantization axis. We construct a set of operators which act as entanglement witnesses on SU(2)-invariant states. A sufficient criterion for $ρ$ having a negative partial transpose is derived in terms of a simple spin correlator. The same condition is a necessary criterion for the partial transpose to have the maximum number of negative eigenvalues. Moreover, we derive a series of sum rules which uniquely determine the eigenvalues of the partial transpose in terms of a system of linear equations. Finally we compare our findings with other entanglement criteria including the reduction criterion, the majorization criterion, and the recently proposed local uncertainty relations.
description: 7 pages, no figures, version to appear in Phys. Rev. A
Search for the Chiral Magnetic Effect with the ALICE detector
Creators: name: Aziz, Sizar
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: In non-central heavy-ion collisions, spectator protons that do not participate in the interaction create strong magnetic fields. The strength of these fields allows testing an effect based on the hypothesized properties of QCD. The presence of so-called topological configurations can give rise to domains that carry net chirality. Coupled with the aforementioned magnetic fields, they may induce a charge separation of the particles generated in the collisions. This charge separation is called the Chiral Magnetic Effect (CME) and can be measured through charged-particle angular correlations. Measurements of the $γ_{1,1}$ correlator, which is sensitive to the CME, are shown for Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}} = 5.02$ TeV as well as for Xe--Xe collisions at $\sqrt{s_{\mathrm{NN}}} = 5.44$ TeV. These are found to have a significant charge dependence between opposite-sign and same-sign charge pairs. This behavior is consistent with a CME-like signal. However, the $δ_{1}$ correlator, which measures charge correlations unrelated to any symmetry plane (i.e. background), was measured in Xe--Xe collisions and also shows a significant charge dependence. This prevents a clear interpretation of the $γ_{1,1}$ correlator. Novel methods to constrain the CME contribution to the $γ_{1,1}$ correlator are necessary.
description: Proceedings of Quark Matter 2019
Mesonic states in the generalised Nambu-Jona-Lasinio theories
Creators: name: Nefediev, A. V.
name: Ribeiro, J. E. F. T.
Publisher: name: arXiv
Year: 2004
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: For any Nambu-Jona-Lasinio model of QCD with arbitrary nonlocal, instantaneous, quark current-current confining kernels, we use a generalised Bogoliubov technique to go beyond BCS level (in the large-Nc limit) so as to explicitly build quark-antiquark compound operators for creating/annihilating mesons. In the Hamiltonian approach, the mesonic bound-state equations appear (from the generalised Bogoliubov transformation) as mass-gap-like equations which, in turn, ensure the absence, in the Hamiltonian, of mesonic Bogoliubov anomalous terms. We go further to demonstrate the one-to-one correspondence between Hamiltonian and Bethe-Salpeter approaches to non-local NJL-type models for QCD and give the corresponding "dictionary" necessary to "translate" the amplitudes built using the graphical Feynman rules to the terms of the Hamiltonian, and vice versa. We comment on the problem of multiple vacua existence in such type of models and argue that mesonic states in the theory should be prescribed to have an extra index - the index of the replica in which they are created. Then the completely diagonalised Hamiltonian should contain a sum over this new index. The method is proved to be general and valid for any instantaneous quark kernel.
description: LaTeX2e, uses aipproc class, Talk given at the conference "Quark Confinement and the Hadron Spectrum VI", 21-25 September 2004, Sardinia, Italy, to appear in Proceedings
Designing haptic icons to support an urgency-based turn-taking protocol
Creators: name: Chan, Andrew
Publisher: name: University of British Columbia
Year: 2009

description: Collaboration is taking place increasingly between individuals living in different cities, countries, or continents. Instead of relying on time-consuming, expensive, and exhausting business travel, companies are turning to web conferencing systems, Internet-based systems that support distributed meetings, training, and collaboration. These systems support view-sharing, where an individual can share an application with his or her collaborators, allowing them to view and interact with the application in real-time. While flexible, these systems only permit one user to control the application at a time, necessitating a turn-taking protocol. Current web conferencing systems depend heavily on visual elements like dialog boxes or tool-tips to deliver messages such as requests for control. However, the collaborative tasks being performed are typically highly visual in nature themselves, meaning that messages can either intrude or be missed. Another shortcoming of current systems is that they fail to support flexibility in requesting control, something we take for granted in face-to-face collaboration. In this thesis, we introduce a novel urgency-based turn-taking protocol, where users can request control with two levels of urgency or immediately take control. Haptic icons, touch-sense stimuli that have been assigned a meaning, are used in this protocol to periodically inform a user of the current turn-taking state. Our research was conducted in three phases. First, we designed the protocol and selected a set of haptic icons. Next, we evaluated the ability of subjects to learn the haptic icons and identify them under different amounts of cognitive workload. Finally, we recruited groups of subjects to use the protocol in a collaborative environment and evaluated their performance. Our results show that haptic feedback is a viable channel for communicating turn-taking information. The haptic icons can be learned in a reasonable amount of time and recalled with high accuracy. As well, users in control are more responsive to requests for control and control is shared more equally among group members when haptic feedback is present. The urgency-based protocol also shows promise when used with haptic feedback.
Transverse Momentum in Semi-inclusive Deep Inelastic Scattering
Creators: name: Ceccopieri, Federico Alberto
name: Trentadue, Luca
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Within the framework of perturbative Quantum Chromodynamics we derive transverse momentum dependent distributions describing both current and target fragmentation in semi-inclusive Deep Inelastic Scattering. We present, to leading logarithmic accuracy, the corresponding crosssections describing final state hadrons on the whole phase space. Phenomenological implications and further developments are briefly discussed.
description: 11 pages, 5 figures
A Demonstration of Issues with Value-Based Multiobjective Reinforcement Learning Under Stochastic State Transitions
Creators: name: Vamplew, Peter
name: Foale, Cameron
name: Dazeley, Richard
Publisher: name: arXiv
Year: 2020
Subjects: subject: Machine Learning (cs.LG)
subject: Multiagent Systems (cs.MA)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: We report a previously unidentified issue with model-free, value-based approaches to multiobjective reinforcement learning in the context of environments with stochastic state transitions. An example multiobjective Markov Decision Process (MOMDP) is used to demonstrate that under such conditions these approaches may be unable to discover the policy which maximises the Scalarised Expected Return, and in fact may converge to a Pareto-dominated solution. We discuss several alternative methods which may be more suitable for maximising SER in MOMDPs with stochastic transitions.
description: 6 pages. Accepted for presentation in the Adaptive and Learning Agents Workshop, AAMAS 2020
Constraints on mass matrices due to measured property of the mixing matrix
Creators: name: Chaturvedi, S.
name: Gupta, Virendra
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: It is shown that two specific properties of the unitary matrix $V$ can be expressed directly in terms of the matrix elements and eigenvalues of the hermitian matrix $M$ which is diagonalized by $V$. These are the asymmetry $Δ(V)= |V_{12}|^2- |V_{21}|^2$, of $V$ with respect to the main diagonal and the Jarlskog invariant $J(V)= {\rm Im}(V_{11}V_{12}^* V_{21}^* V_{22})$. These expressions for $Δ(V)$ and $J(V)$ provide constraints on possible mass matrices from the available data on $V$.
description: 5 pages, Latex
High-redshift Extreme Variability Quasars from Sloan Digital Sky Survey Multi-Epoch Spectroscopy
Creators: name: Guo, Hengxiao
name: Peng, Jiacheng
name: Zhang, Kaiwen
name: Burke, Colin J.
name: Liu, Xin
name: Sun, Mouyuan
name: Wang, Shu
name: Kong, Minzhi
name: Sheng, Zhenfeng
name: Wang, Tinggui
name: He, Zhicheng
name: Gu, Minfeng
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We perform a systematic search for high-redshift ($z >$ 1.5) extreme variability quasars (EVQs) using repeat spectra from the Sixteenth Data Release of Sloan Digital Sky Survey, which provides a baseline spanning up to $\sim$18 yrs in the observed frame. We compile a sample of 348 EVQs with a maximum continuum variability at rest frame 1450 Angstrom of more than 100% (i.e., $δ$V $\equiv$ (Max$-$Min)/Mean $>$1). The EVQs show a range of emission line variability, including 23 where at least one line in our redshift range disappears below detectability, which can then be seen as analogous to low-redshift changing-look quasars (CLQs)". Importantly, spurious CLQs caused by SDSS problematic spectral flux calibration, e.g., fiber drop issue, have been rejected. The similar properties (e.g., continuum/line, difference-composite spectra and Eddington ratio) of normal EVQs and CLQs, implies that they are basically the same physical population with analogous intrinsic variability mechanisms, as a tail of a continuous distribution of normal quasar properties. In addition, we find no reliable evidence ($\lesssim$ 1$σ$) to support that the CLQs are a subset of EVQs with less efficient accretion. Finally, we also confirm the anti-breathing of C IV (i.e., line width increases as luminosity increases) in EVQs, and find that in addition to $\sim$ 0.4 dex systematic uncertainty in single-epoch C IV virial black hole mass estimates, an extra scatter of $\sim$ 0.3 dex will be introduced by extreme variability.
description: 25 pages, 15 figures, 6 tables, published in ApJ
Theory of wavepacket transport under narrow gaps and spatial textures: non-adiabaticity and semiclassicality
Creators: name: Tu, Matisse Wei-Yuan
name: Li, Ci
name: Yao, Wang
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: We generalise the celebrated semiclassical wavepacket approach from the adiabatic to the non-adiabatic regime. A unified description covering both of these regimes is particularly desired for systems with spatially varying band structures where band gaps of various sizes are simultaneously present, e.g. in moiré patterns. For a single wavepacket, alternative to the previous derivation by Lagrangian variational approach, we show that the same semiclassical equations of motion can be obtained by introducing a spatial-texture-induced force operator similar to the Ehrenfest theorem. For semiclassically computing the current, the ensemble of wavepackets based on adiabatic dynamics is shown to well correspond to a phase-space fluid for which the fluid's mass and velocity are two distinguishable properties. This distinction is not inherited to the ensemble of wavepackets with the non-adiabatic dynamics. We extend the adiabatic kinetic theory to the non-adiabatic regime by taking into account decoherence, whose joint action with electric field favours certain form of inter-band coherence. The steady-state density matrix as a function of the phase-space variables is then phenomenologically obtained for calculating the transport current. The result, applicable with a finite electric field, expectedly reproduces the known adiabatic limit by taking the electric field to be infinitesimal, and therefore attains a unified description from the adiabatic to the non-adiabatic situations.
description: 16 pages, 1 figure
Spin Splitting and Spin Current in Strained Bulk Semiconductors
Creators: name: Bernevig, B. Andrei
name: Zhang, Shou-Cheng
Publisher: name: arXiv
Year: 2004
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We present a theory for two recent experiments in bulk strained semiconductors \cite{kato1, kato2} and show that a new, previously overlooked, strain spin-orbit coupling term may play a fundamental role. We propose simple experiments that could clarify the origin of strain-induced spin-orbit coupling terms in inversion asymmetric semiconductors. We predict that a uniform magnetization parallel to the electric field will be induced in the samples studied in \cite{kato1, kato2} for specific directions of the applied electric field. We also propose special geometries to detect spin currents in strained semiconductors.
description: 7 pages, 2 figures
Rotary dynamics of the rigid body electric dipole under the radiation reaction
Creators: name: Duviryak, Askold
Publisher: name: arXiv
Year: 2020
Subjects: subject: Classical Physics (physics.class-ph)
subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: FOS: Physical sciences
subject: 70K20 (Primary), 70K70 (Secondary)

description: Rotation of a permanently polarized rigid body under the radiation reaction torque is considered. Dynamics of the spinning top is derived from a balance condition of the angular momentum. It leads to the non-integrable nonlinear 2nd-order equations for angular velocities, and then to the reduced 1st-order Euler equations. The example of an axially symmetric top with the longitudinal dipole is solved exactly, with the transverse dipole is analyzed qualitatively and numerically. Physical solutions describe the asymptotic power-law slowdown to stop or the exponential drift to a residual rotation; this depends on initial conditions and a shape of the top.
description: 14 pages, 3 figures
Security in the Age of Digital Disruption.pdf
Creators: name: Agus Mailana
name: Moh. Gifari Sono
name: Kundharu Saddono
name: Putra, Andi Agung
name: Shofi'i, Amin
Publisher: name: figshare
Year: 2020
Subjects: subject: 80303 Computer System Security
subject: FOS: Computer and information sciences

description: Digital disruption is the new ordinary. Numerous applications overturned the livery business and transportation. The money related administrations industry has been reshaped by the development of robo-counselors, online banks and nontraditional contenders like Apple Pay. The ascent of distributed computing has shaken up the whole IT industry. A flood of digital transformation is planned for modernizing heritage frameworks and building new stages to stay applicable notwithstanding expanding worldwide challenge. Everything from the Internet of Things to huge information investigation and man-made brainpower, are being applied for procedure improvement and new client support choices. As these new advancements show up, so are new cybersecurity dangers, which, if not oversaw wisely, can bring about loss of income producing capacity and noteworthy notoriety harm.
Complex Dynamics of Real Nanosystems: Fundamental Paradigm for Nanoscience and Nanotechnology
Creators: name: Kirilyuk, Andrei P.
Publisher: name: arXiv
Year: 2004
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: Structure and dynamics of real nanosystems emerge from the unreduced solution of the underlying interaction problem. It has the property of dynamic multivaluedness giving genuine dynamic randomness and complexity (physics/9806002, physics/0405063). Chaoticity is irreducibly high in nanoscale systems and underlies exponentially high efficiency of their real, complex-dynamic operation (physics/0211071). Applications include real, dynamically chaotic quantum devices, nano-biotechnology, and genetics.
description: 4 pages, 13 eqs, 8 refs; Supplement (7 pages) shows conference presentation accents; Report presented at the First Ukrainian Conference "Nanosize Systems: Electronic and Atomic Structure and Properties" (Kyiv, 12-14 October 2004), http://www.imp.kiev.ua/nansys2004
Magic Melters' Have Geometrical Origin
Creators: name: Joshi, Kavita
name: Krishnamurty, Sailaja
name: Kanhere, D. G.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Recent experimental reports bring out extreme size sensitivity in the heat capacities of Gallium and Aluminum clusters. In the present work we report results of our extensive {\it ab initio} molecular dynamical simulations on Ga$_{30}$ and Ga$_{31}$, the pair which has shown rather dramatic size sensitivity. We trace the origin of this size sensitive heat capacities to the relative order in their respective ground state geometries. Such an effect of nature of the ground state on the characteristics of heat capacities is also seen in case of small Gallium and Sodium clusters indicating that the observed size sensitivity is a generic feature of small clusters.
description: 4 pages, 6 figures
Complex Networks on Hyperbolic Surfaces
Creators: name: Aste, T.
name: Di Matteo, T.
name: Hyde, S. T.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We explore a novel method to generate and characterize complex networks by means of their embedding on hyperbolic surfaces. Evolution through local elementary moves allows the exploration of the ensemble of networks which share common embeddings and consequently share similar hierarchical properties. This method provides a new perspective to classify network-complexity both on local and global scale. We demonstrate by means of several examples that there is a strong relation between the network properties and the embedding surface.
description: 8 Pages 3 Figures
Quantifying the nitrate levels in bottled water in New Zealand
Creators: name: Chambers, Tim
name: Joy, Michael
name: Wilson, Nick
name: Hales, Simon
name: Baker, Michael
Publisher: name: Open Access Victoria University of Wellington | Te Herenga Waka
Year: 2021
Subjects: subject: 140299 Applied Economics not elsewhere classified
subject: FOS: Economics and business
subject: 111799 Public Health and Health Services not elsewhere classified
subject: FOS: Health sciences
subject: 160599 Policy and Administration not elsewhere classified
subject: FOS: Political science

description: No description supplied
Michael Roth, Magdalena Bushart und Martin Sonnabend (Hrsg.); Maria Sibylla Merian und die Tradition des Blumenbildes von der Renaissance bis zur Romantik
Creators: name: Modemann, Janina
Publisher: name: Journal für Kunstgeschichte
Year: 2024

description: Rezension zu: Michael Roth, Magdalena Bushart und Martin Sonnabend (Hrsg.); Maria Sibylla Merian und die Tradition des Blumenbildes von der Renaissance bis zur Romantik; Ausstellungskatalog Kupferstichkabinett – Staatliche Museen zu Berlin und Städel Museum Frankfurt am Main; München: Hirmer Verlag 2017; 256 S., 288 farb. Abb.; ISBN 978-3-7774-2787-4
description: Journal für Kunstgeschichte, Bd. 24 Nr. 3 (2020): Journal für Kunstgeschichte
The impact of undetected cases on tracking epidemics: the case of COVID-19
Creators: name: De Simone, Andrea
name: Piangerelli, Marco
Publisher: name: arXiv
Year: 2020
Subjects: subject: Populations and Evolution (q-bio.PE)
subject: Quantitative Methods (q-bio.QM)
subject: Applications (stat.AP)
subject: FOS: Biological sciences
subject: FOS: Computer and information sciences
subject: G.3; I.6

description: One of the key indicators used in tracking the evolution of an infectious disease isthe reproduction number. This quantity is usually computed using the reportednumber of cases, but ignoring that many more individuals may be infected (e.g.asymptomatics). We propose a statistical procedure to quantify the impact of un-detected infectious cases on the determination of the effective reproduction number. Our approach is stochastic, data-driven and not relying on any compartmentalmodel. It is applied to the COVID-19 case in eight different countries and all Italianregions, showing that the effect of undetected cases leads to estimates of the effective reproduction numbers larger than those obtained only with the reported cases by factors ranging from two to ten. Our findings urge caution about deciding when and how to relax containment measures based on the value of the reproduction number.
description: 23 Pages, 10 Figures
CLINICAL AND NEUROLOGICAL CHARACTERISTICS OF CEREBRAL PALSY IN CHILDREN
Creators: name: Jumaev, Fatullo
Publisher: name: Zenodo
Year: 2025

description: Cerebral palsy (CP) is one of the most common neurological disorders in children, caused by early damage to the central nervous system. It is characterized by motor impairments, as well as psycho-emotional and cognitive disorders. In recent years, increasing attention has been given to studying the clinical and neurological features of CP, which is crucial for timely diagnosis and effective treatment..
Observation of Feshbach-like resonances in collisions between ultracold molecules
Creators: name: Chin, C.
name: Kraemer, T.
name: Mark, M.
name: Herbig, J.
name: Waldburger, P.
name: Naegerl, H. -C.
name: Grimm, R.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We observe magnetically tuned collision resonances for ultracold Cs2 molecules stored in a CO2-laser trap. By magnetically levitating the molecules against gravity, we precisely measure their magnetic moment. We find an avoided level crossing which allows us to transfer the molecules into another state. In the new state, two Feshbach-like collision resonances show up as strong inelastic loss features. We interpret these resonances as being induced by Cs4 bound states near the molecular scattering continuum. The tunability of the interactions between molecules opens up novel applications such as controlled chemical reactions and synthesis of ultracold complex molecules.
Enhancing collaborative content delivery with helpers
Creators: name: Wong, Joseph Hao Tan
Publisher: name: University of British Columbia
Year: 2009

description: In the client-server model predominant in today's Internet, the load on a server has a significant impact on the level of service perceived by its clients. In particular, given that a server is connected to its clients via an access link of finite capacity, the data transfer rate to each of its clients drops inversely as the number of clients served by the server. This limitation significantly hampers the scalability of such a setup, especially when long-lived connections are involved in the transfer of large files. It is now commonplace for a particular piece of content on the Internet to experience a sudden spike in popularity and hence also in request rate. Such an occurrence, called a "flash crowd" in Internet parlance, is difficult to address via adjusting the provisioning level alone, as it may come and go so quickly for administrative actions to be taken. To mitigate the problem of the flash crowd, many solutions have been developed. Some of them involve setting up a load-balancing infrastructure, while others rely upon the altruism of clients to provide additional capacity to handle the increased load. In this thesis, we describe a novel hybrid approach, based on the technique of swarming, for scaling up the delivery of large files to many clients. Our design allows machines on the Internet to contribute their bandwidth resources even when they are not interested in the content being disseminated. These peers, known as helpers, are specially tuned to maximize their upload rates while keeping their own download rates to a minimum. We evaluate our approach through simulation, testing it under a variety of conditions involving different bandwidth capacities and node arrival rates. Our results show that helpers are effective in contributing their bandwidth resources under all circumstances, and are able to increase the aggregate upload capacity of the whole system.
Charged open strings in a background field and Euler-Heisenberg effective action
Creators: name: Sciuto, Stefano
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: This talk is based on work made with L. Magnea and R. Russo. We give an explicit expression of the multiloop partition function of open bosonic string theory in the presence of a constant gauge field strength. The Schottky parametrization allows to perform the field theory limit, which at two-loop level reproduces the Euler-Heisenberg effective action for adjoint scalars minimally coupled to the background gauge field.
description: To be published in the Proceedings of ICHEMP '05, Marrakech, Morocco
The Hubble constant from eight time-delay galaxy lenses
Creators: name: Denzel, Philipp
name: Coles, Jonathan P.
name: Saha, Prasenjit
name: Williams, Liliya L. R.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present a determination of the Hubble constant from the joint, free-form analysis of 8 strongly, quadruply lensing systems. In the concordance cosmology, we find $H_0 = 71.8^{+3.9}_{-3.3}\,\mathrm{km}\,\mathrm{s}^{-1}\,\mathrm{Mpc}^{-1}$ with a precision of $4.97\%$. This is in agreement with the latest measurements from Supernovae Type Ia and Planck observations of the cosmic microwave background. Our precision is lower compared to these and other recent time-delay cosmography determinations, because our modelling strategies reflect the systematic uncertainties of lensing degeneracies. We furthermore are able to find reasonable lensed image reconstructions by constraining to either value of $H_0$ from local and early Universe measurements. This leads us to conclude that current lensing constraints on $H_0$ are not strong enough to break the "Hubble tension" problem of cosmology.
description: 19 pages, 11 figures, published in MNRAS