cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Macfarlane Hyperbolic 3-Manfiolds
Creators: name: Quinn, Joseph A.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Geometric Topology (math.GT)
subject: FOS: Mathematics

description: We identify and study a class of hyperbolic 3-manifolds (which we call Macfarlane manifolds) whose quaternion algebras admit a geometric interpretation analogous to Hamilton's classical model for Euclidean rotations. We characterize these manifolds arithmetically, and show that infinitely many commensurability classes of them arise in diverse topological and arithmetic settings. We then use this perspective to introduce a new method for computing their Dirichlet domains. We also give similar results for a class of hyperbolic surfaces and explore their occurrence as subsurfaces of Macfarlane manifolds.
description: 22 pages, 4 figures, 1 table
MPEC 2023-R153 : OBSERVATIONS AND ORBITS OF COMETS AND A/ OBJECTS
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2023
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469
subject: OBSERVATIONS AND ORBITS OF COMETS AND A/ OBJECTS

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
title: Dante e la politica: dal passato al presente
Creators: name: Silvestrini, Flavio
name: Maiolo, Francesco
name: Marcozzi, Luca
Publisher: name: Roma TrE-Press
Year: 2022

description:

Questa raccolta di saggi nasce dall’esigenza di riconsiderare il pensiero politico dantesco e la sua ricezione attraverso diverse prospettive metodologiche e disciplinari: storica, letteraria, politologica, giuridica e filosofica. I saggi qui riuniti sono una rielaborazione di relazioni presentate al Convegno Internazionale “Dante e la politica”, tenutosi all’Università di Roma Tre il 6 e 7 maggio 2021 con il patrocinio del Comitato Nazionale per le celebrazioni del settecentenario dantesco. Gli autori hanno affrontato sia il pensiero politico di Dante così come espresso nelle diverse opere e nel suo contesto storico e teorico, sia la mutevole e talvolta controversa ricezione che lo ha contraddistinto. Il volume non solo offre un quadro ampio e articolato delle conoscenze acquisite in materia, ma presenta anche nuovi spunti esegetici ed interpretativi che mirano a stimolare l’avvio di ulteriori riflessioni sui vari aspetti del pensiero politico dantesco.
Positive Geometries and Canonical Forms
Creators: name: Arkani-Hamed, Nima
name: Bai, Yuntao
name: Lam, Thomas
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Algebraic Geometry (math.AG)
subject: Combinatorics (math.CO)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: Recent years have seen a surprising connection between the physics of scattering amplitudes and a class of mathematical objects--the positive Grassmannian, positive loop Grassmannians, tree and loop Amplituhedra--which have been loosely referred to as "positive geometries". The connection between the geometry and physics is provided by a unique differential form canonically determined by the property of having logarithmic singularities (only) on all the boundaries of the space, with residues on each boundary given by the canonical form on that boundary. In this paper we initiate an exploration of "positive geometries" and "canonical forms" as objects of study in their own right in a more general mathematical setting. We give a precise definition of positive geometries and canonical forms, introduce general methods for finding forms for more complicated positive geometries from simpler ones, and present numerous examples of positive geometries in projective spaces, Grassmannians, and toric, cluster and flag varieties. We also illustrate a number of strategies for computing canonical forms which yield interesting representations for the forms associated with wide classes of positive geometries, ranging from the simplest Amplituhedra to new expressions for the volume of arbitrary convex polytopes.
description: 123 pages, 12 figures, v2: fixed a reference and some minor typos
Spatially correlated photonic qutrit pairs using pump beam modulation technique
Creators: name: Ghosh, Debadrita
name: Jennewein, Thomas
name: Kolenderski, Piotr
name: Sinha, Urbasi
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Higher dimensional quantum systems have a very important role to play in quantum information, computation as well as communication. While the polarization degree of freedom of the photon is a common choice for many studies, it is restricted to only two orthogonal states, hence qubits for manipulation. In this paper, we theoretically model as well as experimentally verify a novel scheme of approximating photonic qutrits by modulating the pump beam in a spontaneous parametric down conversion process using a three-slit aperture. The emerging bi-photon fields behave like qutrits and are found to be highly correlated in the spatial degree of freedom and effectively represent spatially correlated qutrits with a Pearson coefficient as high as 0.9. In principle, this system provides us a scalable architecture for generating and experimenting with higher dimensional correlated qudits.
description: 6 pages, 5 figures, 1 table: New analysis and figure added
Thermal Winds in Stellar Mass Black Hole and Neutron Star Binary Systems
Creators: name: Done, Chris
name: Tomaru, Ryota
name: Takahashi, Tad
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Black hole binaries show equatorial disc winds at high luminosities, which apparently disappear during the spectral transition to the low/hard state. This is also where the radio jet appears, motivating speculation that both wind and jet are driven by different configurations of the same magnetic field. However, these systems must also have thermal winds, as the outer disc is clearly irradiated.We develop a predictive model of the absorption features from thermal winds, based on pioneering work of Begelman et al 1983. We couple this to a realistic model of the irradiating spectrum as a function of luminosity to predict the entire wind evolution during outbursts. We show that the column density of the thermal wind scales roughly with luminosity, and does not shut off at the spectral transition, though its visibility will be affected by the abrupt change in ionising spectrum. We re-analyse the data from H1743-322 which most constrains the difference in wind across the spectral transition and show that these are consistent with the thermal wind models.We include simple corrections for radiation pressure, which allows stronger winds to be launched from smaller radii. These winds become optically thick around Eddington, which may even explain the exceptional wind seen in one observation of GRO J1655-40. These data can instead be fit by magnetic wind models, but similar winds are not seen in this or other systems at similar luminosities. Hence we conclude that the majority (perhaps all) current data can be explained by thermal or thermal-radiative winds.
description: MNRAS accepted, 10 pages, 7 figures
The effect of Mathematics learning activities by usingGeoGebra in topic parabola for grade-9 students
Creators: name: Paweena Khansila
Publisher: name: Faculty of Science, Ubon Ratchathani University
Year: 2023
Subjects: Mathematics learning activities
Parabola
GeoGebra program
Satisfaction

description: Journal of Science and Science Education, 6, 2, 333-343
From 3D Models to 3D Prints: an Overview of the Processing Pipeline
Creators: name: Livesu, Marco
name: Ellero, Stefano
name: Martìnez, Jonás
name: Lefebvre, Sylvain
name: Attene, Marco
Publisher: name: arXiv
Year: 2017
Subjects: subject: Graphics (cs.GR)
subject: FOS: Computer and information sciences

description: Due to the wide diffusion of 3D printing technologies, geometric algorithms for Additive Manufacturing are being invented at an impressive speed. Each single step, in particular along the Process Planning pipeline, can now count on dozens of methods that prepare the 3D model for fabrication, while analysing and optimizing geometry and machine instructions for various objectives. This report provides a classification of this huge state of the art, and elicits the relation between each single algorithm and a list of desirable objectives during Process Planning. The objectives themselves are listed and discussed, along with possible needs for tradeoffs. Additive Manufacturing technologies are broadly categorized to explicitly relate classes of devices and supported features. Finally, this report offers an analysis of the state of the art while discussing open and challenging problems from both an academic and an industrial perspective.
description: European Union (EU); Horizon 2020; H2020-FoF-2015; RIA - Research and Innovation action; Grant agreement N. 680448
Efficient Kinematic Planning for Mobile Manipulators with Non-holonomic Constraints Using Optimal Control
Creators: name: Giftthaler, Markus
name: Farshidian, Farbod
name: Sandy, Timothy
name: Stadelmann, Lukas
name: Buchli, Jonas
Publisher: name: arXiv
Year: 2017
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: This work addresses the problem of kinematic trajectory planning for mobile manipulators with non-holonomic constraints, and holonomic operational-space tracking constraints. We obtain whole-body trajectories and time-varying kinematic feedback controllers by solving a Constrained Sequential Linear Quadratic Optimal Control problem. The employed algorithm features high efficiency through a continuous-time formulation that benefits from adaptive step-size integrators and through linear complexity in the number of integration steps. In a first application example, we solve kinematic trajectory planning problems for a 26 DoF wheeled robot. In a second example, we apply Constrained SLQ to a real-world mobile manipulator in a receding-horizon optimal control fashion, where we obtain optimal controllers and plans at rates up to 100 Hz.
description: 7 pages
Thermal studies on recycled aggregate concrete modified with carbonated and bio-deposited recycled aggregates
Creators: name: Jagan Sivamani
name: Thiyaneswaran Periasamy
Publisher: name: Faculty of Engineering, Khon Kaen University
Year: 2023
Subjects: Recycled aggregate
Carbonation
Bio-deposition
Elevated temperature
Residual strength

description: Engineering and Applied Science Research, 50, 5, 468-477
Cell reprogramming modelled as transitions in a hierarchy of cell cycles
Creators: name: Hannam, R
name: Annibale, A
name: Kuehn, R
Publisher: name: arXiv
Year: 2016
Subjects: subject: Cell Behavior (q-bio.CB)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Molecular Networks (q-bio.MN)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: We construct a model of cell reprogramming (the conversion of fully differentiated cells to a state of pluripotency, known as induced pluripotent stem cells, or iPSCs) which builds on key elements of cell biology viz. cell cycles and cell lineages. Although reprogramming has been demonstrated experimentally, much of the underlying processes governing cell fate decisions remain unknown. This work aims to bridge this gap by modelling cell types as a set of hierarchically related dynamical attractors representing cell cycles. Stages of the cell cycle are characterised by the configuration of gene expression levels, and reprogramming corresponds to triggering transitions between such configurations. Two mechanisms were found for reprogramming in a two level hierarchy: cycle specific perturbations and a noise-induced switching. The former corresponds to a \emph{directed} perturbation that induces a transition into a cycle state of a different cell type in the potency hierarchy (mainly a stem cell) whilst the latter is a priori undirected and could be induced, e.g., by a (stochastic) change in the cellular environment. These reprogramming protocols were found to be effective in large regimes of the parameter space and make specific predictions concerning reprogramming dynamics which are broadly in line with experimental findings.
A leptoquark model to accommodate $R_K^\mathrm{exp}
Creators: name: Bečirević, Damir
name: Sumensari, Olcyr
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We show that a modification of the model with a low energy scalar leptoquark state carrying hypercharge $Y=7/6$ allows to accommodate both $R_K<1$ and $R_{K^\ast}<1$, through loop effects, consistent with recent observations made at LHCb. We describe details of the model, compute the relevant Wilson coefficient and, after discussing a number of constraints, we examine the phenomenological consequences of the model. The bounds on the lepton flavor violating decay rates, induced by this model, include $\mathcal{B}(Z\toμτ) \lesssim \mathcal{O}(10^{-7})$, and $\mathcal{B}(B\to Kμτ) \lesssim \mathcal{O}(10^{-9})$. We also comment on the interpretation of the bounds on the leptoquark mass obtained from the direct searches at LHC.
description: 18 pages, 7 figures (published version)
Cosmological singularity resolution from quantum gravity: the emergent-bouncing universe
Creators: name: Alesci, Emanuele
name: Botta, Gioele
name: Cianfrani, Francesco
name: Liberati, Stefano
Publisher: name: arXiv
Year: 2016
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Alternative scenarios to the Big Bang singularity have been subject of intense research for several decades by now. Most popular in this sense have been frameworks were such singularity is replaced by a bounce around some minimal cosmological volume or by some early quantum phase. This latter scenario was devised a long time ago and referred as an "emergent universe" (in the sense that our universe emerged from a constant volume quantum phase). We show here that within an improved framework of canonical quantum gravity (the so called Quantum Reduced Loop Gravity) the Friedmann equations for cosmology are modified in such a way to replace the big bang singularity with a short bounce {preceded by a metastable quantum phase in which the volume of the universe oscillates between a series of local maxima and minima}. We call this hybrid scenario an "emergent-bouncing universe" since after a pure oscillating quantum phase the classical Friedmann spacetime emerges. Perspective developments and possible tests of this scenario are discussed in the end.
description: 6 pages, 2 figures. Revised version accepted for publication in PRD. In this new version improved numerical simulations show damped oscillations in the pre- bounce phase. Full Discussion section added
Tribe, Islam and state in Libya: analytical study of the roots of the Libyan tribal society and interaction up to the Qaramanli rule (1711-1835)
Creators: name: Najem, Faraj
Publisher: name: University of Westminster
Year: 2004

description: The subject of this study is Tribe, Islam and State in Libya. It is an analytical research of the roots of the Libyan tribal society and the interaction of tribe, Islam and State up to the Qaramänli rule (1711-1835). The study deals with the acclaimed blood lineage and the genealogical descent, which compels all Libyans to feel related to each other. It focused on the events culminating in the composition of the tribal groupings and the relation between tribes and the Qaramänli State, which is considered as the first Libyan State with Islam playing an instrumental role, a State built and destroyed by the tribes. This study endeavours to explain the major synthesising components of Libyan society, namely Berbero-Arab, Muräbitin and Karäghla who established Libya with its three strong dimensions: Islam, Arabism, and Libyan identity in the 18th Century. The inference is an original contribution to the field of Libyan, Arabic and Islamic societal and anthropological studies since the topic has never been tackled in such specificity. The aims of the study were to examine the origins of tribes, and the links with Islam and State, and in doing so the methodological approaches of comparative, analytical and chronological were employed. The study found that Libya is a tribalistic society of multitude of races and backgrounds and based on Islam and Arabism despite the fact that some of its people are not ethnically Arabs. There was, also, a bond between Tribes, Islam and State. Moreover, there was an alignment between Islam and tribes to either aide or diminish the power and authority of the State. The study is divided into seven chapters preceded by an introduction and followed by the conclusion. Likewise, every chapter has its own prelude and ending, and supported by detailed demographical (tribal) maps for Libya's three provinces in addition to family tress and tables of diverse tribes' names.
Fluctuation theorems in feedback-controlled open quantum systems: quantum coherence and absolute irreversibility
Creators: name: Murashita, Yûto
name: Gong, Zongping
name: Ashida, Yuto
name: Ueda, Masahito
Publisher: name: arXiv
Year: 2017
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Thermodynamics of quantum coherence has attracted growing attention recently, where the thermodynamic advantage of quantum superposition is characterized in terms of quantum thermodynamics. We investigate thermodynamic effects of quantum coherent driving in the context of the fluctuation theorem. We adopt a quantum-trajectory approach to investigate open quantum systems under feedback control. In these systems, the measurement backaction in the forward process plays a key role, and therefore the corresponding time-reversed quantum measurement and post-selection must be considered in the backward process in sharp contrast to the classical case. The state reduction associated with quantum measurement, in general, creates a zero-probability region in the space of quantum trajectories of the forward process, which causes singularly strong irreversibility with divergent entropy production (i.e., absolute irreversibility) and hence makes the ordinary fluctuation theorem break down. In the classical case, the error-free measurement ordinarily leads to absolute irreversibility because the measurement restricts classical paths to the region compatible with the measurement outcome. In contrast, in open quantum systems, absolute irreversibility is suppressed even in the presence of the projective measurement due to those quantum rare events that go through the classically forbidden region with the aid of quantum coherent driving. This suppression of absolute irreversibility exemplifies the thermodynamic advantage of quantum coherent driving. Absolute irreversibility is shown to emerge in the absence of coherent driving after the measurement, especially in systems under time-delayed feedback control. We show that absolute irreversibility is mitigated by increasing the duration of quantum coherent driving or decreasing the delay time of feedback control.
description: 16 pages, 8 figures
Unprecedented access? Women instrumentalists in punk bands 1976-1984: an exploration
Creators: name: Reddington, Helen
Publisher: name: University of Westminster
Year: 2004

description: This study has been undertaken because of a gap in popular music and subcultural history. The significance of the first large influx of women into rock music, as punk instrumentalists in the late 1970s, has been underplayed; instead, women punks have been stereotypically documented. Girls' and womens' roles as producers of music, and their consequent contribution to the sound of punk music, have been subjected to a collective amnesia. Four areas of literature have been reviewed to clarify the reasons for, and extent of the gap: writings on subcultures and scenes, writings on women in rock and pop, writings on the socio-political context, and writings on punk. One of the main foci of the study has been to identify the reasons for the fading away of the presence of women instrumentalists in the early 1980s. I wanted to discover why this phenomenon had such a short time span. The primary research involved a newspaper survey (300 local papers were contacted across Britain) from which 24 useful questionnaires were gleaned; I interviewed 15 women who were in bands at the time, as well as a radio DJ, record company owner, band manager, and several male band members and political activists from the scene. Fanzines, music papers and the feminist magazine Spare Rib have also been referred to extensively. I have also had my own recollections of the time to draw upon. Following the literature review, the study is divided into sections on Access (enabling and empowering factors), Media Gatekeepers and Cultural Intermediaries (external controls and filters), The Brighton Scene (a case study of my own local punk enviromnent), Noise, Violence and Femininity (the practice of music making by these women, and the resistance to it), the Aftermath (exploring factors contributing to the ending of the moment), and Conclusions.
Pure states of maximum uncertainty with respect to a given POVM
Creators: name: Szymusiak, Anna
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: One of the differences between classical and quantum world is that in the former we can always perform a measurement that gives certain outcomes for all pure states, while such a situation is not possible in the latter. The degree of randomness of the distribution of the measurement outcomes can be quantified by the Shannon entropy. While it is well known that this entropy, as a function of quantum states, needs to be minimized by some pure states, we would like to address the question how 'badly' can we end by choosing initially any pure state, i.e., which pure states produce the maximal amount of uncertainty under given measurement. We find these maximizers for all highly symmetric POVMs in dimension 2, and for all SIC-POVMs in any dimension.
Fast State Transfer and Entanglement Renormalization Using Long-Range Interactions
Creators: name: Eldredge, Zachary
name: Gong, Zhe-Xuan
name: Young, Jeremy T.
name: Moosavian, Ali Hamed
name: Foss-Feig, Michael
name: Gorshkov, Alexey V.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: In short-range interacting systems, the speed at which entanglement can be established between two separated points is limited by a constant Lieb-Robinson velocity. Long-range interacting systems are capable of faster entanglement generation, but the degree of the speed-up possible is an open question. In this paper, we present a protocol capable of transferring a quantum state across a distance $L$ in $d$ dimensions using long-range interactions with strength bounded by $1/r^α$. If $α< d$, the state transfer time is asymptotically independent of $L$; if $α= d$, the time is logarithmic in distance $L$; if $d < α< d+1$, transfer occurs in time proportional to $L^{α- d}$; and if $α\geq d + 1$, it occurs in time proportional to $L$. We then use this protocol to upper bound the time required to create a state specified by a MERA (multiscale entanglement renormalization ansatz) tensor network, and show that, if the linear size of the MERA state is $L$, then it can be created in time that scales with $L$ identically to state transfer up to multiplicative logarithmic corrections.
description: 6 pages, 4 figures
Geographic Space as a Living Structure for Predicting Human Activities Using Big Data
Creators: name: Jiang, Bin
name: Ren, Zheng
Publisher: name: arXiv
Year: 2017
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Social and Information Networks (cs.SI)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Inspired by Christopher Alexanders conception of the world - space is not lifeless or neutral but a living structure involving far more small things than large ones a topological representation has been previously developed to characterize the living structure or the wholeness of geographic space. This paper further develops the topological representation and living structure for predicting human activities in geographic space. Based on millions of street nodes of the United Kingdom extracted from OpenStreetMap, we established living structures at different levels of scale in a nested manner. We found that tweet locations at different levels of scale, such as country and city, can be well predicted by the underlying living structure. The high predictability demonstrates that the living structure and the topological representation are efficient and effective for better understanding geographic forms. Based on this major finding, we argue that the topological representation is a truly multi-scale representation, and point out that existing geographic representations are essentially single scale, so they bear many scale problems such as modifiable areal unit problem, the conundrum of length, and the ecological fallacy. We further discuss on why the living structure is an efficient and effective instrument for structuring geospatial big data, and why Alexanders organic worldview constitutes the third view of space. Keywords: Organic worldview, topological representation, tweet locations, natural cities, scaling of geographic space
description: 13 pages, 7 figures, 5 tables
Degenerate multi-solitons in the sine-Gordon equation
Creators: name: Cen, Julia
name: Correa, Francisco
name: Fring, Andreas
Publisher: name: arXiv
Year: 2017
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: High Energy Physics - Theory (hep-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We construct various types of degenerate multi-soliton and multi-breather solutions for the sine-Gordon equation based on Bäcklund transformations, Darboux-Crum transformations and Hirota's direct method. We compare the different solution procedures and study the properties of the solutions. Many of them exhibit a compound like behaviour on a small timescale, but their individual one-soliton constituents separate for large time. Exceptions are degenerate cnoidal kink solutions that we construct via inverse scattering from shifted Lamé potentials. These type of solutions have constant speed and do not display any time-delay. We analyse the asymptotic behaviour of the solutions and compute explicit analytic expressions for time-dependent displacements between the individual one-soliton constituents for any number of degeneracies. When expressed in terms of the soliton speed and spectral parameter the expression found is of the same generic form as the one formerly found for the Korteweg de-Vries equation.
description: 21 pages, 5 figures (appendix and figure added)
Randomized Block Frank-Wolfe for Convergent Large-Scale Learning
Creators: name: Zhang, Liang
name: Wang, Gang
name: Romero, Daniel
name: Giannakis, Georgios B.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Optimization and Control (math.OC)
subject: Machine Learning (cs.LG)
subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences

description: Owing to their low-complexity iterations, Frank-Wolfe (FW) solvers are well suited for various large-scale learning tasks. When block-separable constraints are present, randomized block FW (RB-FW) has been shown to further reduce complexity by updating only a fraction of coordinate blocks per iteration. To circumvent the limitations of existing methods, the present work develops step sizes for RB-FW that enable a flexible selection of the number of blocks to update per iteration while ensuring convergence and feasibility of the iterates. To this end, convergence rates of RB-FW are established through computational bounds on a primal sub-optimality measure and on the duality gap. The novel bounds extend the existing convergence analysis, which only applies to a step-size sequence that does not generally lead to feasible iterates. Furthermore, two classes of step-size sequences that guarantee feasibility of the iterates are also proposed to enhance flexibility in choosing decay rates. The novel convergence results are markedly broadened to encompass also nonconvex objectives, and further assert that RB-FW with exact line-search reaches a stationary point at rate $\mathcal{O}(1/\sqrt{t})$. Performance of RB-FW with different step sizes and number of blocks is demonstrated in two applications, namely charging of electrical vehicles and structural support vector machines. Extensive simulated tests demonstrate the performance improvement of RB-FW relative to existing randomized single-block FW methods.
Construction and applications of the manifestly gauge invariant expressions of the solutions of the cosmological perturbation theory
Creators: name: Hamazaki, Takashi
Publisher: name: arXiv
Year: 2017
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: After giving how to construct the gauge invariant perturbation variable in an arbitrarily high order and in the arbitrary background spacetime, we consider the manifestly gauge invariant theory of the cosmological perturbations in the long wavelength limit with the spatially flat homogeneous isotropic universe being the background spacetime. In the previous paper, the physical laws become manifestly gauge invariant, by writing them in terms of only the single time background/scalar like objects. In the present paper, by extending our definition of the background/scalar like objects from the single time case to the many time case and by writing the solution of the physical law in the form where many time background/scalar like objects are vanishing, the solutions become the manifestly gauge invariant. We derive the formula changing the bases of the many time background/scalar like objects by which we can change the time slices for many times appearing in the solution including the initial time and the final time. We use this formula to our treatment of the evolution of the several slow rolling scalar fields using the $τ$ function. In the manifestly gauge invariant manner, we discuss the solution of the many step reheating, that is, the reheating with the arbitrarily many energy transfer steps. By using the useful parametrization of the many step reheating, we manifestly prove that in the many step reheating system the prominent fluctuation generation process the nearest to the present time erases all the fluctuations generated by the previous fluctuation generation processes. Therefore in order to know the first/second order Bardeen parameters at the present time it is sufficient to calculate only the effects of the the prominent fluctuation generation processes such as curvaton and the modulated reheating the nearest to the present time.
Intentions & effects: the rhetoric of current cultural policy in England
Creators: name: Selwood, Sara
Publisher: name: University of Westminster
Year: 2004

description: As its title suggests, this thesis - the critical commentary together with a body of published works - questions the effectiveness of cultural policy with respect to museums and galleries in England. Its focus is on cultural policy under New Labour, and its implementation through the Department for Culture, Media and Sport (DCMS) in particular. The department was established within months of the 1997 election and was intended to ensure the effective delivery of government objectives from the outset. This entailed the department's 'comprehensive reform' of the `cultural framework', its pursuit of an instrumentalist agenda and its desire to determine and direct the effectiveness of its sponsored bodies. This effort was predicated on the assumption that there is an implicit and highly determined relationship between policy, funding, implementation and outcomes. Nevertheless, however strategic DCMS's actions might have been, there is little hard evidence of its effectiveness. The process of converting intention into effect appears to have proved more problematic than the rhetoric suggests. In setting out and supporting that proposition, this thesis describes those policies which have determined support for the cultural sector since 1997, particularly in respect of museums and galleries. It considers their background and implementation, summarises the financial value of the support provided and interrogates the evidence as to their outcomes. It argues that, as yet, many of the objectives shared by DCMS and its so-called 'family' of sponsored bodies have not yet been delivered, and that many of the claims made for the subsidised cultural sector more generally remain unsubstantiated. It also points to recent signs that suggest that the department is now wavering on its original ambitions.
Laminar and turbulent dynamos in chiral magnetohydrodynamics-I: Theory
Creators: name: Rogachevskii, I.
name: Ruchayskiy, O.
name: Boyarsky, A.
name: Fröhlich, J.
name: Kleeorin, N.
name: Brandenburg, A.
name: Schober, J.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: The magnetohydrodynamic (MHD) description of plasmas with relativistic particles necessarily includes an additional new field, the chiral chemical potential associated with the axial charge (i.e., the number difference between right- and left-handed relativistic fermions). This chiral chemical potential gives rise to a contribution to the electric current density of the plasma (\emph{chiral magnetic effect}). We present a self-consistent treatment of the \emph{chiral MHD equations}, which include the back-reaction of the magnetic field on a chiral chemical potential and its interaction with the plasma velocity field. A number of novel phenomena are exhibited. First, we show that the chiral magnetic effect decreases the frequency of the Alfvén wave for incompressible flows, increases the frequencies of the Alfvén wave and of the fast magnetosonic wave for compressible flows, and decreases the frequency of the slow magnetosonic wave. Second, we show that, in addition to the well-known laminar chiral dynamo effect, which is not related to fluid motions, there is a dynamo caused by the joint action of velocity shear and chiral magnetic effect. In the presence of turbulence with vanishing mean kinetic helicity, the derived mean-field chiral MHD equations describe turbulent large-scale dynamos caused by the chiral alpha effect, which is dominant for large fluid and magnetic Reynolds numbers. The chiral alpha effect is due to an interaction of the chiral magnetic effect and fluctuations of the small-scale current produced by tangling magnetic fluctuations (which are generated by tangling of the large-scale magnetic field by sheared velocity fluctuations). These dynamo effects may have interesting consequences in the dynamics of the early universe, neutron stars, and the quark--gluon plasma.
description: 23 pages, 4 figures
Relation between the mass modification of the heavy-light mesons and the chiral symmetry structure in dense matter
Creators: name: Harada, Masayasu
name: Ma, Yong-Liang
name: Suenaga, Daiki
name: Takeda, Yusuke
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We point out that the study of the density dependences of the masses of heavy-light mesons give some clues to the chiral symmetry structure in nuclear matter. We include the omega meson effect as well as the sigma meson effect at mean field level on the density dependence of the masses of heavy-light mesons with chiral partner structure. It is found that the omega meson affects the masses of the heavy-light mesons and their antiparticles in the opposite way, while it affects the masses of chiral partners in the same way. This is because the omega meson is sensitive to the baryon number of the light degrees included in the heavy-light mesons. We also show that the mass difference between chiral partners is proportional to the mean field of sigma, reflecting the partial restoration of chiral symmetry in the nuclear matter. In addition to the general illustration of the density dependence of the heavy-light meson masses, we consider two concrete models for nuclear matter, the parity doublet model and skyrmion crystal model in the sense of mean field approximation.
description: 7 pages
The echoes of grassroots media practices in Greece: a sociological approach
Creators: name: Vatikiotis, Pantelis
Publisher: name: University of Westminster
Year: 2004

description: This thesis probes into grassroots media projects by addressing them in a broad theoretical framework that evaluates such projects in macro terms, along the interplay between 'public sphere' and 'civil society', as well as in micro terms, across the 'lived experience' of their practice, on the grounds of the expression and enactment of 'citizenship' correspondingly. From this perspective, the study researches media projects that are implemented `on the margins' in Greece, drawing both on their contribution to and intervention in the public and political life. By evaluating these projects in a resonant context the study prioritizes the 'agents', citizens/social groups, who are engaged in their practice. Using empirical evidence from fieldwork conducted in Greece in 2003 involving: indepth interviews with people engaged (forty four participants) in the practice of diverse, heterogeneous media projects - one newspaper, two periodicals, three pirate radio stations and three Internet sites - this thesis evaluates the limits and the challenges of the practice of such projects in terms of their contribution to the public sphere and their intervention in the sphere of 'the political'. It argues that while such projects constitute a realm for the representation of various social domains, collectives/social groups and their discourses, as well as, for their intervention in civic life, at the same time their practice is entrapped in traditional 'politics' that deter the expansion of these projects, and negate the potential their practice encompasses for the constitution of `the political' in the realm of everyday life as well.
Ionization spectra of highly Stark shifted rubidium Rydberg states
Creators: name: Grimmel, Jens
name: Stecker, Markus
name: Kaiser, Manuel
name: Karlewski, Florian
name: Torralbo-Campo, Lara
name: Günther, Andreas
name: Fortágh, József
Publisher: name: arXiv
Year: 2017
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We report on the observation and numerical calculation of ionization spectra of highly Stark-shifted Rydberg states of rubidium beyond the classical ionization threshold. In the numerical calculations, a complex absorbing potential (CAP) allows us to predict the energy levels and ionization rates of Rydberg states in this regime. Our approach of adjusting the CAP to the external electric field reduces the number of free parameters from one per resonance to a single one. Furthermore, we have measured the ionization spectra of magneto-optically trapped rubidium atoms which are excited to principal quantum numbers of 43 and 70 at various electric fields. The emerging ions are detected using an ion optics. We find good agreement between the numerically and experimentally obtained spectra.
description: 8 pages, 8 figures
Bibliothekarische Ausbildung im Spannungsfeld von Informationsmanagement und Digitalisierung
Creators: name: Zeiller, Michael
Publisher: name: Humboldt-Universität zu Berlin
Year: 2022
Subjects: subject: Digitalisierung
subject: Digitale Inhalte
subject: Informationsmanagement
subject: Medienkompetenz
subject: Digitization
subject: digital content
subject: information management
subject: media literacy
subject: 020 Bibliotheks- und Informationswissenschaften

description: Die Dominanz von digitalem Content und Digitalisierungsmaßnahmen verändern die Berufswelt von Beschäftigten in Bibliotheken. Die dafür benötigten digitalen Kompetenzen erfordern ständige Adaptierungen in den Ausbildungsprogrammen. Allerdings unterliegen diese Ausbildungsprogramme mehreren Spannungsfeldern, um aktuelle Ausbildungsinhalte anbieten zu können. Unterschiedliche Spannungsfelder, unter anderem Spezialisierung vs. breite Wissensbasis, der Anteil an Informationstechnologien, eine Schwerpunktsetzung im Informationsmanagement oder der Bedarf an einem offenen, erweiterten Kompetenzspektrum werden diskutiert.
description: The dominance of digital content and digitization are changing the professional world of library employees. The new and changed digital competencies require constant adaptations in the training programs. However, these programs are subject to several conflicts in order to be able to offer up-to-date teaching content. Different areas of conflict are discussed, including specialization vs. broad knowledge base, the amount of information technologies, a focus on information management, or the need for an open, broadened spectrum of competencies.
Improving professional practice for mobile operators through the development of a decision support tool for outsourcing: Insights from Egyptian telecommunication sector
Creators: name: Amiri, Ayman
Publisher: name: Cardiff Metropolitan University
Year: 2022
Subjects: Entrepreneurship
International business
Leadership
Quality management
Strategy

description: This is a paper that records the changing thoughts of a Chief Technology Officer in a major telecommunication company in the Middle East. The initial problem was whether to outsource or not, but this led to reflections on decision making, systems thinking, cybernetics and many other ethical, political and professional issues. These thoughts can serve as a roadmap for decision makers and stimulate critical reflection on their actions.
Binding, Release and Functionalization of Intact Pnictogen Tetrahedra Coordinated to Dicopper Complexes
Creators: name: Piesch, Martin
name: Nicolay, Amélie
name: Haimerl, Maria
name: Seidl, Michael
name: Balázs, Gábor
name: Don Tilley, T.
name: Scheer, Manfred
Publisher: name: Universität Regensburg
Year: 2022
Subjects: subject: WHITE PHOSPHORUS; ELECTRON-DIFFRACTION; MOLECULAR-STRUCTURE; CARBENE ACTIVATION; P-4 ACTIVATION; LIGAND; AS-4; TETRAPHOSPHORUS; REACTIVITY; STABILIZATION; carbenes; coordination modes; copper; metal-metal interactions; pnictogens
subject: 540 Chemie

description: The bridging MeCN ligand in the dicopper(I) complexes [(DPFN)Cu-2(mu,eta(1) : eta(1)-MeCN)][X](2) (X=weakly coordinating anion, NTf2 (1 a), FAl[OC6F10(C6F5)](3) (1 b), Al[OC(CF3)(3)](4) (1 c)) was replaced by white phosphorus (P-4) or yellow arsenic (As-4) to yield [(DPFN)Cu-2(mu,eta(2) : eta(2)-E-4)][X](2) (E=P (2 a-c), As (3 a-c)). The molecular structures in the solid state reveal novel coordination modes for E-4 tetrahedra bonded to coinage metal ions. Experimental data and quantum chemical computations provide information concerning perturbations to the bonding in coordinated E-4 tetrahedra. Reactions with N-heterocyclic carbenes (NHCs) led to replacement of the E-4 tetrahedra with release of P-4 or As-4 and formation of [(DPFN)Cu-2(mu,eta(1) : eta(1)-(NHC)-N-Me)][X](2) (4 a,b) or to an opening of one E-E bond leading to an unusual E-4 butterfly structural motif in [(DPFN)Cu-2(mu,eta(1) : eta(1)-(E4NHC)-N-Dipp)][X](2) (E=P (5 a,b), E=As (6)). With a cyclic alkyl amino carbene ((Et)CAAC), cleavage of two As-As bonds was observed to give two isomers of [(DPFN)Cu-2(mu,eta(2) : eta(2)-As(4)(Et)CAAC)][X](2) (7 a,b) with an unusual As-4-triangle+1 unit.
Airport privatisation and performance
Creators: name: Vogel, Hans-Arthur
Publisher: name: University of Westminster
Year: 2004

description: This study assesses the financial performance of a representative sample of 35 European commercial airports for the period 1990 to 1999 inclusive, comparing those subject to partial or full privatisation with those in public ownership. It is hypothesized that privatised airports operate more efficiently than others and that they are an attractive investment as compared to alternative capital projects. Partial factor productivity (PFP), total factor productivity (TFP) indicators and financial ratio analysis (FRA) outcomes are compared, in order to investigate differences which may be attributable to the degree of privatisation. The main results of PFP and FRA indicators are tested by an independent and a paired-samples t-test for differences between airports in public, mixed public-private and fully private ownership. Changes in performance after a change in ownership structure are reviewed. The analysis of sample data reveals economically meaningful and statistically significant differences between publicly owned and privatised airports. The latter group is not a homogeneous one but shows decisive structural differences between partially and fully privatised companies. The major differences lie in operating efficiency, asset utilization and capital structure, which vary substantially with the respective ownership status. Whereas privatised airports are more cost efficient, publicly owned airports generate comparatively higher ratios of unit revenues and work load units to total assets. Their asset turnover is higher but the capital expenditure to total revenue ratio is lower. The increased operating efficiency of partially and fully privatised airports does not, however, translate into higher returns on equity in general. Only partially privatised sample airports may be considered an attractive investment. Regarding capital structure and financing of productive assets, publicly owned airports assume more debt relatively to their respective shareholders' funds, which results in considerably higher gearing and financial leverage, compensating for the comparatively low return rate on assets. Based on the findings of this research, key success factors and value drivers of the airports' business model are identified and consequences for airport management are deduced. Major contributions to the knowledge on the subject result from an application of financial ratio analysis to the sector, including the analysis of capital structures, the usage of performance indicators and financial ratios before and after privatisation and from conducting a DEA analysis strictly based on financial variables.