pinecone/core-2020-05-10-deduplication huggingface dataset:
Offsets, Conchoids and Pedal Surfaces

We discuss three geometric constructions and their relations, namely the offset, the conchoid and the pedal construction. The offset surface F d of a given surface F is the set of points at fixed normal distance d of F. The conchoid surface G d of a given surface G is obtained by increasing the radius function by d with respect to a given reference point O. There is a nice relation between offsets and conchoids: The pedal surfaces of a family of offset surfaces are a family of conchoid surfaces. Since this relation is birational, a family of rational offset surfaces corresponds to a family of rational conchoid surfaces and vice versa. We present theoretical principles of this mapping and apply it to ruled surfaces and quadrics. Since these surfaces have rational offsets and conchoids, their pedal and inverse pedal surfaces are new classes of rational conchoid surfaces and rational offset surfaces
Looking for the pick of the bunch: high-throughput screening of producing microorganisms with biosensors

The engineering of microbial strains for the production of small molecules of biotechnological interest is a time-consuming, laborious and expensive process. This can be mostly attributed to the fact that good producers cannot be readily obtained by high-throughput screening approaches since increased product formation usually does not confer a clear phenotype to producing strain variants. Recently, advances were made in the design and construction of genetically encoded RNA aptamer-based or transcription factor-based biosensors for detecting small molecules at the single-cell level. The first promising examples for the application of these molecular biosensors in combination with fluorescent-activated cell sorting as a high-throughput screening device demonstrated the value and potential of these new tools for microbial strain development
Singly-spinning black rings in D = 5 U(1) 3 supergravity

We construct black ring solutions in five-dimensional U(1) 3 supergravity which carry three dipole charges, three electric charges and one angular momentum parameter. These solutions are written in a form that is sufficiently compact that their global and thermodynamic properties can be studied explicitly. In particular, we find that the Smarr formula is obeyed regardless of whether or not conical singularities are present, whereas the first law of thermodynamics holds only in the absence of conical singularities. We also present black ring solutions with three background magnetic fields
Big Bang synthesis of nuclear dark matter

We investigate the physics of dark matter models featuring composite bound states carrying a large conserved dark “nucleon” number. The properties of sufficiently large dark nuclei may obey simple scaling laws, and we find that this scaling can determine the number distribution of nuclei resulting from Big Bang Dark Nucleosynthesis. For plausible models of asymmetric dark matter, dark nuclei of large nucleon number, e.g. ≳ 10 8 , may be synthesised, with the number distribution taking one of two characteristic forms. If small-nucleon-number fusions are sufficiently fast, the distribution of dark nuclei takes on a logarithmically-peaked, universal form, independent of many details of the initial conditions and small-number interactions. In the case of a substantial bottleneck to nucleosynthesis for small dark nuclei, we find the surprising result that even larger nuclei, with size ≫ 10 8 , are often finally synthesised, again with a simple number distribution. We briefly discuss the constraints arising from the novel dark sector energetics, and the extended set of (often parametrically light) dark sector states that can occur in complete models of nuclear dark matter. The physics of the coherent enhancement of direct detection signals, the nature of the accompanying dark-sector form factors, and the possible modifications to astrophysical processes are discussed in detail in a companion paper
Lepton mixing in A 5 family symmetry and generalized CP

We study lepton mixing patterns which can be derived from the A 5 family symmetry and generalized CP. We find five phenomenologically interesting mixing patterns for which one column of the PMNS matrix is 5 + 5 10 , 1 5 + 5 , 1 5 + 5 T $$ {\left(\sqrt{\frac{5+\sqrt{5}}{10},}\frac{1}{\sqrt{5+\sqrt{5}}},\frac{1}{\sqrt{5+\sqrt{5}}}\right)}^T $$ (the first column of the golden ratio mixing), 5 − 5 10 1 5 − 5 1 5 − 5 T $$ {\left(\sqrt{\frac{5-\sqrt{5}}{10}},\frac{1}{\sqrt{5-\sqrt{5}}},\frac{1}{\sqrt{5-\sqrt{5}}}\right)}^T $$ (the second column of the golden ratio mixing), 1 1 1 T / 3 $$ {\left(1,1,1\right)}^T/\sqrt{3} $$ or 5 + 1 , − 2 , 5 − 1 T / 4 $$ {\left(\sqrt{5}+1,-2,\sqrt{5}-1\right)}^T/4 $$ . The three lepton mixing angles are determined in terms of a single real parameter θ , and agreement with experimental data can be achieved for certain values of θ . The Dirac CP violating phase is predicted to be trivial or maximal while Majorana phases are trivial. We construct a supersymmetric model based on A 5 family symmetry and generalized CP. The lepton mixing is exactly the golden ratio pattern at leading order, and the mixing patterns of case III and case IV are reproduced after higher order corrections are considered
Appearance of vortices and monopoles in a decomposition of an SU(2) Yang–Mills field

A decomposition for the SU(2) Yang–Mills field in the low-energy limit is obtained by supposing that, in the low-energy limit, the field strength tensor of an SU(2) Yang–Mills field can be obtained by multiplying two parts, and , such that . is a space-time tensor and is an isotriplet unit vector field that gives the Abelian direction at each space-time point. By Abelianizing the field strength tensor , we show how (singular) vortices and monopoles can appear in the low-energy limit of SU(2) Yang–Mills theory. If the decomposition is valid on the boundary of the system, then we show that vortices with finite string tension can also appear. The interesting point is that we have started with a decomposed Yang–Mills field and we have ended up with a theory with an Abelian gauge field coupled to a scalar field. The effect of this scalar field on monopoles is also discussed
Spinning the fuzzy sphere

We construct various exact analytical solutions of the SO(3) BMN matrix model that correspond to rotating fuzzy spheres and rotating fuzzy tori. These are also solutions of Yang Mills theory compactified on a sphere times time and they are also translationally invariant solutions of the N = 1 * $$ \mathcal{N}={1}^{*} $$ field theory with a non-trivial chargedensity. The solutions we construct have a ℤ N symmetry, where N is the rank of the matrices. After an appropriate ansatz, we reduce the problem to solving a set of polynomial equations in 2 N real variables. These equations have a discrete set of solutions for each value of the angular momentum. We study the phase structure of the solutions for various values of N . Also the continuum limit where N → ∞, where the problem reduces to finding periodic solutions of a set of coupled differential equations. We also study the topology change transition from the sphere to the torus
Charged black holes with scalar hair

We consider a class of Einstein-Maxwell-Dilaton theories, in which the dilaton coupling to the Maxwell field is not the usual single exponential function, but one with a stationary point. The theories admit two charged black holes: one is the Reissner-Nordstrøm (RN) black hole and the other has a varying dilaton. For a given charge, the new black hole in the extremal limit has the same AdS 2 ×Sphere near-horizon geometry as the RN black hole, but it carries larger mass. We then introduce some scalar potentials and obtain exact charged AdS black holes. We also generalize the results to black p -branes with scalar hair
Double-soft limits of gluons and gravitons

The double-soft limit of gluon and graviton amplitudes is studied in four dimensions at tree level. In general this limit is ambiguous and we introduce two natural ways of taking it: a consecutive double-soft limit where one particle is taken soft before the other and a simultaneous limit where both particles are taken soft uniformly. All limits yield universal factorisation formulae which we establish by BCFW recursion relations down to the subleading order in the soft momentum expansion. These formulae generalise the recently discussed subleading single-soft theorems. While both types of limits yield identical results at the leading order, differences appear at the subleading order. Finally, we discuss double-scalar emission in N = 4 $$ \mathcal{N}=4 $$ super Yang-Mills theory. These results should be of use in establishing the algebraic structure of potential hidden symmetries in the quantum gravity and Yang-Mills S-matrix
Pure Spinors, Free Differential Algebras, and the Supermembrane

The lagrangian formalism for the supermembrane in any 11d supergravity
background is constructed in the pure spinor framework. Our gauge-fixed action
is manifestly BRST, supersymmetric, and 3d Lorentz invariant. The relation
between the Free Differential Algebras (FDA) underlying 11d supergravity and
the BRST symmetry of the membrane action is exploited. The "gauge-fixing" has a
natural interpretation as the variation of the Chevalley cohomology class
needed for the extension of 11d super-Poincare' superalgebra to M-theory FDA.
We study the solution of the pure spinor constraints in full detail
Influence of the exchange-correlation functional on the quasi-harmonic lattice dynamics of II-VI semiconductors

We perform a systematic comparison of the finite-temperature structure and properties of four bulk semiconductors (PbS, PbTe, ZnS, and ZnTe) predicted by eight popular exchange-correlation functionals from quasi-harmonic lattice-dynamics calculations. The performance of the functionals in reproducing the temperature dependence of a number of material properties, including lattice parameters, thermal-expansion coefficients, bulk moduli, heat capacities, and phonon frequencies, is evaluated quantitatively against available experimental data. We find that the phenomenological over- and under-binding characteristics of the local-density approximation and the PW91 and Perdew-Burke-Enzerhof (PBE) generalised-gradient approximation (GGA) functionals, respectively, are exaggerated at finite temperature, whereas the PBEsol GGA shows good general performance across all four systems. The Tao-Perdew-Staroverov-Scuseria (TPSS) and revTPSS meta-GGAs provide relatively small improvements over PBE, with the latter being better suited to calculating structural and dynamical properties, but both are considerably more computationally demanding than the simpler GGAs. The dispersion-corrected PBE-D2 and PBE-D3 functionals perform well in describing the lattice dynamics of the zinc chalcogenides, whereas the lead chalcogenides appear to be challenging for these functionals. These findings show that quasi-harmonic calculations with a suitable functional can predict finite-temperature structure and properties with useful accuracy, and that this technique can serve as a means of evaluating the performance of new functionals in the future
Getting Past the Language Gap: Innovations in Machine Translation

In this chapter, we will be reviewing state of the art machine translation systems, and will discuss innovative methods for machine translation, highlighting the most promising techniques and applications. Machine translation (MT) has benefited from a revitalization in the last 10 years or so, after a period of relatively slow activity. In 2005 the field received a jumpstart when a powerful complete experimental package for building MT systems from scratch became freely available as a result of the unified efforts of the MOSES international consortium. Around the same time, hierarchical methods had been introduced by Chinese researchers, which allowed the introduction and use of syntactic information in translation modeling. Furthermore, the advances in the related field of computational linguistics, making off-the-shelf taggers and parsers readily available, helped give MT an additional boost. Yet there is still more progress to be made. For example, MT will be enhanced greatly when both syntax and semantics are on board: this still presents a major challenge though many advanced research groups are currently pursuing ways to meet this challenge head-on. The next generation of MT will consist of a collection of hybrid systems. It also augurs well for the mobile environment, as we look forward to more advanced and improved technologies that enable the working of Speech-To-Speech machine translation on hand-held devices, i.e. speech recognition and speech synthesis. We review all of these developments and point out in the final section some of the most promising research avenues for the future of MT
Are all sovereigns equal? A test of the common determination of sovereign spreads in the euro area

With the outbreak of the Greek financial crisis in late 2009, spreads on Greek (and other) sovereigns reached unprecedented levels. Using a panel data of euro-area countries, we test whether the markets treated all euro-area countries in an equal manner over the period 1998:m1 to 2012:m6. An F test of the pooling assumptions suggests that Greece, Ireland, and Portugal were not part of the overall pool. In a separate test on the individual coefficients we find that the coefficients on these three countries moved in a similar direction away from the pool, suggesting that markets treated these three countries more acutely than the rest of the pool.Peer-reviewedPost-prin
Asymmetric Effects of Online Consumer Reviews

Consumers tend to seek heuristic information cues to simplify the amount of information involved in tourist decisions. Accordingly, star ratings in online reviews are a critical heuristic element of the perceived evaluation of online consumer information. The objective of this article is to assess the effect of review ratings on usefulness and enjoyment. The empirical application is carried out on a sample of 5,090 reviews of 45 restaurants in London and New York. The results show that people perceive extreme ratings (positive or negative) as more useful and enjoyable than moderate ratings, giving rise to a U-shaped line, with asymmetric effects: the size of the effect of online reviews depends on whether they are positive or negative
Big Data: A Normal Accident Waiting to Happen?

Widespread commercial use of the internet has significantly increased the volume and scope of data being collected by organisations. ‘Big data’ has emerged as a term to encapsulate both the technical and commercial aspects of this growing data collection activity. To date, much of the discussion of big data has centred upon its transformational potential for innovation and efficiency, yet there has been less reflection on its wider implications beyond commercial value creation. This paper builds upon normal accident theory (NAT) to analyse the broader ethical implications of big data. It argues that the strategies behind big data require organisational systems that leave them vulnerable to normal accidents, that is to say some form of accident or disaster that is both unanticipated and inevitable. Whilst NAT has previously focused on the consequences of physical accidents, this paper suggests a new form of system accident that we label data accidents. These have distinct, less tangible and more complex characteristics and raise significant questions over the role of individual privacy in a ‘data society’. The paper concludes by considering the ways in which the risks of such data accidents might be managed or mitigated
Transport Interchange and Local Urban Environment Integration

Among the different interchange design aspects, integrated land use and infrastructure planning is maybe one of the most problematic fields in practice, given that a joint transport and urban planning spills over the regular scope of action of interchange developers, whereas it involves the cooperation and agreement of various authorities. Not only this, but the very issue of land use-transport integration seems to be a long-standing mantra in planning and transport research, lacking scientific evidence. This paper is an output of an ongoing European research project called ?NODES - New tOols for Design and OpEration of Urban Transport InterchangeS?. Its aim is to start re-focusing the academic-scientific evidence on the question and to foresee a specific and practical framework to approach the problem. The underlying hypothesis is that the interchange could be a catalyst of life and security in the city
Assessing quality of volunteer crowdsourcing contributions: lessons from the Cropland Capture game

Volunteered geographic information (VGI) is the assembly of spatial information based on public input. While VGI has proliferated in recent years, assessing the quality of volunteer-contributed data has proven challenging, leading some to question the efficiency of such programs. In this paper, we compare several quality metrics for individual volunteers' contributions. the date were the product of the 'Cropland Capture' game, in which several thousand volunteers assessed 165,000 images for the presence of cropland over the course of 6 months. We compared agreement between volunteer ratings and an image's majority classification with volunteer self-agreement on repeated images and expert evaluations. We also examined the impact of experience and learning on performance. Volunteer self-agreement was nearly always higher than agreement with majority classifications, and much greater than agreement with expert validations although these metrics were all positively correlated. Volunteer quality showed a broad trend toward improvement with experience, but the highest accuracies were achieved by a handful of moderately active contributors, not the most active volunteers. Our results emphasize the importance of a universal set of expert-validated tasks as a gold standard for evaluating VGI quality
Spectroscopy of $^{26}$F

3 pages, 1 figure, accepted for publication in Physical Review C, expérience GANIL/SISSI/SPEGThe structure of the weakly-bound $^{26}_{\;\;9}$F$_{17}$ odd-odd nucleus, produced from $^{27,28}$Na nuclei, has been investigated at GANIL by means of the in-beam $\gamma$-ray spectroscopy technique. A single $\gamma$-line is observed at 657(7)~keV in $^{26}_{9}$F which has been ascribed to the decay of the excited J=$2^+$ state to the J=1$^+$ ground state. The possible presence of intruder negative parity states in $^{26}$F is also discussed
Neutron-induced cross sections of short-lived nuclei via the surrogate reaction method

The conference proceedings will be published (on-line) at the EPJ Web of Conferences.Neutron-induced capture cross sections of short-lived nuclei are of great importance in many areas: fundamental nuclear physics, nuclear astrophysics and nuclear applications, such as nuclear reactors. However, very often the high radioactivity of the samples makes the direct measurement of these cross sections extremely difficult. The surrogate reaction method [1] is an indirect way of determining neutron-induced cross sections for reactions that proceed through a compound nucleus. In this method, the decaying nucleus of the desired reaction is produced via a transfer or an inelastic scattering reaction (figure 1). This technique presents the advantage that the target material can be stable or less radioactive than the material required for a neutron-induced measurement. Nevertheless, a significant question in the use of the surrogate reaction method lies in the difference between the spin and parity population in the neutron-induced and surrogate reactions. The CENBG collaboration has successfully applied this technique to determine the neutron-induced fission cross sections of several short-lived nuclei such as 233Pa[2], 242;243Cm and 241Am[3]. The results are in very good agreement with neutron-induced data. We are currently investigating whether this powerful technique can also be used to determine radiative capture cross sections. For this purpose, we have studied the transfer reactions 174Yb(3He,pg)176Lu and 174Yb(3He,4Heg)173Yb as surrogates for the 175Lu(n,g) and 172Yb(n,g) reactions, respectively. The g probabilities obtained in our experiment show clear discrepancies with already existing neutroninduced data. In this contribution we will present the experimental set-up and the data analysis. Then, we will focus on the origin of these discrepencies. Perspectives for the surrogate method applied to capture cross sections will be discussed
Second-order virial expansion for an atomic gas in a harmonic waveguide

International audienceThe virial expansion for cold two-component Fermi and Bose atomic gases is considered in the presence of a waveguide and in the vicinity of a Feshbach resonance. The interaction between atoms and the coupling with the Feshbach molecules is modeled using a quantitative separable two-channel model. The scattering phase-shift in an atomic waveguide is defined. This permits us to extend the Beth-Uhlenbeck formula for the second-order virial coefficient to this inhomogeneous case
Customer attractiveness, supplier satisfaction and preferred customer status: Introduction, definitions and an overarching framework

International audienceIndustrial markets are frequently characterized by an oligopolistic market structure. As a result, suppliers may become highly selective with respect to decisions that involve collaborating with certain customers. Buying firms must therefore be more attractive than their rivals to obtain opportunities to collaborate with these selective suppliers. This apparently counterintuitive inversion of the classical marketing approach (that is, relationships that involve buyers competing for suppliers rather than the other way round) constitutes the foundation of the special issue that is introduced in this paper. In this paper, we present key terms and propose a model of preferred customership that uses a social exchange perspective to link customer attractiveness, supplier satisfaction and preferred customer status. The papers that contribute to this special issue are introduced within the context of this framework. Finally, this paper concludes with suggestions for future research directions
Global Contests in the Production of Business Knowledge : : Regional Centres and Individual Business Schools

International audienceDrawing on institutional theory, the global production of business research is analysed by examining the system of written outputs using one of the largest databases of journal papers ever assembled, covering over 65,000 articles produced by more than 54,000 authors from over 8,000 different institutions across the period 1992-2005. We begin by pointing out how the US business schools pioneered the modern institutional system of undertaking and disseminating research that involves the intertwining of and university business schools and journals. While Wharton and Harvard are still the leading universities globally, their crowns are slipping, together with the position of the US generally. We observe the greatest challenges to the existing order as coming from European and Asian institutions that have either copied, or been inspired to innovate by adapting, the US system. London Business School, Erasmus, INSEAD and Tilburg are threatening to topple leading US universities in the undertaking of research, and other European and Asian institutions are close behind