pinecone/core-2020-05-10-deduplication huggingface dataset:
Startup valuation by venture capitalists: an empirical study

International audienceHow to value a new venture is critical in entrepreneurial financing. This article develops an integrated theoretical framework to examine whether venture capitalists' valuation of a new venture can be explained by factors identified in the strategy theories as important to firm performance. Empirical results from the analyses of 184 rounds of early-stage venture capital investments in 102 new ventures support the central proposition that venture capitalists do take into consideration those factors that are important to firm performance in their valuation of new ventures. More specifically, this article finds that attractiveness of the industry, the quality of the founder and top management team, as well as external relationships of a new venture significantly and positively affect its valuation by venture capitalists when it seeks venture capital financing in its early stages of development. These empirical findings help to establish an initial linkage between the well-developed theories in strategic management and underresearched venture capital valuation practice. It brings more theoretical rigor to the venture capital investment literature by introducing a systematic approach to identify and measure factors important to new venture valuation. It explores a possibility to develop a supplementary method to value an early-stage new venture when extant valuation methods fail to yield consistent results because these methods require accounting information that a new venture typically cannot provide
Rural residents' opinions about second home owners' pursuit of own interests in the host community

-Many second home owners demand rights, benefits, and influence in their host community, and the article examines how second home owners in pursuit of their interests can gain acceptance among local residents. The analysis is based on interviews with local residents in four rural Norwegian second home municipalities. The findings show that local residents’ attitudes towards second home owners’ pursuit of their own interests in the host community depend to a large degree upon the residents’ perceptions of the outcome of second home tourism in their municipality. Local residents can tolerate second home owners’ demands as long as the second home owners satisfy some of the community's significant economic-material or social needs. When second home owners make demands while their presence does not bring any evident benefits to the host community they are perceived as trying to take without giving. Based on these findings, the author argues that it is not second home owners’ (objective) otherness from locals that is the main problem in cases of a conflictual climate between the two parties. Rather, it is the local structural context that constitutes the main problem if it does not make it possible for second home owners to contribute to the host community
Brunel-Dominated Proton Acceleration with a Few-Cycle Laser Pulse

International audienceExperimental measurements of backward accelerated protons are presented. The beam is produced when an ultrashort (5 fs) laser pulse, delivered by a kHz laser system, with a high temporal contrast (10 8), interacts with a thick solid target. Under these conditions, proton cutoff energy dependence with laser parameters, such as pulse energy, polarization (from p to s), and pulse duration (from 5 to 500 fs), is studied. Theoretical model and two-dimensional particle-in-cell simulations, in good agreement with a large set of experimental results, indicate that proton acceleration is directly driven by Brunel electrons, in contrast to conventional target normal sheath acceleration that relies on electron thermal pressure
The one-dimensional Lyα forest power spectrum          from BOSS

International audienceWe have developed two independent methods for measuring the one-dimensional power          spectrum of the transmitted flux in the Lyman-α forest. The first method          is based on a Fourier transform and the second on a maximum-likelihood estimator. The two          methods are independent and have different systematic uncertainties. Determination of the          noise level in the data spectra was subject to a new treatment, because of its significant          impact on the derived power spectrum. We applied the two methods to 13 821 quasar spectra          from SDSS-III/BOSS DR9 selected from a larger sample of over 60 000 spectra on the basis          of their high quality, high signal-to-noise ratio (S/N), and good spectral resolution. The          power spectra measured using either approach are in good agreement over all twelve          redshift bins from ⟨z⟩ = 2.2 to ⟨z⟩ = 4.4, and          scales from 0.001 km s-1 to 0.02 km s-1. We determined the          methodological andinstrumental systematic uncertainties of our measurements. We provide a          preliminary cosmological interpretation of our measurements using available hydrodynamical          simulations. The improvement in precision over previously published results from SDSS is a          factor 2–3 for constraints on relevant cosmological parameters. For a ΛCDM model and using          a constraint on H0 that encompasses measurements based on the          local distance ladder and on CMB anisotropies, we infer          σ8 = 0.83 ± 0.03 and          ns = 0.97 ± 0.02 based on H i absorption in the range            2.1 < z < 3.7
Are the orbital poles of binary stars in the solar          neighbourhood anisotropically distributed?

International audienceWe test whether or not the orbital poles of the systems in the solar neighbourhood are          isotropically distributed on the celestial sphere. The problem is plagued by the ambiguity          on the position of the ascending node. Of the 95 systems closer than 18 pc from the Sun          with an orbit in the 6th Catalogue of Orbits of Visual Binaries, the pole ambiguity could          be resolved for 51 systems using radial velocity collected in the literature and CORAVEL          database or acquired with the HERMES/Mercator spectrograph. For several          systems, we can correct the erroneous nodes in the 6th Catalogue of Orbits and obtain new          combined spectroscopic/astrometric orbits for seven systems [WDS 01083+5455Aa,Ab;          01418+4237AB; 02278+0426AB (SB2); 09006+4147AB (SB2); 16413+3136AB; 17121+4540AB;          18070+3034AB]. We used of spherical statistics to test for possible anisotropy. After          ordering the binary systems by increasing distance from the Sun, we computed the          false-alarm probability for subsamples of increasing sizes, from N = 1 up to the full sample          of 51 systems. Rayleigh-Watson and Beran tests deliver a false-alarm probability of 0.5%          for the 20 systems closer than 8.1 pc. To evaluate the robustness of this conclusion, we          used a jackknife approach, for which we repeated this procedure after removing one system          at a time from the full sample. The false-alarm probability was then found to vary between          1.5% and 0.1%, depending on which system is removed. The reality of the deviation from          isotropy can thus not be assessed with certainty at this stage, because only so few          systems are available, despite our efforts to increase the sample. However, when          considering the full sample of 51 systems, the concentration of poles toward the Galactic          position l =            46.0°, b =            37°, as observed in the 8.1 pc sphere, totally vanishes (the          Rayleigh-Watson false-alarm probability then rises to 18%)
Ion cyclotron resonance heating systems upgrade toward high power and CW operations in WEST

International audienceThe design of the WEST (Tungsten-W Environment in Steady-state Tokamak) Ion cyclotron resonance heating antennas is based on a previously tested conjugate-T Resonant Double Loops prototype equipped with internal vacuum matching capacitors. The design and construction of three new WEST ICRH antennas are being carried out in close collaboration with ASIPP, within the framework of the Associated Laboratory in the fusion field between IRFM and ASIPP. The coupling performance to the plasma and the load-tolerance have been improved, while adding Continuous Wave operation capability by introducing water cooling in the entire antenna. On the generator side, the operation class of the high power tetrodes is changed from AB to B in order to allow high power operation (up to 3 MW per antenna) under higher VSWR (up to 2:1). Reliability of the generators is also improved by increasing the cavity breakdown voltage. The control and data acquisition system is also upgraded in order to resolve and react on fast events, such as ELMs. A new optical arc detection system comes in reinforcement of the V r /V f and SHAD systems
Negative Hall coefficient of ultrathin niobium in Si/Nb/Si trilayers

International audienceStructural and transport properties of thin Nb layers in Si/Nb/Si trilayers with Nb layer thickness d from 1.1 nm to 50 nm have been studied. With decreasing thickness, the structure of the Nb layer changes from polycrystalline to amorphous at d 3.3 nm, while the superconducting temperature T c monotonically decreases. The Hall coefficient varies with d systematically but changes sign into negative in ultrathin films with d < 1.6 nm. The influence of boundary scattering on the relaxation rate of carriers, and band broadening in the amorphous films, may contribute to this effect
Comparison of two analysis methods for nuclear reaction measurements of 12C +12C interactions at 95 MeV/u for hadrontherapy

During therapeutic treatment with heavier ions like carbon, the beam undergoes nuclear fragmentation and secondary light charged particles, in particular protons and alpha particles, are produced. To estimate the dose deposited into the tumors and the surrounding healthy tissues, the accuracy must be higher than (±3% and±1 mm). Therefore, measurements are performed to determine the double differential cross section for different reactions. In this paper, the analysis of data from 12C +12C reactions at 95 MeV/u are presented. The emitted particles are detected with ΔEthin−ΔEthick−E telescopes made of a stack of two silicon detectors and a CsI crystal. Two different methods are used to identify the particles. One is based on graphical cuts onto the ΔE−E maps, the second is based on the so-called KaliVeda method using a functional description of ΔE versus E. The results of the two methods will be presented in this paper as well as the comparison between both
Time-Frequency Mixed-Norm Estimates: Sparse M/EEG imaging with non-stationary source activations

International audienceMagnetoencephalography (MEG) and electroencephalography (EEG) allow functional brain imaging with high temporal resolution. While solving the inverse problem independently at every time point can give an image of the active brain at every millisecond, such a procedure does not capitalize on the temporal dynamics of the signal. Linear inverse methods (Minimum-norm, dSPM, sLORETA, beamformers) typically assume that the signal is stationary: regularization parameter and data covariance are independent of time and the time varying signal-to-noise ratio (SNR). Other recently proposed non-linear inverse solvers promoting focal activations estimate the sources in both space and time while also assuming stationary sources during a time interval. However such an hypothesis only holds for short time intervals. To overcome this limitation, we propose time-frequency mixed-norm estimates (TF-MxNE), which use time-frequency analysis to regularize the ill-posed inverse problem. This method makes use of structured sparse priors defined in the time-frequency domain, offering more accurate estimates by capturing the non-stationary and transient nature of brain signals. State-of-the-art convex optimization procedures based on proximal operators are employed, allowing the derivation of a fast estimation algorithm. The accuracy of the TF-MxNE is compared to recently proposed inverse solvers with help of simulations and by analyzing publicly available MEG datasets
Dislocation dynamics simulations with climb: kinetics of dislocation loop coarsening controlled by bulk diffusion

International audienceDislocation climb mobilities, assuming vacancy bulk diffusion, are derived and implemented in dislocation dynamics simulations to study the coarsening of vacancy prismatic loops in fcc metals. When loops cannot glide, the comparison of the simulations with a coarsening model based on the line tension approximation shows a good agreement. Dislocation dynamics simulations with both glide and climb are then performed. Allowing for glide of the loops along their prismatic cylinders leads to faster coarsening kinetics, as direct coalescence of the loops is now possible
Bimodal behavior of the heaviest fragment distribution in projectile fragmentation

5 pages, submitted to PRLInternational audienceThe charge distribution of the heaviest fragment detected in the decay of quasi-projectiles produced in intermediate energy heavy-ion collisions has been observed to be bimodal. This feature is expected as a generic signal of phase transition in non-extensive systems. In this paper we present new analyses of experimental data from Au on Au collisions at 60, 80 and 100 MeV/nucleon showing that bimodality is largely independent of the data selection procedure, and of entrance channel effects. An estimate of the latent heat of the transition is extracted
Cassini/VIMS hyperspectral observations of the HUYGENS landing site on Titan

International audienceTitan is one of the primary scientific objectives of the NASA ESA ASI Cassini Huygens mission. Scattering by haze particles in Titan's atmosphere and numerous methane absorptions dramatically veil Titan's surface in the visible range, though it can be studied more easily in some narrow infrared windows. The Visual and Infrared Mapping Spectrometer (VIMS) instrument onboard the Cassini spacecraft successfully imaged its surface in the atmospheric windows, taking hyperspectral images in the range 0.4 5.2 μm. On 26 October (TA flyby) and 13 December 2004 (TB flyby), the Cassini Huygens mission flew over Titan at an altitude lower than 1200 km at closest approach. We report here on the analysis of VIMS images of the Huygens landing site acquired at TA and TB, with a spatial resolution ranging from 16 to14.4 km/pixel. The pure atmospheric backscattering component is corrected by using both an empirical method and a first-order theoretical model. Both approaches provide consistent results. After the removal of scattering, ratio images reveal subtle surface heterogeneities. A particularly contrasted structure appears in ratio images involving the 1.59 and 2.03 μm images north of the Huygens landing site. Although pure water ice cannot be the only component exposed at Titan's surface, this area is consistent with a local enrichment in exposed water ice and seems to be consistent with DISR/Huygens images and spectra interpretations. The images show also a morphological structure that can be interpreted as a 150 km diameter impact crater with a central peak
A general fictitious domain method with immersed jumps and multilevel nested structured meshes

International audienceThis study addresses a new fictitious domain method for elliptic problems in order to handle general and possibly mixed embedded boundary conditions (E.B.C.): Robin, Neumann and Dirichlet conditions on an immersed interface. The main interest of this fictitious domain method is to use simple structured meshes, possibly uniform Cartesian nested grids, which do not generally fit the interface but define an approximate one. A cell-centered finite volume scheme with a non-conforming structured mesh is derived to solve the set of equations with additional algebraic transmission conditions inking both flux and solution jumps through the immersed approximate interface. Hence, a local correction is devised to take account of the relative surface ratios in each control volume for the Robin or Neumann boundary condition. Then, the numerical scheme conserves the first-order accuracy with respect to the mesh step. This opens the way to combine the E.B.C. method with a multilevel mesh refinement solver to increase the precision in the vicinity of the interface. Such a fictitious domain method is very efficient: the L2- and L1-norm errors vary like O(hl*) where hl* is the grid step of the finest refinement level around the interface until the residual first-order discretization error of the non-refined zone is reached. The numerical results reported here for convection–diffusion problems with Dirichlet, Robin and mixed (Dirichlet and Robin) boundary conditions confirm the expected accuracy as well as the performances of the present method
Residence time, mineralization processes and groundwater origin within a carbonate coastal aquifer with a thick unsaturated zone

International audienceThis study aims at establishing groundwater residence times, identifying mineralization processes and determining groundwater origins within a carbonate coastal aquifer with thick unsaturated zone and lying on a granitic depression. A multi-tracer approach (major ions, SiO2, Br-, Ba+, Sr2+, 18O, 2H, 13C, 3H, Ne, Ar) combined with a groundwater residence time determination using CFCs and SF6 allows defining the global setting of the study site. A typical mineralization conditioned by the sea sprays and the carbonate matrix helped to validate the groundwater weighted residence times from using a binary mixing model. Terrigenic SF6 excesses have been detected and quantified, which permits to identify a groundwater flow from the surrounding fractured granites towards the lower aquifer principally. The use of CFCs and SF6 as a first hydrogeological investigation tool is possible and very relevant despite the thick unsaturated zone and the hydraulic connexion with a granitic environment
Competition between CoOx and CoPt phases in Pt/Co/AlOx semi tunnel junctions

10 pagesInternational audienceWe report on the evolution of the structure and composition of a Pt(3 nm)/Co(0.6 nm)/AlOx(2 nm) trilayer sputtered on Si/SiO2 under oxidation and annealing processes by combined x-ray reflectivity and x-ray absorption studies. We describe the progressive and inhomogeneous oxidation of the layers by increasing the oxidation time. Before annealing, the layers have lower density than bulk samples and noticeable roughness. After thermal annealing, a significant improvement of the quality of the alumina layer goes along with the formation of a CoPt alloy that reduces the number of Co-O bonds. These structural outcomes clarify the evolution of the magnetic and transport properties reported at room temperature in these samples
Reaction chain modeling of denitrification reactions during a push-pull test

International audienceField quantitative estimation of reaction kinetics is required to enhance our understanding of biogeochemical reactions in aquifers. We extended the analytical solution developed by Haggerty et al. (1998) to model an entire 1st order reaction chain and estimate the kinetic parameters for each reaction step of the denitrification process. We then assessed the ability of this reaction chain to model biogeochemical reactions by comparing it with experimental results from a push-pull test in a fractured crystalline aquifer (Ploemeur, French Brittany). Nitrates were used as the reactive tracer, since denitrification involves the sequential reduction of nitrates to nitrogen gas through a chain reaction (NO3− → NO2− → NO → N2O → N2) under anaerobic conditions. The kinetics of nitrate consumption and by-product formation (NO2−, N2O) during autotrophic denitrification were quantified by using a reactive tracer (NO3−) and a non-reactive tracer (Br−). The formation of reaction by-products (NO2−, N2O, N2) has not been previously considered using a reaction chain approach. Comparison of Br− and NO3− breakthrough curves showed that 10% of the injected NO3− molar mass was transformed during the 12 h experiment (2% into NO2−, 1% into N2O and the rest into N2 and NO). Similar results, but with slower kinetics, were obtained from laboratory experiments in reactors. The good agreement between the model and the field data shows that the complete denitrification process can be efficiently modeled as a sequence of first order reactions. The 1st order kinetics coefficients obtained through modeling were as follows: k1 = 0.023 h− 1, k2 = 0.59 h− 1, k3 = 16 h− 1, and k4 = 5.5 h− 1. A next step will be to assess the variability of field reactivity using the methodology developed for modeling push-pull tracer tests
From Chaos to Randomness via Geometric Undersampling

Editors: Witold Jarczyk, Daniele Fournier-Prunaret, João Manuel Goncalves CabralWe propose a new mechanism for undersampling chaotic numbers obtained by the ring coupling of one-dimensional maps. In the case of 2 coupled maps this mechanism allows the building of a PRNG which passes all NIST Test. This new geometric undersampling is very effective for generating 2 parallel streams of pseudo-random numbers, as we show, computing carefully their properties, up to sequences of one trillion consecutives iterates of the ring coupled mapping which provides more than 33.5 billions random numbers in very short time
Owen Fracture Zone: The Arabia-India plate boundary unveiled

International audienceWe surveyed the Owen Fracture Zone at the boundary between the Arabia and India plates in the NW Indian Ocean using a high-resolution multibeam echo-sounder (Owen cruise, 2009) for search of active faults. Bathymetric data reveal a previously unrecognized submarine fault scarp system running for over 800 km between the Sheba Ridge in the Gulf of Aden and the Makran subduction zone. The primary plate boundary structure is not the bathymetrically high Owen Ridge, but is instead a series of clearly delineated strike-slip fault segments separated by several releasing and restraining bends. Despite an abundant sedimentary supply by the Indus River flowing from the Himalaya, fault scarps are not obscured by recent deposits and can be followed over hundreds of kilometres, pointing to very active tectonics. The total strike-slip displacement of the fault system is 10-12 km, indicating that it has been active for the past ~3 to 6 Ma if its current rate of motion of 3±1 mm yr−1 has remained stable. We describe the geometry of this recent fault system, including a major pull-apart basin at the latitude 20°N, and we show that it closely follows an arc of small circle centred on the Arabia-India pole of rotation, as expected for a transform plate boundary
How are wages set in Beijing

International audienceChina's export performance over the past fifteen years has been phenomenal. Is this performance going to last? Wages are rising rapidly but a population in excess of one billion represents a large reservoir of labor. Firms in export-intensive provinces may draw on this reservoir to increase competition in their labor market and keep wages low for many years to come. We develop a wage equation from a New Economic Geography model to capture the upward pressure from national and international demand and downward pressure from migration. Using panel data at the province level, we find that migration has moderately slowed down Chinese wage increase over the period 1995-2007