Leading large-x logarithms of the quark-gluon contributions to inclusive Higgs-boson and lepton-pair production

We present all-order expressions for the leading double-logarithmic threshold contributions to the quark-gluon coefficient functions for inclusive Higgs-boson production in the heavy top-quark limit and for Drell-Yan lepton-pair production. These results have been derived using the structure of the unfactorized cross sections in dimensional regularization and the large-x resummation of the gluon-quark and quark-gluon splitting functions. The resummed coefficient functions, which are identical up to colour factor replacements, are similar to their counterparts in deep-inelastic scattering but slightly more complicated.Comment: 8 pages, LaTeX, 1 figure (.eps). DESY address until 31 August 201

On the next-to-next-to-leading order QCD corrections to heavy-quark production in deep-inelastic scattering

The contribution of quarks with masses m >> Lambda_QCD is the only part of the structure functions in deep-inelastic scattering (DIS) which is not yet known at the next-to-next-to-leading order (NNLO) of perturbative QCD. We present improved partial NNLO results for the most important structure function F_2(x,Q^2) near the partonic threshold, in the high-energy (small-x) limit and at high scales Q^2 >> m^2; and employ these results to construct approximations for the gluon and quark coefficient functions which cover the full kinematic plane. The approximation uncertainties are carefully investigated, and found to be large only at very small values, x smaller about 10^-3, of the Bjorken variable.Comment: 62 pages, LaTeX, 13 figures. Erratum for eq.(B.7

Optical Module Front-End for a Neutrino Underwater Telescope: PMT interface

A proposal for a new system to capture signals in the Optical Module (OM) of an Underwater Neutrino Telescope is described. It concentrates on the problem of power consumption in relation to precision. In particular, a solution for the interface between the photomultiplier (PMT) and the front-end electronics is presented

Optimisation of bitumen emulsion properties for ballast stabilisation

: Ballasted track, while providing economical and practical advantages, is associated with high costs and material consumption due to frequent maintenance. More sustainable alternatives to conventional ballasted trackbeds should therefore aim at extending its durability, particularly considering ongoing increases in traffic speed and loads. In this regard, the authors have investigated a solution consisting of bitumen stabilised ballast (BSB), designed to be used for new trackbeds as well as in reinforcing existing ones. This study presents the idea behind the technology and then focuses on a specific part of its development: the optimisation of bitumen emulsion properties and dosage in relation to ballast field conditions. Results showed that overall bitumen stabilisation improved ballast resistance to permanent deformation by enhancing stiffness and damping properties. Scenarios with higher dosage of bitumen emulsion, higher viscosity, quicker setting behaviour, and harder base bitumen seem to represent the most desirable conditions to achieve enhanced in-field performanc

Evaluating degree of compaction of levees using cone penetration testing

Permeability and strength parameters of compacted soils (i.e., levees as well as other earthworks) may be correlated to the degree of compaction. Since the use of conventional and recent testing methods for the assessment of density and water content of earthworks, under construction, cannot be applied to existing levees, an expeditious and accurate method for the assessment of the degree of compaction of existing and new levees, after their completion, appears extremely useful. The purpose of this research is to develop a simple tool for the assessment of the degree of compaction of "compacted", partially saturated, fine grained soils. This paper illustrates the proposed method which combines in situ testing such as electric CPT or CPTu with laboratory penetration testing performed with a mini-cone in a calibration chamber (CC). © 2018, Taiwan Geotechnical Society

Evaluation of the degree of compaction of levees by a CPT- based method

Permeability and strength parameters of compacted soils may be correlated to their degree of compaction. Unfortunately, the use of conventional and recent testing methods for the assessment of density and water content of earthworks under construction cannot be applied to existing levees. Therefore, the development of an expeditious and accurate method for the assessment of the degree of compaction of existing and new levees, after their completion, appears extremely useful. The purpose of this research is to develop a simple tool for the assessment of the degree of compaction of “compacted”, partially saturated, fine grained soils. The proposed method combines in situ testing like electric CPT or CPTu with laboratory penetration testing performed with a mini–cone in a calibration chamber

Augmented GNSS Differential Corrections Minimum Mean Square Error Estimation Sensitivity to Spatial Correlation Modeling Errors

Railway signaling is a safety system that has evolved over the last couple of centuries towards autonomous functionality. Recently, great effort is being devoted inthis field, towards the use and exploitation of Global Navigation Satellite System (GNSS)signals and GNSS augmentation systems in view of lower railway track equipments andmaintenance costs, that is a priority to sustain the investments for modernizing the local andregional lines most of which lack automatic train protection systems and are still manuallyoperated. The objective of this paper is to assess the sensitivity of the Linear Minimum MeanSquare Error (LMMSE) algorithm to modeling errors in the spatial correlation function thatcharacterizes true pseudorange Differential Corrections (DCs). This study is inspired bythe railway application; however, it applies to all transportation systems, including the roadsector, that need to be complemented by an augmentation system in order to deliver accurateand reliable positioning with integrity specifications. A vector of noisy pseudorange DCmeasurements are simulated, assuming a Gauss-Markov model with a decay rate parameterinversely proportional to the correlation distance that exists between two points of a certainenvironment. The LMMSE algorithm is applied on this vector to estimate the true DC, andthe estimation error is compared to the noise added during simulation. The results show thatfor large enough correlation distance to Reference Stations (RSs) distance separation ratiovalues, the LMMSE brings considerable advantage in terms of estimation error accuracy and precision. Conversely, the LMMSE algorithm may deteriorate the quality of the DCmeasurements whenever the ratio falls below a certain threshold

A new peer-to-peer aided acquisition approach exploiting C/N0 aiding

The aim of this paper is to present an acquisition strategy for Global Navigation Satellite System (GNSS) signals exploiting aiding information provided by GNSS receivers in a Peer-to-Peer (P2P) positioning system. This work sheds light on the benefits of sharing information regarding the received satellite signal power: the Carrier-to-Noise density ratio (C/N0) estimated by aiding peers relatively close to each other, is used to optimize signal acquisition capability in terms of detection performance as well as Mean Acquisition Time (MAT). The proposed approach has been validated and assessed using real data collected with an experimental setup in light indoor conditions and by means of simulations. The performance obtained has also been compared with an Assisted-GNSS (A-GNSS) like acquisition strategy, showing the benefits of the availability of C/N0 aiding information in terms of MAT. ©2010 IEEE