Hasil untuk "physics.geo-ph"

B. Bjellqvist, K. Ek, P. Righetti et al.

M. Kosmulski

S. Khanal, Wen‐Hsing Chen, Ling Li et al.

E. Svastova, A. Hulikova, Monika Rafajová et al.

R. A. French, A. Jacobson, Bojeong Kim et al.

J. Wootton, C. Pfister, James D. Forester et al.

I. Mainie, R. Tutuian, S. Shay et al.

C. Hunte, E. Screpanti, M. Venturi et al.

Francisco de Melo Viríssimo

This paper introduces Low-EFFourth (LEF4), a MATLAB-based computational framework designed for generating and studying multilevel model ensembles in continuous dynamical systems. Initially developed to address questions in climate modelling, LEF4 can also be used in other disciplines such as epidemiology, economics, and engineering, with minimal modifications to the code. The framework provides an efficient and flexible approach for investigating uncertainties arising from initial conditions, model parameters, numerical methods, and model formulation. This preprint serves as a formal reference for the LEF4 codebase and provides a concise technical and conceptual overview of its purpose, structure, applications and development pipeline.

Jutaek Nam, Nayoun Won, Ho Jin et al.

Xin Zhang, S. Rehm, Marina M. Safont-Sempere et al.

G. Aad, B. Abbott, J. Abdallah et al.

A measurement of the production processes of the recently discovered Higgs boson is performed in the two-photon final state using 5.4 fb$^{-1}$ of proton-proton collisions data at $\sqrt{s}=7$ TeV and 20.3 fb$^{-1}$ at $\sqrt{s}=8$ TeV collected by the ATLAS detector at the Large Hadron Collider. The number of observed Higgs boson decays to diphotons divided by the corresponding Standard Model prediction, called the signal strength, is found to be $\mu = 1.17 \pm 0.27$ at the value of the Higgs boson mass measured by ATLAS, $m_{H}$ = 125.4 GeV. The analysis is optimized to measure the signal strengths for individual Higgs boson production processes at this value of $m_{H}$. They are found to be $\mu_{\mathrm{ggF}} = 1.32 \pm 0.38$, $\mu_{\mathrm{VBF}} = 0.8 \pm 0.7$, $\mu_{{WH}} = 1.0 \pm 1.6 $, $\mu_{{ZH}} = 0.1 ^{+3.7}_{-0.1} $, $\mu_{{t\bar{t}H}} = 1.6 ^{+2.7}_{-1.8} $, for Higgs boson production through gluon fusion, vector-boson fusion, and in association with a $W$ or $Z$ boson or a top-quark pair, respectively. Compared with the previously published ATLAS analysis, the results reported here also benefit from a new energy calibration procedure for photons and the subsequent reduction of the systematic uncertainty on the diphoton mass resolution. No significant deviations from the predictions of the Standard Model are found.

G. Askarieh, M. Hedhammar, K. Nordling et al.

G. Aad, A. Kupco, P. Davison et al.

The ATLAS detector at the Large Hadron Collider is used to search for high-mass resonances decaying to dielectron or dimuon final states. Results are presented from an analysis of proton-proton (pp) collisions at a center-of-mass energy of 8 TeV corresponding to an integrated luminosity of 20.3  fb−1 in the dimuon channel. A narrow resonance with Standard Model Z couplings to fermions is excluded at 95% confidence level for masses less than 2.79 TeV in the dielectron channel, 2.53 TeV in the dimuon channel, and 2.90 TeV in the two channels combined. Limits on other model interpretations are also presented, including a grand-unification model based on the E6 gauge group, Z∗ bosons, minimal Z' models, a spin-2 graviton excitation from Randall-Sundrum models, quantum black holes, and a minimal walking technicolor model with a composite Higgs boson.

Leonid Petrov, Johnathan York, Joe Skeens et al.

We present here a concept of measuring local ties between collocated GNSS and VLBI stations using the microwave technique that effectively transforms a GNSS receiver to an element of a VLBI network. This is achieved by modifying the signal chain that allows to transfer voltage of the GNSS antenna to a digitizer via a coaxial cable. We discuss the application of this technique to local tie measurement. We have performed observations with a GNSS antenna and FD-VLBA radiotelescope and detected a strong interferometric signal from both radiogalaxies and GNSS satellites.

Balázs Havasi-Tóth, Eszter Fehér

We propose a geometrically motivated mathematical model which reveals the key features of coastal and fluvial fragment shape evolution from the earliest stages of the abrasion. Our \textit{collisional polygon model} governs the evolution through an ordinary differential equation (ODE) that determines the rounding rate of initially sharp corners in the function of the size reduction. As an approximation, the basic structure of our model adopts the concept of Bloore's partial differential equation (PDE) in terms of the curvature dependent local collisional frequency. We tested our model under various conditions and made comparisons with the predictions of Bloore's PDE. Moreover, we applied the model to discover and quantify the mathematical conditions corresponding to typical and special shape evolution. By further extending our model to investigate the self-dual and mixed cases, we outline a possible explanation of the long-term preservation of initial pebble shape characteristics.

Wei Chen, F. Meng, Ru Cheng et al.

G. Malin, R. Morris, Khalid Khan

Objective To evaluate the association between umbilical cord pH at birth and long term outcomes. Design Systematic review and meta-analysis. Data sources Medline (1966-August 2008), Embase (1980-August 2008), the Cochrane Library (2008 issue 8), and Medion, without language restrictions; reference lists of selected articles; and contact with authors. Study selection Studies in which cord pH at birth was compared with any neonatal or long term outcome. Cohort and case-control designs were included. Results 51 articles totalling 481 753 infants met the selection criteria. Studies varied in design, quality, outcome definition, and results. Meta-analysis carried out within predefined groups showed that low arterial cord pH was significantly associated with neonatal mortality (odds ratio 16.9, 95% confidence interval 9.7 to 29.5, I2=0%), hypoxic ischaemic encephalopathy (13.8, 6.6 to 28.9, I2=0%), intraventricular haemorrhage or periventricular leucomalacia (2.9, 2.1 to 4.1, I2=0%), and cerebral palsy (2.3, 1.3 to 4.2, I2=0%). Conclusions Low arterial cord pH showed strong, consistent, and temporal associations with clinically important neonatal outcomes that are biologically plausible. These data can be used to inform clinical management and justify the use of arterial cord pH as an important outcome measure alongside neonatal morbidity and mortality in obstetric trials.

J. Rousk, P. Brookes, E. Bååth

S. Parks, J. Chiche, J. Pouysségur