The LHC Grid Challenge

Proc. on Lin

CP violation and rare B-decays at ATLAS

The primary goal of ATLAS experiment at LHC is to search for the Higgs boson and supersymmetry. However, other physics sectors like CP violation and rare B-decays, can be explored. The full proper-time and angular analyses allow several parameters of physics interest to be investigated using the $B_s^0\to J/\psi\phi$ decays. In the $B_s$ sector measurements, special emphasis is made on the $\Delta M_s$. ATLAS will be able to reach $\Delta M_s$-regions that are today covered by the fit combining all existing data. By investigating rare decays of beauty mesons and baryons, ATLAS will be capable of performing sensitive tests of physics phenomena beyond the Standard Model. The effort concentrate especially on those rare B decays that can be identified already at the first and second trigger level

Le calcul scientifique des expériences LHC. La grille de calcul LCG

Rapport commandé par le ministère de la recherche: "Recueil d'études de cas permettant d'aborder les principaux enjeux soulevés par les données numériques de la recherche et leurs infrastructures

Nature-inspired Cuckoo Search Algorithm for Side Lobe Suppression in a Symmetric Linear Antenna Array

In this paper, we proposed a newly modified cuckoo search (MCS) algorithm integrated with the Roulette wheel selection operator and the inertia weight controlling the search ability towards synthesizing symmetric linear array geometry with minimum side lobe level (SLL) and/or nulls control. The basic cuckoo search (CS) algorithm is primarily based on the natural obligate brood parasitic behavior of some cuckoo species in combination with the Levy flight behavior of some birds and fruit flies. The CS metaheuristic approach is straightforward and capable of solving effectively general N-dimensional, linear and nonlinear optimization problems. The array geometry synthesis is first formulated as an optimization problem with the goal of SLL suppression and/or null prescribed placement in certain directions, and then solved by the newly MCS algorithm for the optimum element or isotropic radiator locations in the azimuth-plane or xy-plane. The study also focuses on the four internal parameters of MCS algorithm specifically on their implicit effects in the array synthesis. The optimal inter-element spacing solutions obtained by the MCS-optimizer are validated through comparisons with the standard CS-optimizer and the conventional array within the uniform and the Dolph-Chebyshev envelope patterns using MATLABTM. Finally, we also compared the fine-tuned MCS algorithm with two popular evolutionary algorithm (EA) techniques include particle swarm optimization (PSO) and genetic algorithms (GA)

Enhanced Andreev reflection in gapped graphene

We theoretically demonstrate unusual features of superconducting proximity effect in gapped graphene which presents a pseudospin symmetry-broken ferromagnet with a net pseudomagnetization. We find that the presence of a band gap makes the Andreev conductance of graphene superconductor/pseudoferromagnet (S/PF) junction to behave similar to that of a graphene ferromagnet-superconductor junction. The energy gap $\Delta_N$ enhance the pseudospin inverted Andreev conductance of S/PF junction to reach a limiting maximum value for $\Delta_N\gg \mu$, which depending on the bias voltage can be larger than the value for the corresponding junction with no energy gap. We further demonstrate a damped-oscillatory behavior for the local density of states of the PF region of S/PF junction and a long-range crossed Andreev reflection process in PF/S/PF structure with antiparallel alignment of pseudomagnetizations of PFs, which confirm that, in this respect, the gapped normal graphene behaves like a ferromagnetic graphene.Comment: 7.2 pages, 5 figures, accepted for publication in Phys. Rev.

Examination and Comparison of the Performance of Common Non-Parametric and Robust Regression Models

ABSTRACT Examination and Comparison of the Performance of Common Non-Parametric and Robust Regression Models By Gregory Frank Malek Stephen F. Austin State University, Masters in Statistics Program, Nacogdoches, Texas, U.S.A. [email protected] This work investigated common alternatives to the least-squares regression method in the presence of non-normally distributed errors. An initial literature review identified a variety of alternative methods, including Theil Regression, Wilcoxon Regression, Iteratively Re-Weighted Least Squares, Bounded-Influence Regression, and Bootstrapping methods. These methods were evaluated using a simple simulated example data set, as well as various real data sets, including math proficiency data, Belgian telephone call data, and faculty salaries at the University of South Florida. In addition, simulations were conducted of common error scenarios to test and evaluate each method. These simulations involved simple regression models in which the error terms were contaminated normal distributions with different amounts and magnitudes of contamination. The models were evaluated based on confidence interval coverage of regression coefficients, as well as bias and confidence interval width. Finally, results were summarized, conclusions drawn, and suggestions for future applications of the results have been provided

The thermal dehydration of magnesium sulfate hexahydrate (MgSO3.6H2O) and magnesium sulfite trihydrate (MgSO3.3H2O)

The thermal dehydration of MgSO3.3H2O and MgSO3.6H2O have been studied by differential thermal analysis, differential scanning calorimetry and thermal gravimetric analysis. Similar studies by other groups led to contradictory conclusions. In this investigation, these results were reconciled and it was concluded that MgSO3.6H2O, under equilibrium conditions, dehydrates in two steps through the intermediate formation of MgSO3.3H2O. One consequence of this work is the development of a simple analytical procedure, using TGA, for the quantitative determination of both hydrates in mixtures and in the presence of thermally inactive material

Development of a solid state thermostat final report

Solid state thermostat for space and airborne application

3-D antenna array analysis using the induced EMF method

The effect of mutual coupling between elements plays a crucial role to the performance of the antenna arrays. The radiation patterns of antenna arrays will be altered by the coupling effect from the adjacent elements thus reducing the accuracy and resolution in direction finding application. This research developed and validated the novel 3-D Algorithm to calculate the far-field pattern of dipole arrays arranged in three dimensions and in any configuration (both in straight and slanted position). The effect of mutual coupling has been accounted using the Induced EMF method. The computation is performed on 2x2 parallel dipoles and 12 dipoles arranged at the edge of a cube. The results are validated with other electromagnetic techniques such as Method of Moment (MoM) and Finite Difference Time-Domain (FDTD). Then, a 2x2 dipole array is chosen for beam steering and experiment validation due to its ease of implementation and feeding network. The array optimisation to control the pattern is performed using a genetic algorithm. The far-field pattern computed using the 3-D algorithm might be less accurate than other 3-D electromagnetic techniques but its array optimisation is faster and efficient. The simulation and measurement results are in good agreement with each other confirmed the validity of the 3-D algorithm