Calibration Systems of the ATLAS Tile Calorimeter

TileCal is the hadronic calorimeter covering the most central region of the ATLAS experiment at the LHC. This sampling calorimeter uses iron plates as absorber and plastic scintillating tiles as the active material. A multi-faceted calibration system allows to monitor and equalize the calorimeter response at each stage of the signal production, from scintillation light to digitization. This calibration system is based on signal generation from different sources: a Cs radioactive source, laser light, charge injection and minimum bias events produced in proton-proton collisions. A brief description of the different TileCal calibration systems is given and the latest results on their performance in terms of calibration factors, linearity and stability are presented.Comment: 4 pages, 2 figures. For the 32nd Symposium on Physics in Collision, Strbske Pleso 12th - 15th September 201

Shifting attitudes and the labor market of minorities: Swedish experiences after 9-11

Several studies suggest that the terrorist attacks in the US on September 11, 2001, caused at least a temporary change of attitude toward certain minorities in Sweden. We study unemployment exit around 9-11 using detailed data on the entire Swedish working-age population to investigate whether this change in attitudes also affected the labor market situation of these minorities. Contrary to what to expect from many theories of labor market discrimination, the time pattern of exits and entries for different ethnic groups, as well as difference-in-differences analyses, show no sign of increased discrimination towards these minorities.Labour market discrimination; minorities; etnic groups

Dangerous Voices: On Written and Spoken Discourse in Plato’s Protagoras

Plato’s Protagoras contains, among other things, three short but puzzling remarks on the media of philosophy. First, at 328e5–329b1, Plato makes Socrates worry that long speeches, just like books, are deceptive, because they operate in a discursive mode void of questions and answers. Second, at 347c3–348a2, Socrates argues that discussion of poetry is a presumptuous affair, because, the poems’ message, just like the message of any written text, cannot be properly examined if the author is not present. Third, at 360e6–361d6, it becomes clear that even if the conversation between Socrates and Protagoras was conducted by means of short questions and answers, this spoken mode of discourse is problematic too, because it ended up distracting the inquiry from its proper course. As this paper 2 sets out to argue, Plato does not only make Socrates articulate these worries to exhibit the hazards of discursive commodifi cation. In line with Socrates’ warning to the young Hippocrates of the dangers of sophistic rhetoric, and the sophists’ practice of trading in teachings, they are also meant to problematize the thin line between philosophical and sophistical practice. By examining these worries in the light of how the three relevant modes of discourse are exemplifi ed in the dialogue, this paper aims to isolate and clarify the reasons behind them in terms of deceit, presumptuousness and distraction; and to argue that these reasons cast doubts on the common assumption that the dialogue’s primary aim is to show how sophistical rhetoric must succumb to Socratic dialectic

A Sparse and High-Order Accurate Line-Based Discontinuous Galerkin Method for Unstructured Meshes

We present a new line-based discontinuous Galerkin (DG) discretization scheme for first- and second-order systems of partial differential equations. The scheme is based on fully unstructured meshes of quadrilateral or hexahedral elements, and it is closely related to the standard nodal DG scheme as well as several of its variants such as the collocation-based DG spectral element method (DGSEM) or the spectral difference (SD) method. However, our motivation is to maximize the sparsity of the Jacobian matrices, since this directly translates into higher performance in particular for implicit solvers, while maintaining many of the good properties of the DG scheme. To achieve this, our scheme is based on applying one-dimensional DG solvers along each coordinate direction in a reference element. This reduces the number of connectivities drastically, since the scheme only connects each node to a line of nodes along each direction, as opposed to the standard DG method which connects all nodes inside the element and many nodes in the neighboring ones. The resulting scheme is similar to a collocation scheme, but it uses fully consistent integration along each 1-D coordinate direction which results in different properties for nonlinear problems and curved elements. Also, the scheme uses solution points along each element face, which further reduces the number of connections with the neighboring elements. Second-order terms are handled by an LDG-type approach, with an upwind/downwind flux function based on a switch function at each element face. We demonstrate the accuracy of the method and compare it to the standard nodal DG method for problems including Poisson's equation, Euler's equations of gas dynamics, and both the steady-state and the transient compressible Navier-Stokes equations.Comment: Minor changes: Reviewer suggestions, typos, et

Now and forever? Initial and subsequent location choices of immigrants

This paper exploits a natural experiment to study the influence of regional factors on initial and subsequent location choices among immigrants. The results suggest that immigrants to Sweden are attracted to regions with high representation from the individual’s birth country and large overall immigrant populations. Labor market opportunities affect location decisions, but people also tend to choose localities with many welfare recipients. The impact of most regional factors does not change over time. Thus, there is little evidence that information improves or that preferences differ between initial and subsequent stages.Immigration; location choice; secondary migration