24,994 research outputs found
Recommended from our members
'Secure, anonymous, unregulated': 'Cryptonomicon' and the transnational data haven
This essay considers how Neal Stephenson’s 1999 epic novel Cryptonomicon engages with the long-standing and complex relationship between cryptology and national/transnational identity. Cryptonomicon's layered and disjointed structure allows it to explore the impact of cryptography and cryptanalysis in the Second World War (as well as their impact on the consequent rewriting of the international political stage), to reflect on the place of technology in the recent history of cryptology, and to consider how emergent (and supposedly secure) data storage technologies not only open up planetary-wide communication traffic but also unsettle the agreed protocols of national and international law. Stephenson provides a sense of technology's global effects by offering not a straightforward narrative of the demise of the nation-state but by showing how technologies are in a process of constant negotiation with the institutions of the nation-state, drawing upon the economic, material, and intellectual resources of the nation state, while at the same time challenging notions of a bordered and coherent national identity and working to disestablish nations of their regulatory authority. The essay is informed by recent work on cryptology, data havens, globalization, transnationalism, and postcoloniality, as well as Derrida's work on archives and technology
Federal Rules of Evidence and the Political Process
An important tenet of American evidence law is the strict regulation on the introduction of character evidence. This principal has begun to be chipped away at through the adoption of amendments that allow character evidence to be introduced in certain types of cases. The Federal Rules of Evidence were subject to very little amendment during their first 20 years of use, and have always represented a blend of conservatism about evidence law and political compromise. This tension has been kept in check until the proposal of Rules 413-415, which represents a concession to the politicization of the rules. Before imposing such a drastic change, Congress should be sure that their proposal is backed by strong empirical evidence
Transversity of quarks and nucleons in SIDIS and Drell Yan
We consider the leading and sub-leading twist -odd and even contributions
to the azimuthal asymmetry in unpolarized dilepton production in
Drell-Yan Scattering and semi-inclusive deep inelastic scattering of pions.Comment: LaTeX2e, 4 pages, 4 ps figures, uses ws-procs9x6. Contribution to the
16th International Spin Physics Symposium, SPIN2004, October 10-16, 2004,
Trieste, Ital
SHARP simulation of discontinuities in highly convective steady flow
For steady multidimesional convection, the Quadratic Upstream Interpolation for Convective Kinematics (QUICK) scheme has several attractive properties. However, for highly convective simulation of step profiles, QUICK produces unphysical overshoots and a few oscillations, and this may cause serious problems in nonlinear flows. Fortunately, it is possible to modify the convective flux by writing the normalized convected control-volume face value as a function of the normalized adjacent upstream node value, developing criteria for monotonic resolution without sacrificing formal accuracy. This results in a nonlinear functional relationship between the normalized variables, whereas standard methods are all linear in this sense. The resulting Simple High Accuracy Resolution Program (SHARP) can be applied to steady multidimensional flows containing thin shear or mixing layers, shock waves, and other frontal phenomena. This represents a significant advance in modeling highly convective flows of engineering and geophysical importance. SHARP is based on an explicit, conservative, control-volume flux formation, equally applicable to one, two, or three dimensional elliptic, parabolic, hyperbolic, or mixed-flow regimes. Results are given for the bench-mark purely convective first-order results and the nonmonotonic predictions of second- and third-order upwinding
Comparison of truncation error of finite-difference and finite-volume formulations of convection terms
Judging by errors in the computational-fluid-dynamics literature in recent years, it is not generally well understood that (above first-order) there are significant differences in spatial truncation error between formulations of convection involving a finite-difference approximation of the first derivative, on the one hand, and a finite-volume model of flux differences across a control-volume cell, on the other. The difference between the two formulations involves a second-order truncation-error term (proportional to the third-derivative of the convected variable). Hence, for example, a third (or higher) order finite-difference approximation for the first-derivative convection term is only second-order accurate when written in conservative control-volume form as a finite-volume formulation, and vice versa
Solving the Schrödinger equation with use of 1/N perturbation theory
The large N expansion provides a powerful new tool for solving the Schrödinger equation. In this
paper, we present simple recursion formulas which facilitate the calculation. We do some numerical calculations which illustrate the speed and accuracy of the technique
Transversity Properties of Quarks and Hadrons in SIDIS and Drell-Yan
We consider the leading twist -odd contributions as the dominant source of
the azimuthal and transverse single spin asymmetries in SIDIS and dilepton
production in Drell-Yan Scattering. These asymmetries contain information on
the distribution of quark transverse spin in (un)polarized protons. In the
spectator framework we estimate these asymmetries at HERMES kinematics and at
for the proposed experiments at GSI, where an anti-proton beam
is ideal for studying the transversity properties of quarks due to the
dominance of {\em valence} quark effects.Comment: 4 pages, 8 figures. To appear in the proceedings of the XIII
International Workshop on Deep Inelastic Scattering (DIS 2005, Madison
A cost-effective strategy for nonoscillatory convection without clipping
Clipping of narrow extrema and distortion of smooth profiles is a well known problem associated with so-called high resolution nonoscillatory convection schemes. A strategy is presented for accurately simulating highly convective flows containing discontinuities such as density fronts or shock waves, without distorting smooth profiles or clipping narrow local extrema. The convection algorithm is based on non-artificially diffusive third-order upwinding in smooth regions, with automatic adaptive stencil expansion to (in principle, arbitrarily) higher order upwinding locally, in regions of rapidly changing gradients. This is highly cost effective because the wider stencil is used only where needed-in isolated narrow regions. A recently developed universal limiter assures sharp monotonic resolution of discontinuities without introducing artificial diffusion or numerical compression. An adaptive discriminator is constructed to distinguish between spurious overshoots and physical peaks; this automatically relaxes the limiter near local turning points, thereby avoiding loss of resolution in narrow extrema. Examples are given for one-dimensional pure convection of scalar profiles at constant velocity
- …