5,050 research outputs found
Security Issues in a SOA-based Provenance System
Recent work has begun exploring the characterization and utilization of provenance in systems based on the Service Oriented Architecture (such as Web Services and Grid based environments). One of the salient issues related to provenance use within any given system is its security. Provenance presents some unique security requirements of its own, which are additionally dependent on the architectural and environmental context that a provenance system operates in. We discuss the security considerations pertaining to a Service Oriented Architecture based provenance system. Concurrently, we outline possible approaches to address them
Global Linear Complexity Analysis of Filter Keystream Generators
An efficient algorithm for computing lower bounds on the global linear
complexity of nonlinearly filtered PN-sequences is presented. The technique
here developed is based exclusively on the realization of bit wise logic
operations, which makes it appropriate for both software simulation and
hardware implementation. The present algorithm can be applied to any arbitrary
nonlinear function with a unique term of maximum order. Thus, the extent of its
application for different types of filter generators is quite broad.
Furthermore, emphasis is on the large lower bounds obtained that confirm the
exponential growth of the global linear complexity for the class of nonlinearly
filtered sequences
The self-consistent quantum-electrostatic problem in strongly non-linear regime
The self-consistent quantum-electrostatic (also known as
Poisson-Schr\"odinger) problem is notoriously difficult in situations where the
density of states varies rapidly with energy. At low temperatures, these
fluctuations make the problem highly non-linear which renders iterative schemes
deeply unstable. We present a stable algorithm that provides a solution to this
problem with controlled accuracy. The technique is intrinsically convergent
including in highly non-linear regimes. We illustrate our approach with (i) a
calculation of the compressible and incompressible stripes in the integer
quantum Hall regime and (ii) a calculation of the differential conductance of a
quantum point contact geometry. Our technique provides a viable route for the
predictive modeling of the transport properties of quantum nanoelectronics
devices.Comment: 28 pages. 14 figures. Added solution to a potential failure mode of
the algorith
Towards Reconstructing the Provenance of Clinical Guidelines
Abstract. Understanding the provenance of clinical guidelines is important for both practitioners and researchers as it allows for deeper understanding of the provided recommendations and could potentially provide a basis for updating guidelines. Often such provenance is incomplete or unavailable. We describe a prototype of a multi-signal pipeline for reconstructing provenance and show preliminary results of reconstructing dependencies between documents in the context of clinical guidelines and associated documents. 1 Prototype description Broadly, we target the problem of reconstructing provenance of files in a shared folder setting, in which several authors can create or edit files at different moments, and only standard filesystem metadata is available. In a previous work [3] we proposed a content-based approach that is able to reconstruct provenance automatically, leveraging several similarity measures and edit distance algorithms, which are then adapted and integrated them into a multi-signal pipeline. Here, we present an improved version of this prototype applied to a clinical guideline and associated biomedical documents. The architecture of our prototype is shown in Fig. 1. <2,4
Sensing electric and magnetic fields with Bose-Einstein Condensates
We discuss the application of Bose-Einstein condensates (BECs) as sensors for
magnetic and electric fields. In an experimental demonstration we have brought
one-dimensional BECs close to micro-fabricated wires on an atom chip and
thereby reached a sensitivity to potential variations of ~10e-14eV at 3 micron
spatial resolution. We demonstrate the versatility of this sensor by measuring
a two-dimensional magnetic field map 10 micron above a 100-micron-wide wire. We
show how the transverse current-density component inside the wire can be
reconstructed from such maps. The field sensitivity in dependence on the
spatial resolution is discussed and further improvements utilizing Feshbach
resonances are outlined.Comment: 4 pages, 3 figure
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