30 research outputs found
Superconductivity Near a Quantum Critical Point in Ba(Fe,Co)2As2
We will examine the possible link between spin fluctuations and the
superconducting mechanism in the iron-based high temperature superconductor
Ba(Fe,Co)2As2 based on NMR and high pressure transport measurements.Comment: Invited paper to m2s-IX (2009
Absence of static magnetic order in lightly-doped Ti1-xScxOCl down to 1.7 K
Impurity-induced magnetic order has been observed in many quasi-1D systems
including doped variants of the spin-Peierls system CuGeO3. TiOCl is another
quasi-1D quantum magnet with a spin-Peierls ground state, and the magnetic Ti
sites of this system can be doped with non-magnetic Sc. To investigate the role
of non-magnetic impurities in this system, we have performed both zero field
and longitudinal field muSR experiments on polycrystalline Ti1-xScxOCl samples
with x = 0, 0.01, and 0.03. We verified that TiOCl has a non-magnetic ground
state, and we found no evidence for spin freezing or magnetic ordering in the
lightly-doped Sc samples down to 1.7 K. Our results instead suggest that these
systems remain non-magnetic up to the x = 0.03 Sc doping level.Comment: 5 pages, 4 figure
A Risk Management Approach to the “Insider Threat”
Recent surveys indicate that the financial impact and operating losses due to insider intrusions are increasing. But these studies often disagree on what constitutes an "insider;" indeed, many define it only implicitly. In theory, appropriate selection of, and enforcement of, properly specified security policies should prevent legitimate users from abusing their access to computer systems, information, and other resources. However, even if policies could be expressed precisely, the natural mapping between the natural language expression of a security policy, and the expression of that policy in a form that can be implemented on a computer system or network, creates gaps in enforcement. This paper defines "insider" precisely, in terms of these gaps, and explores an access-based model for analyzing threats that include those usually termed "insider threats." This model enables an organization to order its resources based on the business value for that resource and of the information it contains. By identifying those users with access to high-value resources, we obtain an ordered list of users who can cause the greatest amount of damage. Concurrently with this, we examine psychological indicators in order to determine which users are at the greatest risk of acting inappropriately. We conclude by examining how to merge this model with one of forensic logging and auditing