5,532 research outputs found
Kernel Code Integrity Protection Based on a Virtualized Memory Architecture
Kernel rootkits pose significant challenges on defensive techniques as they run at the highest privilege level along with the protection systems. Modern architectural approaches such as the NX protection have been used in mitigating attacks, however determined attackers can still bypass these defenses with specifically crafted payloads. In this paper, we propose a virtualized Harvard memory architecture to address the kernel code integrity problem, which virtually separates the code fetch and data access on the kernel code to prevent kernel from code modifications. We have implemented the proposed mechanism in commodity operating system, and the experimental results show that our approach is effective and incurs very low overhead
Gravitational Corrections to Theory with Spontaneously Broken Symmetry
We consider a complex scalar theory with spontaneously broken
global U(1) symmetry, minimally coupling to perturbatively quantized Einstein
gravity which is treated as an effective theory at the energy well below the
Planck scale. Both the lowest order pure real scalar correction and the
gravitational correction to the renormalization of the Higgs sector in this
model have been investigated. Our results show that the gravitational
correction renders the renormalization of the Higgs sector in this model
inconsistent while the pure real scalar correction to it leads to a compatible
renormalization.Comment: 11 pages, 24 figure
Ionized gas outflows in infrared-bright dust-obscured galaxies selected with WISE and SDSS
We present the ionized gas properties of infrared (IR)-bright dust-obscured
galaxies (DOGs) that show an extreme optical/IR color, , selected with the Sloan Digital Sky Survey (SDSS) and Wide-field Infrared
Survey Explorer (WISE). For 36 IR-bright DOGs that show [OIII]5007
emission in the SDSS spectra, we performed a detailed spectral analysis to
investigate their ionized gas properties. In particular, we measured the
velocity offset (the velocity with respect to the systemic velocity measured
from the stellar absorption lines) and the velocity dispersion of the [OIII]
line. We found that the derived velocity offset and dispersion of most
IR-bright DOGs are larger than those of Seyfert 2 galaxies (Sy2s) at ,
meaning that the IR-bright DOGs show relatively strong outflows compared to
Sy2s. This can be explained by the difference of IR luminosity contributed from
active galactic nucleus, (AGN), because we found that (i) (AGN) correlates with the velocity offset and dispersion of [OIII] and
(ii) our IR-bright DOGs sample has larger (AGN) than Sy2s.
Nevertheless, the fact that about 75% IR-bright DOGs have a large ( 300 km
s) velocity dispersion, which is a larger fraction compared to other AGN
populations, suggests that IR-bright DOGs are good laboratories to investigate
AGN feedback. The velocity offset and dispersion of [OIII] and
[NeIII]3869 are larger than those of [OII]3727, which
indicates that the highly ionized gas tends to show more stronger outflows.Comment: 19 pages, 16 figures, and 2 tables, accepted for publication in Ap
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