42,085 research outputs found
Channels of published research communication used by Malaysian authors in computer science and information technology
Analyse 389 records retrieved from Inspec (1990-1999), Compendex (1987-1999) and IEL (IEE/IEEE Electronic library)(1987-1999). The records comprised 159 journal articles, 229 conference papers and 1 monograph chapter. The subject coverage was computer science and information technology. The yearly output of Malaysian publications indicated a gentle upward trend. The highest contributions was 87 published in 1997. The channels used to publish differ slightly from the norm for scientists. Conference papers were preferred to journal articles. The spread of conference papers used to publish indicate three zonal distributions; the nucleus, moderate and low productivity in the ratio of 19 : 41 : 88, leading to a clustering index of 2.15. This shows that Malaysian conference contributions were concentrated in a few proceedings. No clear core journals can be identified for the journal articles and contributions were distributed in a wide variety of journal titles. Malaysian Journal of Computer Science published the highest number of journal articles. More than 83 of the articles were published in journals from the UK, USA, the Netherlands and Malaysia
The Predictability of House Prices
The level and direction of autocorrelation in house price movements differ across areas and change over time. This finding reconciles the conflicting reports in the literature. When quarterly house price indices exhibit negative autocorrelation, autocorrelation shows a positive connection to volatility and a negative connection to rate of return. Autocorrelation between longer time periods is mainly positive; it exhibits a negative relationship with volatility and a positive relationship with rate of return. Volatile house price indices tend to have lower rates of return. It would be possible to obtain excess returns by following a trading strategy based on the estimated autocorrelation.
Scattering on two Aharonov-Bohm vortices with opposite fluxes
The scattering of an incident plane wave on two Aharonov-Bohm vortices with
opposite fluxes is considered in detail. The presence of the vortices imposes
non-trivial boundary conditions for the partial waves on a cut joining the two
vortices. These conditions result in an infinite system of equations for
scattering amplitudes between incoming and outgoing partial waves, which can be
solved numerically. The main focus of the paper is the analytic determination
of the scattering amplitude in two limits, the small flux limit and the limit
of small vortex separation. In the latter limit the dominant contribution comes
from the S-wave amplitude. Calculating it, however, still requires solving an
infinite system of equations, which is achieved by the Riemann-Hilbert method.
The results agree well with the numerical calculations
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Multi-aspect, robust, and memory exclusive guest os fingerprinting
Precise fingerprinting of an operating system (OS) is critical to many security and forensics applications in the cloud, such as virtual machine (VM) introspection, penetration testing, guest OS administration, kernel dump analysis, and memory forensics. The existing OS fingerprinting techniques primarily inspect network packets or CPU states, and they all fall short in precision and usability. As the physical memory of a VM always exists in all these applications, in this article, we present OS-Sommelier+, a multi-aspect, memory exclusive approach for precise and robust guest OS fingerprinting in the cloud. It works as follows: given a physical memory dump of a guest OS, OS-Sommelier+ first uses a code hash based approach from kernel code aspect to determine the guest OS version. If code hash approach fails, OS-Sommelier+ then uses a kernel data signature based approach from kernel data aspect to determine the version. We have implemented a prototype system, and tested it with a number of Linux kernels. Our evaluation results show that the code hash approach is faster but can only fingerprint the known kernels, and data signature approach complements the code signature approach and can fingerprint even unknown kernels
Peculiar Behavior of Si Cluster Ions in Solid Al
A peculiar ion behavior is found in a Si cluster, moving with a speed of
~0.22c (c: speed of light) in a solid Al plasma: the Si ion, moving behind the
forward moving Si ion closely in a several angstrom distance in the cluster,
feels the wake field generated by the forward Si. The interaction potential on
the rear Si may balance the deceleration backward force by itself with the
acceleration forward force by the forward Si in the longitudinal moving
direction. The forward Si would be decelerated normally. However, the
deceleration of the rear Si, moving behind closely, would be reduced
significantly, and the rear Si may catch up and overtake the forward moving Si
in the cluster during the Si cluster interaction with the high-density Al
plasma
Minimal Permutations and 2-Regular Skew Tableaux
Bouvel and Pergola introduced the notion of minimal permutations in the study
of the whole genome duplication-random loss model for genome rearrangements.
Let denote the set of minimal permutations of length
with descents, and let . They derived that
and , where is the -th
Catalan number. Mansour and Yan proved that . In
this paper, we consider the problem of counting minimal permutations in
with a prescribed set of ascents. We show that such
structures are in one-to-one correspondence with a class of skew Young
tableaux, which we call -regular skew tableaux. Using the determinantal
formula for the number of skew Young tableaux of a given shape, we find an
explicit formula for . Furthermore, by using the Knuth equivalence,
we give a combinatorial interpretation of a formula for a refinement of the
number .Comment: 19 page
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