28,828 research outputs found
On the Role of Primary and Secondary Assets in Adaptive Security: An Application in Smart Grids
peer-reviewedAdaptive security aims to protect valuable assets
managed by a system, by applying a varying set of security
controls. Engineering adaptive security is not an easy task. A
set of effective security countermeasures should be identified.
These countermeasures should not only be applied to (primary)
assets that customers desire to protect, but also to other
(secondary) assets that can be exploited by attackers to harm
the primary assets. Another challenge arises when assets vary
dynamically at runtime. To accommodate these variabilities, it
is necessary to monitor changes in assets, and apply the most
appropriate countermeasures at runtime. The paper provides
three main contributions for engineering adaptive security.
First, it proposes a modeling notation to represent primary
and secondary assets, along with their variability. Second,
it describes how to use the extended models in engineering
security requirements and designing required monitoring functions.
Third, the paper illustrates our approach through a set
of adaptive security scenarios in the customer domain of a
smart grid. We suggest that modeling secondary assets aids
the deployment of countermeasures, and, in combination with
a representation of assets variability, facilitates the design of
monitoring function
Heavy-to-Light Meson Transitions in QCD
I discuss QCD sum rules determinations of the form factors governing the
decay . For some of these form factors the computed
dependence on the momentum transferred does not agree with the expectation from
the nearest pole dominance hypothesis. Relations are observed among the form
factors, that seem to be compatible with equations recently derived by B.Stech.
The measurement of a number of color suppressed nonleptonic B decay rates could
shed light on the accuracy of the calculation of these form factors and on the
factorization approximation.Comment: LaTex, 7 pages, 2 figures (files included). Talk given at the 6th
International Symposium on Heavy Flavours, Pisa, 6-10 June 199
Anomalous Magnetic Properties in Ni50Mn35In15
We present here a comprehensive investigation of the magnetic ordering in
Ni50Mn35In15 composition. A concomitant first order martensitic transition and
the magnetic ordering occurring in this off-stoichiometric Heusler compound at
room temperature signifies the multifunctional character of this magnetic shape
memory alloy. Unusual features are observed in the dependence of the
magnetization on temperature that can be ascribed to a frustrated magnetic
order. It is compelling to ascribe these features to the cluster type
description that may arise due to inhomogeneity in the distribution of magnetic
atoms. However, evidences are presented from our ac susceptibility, electrical
resistivity and dc magnetization studies that there exists a competing
ferromagnetic and antiferromagnetic order within crystal structure of this
system. We show that excess Mn atoms that substitute the In atoms have a
crucial bearing on the magnetic order of this compound. These excess Mn atoms
are antiferromagnetically aligned to the other Mn, which explains the peculiar
dependence of magnetization on temperature.Comment: Accepted in J. Phys. D.:Appl. Physic
Diffusion of a Janus nanoparticle in an explicit solvent: A molecular dynamics simulation study
Molecular dynamics simulations are carried out to study the translational and
rotational diffusion of a single Janus particle immersed in a dense
Lennard-Jones fluid. We consider a spherical particle with two hemispheres of
different wettability. The analysis of the particle dynamics is based on the
time-dependent orientation tensor, particle displacement, as well as the
translational and angular velocity autocorrelation functions. It was found that
both translational and rotational diffusion coefficients increase with
decreasing surface energy at the nonwetting hemisphere, provided that the
wettability of the other hemisphere remains unchanged. We also observed that in
contrast to homogeneous particles, the nonwetting hemisphere of the Janus
particle tends to rotate in the direction of the displacement vector during the
rotational relaxation time.Comment: Web reference added for
animations:http://www.wright.edu/~nikolai.priezjev/janus/janus.htm
Gynaecological morbidities among married women and husbandâs behaviour: evidence from a communityâbased study
Aim
To determine the association between gynaecological morbidities and IPV among married women specifically, with attention to the attitudes of the husband and the degree of satisfaction in a marital relationship.
Design
Crossâsectional study design.
Methods
Data were collected using faceâtoâface interviews with married women aged 15â49 years, living in selected communities. Information was collected on demographic characteristics, gynaecological morbidities and IPV using a selfâdeveloped tool. Descriptive and inferential statistics were used to analyse the data.
Results
Logistic Regression showed a significant association between physical violence and burning micturition, increased urinary frequency, constant dribbling of urine, genital ulcers, lower abdominal pain, vaginal discharge and painful coitus (OR: 1.41â1.84). A significant association between sexual and psychological abuse was also found with burning micturition (OR: 1.41) and dribbling of urine (OR: 0.12). Since gynaecological morbidities can have a serious effect on the psychological, physical wellâbeing, and the social status of women in Pakistan; effective interventions are imperative in dealing with their symptoms and decreasing their emergence
Nd:YAG laser welding of stainless steel 304 for photonics device packaging
Although pulsed Nd:YAG laser welding has been widely used in microelectronics and photonics packaging industry, a full understanding of various phenomena involved is still a matter of trials and speculations. In this research, an ultra compact pulsed Nd:YAG laser with wavelength of 1.064 ”m has been used to produce a spot weld on stainless steel 304. The principal objective of this research is to examine the effects of laser welding parameters such as laser beam peak powers, pulse durations, incident angles, focus point positions and number of shots on the weld dimensions: penetration depth and bead width. The ratio of the penetration depth to the bead width is considered as one of the most critical parameters to determine the weld quality. It is found that the penetration depth and bead width increase when the laser beam peak power, pulse duration and number of shot increase. In contrast, the penetration depth decreases when the laser beam defocus position and incident angle increase. This is due to the reduction of the laser beam intensity causing by the widening of the laser spot size. These experimental results provide a reference on an optimal laser welding operations for a reliable photonics device packaging. The results obtained shows that stainless steel 304 is suitable to be used as a base material for photonics device packaging employing Nd:YAG laser welding technique
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