1,494 research outputs found
Adversarial Sample Generation using the Euclidean Jacobian-based Saliency Map Attack (EJSMA) and Classification for IEEE 802.11 using the Deep Deterministic Policy Gradient (DDPG)
One of today's most promising developments is wireless networking, as it enables people across the globe to stay connected. As the wireless networks' transmission medium is open, there are potential issues in safeguarding the privacy of the information. Though several security protocols exist in the literature for the preservation of information, most cases fail with a simple spoof attack. So, intrusion detection systems are vital in wireless networks as they help in the identification of harmful traffic. One of the challenges that exist in wireless intrusion detection systems (WIDS) is finding a balance between accuracy and false alarm rate. The purpose of this study is to provide a practical classification scheme for newer forms of attack. The AWID dataset is used in the experiment, which proposes a feature selection strategy using a combination of Elastic Net and recursive feature elimination. The best feature subset is obtained with 22 features, and a deep deterministic policy gradient learning algorithm is then used to classify attacks based on those features. Samples are generated using the Euclidean Jacobian-based Saliency Map Attack (EJSMA) to evaluate classification outcomes using adversarial samples. The meta-analysis reveals improved results in terms of feature production (22 features), classification accuracy (98.75% for testing samples and 85.24% for adversarial samples), and false alarm rates (0.35%). 
Treatment compliance in relation to source of referral and initial reaction to the diagnosis of tuberculosis
The source of referral and patient’s reaction to diagnosis were studied in relation to
regularity of treatment in 107 patients attending Tuberculosis Research Centre (TRC), Chennai. In all,
29% of the patients were referred by family members, 27% by neighbours and friends, 11% attended
on their own, private practitioners referred 18% and government facilities/NGOs referred 15%. The
initial reactions to diagnosis of tuberculosis were anxiety, fear, worry and/or shock in 59%. Only 31%
of the patients were hopeful of cure at the time.
All those who attended on their own completed > 80% of treatment as did 90% of those who were
hopeful of cure at the time of diagnosis. And, 86% of those who experienced a negative reaction (fear
of death, anxiety and worry) completed > 80% of treatment
Sparse Coding and Autoencoders
In "Dictionary Learning" one tries to recover incoherent matrices (typically overcomplete and whose columns are assumed
to be normalized) and sparse vectors with a small
support of size for some while having access to observations
where . In this work we undertake a rigorous
analysis of whether gradient descent on the squared loss of an autoencoder can
solve the dictionary learning problem. The "Autoencoder" architecture we
consider is a mapping with a single
ReLU activation layer of size .
Under very mild distributional assumptions on , we prove that the norm
of the expected gradient of the standard squared loss function is
asymptotically (in sparse code dimension) negligible for all points in a small
neighborhood of . This is supported with experimental evidence using
synthetic data. We also conduct experiments to suggest that is a local
minimum. Along the way we prove that a layer of ReLU gates can be set up to
automatically recover the support of the sparse codes. This property holds
independent of the loss function. We believe that it could be of independent
interest.Comment: In this new version of the paper with a small change in the
distributional assumptions we are actually able to prove the asymptotic
criticality of a neighbourhood of the ground truth dictionary for even just
the standard squared loss of the ReLU autoencoder (unlike the regularized
loss in the older version
Investigation of a new hot stamping process with improved formability and productivity
In order to improve the drawability of boron steel and also to increase the productivity of hot stamping process, a new hot stamping process with pre-cooling has been proposed. Stress-strain behavior at various temperatures was investigated and compared with that in traditional hot stamping processes. Detailed studies were carried out on the strain hardening parameter, n, at different temperatures and deformation rates. To evaluate this concept, hot stamping experiments were performed with both conventional (without pre-cooling) and new process (with pre-cooling) for a scaled down B-Pillar automotive component. The new hot stamping process with pre-cooling was able to produce the B-Pillar at low temperature (500°C) with less thinning than the hot stamping carried out without precooling at high temperature (765°C). Also the in-die quenching time was reduced by about 60%, by adopting the new hot stamping process with pre-cooling, which would increase the productivity significantly for automotive mass production without compromising the part quality
Interaction of amino acids with glycyl-glycine transport in the mammalian intestine
In order to investigate a possible interaction between free amino acids and dipeptides during their mucosal uptake in man and monkey, perfusion studies in vivo and uptake studiesin vitro using labelled and non-labelled dipeptides and amino acids have been carried out. In contrast to the observations of other workers, inhibition of glycyl-glycine uptake was observed with free leucine and methioninc but not with glycine, proline, hydroxyproline or alanine. Leucine and methionine caused inhibition of cytosol glycyl-glycine hydrolase activity, while glycine had no effect. The dipeptide uptake and dipeptide hydrolysis by cytosol enzyme was competitively inhibited by leucine. Although brush border glycyl-glycine hydrolase was also inhibited by leucine, the inhibition was noncompetitive. These data indicate that a few free amino acids can interact with dipeptides during uptake. This interaction might occur either at the transport step or at the stage of intracellular dipeptide hydrolysis
Oral Hygiene Practices Among Cricketers in Chennai
Oral hygiene refers to the practice of keeping the mouth, teeth and gums clean and healthy to prevent oral disease. Oral hygiene is often taken for granted but it is essential part of our daily life.Oral hygiene is the practice of maintaining a clean oral cavity to prevent dental diseases such as dental cavities, gingivitis, periodontitis and bad breath. A total of 150 cricketers were involved in the study . Self administered questionnaire related to the oral hygiene practices along with sociodemographic details was prepared and it was distributed through an online survey link. Based on hypotonic and isotonic content of the sports drink , the majority of the participants(58.7%) prefer isotonic sports drinks and the remaining participants( 41.3%) prefer Hypotonic .About 58% of participants eat chocolate regularly. 54.6% of participants agreed that dental erosion affects oral health . 56% of participants think oral health has an impact on sports performance. In the present study, the knowledge,attitude and practice of oral hygiene is moderate.For further improvement, awareness about maintaining good oral health should be created among the public. Erosion can be prevented by educating the subjects about the risks associated with carbonated drinks which is more common among sportsmen and young adults
Structure of poly(propyl ether imine) (PETIM) dendrimer from fully atomistic molecular Dynamics Simulation and by Small Angle X-ray scattering
We study the structure of carboxylic acid terminated neutral poly (propyl
ether imine) (PETIM) dendrimer from generation 1 through 6 (G1-G6) in a good
solvent (water) by fully atomistic molecular dynamics (MD) simulations. We
determine as a function of generation such structural properties as: radius of
gyration, shape tensor, asphericity, fractal dimension, monomer density
distribution, and end-group distribution functions. The sizes obtained from the
MD simulations have been validated by Small Angle X-Ray Scattering (SAXS)
experiment on dendrimer of generation 2 to 4 (G2-G4). A good agreement between
the experimental and theoretical value of radius of gyration has been observed.
We find a linear increase in radius of gyration with the generation. In
contrast, Rg scales as ~ N^x with the number of monomers. We find two distinct
exponents depending on the generations: x = 0.47 for G1-G3 and x = 0.28 for
G3-G6 which reveals their non-space filling nature. In comparison with the
amine terminated PAMAM dendrimer, we find Rg of G-th generation PETIM dendrimer
is nearly equal to that of (G+1)-th generation of PAMAM dendrimer as observed
by Maiti et. al. [Macromolecules,38, 979 2005]. We find substantial back
folding of the outer sub generations into the interior of the dendrimer. Due to
their highly flexible nature of the repeating branch units, the shape of the
PETIM dendrimer deviates significantly from the spherical shape and the
molecules become more and more spherical as the generation increases. The
interior of the dendrimer is quite open with internal cavities available for
accommodating guest molecules suggesting using PETIM dendrimer for guest-host
applications. We also give a quantitative measure of the number of water
molecules present inside the dendrimer.Comment: 33 page
A Novel Grip Design for High-Accuracy Thermo-Mechanical Tensile Testing of Boron Steel under Hot Stamping Conditions
Achieving uniform temperature within the effective gauge length in thermo-mechanical testing is crucial for obtaining accurate material data under hot stamping conditions. A new grip design for the Gleeble Materials-Simulator has been developed to reduce the long-standing problem of temperature gradient along a test-piece during thermo-mechanical tensile testing. The grip design process comprised two parts. For the first part, the new design concept was analysed with the help of Abaqus coupled Thermal-Electric Finite element simulation through the user defined feedback control subroutine. The second part was Gleeble thermo-mechanical experiments using a dog-bone test-piece with both new and conventional grips. The temperature and strain distributions of the new design were compared with those obtained using the conventional system within the effective gauge length of 40 mm. Temperature difference from centre to edge of effective gauge length (temperature gradient) was reduced by 56% during soaking and reduced by 100% at 700 °C. Consequently, the strain gradient also reduced by 95%, and thus facilitated homogeneous deformation. Finally to correlate the design parameters of the electrical conductor used in the new grip design with the geometry and material of test-piece, an analytical relationship has been derived between the test-piece and electrical conductor
Role and acceptability of traditional birth attendants (DAIs) in a rural community in South India
Dais are the traditional birth attendants, conducting deliveries at home in the majority
of villages in India. A study was planned to find out the feasibility of utilising the services of
the dais in case-finding in Tuberculosis (TB) and for drug delivery to diagnosed patients. As a
preliminary step, a survey was done with a view to find out the role and acceptability of the
dais by the community in 5% of households in randomly selected 24 of the 48 villages in
Sriperumbudur taluk in Tamil Nadu, where a voluntary organisation. "PREPARE" was
delivering primary health care through dais. A total of 466 individuals, either the head of the
household or any other responsible person available, were interviewed to find out the role and
acceptability of the dais by the community. The salient findings of this study are that 83%
mentioned that the dais reside in their respective villages. hence the services of the dais
were available at ail times and 82 % had stated that the services were useful to them.
This background information is essential for health planners so that this task force
could be effectively utilised in health programmmes, in the rural areas in India
Deduction with XOR Constraints in Security API Modelling
We introduce XOR constraints, and show how they enable a theorem prover to reason effectively about security critical subsystems which employ bitwise XOR. Our primary case study is the API of the IBM 4758 hardware security module. We also show how our technique can be applied to standard security protocols
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