1,020 research outputs found
Evolution and Detection of Polymorphic and Metamorphic Malwares: A Survey
Malwares are big threat to digital world and evolving with high complexity.
It can penetrate networks, steal confidential information from computers, bring
down servers and can cripple infrastructures etc. To combat the threat/attacks
from the malwares, anti- malwares have been developed. The existing
anti-malwares are mostly based on the assumption that the malware structure
does not changes appreciably. But the recent advancement in second generation
malwares can create variants and hence posed a challenge to anti-malwares
developers. To combat the threat/attacks from the second generation malwares
with low false alarm we present our survey on malwares and its detection
techniques.Comment: 5 Page
Earth azimuth effect in the bank of search templates for an all sky search of the continuous gravitational wave
We study the problem of all sky search in reference to continuous
gravitational wave (CGW) whose wave-form are known in advance. We employ the
concept of Fitting Factor and study the variation in the bank of search
templates with different Earth azimuth at t=0. We found that the number of
search templates varies significantly. Hence, accordingly, the computational
demand for the search may be reduced up to two orders by time shifting the
data.Comment: 12 Pages, 3 figure
A Hybrid Laser Ultrasonic Based Systemf ro Composite Molding
Conventional piezoelectric based ultrasonic systems have been extensively employed for material characterization. These systems however, have been challenged by the recent need to rapidly scan large areas of new materials such as composites having complex geometry. A promising candidate addressing this issue is laser ultrasonics. Though laser ultrasonics is not new and has generated considerable research interest in the past two decades, its industrial acceptance has been limited. Among its many benefits, laser ultrasonics promise the flexibility of a couplant free inspection system. Pulsed lasers, in particular, offer energy concentration at high repetition rates which can be readily directed at any location on the specimen for interrogation purposes. The detection of laser ultrasound is usually done through Michaelson or Fabry-Perot type interferometric systems. Though these detection systems have the advantage of couplant free detection, they constitute a major component of system cost owing to the precision required. The sensitivity of such systems are also not satisfactory
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