ONLINE MONITORING USING KISMET

Colleges and universities currently use online exams for student evaluation. Stu- dents can take assigned exams using their laptop computers and email their results to their instructor; this process makes testing more efficient and convenient for both students and faculty. However, taking exams while connected to the Internet opens many opportunities for plagiarism and cheating. In this project, we design, implement, and test a tool that instructors can use to monitor the online activity of students during an in-class online examination. This tool uses a wireless sniffer, Kismet, to capture and classify packets in real time. If a student attempts to access a site that is not allowed, the instructor is notified via an Android application or via Internet. Identifying a student who is cheating is challenging since many applications send packets without user intervention. We provide experimental results from realistic test environments to illustrate the success of our proposed approach

Clustering GCG: a viable option for unified dark matter-dark energy?

We study the clustering Generalized Chaplygin Gas (GCG) as a possible candidate for dark matter-dark energy unification. The vanishing speed of sound ($c_{s}^2 = 0$) for the GCG fluid can be obtained by incorporating higher derivative operator in the original K-essence Lagrangian. The evolution of the density fluctuations in the GCG+Baryon fluid is studied in the linear regime. The observational constraints on the model are obtained using latest data from SNIa, $H(z)$, BAO and also for the $f\sigma_{8}$ measurements. The matter power spectra for the allowed parameter values are well behaved without any unphysical features.Comment: 11 pages, Latex style, 6 eps figure

Electrowetting of a nano-suspension on a soft solid

The wetting of solid surfaces can be manoeuvred by altering the energy balance at the interfacial region. While electric field acts favourably to spread a droplet on a rigid surface, this tendency may be significantly suppressed over soft surfaces, considering a part of the interfacial energy being utilized to deform the solid elastically by capillary forces. Here, we bring out a unique mechanism by virtue of which addition of nano-particles to the droplet brings in a favourable recovery of the electro-spreading characteristics of a soft surface, by realizing an alteration in the effective dielectric constant of the interfacial region. Our experiments further demonstrate that this mechanism ceases to be operative beyond a threshold volume fraction of the particle suspension, due to inevitable contact line pinning. We also develop a theory to explain our experimental observations. Our findings provide a non-contact mechanism for meniscus spreading and droplet control, bearing far-reaching implications in biology and engineering.Comment: 2 figures, 13 page