An Efficient Analytical Solution to Thwart DDoS Attacks in Public Domain

In this paper, an analytical model for DDoS attacks detection is proposed, in which propagation of abrupt traffic changes inside public domain is monitored to detect a wide range of DDoS attacks. Although, various statistical measures can be used to construct profile of the traffic normally seen in the network to identify anomalies whenever traffic goes out of profile, we have selected volume and flow measure. Consideration of varying tolerance factors make proposed detection system scalable to the varying network conditions and attack loads in real time. NS-2 network simulator on Linux platform is used as simulation testbed. Simulation results show that our proposed solution gives a drastic improvement in terms of detection rate and false positive rate. However, the mammoth volume generated by DDoS attacks pose the biggest challenge in terms of memory and computational overheads as far as monitoring and analysis of traffic at single point connecting victim is concerned. To address this problem, a distributed cooperative technique is proposed that distributes memory and computational overheads to all edge routers for detecting a wide range of DDoS attacks at early stage.Comment: arXiv admin note: substantial text overlap with arXiv:1203.240

A Possible Nanometer-scale Computing Device Based on an Adding Cellular Automaton

We present a simple one-dimensional Cellular Automaton (CA) which has the property that an initial state composed of two binary numbers evolves quickly into a final state which is their sum. We call this CA the Adding Cellular Automaton (ACA). The ACA requires only 2N two-state cells in order to add any two N-1 bit binary numbers. The ACA could be directly realized as a wireless nanometer-scale computing device - a possible implementation using coupled quantum dots is outlined.Comment: 8 pages, RevTex, 3 Postscript figures. This version to appear in App. Phys. Let

Peristaltic Transport of a Rheological Fluid: Model for Movement of Food Bolus Through Esophagus

Fluid mechanical peristaltic transport through esophagus has been of concern in the paper. A mathematical model has been developed with an aim to study the peristaltic transport of a rheological fluid for arbitrary wave shapes and tube lengths. The Ostwald-de Waele power law of viscous fluid is considered here to depict the non-Newtonian behaviour of the fluid. The model is formulated and analyzed with the specific aim of exploring some important information concerning the movement of food bolus through the esophagus. The analysis has been carried out by using lubrication theory. The study is particularly suitable for cases where the Reynolds number is small. The esophagus is treated as a circular tube through which the transport of food bolus takes places by periodic contraction of the esophageal wall. Variation of different variables concerned with the transport phenomena such as pressure, flow velocity, particle trajectory and reflux are investigated for a single wave as well as for a train of periodic peristaltic waves. Locally variable pressure is seen to be highly sensitive to the flow index `n'. The study clearly shows that continuous fluid transport for Newtonian/rheological fluids by wave train propagation is much more effective than widely spaced single wave propagation in the case of peristaltic movement of food bolus in the esophagus.Comment: Accepted for publication in Applied Mathematics and Mechanics (AMM), Springe

Acoustic Properties of Soybeans

Acoustic transmission and impact force response methods were investigated for classification of soybeans. The transmission method was slow and not suitable for real-time application. A polynomial was fitted to the deconvolved frequency spectrum of acoustic impulse data for soybeans. The curve fitting procedure successfully predicted the mass of each soybean. The size of soybeans was related to the bandwidth. Diseased soybeans consistently showed narrower bandwidths than healthy soybeans. The diseased and damaged soybeans had broad variations in low frequency which was quantifiable by threshholding the error of fit in the curve fitting procedure

Quantum Information and Entropy

Thermodynamic entropy is not an entirely satisfactory measure of information of a quantum state. This entropy for an unknown pure state is zero, although repeated measurements on copies of such a pure state do communicate information. In view of this, we propose a new measure for the informational entropy of a quantum state that includes information in the pure states and the thermodynamic entropy. The origin of information is explained in terms of an interplay between unitary and non-unitary evolution. Such complementarity is also at the basis of the so-called interaction-free measurement.Comment: 21 pages, 3 figure

INTRINSIC MECHANISM FOR ENTROPY CHANGE IN CLASSICAL AND QUANTUM EVOLUTION

It is shown that the existence of a time operator in the Liouville space representation of both classical and quantum evolution provides a mechanism for effective entropy change of physical states. In particular, an initially effectively pure state can evolve under the usual unitary evolution to an effectively mixed state.Comment: 20 pages. For more information or comments contact E. Eisenberg at [email protected] (internet)