On the investigation of cascade and turbomachinery rotor wake characteristics

The objective of the investigation reported in this thesis is to study the characteristics of a turbomachinery rotor wake, both analytically and experimentally. The constitutive equations for the rotor wake are developed using generalized tensors and a non-inertial frame of reference. Analytical and experimental investigation is carried out in two phases; the first phase involved the study of a cascade wake in the absence of rotation and three dimensionality. In the second phase the wake of a rotor is studied. Simplified two- and three-dimensional models are developed for the prediction of the mean velocity profile of the cascade and the rotor wake, respectively, using the principle of self-similarity. The effect of various major parameters of the rotor and the flow geometry is studied on the development of a rotor wake. Laws governing the decay of the wake velocity defect in a cascade and rotor wake as a function of downstream distance from the trailing edge, pressure gradient and other parameters are derived

DPRAODV: A Dynamic Learning System Against Blackhole Attack In AODV Based MANET

Security is an essential requirement in mobile ad hoc networks to provide protected communication between mobile nodes. Due to unique characteristics of MANETS, it creates a number of consequential challenges to its security design. To overcome the challenges, there is a need to build a multifence security solution that achieves both broad protection and desirable network performance. MANETs are vulnerable to various attacks, blackhole, is one of the possible attacks. Black hole is a type of routing attack where a malicious node advertise itself as having the shortest path to all nodes in the environment by sending fake route reply. By doing this, the malicious node can deprive the traffic from the source node. It can be used as a denial-of-service attack where it can drop the packets later. In this paper, we proposed a DPRAODV (Detection, Prevention and Reactive AODV) to prevent security threats of blackhole by notifying other nodes in the network of the incident. The simulation results in ns2 (ver-2.33) demonstrate that our protocol not only prevents blackhole attack but consequently improves the overall performance of (normal) AODV in presence of black hole attack

Assessing Co-ordinated Asian Exchange Rate Regimes

This study assesses alternative Asian exchange rate regimes and finds short- and long-run currency dynamics more conducive to the possibility of introducing a common peg based on a basket of the European euro, the United States dollar and the Japanese yen than the alternative of re-introducing a United States dollar peg exchange rate regime. Exchange rate systems of 3- 4- and 5- Asian currencies are examined and the dynamics in a set of 4 European currencies prior to the introduction of the Euro provides benchmark evidence. The evidence for an Asian basket peg regime is strengthened when, unlike in prior studies, the long-run parameters are estimated while accounting for generalised autoregressive conditional heteroscedasticity effects.Exchange Rate Regimes, Asia, Currency Pegs, Basket Exchange Rates

On the Noisy Feedback Capacity of Gaussian Broadcast Channels

It is well known that, in general, feedback may enlarge the capacity region of Gaussian broadcast channels. This has been demonstrated even when the feedback is noisy (or partial-but-perfect) and only from one of the receivers. The only case known where feedback has been shown not to enlarge the capacity region is when the channel is physically degraded (El Gamal 1978, 1981). In this paper, we show that for a class of two-user Gaussian broadcast channels (not necessarily physically degraded), passively feeding back the stronger user's signal over a link corrupted by Gaussian noise does not enlarge the capacity region if the variance of feedback noise is above a certain threshold.Comment: 5 pages, 3 figures, to appear in IEEE Information Theory Workshop 2015, Jerusale

Zinc and boron nutrition in pulses: A review

Zn plays major role in many physiological processes viz., chlorophyll formation, pollen formation, fertilization, protein synthesis, cell elongation, nodule formation etc. Hence, Zn nutrition favourably influences the growth, yield, physiological parameters and nodule formation in pulses. Similar to that of Zn, B also plays a major role in the functioning of reproductive tissues, structural integrity of plasma membrane, sugar transport, nodule development etc. Boron nutrition reduces the flower drop, increases the pod setting in pulses and also increased nodulation in pulses. The review elaborates the effect of Zn and B nutrition on the physiological, growth and yield parameters and yield of pulses and their effect on nodule formation and uptake of nutrients in pulses