Rashid Ahmad

Quality of Service of Routing Protocols in Wireless Sensor Networks: A Review

Due to distributed nature, dynamic topology and resources constraints of tiny sensing nodes in wireless sensor networks (WSNs), the quality of service (QoS) support is a challenging issue. However, satisfying the stringent QoS requirements is an open problem. QoS aware protocols for WSNs have gained recently considerable attention of the researchers. In this paper, we focus on the QoS satisfaction in WSNs, basics of QoS support in WSNs, and more importantly challenge, requirements of QoS at each layer. Furthermore, we review the QoS protocols and categorize the QoS aware protocols and elaborate their pros and cons. We also discuss the QoS parameters with respect to each protocol performance parameters. A survey and comprehensive discussion on the QoS aware protocols of WSNs are presented, including their strengths and limitations. Finally, we also survey some computational intelligence (CI) techniques and find the basic requirements of such techniques. Moreover, we study these CI techniques in the light of QoS management and tabulate the level of each CI technique for QoS management. The paper is concluded with open research issues.

Nonlinear electrostatic solitary pulses in magnetized quantum plasma with relative density effects of spin-up and spin-down electrons

A separated spin evolution quantum hydrodynamics model is employed to study low frequency electrostatic waves in plasmas having inertia-less degenerate electrons with spin-up n e ↑ and spin-down n e ↓ states and inertial classical ions. A two-dimensional plasma geometry is assumed having a uniform magnetic field, directed along the z-axis, i.e., B = B 0 z . A Zakharov-Kuznetsov (ZK) type equation is derived for the electrostatic potential via the Reductive Perturbation Technique. The parametric role of the spin density polarization ratio κ in the characteristics of solitary wave structures is investigated. We have observed that both the amplitude and width of the soliton are significantly affected by the spin polarization but the amplitude remains largely un-affected by variation in the magnetic field strength. We have also carried out pulse stability analysis and have found that the pulse soliton solution of the ZK equation is unstable to oblique perturbations. The dependence of the instability growth r...

Nonlinear interaction of electromagnetic waves with 3-component relativistic quantum plasma

The interaction of intense circularly polarized electro-magnetic (CPEM) wave with 3-component relativistic-quantum plasma consisting of relativistic-degenerate electrons and positrons, and dynamic degenerate ions is theoretically studied. A mathematical model is structured by coupling Klein-Gordon equations for the electrons and positrons, and Schrodinger equation for the ions with Maxwell equations through Poisson equations. The solutions of the dispersion relation are plotted for relativistic quantum plasma in the density-range of ∼ 10 30 → 10 36 m − 3 for several positron concentrations. Three wave modes are observed: electrons, ions, and positrons. The pair branch mode having a possible association with the positron states stays unaltered by variation in the positron concentration but varies significantly with a change in the quantum parameter defined in terms of the particles number density. The addition of positron to the plasma and increasing the positron concentration suggest enhancement of the op...

Linear and non-linear propagation of electrostatic positron-acoustic waves and envelope solitons in 4-component quantum plasma containing relativistically degenerate electrons and positrons

A hydrodynamic model is employed to investigate the linear and non-linear propagation of electrostatic positron acoustic waves (EPAWs) in a 4-component relativistic-degenerate electron-positron-ion plasma. The plasma constituents are cold positrons, hot relativistic-degenerate electrons and positrons, and cold static ions in the background. The hot electrons and positrons are treated as inertialess, and the cold positrons provide the inertia while the restoring force comes from the hot species. A dispersion relation for low-frequency EPAWs is derived. It is observed that an increase in the relative density of hot positrons to cold positrons and relativistic effects tend to reduce the speed of the EPAWs. Employing the standard Reductive Perturbation Technique, a Korteweg de Vries (KdV)-type equation is derived, and the existence of KdV solitons is demonstrated. In this case, an increase in the relative density of hot to cold positrons and relativistic effects decreases both the amplitude and width of the s...

Game-Theoretic Solutions for Data Offloading in Next Generation Networks

In recent years, global mobile data traffic has seen an unprecedented increase. This is due to worldwide usage of smart devices, availability of fast internet connections, and the popularity of social media. The Mobile Network Operators (MNOs) are, therefore, facing problems in handling this huge traffic flow. Each type of traffic, including real-time video, audio, and text has its own Quality of Services (QoS) requirements which, if not met, may cause a sufficient loss of profit. Offloading of these traffics can be made more efficient so that values of QoS parameters are enhanced. In this work, we propose an incentive-based game-theoretic frame work for downloading data. The download of each type of data will get an incentive determined by the two-stage Stackelberg game. We model the communication among single Mobile Base Station (MBS) and multiple Access Points (APs) in a crowded metropolitan environment. The leader offers an economic incentive based on the traffic type and followers respond to the incentive and offload traffic accordingly. The model optimizes strategies of both the MBS and APs in order to make the best use of their utilities. For the analysis, we have used a combination of analytical and experimental methods. The numerical outcome characterized a direct process of the best possible offloading ratio and legalized the efficiency of the proposed game. Optimal incentives and optimal offloading was the achievement of our proposed game-theoretic approach. We have implemented the model in MATLAB, and the experimental results show a maximum payoff was achieved and the proposed scheme achieved Nash Equilibria.

Electron acoustic waves and parametric instabilities in a 4-component relativistic quantum plasma with Thomas-Fermi distributed electrons

The interaction of Circularly Polarized Electro-Magnetic (CPEM) waves with a 4-component relativistic quantum plasma is studied. The plasma constituents are: relativistic-degenerate electrons and positrons, dynamic degenerate ions, and Thomas-Fermi distributed electrons in the background. We have employed the Klein-Gordon equations for the electrons as well as for the positrons, while the ions are represented by the Schrodinger equation. The Maxwell and Poisson equations are used for electromagnetic waves. Three modes are observed: one of the modes is associated with the electron acoustic wave, a second mode at frequencies greater than the electron acoustic wave mode could be associated with the positrons, and the third one at the lowest frequencies could be associated with the ions. Furthermore, Stimulated Raman Scattering (SRS), Modulational, and Stimulated Brillouin Scattering (SBS) instabilities are studied. It is observed that the growth rates of both the SRS and SBS instabilities decrease with incre...

EFFECT OF PULSING WITH VARIOUS PRESERVATIVES ON POSTHARVEST PERFORMANCE OF CUT Polianthes tuberosa L. 'SINGLE' SPIKES

In Punjab-Pakistan, growing tuberose is a profitable business as returns are double than cost despite of certain bottlenecks such as fluctuations in the prices and unawareness of farmers regarding its post-harvest handling. Keeping in view high market demand in local flower markets, the present study was conducted to extend the postharvest life of cut tuberose spikes by pulsing cut spikes with various preservatives. Among various pulsing treatments, 10% sucrose plus 50 mg L -1 salicylic acid (SA) for 24 hours proved best with the longest vase life (10.2 d), more number of days required to open 50% florets (5.0 days), maximum dry weight percentage (13.2%) and superior quality spikes (7.6). Moreover, longest florets (7.0 cm) with greater floret diameter (4.2 cm), highest percentage of opened florets (90.0%) and minimum ion leakage of florets (140.0%) was recorded for spikes pulsed with 10% sucrose plus 50 mg L -1 salicylic acid for 24 hours. On the other hand, highest water uptake (106.0 mL) and the maximum relative fresh weight percentage (109.9%) were observed in cut tuberose spikes treated with 50 mg L -1 salicylic acid without sucrose solution. In summary, pulsing of cut tuberose spikes with 50 mg L -1 SA with or without 10% sucrose