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Effects of Chemical Reaction and Radiation Absorption on MHD Flow of Dusty Viscoelastic Fluid
Get PDFThis investigation is undertaken to study the effects of heat source and radiation absorption on unsteady hydro-magnetic heat and mass transfer flow of a dusty viscous incompressible, electrically conducting fluid between two vertical heated, porous, parallel plates in the presence of chemical reaction under the influence of a transverse applied magnetic field. Initially, the channel walls as well as the dusty fluid are assumed to be at the same temperature and the mass is assumed to be present at low level concentration so that it is constant everywhere. It is also assumed that the dusty particles are non-conducting, solid, spherical and equal in sizes, these are uniformly and symmetrically distributed in the flow field. The governing equations are solved analytically using the perturbation technique. Non-dimensional velocity, temperature, concentration and skin-friction are discussed through graphs for various physical parameters entering into the problem. It is found that velocity of the dusty particles is less than that of the dusty fluid and the skin-friction of the dusty particles is greater than that of the dusty fluid. It is observed that the temperature is minimal at the centre of the channel and decreases towards the plates whereas the concentration is minimal at the center of the channel but increases towards the plates
Dynamics of Phytoplankton, Zooplankton and Fishery Resource Model
Get PDFIn this paper, a new mathematical model has been proposed and analyzed to study the interaction of phytoplankton- zooplankton-fish population in an aquatic environment with Holloing’s types II, III and IV functional responses. It is assumed that the growth rate of phytoplankton depends upon the constant level of nutrient and the fish population is harvested according to CPUE (catch per unit effort) hypothesis. Biological and bionomical equilibrium of the system has been investigated. Using Pontryagin’s Maximum Principal, the optimal harvesting policy is discussed. Chaotic nature and bifurcation analysis of the model system for a control parameter have been observed through a numerical simulation
A numerical method for the controls of the heat equation
No full textThis work is devoted to analyze a numerical scheme for the approximation of the linear heat equation\u27s controls. It is known that, due to the regularizing effect, the efficient computation of the null controls for parabolic type equations is a difficult problem. A possible cure for the bad numerical behavior of the approximating controls consists of adding a singular perturbation depending on a small parameter ε which transforms the heat equation into a wave equation. A space discretization of step h leads us to a system of ordinary differential equations. The aim of this paper is to show that there exists a sequence of exact controls of the corresponding perturbed semi-discrete systems which converges to a control of the original heat equation when both h (the mesh size) and ε (the perturbation parameter) tend to zero. © EDP Sciences, 2014
Using data mules to preserve source location privacy in Wireless Sensor Networks
No full textWireless Sensor Networks (WSNs) have many promising applications for monitoring critical regions, like military surveillance and wildlife monitoring. In such applications, it is critical to protect the location of the source sensor that generates the data, as exposure of this information usually reveals the location of the object being monitored. Traditional security mechanisms, like encryption, have been proven to be ineffective as the location of the source can also be revealed by analyzing the traffic flow in the network. In this paper, we investigate the source-location privacy issue. We first propose a realistic semi-global eavesdropping attack model and show its effectiveness in compromising an existing source-location preserving technique. Furthermore, to measure source location privacy against the semi-global eavesdropper, we define a model for α-angle anonymity. Additionally, we design a new protocol called Mule-Saving-Source (MSS) that preserves α-angle anonymity by adapting the conventional function of data mules. We theoretically analyze the delay incurred by using data mules in MSS, and we examine via extensive simulations the trade-off between the delay and privacy preservation under different data mule mobility patterns. We categorize the delay in MSS as being caused primarily due to the buffering time at the source sensor and the data mules. Motivated by this observation, we propose two modifications to MSS, Mule-Saving-Source-Shortest Path (MSS-SP) and Mule-Saving-Source-Two Level (MSS-TL), both aimed at reducing the total delay by reducing the buffering time at the data mule and source respectively. Through theoretical analysis, we examine the delay in the proposed modifications and evaluate their performance with the MSS protocol using a comprehensive set of simulations. Furthermore, to study the impact of the mobility model of the data mules on the MSS protocol, we compare the performance of the MSS protocol by changing the mobility model of data mules to a Random Waypoint based model. © 2012 Elsevier B.V. All rights reserved
Guessing and abduction
No full textDespite the great importance placed upon the operation of abduction as an inferential process, few studies have been devoted specifically to the process of guessing as a piece of the abduction puzzle. This is surprising since Charles Peirce indicated that guessing is a fundamental part of the abductive process. Most literature concerning Peirce\u27s conception of abduction mentions guessing only in passing; what guessing actually is, especially with regard to the abductive process, is left vague at best, and this leaves a blind spot in the literature so that the broader conception of abduction remains unclear. In response to this, I explain the role of guessing in Peirce\u27s concept of abduction, placing the operation of guessing within the wider scope of the process of inquiry. I consider the guessing process as a deliberate and creative part of abduction, as well as alternative claims that have led to neglect of guessing as a creative operation. This analysis includes consideration of ethical, esthetic, and economic aspects of the guessing process as described by Peirce. As a specific example to elucidate how guessing functions within a particular scientific domain, I utilize the index case of AIDS. My argument sets the stage for further work to be done concerning the function of guessing as it pertains to scientific inquiry more generally. © 2014
Use of natural ventilation in Malaysia\u27s future green housing
No full textWithin the Asia Pacific region, Malaysia\u27s WAWASAN 2020 creates the vision of being a green country. Accordingly, the Malaysian Government has established the mission of reducing the carbon emission. The programs include the projects targeting the energy efficiency and saving within the housing and residential buildings that must meet the Green Building criteria to achieve the sustainable architectural design. Renewable energy sources, like wind or solar energy, can be used to ventilate. The review of previous researchers shows that the use of the natural ventilation system decreases the electricity consumption of a simulated housing in the hot and humid climatic conditions such as Malaysia. The purpose of this research is a review of consumes renewable energies such as solar energy and wind for passive cooling. To test the benefit of natural ventilation system, this paper reviewed some analysis that had used simulation software such as CFD. © (2014) Trans Tech Publications, Switzerland
Delay Analysis of a Discrete-Time Non-Preemptive Priority Queue with Priority Jumps
Get PDFIn this paper, we consider a discrete-time non-preemptive priority queueing model with priority jumps. Two classes, real-time (high priority) and non-real time (low priority), of traffic will be considered with providing jumps from lower priority traffic to the queue of high priority traffic. We derive expressions for the joint probability generating function of the system contents of the high and the low priority traffic in the steady state and also for some performance measures such as the mean value of the system contents and the packet delay. The behavior of the priority queues with priority jumps will be illustrated by using these results and is compared to the FIFO scheme
Certain Results for the Laguerre-Gould Hopper Polynomials
Get PDFIn this paper, we derive generating functions for the Laguerre-Gould Hopper polynomials in terms of the generalized Lauricella function by using series rearrangement techniques. Further, we derive the summation formulae for that polynomials by using different analytical means on its generating function or by using certain operational techniques. Also, generating functions and summation formulae for the polynomials related to Laguerre-Gould Hopper polynomials are obtained as applications of main results
Oscillation Results for Even Order Trinomial Functional Differential Equations with Damping
Get PDFIn this paper, we investigate the oscillatory behavior of solutions to a certain class of nonlinear functional differential equations of the even order with damping. By using the integral averaging technique and Riccati type transformations, we prove four new theorems on the subject. Several examples are also considered to illustrate the main results
Mathematical Model of Blood Flow through a Composite Stenosis in Catheterized Artery with Permeable Wall
Get PDFThe present mathematical analysis, the study of blood flow through the model of a composite stenosed catheterized artery with permeable wall, has been performed to investigate the blood flow characteristics. The expressions for the blood flow characteristics-the impedance (resistance to flow), the wall shear stress distribution in stenosis region, the shear stress at the throat of the stenosis have been derived. The results obtained are displayed graphically and discussed briefly